Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.35848/1347-4065/ac916b

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2022.08.011

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2022.07.013

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cirp.2022.04.060

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.cirp.2021.04.073

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2021.03.017

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Language：English   Publishing type：Research paper (scientific journal)  

To maximize the potential for high material removal rates in simultaneous processes such as parallel milling, developing strategies for successful chatter suppression/avoidance is an important concern for manufacturers. In this study, the effectiveness of the spindle speed difference method (SDM) for chatter suppression is discussed in a parallel end-milling process where a flexible workpiece is machined by two tools rotating in opposite direction. The process model is developed, considering that the dynamic variation due to the regenerative effect occurs on a plane perpendicular to the tool axis direction. Through the process simulations and the experiments, this study provides informative discussion for comprehending the process behavior. Additionally, a real-time active chatter suppression system with adaptive SDM, where the spindle speed difference is sequentially optimized during the process according to the tracked chatter frequency, is developed by integrating a chatter monitoring system based on sensorless cutting force estimation with sliding discrete Fourier transform. The results show that the developed real-time adaptive system of spindle speed suppresses chatter vibrations more effectively than non-adaptive SDM system; hence, the integrated system can contribute self-optimizing machining systems oriented to Industry 4.0.

DOI： 10.1007/s12541-021-00469-2

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：American Society of Mechanical Engineers  

A number of analysis methods for the process with chatter vibration have been proposed so far. These methods can be used to improve processes stability resulting in better production efficiency. However, the poor estimation accuracy of the phenomenon severely limits the performance of process optimization using the simulation-assisted approach. One of the causes of accuracy deterioration is the modeling error of the phenomenon accompanied by chatter vibration with finite amplitude. In this study, we developed a model that can consider the non-linear uncut chip thickness fluctuation caused by the influence of finite amplitude and the process damping due to the contact of the tool flank face against the finished workpiece surface. Furthermore, we developed a time domain simulator that implements the proposed model, and estimated the finished surface profile of the workpiece based on the results of the time domain simulation. To verify the proposed method, corner machining experiments with an end mill were conducted. Corner machining is frequently used in industrial, but it is known that chatter vibration is likely to occur. In corner machining, machine tools generate motions that accompany acceleration and deceleration. The motion of this feed drive system strongly depends on the dynamic characteristics of the machine tool and the trajectory generation algorithm, which greatly affects the emersion angle of the cutter. Therefore, we simulated the dynamic corner machining process considering the measured data of the motion trajectory of the feed drive system. The estimation result of chatter vibration in corner machining is in good agreement with the measurement result of the machining process. In addition, high-precision estimation of the machined surface profile with chatter mark has been realized.

DOI： 10.1115/MSEC2021-60651

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2020.12.007

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2020.11.008

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2020.11.007

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00170-020-05951-1

J-GLOBAL

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cirp.2020.04.037

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：American Society of Mechanical Engineers  

This paper presents a new approach to predict chatter stability in cutting considering process damping. Traditional chatter stability analysis methods enable to predict stable or unstable conditions. Under unstable conditions, the chatter vibration can increase theoretically infinitely. However, chatter vibration is damped at a certain amplitude in real process due to process damping, i.e., the cutting process is stabilized by means of tool flank face contact to the machined surface. In order to consider the influence of the process damping, a simple process damping force model is introduced. The process damping force is assumed to be proportional to the structural displacement. The process damping coefficient is a function of the vibration amplitude and the wavelength. In order to identify the coefficients, a series of finite element analysis is conducted in the present study. Identified coefficients are introduced into the conventional zero-order-solution in frequency domain. The proposed model calculates chatter stability limit assuming process damping with finite amplitude. Hence, this analysis enables to estimate the amplitude-dependent quasi-stable conditions. Analytical results for thee face turning operation demonstrated influence of process damping effect on resultant vibration amplitude quantitatively.

DOI： 10.1115/LEMP2020-8556

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2019.11.008

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Language：English   Publishing type：Research paper (scientific journal)  

External sensor-less cutting force estimation has good potential in terms of its sustainability. However, its accuracy will deteriorate due to variation of machine dynamics depending on the stage position and cutting force amplitude. In the conventional methods, the physical model parameters such as the axial stiffness and viscous damping coefficient are regarded as constant values identified at a certain condition. As a result, the estimation accuracy decreases because the above parameter variation is not considered. To tackle this issue, a simple parameter identification method in time domain by employing the least-squares method (LSM) and a cutting force estimation by a load-side disturbance observer (LDOB) are proposed for a full-closed controlled ball-screw-driven stage. A series of excitation tests were conducted at different stage positions and various excitation amplitudes in order to capture the position and force-amplitude dependent model parameters. The difference of model behavior in the moving and stopped condition of the stage was also investigated. The position and force-amplitude dependent model parameters captured by the proposed method are installed into the observer. The validity of the proposed method was evaluated through end-milling tests. The experimental results clearly showed that the estimation accuracy of cutting force can be greatly improved in both feed and cross-feed directions by taking into account the position and force-amplitude dependency of physical model parameters.

DOI： 10.1007/s00170-019-04080-8

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Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.precisioneng.2019.06.001

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

<p>Parallel turning technology has been attracting attention as an important technology to enhance the productivity of multitasking machine tools. To maximize the productivity advantage of parallel turning, chatter avoidance or suppression is one of the most noteworthy concerns. In this study, a novel chatter suppression technique using tool swing motion is provided by a feed drive system. The optimal design methodology of the tool swing motion for effective chatter suppression is also introduced based on its analogy with the spindle speed variation technique under the shared-surface parallel turning and rigid-tool and flexible-workpiece assumptions. The proposed method was evaluated with regard to the chatter stabilizing performance and workpiece runout as compared to conventional equal pitch turning and unequal pitch turning for chatter suppression. As a result, the proposed tool swing parallel turning exhibited a high chatter stabilizing performance without eccentricity of the workpiece and enhanced surface quality, although particular swing marks were left on the machined surface.</p>

DOI： 10.20965/ijat.2019.p0080

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Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.promfg.2019.07.056

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Publishing type：Research paper (international conference proceedings)  

The cutting force measurement is a basic technology for process monitoring and optimization. For practical operations, the sensorless techniques for cutting force estimation based on internal information on machine tools is more desirable. In this study, the load-side disturbance observer (LDOB) is introduced in full-closed controlled ball-screw-driven stage to estimate the cutting force with high accuracy. Since the LDOB is a model-based technique, appropriate model parameters such as stiffness and damping, which precisely represent the dynamic characteristics of the feed drive system, are necessary for accurate force estimation. Generally, the model parameters are identified by dynamic identification tests such as tap testing or motor sweep test. However, it has been known that the dynamic characteristics of ball-screw-driven-stage is changed, for instance, depending on stage position and amplitude of exciting force. Therefore, the model parameters should be determined under actual cutting state. In this paper, from the above viewpoints, the concept and methodology, that the machine tools determine the model parameters of the cutting force observer by themselves based on their own responses to cutting test, is also proposed.

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Language：English   Publishing type：Part of collection (book)   Publisher：Springer International Publishing  

Textured surfaces with sophisticated micro/nanostructures can provide advanced and useful functions. To promote widespread use of these textured surfaces with mass production, manufacturing technology of structured surfaces for ultra-precision dies and molds made of hardened steel and tungsten carbide becomes essential. Nowadays, elliptical vibration cutting (EVC) is attracting more and more attention due to its excellent machining performances in precision machining of difficult-to-cut materials. The emphasis on this chapter is the practical applications of EVC in micro/nanomanufacture process. The development of the EVC technology is introduced firstly, and then, the advantageousness of EVC in the micro/nanomachining process is explored in detail. Moreover, a unique amplitude control sculpturing method, where the depth of cut is arbitrary changed by controlling the vibration amplitude, is introduced. As following, a criterion to indicate how to obtain ductile machining of tungsten carbide is clarified by applying EVC. The feasibility of highly accurate micro/nanomachining of tungsten carbide and hardened steel is experimentally verified with a machining accuracy of about ±1 nm in the depth-of-cut direction. A series of functional surfaces with textured grooves, dimple patterns, and sinusoidal grids were successfully fabricated on tungsten carbide, hardened steel, and single-crystal silicon, which could be applied to the molding, encoder, optoelectronics, and semiconductor industries. The EVC technology is expected to promote the development of micro/nanomachining process in the actual industrial applications.

DOI： 10.1007/978-981-13-3335-4_7

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Publishing type：Research paper (scientific journal)  

Simultaneous processes such as parallel turning or milling offer great opportunities for more efficient manufacturing because of their higher material removal rates. To maximize their advantages, chatter suppression technologies for simultaneous processes must be developed. In this study, we constructed an automatic chatter suppression system with optimal pitch control for shared-surface parallel turning with rigid tools and a flexible workpiece, integrating in-process chatter monitoring based on the cutting force estimation. The pitch angle between two tools is tuned adaptively in a position control system in accordance with the chatter frequency at a certain spindle speed, in a similar manner as the design methodology for variable-pitch cutters. The cutting force is estimated without using an additional external sensor by employing a multi-encoder-based disturbance observer. In addition, the chatter frequency is measured during the process by performing a low-computational-load spectrum analysis at a certain frequency range, which makes it possible to calculate the power spectrum density in the control system of the machine tool. Thus, the constructed system for automatic chatter suppression does not require any additional equipment.

DOI： 10.1007/s40436-018-0222-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Society of Mechanical Engineers (ASME)  

Parallel turning is garnering attention as one of the most important technologies for multitasking machine tools. This is because a potential exists to enhance the stability limits compared to the turning operation using a single tool when cutting conditions are properly selected. Although stability prediction models for parallel turning have been developed in recent years, in-process monitoring and in-process chatter techniques are almost not discussed. In this study, to suppress chatter vibration, an unequal pitch turning method was proposed. In this method, the upper tool was controlled based on the optimum pitch angle calculated from spindle speed and chatter frequency. Chatter frequency was identified from estimated cutting force by a disturbance observer (DOB). From the result of the parallel turning test, it is clear that chatter vibration can be avoided by controlling the upper tool based on optimum pitch angle. Meanwhile, the pitch angle difference that can suppress chatter had a certain range. Subsequently, the robustness of the optimum pitch angle difference is experimentally evaluated by both the continuous moving test and the stepwise moving test of the pitch angle.

DOI： 10.1115/1.4039111

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

&lt;p&gt;Ni基耐熱合金に対して従動式ロータリ機構を備えたミーリング工具による正面フライスを実施し，その実用性について検討を行った．実験の結果，回転運動を伴わない通常切削に対して約12倍の工具寿命延長効果が確認された．また，切削シミュレーションを援用したプロセスの見える化技術を開発し，その分析を行った．諸検討により，ランピング加工においてランピング角の制約が厳しいことが明らかとなり，その解決手法を提案した．&lt;/p&gt;

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

&lt;p&gt;3Dプリンタの普及に伴い，3次元積層造形構造の利用が急速に進められている．造形技術が急速に発展した一方で，その表面に形成される積層段差の後処理技術に関しては，自動化技術が確立されていない．本研究では，3次元積層造形構造の表面除去加工における自動化技術について検討を行った．汎用工作機械に，柔軟な治具をかいして工作物を固定し，研削と研磨による定圧加工を行うことで，自動化の可能性があることを明らかにした．&lt;/p&gt;

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

モデルベースシミュレーションを利用して，構造物の動特性や切削プロセスのパラメータを同定する手法が提案されている．本稿では，ボールねじ駆動系の多慣性モデルを考慮したCNC工作機械の外乱オブザーバを検討した．これをすでに提案されているプロセス同定システムに適用し，汎用的な工作機械を対象とした知的同定の実行可能性について検討を行った．検証実験の結果，ミリングプロセスの同定を概ね実現し得ることを確認した．

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier USA  

This paper presents a CMP process analysis considering an airbag type wafer carrier, which is used in semiconductor devices manufacturing. In the CMP process, a wafer is compressed against the polishing pad inside the wafer carrier, which consists of the retainer ring and the membrane film. Structural analysis model is developed to estimate contact pressure distribution over the wafer surface considering the airbag compression behaviour. The polishing experiment without wafer rotation indicated a unique pressure variation around the trailing edge of the wafer. The developed analysis estimated the same phenomena accurately and clarified the mechanism deteriorating the polishing pressure uniformity.

DOI： 10.1016/j.cirp.2017.04.088

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Inderscience Enterprises Ltd.  

Surfaces textured by sophisticated micro/nano structures can provide advanced and useful functions and features as compared with simply smooth surfaces. To promote widespread use of the structured surfaces, manufacturing technology of structured surfaces for ultra-precision dies and moulds made of hardened steel is absolutely essential. Conventional diamond cutting is not applicable to machining of steel due to rapid tool wear and surface deterioration. On the other hand, elliptical vibration cutting (EVC) equipped with the ultra-precision amplitude control sculpturing method is considered as a potential candidate for the functional surface fabrication on steel materials. In this method, tool geometry, especially the clearance angle, imposes a limit on the machinable part geometry due to the flank face contact to the target shape in the downhill machining. In order to clarify the influence of flank face contact on the machining accuracy and the tool wear, a series of theoretical and experimental investigations are conducted in this paper. A surface with micro sine-sweep profile is fabricated on hardened steel by applying the proposed amplitude control sculpturing method. It verified that the interference between flank face and fabricated structure causes not only the serious machining accuracy deterioration but also the serious tool damage due to the enhancing of ploughing process.

DOI： 10.1504/IJNM.2017.087536

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>Multi-tasking machine tools attract attention, because they can perform highly efficient machining by using multiple tools. Parallel turning with two tools can realize high material removal rate and the productivity is remarkably improved when appropriate cutting condition is selected. On the other hand, compared to turning with a single tool, the stability of the process reduces, and chatter vibration tends to occur. Chatter vibration does not only limit productivity but also cause poor surface and dimensional accuracy. In this research, to suppress chatter vibration in parallel turning, we propose swing motion assisted parallel turning with an optimum amplitude ratio, calculated from chatter frequency and spindle speed. The proposed method aims to suppress chatter vibration by giving variations in phase delay due to high speed swing of tool. Chatter frequency is measured from estimated cutting force applying disturbance observer. The result of swing motion assisted turning test indicates that chatter vibration can be suppressed by dynamically changing cutting point based on the optimum amplitude ratio.</p>

DOI： 10.1299/jsmemecj.2017.S1330101

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Language：Japanese   Publisher：公益社団法人 精密工学会  

切削加工における高能率化を実現する上でびびり振動対策は極めて重要である．不等ピッチ・不等リード工具は，不安定化を引き起こす再生振動の抑制に効果的に利用することができる．本稿では，びびり振動の周波数および軸方向切込み条件に対して高いロバスト性を満たす，実用的な工具設計理論を紹介する．さらに，再生効果抑制理論を応用したインデクサブルカッタの設計法およびパラレールターニングの研究事例を紹介する．

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.11522/pscjspe.2017S.0_989

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

Parallel turning attracts attention as one of the important technologies for the multi-tasking machine tools. This is because there is a potential to enhance the stability limits compared to turning operation using single tool when cutting conditions are properly selected. Although stability prediction models for parallel turning have been developed in recent years, in-process monitoring technique of chatter is almost out of focus.
In this study, to suppress chatter vibration, unequal pitch turning method was proposed. In this method, the upper tool was controlled based on optimum pitch angle calculated from spindle speed and chatter frequency. Chatter frequency was identified from estimated cutting force by disturbance observer. From the result of parallel turning test, it is clear that chatter vibration can be suppressed by controlling the upper tool based on optimum pitch angle.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

This paper presents design of a novel boring bar with a ratio of cylinder length to diameter (L/D) of 10 to suppress chatter vibration regardless of low stiffness. It is essentially difficult to decrease the compliance of the long slender structures. However, nominal compliance of the displacement along the depth of cut direction against the resultant cutting force may be. regulated by giving the designated anisotropy upon the boring bar dynamics. The past research has clarified the feasibility through turning experiments by using the developed boring bar with L/D of 4. In the present study, much slenderer ones with L/D of 10 are designed, which are significantly flexible but attractive to manufacturers. Finite element analysis (FEA) is utilized to estimate dynamics of the anisotropic boring bar. Through analytical investigations, two kinds of boring bars were designed, where the compliance ratio of 1.53 or 1.88 was accomplished. Influence of several conditions on the chatter stability was investigated. Analytical investigations revealed that the chatter stability is significantly improved at a designated depth of cut by utilizing the proposed designs regardless of feed rate. In particular, the compliance ratio of 1.55 showed wider stable zone to attain chatter free boring, while chatter avoidance is impossible by use of the conventional isotropic boring bar under the same conditions.

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.11522/pscjspe.2017S.0_919

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：VDE Verlag GmbH  

This paper presents a novel method to improve material removal efficiency by optimizing anisotropic contact of pad surface asperities. In chemical mechanical polishing process, asperities of the polishing pad surface affect material removal process indirectly. Past researchers have proposed several material removal models considering surface asperity. One of the models indicates interesting role of Feret's diameter, where larger Feret's diameter increases number of working abrasives, resulting in higher material removal rate. Based on Feret's diameter model, an optimization method of the relative dress motion against the polishing pad is proposed by means of the dress simulation, where radial velocity component of the diamond dresser is maximized with respect to the tangential component. Three conditions, i.e., optimal (Cond. 1), worst (Cond. 2) and ordinary (Cond. 3), are compared in the present study. Analytical investigations clarified that the velocity ratio is improved significantly in Cond. 1, resulting in larger Feret's diameter. Comparing with Cond. 2 and Cond. 3, not only the cumulative Feret's diameter but also material removal rate are increased in Cond. 1. Hence, anisotropy control for pad asperities is effective to improve the material removal efficiency.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER LONDON LTD  

In general practice, chip breakers are used to break chips in turning operations for chip disposal. However, chips of highly ductile materials such as low carbon steel or thin chips generated in finishing operations may not be broken easily with conventional chip breakers. They cause chip-jam and significant downtime in actual production. This paper proposes a novel approach where the generated chip is not broken but guided to overcome first the chip-jam and next to improve the efficiency of conventional turning operations by realizing the chip-pulling turning process. A novel cutting tool geometry is developed to suppress the chip's side curl to generate straight continuous chip flowing away from the cutting point and hence suppress the chip-jam. The proposed tool tip geometry contains "guide grooves" engraved onto the rake face. The groove topography is optimized to control the chip flow robustly at various cutting conditions so that the cut chip can be guided for effective chip guidance. Continuously flowing guided chip is then pulled to reduce the friction force on the rake face to enhance the machinability. Experimental results show that the designed cutting tool geometry robustly controls the chip flow, and the chip-pulling turning process shows significant potential towards achieving higher machinability in hard turning.

DOI： 10.1007/s00170-015-7990-5

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

低切削速度条件ではプロセスダンピングという現象が発現してびびり振動の安定性が向上する．多くのモデルが提案されてきたが，その現象の詳細なメカニズムは不明であり，切削力モデルも検証されていない．そこで，本研究では，低速領域でびびり振動が発生する場合の切削現象について検討を行う．有限の振動変位を持つびびり振動が発生する場合の新しい切削力モデルを提案し，有限要素解析による検討を通じてその検証を行う．

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

The mechanics of &amp;ldquo;chip-guiding cutting&amp;rdquo; with grooved tools are investigated in the present study. The chip-guiding cutting has been proposed by the authors to realize continuous chip disposal. It has been clarified in the previous study that chips can be guided successfully into desired directions with the grooved round-nose tools, but the mechanics of the new cutting process with the guide grooves has not been clarified. Fundamental chip-guiding cutting experiments are carried out with grooved straight-edge tools in this study. An analytical model for the chip-guiding cutting process is developed. Effects of the chip-guiding on the process parameters such as cutting forces are investigated accurately by the proposed model and validated by cutting experiment. Both experimental and analytical results unveil that chip flow direction can be controlled by chip-guiding forces generated by the side-walls of the groove structure engraved on the rake face. It is shown that as the chip flow direction can be altered to the various guide directions from the original one, and the proposed model predicts that as the guiding force increases, shear angle decreases and thus resultant cutting force is increased only slightly. Therefore, when the guide direction is not dramatically different from the original chip flow direction, the resultant cutting force is not increased significantly, which make the process favorable. These results support the fact that proposed model captures the critical cutting mechanics accurately.

DOI： 10.2493/jjspe.82.75

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

本研究では，外乱力の推定結果に基づいてモデルベースで動的切削プロセスのパラメータ同定を行う新しい手法を提案する．まず，加工に用いる機械構造の動剛性モデルと再生効果を含めた切削プロセスモデル，および各モデルに基づく時間領域シミュレータを開発する．加工中にCNC制御系に作用する外乱力の推定値から，逆解析を行うことでプロセスモデルのパラメータ同定を行う．断続切削実験により，提案手法の実現可能性を確認する．

DOI： 10.11522/pscjspe.2016S.0_763

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

不等リードエンドミルを用いて浅切込み加工を行う場合に，びびり振動を効果的に抑制することができる．しかし，このプロセスでは切削の断続性に起因して，高精度な安定性解析が難しいことが知られている．このような時間遅れを伴う常微分方程式の解法としてSemidiscrete method（SD法）が提案されている．本研究では，不等リードエンドミルを用いるプロセスに対応したSD法を提案し，先行研究の解析モデルとの比較による検証を行った．

DOI： 10.11522/pscjspe.2016S.0_651

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：AMER SOC MECHANICAL ENGINEERS  

This study presents a new method to identify parameters representing cutting process and transfer function of flexible mechanical structures mounted on a traveling stage by utilizing only internal information of computerized numerical control (CNC) system. Disturbance force input to CNC is estimated by disturbance observer and cutting force is estimated based on cutting force model. Analyzing influence of the estimated cutting force on the disturbance force, parameters used in the assumed models of cutting process and structural dynamics are identified in quasi-real-time. Least square method (LSM) is utilized for the parameter identification. Face turning experiment using an ultra-precision machine tool was conducted to verify feasibility of the proposed method. Experimental results clarified that the cutting force coefficient and the modal parameters representing the dynamic characteristics of the force transfer function can be identified accurately by the proposed method.

DOI： 10.1115/MSEC2016-8872

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier USA  

This paper presents a design method of irregular pitch end mills, which ensures robust suppression of total regeneration in milling. Firstly, general formulation of irregular pitch angles is explained for simultaneous suppression of multi-mode regenerations. An index named “Regeneration Factor (RF)” is introduced to quantify regenerative effect. Minimizing the mean value of the |RF| within a certain frequency range, suppression frequencies are distributed in the proposed method, resulting in robust suppression of regeneration regardless of chatter frequency and/or spindle speed variations. Experimental investigations verified significant robustness of the end mill with the proposed design against the spindle speed variation.

DOI： 10.1016/j.cirp.2016.04.041

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

<p>Multi-tasking machine tool with multi-turret is attracting a great deal of attention, which can offer higher efficiency and higher accuracy. However, chatter vibration generated during parallel turning with two tools might be one of the bottlenecks for higher material removal rate. To suppress chatter vibration, we proposed unequal pitch turning method in this research. In this method, the upper tool was properly controlled based on optimum pitch angle calculated from spindle speed and chatter frequency. Chatter frequency was identified from estimated cutting force by disturbance observer. From the result of parallel turning test, it is clear that chatter vibration can be suppressed by controlling the upper tool based on optimum pitch angle.</p>

DOI： 10.1299/jsmemmt.2016.11.A07

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

&lt;p&gt;In order to improve milling performance of difficult-to-cut materials, a unique milling cutter with SPRT (Self-Propelled-Rotary-Tool) was developed. Use of slide bearings enables a compact SPRT mechanism, while influence of bearing friction becomes not negligible. To attain self-revolution of a circular insert regardless of the bearing friction, the cutter geometry was optimized. Through face milling experiments of Inconel 718, superior tool wear resistance was verified as compared to the conventional milling without insert rotation. Analytical result of the measured cutting forces also indicated interesting phenomena in SPRT milling.&lt;/p&gt;

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

研磨プロセスのミクロな材料除去メカニズムを説明可能な理論は確立されていない．これが研磨効率の推定を困難にし，効率的なプロセス開発の妨げとなっている．本研究では，研磨効率のその場観察手法を提案する．材料除去に起因する赤外線をウェハ越しに観察することで，研磨中の局所的な材料除去の発生個所を特定する．表面凹凸が制御された織布パッドによる検証実験を実施し，ミクロな材料除去メカニズムについて考察を行った．

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

研磨パッド表面に存在する凹凸構造は研磨効率に直接的に影響するため，その分析は研磨メカニズムを理解する上で重要である．本研究では，研磨パッドの表面アスペリティを楕円球と楕円錐の集合体としてモデル化し，状測定結果から研磨に作用すると考えられる箇所の形状パラメータを同定する手法を考案した．さらに，弾性変形を仮定した力学モデルを定式化し，動的圧縮試験の結果から，材料物性パラメータについて分析を行った．

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

This paper studies the nano-structure fabrication on hardened steel by means of elliptical vibration cutting equipped with the ultra-precision amplitude control sculpturing method. Machining performance of the amplitude control sculpturing method is investigated, and the limitation in nano-scale machining is explored. In this proposed method, machinable part geometry is essentially restricted by vibration conditions and tool geometry. In addition, a considerable error between the amplitude command and the envelope of the tool trajectory is generated when the slope of the machining part geometry becomes steep. To overcome this error, a compensation method for the amplitude control command is proposed. In order to clarify the machining performance of the proposed technology, a series of analytical and experimental investigations are conducted. Furthermore, by applying the proposed command compensation method, nano-structures with a large ratio of structure height to wave length are machined accurately. The proposed sculpturing method is subsequently applied to the machining of nano-textured grooves and a three-dimensional grid surface, which verifies the feasibility of the proposed amplitude control sculpturing method. (C) 2014 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.precisioneng.2014.07.009

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Chatter vibration in milling often results in poor surface finish and rapid tool wear, consequently limiting productivity. It is known that regenerative effect, which causes chatter vibration, can be suppressed by utilizing irregular pitch cutters. In order to attain robust regeneration suppression for arbitrary chatter frequency, the authors have proposed a novel design theory of irregular pitch cutters. The fundamental mechanism of it is the simultaneous suppression of multi-mode regenerations. In the present study, the effect on chatter suppression has been verified through a series of end milling experiment. Analytical and experimental results indicated that the chatter stability is effectively increased by utilizing the irregular pitch cutter designed by the proposed theory.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

機械構造の振動モデルを仮定し，切削力モデルと外乱オブザーバ技術を利用して切削力と外乱力を推定することで，工作機械の制御ループ外に存在する機械構造の伝達関数をCNCの内部情報のみから推定する新しい手法を提案する．剛性が低くなるように設計したツールホルダを超精密工作機械のテーブルに固定して断続的な旋削実験を行い，提案手法により周波数伝達関数の計測とモーダルパラメータの推定が可能であることを確認した．

DOI： 10.11522/pscjspe.2015A.0_261

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

研磨加工において，研磨パッド表面に存在する突起の構造とその微視的な変形挙動は，加工メカニズムを考察する上で重要となる．本研究では，レーザ顕微鏡を用いて研磨に使用した研磨パッド表面形状の評価観察を行い，突起構造の分析とモデル化について検討した．そして，突起構造の変形挙動を表現する新しい力学モデルの検討を行った．

DOI： 10.11522/pscjspe.2015S.0_541

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

This paper presents essential investigations on the feasibility of ductile mode machining of sintered tungsten carbide assisted by ultrasonic elliptical vibration cutting technology. It lays out the foundations toward efficient application of elliptical vibration cutting technology on tungsten carbide. Tungsten carbide is a crucial material for glass molding in the optics manufacturing industry. Its grain size and binder material have significant influence not only on the mechanical and chemical properties but also on the machining performance of tungsten carbide. In order to investigate the influence of material composition on tungsten carbide machining, a series of grooving and planing experiments were conducted utilizing single crystal diamond tools. The experimental results indicated that as compared to ordinary cutting where finished surface deteriorates seriously, ductile mode machining can be attained successfully by applying the elliptical vibration cutting technique. It was also clarified that the binder material, the grain size, cutting/vibration conditions as well as crystal orientation of the diamond tool have significant influence on the tool life and the machined surface quality. Based on these fundamental results, feasibility of micro/nano-scale fabrication on tungsten carbide is investigated. By applying amplitude control sculpturing method, where depth of cut is arbitrary changed by controlling the vibration amplitude while machining, ultra-precision textured grooves and a dimple pattern were successfully sculptured on tungsten carbide in ductile mode. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jmatprotec.2014.05.024

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：IOP PUBLISHING LTD  

Polishing pads used for chemical mechanical polishing (CMP) process have strong nonlinear viscoelasticity, which is considered to affect resultant polishing performance. In order to evaluate the material properties of polishing pads, a series of fundamental compression tests were conducted by using a developed on-machine compression tester. From measured stress-strain curves, parameters representing nonlinear elasticity and viscosity of the CMP pads are identified. Analytical results indicated unique nonlinear elasticity due to pad surface asperities and not negligible viscous damping. (C) 2014 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.53.05GB01

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

Thus far, Elliptical Vibration Cutting has shown its superior machining performance in steel machining by using which the diamond tool life can be significantly improved. However, this machining technology is currently limited to the relatively small-size workpiece machining due to the small feed rates. If it is used to machine large-size steel workpiece, the machining time and cumulative cutting distance (or tool wear) will be remarkably increased which in turn dramatically increase the machining cost and cycle time. In order to apply this emerging machining technology effectively in industrial application, Elliptical Vibration Cutting with large nose radius single crystal diamond tool was proposed in this paper. However, the minimum uncut chip thickness (under which the material is not sheared but ploughed), that due to the presence of the tool edge radius becomes a major challenge when the large nose radius diamond tool is employed. Therefore, the influence of the minimum uncut chip thickness on material removal behavior during diamond machining needs to be understood and implemented in models. In this paper a simple but practical analytical model was developed for the optimizat

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Authorship：Lead author,　Corresponding author   Language：English   Publisher：Fuji Technology Press  

DOI： 10.20965/ijat.2014.p0837

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

This paper presents analytical investigation on polishing pressure distribution in Chemical Mechanical Polishing (CMP) process. In general, the polishing pressure is distributed unevenly around a wafer edge. This uneven distribution is essentially due to discontinuous contact of a wafer against a polishing pad. An edge profile of the wafer and nonlinear viscoelastic properties of the polishing pad affect the polishing pressure distribution significantly. The compression by a retainer ring against the polishing pad also has an indirect effect on the polishing pressure distribution. These phenomena are empirically known in industry. In order to quantify the influence of these factors, a series of analytical investigations on the polishing pressure distribution are conducted in the present study. The simulator developed by authors is utilized. Arbitrary Lagrangian-Eulerian (ALE) Finite Element Method (FEM) is employed in dynamic nonlinear analysis. In a series of process simulations, material properties, i.e., Young's modulus, Poisson's ratio and proportional damping factor, of the polishing pad and geometries of the wafer and the retainer ring are changed, respectively. The calculated results indicated that the polishing pressure distribution around the wafer edge varies considerably depending on the parameters.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE BV  

This paper presents a model to predict cutting force and motion of the rotating insert in cutting processes with self-propelled rotary tools (SPRT). Metal cutting utilizing rotary tools is effective to suppress tool wear and thus it is considered to be suitable to attain high performance machining of difficult-to-cut materials. It is well known that a circular insert attached to a rotational axis is self-propelled due to inclined chip flow on rake face plane by setting certain oblique angle. A resultant insert rotation speed can be easily predicted considering a frictionless rotary axis. However, friction at the rotary axis of SPRTs may not be negligible in practice especially when slide bearings are employed. In order to investigate the influence of the friction at the rotation axis on the rotary cutting process, a new cutting model is proposed. As the friction at the rotation axis causes a decrease in a speed of round insert rotation, an equivalent oblique cutting process is taken into account in the proposed model utilizing conventional theoretical model. In the equivalent process, the tangential component of the resultant cutting force corresponds to the friction force at the rotary axis. The friction force is determined by cutting force component normal to force-bearing mechanism and the bearing's friction coefficient. Considering the equilibrium condition in cutting and friction forces, the resultant cutting force and the insert rotation speed are iteratively computed in the proposed model. Edge force model is also associated with the oblique cutting model, which is not negligible especially in machining difficult-to-cut materials. The developed model is extended to simulate milling processes with SPRTs. The proposed model is experimentally verified, and influence of the bearing friction of SPRT on the process is clarified. (C) 2014 Published by Elsevier B.V.

DOI： 10.1016/j.procir.2014.03.033

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

航空機部品等に用いる耐熱合金の加工では，セラミック工具を用いた高速ミーリングによる高能率加工が利用されている．しかし，工具損耗が激しく寿命が短いという問題があり，その改善が要求されている．本研究では，インコネル718の加工で摩耗した工具形状を評価し，これを考慮した切削力モデルを考案した．さらに，切削力測定結果との比較により工具表面に生じる応力場を推定し，特徴的な工具損耗メカニズムについて考察を行った．

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

著者らはこれまでに，CMPプロセスに対する研磨パッドの粘性特性と研磨パッド表面の凹凸形状による非線形弾性特性を考慮した解析手法を開発している．本報では，ジンバル方式の研磨ヘッド構造を利用するCMPプロセスを対象とした検討により，各種物性や形状のモデル化が研磨圧力シミュレーションの結果に与える影響について明らかにする．さらに，実験結果と比較することにより解析精度を検証する．

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

低切削速度領域においてプロセスダンピングと呼ばれる現象が発現し，びびり振動の安定性が向上することが知られている．多くの解析モデルがすでに提案されているのに対し，実験的なプロセスの評価は十分になされていない．本研究では，端面旋削実験により切削プロセスに対するプロセスダンピングの影響について評価を行う．さらに，材料物性と工具形状に基づきプロセスダンピングの影響を定量化する新しい解析モデルを提案する．

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

This paper presents a new method and its analysis to suppress regenerative chatter vibration in simultaneous multiple milling with a flexible mechanical structure. Precision steel plates are conventionally finished by one-sided face milling with a rigid electro-magnetic chuck. However, it is difficult to obtain the desired flatness with this method since the thin workpiece deforms to fit the chuck surfaces when chucked. The authors have solved this problem to realize both high accuracy and productivity by applying the simultaneous double-sided milling technique utilizing the developed speed difference method, in which the regenerative chatter is cancelled by rotating two milling cutters at different speeds on both sides of the workpiece. The present study represents an analytical model of the simultaneous double-sided milling including the regenerative chatter vibration effect on the process. Machining experiments are conducted to validate the developed analytical model. Experimental results match with the analytically predicted ones proving that the proposed model accurately predicts the regenerative stability limits in double-sided milling. The results also show that the developed speed difference method can provide great advantage to increase the chatter stability and carry great potential to enhance the productivity in machining of flexible thin workpieces. Furthermore, simultaneous multiple-spindle machining methods have become much desired in mass manufacturing systems as they prove higher manufacturing efficiency. The proposed speed difference method is extended and generalized to those multi-spindle simultaneous milling operations with flexible mechanical structures. Analytical derivations and the foundation are presented here on how to calculate the necessary speed differences between milling spindles to suppress regenerative chatter vibrations. (C) 2013 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.precisioneng.2013.01.003

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

ベースの剛性不足に起因して機械構造全体で生じる低周波振動により，工作機械の制御系の性能が低下する問題がある．本研究では，問題となりやすいベースのねじり振動モードの影響を考慮したガントリーテーブルの制御システムをモデル化する．そして，ベースのねじれ振動を抑制する新しい補償器とその設計手法を提案する．実機を用いて検証を行い，提案手法によってねじり振動が効果的に抑制されることを確認した．

DOI： 10.11522/pscjspe.2013S.0.817.0

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

A soft EHL analysis model of Chemical Mechanical Polishing (CMP) is developed in the present study. Since a surface of a polishing pad is filled with micro asperities due to conditioning, the polishing pad deforms in a nonlinear manner by contacting to a wafer. A viscosity of the polishing pad also affects stress concentration beneath the edge of the wafer. In order to take into account both effects, damping behavior of the polishing pad and macroscopic characteristics of the polishing pad asperity deformation are considered at the same time in the proposed analysis. Based on the traditional contact model, i.e., Greenwood-Williamson model, nonlinear elasticity of the surface asperity layer of the polishing pad is formulated, and Arbitrary Lagrangian-Eulerian (ALE) method is applied to deal with dynamic structure analysis. A series of three-dimensional EHL analysis was conducted using the proposed model. Effects of viscosity of the polishing pad and the nonlinear elasticity caused by the polishing pad asperities on distributions of contact stress and fluid pressure were examined. Analytical results indicated that both distributions greatly depend on the viscosity and the nonlinear elasticity of the polishing pad, and thus the consideration of nonlinear viscoelastic behavior in the pad-wafer contact is important to predict the polishing pressure distribution, especially beneath wafer leading edge.

DOI： 10.2493/jjspe.79.73

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE BV  

Regeneration is major mechanism to generate self-excited chatter vibration in cutting. Variable helix cutters are useful to suppress regeneration. Although optimization of pitch/helix angles is significantly important at the same time, there is no practical design method to optimize the variable helix cutter geometry so far. In order to attain robust regeneration suppression, a new design method of variable helix cutters is proposed in the present study. The pitch angles vary along axial position due to disagreement of the helix angles. Because of this nature, regeneration can be suppressed in a robust manner with respect to changes of chatter frequency and/or spindle speed. Optimal pitch/helix angles are formulated on the basis of distinctive relationship between the cutter geometry and "Regeneration Factor (RF)", which is an index to quantify influence of regeneration in the process. Through analytical investigations, it is confirmed that regeneration can be suppressed effectively in low immersion milling with variable helix cutters by the proposed method, resulting in significant chatter stability increase. (C) 2013 The Authors. Published by Elsevier B.V.

DOI： 10.1016/j.procir.2013.06.117

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

半導体CMPの量産工程で一般に用いられるエアーバッグ研磨ヘッド構造を考慮したCMPプロセスのEHL解析モデルを開発した．本研究では，研磨ヘッドの構造として，リテーナリングやメンブレンゴムを考慮するとともに，ウェハ等との接触問題を考慮する．また，ALE有限要素法を適用することで動的な問題を取り扱うとともに，研磨パッドの非線形粘弾性を同時に考慮することで，従来不可能であった実用的な研磨プロセスの解析の実現に挑戦する．

DOI： 10.11522/pscjspe.2013S.0.645.0

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

切削加工において再生効果は自励びびり振動の安定性に大きく影響する．不等リードエンドミルはびびり振動の周波数や主軸回転数などの変化に対してロバストに再生効果を抑制することができる特徴を持つ．しかし，最適な工具形状を設計しなければ優れた抑制効果を実現することはできない．本研究では，再生効果の影響をロバストに抑制することのできる不等リードエンドミルの工具形状の新しい設計手法を提案する．

DOI： 10.11522/pscjspe.2013S.0.463.0

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Language：English   Publishing type：Research paper (scientific journal)  

A new and basic analytical model of three-dimensional cutting is proposed by assuming multiple thin shear planes with either the maximum shear stress or minimum energy principle. The three-dimensional cutting process with an arbitrarily shaped cutting edge in a flat rake face is formulated with simple vector equations in order to understand and quickly simulate the process. The cutting edge and workpiece profile are discretized and expressed by their position vectors. Two equations among three unknown vectors, which show the directions of shear, chip flow, and resultant cutting force, are derived from the geometric relations of velocities and forces. The last vector equation required to solve the three unknown vectors is obtained by applying either the maximum shear stress or minimum energy principle. It is confirmed that the directions and the cutting forces simulated by solving the proposed vector equations agree with experimentally measured data. Furthermore, the developed model is applied to consider the three-dimensional cutting mechanics, i.e., how the chip is formed in the three-dimensional cutting with compressive stress acting between the discrete chips, as an example. Copyright © 2013 by ASME.

DOI： 10.1115/1.4024531

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Elsevier B.V.  

The authors have proposed a unique micro/nano sculpturing technology for difficult-to-cut materials by controlling vibration amplitude in elliptical vibration cutting. In the present research, machining performance of the amplitude control sculpturing method is investigated, and limitation in nano-scale machining is explored. In the proposed machining method, the machinable part geometry is essentially restricted by cutting tool geometry and vibration conditions. In order to clarify the machining performance of the proposed technology, a series of analytical and experimental investigations were conducted. From the experimental results, it was confirmed that nano structures with a step height of more than 2 nm and a pitch of more than 250 nm can be machined with surprisingly high accuracy of about 1 nm. On the other hand, a considerable error between the amplitude command and the envelope of tool trajectory is generated when the slope of the machining part geometry becomes large. In order to overcome this error, a compensation method of the amplitude command is proposed. By applying the proposed compensation, nano structures with large ratio of the step height to the pitch were machined accurately. The proposed machining method was subsequently applied to a three-dimensional grid surface machining, and successful experimental results verified feasibility of practical machining application by applying proposed technology. Copyright © 2013 Elsevier B.V.

DOI： 10.1016/j.procir.2013.06.111

Scopus

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

従来，旋削加工の高精度化のため，各種機上計測手法が実用に供されている．しかし，これらの従来手法では，工作物への接触や計測装置の大きさによって計測範囲や形状に制約が多い．そこで本研究では，工具をイメージセンサに取り換えて工作物を回転し，加工面の移動距離と回転角度から直径を計測することで，制約の少ない機上計測手法を提案・開発する．本報では，提案手法とその画像処理方法，計測の繰返し性等について報告する．

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Analysis of the stability limits in self-excited chatter vibration requires the transfer function of the mechanical structure, and thus the accuracy of the analytical prediction strongly depends upon the accuracy of the transfer function, which is generally measured by the impulse response method. However, it is often difficult to measure the transfer function accurately, especially in a case where a small-diameter tool or a workpiece is flexible, or when the transfer function changes as a result of spindle rotation. This paper presents a novel method of identifying the transfer function by utilizing inverse analysis of the self-excited chatter vibration measured during an end milling experiment. In the proposed method, the transfer function can be identified to minimize errors between chatter analysis and experimental results. A basic end milling test verified that the transfer function identified by the developed method is similar to that measured by the impulse response method, and that it yields a more accurate prediction of the stability limits. Further applications using a small-diameter end mill were conducted, and the feasibility of identifying the transfer function by using the proposed method was investigated. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.precisioneng.2012.04.004

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC ANALYTICAL CHEMISTRY  

We developed a confocal microscopic method for a quantitative evaluation of the mixing performance of a three-dimensional microfluidic mixer. We fabricated a microfluidic baker's transformation (MBT) mixer as a three-dimensional passive-type mixer for the efficient mixing of solutions. Although the MBT mixer is one type of ideal mixers, it is hard to evaluate its mixing performance, since the MBT mixer is based on several cycles of complicated three-dimensional microchannel structures. We applied the method developed here to evaluate the mixing of water and a fluorescein isothiocyanate (FITC; diffusion coefficient, 4.9 x 10(-10) m(2) s(-1)) solution by the MBT mixer. This method enables us to capture vertical section images for the fluid distributions of FITC and water at different three-dimensional microchannel structures of the MBT device. These images are in good agreement with those of mixing images based on numerical simulations. The mixing ratio could be calculated by the fluorescence intensity at each pixel of the vertical section image; complete mixing is recognized by a mixing ratio of more than 90%. The mixing ratios are measured at different cycles of the MBT mixer by changing the flow rate; the mixing performance is evaluated by comparisons with the mixing ratio of the straight microchannel without the MBT mixer.

DOI： 10.2116/analsci.28.57

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PubMed

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

We developed a new passive-type lamination mixer for high viscosity fluid with a low Reynolds number, based on the baker's transformation (BT). BT is the best transformation for mixing fluids of laminar flow. However, there was difficulty in mass-producing the BT structure especially for micro devices like MicroTAS, Lab-on-a-Chip and Micro-Reactors, because conventional BT mixers require three-dimensional (3D) piping structures. We have successfully developed the easy-to-massproduce BT mixer by changing that concept of 3D piping structures to 3D channel structures. The 3D channel structures are not easy to produce by photolithography unlike the conventional mixers, while they can be easily mass-produced by molding once their 3D molds are produced. In this report, we newly developed a miniature scale BT mixer to meet the needs for mixing high viscosity fluids in food processing, resin blending, etc. An experiment for mixing different colored hardening silicone elastomers was performed by using the prototype mixer made of aluminum alloy, and the good BT mixing result was obtained, with observing several cross sectional patterns. The numerical fluid analysis also gave similar results of the patterns to those observed in the experiment.

DOI： 10.1299/kikaib.78.762

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

本研究では，工具軌跡／姿勢を最適化することで再生型びびり振動を回避する新たな手法を提案する．びびり振動安定性が主軸回転数や切込み量等の切削条件に依存することはよく知られているが，工具軌跡にも依存することはあまり知られていない．本稿では，旋削加工を例に，工具形状や切込み量，送り量を考慮した上で工具軌跡／姿勢を最適化するための簡易指標を示し，その指標の有用性を解析及び実験的に検証する．

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE BV  

It is known that regenerative effect, which causes self-excited chatter vibration, can be suppressed in many cases by utilizing irregular pitch tools. In order to suppress the regenerative effect sufficiently, a suitable combination of irregular pitch angles needs to be designed. Although the past researches proposed a basic idea to design irregular pitch angles for the regeneration suppression, they are only applicable to the suppression of single-mode regeneration. The present study proposes a novel design method of irregular pitch cutters, which ensures the simultaneous suppression of multi-mode regenerations. In order to quantify the regenerative effect, a new parameter called as the "Regeneration Factor" is proposed. The effect of pitch angles designed by the proposed method on chatter suppression is investigated analytically, and its validity is verified. (C) 2012 The Authors. Published by Elsevier B. V. Selection and/or peer-review under responsibility of Prof. Eiji Shamoto

DOI： 10.1016/j.procir.2012.10.018

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

インコネル等に代表される難削材の切削加工では，工具摩耗の抑制にロータリ切削が効果的であることが知られている．本研究では，傾斜切削理論に基づいたロータリ切削機構のモデル化を行う．さらに，その切削機構の特徴を示すとともに基礎的なロータリ切削実験による検証を行う．さらに，従動式ロータリ機構を適用したロータリミリング工具を試作し，インコネル718のロータリミリングにおける工具摩耗抑制効果について評価を行う．

DOI： 10.11522/pscjspe.2012S.0.239.0

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

切削加工における自励びびり振動は再生効果に強く依存する．不等ピッチ工具を用いて再生効果を抑制することで安定限界を効果的に向上することもできるが，その効果はピッチ角の設計に依存する．本研究では，エンドミル加工における再生効果の新しい定量化手法を提案するとともに，共振周波数の異なる複数の振動モードが存在する際に，それらの振動モードに対して同時に再生効果を打ち消す新しいピッチ角の設計手法を提案する．

DOI： 10.11522/pscjspe.2012S.0.181.0

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

本研究では，進行波を利用した新たな非接触流体軸受を提案している．本軸受は，軸受面上に発生させた進行波によって軸受中心に向かう力を流体に与えることで，軸受隙間内の圧力を上昇させ非接触支持を実現する．本報では，装置の製作性と性能を向上させるためにモジュール化した進行波圧電アクチュエータを開発し，そのアクチュエータを用いた軸受の開発・評価を行う．また本軸受を用いた精密スライダの開発を目指す．

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Language：Japanese   Publisher：砥粒加工学会  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELSEVIER SCIENCE BV  

A novel chatter suppression method in boring operation is proposed in the present study. The anisotropic boring tool with a step portion and notches on the cylinder periphery is designed, which has anisotropic dynamic characteristics. Since the direct and the cross transfer function components of the proposed tool are designed to cancel out each vibration, the nominal compliance of the boring tool in cutting process can be reduced significantly. Hammering tests of the developed tool clarified that appropriate anisotropic frequency response function is roughly attained by the proposed design. The developed tool was subsequently applied to turning experiments, and it was clarified that the stability limit in the radial depth of cut significantly increases by using the proposed boring tool as compared to the ordinary boring tool. (C) 2012 The Authors. Published by Elsevier B.V. Selection and/or peer-review under responsibility of Professor Konrad Wegener

DOI： 10.1016/j.procir.2012.04.008

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：TRANSACTION PUBLISHERS  

Tungsten carbide is a crucial material for glass molding in optical industry. The present study investigated a feasibility of ductile machining of sintered tungsten carbide for glass molding by applying ultrasonic elliptical vibration cutting techriology with single crystal diamond tool. Grain size and binder material of sintered tungsten carbide have an influence on hardness and/or toughness of the material. Binder material also has a chemical affinity to diamond. In order to examine the influence of material composition on ductile machining of tungsten carbide, a series of grooving and planing experiments were conducted to several different tungsten carbide workpieces with the different binder phase and the different grain size. The experimental results indicated that micro grooving in a ductile mode can be attained successfully by applying ultrasonic elliptical vibration cutting, while finished surface deteriorates with brittle fractures in ordinary cutting. It was also clarified that grain size and binder material have significant influence on the deteriorations in the surface quality, the tool shape and the cutting forces.

DOI： 10.4028/www.scientific.net/KEM.523-524.113

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This research presents novel strategies to optimize tool path/posture to avoid chatter vibration in various machining operations. It is well known that the chatter stability depends on tool geometry and cutting conditions; whereas it is less known that it also depends on tool path/posture relative to the dynamically most compliant direction. In order to realize an intelligent tool path/posture planning with consideration of the chatter stability, a simple index is proposed to represent the machining stability due to the tool path/posture. As an example, the stability in turning is considered, and the use of proposed stability index is verified experimentally. (c) 2012 CIRP.

DOI： 10.1016/j.cirp.2012.03.133

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：VDE Verlag GmbH  

This paper presents measurement of nonlinear viscoelasticity of a polishing pad and identification of nonlinear viscoelasticity parameters. Since the polishing pad consists of high polymer foam with rough asperity surface, it behaves as a nonlinear viscoelastic material against the wafer contact during polishing. Thus, mechanical properties of the polishing pad directly affect polishing performance, and identification of the nonlinear viscoelasticity of the polishing pad is significantly important especially to attain analysis of the polishing process. In order to measure the nonlinear elasticity of the polishing pad, an on-machine compression tester was developed in the present study. The developed compression tester can be attached to the polishing machine and high-speed compression can be attained by using PZT actuator. From measured stress-strain curve, nonlinear elasticity parameters are identified based on the proposed asperity layer model based on the traditional contact model. The viscosity parameter is also calculated by comparing the measured compression data at different compression speeds. By implementing compression tests, the nonlinear elasticity and the viscosity coefficient of the polishing pad were identified successfully. Soft EHL analysis of the CMP process was also conducted by using identified parameters. Calculated results indicated an importance of the consideration of the nonlinear viscoelastic properties.

Scopus

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Authorship：Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

Rapid tool wear in diamond machining of steel can cause catastrophic failures. Despite several approaches to reducing tool wear, diamond machining of steel for industrial applications remains limited. We investigated two solutions, namely plasma nitriding treatment for workpiece surface modification and elliptical vibration cutting for cutting process modification, to determine their effect on reducing tool wear in diamond machining of AISI 4140 die steel. Furthermore, a new approach by combining the two solutions was also explored. Experimental results showed that diamond tool wear could be reduced by several orders of magnitude and mirror-quality surface can be obtained by using either the plasma nitriding treatment or the elliptical vibration cutting. However, in contrast to our expectations, combining the two solutions did not yield further improvement of either the surface finish or the reduction of tool wear compared with that of elliptical vibration cutting alone due to microchipping. Care has been taken to investigate the mechanism responsible for microchipping, and it was found that microchipping is highly dependent on the crystal orientation of the diamond. A diamond tool with the (1 1 0) plane as the rake face and the (1 0 0) plane as the flank face was more resistant to damage, and the microchipping induced in the combined cutting process was almost completely suppressed. (C) 2011 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.precisioneng.2011.05.003

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE INC  

A new ultra-precision sculpturing method in micro/nano scale for difficult-to-cut materials is proposed in the present research Elliptical vibration cutting technology is well-known for its excellent performance in achieving ultra-precision machining of steel materials with single crystal diamond tools Elliptical vibration locus is generally controlled and held to a constant in practice On the contrary the proposed method utilizes the variations of the elliptical vibration locus in a positive manner Depth of cut can be actively controlled in elliptical vibration cutting by controlling vibration amplitude in the thrust direction By utilizing this as a fast tool servo function in elliptical vibration cutting high performance micro/nano sculpturing can be attained without using conventional fast tool servo technology A high speed amplitude control system is developed for elliptical vibration with a bandwidth of more than 300 Hz where the vibration amplitude can be controlled within 4 mu m(p-p) The developed control system is applied to sculpturing ultra-precision nano textured grooves on hardened steel with single crystal diamond tools It is confirmed that the textured grooves have the desired shapes and their profiles agree well with the vibration amplitude commands input to the control system Further a high performance micro/nano sculpturing system for plane surfaces is developed where the vibration amplitude is controlled in synchronization with the planing motion of an ultra-precision machine tool Nano sculpturing experiments on hardened steel earned out by the developed system are reported as well as consequent picture images and a variety of dimple patterns that were formed successfully on the hardened steel as nano scale sculptures (C) 2010 Elsevier Inc All rights reserved

DOI： 10.1016/j.precisioneng.2010.09.006

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

This paper presents a new chip control method with guide grooves formed on the rake face to realize continuous chip disposal and chip-pulling turning. Chips are conventionally broken using chip breakers during turning operations for disposal. However, chips of highly ductile materials or thin chips generated in finishing can not be broken easily. In order to prevent the chips from jamming up, the authors propose to continuously guide the chips away from the cutting point. Special tool tips were developed and tested for guiding the chip. Chip controllability and mechanics of the chip-guided cutting are discussed in the present research. (C) 2011 CIRP.

DOI： 10.1016/j.cirp.2011.03.081

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Publisher：The Japan Society for Precision Engineering  

DOI： 10.11522/pscjspe.2011A.0.315.0

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Publisher：The Japan Society for Precision Engineering  

DOI： 10.11522/pscjspe.2011A.0.161.0

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Publisher：The Japan Society for Precision Engineering  

航空機エンジン部品等に用いられる超耐熱合金インコネル718の加工では，従来の超硬工具による低速加工に置き換わり，セラミック工具を用いた高速ミリングによる高能率加工が普及してきている．しかし，工具損耗が極めて激しいため，工具寿命の改善が必要とされている．本研究では，工具損耗に影響を与える因子として機械構造の動剛性や加工条件に着目し，各条件が工具損耗に与える影響について実験に基づいた基礎検討を行った．

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

Self-excited chatter vibration in end milling is caused by the regeneration and mode coupling mechanisms. In order to avoid chatter vibration, both mechanisms need to be investigated. Past researches have shown that the mode coupling effect in end milling can be suppressed by using cutting tools with anisotropic dynamic characteristics. However, it is difficult to apply previously developed analytical models for predicting the chatter stability limits in end milling with the anisotropic tools. Hence, suitable conditions for chatter suppression and the overall phenomena have not been clarified thoroughly yet. This paper proposes a new analytical model to predict chatter stability limits in end milling with tools that have anisotropic transfer functions. The model considers the anisotropic tool to vibrate steadily in a rotating coordinate system rather than in an inertial coordinate system. The cutting process is formulated in this rotating coordinate system, and variation in the transfer function of the anisotropic tool with respect to the spindle speed is considered. Fundamental cutting tests have been conducted to verify the proposed model. Experimentally identified stability limits agreed closely with the predictions. Furthermore, analytical investigations have shown that the transfer function of the cutting tool changes considerably with the spindle speed. This affects the chatter stability prediction significantly. Using the proposed model, it is concluded that higher stability limits can be achieved only at low spindle speed conditions by using anisotropic tools. However, the number of flutes on the tool is limited to be less than three, and they need to be arranged at suitable positions. The effect of the cutter helix also needs to be negligible.

DOI： 10.2493/jjspe.77.97

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

We developed a new passive-type micromixer based on the baker's transformation and realized a fast mixing of a protein solution, which has lower diffusion constant. The baker's transformation is an ideal mixing method, but there is no report on the microfluidic baker's transformation (MBT), since it is required to fabricate the complicated three-dimensional (3D) structure to realize the MBT device. In this note, we successfully fabricate the MBT device by using precision diamond cutting of an oxygen-free copper substrate for the mould fabrication and PDMS replication. TheMBTdevice with 10.4 mm mixing length enables us to achieve complete mixing of a FITC solution (D = 2.6 x 10(-10) m(2) s(-1)) within 51 ms and an IgG solution (D = 4.6 x 10(-11) m(2) s(-1)) within 306 ms. Its mixing speed is 70-fold higher for a FITC solution and 900-fold higher for an IgG solution than the mixing speed by the microchannel without MBT structures. The Peclet number to attain complete mixing in the MBT device is estimated to be 6.9 x 10(4).

DOI： 10.1039/c1lc20342h

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PubMed

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

Chips are generally assisted to curl and then broken into pieces by chip breakers. This conventional concept sometimes fails especially when the workpiece is highly ductile or the chip is thin and flexible. Contrary to this conventional method, a new concept of continuous chip disposal is proposed in the present research, where the chip is controlled not to curl and guided to a chip disposer. The key to this concept is chip control to suppress the curl and to guide the chip to desired direction. The continuous chip disposal can also be combined easily with chip-pulling cutting. It is known that the cutting process is improved drastically by pulling the chip, i.e. cutting force, energy and heat are all reduced remarkably. Therefore, new chip control methods are developed as basic technologies to realize the continuous disposal and the chip-pulling. A chip control method is proposed to suppress the up-curl by convex tool geometry, i.e. curved rake face with inverse curvature to the up-curl. Tools with the inversely curved rake faces are developed, and it is confirmed that the up-curl can be suppressed at a certain inverse curvature. Another chip control method is proposed to suppress the side-curl and to control the chip flow direction at the same time by forming guide grooves on the rake face. The tools with the guide grooves and a guide tunnel are developed, and it is demonstrated that the chip can be guided successfully along the guide grooves into the guide tunnel over a fairly wide range of conditions.

DOI： 10.2493/jjspe.77.520

CiNii Books

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A dynamic analysis model of CMP process is developed by utilizing a finite element method in the present study. By considering relative motion of a wafer and a polishing pad in a steady-state process, a nonlinear equation of motion is derived based on Arbitrary Lagrangian-Eulerian (ALE) method in the proposed model. Since the dynamic CMP process in the steady-state can be treated as a static problem in an ALE coordinate system, computation time can be reduced significantly and meshing procedure can be simplified as compared with conventional dynamic structural analysis, i.e., time history response analysis. As a result, practical large scale problems can be solved accurately with consideration of the dynamic structural behavior. Two-dimensional structural analysis was carried out by applying the proposed model, and it was verified that the computation time can be reduced significantly as compared with the conventional analysis. Effects of viscosity of the polishing pad on polishing pressure distribution were examined, and it was clarified that stress concentration beneath the leading edge of the wafer greatly depends on the viscosity of the polishing pad, i.e., the consideration of dynamic viscoelastic behavior of the polishing pad is important to predict the polishing pressure distribution. The proposed model was subsequently applied to three-dimensional analysis of CMP process, and reasonable polishing pressure distribution, which was similar to that in the two-dimensional analysis, was derived successfully.

DOI： 10.2493/jjspe.77.513

CiNii Books

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Publisher：The Japan Society for Precision Engineering  

本研究では，まず，狭いすき間で振動する軸受面に，外部から気体を吸込んで圧力増加する現象が存在することを見出した．これを多段にして複数回の圧力増加を繰返し，より高圧を発生する新しい軸受として，多段振動気体軸受を提案する．さらに本報では，試作開発した本軸受装置の測定と，軸受隙間内気体の有限要素モデルによる解析により，軸受性能について検討した結果について報告する．

DOI： 10.11522/pscjspe.2010A.0.661.0

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DOI： 10.20965/ijat.2010.p0252

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC MECHANICAL ENGINEERS  

An accurate analytical model for regenerative chatter vibration in plunge cutting is proposed. Effects of the cross transfer function and the cutting force ratio on chatter stability are considered in the proposed model. Equivalent transfer function is defined, which is useful to understand those effects on chatter stability. Basic plunge cutting experiments were conducted to verify the proposed model. Although the critical widths of cut in the CW and CCW rotation processes were significantly different from each other in the experiment, even when the other conditions were the same, chatter stability limits were predicted accurately by the proposed model as compared with the conventional model.

DOI： 10.1299/jamdsm.4.883

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOC MECHANICAL ENGINEERS  

Process damping in metal cutting is caused by the contact between the flank face of the cutting tool and the wavy surface finish, which is known to damp chatter vibrations. An analytical model with process damping has already been developed and verified in earlier research, in which the damping coefficient is considered to be proportional to the ratio of vibration and cutting velocities. This paper presents in process identification of the process damping force coefficient derived from cutting tests. Plunge turning is used to create a continuous reduction in cutting speed as the tool reduces the diameter of a cylindrical workpiece. When chatter stops at a critical cutting speed, the process damping coefficient is estimated by inverse solution of the stability law. It is shown that the stability lobes constructed by the identified process damping coefficient agrees with experiments conducted in both turning and milling.

DOI： 10.1299/jamdsm.4.1107

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

The chatter vibration excited during machining process deteriorates quality of workpiece surfaces, and accelerates tool wear. In addition, it often takes long time to find chatter-free cutting conditions. Therefore, a new control system is developed in the present research for searching the optimum spindle speed at which chatter stability is maximized. The developed system detects the chatter vibration that occurs during machining process using a vibration sensor, and then optimizes the spindle speed automatically in real time. This report presents an overview and an application of the developed system.

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Publisher：The Japan Society for Precision Engineering  

適切な不等ピッチ工具を利用することにより，自励びびり振動の発生原因となる再生効果を抑制し得ることが知られている．本研究ではボーリング加工を対象とし，不等ピッチ工具による自励びびり振動の抑制効果について検討を行う．まず，解析モデルを構築し実験的に検証を行った．さらに，モードカップリングの影響が小さい条件では効果的に抑制されるのに対し，大きい条件ではむしろ不安定になることを確認した．

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

The accurate analytical model for the dynamic structure analysis of Chemical Mechanical Polishing (CMP) process has been proposed by the authors. By applying to the three dimensional (3D) coupled fluid-structure analysis of the CMP process, the effect of the damping property of the polishing pad on the process was investigated. It was confirmed that the stress concentration beneath the leading edge of the wafer changes significantly depending on the consideration of the damping property. Consequently, the analytical results of polishing pressure and fluid pressure distributions considerably depend on the damping property too. The fluid pressure measuring experiment was also carried out, and it is confirmed that the feature of the measured fluid pressure distribution agrees with that simulated by developed CMP process analytical model.

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

Chatter vibrations limit machining productivity and sometimes result in reduction of tool life in the end-milling process. There are two major types of chatter vibrations, i.e., forced and self-excited types. Their generation mechanics are different, and thus their characteristics and strategies to avoid them are also different. It is, therefore, needed in practice to understand their relationship and to select efficient milling conditions to stabilize the process for the self-excited chatter vibration and to minimize the forced chatter vibration at the same time. However, most of past research works have been focused only on the self-excited chatter vibration, and detailed analysis of the forced chatter vibration and its relationship to the self-excited chatter vibration can not be found in the literature. Thus, an analytical model of the end milling process with the forced chatter vibration is developed and verified experimentally. Then, the characteristics of the forced type and its relationship to the self-excited type are clarified, and the milling conditions to avoid the both types are clarified by utilizing the analytical model developed here and the model of the self-excited type developed in the past research.

DOI： 10.2493/jjspe.75.908

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)  

Precision machining, named 'elliptical vibration cutting', and its application to ultraprecision / micro machining of some hard / brittle materials are introduced in the present paper. The elliptical vibration cutting has a superior cutting performance in terms of low cutting force, low cutting energy, low heat generation, long tool life for steels, sintered tungsten alloy, etc., and large critical depth of cut for ductile machining of brittle materials such as glasses and single crystal calcium fluoride, etc. Based on these basic advantages, practical ultraprecision / micro machining of the hard / brittle materials is successfully realized by employing the ultrasonic elliptical vibration tools, which have been developed for ultraprecision machining. © (2009) Trans Tech Publications, Switzerland.

DOI： 10.4028/www.scientific.net/AMR.69-70.133

Scopus

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Publisher：The Japan Society for Precision Engineering  

The accurate analytical model for the dynamic structure analysis of Chemical Mechanical Polishing (CMP) process has been proposed by the authors. By extending to the three dimensional (3D) analysis and applying to the coupled fluid-structure analysis of the CMP process, the accurate CMP process model, which can consider the nonlinear dynamic motion, the damping effects and the stress concentration simultaneously, was developed in the present research. It was applied to the 3D CMP process analysis, and the effect of the damping property of the polishing pad on the process was investigated. It was confirmed that the stress concentration beneath the leading edge of the wafer changes significantly depending on the consideration of the damping property. Thus, there is a possibility that the developed model can estimate the polishing stress and fluid pressure distributions of the CMP process accurately.

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Publisher：The Japan Society for Precision Engineering  

CMPプロセスでは，ウェハと研磨パッド間が潤滑状態となり，流体圧力が生じることが知られている．しかし，研磨パッドや研磨ヘッドは回転運動を行うため，その界面の流体圧力の測定は難しい．本研究では，無線通信により流体圧力を遠隔計測する装置を試作し，ウェハ－研磨パッド間の流体圧力の計測実験を行った．さらに，著者らが開発しているCMPプロセス解析との比較を行った．

DOI： 10.11522/pscjspe.2009A.0.321.0

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Publisher：The Japan Society for Precision Engineering  

インサート工具の突き出し長さが大きく，傾斜した方向に軸振動を発生する自由曲面加工用の2自由度超音波楕円振動工具を開発した．さらに，焼入れ鋼の溝加工実験に適用し，びびり振動の発生メカニズムについて考察を行うとともに，安定限界向上の可能性について検討を行った．その結果，インサート工具の形状を非対称にすることでモードカップリング型のびびり振動が抑制され，安定限界切込みが増大することを確認した．

DOI： 10.11522/pscjspe.2009A.0.47.0

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Publisher：The Japan Society for Precision Engineering  

振動切削では，超音波領域の振動を用いて断続的な加工を行うことによりなどさまざまな優れた効果が得られることが知られている．一般に20～40kHz程度の周波数が利用されるが，それ以上の高周波振動を利用した場合にどのような効果が得られかについては詳しく検討されていない．そこで，本研究では従来と比べて1桁程度周波数の高いサブMHzの楕円振動工具を試作し，その加工特性について評価を行った．

DOI： 10.11522/pscjspe.2009A.0.49.0

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Language：English   Publishing type：Research paper (international conference proceedings)  

Chatter vibration in milling often results in poor surface finish and rapid tool wear, consequently limiting productivity. Thus, chatter suppression is one of the most important themes in industry. Self-excited chatter vibration in milling is generally caused by two kinds of mechanisms, i.e., regeneration and mode-coupling, and both mechanisms should be handled simultaneously to suppress the chatter vibration. Since the mode-coupling can be restricted by separating the natural frequencies of the vibration modes, it has been considered that use of an anisotropic rotating tool is effective on suppressing the chatter vibration in milling. However, the practical effects of the several parameters have not been revealed because it was difficult to predict the chatter stability accurately. On the other hand, the accurate analytical model of the milling process with the anisotropic rotating tool have been developed and verified experimentally by the authors. In order to reveal the practical chatter suppression effect of the anisotropic rotation tool, several cutting conditions, i.e., the immersion angle, the spindle speed and the number of flutes, on the chatter stability are investigated with the developed analytical model in the present study. By comparing the analytical results, it is confirmed that the mode-coupling is restricted and the stability limit in the axial depth of cut increases especially within the low spindle speed range by using the anisotropic rotating tool. The chatter suppression effect also depends on the radial depth of cut considerably. The relationships between the tool conditions, such as the difference of the natural frequencies and flute's angular position, and the chatter suppression effect are also investigated, and it is revealed that both affect the chatter stability significantly. ©2009 IEEE.

DOI： 10.1109/MHS.2009.5351857

Scopus

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Publisher：The Japan Society for Precision Engineering  

従来提案されているマイクロミキサは主に半導体プロセスにより作成される．振動装置などの特殊な機構を必要とする場合も多い．これに対し著者らは，金型により量産成形することができ，かつ特殊な機構を必要としない高効率マイクロミキサを考案した．本発表では，考案したミキサについて流体解析と模型実験を行い，ともにおおむね目的とする流体の挙動が確認されたことについて述べる．

DOI： 10.11522/pscjspe.2009S.0.795.0

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Publisher：The Japan Society for Precision Engineering  

圧電素子は高剛性、高分解能、高速応答性といった長所を持つため、位置決め装置のアクチュエータとして利用される。しかし、ヒステリシス、クリープといった非線形性を持つため位置決め性能が低下する。そこで本研究では、クリープの生じない変位と電圧の関係（非クリープ線）の発見に基づき、非線形性を補償するようにオープンループで位置決めを行う方法を開発している。本報では駆動速度、プリロードの影響について報告する。

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Publisher：The Japan Society for Precision Engineering  

板材の加工は裏面をマグネットにより固定し，表面をフライス加工する方法が一般的である．しかし，二面を片面ずつ切削するために効率が低く，また弾性変形させた状態で切削することにより加工精度も低いことが問題となっている．これに対し，著者らは両面同時フライス加工法を採用し，それに伴う板材の剛性低下や複数主軸の同時使用に起因する再生型びびり振動を，左右主軸に回転数差を設けることにより抑制する手法を考案した．

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Publisher：The Japan Society for Precision Engineering  

切削加工において，低速領域ではプロセスダンピングの影響によりびびり振動が発生しにくいことが知られている．これを考慮した簡易的な解析モデルが考案されているが，従来手法はその影響を考慮するための変数の同定精度が低く，高精度な解析が難しいという問題があった．これに対し，本研究ではびびり振動の逆解析を利用した変数の新しい同定手法を考案し，高精度な安定限界解析が可能であることを実験的に確認した．

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

Two new heuristic procedures for re-entrant flow shop scheduling problem are proposed to plan a feasible production schedule in industrial manufacturing factories. Each job is assigned to one of idle periods within a limited time on a cyclic Gantt chart. One heuristic procedure is for an assignment of a target job on the machine while an adequate the idle time is remained for undecided jobs. Another heuristic procedure is based on solutions for two classical optimization problems, or a job assignment problem and a knapsack problem. The starting time of the target job is optimally determined at each step in the scheduling. The results indicate that the proposed procedures give a good schedule in comparison with the optimal schedule derived theoretically. The Calculation times are also evaluated and verified a validity of the use in actual manufacturing factories.

DOI： 10.2493/jjspe.74.1225

CiNii Books

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A new theoretical formulation for re-entrant flow shop scheduling problem is derived to plan an optimum production schedule by mixed integer programming. Flow time, which is an index of the evaluation of the planned schedule, is minimized to decrease amount of work-in-process. Cycle time, which is another important index, is determined by the total load time on a bottleneck machine to manufacture the products at the highest productivity. Both objective function and constraint conditions are described in linear expressions and a general optimization tool is adopted to solve the formulated scheduling problems. Another objective function is also introduced in order to shorten the time for the optimization. Computational scheduling results obtained by the optimization are evaluated and discussed in the present paper.

DOI： 10.2493/jjspe.74.1119

CiNii Books

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Publisher：The Japan Society for Precision Engineering  

CMPにおける従来のウェハ－研磨パッド間の接触応力解析においては，動的な解析モデルを扱う際に解析精度が低くなるという問題があった．これに対し，動的なプロセスを準静的に扱う構造解析モデルを考案し，動的接触応力解析の高精度化・高速化について検討を行った．その結果，提案手法を用いることにより，ウェハエッジ部における応力集中などの従来困難であった解析の精度が向上し，解析時間が大幅に短縮されることを確認した．

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：SPRINGER  

A new method for controlling the WIP inventory is proposed in order to restrict the excessive production of unfinished products, while the manufacturing productivity is kept at a certain high value. Excessive WIPs decrease business profits and prevent the realization of agile manufacturing along with changes in markets, while insufficient number of WIPs reduce manufacturing productivity and flexibility to cope with malfunctions of production resources. Theoretical formulations of a scheduling problem without buffer is derived, and heuristic procedure is adopted to plan a feasible schedule. The proposed control methods are verified by computational simulations regarding job-shop type production system.

DOI： 10.1007/978-1-84800-267-8_45

Web of Science

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD  

Simple analytical models of three dimensional (3D) elliptical vibration cutting are developed in order to simulate the cutting process quickly and to understand the basic mechanics. The elliptical vibration cutting has recently been applied in industry mainly to ultraprecision machining of dies and molds, where the vibration locus is not generally perpendicular to the cutting edge and thus all directions of shear, chip flow and cutting force have the 3D components. Therefore, the 3D elliptical vibration cutting models are developed, and the basic cutting mechanics are discussed in the present research. (c) 2008 CIRP.

DOI： 10.1016/j.cirp.2008.03.073

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Publisher：The Japan Society for Precision Engineering  

切削加工におけるびびり振動の安定限界に対して，機械構造の伝達特性におけるクロス項が与える影響について検討した研究はこれまでになく，ほとんどの場合には考慮すらされることがない．これに対し本研究では，びびり振動の安定限界に対して伝達特性のクロス項が与える影響について，その本質的な意味を明らかにするとともに，突切り切削を対象としてクロス項を考慮した再生型びびり振動の安定限界解析手法を提案する．

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Publisher：The Japan Society for Precision Engineering  

エンドミル加工のびびり振動の安定限界解析には伝達関数が必要となるが，小型もしくは複雑形状の機械構造や，回転中に伝達特性の変化する機械構造がびびり振動する場合には，伝達関数の高精度測定が難しいという問題がある．そこで，従来の伝達関数測定手法と異なり，加工実験中に計測されるびびり振動の周波数と実際の安定限界切込みから伝達関数を逆同定する手法を考案した．そして，加工実験により考案手法の検証を行った．

DOI： 10.11522/pscjspe.2008S.0.69.0

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Publisher：The Japan Society for Precision Engineering  

新しいガラス成型用金型材料として期待されているタングステン合金の超音波楕円振動切削においては，従来の研究によってダイヤモンド工具の急激な摩耗が仕上げ面性状の劣化を引き起こし問題となることが明らかになっている．本研究ではこの摩耗メカニズムに着目し，工具形状や結晶方位などの変更による工具寿命の延長について検討を行う．さらに，各種工具を用いた寿命試験により，その効果について検証を行った．

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Publisher：The Japan Society for Precision Engineering  

著者らは楕円振動切削を利用した焼入れ鋼の自由曲面加工法を提案し，これを実現するための3自由度超音波楕円振動工具を開発している．従来の振動工具においては，大きな切削負荷が生じた際に振動軌跡が乱れて仕上げ面性状の劣化や工具の欠損を引き起こす問題があった．そこで，本研究では振動子に取り付けるシャンク形状の変更による負荷特性の改善を検討した．その結果，大幅に負荷特性を改善し得ることを確認した．

DOI： 10.11522/pscjspe.2008A.0.123.0

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Publisher：The Japan Society for Precision Engineering  

本研究では進行波を利用した新しい流体軸受を提案している．本軸受では圧電素子を用いて軸受面に進行波を発生し，軸受面中心に向かう力を流体に与えることで軸受面下の圧力を上昇させ，非接触の支持を実現する．本報では本軸受の試作機に対する測定と既に構築している本軸受の軸受隙間の有限要素モデルによる解析により，本原理による軸受としての性能について検討する．

DOI： 10.11522/pscjspe.2008A.0.937.0

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

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Publisher：The Japan Society for Precision Engineering  

楕円振動切削では，切込方向の振動振幅を能動的に制御することによって切込み深さに変動を与えることができる．本研究では，この特徴に基づき，振動振幅制御を利用した高硬度材の超精密微細テクスチャ加工技術を提案する．振動振幅を高速制御することが可能な約40kHzの楕円振動制御装置を用いて，焼入れ鋼のテクスチャ加工実験を行った．基礎的な溝加工実験の結果，良好な超精密微細加工を実現できることを確認した．

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Publisher：The Japan Society for Precision Engineering  

Ultrasonic vibration cutting processes are modeled and simulated in the present research, utilizing MSC-Marc FEM software. The vibration is applied to the cutting tool in one or two directions denoted by vibration cutting (VC) and elliptical vibration cutting (EVC), respectively. The cutting forces and the stresses developed within the workpiece during the vibration cutting processes are estimated and compared with those in the conventional cutting (CC) process. The influence of various parameters such as speed ratio and amplitude are subsequently investigated. It is partially concluded that though the cutting force fluctuates periodically in VC and EVC, its average value changes from CC to VC and EVC in descending order. The cutting force decreases with a rise in the speed ratio in EVC and does not change in VC.

DOI： 10.11522/pscjspe.2008A.0.125.0

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Publisher：The Japan Society for Precision Engineering  

回転工具を用いる加工では，一般に再生効果とモードカップリングの影響が混在した自励型びびり振動が発生するが，通常これらの影響はほとんど区別されることはない．これに対し，本研究ではボーリング加工を対象として，再生効果とモードカップリングの影響を切り分けた実験条件において安定限界解析の比較を行った．その結果，それぞれの影響が小さくなる条件において安定限界が最も大きくなることを確認した．

DOI： 10.11522/pscjspe.2008A.0.295.0

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Optical Society of America (OSA)  

A cutting method named 'elliptical vibration cutting' is introduced in the present paper. It has a superior cutting performance and has been successfully applied to practical ultraprecision / micro machining of hard / brittle materials. © 2008 Optical Society of America.

DOI： 10.1364/oft.2008.otub1

Scopus

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society of Mechanical Engineers  

A scheduling problem is formulated focusing on jobs stored in production resources in the present paper. In a production system with finite buffer capacity, the job are stored in not only buffers but also production resources such as machine tools and assembly robots. Therefore, successive jobs cannot be processed by the resources until the previous jobs are removed from them. In such a scheduling problem, certain processing orders of jobs are infeasible because start times and release times of the jobs can not be determined. The graph representation method for conventional scheduling problems is extended in order to judge feasibility of the present schedules, in which the jobs stored in the resources are taken into account. A local searching method is applied to improve the schedules of the production systems with finite buffer capacity. It gives an appropriate schedule in combination with the dispatching procedure proposed in the first report.

DOI： 10.1299/kikaic.73.3084

CiNii Books

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

This study deals with scheduling problems with consideration of synchronized operations by multiple production resources. Transfer of a material between a machine tool and a conveying device by a human operator is a typical example of the synchronized operations. When the synchronized operations are taken into consideration, it is necessary to check conflicts between the resources before an appropriate job is assigned by Earliest Starting Time rule, which is one of the popular dispatching rules. A new sequence is proposed in the present paper to check the conflicts. Feasible scheduling with the consideration of synchronized operations is realized by combining the proposed sequence with a conventional dispatching rule. Computational scheduling results are shown in order to verify the effectiveness of the selecting sequences proposed here. Computational scheduling is carried out, and the results show that a practical production schedule can be planned without any conflicts by the proposed sequence, despite complex constraints due to the consideration of synchronized operations. Furthermore, a blocked status of the machine tool, the conveying device and the buffer appears on the Gantt chart unlike the conventional scheduling methods.

DOI： 10.2493/jjspe.73.834

CiNii Books

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

&#039;Ultrasonic elliptical vibration cutting&#039; technology is applied in the present research to ultraprecision machining of tungsten alloy, which is expected as a material of molds for glass parts instead of sintered tungsten carbide or CVD-silicon carbide. It is confirmed that ulptraprecision grooving of the tungsten alloy cannot be realized by the ordinary cutting. On the other hand, it can be realized by the elliptical vibration cutting at a cutting depth of less than 0.8 μm. Effects of the cutting distance on the cutting force and the surface roughness are also clarified, and it is found that surface roughness of less than 100 nm Rz can be attained up to a cutting distance of 35 m. Practical molds of the tungsten alloy for spherical glass lenses and a glass prism are successfully machined by the elliptical vibration cutting.

DOI： 10.2493/jjspe.73.360

CiNii Books

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A new ultrasonic elliptical vibration tool is developed in the present research to realize sculptured surface machining of die steel by applying &quot;elliptical vibration cutting&quot;. The new vibration tool is designed to have three degree-of-freedom (3 DOF), so that it is suitable to machine the three-dimensional sculptured surfaces. The 3 DOF ultrasonic elliptical vibration tool generates an arbitrary ultrasonic elliptical vibration in the three-dimensional space by combining two directional bending vibrations and a longitudinal vibration. It is excited by piezoelectric actuators at 34.4kHz, which is an average resonant frequency of the three vibrations. The developed vibration tool is attached to the 4 axis precision machine tool developed in the previous report, and mirror surfaces of hardened steel are obtained successfully by the proposed method.

DOI： 10.2493/jjspe.73.117

CiNii Books

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Publishing type：Research paper (international conference proceedings)  

Herein we report the development of a new passive micromixer with 3-D structure based on Baker's transformation. The 3-D structure was fabricated on an oxygen-free copper block by using an ultrasonic elliptical vibration cutting method [1] and was used as a mold master. Using this master mold, we fabricated a PDMS micromixer chip. The mixing efficiency of the micromixer was evaluated by measuring the fluorescence image that results from mixing of two liquids (FITC solution and water). From these measurements, we found that the mixing efficiency at relatively high flow rate conditions is much better than that of low flow rate conditions. The mixing behavior in the microchannel was observed by a confocal fluorescence microscopy.

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

The present study performs an experimental verification of an analytical model of the Chemical Mechanical Polishing (CM-P) process, focusing on friction force and the distribution of the material removal rate. A coupled Fluid-Structure analytical model, which can predict the friction force and the distribution of the material removal rate, is developed. Oxide CMP experiments are conducted using a fabricated CMP system, and measured friction force and distribution of the material removal rate are compared with the analytical results. As a result, it is confirmed that the wafer's rotational speed affects the friction force and the distribution of the material removal rate. Additionally, the results determined by the developed analytical model agree with the measurements. The magnitude of the friction force under a condition in which the wafer does not rotate becomes smaller than when the wafer rotates at the same speed as the polishing pad. The direction of the friction force inclines against the rotational center of the polishing pad. The material removal rate when the wafer does not rotate is high around the edge of the wafer as compared with that at other areas. In particular, it becomes high around the leading edge and the area where the rotational radius of the polishing pad is large. These specific characteristics of the friction force and the distribution of the material removal rate are explained using the analytical results.

DOI： 10.1109/MHS.2007.4420922

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：TECHNISCHE RUNDSCHAU EDITION COLIBRI LTD  

Elliptical vibration cutting is applied to ultra-precision machining of tungsten alloy molds for optical glass parts in the present research. The tungsten alloy is expected as a new mold material instead of conventional ones such as sintered tungsten carbide and CVD-silicon carbide. However, it cannot be finished precisely by ordinary cutting because of rapid tool wear, brittle fracture and adhesion to the tool. Therefore, the ultrasonic elliptical vibration cutting is applied to the ultra-precision machining of tungsten alloy. Practical ultra-precision molds are obtained by the elliptical vibration cutting, and they are applied to glass molding successfully.

DOI： 10.1016/j.cirp.2007.052.032

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Publisher：The Japan Society for Precision Engineering  

Elliptical vibration cutting is applied to ultra-precision machining of tungsten alloy molds for optical glass parts in the present research. The tungsten alloy is expected as a new mold material instead of conventional ones such as sintered tungsten carbide and CVD-silicon carbide. Ultra-precision molds of the tungsten alloy for a prism, a small spherical lens and an array of micro V-grooves were machined by the elliptical vibration cutting. It is confirmed that surface roughness of less than 100 nmRz and desired shape can be attained. They were applied to glass molding of borosilicate glass BK7 without any coatings, and it is found that accurate transcript with no adhesion can be achieved successfully.

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Publisher：The Japan Society for Precision Engineering  

従来のエンドミル加工におけるびびり振動安定限界解析では，空間に固定された座標系内で構造物の伝達関数を定義し，固定座標系内で一定の振動が生じることを前提としている．これに対して著者らは，低剛性の回転工具に，その工具に固定された座標系内で一定の振動が発生する場合に対応した安定限界解析モデルを構築している．本研究では，異方性を持つエンドミル工具を用いた切削実験を行い，本手法の有効性について検証を行った．

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Publisher：The Japan Society for Precision Engineering  

びびり振動を抑制・回避するためには，安定限界解析手法を利用した適切な加工条件の選択や構造の改善が有効となる．これに対し，本研究では，強制型びびり振動を引き起こす主要因となる切削力の周期変動を考慮した，エンドミル加工における強制型びびり振動の安定限界解析手法を考案した．さらに，エンドミル加工による検証実験を行い，本解析手法により強制型びびり振動の安定限界を高精度に予測し得ることを確認した．

DOI： 10.11522/pscjspe.2007A.0.569.0

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Publisher：The Japan Society for Precision Engineering  

本研究では新しい振動切削加工法として，放物線振動切削加工法を提案する。本手法では工具刃先を切削方向に放物線軌跡で超音波振動させながら加工を行うことにより、間欠切削と引き切りの効果を同時に得るとともに、切れ刃方向の力が反転し相殺するため，実質的に著しい切削抵抗の低減が期待される。本報では、超音波放物線振動子を開発し，通常切削および従来振動切削と本手法の基礎的な比較実験を行った結果について報告する。

DOI： 10.11522/pscjspe.2007A.0.433.0

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Publisher：The Japan Society for Precision Engineering  

CMPプロセスでは，研磨に使用する材料の形状や機械特性が研磨特性に大きく影響することが経験的に知られている．著者らは，複雑なCMPプロセスのメカニズムの解明を目的とし，これまでに流体－構造連成解析を利用したCMPプロセスの解析手法について検討を行っている．本稿では，本解析手法を利用し，研磨パッドの材質やウェハ形状などの各種パラメータが研磨特性に及ぼす影響について評価を行った結果について報告する．

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Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

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Language：English   Publishing type：Research paper (international conference proceedings)  

Scopus

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A new non-contact fluid bearing, which utilizes traveling waves, is proposed in the present research. The moving part is supported with a thin fluid film compressed by the waves traveling radially on the bearing surface. Conventional hydrostatic bearings utilize externally compressed fluid, which requires plumbing and large facilities. The proposed bearing realizes non-contact precision motion without those facilities, and furthermore it has a capability to electrically control the bearing force or clearance. A prototype air bearing was developed on the basis of the proposed principle by utilizing piezo-electric actuators. Its non-contact smooth motion was confirmed, and its basic performance is clarified experimentally in terms of stiffness, bearing clearance, load capacity, pressure distribution of the air film, etc.

DOI： 10.2493/jspe.72.1483

CiNii Books

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

New machining method and system are developed in the present research to realize sculptured surface machining of die steel by applying &quot;elliptical vibration cutting&quot;. The present report presents the new machining method, and a 4-axis controlled precision machine tool and special CAM software for the proposed method. It is expected that shape accuracy, tool life, machining efficiency and energy consumption are all improved by the proposed method as compared with the conventional ball end milling. The prototype machine tool is developed by employing an air spindle driven directly by a coreless servo mortar, precision ball screws and precision linear roller guides. The CAM software is developed by utilizing a commercial main processor and developing a new post processor to generate tool paths for the 4-axis controlled motion. A new 3-DOF elliptical vibration system, which is required to complete the present technology, and application to hard materials will be presented in the next reports. It is confirmed in the present report that mirror surface machining of aluminum alloy can be realized by applying the proposed machining method and the developed machine tool and CAM software.

DOI： 10.2493/jspe.72.1139

CiNii Books

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Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

Sintered tungsten carbide is machined in ductile mode by applying &quot;elliptical vibration cutting&quot;, and the mechanics of the ductile mode cutting are investigated in the present research. Grooving experiments of the sintered tungsten carbide are carried out at low vibration frequency so that the vibration cutting process can be monitored easily. The groove machined by the elliptical vibration cutting is smooth without any visible fractures, while those machined by the conventional linear vibration cutting and the ordinary cutting are rough with numerous micro fractures. It is considered that the difference is caused by reduction of thickness of workpiece material cut in each cycle of the elliptical vibration. The same difference is confirmed at ultrasonic frequency, and it is also clarified that high quality surfaces are obtained when the vertical amplitude of the elliptical vibration is lower than 0.5 μm_&lt;0-p&gt;, which corresponds to grain size of the sintered tungsten carbide. Based on these fundamental results, the ultrasonic elliptical vibration cutting is applied to ultraprecision planing of the sintered tungsten carbide, and ultraprecision machining with surface roughness of less than 50 nm Rz is realized, although the tool life is relatively short.

DOI： 10.2493/jspe.72.539

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

An analytical approach to estimate the coefficient of friction (COF) in chemical mechanical polishing (CMP) process in mixed lubrication is developed in the present research. The Stribeck curve is calculated by experimental and analytical results of friction resistances. An analytical model, which can predict the distribution of contact stress and fluid pressure under the condition of nonuniform velocity distribution by utilizing the Stribeck curve, is developed. Polishing experiments are carried out for the verification of the model in terms of the friction resistance. It is confirmed that the effect of the wafer rotational speed on the friction resistance can be predicted successfully by the developed analytical model.

CiNii Books

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

'Ultrasonic elliptical vibration cutting' technology, which has been developed by the authors, is applied to ultraprecision machining of single crystal germanium in the present research. The germanium is an excellent material for infrared optical devices, whereas ultraprecision micro-machining of the germanium is difficult due to its brittleness. Micro grooving experiments are carried out on the (100), (110) and (111) surfaces of single crystal germanium substrates, and basic effects of the elliptical vibration on the ductile micro-machining are clarified as follows. Critical depth of cut to generate a completely fracture-free surface on the single crystal germanium is increased significantly in all crystal orientations on the (100) and (111) surfaces, and ultraprecision micro grooving is realized successfully at a large depth of cut of 1 pin by applying the elliptical vibration cutting. This improvement by the elliptical vibration cutting is considered to be caused by reduction of instantaneous uncut chip thickness and cutting force in each cycle of the elliptical vibration. When the rake angle becomes negative, influence of the crystal orientation on the critical depth of cut becomes negligible, while it is considerable at 0 degree. On the other hand, the rake angle does not have considerable influence on average values of the critical depth of cut between -20 to 0 degree. The critical depth of cut is increased in all crystal orientations as the cutting speed is reduced in the elliptical vibration cutting.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier USA  

A new non-contact fluid bearing, which utilizes traveling waves, is proposed in the present research. The moving part is supported with a thin fluid film compressed by the waves traveling radially on the bearing surface. Conventional hydrostatic bearings utilize externally compressed fluid, which requires plumbing and compressors. On the other hand, the proposed bearing realizes non-contact smooth motion without such a large apparatus, and furthermore it has a capability to electrically control the bearing force or clearance. A prototype air bearing is developed on the basis of the proposed principle by utilizing piezo-electric actuators, and its non-contact smooth motion is confirmed.

DOI： 10.1016/S0007-8506(07)60447-8

Scopus

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Publisher：The Japan Society for Precision Engineering  

&amp;prime;Ultrasonic elliptical vibration cutting&amp;prime; technology is applied in the present research to ultraprecision machining of Tungsten alloy, which is expected as a material of molds for glass parts instead of sintered tungsten carbide. It is confirmed that ulptraprecision grooving cannot be realized by the ordinary cutting. On the other hand, it can be realized by the elliptical vibration cutting at a cutting depth of less than 1 um. Effects of the cutting distance on the cutting force and the roughness are also clarified, and it is found that surface roughness of less than 100 nm Rz can be realized up to a cutting distance of 35 m. Practical molds for spherical glass lenses and a glass prism are successfully machined.

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Publisher：The Japan Society for Precision Engineering  

Polishing experiments are carried out in the present research in order to verify an analytical model for a simulation of Chemical Mechanical Polishing (CMP) process. A three-dimensional finite element analysis of CMP process, which considers the boundary lubrication between a wafer and a polishing pad, is utilized to predict a friction resistance. Additionally, the friction forces are measured in the polishing experiments by force sensors built into the experimental setup. It is conformed that the predictions of friction resistance directions fit experimental results. These results indicate that the friction resistance direction depends on the ratio of the wafer to the polishing pad rotation speeds.

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Publisher：The Japan Society for Precision Engineering  

&amp;prime;Ultrasonic elliptical vibration cutting&amp;prime; technology is applied in the present research to ultraprecision machining of single crystal germanium, which is an excellent substrate material for optical devices. Micro grooving experiments are carried out on (100), (110) and (111) faces of the single crystal germanium to clarify the basic effects of the elliptical vibration on the ductile micro machining. It is confirmed that a groove formed in &lt;011&gt; direction on the (111) surface is filled with asperities at a depth of 0.19 um due to cleavage fractures in the ordinary cutting. While a smooth mirror surface is obtained by the elliptical vibration cutting at a depth of cut of less than 1.04 um in same direction. These experimental results indicate that the critical depth of cut is increased at a specific orientation angle by applying the elliptical vibration cutting. However critical depths of cut depend on cutting directions and crystal orientations. We also clarified that the critical depth of cut can be increased at the lower cutting speed.

DOI： 10.11522/pscjspe.2006A.0.785.0

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This paper presents a new ultraprecision alignment device with high load capacity, which is targeted for ultraprecision bonding in a vacuum. The ultraprecision bonding is recently needed for emerging production technologies such as nanoimprint, MEMS and WOW. The device is driven by &#039;Walking Drive&#039;, which is an unique driving method to realize ultraprecision positioning with long stroke by utilizing piezoelectric actuators. The method is suitable for high load capacity and the ultraprecision positioning in a vacuum. Mechanical parts of the device are designed by utilizing FEM analysis, so that the device has a high load capacity of greater than 1 ton. It is confirmed experimentally that the developed alignment system has the high load capacity and also fine positioning resolution of less than 10nm.

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Publisher：The Japan Society for Precision Engineering  

A new machining method is proposed to obtain precise sculptured surfaces by applying &amp;Prime;elliptical vibration cutting&amp;Prime;. A 4&amp;ndash;axis controlled precision machine tool, which consists of an air spindle and precision elements, is developed. 4&amp;ndash;axis control tool paths for machining sculptured surfaces are also generated by utilizing commercial CAM software and a special post processor. It is confirmed that mirror surface machining of hardened die steel can be realized by integrating the precision machine tool, the special CAM system and the 3 DOF vibration system developed in the previous research.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Hallwag Publishing Ltd  

A new machining method is proposed to obtain sculptured mirror surfaces by applying elliptical vibration cutting. The tool is vibrated elliptically unlike rotated end mills and fed along the sculptured surface in the proposed method. A 3 DOF ultrasonic vibration tool is developed, which can generate an arbitrary ultrasonic elliptical vibration in the 3D space so that it is suitable to machine the 3D sculptured surfaces. A precision machine tool is also developed, and the proposed method is successfully applied to mirror surface machining of hardened die steel.

DOI： 10.1016/S0007-8506(07)60113-9

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Language：English   Publishing type：Research paper (international conference proceedings)  

A new machining method is proposed to obtain sculptured mirror surfaces by applying elliptical vibration cutting. The tool is vibrated elliptically, unlike conventional rotating end mills, and is fed along the sculptured surface while the rotational position of the tool is controlled in accordance with the sculptured surface orientation in the proposed method. In order to realize the sculptured surface machining of hardened die steel with single crystal diamond tool, special components are required, i.e. a vibration system that can generate an arbitrary ultrasonic elliptical vibration in the 3D space, a 4-axis controlled precision machine tool and a special CAM system. The elliptical vibration system, which consists of a 3 DOF ultrasonic vibration tool and a vibration controller, is developed. The vibration tool can generate the arbitrary elliptical vibration at 34.4 kHz by combining two bending vibrations and a longitudinal vibration. The vibration controller is fabricated to keep the elliptical vibration to have a desired locus in the 3D space. The 4-axis controlled precision machine tool, which consists of an air spindle, precision linear guides, precision ball screws and so on, is developed. Commercial CAM software is utilized and a special post processor is developed to generate tool paths for the 4-axis control machining of sculptured surfaces. The developed ultrasonic elliptical vibration machining system is applied to precision diamond cutting of hardened die steel, and it is confirmed that mirror surface machining with surface roughness of less than 0.28 μm Rz can be realized for spherical surface machining of hardened die steel.

DOI： 10.1109/MHS.2005.1589969

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Publisher：The Japan Society for Precision Engineering  

A new non-contact fluid bearing, which utilizes traveling wave, is proposed in the present research. The moving part is supported with a thin fluid film compressed by the wave traveling on the bearing surface. Conventional fluid bearings utilize externally compressed fluid, which requires some cost and large facilities. The proposed bearing realizes non-contact precision tables without the large facilities, and furthermore it has a capability to electrically control the bearing force and moment. A prototype device is developed on the basis of the proposed principle, and its non-contact smooth motion has been observed.

DOI： 10.11522/pscjspe.2005S.0.658.0

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Publisher：The Japan Society for Precision Engineering  

A prototype slider is developed in the present research by utilizing a new fluid bearing proposed in the previous research. The moving part is supported with a thin fluid film held on the bearing surface by surface tension. Conventional hydrostatic sliders utilize externally compressed fluid, which requires some cost and large facilities and causes micro vibrations by ripple of the fluid pressure. The non&amp;ndash;contact precision slider is realized without the large facilities by utilizing the proposed bearing, and it has high load capacity and enough rigidity for the simple structure. The prototype slider is fabricated by utilizing a water film and a guide rail of polished glass, and its resistance force against the feed motion is investigated here.

DOI： 10.11522/pscjspe.2005A.0.875.0

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Publisher：The Japan Society for Precision Engineering  

本研究では、CMPプロセスにおいて実用的な解を与える研磨レート分布解析手法の確立を目指している。本報では、基礎的なCMPプロセスの解析モデルを構築し、有限要素解析を利用してウェハ&amp;ndash;研磨パッド間の流体圧力分布及び接触応力分布の解析を行うと同時に、研磨レート分布の推定を行った。さらに酸化膜CMPにおける基礎的な研磨実験を行い、研磨条件がCMPプロセスに及ぼす影響について検証を行った。

DOI： 10.11522/pscjspe.2005A.0.277.0

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Publisher：The Japan Society for Precision Engineering  

An analytical model of three dimensional cutting process with two cutting edges is presented without relying on empirical rules in the present research. The shear deformation zone is simplified to a thin shear plane, and Krystof&amp;prime;s maximum shear stress model and Merchant&amp;prime;s minimum energy model for the orthogonal cutting process are extended to the three dimensional cutting process to predict the shear direction. The three dimensional cutting parameters including cutting forces and chip flow direction are computed with the developed model, and it is confirmed that the computed chip flow direction agrees roughly with Colwell&amp;prime;s empirical law of chip flow.

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Publisher：The Japan Society for Precision Engineering  

著者らが考案している楕円振動切削加工法では、背分力をゼロもしくは反転させることが可能である。また、振動軌跡における振動振幅や位相差などの各振動パラメータを変化させることにより、切削プロセスを意図的に変化させることができる。本研究では、振動振幅や位相差を変化させることにより切削力を制御する切削プロセス制御システムの開発を行った.さらに切削実験を行い、開発した制御システムの有効性を検討した。

DOI： 10.11522/pscjspe.2004A.0.427.0

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Publisher：The Japan Society for Precision Engineering  

本研究では、表面張力を利用した新しい流体軸受を考案している。提案する装置では、軸受隙間に水の膜を作り、表面張力によってその状態を維持する。従来の非接触軸受と異なり、外部装置を必要としない単純な構造のため、使用する場所に制限されず、流体の脈動による微振動も無くす事ができる。実際に表面張力によって移動部を浮上させ、滑らかな送り動作が可能である事を確認している。また剛性等の測定も検討している。

DOI： 10.11522/pscjspe.2004S.0.384.0

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Publisher：The Japan Society for Precision Engineering  

エンドミル加工では、加工時に発生するびびり振動により、切削条件が制限されることが多い。このびびり振動を抑制し切削安定限界を上げることは、加工能率の向上へとつながる。本研究では、工具を主体としたびびり振動の発生機構をモデル化し、解析的に求めた切削安定限界と実験値を比較する。また、積極的に安定限界領域を拡大する手法についても検討を行う。

DOI： 10.11522/pscjspe.2004S.0.462.0

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Publisher：The Japan Society for Precision Engineering  

筆者らは楕円振動切削と呼ぶ加工法を提案し、優れた切削性能を持つことを確認している。実用的な自由曲面を加工するためには多様な加工形状に対応できる振動装置が必要となる。しかし、既に開発している2自由度型超音波楕円振動切削装置では振動子と被削材の干渉により加工形状が制約されてしまう。そこで、任意の面内で楕円振動軌跡を得ることができ、加工形状の制約が少ない3自由度型超音波楕円振動切削装置の開発を行った。

DOI： 10.11522/pscjspe.2004S.0.670.0

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Publisher：The Japan Society for Precision Engineering  

微細形状を有するガラス製品の量産を目的とし、超硬合金製金型に対する超精密微細加工の要求が増加している。これに対し、筆者らは楕円振動切削の適用を試み、すでに良好な延性モード加工を行い得ることを確認している。本報では、低周波振動における溝加工実験を行い、楕円振動切削による延性モード加工のメカニズムについて検討を行った。その結果、低周波振動においても延性モード加工行い得ることを確認した.

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Publisher：The Japan Society for Precision Engineering  

著者らは楕円振動切削を適用することにより焼入れ鋼金型に対して直接ダイヤモンド鏡面切削を行うことが可能な新しい加工技術の開発を目指している.これまでの研究において,1方向のたて振動と2方向のたわみ振動を同一周波数で発生させることのできる3自由度型の振動工具の開発を行っている.本報では,開発した3自由度型振動工具を安定して制御することが可能な制御システムを設計・試作を行い,その制御特性の評価を行った.

DOI： 10.11522/pscjspe.2004A.0.426.0

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A new &quot;elliptical vibration cutting machine&quot; is fabricated by developing a unique double spindle mechanism, and its basic performance is evaluated in the present research. The developed machine generates circular vibration mechanically by rotating an eccentric sleeve with a built-in motor. The tool spindle is inserted within the rotating sleeve and connected to a servo motor via a flexible coupling. Radius and maximum frequency of the circular vibration are set to 0.5 mm and 167 Hz respectively. The developed machine is evaluated by measuring accuracy and stiffness of the rotating and vibrating spindle. The developed machine is applied here to &quot;elliptical vibration planing&quot; of hardened steel by clamping the tool spindle, though it can also be applied to &quot;elliptical vibration milling&quot; by rotating the inner tool spindle at the same time. The &quot;elliptical vibration planing&quot; is conducted with a CBN tool, and the results show that the present method is better than conventional ball end milling in all aspects of tool life and cost, surface roughness, cutting time and cutting force. Furthermore, a hardened steel mirrow with roughness of about 0.1μm Ra is obtained by the elliptical vibration planing with a single crystal diamond tool.

DOI： 10.2493/jjspe.69.542

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Publisher：The Japan Society for Precision Engineering  

単結晶フッ化カルシウム（CaF2）は切削による延性モード加工が困難であるため，通常はポリシングにより加工されることが多い．本研究では切削性能の向上を目的として考案されている楕円振動切削加工を適用することにより単結晶材料の延性モード切削を試みた．&lt;br&gt;基礎的な溝加工実験により超音波楕円振動付加による影響の評価を行った．その結果，楕円振動切削を用いることで大幅に臨界切込み量が増大することがわかった．

DOI： 10.11522/pscjspe.2003A.0.419.0

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers Inc.  

Utraprecision micromachining of hardened steel with a single point diamond tool, which is practically impossible due to rapid tool wear, is realized by applying 'Elliptical Vibration Cutting technology, which has been developed by the authors. A practical ultrasonic elliptical vibration cutting system is developed in the present research, which consists of a practical vibration control system and an ultraprecision planing machine. The control system is fabricated to keep the elliptical vibration to have a desired locus, where the amplitudes of the two directional vibrations and their phase shift are kept to be desired values, and the vibration frequency is locked to an average value of their resonant frequencies. The vibration control system is mounted on the ultraprecision planing machine, which consists of three feed tables with double hydrostatic oil guideways in XVZ axes, two rotary index tables in BC axes and a five axis control system. The developed elliptical vibration cutting system is applied to ultraprecision diamond planing of hardened die steel, and a high quality mirror surface is obtained over a targe area of the whole finished surface. Maximum roughness of the finished surface is less than 0.04 μm Ry, although the cutting distance reaches 1110 m. On the other hand, the surface finished by ordinary cutting without the vibration, is cloudy with maximum roughness of more than 0.52 μm Ry within a cutting distance of 1 m. Based on this advantage, the elliptical vibration cutting system is successfully applied to ultraprecision micromachining of dies for a front light panel of LCD. An optical quality surface with fine microgrooves over a Urge area of 122 x 91 mm2 and with surface roughness of less than 0.04 μm Ry is obtained by the developed system, which is difficult for any conventional machining methods including grinding, polishing and ordinary cutting.

DOI： 10.1109/MHS.2003.1249936

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

CMPプロセスにおける研磨パッドの表面状態は研磨レート等の基本的な研磨特性に大きな影響を与える．研磨パッドの表面状態について，これまで筆者らは表面あらさを用いた評価を試みてきたが，測定箇所の発泡状態等により測定結果が大きくばらつき，研磨特性との相関を明瞭とするために多量の測定を要する問題があった．そこで本研究では，研磨パッドの損耗に伴うパッド表面の平滑化に着目し，研磨パッド表面の画像から平滑化の度合いを算出する簡便な研磨パッド表面状態の評価方法について検討を行った．実験の結果、本測定法は研磨パッドの表面あらさRaによる評価と比較して研磨パッド表面状態を精度良く評価できることが判った．

DOI： 10.11522/pscjspe.2002A.0.477.0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Hallwag Publishing Ltd  

A new ultrasonic vibration controller is elaborated for ultrasonic elliptical vibration cutting. A method is developed to remove cross talks between the two directional vibrations of the stepped vibrator excited in the same bending mode in two directions, so that the two directional vibrations can be controlled independently. A controller is fabricated to keep the elliptical vibration to have a desired locus, where the amplitudes of the two directional vibrations and their phase shift are kept to be desired values, and the vibration frequency is locked to an average value of their resonant frequencies. The developed vibration control system is applied to ultraprecision diamond turning of hardened die steel, and an ultraprecise mirror surface with a shape accuracy of less than 0.2 μm is obtained.

DOI： 10.1016/S0007-8506(07)61528-5

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Precision Engineering  

A new tool vibration system is developed for the ultrasonic elliptical vibration cutting, and it is applied to ultraprecision cutting of hardened steel in the present research. A method and a device to remove crosstalks between the two directional vibrations are developed, so that the two directional vibrations can be controlled independently. Then, a controller is developed to keep the elliptical vibration to have a desired locus, where the amplitudes of the two directional vibrations, phase shift between them are kept to be desired values and the vibration frequency is locked to an average of their resonant frequencies. The developed vibration control system is applied to ultraprecision diamond turning of hardened steel, and an ultraprecise steel mirror with a shape accuracy of about 0.1μm is achieved.

DOI： 10.2493/jjspe.67.1871

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

A new system is developed to control the ultrasonic elliptical vibration applied to the cutting tool, and it is applied to the ultraprecision elliptical vibration cutting of hardened stainless steel in the present research. Steady feedback control of the vibration locus is realized by developing a cross talk remover, which eliminates interference between the two directional vibrations. The controller keeps the vibration amplitudes and the phase difference between the two vibrations to be desired values and to chase the average resonant frequency of the vibrations simultaneously. The machining experiments show that shape accuracy and roughness of the finished surface are improved significantly by applying the developed system.

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Language：Japanese   Publisher：Japanese Society of Tribologists  

DOI： 10.18914/tribologist.61.7_457

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Language：English   Publisher：The Japan Society of Mechanical Engineers  

This study presents a novel method to estimate transfer function of flexible mechanical structures mounted on a traveling stage by utilizing only internal information of computerized numerical control (CNC) system. Disturbance force input to CNC is estimated by observer technique and cutting force is estimated based on cutting force model. Analyzing both the forces, frequency response function (FRF) of the mechanical structure is estimated by the proposed method. Assuming a simple dynamic model of the mechanical structure, modal parameters representing the dynamic characteristics of the structure are also identified. Experimental results of a face turning test indicated that the transfer function can be estimated accurately by the proposed method.

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Language：Japanese   Publisher：砥粒加工学会  

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Language：Japanese   Publisher：砥粒加工学会  

CiNii Books

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

This study presents the micro-/nano-structure machining of hardened steel by means of elliptical vibration cutting equipped with the ultra-precision amplitude control sculpturing method. Machining performance of the amplitude control sculpturing method is investigated, and the limitation in nano-scale machining is explored. In this method, machinable part geometry is essentially restricted by vibration/machining conditions and tool geometry. In addition, a considerable error between the amplitude command and the envelope of the tool trajectory is generated when the slope of the machining part geometry becomes steep. To overcome this error, a compensation method for the amplitude control command is proposed. In order to clarify the machining performance of the proposed technology, experimental investigations are conducted. By applying the proposed method, highly accurate machining of the sinusoidal sweep structure is attained with a machining error of less than 20 nm. The proposed sculpturing method is subsequently applied to the machining of a three-dimensional grid surface, which verifies the feasibility of the proposed amplitude control sculpturing method.

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Language：Japanese   Publisher：精密工学会 ; 1986-  

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Language：Japanese   Publisher：日刊工業出版プロダクション ; 1953-  

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Language：Japanese   Publisher：日刊工業出版プロダクション ; 1953-  

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Language：Japanese   Publisher：精密工学会 ; 1986-  

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.79.879

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Language：Japanese   Publisher：公益社団法人 精密工学会  

DOI： 10.2493/jjspe.79.571

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.78.919

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Language：English   Publisher：Elsevier B.V.  

DOI： 10.1016/j.procir.2012.10.001

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J-GLOBAL

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

Rotary cutting process is modeled and its cutting performances are discussed in the present study. Actively or passively driven rotary cutting can be equivalent to oblique cutting. Assuming bearing resistance is negligible, passively driven rotary cutting can be further simplified as orthogonal cutting. Rotary milling tool is developed and applied to face milling tests of Inconel 718. Comparing with the conventional milling, experimental results indicated the feasibility of higher performance machining of Inconel 718 by the rotary tool.

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Language：Japanese   Publisher：一般社団法人 日本機械学会  

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Language：Japanese   Publisher：砥粒加工学会  

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Language：Japanese   Publisher：砥粒加工学会  

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Language：Japanese   Publisher：日刊工業出版プロダクション  

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Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.76.404

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Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.76.280

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Language：English   Publisher：The Japan Society of Mechanical Engineers  

An accurate analytical model for the regenerative chatter vibration in the plunge cutting is proposed in the present research. Effects of the cross transfer function and the cutting force ratio on the chatter stability are considered in the proposed model. Equivalent transfer function is defined, which is useful to understand those effects on the chatter stability. It is verified experimentaly that the chatter stability limits can be predicted accurately by the proposed model as compared with the conventional model.

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Language：Japanese   Publisher：The Japan Society of Mechanical Engineers  

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Language：Japanese   Publisher：砥粒加工学会  

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Language：Japanese   Publisher：日本工業出版  

CiNii Books

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Language：Japanese   Publisher：日本工業出版  

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J-GLOBAL

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Language：Japanese   Publisher：日本工業出版  

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Language：Japanese   Publisher：The Japan Society for Precision Engineering  

DOI： 10.2493/jjspe.72.440

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Language：Japanese   Publisher：日刊工業新聞社  

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Language：Japanese   Publisher：日刊工業新聞社  

CiNii Books

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Language：Japanese   Publisher：日刊工業新聞社  

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Language：Japanese  

CiNii Books

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Event date： 2023.8 　 　

Presentation type：Oral presentation (general)  

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Event date： 2023.6 　 　

Presentation type：Oral presentation (general)  

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Event date： 2023.3 　 　

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Event date： 2022.11 - 2022.12

Language：English   Presentation type：Oral presentation (general)  

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Event date： 2022.11 - 2022.12

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Event date： 2022.9 　 　

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Event date： 2022.9 　 　

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Language：English   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (invited, special)  

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Language：English   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

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Language：Japanese   Presentation type：Oral presentation (invited, special)  

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Language：English   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (invited, special)  

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Language：Japanese   Presentation type：Oral presentation (invited, special)  

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Event date： 2018 　 　

Language：Japanese  

&lt;p&gt;Ni基耐熱合金に対して従動式ロータリ機構を備えたミーリング工具による正面フライスを実施し，その実用性について検討を行った．実験の結果，回転運動を伴わない通常切削に対して約12倍の工具寿命延長効果が確認された．また，切削シミュレーションを援用したプロセスの見える化技術を開発し，その分析を行った．諸検討により，ランピング加工においてランピング角の制約が厳しいことが明らかとなり，その解決手法を提案した．&lt;/p&gt;

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Event date： 2018 　 　

Language：Japanese  

&lt;p&gt;3Dプリンタの普及に伴い，3次元積層造形構造の利用が急速に進められている．造形技術が急速に発展した一方で，その表面に形成される積層段差の後処理技術に関しては，自動化技術が確立されていない．本研究では，3次元積層造形構造の表面除去加工における自動化技術について検討を行った．汎用工作機械に，柔軟な治具をかいして工作物を固定し，研削と研磨による定圧加工を行うことで，自動化の可能性があることを明らかにした．&lt;/p&gt;

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Event date： 2017 　 　

Language：Japanese  

著者らは，モデルベースシミュレーションを利用して，構造物の動特性や切削プロセスを代表するパラメータの新しい同定手法を提案している．本稿では，一般的なミリング様式のプロセスをモデル化し，構造物の動的挙動と加工プロセスを推定する時間領域シミュレータを開発した．さらに，パラメータ同定アルゴリズムを考案した．シミュレーションによる検証を通じて，提案手法により知的なプロセス同定を実現し得ることを確認した．

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Event date： 2017 　 　

Language：Japanese  

切削加工においては，低速度条件でびびり振動の安定性が向上することが知られている．これはプロセスダンピングと呼ばれる工具逃げ面と被削材が接触して振動を減衰する現象が発現するためである．本研究では，プロセスダンピングを効果的に利用することが可能な逃げ面テクスチャを提案する．切削シミュレーションに基づく簡易的な形状設計手法について解説するとともに，検証実験を通じて提案手法の効果を明らかにする．

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Event date： 2017 　 　

Language：Japanese  

切削加工における高能率化を実現する上でびびり振動対策は極めて重要である．不等ピッチ・不等リード工具は，不安定化を引き起こす再生振動の抑制に効果的に利用することができる．本稿では，びびり振動の周波数および軸方向切込み条件に対して高いロバスト性を満たす，実用的な工具設計理論を紹介する．さらに，再生効果抑制理論を応用したインデクサブルカッタの設計法およびパラレールターニングの研究事例を紹介する．

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Event date： 2017 　 　

Language：Japanese  

モデルベースシミュレーションを利用して，構造物の動特性や切削プロセスのパラメータを同定する手法が提案されている．本稿では，ボールねじ駆動系の多慣性モデルを考慮したCNC工作機械の外乱オブザーバを検討した．これをすでに提案されているプロセス同定システムに適用し，汎用的な工作機械を対象とした知的同定の実行可能性について検討を行った．検証実験の結果，ミリングプロセスの同定を概ね実現し得ることを確認した．

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Event date： 2017 　 　

Language：Japanese  

&lt;p&gt;Multi-tasking machine tools attract attention, because they can perform highly efficient machining by using multiple tools. Parallel turning with two tools can realize high material removal rate and the productivity is remarkably improved when appropriate cutting condition is selected. On the other hand, compared to turning with a single tool, the stability of the process reduces, and chatter vibration tends to occur. Chatter vibration does not only limit productivity but also cause poor surface and dimensional accuracy. In this research, to suppress chatter vibration in parallel turning, we propose swing motion assisted parallel turning with an optimum amplitude ratio, calculated from chatter frequency and spindle speed. The proposed method aims to suppress chatter vibration by giving variations in phase delay due to high speed swing of tool. Chatter frequency is measured from estimated cutting force applying disturbance observer. The result of swing motion assisted turning test indicates that chatter vibration can be suppressed by dynamically changing cutting point based on the optimum amplitude ratio.&lt;/p&gt;

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Event date： 2016 　 　

Language：Japanese  

研磨パッド表面に存在する凹凸構造は研磨効率に直接的に影響するため，その分析は研磨メカニズムを理解する上で重要である．本研究では，研磨パッドの表面アスペリティを楕円球と楕円錐の集合体としてモデル化し，状測定結果から研磨に作用すると考えられる箇所の形状パラメータを同定する手法を考案した．さらに，弾性変形を仮定した力学モデルを定式化し，動的圧縮試験の結果から，材料物性パラメータについて分析を行った．

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Event date： 2016 　 　

Language：Japanese  

研磨プロセスのミクロな材料除去メカニズムを説明可能な理論は確立されていない．これが研磨効率の推定を困難にし，効率的なプロセス開発の妨げとなっている．本研究では，研磨効率のその場観察手法を提案する．材料除去に起因する赤外線をウェハ越しに観察することで，研磨中の局所的な材料除去の発生個所を特定する．表面凹凸が制御された織布パッドによる検証実験を実施し，ミクロな材料除去メカニズムについて考察を行った．

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Event date： 2016 　 　

Language：Japanese  

低切削速度条件ではプロセスダンピングという現象が発現してびびり振動の安定性が向上する．多くのモデルが提案されてきたが，その現象の詳細なメカニズムは不明であり，切削力モデルも検証されていない．そこで，本研究では，低速領域でびびり振動が発生する場合の切削現象について検討を行う．有限の振動変位を持つびびり振動が発生する場合の新しい切削力モデルを提案し，有限要素解析による検討を通じてその検証を行う．

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Event date： 2016 　 　

Language：Japanese  

不等リードエンドミルを用いて浅切込み加工を行う場合に，びびり振動を効果的に抑制することができる．しかし，このプロセスでは切削の断続性に起因して，高精度な安定性解析が難しいことが知られている．このような時間遅れを伴う常微分方程式の解法としてSemidiscrete method（SD法）が提案されている．本研究では，不等リードエンドミルを用いるプロセスに対応したSD法を提案し，先行研究の解析モデルとの比較による検証を行った．

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Event date： 2016 　 　

Language：Japanese  

本研究では，外乱力の推定結果に基づいてモデルベースで動的切削プロセスのパラメータ同定を行う新しい手法を提案する．まず，加工に用いる機械構造の動剛性モデルと再生効果を含めた切削プロセスモデル，および各モデルに基づく時間領域シミュレータを開発する．加工中にCNC制御系に作用する外乱力の推定値から，逆解析を行うことでプロセスモデルのパラメータ同定を行う．断続切削実験により，提案手法の実現可能性を確認する．

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Event date： 2016 　 　

Language：Japanese  

&lt;p&gt;Multi-tasking machine tool with multi-turret is attracting a great deal of attention, which can offer higher efficiency and higher accuracy. However, chatter vibration generated during parallel turning with two tools might be one of the bottlenecks for higher material removal rate. To suppress chatter vibration, we proposed unequal pitch turning method in this research. In this method, the upper tool was properly controlled based on optimum pitch angle calculated from spindle speed and chatter frequency. Chatter frequency was identified from estimated cutting force by disturbance observer. From the result of parallel turning test, it is clear that chatter vibration can be suppressed by controlling the upper tool based on optimum pitch angle.&lt;/p&gt;

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Event date： 2016 　 　

Language：Japanese  

&lt;p&gt;In order to improve milling performance of difficult-to-cut materials, a unique milling cutter with SPRT (Self-Propelled-Rotary-Tool) was developed. Use of slide bearings enables a compact SPRT mechanism, while influence of bearing friction becomes not negligible. To attain self-revolution of a circular insert regardless of the bearing friction, the cutter geometry was optimized. Through face milling experiments of Inconel 718, superior tool wear resistance was verified as compared to the conventional milling without insert rotation. Analytical result of the measured cutting forces also indicated interesting phenomena in SPRT milling.&lt;/p&gt;

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Event date： 2015 　 　

Language：Japanese  

Chatter vibration in milling often results in poor surface finish and rapid tool wear, consequently limiting productivity. It is known that regenerative effect, which causes chatter vibration, can be suppressed by utilizing irregular pitch cutters. In order to attain robust regeneration suppression for arbitrary chatter frequency, the authors have proposed a novel design theory of irregular pitch cutters. The fundamental mechanism of it is the simultaneous suppression of multi-mode regenerations. In the present study, the effect on chatter suppression has been verified through a series of end milling experiment. Analytical and experimental results indicated that the chatter stability is effectively increased by utilizing the irregular pitch cutter designed by the proposed theory.

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Event date： 2015 　 　

Language：Japanese  

研磨加工において，研磨パッド表面に存在する突起の構造とその微視的な変形挙動は，加工メカニズムを考察する上で重要となる．本研究では，レーザ顕微鏡を用いて研磨に使用した研磨パッド表面形状の評価観察を行い，突起構造の分析とモデル化について検討した．そして，突起構造の変形挙動を表現する新しい力学モデルの検討を行った．

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Event date： 2015 　 　

Language：Japanese  

機械構造の振動モデルを仮定し，切削力モデルと外乱オブザーバ技術を利用して切削力と外乱力を推定することで，工作機械の制御ループ外に存在する機械構造の伝達関数をCNCの内部情報のみから推定する新しい手法を提案する．剛性が低くなるように設計したツールホルダを超精密工作機械のテーブルに固定して断続的な旋削実験を行い，提案手法により周波数伝達関数の計測とモーダルパラメータの推定が可能であることを確認した．

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Event date： 2014 　 　

Language：Japanese  

This study presents the micro-/nano-structure machining of hardened steel by means of elliptical vibration cutting equipped with the ultra-precision amplitude control sculpturing method. Machining performance of the amplitude control sculpturing method is investigated, and the limitation in nano-scale machining is explored. In this method, machinable part geometry is essentially restricted by vibration/machining conditions and tool geometry. In addition, a considerable error between the amplitude command and the envelope of the tool trajectory is generated when the slope of the machining part geometry becomes steep. To overcome this error, a compensation method for the amplitude control command is proposed. In order to clarify the machining performance of the proposed technology, experimental investigations are conducted. By applying the proposed method, highly accurate machining of the sinusoidal sweep structure is attained with a machining error of less than 20 nm. The proposed sculpturing method is subsequently applied to the machining of a three-dimensional grid surface, which verifies the feasibility of the proposed amplitude control sculpturing method.

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Event date： 2014 　 　

Language：Japanese  

Thus far, Elliptical Vibration Cutting has shown its superior machining performance in steel machining by using which the diamond tool life can be significantly improved. However, this machining technology is currently limited to the relatively small-size workpiece machining due to the small feed rates. If it is used to machine large-size steel workpiece, the machining time and cumulative cutting distance (or tool wear) will be remarkably increased which in turn dramatically increase the machining cost and cycle time. In order to apply this emerging machining technology effectively in industrial application, Elliptical Vibration Cutting with large nose radius single crystal diamond tool was proposed in this paper. However, the minimum uncut chip thickness (under which the material is not sheared but ploughed), that due to the presence of the tool edge radius becomes a major challenge when the large nose radius diamond tool is employed. Therefore, the influence of the minimum uncut chip thickness on material removal behavior during diamond machining needs to be understood and implemented in models. In this paper a simple but practical analytical model was developed for the optimization of machining conditions to minimize ploughing effect. The analytical model was then validated in a qualitative manner with experimental tests using steel workpieces.

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Event date： 2014 　 　

Language：Japanese  

低切削速度領域においてプロセスダンピングと呼ばれる現象が発現し，びびり振動の安定性が向上することが知られている．多くの解析モデルがすでに提案されているのに対し，実験的なプロセスの評価は十分になされていない．本研究では，端面旋削実験により切削プロセスに対するプロセスダンピングの影響について評価を行う．さらに，材料物性と工具形状に基づきプロセスダンピングの影響を定量化する新しい解析モデルを提案する．

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Event date： 2014 　 　

Language：Japanese  

著者らはこれまでに，CMPプロセスに対する研磨パッドの粘性特性と研磨パッド表面の凹凸形状による非線形弾性特性を考慮した解析手法を開発している．本報では，ジンバル方式の研磨ヘッド構造を利用するCMPプロセスを対象とした検討により，各種物性や形状のモデル化が研磨圧力シミュレーションの結果に与える影響について明らかにする．さらに，実験結果と比較することにより解析精度を検証する．

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Event date： 2014 　 　

Language：Japanese  

航空機部品等に用いる耐熱合金の加工では，セラミック工具を用いた高速ミーリングによる高能率加工が利用されている．しかし，工具損耗が激しく寿命が短いという問題があり，その改善が要求されている．本研究では，インコネル718の加工で摩耗した工具形状を評価し，これを考慮した切削力モデルを考案した．さらに，切削力測定結果との比較により工具表面に生じる応力場を推定し，特徴的な工具損耗メカニズムについて考察を行った．

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Event date： 2013 　 　

Language：Japanese  

切削加工において再生効果は自励びびり振動の安定性に大きく影響する．不等リードエンドミルはびびり振動の周波数や主軸回転数などの変化に対してロバストに再生効果を抑制することができる特徴を持つ．しかし，最適な工具形状を設計しなければ優れた抑制効果を実現することはできない．本研究では，再生効果の影響をロバストに抑制することのできる不等リードエンドミルの工具形状の新しい設計手法を提案する．

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Event date： 2013 　 　

Language：Japanese  

半導体CMPの量産工程で一般に用いられるエアーバッグ研磨ヘッド構造を考慮したCMPプロセスのEHL解析モデルを開発した．本研究では，研磨ヘッドの構造として，リテーナリングやメンブレンゴムを考慮するとともに，ウェハ等との接触問題を考慮する．また，ALE有限要素法を適用することで動的な問題を取り扱うとともに，研磨パッドの非線形粘弾性を同時に考慮することで，従来不可能であった実用的な研磨プロセスの解析の実現に挑戦する．

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Event date： 2013 　 　

Language：Japanese  

ベースの剛性不足に起因して機械構造全体で生じる低周波振動により，工作機械の制御系の性能が低下する問題がある．本研究では，問題となりやすいベースのねじり振動モードの影響を考慮したガントリーテーブルの制御システムをモデル化する．そして，ベースのねじれ振動を抑制する新しい補償器とその設計手法を提案する．実機を用いて検証を行い，提案手法によってねじり振動が効果的に抑制されることを確認した．

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Event date： 2013 　 　

Language：Japanese  

従来，旋削加工の高精度化のため，各種機上計測手法が実用に供されている．しかし，これらの従来手法では，工作物への接触や計測装置の大きさによって計測範囲や形状に制約が多い．そこで本研究では，工具をイメージセンサに取り換えて工作物を回転し，加工面の移動距離と回転角度から直径を計測することで，制約の少ない機上計測手法を提案・開発する．本報では，提案手法とその画像処理方法，計測の繰返し性等について報告する．

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Event date： 2012 　 　

Language：Japanese  

インコネル等に代表される難削材の切削加工では，工具摩耗の抑制にロータリ切削が効果的であることが知られている．本研究では，傾斜切削理論に基づいたロータリ切削機構のモデル化を行う．さらに，その切削機構の特徴を示すとともに基礎的なロータリ切削実験による検証を行う．さらに，従動式ロータリ機構を適用したロータリミリング工具を試作し，インコネル718のロータリミリングにおける工具摩耗抑制効果について評価を行う．

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Event date： 2012 　 　

Language：Japanese  

本研究では，工具軌跡／姿勢を最適化することで再生型びびり振動を回避する新たな手法を提案する．びびり振動安定性が主軸回転数や切込み量等の切削条件に依存することはよく知られているが，工具軌跡にも依存することはあまり知られていない．本稿では，旋削加工を例に，工具形状や切込み量，送り量を考慮した上で工具軌跡／姿勢を最適化するための簡易指標を示し，その指標の有用性を解析及び実験的に検証する．

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Event date： 2012 　 　

Language：Japanese  

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Event date： 2012 　 　

Language：Japanese  

本研究では，進行波を利用した新たな非接触流体軸受を提案している．本軸受は，軸受面上に発生させた進行波によって軸受中心に向かう力を流体に与えることで，軸受隙間内の圧力を上昇させ非接触支持を実現する．本報では，装置の製作性と性能を向上させるためにモジュール化した進行波圧電アクチュエータを開発し，そのアクチュエータを用いた軸受の開発・評価を行う．また本軸受を用いた精密スライダの開発を目指す．

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Event date： 2012 　 　

Language：Japanese  

切削加工における自励びびり振動は再生効果に強く依存する．不等ピッチ工具を用いて再生効果を抑制することで安定限界を効果的に向上することもできるが，その効果はピッチ角の設計に依存する．本研究では，エンドミル加工における再生効果の新しい定量化手法を提案するとともに，共振周波数の異なる複数の振動モードが存在する際に，それらの振動モードに対して同時に再生効果を打ち消す新しいピッチ角の設計手法を提案する．

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Event date： 2011 　 　

Language：Japanese  

Rotary cutting process is modeled and its cutting performances are discussed in the present study. Actively or passively driven rotary cutting can be equivalent to oblique cutting. Assuming bearing resistance is negligible, passively driven rotary cutting can be further simplified as orthogonal cutting. Rotary milling tool is developed and applied to face milling tests of Inconel 718. Comparing with the conventional milling, experimental results indicated the feasibility of higher performance machining of Inconel 718 by the rotary tool.

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Event date： 2011 　 　

不等ピッチ/リードエンドミルは自励びびり振動の発生原因である再生効果を抑制し得るが，条件によっては効果的に自励びびり振動を抑制し得ないこともある．本研究では，Multi-Frequencyモデルを用いて，これらの工具を用いた場合の安定限界に対する半径方向切込みの影響について検討した．解析の結果，切込みが浅くモードカップリングが生じにくい条件で自励びびり振動を効果的に抑制し得ることを確認した．

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Event date： 2011 　 　

CMPに用いられる研磨パッドの圧縮試験を行い，その非線形弾性特性および比例減衰係数の同定を試みた．粘性特性を精度よく同定するには，高ひずみ速度で圧縮試験を行う必要があるため，本研究では，VCM（ボイスコイルモータ）を用いた圧縮試験装置を開発した．さらに，古典的な力学モデルに基づいて研磨パッド表面層のモデル化を行い，実験結果と比較することでその凹凸パラメータを同定し，研磨圧力の解析に適用した．

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Event date： 2011 　 　

航空機エンジン部品等に用いられる超耐熱合金インコネル718の加工では，従来の超硬工具による低速加工に置き換わり，セラミック工具を用いた高速ミリングによる高能率加工が普及してきている．しかし，工具損耗が極めて激しいため，工具寿命の改善が必要とされている．本研究では，工具損耗に影響を与える因子として機械構造の動剛性や加工条件に着目し，各条件が工具損耗に与える影響について実験に基づいた基礎検討を行った．

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Event date： 2010 　 　

Language：Japanese  

The chatter vibration excited during machining process deteriorates quality of workpiece surfaces, and accelerates tool wear. In addition, it often takes long time to find chatter-free cutting conditions. Therefore, a new control system is developed in the present research for searching the optimum spindle speed at which chatter stability is maximized. The developed system detects the chatter vibration that occurs during machining process using a vibration sensor, and then optimizes the spindle speed automatically in real time. This report presents an overview and an application of the developed system.

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Event date： 2010 　 　

適切な不等ピッチ工具を利用することにより，自励びびり振動の発生原因となる再生効果を抑制し得ることが知られている．本研究ではボーリング加工を対象とし，不等ピッチ工具による自励びびり振動の抑制効果について検討を行う．まず，解析モデルを構築し実験的に検証を行った．さらに，モードカップリングの影響が小さい条件では効果的に抑制されるのに対し，大きい条件ではむしろ不安定になることを確認した．

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Event date： 2010 　 　

本研究では，まず，狭いすき間で振動する軸受面に，外部から気体を吸込んで圧力増加する現象が存在することを見出した．これを多段にして複数回の圧力増加を繰返し，より高圧を発生する新しい軸受として，多段振動気体軸受を提案する．さらに本報では，試作開発した本軸受装置の測定と，軸受隙間内気体の有限要素モデルによる解析により，軸受性能について検討した結果について報告する．

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Event date： 2009 　 　

板材の加工は裏面をマグネットにより固定し，表面をフライス加工する方法が一般的である．しかし，二面を片面ずつ切削するために効率が低く，また弾性変形させた状態で切削することにより加工精度も低いことが問題となっている．これに対し，著者らは両面同時フライス加工法を採用し，それに伴う板材の剛性低下や複数主軸の同時使用に起因する再生型びびり振動を，左右主軸に回転数差を設けることにより抑制する手法を考案した．

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Event date： 2009 　 　

圧電素子は高剛性、高分解能、高速応答性といった長所を持つため、位置決め装置のアクチュエータとして利用される。しかし、ヒステリシス、クリープといった非線形性を持つため位置決め性能が低下する。そこで本研究では、クリープの生じない変位と電圧の関係（非クリープ線）の発見に基づき、非線形性を補償するようにオープンループで位置決めを行う方法を開発している。本報では駆動速度、プリロードの影響について報告する。

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Event date： 2009 　 　

従来提案されているマイクロミキサは主に半導体プロセスにより作成される．振動装置などの特殊な機構を必要とする場合も多い．これに対し著者らは，金型により量産成形することができ，かつ特殊な機構を必要としない高効率マイクロミキサを考案した．本発表では，考案したミキサについて流体解析と模型実験を行い，ともにおおむね目的とする流体の挙動が確認されたことについて述べる．

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Event date： 2009 　 　

Language：Japanese  

The accurate analytical model for the dynamic structure analysis of Chemical Mechanical Polishing (CMP) process has been proposed by the authors. By applying to the three dimensional (3D) coupled fluid-structure analysis of the CMP process, the effect of the damping property of the polishing pad on the process was investigated. It was confirmed that the stress concentration beneath the leading edge of the wafer changes significantly depending on the consideration of the damping property. Consequently, the analytical results of polishing pressure and fluid pressure distributions considerably depend on the damping property too. The fluid pressure measuring experiment was also carried out, and it is confirmed that the feature of the measured fluid pressure distribution agrees with that simulated by developed CMP process analytical model.

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Event date： 2009 　 　

Language：Japanese  

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Event date： 2009 　 　

切削加工において，低速領域ではプロセスダンピングの影響によりびびり振動が発生しにくいことが知られている．これを考慮した簡易的な解析モデルが考案されているが，従来手法はその影響を考慮するための変数の同定精度が低く，高精度な解析が難しいという問題があった．これに対し，本研究ではびびり振動の逆解析を利用した変数の新しい同定手法を考案し，高精度な安定限界解析が可能であることを実験的に確認した．

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Event date： 2009 　 　

振動切削では，超音波領域の振動を用いて断続的な加工を行うことによりなどさまざまな優れた効果が得られることが知られている．一般に20～40kHz程度の周波数が利用されるが，それ以上の高周波振動を利用した場合にどのような効果が得られかについては詳しく検討されていない．そこで，本研究では従来と比べて1桁程度周波数の高いサブMHzの楕円振動工具を試作し，その加工特性について評価を行った．

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Event date： 2009 　 　

インサート工具の突き出し長さが大きく，傾斜した方向に軸振動を発生する自由曲面加工用の2自由度超音波楕円振動工具を開発した．さらに，焼入れ鋼の溝加工実験に適用し，びびり振動の発生メカニズムについて考察を行うとともに，安定限界向上の可能性について検討を行った．その結果，インサート工具の形状を非対称にすることでモードカップリング型のびびり振動が抑制され，安定限界切込みが増大することを確認した．

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Event date： 2009 　 　

CMPプロセスでは，ウェハと研磨パッド間が潤滑状態となり，流体圧力が生じることが知られている．しかし，研磨パッドや研磨ヘッドは回転運動を行うため，その界面の流体圧力の測定は難しい．本研究では，無線通信により流体圧力を遠隔計測する装置を試作し，ウェハ－研磨パッド間の流体圧力の計測実験を行った．さらに，著者らが開発しているCMPプロセス解析との比較を行った．

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Event date： 2009 　 　

The accurate analytical model for the dynamic structure analysis of Chemical Mechanical Polishing (CMP) process has been proposed by the authors. By extending to the three dimensional (3D) analysis and applying to the coupled fluid-structure analysis of the CMP process, the accurate CMP process model, which can consider the nonlinear dynamic motion, the damping effects and the stress concentration simultaneously, was developed in the present research. It was applied to the 3D CMP process analysis, and the effect of the damping property of the polishing pad on the process was investigated. It was confirmed that the stress concentration beneath the leading edge of the wafer changes significantly depending on the consideration of the damping property. Thus, there is a possibility that the developed model can estimate the polishing stress and fluid pressure distributions of the CMP process accurately.

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Event date： 2008 　 　

Language：Japanese  

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Event date： 2008 　 　

本研究では進行波を利用した新しい流体軸受を提案している．本軸受では圧電素子を用いて軸受面に進行波を発生し，軸受面中心に向かう力を流体に与えることで軸受面下の圧力を上昇させ，非接触の支持を実現する．本報では本軸受の試作機に対する測定と既に構築している本軸受の軸受隙間の有限要素モデルによる解析により，本原理による軸受としての性能について検討する．

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Event date： 2008 　 　

CMPにおける従来のウェハ－研磨パッド間の接触応力解析においては，動的な解析モデルを扱う際に解析精度が低くなるという問題があった．これに対し，動的なプロセスを準静的に扱う構造解析モデルを考案し，動的接触応力解析の高精度化・高速化について検討を行った．その結果，提案手法を用いることにより，ウェハエッジ部における応力集中などの従来困難であった解析の精度が向上し，解析時間が大幅に短縮されることを確認した．

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Event date： 2008 　 　

回転工具を用いる加工では，一般に再生効果とモードカップリングの影響が混在した自励型びびり振動が発生するが，通常これらの影響はほとんど区別されることはない．これに対し，本研究ではボーリング加工を対象として，再生効果とモードカップリングの影響を切り分けた実験条件において安定限界解析の比較を行った．その結果，それぞれの影響が小さくなる条件において安定限界が最も大きくなることを確認した．

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Event date： 2008 　 　

Ultrasonic vibration cutting processes are modeled and simulated in the present research, utilizing MSC-Marc FEM software. The vibration is applied to the cutting tool in one or two directions denoted by vibration cutting (VC) and elliptical vibration cutting (EVC), respectively. The cutting forces and the stresses developed within the workpiece during the vibration cutting processes are estimated and compared with those in the conventional cutting (CC) process. The influence of various parameters such as speed ratio and amplitude are subsequently investigated. It is partially concluded that though the cutting force fluctuates periodically in VC and EVC, its average value changes from CC to VC and EVC in descending order. The cutting force decreases with a rise in the speed ratio in EVC and does not change in VC.

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Event date： 2008 　 　

楕円振動切削では，切込方向の振動振幅を能動的に制御することによって切込み深さに変動を与えることができる．本研究では，この特徴に基づき，振動振幅制御を利用した高硬度材の超精密微細テクスチャ加工技術を提案する．振動振幅を高速制御することが可能な約40kHzの楕円振動制御装置を用いて，焼入れ鋼のテクスチャ加工実験を行った．基礎的な溝加工実験の結果，良好な超精密微細加工を実現できることを確認した．

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Event date： 2008 　 　

著者らは楕円振動切削を利用した焼入れ鋼の自由曲面加工法を提案し，これを実現するための3自由度超音波楕円振動工具を開発している．従来の振動工具においては，大きな切削負荷が生じた際に振動軌跡が乱れて仕上げ面性状の劣化や工具の欠損を引き起こす問題があった．そこで，本研究では振動子に取り付けるシャンク形状の変更による負荷特性の改善を検討した．その結果，大幅に負荷特性を改善し得ることを確認した．

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Event date： 2008 　 　

新しいガラス成型用金型材料として期待されているタングステン合金の超音波楕円振動切削においては，従来の研究によってダイヤモンド工具の急激な摩耗が仕上げ面性状の劣化を引き起こし問題となることが明らかになっている．本研究ではこの摩耗メカニズムに着目し，工具形状や結晶方位などの変更による工具寿命の延長について検討を行う．さらに，各種工具を用いた寿命試験により，その効果について検証を行った．

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Event date： 2008 　 　

エンドミル加工のびびり振動の安定限界解析には伝達関数が必要となるが，小型もしくは複雑形状の機械構造や，回転中に伝達特性の変化する機械構造がびびり振動する場合には，伝達関数の高精度測定が難しいという問題がある．そこで，従来の伝達関数測定手法と異なり，加工実験中に計測されるびびり振動の周波数と実際の安定限界切込みから伝達関数を逆同定する手法を考案した．そして，加工実験により考案手法の検証を行った．

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Event date： 2008 　 　

切削加工におけるびびり振動の安定限界に対して，機械構造の伝達特性におけるクロス項が与える影響について検討した研究はこれまでになく，ほとんどの場合には考慮すらされることがない．これに対し本研究では，びびり振動の安定限界に対して伝達特性のクロス項が与える影響について，その本質的な意味を明らかにするとともに，突切り切削を対象としてクロス項を考慮した再生型びびり振動の安定限界解析手法を提案する．

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Event date： 2008 　 　

Language：Japanese  

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Event date： 2007 　 　

CMPプロセスでは，研磨に使用する材料の形状や機械特性が研磨特性に大きく影響することが経験的に知られている．著者らは，複雑なCMPプロセスのメカニズムの解明を目的とし，これまでに流体－構造連成解析を利用したCMPプロセスの解析手法について検討を行っている．本稿では，本解析手法を利用し，研磨パッドの材質やウェハ形状などの各種パラメータが研磨特性に及ぼす影響について評価を行った結果について報告する．

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Event date： 2007 　 　

本研究では新しい振動切削加工法として，放物線振動切削加工法を提案する。本手法では工具刃先を切削方向に放物線軌跡で超音波振動させながら加工を行うことにより、間欠切削と引き切りの効果を同時に得るとともに、切れ刃方向の力が反転し相殺するため，実質的に著しい切削抵抗の低減が期待される。本報では、超音波放物線振動子を開発し，通常切削および従来振動切削と本手法の基礎的な比較実験を行った結果について報告する。

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Event date： 2007 　 　

びびり振動を抑制・回避するためには，安定限界解析手法を利用した適切な加工条件の選択や構造の改善が有効となる．これに対し，本研究では，強制型びびり振動を引き起こす主要因となる切削力の周期変動を考慮した，エンドミル加工における強制型びびり振動の安定限界解析手法を考案した．さらに，エンドミル加工による検証実験を行い，本解析手法により強制型びびり振動の安定限界を高精度に予測し得ることを確認した．

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Event date： 2007 　 　

従来のエンドミル加工におけるびびり振動安定限界解析では，空間に固定された座標系内で構造物の伝達関数を定義し，固定座標系内で一定の振動が生じることを前提としている．これに対して著者らは，低剛性の回転工具に，その工具に固定された座標系内で一定の振動が発生する場合に対応した安定限界解析モデルを構築している．本研究では，異方性を持つエンドミル工具を用いた切削実験を行い，本手法の有効性について検証を行った．

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Event date： 2007 　 　

Elliptical vibration cutting is applied to ultra-precision machining of tungsten alloy molds for optical glass parts in the present research. The tungsten alloy is expected as a new mold material instead of conventional ones such as sintered tungsten carbide and CVD-silicon carbide. Ultra-precision molds of the tungsten alloy for a prism, a small spherical lens and an array of micro V-grooves were machined by the elliptical vibration cutting. It is confirmed that surface roughness of less than 100 nmRz and desired shape can be attained. They were applied to glass molding of borosilicate glass BK7 without any coatings, and it is found that accurate transcript with no adhesion can be achieved successfully.

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Event date： 2006 　 　

Language：Japanese  

An analytical approach to estimate the coefficient of friction (COF) in chemical mechanical polishing (CMP) process in mixed lubrication is developed in the present research. The Stribeck curve is calculated by experimental and analytical results of friction resistances. An analytical model, which can predict the distribution of contact stress and fluid pressure under the condition of nonuniform velocity distribution by utilizing the Stribeck curve, is developed. Polishing experiments are carried out for the verification of the model in terms of the friction resistance. It is confirmed that the effect of the wafer rotational speed on the friction resistance can be predicted successfully by the developed analytical model.

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Event date： 2006 　 　

Language：Japanese  

This paper presents a new ultraprecision alignment device with high load capacity, which is targeted for ultraprecision bonding in a vacuum. The ultraprecision bonding is recently needed for emerging production technologies such as nanoimprint, MEMS and WOW. The device is driven by &#039;Walking Drive&#039;, which is an unique driving method to realize ultraprecision positioning with long stroke by utilizing piezoelectric actuators. The method is suitable for high load capacity and the ultraprecision positioning in a vacuum. Mechanical parts of the device are designed by utilizing FEM analysis, so that the device has a high load capacity of greater than 1 ton. It is confirmed experimentally that the developed alignment system has the high load capacity and also fine positioning resolution of less than 10nm.

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Event date： 2006 　 　

&amp;prime;Ultrasonic elliptical vibration cutting&amp;prime; technology is applied in the present research to ultraprecision machining of single crystal germanium, which is an excellent substrate material for optical devices. Micro grooving experiments are carried out on (100), (110) and (111) faces of the single crystal germanium to clarify the basic effects of the elliptical vibration on the ductile micro machining. It is confirmed that a groove formed in &lt;011&gt; direction on the (111) surface is filled with asperities at a depth of 0.19 um due to cleavage fractures in the ordinary cutting. While a smooth mirror surface is obtained by the elliptical vibration cutting at a depth of cut of less than 1.04 um in same direction. These experimental results indicate that the critical depth of cut is increased at a specific orientation angle by applying the elliptical vibration cutting. However critical depths of cut depend on cutting directions and crystal orientations. We also clarified that the critical depth of cut can be increased at the lower cutting speed.

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Event date： 2006 　 　

Polishing experiments are carried out in the present research in order to verify an analytical model for a simulation of Chemical Mechanical Polishing (CMP) process. A three-dimensional finite element analysis of CMP process, which considers the boundary lubrication between a wafer and a polishing pad, is utilized to predict a friction resistance. Additionally, the friction forces are measured in the polishing experiments by force sensors built into the experimental setup. It is conformed that the predictions of friction resistance directions fit experimental results. These results indicate that the friction resistance direction depends on the ratio of the wafer to the polishing pad rotation speeds.

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Event date： 2006 　 　

&amp;prime;Ultrasonic elliptical vibration cutting&amp;prime; technology is applied in the present research to ultraprecision machining of Tungsten alloy, which is expected as a material of molds for glass parts instead of sintered tungsten carbide. It is confirmed that ulptraprecision grooving cannot be realized by the ordinary cutting. On the other hand, it can be realized by the elliptical vibration cutting at a cutting depth of less than 1 um. Effects of the cutting distance on the cutting force and the roughness are also clarified, and it is found that surface roughness of less than 100 nm Rz can be realized up to a cutting distance of 35 m. Practical molds for spherical glass lenses and a glass prism are successfully machined.

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Event date： 2005 　 　

A prototype slider is developed in the present research by utilizing a new fluid bearing proposed in the previous research. The moving part is supported with a thin fluid film held on the bearing surface by surface tension. Conventional hydrostatic sliders utilize externally compressed fluid, which requires some cost and large facilities and causes micro vibrations by ripple of the fluid pressure. The non&amp;ndash;contact precision slider is realized without the large facilities by utilizing the proposed bearing, and it has high load capacity and enough rigidity for the simple structure. The prototype slider is fabricated by utilizing a water film and a guide rail of polished glass, and its resistance force against the feed motion is investigated here.

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Event date： 2005 　 　

A new machining method is proposed to obtain precise sculptured surfaces by applying &amp;Prime;elliptical vibration cutting&amp;Prime;. A 4&amp;ndash;axis controlled precision machine tool, which consists of an air spindle and precision elements, is developed. 4&amp;ndash;axis control tool paths for machining sculptured surfaces are also generated by utilizing commercial CAM software and a special post processor. It is confirmed that mirror surface machining of hardened die steel can be realized by integrating the precision machine tool, the special CAM system and the 3 DOF vibration system developed in the previous research.

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Event date： 2005 　 　

本研究では、CMPプロセスにおいて実用的な解を与える研磨レート分布解析手法の確立を目指している。本報では、基礎的なCMPプロセスの解析モデルを構築し、有限要素解析を利用してウェハ&amp;ndash;研磨パッド間の流体圧力分布及び接触応力分布の解析を行うと同時に、研磨レート分布の推定を行った。さらに酸化膜CMPにおける基礎的な研磨実験を行い、研磨条件がCMPプロセスに及ぼす影響について検証を行った。

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Event date： 2005 　 　

An analytical model of three dimensional cutting process with two cutting edges is presented without relying on empirical rules in the present research. The shear deformation zone is simplified to a thin shear plane, and Krystof&amp;prime;s maximum shear stress model and Merchant&amp;prime;s minimum energy model for the orthogonal cutting process are extended to the three dimensional cutting process to predict the shear direction. The three dimensional cutting parameters including cutting forces and chip flow direction are computed with the developed model, and it is confirmed that the computed chip flow direction agrees roughly with Colwell&amp;prime;s empirical law of chip flow.

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Event date： 2005 　 　

A new non-contact fluid bearing, which utilizes traveling wave, is proposed in the present research. The moving part is supported with a thin fluid film compressed by the wave traveling on the bearing surface. Conventional fluid bearings utilize externally compressed fluid, which requires some cost and large facilities. The proposed bearing realizes non-contact precision tables without the large facilities, and furthermore it has a capability to electrically control the bearing force and moment. A prototype device is developed on the basis of the proposed principle, and its non-contact smooth motion has been observed.

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Event date： 2004 　 　

著者らが考案している楕円振動切削加工法では、背分力をゼロもしくは反転させることが可能である。また、振動軌跡における振動振幅や位相差などの各振動パラメータを変化させることにより、切削プロセスを意図的に変化させることができる。本研究では、振動振幅や位相差を変化させることにより切削力を制御する切削プロセス制御システムの開発を行った.さらに切削実験を行い、開発した制御システムの有効性を検討した。

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Event date： 2004 　 　

著者らは楕円振動切削を適用することにより焼入れ鋼金型に対して直接ダイヤモンド鏡面切削を行うことが可能な新しい加工技術の開発を目指している.これまでの研究において,1方向のたて振動と2方向のたわみ振動を同一周波数で発生させることのできる3自由度型の振動工具の開発を行っている.本報では,開発した3自由度型振動工具を安定して制御することが可能な制御システムを設計・試作を行い,その制御特性の評価を行った.

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Event date： 2004 　 　

微細形状を有するガラス製品の量産を目的とし、超硬合金製金型に対する超精密微細加工の要求が増加している。これに対し、筆者らは楕円振動切削の適用を試み、すでに良好な延性モード加工を行い得ることを確認している。本報では、低周波振動における溝加工実験を行い、楕円振動切削による延性モード加工のメカニズムについて検討を行った。その結果、低周波振動においても延性モード加工行い得ることを確認した.

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Event date： 2004 　 　

筆者らは楕円振動切削と呼ぶ加工法を提案し、優れた切削性能を持つことを確認している。実用的な自由曲面を加工するためには多様な加工形状に対応できる振動装置が必要となる。しかし、既に開発している2自由度型超音波楕円振動切削装置では振動子と被削材の干渉により加工形状が制約されてしまう。そこで、任意の面内で楕円振動軌跡を得ることができ、加工形状の制約が少ない3自由度型超音波楕円振動切削装置の開発を行った。

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Event date： 2004 　 　

エンドミル加工では、加工時に発生するびびり振動により、切削条件が制限されることが多い。このびびり振動を抑制し切削安定限界を上げることは、加工能率の向上へとつながる。本研究では、工具を主体としたびびり振動の発生機構をモデル化し、解析的に求めた切削安定限界と実験値を比較する。また、積極的に安定限界領域を拡大する手法についても検討を行う。

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Event date： 2004 　 　

本研究では、表面張力を利用した新しい流体軸受を考案している。提案する装置では、軸受隙間に水の膜を作り、表面張力によってその状態を維持する。従来の非接触軸受と異なり、外部装置を必要としない単純な構造のため、使用する場所に制限されず、流体の脈動による微振動も無くす事ができる。実際に表面張力によって移動部を浮上させ、滑らかな送り動作が可能である事を確認している。また剛性等の測定も検討している。

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Event date： 2003 　 　

Language：Japanese  

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Event date： 2003 　 　

単結晶フッ化カルシウム（CaF2）は切削による延性モード加工が困難であるため，通常はポリシングにより加工されることが多い．本研究では切削性能の向上を目的として考案されている楕円振動切削加工を適用することにより単結晶材料の延性モード切削を試みた．&lt;br&gt;基礎的な溝加工実験により超音波楕円振動付加による影響の評価を行った．その結果，楕円振動切削を用いることで大幅に臨界切込み量が増大することがわかった．

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Event date： 2002 　 　

CMPプロセスにおける研磨パッドの表面状態は研磨レート等の基本的な研磨特性に大きな影響を与える．研磨パッドの表面状態について，これまで筆者らは表面あらさを用いた評価を試みてきたが，測定箇所の発泡状態等により測定結果が大きくばらつき，研磨特性との相関を明瞭とするために多量の測定を要する問題があった．そこで本研究では，研磨パッドの損耗に伴うパッド表面の平滑化に着目し，研磨パッド表面の画像から平滑化の度合いを算出する簡便な研磨パッド表面状態の評価方法について検討を行った．実験の結果、本測定法は研磨パッドの表面あらさRaによる評価と比較して研磨パッド表面状態を精度良く評価できることが判った．

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Event date： 2000 　 　

Language：Japanese  

A new system is developed to control the ultrasonic elliptical vibration applied to the cutting tool, and it is applied to the ultraprecision elliptical vibration cutting of hardened stainless steel in the present research. Steady feedback control of the vibration locus is realized by developing a cross talk remover, which eliminates interference between the two directional vibrations. The controller keeps the vibration amplitudes and the phase difference between the two vibrations to be desired values and to chase the average resonant frequency of the vibrations simultaneously. The machining experiments show that shape accuracy and roughness of the finished surface are improved significantly by applying the developed system.

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