研究一覧（2006年1月〜12月）

CO₂レーザによるマグネシウム合金板の曲げ加工に関する研究（第２報）

−レーザスポット径の曲げ変形挙動に及ぼす影響−

　　奥田孝一，戸田吉宣，布引雅之
　　 精密工学会誌，Vol.72，No.2，pp.214-218 (2006)

　The property of bending deformation in a laser forming of magnesium alloy plate has been investigated in the previous work. In this continued study, an effect of laser spot diameter on bending deformation behavior was studied in order to examine a feasibility of control of the bending direction and angle. The experiments of CO2 laser forming of magnesium alloy plate were carried out under the machining conditions with a various laser spot diameter by changing the focal point of laser. In principle, the metal plate bends toward the laser head except for a very thin plate when the focal point of laser is on the work surface. In the experimental results, it was found that the bending angle decreased with an increase in the laser spot diameter and the plate continued to bend toward the opposite direction of the laser head when the laser spot exceeded a certain diameter. In this case, the plate bends toward the opposite direction of the laser head with a larger angle during the cooling period than a bending angle to the laser head side during the heating period.

ベリリウム銅の微小切削における仕上面性状
　　奥田孝一，桂樹 潤
　　銅と銅合金，Vol.45，No.1，pp.256-260 (2006)

　Demands of micro parts by precision cutting have been increased. In this study, we have focused on a micro cutting technology of beryllium copper alloy which is used for micro electric parts such as the contact probe for an electric inspection of semiconductor circuit. In the micro cutting of beryllium copper, the surface integrity and the tool wear become a big problem because of its high strength. In order to clarify the micro cutting properties in point of view of the surface integrity, the micro cutting experiments with a tungsten carbide and the diamond cutting tools were carried out using an ultra-precision cutting machine. The machinability of beryllium copper alloy by micro cutting was examined and then the effect of the cutting condition, especially the cutting speed, on the surface integrity was mainly discussed. The results are summarized as following. In case of using the tungsten carbide tool, the surface roughness of 0.2〜0.4?m Ry was obtained when the cutting speed ranges from 10 to 180 m/min. Ry tended to increase with an increase in the cutting speed. On the other hand, in case of using diamond tool, Ry was almost constant not depending on the cutting speed and good surface with smaller roughness was obtained.

Surface finish of thick photo resist and nickel electroplating structure by ultra-precision cutting
　　K. Okuda, N. Fujiwara, *T. Hattori
* Lab. of Advanced Science and Technology for Industry
　　Proceedings of the 6th euspen International Conference, Vol.2，pp.340-343 (2006)

　The flat surface is required to fabricate the micro parts with 3-D or complicated structure. In this study, an ultra-precision cutting technique was applied to UV lithography process and the direct cutting of the resist layer and nickel electroplating structure by diamond cutting tool was attempted. The integrity and the flatness of the cut surface were evaluated. As a result, it was found that the surface roughness of the resist and the nickel electroplating complex was an order of 0.01um in arithmetic average roughness Ra and the step occurred at the interface between the resist and the nickel electroplating.

Machinability in Precision Cutting of Carbon Tool Steel for Small-size Parts
　　K. Okuda, Y. Takeno
　　Key Engineering Material, Vols. 329, pp.571-576 (2006)

　High accuracy and high efficiency machining of micro parts such as a contact probe for a current inspection of semiconductor is increasingly demanded. In this study, we have focused on a micro cutting technology of a carbon tool steel which is a typical material for a contact probe. In order to put the precision cutting of the high strength material into practice, it is essential to understand the micro cutting phenomenon such as the surface texture, the tool wear with small depth of cut and low cutting speed. Then, the precision cutting experiments of a carbon tool steel (SK105) by titanium carbide and ultra-fine grained tungsten carbide tools were carried out with an ultra-precision cutting machine. It was found that the feed rate, the cutting speed and the edge sharpness of tool significantly influence the surface finish.

Bending Deformation of Pure Titanium Plate in CO₂ Laser Forming
　　K. Okuda, Y. Sugie, M. Nunobiki
　　Key Engineering Material, Vols. 329, pp.625-630 (2006)

　This study deals with behavior of bending deformation in CO2 laser forming process of titanium. CO2 laser forming technique was applied for a pure titanium plate with thickness of 1 mm to aim the development of new bending process. The experiments of laser forming were carried out with a CO2 laser machine. The bending angle and the temperature of workpiece were examined under the condition of various laser power, feed speed and laser spot diameter. Based on the experimental results, it was found that the bending deformation behaved greatly depending on the laser power and the laser spot diameter. The bending angle increased with an increase in the laser power. The bending direction tended to change from the laser irradiation side to its opposite side when the large laser spot diameter was applied.

FEM ANALYSIS OF BENDING DEFORMATION IN LASER FORMING OF Mg ALLOY
　K. Okuda, H. Hayashida, M. Nunobiki
　Progress of Machining Technology, Vol.8, pp.249-252 (2006)

　Plastic bending properties and deformation mechanism of magnesium alloy plate (AZ31) by CO2 laser forming process are investigated based on a simulation analysis. In this paper, the analysis of heat transfer by conduction and thermal deformation are conducted with a finite element method. The simulation model that the shuttle motion of the laser is given along the width (60mm) of the plate (a thickness of 1mm) is made. The moving heat source with Gaussian distribution strength is given. The temperature distribution, the thermal stress and the thermal deformation are calculated and then their interrelation is discussed. It was found that the laser spot diameter and the thickness of plate greatly influence the bending direction.

STUDY ON STEP AT GRAIN BOUNDARY IN ULTRA-PRECISION CUTTING OF PHOSPHOR BRONZE
　　K. Okuda, E. Ogawa
　　Progress of Machining Technology, Vol.8, pp.393-396 (2006)

　This paper deals with the step generated at the grain boundary in an ultra-precision diamond cutting of phosphor bronze for a metal mold of Fresnel lens. In this study, the cutting experiments were carried out with an ultra-precision cutting machine by a single crystal diamond tool in order to investigate the relationship between the generation of grain boundary step and the cutting conditions. It was found that the thrust component of the cutting force and the feed rate condition greatly influence the magnitude of the step at grain boundary.

EFFECT OF SURFACE TEXTURE OF PTFE ON ADHESION PROPERTY OF METAL THIN FILM
　　K. Okuda, T. Tsuneyoshi, S. Yamashita, * T. Hattori
* Lab. of Advanced Science and Technology for Industry
　　Progress of Machining Technology, Vol.8, pp.503-506 (2006)

　In this paper, the effect of the surface texture of PTFE on the adhesion property of metal thin film by sputtering Cr is described. The surface is finished by some machining methods such as an ultra-precision cutting, a conventional cutting and an abrasive machining. The relationship between the surface texture parameters such as the surface roughness, the anisotropy and the surface properties such as the hydrophilic property, the friction coefficient, the adhesion strength of sputtered Cr film is investigated. The following remarks were found. When the surface roughness became larger, the hydrophilicity was slightly reduced and the adhesion strength of Cr film was improved. The adhesion strength with the cut surface exceeded that with the ground surface.

Fabrication of Cylindrical Microcoil Line with High Aspect Ratio for Electromagnetic Actuators
　　S. Yamashita, * Y. Matsumoto, * K. Idei, K. Okuda, * D. Noda, and * T. Hattori
* Lab. of Advanced Science and Technology for Industry

　　Proceedings of 2006 INTETNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SIENCE (IEEE), pp.497-502 (2006)

　We designed a scheme a scheme to introduce the LIGA process,　Reduce the coil line width while improving the performance, and Thereby drastically cut the production costs. Consequently, we succeeded in fabricating prototype microcoils (line width: 10 ?m approx. 1). However, improvement in performance of the microcoils requires an increased aspect ratio. We set an objective to fabricate microcoil line of a high aspect ratio with the dipping method and 3D X-ray lithography in an effort to improve the performance of microcoils. And we succeeded in fabricating microcoils line with a line width of 10 ?m and an aspect ratio greater than 5.

Fabrication of Gratings for an X-ray Talbot Interferometer

　　M. Tanaka, *Ｙ. Takeda , *Ｄ. Noda, **Ｗ. Yashiro, K. Okuda, **A. Momose, *T. Hattori
* Lab. of Advanced Science and Technology for Industry
**The University of Tokyo

　Proceedings of 2006 INTETNATIONAL SYMPOSIUM ON MICRO-NANOMECHATRONICS AND HUMAN SIENCE (IEEE), pp.491-496 (2006)

　X-ray-based imaging measurement has found applications in fields such as medical diagnosis and nondestructive inspection, having become one of essential technologies. However, its low sensitivity to biologically soft tissues limits scope of applications. Several methods have been developed for X-ray phase imaging. We proposed a method using an X-ray Talbot interferometer. It offers advantages; it is a very simple setup using two gratings; it has a potential of phase imaging with a compact laboratory X-ray source. But the fabrication of an amplitude X-ray grating is a difficult, because the structure of grating must have high aspect ratio. We used deep X-ray lithography and electroforming of Au in fabricating gratings. The period and height of the grating were 5.3?m and 31?m. We evaluated the gratings, successfully achieved a high visibility of 71％. With the gratings that had a period of 8?m and a height of 29?m, we conducted X-ray phase tomography of rabbit liver and a mouse tail. As a result, we successfully observed soft tissues　and　high-density tissues. The gratings, therefore, had sufficient performance to conduct phase tomography.

FABRICATION OF CYLINDRICAL MICROCOIL LINE THROUGH SURFACE MODIFICATION FOR MICROACTUATORS
　　S. Yamashita, *S. Kusumi, *O. Shimada, K. Okuda, **D. Noda and **T. Hattori
* Susumu Co., Ltd.
** Lab. of Advanced Science and Technology for Industry

　　Proceedings of 10th International Conference on New Actuator, pp.701-704 (2006)

　We have been focusing our attention on cylindrical solenoidal actuators that have high-efficiency, are small in size with high out-put power. We began by fabricating micro coil with the expectation that it would broaden the applications for cylindrical solenoidal actuators. However, heat-resistant resins including liquid crystal polymer (LCP) and polytetrafluoroethylene (PTFE) used in the coil core had the unfavorable characteristic of extremely low adhesiveness on copper and other metals. Our trial used the application of a surface modification technique using H2O- and Ar-ion beams. This increased peel strength between the ion irradiated sample of PTFE plate and a thin copper film deposited on the sample at 0.8MPa to 8.5 MPa.

Study of Thermal Deformation of a Base Sheet Caused by Laser Cutting
　　M. Nunobiki, K. Okuda, T. Yohsida, S. Kita
　　Toward Synthesis of Micro-Nano-systems, The 11th Int. Conf. of Precision Engineering, pp.249-254 (2006)

　In case that a lot of products were cut out from a wide base sheet by laser cutting, the sheet had been much deformed so that the error occurred in a height regulator. This paper deals with thermal deformation of a base sheet caused by laser cutting. We clarified that the thermal deformation was influenced by the cutting sequence in the case of SUS304 sheets of 1mm thickness. The workpieces bent upward in inward sequence, and the workpieces bent downward in outward sequence. It is expected that the deformation was able to be controlled by cutting sequence.

An Effective State-Space Construction Method for Reinforcement Learning of Multi-Link Mobile Robot
　　M. Nunobiki, K. Okuka, S. Maeda
　　Mechatronics for Safety, Security and Dependability in a New Era, pp.385-388. (2006)

One of the problems in reinforcement learning with real robots is to need a large number of trials. This paper proposes a reinforcement learning system that uses fuzzy ART neural networks for segmentation of state-space. By using an incremental state-space construction method with fuzzy ART neural networks, we are able to increase learning speed and reduce memory requirements. Whenever the fuzzy ART neural network encounters a new situation, it generates a new category node to the state-space. We proposed generating methods of a new category node that inherit the state-value and the policy from a similar node. Proposed methods were estimated from simulations of a two-link robot and experiments of a multi-link mobile robot. It was confirmed that the proposed method was able to increase the learning speed and reduce the size of state-space.

イオン照射によるPTFE とCu 薄膜の密着力向上
　　山下修平，*植田寛康，*糸魚川貢一，**野田大二，奥田孝一，**服部正
*(株)東海理化
**高度研

　　平成18年電気学会全国大会講演論文集，No.3，p.197 (2006)

X 線タルボ干渉計用回折格子の作製と評価
　　田中誠人，*松本昌岳，**野田大二，奥田孝一，***百生 敦，**服部 正
*(株ナガセケミテックスか ナガセケミテックス
**高度研
***東京大学

　　平成18年電気学会全国大会講演論文集，No.3，p.204 (2006)



PTFEの超精密切削仕上面の表面特性と金属膜の接着
　　恒吉辰典，奥田孝一

　　精密工学会2006年度関西地方定期学術講演会講演論文集，pp.9-10 (2006)

りん青銅の超精密切削仕上面における結晶粒界段差
　　奥田孝一，小川恵美

　　日本機械学会第６回生産加工・工作機械部門講演会講演論文集，pp.139-140 (2006)

レーザ切断における被加工母材の熱変形抑制に関する研究
　　布引雅之，奥田孝一，吉田敏幸

　　2006 年度精密工学会春季大会学術講演会講演論文集，pp.1267-1268 (2006)

多リンク型ロボットにおける強化学習の効率化に関する研究−非単調な状態空間構築法を用いた強化学習―
　　小谷直樹，布引雅之，奥田孝一

　　第２４回日本ロボット学会学術講演会講演概要集，pp.178-180 (2006)

レーザ切断における加工形状が被加工母材の変形に及ぼす影響
　　布引雅之，奥田孝一，北章平

　　2006年度精密工学会秋季大会学術講演会講演論文集，pp.316-614 (2006)

多リンクロボットの経路決定を行う強化学習に関する研究−状態価値を用いて状態空間を構築する強化学習―
　　布引雅之，奥田孝一,小谷直樹

　　2006年度精密工学会秋季大会学術講演会講演論文集，pp.467-468 (2006)

ショットピーニングによる異種薄板同士の突き合わせ接合
　　原田泰典，福永誠，深浦健三，布引雅之，宇治橋諭，小林祐次

　　日本金属学会春期講演会，第140回，p.291 (2007)



生産加工技術の知能化，高度化を目指して
　　奥田孝一

　　精密工学会誌，Vol.72，No.8，pp.979-980 (2006)

マグネシウム合金の超精密切削加工
　　奥田孝一
　　日本マグネシウム協会第13回切削分科会，pp.27-32 (2006)

　構造用金属材料の中で最も軽量なマグネシウム合金の普及に伴い、高度で安全な切削加工技術の普及が望まれ、最新のマグネシウム合金に関する切削加工技術並びに加工設備、加工事例並びに加工切り粉処理など最新の動向についての講演．マグネシウム合金の超精密切削特性について述べた．

マグネシウム合金の超精密切削加工
　　奥田孝一
　　第21回先端Mg合金研究会，pp.1-27 (2006)

　超精密切削によるマグネシウム合金の鏡面加工特性について述べた．ポリゴンミラーやハードディスク基板用アルミニウムの鏡面加工特性と比較しながら，マグネシウム合金のもつ金属組織が仕上面性状に及ぼす影響について解説した．

超精密超微小切削のメカニズムとその応用
　　奥田孝一
　　日本テクノセンター超精密切削加工技術と高精度化セミナーテキスト，pp.1-56 (2006)

　「超精密切削加工技術と高精度化」講座では，切削加工の基本メカニズムについて解説するとともに，超精密超微小切削における特異性，通常切削では無視しえた要因とそれらの超微小切削メカニズムに及ぼす影響について述べる．高精度加工技術課題に対処しうる超精密切削加工の基礎的な知識を習得できることを目的としたテキストである．

超精密切削加工技術入門講座
　　奥田孝一
　　日本テクノセンター超精密切削加工入門講座テキスト，pp.1-89 (2006)

　近年の各種製品・部品の高機能化，微小化に伴って，要求される加工精度はますます高くなっている．そのため各種の超精密加工技術が用いられているが，本講座ではその中でも代表的な超精密加工法である超精密切削加工技術について基礎からわかりやすく解説する．

超精密・マイクロ加工
　　奥田孝一
　　経産省産学連携製造中核人材育成事業　実証講義テキスト，pp.6.1-6.28 (2006)

　「医療福祉機器等の開発・製造を中心とする機械金属製造業の新産業創造人材育成事業」における実証講義テキストの第６章として，超精密部品，微細形状部品の加工技術についてまとめた．