研究一覧（1994年1月〜12月）
切削表面のカオス特徴抽出−続報：加工条件とリアプノフ指数および相関次元との関係について−
長谷川素由, 奥田孝一, 布引雅之, 劉 建成
1994年度精密工学会春期大会学術講演会講演論文集, p505 (1994)
前報では、切削加工面の断面曲線にカオス解析を適用し、カオス特徴が抽出されることを示した。本報では、工具ノーズ半径、送り量、切削速度を変化させて得られた切削表面のカオス解析を行い、加工条件とリアプノフ指数および相関次元との関係について検討した。本実験条件内で得られた断面曲線はいずれもカオス特徴を有しており、リアプノフ指数および相関次元は加工条件と密接に関係していることが明らかとなった。超精密２次元切削過程の単一せん断面モデル解析
奥田孝一, 長谷川素由, 森脇俊道*
＊神戸大学
1994年度精密工学会春期大会学術講演会講演論文集, p167 (1994)
超精密２次元切削過程に単一せん断面モデルを仮定して、実験測定量より応力、切削温度などの諸量の計算を行い、主として、微小切削における切削熱の発生量と切りくずおよび工具、工作物への流入割合、切削温度について検討した。その結果、平均切削温度上昇のほとんどはせん断面における発生熱で生じ、また、切削熱の大部分は工作物に流入することが明らかとなった。
Chaotic Characteristics of Cut Surface Texture
M. Hasegawa, J. Liu,K. Okuda and M. Nunobiki
Int. J. Japan Soc. Proc. Eng., 28 , p45 (1994)
The characterization methods about the engineering surface texture, in which the profile are considered as a stochastic process in the past, pay less attention to the comparatively smooth profile such as cut surface profile produced by single point tool. Using a mathematical model to describe this kind of profile is still remained to be done. We make an attempt to employ the chaos theory, which can suitably describe the unpredictable behavior of nonlinear dynamical systems, to characterize the profile mentioned above and search a model finally to express it. As the first step, the chaotic characteristics of the profile are investigated in this paper.
旋削加工面のカオス挙動に関する研究
長谷川素由, 奥田孝一, 布引雅之, 劉 建成
精密工学会誌, 60, p1460 (1994)
The chaotic behavior of surface profile produced by turning is investigated in this paper. A new method based on the chaotic theory for characterizing the machined surface texture is proposed. It is recognized by calculating the Lyapunov exponents of the attractor in 3-dimensional phase space and its correlation dimension whether the surface profile has the chaotic characteristic or not. All of the surface profiles produced by turning under the different machining conditions in experiments show the chaotic characteristics. It is also found that the strange attractors, the correlation dimensions and the Lyapunov exponents of the surface profiles produced by turning have relation with the machining conditions and the measurement conditions of the profiles.
Fractal Dimension of Machined Surface Texture
M. Hasegawa, J. Liu,K. Okuda and M. Nunobiki
Progressof Cutting and Grinding, Vol. 2, p727-732 (1994)
This paper deals with the fractal dimension of the surface profiles produced by cutting, grinding and electrical discharge machining (EDM). The fractal dimensions are calculated by the application of the variation method using the discrete profile data measured by the contact stylus profiler. It is recognized that the variation method has the best accuracy to calculate the fractal dimension among the other methods such as power spectrum, cover and rectangular cell counting (RCC). The relationships between the fractal dimensions of surface profile and the machining conditions are also investigated. The results suggest that the fractal dimensions of different kinds of machined surface profiles are different and are related to the machining conditions. In the case of cutting, the fractal dimensions of the surface profiles are found to decrease with the increment of the feed rate and are influenced by the cutting speed, the nose radius and the work material. The surface profiles derived from EDM exhibit fractal dimensions which are approximately independent of the machining conditions such as the peak discharge currents and the pulse durations.
Study on Processing of Micro Groove by CO2 Laser Beam
M. Hasegawa, K. Okuda, M. Nunobiki and M. Kanita
Progressof Cutting and Grinding, Vol.2, p721-726 (1994)
This paper deals with processing of micro groove on the stainless steel sheet (SUS304) by CO2 laser beam. Experiments of micro grooving with CW and PW lasers are carried out under the various machining conditions. The grooves are produced by single-pass beam and by overlapping multiple grooves. The shape of groove on surface and its cross sections are observed with the microscope. The width and the depth of grooves are also measured. The relationship between the laser grooving conditions and the integrity of grooves is experimentally investigated. The integrity of the grooves are remarkably affected by dross. In this experiments, the grooves with the minimum width and the depth of 300 mm and 100 mm respectively can be obtained in dross free under the appropriate machining conditions. The width and depth of groove increases with an increase in laser beam power. In the case of using PW laser beam, the grooves with regular contour corresponding to the frequency and the beam power are obtained. However, in the case of using CW laser, the grooves are damaged by heat and dross. The width and the depth of groove can be controlled by technique of overlapping multiple grooves with PW laser beam.
Statistical Analysis of Property of Carbon Ceramics Electrode in Electrical Discharge Machining
M. Hasegawa, K. Okuda, Y. Konishi and M. Nunobiki
Progressof Cutting and Grinding, Vol. 2, p715-720 (1994)
In this paper, the properties of a new electrode material, carbon ceramics, for electrical discharge machining (EDM) are investigated by the applications of the design method of experiments and the analysis of variance. Experiments are carried out under the machining conditions determined based on the orthogonal array of L18 (61 x 36), In the experiments, the electrodes of copper and graphite are also employed for the comparison. The rate of workpiece removal, the wear rate of electrode materials and the surface roughness are measured with each electrodes. From the statistical analysis, the performances of the electrode are evaluated. And the relationship between the machining conditions and the machinabilities are investigated. The availability of the carbon ceramics as the electrode tool for the EDM is shown through the results of the experiments and the statistical analysis.
超精密２次元切削過程の単一せん断面モデル解析
1994年度精密工学会春期大会学術講演会講演論文集, p167 (1994)
奥田孝一, 長谷川素由, 森脇俊道*
＊神戸大学
姫路工業大学工学部研究報告No.46 p35 (1994)
The orthogonal cutting tests were carried out on an ultraprecision fly-cutting machine at various depths of cut from 3 mm down to 0.0015 mm (1.5nm). Micro cutting process was analyzed by using the thin-shear model and the experimental results such as cutting force, thickness of chip and contact length between the chip and the rake face of tool. The effects of the depth of cut on the shear angle, the cutting heat and the cutting temperature are presented and compared with the results of conventional orthogonal cutting process. In micro cutting, the cutting heat generates almost on the shear plane and conducts into the workpiece instead of chip and tool. The analytical results have a good agreement with that of conventional cutting process at the depths of cut more than 0.4 mm but not at smaller depths of cut than 0.4 mm due to the notable size effect.