著者

貝原 俊也 白瀬 敬一 藤井 信忠

出版者

公益社団法人 精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.75, no.10, pp.1153-1157, 2009-10-05 (Released:2011-02-07)

参考文献数

17

著者

白瀬 敬一 稲村 豊四郎 安井 武司

出版者

公益社団法人 精密工学会

雑誌

精密工学会誌 (ISSN:09120289)

巻号頁・発行日

vol.57, no.2, pp.286-291, 1991-02-05 (Released:2009-10-08)

参考文献数

5

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A hybrid bearing is proposed for high speed machine tool spindle. The bearing composed of two angular contact ball bearings in a series arrangement and has a middle race between double column rolling elements besides the inner and outer race. The third race rotates with keeping a balance of the inner and outer bearing's friction. The spindle rotates at the speed of the sum of the inner and outer bearing's speed. The friction torque of the proposed bearing is less than a conventional bearing's one. But the simulation showed that the bearing has an effective speed range due to the retainer speed and the centrifugal force of the balls. At the critical speed, the friction torque of the bearing coincides with a conventional bearing's one. The critical speed can be rised by use of ceramics balls or small steel balls and an optimum lubricant system. A preliminary experiment of the proposed bearing showed that the final temperature rise of outer race is three degrees C only at 10000 rpm. The experimental critical spindle speed was about 8000 rpm against theoretical 17500 rpm.

著者

野口 晋 西田 勇 佐藤 隆太 白瀬 敬一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00254-17-00254, 2017 (Released:2017-12-25)

参考文献数

14

被引用文献数

1

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It is known that the cutting force excites the structural vibration of machine tool. In addition, cutting force acts on feed and spindle drive system as a force disturbance, and feed speed and spindle speed are changed. As the results, cutting force is also changed because the depth of cut and cutting speed are changed due to the machine vibration, feed and spindle speed changes. The purpose of this study is to analyze the coupled vibration between the machine tool behavior and the cutting force. In order to achieve the purpose, in this study, a coupled simulation method of the vibration of machine tool, the dynamic behaviors of feed and spindle drive systems and the cutting force is developed. Cutting force and machined surface geometry is simulated using the voxel simulator in which the workpieces is represented by voxels. Undeformed chip thickness can be calculated based on the relative position between the tool and workpieces, and the tool rotational angle at the each time step based on the voxel model. The cutting force is estimated based on the calculated undeformed chip thickness. The relative position between tool and workpiece at each time step is simulated by the feed drive system and machine tool structural models. The tool rotational angle is simulated by the spindle drive system model. The coupled simulation between the cutting force, structural vibration of machine tool and feed and spindle drive systems is carried out by applying the simulated cutting force and cutting torque as a disturbance to the feed and spindle drive systems and machine tool structure. Cutting tests and simulations are carried out with two kinds of radial depth of cut, 5 mm and 20 mm. It is confirmed that the machine tool dynamic behaviors due to the cutting force and torque which is also influenced by the machine tool behaviors can be simulated by the proposed method. It is also confirmed that the chatter vibration which is observed in case of the 20 mm depth of cut can be simulated by the proposed method.

著者

金子 和暉 西田 勇 佐藤 隆太 白瀬 敬一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.856, pp.17-00247-17-00247, 2017 (Released:2017-12-25)

参考文献数

9

被引用文献数

3

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In end milling, in order to improve machining efficiency and accuracy, instantaneous rigid force model is widely used to predict cutting force and improve cutting conditions. The instantaneous rigid force model is well known as the practically simple model to predict cutting force. However this model requires the six parameters called cutting coefficients which have to be determined by the experimental milling operation. So several experimental milling operations are needed before cutting force prediction. In this study, a new instantaneous rigid force model based on oblique cutting is proposed. In this force model, the end milling process is modeled using the oblique cutting model. Therefore, cutting force prediction can be realized using only the one parameter such as shear angle instead of the six parameters such as cutting coefficients required for a conventional instantaneous rigid force model. The shear angle can be determined from tangential milling force or milling torque. And this force model is easier to apply for practical cutting force prediction, because time and effort to determine the parameter(s) before cutting force prediction. The validation of this force model compared with the conventional force model is performed. As the result, cutting forces predicted by the proposed force model has good agreement with the measured cutting forces. Also, the proposed force model has good performance in a wide range of cutting conditions compared with the conventional force model.

著者

西田 勇 前田 正登 川野 常夫 白瀬 敬一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.840, pp.16-00006-16-00006, 2016 (Released:2016-08-25)

参考文献数

11

被引用文献数

1

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For several decades, factory automation or unmanned factory productivity has been progressed to realize much higher productivity in manufacturing. However, human centered manufacturing system is getting attention to realize much more flexibility for manufacturing of wide product variety and volume. So it is necessary to provide the safe and efficient environment to workers considering their own physical properties. This study investigated a mechanism of muscle fatigue and proposed a muscular fatigue model to evaluate muscle fatigue progress under several muscular force patterns. Previous studies have already proposed a muscular fatigue model. However, these previous studies discussed about the condition of maximum voluntary contraction. The new point of this study is considering several muscular force patterns including muscle recovery progress. This study proposed the method to estimate the endurance times for keeping constant forces considering the physical characteristics. This study also proposed the method to estimate the iteration numbers for keeping constant forces with interval. To validate the effectiveness of the proposed method, experimental verifications were conducted. The experimental results had a good agreement with the evaluation of muscle fatigue progress using the proposed method although it is necessary to consider the method to raise the precision of determining the physical parameters and the method to decrease the dispersion of experiments derived from the subjective judgement of participants. Success of resolving these issues will provide ergonomically safe and efficient working environments considering the physical properties of each worker.

著者

柴坂 敏郎 木曽田 雄星 白瀬 敬一

出版者

公益社団法人 精密工学会

雑誌

精密工学会学術講演会講演論文集

巻号頁・発行日

vol.2011, pp.263-264, 2011

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光学機器製造用の金型あるいはマイクロ溝/パターン加工などの微細形状加工において、表面にメッキを施し、メッキ層で要求精度、微細形状を得る場合がある。メッキ材料としては、無酸素銅、無電解Ni-Pなどが現在用いられているが、本研究では新たなめっき被膜材料について、単結晶ダイヤモンドによる超精密切削加工の可能性を報告する。

著者

木曾田 雄星 柴坂 敏郎 白瀬 敬一

出版者

一般社団法人日本機械学会

雑誌

生産加工・工作機械部門講演会 : 生産と加工に関する学術講演会

巻号頁・発行日

vol.2010, no.8, pp.159-160, 2010-11-19

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Plated alloy have been attempted to improve heat and wear resistance and insulation properties of machine parts. Particularly alloy of nickel and phosphorus(Ni-P) have benefit for the mold of glass or plastic lens which have property of highly heat and wear resistance. Ordinarily the plated Ni-P is made by a process of electroless plating. In this study, I used the plated Ni-P which made by a process of electroplating. In this process, a plated alloy can contain more amount of phosphorus. Single crystal diamond turning experiment for the cylindrical end face plated electrolytic Ni-P was carried out, and analyzed the potential of ultra precision cutting of electrolytic Ni-P and the effect of amount of content phosphorous. It was turned out that Electrolytic Ni-P have potentiality to be worked as electroless Ni-P, and to improve the surface roughness by the increase of the amount of content phosphorous.