Paper:

# Machine Bed Support with Sliding Surface for Improving the Motion Accuracy

## Yusaku Shirahama^{†}, Ryuta Sato, Yusuke Takasuka, Hidenori Nakatsuji, and Keiichi Shirase

Department of Mechanical Engineering, Kobe University

1-1 Rokko-dai, Nada, Kobe 657-8501, Japan

^{†}Corresponding author, E-mail: 158t329t@stu.kobe-u.ac.jp

The purpose of this study is to develop a new machine bed support mechanism for reducing the vibration generated during the high-speed tracking motion of numerical control machine tools. In order to achieve this, the frequency response and motion trajectory of a machine tool with the proposed machine bed, which has a sliding surface, are measured and compared with that of the conventional support. Based on the modal analysis of the machine tool structure, a mathematical model representing the influence of the machine bed characteristics on the vibration is also developed. The model consists of a bed, saddle, table, column, and spindle head. Every component has three degrees of freedom for each of the translational and rotational axes. In order to evaluate the characteristics of the machine bed, the mathematical model determines the stiffness and damping along the X-, Y-, and Z-axis between the bed and the ground. The frequency response curves simulated by using the mathematical model are compared with that of the measured ones. From the results of the experiments and simulations, it is confirmed that the vibration generated during high-speed tracking motions can be reduced by using the proposed machine bed with a sliding surface.

*Int. J. Automation Technol.*, Vol.10, No.3, pp. 447-454, 2016.

- [1] E. I. Rivin, “Vibration isolation of precision equipment,” Precis Engineering, pp. 41-56, 1995.
- [2] K. Yoshida, H. Shimura, H. Yahagi, and J. Yoshioka, “Effects of mounting conditions of surface gridding machines upon their rocking mode vibrations,” Proc. 6
^{th}I.C.P.E, p. 477, 1995. - [3] D. Huo, K, Cheng, and F. Wardle, “A holistic integrated dynamic design and modeling approach applied to the development of ultraprecision micro milling machine,” Int. J. of Machine Tools & Manufacture, Vol.50, pp. 335-343, 2010.
- [4] Z. Yu, K. Nakamoto, T, Ishida, and Y, Takeuchi, “Interactive design assistance system of machine tool structure in conceptual and fundamental design stage,” Int. J. of Automation Technology, Vol.4, pp. 303-311, 2010.
- [5] B. Li, J. Hong, and Z. Liu, “Stiffness design of machine tool structures by a biologically inspired topology optimization method,” Int. J. of Machine Tools & Manufacture, Vol.84, pp. 33-44, 2014.
- [6] D. Kono, Y Inagaki, and A. Matsubara, “Influence of contact stiffness on support stiffness of machine tool,” Proc. of 2011 Autumn Meeting of the Japan Society for Precision Engineering, pp. 413-414, 2011 (in Japanese).
- [7] D. Kono, Y. Inagaki, A. Matsubara, and I. Yamaji, “A study on estimation of the support stiffness of machine tools,” Proc. of 2012 Spring Meeting of the J. of The Japan Society for Precision Engineering, pp. 351-452, 2012 (in Japanese).
- [8] D. Kono, S. Nishino, I. Yamaji, and A. Matsubara, “A method for stiffness tuning of machine tool support considering contact stiffness,” Int. J. of Machine Tools & Manufacture, Vol.90, pp. 50-59, 2015.
- [9] K. Mori, D. Kono, I. Yamaji, and A. Matsubara, “Support placement for machine tools using stiffness model,” Int. J. of Automation Technology, Vol.9, pp. 680-688, 2015.
- [10] K. Yoshida, H. Shimura, H. Yahagi, and J. Yoshioka, “Effects of mounting elements of surface grinding machines upon their relative receptances between grinding wheel and work table,” J. Mech. Working Technol., Vol.17, pp. 377-386, 1988.
- [11] D. B. DeBra, “Vibration isolation of precision machine tools and instruments,” Annals of the CIRP, Vol.41, pp. 711-718, 1992.
- [12] Y. Altintas, C. Brecher, M. Weck, and S. Witt, “Virtual machine tool,” Annals of CIRP, Vol.54, pp. 115-138, 2005.
- [13] M. Law, Y. Altintas, and A. Srikantha Phani, “Rapid evaluation and optimization of machine tools with position-dependent stability,” Int. J. of Machine Tools & Manufacture, Vol.68, pp. 81-90, 2013.
- [14] D. H. Lee, M. Y. Yang, C. W. Oh, T. W. Gim, and Y. J. Ha, “An integrated prediction model including the cutting process for virtual product development of machine tools,” Int. J. of Machine Tools & Manufacture, Vol.90, pp. 29-43, 2015.
- [15] G. Bianchi, S. Cagna, N. Cau, and F. Paolucci, “Analysis of vibration damping in machine tools,” Procedia CIRP, Vol.21, pp. 367-372, 2014.
- [16] M. Nakaminami, T. Tokuma, T. Moriwaki, and K. Nakamoto, “Optimal structure design methodology for compound multiaxis machine tools – I,” Int. J. of Automation Technology, Vol.1, pp. 78-86, 2007.
- [17] M. Nakaminami, T. Tokuma, K. Matsumoto, S. Sakashita, T. Moriwaki, and K. Nakamoto, “Optimal structure design methodology for compound multiaxis machine tools – II,” Int. J. of Automation Technology, Vol.1, pp. 87-93, 2007.
- [18] A. Scippa, N. Grossi, and G. campatelli, “Milling surface generation model for chip thickness detection in peripheral milling,” Procedia CIRP, Vol.8, pp. 450-455, 2013.
- [19] K. Mori, D. Kono, I. Yamaji, and A. Matsubara, “Additional damper mounts for machine tool to reduce rocking vibration,” Proc. of the 8
^{th}LEM21, A05, 2015. - [20] Y. Takasuka, Y. Shirahama, R. Sato, and K. Shirase, “State space equation model of NC machine tool with torsional bed and feed drive systems,” Proc. of ICSV22, No.457, 2015.
- [21] R. Sato, G. Tashiro, and K. Shirase, “Analysis of coupled vibration between feed drive systems and machine tool structure,” Int. J. of Automation Technology, Vol.9, pp. 689-697, 2015.
- [22] Y. Furukawa, M. Miaukane, and S. Shiozaki, “An analysis of dynamic performance of Half-floating slideways and its application to machine-tool feed drive systems,” Annals of the CIRP, Vol.27, No.1, pp. 295-299, 1978.
- [23] S. Kaneko, R. Sato, and M. Tsutsumi, “Mathematical model of linear motor stage with non-linear friction characteristics,” J. of Advanced Mechanical Design, Systems, and Manufacturing, Vol.2, No.4, pp. 675-684, 2008.

This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.