Micro-End-Milling with Small Diameter Left Hand Helical Tool for High Quality Vertical Wall Machining
Keiji Ogawa*1,, Takumi Imada*2, Haruki Kino*3, Heisaburo Nakagawa*4, and Hitomi Kojima*5
1-5 Yokotani, Seta Oe-cho, Otsu-shi, Shiga 520-2194, Japan
*2Industrial Research Center of Shiga Prefecture, Ritto, Japan
*3Mitsubishi Hitachi Tool Engineering, Ltd., Tokyo, Japan
*4Nakagawa Machining R&D Center, Wakayama, Japan
*5Big Daishowa Seiki Co., Ltd., Higashiosaka, Japan
The demand for micro-end-milling for products in fields such as the medical, optical, and electronics industry is increasing. However, when machining with a small diameter end-mill (micro-end-mill) with diameters such as 0.5 mm, the rigidity of the tool itself is low; hence, the cutting conditions must be set to low values to achieve stable machining. Therefore, we examined various cutting phenomena that occur during actual machining processes to achieve high machining accuracy, high finished-surface quality, and long tool life. Some studies on micromachining achieved high accuracy, high-grade machining by considering the cutting phenomena. In previous papers, we dealt with the side-cutting phenomena in micro-end-milling of hardened die steels using a high-speed air-turbine spindle with rolling bearing. Cutting experiments were carried out by measuring the cutting force and flank wear of a cutting tool to investigate the difference in cutting phenomena caused by cutting direction in high-speed micro-end-milling. Observation of the machined surface and measurement of the profile of the cutting edge and machined surface were demonstrated. It was revealed that machining quality in high-speed up-cut milling was better than that in down-cut milling. Shoulder cutting, in which both peripheral and bottom cutting edges act simultaneously on the workpiece, was also investigated. A novel small diameter end-mill with left-hand helical tool with right-hand cut was developed to avoid damaging the cutting edge in the initial cutting stage. In the present study, high-quality shoulder cutting of a vertical wall using the new tool was proposed and demonstrated.
-  D. Goto, Y. Maeda, H. Tanaka, K. Kato, and T. Yazawa, “Influence of Tool Run-Out on Machining Accuracy with Multi-Tooth Endmill,” Int. J. Automation Technol., Vol.10, No.5, pp. 759-766, 2016.
-  H. Shibahara, M. Kumagai, S. Kohda, and K. Okuda, “An approach for improvement of machining accuracy in micro end milling.” Adv. Mat. Res., Vols.76-78, pp. 514-519, 2009.
-  M. Masuda, W. Takahashi, O. Horiuchi, T. Shibata, and Y. Murakami, “Investigation on Profile Errors of Groove Cross-section in Micro end Milling,” J. Jpn. Soc. Prec. Eng., Vol.79, No.4, pp. 361-367, 2013 (in Japanese).
-  W. Chen, D. Huo, X. Teng, and Y. Sun, “Surface Generation Modelling for Micro end Milling Considering the Minimum Chip Thickness and Tool Runout,” Procedia CIRP, Vol.58, pp. 364-369, 2017.
-  H. Ding, N. Shen, and Y. Shin, “Experimental Evaluation and Modeling Analysis of Micromilling of Hardened H13 Tool Steel,” J. of Manufacturing Science and Engineering, Vol.133, 041007, 2011.
-  X. Zhang, K. Ehmann, T. Yu, and W. Wang, “Cutting forces in micro-end-milling processes,” Int. J. of Mach. Tools and Manuf., Vol.107, pp. 21-40, 2016.
-  J. Liu, J. Li, and C. Xu, “Cutting Force Prediction on Micromilling Magnesium Metal Matrix Composites With Nanoreinforcements,” J. Micro Nano-Manuf., Vol.1, No.1, 011010, 2013.
-  E. Yı lmaz, E. Budak, and H. Özgüven, “Modeling and Measurement of Micro End Mill Dynamics using Inverse Stability Approach,” Procedia CIRP, Vol.46, pp. 242-245, 2016.
-  X. Jin and Y. Altintas, “Chatter Stability Model of Micro-Milling with Process Damping,” J. of Manuf. Sci. and Eng., Vol.135, No.3, 031011, 2013.
-  S. M. Afazov, D. Zdebski, S. M. Ratchev, J. Segal, and S. Liu, “Effects of micro-milling conditions on the cutting forces and process stability,” J. of Mat. Proc. Tech., Vol.213, No.5, pp. 671-684, 2013.
-  S. Filiz and O. Burak Ozdoganlar, “Microendmill Dynamics Including the Actual Fluted Geometry and Setup Errors – Part I: Model Development and Numerical Solution,” J. of Manuf. Sci. Eng., Vol.130, 031119, 2008.
-  I. Takahashi, M. Anzai, and T. Nakagawa, “Tool Wear Characteristics of Small Diameter Ball End Mill on Ultra High Speed Milling at 100000min-1 Rotation Speed,” J. Jpn. Soc. Prec. Eng., Vol.65, No.6, pp. 867-871, 1999 (in Japanese).
-  O. Horiuchi, B. X. Ma, M. Nomura, T. Shibata, Y. Murakami, M. Masuda, Y. Murakami, and M. Masuda, “Study on Tool Life by Breakage in Micro Endmilling,” Adv. Mat. Res., Vols.126-128, pp. 214-219, 2010.
-  N. Kawasegi, H. Sugimori, N. Morita, and T. Sekiguchi, “Improvement of Machining Performance of Small-Diameter End Mill by Means of Micro- and Nanometer-Scale Textures,” Int. J. Automation Technol., Vol.10, No.6, pp. 882-890, 2016.
-  A. A. Ramcharoen, P. T. Mativenga, S. Yang, K. E. Cooke, and D. G. Teer, “Evaluation and selection of hard coatings for micro milling of hardened tool steel,” Int. J. of Mach. Tools and Manuf., Vol.48, No.14, pp. 1578-1584, 2008.
-  H. Kino, Y. Oda, T. Imada, H. Nakagawa, K. Ogawa, and H. Kojima, “Basic Study on Micro End-mill: Cutting Phenomena of Side Cutting,” J. of SME-Japan, Vol.3, pp. 6-10, 2014.
-  K. Ogawa, H. Kino, T. Imada, H. Nakagawa, and H. Kojima, “Experimental Investigations on Micro-End-Milling of Hardened Die Steel: Effects of High-Speed Cutting,” Proc. of ASPEN 2015, pp. 1-6, 2015.
-  H. Kino, K. Ogawa, H. Nakagawa, H. Kojima, and T. Imada, “A Fundamental Study of Cutting Phenomena in the Micro-end-milling process: In case of the side milling operation,” Proc. of ICPMT 2012, pp. 187-190, 2012.
-  K. Ogawa, H. Kino, T. Imada, H. Nakagawa, and H. Kojima, “Improvement of Micro-end-milling Quality by High-speed Up-cut Milling for Hardened Die Steel,” Proc. of ASPEN 2017, pp. 1-4, 2017.
-  T. Imada, K. Ogawa, H. Kino, H. Nakagawa, and H. Kojima, “Experimental investigations on micro-end-milling of hardened die steel: Fundamental phenomena in shoulder cutting,” Proc. of LEM21, pp. 1-6, 2015.