Machining, Measurement, and Control Laboratory

Advanced Feed Forward Control for Constant Cutting Forces in Die Machining
Hirotshi Otsuka (Oita Industrial Research Institute)
Iwao Yamaji (Kyoto University)
Yoshiaki Kakino (Kyoto University)
Atsushi Matsubara (Kyoto University)
Tetsufumi Ito (Graphic Products, Inc.)
Yukitoshi Ihara (Osaka Institute of Technology)

In this paper, the proposed quadratic model of cutting forces during endmilling of hardened steel is verified for its general usefulness by applying this model to more extreme cutting conditions and other applications. Cutting conditions discussed here include concave contour cutting with a smaller radius than that of the end mill. For this purpose, the operability region by two variables of the arc length of cutting engagement and the maximum undeformed chip thickness is divided into some sub-regions of interest which correspond geometrically to the cutting conditions. The control of cutting forces in concave and convex contour endmilling using quadratic polynomials obtained based on response surface methodology was fairly effective. Furthermore, this mathematical model was applied for the case of general problems such as profile endmilling and trochoid tool path endmilling where the cutting force changes rapidly with successive change of geometrical conditions. It was found that the prediction and control of cutting forces was also possible for these problems.

Keywords:   Endmilling, hardened steel for die and mold, cutting force control, response surface methodology