2009 年 75 巻 10 号 p. 1216-1221
In milling with ball end mills of inclined surface, geometric quantities such as contact region between the cutting edge and the workpiece surface, undeformed chip thickness along the cutting edge and area of cutting cross-section vary with feed direction of the tool, so cutting forces and chip formation change with tool path. In the first and second parts of this investigation, to predict cutting forces and chip formation in milling for various tool paths, a cutting model proposed in previous paper was extended to the milling process in which both cutting edges of sphere and cylindrical portions engage with the workpiece. It was shown that the cutting forces and the chip formation in upward or downward milling for inclined surface can be predicted by using the developed cutting model and energy method. In this paper, the cutting model is applied to the milling process with pick-feed, and three components of the cutting force and the chip formation under various pick-feeds are predicted. It is shown that the tendency of variation of the cutting forces and the chip formation with tool rotational angle considerably changes by given direction of pick-feed, furthermore in the milling process for the tool moving downward on the inclined surface, interrupted cutting or continuous cutting takes place with magnitudes of pick-feed. Predicted results of the cutting forces are good agreement with experimental results.