Generating HSM-adapted pocketing tool path by region subdivision

Abstract

High-speed machining (HSM) is an effective manufacturing process to produce parts. In HSM, it is required that the tool path should be smooth and the material removal rate should be constant. However, in geometry, it is nearly impossible to cover an arbitrary pocket with a single form of curves that satisfy both the above two requirements. In this paper, a compromise is made by subdividing the pocket into two kinds of regions: the HSM regions and the low-speed machining (LSM) regions. The HSM regions are selected to be the maximum inscribed circles (MICs) of the pocket. These MICs are calculated in an offset manner. Inside each HSM region, successive concentric circles are filled. The radii of the circles are controlled so that the material removal rate remains constant. The obtained concentric circles are then smoothly linked with pairs of arcs and used as the HSM tool path. For the rest LSM regions, conventional contour parallel tool paths are filled and low cutting speed is applied considering that there might be sharp angles on the pocket boundary. As the HSM regions could take up to 50% of the whole pocket and the cutting speed in HSM regions can be set very high, the average cutting speed for the whole pocket can be enhanced. Several pocket examples are used to verify the feasibility of the proposed HSM tool path generation method.