Constant Engagement Tool Path Generation to Enhance Machining Accuracy in End Milling(Precision positioning and control technology)

Abstract

During end milling with contour-parallel (CP) offset tool paths, the tool experiences a varying engagement with the workpiece, which leads to a variation in cutting forces. In a finishing process, such variation of cutting forces causes the degradation of machining accuracy and surface finish. Presented in this paper is to propose an algorithm to generate a new offset tool path generation scheme, which regulates a constant cutting engagement with workpiece in 2.5D end milling. By maintaining cutting engagement constant, the cutting force can be regulated approximately constant, thus minimizing the variation of tool deflection, and improving machining accuracy. The validity of the proposed tool path generation scheme is realized experimentally when is applied to a semi-finishing path in pocket milling. Potential benefits revealed from the experimental results include far less variation of cutting forces, and consequently enhanced machining accuracy without increasing the machining time.