An Approach to Strip-maximization Machining Based on Tolerance Constraints for Sculptured Surfaces

Abstract

To improve the efficiency of complex surfaces machining with toroidal tools,an approach about the tool path planning of strip-maximization machining is proposed by combining with the design tolerance zone.According to second-order Taylor approximation method,the strip width within the entire tool path is calculated,and then its adjustability is assessed based on the predefined strip-width-ratio threshold.For these adjustable tool path,the cutting contact points(CCPs) which decrease the strip width are analyzed.Each point of them is transformed into another actual CCP with a reasonable translation distance along the normal vector on the corresponding surface,where the value is in the constraints of tolerance zone.Thus the optimal strip-width is obtained.The influence analysis of strip-width from surface characteristic indicates that the theory based on the tolerance constraints is versatile.Example shows that the strip-width calculated by the proposed method is significantly expanded by 26.5%,comparing to second-order Taylor approximation method.Meanwhile,the length of the CCPs path is shortened by 22.7%.Therefore,the simulation result verifies the effectiveness in the complex surface machining with toroidal cutters.