Incremental sheet punching on the base of sinusoidal tool path

Abstract

To carry out incremental sheet-punching process without adding any additional device on a common numerical control machine or a specialized incremental sheet-forming machine, a method was proposed by modifying the tool path generated by commercial CAD/CAM software. The method consists of a few steps: generating the tool path for the three dimensions model of the desired part, exporting the tool path as dispersed points, interpolating the tool points with liner polynomial, modifying the tool points to sinusoid in the vertical direction to the clamped sheet, exporting the new sinusoidal tool path, etc. Different geometries were formed using two kinds of sheets, non-perforated sheet and perforated sheet, to determine the feasibility of the method. Furthermore, the effects of the wavelength and the amplitude of the sinusoidal tool path on material formability and surface quality of the formed sheet were analyzed on the basis of forming truncated funnels and pyramids. The results show that it is feasible to form both non-perforated sheet and perforated sheet by the proposed method. Additionally, they show that the wavelength has obvious influence on material formability and surface quality while the amplitude only influences material formability significantly.