Toolpath Regeneration in Subregional Contour-Parallel Processing Based on Isoscallop Method

Advanced manufacturing technologies have made great progress in the fields of aerospace, resources, and power, and the complex curved surface parts with local rapidly varied geometric feature are increasingly and widely used. On account of the complex geometric feature for this kind of parts, global processing technology cannot meet the requirements of high quality and high-efficiency processing, and the subregional processing method is used. However, the existing methods usually lead to bad machining quality at the boundary and are also prone to form obvious machined trace at the center of machining region in subregional processing. Hence, in this article, a subregional toolpath regeneration method for contour-parallel processing based on the isoscallop method is proposed. First, the initial toolpath generation is finished, which can ensure machining quality at the boundary. Then, establishing the arc length error calculation model for the innermost loop of toolpaths, the arc length error is averaged in the side-step direction and the feeding direction by modifying the cutter contact points. Finally, the toolpath regeneration is realized, which can reduce machined trace at the center of machining region. Experimental results show that with the proposed method, the profile arithmetic average error and the maximum of profile deviation decrease by 32.03% and 53.38%, respectively, at the innermost loop of toolpaths compared with the results of the conventional isoscallop method. For that, the proposed method can improve the machining quality effectively for complex curved surface in subregional contour-parallel processing.