Toolpath Generation Based on Mathematical Algorithms with Shape Simulation for Mold Machining

Owing to the shortening of product life cycles and the diversification of consumer needs, the mold industry is also facing increasing demands for shorter lead times, higher quality, and lower costs in mold manufacturing. To meet these demands, automation, high-precision, and high-efficiency technologies in both the pre-processing and post-processing of mold machining are essential. This study proposes and develops a system that includes solution methods of the mathematical Traveling Salesman Problem (TSP) to generate toolpaths with suppressed redundant motions from standard triangulated language (STL)-format computer-aided design (CAD) models, which represent the surface of a three-dimensional shape as a set of triangular meshes and are independent of the type of CAD software, as input data. In the proposed system, a dexel-based workpiece simulation is conducted in parallel with toolpath analysis to identify unmachined regions remaining after pre-machining processes. By detecting these remaining removal regions and calculating efficient paths based on the TSP, the system can output toolpaths from which idle tool motions without cutting have been reduced. To verify the effectiveness of the system, two case studies are conducted using two mold CAD models. The results of the case studies show that toolpaths for both mold models are automatically generated from their STL-format CAD models. The generated toolpaths are then used for actual machining, and the results confirm that the molds have been successfully machined without any critical issues.