Abstract:

The CNC machining of molds and various 3D parts involves numerous pocket features, and the design of machining toolpaths directly affects machining quality and efficiency. With advancements in high-speed milling technology, CNC machines provide the hardware foundation for improving pocket machining efficiency, but they also place higher demands on CAM toolpath design. Traditional CAM toolpaths tend to cause abrupt changes in cutting load when dealing with areas such as pocket corners, slots, and intersections of circular paths. This load instability limits the improvement of feed rate and cutting depth, negatively impacting both machining efficiency and quality. To address these issues, this paper proposes a combined toolpath design and optimization method aimed at achieving constant load machining for pockets. The method is based on a multi-level block structure, first calculating the material removal rate (MRR) and then dividing the machining areas into stable, semi-stable, and load fluctuation regions. Different strategies are applied to each region, including circular toolpaths, feed speed optimization, and variable-radius trochoidal paths, to ensure smooth load control throughout the machining process.By applying trochoidal paths in areas prone to load fluctuations, the method reduces sudden load variations and ensures the stability of the machining process. Experimental results show that the proposed design and optimization method is suitable for generating CAM toolpaths for various complex pockets, ensuring load stability and improving machining quality.

Key words: complex cavity, constant load machining, machining trajectory, feed rate optimization