Hybrid Toolpath Planning and Feed Rate Optimization for Cavity Machining Under Constant Loads

doi:10.12141/j.issn.1000-565X.240467

Abstract

Abstract:

The CNC machining of molds and various 3D parts involves numerous cavity features, and the design of machining toolpaths directly affects machining quality and efficiency. With the advancements in high-speed milling technology, CNC machines provide the hardware foundation for improving cavity 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 cavity 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 hybrid toolpath planning and feed rate optimization method aiming at achieving constant load machining for cavities. The method, which is based on a multi-level block structure, first calculates the material removal rate and then divides the machining areas into stable, semi-stable and load fluctuation regions. For different regions, circular toolpaths, feed speed optimization and variable-radius trochoidal paths are comprehensively adopted to ensure smooth load control throughout the machining process. By applying trochoidal paths in areas prone to load fluctuations, sudden load variations can be reduced and stable machining process can be ensured. Experimental results show that the proposed toolpath planning and feed rate optimization method is suitable for generating CAM toolpaths for various complex cavities, with good load stability and better machining quality.

Key words: complex cavity, numerical control machining, constant load machining, machining toolpath, feed rate optimization

CLC Number:

TP391.73

WANG Qinghui, WANG Jinqiang, DING Xuesong, LIAO Zhaoyang. Hybrid Toolpath Planning and Feed Rate Optimization for Cavity Machining Under Constant Loads[J]. Journal of South China University of Technology(Natural Science Edition), 2025, 53(5): 1-10.

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轨迹类型	加工时间/s	最大MRR/（mm³·s^-1）
SIMENS NX生成的轨迹	2 084	8.54
文中轨迹	1 772	3.33

性能参数	参数值		提高率/%
性能参数	SIMENS NX 生成的轨迹	文中方法生成的轨迹	提高率/%
加工时间/s	2 084	1 774	14.88
轨迹长度/mm	3 474	2 723	21.62
最大切削力/N	174.5	137.8	21.03