A novel method for trochoidal milling tool path tailoring based on curvature variation

Abstract

Trochoidal milling has gained popularity in high-speed milling owing to its ability to reduce cutting force, accelerate thermal dissipation, and increase tool life. Nevertheless, it has the drawbacks of poor cutting efficiency and longer machining time due to decreased cutter-workpiece engagement (CWE). This paper studied the tailoring of trochoidal milling tool path curves subjected to improve machining efficiency by controlling curvature variation while meeting predefined CWE angle criteria. The relationship between the instantaneous CWE angle and the curvature variation of the tool path curve was quantitatively established. Then, a negative exponential function-based governing function was introduced to regulate the curvature variation. Finally, the proposed method was experimentally validated via trochoidal milling of curved slots by evaluating machining efficiency and surface quality. The results showed that compared with the circular, elliptical, and polynomial tool path, the tailored tool path-related average CWE angle increased by 40.5 %, 17.9 %, and 6.3 %; while the machining efficiency improved by 25 %, 16 %, and 14 %, respectively. Although the surface quality (surface roughness varies within 5 % and flatness raised by 27 %) is worse than that of the other three tool path patterns, benefiting from the highly improved machining efficiency, it is still applicable in high-efficiency rough milling of components.