Machining, Measurement, and Control Laboratory

Cutting Process Design for Minimizing Workpiece Displacement at Cutting Point

Yusuke KOIKE, Atsushi MATSUBARA, Shinji NISHIWAKI, Kazuhiro IZUI and Iwao YAMAJI

Vibrations of a tool or a workpiece in cutting shorten tool life and deteriorate a surface roughness. In this research, we propose a method to reduce vibrations of the workpiece at a cutting point. An algorithm that generates a cutting path to minimize workpiece displacements at a cutting point is developed. In this algorithm, the cutting path is generated with changing feed directions, tool posture and material removal process by considering workpiece compliance matrices and cutting force vectors. Feed directions and tool posture are changed to control the direction of the cutting force vector. Material removal process is changed to control the change of the workpiece compliance. FEM (Finite Element Method) is used to calculate workpiece compliance matrices. SVD (Singular Value Decomposition) is used to calculate the direction which has the lowest compliance in the workpiece compliance matrices. Minimum workpiece displacement at a cutting point is calculated from these calculated results. The algorithm is applied to the cutting path of end milling for a simple bar and the cutting path is compared with two conventional cutting paths by conducting a simulation and a cutting test. As a result, mean values of workpiece displacement were reduced by applying the algorithm.
Key Words:   cutting path, workpiece displacement, compliance, FEM, SVD, end mill