Optimizing tool-path generation for three-axis machining of a sculptured impeller blade surface

Abstract

This paper presents an algorithm to optimize the tool-path generation for three-axis machining of a sculptured impeller blade surface. Owing to the specific character of the sculptured compressor impeller blade surface, four sub-surfaces are obtained by combining the steepest-ascent tool-path generation method with the specialty of the fluid flow in the duct composed by the blade surfaces. Slighter curvature and more efficient calculations are achieved on the four sub-surfaces compared with that on the entire sculptured blade surface. An optimizing algorithm is proposed to calculate the four tool sub-paths on the sub-surfaces, and efficient machining is achieved by using the efficient bull-nose-end mill. The global–local machining strategy is advanced by connecting the tool paths on the sub-surfaces and the different feed direction is proposed due to the up-milling method. The proposed three-axis machining optimizing algorithm achieves consummate equilibrium between the efficiency and aerodynamics, and significantly reduces the machining time and the machine cost compared with conventional five-axis machining. An example test mould and its practical machining are also presented in the paper.