The Research Of Tool-path Planning For Flank Milling Of Impeller Surface

Impeller is typical representative of complex parts, which is efficient"heart"part of compressors, blowers and other fluid mechanical and is represents of in actual production. The complexity of impeller machining mainly shows in its leaves which is usually intractable ruled surface. And it is called "difficulty" in the machining. There is principle error in the flank machining for the blade surface.therefore, how to perform tool path planning, decrease the machining error in order to approximate the blade surface furthest which is valuable and significant research topic.Firstly, previous research started by our group, such as theoretical methods and results involved in the geometric modeling and solid modeling of leaf surface, the initial tool-path planning of cylindrical cutter is summarized. which is foundation of the later work in this paper.Secondly, based on previous studies, this paper focuses on planning issues and calculation of cylindrical cutter knife. the initial cutter shaft track surface is given by means of two-point offsetting. By the thinking that some points in the cutter shaft track surface approximate the blade surface, the overdetermined equation is established between the cutter shaft track surface and the offset surface of the blade surface by selecting some points of the initial cutter shaft track surface, which is solved using least square method, the result of tool path optimization and the envelope error is given, and comparison of the machining error for tool path optimization is also given.Finally, the tool path planning of coned cutter for side milling of the blade surface is studied, the generation method of the generating tool axis vector and cone knife surface equation. Based on the conjugate surface of the digital simulation method, The benchmarking length is used to describe the machining error based on the theory of conjugate surface. based on the calculated results, the position of the generating tool axis is optimized, the approximation error optimized of the cutter envelope surface is shown finally.