关键词: 参数映射, 叶轮流道, 椭圆摆线, 刀具轨迹优化, 走刀路径

Abstract: In order to improve the opening groove processing efficiency of complex curved blade passages, a cycloid tool path planning method for surface rough machining was proposed. Firstly, the processable area of the passages was parameterized. Then, a mathematical model of key parameters for elliptical cycloid tool path, with the optimization goal of minimizing machining time, was established in the parameter domain. The best short-axis length of the ellipse and the cycloid step that satisfied the machining requirements were solved by the interval narrowing method, then the cycloid tool path could be determined in the parameter domain accordingly. Afterwards, the trajectory of the parameter domain was mapped to the physical domain to obtain the cutting path. Finally, the efficiency of the proposed trajectory planning method was evaluated with an example of calculation of elliptical cycloidal open rough machining trajectory for an impeller, whose calculation time is 19.4% faster than the traditional line cutting method. In addition, the simulation results of cycloidal channel opening and line cutting show that the machining efficiency of the proposed method is 22.4% higher than that of the traditional line cutting method under the same parameter setting. The practical results of cycloidal milling show that the shape of impeller runner cut is consistent with the cycloidal track, whose surface residue meets the rough machining requirements. This paper provides a new trajectory planning method for rough machining of impeller flow channels to improve the machining efficiency, which is a substitution for the traditional line cutting method. 

Key words: parameter mapping, impeller channel, elliptical cycloid, tool path optimization, cutting path