微小叶轮精加工轨迹多目标优化方法研究

Research on multi-objective optimization Method for small impeller finishing trajectory

微小叶轮作为微型发动机的重要组成部分,其加工质量将直接影响到发动机的整体性能。在讨论了加工过程中需要克服一般整体叶轮叶片扭曲严重且为自由曲面、流道狭窄容易撞刀等共同难点外,加上其整体尺寸的缩小将使加工表面质量更加难以保证,从而提出了一种针对微小叶轮的刀具轨迹规划及精加工轨迹优化方法。即首先确定了以效率为主的粗加工轨迹规划和在保证质量基础上的精加工轨迹规划目标,运用仿真软件保证刀具轨迹无撞刀、干涉的情况下,其次对精加工刀具轨迹参数进行了以表面残留高度最小的优化目标,运用双因素方差分析法确定影响表面质量的主要因素为走刀步长,最后通过图表的形式分析走刀步长对叶片和轮毂表面质量的影响规律,从而得到了一套完整的保证微小叶轮加工效率和整体表面质量的加工方法,对实际加工有一定的指导意义。

The tiny impeller is an important part of the micro-engine,and its processing quality will directly affect the overall performance of the engine.In the process of processing,it is necessary to overcome the common difficulties of the general impeller blade and the common difficulty of free-form surface,narrow flow path and easy collision.The reduction of the overall size will make the quality of the machined surface more difficult to guarantee.Therefore,a tool path planning and finishing trajectory optimization method for micro impellers is proposed.Firstly,the rough machining trajectory planning based on efficiency and the finishing trajectory planning target based on the quality assurance are determined.The simulation software is used to ensure that the tool trajectory has no collision and interference.Secondly,the optimization target of the finishing tool trajectory parameters is minimized with the minimum surface residual height.The main factor affecting the surface quality is the step size by the two-way ANOVA.Finally,the influence of the step size on the surface quality of the blade and the hub is analyzed by the form of a graph.A complete set of processing methods to ensure the processing efficiency and overall surface quality of the micro impeller has obtained a certain guiding significance for the actual processing.