精密展成电解加工整体叶轮的展成运动轨迹确定

Determination of Tool-cathode Movement Path of Precision Electrochemical Contour Evolution Machining of Integral Impeller

介绍了以四轴联动方式精密展成电解加工直纹面叶型整体叶轮叶片型面时,叶片型面的拟合方法、展成运动的组成以及展成运动轨迹的计算方法。结合实际加工工艺,考虑加工间隙变化情况、工具阴极加工刃边宽度影响以及叶片表面形状影响等因素,对展成运动轨迹的修正算法进行了研究,并对某小型整体叶轮叶片型面进行了加工试验。加工后的叶片型面,其各给定截面内的叶片型线误差小于0.1mm,表面粗糙度Ra小于0.8μm。

The fitting of ruled surface blade profile, the components of contour evolution move ment and the computation of contour evolution movement path were introduced in the case of precision electrochemical contour evolution machining of ruled surface integral impellers. According to actual machining conditions, considering the variations of inter electrode gap, the width of tool-cathode＇s working edge as well as the shape of blade profile, a modified algorithm of tool-cathode movement path was studied, and corresponding methods were presented. Experiments for machining one kind of small sized integral impeller＇s blade profile by means of the kind of new tool--cathode with rectangle section were carried out. For the machined blade profile, the contour errors in every given section are less than 0. 1mm, and the surface roughness is less than 0.8μm.