复杂曲面电解加工阴极空间进给方向优化方法研究

Research on Optimization Method of Cathode Spatial Feeding Direction in ECM of Complex Curved Surface

电解加工是航空发动机叶片、整体叶盘等复杂曲面零件的核心制造技术。阴极空间进给方向与阳极型面法线方向之间的θ角大小是影响电解加工精度的重要因素。传统阴极进给方向优化中,通常以θ角方差作为目标函数,在局部区域存在曲率突变的复杂曲面优化时,局部区域θ角仍可能较大,存在一定局限性。为了使全型面θ角最小,提出了以θ角集合最大夹角值为目标函数的优化新方法。以典型复杂曲面叶片为例,采用传统与提出方法分别开展进给方向优化,优化结果表明提出方法获得了合理的θ角分布。开展了两种优化方法的加工比较试验,提出方法试验样件具有更优的型面轮廓精度,证明了优化方法的可行性。

Electrochemical machining( ECM) is one of the main technologies to produce complex curved surface part,such as blade and blisk. The θ angles,which between the feeding direction and the workpiece surface normal directions,is a critical factor affecting the ECM processing accuracy. The traditional method is to use the variance of θ angles as the objective function. In the optimization of complex curved surface with curvature mutation,the traditional method is limited. In order to reduce the θ angles on whole curved surface,a novel optimization method of tool spatial feeding direction evaluated by the maximum θ angle was proposed. Taking blade complex parts as example,the optimization experiment was carried out with the traditional and novel method. The results revealed that the θ angle distribution was more uniform with new optimization method. Based on the best spatial feeding directions of traditional and novel optimization method,the processing experiment of ECM blades was carried out.The present result shows that the specimen with novel optimization method has better contour accuracy. The feasibility of optimization method has been proved.