Research On Algorithm Of Polishing Path Planning Process For Blade Surface

Blades are important core parts of aircraft engine, machining precision and machining quality of which have important effects for the overall performance of the aircraft engine. The processing of polishing blade is difficult, which result in the blade’s surface is complex and diverse. At present, the free-form surface(such as blade)modeling technology is mature, however, such a complex curved surface processing technology development slightly behind. As the connector between free curved surface design and programming of multi-axis linkage of the polishing surface, research on algorithm of polishing path planning for blade surface, to improve the precision machining technology,which provide resource power for the development of our country aerospace enterprise and machinery manufacturing industry.In this paper, we deal with the point cloud data collected on the blade surface by reverse engineering software, and reconstruct triangular mesh model of blade. In order to solve the contradictions of model accuracy and file size effectively, this paper proposes a local precision compensation algorithm, simultaneously improves the computational efficiency of blade section contour curve. Reconstructing the topology of the optimized model file, this paper cites the grouping sorting and hierarchical algorithm for edge intersection, by adjusting the two to intercept direction for horizontal, vertical blade section contour curve.Analyzing the topology of free-form surface machining tool path, we provide the two processing strategies, both rotary polishing method and secondary fragmentation polishing method. Rotary polishing method is based on three uniform B-spline smoothing curve fitting theory, by using the transverse section points as control vertices. After analyzing curvature of the curve, we adopting equal chord deviation algorithm to discrete it. According to obtain the polishing contact points and cutter axis vector, the paper through side-milling tool location computing to get ideal cutter location points. In the analysis of blade geometry features, we divide the polishing area into four patches, namely the suction surface, the pressure surface, the leading and trailing edge surfaces, and subdivide the polishing processing path. For small curvature surface, which consist of the suction surface and the pressure surface, we get polishing track by screening both horizontal and vertical selection cutting points before connecting them. In view of large curvature surface, including the leading and trailing edge surfaces, we reconstruct parametric surface and quadratic programming processing.For multi-axis linkage blade grinding &polishing machine(B-A structure), we set up machine kinematics model and inverse kinematic solution of each shaft of machine tool when polishing blade. The paper solve the problem of consistency, continuity of the polishing track processing direction, finally accomplish machining simulation by using VERICUT.