面向自适应加工的精锻叶片前后缘模型重构

针对精锻叶片前后缘数控加工在加工边界出现"台阶"等问题,提出面向自适应加工的模型重构方法。首先,根据精锻叶片的特点给出前后缘加工工艺方案。其次,根据工艺方案建立在机测量模型并进行路径规划。在此基础上,依据前后缘实际几何型面参数以及理论模型各截面前后缘圆弧圆心和半径允差,提出重构模型圆弧圆心及半径搜索算法;根据各截面的测量点拟合线、理论截面线以及搜索的圆弧圆心和半径,建立重构前后缘模型。最后,通过对比重构模型与理论模型的偏差以及数控加工试验证明该方法能够有效地减小锻造叶片叶身实际型面与前后缘在衔接处的"台阶"缺陷问题,为复合制造工艺背景下精锻叶片前后缘加工成型提供依据。

Model restructuring about leading edge and tailing edge of precision forging blade for adaptive machining

In order to solve the problems such as "steps" which are caused by precision forging NC machining of the leading edge and the tailing edge in machining boundary, the model reconstruction method of adaptive machining is proposed. Firstly, according to the characteristics of precision forging blades, the machining program of leading edge and tailing edge is put forward. Secondly, according to the machining program, on-machine measurement model and the path planning are proposed. On this basis, according to the actual geometrical parameters of the leading edge and the tailing edge, as well as the tolerance of the center of circle and arc radius in the leading edge and the tailing edge of the theoretical models, a search algorithm is put forward to ascertain a new arc radius and center of the circle of the reconstruction model. Besides, according to the fitting line of the measurement points in each cross section line, theoretical cross section line and the circular arc of the search center and radius,models of the leading edge and the tailing edge are reconstructed. Finally, by comparing the deviation between the reconstruction model and the theoretical model, and the NC machining test, the proposed method is proved to be efficient in weakening the adverse effect of the "steps" between the actual type surface of the forging blade and the leading edge and tailing edge. In addition, this method can also provide evidence for the machining forming in the leading edge and tailing edge of precision forging blade under the background of the composite manufacturing process.