Research On Model Reconstruction Technology In Adaptive Machining Of Hollow Blade

Wide chord hollow fan blade is one of the important parts of the turbofan engine,its quality directly affects the performance of the engine.At present,the wide chord hollow fan blades are made by super plastic forming/diffusion bonding(SPF/DB)and machining.When they are machined,there are some problems,such as blank being personalized,allowance being uneven,and internal shape restricting machining of outside shape.Adaptive processing technology is the effective method to solve these problems.In the process of machining hollow blades,the part model usually can not match with its blank.So this thesis researches the model matching technology in the process of adaptive machining.The main work is listed as followed:(1)The technology of measuring the shape and wall thickness of the wide chord hollow fan blade is studied.This paper introduces the method of measuring the shape and the wall thickness of the wide chord hollow fan blade,and presents the method of the probe radius compensation and the normal direction alignment.(2)The model reconstruction method is proposed based on the measured data.Based on the structural point data,the NURBS surface interpolation technique is studied,and the blade model is established.Based on scattered point data,a triangular mesh reconstruction method is studied.(3)A modified method of hollow blade model is put forward.In view of the mismatch between the part model and the blank in the NC machining of hollow blade,the free deformation of the point model is studied,and the blade machining model is modified.(4)On the basis of the theoretical algorithm proposed in this paper,the adaptive numerical control machining of the hollow blade is carried out,and the blade edge is processed successfully.