Research On Springback Control And Die-face Compensation Technology Of Vehicle Exterior Panels

Spring back is a common phenomenon in the forming process of sheet metal. Spring back influences the shape and dimension error of stamping parts, which causes the following problems of quality and assemble. Recently, high strength light steel sheet and alufer sheet have a widely application in car body manufacture, it makes spring back more outstanding. Compared with Internal plate, outer plate stamping products should not only satisfy the tolerance requirements but also the requirments of fairing、streamline、outer convex and well-regulated reflection appearance.When high light evaluate outer plate surface that after compensation, brightening curve must have a common curvature feature, which contour is continuous and uniform transition, gradually.divergence or contract other than together disappeared to a point at a draught. In addition, the surface should satisfy other requirements of A-level surface, so outer plate has great difficulty in stamping spring back control and spring back compensation.The traditional spring back control uses method of trial and error, which wastes a lot of time and money, and this method is used in simple shape and common material panel, it depends more on operator’s experience and skills, which leads long development period and confines the development of mold industry. With the constant perfection of plastoelasticity, through analysising the main reason of spring back, combining numerical simulation technology with optimization technique to control spring back which has been a effective method.This paper mainly studies the influence of a rebound in the main factors, including design variables and noise variable. Through the Autoform own Sigma module to springback do sensitivity analysis, this paper summarizes the key factors affect the resilience, which can be used as the subsequent optimization design variables. By determining the springback evaluation function and constraint conditions,the super Latin square sample drawn, structure reasonable rebound process control approximation model, and use genetic algorithm to optimize the engine cover plate of the springback problem.But for springback process control and optimization and can’t eliminate fundamentally the rebound, rebound after optimization may beyond product tolerance requirements, so need to forming type surface do the springback compensation. Based on the full process simulation technology and geometric displacement compensation principle of drawing model surface and trimming model surface are global the springback compensation, and to repair edge and the corresponding compensation, which greatly improve the dimension precision of products and the stability of the forming process. In addition to the springback compensation after the type surface do A level surface quality testing, the results show that after the compensation of type surface basic meet A level surface requirement, if not satisfied, then continue in CATIA do follow-up A surface treatment.The spring back method in this paper has been applied in practical production, and the product has good effect. It has an important application value in shortening the mould development period and improving the quality of product.