Springback Analysis And Stamping Die Design Of Reinforcing Ring Of Automobile Skylight

The increasing environmental pollution and energy crisis has cropped up due to the rapid development of the auto-industry,coupled with the vehicle holdings year by year.In recognition of that fact,auto-industry has chosen to replace steel with high-strength steel to reduce body weight and exhaust emissions,with a view to mitigating the growing energy crisis and environmental pollution.Although high strength steel can effectively reduce body weight to a great extent,it also sparks new challenges.Because the hardening index of steel is lower than that of traditional steel,it is easy to crack in the course of manufacture.Moreover,the resilience value of panel veneer can be larger as higher yield strength of high strength steel.Given the high strength steel in the stamping planning stage and the die debugging stage of the time and debugging difficulty is much more than before,how to ensure a short time to design a reasonable stamping process is of great importance to the stamping parts manufacture.Taken reinforcing ring of auto skylight as the research object,applicable technology and technological parameter were discussed in line with the process parameters fluctuation in this paper.The reinforced ring of automobile skylight is a typical automobile covering piece,with large size,complex structure,large area hollowed area and so on,coupled with its difficult forming,it is easy cracking and springback,the following steps shall be conducted based on the above characteristics:(1)Taking the U-shaped parts as the object of study,the influence of different stamping process parameters on sheet metal forming was studied.With the draw beads,blank holder force,stamping speed,clearance between punch and die,and friction coefficient as the factors,an orthogonal test table was established to study the reduction rate and spring back of the sheet metal.And the influence of different process parameters on the outcome of sheet metal forming was analyzed by using the grey correlation analysis method.Then,the influence of different process parameters on sheet metal forming was obtained by the grey relation analysis method,which provides a reference for the following robust optimization of process parameters.(2)According to the geometry and material characteristics of the reinforcing ring of the automobile sunroof,the preliminary drawing process was drafted,and the stamping direction,process supplement,and the die binder wrap were designed.The numerical simulation analysis of the reinforcing ring of the automobile sunroof was carried out,and the draw beads were arranged according to the structural characteristics of the parts and the actual production,and the range of stamping process parameters were determined.Thus,it can make up for the defects caused by the structure of the material parts in the drawing process,and provide a reference for the subsequent robust optimization of process parameters.(3)On the basis of the above contents,the 6a robust optimization method was adopted to optimize the drawing process parameters of the reinforcing ring of the automobile sunroof.Then,in consideration of the fluctuations of parameters,a robust optimization model was built with the cracking and inadequate drawing as a constraint function and spring back as an objective function.The results were verified by AUTOFORM to prove that robust optimization plays a practical role in improving the quality of sheet metal forming.(4)Based on the results of robust optimization,the stamping die of the reinforcing ring of the automobile sunroof was designed,and the force analysis of the drawing die with large stress was carried out to ensure the reliability of the stressed structure.The designed stamping die was put into actual production.It shows that the stamped reinforcing ring of the automobile sunroof has high quality,thus verifying the rationality of the process plan and die structure.