Analysis And Optimization Of Stamping Process For A Passenger Car Fender

As a typical outer cover of the body-in-white,the fender has very high requirements on surface quality and dimensional accuracy due to its small size and complex shape.The efficient formulation of its stamping forming process has always been a difficult problem in actual production.In this paper,the finite element method is used to simulate and analyze the stamping and forming of the fender,so as to formulate the optimal process plan,which can greatly shorten the development cycle and reduce the cost.Taking the fender of a passenger car as the research object,this paper first analyzes the stamping process of the fender,determines the number of production processes of the fender according to the part characteristics of the fender and the actual situation of the production workshop,and reasonably divides the work content of each process.Among them,the finite element method is mainly used to study the drawing process of fender parts,including the setting of stamping direction,binder surface,addendum surface and drawbead,etc.In addition,the setting content of the finite element method of the subsequent process is briefly analyzed.Secondly,the process parameters of the fender are optimized by orthogonal test.The maximum thinning rate and maximum trimming springback are selected as objective functions,and the parameters of blank holder force A,friction coefficient B,stamping speed C and material thickness D are selected as optimization variables.First,the two objective functions were optimized by the direct analysis method,and the corresponding optimized parameter combinations were obtained.Then,the Taguchi algorithm is used to jointly analyze the maximum thinning rate and the maximum trimming springback,to explore the parameter combination when both objective functions are optimal,and finally to carry out the springback compensation work for the large springback of the parts.The obtained process plan and analysis results can be used for subsequent mold development work and guide stamping formability verification analysis.Including the design and manufacture of the mold structure,and the analysis of the content of the automation transformation.Finally,the optimized parameters are used to verify and analyze the drawing process,and the springback measurement is used to verify the springback compensation effect,and the problems existing in mold debugging and production of the rest of the fender process are analyzed.Through analysis,it is determined that the fender adopts four-sequence production,and the finite element analysis model of the whole process is successfully established by the finite element method.Then,the process parameter optimization study shows that the friction coefficient has a significant effect on the maximum thinning rate and the maximum trimming springback.When the blank holder force is 800 KN,the friction coefficient is 0.15,the stamping speed is 500 mm/s,and the material thickness is 0.65 mm,the fender stamping simulation effect is the best,and on this basis,the springback compensation is performed to keep the springback within a controllable range.The optimized process parameters are tested and verified,and the mold design and manufacturing work and automation transformation are completed during the period.The verification results show that the optimized process parameters meet the production requirements,and the springback of the parts is basically controlled within ±0.5mm,and finally the fenders are successfully delivered.