Simulation And Optimization On Multi-station Stamping Of A Round Pin

Progressive die stamping is the main production mode of small parts at present.It has the advantages of high precision,stable forming and high efficiency.The round pin is belongs to the automobile metal parts which has high precision requirements,In progressive die,it is formed by punching,adjusting and cold forging.The round pin's forging is difficult to meet the tolerance.It often needs a long time of adjusting the dimensions and the blank shape produced by the punching station also affects the forging of round pin.At present,most of the research on multi-station simulation of progressive die in china and foreign countries is bending or drawing.a few literatures simulate the Die-roll and the height of fracture zone caused by thick plate blanking.However,the accuracy of blanking simulation is not enough and there is almost no continuous multi-station simulation research of thick plate blanking and round forging.Considering the lack of continuous simulation research on thick plate blanking and round forging,In this paper,the continuous simulation of rough blanking,adjusting,fine blanking,forging conner and round forging stage in the progressive die of round pin is carried out in Simufact finite element software.First of all,Obtaining raw material parameters by tensile test.Secondly,The constitutive model of C5191 phosphor bronze is obtained and verified by the finite element tensile simulation.The damage models of Lemaitre and Normalized C&L are compared by tensile damage result.Thridly,the 2D forging finite element model of the circular pin's blanks with different aspect ratio is simulation.The optimal aspect ratio of the blanks is obtained.The 2D blanking simulation of 1.6mm thick material is carried out and the height of the fracture zone is obtained.Using the optimal aspect ratio and the height of fracture zone to establish the rough and fine 3D blanking model while Boolean operation is used in blanking simulation,Then,Continue to import fine blanking result in the forging simulation,Thus,the stamping and forging simulation of progressive die are linked together,and the influence of blanking's Die-roll and fracture zone on forging is considered,which lays the foundation for combine multi-station simulation of punching and cold forging of round pin.The paper pointed out the main defects that the unformed width of the small plane on the round pin is easy to exceed the tolerance,The material flow rate,contact pressure distribution of 3D round forging are analyzed by using simufact software.According to the result of contact pressure distribution,the width of the small plane in three directions of the circular pin is consistent with the actual situation,The influences of pre forging conner,round head forging clearance,stamping speed and friction coefficient on the three indexes of small plane width,burr height and maximum forming load of the round pin are studied Based on the orthogonal experiment.The parameter's selection under each index is analyzed.The comprehensive index evaluation method of circular pin forming is established and the optimal parameters are obtained.The simulation results of the optimal parameters are compared with the actual production which verify the correctness of the finite element simulation optimization.