Research On Springback And Compensation Of Automobile Outer Panels

Many automobile panels can be obtained by stamping process,which plays an important role in the production and manufacturing of automobiles.However,parts obtained by stamping are prone to some quality problems,mainly including wrinkling,cracking and springback.Among them,wrinkling and cracking can be well controlled by adjusting the process parameters,but the springback has always been a difficult problem to deal with,especially the springback of automobile outer panel.Because the accuracy of size and shape of automobile outer panel is relatively high,and the springback will make the part deviate from the preset size and shape.So,it is of great significance to study the springback of outer plate forming.This paper will take the engine hood outer panel of a certain vehicle as an example to study the springback and its control of it.The main research contents are as follows :(1)Optimization of process parameters by Analytic Hierarchy Process.Experimental results of typical schemes are obtained by Orthogonal Experiment.Then,taking the thinning rate and the maximum springback as the optimization objective,,the extremum calculated in the orthogonal experiment is used as the data basis.And the weight of each scheme is calculated by the analytic method,so as to det ermine the optimal parameter combination.(2)The calculation formula of springback compensation coefficient is deduced.And then obtain the compensation coefficient value of the engine hood outer panel by it.The calculation model of springback compensati on coefficient is established.The calculation formula of compensation coefficient can be obtained by introducing the calculation formula of springback radius and compensation radius and combining with mathematical relationship.The compensation coefficient at maximum springback section can be calculated by using this formula,which provides a basis for determining the initial value of compensation coefficient in the future.(3)Establish BP neural network to predict the springback compensation results of engine hood outer panels a vehicle,and assist to get the optimal value of the springback compensation coefficient.Since there is a one-to-one correspondence between the springback compensation coefficient and the springback compensation results,BP neural network can be introduced to predict the springback compensation results.The prediction model of the compensation results is established,which has a good prediction accuracy.According to this model,the optimal value of the compensation coefficient is obtained.(4)Stamping experiment and verification of engine hood outer panel s.The forming part of the outer panel is obtained through the punching experiment,and its forming state is similar to the simulation state.The springback value of the compensated part is not much different from the simulation value,and the springback trend is consistent.The surface quality can also meet the quality requirements of the outer panel.