Stamping Forming Analysis And Springback Optimal Control Of Passage In Passenger Car

This paper is combined with innovation fund projects of Science and Technology Ministry, which is jointly undertaken with the master workstation(Number:12C26213202181):Precision mold development of vehicle high-strength plate bottom beam is based on springback compensation.The floor for the middle channel of high-strength steel covering panel of a car was taken as the research object to analyze its structural features,thereby developing a complete stamping process, namely pull extension-trimming punching-flanging-side plastic-side punching.By adopting the technology of sheet metal forming CAE numerical simulation, the simulation analysis of the whole stamping process of the floor inside passage is finished, by setting the process parameters of corresponding process and mold geometric parameters in the DynaForm software. The pull extension process is emphatically analyzed, including the choice of drawing direction,the design of blank-holder surface,the design of shape of addendum and the design of draw beads. Aiming at the phenomenon of ruptureand wrinkling duing the pull extension process,some meshures are taken to adjust forming process parameters and appropriately modification mould geometric parameters to better overcome theforming defects,such as wrinkling, excessive thinning, rupture.Researching the mechanical mechanism of sheet metal springback, and simulating the springback of the floor for the middle channel by utilizing DynaForm Springback of the module, then analyzing the simulation results. As for how to control the springback of the floor for the middle channel caused during the forming process, this paper has used the method combining the method of process control with the method of the geometric compensation, that adjusts reasonably a series process parameters such as blank holder force, die clearance, friction coefficient, stamping speed and repairs the geometric profile of the mold properly, to reduce springback of parts effectively, but not to make it the minimum. Therefore, after the analysis of some main factors influencing the springback of sheet, the research does the orthogonal experiment on the springback of the floor for the middle channel in which the samples of blank holder force, the friction coefficient and the ram speed are selected as factor levels, so we can find the optimal parameter combination to control the amount of springback to minimum. Through variance analysis, range analysis and significance analysis of the experiment resultsby by using the method of mathematical statistics, we obtain the law that springback angle varies with the variation of the level of each factor and the influence of three factors on the sheet metal springback The conclusions are drawn as follows:ram speed and blank holder force should be the two technical parameters need much more consideration when the floor for the middle channel is in the process of flanging and reshaping. This research provides a favorable theoretical reference for complex-shape automobile panels of high-strength sheets to control springback caused in the multi-step forming process, which helps the company to improve the products percent of pass and makes more economic value.We take advantage of the enterprise existing stamping equipment and begin the actual stamping experiments according to the optimal process parameters combination and the geometric parameters of the mold. By comparing the results of numerical simulation with the experimental data, it indicates they agree well. The experiment proves the accuracy of the results of numerical simulation. What is more, it shows that the analysis on the result of the orthogonal optimization is credible, as well as the conclusion.