| With the development of automobile industry,the worldwide fuel crisis and environmental pollution is increasingly severe.In this case,high requirements are put forward for energy conservation and emission reduction in all areas including automobiles.An effective way to achieve this goal is to reduce the weight of automobiles under the precondition of safety.High-strength steel owns the advantages of both low weight and safety owing to its high strength and high crash performance,thus attracts great interests from automobile manufacturers.However,high-strength steel has severe springback in the molding process,leading to low precision of stamping products.In this situation,improving the molding precision of high-strength steel in automobiles becomes a top priority for the manufactures.In this paper,the influence of mold face compensation mode on the precision of automotive structural part is investigated in simulation and manufacture process.Taking the reinforcing plate around the front door stopper in Shandong Xiaoya Precise Machinery Co.,Ltd as example,this paper is committed to improving the precision of automotive structural parts.Forming analysis was carried out on the reinforcing plate around the front door stopper and the initial process plan is confirmed based on the structural characteristics and the company's requirements.The whole process for the workpiece is simulated with the finite element analysis software AUTOFORM.Drawbead and puncture knife are applied to optimize the wrinkling and cracking problem rising from the drawing simulation.The springback optimization is carried out with the Compensatory module in the ThinkDesigh software to determine the best parameters for stamping process.Based on the parameters,the 3D DL drawings are completed for the design of mold structure.There are several problems in the mold assembly and debugging process such as the wrinkling and cracking problems of lateral piercing punch with wedges during the installation and manufacturing process.Solutions with practical experience are come up with to settle the above problems in this paper.The stampings are checked by customized gauge and the mold is adjusted.The products are successfully put on production.In this paper,the drawbacks of traditional mold face compensation mode are analyzed and an effective way to improve the precision of automotive components is proposed by changing the mold surface of the last process.On the basis of finite element modelling,the spring back value of the molded surfaces after the springback compensation by changing the mold surface of the last process is analyzed.By comparison,the spring back value of stamping parts with original product surface is much smaller.An extra simulation is applied to investigate the reinforcing plate of inner belt around the front door and a same conclusion is gotten,indicating the validity of the results.The simulation results is further verified with the GOM contactless grid strain system.The actual strain of the workpieces is derived by capturing the surface data of the workpieces with ARGUS to provide guidance for debugging.The surface data of the actual workpieces and the corresponding simulation results are imported into SVIEW and compared in between.The tiny surface error in allowance theoretically verifies the reliability of the finite element modelling,making promising reference for mould development of automobile structural products in relevant companies. |
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