The Study About Springback Control Of Car-body Cover Base On Optimization Of Process Parameter And Mold Surface Compensation

Sheet metal stamping technology is the most important mode of production in Automotive Manufacturing. It has been gradually became the measure of a country’s Automobile industry, or even an important indicator of the strength of Manufacturing, with the rapid development of Automobile industry. Data shows that, Car bodies are about60%to70%of the parts are produced by a stamping process, which is required for low-skilled workers, high production efficiency, suitable for large-scale automated production.The defect of springback is the most difficult to control in those three common defects which are wrinkling, rupture and springback. The error of shape and size caused by springback seriously affect the surface quality and the tightness of the body, what is more, it will hinder automatic production process. Traditional mold design of car-body cover is a time-consuming, laborious, and costly process, need to make real mold and repeated tryout and repair mode, It will extend the car’s development cycle.In recent years, Numerical simulation of sheet metal forming technology is developing rapidly, most commercial CAE software has been able to simulate the forming process of sheet metal very well, The accuracy of Springback simulation is also improving continually. But So far, there is no one universal and effective method to solve the problem, which is how to control springback, especially how to use the results of the FEM data during springback simulation to compensate mold surface. In this paper, we use an outer panel of fender as the example to show how to select the most process parameters, and then proposed a method of compensation both base on the feature of original surface and FEM data. It control springback through these two aspects.First of all, Use the CAD data of outer panel fender as the sources data of mold design, Describes the methods and principles of car-body cover mold design in Dynaform, which is a widely used numerical Simulation Software, and select the optimal combination of drawbeads parameters, and then get a good forming quality of the part. Secondly, Introduce the application of springback compensator both in the SCP module built-in Dynaform and ThinkDesign’s Compensator module, Compared the advantages and disadvantages of both these two methods. Then presented a new thought of springback compensator,It is extracting separately some characteristic lines from the original surface and elastic mesh based on the feature of original surface and the result of springback simulation, Then compensate the original surface based on the matching relationship between this two groups of characteristic lines, Thereby obtaining a new mold surface. Finally, Use examples to verify the feasibility of this idea, Experimental results show that a springback compensation only by the back plate to the springback between the material and the desired shape error control within the allowable range, and maintain a good surface quality.The research ideas and processes of this paper provide a practical engineering course, especially in springback control, it will reduce the time of mold design of car-body cover, improve efficiency and enhance the competitiveness of an automobile plant.