Research On Drawing Quality Of B-column Structural Reinforcement Panel

Automobile framework parts such as B-column structural reinforcement panel mostly have complex and irregular shapes, that their forming processes are often affected by blank shape, stamping direction and speed, binder force, draw-bead structure and layout, friction condition and gap between die and punch, etc. These effects can lead to many product quality problems, such as severe thinning, wrinkle, warping, crack and insufficient sketch.To seek the best forming plan and mould structure, the conventional approaches lied on experiences or test-stamping can neither ensure the product quality nor reduce the prime cost, but will become the bottleneck prevented new-type car from coming into the market. By means of the CAE software, not only may the forming drawbacks be discovered in advance which are detected in stamping process or mould debugging formerly, but also the stamping scheme and the mould design scheme may be simplified and optimized, the time of studying and developing die may be shortened, the quality of forming-product and assembling-car may be improved, as well as the production costs may be reduced.In this thesis, based on the elastic-plasticity theory of sheet forming and Dynaform software, the drawing processes of a B-column structural reinforcement panel were studied, the drawing parameters and mould parameters were designed by use of orthogonal experiment method, and the effect of stamping speed, friction coefficient, drawbead depth and radius, as well as the gap between punch and die on the drawing quality of the reinforcement panel were carefully examined. According to numerical simulation, the reasons for wrinkle, crack and insufficient sketch were comprehensively analyzed, and the corresponding solution for controlling drawing quality was given.The experiment shows that the impact of gap between punch and die on the least local thickness is main, which can be described as that the less of the gap, the thinner of the reinforcement panel local thickness after drawing, and the panel local crack is easier induced. The effect of stamping speed on the least local thickness is secondary, which can be described as that if the stamping speed is increased, the local thickness of the reinforcement panel will reduce and the crack risk will raise; but if the stamping speed is too slow, the local thickness of the panel will increase and the probability of panel wrinkle will also increase. The drawbead layout, quantities, style and structure play an important role in the drawing quality control of the B-column structural reinforcement panel. By means of setting up the semicircle drawbead appropriately and using the orthogonal experiment to optimize the drawbead depth and radius, the drawing quality of B-column structural reinforcement panel is apparently improved, and besides, the wrinkle, crack and insufficient stretch are effectively prevented.