Research On The Anti-extrusion And Bottom Compression-drawing Molding Method Of Bulge Deforming

Lightweight of the products, that is, at the premise of ensuring product functionality, to reduce the total mass of the product as much as possible. At present, lightweight is a trend of all kinds of products, mainly by reducing parts, replacing lightweight materials or simplifying product structure to achieve. For plastic processing forming metallic cavity, box and box body products shell, forming various shapes of bulge in its surface can reduce the weight of shells. Because the bulge structure has the function of position, shaft, clamping, riveting, strengthening the structure and many other role, simplified structure.The processing principles of the anti-extrusion and bottom compression-drawing molding method of bulge deforming was described in this article. Two methods of bulge deforming were analyzed in elements by the software of Deform-3D.Obtained the deformation of the molding process and related performance parameters. The influence of processing speed, initial thickness, friction coefficient and back pressure on the forming process was discussed. Bottom compression-drawing molding method of bulge deforming was validated by experiment. Summarized that the key conclusions as follow:1.The following characteristics was found in bulge forming process:(1) the shrinkage defects occurred;(2) Processing speed just speed up the forming speed;(3) The thicker the initial sheet is, the higher the bulge height limit, and shrinkage defects arise more difficult;(4) The bigger the friction coefficient is, the higher the anti-extrusions bulge's height limit, the lower the bottom compression-drawing bulge's height limit; the shrinkage defect arise more difficult;(5) These ways are taken to avoid shrinkage defects arising: appropriately selecting the initial thickness and coefficient of friction, control the processing schedule .2.The anti-extrusion processing load changes, when the bottom compression- drawing method of processing load stability;3.The bottom compression-drawing method's maximum processing load is bigger then anti-extrusion, because it imposes a back pressure at the bottom of the workpiece. The greater the back pressure imposes, the bigger the load is and the higher the bulge height limits but shrinkage defect arise more easily.4. Experimental results show that bottom compression-drawing molding method of bulge deforming can be used for actual production by reasonable lubrication conditions and die structure.5.The bottom compression-drawing method is preferred by its low cost.