Research And Development Of Control Equipment For TWB Stamping Process

The high-speed development of auto panels manufacturing comes with the high-speed development of the auto industry. With consideration of problems such as resources, environmental protection, and safety, more and more countries put their attention on the automobile-weight reduction and the resources protection. Further more, Tailor Welded Blanks(TWB) forming technology is one of the most important ways to solve the auto lightweight problem. For these cause, TWB stamping forming technology is becoming more and more attractive. Especially, the most famous auto suppliers including VW, GE, Toyota etc. have developed it as important research project.TWB consist of tailor blanks with different thickness, performance, and surface coating, which are weld together before forming. After stamping, TWB become higher performances products. During TWB stamping process, because of inhomogeneous deformation of TWB with weld and different sheet metal, weld moves and make formability worse. As a result, it is very difficult to get the qualified products with the reasonable shape, and the performance as we defined before.The apparatus to control stamping process of TWB are discussed in the article. The control apparatus includes mold equipment, hydraulic equipment and control system based on PLC. Clamping block and different pieces of blank holders are especially designed in mold equipment. The clamping block is used to constrain the weld movement and the different pieces of blank holders provide the blank holder force for the different blanks. he hydraulic system gives the clamping force and the blank holder force on the clamping block and blank holders by back-pressure. PLC system controls the hydraulic system to realize the flexible control for clamping force and blank holder force.The experiments prove that, the flexible control of clamping force and blank holder force is realized to control the weld movement, provides effectively different blank holder force and clamping force, and increases formability of TWB. Therefore, the control system has theoretical signification and engineering application values for optimizing TWB forming technology, enhancing the performance of stamping parts, and attaining high quality products.