Study Of The Key Problem On Sinking Forming With Middle Thick-Walled Tube And Cylindrical Cup

The need of high strength,lightweight and low cost is hastening the automobilestructure improving continuously. More and more parts are produced by sinkingdeformation with middle thick-walled tube or cylindrical cup which become shaped byplate, such as transmission shaft,back spring-seat,input and output shaft,the top ofveering shaft and the below of veering shaft and so on. For more and more productsstructure updating continuously, it is the most power of manufacturing to adopt a lowcost and high quality forming technique. The tube can form some parts of differentdiameter by the push-reducing deformation, and this is a key technology for highcapability,high strength and lightweight of automobile.When automobile parts are manufactured by the push reducing deformation withtube, must use an opening die. And the characteristic of forming is different betweensinking and drawing deformation with tube. Many scholars have studied the drawingdeformation of the tube with core or without core theoretically. In 70's, some scholarshave analyzed the reducing deformation of tube without core systemically. And thiswork has promoted the development of the reducing forming with tube. The theory ofreducing forming has been perfected by a great deal of theory study work, and thistheory has come to maturity finally. But with the demand of precision about figure anddimension being higher little by little , the push reducing forming without core is goingto can't satisfy the need of manufacturing industry for its characteristic of forming. Sothe push reducing forming with core will be adopted to produce the products with highprecision at port of parts. However, when the tube deform by the opening push-reducingdeformation with core, the axial force will increase greatly. So the outstanding problemis the buckling forming of the passing power area of the tube. In fact, the axial carryingcapacity of the tube is littler than the rod, especially when the ratio of thickness andradius is very small. The key problem of processing is to calculate the critical load ofbuckling forming about the tube exactly。At the same time, when complex figure products are manufactured through sinkingforming with cylindrical cup, the bearing force is more complex. What's more, thesinking buckling will occur at the coping. So should the defects be thought over, such aswrinkling at the end,buckling about the can wall,sinking at the coping. At present, thetheory study of the critical load is hotspot and difficulty in the international. And now it...