Study on the Formability of the Seam Welded Tube for Manufacturing the Drive Shaft

In this study, cold reduction process of the tubular metal is applied to manufacture the drive shaft for the rear wheel drive system. With this method during forming process, chip forming such as hobbing and broaching method is not involved. The manufacturing process is as follows; the tube which the sheet is formed and welded to by roll forming machine, is mounted on a suitable mandrel. This mandrel has an external toothing which corresponds to internal toothing of the final product. During axial moving and rotating of the workpiece, forming operation is carried out in lengthwise direction of the toothing. This forming rolls is positioned on the roll head and have a rolling axis vertical with the one of a mandrel. The total forming load needed in the cold reduction process is separated into numerous forming steps along the entire cylindrical length of the zone to be formed. In the process of cold forming on the profiled mandrel during the impact forming operation, material is pushed into depression of toothing of a mandrel mainly in a radial direction. Finally splines can be generated on the surface of components and overall elongated. If the process parameter such as the length of forming per 1rotation of 1roll is not optimized, the impact force from the rolls of the forming process causes geometrical defects. So the optimal parameters such as feeding and rotating speed of workpiece and the forming length should be properly determined. And the effects of the weld line positioning on the formability of the forming process is analyzed to minimize the generation of the defects such as crack on the surface of splined zone.