Abstract: A new forming process of stepping press forging with the uniform thickness is put forward because of the interference problem when unfolding uniform thickness sheet parts with the smaller distance between two vertical walls of magnetic bracket. In this method, the part of sheet metal with a larger distance between two vertical walls is manufactured by stamping process, and then the larger distance is shortened gradually by drawing the connection body for two vertical walls during several working steps until the target value. It is noteworthy that in each step the local thickened material is reduced to the original plate thickness by press forging process. The drawing shape of the connecting body is analysized and optimized by the theoretical study and experiments, and a mathematical model for the streamlined shape drawing is established. Based on the mathematical model, and the magnetic bracket without process defects are regarded as the goal, the process parameters of streamlined shape drawing are optimized. Mean while, the stepping coefficient of press forging with uniform thickness for magnetic bracket is obtained. It is shown that the magnetic bracket parts without process defects can be produced by a new forming process of stepping press forging with the uniform thickness during three working steps, and the simulation results are in good agreement with experimental data.

Key words: magnetic bracket, numerical simulation, stepping press forging with the uniform thickness, streamlined shape drawing