Study on manufacturing of special-shaped ends blank for cross wedge rolling without stub bar

Prefabricating blank ends into special shape is the most effective and commonly used method to eliminate end-face cavities for realizing cross-wedge rolling (CWR) without stub bar. A hot rotary shearing forming method based on metal-plastic forming together with its implementing mechanism for the manufacturing of special-shaped ends blank was proposed in this paper. The hot rotary shearing forming method was firstly investigated by finite element simulation, and the forming process of the special-shaped end with the movement of the shear blade is analyzed. Then the implementing mechanism characterized by the combination of a differential elliptical gear train with conjugate cam was designed. To obtain the structural parameters that can make the shear blade move as designed, kinematics model of the mechanism was deduced by analyzing its working principle. Based on the model, a computer-aided analysis program for the hot rotary shearing mechanism, using MATLAB, is developed. Finally, one application example was conducted. The experimental results revealed that the dimension of the special-shaped end blank obtained by this method was close to the designed dimension. The research result verifies the correctness of the kinematic model and the feasibility of the forming method.