Forging of spur gears with internal serrations and design of the dies

Numerical calculation tools based on the upper-bound method, which could be used in the forging of gear-like components having various deformation features, are suggested. The numerical calculation tools can calculate both the internal and external flow of metal within dies, such as an external involute spur gear, a square spline and internal serrations. A complex calculation tool for the forging of gear-like components has been developed by combining these calculation tools. The workpiece, which has external and internal teeth, was divided into two blocks. The deformation of the two blocks was also analyzed by testing the numerical calculation tool, which was derived from a kinematically admissible velocity field. Experimental inspection was carried out with a 200 t hydraulic press, the results showing good agreement with the calculated solution. Therefore, the calculation tool could be useful to predict the capacity of a forging facility and in the design of dies.