The stroke load curve of the die in the general forging process of the spiral bevel gear blank is shown in Figure 1. The overall forming process includes two stages: upsetting and die forging. Figure (a) shows that the load at the beginning of the upsetting process is 0t, and the load gradually increases with the upsetting process. When the upper die stroke is 118mm, the upsetting process is completed, and the forming load reaches 1.08t, as shown in figure (b). After the start of die forging, in step 450, the upper die stroke is 119mm and the load is 0.537t, as shown in figure (c).
With the process of die forging, the blank is gradually filled into the mold cavity. With the increase of filling degree, the deformation resistance and friction resistance gradually increase, and the forming load gradually increases. When the die cavity is filled, the blank flows to the flash groove, the material flow is difficult, and the forming load increases abruptly. When the forging of spiral bevel gear blank is completed, the upper die stroke is 147mm and the forming load is 16.4t, as shown in figure (d).