From the figure, it can be seen that in the simulation of cold precision forging process, the equivalent stress distribution diagram of blank model under different stages. In the first step, the overall color of spiral bevel gear blank is the same. At this time, the blank is not in contact with the upper die, and the equivalent stress value is about zero, which belongs to the forging preparation stage. In the actual processing, it corresponds to the empty stroke of forging press; In steps 5-10, the blank color of spiral bevel gear begins to change, which appears in the tooth slot and the bottom of the tooth. The equivalent stress value here is mostly 600-900mpa, which belongs to the forging stage.
In the process of steps 15 ~ 25, the color of the gear teeth is gradually deepened, indicating that the gear teeth and the gear groove are places with large stress in this stage. The upper die has a loading force on the blank gear teeth as a whole, which belongs to the forging termination stage. The deformation degree of the blank gear teeth is deepened, and the tooth shape is gradually formed, and the equivalent stress value is above 900MPa, The integral spiral bevel gears are under large stress values.
On the whole, in the forming process, the equivalent stress on the gear tooth is the largest. Except that at the beginning of forging, only the stress on the gear groove is large, and then the whole gear tooth is in a large stress state, which shows that the gear tooth is the position with the largest deformation resistance and the main deformation position where the blank becomes the forging. Accordingly, the stress state of the die can be known, The tooth shape of the die is also the place with the greatest stress, which is in line with the actual situation of spiral bevel gear forging, and is of great significance to the manufacturing process, use and maintenance of the die.