Strain is a physical quantity used to express the deformation size of the deformed body. Through the analysis of the corresponding strain field distribution, we can intuitively obtain the deformation of each part in the precision forging process of spiral bevel gear and master its forming law. As shown in the figure, the strain field distribution of the upper die under different reduction is shown.
In the early stage of deformation, because the tooth top part of the tooth die contacts before the outer contour of the blank, the deformation mainly exists here, forming the tooth root part of the spiral bevel gear, and the strain decreases from the tooth root of the spiral bevel gear forging to both sides. With the downward movement of the upper die, the contact area between the tooth top part of the tooth die and the blank becomes larger and larger. On the one hand, the tooth root part of the spiral bevel gear continues to deform under the pressure of the tooth die, on the other hand, the whole blank is subject to axial upsetting deformation. In the later stage of forming, the deformation is mainly the filling of the top part of the forging. The small end tooth shape of the spiral bevel gear is formed first, and finally the large end tooth shape of the spiral bevel gear. In this process, the metal of the top part of the spiral bevel gear is forced to fill the tooth cavity under the action of the metal of the tooth root part, and the strain is large, but in terms of cumulative strain, The metal of the tooth root is still the largest. It can be seen from the figure that at the end of the forming of the spiral bevel gear forging, the tooth shape of the formed forging is full, the tooth root part is excessively smooth, and there are no defects such as collapse and folding, so the effect is very good.