The precision forging blank size of spiral bevel gear is determined according to the principle that the forging volume is equal to the blank volume. The volume of spiral bevel gear forging is 784723mm3 measured by three-dimensional modeling software UG, so we can know the volume of spiral bevel gear precision forging blank. Considering increasing the free surface of metal flow in the forming process and promoting the metal flow in the forming process, the precision forging blank of spiral bevel gear is processed into a ring shape as shown in the figure according to the principle of split forging.
In order to improve the plasticity of the deformed metal, reduce the deformation resistance and make the metal easier to flow during forming, the blank metal must be heated before forging the spiral bevel gear. In general industrial production, the metal is heated in an aerobic atmosphere, which is likely to cause oxide scale and surface decarburization on the metal surface. In order to prevent these defects, when heating the metal blank, its temperature should meet the requirements of the forging temperature of spiral bevel gear in the shortest time. The heating speed of induction heating is very fast. Under the condition of no protective atmosphere, less and no oxidation heating can also be realized. The burning loss rate of the heated blank is less than 0.5%. Moreover, induction heating is easy to realize automation, the heating process is standardized and stable, and the heating temperature control is accurate. Induction heating can be divided into high frequency heating (frequency f = 105 ~ 106hz), medium frequency heating (frequency f = 500 ~ 10000hz) and power frequency heating (frequency f = 50Hz) according to the different current frequencies used. Among them, medium frequency induction heating is most widely used in the forging production of spiral bevel gear.