The double split precision forging method of spiral bevel gear is used for finite element numerical simulation, the forming process is analyzed, and the influence laws of various process parameters on metal forming quality and forming force are obtained:
a) The structure of spiral bevel gear preform shall be cylindrical inner hole conical preform, and the internal and external diameter shall be close to the size of formed parts. When the inner diameter of the preform is too small, its annular inner wall is in direct contact with the lower ejector rod; When the inner diameter of the preform is too large, at the end of the forming, the deformation degree is large, the internal metal flow is violent, and the material filling in the mold cavity is irregular, which is easy to cause the tooth shape of the spiral bevel gear to be filled incompletely.
b) Different cone angles of spiral bevel gear preforms directly affect the filling order of spiral bevel gear tooth profile. If the cone angle of the preform is too small, it is very easy to cause the large end of the concave die tooth cavity to be not fully filled. If the cone angle is too large, it is easy to cause the middle part of the spiral bevel gear tooth shape not to be filled in time, resulting in depression. If the cone angle is too large or too small, it will increase the forming force.
c) The position of the inner diversion surface affects the filling of the tooth profile of the spiral bevel gear. When the position of the inner diversion surface is close to the tooth shape of the female die, the metal material flows out directly radially along the diversion gap, the diversion gap has not played the role of diversion, and the filling of the tooth shape of the spiral bevel gear is not full. The position of the shunting surface shall be far away from the tooth shape of the female die.
d) The position of the outer split surface also has an influence on the filling of the tooth profile of the spiral bevel gear. The position of the outer diffluence surface determines the flow velocity of the metal material in the inner and outer diffluence gap and the filling quality of the tooth profile of the spiral bevel gear.
e) The thickness of internal flash formed by different internal split clearance directly affects the forming force of spiral bevel gear. The forming force decreases gradually with the increase of the internal shunt gap. When the internal shunt gap is too large, the metal materials flow out of the shunt gap prematurely, resulting in unnecessary waste of materials.
f) The size of the outer shunt gap determines the forming force and forming quality. If the outer split gap is too small, the forming force will increase. If the outer split gap is too large, the tooth shape of spiral bevel gear is not fully filled. Selecting an appropriate split gap can save materials and reduce the forming force.