Patent ID: 11897025
Assignee: NTN CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B  F | IPC B  F

Claim 1:
2. The forging method for an outer joint member of a constant velocity universal joint according to claim 1,
wherein the inner peripheral surface of the cylindrical portion of the pre-processing material has:
an arc-shaped track groove surface having a shape and being formed in a part in an axial direction on a far side so as to be inclined in the circumferential direction; and
a linear track groove surface having a preliminary shape and being formed in a substantially half part in the axial direction on an opening side so as to be prevented from being inclined in the circumferential direction,

wherein, in an inlet portion of the inner peripheral surface of the cylindrical portion, portions of the pre-processing material each between the grooves adjacent to each other in the circumferential direction are thin portions or thick portions, and the thin portions and the thick portions are alternately arranged along the circumferential direction, and
wherein the phase alignment mechanism comprises a phase alignment jig comprising:
a pair of convex portions to be fitted along the axial direction to the grooves of the pre-processing material which are adjacent to each other in the circumferential direction; and
a coupling portion, which is formed between the convex portions, is allowed to be internally fitted to corresponding one of the thin portions of the pre-processing material along the axial direction, and is prevented from being internally fitted to corresponding one of the thick portions of the pre-processing material along the axial direction.