Forging apparatus for inner race of constant velocity universal joint

A forging apparatus for an inner race of a constant velocity universal joint, comprising a lower punch which is disposed on a side of a lower die and which is displaceable in an axial direction of a material, an upper punch which is disposed on a side of an upper die and which is displaceable in said axial direction of said material, and a plurality of segmented dies each of which is displaceable in a direction directed from an outer circumference to a central axis of said material and each of which has a die surface corresponding to a ball groove of said inner race of said constant velocity universal joint, to forge said material, said forging apparatus further comprising:

• a reinforcing ring which is disposed on said lower die and which has inclined surfaces inclined in directions to make approach or separation with respect to said central axis of said material respectively for allowing said segmented dies to slide thereon;
• and
• guide mechanisms each of which includes an engaging projection and a groove extending in parallel to said inclined surface, any one of said engaging projection and said groove being disposed on said segmented die, and the other being disposed on said reinforcing ring, said one of said engaging projection and said groove which is disposed on said segmented die extending along a face of said segmented die from an upper side to a lower side of said segmented die, and said other which is disposed on said reinforcing ring being substantially equal in length to said inclined surface,
• wherein said segmented dies make displacement along said inclined surface in accordance with a guiding action of said guide mechanisms so that said plurality of segmented dies make approach or separation with respect to one another.