A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

Outer ball grooves of an outer joint member of a constant velocity joint each have a first ball groove for allowing a ball to roll therein when the constant velocity joint operates, and a second ball groove having a ball groove radius larger than a ball groove radius of the first ball groove. The second ball groove has a curved line and a connecting line. The curved line is connected to a groove bottom end of the first ball groove located closer to an opening of the outer joint member and is curved radially outward in a concave manner. The connecting line connects the curved line and the opening. The curved line is curved with a curvature center that is located closer to the opening than the groove bottom end of the first ball groove and that is located radially inside the outer joint member.

A method is provided for manufacturing an outer ring of a constant velocity joint including an outer ring, an inner rotational member, a torque-transmitting rolling element, and a defining member. The outer ring includes: a first inner peripheral surface to which the defining member is attached; a second inner peripheral surface; and protrusions protruding radially inward of the first inner surface and the second inner peripheral surface so as to restrict axial movement of the inner rotational member and the rolling element. The manufacturing method includes: a plastic working step involving providing a base member; and a bottom removing step involving partially removing a bottom of the base member so as to form a through hole. The plastic working step further involves providing the second inner peripheral surface. The bottom removing step further involves providing the protrusions.

An inspection device inspects a joint-type outer joint member of a constant velocity universal joint that includes a cup section having a bottomed cylindrical shape and track grooves in an inner periphery thereof for torque transmitting elements, and a shaft section extending from a bottom of the cup section. The inspection device inspects the outer joint member, which is obtained through melt-welding on a cup member forming the cup section and a shaft member forming the shaft section. The inspection device includes a surface inspection unit to inspect for a defect which appears on a surface of the outer joint member due to welding, an internal inspection unit to inspect for an internal defect of a welded portion, and a recording unit to record an inspection result of the inspection. The inspection device is configured to efficiently perform in-line total inspection for the melt-welded joint-type outer joint member.

A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

A method is used to forge an outer joint member of a constant velocity universal joint. Track grooves of the outer and inner joint members each have an arc-shaped ball raceway center line having a curvature center that is not offset in an axial direction with respect to a joint center. The forging method includes performing ironing by press-fitting a cylindrical portion of one end of a shaft portion of a pre-processing material of the outer joint member including the shaft portion and the cylindrical portion into a die hole of a die while a punch set that is radially expandable and contractable is fitted to an inner peripheral surface of the cylindrical portion. The punch set includes punches and a punch base to guide the punches to enable advancing and retreating. Each of the punches has a pair of forming surfaces for forming the adjacent track grooves.

A method of manufacturing a rotating bearing unit includes to cause one end surface in the axial direction of the forming punch (46), formed by combining a plurality of punch elements (46, 46) divided in the circumferential direction, which are displaceable in the axial direction and which are not displaceable in the circumferential direction, and having a processing teeth (44, 44) at one end surface in the axial direction, to face the other end surface of the caulking section (20) in the axial direction. In this state, rolls (30a) are rotated about the central axis (α) of the hub main body (8) while pressing the other end surface of the forming punch (46) in the axial direction with a pressing surface (43) of the roll (30a) having a central axis (β) that is inclined with respect to the central axis (α) of the hub main body (8).

A forging apparatus includes an ironing mechanism and a phase alignment mechanism. The ironing mechanism includes: a punch set, which is fitted into a cylindrical portion of a pre-processing material to be formed into the outer joint member, and is radially expandable and contractible, the cylindrical portion having grooves formed in an inner peripheral surface thereof; and a die having a hole into which the cylindrical portion is press-fitted. The phase alignment mechanism is configured to align phases of the grooves in the inner peripheral surface of the pre-processing material and phases of track groove portion forming surfaces of the punch set with each other before the pre-processing material is fitted to the punch set.

A method of manufacturing an outside joint member, the outside joint member including a cup portion in a bottomed tubular shape and a shaft portion that is a shaft-like portion extending from a bottom portion of the cup portion and that has a spline shaft having an outer peripheral surface on which spline teeth are formed, includes forging a forming material to form a shape of the cup portion and a shape of the spline shaft on the shaft portion simultaneously using a forging die.

The present disclosure relates to a steel forging process, in particular a hot steel forging process in horizontal press of a metal tube, preferably a cylindrical steel tube.