Abstract: Provided is a heat treatment apparatus (1), including: a heating unit (2), which is configured to inductively heat a workpiece (W) to a target temperature; and a drive mechanism, which is configured to move a plurality of the coaxially held workpieces (W) relative to the heating unit (2) being in an energized state in an axial direction of the workpiece (W), wherein the heating unit (2) includes: a plurality of coil members (11) respectively including a ring-shaped coil portion (11a) arranged coaxially with the workpiece (W) so as to be capable of surrounding the workpiece (W); and a frame body (21), which is configured to support each of the plurality of coil members (11) so as to be movable in the axial direction of the workpiece while maintaining the coaxial arrangement between the coil portions (11a).

Abstract: A forging method for a shaft member includes preforming at least one of a plurality of enlarged diameter portions to obtain a semi-finished member, and forming a remainder of the enlarged diameter portions in the semi-finished member using a mold. The mold includes a punch, split dies, and a workpiece receiving member. The forming of the remainder of the enlarged diameter portions includes allowing the semi-finished member having the at least one of the enlarged diameter portions to be placed on the workpiece receiving member, cramping the semi-finished member in its radial direction by closing the split dies, and filling the semi-finished member into forming surfaces of the split dies by the pressure applied by the punch under the state in which the semi-finished member is cramped.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion after the forging, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

Abstract: Provided is an induction heating apparatus including a conveying device, which is configured to convey a rotatable workpiece along a linear guiding conveyance path, and a heating coil, which is configured to inductively heat the workpiece being conveyed along the guiding conveyance path. The conveying device includes a first shaft member and a second shaft member, which are arranged in parallel so as to be separated from each other, and a rotary mechanism, which is configured to rotationally drive at least one of the first shaft member and the second shaft member about an axis thereof. The second shaft member is formed of a threaded shaft having a helical convex portion formed along an outer periphery of the second shaft member. The guiding conveyance path is formed by a groove bottom surface of a helical groove defined on the second shaft member by the helical convex portion.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members using medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed, and a joining end surface formed on an outer surface of the bottom portion, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion.

Abstract: Provided is a heat treatment apparatus (1), including: a heating unit (2), which is configured to inductively heat a workpiece (W) to a target temperature; and a drive mechanism, which is configured to move a plurality of the coaxially held workpieces (W) relative to the heating unit (2) being in an energized state in an axial direction of the workpiece (W), wherein the heating unit (2) includes: a plurality of coil members (11) respectively including a ring-shaped coil portion (11a) arranged coaxially with the workpiece (W) so as to be capable of surrounding the workpiece (W); and a frame body (21), which is configured to support each of the plurality of coil members (11) so as to be movable in the axial direction of the workpiece while maintaining the coaxial arrangement between the coil portions (11a).

Abstract: A forging method for a shaft member includes preforming at least one of a plurality of enlarged diameter portions to obtain a semi-finished member, and forming a remainder of the enlarged diameter portions in the semi-finished member using a mold. The mold includes a punch, split dies, and a workpiece receiving member. The forming of the remainder of the enlarged diameter portions includes allowing the semi-finished member having the at least one of the enlarged diameter portions to be placed on the workpiece receiving member, cramping the semi-finished member in its radial direction by closing the split dies, and filling the semi-finished member into forming surfaces of the split dies by the pressure applied by the punch under the state in which the semi-finished member is cramped.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members using medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed, and a joining end surface formed on an outer surface of the bottom portion, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member under a state in which a hollow cavity portion is formed inside the abutment portion.

Abstract: A method of manufacturing an outer joint member of a constant velocity universal includes forming cup and shaft members of medium carbon steel, preparing, as the cup member, a cup member having cylindrical and bottom portions integrally formed by forging, and a joining end surface formed on an outer surface of the bottom portion after the forging, preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member, and bringing the joining end surfaces of the cup and shaft members into abutment against each other. The method also includes welding the cup and shaft members from an outer side of the cup member to an abutment portion between the cup and shaft members in a radial direction of the cup member.

Abstract: A method for producing a holder in which sagging is suppressed in a bent part to be formed into a flange portion, without using bulge forming and a split mold that restrains the inside of a working target article; and a holder. An upper punch presses and bends one end portion of a working target article inward, whereby a flange portion is formed in the one end portion. A smaller-diameter portion of the working target article is restrained from the inside and outside by a lower punch and split mold portions. Then, a peripheral surface portion of a convex portion of the upper punch receives the end portion of the working target article and applies an outward pressure to the end portion. A bent part is pushed toward a larger-diameter portion restraining part of a split die, so that sagging is prevented from occurring in the bent part.

Abstract: A method for producing a holder in which sagging is suppressed in a bent part to be formed into a flange portion, without using bulge forming and a split mold that restrains the inside of a working target article; and a holder. An upper punch presses and bends one end portion of a working target article inward, whereby a flange portion is formed in the one end portion. A smaller-diameter portion of the working target article is restrained from the inside and outside by a lower punch and split mold portions. Then, a peripheral surface portion of a convex portion of the upper punch receives the end portion of the working target article and applies an outward pressure to the end portion. A bent part is pushed toward a larger-diameter portion restraining part of a split die, so that sagging is prevented from occurring in the bent part.