Ntn Corporation

Suzuki Motor Corporation

Shintaro Suzuki

Tatsuro Sugiyama

Tsuneaki Hiraoka

Masazumi Kobayashi

Naoki Nakagawa

Hiromi Nagai

Yoshiya Mano

Yuuki Tabuchi

Tsuyoshi Ueno

Masafumi Osugi

Renji Natsume

Takeshi Shimasawa

Kazuhiko Yoshida

Tatsuhiro Goto

Takafumi Iwamoto

Taku Itagaki

Takuya Fujita

Yasutoshi Ito

Shigeki Matsushita

Kiyohiro Suzuki

Kenichi Nakano

Masato Chokyu

Hiromi Hayashi

Atsushi Tokuda

Daisuke Kagawa

Akira Nagatake

Shunichirou Tsuboi

Eri Hirayama

Toshihiro Nishio

Yoshio Enomoto

A coating film having excellent adhesion, even without the presence of a chemical conversion film treatment as an undercoat, and a metal automotive part having the coating film. A powder is deposited by powder-coating onto the surface of a metal automotive part that has been quenched after simultaneously forging, and tempering the metal automotive part and bake-hardening the deposited powder to form a skin film on the surface of the metal automotive part. The surface of the metal automotive part before the powder is powder-coated thereon is a work-hardened material surface that has not been subjected to a chemical conversion filming treatment.

Method for forming coating film on constant velocity universal joint

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

Heat-processing device and heat-processing method

Provided is a heat treatment apparatus (), including: a conveying device (), which is configured to convey a rod-shaped workpiece (W) at a predetermined velocity along an axial direction of the workpiece (W); and a heating device () including a heating coil () configured to inductively heat the workpiece (W) being conveyed to a quenching temperature, wherein the heating coil () includes a first heating section (A) and a second heating section (B), which are coupled to each other in series along the axial direction of the workpiece (W), and is electrically connected to a single high-frequency power supply (), and wherein a coil pitch (D) of the second heating section (B) arranged relatively on a front side in a conveying direction for the workpiece (W) is larger than a coil pitch (D) of the first heating section (A) arranged relatively on a rear side in the conveying direction.

Heat treatment equipment and heat treatment method

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.

Method for forging shaft member of constant velocity universal joint

When a rod-shaped workpiece (W) having an outer peripheral surface with a circular cross section is inductively heated to a quenching temperature while being conveyed at a predetermined velocity along an axial direction of the rod-shaped workpiece (W), the rod-shaped workpiece (W) being currently conveyed is heated to a predetermined temperature equal to or lower than the quenching temperature by a first heating coil (A), which is electrically connected to a first high-frequency power supply () and has a constant output. Then, the rod-shaped workpiece (W) being currently conveyed is heated so as to be maintained at the quenching temperature by a second heating coil (B), which is electrically connected to a second high-frequency power supply () and has a constant output.

Heat treatment method of rod-shape workpiece

Provided is a method of manufacturing an outer joint member of a constant velocity universal joint, which is constructed by forming a cup section having track grooves, and a shaft section, and by welding a cup member and a shaft member, the method including: forming the cup member and the shaft member of medium carbon steel; preparing a cup member having a cylindrical portion and a bottom portion integrally formed by forging, and a joining end surface in a machining step; preparing a shaft member having a joining end surface formed in a machining step; bringing the joining end surface of the cup member and the joining end surface of the shaft member into abutment against each other; welding the cup member and the shaft member by radiating a beam; and performing, after the welding, an ultrasonic flaw detection-inspection step.

Outer joint member of constant velocity universal joint

A workpiece conveyance jig, which is formed of a threaded shaft made of a ceramic, includes an inner member, which is formed of a solid shaft having a constant diameter, and is configured to receive a rotational driving force, and an outer member, which has a hollow shaft-like shape, has a helical protrusion, and is mounted on an outer periphery of the inner member so as to be rotatable integrally with the inner member. The outer member includes a plurality of cylindrical bodies arranged in a row in an axial direction of the workpiece conveyance jig, and has a convex and concave fitting portion formed between two adjacent ones of the plurality of cylindrical bodies, which is configured to engage the two adjacent cylindrical bodies with each other in a direction of rotation of the inner member.

Work piece conveyance jig and conveyance device provided with same, and induction heating device

A method of manufacturing an outer joint member of a constant velocity universal joint 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, and preparing, as the shaft member, a shaft member having a joining end surface to be joined to the bottom portion of the cup member. The method also includes bringing the joining end surfaces of the cup and shaft members into abutment against each other, and 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 members.

Method for manufacturing outer joint member for constant-velocity universal joint and outer joint member

When a plurality of outer rings (R) are sequentially and inductively heated to a target temperature by energizing a heating coil () elongated more than each of the plurality of outer rings (R), which are made of steel and retained coaxially by a retaining unit (), while relatively moving the outer rings (R) and the heating coil () in an axial direction, an output of the heating coil () is varied in consideration of the number of outer rings (R) present in an opposing region of the heating coil ().

Method for thermally treating ring-shaped member

For butt-welding, which includes bringing joining end surfaces of a cup member and a shaft member into abutment against each other and radiating a high energy intensity beam from a radially outer side, the shaft member has a recess on a radially inner side of the joining end surface to obtain a welded portion having a closed hollow cavity on a radially inner side after butt-welding. The joining end surface (protruding surface) of the cup member protrudes toward a radially inner side with respect to an inner diameter of the joining end surface of the shaft member. With this, a welded portion of an outer joint member of a constant velocity universal joint, which is manufactured by joining the cup member and the shaft member, can be improved in strength and quality.

Method for butt welding, butt welded joint, and outside joint member for constant velocity universal joint

In an outer joint member of a constant velocity universal joint, a cup member and a shaft member are made of medium to high carbon steel and welded together. The cup member has a bottomed cylindrical shape that is opened at one end, and includes a cylindrical portion, a bottom portion, and a short shaft section of a solid shaft shape protruding from the bottom portion and having a joining end surface. The shaft member has a solid shaft shape and a joining end surface. The joining end surfaces of the cup and shaft members are brought into abutment against each other, and a high energy intensity beam is radiated from an outer side in a radial direction to form a welded portion. A structure of a molten metal at the welded portion is in a mixed phase of ferrite and granular cementite.

Constant velocity universal joint outer joint member and manufacturing method for same

Method of manufacturing outer joint member of constant velocity universal joint, outer joint member, shaft member and cup member

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.

A method of manufacturing an outer joint member of a constant velocity universal joint includes forming cup and shaft members of medium carbon steel, the cup member being manufactured by preparing a cup member having cylindrical and bottom portions being integrally formed, and a fitting hole formed in a thick portion of the bottom portion, the shaft member being manufactured by preparing a shaft member having a fitting outer surface formed at an end portion of the shaft member to be joined to the bottom portion of the cup member, and fitting the fitting hole of the cup member to the fitting outer surface of the shaft member. The method also includes welding the cup and shaft members from an inner side of the cup member to a fitted portion between the cup and shaft members.

Manufacturing method for constant velocity universal joint outer joint member and outer joint member

A method for producing a columnar or cylindrical metal automotive part whose outer circumferential surface includes a portion to be coated with paint and a portion to be uncoated therewith includes the following processes: (1) a process of providing a convergent nozzle-shaped covering jig which covers an outer circumferential surface of the columnar or cylindrical part at an axial end thereof and covers the portion to be uncoated with the paint, with a gap formed between the covering jig and the outer circumferential surface of the part; (2) a process of discharging a gas from the gap toward an end of a nozzle of the covering jig with the columnar or cylindrical part being rotated; (3) a process of sticking a film-forming substance to the columnar or cylindrical part from an axial side surface thereof.

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Shizuoka, Japan

Shintaro Suzuki