METHOD OF MANUFACTURING A TUBULAR MEMBER

• US 20110214474A1
• Filed: 05/16/2011
• Published: 09/08/2011
• Est. Priority Date: 11/18/2008
• Status: Active Grant

• Current Assignee: Topy Kogyo Kabushiki Kaisha
• Original Assignee: Topy Kogyo Kabushiki Kaisha
• Inventors: Takeuchi, Koji, Nakamura, Akira, Watanabe, Tsuneo, Kato, Katsuki, Iwakura, Yuji, Taguchi, Kenji, ABE, Kishiro, Nonaka, Takayuki, Miyashita, Satoru, Takano, Takamitsu
• Granted Patent: US 9,085,027 B2
• Time in Patent Office: Days
• US Class Current: 72/356
• CPC Class Codes: B21D 22/025 for tubular articles
• CPC Class Codes: B21D 45/003 in punching machines or punching tools
• CPC Class Codes: B21D 53/30 wheel rims

Abstract

A method of manufacturing a tubular member having a non-constant thickness by ironing at least a portion of the tubular material. The ironing apparatus can have a punch and a die, and the die can have a convex and concave side surface opposing the punch. The method can include bending an axial end portion of the tubular material to form a bent portion. The tubular material can then axially engage the die at the bent portion, and then the punch can be moved relative to the die to iron at least a portion of the tubular material.

Claims

1. A method of manufacturing a tubular member comprising:

bending an axial end portion of a tubular material having a constant thickness in a direction crossing an axial direction of the tubular material thereby forming a bent portion in the tubular material; and

ironing the tubular material to form a tubular member having a non-constant thickness by ironing at least a portion of the tubular material other than the bent portion using an ironing apparatus which has a punch and a die having a convex and concave side surface opposing the punch.

2. A method of manufacturing a tubular member according to claim 1, wherein the ironing includes:

causing the bent portion to axially engage the die;

operating the ironing apparatus by moving one of the punch and the die relative to the other of the punch and the die; and

ironing the tubular material to form the tubular member accompanied by a change in a diameter and a thickness of the tubular material caused by the convex and concave surface of the die and the punch.

3. A method of manufacturing a tubular member according to claim 1, wherein the convex and concave surface is formed by providing at least one convex portion making a space between the die and the punch narrower than a thickness of the tubular material at the die, in an axial direction of the die along the side surface of the die opposing the punch.

4. A method of manufacturing a tubular member according to claim 1, wherein after manufacturing the tubular member having a non-constant thickness, the tubular member is taken out from the die by adding an axial force to the tubular member so that the tubular member is deformed in a radial direction of the tubular member.

5. A method of manufacturing a tubular member according to claim 1, wherein the convex and concave surface is formed by providing at least one convex portion making a space between the die and the punch narrower than a thickness of the tubular material at the die, in a circumferential direction of the die along the side surface of the die opposing the punch.

6. A method of manufacturing a tubular member according to claim 1,

wherein the bent portion of the tubular material is caused to axially engage the die and is squeezed between the die and a pressing member and then the ironing is performed.

7. A method of manufacturing a tubular member according to claim 1, further comprising manufacturing the tubular material from a flat material having a constant thickness before the ironing.

8. A method of manufacturing a tubular member according to claim 1, further comprising roll-forming the tubular member having a non-constant thickness to form a vehicle wheel rim.