Topy Kogyo Kabushiki Kaisha

Katsuki Kato

Kishiro Abe

Satoru Miyashita

Takamitsu Takano

Kenji Taguchi

Tsuneo Watanabe

Shingo Tsukui

Koji Takeuchi

Yuji Iwakura

Shojiro Yokomizo

Morishi Kunou

Nobuyuki Soma

Kenji Hayashi

Akira Nakamura

Masaaki Hara

Takayuki Nonaka

Takenobu Hasegawa

Kenichi Inada

Katsunori Todoko

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.

Method of manufacturing a tubular member

A method of manufacturing a wheel rim for a vehicle includes an ironing step for ironing a tubular material to manufacture a tubular member having a non-constant thickness, using an ironing apparatus provided with a punch, a die whose side surface opposing the punch is a convex and concave surface, and a pressing member. At the ironing step, a flange portion of the tubular material is set at the die, then the pressing member is moved relative to the die thereby to squeeze the flange portion of the tubular material by the pressing member and the die, and then the punch is moved relative to the die to iron at least a portion of the tubular material except the flange portion of the tubular material to manufacture the tubular member having a non-constant thickness.

Method of manufacturing a wheel rim for a vehicle

A rim material having a non-uniform thickness, a rim manufactured from the rim material, and a method for manufacturing the rim from the rim material. The rim material includes a first material portion which forms an axially curved portion of the rim after the rim material is formed to the rim and a second material portion which forms an intermediate portion between adjacent axially curved portions after the rim material is formed to the rim. The first material portion has a thick parallel-surface portion including opposite surfaces parallel to each other. The parallel-surface portion has a width greater than a maximum amount of an axial dislocation of the parallel-surface portion expected to occur when the parallel-surface portion is formed to a corresponding curved portion. The second material portion has a thickness varying portion. The thickness varying portion includes a surface having a configuration defined by a line including a straight line and/or a slightly curved line.

Rim having a non-uniform thickness

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Atsugi, Japan

Katsuki Kato