Nissan Motor Company Limited

Shinji Ooe

Kazuhiro Mitamura

Masaaki Yoshitome

Hideto Kanafusa

Kazuto Ueno

Satoru Majima

Takashi Haraoka

Hajime Minagawa

Tomoyuki Hirota

Tomoaki Watari

Hiroshi Sakurai

Eizaburou Nakanishi

Masanobu Hayasaka

Junji Katamura

A preform having edges overlapped and jointed, two outer members for forming outer surfaces of a hydroformed product, and reinforcement members for forming reinforcement ribs that divide a hollow cross section of the hydroformed product, including a joint formed by, when more than three sheet materials for forming the outer members and the reinforcement members are overlapped together, welding a first sheet material on a surface of the overlapped sheet materials to a second sheet material positioned inside the first sheet material, and a space disposed and aligned with a joint plane between the second sheet material and a third sheet material located inside the second sheet material during the welding process.

Preform, hydroforming method, and hydroformed product

For forming a tubular work into a shaped hollow product by using hydroforming process, a method and a device are described. In the method, female and male dies are prepared. The female die has a longitudinally extending cavity which has a polygonal cross section when receiving the male die. The tubular work is placed into the cavity of the female die. The interior of the tubular work is then fed with a hydraulic fluid, and the pressure of the fluid is increased to a given level. The given level is smaller than a critical level that causes a bulging of the tubular work. The male die is then pressed against the tubular work to deform the same while keeping the hydraulic fluid at the given level, thereby forming a shaped hollow product that has a polygonal cross section that conforms to that of the cavity. The pressing work is continued until a circumferential length of the shaped hollow product becomes shorter than that of the tubular work.

Method and device for forming tubular work into shaped hollow product by using tubular hydroforming

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Kanagawa, Japan

Shinji Ooe