Dai-ichi High Frequency Co., Ltd.

Daiwa House Industry Co., Ltd

Susumu Hanyoh

Yasuo Watanabe

Akira Fukuda

Kenji Furumi

A method of and an apparatus for manufacturing an elongated metallic member (1) having at least one thickened wall area defined at a portion thereof. That portion of the elongated metallic member (1) is heated to a plasticizable temperature to form a heated area (5) while the latter is moved along the metallic member (1) and, at the same time, axially inwardly compressed to allow upsetting at the heated area (5), to thereby form a thickened wall area. A trailing portion (1a) of the thickened wall area of the elongated metallic member (1) immediately after the heated area (5) is cooled. The ratio (V/W) of a compressing speed V relative to the moving speed W of the position of the heated area (5) in reference to the thickened portion (1a) of the metallic member (1) is progressively increased from a small value, employed at an initial stage of wall thickening, along the metallic member (1) to an aimed value, employed at a steady stage of wall thickening, to thereby progressively increase a wall thickening ratio along the metallic member (1) to a designed value. The subsequent wall thickening is carried out while the ratio is maintained at said designed value for the steady stage of wall thickening. A method of connecting two metallic members (1) in end-to-end fashion and a method of connecting a beam to the metallic member (1) are also disclosed.

Growing community of inventors

Tokyo, Japan

Susumu Hanyoh