Japanese National Railways

Hakusan Seisakusho Co., Ltd.

Hakusan Seissaku-sho Co., Ltd.

Tadashi Takimoto

Hirotsugu Oishibashi

Muneyuki Ohara

Katsuyoshi Ueyama

Mitsuo Nakamura

Keiichi Aoki

Kenzo Hagiwara

Takayoshi Amano

Akio Kobayashi

A gas pressure welding machine comprises a movable clamp means for clamping one of reinforcing rods to be joined together, a stationary clamp means for clamping the other reinforcing rod, a punching die for punching-shearing a bulge being formed around a joint portion of the reinforcing rods, and a key connection mechanism for detachably connecting the movable clamp means and the punching die, whereby the reinforcing rods are subjected to pressure butt welding to form a bulge around a joint portion thereof and the bulge is immediately punching-sheared under red heat by the punching die.

Gas pressure welding machine

A punching-shearing method for inspecting the quality of a butt welded joint comprises pressure butt welding steel members under heat to form an annular bulge around the joint portion of the steel members, punching-shearing the bulge under red heat immediately after the pressure butt welding process from one side of the bulge in parallel with the axes of the steel members by use of a shearing die having higher and lower shearing edge portions so that the higher shearing edge portions penetrate the bulge prior to the lower shearing edge portions, so as to cause the base of the bulge to remain around the joint portion in a slightly higher position than the peripheral surfaces of the steel members, and determining the quality of the joint portion from the peripheral surface of the base of the bulge remaining on the joint portion.

Punching-shearing method for inspecting quality of butt welded joint

Growing community of inventors

Fuchu, Japan

Tadashi Takimoto