BUTT WELDING APPARATUS, BUTT WELDING METHOD AND BUTT WELDED PRODUCT

摘要

A butt welder, its butt welding method and a product produced by that welding method. Two electrode rollers (3, 4) disposed on the surfaces and rear surfaces of a thick plate material (1) and a thin plate material (2) having end faces (1A, 2A) abutted each other and welding the butting part (6) of these plate materials (1, 2) by melting it with electric resistance heat when power is supplied have a thickness straddling these plate materials (1, 2), and comprise first small diameter parts (3A, 4A) on the thick plate material (1) side and second large diameter parts (3B, 4B) on the thin plate material (2) side. The first parts (3A, 4A) touch the thick plate material (1) before the second parts (3B, 4B) touch the thin plate material (2) and press the thick plate material (1). Since the end face (1A) of the thick plate material (1) inflates and deforms to the thin plate material (2) side and touches the end face (2A) of the thin plate material (2) surely, power is conducted between the end faces (1A, 2A) even if they are not finished by polishing, or the like.