Patent ID: 7089869

Claim:
A manufacturing method of a structural body, characterized in that manufacturing a first plate and a second plate for abutting and welding said first plate; said first plate comprising a first flange provided by bending a first side of said first plate, a second flange being orthogonal substantially to said first flange and provided by bending a second side of said first plate, and a recessed portion between an end portion in a longitudinal direction of said first flange and an end portion in a longitudinal direction of said second flange; said second plate comprising a third flange provided by bending a first side of said second plate and for connecting to said end portion in the longitudinal direction of said first flange, and an extended portion protruded from a third side of said second plate, said third side being orthogonal substantially to said first side of said second plate and to a second side which is parallel substantially to said first side, said extended portion extending to a vicinity of an end portion in a longitudinal direction of said third flange; abutting said end portion in the longitudinal direction of said first flange and said end portion of the longitudinal direction of said third flange; abutting said third side to an outer side of a circular arc of said second flange from said first plate; inserting and abutting said extended portion to said recessed portion; and welding the respective abutted portions.