Patent ID: 7562802

Claim:
A structure body comprising: a first member having a first plate, a second plate which is substantially parallel to the first plate, and a third plate for connecting said first plate and said second plate, said third plate being substantially perpendicular to the first and second plates, and the third plate having one recessed portion in one corner portion of one end portion thereof, and another recessed portion in another corner portion of another end portion thereof, and a second member having a first plate and a second plate which is substantially parallel to the first plate of the second member, an end portion of the first plate of the second member being positioned in said one recessed portion so as to overlap said third plate with said end portion of the first plate of the second member, and an end portion of the second plate of the second member being positioned in said another recessed portion so as to overlap said third plate with said end portion of the second plate of the second member, and wherein the first plate of the first member and the first plate of the second member are on a same plane, and the second plate of the first member and the second plate of the second member are on a same plane, with a first friction stir weld between said first plate of the first member and the first plate of the second member, at the end portion of the second member in said one recessed portion, and with a second friction stir weld between said second plate of said first member and said second plate of said second member in said another recessed portion, the structure body being formed by: carrying out a first friction stir welding to the end portion of the first plate of the second member overlapping said third plate of the first member in the one recessed portion of the first member, carrying out a second friction stir weld to the end portion of the second plate of the second member overlapping said third plate of the first member in the another recessed portion of the first member, the first and second friction stir weldings being carried out from a side of an outer face of one side of said second member and a side of another outer face thereof, respectively, the first friction stir welding being carried out between the first plate of the first member and the first plate of the second member at an extension line of a center of a width of a first bead of a first friction stir welding portion formed at the end portion of the first plate of the second member overlapping the third plate of the first member, and the second friction stir welding being carried out between the second plate of the first member and the second plate of the second member at an extension line of a center of a width of a second bead of a second friction stir welding portion formed at the end portion of the second plate of the second member overlapping the third plate of the first member.