Method of friction stir welding structural body, structural body, and extruded material

Abstract

The object of the present invention is to weld a hollow-shaped material from one side, regardless of the size accuracy of the hollow-shaped material or the like, and to form the joint with higher strength. Projecting segments 12 b, 22 b of face plates of hollow-shaped materials 10, 20 are friction stir welded from above. Next, a connecting material 30 is placed on the upper face plates 11, 21 of the hollow-shaped materials 10, 20, and is friction stir welded from above. The welding region exists at the node between a rib connecting the two face plates 11, 12 ( 21, 22 ) and the face plate 11 ( 21 ,). The joint of the connecting material 30 and the face plates 11, 21 are lap joint. Not butt joint. Therefore, the hollow-shaped materials could be welded with ease, even though there exists manufacturing tolerance, or tolerance in arrangement of the hollow-shaped materials 10, 20.

We claim:  
     
         1 . A structural body, comprising 
 two hollow-shaped materials welded together;    each of said hollow-shaped materials includes two face plates which are connected by a plurality of ribs, and an end portion of one of said face plates is projected further than an end portion of the other of said face plates;    the projected end portions are friction stir welded together;    a connecting material which is substantially parallel to said projected one of said face plates overlaps an end portion of each of said other face plates of said hollow-shaped materials, with the overlap being friction stir welded; and    an external surface of said other face plate is provided with a convex portion along the end portion of said connecting material.    
     
     
         2 . A structural body, comprising: 
 two hollow-shaped materials welded together;    each of said hollow-shaped materials includes two face plates which are connected by a plurality of ribs, and an end portion of one of said face plates is projected further than an end portion of the other of said face plates;    the projected end portions are friction stir welded together;    a connecting material which is substantially parallel to said projected one of said face plates overlaps an end portion of each of said other face plates of said hollow-shaped materials, with the overlap being friction stir welded; and    a surface of said connecting material facing said projected face plate is provided with a convex portion, and said convex portion is positioned in the vicinity of said other face plate.    
     
     
         3 . A structural body, comprising: 
 two members having overlapping surfaces, the overlapping surfaces being friction stir welded; and    a convex portion is provided to a surface of one of the two members adjacent an end portion of the other of the two members, said surface from which the convex portion extends being adjacent the other member.    
     
     
         4 . An extruded material for friction stir welding, comprising: 
 two face plates connected by a plurality of ribs;    an end portion of one of said face plates is positioned near a rib at an end portion of said one of said face plates;    an end portion of the other face plate is projected further than an end portion of said one of said face plates; and    a convex portion is provided to a surface of said other face plate, closest to said one of said face plates, along the end portion of said other face plate.    
     
     
         5 . An extruded material for friction stir welding according to  claim 4 , wherein: 
 said rib at an end portion and a rib adjacent thereto are substantially connected to one point of said other face plate.    
     
     
         6 . An extruded material for friction stir welding according to  claim 4 , wherein: 
 said rib at an end portion of said one of said face plates is substantially perpendicular to said other face plate.    
     
     
         7 . An extruded material for friction stir welding, comprising: 
 a first convex portion provided to one of the surfaces at both ends of a plate; and    a pair of second convex portions having narrower width than that of said first convex portion, provided to the opposite surface of the plate to that provided with said first convex portion at both ends.    
     
     
         8 . An extruded material for friction stir welding, comprising: 
 a convex portion provided to one of the surfaces at both ends of a plate; and    a pair of concave portions provided to the surface of the plate opposite to the surface having said convex portion, the width of each of said concave portions being narrower than the width of said convex portion.