Frame and method for fabricating the same

Abstract

A frame 1 is formed of an outer chord 2 of T-shaped section having an extension 4 extending inwardly, and an inner chord 3 having a flat portion 5 abutting against the extension 4 of the outer chord 2 . The extension 4 of the outer chord 2 and the flat portion 5 of the inner chord 3 are friction stir welded together with one abutted against the other.

1 . A frame comprising: 
 an outer frame member of T-shaped section having an extension extending inwardly; and    an inner frame member having a flat portion abutting against the extension of the outer frame member,    wherein the outer frame member and the inner frame member are friction stir welded together with the edge of the extension of the outer frame member abutted against the edge of the flat portion of the inner frame member.    
   
   
       2 . The frame of  claim 1 , wherein the inner frame member is formed of two or more frame members friction stir welded together with one abutted against another.  
   
   
       3 . A method for fabricating a frame, comprising the steps of: 
 preparing an outer frame member of T-shaped section having an extension extending inwardly;    preparing an inner frame member having a flat portion abutting against the extension of the outer frame member; and    friction stir welding the outer frame member and the inner frame member with the edge of the extension of the outer frame member abutted against the edge of the flat portion of the inner frame member.    
   
   
       4 . The method for fabricating a frame of  claim 3 , wherein the step of preparing an inner frame member comprises the step of friction stir welding two or more frame members with one abutted against another.  
   
   
       5 . The method for fabricating a frame of  claim 3 , further comprising, after friction stir welding the outer frame member and the inner frame member, the step of subjecting the outer and inner frame members together to surface treatment or finish coating.  
   
   
       6 . The method for fabricating a frame of  claim 4 , further comprising, after friction stir welding the outer frame member and the inner frame member, the step of subjecting the outer and inner frame members together to surface treatment or finish coating.