Frame joint structure joining method

Abstract

A structure of joining in a T shape two frame members of U-shaped cross sections having openings is provided. At a joint of the first frame member and the second frame member, a reinforcing member mounted with unfoamed resin is set within the first and second frame members. A foamed resin fills the spaces between the first and second frame members and the reinforcing member. The first and second frame members, foamed resin and reinforcing member are integrally united, having a high strength at the joint of the two frame members.

1 . A method for forming a frame joint structure, comprising the steps of: 
 welding an end portion of a second frame member of a U-shaped cross section having an opening to a first frame member of a U-shaped cross section having an opening so as to temporarily secure said first and second frame members together;    mounting a foam resin to a reinforcing member to be extended by predetermined lengths into the first frame member and the second frame member at a temporarily welded joint;    setting the reinforcing member mounted with the foam resin within the first frame member and within the second frame member;    closing the openings of the first and second frame members by a plate member so that the frame members have closed cross sections; and    heating and foaming the foam resin within the first and second frame members.    
   
   
       2 . The frame joint structure forming method according to  claim 1 , further comprising the step of applying a coat of paint to a surface of the plate member after the closed cross-section forming step, wherein the heat foaming step comprises heat drying of the applied paint.