Heat exchanger

Abstract

A heat exchanger comprising: a plurality of tubes inside of which a fluid passes; fins which are joined to the outer surfaces of the tubes and promote heat exchange between a fluid passing around the tubes and the fluid passing through inside the tube; and tank sections comprising core plates having insertion holes formed for the tubes to be inserted therein and tank bodies having the core plates joined thereto for distributing or collecting the fluid to be passed through the tubes; the tube comprises a first and a second tube plates joined in opposition to each other and inner fins disposed between the first and second tube plates, and that the portion of the tube to be inserted into the insertion hole of the core plate has generally the same outer shape as the periphery of the insertion hole, and that the portions of the first and second tube plates not to be inserted into the insertion hole of the core plate have overlapping sections which overlap each other in laminating direction of the tubes.

1 . A heat exchanger comprising:
 a plurality of tubes inside of which a fluid passes;   fins which are joined to the outer surfaces of said tubes and promote heat exchange between a-fluid passing around said tubes and the fluid passing through inside said tube; and   tank sections comprising core plates having insertion holes formed for said tubes to be inserted therein and tank bodies having said core plates joined thereto for distributing or collecting the fluid to be passed through said tubes;   characterized in that said tube comprises a first and a second tube plates joined in opposition to each other and inner fins disposed between said first and second tube plates, and that the portion of said tube to be inserted into said insertion hole of said core plate has generally the same outer shape as the periphery of said insertion hole, and that the portions of said first and second tube plates not to be inserted into said insertion hole of said core plate have overlapping sections which overlap each other in laminating direction of said tubes.   
   
   
       2 . A heat exchanger as claimed in  claim 1 , wherein said overlapping sections are formed by attaching inner surfaces of said first tube plate and said second tube plate to each other. 
   
   
       3 . A heat exchanger as claimed in  claim 2 , wherein said overlapping sections are fixed in calking by bending one of said first tube plate and said second tube plate. 
   
   
       4 . A heat exchanger as claimed in  claim 1 , wherein said overlapping sections are formed outside said tube, and the end portion of said overlapping section in the tube longitudinal direction is abutted to said core plate.