Tube for heat exchanger and method of manufacturing the same

Abstract

A tube for a heat exchanger has a tube member and a fin inserted in the tube member. The tube member has a first wall having a first end portion and a second wall having a second end portion. The second end portion of the second wall is folded over the first end portion of the first wall. Also, an end of the fin is held between the first end portion and the second end portion of the tube member. Further, the end of the fin has a bent portion at an end of the first end portion within the folded second end portion. The bent portion of the fin is engaged with the first end portion of the tube member for positioning the fin with respect to the tube member.

1 . A tube for a heat exchanger, comprising: 
 a tube member having a first wall and a second wall that are opposed to each other, the first wall having a first end portion, the second wall having a second end portion, the second end portion folded over the first end portion; and    a fin disposed in the tube member, the fin having an end held between the first end portion and the second end portion of the tube member, wherein    the end of the fin has a fin bent portion over an end of the first end portion of the tube member for positioning the fin with respect to the tube member.    
   
   
       2 . The tube according to  claim 1 , wherein 
 the first wall connects to the second wall through a tube bent portion on a side opposite to the first end portion and the second end portion.    
   
   
       3 . The tube according to  claim 1 , wherein 
 the fin bent portion has a dimension with respect to a direction perpendicular to the first end portion of the tube member equal to or smaller than a thickness of the first end portion.    
   
   
       4 . The tube according to  claim 1 , wherein the fin bent portion has a substantially L-shape.  
   
   
       5 . A heat exchanger comprising a tube according to  claim 1 .  
   
   
       6 . The heat exchanger according to  claim 5 , further comprising: 
 a header tank formed with a plurality of tube holes, wherein    the tube is one of a plurality of tubes and ends of the tubes are received in the tube holes of the header tank.    
   
   
       7 . A method of manufacturing a tube for a heat exchanger, comprising: 
 forming a tube member to have a first wall having a first end portion and a second wall having a second end portion;    inserting a fin between the first wall and the second wall of the tube member;    folding the second end portion of the second wall over the first end portion of the first wall in a condition that an end of the fin is interposed between the first end portion and the second end portion and the end of the fin is engaged with the first end portion of the first wall by a fin bent portion.    
   
   
       8 . The method according to  claim 7 , further comprising: 
 forming the fin bent portion on the end of the fin before the inserting.    
   
   
       9 . The method according to  claim 7 , wherein 
 the folding includes bending the end of the fin over an end of the first end portion of the tube member to form the fin bent portion.    
   
   
       10 . The method according to  claim 9 , wherein 
 the inserting includes placing the fin such that the end of the fin protrudes from the first end portion of the tube member.    
   
   
       11 . The method according to  claim 7 , further comprising: 
 cutting the tube member into a predetermined length after the folding.    
   
   
       12 . The method according to  claim 7 , wherein 
 the forming of the tube member includes folding a plate member to have the first wall, the second wall and a tube bent portion between the first wall and the second wall.