Multi-chamber flat tube

Abstract

The invention relates to a multi-chamber tube, produced from a flat sheet, welded along the longitudinal surfaces with two planar face surfaces, two curved narrow sides and webs, folded from the flat strip which divide adjacent chambers and which are soldered to the opposing tube inner wall and a method for production thereof. According to the invention, the flat strip comprises inward projections in the region of the soldering of the webs.

1 . A multi-chamber tube which is manufactured from a flat strip, comprising: a hollow interior that is defined by two flat longitudinal wall faces and two curved narrow wall faces and that is closed by means of a longitudinal seam; at least one web which is folded out of the flat strip toward the tube interior and which divides adjacent chambers within the tube, the at least one web being soldered to the inner surface of the opposing tube wall; and in the region of the soldered connection of the at least one web to the opposing tube wall, means, located in the opposing tube wall, for compensating by deformation for varying lengths of the at least one web without increasing the external thickness dimension of the tube, said compensating means including an embossment which is directed toward the inside of the tube, and which forms a surface that contacts the end of the at least one web and has a width and a configuration sufficient so that the surface is deformed to compensate for variations in length of the at least one web, and wherein the embossment has a height that is less than about one half of the thickness of the flat strip.  
   
   
       2 . A multi-chamber tube which is manufactured from a flat strip, comprising: a hollow interior that is defined by two flat longitudinal wall faces and two curved narrow wall faces and that is closed by means of a longitudinal seam; at least one web which is folded out of the flat strip toward the tube interior and which divides adjacent chambers within the tube, the at least one web being soldered to the inner surface of the opposing tube wall; and in the region of the soldered connection of the at least one web to the opposing tube wall, an embossment in the opposing tube wall which is directed toward the inside of the tube and which forms a surface that is deformable to compensate for a length of the at least one web that extends beyond the length necessary to contact said surface when the tube is conformed to a predetermined standard external size, wherein the embossment is constructed in the manner of a plateau, having a width b, which corresponds at least to three times the thickness s of the flat strip, and at a height h, which is less than half of the thickness s of the flat strip.  
   
   
       3 . A multi-chamber tube as claimed in  claim 2 , wherein the thickness of the flat strip is 0.1≦s≦0.5 mm.  
   
   
       4 . A multi-chamber tube as claimed in  claim 1 , wherein the tube has a breadth t in the range of 20 mm≦t≦60 mm and wherein the tube has a thickness d in the range of 1.5 mm≦d≦2.0 mm.  
   
   
       5 . A multi-chamber tube as claimed in  claim 1 , comprising at least a first and a second of said webs, and first and second of said embossments arranged respectively on the longitudinal tube wall which is located opposite one of said first and second webs.  
   
   
       6 . A multi-chamber tube as claimed in  claim 5 , wherein the first and second webs are alternately folded out of the first longitudinal wall face and out of the second opposite longitudinal wall face and said embossments also alternately arranged on the longitudinal face which is located opposite each web.  
   
   
       7 . A multi-chamber tube as claimed in  claim 5 , wherein the first and second webs are folded out of only one longitudinal wall face, and the embossments are arranged on the opposite longitudinal face.  
   
   
       8 . A multi-chamber tube as claimed in  claim 1 , wherein the embossment forms a resilient surface.  
   
   
       9 . A multi-chamber tube as claimed in  claim 1 , wherein the embossment has a height that corresponds to the variations in length of the at least one web during manufacture of the tube.  
   
   
       10 . A multi-chamber tube as claimed in  claim 1 , wherein the embossment has an indentation into the outer surface of the tube that has a depth sufficiently small that it will not interfere with formation of a continuous solder connection between the tube and a subsequently attached corrugated heat exchange fin.  
   
   
       11 . A method for manufacturing a multi-chamber tube as claimed in  claim 1 , comprising: 
 forming at least one web protruding from a flat strip;    forming at least one said embossment on the flat strip;    forming the flat strip into a flat tube shape having a longitudinal seam, such that the at least one web faces the embossment;    closing the seam to form a closed tube;    moving the distal end of the at least one web into abutment with the embossment; and    standardizing the flat tube to a predetermined constant thickness d between its two flat longitudinal wall faces, whereby any tolerance variation in the length of the at least one web is accommodated by deformation of the at least one said embossment.    
   
   
       12 . A method as claimed in  claim 11 , further comprising: 
 applying corrugated heat exchange fins to both flat sides of the tube to form a tube and fin assembly; and    brazing the tube and fin assembly to braze-connect the fins to the tube and the distal end of the at least one web to the embossment.    
   
   
       13 . A multi-chamber tube as claimed in  claim 1 , further comprising a corrugated heat exchange fin brazed to at least the flat side of the tube in which the embossment is located.  
   
   
       14 . A multi-chamber tube as claimed in  claim 13 , wherein the embossment has a height that is sufficiently small to form a continuous brazed connection with the tube surface across the region of the embossment.  
   
   
       15 . A multi-chamber tube as claimed in  claim 14 , wherein the embossment has a height that is less than about the thickness of the flat strip.  
   
   
       16 . A multi-chamber tube as claimed in  claim 1 , wherein said surface has a width that is at least twice the thickness of the flat strip.  
   
   
       17 . A multi-chamber tube as claimed in  claim 1 , wherein the external thickness dimension of the tube comprises a thickness produced after standardization of the size of the tube after its fabrication.  
   
   
       18 . A multi-chamber tube as claimed in  claim 1 , wherein said surface has a configuration that is generally flat.