Soldered flat tube for condensers and/or evaporators

Abstract

The present invention relates to a soldered flat tube for condensers and/or for evaporators in air-conditioning systems, in particular in motor vehicles, which can be produced by deformation of endless aluminum sheet-metal strips, has two narrow sides and two wide sides and also has inner passages with a hydraulic diameter which is greater than or equal to 0.254 mm, and the flat tube has a tube wall thickness of less than 0.25 mm, wherein both narrow sides are reinforced by having at least double the thickness of the remaining tube wall thickness.

1 . A soldered flat tube for one of a condenser and an evaporator in motor vehicle air-conditioning systems, the tube comprising:
 one or more endless aluminum-containing sheet-metal strips shaped so as to have two narrow sides, two wide sides, and inner passages with a hydraulic diameter, which is greater than or equal to 0.254 mm; and   a tube wall thickness of less than 0.25 mm;   wherein both narrow sides are reinforced so as to have a thickness of at least two times the remaining tube wall thickness.   
     
     
         2 . The flat tube according to  claim 1 , wherein the flat tube comprises three sheet-metal strips, two of the sheet-metal strips forming the tube wall and the third sheet-metal strip forming an inner insert. 
     
     
         3 . The flat tube according to  claim 2 , wherein the two sheet-metal strips which form the tube wall are substantially identical in form, one longitudinal edge of the sheet-metal strips having a larger arc and the other longitudinal edge of the sheet-metal strips being configured with a smaller arc, the sheet-metal strips being disposed in such a manner with respect to one another that the larger arc of one longitudinal edge of one of the two sheet-metal strips engaging around the smaller arc of the longitudinal edge of the other of the two sheet-metal strips, and vice versa. 
     
     
         4 . The flat tube according to  claim 2 , wherein the inner insert has two deformed longitudinal edges which bear against insides of the narrow sides. 
     
     
         5 . The flat tube according to  claim 1 , wherein the flat tube can be produced either from one single sheet-metal strip or from two sheet-metal strips. 
     
     
         6 . The flat tube according to  claim 1 , wherein the flat tube is formed from two sheet-metal strips, one of the narrow sides comprising a bend which lies in a fold of one of the sheet-metal strips, and wherein an other narrow side foamed by a longitudinal edge of the one of the sheet-metal strips is configured with a larger arc, which is placed around a smaller arc at an other longitudinal edge of the one of the sheet-metal strips, an other of the sheet-metal strips being configured as a corrugated inner insert, the longitudinal edges of which bear or do not bear against the inside of the narrow sides. 
     
     
         7 . The flat tube according to  claim 1 , wherein the passage wall thickness is between about 0.03 mm and about 0.15 mm. 
     
     
         8 . The flat tube according to  claim 1 , wherein the tube wall thickness is between about 0.08 mm and about 0.20 mm. 
     
     
         9 . The flat tube according to  claim 1 , wherein a small dimension of the flat tube is between about 0.8 mm and about 1.3 mm and a large dimension is between about 8 mm and about 20 mm 
     
     
         10 . The flat tube according to  claim 9 , wherein the large dimension is between about 12 mm and about 16 mm. 
     
     
         11 . The flat tube according to  claim 1 , wherein the hydraulic diameter is between about 0.30 mm and about 0.70 mm. 
     
     
         12 . A condenser or evaporator as a component of an air-conditioning system of motor vehicles, the condenser or evaporator comprising:
 a soldered heat exchanger network made up of flat tubes and fins which are disposed between the flat tubes and through which cooling air flows, at least one of the flat tubes including
 one or more endless aluminum-containing sheet-metal strips shaped so as to have two narrow sides, two wide sides, and inner passages with a hydraulic diameter which is greater than or equal to 0.254 mm; and 
 a tube wall thickness of less than 0.25 mm; 
 wherein both narrow sides are reinforced so as to have a thickness of at least two times the remaining tube wall thickness.