Flat tube for heat exchanger

Abstract

A tube ( 10 ) for a motor vehicle heat exchanger exhibits a cross section comprising two opposite longitudinal walls ( 12 ), each provided with at least two concave portions ( 14 ).

1 . A tube for a motor vehicle heat exchanger exhibiting a cross section comprising two opposite longitudinal walls, wherein each wall is provided with at least two concave portions. 
     
     
         2 . The tube as claimed in  claim 1 , wherein two concave portions are separated by a convex portion. 
     
     
         3 . The tube as claimed in  claim 2 , wherein the convex portion is of such a size that the internal perimeter of the section has a value that is at least 2% greater than the section of a tube in which the walls are straight. 
     
     
         4 . The tube as claimed in  claim 1 , wherein the walls of the tube are connected to one another by end sections which are substantially circular in shape. 
     
     
         5 . The tube as claimed in  claim 4 , exhibiting, according to the cross section of the tube, a length L Tube  denoting the greatest distance between the sections with a substantially circular shape on the outside of the tube, a width I Tube  denoting the smallest distance between the two walls of the tube on the outside of the tube and a flatness ratio T f  of the tube defined by the relationship: 
       
         
           
             
               
                 T 
                 f 
               
               = 
               
                 
                   l 
                   Tube 
                 
                 
                   L 
                   Tube 
                 
               
             
           
         
         where the flatness coefficient Tf is strictly lower than 0.20 to ±0.01. 
       
     
     
         6 . A fin comprising at least one substantially oblong opening, wherein the opening comprises an edge provided with two opposite longitudinal walls, each provided with at least two convex portions. 
     
     
         7 . The fin as claimed in  claim 6 , in which two convex portions are separated by a concave portion. 
     
     
         8 . A heat exchanger provided with at least one fin as claimed in  claim 7  and comprising at least one tube for a motor vehicle heat exchanger exhibiting a cross section comprising two opposite longitudinal walls, wherein each wall is provided with at least two concave portions. 
     
     
         9 . An assembly of at least one tube for a motor vehicle heat exchanger exhibiting a cross section comprising two opposite longitudinal walls, wherein each wall is provided with at least two concave portions and at least one fin as claimed in  claim 6 , wherein the tube is configured to be introduced into the inside of an opening in the fin with play existing between the tube and the opening.