Aluminum flat tube for heat exchanger

Abstract

An aluminum flat tube for a heat exchanger is fabricated from an aluminum strip-shaped material which is structured by a core material coated with a sacrificial anode material on the inner face thereof and coated with a brazing filler metal on the outer face thereof by bending in the width direction to form a nearly B-shaped flat cross section. To improve the corrosion resistance of the inner face of the tube, the both edge parts of the strip-shaped material in the width direction thereof are bent inward into the tube so as the front end edge of the edge part to become apart from the flat inner face of the tube.

1 . An aluminum flat tube for a heat exchanger, fabricated by an aluminum strip-shaped material being structured by a core material coated with a sacrificial anode material on the inner face thereof and coated with a brazing filler metal on the outer face thereof into a nearly B-shaped flat cross section, the strip-shaped material being bent in the width direction thereof to have: a pair of a first flat plane and a second flat plane, facing and extending in parallel to each other; a pair of curved parts connecting the first flat plane and the second flat plane in the width direction; a partition part being formed by turning-up the first flat plane at the center in the width direction thereof vertically inward therefrom; a joint part formed by turning-up each edge part of the strip-shaped material at the center in the width direction of the second flat plane to butt the turned-up edges with each other, and by connecting the turned-up edge parts to the partition part; wherein the both edge parts in the width direction of the strip-shaped material are folded inward into the tube, and the edges are apart from the inner face of the second flat plane.  
     
     
         2 . The aluminum flat tube for a heat exchanger as in  claim 1 , wherein the both edge parts in the width direction are formed to butt to each other in a form of umbrella-shape cross section, and the top of the partition part contacts the inner top face of the umbrella.  
     
     
         3 . The aluminum flat tube for a heat exchanger as in  claim 2 , wherein a concave brazing filler metal basin is formed near the front end of each edge part.  
     
     
         4 . The aluminum flat tube for heat exchanger as in  claim 1 , wherein the both edge parts in the width direction have their respective leg parts formed by bending orthogonal to the second flat plane, while the front end portion of each bent part is turned-up toward the second flat plane by a length shorter than the length of the leg part, and the turned-up top face contacts the top of the partition part.  
     
     
         5 . The aluminum flat tube for a heat exchanger as in  claim 1 , wherein the both edge parts in the width direction have their respective leg parts bent orthogonal to the second flat plane, while the front end portion of each bent part is further bent to nearly parallel to the second flat plane, and the bent top face contacts the top of the partition part.  
     
     
         6 . An aluminum flat tube for heat exchanger, fabricated by an aluminum strip-shaped material being structured by a core material coated with a sacrificial anode material on the inner face thereof and coated with a brazing filler metal on the outer face thereof into a nearly B-shaped flat cross section, the strip-shaped material being bent in the width direction thereof to have: a first flat plane and a second flat plane, facing and extending in parallel to each other; a pair of curved parts connecting the first flat plane and the second flat plane in the width direction; a partition part being formed by turning-up the first flat plane at the center in the width direction thereof vertically inward therefrom; an overlapping part formed by overlapping each edge part of the strip-shaped material at the center in the width direction of the second flat plane with each other, and by connecting the overlapped part to the partition part; wherein an edge part in the width direction of the strip-shaped material extends over the second flat plane, while the other edge part is formed into a step inward the inner face by the thickness of the strip-shaped material, and the front end part of the stepped part is turned-up to a middle position of the stepped part, then a turned-up overlapped part contacts the top of the partition part.