Heat exchanger

Abstract

The invention relates to heat exchangers for use in motor vehicles or for industrial use, for example, to heat exchangers for use as evaporators, condensers, oil coolers, intercoolers, heater cores, etc. The invention provides a heat exchanger comprising pairs of plates with each plate of the pair having formed on one side thereof a peripheral ridge, central ridge and channel dividing U-shaped ridges which are formed by forging or cutting. Each pair of plates are fitted together and joined, with channel recesses thereof opposed to each other to form a flat tube and a plurality of U-shaped divided fluid passageways in a U-shaped fluid channel inside the tube. Each pair of adjacent flat tubes are joined by spectacle-shaped header members interposed between the upper ends of the tubes and each comprising a front and a rear fluid passing tube portion and a connecting portion therebetween to provide a front and a rear header in communication with the upper ends of the flat tubes. The flat tubes have a reduced front-to-rear width, diminished wall thickness (thinner layers) and increased heat transfer efficiency to provide a heat exchanger which achieves a higher heat transfer efficiency and greatly improved heat exchange performance.

1 . A heat exchanger comprising ridged plates each having a peripheral ridge provided on one side of the plate along a periphery thereof and a central ridge provided on said one side of the plate at a center of the width thereof and extending downward from an upper end of the plate to a position where a return channel can be formed, the ridges being formed by forging, each of the ridged plates having a U-shaped channel recess formed inwardly of the peripheral ridge and comprising a front and a rear channel recess portion formed on opposite sides of the central ridge and a return channel recess portion positioned under the central ridge, the channel recess having one of two fluid inlet-outlet through holes formed at one end thereof and the other through hole formed at the other end thereof, each of the ridged plates having a flat surface on the other side thereof and being fitted to each of flat plates face-to-face, each of said flat plates having the same contour and the same size as the ridged plate and two fluid inlet-outlet through holes corresponding to said through holes, the peripheral ridge of the ridged plate having a top end thereof joined to a peripheral edge of the flat plate, the central ridge of the ridged plate having a top end thereof joined to a flat surface of a corresponding central portion of the flat plate, whereby a flat tube having a U-shaped fluid channel inside thereof is formed so that a plurality of flat tubes are arranged in parallel with a header member interposed between upper ends of each pair of adjacent flat tubes to provide a front and a rear header in communication with the upper ends of the said pair of adjacent flat tubes, the header member comprising a pair of front and rear fluid passing tube portions in communications with the respective inlet-outlet through holes of the plates of said pair of adjacent flat tubes and a connecting portion between the tube portions.  
   
   
       2 . A heat exchanger according to  claim 1 , wherein a plurality of channel dividing U-shaped ridges are formed in the U-shaped channel recess of each ridged plate by forging, and each ridged plate and each flat plate are fitted together face-to-face with the channel dividing U-shaped ridges of the ridged plate joined to the flat surface of the corresponding central portion of the flat plate to form a plurality of U-shaped divided fluid passageways in the U-shaped fluid channel inside the flat tube.  
   
   
       3 . A heat exchanger according to  claim 1 , wherein the header member interposed between the ends of each pair of adjacent flat tubes has its fluid passing tube portions joined at their opposite end faces to the flat surfaces on the other sides of the opposed plates of the pair of flat tubes.  
   
   
       4 . A heat exchanger according to  claim 1 , wherein tacks for temporarily holding the header member are provided respective edges defining the inlet-outlet through holes in the end of each plate.  
   
   
       5 . A heat exchanger according to  claim 2 , wherein a plurality of cutouts are formed in the channel dividing ridges on each plate to cause the adjacent divided fluid passageways inside the flat tube to communicate with each other through the cutouts.  
   
   
       6 . A heat exchanger according to  claim 1 , wherein a fin is provided between each pair of adjacent flat tubes included in the flat tubes arranged in parallel, and the fin has opposite sides edges thereof joined to the flat surfaces on the other sides of the plates of the pair of flat tubes.