Heat Exchanger

Abstract

A heat exchanger such as a radiator including heat exchange tubes for a fluid and a heat exchange wall such as a header with an opening into which each tube extends and an exterior flange on each tube extending generally longitudinally of the tube and substantially spanning the space between the tube and the opening. Joining metal is provided in the opening uniting the tube, the flange and the wall at the opening with the joining metal when in the molten state wetting the tube, flange and wall in the region of the opening. The flange comprises a relatively soft metal such as aluminum for easy removal of the outer edge of the flange as by peeling it back when the opening is smaller than the space spanned by the tube plus the flange.

Description

SUMMARY OF THE INVENTION

One of the features of this invention is to provide a heat exchanger comprising one or more tubes each positioned in an opening in a heat exchange wall such as a header and with the tube including an exterior flange that will substantially span the opening when the opening is too large and that can be easily reduced in lateral length as by peeling its outer edge back to remove excess flange when the dimensions of the opening make such removal necessary.

Other features and advantages of the invention will be apparent from the following description of one embodiment thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary side elevational view partially broken away for clarity of illustration of a tube, fin and tank heat exchanger embodying the invention.

FIG. 2 is an enlarged cross sectional view of the heat exchanger tube only of FIG. 1.

FIG. 3 is a sectional view similar to FIG. 2 but illustrating the assembly of the tube of FIG. 2 in a corresponding opening in a metal wall which in this embodiment is a header plate.

FIG. 4 is an enlarged side elevational view partially broken away illustrating a portion of an embodiment where the flange means of a tube would normally extend beyond the header plate opening.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the embodiment of FIG. 1 the heat exchanger 10 comprises a header sheet or plate 11 forming a part of a tank 12 in which the heat exchanger is a radiator for cooling the liquid of an internal combustion engine. The heat exchanger 10 also includes a plurality of parallel liquid coolant tubes 13 each having an end 14 extending through a corresponding opening 15 in the header sheet 11.

Between each pair of adjacent parallel tubes 13 there is positioned a serpentine cooling fin 16 of customary construction having the peaks 32 of the undulations connected to the respective tubes 13.

Each tube 13 as illustrated in FIGS. 2 and 3 is of flattened oval construction with parallel sides 17 connected by integral end curved walls 18 and an internal fin 19 integral with the tube.

The tube 13 is provided with exterior flange means embodied in a pair of oppositely located flanges 20 that are integral with the tube 13 and positioned symmetrically at the ends 18 of the tube. This flange means extends longitudinally of each tube.

In the embodiment of FIG. 3 each tube 13 is positioned in an opening 15 in the header sheet 11 that is larger than the cross sectional length of the tube 13 so that the flanges 20 span the excess length 21 as illustrated.

In connecting walls such as the header sheet 11 to the tube illustrated at 13 it is customary to use a joining metal composition such as solder, brazing metal or the like which is molten when applied and capable of wetting the metal of the head exchanger parts and which forms a joint between the header sheet 11 and the tube 13 as illustrated at 22 in FIG. 3.

Because of the provision of the space spanning flanges 20 on the tube 13 the joint 22 metal, when in liquid form such as in a molten state, is held in space between the sheet and the tube by surface tension and capillary forces. Then when the metal hardens to the state shown in FIG. 3 the space is completely filled by the metal joint 22 and the parts are securely joined together.

The embodiment of FIG. 4 illustrates the conditions when the tube 23 plus the end flanges 24 cover a space greater than the length of the opening 25 in the header sheet 26. Under such conditions the end 27 of the tube 23 will extend through the opening 25 into the interior of the tank 28 and excess flange metal 29 is peeled back. In order to aid this peeling back in a simple rapid manner it is preferred that the metal of the tube 23 and flanges 24 be relatively soft such as copper, aluminum and the like. In fact, in these embodiments the entire heat exchanger is constructed of aluminum.

The chief advantage of this invention is that in spite of the fact that the openings 15 and 25 in which the tube 13 and 23 ends are located often vary greatly in size from a snug fit through a very loose fit as illustrated in FIG. 3, the flange means 20 provides an automatic compensating factor so that the tube plus flange means adapts itself readily to openings of varying length while still providing a fluid tight secure seal.

Thus experience has shown that the clearance between the header openings and the tube ends should not be greater than about 0.020 inch in order that the liquid filler or brazing metal will remain in the space, held there by surface tension and capillary forces. When the space is greater than this the molten metal often will not span the space so that imperfect joints result that readily leak particularly in high pressure systems.

Ordinarily when there is space of this type plain tubes can be expanded to fit the opening. When, however, as is customary the tubes contain internal heat exchange fins as illustrated by the single fin 19 this is not practical or advisable.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is may intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

Claims

I claim:

1. A heat exchanger, comprising: a tube for a heat exchange fluid; a heat exchange wall with an opening therein into which said tube extends; an exterior flange means on said tube extending generally longitudinally on the tube, said flange means being in contact with said wall at said opening when said opening is larger than said tube at said flange means and thereby substantially spanning the resulting space between said tube and said opening; and joining metal filling said space and uniting said tube, flange and wall at said opening, said joining metal when in the molten state wetting said tube, flange and wall in the region of said opening prior to and during solidification of said joining metal, said flange means comprising a relatively soft metal for easy removal of the outer edge of the flange means when the opening is smaller than the space spanned by the tube plus flange means.

2. The heat exchanger of claim 1 wherein said flange means comprises a spaced pair of said flanges on said tube.

3. The heat exchanger of claim 2 wherein said tube is of oval cross section and said flanges are located at the ends of the oval.

4. The heat exchanger of claim 1 wherein said flange means metal comprises aluminum.

5. The heat exchanger of claim 1 wherein said wall comprises a header, and there are provided a plurality of spaced said tubes each positioned in its said opening.

6. The heat exchanger of claim 5 wherein each said flange means comprises a spaced pair of said flanges on said tube, and wherein said tube is of oval cross section and said flanges are located at the ends of the oval.

7. The heat exchanger of claim 6 wherein said flange means metal comprises aluminum.