Heat exchanger for motor vehicles

Priority is hereby claimed to German Patent Application No. DE 10 2006 019 024.6, filed Apr. 25, 2006 and to International Patent Application PCT/EP2007/002271, filed Mar. 15, 2007, the entire contents of each of which is incorporated herein by reference.

The invention relates to a heat exchanger (e.g., a charge air cooler or cooling liquid cooler) for motor vehicles and can include tubes which are each formed from two plates and have two opposite longitudinal sides and two opposite narrow sides, with one of the longitudinal sides constituting the inflow side for cooling air, for example, and composed of heat transfer fins or the like which are arranged between the tubes and through which the cooling air flows freely, and composed of collecting spaces which are formed on the ends of the tubes or of the plates. The invention also relates to a cooling module for motor vehicles.

DE 30 17 701 describes conventional heat exchangers. In said document, the plates are of approximately rectangular design. The collecting spaces are formed by apertures which are arranged in the plates and are formed at the opposite ends of the plates. The two plates which together form one tube are for this purpose stacked congruently one over the other with their apertures aligned. The heat transfer fins are placed into the spacings between the tubes. The cooling air then flows freely through said spacings.

In comparison to other and possibly most heat exchangers of the type which have collecting tanks at the ends of flat tubes (DE 197 02 183 A1)—that is to say at the opposite narrow sides of tubes—the spatial requirement of the heat exchanger was therefore reduced. The collecting tanks require installation space which is not available for heat transfer. However, in the heat exchanger from DE 30 17 701, there is likewise no effective heat transfer in the region of the collecting spaces.

For this reason (installation space), in DE 197 02 183 A1, the collecting tanks were designed to be as flat as possible, as shown in FIG. 1 of said document by the reference symbol 22. In said heat exchanger, therefore, the heat exchanger network composed of flat tubes and corrugated fins can be configured to be slightly larger for the same installation space.

Another heat exchanger whose tubes are likewise formed from in each case two plates is known from DE 44 07 080 A1. Said heat exchanger could indeed be used as a charge air cooler. It is however of a different generic type, that is to say the generic type in which the plate stack which forms the tubes is arranged in a housing. In said heat exchanger, the charge air flows in at one side of the housing, is in heat-transferring contact with a cooling liquid which flow in the tubes, and leaves the housing at the opposite side.

Further prior art can be gathered for example from DE 103 28 638 A1 and from DE 103 59 806 A1. The heat exchanger shown and described in said documents are of a similar generic type, that is to say a generic type which is likewise not freely traversed by a coolant. Said documents describe in particular exhaust gas heat exchangers in which both the ducts for the exhaust gas and the ducts for a cooling liquid are formed by the configuration of the plates. The two media thus flow within the ducts formed by the specific plate configuration.

Finally, reference should also be made of a further heat exchanger which is shown and described in DE 40 12 046 A1. Said heat exchanger is of the type in which cooling air can flow freely through the heat transfer fins. In said heat exchanger, the ends of flat tubes have been bent around and attached directly to one another. Collecting tanks can be attached to the ends. The bending region or the attachment region of the collecting tanks in said heat exchanger is likewise not available for heat transfer.

In some embodiments, the object of the invention is that of providing comparatively large heat transfer faces in a heat exchanger of the generic type described in the introduction. The features of the present invention, as described in more detail below, can lead to the achievement of said object.

Because preferably both ends of the tubes open out in the longitudinal side which is remote from the inflow side, and which therefore faces away from the cooling air flowing in, it is possible to form the entire area of the heat exchanger which has air flowing in, or at least a relatively large part thereof, as a heat transfer face, resulting in the heat transfer face being comparatively enlarged. It was possible to provide the enlargement of the heat transfer faces despite the collecting tanks which are also arranged on the ends of the tubes of the heat exchanger according to the invention. The far ends of the plates or of the tubes are preferably slightly enlarged in cross section and bear against one another with their narrow sides. The collecting tanks can thereby be attached without the provision of a tube base. If the cross-sectional enlargement of the far ends is to be dispensed with, tube bases must be attached to the ends of the tubes to which the collecting tanks are to be fastened.

It is possible to have only one end of the tubes open out in the longitudinal side which is remote from the inflow side, and to provide the other end of the tubes on the narrow side which is remote from the opening-out point.

Because at least one end of the tubes opens out at a longitudinal side, the geometry or the configuration of the plates is accordingly not rectangular as in the prior art but is for example L-shaped, U-shaped or Z-shaped.

Another exemplary embodiment which is similar to the exemplary embodiment with U-shaped plates has plates or tubes whose configuration has a convex contour. The contour is arched in the direction of the inflow side.

In each case two plates are attached with their edges to one another in order to form a tube. The plates can be identical. Both plates then have an upright edge at which the two plates bear against one another and are connected in order to form the tube. It is however also possible to make one plate approximately planar, that is to say to form said plate without an upright edge, and to provide the other plate with an upright edge. It is also possible to place the upright plate edges into one another in order to connect them.

The ends of each of the tubes or plates have, as already indicated above, one angled contour in order to be able to open out in a corresponding longitudinal side.

The angled contoured piece can be kept very short—specifically long enough in order to be able to attach collecting tanks thereto.

Heat transfer fins or other elements which promote the transfer of heat are inserted between the tubes. Elements of said type are also arranged in the region with the angled or curved contour.

In an application as a charge air cooler, inserts for turbulence generation are situated in the tubes. It is also possible here, however, to provide other formations, such as deformed portions or the like, which act in the same direction. Said connection of the plates and the connection of the plates or of the tubes to the heat transfer fins is preferably carried out by means of a soldering process. The collecting tanks can be composed of plastic or of metal.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.