Heat exchanger comprising a connection flange that is joined to the manifold

A heat exchanger having tubes and at least one collecting tube is used, especially for air conditioning units of motor vehicles. The heat exchanger has pipes, at least one manifold that communicates with the pipes, and at least one connection flange. The connection flange is connected in a communicating manner to the manifold via a nozzle and can be connected to a conduit.

BACKGROUND OF THE INVENTION

The invention relates to a heat exchanger, in particular a condenser for an air conditioning system of a motor vehicle.

Condensers for air conditioning systems, as are disclosed for example by EP-A 915 308, have a coolant flowing through them, said coolant entering the condenser via a coolant connecting flange and leaving the condenser again via a further coolant flange. The connecting flanges have a continuous coolant duct which is connected, on the one hand, to a collecting tube of the condenser and, on the other hand, to a coolant inlet line or coolant outlet line. The entire condenser, composed essentially of a tube/rib block, the collecting tubes and the connecting flanges, is soldered in one operation in a soldering oven. For this purpose, it is necessary for the connecting flanges for the soldering process to be secured to the collecting tubes. Hitherto this was done by means of additional parts or soldering devices which has delayed the fabrication process.

A two-part connecting flange for attaching a coolant line to a condenser has been disclosed by U.S. Pat. No. 5,163,716. The condenser has a collecting box with a planar connecting face onto which a cuboid connecting block is fitted and is soldered to the collecting box. A coolant line is welded to an adaptor piece which is screwed to the connecting block. The coolant connection from the coolant line is made via the adaptor and a coolant duct in the connecting block. This coolant connection has a plurality of parts and mounting steps and is therefore associated with relatively high manufacturing costs.

EP-A 1 167 897 has disclosed a soldered flat tube condenser with two collecting tubes and one collector which is arranged parallel to one of the collecting tubes and is connected on the coolant side to this collecting tube by means of a connecting block with two connecting ducts. Coolant flows out of the condenser into the collector and back again into the condenser from the collector via this connecting block which is soldered to the collecting tube of the condenser. The connecting block has connectors, which are each extensions of the coolant connecting ducts and are inserted into openings in the collecting tube and secured thereto by tack welding or interference fitting. The parts are then soldered. Subsequent to the soldering process, the collecting container is screwed to the connecting block and sealed with respect to it. The collecting container is additionally connected in its upper region to the collecting tube by means of a clamp. The connecting block is thus a connecting and attachment part between the collecting tube and collecting container. The coolant lines are connected, in a way which is not illustrated, to the collecting tubes via an inlet flange and an outlet flange.

SUMMARY OF THE INVENTION

An object of the present invention is to improve the heat exchanger mentioned at the beginning to the effect that a connecting flange is constructed from a small number of individual components and can be secured easily with respect to the collecting tube for the soldering process and can, if appropriate, be soldered to the heat exchanger in one operation.

The invention provides for the connecting flange to be secured in a positively locking fashion with respect to the collecting tube by means of a connector, i.e. the connecting flange does not require any other components for securing purposes before the soldering process. The entire heat exchanger can thus be soldered to the connecting flange in a soldering oven.

According to one advantageous refinement of the invention, the connector is arranged on the collecting tube and is preferably formed from the collecting tube. It is advantageous if the collecting tube is of two-part construction, i.e. is composed of a bottom and a lid from which the connector can easily be formed, in a similar way to a passage. A corresponding receiving opening, which is also adapted to the round shape of the lid, is provided in the coolant connecting flange—said receiving opening receiving the connector in a positively locking and also frictionally locking fashion so that the two parts are secured.

According to a further, particularly advantageous refinement of the invention, the connector is arranged on the connecting flange and is preferably constructed in one piece with the connecting flange. The connecting flange can thus easily be placed on the collecting tube, which may either be of single-part or two-part construction, and inserted into a corresponding opening and this is sufficient to secure the connecting flange. In one advantageous refinement, the connector projects into the interior of the collecting tube and forms an excess length there which can be widened with respect to the opening in the collector tube. This improves the securing effect. Therefore, basically only two parts are necessary to secure the connecting flange and collecting tube, i.e. there is no need for any further securing means or parts. This simplifies the manufacturing and mounting process.

In one advantageous refinement of the invention, a further support face is also provided on the connecting flange, specifically at a distance from the connector. The support face is adapted to the rounded shape of the collecting tube or its lid and therefore fits snuggly against its surface. As a result, improved support of the connecting flange with respect to the collecting tube is obtained, specifically both before the soldering process and after the soldering process because the flange is soldered to the collecting tube in the region of this second bearing face.

In a further refinement of the invention, a blind hole bore is provided in the connecting flange and said blind hole bore can receive, for example, a holding element for attaching additional parts or a bearing pin for supporting the heat exchanger.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1shows a coolant condenser1which is composed of a tube/rib block2and laterally arranged collecting tubes3,4. The tube/rib block2is constructed from flat tubes (not illustrated in more detail) and corrugated ribs arranged between them. The ends of the flat tubes are received in passages of the collecting tubes3,4. The entire condenser1, composed of flat tubes, corrugated ribs and collecting tubes3,4, is soldered in a soldering oven. A coolant connecting flange5is attached to the collecting tube4and a coolant line (not illustrated) can be connected to said coolant connecting flange5. A further connecting flange for a second coolant line is not illustrated here.

FIG. 2shows the collecting tube4with the coolant connecting flange5in a somewhat enlarged representation. The connecting flange5is, on the one hand, connected (soldered) to the collecting tube4in a firm and sealed fashion and has an opening6for the connection of a coolant inlet line or coolant outlet line (not illustrated).

FIG. 3shows the collecting tube4which is of two-part construction and is composed of a shell-shaped bottom7and a shell-shaped lid8. The bottom has a series of passages9in which the abovementioned tubes are inserted.

FIG. 4shows the lid8as an individual part, said lid8having a connector10in a central region. The coolant connecting flange5is secured to the lid8by means of this connector10, and this is explained below.

FIG. 5shows a further view of the collecting tube4, i.e. a side view. The coolant connecting flange5is connected only to the lid8and has a planar connecting face11in which the coolant connecting opening6is arranged.

FIG. 6shows a section through the collecting tube4and the coolant connecting flange5along the section line VI-VI inFIG. 5. The coolant connecting flange5has an angled coolant duct12which communicates, on the one hand, with the collecting tube4and, on the other hand, with the connecting opening6. The connector10is formed from the lid (half shell)8, i.e. the connector10is constructed in one piece with the lid8. Since the lid forms an individual part of the collecting tube4, the connector10can easily be manufactured by punching a passage, preferably with a circular cross section. The coolant connecting flange5has a connecting end13on the collecting tube side, which connecting end13is, on the one hand, adapted to the contour of the lid8and, on the other hand, has a receiving bore13aof the size and shape of the connector10. The internal diameter of the receiving bore13aand the external diameter of the connector10are matched to one another in such a way that a slight clamping fit is produced. The coolant connecting flange5is thus secured to the collecting tube4after said coolant connecting flange5has been fitted onto the connector10and can thus be placed with the entire condenser1—without further resources or clamping means—in a soldering oven for the soldering process. After the soldering process, the end13of the connecting flange5is soldered to the connector10or to the lid8in a sealed and firm fashion. The connector5is thus also able to absorb forces which result from the attachment of a coolant line (not illustrated). From the description above it becomes clear that the coolant connecting flange5and the collecting tube4have been connected to one another in a fashion which is sealed with respect to coolant, without further parts in the form of connecting means.

FIG. 7shows a further exemplary embodiment of the invention, specifically a coolant connecting flange14in a view from above with a coolant connecting opening15and a blind hole bore16.

FIG. 8shows a section along the line VIII-VIII inFIG. 7. The coolant connecting flange14is manufactured from an aluminum block and has a continuous coolant duct17which ends in the connecting opening15at one end and in a connector18at the other. The connector18of the coolant connecting flange14is inserted into a corresponding receiving opening in a collecting tube19(illustrated by dashed lines). The coolant connecting flange14rests here with a collar20, adjoining the connector18via a shoulder, on the collecting tube19. The connecting flange14has, in addition to the collar20, a further support face21which is adapted to the contour of the collecting tube19. These two support faces, the collar20and the second support face21, mean that the connecting flange14is supported doubly with respect to the collecting tube19. The length of the connector18is dimensioned such that it projects into the collecting tube19and forms an excess length ü with the inner wall. The connector18can be widened conically (not illustrated) in the region of the excess length ü as a result of which better anchoring and securing of the connecting flange14with respect to the collecting tube19is achieved. The blind hole bore16is used to receive a pin-shaped holding element (not illustrated) to which additional parts can be attached.

FIG. 9shows a view of the connecting flange14from below, i.e. in the direction of the coolant duct17and with a view of the circular support face of the collar20and the end face of the connector18. Furthermore, the arched support face21which is stepped with a radius R can be seen.

FIG. 10shows the coolant connecting flange14from the side, it being possible to see an arcuate contour21aof the support face21: said contour21ais designed to correspond to the contour of the collecting tube19so that closely fitting abutment between the collecting tube19and the support face21is produced in this region.

From the above description, it is in turn clear that the coolant connection14and the collecting tube19are connected to one another without further additional parts, with the connector18assuming the securing function. The seal-forming soldering process takes place between the external circumference of the connector18and the corresponding receiving opening in the collecting tube19. The soldering process is preferably carried out in accordance with the Nocolok method.

The invention has been described using the example of a coolant condenser for an air conditioning system. However, it is to be noted that the heat exchanger according to the invention is also suitable for other application purposes.