EP2648862B1 - Assembly of two parts crimped one over the other - Google Patents

Description

The invention relates to a collector of a heat exchanger according to the preamble of claim 1 (see for example EP-A-0 676 607 ) and a heat exchanger comprising said collector.

Although not exclusively, the heat exchangers concerned are intended to equip vehicles and correspond, in a preferred application, condensers provided on the loops or air conditioning circuits of the vehicles. However, other applications of these heat exchangers are also conceivable without departing from the scope of the invention.

Condensers comprising a bundle of parallel tubes and two collectors are known in which the corresponding ends of the tubes are connected in a fixed and sealed manner. Thus, the fluid of the air conditioning loop, can flow from one manifold to the other, through the tubes in which the fluid passes from the vapor phase to the liquid phase by heat exchange with a flow of air, sweeping the tubes. These exchangers are assembled by soldering.

The collectors comprise a collector plate with a wall open longitudinally and a cover closing the collector plate after brazing. To pre-assemble the lid and the collector plate before soldering, it is known to crimp them. For this, the collector plate has raised edges, a peripheral portion is crimped around the cover to close the collector.

These known collectors have the disadvantage of having to apply to the peripheral edge portion of the collector plate excessive force during the crimping operation and thus risk the deformation of the cover, which may prevent proper brazing of the cover and the collector plate.

One solution to avoid the problems of deformation during the crimping operation is to use a counter form, called "fork" to prevent the transmission of crimping forces to the lid. Such a solution remains complicated to implement because requiring specific tools.

The object of the invention is to overcome the aforementioned problems.

It proposes for this purpose a collector of a heat exchanger as defined in claim 1. According to the invention, said first piece has a hinge area facilitating the folding of said peripheral edge portion.

The force required to apply to said peripheral edge portion during crimping of said first piece on said second piece will be less important and reduce the risk of deformation of the collector. In addition, it can be implemented without coin counterpart.

According to the invention, said peripheral edge portion has a thinned portion relative to another part of the first piece, intended to provide resistance to the pressure of a fluid. In this way, said hinge zone is defined.

For example, the thinned portion may extend from said hinge zone to the distal edge of said first piece.

Said first piece having a dimension of longitudinal extension, the thinned portion is, for example, continuous along said longitudinal extension.

Advantageously, a folding primer can be provided at said hinge zone, for example located at a base of said thinned portion.

Preferably, said thinned portion has a thickness between 25% and 75% of the thickness of the other part.

In particular, it may have a thickness of between 40% and 60% of the thickness of the other part.

Preferably, said manifold comprises a U-shaped lid with a base and longitudinal wings connected to the base by a curved area. The hinge zone is vis-à-vis the wings, near the curved area.

The invention also relates to a heat exchanger, including a condenser of a motor vehicle air conditioning system, provided with a collector as defined above.

• La figure 1 est une vue schématique en plan d'un exemple de réalisation d'un échangeur de chaleur dont les collecteurs comprennent une plaque collectrice et un couvercle conformément à l'invention.
• La figure 2 est une coupe transversale du collecteur après sertissage de la plaque collectrice autour du couvercle.
• La figure 3 est une coupe transversale de la plaque collectrice avant l'opération de sertissage.
• La figure 4 est une vue similaire à la figure 3, illustrant une variante de réalisation.

The appended figures will make it clear how the invention can be realized. In these figures, identical references designate similar elements.

• The figure 1 is a schematic plan view of an exemplary embodiment of a heat exchanger whose collectors comprise a header plate and a cover according to the invention.
• The figure 2 is a cross section of the collector after crimping the collector plate around the cover.
• The figure 3 is a cross section of the header plate before the crimping operation.
• The figure 4 is a view similar to the figure 3 , illustrating an alternative embodiment.

The invention can be applied in a heat exchanger as shown in FIG. figure 1 . This exchanger is, for example, a condenser of an air conditioning loop of the passenger compartment of a vehicle.

The exchanger 1 may comprise a bundle of parallel tubes 2 whose ends 2A are connected, in a fixed and sealed manner, to collectors or manifolds respectively upstream 3 and downstream 4 according to the direction of flow of the fluid, in particular Freon, circulating in the considered loop. To these collectors are respectively reported inlet fluid connection flanges 5 and outlet 6.

In particular, the tubes 2 in which the fluid circulates have an oblong cross section and between these are arranged interleaves 7 increasing the heat exchange surface between the fluid flowing in the exchanger 1 and the outside air flow therethrough this one. The inside of the tubes 2 may also include disrupters which, like the spacers, increase the heat exchange surface and the mechanical strength of the tubes. It may also be extruded tubes. Each tube defines, for example, a plurality of internal, parallel, fluid flow channels.

The upstream and downstream 3 and 4 collectors are generally identical and have a generally tubular shape. They are of "bipartite" type, that is to say that each of them consists of a collector plate 8 and a cover 9.

The set example of two pieces set on top of each other represented on the figure 2 is a heat exchanger collector according to a preferred embodiment of the invention. The first part shown is a header plate 8 and the second, a cover 9 of said manifolds.

The collecting plate 8 has, for example, a substantially U-shaped cross section and its wall thus defines an extended base 11 of two parallel branches or side wings 14 whose distal end of the peripheral edges delimit a longitudinal opening 15 closed by the cover on the figure. In the bottom 11 of the header plate 8 oblong slots 18 are formed all along thereof, in which the corresponding ends of the parallel tubes 2 are received. They may be flanked by flanges 30.

The cover 9 has, for example, also a U-shaped cross section whose wall 20 forms a slightly concave bottom 21 extended by parallel branches or side wings 22, shorter than those of the collecting plate 8. The dimension, in particular in width of the lid, is such that the lateral branches 22 fit head to tail between the lateral branches 14 of the header plate 8.

The assembly of the cover 9 and the manifold plate 8 defines an internal space 24 in which is circulated the fluid of the loop. Due to the nested shape of the U of the plate 8 and the cover 9, the cross section of the collector 3 or 4 is approximately rectangular, but could be different.

Partitions, not shown, are optionally provided at each of the longitudinal ends of the collector to close the collector. Intermediate partitions, which can make two parts of the collector hermetic to one another can also be provided. These partitions comprise, for example, a stop for positioning the cover 9.

If we go back to the figure 1 it can be seen that the inlet and outlet flanges 6 are provided respectively on the upstream and downstream collectors. The two flanges 5, 6 especially in the case of collectors with internal partition walls could be on the same tubular collector 5 respectively at the ends thereof, as shown by the flange 6 dashed line on the figure 1 .

The function of the inlet and outlet flanges 6 is to ensure the fluidic connections via unrepresented ducts between, in the example, a compressor of the loop in question, facing the upstream collector 3 and the interior space. tubular upstream collector 3, and between the inner space 24 of the tubular downstream collector 4 and an expander turned towards it, via fluid passages in the flanges.

For information, there is shown, by reference 35, other flanges reported by crimping on the tubular collectors 3, 4 and intended for fixing the exchanger 1 on appropriate supports of the vehicle and / or the attachment of a fluid storage bottle in fluid communication with one of the collectors.

Such a bottle, for example connected to the downstream collector, is intended to ensure the filtration and dehydration of the refrigerant, to compensate for the variations in the volume of the refrigerant and / or to ensure the separation of the fluid portion that could still be in the gas phase at the condenser outlet of the liquid phase fluid portion.

The crimping operation may allow to pre-assemble not only the manifold plate 8 and the cover 9, but also the inlet flanges 5 and the fluid outlet flanges 6, the flanges 35 intended for the attachment of the exchanger 1 to appropriate supports of the vehicle and / or attachment of the fluid storage bottle. These elements are crimped, for example, between the cover 9 and the peripheral edge portion 12 of the collector plate 8. In this way, a pre-assembly of all these elements is obtained in a single operation.

The figure 2 more generally illustrates a set of two pieces crimped on one another by folding at least a peripheral edge portion 12 of said one piece, here the manifold plate 8, on the other said second piece, here the cover 9. In the illustrated example, the peripheral edge portion 12, intended to be crimped, is located at a free end of the lateral flanges 14 of the header plate 8.

According to the invention, the crimping of the peripheral edge portion 12 of said first piece 8 on the second piece 9 is facilitated by the presence of a hinge zone 16 on said first piece 8.

The force required will be less important to crimp said peripheral edge portion 12 of said first part 8 of said second part 9. This will not only reduce the risk of deformation of the collector but also to avoid the use of part making against form.

In addition, in the case of a more complete pre-assembly where the bottle is pre-assembled between the collector plate and the lid to be crimped together with them, the narrowness between the lid and the bottle involves the use of crimping blades of small section thus brittle. By reducing the effort required to crimp the said portion of peripheral edge 12 of said first piece 8 on said second piece 9 is also reduced the risk of breakage crimping blades small section.

Preferably, but not exclusively, crimping is facilitated by the thinning of all or part of said peripheral edge portion 12 of the first piece 8 relative to another portion 14 of the first piece, intended to provide resistance to the pressure of a fluid, here the rest of the lateral wings 14 and the bottom 11 of the collector plate 8. The wall thinning is obtained by any appropriate mechanical operation (rolling, drawing, stamping, etc.).

In other words, the peripheral edge portion 12, intended for crimping, has a thinned portion 13, that is to say, a part whose thickness of material is smaller than the thickness of material at a part of the first part, intended to resist the pressure of the fluid. In the example illustrated, the thinned portion 13 has a thickness less than that of the rest of the lateral wings 14 and / or the bottom 11 of the header plate 8.

The figure 3 shows us a sectional view of the first part 8 before crimping the peripheral edge portion 12 around the second part 9. In this example, the thinned portion 13 extends from the hinge zone to the distal edge of the first piece. In other words, it covers the entire portion 12 for crimping.

The thinned portion 13 may, in the case where, as in the example illustrated, the first piece has a dimension of longitudinal extension, be continuous along said longitudinal extension dimension.

The figure 4 we illustrate an example further facilitating the crimping folding of the peripheral edge portion 12 of the first piece 8 on the second piece 9 by adding at the level of the crimping zone 16, a folding primer 17. This folding primer 17 is for example the inner side of said first piece 8.

In order to facilitate the crimping of the periphery edge portion 12 of the first part 8 on the second part 9 without any risk of breakage, it is provided that the thinned portion 13 of said peripheral edge portion 12 has a thickness of for example, between 25% and 75% of the thickness of the other part.

More specifically, it is expected that the thinned portion 13 of the peripheral edge portion 12 has a thickness of between 40% and 60% of the thickness of the other portion, in particular about 50%

In the case where, as illustrated, the set of two pieces crimped to one another is a collector whose lid 9 is U-shaped with a base 21 and longitudinal wings 22 connected to the base by a zone 23, the hinge zone 16, here the base of the thinned zone 13, can be located vis-à-vis the longitudinal wings 22, near the curved zone 23. In other words, the hinge zone 16 is closer to the curved area of the cover 9 only from the opposite edge of said wings 22.

Claims (8)

1. Manifold (3,4) of a heat exchanger comprising a collector plate and a cover, said collector plate constituting a first part (8) and said cover constituting a second part (9) of an assembly of two parts crimped together by folding at least one portion of peripheral edge (12) of said first part (8) over said second part (9), characterized in that said first part (8) has a hinge-forming region (16) facilitating the folding of said portion of peripheral edge (12), said portion of peripheral edge (12) having a thinned portion (13) relative to another portion (14) of said first part (8) intended to offer a resistance to the pressure of a fluid.
2. Manifold according to Claim 1, in which the thinned portion (13) extends from said hinge region (16) to the distal edge of said first part (8).
3. Manifold according to Claim 1 or 2, in which the first part (8) has a longitudinal extension dimension and the thinned portion (13) is continuous along said longitudinal extension dimension.
4. Manifold according to any one of the preceding claims, in which a start of fold (17) is provided at the level of a base of the thinned portion.
5. Manifold according to any one of the preceding claims, in which said thinned portion (13) has a thickness of between 25% and 75% of the thickness of the other portion (14).
6. Manifold according to Claim 5, in which said thinned portion (13) has a thickness of between 40% and 60% of the thickness of the other portion (14).
7. Manifold (3,4) according to any one of the preceding claims, in which the cover (9) is U-shaped with a base (21) and longitudinal wings (22) linked to the base (21) by an incurved region (23) and in which the hinge region (16) is facing the longitudinal wings, in proximity to the incurved region (23).
8. Heat exchanger, in particular a condenser of a motor vehicle air conditioning system, provided with a manifold (3,4) according to any one of the preceding claims.

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