EP1813903B1 - Collector with tap for high pressure fluid, heat exchanger with the collector and fabrication process - Google Patents

Abstract

The box has a collector plate (26) comprising openings (28) for inserting heat exchange tubes (18). A cover (44) is formed by machining a metal bar and comprises an internal surface (72) and external surface. Distribution channels (70) e.g. groove, are formed in the metal bar by emerging on the internal surface while permitting material of the bar to close a volume of the cover at the level of longitudinal ends of the cover, where the channels communicate with the heat exchange tubes. An independent claim is also included for a method for fabricating a collector box.

Description

The invention relates to the field of heat exchangers and in particular to exchangers intended to be traversed by a fluid under high pressure.

In this respect, the invention relates more particularly to air conditioning evaporators that can be traversed by a gaseous refrigerant, as is the case with natural gases such as carbon dioxide or CO ₂ . Such exchangers find particular application in motor vehicles.

It will be recalled that, in an air conditioning circuit traversed by a refrigerant of this type, this fluid remains substantially in the gaseous state and under a very high pressure which is between 100 and 150 bar. As a result, such heat exchangers, and in particular their manifolds, must be able to withstand such high pressures, the recommended burst pressure being generally three times the value of the nominal operating pressure.

Collecting boxes, obtained by soldering, which are designed to withstand such high pressures, are already known.

Thus, the document FR 2 793 016 discloses a collector box formed of a multiplicity of flat plates stacked having fluid passage slots. The distribution is ensured by these flat plates and the header comprises a cover also composed of a multiplicity of stacked plates. All these plates are assembled together by brazing.

The document JP 2002-1588722 discloses a header comprising an extruded tank closed by flat end plates. The abutment of the tubes is provided either by an intermediate flat plate disposed between the tubes and the tank, or by a specific profile of the tank section.

Other boxes of this type are also disclosed by the documents JP 2002-43332 , WO / 03 102 486 and EP 0 563 471 .

The document FR 2 793 015 discloses a header according to the preamble of claim 1.

All these collector boxes known either are difficult to braze, or require a large number of manufacturing operations making their manufacturing process complex and expensive to achieve.

The object of the invention is in particular to overcome the aforementioned drawbacks.

The invention proposes for this purpose a heat exchanger collector box, comprising a collector plate provided with openings for the insertion of heat exchange tubes, and a lid defining distribution channels communicating with the tubes.

According to the invention, the lid is a metal bar having an inner face and a face opposite outer, while the distribution channels are grooves made in the material thickness of the metal bar, opening on the inner face, while allowing material to remain in order to close the volume of the lid at its level. longitudinal ends. '

Thus, the cover is made by machining a thick metal bar, which simplifies its manufacture and allows for an element that can withstand high pressures.

Communication passages are advantageously provided between the cover and the collector plate.

In a first embodiment of the invention, the communication passages are delimited by a distribution plate interposed between the collector plate and the inner face of the cover.

In a second embodiment of the invention, the communication passages are grooves of the metal bar opening on the one hand on the distribution channels and on the other hand on the inner face of the cover. This embodiment thus makes it possible to economize the distribution plate of the preceding embodiment, which eliminates a component.

According to an advantageous characteristic of the invention, the distribution channels and the communication passages are machined.

Because the grooves forming the channels are non-emerging, it avoids the use of end plates and thus reduces the number of parts.

According to another characteristic of the invention, the lid is obtained from an extruded metal bar.

In an advantageous embodiment, the outer face of the extruded metal bar is shaped so as to have a profile comprising a plurality of domes, or arches, in correspondence of the channels. The distribution channels may have a constant inner section along their entire length, or a variable inner section over their entire length.

The lid may comprise a single series of channels which each extend over the length of the metal bar. This is particularly the case of a return cover, located opposite a cover having arrangements for the entry and exit of the fluid.

The lid may also include at least two sets of channels each extending over a portion of the length of the metal bar. This is particularly the case of a lid comprising, as mentioned above, arrangements for the entry and exit of the fluid.

In the invention, the channels advantageously have a bottom with a U-shaped transverse profile, which makes it possible to improve the resistance to the pressure of the fluid.

The channels advantageously, in the vicinity of an end face of the metal bar, a curved longitudinal profile delimited by a radius.

In another aspect, the invention relates to a heat exchanger comprising a bundle of tubes and at least one header as previously defined. This heat exchanger is advantageously made in the form of an evaporator.

A particular embodiment proposes that the heat exchanger comprises at least two passes and that the inner sections of the distribution channels make it possible to control and balance the flow rate of the fluid in the passes.

1. a) réaliser une plaque collectrice comportant des ouvertures de réception de tubes ;
2. b) réaliser des moyens de distribution comportant des passages de communication ;
3. c) réaliser un couvercle à partir d'une barre métallique présentant une face intérieure et une face extérieure opposée, en usinant des canaux de distribution sous la forme de gorges obtenues par usinage de la barre métallique dans la direction longitudinale de celle-ci en débouchant sur ladite face intérieure ; et
4. d) assembler le couvercle sur la plaque collectrice avec interposition des moyens de distribution en sorte que les passages de communication débouchent d'une part sur les canaux de distribution et d'autre part sur les ouvertures de la plaque collectrice.

In yet another aspect, the invention relates to a method of manufacturing a heat exchanger collector box, as defined above, which comprises the following operations:

1. a) forming a header plate having tube receiving apertures;
2. b) providing distribution means comprising communication passages;
3. c) producing a cover from a metal bar having an inner face and an opposite outer face, by machining distribution channels in the form of grooves obtained by machining the metal bar in the longitudinal direction thereof by opening on said inner face; and
4. d) assembling the cover on the collector plate with the interposition of the dispensing means so that the communication passages open on the one hand on the distribution channels and on the other hand on the openings of the collector plate.

In a first embodiment, the operation b) comprises the preparation of a distribution plate delimiting the communication passages, while the operation d) comprises the interposition of the distribution plate between the collector plate and the face inside the lid.

In a second embodiment, the operation b) comprises the realization of the communication passages in the form of grooves made by machining in the transverse direction of the metal bar, opening on the one hand on the distribution channels and on the other hand. on the other hand on the inside of the lid, while the operation b) comprises the direct assembly of the collector plate against the inner face of the lid.

Advantageously, the operation c) comprises the preparation of an extruded metal bar and the machining of the channels by means of a multistage rotary tool capable of simultaneously machining the channels over at least a portion of the length of the metal bar. .

• la figure 1 est une vue en perspective éclatée d'un échangeur de chaleur, dans l'exemple un évaporateur pour circuit de climatisation, comportant un faisceau de tubes monté entre deux boîtes collectrices selon l'invention ;
• la figure 2 est une vue en coupe transversale partielle d'une des boîtes collectrices de l'échangeur de chaleur de la figure 1 ;
• la figure 3 est une vue d'extrémité du couvercle de la boîte collectrice de la figure 2, avant usinage ;
• la figure 4 est une vue analogue à la figure 3, après usinage des canaux du couvercle ;
• la figure 5 représente schématiquement l'usinage d'un couvercle au moyen d'un outil rotatif multi-étagé;
• la figure 6 est une vue partielle en coupe longitudinale du couvercle montrant l'extrémité d'un canal, réalisée de manière non débouchante ;
• la figure 7 est une vue en coupe longitudinale d'un couvercle comportant deux séries de canaux ;
• la figure 8 est une vue en coupe longitudinale d'un couvercle comportant une seule série de canaux ;
• la figure 9 est une variante de la figure 7 dans laquelle la section des canaux a une forme évolutive ;
• la figure 10 est une variante de la figure 8 dans laquelle la section des canaux a une forme évolutive ;
• la figure 11 est une vue en coupe longitudinale d'un couvercle dont un canal présente une autre forme évolutive;
• la figure 12 est une vue analogue à la figure 11 dans une autre variante de réalisation ;
• la figure 13 illustre schématiquement une distribution d'écoulement pour un évaporateur à quatre passes comportant deux boîtes collectrices selon l'invention ;
• la figure 14 illustre la face intérieure d'un couvercle qui comprend à la fois des gorges longitudinales et des gorges transversales parallèles réalisées par usinage ;
• la figure 15 est une vue en coupe transversale partielle d'une boîte collectrice comprenant un couvercle selon la figure 14 ; et
• la figure 16 est une autre vue en coupe transversale partielle de la boîte collectrice de la figure 15.

In the description which follows, made only by way of example, reference is made to the appended drawings, in which:

• the figure 1 is an exploded perspective view of a heat exchanger, in the example an evaporator for an air conditioning circuit, comprising a bundle of tubes mounted between two manifolds according to the invention;
• the figure 2 is a partial cross-sectional view of one of the manifolds of the heat exchanger of the figure 1 ;
• the figure 3 is an end view of the lid of the collector box of the figure 2 before machining;
• the figure 4 is a view similar to the figure 3 after machining the lid channels;
• the figure 5 schematically shows the machining of a cover by means of a multi-stage rotary tool;
• the figure 6 is a partial view in longitudinal section of the lid showing the end of a channel, made in a non-emergent manner;
• the figure 7 is a longitudinal sectional view of a lid comprising two series of channels;
• the figure 8 is a longitudinal sectional view of a cover comprising a single series of channels;
• the figure 9 is a variant of the figure 7 wherein the section of the channels has an evolutionary form;
• the figure 10 is a variant of the figure 8 wherein the section of the channels has an evolutionary form;
• the figure 11 is a longitudinal sectional view of a lid whose channel has another evolutionary form;
• the figure 12 is a view similar to the figure 11 in another variant embodiment;
• the figure 13 schematically illustrates a flow distribution for a four-pass evaporator comprising two manifolds according to the invention;
• the figure 14 illustrates the inner face of a cover which comprises both longitudinal grooves and parallel transverse grooves made by machining;
• the figure 15 is a partial cross-sectional view of a header comprising a lid according to the figure 14 ; and
• the figure 16 is another partial cross-sectional view of the collector box of the figure 15 .

We first refer to the figure 1 which shows, in exploded view, a heat exchanger 10 having a beam 12 mounted between an upper header box 14 and a lower manifold 16, the heat exchanger being considered in a vertical position.

The beam 12 is composed, in the example, of two rows of tubes 18 (only one of which is visible on the figure 1 ) and corrugated inserts 20 common to both rows of tubes. The header box 14 is provided with two inlet / outlet pipes 22 and 24 serving respectively to the admission and evacuation of a fluid flowing through the tubes of the bundle.

In the example, the heat exchanger 10 is in the form of an evaporator capable of being traversed by a refrigerant fluid operating in the supercritical state, in particular CO ₂ , the pressure of which can reach values of order of 100 to 150 bar. This fluid exchanges heat with a flow of air that scans the tube bundle to produce a flow of air conditioning, especially in a motor vehicle.

It can be seen that the header box 14 comprises a header plate 26 provided with openings 28 for receiving the tubes of the bundle. The openings 28 are of elongate shape and arranged in two rows corresponding to the two rows of tubes.

The collecting plate 26 is generally rectangular in shape and comprises, along its two long sides, crimping members 30. It comprises an extension 32 in which holes 34 and 36 are provided for the respective mounting of the tubes 22 and 24. .

Above the manifold plate 26 is placed a distribution plate 38 having two rows of slotted communication passages 40, each communicating with a tube 18 and a row of slotted communication passages 42, of greater width which each communicate with two adjacent tubes belonging to the two rows of the beam. The passages 40 and 42 contribute to the distribution of the fluid and to its circulation in the tubes of the bundle according to a defined path, which will be described later with reference to the figure 13 .

Above the distribution plate 38 is placed a cover 44 intended to be held against the collector plate, trapping the distribution plate 38, under the action of the crimping members 30.

The lower manifold 16 is made in a similar manner except that it has no extension. It consists of a manifold plate 46, a distribution plate 48 and a cover 50. Note that the distribution plate 48 has two rows of passages 52, slot-shaped, each communicating with a tube of beam at its lower part.

We now refer to the figure 2 which represents a cross-sectional view of the manifold 14. We find on the figure 2 the collecting plate 26, the distribution plate 38 and the cover 44. The collecting plate 26 is a stamped plate having a flat inner face 54 for receiving the distribution plate 38 and an outer face 56 from which extend flanges 58 respectively surrounding the openings 28 for receiving the tubes.

In the example shown, the outer face 56 is directed downwards and the collars 58 are also directed downwards. These collars are thus arranged in two rows corresponding to the two rows of openings 28. In the example, the collars and the openings have a rectangular general section to allow the reception of flat tubes 18 having a homologous external section.

The crimping members 30 are, as already indicated, formed along the two long sides of the collecting plate 26. They are in the form of a folded, slot-shaped edge with a number of tabs or teeth 60 (see also figure 1 ).

The distribution plate 38 has a flat inner face 62 adapted to come into contact with the flat inner face 54 of the header plate and an opposite outer plane face 64, able to receive the cover 44.

In the thickness of the distribution plate, are arranged passages 40 and 42, in the form of slits, supra. On the figure 2 we see two passages 40 which communicate respectively with two adjacent tubes respectively belonging to the two rows of tubes of the beam.

The distribution plate 38 forms at the same time the insertion stop for the tubes as seen on the figure 2 . As a result, the respective ends of the tubes can not exceed the plane defined by the inner face 54 of the header plate.

The lid 44 is made from a thick metal bar having two parallel edges 66 ( figure 2 ) for the support of the crimping members 30. Thus when the tabs 60 are folded, they maintain the lid in support of the header plate by trapping the distribution plate. The cover 44 has, as seen on the section of the figure 2 , a series of bosses 68, six in each direction cross. These bosses 68 respectively define channels 70 communicating with the tubes of the beam via the communication passages 40 and 42 (slot-shaped) of the distribution plate.

These bosses are suitably arranged to allow the refrigerant fluid to penetrate inside the manifold 14 via the manifold 22, then circulate in the tubes of the bundle between the manifold 14 and the manifold 16 and leave the exchanger by the outlet pipe 24. The manner in which the circulation of the fluid occurs in the beam will be described in detail below.

As we see on the figures 1 and 2 , the cover 44 has a generally rectangular shape, the bosses 68 each extending in the longitudinal direction.

The metal bar forming the cover 44 is a thick bar having an inner surface 72, made planar, adapted to be applied against the flat outer face 64 of the distribution plate 38 ( figure 2 ). It is more precisely an extruded bar whose profile, before machining, is represented on the figure 3 . We see that this bar comprises, opposite the inner face 72, a shaped outer face 74, whose profile defines the six bosses 68, dome-shaped or arched, and the two bearing edges 66. The profile of the bar is further limited by two lateral faces 76.

According to the invention, the channels 70 are obtained by machining from the inner face 72 to obtain the profile shown on the figure 4 . We see that the channels 70 are formed by U-shaped grooves with a rounded bottom in correspondence with the aforementioned domes or arches. As a result, the profile obtained after machining ( figure 4 ) defines a succession of arches having a sufficient thickness to allow good resistance to pressure. Given the fact that the machining is performed in a metal bar, the thickness of the latter can be controlled so as to obtain each time a wall of sufficient thickness to withstand the operating pressures of the manifold and therefore of the heat exchanger.

The figure 5 shows how the machining of the channels can be achieved by means of a single rotating tool 78 made in the form of a multi-stage milling device rotatable about an axis XX and having a succession of crowns 80 with a rounded profile, here six in number, to simultaneously realize the six channels 70 in the cover 44. The machining is performed by moving the tool in the longitudinal direction of the bar, the axis of rotation of the tool being oriented transversely.

We now refer to the figure 6 which shows a channel 70 having an end 82 terminating at a distance A from an end face 84 of the cover 44. This end 82 has, in the vicinity of the end face 84, a curved longitudinal profile delimited by a radius R. The latter advantageously corresponds to the radius of the crowns 80 of the machining tool 78. As a result, the end of each of the channels 70 is non-emerging, which makes it possible to avoid the use of end plates for closing. canals. The other end of the channels 70 is made analogously. In other words, the throats that the channels are formed in the thickness of material of the metal bar, opening on the inner face 72, while allowing the material to remain so as to close the volume of the lid at its longitudinal ends (end faces 84).

We now refer to the figure 7 which shows, in longitudinal section, a cover 44 according to the invention in one embodiment. It can be seen that this cover has two series of channels 70A and 70B, the channels 70A having a longer length than the channels 70B and extending on the extension side 32 (FIG. figure 1 ). In the example, the channels 70A and 70B have a constant inner section along their entire length.

The figure 8 shows, in longitudinal section, the cover 50 of the opposite header, which extends over a shorter length than the cover 44 and which has a single series of channels 70C to form return. The channels 70C extend over the entire length and here again have a constant inner section. As will be seen below, the cover 44 of the figure 7 and the lid 50 of the figure 8 allow to define an evaporator with four circulation passes.

The figure 9 illustrates a variant of the cover 44 of the figure 7 wherein the channels 70B have a constant inner section, while the channels 70A have a variable inner section, the bottom of the channels having a slope having an angle A1.

The figure 10 illustrates a variant of the cover 50 of the figure 8 and we see that the 70C channels also have a variable inner section whose bottom has a double slope defined by two opposite angles A2.

The figure 11 shows another type of variable internal section profile for a 70C channel. Each of the channels 70C has a main portion 85 made by a first machining and a deeper central portion 86 made by a second machining. This profile requires a first machining by a tool similar to that described above and a second machining to form, over a portion of the length of the channel, the central portion 86 deeper.

The figure 12 illustrates another variant in which the channels 70 have a variable inner section made by a single machining, so by a single tool. The bottom of each channel has an inclined portion 87 defined by a slope of angle A3 and a portion 89 of constant depth. It is understood that the machining tool must be moved in a controlled manner relative to the metal bar to control the machining depth.

The use of channels of variable internal section, so of varying depth, allows each time to control the flow of fluid in the tubes that open into the channels in question.

The figure 13 shows, schematically, the distribution of a fluid for a four-pass exchanger, here an evaporator, in which there is shown schematically the covers 44 and 50. The fluid enters the manifold associated with the cover 44 as shown by the F1 arrow. It opens into 70.1 channels of decreasing depth.

The fluid then travels a portion of the tubes 18 of a first row corresponding to a first pass P1 to open into a series of channels 70.2 of variable profile cover 50. These channels 70.2 extend over the entire length of the cover 50 and have a profile similar to that of the figure 10 . The fluid then leaves the channels 70.2 by another part of the tubes of the first row to form a second pass P2 and thus gain channels 70.3 of the cover 44 which, in the example, have a constant inner section. The fluid flows from these channels 70.3 to other channels 70.4 as shown by the arrow F2. These channels 70.4 also have a constant inner section.

The fluid then leaves the upper header by traversing a portion of the tubes of the second row to constitute a third pass P3 and win channels 70.5 also extending over the entire length of the cover 50. These channels 70.5 have a profile similar to the channels 70.2. The fluid then leaves the lower manifold to form a fourth pass P4 through a portion of the tubes of the second row. The fluid thus gains 70.6 channels having a variable inner section similar to that of the channels 70.1. The fluid then leaves the heat exchanger as shown by the arrow F3.

Thus, it is possible to work on the distribution of the fluid in the channels by making channels with variable inner section. It is possible to control and balance the flow rate of the fluid in the different passes P1 to P4, and this playing on the speed of the fluid thanks to the different internal sections of the channels.

The components of the manifold (collecting plate 26, distribution plate 38 and cover 44) are each made from a metal plate, preferably aluminum alloy, with a thickness sufficient to withstand the significant pressures of the refrigerant fluid. . The fact of making several bosses 68 on the cover makes it possible to form small volume channels 70 limiting the effect of the pressure of the fluid on the components of the collector plate.

These components are intended to be assembled by soldering once a provisional assembly obtained by crimping. It is therefore necessary to provide a braze plating.

1. a) réaliser une plaque collectrice 26 ou 46 ;
2. b) réaliser des moyens de distribution, ici une plaque de distribution 38 ou 48 ;
3. c) réaliser un couvercle 44 ou 50 à partir d'une barre métallique comme défini plus haut; et
4. d) assembler le couvercle sur la plaque collectrice avec insertion des moyens de distribution en sorte que les passages de communication 40 ou 42 débouchent d'une part sur les canaux de distribution 38 ou 48 et d'autre part sur les ouvertures 28 de la plaque collectrice 26 ou 46.

The method of manufacturing the header box 14 essentially comprises the following operations:

1. a) producing a collector plate 26 or 46;
2. b) achieve distribution means, here a distribution plate 38 or 48;
3. c) making a cover 44 or 50 from a metal bar as defined above; and
4. d) assembling the cover on the header plate with insertion of the distribution means so that the communication passages 40 or 42 open on the one hand to the distribution channels 38 or 48 and on the other hand to the openings 28 of the plate collector 26 or 46.

In the previous embodiment, operation b) comprises the preparation of a distribution plate 38 or 48 which delimits the communication passages 40 and 42, while the operation d) comprises the interposition of the distribution plate between the header plate 26 or 46 and the inner face 72 of the cover.

Then, the cover 14 is crimped on the header plate 26 by means of crimping members 30, enclosing the distribution plate.

We now refer to the figure 14 which relates to another embodiment in which the cover 88 is similar to the cover 44 described above and comprises two series of channels 70A and 70B in the form of parallel longitudinal grooves made in the longitudinal direction of the metal bar. The cover further includes communication passages 90 and 92 which are functionally analogous to the previously described communication passages 40 and 42. However, these communication passages 90 and 92 are here parallel transverse grooves made by machining in the transverse direction of the metal bar, opening on the one hand on the distribution channels 70A and 70B and on the other hand on the inner face 94 of the lid ( Figures 15 and 16 ). The communication passages 90 and 92 are spaced apart by a pitch P corresponding to that of the tubes.

As a result, it is no longer necessary to insert a distribution plate between the cover and the header plate, which eliminates a component. The assembly operation d) thus comprises the direct assembly of the manifold plate 28 or 46 against the inner face 94 of the cover 88. The cover is crimped directly on the collector plate.

1. 1) usinage des gorges longitudinales (canaux 70A et 70B),
2. 2) usinage des gorges transversales (passages 90 et 92).

In the embodiment of the Figures 14 to 16 , the machining of the grooves of the lid is performed in two steps:

1. 1) machining longitudinal grooves (channels 70A and 70B),
2. 2) machining of the transverse grooves (passages 90 and 92).

The cover 88 thus groups the functions of passage and distribution of the fluid. This makes it possible to reduce the number of parts of the heat exchanger, to facilitate the assembly process and to reduce the risk of leakage. In addition the inner face 94 of the cover 88 can be machined by forming recesses or steps 96 ( Figures 15 and 16 ) forming stops for the introduction of the tubes 18. Once the manifold thus assembled, the assembly of the heat exchanger can be assembled. The components of the bundle 12 (tubes and spacers) are arranged against each other and the ends of the tubes are placed, on one side, in the openings of the manifold 14 and, on the opposite side, in the openings of the box collector 16.

Whatever the embodiment of the header, the entire heat exchanger can be then brazed, in a single operation, by passing through a suitable brazing furnace. During soldering, solder plating provides a connection between the various components.

It is possible, in a variant, to solder the manifolds separately before assembling them to the bundle and brazing the entire heat exchanger.

The manifold 16 is made in a similar manner to the manifold 14, except that it does not have an extension for mounting fluid inlet and outlet manifolds.

The manifold of the invention is capable of many variants. It finds a main application to heat exchangers traversed by a high-pressure refrigerant, in particular to air-conditioning evaporators traversed by a fluid in the supercritical state such as CO ₂ , such as those intended for motor vehicles.

Claims (24)

1. Heat exchanger manifold housing, comprising a manifold plate (26, 46)) equipped with orifices (28) into which heat exchanger tubes (18) are inserted, and a cover (44, 50, 88) which defines distribution ducts (70) that communicate with the tubes, characterised in that the cover (44, 50, 88) is a metal bar with an inside face (72, 94) and an outside face (74) that is opposed, and in that the distribution ducts (70) are grooves in the thickness of the metal bar, opening onto the inside face (72, 94), while leaving material remaining so that it seals the cover volume at its longitudinal ends.
2. Manifold housing of claim 1, characterised in that communication passages (40, 42, 90, 92) are provided between the cover (44, 50, 88) and the manifold plate (26, 46).
3. Manifold housing of claim 2, characterised in that the communication passages (40, 42) are defined by a distribution plate (38, 48) interposed between the manifold plate (26, 46) and the inside face (72) of the cover (44, 50).
4. Manifold housing of claim 2, characterised in that the communication passages (90, 92) are grooves in the metal bar which open out onto the distribution ducts (70) and onto the inside face (94) of the cover (88).
5. Manifold housing of any of claims 2 to 4, characterised in that the distribution ducts (70) and the communication passages (40, 42, 90, 92) are machined.
6. Manifold housing of any of claims 1 to 5, characterised in that the cover (44, 50, 88) is made from an extruded metal bar.
7. Manifold housing of claim 6, characterised in that the outside face (74) of the extruded metal bar is formed so that it has a profile with a plurality of domes (68) matching the distribution ducts (70).
8. Manifold housing of any of claims 1 to 7, characterised in that the distribution ducts (70) have an inside cross section that is constant along their entire length.
9. Manifold housing of any of claims 1 to 7, characterised in that the distribution ducts (70) have an inside cross section that is variable along their entire length.
10. Manifold housing of claim 9, characterised in that the distribution ducts (70) have ducts (70A) with a variable inside cross section of which the base has a slope of an angle (A1).
11. Manifold housing of claim 9, characterised in that the distribution ducts (70) have ducts (70C) with a variable inside cross section of which the base has two slopes defined by two opposed angles (A2).
12. Manifold housing of claim 9, characterised in that the distribution ducts (70) have ducts (70C) with a variable inside cross section with a main portion (85) that is created by a first machining operation and a deeper, central portion (86) that is created by a second machining operation.
13. Manifold housing of claim 9, characterised in that the distribution ducts (70) have ducts (70C) with a variable inside cross section created by a single machining operation, of which the base has a sloped portion (87) defined by a slope of an angle (A3) and a portion (89) of constant depth.
14. Manifold housing of any of claims 1 to 13, characterised in that the cover (50) has a single series of distribution ducts (70) which each extend along the entire length of the metal bar.
15. Manifold housing of any of claims 1 to 13, characterised in that the cover (44) has at least two series of distribution ducts (70) which each extend along part of the length of the metal bar.
16. Manifold housing of any of claims 1 to 15, characterised in that the distribution ducts (70) have a base with a transversal U-shaped profile.
17. Manifold housing of claims 16, characterised in that the distribution ducts (70) have next to one end face (84) of the metal bar, an incurved longitudinal profile defined by a radius (R)
18. Heat exchanger comprising an array of tubes (18) and at least one manifold housing (14, 16) according to any of claims 1 to 17.
19. Heat exchanger of claim 18, characterised in that said exchanger comprises at least two passes and in that said inside cross of the distribution ducts (70) permit the flow rate of the fluid in said passes (P1, P2, P3 and P4) to be controlled and equalised.
20. Heat exchanger of claim 19, characterised in that it is made in the form of an evaporator.
21. Manufacturing process for a heat exchanger manifold housing according to any of claims 1 to 17, characterised in that it comprises the following operations:

    a) the creation of a manifold plate (26, 46) featuring orifices (28) to accommodate tubes;

    b) the creation of distribution means featuring communication passages (40, 42, 90, 92);

    c) the creation of a cover (44, 50, 88) from a metal bar with an inside face (72, 94) and an outside face (74) that are opposed by machining distribution ducts (70) in the form of grooves, obtained by machining the metal bar in its longitudinal direction opening out onto said inside face, while leaving material remaining so that it seals the cover volume at its longitudinal ends; and

    d) the assembly of the cover (44, 50, 88) onto the manifold plate (26, 46), inserting the distribution means so that the communication passages (40, 42, 90, 92) open out onto the distribution ducts (70) and the orifices (28) of the manifold plate (26, 46).
22. Process of claim 21, characterised in that operation b) comprises.the preparation of a manifold plate (38, 48) defining the communication passages (40, 42) and that operation d) comprises the interposition of the distribution plate (38, 48) between the manifold plate (26, 46) and the inside face (72) of the cover.
23. Process of claim 21, characterised in that operation b) comprises the creation of the communication passages (90, 92) in the form of grooves, by machining them in the longitudinal direction of the metal bar, opening out onto the distribution ducts (70) and the inside face (94) of the cover, and in that operation d) comprises he direct assembly of the manifold plate (26, 46) against the inside face (94) of the cover (88).
24. Process of any of claims 21 to 23, characterised in that operation c) comprises the preparation of an extruded metal bar and the machining of ducts (70) by means of a multi-stage rotary tool (78) capable of simultaneously machining the ducts onto at least part of the length of the metal bar.

Images