WO2018060625A1

WO2018060625A1 - Heat exchanger, in particular for a motor vehicle

Info

Publication number: WO2018060625A1
Application number: PCT/FR2017/052632
Authority: WO
Inventors: José TRINDADE; Xavier Marchadier; Fabien BIREAUD; Rémi TOURNOIS; Valériane HIDDEN
Original assignee: Valeo Systemes Thermiques
Priority date: 2016-09-28
Filing date: 2017-09-27
Publication date: 2018-04-05
Also published as: FR3056735B1; FR3056735A1

Abstract

The invention relates to a heat exchanger, comprising: - a heat exchange bundle comprising a plurality of tubes (11) the ends of which are substantially elongate in cross-section, - at least one header box comprising a header plate (21), the header plate (21) having a plurality of openings (211) respectively receiving one end of a tube (11), the openings (211) of the header plate (21) being substantially elongate in cross-section, and - at least one compressible seal (25) arranged around the ends of the tubes (11). According to the invention, - the tubes (11) are mechanically assembled to the header plate (21) by flaring the ends of the tubes (11), so as to at least partially increase the width of the ends of the tubes (11) in such a way as to compress the sealing means (25), and - the width (A) of each opening (211) of the header plate (21) is less than the width (li) of a tube end (11) before flaring.

Description

Heat exchanger, in particular for a motor vehicle

The invention relates to the field of heat exchangers, especially for motor vehicles.

Heat exchangers conventionally comprise a heat exchange bundle with a plurality of tubes and at least one, generally two manifolds or boxes for dispensing a fluid. In known manner, each manifold comprises at least two parts: a collector plate receiving the ends of the tubes and a cover that caps the collector plate to at least partially close the collector box. The collector boxes make it possible to distribute and / or collect a first fluid such as a heat transfer fluid through or from the tubes of the heat exchange bundle. In operation, the tubes are traversed by the first fluid such as a heat transfer fluid which exchanges heat with a second fluid, such as an air flow that scans the beam. Interlayers or fins may also be provided between the tubes to improve heat exchange.

The search for increased thermal performance leads to the use of increasingly flattened and elongated section tubes. Thus, the tubes of the heat exchange bundle generally have a cross section of substantially flattened shape and have two large parallel flat faces, joined together by two small curved faces.

Heat exchangers known as brazed, that is to say, whose different elements are permanently fixed to each other by a soldering operation is called brazed heat exchanger. In this case, the various elements of a heat exchanger are metallic, for example aluminum or aluminum alloy, and can be assembled and soldered by passing through a brazing furnace, to ensure the joining of all the elements. .

With this brazed technology, the tubes can be arranged with a tight pitch, for example of the order of 6 mm. The increase in the number of tubes of the heat exchange bundle makes it possible to improve the performance of the so-called brazed heat exchangers.

The flat tubes may be extruded metal tubes having micro-shaped refrigerant circulation channels in the form of parallel holes extending the full length of the tubes. The tubes thus produced are naturally watertight. However, the manufacture of extruded tubes requires specific dies for each type of tubes and the extrusion process does not make it possible to reduce the thicknesses of the tubes below a certain limit. This results in significant bulk and high cost.

Alternatively, the tubes can be made respectively from a single metal strip and in this case the sealing of each tube is provided by brazing or welding.

In particular, it is known to make the tubes by folding the metal strip on itself in order to define two parallel channels, possibly substantially identical section, separated by a spacer. The spacer results from the joining of two edges of the strip which are each folded substantially at right angles and which abut on a flat face facing the two channels. This spacer, also called a leg, improves the resistance of the tube to the internal pressure. In this case it is referred to as folded tube, and the cross section of such folded tube is generally substantially "B".

According to another example of known embodiment of tube from a metal strip and whose sealing is provided by brazing, the tube is closed along one of its faces, generally a small face, by covering two layers of the metal strip. We also talk about stapled tube.

However, such flat tubes whose sealing is achieved by brazing do not have good resistance to the forces that can be applied to the tubes once the heat exchanger assembled.

In addition, the heat exchangers are subjected to many stresses and thermal variations during the various operating cycles. In particular, phenomena of expansion and shrinkage related to temperature variations can occur, particularly at the level of the connections between the collector plate and the tubes. These connections being rigid in a brazed heat exchanger, this does not compensate for such phenomena of expansion and retraction. Over time, these bonds weaken and breaks and consequently leakage of the fluid can occur. Another known assembly technology of the heat exchanger is a mechanical technology, namely at ambient temperature, for example by crimping, flaring, clipping or other mechanical connection. In particular, the tubes are assembled to each collector plate by flaring their ends so as to compress a sealing means between the ends of the tubes and the collector plate. This sealing means makes it possible to compensate for the phenomena of expansion and retraction that may occur. Such a mechanical assembly therefore reduces the risk of leakage of the fluid.

The tubes of such a mechanical assembly heat exchanger must be able to withstand the pressure exerted by the sealing means. In other words, in mechanically-assembled heat exchangers, it is necessary for each tube end to have sufficient mechanical strength to compress the sealing means, without this end of the tube being deformed, which would result in a loss of pressure. sealing between the collector plate and the heat exchange bundle.

Moreover, in known mechanical assembly heat exchangers, the tubes are of lower density than in a brazed heat exchanger, the number of tubes passing through the header plate being limited by the thickness of the flanges generally bordering the openings of each header plate. This results in a lower thermal performance in a mechanical assembly heat exchanger compared to a brazed heat exchanger for an equivalent size.

The invention therefore aims to at least partially overcome these problems of the prior art by providing a heat exchanger comprising a heat exchange bundle optimized thermal performance and the resistance of the tubes is increased while reducing the risk of leakage of the heat exchanger.

For this purpose, the subject of the invention is a heat exchanger, in particular for a motor vehicle, said exchanger comprising:

a heat exchange bundle comprising a plurality of tubes whose ends are of substantially elongate section,

at least one collecting box comprising a collecting plate, the collecting plate having a plurality of openings respectively receiving an end of a tube, the openings of the collector plate being of section substantially elongated, and

compressible sealing means arranged around the ends of the tubes.

According to the invention,

the tubes are mechanically assembled to the header plate by flaring the ends of the tubes, so as to at least partially increase the width of the ends of the tubes so as to compress the sealing means, and

the width of each opening of the header plate is less than the width of a tube end after flaring.

Such dimensioning of the openings of the collector plate makes it possible, after assembly of the heat exchanger, to prevent the flaring made at the ends of the tubes of the heat exchange bundle from propagating over the remaining length of the tubes of the Heat exchange beam, out of the collector box.

According to one aspect of the invention, the width of each opening of the header plate is less than the width of a tube end after flaring added to twice the thickness of the assembled state seal means. heat exchanger, according to the following equation: A <li + 2e, with

A = the width of an opening of the header plate,

li = the width of a tube end after flaring, and e = the thickness of the sealing means in the assembled state of the heat exchanger.

The heat exchanger may further comprise one or more of the following features, taken separately or in combination:

the length of each opening of the header plate is less than the length of a tube end after flaring;

the length of each opening of the collector plate is less than the length of one end of the tube after flaring added to twice the thickness of the sealing means in the assembled state of the heat exchanger, according to the following equation : C <L '+ 2e, with

C = the length of an opening of the collector plate,

The = the length of a tube end after flaring, and

e = the thickness of the sealing means in the assembled state of the heat exchanger; the manifold further comprises an inner plate separate from the plate collector, the inner plate comprising a plurality of openings of substantially elongate section for receiving the ends of the tubes and the sealing means arranged around the ends of the tubes;

the sealing means is configured to be compressed between each tube end and the inner plate;

the width of the openings of the header plate is less than the width of the openings of the inner plate;

the length of the openings of the header plate is less than the length of the openings of the inner plate;

the sealing means comprises:

At least one base arranged between the header plate and the inner plate,

A plurality of standard collars configured to receive the ends of the tubes of the heat exchange bundle of said heat exchanger and extending from the base through the openings of the inner plate, and

A plurality of inverted collars configured to receive the tubes and extending from the base opposite the standard collars, and through the openings of the collector plate;

the collector box further comprises a lid assembled to the collector plate so as to close the collector box, and

the inner plate is arranged between the sealing means and the cover;

the ends of the tubes respectively have at least one flare located on a portion of the tube end;

the width of the ends of the tubes at said at least one flare can be of the order of 1.5 times to 2.5 times the width of the ends of the tubes before flaring; the ends of the tubes comprise respectively at least one internal flare compressing the sealing means against the collector plate;

the ends of the tubes respectively comprise at least one outer flare compressing the sealing means against the inner plate;

the width of the ends of the tubes at the level of external flare is greater than the width of the ends of the tubes at the level of internal flare;

the inner plate has local deformations around the openings, and the ends of the tubes are flared so as to conform to the shape of the edge of the openings of the inner plate;

the ends of the tubes are of substantially oblong shape with two long sides connected by two small sides substantially rounded, and the short sides are flared so as to have an increase in radius of the order of 5% to 30%, preferably less than 15%;

the tubes are made from a metal strip and the tubes are sealed by soldering, for example the tubes are formed by folding or stapled;

the tubes are folded and have at least one partition separating two circulation channels, and the tubes are devoid of flaring near said at least one partition, preferably over a distance of between 1 mm and 3 mm around said at least one partition ;

the bent tubes have a substantially "B" cross section;

the heat exchange bundle is assembled by soldering.

A heat exchanger is thus obtained with a compact tube bundle comprising tubes with a tighter pitch, such as folded or stapled tubes, whose sealing is ensured by brazing, and whose ends are flared for mechanical assembly to the plates. collectors to meet pressure and endurance constraints and reduce the risk of leakage. Other features and advantages of the invention will emerge more clearly on reading the following description, given by way of illustrative and nonlimiting example, and the appended drawings among which:

FIG. 1 is a sectional view of a heat exchanger according to the invention showing partly a heat exchange bundle and a collector box; FIG. 2 is a perspective view of the heat exchanger of FIG. 1; on which the cover of the collector box has been removed,

FIG. 3 is an enlarged view of a portion of FIG.

FIG. 4a is a cross-sectional view of a bent tube for a heat exchanger,

FIG. 4b is a cross-sectional view of a stapled tube for a heat exchanger, FIG. 5 is a partial sectional view showing an end of a tube of the heat exchange bundle assembled to the manifold box before flaring of the end of the tube;

FIG. 6 is a perspective view showing tube ends of the heat exchange bundle opening into a collecting box,

- Figure 7 a partial longitudinal sectional view of the manifold showing an end of a tube of the heat exchange bundle assembled to the manifold after a double flare of the end of the tube,

FIG. 8 schematically represents a tool for flaring the ends of the tubes of FIGS. 1 to 7,

FIG. 9a is a cross-sectional view of the manifold box showing an end of a tube of the heat exchange bundle assembled to the manifold after a double flare of the end of the tube,

FIG. 9b is a perspective view showing a tube of the heat exchange bundle assembled to a collector plate of the collector box,

FIG. 9c is a perspective view showing the tube end of FIGS. 9a and 9b,

FIG. 10 is a perspective view of a collector plate of a collector box of the heat exchanger of FIGS. 1 and 2,

FIG. 11 is a perspective view of a sealing means of the collector box of FIGS. 1 and 2,

FIG. 12a is a perspective view of a lower face of an internal plate of the collecting box,

FIG. 12b is a perspective view of an upper face of the inner plate of the manifold,

FIG. 12c is an enlarged partial view of a portion of FIG. 12b, and

- Figure 12d is a partial view in a cross section I-I of Figure 12b.

In these figures, the identical elements bear the same references.

The following achievements are examples. Although the description refers to one or more embodiments, this does not necessarily mean that each reference relates to the same embodiment, or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined or interchanged to provide other embodiments.

In the description, it is possible to index certain elements, such as for example first element or second element. In this case, it is a simple indexing to differentiate and name close but not identical elements. This indexing does not imply a priority of one element with respect to another and it is easy to interchange such denominations without departing from the scope of the present description. This indexing does not imply an order in time either. Heat exchanger

The invention relates to a heat exchanger 1 for a motor vehicle, such as a radiator.

As is partially illustrated in FIGS. 1 and 2, a heat exchanger 1 conventionally comprises:

a heat exchange bundle comprising a plurality of tubes 11, arranged in one or more rows of tubes 11, and

- At least one manifold 20, generally two manifolds 20, each comprising a header plate 21 traversed by the tubes 11, and a cover 23 intended to be fixed on the header plate 21 to at least partially close the manifold 20.

The tubes 11 can extend longitudinally and be mounted between two manifolds 20, through the manifold plates 21 arranged transversely with respect to the tubes 11 and through which the ends of the tubes 11 pass through.

The manifold or boxes 20 can distribute a first fluid to the tubes 11 or collect the first fluid having traveled through these tubes 11. The tubes 11 are therefore intended to be traversed by the first fluid.

The or each manifold 20 comprises a sealing means 25, made in the form of a seal. More specifically, it is a compressible sealing means 25 intended to be arranged on the collecting plate 21 and around the ends of the tubes 11 opening into the manifold 20 to the heat exchanger assembly 1. According to the illustrated embodiment, the manifold 20 may further comprise an inner plate 27, visible in Figures 1 to 3, distinct from the header plate 21, and arranged at least partly against the sealing means 25 so to maintain the sealing means 25 around the ends of the tubes 11 in the assembled state of the heat exchanger 1. This plate 27 is called "internal plate" because of its arrangement in the interior volume of the manifold box 20 defined between the collector plate 21 and the cover 23.

Heat exchange bundle

The heat exchange bundle 10 of the heat exchanger 1 is described in more detail below.

This is for example a heat exchange bundle 10 assembled by brazing, that is to say whose various elements are assembled together and then brazed by passing through a brazing furnace, to ensure the joining of the all of the elements of the heat exchange bundle 10. For this purpose, the various elements of the heat exchanger heat exchange bundle 10 may be metallic, preferably aluminum or aluminum alloy.

tubing

The tubes 11 are advantageously made in the form of flat tubes, that is to say with a ratio of between 5 and 30, for example of the order of 10 between the thickness or height of the tube 11 and its width. By way of non-limiting example, the tubes 11 may have a width of the order of 27 mm and a thickness of about 1.4 mm.

The tubes 11 of the heat exchange bundle can be made from a strip or sheet metal. The sealing of each tube 11 can be provided by soldering. For example the tubes 11 are formed by folding, so-called "folded tube" (see Figure 4a), or they can be stapled (see Figure 4b) or it can be electro-welded tubes.

The ends of the tubes 11 are of substantially elongated section, in the illustrated example. Preferably, the ends of the tubes 11 are of substantially oval or oblong section so as to increase the resistance of the tubes 11. The ends of the tubes 11 thus extend mainly along a length L and have a width 1 more The ends of the tubes 11 thus have two long opposite sides in the direction of the length L and two small opposite sides in the direction of the width 1.

In other words, when one is located at one end of a tube 11, the width 1 is the dimension joining the two large opposite sides of the tube 11, and corresponds to the thickness or height of the tube 11.

According to the embodiments illustrated in Figures 3 and 4a, the cross section of a tube 11 may have two parallel fluid circulation channels juxtaposed 111 and separated by at least one partition 113, also called leg forming spacer. For example, each tube 11 may have a cross section substantially "B". Of course, any other type of folding can be provided. Alternatively, other sections may be provided, for example of substantially oblong shape defining a single channel 111 for fluid circulation, as illustrated in the example of Figure 4b.

In addition, the brazed heat exchange bundle 10 is intended to be assembled mechanically to the or each header box 20.

To do this, the tubes 11 are mechanically assembled to each manifold 20. In a detailed manner, the tubes 11 can be assembled to the manifold 20 so as to pass through the manifold plate 21, the sealing means 25 and the inner plate 27, as illustrated in Figure 5. The ends of the tubes 11 opening into the manifold 20 are then deformed plastically. According to the embodiment described, this mechanical assembly is done by flaring the ends of the tubes 11. For this purpose, the ends of the tubes 11 are flared so as to increase at least partially the width of the ends of the tubes 11 and bear on the sealing means 25, as is best seen in Figures 6 and 7.

Note that throughout the application, the width of the ends of the tubes, the width of the openings defined by the ends of the tubes, or in other words, the internal width of the ends of the tubes.

The flaring of the ends of tubes 11 is for example made by punching these ends, in particular with the aid of a tool 30 of complementary shape shown schematically in FIG. 8. Preferably, the flare is made localized. By localized evaporation, it is meant that the flaring is not carried out over the entire periphery of the end of a tube 11. In other words, the flaring is carried out on one or more portions of the end of the tube 11. In particular in the case of tubes 11 bent for example in "B" having in cross section a substantially oblong shape with a partition 113 connecting the long opposite sides, the ends of the tubes 11 are flared at the long sides but not at the level of the partition 113 separating the channels 111, as in the example of Figures 2, 3 and 9a to 9c. In this example with the partition 113 substantially in the center, there is therefore no central flaring of the ends of the tubes 11. In particular, one can provide an absence of flaring on 2mm to 3mm around the center of the ends of the tubes 11.

In the particular example shown in Figures 2, 3 and 9a to 9c, the ends of the tubes 11 comprise four local flares 115 arranged on the long sides on either side of the partition 113. These flares 115 give a substantially corrugated profile to long sides of the ends of the tubes 11.

The flares 115 on the peripheries of the ends of the tubes 11 therefore form bearing areas on the sealing means 25. At the flare or flares 115, the width of the ends of the tubes 11 increases. By way of non-limiting example, the width of one end of a tube 11 at the flares 115 may be of the order of 1.5 times to 2.5 times the width 1 of the end of the tube 11 before flaring.

One can also speak of the height or thickness of the tube 11 which is larger at the level of the flares 115 at its end.

Preferably, it limits the flaring at the narrow sides of the ends of the tubes 11, so as to avoid tearing of the tubes 11. In case of additional flare at the short sides of the ends of the tubes, this flaring can be achieved with a smaller section increase than the flares 115 on the long sides of the ends of the tubes 11. For example, in the case of a substantially oblong section whose short sides are rounded, a flare can be made at the level of these small sides with an increase in radius of the order of 5% to 30% after flaring, preferably less than 15% after flaring. In particular, the ends of the tubes 11 are flared to fit the shape of the inner plate 27 described in more detail later.

It is possible to flare at least locally the ends of the tubes 11, so as to define one or more flares 115 only on the periphery of the ends of the tubes 11.

Alternatively, the ends of the tubes 11 are evacuated in at least two distinct transverse sections of the ends of the tubes 11, as illustrated in FIGS. 6, 7, 9a and 9b. In particular, the ends of the tubes 11 may have:

on the one hand one or more so-called external flares 115 on the periphery of the ends of the tubes 11 opening into the manifold box 20, that is to say on the outside of the heat exchange bundle 10, and

on the other hand one or more other flares 117 said internal, made on the side of the remainder of the heat exchange bundle 10, the inner side of the heat exchange bundle 10.

The internal flare (s) 117 squeeze the sealing means 25 against the manifold plate 21. According to the illustrated embodiment, an internal flare 117 is formed over the entire internal cross section of the end of the tube 11.

The outer flare (s) 115 compress the sealing means 25 against the inner plate 27. The heat exchanger 1 may advantageously comprise one or more locking members (not shown) arranged at the end of one or more tubes. 11 so as to maintain the outer flare (s) 115, and thus maintain the compression of the sealing means 25.

Referring to Figure 7, the width of the ends of the tubes 11 at the outer flares 115 is greater than the width li of the ends of the tubes 11 at the inner flares 117. The width of the ends of the tubes 11 at the level of External flares 115 and width li of the ends of the tubes 11 at the inner flares 117 are of course greater than the width 1 of the ends of the tubes 11 before flaring.

Flares 115; 117 allow to compress the sealing means 25 to ensure the seal between the header plate 21 and the tubes 11. In addition, the external flares 115 have a function of mechanical retention of the sealing means 25 ensuring the holding in place and the compression of the sealing means 25.

To achieve such a double flare at the ends of tubes 11 bent "B", the tool 30 (Figure 8) is advantageously made with two punching portions 301 each having a first counter-form 303 to achieve an internal flare 117 and another counterform 305 for providing an external flare 115. The two punching portions 301 are identical. The two punching portions 301 extend from a common base 307 and are separated by a slot 309 substantially in the center of the tool 30 which is shaped to receive the partition 113 when the tool 30 is inserted into the end of a tube 11.

Dividers

Furthermore, the heat exchange bundle 10 further comprises in this example tabs 13 (see Figures 1 to 3) separating the tubes 11 from each other, and intended to be traversed by a second fluid for a heat exchange with the first fluid intended to pass through the tubes 11. The disturbance generated by the presence of these spacers 13 facilitates heat exchange between the two fluids. These spacers 13, shown schematically in FIG. 6, may have a substantially corrugated shape as illustrated in FIGS. 1 to 3. These spacers 13 are well known to those skilled in the art and are not described in greater detail in the art. present.

The spacers 13 are for example brazed to the tubes 11 at the vertices of their corrugations.

Play

The heat exchange bundle 10 may furthermore comprise two lateral flanges 15 on either side of the plurality of tubes 11, in this example on either side of the alternating stack of tubes 11 and dividers 13. .

According to the illustrated embodiments, the lateral cheeks 15 respectively comprise means for attaching to the cover 23 of the manifold 20. These are mechanical fixing means such as crimping tabs 151 configured to be folded on the lid 23 to the assembly of the heat exchange bundle 10 to the manifold 20. These mechanical fastening means between the side cheeks 15 and the lid 23 allow to lock the mechanical assembly between the bundle heat exchange 10 and the manifold 20.

Collector box

The elements of the header box 20, namely the header plate 21 (FIG. 10), the cover 23 (FIG. 1), the sealing means 25 (FIG. 11) and the internal plate 27 are described in more detail below. (Figures 12a to 12d).

Collector plate

With regard to the collector plate 21, reference is made more particularly to FIGS. 7, 9a, 9b and 10.

A plurality of openings 211 are formed on the header plate 21 for the passage of the ends of the tubes 11 of the heat exchange bundle 10. Complementary to the ends of the tubes 11 before flaring, the openings 211 are respectively substantially elongated section. For example, the openings 211 are substantially oblong, and extend longitudinally substantially transversely to the longitudinal axis of the tubes 11 in the assembled state of the heat exchanger 1.

The openings 211 of the header plate 21 therefore extend along a width A (shown in FIG. 7) and a length C (represented in FIG. 9a) larger than the width A.

Referring to Figure 7, the width A of each opening 211 of the header plate 21 is substantially equal to the width 1 of the end of a tube 11 before flaring added to twice the thickness e of the sealing means After compression.

More specifically, the header plate 21 is dimensioned so that the width A of each opening 211 is smaller than the width li of a tube end 11 after flaring.

More specifically, the width A of each opening 211 is smaller than the width li of a tube end 11 after flaring added to twice the thickness e of the sealing means 25 in the assembled state of the heat exchanger 1 , that is to say when the means Sealing 25 is compressed following the flaring of the ends of the tubes 11. This is in particular here the width li at the level of the internal flares 117 of the ends of the tubes 11. The state of the means is subsequently defined. sealing 25 after flaring the ends of the tubes 11 compressing the sealing means 25, by "the compressed state of the sealing means 25". Thus the width A of the openings 211 of the collecting plate 21 corresponds to the following equations (1) and (2):

(\) A = l + 2e

(2): A <li + 2e

This makes it possible to prevent any propagation of the flaring on the remainder of the tube 11. In addition, by preventing the propagation of the flaring, this dimensioning allows, when it comes to tubes 11 bent in "B", to prevent the tubes 11 from tearing or in other words that the solder sealing of such bent tubes 11 is broken. Also, in the case of stapled tubes 11, a representation of which is illustrated in FIG. 4b, such dimensioning of the openings 211 of the plate 21 makes it possible to prevent the tubes 11 from opening at the level of the covering of the two thicknesses of the sheet metal due to spreading of the flare.

Furthermore, with reference to FIGS. 9a and 9c, the length C of each opening 211 of the collecting plate 21 is substantially equal to the length L of the end of a tube 11 before flaring added to twice the thickness e of the sealing means 25 after compression.

Specifically, the header plate 21 is further dimensioned so that the length C of each opening 211 is smaller than the length L 'of a tube end 11 after flaring. In particular, the length C of each opening 211 is less than the length L 'of a tube end 11 after flaring added to twice the thickness e of the sealing means 25 in the compressed state. This is in particular the length L 'of a tube end 11 at an internal flare 117. Thus the length C of the openings 211 of the collector plate 21 corresponds to the following equations (3) and (4) :

(3): C = L + 2e

(4): C <L '+ 2e

This optimizes the dimensioning of the header plate 21 to limit the propagation of the flare on the rest of the tubes 11. According to the illustrated embodiment, the manifold plate 21 further comprises fastening means 213 to the lid 23. This is mechanical fastening means 213, such as crimping tabs that can be folded on the lid 23 .

For example, the header plate 21 has a peripheral edge

215 having these fastening means 213. In this example, the collector plate 21 can be folded around its periphery to form the peripheral edge 215.

Furthermore, according to the illustrated embodiment, the header plate 21 is substantially flat and free of collet, more specifically comprises a substantially planar bottom 217 and without collar, on which are formed the openings 211 and relative to which the peripheral edge 215 is elevated.

In addition, according to this embodiment, the header plate 21 has no groove, groove or the like to accommodate the sealing means 25. Alternatively, the header plate 21 could include a groove or groove to accommodate at least a portion sealing means 25 serving to seal between the cover 23 and the collector plate 21.

Lid

Referring again to Figure 1, the cover 23 is for example made of plastic. In this case, it is the sealing means 25 which provides a tight connection between the cover 23 and the collector plate 21.

In addition, the cover 23 has a cover foot 231 intended to be fixed to the collector plate 21, for example by means of the crimping tabs 213 of the collector plate 21 which are crimped on the cover foot 231 to the assembly. The term "cover foot", the lower portion of the cover 23 which is on the side of the heat exchange bundle 10 assembly. The cover foot 231 then bears against the sealing means 25, more precisely against a peripheral portion of the sealing means 25, between the cover 23 and the collector plate 21 during crimping.

Sealing means According to the embodiment illustrated in Figures 1 to 3, 5 to 7, 9a, 9b and 11, the sealing means 25 is arranged to be compressed between the ends of the heat exchange tubes 11 and the inner plate 27, in the assembled state of the heat exchanger 1.

The sealing means 25 is for example made of elastomer such as an ethylene-propylene-diene monomer known under the acronym EPDM.

According to the embodiment, the sealing means 25 comprises at least two parts: a first peripheral portion 251 shaped to follow the periphery of the header plate 21, and a second portion 253, 254, 255 configured to surround the ends of the tubes 11 at the heat exchanger assembly 1.

The first peripheral portion 251 seals between the cover 23 and the collector plate 21.

The second portion 253, 254, 255 of the sealing means 25 comprises a plurality of collars 253, hereinafter referred to as standard collars, delimiting openings 254 for the passage of the tubes 11 and extending towards the cover 23 to the assembly of the manifold 20. The standard collars 253 are intended to be received in the inner plate 27.

In addition, these standard collars 253 are adapted to receive the ends of the tubes 11 at the assembly of the heat exchange bundle 10 with a collector plate 21.

More precisely, the standard collars 253 extend in the same direction as the insertion direction of the tubes 11 into the collector plate 21.

In addition, the shape of the standard collars 253 is complementary to that of the ends of the tubes 11. In the example illustrated in FIG. 11, the standard collars 253 have, in cross section, a substantially oblong shape before assembly of the manifold 20 The standard collars 253 are intended to be compressed during the flaring of the ends of the tubes 11. The tightness between the tubes 11 and the collector plate 21 is ensured by this compression of the standard collars 253 around the ends of the tubes 11.

In particular, it is the thickness e of the standard collars 253 after compression which is added twice to the width li of a tube end 11 after flaring. in equation (2) for sizing the width A of the openings 211 of the header plate 21.

In addition, the standard flanges 253 are dimensioned so that at the assembly of the heat exchange bundle 10 to the manifold 20, the ends of the tubes 11 are substantially flush with the standard flanges 253, that is, practically without any overtaking, or even without the slightest excess, of the ends of the tubes 11 with respect to the standard collars 253 of the sealing means 25.

Furthermore, as is best seen in Figures 1, 7 and 9a, 9b, the second portion of the sealing means 25 may also include a plurality of inverted collars 255, extending opposite the standard collars 253, that is to say in the direction of the heat exchange bundle 10 in the assembled state of the heat exchanger 1. The inverted collars 255 extend in the opposite direction to the insertion direction of the tubes 11 in the plate collector 21.

There are then as many standard collars 253 as reverse collars 255. The inverted collars 255 are made in the extension of standard collars 253.

The inverted collars 255 extend through the openings 211 of the collector plate 21 when the sealing means 25 is arranged on the collector plate 21.

These inverted collars 255 are also adapted to receive the ends of the tubes 11 at the assembly of the heat exchange bundle 10 at the manifold 20. In addition, the shape of the inverted collars 255 is also complementary to that of the tubes 11. Inverted collars 255 may have a substantially oblong shape. The inverted collars 255 of the sealing means 25 contribute to facilitating the insertion of the tubes 11 and also contribute to sealing between the tubes 11 and the collector plate 21.

The standard collars 253 and the inverted flanges 255 extend in a direction parallel to the longitudinal axis of the tubes 11 in the assembled state of the heat exchanger 1.

In particular, it is the thickness e of the inverted collars 255 after compression which is considered in equation (1) for the dimensioning of the width A of the openings 211 of the collector plate 21. According to the embodiment described, the way Sealing 25 has the same thickness e after compression at the level of the standard collars 253 and at the level of the inverted collars 255.

In addition, the dimensions of the openings 254, namely the width and the length, on the side of the inverted collars 255 are smaller than the dimensions of these openings 254 on the side of the standard collars 253.

Finally, the standard collars 253 and the inverted collars 255 are flexible and adapt to the shape of the tubes 11 and the openings 211 of the collector plate 21. Thus, the sealing means 25, in particular its standard collars 253 and inverted 255, ensures a flexible connection between the collector plate 21 and the tubes 11, which makes it possible to absorb the stresses of deformation due to thermal expansion.

The sealing means 25 further comprises in this example a base 257, better visible in Figure 11, from which extend on one side the standard collars 253 and the opposite side the reverse collars 255. The base 257 connects the peripheral portion 251 to these standard collars 253 and inverted collars 255.

In addition, the sealing means 25 has at least one part, formed in this embodiment by the base 257, which rests on the header plate 21 and on which the inner plate 27 is placed. This base 257 is therefore arranged between the manifold plate 21 and the inner plate 27. Internal plate

With reference to FIGS. 12a to 12d, the inner plate 27 is described in more detail. The inner plate 27 is advantageously made of plastic.

The inner plate 27 has for example a generally parallelepipedal shape, here parallelepiped rectangle.

This inner plate 27 comprises a plurality of openings 271 for receiving the ends of the tubes 11 and the sealing means 25 around the ends of the tubes 11, more precisely the standard collars 253 of the sealing means 25.

The shape of the openings 271 is adapted to the shape of the standard collars 253 and the ends of the tubes 11. The openings 271 of the inner plate 27 are of substantially elongate section to receive the ends of the tubes 11 and extend longitudinally substantially transversely to the longitudinal axis of the tubes 11 to the assembled state of the heat exchanger 1. In this example, the openings 271 are substantially oblong. Of course, any other shape complementary to the shape of the standard flanges 253 of the sealing means 25 and the ends of the tubes 11 may be provided.

The openings 271 of the inner plate 27 therefore extend along a width B

(shown in Figures 7, 12a and 12c) and a length D (shown in Figures 9a, 12a and 12c) larger than the width B.

Referring to Figure 7, the width B of each opening 271 of the inner plate 27 is substantially equal to the width li of the end of a tube 11 after flaring added to twice the thickness e of the sealing means After compression. This is in particular here the width li at the level of the internal flares 117 of the ends of the tubes 11.

The collecting plate 21 is dimensioned so that the width A of its openings 211 is smaller than the width B of the openings 271 of the inner plate 27. Thus the width B of the openings 271 of the inner plate 27 corresponds to the equations (5) and (6): (5): B = li + 2e

(6): A <B

Furthermore, with reference to FIGS. 9a and 12a, 12c, the length D of each opening 271 of the inner plate 27 is substantially equal to the length L 'of the end of a tube 11 after flaring added to twice the thickness e of the sealing means 25 after compression. This is in particular the length L 'of a tube end 11 at an internal flare 117. The collector plate 21 is dimensioned so that the length C of its openings 211 is smaller than the length D openings 271 of the inner plate 27. Thus the length D of the openings 271 of the inner plate 27 corresponds to the following equations (7) and (8):

(7): D = L '+ 2e

(8): C <D

Moreover, with the exception of the openings 271, the inner plate 27 is substantially flat.

In addition, the inner plate 27 is arranged so that the sealing means 25 is compressed between each tube end 11 and the inner plate 27, during the mechanical assembly of the tubes 11 to the manifold 20. More specifically, Those are the standard protruding collars 253 of the sealing means 25 which are compressed between the ends of the tubes 11 and the inner plate 27.

The inner plate 27 has a lower face 27a shown in Figure 12a and an opposite upper face 27b, shown in Figures 12b to 12d. Referring to Figure 1, the lower face 27a is intended to be arranged facing the base 257 of the sealing means 25 and the upper face 27b facing the cover 23, the assembly of the manifold 20. The internal plate 27 is thus arranged between the base 257 of the sealing means 25 and the cover 23. In other words, the base 257 of the sealing means 25 is interposed between the inner plate 27 (its lower face 27a) and the header plate 21. The inner plate 27 thus forms a collector plate against cooperating with the header plate 21 to maintain the sealing means 25.

Advantageously, the inner plate 27 is arranged and in particular sized so as to fill the spaces between the ends of the tubes 11. According to the embodiment, the inner plate 27 makes it possible to fill the spaces between the base 257 of the means of 25 and the standard collars 253 of the sealing means 25. The inner plate 27 thus forms a sheet that occupies almost all of the space between the protruding ends of the tubes 11 passing through the standard collars 253. In particular, the plate internal 27, more precisely its upper face 27b, is arranged closer to the ends of the tubes 11. In other words, the ends of the tubes 11 flanked by the standard collars 253 of the sealing means 25 do not exceed almost, that is to say - say exceed on a height less than 2mm, or not exceed at all, the plane that extends the inner plate 27. This reduces the loss of flow, not amment by limiting the formation of vortices or turbulence in the zone where the tubes 11 open into the manifold 20 in the assembled state of the heat exchanger 1.

Furthermore, as is best seen in Figures 12b to 12d, the inner plate 27 is deformed locally around the openings 271. More specifically, the inner plate 27 is locally deformed only on the upper face 27b.

The inner plate 27 therefore has local deformations 273 provided so that the edge of the openings 271 serves as a complementary counterform to the shape of the ends of the tubes 11 after flaring. The local deformations 273 of the inner plate 27 are for example made by flares 273. Thus, according to the embodiment described, during the assembly of the tubes 11 to the collector plate 21, the ends of the tubes 11 are flared so that to follow the shape of the borders delimiting the openings 271 of the inner plate 27.

According to a first variant embodiment, the inner plate 27 and the sealing means 25 are two separate parts.

According to a second variant embodiment not shown, the inner plate 27 and the sealing means 25 may be made in one piece. It may be a single piece bi-materials that is to say having two materials: a first part in a first material acting as sealing means 25 as described above, and a second part in one second material acting as an inner plate 27 as previously described.

Such a part 25, 27 is for example made by co-molding. This second variant makes it possible to limit the number of parts while allowing the assembly process of the heat exchanger 1 to be accelerated. In this case, this single piece 25, 27 is dimensioned so that its openings on the side of the inverted collars 255 have a width:

substantially equal to the width 1 of the end of a tube 11 before flaring and - less than the width of its openings on the side of the standard flanges 253 which is substantially equal to the width li of a tube end 11 after flaring. This is in particular here the width li at the level of the internal flares 117 of the ends of the tubes 11.

Similarly, the length of the openings of this single piece 25, 27 on the side of the inverted collars 255 is:

substantially equal to the length L of the end of a tube 11 before flaring and less than the length of its openings on the side of the standard flanges 253 which is substantially equal to the length L 'of a tube end 11 after flaring. This is in particular the length L 'of a tube end 11 at an internal flare 117. Method of assembling the heat exchanger

With reference to all the figures, a method of assembly of a heat exchanger 1 as described above is described below.

The method comprises a step of assembling the heat exchange bundle

10 followed by a brazing step of the heat exchange bundle 10 by passing through a dedicated oven.

For the assembly of a manifold 20, there is a sealing means 25 on a header plate 21, so that the inverted flanges 255 of the sealing means 25 are inserted into the openings 211 of the header plate 21. An inner plate 27 is then provided, so that the standard collars 253 of the sealing means 25 extend through the openings 271 of the inner plate 27. If the sealing means 25 and the inner plate 27 are made of In one piece, this single piece is provided forming both the sealing means 25 and the inner plate 27 in a single step.

The ends of the heat exchange tubes 11 of the heat exchange bundle 10 are inserted through the header plate 21, the sealing means 25 and the inner plate 27, so that the standard collars 253 of the sealing means 25 are arranged around the protruding ends of the tubes 11.

For the mechanical assembly of the heat exchange bundle 10 to the manifold 20, the ends of the tubes 11 are flared a first time thus forming an internal flare 117 so as to compress the sealing means 25 against the collector plate 21. The ends of the tubes 11 are advantageously flared again thus forming one or more external flares 115 so as to compress the sealing means 25, more precisely its standard flanges 253, against the inner plate 27.

Then, the cover 23 is placed in such a way that the cover foot 231 is housed in the space delimited by the raised peripheral edge 215 of the collecting plate 21 while coming on the peripheral part 251 of the sealing means 25.

After that, the lid 23 is assembled to the rest of the heat exchanger 1, for example by crimping by folding the crimping tabs 213 of the collector plate 21 and the crimping tabs 151 of the lateral cheeks 15 of the heat exchange bundle 10 brazed, which ensures the compression of the sealing means 25, more precisely its peripheral portion 251. Thus, it combines optimized thermal performance by means of the heat exchange bundle 10 brazed with tubes 11 having a tight pitch to thermal shock resistance on the side of the collector plate 21 thanks to the mechanical connection between the tubes 11 of this brazed bundle 10 and the collector plate 21 .

The sealing means 25 provides both a mechanical connection function between the heat exchange bundle 10 brazed and the manifold 20, but also a sealing function of the manifold 20 and between the tubes 11 and the package In addition, the inner plate 27 participates in the compression of the sealing means 25 to ensure the seal between the header plate 21 and the tubes 11.

In addition, the sizing of the openings 211 of the header plate 21 as described above, makes it possible to prevent the propagation of the flare and in particular makes it possible to increase the resistance of the tubes 11, which may be flat tubes and whose sealing is ensured by brazing. The inner plate 27 also helps to prevent the propagation of the flare on the remainder of the tubes of the heat exchange bundle.

Moreover, because of the presence of the inner plate 27 acting collector counterplate and the presence of flanges 253; 255 on the sealing means 25, the header plate 21 can be simplified and be made without collars contrary to the solutions of the prior art.

Claims

1. Heat exchanger (1), in particular for a motor vehicle, said exchanger comprising:

a heat exchange bundle (10) comprising a plurality of tubes (11) whose ends are of substantially elongated section,

at least one manifold (20) having a header plate (21), the header plate (21) having a plurality of openings (211) respectively receiving an end of a tube (11), the openings (211) of the collector plate (21) being of substantially elongate section, and

a compressible sealing means (25) arranged around the ends of the tubes (H),

characterized in that

the tubes (11) are mechanically assembled to the header plate (21) by flaring the ends of the tubes (11) so as to at least partially increase the width of the ends of the tubes (11) so as to compress the sealing means (25), and in that

the width (A) of each opening (211) of the header plate (21) is less than the width (l _e, 1) of a tube end (11) after flaring. 2. Heat exchanger (1) according to the preceding claim, wherein the width (A) of each opening (211) of the header plate (21) is less than the width (li) of a tube end (11) after flaring added to twice the thickness

(e) sealing means (25) in the assembled state of the heat exchanger (1), according to the following equation:

A <li + 2e, with

A = the width of an opening (211) of the header plate (21),

li = the width of a tube end (11) after flaring, and e = the thickness of the sealing means (25) in the assembled state of the heat exchanger (1). 3. Heat exchanger (1) according to one of the preceding claims, wherein the length (C) of each opening (211) of the header plate (21) is less than the length (L ') of a tube end (11) after flaring.

Heat exchanger (1) according to the preceding claim, wherein the length (C) of each opening (211) of the header plate (21) is less than the length (L ') of a tube end (11) after flaring added to twice the thickness (e) of the sealing means (25) in the assembled state of the heat exchanger (1)), according to the following equation:

C <L '+ 2e, with

C = the length of an opening (211) of the header plate (21),

L = the length of a tube end (11) after flaring, and

e = the thickness of the sealing means (25) in the assembled state of the heat exchanger (1).

Heat exchanger (1) according to any one of the preceding claims, wherein:

the manifold (20) further comprises an inner plate (27) separate from the header plate (21), the inner plate (27) comprising a plurality of openings (271) of substantially elongate section for receiving the ends of the tubes ( 11) and the sealing means (25) arranged around the ends of the tubes (11), wherein

the sealing means (25) is configured to be compressed between each tube end (11) and the inner plate (27), and wherein

the width (A) of the openings (211) of the header plate (21) is smaller than the width (B) of the openings (271) of the inner plate (27).

Heat exchanger (1) according to the preceding claim, wherein the length (C) of the openings (211) of the header plate (21) is less than the length (D) of the openings (271) of the inner plate (27).

Heat exchanger (1) according to one of claims 5 or 6, wherein the sealing means (25) comprises:

at least one base (257) arranged between the header plate (21) and the inner plate (27),

a plurality of standard collars (253) configured to receive the ends tubes (11) of the heat exchange bundle (10) of said heat exchanger (1) and extending from the base (257) through the openings (271) of the inner plate (27), and

a plurality of inverted collars (255) configured to receive the tubes (11) and extending from the base (257) away from the standard collars, and through the openings (211) of the collector plate (21) .

8. Heat exchanger (1) according to any one of the preceding claims, wherein the ends of the tubes (11) respectively have at least one flare (115; 117) located on a portion of the tube end (11). 9. Heat exchanger (1) according to the preceding claim, wherein the width (le; li) of the ends of the tubes (11) at said at least one flare (115;

117) is of the order of 1.5 times to 2.5 times the width (1) of the ends of the tubes (11) before flaring.

10. Heat exchanger (1) according to any one of the preceding claims, wherein the ends of the tubes (11) respectively comprise at least one inner flare (117) compressing the sealing means (25) against the header plate (21). ).

11. Heat exchanger (1) according to claim 5 taken together with any one of the preceding claims, wherein the ends of the tubes (11) respectively comprise at least one outer flare (115) compressing the sealing means (25). against the inner plate (27).

12. Heat exchanger (1) according to claims 10 and 11, wherein the width (the) of the ends of the tubes (11) at the outer flaring level (115) is greater than the width (li) of the ends of the tubes (11). ) at the internal flare (117). The heat exchanger (1) of claim 5 taken together with any one of the preceding claims, wherein:

the inner plate (27) has local deformations (273) around the openings (271), and wherein

the ends of the tubes (11) are flared so as to conform to the shape of the edges of the openings (271) of the inner plate (27).

14. Heat exchanger (1) according to any one of the preceding claims, wherein the ends of the tubes (11) are substantially oblong in shape with two long sides connected by two small sides substantially rounded, and in which the short sides are flared so as to have an increase in the radius of the order of 5% to 30%, preferably less than 15%.

15. Heat exchanger (1) according to any one of the preceding claims, wherein the tubes (11) are made from a metal strip and the sealing of the tubes (11) is provided by soldering, for example the tubes are formed by folding or stapled.

16. Heat exchanger (1) according to the preceding claim, wherein the tubes (11) are folded and have at least one partition (113) separating two circulation channels (111), and wherein the tubes (11) are devoid of flaring near said at least one partition (113), preferably at a distance of between 1mm and 3mm around said at least one partition (113).

17. Heat exchanger (1) according to any one of the preceding claims, wherein the heat exchange bundle (10) is assembled by soldering.