WO2020099808A1

WO2020099808A1 - Tube for a heat exchanger

Info

Publication number: WO2020099808A1
Application number: PCT/FR2019/052732
Authority: WO
Inventors: Olivier MAQUIN; Xavier MAUCOURANT; Jérôme MOUGNIER
Original assignee: Valeo Systemes Thermiques
Priority date: 2018-11-16
Filing date: 2019-11-15
Publication date: 2020-05-22
Also published as: WO2020099808A8; FR3088709A1; FR3088709B1

Abstract

The invention relates to a tube (20) for a heat exchanger (10) of a motor vehicle, the tube (20) having a wall (21) delimiting a duct (22), in which a cooling fluid is able to circulate, the wall (21) being folded to have two opposite end edges (41, 42) in a longitudinal direction on either side of a median part (43) and an upper and a lower part (44, 45) opposite each other in a vertical direction. The wall (21) of the tube (20) has a first groove (95) provided on the upper and the lower part (44, 45) in the vicinity of one of the end edges (41) of the tube (20), the first groove (95) being configured to receive a catching portion (111) of a protection profile (90) of the end edge of the corresponding tube. Said invention applies to motor vehicles.

Description

Tube for heat exchanger

The field of the present invention is that of heat exchangers, in particular for a motor vehicle, and it relates more particularly to heat exchangers comprising a bundle of tubes and arranged in particular on the front face of the motor vehicle.

Such heat exchangers are in particular arranged on a loop of a cooling circuit, making it possible to dissipate calories, coming from an internal combustion engine, or from a device, such as an air conditioning module, of the vehicle. automobile. In known manner, a heat exchanger for a motor vehicle comprises a plurality of tubes extending parallel to each other and in which the coolant present in the cooling circuit loop mentioned above can circulate. The heat exchanger is configured to allow an exchange of calories between an air flow passing through it and the coolant circulating inside the tubes, knowing that the heat exchanger can also include a plurality of fins s 'extending between the tubes, on the passage of the air flow, thus promoting the dissipation of calories at the heat exchanger.

A tube heat exchanger can in particular be located at a front face of the motor vehicle. Thus, when the motor vehicle moves forward, the fins of the heat exchanger are exposed to a flow of air from outside the motor vehicle, thereby improving the dissipation of calories at the heat exchanger.

The heat exchanger thus located on the front face of the motor vehicle is exposed to possible projections, in particular gravel located on the track on which the motor vehicle circulates, the projections then risking damaging the heat exchanger, and in particular the tubes of the heat exchanger. Damage to a tube of the heat exchanger, and in particular the drilling of this tube, can lead to a leak of the cooling fluid, which has several drawbacks, both environmental and behavioral. The leakage of the heat exchanger coolant results in in particular by an ineffectiveness of the heat exchanger, the tubes of the heat exchanger no longer comprising cooling fluid circulating inside, thus obliging the user of the motor vehicle to repair the heat exchanger. heat. Furthermore, the leakage of the coolant at the heat exchanger means that no more coolant circulates in the coolant circuit and this can damage vehicle components whose cooling is then no longer ensured.

In the state of the art, it is known to have means of protection upstream of the bundle of tubes of the heat exchangers with respect to the road scene, so that these form a protection of the part of the tube facing towards the front of the vehicle, i.e. the part most likely to be impacted by projectiles.

Thus, the protection can be formed by a grid fixed on the front face of the exchanger, the grid comprising a plurality of metallic members intersecting, thereby reducing the surface of the front face of the exchanger exposed to projections, thus reducing the risk of damage to the tubes.

There are also known heat exchangers in which the protection is formed by an elastic element, for example made of silicone, placed opposite or in contact with the edge of the tube facing the front of the vehicle. Thus, the elastic element absorbs the impacts of projections, thus preventing the tube, in front of which it is positioned, from being pierced. These known heat exchangers are not entirely satisfactory and have drawbacks. Indeed, the known solutions may not be compatible with constraints of space requirement when the heat exchanger is positioned in the motor vehicle. In addition, they can also cause additional mass constraints, which are not necessarily compatible with the constraints formulated by motor vehicle manufacturers.

Thus, the object of the present invention is to propose a particular tube for a heat exchanger, in order to at least largely respond to the drawbacks mentioned above and also to lead to other advantages. The invention achieves this, according to a first aspect, thanks to a tube for a heat exchanger of a motor vehicle, the tube comprising a wall delimiting a duct in which is able to circulate a cooling fluid, the wall being folded to present two edges. opposite ends in a longitudinal direction on either side of a middle part and two upper and lower parts opposite to each other in a vertical direction. According to the invention, the wall of the tube comprises a first groove formed on one of the upper and lower parts in the vicinity of one of the end edges of the tube, the first groove being configured to receive a hooking part of a protective profile of the end edge of the corresponding tube.

The tube has a thickness in the vertical direction which is less at the level of the groove than in the rest of the wall formed by a metal sheet folded back on itself. The smaller thickness of the tube at the level of the groove makes it possible to create an anchoring point making it possible to partially accommodate a portion of the profile attachment in order to maintain the profile at the corresponding end edge of the tube.

This configuration makes it possible to position a single section facing a single tube of the heat exchanger, and this makes it easier to target the areas of a heat exchanger where it is desired to apply these sections forming a protective element of the corresponding tube. The profile forms an additional thickness of material at the end to be protected of the tube, the thickness of additional material thus forming a protection against possible projections, such as gravel, liable to impact this end of the tube and cause a coolant leak making it necessary to repair or replace the heat exchanger.

On the other hand, the profile is located outside the tube. In other words, the profile is not in contact with the cooling fluid circulating inside the tube. This configuration thus makes it possible to be able to dispense with adapting the volume of the conduit in order to obtain an equivalent heat dissipation capacity. Indeed, positioning an additional thickness of material inside the duct to reinforce the end edge of the tube liable to be impacted by gravel, thus occupying a volume normally occupied by the cooling fluid, requires increase the volume of the duct in order to obtain an identical heat dissipation capacity. When the material thickness is positioned outside the duct, there is therefore no need to have adapt the volume of the conduit so that the tube has an identical heat dissipation capacity.

The tube according to the first aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements can be taken alone or in combination:

- The wall includes a second groove located on the other of the lower and upper parts, the second groove being located at the same distance from the corresponding end edge as the first groove. This configuration ensures more effective maintenance of the profile relative to the end edge of the tube that it helps protect. Indeed, the profile is held relative to this end edge by the two grooves then located on one on the upper part and the other on the lower part of the tube.

- The wall includes a third groove located at a horizontal face of the rear end of the tube. This configuration ensures the protection of the rear end of the tube against possible projections likely to damage the rear end of the tube.

- The groove (s) extend along a transverse axis perpendicular to the longitudinal and vertical directions.

- The groove (s) extends only over part of the transverse dimension of the corresponding end edge of the tube; the profile is fixed to the tube at the end edge exposed to the projection of gravel by an elastic locking operation.

- The tube has transversely a central portion equipped with the groove or grooves and two transverse end portions arranged transversely on either side of the central portion, the groove or grooves not extending in these end portions transverse. This configuration makes it possible, during the implementation of the tube in a heat exchanger, not to have to modify the configuration of the collecting chambers, located at the transverse ends of the tubes, the collecting chambers making it possible to connect the different tubes of the plurality of heat exchanger tubes so that the coolant can circulate within the heat exchanger within the plurality of tubes. - The groove or grooves extends over the entire transverse dimension of the corresponding end edge of the tube, the groove or grooves opening onto the transverse ends of the tube. This configuration makes it possible to maximize the area for fixing the profile to the tube. In addition, this configuration makes it possible to manufacture the tube by an extrusion process. This configuration also allows, during assembly of the heat exchanger comprising a tube according to the first aspect of the invention, to insert the profile on the tube by translation along the transverse axis, or by clipping along the 'longitudinal axis. Thus, when the profile is clipped onto the front end of the tube, the profile undergoes elastic deformation, along the vertical axis, before returning to its initial state when it is housed partly in the groove, the groove defining a thickness smaller, along the vertical axis, than the thickness of the rest of the front end of the tube.

- The wall of the tube is made of aluminum. This configuration makes it possible to have a tube made of light material and having a high heat dissipation capacity.

- The tube is obtained by extrusion. Alternatively, the tube is obtained by successive folding of a metal plate forming the wall, the groove then being obtained by stamping the metal plate before it is folded. Alternatively, the groove can be obtained by machining the wall of the tube, this latter alternative requiring that the groove be configured so that the thickness of the wall at the level of the groove is sufficient to withstand the mechanical forces and the stresses of pressure exerted by the coolant to avoid leakage at the groove.

- The profile comprises a hooking portion capable of being fixed on the tube and a protective portion extending projecting from the tube. The protective portion may include at least one cavity which extends along the transverse axis. The cavity can be opened, taking the form of a groove. Alternatively, the cavity can be closed. The cavity accommodates an additional protective element. The protective element can be, for example, a thread of silicone or other elastic material to absorb impacts at the front end of the tube. The protective element can also be a metal wire, increasing the resistance of the profile to impacts.

- The profile is made of metal or plastic or thermoplastic material. The use of a metal profile allows the profile to be brazed to the front end edge of the tube. Of advantageously, the profile is then made of aluminum. The profile can also be produced with a thermoplastic elastomer, thus making it possible to absorb the shocks caused by projections in order to reduce the risk of damage to the front end of the tube.

- The profile can be made from two separate materials. Advantageously, the protective part of the profile is made of a first material and the attachment part is made of a second material having different technical characteristics. According to a first alternative, the first material is rigid in order to resist the impacts of projections, the second material being elastic, facilitating the deformation of the attachment portion of the profile during insertion of the profile on the front end of the wall . According to a second alternative, the first material is an elastic material in order to absorb the impacts occurring at the level of the protective part of the profile.

- The coolant is water or an aqueous solution comprising ethylene glycol. The use of an aqueous solution comprising ethylene glycol allows the use of a cooling circuit comprising such a cooling fluid in a motor vehicle intended to be used or stored by negative atmospheric temperatures, ethylene glycol allowing the solidification temperature of the aqueous solution to be reduced. Alternatively, the coolant can be a supercritical fluid. More particularly, the supercritical fluid is advantageously C02, also known under the name R744.

According to a second aspect, the invention relates to a heat exchanger comprising a plurality of tubes arranged in a stack in series, the plurality of tubes comprising at least one tube according to the first aspect of the invention, the heat exchanger comprising a space between two tubes, the space allowing the passage of an air flow promoting thermal exchange with the cooling fluid, the tubes being arranged in the heat exchanger so that the groove or grooves are arranged in the vicinity of a front end edge of the tube, that is to say the end edge intended to be turned towards the front of the vehicle.

This configuration provides a heat exchanger having the advantages provided by the tube according to the first aspect of the invention. The heat exchanger according to the second aspect of the invention advantageously comprises at least one of the improvements below, the technical characteristics forming these improvements can be taken alone or in combination:

- At least one tube is associated with a profile comprising a hooking part and a protective part arranged in longitudinal projection from the front end edge of the tube, the hooking part being configured to accommodate in the groove or grooves.

- The profile is fixed to the tube by snap-fastening, the attachment part being elastically deformable to allow it to be housed in the groove or grooves.

- The at least one tube according to the first aspect of the invention is located, during the implementation of the heat exchanger on a motor vehicle, on a lower part of the front face of the heat exchanger, the lower part being the part of the heat exchanger situated towards the bottom of the motor vehicle. Indeed, the lower part is the part of the heat exchanger which is the most exposed to possible projections, the upper part of the front face being in fact less subject to projections. In addition, the upper part, being raised relative to the lower part of the front face of the heat exchanger, is generally located behind various components of the chassis and / or body of the motor vehicle, these components ensuring protection against projections, thus reducing the need for the presence of a tube in accordance with the first aspect of the invention, ensuring resistance to projections, at the level of the upper part of the front face of the heat exchanger, the part high of the heat exchanger then being equipped with known tubes.

- Alternatively, all of the tubes of the heat exchanger according to the second aspect of the invention are tubes according to the first aspect of the invention, thus making it possible to maximize the protection of each of the tubes of the exchanger heat to avoid the risk of coolant leakage.

- The heat exchanger comprises at least one fin located between two adjacent tubes. In other words, the fin is located at a space in the heat exchanger. The fin increases the exchange surface between the heat exchanger and the air flow, so that the heat dissipation of the heat exchanger can be improved. Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given by way of non-limiting indication with reference to the schematic drawings annexed on the other share, on which:

- Figure 1 is a perspective view of an exemplary embodiment of a tube heat exchanger according to one aspect of the invention;

- Figure 2 is a perspective view of an exemplary embodiment of a tube according to the first aspect of the invention, which is associated with a protective element against the projection of gravel in the form of a profile;

- Figure 3 is a perspective view of the tube illustrated in Figure 2, the profile having been removed here to make more clearly visible a groove configured to receive a hooking portion of the profile;

- Figure 4 is a perspective view of the profile illustrated in Figure 2;

- Figure 5 illustrates a partial perspective view of an alternative embodiment of a tube according to the first aspect of the invention, the tube being shown here without the profile;

- Figures 6a, 6b, and 6c illustrate in sectional views three embodiments of a profile capable of being fixed to a tube according to the first aspect of the invention.

The characteristics, variants and different embodiments of the invention can be combined with one another, in various combinations, insofar as they are not incompatible or mutually exclusive of each other. It is possible in particular to imagine variants of the invention comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from in the prior art.

In particular, all the variants and all the embodiments described can be combined with one another if nothing is technically opposed to this combination. Figure 1 illustrates a perspective view of an exemplary embodiment of a heat exchanger 10 according to the first aspect of the invention.

The heat exchanger 10 comprises a plurality of tubes 20 each extending mainly along a first longitudinal axis X and a second transverse axis Y perpendicular to the first axis X, thus defining a first plane D. The tubes 20 are stacked in series the one above the other along a third vertical axis Z perpendicular to the first plane D.

The heat exchanger 10 comprises a front face 11 and a rear face 12 situated opposite the heat exchanger 10 relative to the front face 11, it being understood that the heat exchanger is arranged in the front face of the motor vehicle so that the front face 11 faces the front AV of the vehicle and the rear face faces the rear AR of the vehicle. The front face 11 and the rear face 12 extend substantially in parallel planes and defined by the transverse axes Y and vertical Z.

The heat exchanger 10 is configured so that an air flow, generated by the movement of the motor vehicle in which the heat exchanger 10 is installed, or also by a fan installed near the heat exchanger , flows along the first longitudinal axis X through the heat exchanger 10 from the front face 11 towards the rear face 12.

The heat exchanger 10 comprises spaces 15 interposed between the tubes 20 along the third axis Z, the spaces 15 allowing the passage of the air flow between the tubes 20 in order to promote the exchange of calories between the circulating coolant inside the tubes and the air flow coming to lick the walls of these tubes 20.

The heat exchanger 10 is connected to a loop of a cooling circuit by a first connector 13 and a second connector 14 respectively disposed at a transverse end here of the bundle of tubes 20 arranged one above the other. Each connector is fluidly connected to a collecting chamber 130, 140 into which the transverse ends of the tubes are introduced, so that each connector is configured to distribute or collect fluid in the set of tubes 20 of the heat exchanger 10. In this way, the cooling fluid can circulate in the plurality of tubes 20 of the heat exchanger 10. The heat exchanger 10 comprises a high zone Zh and a low zone Zb, these zones being located one next to the other along the third vertical axis Z. The high zone Zh is intended to be oriented upwards during the implementation of the heat exchanger 10 on a motor vehicle, the lower zone Zb being intended to be directed downwards, that is to say near the roadway on which the motor vehicle is traveling. The tubes according to one aspect of the invention, that is to say equipped with a profile forming a means of protection against the projection of gravel and therefore comprising a suitable groove to allow the fixing of this profile, can only be arranged in the lower zone Zb of the heat exchanger, more likely to be impacted by gravel. FIGS. 2 and 3 are perspective views of an exemplary embodiment of a tube according to the first aspect of the invention, the associated profile being illustrated in FIG. 2 and removed in FIG. 3.

The tube 20 comprises a wall 21 folded back on itself, thus delimiting a conduit 22 in which a cooling fluid circulates. The tube 20 has, with respect to the first longitudinal axis X, a front end edge 41 and a rear end edge 42 oriented respectively towards the front AV and the rear AR. The tube 20 also includes a middle portion 43 located between the front end edge 41 and the rear end edge 42. Thus, the wall 21 forms a tube of substantially rectangular section whose short sides are formed by the edge of front end 41 and rear end edge 42, the front end edge 41 being more directly exposed to gravel projections than the rear end edge 42. As illustrated in the figures, the short sides of the tube can be made by a curvature of the wall 21, so as to have a curved shape, curved towards the outside of the tube.

The tube 20 has an upper part 44 and a lower part 45 situated opposite the tube 20 relative to the upper part 44, the upper part 44 and the lower part 45 extending mainly along the first plane D and forming the long sides of the substantially rectangular section of the tube. It is understood that the qualification of upper and lower parts formed by the long sides of the tube is here arbitrary to simplify the description and made according to the orientation illustrated in the figures, and it is understood that one or more tubes could be implanted in a vehicle heat exchanger automobile with the upper part facing the ground without departing from the context of the invention.

As previously specified, the tube is obtained here by folding a wall 21 and the upper and lower parts and the front and rear end edges are formed in the extension of each other by this same wall. The two end edges are opposite to each other in a longitudinal direction on either side of the middle part 43 and the two upper and lower parts are opposite to each other in a vertical direction . In this way, the upper part 44 and the lower part 45 participate in delimiting the conduit 22 along the third vertical axis Z and the front and rear end edges participate in delimiting the conduit 22 along the first longitudinal axis X.

More particularly, the upper part 44 is formed of two portions extending respectively in the extension of an end edge and joining in the middle part 43. The wall 21 is folded back on itself so that a first support leg 51 and a second support leg 52 extend respectively from one of the portions of the upper part along the third vertical axis Z in the direction of the lower part 45. The first support leg 51 and the second support leg 52 are each formed by a termination of the metal plate forming the wall 21 of the tube 20 which extends through the conduit 22. Thus, as illustrated, the tube 20 here has a general shape in "B »Defining a conduit 22 which comprises two sub-conduits each extending between the terminations across the conduit and one of the end edges. In addition, this configuration allows the tube 20 to withstand the pressure exerted by the cooling fluid, along the third vertical axis Z. More particularly, this conformation makes it possible to avoid deformation of the upper part 44 and / or of the lower part 45 at the middle portion 43, the first support leg 51 and the second support leg 52 being able to provide a physical connection between the upper part 44 and the lower part

45.

The tube 20 is associated with a profile 90 which forms a protective element projecting from an end edge of the tube, and more particularly the front end edge 41, that is to say the edge intended to be turned towards the front of the vehicle when the heat exchanger, in which such a tube is installed, is mounted on the vehicle. It is understood that the section 90 makes it possible to protect the tube from any projections, such as gravel, and that it is positioned, relative to the trajectory of these possible projections, upstream from the front end 41 of the tube 20.

The profile 90, which will be described in more detail with reference to FIG. 4, forms an additional thickness of material, thus reducing the risk of damage to the front end 41 of the tube 20, projections liable to pierce the wall 21 of the tube 20 and therefore lead to a leak of the cooling fluid circulating inside the duct 22.

In order to achieve this protection function, the profile 90 is fixed to the corresponding tube by means of attachment means respectively carried by the tube and by the profile. FIG. 3 illustrates a perspective view of the tube 20 alone to make the attachment means carried by the tube more visible to allow the fixing of the profile 90 opposite the front end edge of the tube.

The attachment means carried by the tube 20 consists of at least one first groove 95 formed on one of the lower and upper parts, here the upper part 44, in the vicinity of the end edge to be protected, here the edge of front end of the tube.

The groove 95 extends along the second transverse axis Y, namely the axis perpendicular to the longitudinal and vertical directions previously mentioned.

The groove 95 extends here continuously, without interruptions, it being understood that an interrupted groove could not be considered to depart from the context of the invention, since it allows cooperation with attachment means carried by a profile forming a protective element against the projection of gravel.

In the embodiment illustrated in FIGS. 2 and 3, the groove 95 extends only over part of the transverse dimension of the front end edge 41 of the tube 20. More particularly, the groove does not open at the ends transverse of the tube and at least a portion of the tube in which the groove does not extend is provided between the transverse end edge of the tube and the corresponding transverse end of the groove.

In this way, the tube 20 has transversely a central portion 201 equipped with the groove 95 and two transverse end portions 202 arranged transversely of on either side of the central portion, the groove not extending in these transverse end portions.

More particularly, the central portion 201 of the groove 95 can be centered transversely on the tube, being arranged on either side of a central portion 96 of the front end edge 41, and the transverse end portions can have equal transverse dimensions. It should be noted that the illustrated tube is placed in a heat exchanger by being fixed at each of its transverse ends in orifices formed for this purpose in a collecting chamber 130, 140 (visible in Figure 1) inlet / outlet coolant. The transverse dimension can thus be chosen so that the connection in the collecting chamber is made with a part devoid of a groove, so that one does not have to adapt accordingly the shape of the orifices formed in the collecting chamber for questions. sealing.

It is understood from the illustration and the preceding description of the exemplary embodiment that the profile 90 must be fixed to the tube by appropriate latching means. As will be described below, the profile is configured for this purpose to deform elastically and allow it to be taken in the groove.

The tube 20 may also include a second groove formed on the lower part 45, said second groove, not visible in FIGS. 2 and 3, being identical to the first groove 95 present on the upper part 44 and participating in forming with the first groove the attachment means carried by the tube. Advantageously, the first groove and the second groove are arranged on their respective part, upper or lower, equidistant from the corresponding end edge, here the front end edge of the tube.

The depth of a groove is configured to form a housing adapted to the shape of the profile intended to be housed in the groove. It should be noted that, whatever the depth chosen, the groove forms a blind hole in the corresponding upper or lower part, that is to say a hole which does not open into the duct 22 so as not to compromise the sealing of the coolant flow inside the duct 22. H

We will now describe, with reference to FIG. 4, the section 90 capable of being fixed on the tube 20 as illustrated in FIG. 2 and forming a protective element of the tube against the projection of gravel.

The profile 90 comprises a protective part 110 and a hooking part 111, these two parts being arranged in continuity with one another along the first longitudinal axis X. The protective part 110 is arranged opposite of the tube 20 on which the profile is fixed, the hooking part 111 being configured to cooperate with the tube to allow the protective part 110 to protrude from the tube and perform its function of protection against projections of gravel . When the tube and the profile are in place in a heat exchanger mounted in a vehicle, it is understood that, the profile 90 being mounted opposite the front end edge 41 of the tube 20, the protective part is oriented towards the front AV and the attachment part 111 being situated towards the rear AR with respect to the protective part 110.

The protective part 110 here has the form of a hollow body defining a cavity 101. More particularly, in the example illustrated in FIG. 4, the protective part 110 is closed and the cavity forms a tube of generally circular cross section along the plane E perpendicular to the transverse direction.

The attachment portion 111 has the shape of an elastic clamp defining an opening 112 delimited by two fixing lugs 113. In the example illustrated, in order to cooperate with the front end edge 41 of the tube 20 which has a curved shape towards the outside of the tube, the hooking part has substantially a C shape with the fixing lugs 113 which have a curvature of radius substantially equal to the radius of curvature of the front end edge 41 of the tube 20. The opening 112 extends over the entire transverse dimension of the profile 90, so that this profile 90 can be clipped onto the end edge of the tube.

As illustrated, in order to allow this fixing by elastic deformation, the spacing of the free ends of the fixing lugs 113 should be in the rest position of the profile, that is to say when it is not deformed. elastically, is smaller than the dimension of the front end edge of the tube, so that the engagement of the profile against this edge of the tube generates a separation from each other of the fixing lugs. The fixing lugs 113 tend to return to their original spacing and thus force their free end, if necessary provided with hooks, to come to be housed in the groove or grooves 95, 95 '. The restoring effort of the fixing lugs, essentially vertical in the direction of the bringing together of the fixing lugs 113 from one another, tends to press the free ends of the fixing lugs into the corresponding grooves.

In the example illustrated in FIG. 4, the attachment part 111 and the fixing part 110 have the same transverse dimension, equal to the corresponding transverse dimension of the groove or grooves made in the tube. It will be understood that it would be possible, without departing from the context of the invention and of this exemplary embodiment, to provide a fixing part which protrudes transversely on either side of the attachment part, to ensure that the protection against the projection of gravel is effective over the entire surface of the tube liable to be impacted, that is to say the surface left free between the collecting chambers of the heat exchanger.

Figure 5 illustrates a partial perspective view of an alternative embodiment of a tube 20 according to the first aspect of the invention, the tube 20 being shown without the associated profile.

The tube 20 comprises in this variant two grooves 95, 95 'located respectively on the upper part 44 and on the lower part 45 and extending equidistant from the front end edge 41, the grooves 95, 95' being distinguished from which has been previously described in that they extend over the entire transverse dimension of the corresponding end edge 41 of the tube. Thus, the grooves 95, 95 'extend from the first transverse end 97 to the second opposite transverse end 98 of the tube, it being noted that the second transverse end 98 is not visible in FIG. 5. The section 90 can then be fixed to the front end 41 by clipping, as previously described, or else by a relative translational movement of the profile 90 relative to G front end 41 along the second axis Y, by making the fixing lugs 113 of the profile 90 (visible in Figure 4) by one end of the groove opening onto one of the transverse ends of the tube.

This embodiment requires adapting the configuration of the collecting chambers 130, 140 of the heat exchanger 10 in order to ensure the sealing of the heat exchanger i6

10 between the tubes 20 and the collecting chambers 118, in particular by modifying the profile of the openings made in each collecting chamber to receive a transverse end of the tubes.

This embodiment also implies that at least the protective part of the profile has a transverse dimension smaller than that of the groove, so that the protective part extends between the collecting chambers.

The tube 20 is produced by bending a metal sheet on itself. In this context, the profile 90 can be made of plastic or thermoplastic material and fixed to the tube once the brazing operations of the tube are completed. This fixing of the profile can occur before the assembly of the tube between the collecting chambers of the heat exchanger according to one aspect of the invention, the tube and the profile then forming an assembly subsequently attached to the collecting chambers, or the profile can be fixed after assembly of the tube between the collecting chambers in the heat exchanger, the profile being clipped onto the tubes already in place. Of course, this fixing of the profile after assembly of the tube is only possible insofar as the profile is snap-fitted on a groove extending only over part of the transverse dimension of the tube, as illustrated in Figures 2 and 3.

Alternatively, the profile 90 can be made of a metallic material, advantageously of the same material as that used for the tube, for example aluminum. In this case, the profile can be fixed either before or after the tube brazing operations are carried out.

Figures 6a, 6b, and 6c illustrate three embodiments of a profile 90 capable of cooperating with a tube according to the first aspect of the invention as it has just been described. The three embodiments differ from each other only by the configuration of the protective part 110 of the profile 90.

It should be noted that for each of the embodiments illustrated in these figures, the hooking part 111 of the profile is always the same, having a circular arc section of shape complementary to the curved shape of the end edge. before 41 of the tube. In each of the embodiments of the protective part 110, when the latter is made of a material with elastic properties, the protective part 110 can resume its initial shape after the impact of the gravel.

The profile 90 according to the embodiment illustrated in Figure 6a comprises a protective portion 110 formed of a longitudinal wall 115. In this configuration, the protective portion prevents the projection of gravel on a central portion of the tube and the portion d The grip also plays a role in protecting the tube for the gravel passed next to the longitudinal wall 115.

The profile 90 according to the embodiment illustrated in Figure 6b comprises a protective part 110 which comprises, in accordance with what has been described above in connection with Figure 4, a cavity 101 closed. More particularly, the protective part 110 comprises a general accordion shape extending in the longitudinal extension of the tube, the protective part 110 thus comprising folds of material, allowing a longitudinal deformation of the protective element under the effect of the impact of the gravel, and thus making it possible to absorb the shocks and to prevent the deformation of the tube.

The profile 90 according to the embodiment illustrated in FIG. 6c comprises a protective part 110 which this time comprises two cavities 101 successively closed longitudinally. A groove 101a is formed between the folds of the protective part forming these two cavities in order to facilitate the deformation of the cavity located furthest from the tube. If necessary, a bead of silicone may be placed in the groove 101a in order to prevent the deposition of dirt and still allow the relative displacement of one fold relative to the other under the effect of the impact of gravel.

These different embodiments of the profile 90 each include specific characteristics, G use of one or the other of these embodiments being a function of established constraints which the tube must be able to bear, and more particularly of the impact resistance constraints. likely to damage the front end 4L

The invention, as just described, achieves the goals it set for itself and allows, by simple means, to produce a device for protecting the tubes of a heat exchanger against splashing gravel which could otherwise lead to a i8

perforation of one of these tubes. Variants here not described could be implemented without departing from the context of the invention, since a tube for heat exchanger does indeed include a groove in which is housed a specific attachment portion of the profile, the profile being associated to a single tube. One could for example provide that the conduit 22 formed in the tube houses an internal insert, in contact with the refrigerant circulating in the conduit so as to increase the contact surface between the tube and the cooling fluid, thus promoting heat dissipation.

Claims

1. Tube (20) for a heat exchanger (10) of a motor vehicle, the tube (20) comprising a wall (21) delimiting a duct (22) in which is able to circulate a cooling fluid, the wall (21) being folded to present two end edges (41, 42) opposite in a longitudinal direction on either side of a middle part (43) and two upper and lower parts (44, 45) opposite one to the other other in a vertical direction, characterized in that the wall (21) of the tube (20) comprises a first groove (95) formed on one of the upper and lower parts (44, 45) in the vicinity of one of the edges end (41) of the tube (20), the first groove (95) being configured to receive a hooking part (111) of a profile (90) for protecting the end edge of the corresponding tube.

2. Tube (20) according to the preceding claim wherein the wall (21) comprises a second groove (95 ') located on the other of the upper and lower parts (44, 45), the second groove (95') being located at the same distance from the corresponding end edge as the first groove (95).

3. Tube (20) according to any one of the preceding claims, in which the groove or grooves (95, 95 ’) extend along a transverse axis (Y) perpendicular to the longitudinal and vertical directions.

4. Tube (20) according to the preceding claim, wherein the groove or grooves (95, 95 ’) extends only over a part of the transverse dimension of the corresponding end edge (41) of the tube (20).

5. Tube (20) according to the preceding claim, wherein the tube (20) has transversely a central portion (201) equipped with the groove or grooves (95, 95 ') and two transverse end portions (202) arranged transversely. on either side of the central portion, the groove or the grooves not extending in these transverse end portions.

6. Tube (20) according to claim 3, wherein the groove or grooves (95, 95 ') extends over the entire transverse dimension of the corresponding end edge (41) of the tube (20), the or the grooves (95, 95 ') opening onto the transverse ends of the tube.

7. Heat exchanger (10) for a motor vehicle, the heat exchanger (10) comprising a plurality of tubes (20) arranged in a stack in series, the plurality of tubes comprising at least one tube (20) according to the any one of the preceding claims, the heat exchanger (10) comprising a space (15) between two tubes, the space (15) allowing the passage of an air flow promoting heat exchange with the cooling fluid , the tubes being arranged in the heat exchanger so that the groove or grooves (95, 95 ') is arranged in the vicinity of a front end edge (41) of the tube, that is to say say the end edge intended to be facing the front of the vehicle.

8. Heat exchanger (10) according to the preceding claim, wherein at least one tube (20) is associated with a profile (90) comprising a hooking part (111) and a protective part (110) arranged in projection longitudinal from the front end edge (41) of the tube, the hooking part being configured to accommodate in the groove (s) (95, 95 ').

9. Heat exchanger (10) according to any one of claims 6 or 7, in which the profile (90) is fixed on the tube (20) by snap-fastening, the attachment part (111) being elastically deformable to allow its housing in the groove (s) (95, 95 '). îo. Heat exchanger (10) according to any one of the preceding claims, in which the profile (90) is made of plastic or thermoplastic material, the tube being produced by folding on itself a metal sheet.