Heat exchange device and method for connecting said device

Abstract

The present invention relates to a heat exchange device comprising: a main part (10) provided with a flat assembly surface, the main part (10) comprising aluminium and forming fluid circulation channels leading to ports arranged on the assembly surface; and a connecting end piece comprising a connection base, the connecting base comprising a connection surface into which the connection channels open, the connecting base being assembled with the main part (10) by means of an adhesive substance linking an assembly zone of the assembly surface in the periphery of the ports to a connection zone of the connection surface in the periphery of the ports, the openings and the ports corresponding to each other, the adhesive substance comprising an adhesive substance which is either an epoxy, a polyurethane, an acrylic or a hybrid, the hybrid adhesive substance comprising at least two chemical functional groups selected from one of the following: epoxy, cyanoacrylate, acrylic and polyurethane.

Description

[Technical field]

[0001] The present invention relates to the field of heat exchange devices, in particular to a heat exchange device suitable for use in the automotive sector. More particularly, the present invention relates to a heat exchange device and also to a method for connecting heat exchanger plates. [Background technology]

[0002] Automotive battery packs typically consist of individual cells coupled to heat exchange means which are mounted on a chassis and which are configured to regulate the temperature (heating or cooling) of the individual cells during operation.

[0003] In particular, these heat exchange means may comprise heat exchanger plates providing fluid circulation channels inside which a heat transfer fluid can flow.

[0004] The heat exchange means are also connected to an external fluid circuit, in particular by means of connecting end pieces, which are usually crimped, soldered or brazed onto the surface of the heat exchanger plates.

[0005] In this regard, WO 2020 / 254757 A1, WO 2020 / 031221 A1 and FR 2 832 790 A1 disclose a method for connecting a heat exchanger to an external heat exchange circuit by means of a connecting end piece. In addition to its specific configuration, this connecting means can be welded or glued to the heat exchanger plate.

[0006] However, the solutions proposed in the above mentioned documents are not satisfactory: in fact, the methods considered for attaching the connecting end pieces to the heat exchanger are still complicated to implement, without necessarily fully meeting the requirements of temperature resistance, sealing or mechanical strength.

[0007] It is therefore one object of the present invention to provide a heat exchange device having a connection end piece which allows for an attachment that meets the requirements regarding temperature resistance, sealing and mechanical strength.

[0008] Another object of the invention is to propose a method for the fluid connection of pipes by means of a connecting end piece, which is simple to implement and which meets the requirements regarding temperature resistance, sealing and mechanical strength. Summary of the Invention

[0009] The objects of the present invention are achieved, at least in part, by a heat exchange device comprising: a main member having an essentially flat assembly surface, the main member comprising aluminum and forming fluid circulation channels leading to ports arranged on the assembly surface of the main member; a connecting endpiece comprising a flat connecting base, the connecting base comprising a surface called the connecting surface into which the connecting channels open, the connecting base being assembled with a main part by means of an adhesive substance linking an assembly zone of the assembly surface around a port to a connection zone of the connecting surface around an opening, the opening and the port corresponding to each other, the adhesive substance comprising an adhesive substance which is either an epoxy or polyurethane or an acrylic or a hybrid, the hybrid adhesive substance being at least two chemical functionalities selected from one of the following: epoxy, cyanoacrylate, acrylic and polyurethane.

[0010] According to one embodiment, the adhesive substance mechanically, advantageously chemically and sealingly bonds the assembly zone to the connection zone.

[0011] According to one embodiment, the end piece comprises an internal shim, advantageously annular or elliptical, protruding relative to and surrounded by the connection zone and configured to define a space between the connection zone and the assembly zone, called the adhesive space, in which the adhesive substance is received.

[0012] According to one embodiment, the end piece also comprises a peripheral shim which projects relative to the connection zone, surrounds the connection zone and defines, together with the internal shim, the gluing space.

[0013] According to one embodiment, a seal, preferably an O-ring seal or a lip seal, is arranged in a groove provided in the connecting surface and is inserted between the opening and an internal shim, which is inserted between the adhesive material and the groove, the seal being preferably in a compressed state within the range of 10% to 35% of its free state volume.

[0014] According to one embodiment, the ratio of the surface area of ​​the connection zone to the surface area of ​​the port is adjusted so that the joint between the connection surface and the assembly zone has a tensile strength greater than 1 MPa, advantageously greater than 1.6 MPa, and even more advantageously greater than 4.3 MPa.

[0015] According to one embodiment, the ratio between the surface area of ​​the connection zone and the surface area of ​​the port is adjusted such that the assembly of the connection surface and the assembly zone at the end of step d) is sealed when the fluid is circulated at a pressure greater than 1 bar, advantageously greater than 3 bar and even more advantageously greater than 7 bar.

[0016] The invention also relates to a motor vehicle equipped with a battery pack connected to a heat exchange device according to the invention, for the purpose of regulating the temperature of the battery pack by means of the heat exchange device according to the invention.

[0017] The invention also relates to a method for fluidly connecting a pipe by means of a connecting end piece to a main part comprising aluminium and having a substantially flat assembly surface, the main part comprising a fluid circulation channel leading to a port arranged on the assembly surface, the connecting end piece comprising a flat base called the connecting base, the connecting base comprising a surface called the connecting surface, the opening of a channel, called the connecting channel, of the connecting end piece extending through the connecting base, the method comprising the following steps: a) a first step of preparing the surface of the assembly zone around the port, comprising a laser treatment, an abrasive treatment and / or a chemical treatment, advantageously an electrochemical treatment; b) depositing an adhesive material on the assembly zone and / or on the connection zone of the connection surface, the connection zone being around the opening, the adhesive material comprising an epoxy adhesive material or a polyurethane adhesive material or an acrylic adhesive material or a hybrid adhesive material, the hybrid adhesive material comprising at least two chemical functional groups from an epoxy functional group, a cyanoacrylate functional group, an acrylic functional group or a polyurethane functional group; c) assembling the assembly zone and the connection surface.

[0018] According to one embodiment, the method comprises a step d) of heat treatment intended to crosslink the adhesive substance.

[0019] According to one embodiment, step c) is preceded by a step c0) of arranging a seal, in particular an O-ring seal or a lip seal, in a groove provided on the connection surface and inserted between the opening and the connection zone.

[0020] According to one embodiment, the assembly step c) comprises applying a force, called the assembly force, suitable to keep the seal compressed within the range of 10% to 35% until a predetermined level of cross-linking of the adhesive substance is reached, the predetermined cross-linking being a cross-linking that makes it possible to maintain the compression of the seal at 10% to 35% compression as soon as the assembly force is no longer applied.

[0021] According to one embodiment, the ratio between the surface area of ​​the connection zone and the surface area of ​​the port is adjusted so that the assembly between the connection surface and the assembly zone at the end of step d) has a tensile strength greater than 1 MPa, advantageously greater than 1.6 MPa and even more advantageously greater than 4.3 MPa.

[0022] According to one embodiment, the ratio between the surface area of ​​the connection zone and the surface area of ​​the port is adjusted such that the assembly of the connection surface and the assembly zone at the end of step d) is sealed when the fluid is circulated at a pressure greater than 1 bar, advantageously greater than 3 bar and even more advantageously greater than 7 bar.

[0023] According to one embodiment, the first preparation step comprises removing a layer of native aluminium oxide likely to be present in the assembly zone and adjusting the roughness of the assembly zone within a roughness range between 1.4 μm and 2.6 μm, advantageously above 1.9 μm, the first step comprising a laser method or a mechanical polishing method.

[0024] According to one embodiment, the first preparation step comprises the formation of an adhesive layer on the assembly zone, the adhesive layer advantageously having the following properties: - a sub-step of anodization or chemical conversion treatment of the assembly zone, and - forming a layer of Ti / Zr on the assembly zone.

[0025] According to one embodiment, the method comprises a second step b0) of preparing the surface of the connection surface, carried out before step b), which second step b0) comprises a plasma, chemical and / or laser treatment suitable for giving the connection surface a surface energy of more than 36 mN / m, advantageously more than 50 mN / m. [Brief description of the drawings]

[0026] Other features and advantages of the present invention will become apparent from the following detailed description of the invention which refers to the accompanying drawings. [Figure 1] 1 is a schematic view of a heat exchanger plate implemented within the scope of the connection method according to the invention; [Diagram 2] 1 is a schematic view of a connection endpiece which can be used within the scope of the connection method according to the invention, in particular the connection endpiece is shown in vertical cross section through the axis XX'. [Diagram 3] FIG. 4 is a schematic diagram showing the formation of an adhesive layer, and in particular in this FIG. 3 the heat exchange plate is shown in a cross section through the port, perpendicular to the assembly plane. [Figure 4] 3 is a schematic representation of the execution of step b) corresponding to the deposition of adhesive substance on the connection zone of the connection endpiece shown in FIG. 2, in which in particular the connection endpiece is shown in vertical planar section through the axis XX'. [Diagram 5] FIG. 2 is a schematic representation of the execution of step c) corresponding to the assembly of the connection zone and the adhesive zone, in particular the connection end piece and the heat exchanger plate, shown in a planar section through the axis XX′. [Figure 6] FIG. 2 is a schematic representation of the execution of step c0) on a connection endpiece provided with a groove intended to receive a seal, the connection endpiece being shown in particular in a vertical cross section through the axis XX'. [Figure 7] FIG. 7 is a schematic diagram of the execution of step c) corresponding to the deposition of adhesive substance on the connection zone of the connection end piece shown in FIG. 6, in which in particular the connection end piece and the heat exchange plate are shown in a vertical cross-section through the axis XX'. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention relates to a heat exchange device, more particularly, to a heat exchange device comprising a main member provided with a substantially flat assembly surface, the main member comprising aluminum and defining fluid circulation channels leading to ports disposed on the assembly surface of the main member.

[0028] The heat exchange device also comprises a connection end piece comprising a flat connection base.

[0029] In particular, the connection base comprises a surface, referred to as the connection surface, into which the connection channel opens.

[0030] In this regard, the connection base is assembled with the primary member by means of an adhesive substance linking an assembly zone of the assembly surface around the port with a connection zone of the connection surface around the opening, the opening and the port corresponding to each other.

[0031] In accordance with the present invention, the adhesive comprises either an epoxy adhesive, a polyurethane adhesive, an acrylic adhesive, or a hybrid adhesive, where the hybrid adhesive comprises at least two chemical functional groups selected from one of epoxy, cyanoacrylate, acrylic, and polyurethane.

[0032] The main member may comprise a heat exchanger plate, a beam or a diffuser. The following description shall be considered exclusively in terms of heat exchanger plates. However, a person skilled in the art will be able to adapt the principles described below to other elements such as beams or diffusers.

[0033] The invention also relates to a method for fluidly connecting a pipe with a primary member by means of a connecting end piece, in particular the primary member comprises an essentially flat assembly surface and comprises aluminium.

[0034] The main member also comprises a fluid circulation channel which leads to a port located in the assembly face. The connecting endpiece comprises a flat base, called the connecting base, which comprises a surface, called the connecting face, through which opens a channel, called the connecting channel, of the connecting endpiece.

[0035] The method according to the invention comprises the steps of: a) a first step of preparing a surface of an assembly zone around a port, the first step including a laser treatment, an abrasive treatment and / or a chemical treatment; b) depositing an adhesive material on the assembly zone and / or on the connection zone of the connection surface, the connection zone being around the opening, the adhesive material comprising an epoxy adhesive material, a polyurethane adhesive material, an acrylic adhesive material or a hybrid adhesive material, the hybrid adhesive material comprising at least two chemical functional groups from an epoxy functional group, a cyanoacrylate functional group, an acrylic functional group or a polyurethane functional group; c) assembling the assembly zone and the connection surface.

[0036] Figure 1 shows a partial view of a heat exchanger plate 10. The heat exchanger plate 10 is made of aluminum.

[0037] The heat exchanger plate 10 is in particular a heat exchanger plate and defines fluid circulation channel openings which lead to ports 11 in an assembly face 12 of the heat exchanger plate 10 .

[0038] In FIG. 2 a schematic diagram of a connecting end piece 20 intended to be attached to a heat exchanger plate is shown.

[0039] In particular, the connection endpiece 20 comprises a substantially cylindrical body 21 terminated at one end by a base, referred to as the connection base 22. The connection endpiece 20 comprises a channel, referred to as the connection channel 23, which extends in a direction defined by the axis of rotation XX' of the body 21 and leads to an opening 24 arranged in a surface, referred to as the connection surface 25, of the connection base 23.

[0040] The method according to the invention comprises a first step a) of surface preparation of the assembly zone 13 around the port 11 .

[0041] The scope and / or characteristics of assembly zone 13 are discussed below in the description of the invention.

[0042] According to the invention, the first surface preparation step a) can be performed by laser treatment, polishing treatment, chemical treatment and / or chemical transformation.

[0043] It is understood that surface treatments are used to decontaminate the assembly zone 13 and to provide the assembly zone 13 with certain surface energies and / or chemical conditions, particularly surface energies and / or chemical conditions compatible with the application of adhesive materials as described in the remainder of this disclosure.

[0044] The native aluminum oxide layer remains uncontrollable. In particular, it has limited adhesion and may therefore form a weak zone. Thus, according to a particular embodiment, a first step a) can be carried out in order to remove the layer of native aluminum oxide likely to be present in the assembly zone. It is understood that the removal of the aluminum oxide layer during the implementation of the first step is only effective in the assembly zone.

[0045] Particularly advantageously, a laser process can be used to grow a new aluminum oxide layer of controlled thickness and texture when the native aluminum oxide layer is removed. In this regard, the laser method is a laser radiation of wavelength 1 between 900 nm and 1550 nm, for example equal to 1064 nm, with a power of 5 J / cm 2 ~134J / cm 2 , advantageously 5 J / cm 2 ~15J / cm 2 The laser used may be a pulsed or continuous laser.

[0046] Further according to this embodiment, the first step a) can be carried out to adjust the roughness of the assembly zone in a roughness range Ra between 1.4 μm and 2.6 μm, advantageously above 1.9 μm. This roughness is advantageously measured using a roughness gauge with a tip, such as a Marsurf PS10 roughness gauge with a PHT6-350 probe and a 2 μm tip. The measurement parameters are: -Measurement speed: 1.0mm / s - Measurement length: 10mm -Measuring force: 0.75mN - Compliance with standards: DIN EN ISO 4287

[0047] According to another embodiment, shown in Figure 3, the first preparation step a) may also comprise the formation of an adhesive layer 14 on the assembly zone. It is understood that the formation of the adhesive layer may be limited to the assembly zone 11 only.

[0048] In a first alternative, the adhesion layer 14 is formed, for example selectively, by anodizing the assembly zone. Alternatively, the adhesion layer may comprise a Ti / Zr layer formed on the assembly zone 11. Also alternatively, the chemical treatment may comprise a chemical conversion treatment.

[0049] The connection method according to the invention also comprises a step b) of depositing an adhesive substance on one or / and the other of the assembly zone 13 and the connection zone 26 of the connection surface 25, here around the opening 24.

[0050] The adhesive material includes either an epoxy adhesive material, a polyurethane adhesive material, an acrylic adhesive material, or a hybrid adhesive material, where the hybrid adhesive material includes at least two of the following chemical functionalities: an epoxy functional group, a cyanoacrylate functional group, an acrylic functional group, and a polyurethane functional group.

[0051] FIG. 4 shows the deposition of adhesive material 27 on the connection zone 26 .

[0052] Particularly advantageously, the connection zone 26 can be bounded on its inner side by an internal shim 28. In particular, the internal shim 28 projects relative to the connection zone 27 and is surrounded by the connection zone. For example, the internal shim is annular or elliptical in shape.

[0053] More advantageously, the connection zone 26 may also be bounded on its outer side by a peripheral shim 29 which projects relative to and surrounds the connection zone 26 .

[0054] FIG. 5 is a schematic diagram of step c) of assembling the assembly zone and the connection zone.

[0055] During this assembly step c), the openings 24 and the ports 11 correspond to one another and the adhesive substance 27 spreads and fills the space between the assembly zone 13 and the connection zone 26. The application of the adhesive substance 28 thus enables the assembly zone 13 to be mechanically, advantageously chemically and sealably bonded to the connection zone 26.

[0056] By "sealably" it is meant that the seal is watertight to coolants, particularly liquids which will likely include glycol.

[0057] In this regard, the use of the internal shim 28 and the peripheral shim 29 also makes it possible to define a space between the connection zone 26 and the assembly zone 13, called the adhesive space 30 (FIG. 5), in which the adhesive material 27 is intended to be received. In other words, the internal shim 28 and the peripheral shim 29 make it possible to limit the space in which the adhesive material can spread when steps b) and c) are carried out. In particular, the internal shim 28 and the peripheral shim 29 limit any spillage of the adhesive material 27 that may occur during step c).

[0058] Additionally, the internal shim 28 isolates the opening from the adhesive space and, therefore, from the adhesive material 27 .

[0059] In addition, it is understood that the internal shim 28 and the peripheral shim 29 are in contact with the assembly surface 12 at the end of step c).

[0060] In a particularly advantageous embodiment, it is possible to consider an internal shim 28 only (a device without a peripheral shim 29), this latter configuration thus providing a spill (and / or creep) path for the adhesive material other than to the opening 24.

[0061] In a further particularly advantageous embodiment, a discontinuous (open, e.g. slot-shaped) peripheral shim 29 can be considered, thus providing a path for adhesive material to flow (and / or creep out) other than towards the opening 24.

[0062] In one particularly advantageous embodiment, the adhesive substance may comprise beads, for example glass beads, the dimensions of which (it is understood that they relate to an average dimension) are adapted to impose a predetermined distance between the connection zone 26 and the assembly zone 13. It is understood that, if the beads in question are spherical, the dimensions are equal to the diameter of the beads. This particular embodiment may be considered on its own or in combination with one and / or the other of the internal and peripheral shims.

[0063] In addition, the connection endpiece 20 may comprise guide means for the connection endpiece 20, which extend from the body 21 and protrude from the connection face 25. More specifically, the guide means are configured to enable the opening 24 and the port 11 to coincide. The guide means may comprise a shim, called a guide shim 31, located around the opening and intended to be inserted into the hole 11. In this respect, the guide shim 31 may be shaped to match the hole 11 and / or may be frusto-conical.

[0064] Optionally, after step c), it may also be considered to carry out a heat treatment step d) in order to promote crosslinking of the adhesive material. The details of step d), and in particular the thermal cycles considered, depend on the adhesive material in question.

[0065] The heat treatment considered for step d) may comprise a local heating step. In particular, the heat treatment may comprise induction heating, more particularly induction heating of the heat exchanger plate 10, for example made of aluminum. The induction heating accelerates the crosslinking process of the adhesive material. In particular, the induction heating may be adapted to sufficiently accelerate the crosslinking over a period of less than 2 minutes, advantageously less than 1 minute 30 seconds. For example, the crosslinking cycle may comprise a heating time followed by a cooling time. In particular, the heating time may be less than 1 minute 30 seconds, advantageously less than 1 minute. This last aspect allows an online check of the seal of the assembly, for example sealed at a pressure of 3 bar.

[0066] Alternatively or additionally, both the connecting end piece 20 and the heat exchanger plate 10 can be preheated before step c). In particular, this last aspect helps to compensate for any differences in thermal expansion that may occur during step d). This preheating also helps to maintain a precise alignment between the connecting end piece 20 and the heat exchanger plate.

[0067] Advantageously, the ratio between the surface area of ​​the connection zone and the surface area of ​​the port is adjusted so that the assembly between the connection surface and the assembly zone at the end of step d) has a tensile strength greater than 1 MPa, advantageously greater than 1.6 MPa and even more advantageously greater than 4.3 MPa.

[0068] Also advantageously, the ratio between the surface area of ​​the connection zone and the surface area of ​​the port is adjusted such that the assembly between the connection surface and the assembly zone at the end of step d) is sealed when the fluid is circulated at a pressure of more than 1 bar, advantageously more than 3 bar, even more advantageously more than 7 bar, such as more than 9 bar, for example more than 11 bar.

[0069] The method according to the invention can also comprise the implementation of a second step b0) for surface preparation of the connection surface, carried out before step b). The second step b0) comprises a plasma, chemical and / or laser treatment suitable for giving the connection zone a surface energy of more than 36 mN / m, advantageously more than 50 mN / m. The latter aspect ensures an improvement of the wettability of the connection zone by the adhesive substance.

[0070] The surface energy can be measured with a goniometer (for example the Kruss Mobile Surface Analyzer (MSA) from the company Kruss). The method used involves the measurement of the contact angle of a double drop, in particular two drops of different liquids (water and diiodomethane), followed by the calculation of the surface energy of the solid.

[0071] According to a particularly advantageous embodiment essentially reproducing the above mentioned features, the method according to the invention can comprise carrying out a step c0). In particular, step c0) is carried out before step c). As shown in Fig. 6, step c0) comprises placing a seal 32 (for example an O-ring or a lip seal) in a groove 33 provided on the connection surface and inserted between the opening and the connection zone. The seal 32 advantageously comprises at least one of the materials selected from EPDM, NBR, HNBR, FKM, AEM, FVMQ, silicone. Advantageously, no second treatment step is applied to the groove.

[0072] 7 is a schematic diagram of step c) for assembling the assembly zone and the connection zone after the seal 32 is in place. In particular, the assembly step c) comprises the application of a force, called the assembly force, suitable to keep the seal in a compressed state within the range of 10% to 35% until a predetermined level of cross-linking of the adhesive substance is reached, the predetermined cross-linking being a cross-linking that makes it possible to maintain the compression of the seal at 10% to 35% compression as soon as the assembly force is no longer applied.

[0073] The degree of crosslinking of an adhesive material depends on its chemical nature and thermal history. A person skilled in the art can establish the best possible conditions to achieve a given degree of crosslinking based on his general knowledge and the chemistry involved.

[0074] It is understood that the device thus obtained may be devoid of seal 32. The function of adhesive substance 27 is not only to ensure the assembly of the various elements, but also to seal the assembly according to specifications defined herein, depending on its chemical and / or physical properties.

[0075] The invention also relates to a heat exchange device essentially comprising the above mentioned features.

[0076] The invention also relates to a motor vehicle equipped with a battery pack connected to a heat exchange device according to the invention, for the purpose of regulating the temperature of the battery pack by means of the heat exchange device according to the invention.

[0077] Naturally, the invention is not limited to the embodiments described and variants can be envisaged without departing from the scope of the invention as defined by the claims.

Claims

1. 1. A heat exchange device comprising: a main member (10) provided with a substantially flat assembly surface (12), said member comprising aluminum and providing fluid circulation channels leading to ports (11) arranged on said assembly surface (12) of said main member (10); a connecting end piece (20) comprising a flat connecting base (22), said connecting base (22) having a surface called connecting surface (25), through which a connecting channel (23) opens into an opening (24), said connecting base (22) being assembled with said main part (10) by means of an adhesive substance (27) connecting an assembly zone (13) of said assembly surface (12) around said port (11) to a connecting zone (26) of said connecting surface (25) around said opening (24), said opening (24) and said port (11) corresponding to each other, said adhesive substance (27) being selected from the group consisting of epoxy adhesives, polyurethane adhesives, acrylic adhesives, a connecting end piece (20) comprising an adhesive material or a hybrid adhesive material, the hybrid adhesive material comprising at least two chemical functional groups selected from one of epoxy, cyanoacrylate, acrylic or polyurethane, the end piece comprising an internal shim (28), the internal shim (28) being advantageously annular or elliptical, protruding relative to and surrounded by the connection zone (26), and configured to define a space between the connection zone (26) and an assembly zone (13), referred to as a bonding space (30), in which the adhesive material (27) is received.

2. 2. Heat exchanger device according to claim 1, wherein the adhesive material (27) mechanically, preferably chemically and sealably connects the assembly zone (13) to the connection zone (26).

3. 2. The heat exchange device according to claim 1, wherein the end piece also comprises a peripheral shim (29) that protrudes relative to the connection zone (26), surrounds the connection zone (26), and defines the bonding space (30) together with the internal shim (28).

4. 2. The heat exchange device according to claim 1, wherein a seal (32), preferably an O-ring seal or a lip seal made of EPDM or silicone, is arranged in a groove (33) provided in the connecting surface (25) and is inserted between the opening (24) and the internal shim (28), the internal shim (28) being inserted between the adhesive material (27) and the groove (33), the seal (32) being preferably in a compressed state within a range of 10% to 35% of its free state volume.

5. 2. The heat exchange device according to claim 1, wherein the ratio between the surface area of ​​the connection area (26) and the surface area of ​​the port (11) is adjusted so that the assembly of the connection surface (25) and the assembly zone (13) has a tensile strength greater than 1 MPa, advantageously greater than 1.6 MPa, and even more advantageously greater than 4.3 MPa.

6. 2. Heat exchanger device according to claim 1, wherein the ratio between the surface area of ​​the connection zone (26) and the surface area of ​​the ports (11) is adjusted so that at the end of step d) the assembly between the connection surface (25) and the assembly zone (13) is sealed when a fluid is circulated at a pressure greater than 1 bar, advantageously greater than 3 bar, even more advantageously greater than 7 bar.

7. 7. A motor vehicle comprising a battery pack connected to a heat exchange device according to claim 1, for the purpose of regulating the temperature of the battery pack by said heat exchange device.

8. 1. A method for fluidly connecting a pipe by means of a connecting end piece (20) to a main member (10) comprising aluminium and having a substantially flat assembly surface (12), said main member (10) comprising a fluid circulation channel leading to a port (11) arranged on said assembly surface (12), said connecting end piece (20) having a flat base called a connecting base (22), said connecting base (22) having a surface called a connecting surface (25), said openings (24) of channels called connecting channels (23) of said connecting end piece (20) extending through said connecting surface (25), said method comprising: a) a first step of preparing the surface of the assembly zone (13) around said port (11), comprising a laser treatment, an abrasive treatment and / or a chemical treatment, preferably an electrochemical treatment; b) depositing an adhesive substance (27) on one and / or the other of the assembly zone (13) and a connection zone (26) of the connection surface (25), the connection zone being located around the opening (24), the adhesive substance (27) comprising an epoxy adhesive substance, a polyurethane adhesive substance, an acrylic adhesive substance, or a hybrid adhesive substance, the hybrid adhesive substance comprising at least two chemical functional groups of epoxy, cyanoacrylate, acrylic, or polyurethane; c) assembling said assembly zone (13) and said connection surface (25), The connecting end piece comprises an internal shim (28), advantageously annular or elliptical, protruding relative to the connection zone (26) and surrounded by the connection zone (26), and configured to define a space between the connection zone (26) and the assembly zone (13), called the adhesive space (30), in which the adhesive substance (27) deposited during step b) is received.

9. 9. A fluid connection method according to claim 8, wherein the method comprises a step d) of heat treatment intended to crosslink the adhesive substance (27).

10. 9. The method for fluid connection according to claim 8, wherein step c) is preceded by step c0) of placing a seal (32), in particular an O-ring seal or a lip seal, in a groove (33) provided on the connection surface (25) and inserted between the opening (24) and the connection zone (26).

11. 11. The fluid connection method according to claim 10, wherein the assembly step c) comprises applying a force, called assembly force, suitable to keep the seal (32) compressed within the range of 10% to 35% until a predetermined cross-linking level of the adhesive substance (27) is reached, the predetermined cross-linking being a cross-linking that makes it possible to maintain the compression of the seal (32) between 10% and 35% compressed as soon as the assembly force is no longer applied.

12. 9. A fluid connection method according to claim 8, wherein the ratio between the surface area of ​​the connection zone (26) and the surface area of ​​the port (11) is adjusted so that the assembly between the connection surface (25) and the assembly zone (13) at the end of step d) has a tensile strength greater than 1 MPa, advantageously greater than 1.6 MPa, even more advantageously greater than 4.3 MPa.

13. 9. A fluid connection method according to claim 8, wherein the ratio between the surface area of ​​the connection zone (26) and the surface area of ​​the port (11) is adjusted so that at the end of step d) the assembly between the connection surface (25) and the assembly zone (13) is sealed when the fluid is circulated at a pressure greater than 1 bar, advantageously greater than 3 bar, even more advantageously greater than 7 bar.

14. 9. A fluid connection method according to claim 8, wherein the first preparation step comprises removing a layer of native aluminium oxide likely to be present in the assembly zone (13) and adjusting the roughness of the assembly zone (13) within a roughness range between 1.4 μm and 2.6 μm, advantageously within a roughness range greater than 1.9 μm, the first step comprising a laser method or a mechanical polishing method.

15. 9. A fluid connection method according to claim 8, wherein the first preparation step comprises forming an adhesive layer (14) on the assembly zone (13), said adhesive layer (14) advantageously comprising: - a sub-step of anodization or chemical conversion treatment of said assembly zone (13), - forming a layer of Ti / Zr on said assembly zone (13).

16. 9. The fluid connection method according to claim 8, wherein the method comprises a second step b0) of preparing the surface of the connection surface (25), which is carried out before step b), and wherein the second step b0) comprises a plasma, chemical and / or laser treatment suitable for giving the connection surface (25) a surface energy of more than 36 mN / m, advantageously more than 50 mN / m.

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