Electrical connection box for battery, battery and motor vehicle

Abstract

The invention relates to an electrical connection box for a battery (2), comprising:-a platform (4) suitable for receiving electrical components (5, 6, 7), in which platform at least one circulation duct (18) for a heat transfer fluid is arranged; -a bus bar (8, 9, 10, 11) providing an electrical connection between the at least two electrical components; and-at least one heat pipe (14), a first portion (20) of the at least one heat pipe having a first area in contact with the platform and a second portion (21) of the at least one heat pipe having a second area in contact with the bus bar and / or with at least one of the electrical components. The invention also relates to a battery equipped with such a cartridge and to a motor vehicle equipped with such a battery.

Description

Technical Field

[0001] This invention generally relates to the cooling of electrical devices.

[0002] The present invention relates more particularly to an electrical connection box for a storage battery, a storage battery equipped with such a box, and a motor vehicle equipped with such a storage battery. Background Technology

[0003] Electric or hybrid vehicles are equipped with a battery that includes a housing containing multiple electrochemical cells connected together and supplying a high voltage, typically several hundred volts, to the terminals of the battery.

[0004] Therefore, it is necessary for the battery to be equipped with an electrical junction box, which includes electrical safety components (relays, fuses) to cut off the current when necessary. These components are positioned along the busbar (in which the battery's input or output current flows).

[0005] In certain situations, the battery supplies or receives high electrical power. This is true, for example, during so-called fast charging of a vehicle's battery, or when the vehicle must provide significant traction. In these cases, the flow of high current causes a significant increase in battery temperature, particularly at the battery terminals and busbar terminals.

[0006] Certain areas of the box are prone to experiencing particularly significant temperature rises; these areas are often referred to as "hot spots." The risk of degradation increases for components located in these hot spots. To protect these components, systems exist that can be used to cool the entire box. However, given the large volume of the box, these solutions are not very effective and result in a significantly large volume and excessively increase the weight of the box. Summary of the Invention

[0007] In order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes to locally cool the box at the hot spot.

[0008] According to one aspect, an electrical connection box for a storage battery is proposed, the electrical connection box comprising:

[0009] - A platform designed to house electrical components and in which at least one circulation conduit is formed for circulating heat transfer fluids;

[0010] - A busbar that provides an electrical connection between at least two electrical components; and

[0011] - At least one heat pipe, a first portion of which has a first area in contact with the platform, and a second portion of which has a second area in contact with the busbar and / or with at least one electrical component.

[0012] One or more heat pipes allow for targeted cooling of areas on the busbars or components, thus advantageously enabling efficient cooling of the box. Furthermore, the use of heat pipes eliminates the need for loops to circulate heat transfer fluid through electrical components or busbars. Therefore, the weight and volume of the box's cooling elements are advantageously limited.

[0013] Further advantageous and non-limiting features of the electrical connection box according to the invention, whether considered individually or in any technically possible combination, are as follows:

[0014] - The surface area of ​​the first contact region is at least equal to the surface area of ​​the second contact region, and preferably, the surface area of ​​the first contact region is at least three times the surface area of ​​the second contact region.

[0015] - The first part is covered with an electrically insulating coating and / or the second part is covered with an electrically insulating coating.

[0016] - The circulation piping is configured to connect to a heat transfer fluid circulation loop that includes at least one pump.

[0017] - A tunnel adjacent to the circulation pipe is formed in the platform, and the heat pipe is fastened to the platform by means of screws configured to be inserted into threaded holes formed in the platform and leading to the tunnels.

[0018] - The support plate is fastened to the platform and configured to receive electrical components.

[0019] The support plate is fastened to the platform by means of studs, which are welded to the platform and configured to insert into corresponding holes in the support plate.

[0020] - The support plate is made of acrylonitrile butadiene styrene.

[0021] - The first side of the electrical component contacts the platform, and the box includes a distal plate that contacts the second side of the electrical module. This distal plate is fastened to a support plate and configured to clamp the electrical component onto the platform.

[0022] - The second part of the heat pipe has a second area that contacts the busbar. The contact between the heat pipe and the busbar is provided by two flanges that are fastened to each other, and the second part and the busbar remain abutting each other between the two flanges.

[0023] The present invention also proposes a battery for motor vehicles, the battery comprising an electrochemical cell and at least one electrical connection box according to the present invention.

[0024] The present invention also proposes a motor vehicle comprising a battery according to the invention.

[0025] Of course, the various features, variations and embodiments of the present invention can be combined with each other in various combinations, as long as they are not incompatible or mutually exclusive. Attached Figure Description

[0026] The following description, given by way of non-limiting example with reference to the accompanying drawings, will make it easy to understand what the invention includes and how it can be practiced.

[0027] In the attached diagram:

[0028] [ Figure 1 [Illustration of a motor vehicle according to the present invention, the motor vehicle being provided with a storage battery and the storage battery being equipped with an electrical connection box;]

[0029] [ Figure 2 ]yes Figure 1 A detailed schematic diagram of the electrical connection box in the diagram;

[0030] [ Figure 3 This is a schematic representation. Figure 2 The platform of the connecting box in the middle;

[0031] [ Figure 4 This is a schematic representation. Figure 2 The heat pipes in the electrical connection box;

[0032] [ Figure 5 This is a schematic representation. Figure 4 The horizontal fastening flange of the heat pipe in the middle;

[0033] [ Figure 6 This is a schematic representation. Figure 4 The vertical fastening flange of the heat pipe in the middle;

[0034] [ Figure 7 This schematically demonstrates the use of Figure 5 The horizontal flange in the middle will Figure 4 The heat pipe in the middle is fastened to Figure 3 The platform in;

[0035] [ Figure 8 This schematically demonstrates the use of Figure 6 The vertical flange in the middle will Figure 4 The heat pipe in the middle is fastened to Figure 3 The platform in China. Detailed Implementation

[0036] An electrical connection box according to an embodiment of the present invention (such as...) Figure 1 (As indicated and generally referred to by reference numeral 1 in the accompanying drawings) is the electrical network 3 used to connect the battery 2 to the electric or hybrid motor vehicle V. Therefore, this electrical connection box is assembled to the battery 2 and connected to one of the two electrical terminals of the battery. For example, two identical electrical connection boxes are respectively connected to the two electrical terminals of the battery 2.

[0037] like Figure 2 The electrical connection box 1 shown includes:

[0038] - Platform 4, which accommodates electronic components 5, 6, and 7.

[0039] - Busbars 8, 9, 10, and 11, which are configured to provide electrical connections between: electrical components 5, 6, and 7; connection terminal 12 for connection to battery 2; and connection terminal 13 for connection to electrical network 3 of motor vehicle V.

[0040] Platform 4 is generally parallelepiped in shape, with two main faces: a top face and a bottom face. In this case, platform 4 serves as the wall of the battery 2 box of vehicle V and can be mounted horizontally on the vehicle, such that the top face of the platform itself extends horizontally. Throughout the remainder of this disclosure, the electrical connection box 1 will be described in this particular orientation.

[0041] Electrical components 5, 6, 7 and busbars 8, 9, 10, 11 are secured to the receiving surface F (in this case, the upper surface) of platform 4 by means of support plate 15. In this case, support plate 15 is secured to the receiving surface F of platform 4 by means of studs 16, which are welded to platform 4 and configured to insert into corresponding holes in support plate 15 and receive bolts that fix support plate in place. In this case, electrical components 4, 5, 6 and busbars 8, 9, 10, 11 are secured to support plate 15 using fastening screws 17. Support plate 15 is made of, for example, a polymer material, preferably acrylonitrile butadiene styrene (ABS).

[0042] Busbars 8, 9, 10, and 11 are configured to carry a large current, such as greater than or equal to 500 amperes. In this example, busbars 8, 9, 10, and 11 comprise multiple separate sections, in this case four separate sections, each providing an electrical connection between two electrical components (in this case sections 9 and 10), an electrical connection between an electrical component and terminal 12 for connection to a battery (section 8), or an electrical connection between an electrical component and terminal 13 for connection to an electrical network of the motor vehicle V (section 11).

[0043] Electrical components 5, 6, and 7 are configured in this case to interrupt the electrical connection between the battery 2 and the vehicle's electrical network 3 (in this case, between terminals 12 and 13). These components include, for example, an electromechanical relay 5, a switch 6, and a fuse 7.

[0044] During normal use of the vehicle, the electromechanical relay 5 is configured to reversibly disconnect the connection between the battery 2 and the electrical network 3, for example, after the vehicle V has been parked. This electromechanical relay is controlled, for example, by the driver of the motor vehicle.

[0045] In this case, switch 6 is a pyrotechnic safety switch (pyrotechnic switch) and is configured to interrupt the electrical connection in the event of an accident involving motor vehicle V. This switch is controlled, for example, by sensors of the motor vehicle (e.g., collision sensors).

[0046] Fuse 7 is configured to interrupt the electrical connection when an excessive current (e.g., caused by a short circuit) flows through the fuse.

[0047] During the use of the motor vehicle V, such as during the rapid charging of the battery 2 or when the vehicle's traction is provided by an electric motor powered by the battery, the temperature of the busbars 8, 9, 10, and 11 may rise significantly and generate hot spots, especially at the fastening screw 17.

[0048] The configuration of the box 1 according to the invention advantageously allows heat generated at the manifolds 8, 9, 10, and 11 to be dissipated, and thus neutralizes the corresponding hot spots. For this purpose, the box 1 includes at least one heat pipe 14 configured to dissipate at least some of the heat from the manifolds 8, 9, 10, and 11 to the platform 4. To prevent heat accumulation in the platform 4, at least one heat transfer fluid circulation conduit 18 is formed therein.

[0049] Within the meaning of this invention, "heat pipe" should be understood to refer to an airtight tubular casing containing a fluid in a vapor-liquid equilibrium state, a first end of which is configured to be positioned against a heat source, and a second end of which is configured to be positioned on a cooling element or radiator. The fluid is configured to vaporize by absorbing heat energy dissipated by the heat source, circulate through the heat pipe to the second end, and condense therein to return to a liquid state.

[0050] In this case, such as Figure 3As shown in more detail, platform 4 has a molded structure, for example, obtained by extrusion. Therefore, the platform includes a plurality of pipes 18 and a plurality of tunnels 19 extending longitudinally from one end of the platform to the other. In this context, the terms "pipes" and "tunnels" refer to entities of the same type, except that the pipes 18 are configured to connect to a loop for circulating a heat transfer fluid (e.g., ethylene glycol fluid). This circulation loop (not shown and not constituting the subject matter of the invention) typically includes a pump for forcing the heat transfer fluid to circulate through the pipes 18, and a heat exchanger for cooling the fluid.

[0051] In this configuration, pipe 18 has a circular cross-section. Therefore, a connector R for connecting to the heat transfer fluid circulation loop is screwed into the end of pipe 18. Tunnels 19 (generally having a rectangular cross-section in this configuration) also extend into platform 4, such that each tunnel 19 abuts at least one circulation pipe 18. Threaded holes 32 leading to the tunnels 19 are formed in the receiving surface F of platform 4.

[0052] In this example, box 1 includes five identical heat pipes 14, each in contact with a portion of busbars 8, 9, 10, and 11 and platform 4. In this case, two heat pipes are in contact with portion 10 of the busbar (providing the electrical connection between electromechanical relay 5 and fuse 7), and individual heat pipes are in contact with each of the other portions 8, 9, and 11 of the busbar. In practice, the number of heat pipes used in each portion of the busbar depends on the amount of heat to be dissipated.

[0053] Figure 4 A heat pipe 14, isolated from the rest of box 1, is shown. In this case, heat pipe 14 has an overall L-shape. Therefore, the heat pipe includes a first straight section 20 and a second straight section 21. The first straight section is configured to establish a region in contact with platform 4, and the second straight section is orthogonal to the first straight section 20 and configured to establish a second region in contact with busbars 8, 9, 10, and 11. The first straight section 21 and the second straight section 22 are connected by a curved intermediate section 22.

[0054] The heat pipe 14 has a planar surface at the contact area. More specifically, the heat pipe 14 is a flat heat pipe in this case, which has a rectangular cross-section in general and uses capillary action (i.e., its inner wall is lined with a capillary wick, which in this case is a sintered capillary wick).

[0055] The second straight portion 21 of the heat pipe 14 (which forms the second area in contact with the busbars 8, 9, 10, 11) is covered with an electrically insulating coating, in this case a polyimide film, particularly Kapton. © .

[0056] In this case, a system of fastening flanges 23 and 24 is used to fasten the heat pipe 14, including horizontal fastening flanges 23 that fasten the heat pipe to the platform. Figure 5 ) and the vertical fastening flange 24 that secures the heat pipe 14 to the busbar ( Figure 6 ).

[0057] Fastening flanges 23 and 24 extend longitudinally along the axis of the straight portions 20 and 21 of the stationary heat pipes. These fastening flanges each have a U-shaped cross-section defined by a main base 25 from which two lateral branches 26 extend orthogonally to define the housing 27. Because the two fastening flanges 23 and 24 have similar profiles, the same reference numerals will be used to indicate the main base 25 and the lateral branches 26 of the two flanges 23 and 24.

[0058] The inner surface of the fastening flange is covered at the lateral branches 26 by two protective strips 28, in this case two polymer (e.g., ABS) strips, which are adhesively bonded to the lateral branches 26 and extend over the entire length of these lateral branches 26.

[0059] Figure 5 The horizontal fastening flange 23 shown includes through holes 29 (in this case, six smooth holes) that are formed vertically through the lateral branches and orthogonal to the main base 25.

[0060] Figure 6 The vertical fastening flange 24 shown also includes through holes 31 (in this case, four threaded holes) which are formed horizontally through the lateral branches and orthogonal to the main base 25.

[0061] In this case, the end face of the branch of the horizontal fastening flange 23 is flat to abut against the receiving surface of the platform 4.

[0062] In contrast, the end faces of the branches of the vertical fastening flange 24 each have a notch forming a recess 30. This recess is configured to receive the busbars 8, 9, 10, and 11 in a tight fit (without clearance or with a small amount of clearance), as will be seen below.

[0063] In the vertical flange 24, the main base 25 has a notch at its lower end to allow the curved middle portion of the heat pipe 14 to pass through, as will be seen below.

[0064] Figure 7 and Figure 8 This is an exploded view showing the heat pipe being secured to the receiving surface F of platform 4 using fastening flanges 23 and 24.

[0065] like Figure 7As shown, the heat pipe 14 is positioned against the receiving surface F of the platform 4, such that the first straight portion 20 of the heat pipe establishes a first area in contact with the platform 4, and the second straight portion 21 of the heat pipe extends orthogonally to the receiving surface F.

[0066] The horizontal flange 23 is positioned against the receiving surface F such that the first straight portion 20 of the heat pipe 14 is located within the housing 27, and each through hole 29 formed in the lateral portion 26 faces a corresponding threaded hole 32 leading to one of the tunnels 19. A fastening screw 33 is inserted through the through hole 29 and screwed into the threaded hole 32, such that the lateral branch 26 of the horizontal flange 23 remains in contact with the platform 4, and the main base 25 remains in contact with the first straight portion 20 of the heat pipe 14.

[0067] In this case, the contact between the lateral branch 26 and the receiving surface F, the contact between the first straight portion 20 of the heat pipe 14 and the main base 25 of the horizontal fastening flange 23, and the contact between the first straight portion 20 and the receiving surface F are achieved by means of the thermal interface material 34 (typically, thermal paste).

[0068] like Figure 8 As shown, the heat pipe 14 is arranged such that its second straight portion 21 contacts the busbar (e.g., in this case, portion 8 of the busbar).

[0069] The vertical flange 24 is positioned such that the second straight portion 21 of the heat pipe 14 is located in the housing 27 and in contact with the main base 25, and such that the portion 8 of the busbar is positioned in the recess 30 in a close fit, such that the first surface of the surface of this portion of the busbar establishes an area in contact with the lateral branch 26.

[0070] The closing flange 35 (in this case, a rectangular plate including through holes 36) is positioned to contact the second surface of the busbar 8 on the opposite side of the first surface, such that each through hole 36 is positioned facing the threaded hole 31 of the vertical flange 24. A fastening screw 37 is inserted through the through hole 36 and screwed into the threaded hole 31, such that the second straight portion 21 of the heat pipe 14 remains in contact with the first surface of the busbar portion 8, and the closing flange 35 remains in contact with the second surface of the busbar portion 8 and with the vertical flange 24.

[0071] In this case, the contact between the second straight portion 21 of the heat pipe 14 and the main base 25 of the vertical fastening flange 24, the contact between the second straight portion 21 and the portion 8 of the busbar, and the contact between the portion 8 and the closed flange 35 are formed by means of the thermal interface material 34.

[0072] In this example, the dimensions of the heat pipe 14 are chosen such that the surface area of ​​the contact region between the first portion 20 and the receiving surface F is three times the surface area of ​​the contact region between the second portion 21 and the busbar 8. Since heat exchange inside the heat pipe 14 is lower in the second portion 21 (the hottest portion), this ratio between these surface areas advantageously allows for a reduction in heat flux density.

[0073] To further improve the thermal management of box 1, particularly the dissipation of heat generated by the internal windings of the relay (which, for illustration, might require 5 watts of dissipation), the first surface of the electromechanical relay 5 is positioned to contact the receiving surface F, in this case via the thermal interface material 34. The distal plate 38 is positioned to contact the second surface of the thermal interface relay 5 on the opposite side of the first surface and is screwed onto the support plate 15 to clamp the thermal interface relay 5 onto the receiving surface F.

[0074] To ensure excellent heat dissipation of hot spots, the materials of platform 4 and flanges 23, 24, and 34 have high thermal conductivity, for example, greater than 100 W. m -1 K -1 Thermal conductivity. For example, these components are made of aluminum or aluminum alloys.

[0075] The above reference Figure 1 The embodiments described up to Figure 9 are by no means limiting.

[0076] In particular, an electrical junction box comprising five heat pipes has been described. The invention is not limited to this number, and the box according to the invention may include any number of heat pipes, particularly a single heat pipe, and may also include any number of heat pipes corresponding to each busbar section, such as one, two, or three heat pipes.

[0077] In embodiments where at least a portion of the busbar is connected to multiple heat pipes, these heat pipes can be fastened using the same set of flanges. For example, as in Figure 1 As can be seen, two heat pipes 14 are held on the busbar portion 10 by the same set of flanges 39. Thus, the straight portions of these heat pipes are positioned in the same housing within the corresponding flanges and separated from each other by protective strips. Multiple heat pipes in contact with the same portion of the busbar can also be secured using separate sets of flanges.

[0078] The foregoing has described multiple heat transfer fluid circulation conduits and multiple tunnels formed by an extrusion platform. The box according to the invention is not limited to this configuration, and the conduits and / or tunnels can be produced by any other means, such as by drilling or by molding the platform. Furthermore, the box according to the invention can include any number of heat transfer fluid circulation conduits (e.g., a single conduit), and any number of tunnels, or no tunnels. In the latter case, a threaded hole (formed in the receiving surface of the platform and used for screw fastening of the fastening flange) extends through the platform or is a blind hole.

[0079] The box including the support plate has been described above. The invention is not limited to the presence of the support plate, and in some embodiments, these components are directly fastened to the platform.

Claims

1. An electrical connection box for a storage battery (2), the electrical connection box comprising: - Platform (4), which is designed to receive electrical components (5, 6, 7) and form at least one circulation pipe (18) for circulating heat transfer fluid. - Busbar (8, 9, 10, 11) that provides electrical connection between at least two electrical components (9, 10); and - At least one heat pipe (14), the first portion (20) of which has a first area in contact with the platform (4), and the second portion (21) of which has a second area in contact with the busbar (8, 9, 10, 11) and / or with at least one of the electrical components (5, 6, 7).

2. The box as claimed in claim 1, wherein, The surface area of ​​the first contact region is at least equal to the surface area of ​​the second contact region.

3. The box as claimed in claim 1 or 2, wherein, The second part (21) is covered with an electrically insulating coating.

4. The box as claimed in any one of claims 1 to 3, wherein, The circulation pipe (18) is configured to be connected to a heat transfer fluid circulation loop including at least one pump.

5. The box as claimed in any one of claims 1 to 5, wherein, The platform (4) has a tunnel (19) adjacent to the circulation pipe (18), and the heat pipe (14) is fastened to the platform (4) by means of a screw (33) configured to be inserted into a threaded hole (32) formed in the platform and leading to the tunnel (19).

6. The box as claimed in any one of claims 1 to 5, wherein, The support plate (15) is fastened to the platform (4) and is configured to receive these electrical components (5, 6, 7).

7. The box as claimed in claim 6, wherein, The support plate (15) is fastened to the platform (4) by means of a stud (16), which is welded to the platform (4) and configured to be inserted into a corresponding hole in the support plate (15).

8. The box as claimed in claim 6 or 7, wherein, The support plate (15) is made of acrylonitrile butadiene styrene.

9. The box as claimed in any one of claims 6 to 8, wherein, The first side of the electrical component (5) contacts the platform (4), the box (1) includes a distal plate (38) that contacts the second side of the electrical component (5), the distal plate is fastened to the support plate (15) and configured to clamp the electrical component (5) onto the platform (4).

10. The box as claimed in any one of claims 1 to 9, wherein, The second portion (21) of the heat pipe (14) has a second region that contacts the busbar (8, 9, 10, 11). The contact between the heat pipe (14) and the busbar (8, 9, 10, 11) is provided by two flanges (24, 35) that are fastened to each other, and the second portion (21) and the busbar (8, 9, 10, 11) remain abutting against each other between the two flanges.

11. A storage battery for a motor vehicle (V), the storage battery comprising an electrochemical cell and at least one electrical connection box (1) as claimed in any one of claims 1 to 10.

12. A motor vehicle comprising the battery (2) as claimed in claim 11.

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