Electrical connection box, battery and motor vehicle

Abstract

The invention relates to an electrical connection box for a storage battery, comprising a box (4) containing at least one electrical and / or electronic component (8, 9, 10) and a cooling system (13) configured to cool the electrical component, characterized in that the cooling system comprises a flexible pouch (14, 15) configured to contain a heat transfer fluid and which is placed in contact with the electrical component. The invention further relates to a storage battery equipped with such a box and a motor vehicle equipped with such a battery. Figure for the abstract: Fig. 2

Description

Title of the invention: electrical connection box, battery pack and motor vehicle Technical field of the invention

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

[0002] It relates more particularly to an electrical connection box for a battery of accumulators, a battery of accumulators equipped with such a box, and a motor vehicle equipped with such a battery of accumulators. State of the art

[0003] Electric or hybrid vehicles are equipped with a battery pack comprising a protective casing which houses several electrochemical cells connected together and providing a high voltage at the battery terminals, typically a voltage of several hundred volts.

[0004] It is then necessary to equip the battery with an electrical connection box containing safety electrical components (relay, fuse) in order to cut off the current when necessary. These components are positioned along a busbar through which the input or output current from the battery flows.

[0005] In certain situations, the battery supplies or receives a high electrical power. This is the case, for example, during so-called fast charging of the vehicle's battery, or when the vehicle must exert significant traction. In these situations, the flow of a high-intensity current generates a sharp increase in the battery's temperature, particularly in the components of the connection box.

[0006] The components of the connection box are thus at increased risk of degradation. To protect these components, systems exist for cooling the box. However, these solutions are bulky or require modifying the box structure, and are therefore incompatible with existing boxes. Presentation of the invention

[0007] In order to remedy the aforementioned drawbacks of the prior art, the present invention proposes a simple means of cooling or limiting the temperature rise in the connection box, which can be fitted to prior art boxes without modifying the latter in a significant way.

[0008] More particularly, the invention proposes an electrical connection box for a battery, comprising a box containing at least an electrical component and a cooling system configured to cool the electrical component, this cooling system comprising a flexible pouch which is configured to contain a heat transfer fluid and which is placed in contact with the electrical component.

[0009] For the purposes of this invention, an electrical component is understood to be a component that operates on electricity. Therefore, this term includes electronic components.

[0010] For the purposes of this invention, the term "flexible" refers to the ability to deform even under a weak force. For example, a flexible pouch is made of a material with a stiffness of less than 1 N / mm². In particular, a flexible pouch is adapted to conform to the shape of the elements on which it is placed, under the effect of its own weight and / or the weight of the fluid and / or under the effect of external pressure, for example, that exerted by a wall of the container. Thus, the internal volume of a flexible pouch that is not yet sealed is highly variable, particularly depending on the pressure difference between the inside and outside of the flexible pouch.Thus, a bag described as "flexible" is flattened when it does not contain fluid (when the pressure is the same inside and outside the bag), its internal volume being then close to zero, it can then be folded or rolled up on itself, and inflated when it contains a fluid which increases the pressure inside the bag.

[0011] The use of such a flexible pocket allows for better integration of the cooling system into the housing, since it adapts by deforming to the arrangement and shape of the components. It therefore allows for greater flexibility in component placement and thus simplifies the busbar design. A simpler design, for example, allows for a reduction in the length of the busbars, and therefore saves material.

[0012] Other advantageous and non-limiting features of the electrical connection box according to the invention, taken individually or in all technically possible combinations, are as follows: - the cooling system includes a heat transfer fluid circulation circuit, the circulation circuit including the flexible pouch through which the heat transfer fluid circulates; - the flexible pocket is held against the electrical component by clamping between the electrical component and a wall of the box; - the box includes a platform (or base) accommodating the electrical component and a lid forming said wall; - the circulation circuit includes a fluid inlet pipe configured to supply the flexible bag with heat transfer fluid from outside the box and a fluid outlet pipe configured to evacuate the fluid to the outside of the box; - the electrical component is chosen from an electromechanical relay, a fuse and a busbar;

[0013] According to another aspect, a battery of accumulators for motor vehicles is proposed, comprising electrochemical cells and at least one electrical connection box according to the invention, of which said at least one electrical component is connected to the electrochemical cells.

[0014] Other advantageous and non-limiting features of the battery according to the invention, taken individually or in all technically possible combinations, are as follows: - the battery has a separate (i.e., not fluidically connected) electrochemical cell cooling circuit from the heat transfer fluid circulation circuit; - the accumulator battery includes a protective casing containing the electrochemical cells and the connection box, the fluid circulation circuit including a portion of the circuit which extends outside the connection box, the portion of the circuit being thermally coupled to a heat sink and a fan which cooperate to evacuate the heat from the fluid to the outside of the protective casing; - the accumulator battery includes a fluidic circuit for cooling the electrochemical cells, the fluid circulation circuit being connected to the fluidic circuit for cooling the electrochemical cells.

[0015] According to another aspect, a motor vehicle equipped with a battery of accumulators according to the invention is proposed.

[0016] Of course, the various features, variants, and embodiments of the invention can be combined with one another in various ways, provided they are not incompatible or mutually exclusive. Detailed description of the invention

[0017] The following description, in relation to the attached drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be implemented.

[0018] On the attached drawings:

[0019] [Fig-1] is a schematic view of a motor vehicle according to a mode of realization of the invention, provided with a battery of accumulators equipped with an electrical connection box;

[0020] [Fig.2] is a schematic front view of the electrical connection box of the [Fig.l];

[0021] [Fig.3] is a schematic top view of the electrical connection box of the [Fig.2];

[0022] [Fig.4] is a schematic view of the battery of accumulators of the motor vehicle of [Fig.1], according to an embodiment of the invention;

[0023] [Fig.5] is a schematic view of the battery of accumulators of the motor vehicle of [Fig.1], according to another embodiment of the invention.

[0024] An electrical connection box according to an embodiment of the invention, as shown in [Fig. 1] and designated as a whole by the reference numeral 1, is used for connecting a battery 2 to the electrical network 3 of an electric or hybrid motor vehicle V. It is thus fitted to the battery 2 and connected to one of its two electrical terminals. For example, two identical electrical connection boxes are respectively connected to the two electrical terminals of the battery 2. In the remainder of this description, only one of these two electrical connection boxes 1 will be described.

[0025] As illustrated in Figures 2 and 3, this electrical connection box 1 comprises at least one electrical component and a box 4 housing each electrical component. This box 4 is here in two single-piece parts, namely a base and a cover 7. The base has a platform 5 forming the bottom of the box 4 and accommodating each electrical or electronic component, and a side wall 6 that borders the platform 5 and rises orthogonally with respect to it. The cover 7 is removable from the base and is configured to close the box 4.

[0026] The box 4 has an overall parallelepiped shape. The platform 5 is, for example, a wall of a protective casing for the vehicle's accumulator battery 2 V and can be installed horizontally on the vehicle (i.e., parallel to the vehicle floor), so that the face of the platform 5 that accommodates the components (receiving face F) extends horizontally and is oriented upwards. In the remainder of this description, the electrical connection box 1 will be described in this particular orientation.

[0027] Electrical components 8, 9, 10 are here fixed to the receiving face F of the platform 5, here the upper face (i.e. opposite the plane containing the floor of the vehicle V) of the box 4 is for example made of a polymer material, for example polyamide (for example polyamide 6, commonly abbreviated PA6) or polypropylene (PP).

[0028] In this example, the box 4 houses several electrical or electronic components. It thus houses busbars 10, electromechanical relays 8 and fuses 9.

[0029] The bus bars 10 are configured to provide an electrical connection between the other electrical components 8, 9, a connection terminal 11 to the storage battery 2 and a connection terminal 12 to the vehicle's electrical network 3 automotive V. Thus, they are configured to carry a high-intensity current, for example, a current greater than or equal to 500 amps. In this example, each bus bar 10 provides an electrical connection between two electrical components, between an electrical component and terminal 11 for connection to the battery, or between an electrical component and terminal 12 for connection to the electrical network of the automotive V.

[0030] The other electrical components 8, 9 are here configured to cut the electrical connection between the accumulator battery 2 and the electrical network 3 of the motor vehicle (here between terminal 11 and terminal 12).

[0031] The electromechanical relay 8 is configured to, during normal use of the vehicle, reversibly cut off the connection between the accumulator battery 2 and the electrical network 3, for example after parking the vehicle V. It is, for example, controlled by a computer, according to the driver's wishes to start or stop the motor vehicle's powertrain.

[0032] The fuses 9 are configured to break the electrical connection when they are traversed by a current of too high intensity, which would be caused for example by a short circuit.

[0033] During the use of the motor vehicle V, for example during a rapid charge of the accumulator battery 2 or when the traction of the vehicle is provided by an electric motor powered by the accumulator battery, the temperature of the bus bars 10, fuses or electromechanical relays is likely to increase significantly, which may impair the proper functioning of the housing and accelerate the degradation of the components.

[0034] The configuration of the electrical connection box 1 according to the invention advantageously allows the heat generated at the component level to be dissipated. To this end, the electrical connection box 1 includes a cooling system 13 comprising at least one flexible pocket configured to contain a heat transfer fluid, for example water, oil or glycol, so as to be able to dissipate at least part of the heat from the components, preferably to the outside of the box 4.

[0035] In the example illustrated in Figures 2 and 3, the cooling system 13 comprises two flexible bags 14, 15, each placed in contact with at least one of the electrical components 8, 9, 10 and held against it by clamping between the component and a wall of the box 4. Here, the flexible bags 14, 15 are placed above the components and the aforementioned wall is the cover 7. The first flexible bag 14 is in contact with two electromechanical relays 2 and a fuse 3 and the second flexible bag 15 is in contact with two other electromechanical relays 2. It could further be provided that one and / or the other of them is in contact with one and / or the other of the bus bars.

[0036] For example, each pouch is made of a flexible and impermeable thermoplastic material, for example polyvinyl chloride (PVC) or polyethylene terephthalate (PET), and has a thickness of between 0.1 millimeter and 1 millimeter, for example 0.2 millimeter. Their lengths are adapted to cover the entire upper surfaces of the components with which they are in contact and, once inflated, they have a maximum fluid passage thickness of between 1 and 5 millimeters.

[0037] It could be envisaged that the pockets are hermetically sealed and ensure the evacuation of heat towards the lid 7.

[0038] However, the cooling system 13 preferably includes a circulation circuit 35 of a heat transfer fluid comprising, in addition to the first flexible bag 14 and the second flexible bag 15, several heat transfer fluid circulation pipes 16, 17, 18, including a fluid inlet pipe 16 configured to supply the first flexible bag 14 with heat transfer fluid from outside the box 4, a fluid outlet pipe 17 configured to evacuate the fluid from the second flexible bag 15 to the outside of the box 4, and an intermediate pipe 18 configured to circulate the heat transfer fluid from the first flexible bag 14 to the second flexible bag 18.

[0039] Thus, the connection box 1 is configured in such a way that the heat transfer fluid can pass through the box 4 through the fluid inlet pipe 16, the first flexible bag 14, the intermediate pipe 18, the second flexible bag 15 and then the fluid outlet pipe 17, and absorb at least part of the heat released by the components 8, 9, 10 which are in contact with the flexible bags 14, 15.

[0040] Such a connection box 1 is configured to be placed inside a protective casing 19 of the accumulator battery 2 which equips the vehicle 1. [Fig.4] illustrates such a configuration, seen from above.

[0041] Here, the storage battery 2 comprises, in addition to the protective casing 19, a plurality of modules 20 housed within this casing. Each module comprises a plurality of storage cells (not shown) housed in a compartment. The connection between the connection terminals 11, 12 of the connection box 1 and the terminals of the storage battery 2 is not shown here for the sake of simplicity.

[0042] In this example, the battery 2 includes a cooling fluid circuit 21 configured to cool the battery cells of the modules 20. The cooling fluid circuit 21 has a first inlet 22 and a first outlet 23 provided in the protective housing 19, and a circulation conduit 24 configured to conduct the fluid from the first inlet 22 to the first outlet 23 so as to enable heat transfer from each module 20 to the fluid. For example, in the illustrated example, the conduit fluid circulation 24 meanders in the protective housing 19 so as to pass as close as possible to the modules 20. For example, the fluid circulation conduit 24 can be made in a floor of the protective housing 19 to which the modules 20 are fixed (the conduit can for example be made simultaneously with the floor of the protective housing 19, by extrusion).

[0043] In the embodiment of [Fig.4], the cooling system 13 is here connected to the outside of the protective housing 19 by means of a second inlet 25 provided in the protective housing 19, to which the fluid inlet pipe 16 is connected, and a second outlet 26 provided in the protective housing 19, to which the fluid outlet pipe 17 is connected.

[0044] In this embodiment, the housing cooling system 13 and the battery cooling fluid circuit 21 are fluidically connected to form two parallel branches of the same main cooling circuit, which join outside the protective housing 19. The main cooling circuit here includes a main supply conduit 27 whose outlet is connected to a first bypass device 28 configured to distribute the fluid supplied by the main supply conduit into the cooling system 13 and into the cooling fluid circuit 21. As a result, the first bypass device is connected to the first inlet 22 and to the second inlet 25.The main cooling circuit further includes a main drain duct 29 whose inlet is connected to a second bypass device 30 configured to drain the fluid from the cooling system 13 and the cooling fluid circuit 21. Thus, the second bypass device 30 is connected to the first outlet 23 and the second outlet 26.

[0045] The main circuit is a closed circuit further comprising means for cooling the fluid and means for circulating the fluid (for example, a pump), located outside the protective housing 19. For the sake of simplification, these means for cooling and circulating the fluid are not shown in the figures.

[0046] According to another embodiment illustrated in [Fig. 5], the fluid circulation system equipping the connection box 1 is specific to the battery, either because the battery is not equipped with a cooling circuit, or because it is equipped with a separate cooling circuit. Here, the cooling system 13 and the cooling fluid circuit are separate (there is no connection from one to the other, and the fluids circulating in each of the circuits never meet).

[0047] Here, the cooling system includes a heat dissipation module 31 located outside the box 4 and inside the protective housing 19. The module The heat dissipation 31 includes a heat sink 32 in which a conduit 36 ​​is provided, which here forms a portion of the circulation circuit 35 extending outside the housing 1. A first end of the conduit is connected to the fluid inlet pipe 16 and a second end is connected to the fluid outlet pipe 17.

[0048] A ventilation system 33, comprising at least one fan, is placed between the heat sink 32 and a portion of the wall of the protective housing 19 in which one or more openings 34 are provided, for example forming a grille. In this way, the air set in motion by the fans 33 is exhausted from the inside of the protective housing 19 to the outside of the protective housing 19 through the opening 34.

[0049] The invention is not limited to the embodiments described above, and is compatible with all conceivable variants within the scope of the annexed claims.

[0050] For example, a housing whose cooling system comprises two flexible pouches, each in contact with several components, has been described previously. The system according to the invention is nevertheless compatible with any number of flexible pouches, each in contact with any number of component(s). For example, in some embodiments, the cooling system comprises a single flexible pouch in contact with several components of the housing, for example, all the components of the housing. According to other embodiments, at least one of the flexible pouches is in contact with a single component. In particular, two flexible pouches of the same housing may have different dimensions and geometries.

[0051] Furthermore, a connection box comprising fuses, electromechanical relays, and busbars has been described above. The invention is not limited to these components, nor to the number mentioned, nor to the arrangement illustrated in the figures. According to embodiments, the box can accommodate any number and any type of electrical or electronic component. Indeed, an advantage of a box cooling system according to the invention is its adaptability to different box configurations.

[0052] Furthermore, a cooling system has been described in which the flexible pockets are located on the components, in particular between the components and the case lid. According to other embodiments, at least one flexible pocket of the cooling system is placed between at least one component and a side wall of the case.

[0053] A cooling system comprising a heat transfer fluid circulation circuit has been described. According to some embodiments, the cooling system It does not include a fluid circulation circuit, but simply at least one flexible pouch in contact with at least one component. For example, this flexible pouch establishes a thermal bridge between the component and a heat sink.

[0054] Furthermore, a generally parallelepiped-shaped box, the walls of which are substantially flat, has been described above. Within the scope of the invention, it is possible that certain walls of the box, for example the lid, may have recesses, or housings, in which the flexible pouches can be at least partially housed.

[0055] Finally, although the invention is particularly suited to accumulator batteries for motor vehicles, it is nonetheless compatible with any type of accumulator battery, for example accumulator batteries intended for home energy storage.

Claims

Demands

1. Electrical connection box (1) for accumulator battery (2), comprising a box (4) containing at least one electrical component (8, 9, 10) and a cooling system (13) adapted to cool each electrical component (8, 9, 10), characterized in that the cooling system (13) comprises at least one flexible pouch (14, 15) which contains a heat transfer fluid and which is placed in contact with said at least one electrical component (8, 9, 10).

2. Electrical connection box (1) according to claim 1, in which the cooling system (13) comprises a circulation circuit (35) of the heat transfer fluid, the circulation circuit (35) comprising the flexible pouch (14, 15) through which the heat transfer fluid circulates.

3. Electrical connection box (1) according to claim 2, in which the flexible pocket (14, 15) is held against said at least one electrical component (8, 9, 10) by clamping between the electronic component (8, 9, 10) and a wall of the box (4).

4. Electrical connection box (1) according to claim 3, in which the box comprises a platform (5) on which the electronic component (8, 9, 10) is fixed and a cover (7) forming said wall.

5. Electrical connection box (1) according to any one of claims 2 to 4, wherein the circulation circuit (35) includes a fluid inlet pipe (16) configured to supply the flexible bag (16) with heat transfer fluid from outside the box (4), and a fluid outlet pipe (17) configured to discharge the heat transfer fluid to the outside of the box (4).

6. Electrical connection box (1) according to any one of claims 1 to 5, wherein the electrical component (8, 9, 10) is selected from an electromechanical relay (8), a fuse (9) and a busbar (10).

7. A motor vehicle battery comprising electrochemical cells and at least one electrical connection box (1) according to any one of claims 1 to 6, the electrical component of which is electrically connected to the electrochemical cells.

8. Accumulator battery according to claim 7, comprising an electrical connection box (1) according to claim 2, and a cooling circuit (21) adapted to cool the electrochemical cells, which is separate from said circulation circuit (35) of the heat transfer fluid.

9. Accumulator battery according to claim 8, comprising a protective casing (19) containing the electrochemical cells and the connection box (1), the circulation circuit (35) comprising a circuit portion (36) extending outside the connection box (1), the circuit portion (36) being thermally coupled to a heat sink (32) and a fan (33) which cooperate to remove heat from the fluid to the outside of the protective casing (19).

10. Accumulator battery according to claim 7, comprising an electrical connection box (1) according to claim 2, and a cooling fluid circuit (21) adapted to cool the electrochemical cells, the circulation circuit (35) being fluidically connected to the cooling fluid circuit (21) of the electrochemical cells.

11. Motor vehicle (V) equipped with a battery of accumulators (2) according to any one of claims 7 to 10.

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