Thermal conduction device and electrical connection box, electrical energy storage device, in particular a battery pack, and / or motor vehicle comprising such a thermal conduction device

Abstract

The invention relates to a thermal conduction device, in particular for a motor vehicle, which device is configured to form a thermal bridge between electrical connection terminals (10a, 10b), provided at distinct electrical potentials, of the same electrical member (12) forming a heat source, the device comprising a first housing (14) configured to form an electrical insulation between the connection terminals (10a, 10b), the first housing (14) receiving a dielectric fluid so as to establish a heat exchange between the connection terminals (10a, 10b) through the fluid, the first housing (14) comprising an electrically insulating armature (16) and closing walls (18), the closing walls (18) being thermally conductive and arranged on either side of the armature (16) so as to be electrically insulated from one another, the closing walls (16) being configured such that they are capable of exchanging heat with the connection terminals (10a, 10b).

Description

Description Title of the invention: Thermal conduction device as well as electrical connection box, electrical energy storage device, in particular accumulator battery, and / or motor vehicle comprising such a thermal conduction device

[0001] The invention relates to a thermal conduction device, particularly for motor vehicles. It also relates to an electrical connection box for an electrical energy storage device, particularly a battery, comprising such a conduction device. It further relates to said electrical energy storage device comprising such an electrical connection box and / or such a thermal conduction device. It also relates to a vehicle comprising such a storage device, such a box, and / or such a thermal conduction device.

[0002] In this field, it is known that electric or hybrid vehicles equipped with a battery pack include a casing that houses several electrochemical cells connected together and providing a high voltage at the battery terminals, typically a voltage of several hundred volts.

[0003] It is then necessary to equip the battery with an electrical connection box containing safety electrical components (relays, fuses) in order to cut off the current when needed. These components are connected using busbars through which the battery's input or output current flows.

[0004] 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 temperature, particularly in areas commonly referred to as "hot spots," such as safety-critical electrical components, which are then at increased risk of damage.

[0005] To mitigate this risk, it is common practice to oversize these components. However, this results in significant bulk, an excessive increase in weight, and additional costs.

[0006] The invention aims to overcome, at least in part, the aforementioned drawbacks and, to this end, proposes a thermal conduction device, particularly for motor vehicles, said device being configured to form a thermal bridge between electrical connection terminals, provided at distinct electrical potentials, of a same electrical component forming a heat source, said device comprising a first housing configured to form electrical insulation between said connection terminals, said first housing containing a dielectric fluid so as to establish heat exchange between said connection terminals through said fluid, said first housing comprising an electrically insulating armature and closing walls, said closing walls being thermally conductive and arranged on either side of said armature so as to be electrically insulated from each other.

[0007] By "configured to form a thermal bridge", we understand, in particular, configured to exhibit high thermal conductivity so as to create a path of least resistance for heat transfer.

[0008] Such a thermal conduction device allows for better cooling of the electrical component between the electrical connection terminals where it is positioned, via said electrical connection terminals. Indeed, by establishing a thermal bridge between these terminals, if one is better cooled than the other, the latter benefits from the cooling capacity of the former. This allows for the sharing of cooling resources and limits the heating of the electrical component without having to oversize the electrical component and / or each of its cooling systems. Furthermore, this thermal conduction device allows for temperature equalization between the connection terminals of the electrical component, which is a factor in its proper operation.

[0009] It should also be noted that the configuration of said conduction device in the form of a housing containing a dielectric fluid improves the efficiency of the electrical insulation provided by said device between the connection terminals of said electrical component as well as the reliability of said conduction device over time.

[0010] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: - said device further comprises thermal conductors, in heat exchange with said first housing and intended to be connected respectively to one of said electrical connection terminals, - said thermal conductors include heat transfer bars, - said heat transfer bars are metallic, - said first housing is configured to be positioned between said heat transfer bars, - said enclosure walls are configured to be in thermal exchange relationship with said connection terminals, - said closure walls are configured to be fixed to said thermal conductors, in particular to said heat transfer bars, - said framework and said enclosure walls together define a housing containing said fluid, - said closing walls are made of copper, copper alloy, aluminum and / or aluminum alloy, - said frame is made of plastic material, in particular polymer material and / or ABS, - said first housing, in particular said closing walls, has a pin for attaching thermal conductors, in particular said thermal transfer bars, - said pawl is formed from a threaded rod, - said thermal transfer bars have a fixing flange for said first housing.

[0011] The invention also relates to an electrical connection box, for example, for an electrical energy storage device, in particular a battery of accumulators, comprising an electrical element forming a heat source, said electrical element comprising electrical connection terminals, provided at distinct electrical potentials, said connection box further comprising a conduction device as described above for heat conduction between said terminals.

[0012] According to various additional features of the invention, which may be taken together or separately and which constitute so many embodiments of the invention: - said electrical component includes an electrical protection component, - said electrical protection device includes an electrical relay, - said electrical component includes a second housing with said electrical connection terminals, - said connection box includes electrical conduction busbars, - said thermal conductors, in particular said thermal transfer bars, are respectively connected to said electrical connection terminals, - said busbars are sandwiched between said second housing and said thermal conductors, in particular said thermal transfer bars, - said electrical conductors, in particular said thermal transfer bars, are configured so that said first enclosure is offset from said second enclosure, - said connection box further includes a cold source, - said connection box further includes one or more heat dissipation systems enabling heat exchange between said cold source and said electrical connection terminals, - said dissipation system is unique and associated with only one of said electrical connection terminals, - said cold source comprises a plate exhibiting a thermal inertia much greater than that of said heat source, - said plate includes all or part of a lower face of a casing of the electrical energy storage device.

[0013] The invention also relates to an electrical energy storage device, in particular a battery of accumulators, comprising a connection box and / or conduction device as described above.

[0014] The invention also relates to a vehicle comprising an electrical energy storage device, a connection box and / or a conduction device as described above.

[0015] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the course of the detailed explanatory description which follows, of at least one embodiment of the invention given by way of purely illustrative and non-limiting example, with reference to the accompanying schematic drawings, among which:

[0016] [Fig.1] schematically illustrates in side view a motor vehicle comprising a connection box according to the invention;

[0017] [Fig.2] schematically illustrates in perspective, in exploded view, an example of a thermal conduction device according to the invention;

[0018] [Fig.3] schematically illustrates in perspective, in assembled mode, the thermal conduction device of [Fig.2];

[0019] [Fig.4] schematically illustrates in perspective exploded view of a housing of the thermal conduction device of figures 2 and 3;

[0020] [Fig.5] schematically and partially illustrates a connection box including the thermal conduction device of [Fig.2] and 3.

[0021] It should first be noted that the terms "first", "second", "third", ... are only used to distinguish the components concerned from each other and do not imply any order or possible importance of said components.

[0022] The invention relates to a thermal conduction device, particularly for motor vehicles.

[0023] As illustrated in [Fig. 1], the invention also relates to an electrical connection box 1, an electrical energy storage device 2, in particular a battery of accumulators, and a vehicle V comprising such a conduction device. The latter is placed, for example, in the electrical connection box 1, said connection box 1 being used to electrically connect said electrical energy storage device 2 to an electrical network 3 of the motor vehicle V. Said vehicle V is advantageously an electric or hybrid motor vehicle, connected to said electrical network 3.

[0024] As illustrated in the following figures, the thermal conduction device is configured to form a thermal bridge between electrical connection terminals 10a, 10b, which are provided at distinct electrical potentials. Preferably, these are electrical connection terminals of an electrical component 12.

[0025] The aforementioned connection terminals 10a, 10b are thus at approximately the same temperature. Furthermore, if one of the terminals 10a, 10b is better cooled than the other, the latter then benefits from the cooling capacity of the former, which promotes overall cooling of the electrical component 12. However, in order to prevent short circuits at the terminals of said electrical component 12, said thermal conduction device is electrically insulating between said connection terminals 10a, 10b.

[0026] For this purpose, according to the invention, said device comprises a first housing 14 configured to form an electrical insulation between said connection terminals 10a, 10b. In addition, said first housing accommodates a dielectric fluid, not illustrated, so as to establish a heat exchange between said connection terminals 10a, 10b through said fluid.

[0027] The thermal bridge combined with the electrical insulation provided between the connection terminals 10a, 10b according to the invention is thus obtained by means of the dielectric fluid contained in said first housing 14. The housing configuration of the electrical conduction device further promotes the electrical insulation between the connection terminals 10a, 10b as well as the durability of said conduction device.

[0028] As more clearly seen in [Fig. 4], the first housing 14 comprises an electrically insulating frame 16 and walls 18 for closing said frame 16. These walls 18 are thermally conductive and arranged on either side of said frame 16 so as to be electrically insulated from each other. This is a particularly simple and robust configuration.

[0029] The said frame 16 and the said closing walls 18 together define a housing 19 for the said dielectric fluid. Advantageously, the said walls 18 are fixed in a sealed manner to the said frame 16, in particular at a shoulder 20 provided inside the said frame 16, here in the vicinity of a longitudinal edge.

[0030] The first housing 14, for example, has a cylindrical configuration. In the illustrated embodiment, the frame 16 is tubular and has opposite longitudinal ends. The walls 18 have a disc shape, closing the frame 16 at each of the longitudinal ends.

[0031] To facilitate the filling of said first housing 14 with said dielectric fluid, said first housing 14 is optionally provided with a filling orifice intended to be closed by a locking rivet, both of which are not shown. Said orifice is preferably located at the level of said reinforcement 16. Alternatively or additionally, a filling valve is provided.

[0032] The frame 16 is, for example, made of plastic material, in particular polymer material, more specifically ABS. The closing walls 18 are, for example, made of copper, copper alloy, aluminum and / or aluminum alloy.

[0033] Referring to the other figures, we can see that the said conduction device also includes thermal conductors 22, in heat exchange with the said first housing 14 and intended to be connected respectively to one of the said electrical connection terminals 10a, 10b.

[0034] As can be more clearly seen in Figures 2 and 3, said thermal conductors 22 comprise, for example, heat transfer bars 24. Said heat transfer bars 22 are, for example, metallic, in particular made of copper.

[0035] The walls 18 are advantageously configured to be fixed to the bars 24. For this purpose, in the illustrated embodiment, the closing walls 18 have a pin 26 for attaching the heat transfer bars 24. This pin is formed, for example, by a threaded rod. It is located, in particular, at the center of the walls 18.

[0036] Preferably, the first housing 14 is configured to be positioned between the heat transfer bars 24. These bars are symmetrical with respect to each other with respect to the first housing 14.

[0037] The said heat transfer bars 24 have, for example, a rod 30 and / or a flange 28 for fixing to said first housing 14. The said flange 28 is formed, for example, by a wall at 90° to the rod 30. The said flanges 28 are substantially parallel to the walls 18. The rods 30 are here parallel to each other and / or located in the same plane substantially tangential to said first housing 14.

[0038] The said flange 28 has, for example, an orifice 32 for the passage of one of the said pins 26.

[0039] The said conduction device further includes nuts 33 for fixing said heat transfer bars 24 onto said pins 26 by screwing.

[0040] As more clearly seen in [Fig. 5], said electrical connection box 1 includes said electrical component 12 which forms a heat source. Said connection box I further includes a conduction device as described above for heat conduction between said terminals 10a, 10b of said electrical component 12.

[0041] The electrical component 12 includes, for example, an electrical protection component such as, in particular, an electrical relay and / or a fuse. In this case, it is a relay. The relay includes, for example, a coil, not visible, electrically connected to each of the electrical connection terminals 10a, 10b.

[0042] The electrical component 12 includes, for example, a second housing 34 having the electrical connection terminals 10a, 10b. More specifically, here, the connection terminals 10a, 10b open onto the surface of the second housing 34. The coil is housed in the second housing 34.

[0043] The said connection terminals 10a, 10b include, for example, sockets, passing through said second box 34. The said electrical connection terminals 10a, 10b, in particular said sockets, are flush with said second protective box 34. The said sockets are located, for example, at the level of a face 36 of said second box 34.

[0044] The said second box 34 is, in particular, of a substantially parallelepiped shape. It is fixed, for example, to a cold source 38 of said connection box 1, in particular by means of fixing tabs.

[0045] In the illustrated embodiment, said connection box 1 further includes one or more bus bars 40 for electrical conduction.

[0046] The busbars 40 are respectively connected to the electrical connection terminals 10a, 10b. The busbars 40 are sandwiched between the second housing 34, more specifically its face 36 equipped with the sockets, and the heat transfer bars 24. In other words, the busbars 40 are in contact on one of their faces with the electrical connection terminals 10a, 10b, for the passage of electric current, and / or on the opposite face with the heat transfer bars 24, for the conduction of heat. Put another way, the busbars 40 form a thermal bridge between the connection terminals 10a, 10b and the conduction device.

[0047] The connection box 1 includes screws 44 for fixing the bus bars 40 and / or the conduction device. The bus bars 40 and / or the heat transfer bars 24 have a first, non-visible hole for the passage of the screw 44. The screw is oriented substantially perpendicular to the face 36 of the second box 34. The screw 44 passes through the first holes to engage with the socket of the electrical connection terminals 10a, 10b.

[0048] In other words, more generally, the said conduction device is carried by the said second housing 34. It is further noted that, thanks to the said bars 22 of thermal transfer, said first housing 14 is offset from said second housing 34. This allows said first housing 14 to be placed at least partially opposite one of the faces of said second housing 34.

[0049] The said bus bars 40 also have here second ports 42 for electrical connection to other electrical components, not shown, of said connection box 1 and / or to the rest of the circuit 3. The said bus bars are here bent and the said first and second ports are located at opposite longitudinal ends of the said bus bars 40.

[0050] The said cold source 38 includes, for example, a plate 46 having a thermal inertia much greater than the thermal inertia of the heat source formed by the electrical component 12. Advantageously, said plate 46 includes all or part of a lower face of a housing of the electrical energy storage device 2. Said plate 46 advantageously has one or more circulation channels for a heat transfer fluid.

[0051] For its cooling, the said electrical component 12 is here in thermal exchange contact with the said plate 46, in particular through one of the faces of the said second housing 34.

[0052] Alternatively or cumulatively, although not shown, said connection box 1 further includes one or more heat dissipation systems enabling heat exchange between said cold source 38 and said electrical connection terminals 10a, 10b, possibly via said bus bars 40. Said heat dissipation systems include, for example, one or more heat pipes.

[0053] Advantageously, rather than having a dissipation system for each of said electrical connection terminals 10a, 10b, said dissipation system is unique and associated with only one of said electrical connection terminals 10a, 10b of the same electrical component 12.

Claims

Demands [Claim 1] A thermal conduction device, particularly for a motor vehicle, said device being configured to form a thermal bridge between electrical connection terminals (10a, 10b), provided at distinct electrical potentials, of the same electrical component (12) forming a heat source, said device comprising a first housing (14) configured to form electrical insulation between said connection terminals (10a, 10b), said first housing (14) containing a dielectric fluid so as to establish heat exchange between said connection terminals (10a, 10b) through said fluid, said first housing (14) comprising an electrically insulating frame (16) and closing walls (18), said closing walls (18) being thermally conductive and arranged on either side of said frame (16) so as to be electrically insulated from each other,said closure walls (16) being configured to be in thermal exchange relationship with said connection terminals (10a, 10b). [Claim 2] Device according to the preceding claim in which said frame (16) and said closure wall (18) together define a housing (19) receiving said fluid. [Claim 3] Device according to any one of the preceding claims further comprising thermal conductors (22), in heat exchange with said first housing (14) and intended to be connected respectively to one of said electrical connection terminals (10a, 10b). [Claim 4] Device according to the preceding claim in which said first housing (14) has a hook pin (26) for said thermal conductors (22). [Claim 5] Electrical connection box for an electrical energy storage device, in particular a battery of accumulators, comprising an electrical element (12) forming a heat source, said electrical element (12) comprising electrical connection terminals (10a, 10b), provided at separate electrical potentials, said connection box further comprising a conduction device according to any one of the preceding claims for heat conduction between said terminals (10a, 10b). [Claim 6] Connection box according to the preceding claim comprising a second box (34) having said electrical connection terminals (10a, 10b). [Claim 7] Connection box according to the preceding claim, claim 5 being taken in its connection with any one of claims 3 or 4, wherein said electrical conductors (22) are configured so that said first box (14) is offset from said second box (34). [Claim 8] Connection box according to any one of claims 5 to 7 further comprising a cold source (38) and a unique heat dissipation system enabling heat exchange between said cold source (38) and one of said electrical connection terminals (10a, 10b). [Claim 9] Electrical energy storage device, in particular accumulator battery, comprising a conduction device according to any one of claims 1 to 4. [Claim 10] Vehicle comprising a driving device according to any one of claims 1 to 4.

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