Connection member for connecting electrical terminals of electrical devices in an electric vehicle

Abstract

Connection member (4) or bus bar for electrically connecting an electrical terminal of a first electrical device to an electrical terminal of a second electrical device, the connection member extending between end zones (E1, E2) with coupling head, each coupling head (6) comprising a lower electrical contact face (60), edge faces perpendicular to the lower face, the electrical contact face extending along a reference plane (PR), the connection member comprising a conductive body (1) and a main insulating coating (2) covering the conductive body except in certain portions intended to establish an electrical contact, the first coupling head (6) comprising a flexible lip (3) extending from the main insulating coating and projecting from the first coupling head in a plane parallel to the reference plane, from the edge faces. Abstract figure: Fig. 3

Description

Title of the invention: Connection member for connecting electrical terminals of electrical devices in an electric vehicle

[0001] The present invention relates to a connection member for connecting electrical terminals of electrical devices in an electric vehicle, in particular in a context of using high voltages in the electrical system of the vehicle.

[0002] One of the electrical devices in question may be, for example, a traction battery module for an electric vehicle or an electrical collector for a traction battery. The electrical device in question may be a motor, an inverter, a distribution box for the high-voltage network.

[0003] In an electric vehicle, the battery pack has a high voltage at its terminals, in practice greater than 100 volts, most often between 200 volts and 800 volts. Voltages greater than 800 volts are also not excluded.

[0004] In the motor vehicle industry, we therefore speak of “high voltage” and “high voltage network” with regard to all equipment which is connected to the voltage of the traction battery.

[0005] A voltage of this type thus extends beyond the very low voltage (VLV, i.e. < 50 volts) range and it is necessary to take precautions; there are indeed regulatory protection requirements, in particular with regard to possible contacts induced by an action by an operator (e.g. a repairer or an emergency responder) either with bare hands or using a tool.

[0006] Of particular interest is an electrical connection member, which in practice is called a bus bar. Such a bus bar is used to electrically connect an electrical terminal of a first electrical device to an electrical terminal of another electrical device. Such a bus bar has a fairly substantial rigidity, unlike the flexible multi-strand conductors used in conventional motor vehicle wiring. Such a bus bar comprises at each end a coupling head, in particular for a screwed connection, without screwing being considered a limitation in this document.

[0007] Furthermore, the positioning tolerance of the first electrical device mentioned above relative to the other electrical device mentioned above implies a certain dispersion of dimensions linked to the intrinsic dispersions of the parts involved and also to the assembly process of these parts. Thus, in series production, for two theoretically identical vehicles, the relative position of the first electrical device relative to the other electrical device is not identical and suffers from the aforementioned dispersion.

[0008] This dispersion is found at the location of the interface between the bus bar and the terminal to be connected and its surroundings, this dispersion has, due to the significant rigidity of the bus bar, a consequence at the level of the protection of the electrical terminals, with respect to the need to protect them from access to the live parts by a tool end, this access being able to be intentional or not.

[0009] Each electrical terminal considered comprises a generally flat electrical contact surface, bordered by one or more rising protective walls made of non-conductive material, but there may remain a gap or interval between the coupling head and the rising protective wall(s), in particular depending on the dispersion phenomenon explained above. The size of this interval may be greater than the size of a control template according to a prescribed IP protection level.

[0010] When the dispersions and the assembly result in the presence of a gap of too large a size, it is known in the prior art to add an insulating adhesive over the coupling head in order to prevent access of a tool tip into this gap. The addition of this insulating adhesive is however not ideal because in the event of maintenance intervention on the vehicle, the workshop operator may forget to reinstall this insulating adhesive after having removed it to remove the bus bar.

[0011] The inventors thus sought to propose a more reliable solution for managing the prohibition of access in the intervals caused by the dispersion phenomenon explained above.

[0012] For this purpose, a connecting member (4) is proposed for electrically connecting a first electrical terminal (71) of a first electrical device to a second electrical terminal (72) of a second electrical device, the connecting member extending between a first end zone (El) comprising a first coupling head (6) and a second end zone (E2) comprising a second coupling head, the connecting member extending in a longitudinal direction (L) in the vicinity of the first end zone (El), each coupling head comprising a lower electrical contact face, edge faces perpendicular to the lower face (including an end face and two lateral faces) and an upper face opposite the lower face, the electrical contact face extending in a reference plane (PR) including the longitudinal direction (L) and a transverse direction (T), the electrical contact face being perpendicular to a contact pressure direction (V), the connecting member comprising a conductive body (1) and a main insulating coating (2) covering the conductive body except in certain portions intended to establish an electrical contact (eg above and below the clamping screw), characterized in that at least the first coupling head comprises a flexible lip (3) extending from the main insulating coating and projecting from the first coupling head in a plane parallel to the reference plane PR, from one or more edge faces (i.e. from the end face and / or one of the side faces).

[0013] Thanks to these arrangements, the flexible lip closes access to the gap left free between the coupling head and the rising protective wall(s) of the terminal.

[0014] Advantageously, the flexible lip covers a protected (voltage-free) area of ​​the first electrical device in the vicinity of the electrical terminal and thus forms a bridge which spans the gap of interest and closes access to it from above. This reduces the overhanging effect presented by the flexible lip before docking on the protected (voltage-free) area of ​​the first electrical device.

[0015] The edge faces, for example the three edge faces perpendicular to the bottom face, comprise an end face perpendicular to the longitudinal axis and two side faces parallel to the longitudinal axis.

[0016] The end face and the two side faces of the first coupling head are formed by the main insulating coating.

[0017] It should be noted that the “conductive body” is an elongated conductive element interposed between the two coupling heads, which can be formed as a metal bar, a metal strip, a multi-layer assembly, without the preceding list being limiting. The elongated conductive body can be rectilinear but it can also include portions of curves similar to turns to connect one electrical device to another by an available path.

[0018] It is noted that the term "contact pressure direction" designates, in the case of a screwed connection, the axial direction of the screw. It is noted that in the case of a screwed connection, a hole is provided in the conductive body to allow the screw to pass through, which presses the coupling head onto the terminal.

[0019] The electrical device of interest here may be a battery module, a motor, an inverter, a high voltage network distribution box, or any other equipment connected to the high voltage network without the preceding list being limiting.

[0020] It is noted that it is possible to have a flexible lip only on the first coupling head and that it is also possible to have a flexible lip on the first coupling head and a flexible lip on the second coupling head, with identical or specific geometries linked to the intended application.

[0021] According to one embodiment, the flexible lip is made in one piece with the main insulating coating.

[0022] Advantageously, the cost price of the part remains entirely reasonable. The main insulating coating and the flexible lip are formed in a single operation. It should be noted that the thickness of the lip is small in this configuration to give the lip the desired flexibility. For example, the thickness of the flexible lip may be the order of 0.3 mm to 0.5 mm.

[0023] According to one embodiment, the flexible lip is a separate part from the main insulating coating, the flexible lip being made from a more flexible material than the material constituting the main insulating coating.

[0024] As a result, it is possible to make an optimum choice of material for the flexible lip and its thickness, and to remain on a fairly rigid and inexpensive material for the main insulating coating.

[0025] According to one embodiment, a polymer material based on ethylene and / or propylene is chosen for the flexible lip. For example, a synthetic EPDM rubber (ethylene-propylene-diene monomer) can be chosen. A silicone-based material can be chosen.

[0026] For the main insulating coating, one can choose, for example, a material based on polyamide or polyethylene, depending on the temperature resistance requirements. More particularly, one can choose a fiber-filled polyamide such as PA6 GF30.

[0027] According to one embodiment, the flexible lip comprises a root portion and a cantilevered projection portion.

[0028] The root portion allows the flexible lip to be fixed to the coupling head. The cantilevered projection portion forms a skirt which extends the protection in a plane perpendicular to the pressure axis (i.e. the screwing axis) to span the gap.

[0029] According to one embodiment, the flexible lip is obtained by overmolding onto the main insulating coating. This avoids having a part or a fixing element to secure the lip with the main insulating coating of the coupling head, and furthermore this provides a robust fixing.

[0030] According to an alternative embodiment, the flexible lip is bonded to the main insulating coating. For example, structural bonding can be used.

[0031] According to one embodiment, the flexible lip is mounted in a groove or a throat provided on the main insulating coating.

[0032] In other words, the flexible lip is mounted by complementary shape relative to the main insulating coating.

[0033] According to one embodiment, the first coupling head comprises a housing for receiving a screw, the housing having an upper screwing hole. This housing is closed on all four sides.

[0034] The screw is under tension (at the voltage of the terminal and the conductive metal body), the screw is hidden and protected from possible contacts by an external element, in particular including either a finger of the user or a tool.

[0035] According to one embodiment, an oblong hole is provided at the first coupling head in the conductive body and the flexible lip projects from the first coupling head. coupling from the end face.

[0036] This solution allows adaptation to a longitudinal distance difference between the first terminal and the second terminal. The major axis of the oblong hole is arranged along the longitudinal direction L. If the distance between terminals turns out in practice to be at the top of the dispersion range, then the gap which is opposite the upright face with respect to the rising wall is substantial and the flexible lip cleverly covers this gap.

[0037] According to one embodiment, the flexible lip projects at least 5 mm from the first coupling head. The cantilever projection is sufficient to handle the most common gap sizes in the context of the dispersion phenomenon. A flexible lip projecting around 10 mm may be suitable.

[0038] The invention also relates to an assembly comprising a first electrical device (91) with a first electrical terminal (71), a second electrical device (92) with a second electrical terminal (72), a connecting member (4) as described previously, and first and second screws (5) configured to tighten the conductive body on the first and second electrical terminals.

[0039] According to one embodiment, the assembly complies with the prescribed IP protection index.

[0040] The invention will be further detailed by the description of non-limiting embodiments, and on the basis of the appended figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates three examples of configurations involving a connection member between two electrical devices, in which the implementation of the present invention is relevant, in top view; - [Fig.2] schematically illustrates a first example of a rac organ rope, with a view to elevation; - [Fig.3] shows the first example of a connecting member, in top view; - [Fig.4] shows the first example of a connecting member, with a view to below; - [Fig.5] shows the first example of a connecting member, in perspective view; - [Fig.6] schematically illustrates in sectional view two battery modules connected to each other by another example of a connection member; [Fig.7] illustrates in perspective view an end zone of another example of a connecting member; - [Fig.8] schematically illustrates, according to three different sectional views, another example of a connecting member; - [Fig.9] illustrates a detail of an example of implantation of the flexible lip on the main insulating coating; - [Fig.10] illustrates a detail of another example of implantation of the lip on the main insulating coating; - [Fig.l 1] illustrates an example of a connection member configuration on a battery module; - [Fig. 12] illustrates an example of a connection member configuration on a connection box.

[0041] In the various figures, the same references designate identical or similar elements. For reasons of clarity of the description, certain elements are not necessarily represented to scale.

[0042] We now describe a connection member 4 for connecting electrical terminals of electrical devices in an electric vehicle.

[0043] Turning to Figures 1 to 5, the connecting member 4 (called in practice "bus bar") electrically connects a first electrical terminal 71 of a first electrical device 91 with a second electrical terminal 72 of a second electrical device 92.

[0044] The electrical devices of interest here may be one of: a traction battery module, a motor, an inverter, a high voltage network distribution box, without this previous list being limiting.

[0045] The connecting member 4 extends between a first end zone E1 comprising a first coupling head 6 and a second end zone E2 comprising a second coupling head 6. Between the two end zones E1, E2, the connecting member 4 comprises an intermediate portion 40 called the current section here.

[0046] A spatial reference is defined for the first end zone E1, which comprises a longitudinal direction denoted L which is the direction extending along the largest dimension of the bus bar 4. A so-called contact pressure direction denoted V is perpendicular to the longitudinal direction L. The so-called contact pressure direction g corresponds in the case of the screwing illustrated here to the screwing axis V.

[0047] Thus, the connecting member 4 extends in a longitudinal direction L in the vicinity of the first end zone El.

[0048] To finish the definition of the spatial location of interest, a so-called transverse direction T is perpendicular to the longitudinal direction L and perpendicular to the contact pressure direction V.

[0049] In the example illustrated in Figures 2 to 5, the bus bar 4 is rectilinear and of small longitudinal dimension. But the invention applies whatever the intermediate configuration of the bus bar, whether it is rectilinear or has curves, and whatever its main length.

[0050] On the left part IA of [Fig. 1], the interval discussed in the introductory part is present on only one side of the coupling head, it is materialized by zone 8 surrounded by dotted lines on diagram IA.

[0051] On the middle part IB of [Fig. 1], the interval discussed in the introductory part is present on two sides of the coupling head, it is materialized by the zone 8 surrounded by dotted lines on the diagram IB.

[0052] On the right part IC of [Fig. 1], the interval discussed in the introductory part is present on two sides of the coupling head on the side of the first electrical device 91 and it is present on three sides of the coupling head on the side of the second electrical device 92. The area to be treated is materialized by the area 8 surrounded by dotted lines on the diagram IC.

[0053] It will be understood that the configuration of the first coupling head may be different from the configuration of the second coupling head. The need to protect the gap between the coupling head and one or more rising walls 78 of the terminal depends on the local configuration of the electrical device to be connected.

[0054] Each coupling head 6 comprises a lower electrical contact face 60. The electrical contact face has the metal of the conductive body 1 exposed. The electrical contact face 60 extends along a reference plane PR including the longitudinal direction L and a transverse direction T, the electrical contact face being perpendicular to a contact pressure direction V.

[0055] As visible in [Fig.2], the lower electrical contact face 60 of the coupling head 6 comes into contact with an upper surface 75 of the first electrical terminal 71. The electrical contact is firmly established by means of a screwing system or any other pressure system pressing the coupling head against the upper face of the electrical terminal.

[0056] Each coupling head 6 comprises so-called “edge” faces. The edge faces are perpendicular to the lower face 60. Among the edge faces, there is an end face 61 and two side faces, left 62 and right 63.

[0057] The end face 61 is perpendicular to the longitudinal axis L, it extends in a plane VT. The two lateral faces 62, 63 are parallel to the longitudinal axis L, they extend in a plane VL.

[0058] Each coupling head 6 comprises an upper face 64 opposite the lower face 60.

[0059] The conductive body 1 is a metallic conductive element interposed between the two coupling heads. The conductive body 1 is formed as a metal bar, or a metal strip. The conductive metal body 1 can be rectilinear as in the cases illustrated in the figures, but it can also include portions of curves similar to bends to connect one electrical device to another by a path available.

[0060] The conductive body 1 can also be a multi-layer assembly, in order to present a certain flexibility in bending or in torsion.

[0061] The conductive body 1 is capable of circulating electric current between the first electrical device and the second electrical device, it is subjected to the voltage of the terminal and must therefore be well protected.

[0062] At each coupling head 6, the conductive body 1 is pierced with a hole 11. As seen in [Fig.8], this hole 11 is provided to allow a fixing screw marked 5 to pass through. This fixing screw 5 is screwed into a threaded hole 96 provided in the terminal (see [Fig.6]).

[0063] To install the screw 5, it is provided that the upper face 64 is openable; the upper face can preferably be connected to the edge faces by a hinge 95. A closing solution by removable upper cover is also possible.

[0064] A screw hole 51 is provided on the upper face 64, located in the screw axis V. The diameter of the screw hole 51 is small, eg from 3 mm to 5 mm, to allow only one end of the screwdriver to pass through.

[0065] Hole 11 is round or oblong as will be seen later.

[0066] The conductive body 1 is covered by a main insulating coating 2 which covers the conductive body except in certain portions intended to establish an electrical contact.

[0067] The upper face and the edge faces are formed by the main insulating coating 2.

[0068] For the main insulating coating, one can choose, for example, a material based on polyamide or polyethylene, depending on local temperature resistance requirements. More particularly, one can choose a fiber-filled polyamide such as PA6 GF30.

[0069] Wherever the conductive body is protected, there is a sufficient thickness of insulating material, for example between 1 mm and 2 mm.

[0070] Advantageously according to the present invention, a flexible lip 3 is provided to form a protective skirt preventing access to the gap discussed above, illustrated by the reference 77 visible in Figures 2 and 6.

[0071] The flexible lip 3 extends from the main insulating coating 2 and projects from the first coupling head 6 in a lip plane P3 parallel to the reference plane PR. The flexible lip 3 is formed as a thin web which extends cantilevered in said lip plane. It has a thickness e3 which may be constant or which may decrease from the root to the free edge of the cantilevered portion.

[0072] It should be noted that lip plane P3 can be located at any height between the level of the lower face 60 of the coupling head and the level of the upper face 64 of the coupling head; it could even be located above the upper face of the coupling head.

[0073] It is expected that the extension plane of the lip P3 coincides substantially with the height of the electrical device to be covered in the vicinity of the electrical terminal.

[0074] The flexible lip 3 extends from the end faces 61 and / or one of the side faces 62, 63.

[0075] Depending on the possible scenarios, the flexible lip 3 may extend from the end face 61 only, that is to say generally longitudinally, as illustrated in [Fig. 12]. The flexible lip 3 may extend only from one of the lateral faces 62 or 63 as in the configuration illustrated in the left part 1A of [Fig.l]. The flexible lip 3 may extend on two sides from the end face 61 and from one of the lateral faces as in the configuration illustrated in the middle part 1B of [Fig.l] and in figures 2 to 5. Finally, the flexible lip 3 may extend on three sides at the same time from the end face 61 and from the two lateral faces 62, 63, as visible in [Fig.8] on the first end of the bus bar illustrated and in the right part IC of [Fig.l].

[0076] According to one option, the flexible lip 3 is made in one piece with the main insulating coating 2 as shown in Figures 2 to 5.

[0077] According to another option, the flexible lip 3 is a separate part from the main insulating coating 2, the flexible lip being made from a more flexible material than the material constituting the main insulating coating.

[0078] According to one embodiment, the flexible lip 3 comprises a root portion 30 and a cantilevered projection portion 31. The root portion 30 is fixed to the main insulating coating 2. The flexible lip is made of a polymer material based on ethylene and / or propylene. For example, a synthetic rubber EPDM (ethylene-propylene-diene monomer) can be chosen. A silicone-based material can be chosen.

[0079] The thickness e3 of the flexible lip 3 may be between 0.3 mm and 0.5 mm, in particular in the case where it is made of the same material as the main insulating coating. The thickness e3 of the flexible lip 3 may be between 0.5 mm and 1 mm when it is made of synthetic rubber or silicone.

[0080] According to one option, the flexible lip is obtained by overmolding on the main insulating coating.

[0081] According to another option, illustrated in [Fig.9], the flexible lip is mounted in a groove 80 or a groove provided on a face of the edge of the main insulating coating. Generally speaking, any clipping or shape-matching mounting solution may be suitable for fixing the flexible lip relative to the head of the coupling 6.

[0082] According to another option, illustrated in [Fig. 10], a lip 83 is provided mounted on a hinge 82 with an elastic element 84 biasing the flexible lip downwards and an angular stop. The elastic element 84 is anchored in a slot 85. A lower stop 81 is provided for the rotational movement of the pivoting lip.

[0083] According to an advantageous aspect observable in [Fig.8], an oblong hole 11 is provided at the level of the first coupling head in the conductive body 1.

[0084] This solution of the oblong hole allows an adaptation to a longitudinal distance difference between the first terminal 71 and the second terminal 72. The major axis of the oblong hole 11 is arranged along the longitudinal direction L. The other hole 12 is round at the second end, it is at the first end that the adaptation in length is made.

[0085] If the distance turns out in practice to be at the top of the possible dispersion range, then the interval 77 which is located opposite the end face 61 with respect to the rising wall 78 is substantial.

[0086] The flexible lip 3 projects from the first coupling head from the end face 61 and the flexible lip 3 cleverly covers the gap 77 of a good size. In addition, the flexible lip bears on an upper surface 39 of the electrical device opposite in the vicinity of the rising wall 78, the flexible lip thus spans the gap 77 which could allow access to a tool end.

[0087] The first coupling head 6 comprises a housing 52 for receiving a screw 5, the housing having an upper screwing hole 51. This housing is closed on all four sides.

[0088] The cantilevered projection portion 31 of the flexible lip projects at least 5 mm from the first coupling head. The cantilevered projection is sufficient to cover the most common gap sizes in the context of the dispersion phenomenon. A flexible lip projecting by a dimension around 10 mm may be suitable.

[0089] It is noted that the flexible lip 3 can be mounted by elastic clipping around the first coupling head 6 using the hooks 36 visible in [Fig.8] on section BB.

[0090] As seen in [Fig.3], the cantilever projection in the longitudinal direction has a dimension denoted el and the size of the cantilever projection in the transverse direction is denoted e2. The dimension el can be between 5 mm and 15 mm. The dimension e2 can be between 5 mm and 15 mm, el and e2 can be identical or different depending on the application cases.

[0091] In [Fig.7] two battery modules 91,92 are considered. In the present context, these are battery modules of a battery pack for an electric or hybrid vehicle.

[0092] The battery modules comprise a positive terminal 71 and a negative terminal 72. Each of the electrical terminals is located in a recess relative to the general parallelepiped envelope.

[0093] The battery modules 91,92 comprise fixing wells 97 in the four corners. A threaded rod 98 is received in the fixing well 97 with a nut 99 on the upper end, which is located directly below the connecting member 4. Above the nut 99, the connecting member is coated by the main insulating coating. Said configuration ensures the mechanical fixing and the electrical coupling of two neighboring battery modules, without risk of unwanted electrical contact.

[0094] [Fig. 11] shows a configuration with the flexible lip 3 extending from the end face 61 of the coupling head and extending on the right side from the coupling head. The screw access hole 51 is circular. The first electrical device here is a battery module 94.

[0095] In [Fig. 12], the first electrical device is here a connection box 93.

[0096] The screw access hole 51 is oblong as is the hole 11 in the conductive body. 1.

[0097] It is noted that a slide 54 is provided for closing the screw hole. The slide 54 is mounted in a guide rail 55. The figure illustrates the open position of the slide but by moving it to the left it can move into the closed position and completely obstruct access to the head of the clamping screw 5.

[0098] The present invention is presented in the case of a conventional point-to-point bus bar but it can also be used in a system with a bus bar in T or Y configuration.

Claims

Claims

1. Connection member (4) for electrically connecting a first electrical terminal (71) of a first electrical appliance to a second electrical terminal (72) of a second electrical appliance, the connection member extending between a first end zone (El) comprising a first coupling head (6) and a second end zone (E2) comprising a second coupling head, the connection member extending in a longitudinal direction (L) in the vicinity of the first end zone (El), each coupling head comprising a lower electrical contact face (60), three edge faces (61, 62, 63) perpendicular to the lower face and an upper face (64) opposite the lower face, the electrical contact face extending in a reference plane (PR) including the longitudinal direction (L) and a transverse direction (T), the electrical contact face being perpendicular to a contact pressure direction,the connecting member comprising a conductive body (1) and a main insulating coating (2) covering the conductive body except in certain portions intended to establish an electrical contact, characterized in that at least the first coupling head (6) comprises a flexible lip (3) extending from the main insulating coating and projecting from the first coupling head in a plane parallel to the reference plane, from one or more edge faces.,

2. Connection member according to claim 1, characterized in that the flexible lip is made in one piece with the main insulating coating.

3. Connection member according to claim 1, characterized in that the flexible lip is a separate part from the main insulating coating, the flexible lip being manufactured from a more flexible material than the material constituting the main insulating coating.

4. A connecting member according to claim 3, wherein the flexible lip comprises a root portion (30) and a cantilevered projection portion (31).

5. Connection member according to any one of claims 3 to 4, in which the flexible lip (3) is obtained by overmolding on the main insulating coating.

6. A connecting member according to any one of claims 3 to 6. 4, wherein the flexible lip (3) is mounted in a groove (80) or a throat provided on the main insulating coating (2).

7. A connecting member according to any one of claims 1 to 6, wherein the first coupling head (6) comprises a housing for receiving a screw (5), the housing having an upper screwing orifice (51).

8. A connecting member according to any one of claims 1 to 7, wherein an oblong hole is provided at the first coupling head in the conductive body and the flexible lip (3) projects from the first coupling head from the end face (61).

9. A connecting member according to any one of claims 1 to 8, wherein the flexible lip (3) projects at least 5 mm from the first coupling head.

10. An assembly comprising a first electrical device (91) with a first electrical terminal (71), a second electrical device (92) with a second electrical terminal (72), a connecting member (4) according to any one of claims 1 to 9, and first and second screws (5) configured to tighten the conductive body onto the first and second electrical terminals.

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