Connection device for linking electrical terminals of electrical devices in an electric vehicle

Abstract

Connecting member (4) or busbar for electrically connecting an electrical terminal of a first electrical device to an electrical terminal of a second electrical device, the connecting member extending between end zones (E1, E2) with coupling heads, each coupling head (6) comprising an electrically contacting lower face (60), edge faces perpendicular to the lower face, the electrically contacting face extending along a reference plane (PR), 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 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. Illustration: Fig. 3

Description

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

[0001] The present invention relates to a connection element for connecting electrical terminals of electrical devices in an electric vehicle, particularly in a context of use of high voltages in the vehicle's electrical system.

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

[0003] In an electric vehicle, the battery pack has a high voltage at its terminals, in practice exceeding 100 volts, most often between 200 volts and 800 volts. Voltages exceeding 800 volts are also possible.

[0004] In the automotive industry, we speak of "high voltage" and "high voltage network" when referring to all equipment that is connected to the traction battery voltage.

[0005] A voltage of this type thus extends beyond the extra low voltage (ELV, i.e. < 50 volts) range and it is necessary to provide precautions, there are indeed regulatory protection requirements, in particular with regard to possible contacts induced by an action of an operator (e.g. a repairman or a rescue worker) either with bare hands or with the aid of a tool.

[0006] We are particularly interested in an electrical connection device, which is commonly referred to as a busbar. Such a busbar is used to electrically connect an electrical terminal of one electrical device to an electrical terminal of another electrical device. Unlike the flexible multi-strand conductors used in conventional automotive wiring, such a busbar has considerable rigidity. Each end of such a busbar includes a coupling head, notably for a screw connection, although screw connection is not 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 due to the intrinsic variations 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 with respect to the other electrical device is not identical and is subject to the aforementioned dispersion.

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

[0009] Each electrical terminal considered comprises a generally flat electrical contact surface, bordered by one or more protective risers made of non-conductive material, but a gap or interval may remain between the coupling head and the protective riser(s), particularly depending on the dispersion phenomenon described above. The size of this interval may be greater than the size of a test gauge according to a prescribed IP protection level.

[0010] When the dispersion and assembly result in an excessively large gap, it is known in the prior art to add an insulating adhesive over the coupling head to prevent access by a tool tip within this gap. However, adding this insulating adhesive is not ideal because, during vehicle maintenance, the workshop operator may forget to reinstall this insulating adhesive after removing it to remove the bus bar.

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

[0012] To this end, a connecting element (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 along 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 a upper face opposite the lower face, the electrical contact face extending 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), the connecting member comprising a conductive body (1) and a main insulating casing (2) covering the conductive body except in certain portions intended to establish electrical contact (e.g., above and below the tightening screw), characterized in that at least the first coupling head comprises a flexible lip (3) extending from the main insulating casing 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 the 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 (non-voltage) area of ​​the first electrical device in the vicinity of the electrical terminal, thus forming a bridge that spans the interval of interest and closes off access to it from above. This reduces the cantilever effect presented by the flexible lip before docking on the protected (non-voltage) 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 lateral faces parallel to the longitudinal axis.

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

[0017] It should be noted that the "conducting body" is an elongated conductive element interposed between the two coupling heads, which may be formed as a metal bar, a metal strip, a multilayer assembly, without the preceding list being exhaustive. The elongated conductive body may be straight but may also include curved portions similar to bends to connect one electrical device to another via an available path.

[0018] It should be noted that the term "direction of contact pressure" refers, in the case of a screw connection, to the axial direction of the screw. It should also be noted that in the case of a screw connection, a hole is provided in the conductive body to allow the screw to pass through and press 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 exhaustive.

[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 related to the intended application.

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

[0022] Advantageously, the cost of the part remains quite reasonable. The main insulating coating and the flexible lip are formed in a single operation. Note that the lip thickness is small in this configuration to give the lip the desired flexibility. For example, the thickness of the flexible lip can 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 cladding, the flexible lip being made from a material that is more flexible than the material constituting the main insulating cladding.

[0024] Wherefore, an optimum choice of material can be made for the flexible lip and its thickness, and a fairly rigid and inexpensive material can be used for the main insulating coating.

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

[0026] For the main insulating coating, a polyamide or polyethylene-based material can be chosen, for example, depending on the temperature resistance requirements. More specifically, a fiber-reinforced polyamide such as PA6 GF30 can be chosen.

[0027] According to one embodiment, the flexible lip includes 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 that extends the protection in a plane perpendicular to the pressure axis (i.e., the screw axis) to span the gap.

[0029] According to one embodiment, the flexible lip is obtained by overmolding onto the main insulating cladding. This eliminates the need for a part or fastener to secure the lip to the main insulating cladding of the coupling head, and also provides a robust attachment.

[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 channel formed on the main insulating coating.

[0032] Put another way, the flexible lip is mounted by complementarity of shape with respect to the main insulating coating.

[0033] According to one embodiment, the first coupling head includes a housing for receiving a screw, the housing having a top 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 contact by an external element, including either a finger of the user or a tool.

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

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

[0037] According to one embodiment, the flexible lip protrudes at least 5 mm from the first coupling head. The cantilevered projection is sufficient to handle the most common gap sizes in the context of the dispersion phenomenon. A flexible lip protruding 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 above, and first and second screws (5) configured to clamp the conductive body onto the first and second electrical terminals.

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

[0040] The invention will be further detailed by describing non-limiting embodiments, and based on the accompanying figures illustrating variants of the invention, in which: - [Fig.l] schematically illustrates three examples of configurations involving a connecting element 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 race organ rope, for the purpose of elevation; - [Fig.3] shows the first example of a connecting element, in top view; - [Fig. 4] shows the first example of a connecting element, for the purpose of below; - [Fig.5] shows the first example of a connecting organ, in perspective view; - [Fig.6] schematically illustrates in cross-section two battery modules connected to each other by another example of a connecting device; [Fig.7] illustrates in perspective view an end zone of another example of a connecting element; - [Fig.8] schematically illustrates, according to three different cross-sectional views, another example of a connecting element; - [Fig.9] illustrates a detail of an example of soft lip implantation on the main insulating coating; - [Fig.10] illustrates a detail of another example of lip placement on the main insulating coating; - [Fig.l 1] illustrates an example of a connection device configuration on a battery module; - [Fig. 12] illustrates an example of a connection device configuration on a junction box.

[0041] In the various figures, the same reference numerals designate identical or similar elements. For the sake of clarity, some elements are not necessarily shown to scale.

[0042] We now write a connection element 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 the following: a traction battery module, a motor, an inverter, a high-voltage network distribution box, without the preceding list being exhaustive.

[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 referred to here as the current section.

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

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

[0048] To complete 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 busbar 4 is straight and of small longitudinal dimension. But the invention applies regardless of the intermediate configuration of the busbar, whether it is straight or has curves, and regardless of 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 the area 8 surrounded by dotted lines on the 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 area 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 IC diagram.

[0053] It will be understood that the configuration of the first coupling head may differ 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 presents the bare metal of the conductive body 1. 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 seen in [Fig.2], the lower electrical contact face 60 of the coupling head 6 makes contact with an upper surface 75 of the first electrical terminal 71. The electrical contact is firmly established by means of a screw system or any other pressure-setting system pressing the coupling head against the upper face of the electrical terminal.

[0056] Each coupling head 6 includes 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 lateral 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 metallic conductive body 1 may be straight, as in the cases illustrated in the figures, but it may also include curved portions similar to bends to connect one electrical device to another by a path available.

[0060] The conductive body 1 can also be a multilayer assembly, in order to exhibit a certain flexibility in bending or torsion.

[0061] The conductive body 1 is capable of carrying 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 drilled with a hole 11. As observed in [Fig.8], this hole 11 is provided to allow passage of a fixing screw marked 5. This fixing screw 5 is screwed into a threaded hole 96 provided in the terminal (cf. [Fig.6]).

[0063] To install the screw 5, the upper face 64 is intended to be openable; the upper face can preferably be connected to the edge faces by a hinge 95. A closure 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, e.g. 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 electrical contact.

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

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

[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 interval discussed above, illustrated by reference 77 visible in figures 2 and 6.

[0071] The flexible lip 3 extends from the main insulating casing 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 sheet that cantilevers over said lip plane. It has a thickness e3 that may be constant or may decrease from the root to the free edge of the cantilevered portion.

[0072] It should be noted that the 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 anticipated that the extension plane of the lip P3 will substantially coincide 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 from one of the lateral faces 62,63.

[0075] Depending on the possible configurations, the flexible lip 3 can extend from the end face 61 only, that is, generally longitudinally, as illustrated in [Fig. 12]. The flexible lip 3 can extend only from one of the lateral faces 62 or 63, as in the configuration illustrated in the left-hand part IA of [Fig. 1]. The flexible lip 3 can 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 IB of [Fig. 1] and in Figures 2 to 5. Finally, the flexible lip 3 can extend on three sides simultaneously from the end face 61 and from the two lateral faces 62 and 63, as can be seen in [Fig. 8] on the first end of the illustrated busbar and in the right-hand part IC of [Fig. 1].

[0076] According to one option, the flexible lip 3 is made of material 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 of the main insulating cladding 2, the flexible lip being made from a more flexible material than the constituent material of the main insulating cladding.

[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 attached to the main insulating casing 2. The flexible lip is made of a polymer material based on ethylene and / or propylene. For example, EPDM (ethylene-propylene-diene monomer) synthetic rubber may be chosen. A silicone-based material may also be chosen.

[0079] The thickness e3 of the flexible lip 3 can be between 0.3 mm and 0.5 mm, particularly when it is molded from the same material as the main insulating coating. The thickness e3 of the flexible lip 3 can 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 onto 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 formed on an edge face of the main insulating coating. Generally, any clip-on or form-complementary mounting solution can be used to fix the flexible lip to the coupling head 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 that pulls 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 conducting body 1.

[0084] This oblong hole solution allows 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 length adaptation is made.

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

[0086] The flexible lip 3 protrudes from the first coupling head from the end face 61 and cleverly covers the appropriately sized gap 77. Furthermore, the flexible lip bears against an upper surface 39 of the opposite electrical device near the rising wall 78, thus spanning the gap 77 which could otherwise allow access to a tool end.

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

[0088] The cantilevered projection portion 31 of the flexible lip protrudes 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 protruding by a dimension of around 10 mm could be suitable.

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

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

[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-shaped envelope.

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

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

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

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

[0097] It should be noted that a sliding 54 is provided for closing the screw hole. The sliding 54 is mounted in a guide rail 55. The figure illustrates the open position of the sliding, but by moving it to the left it can move to 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 classic point-to-point bus bar, but it can also be used in a system with a bus bar in a T or Y configuration.

Claims

Demands

1. Connecting member (4) 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 (E1) comprising a first coupling head (6) and a second end zone (E2) comprising a second coupling head, the connecting member extending along a longitudinal direction (L) in the vicinity of the first end zone (E1), each coupling head comprising a lower electrical contact face (60), three edge faces (61, 62, 63) perpendicular to the lower face and a top face (64) opposite the lower face, the electrical contact face extending 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,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 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. Connecting member according to claim 1, characterized in that the flexible lip is made of material with the main insulating coating.

3. Connecting member according to claim 1, characterized in that the flexible lip is a separate part from the main insulating cladding, the flexible lip being made from a material more flexible than the constitutive material of the main insulating cladding.

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

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

6. Connecting element according to any one of claims 3 to 4, in which the flexible lip (3) is mounted in a groove (80) or a groove formed on the main insulating coating (2).

7. Connecting member according to any one of claims 1 to 6, wherein the first coupling head (6) includes a housing for receiving a screw (5), the housing having a top screwing orifice (51).

8. Connecting member according to any one of claims 1 to 7, wherein at the first coupling head there is an oblong hole in the conducting body and the flexible lip (3) protrudes from the first coupling head from the end face (61).

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

10. 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 clamp the conductive body onto the first and second electrical terminals.

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