Bolted busbar with finger protection

Abstract

A bus bar assembly (16) includes a non-conductive terminal cover (22) configured to be fixed to a conductive terminal (14) by an attachment feature (24). The terminal cover (22) has a slot (54) configured to expose a terminal portion (19) of the terminal (14) in an assembled state. The bus bar (40) has an end (52) configured to be received in the slot (54) in an assembled state, wherein the end (52) is in electrical contact with the terminal portion (19) of the terminal (14). A non-conductive shroud (26) encloses the bus bar (40). The end (52) extends through the shroud (26).

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 865,470, filed on Jun. 24, 2019, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] The present disclosure relates to, for example, busbars for connecting battery cells. Background art

[0004] A battery module has a plurality of battery cells with terminals, and these battery cells are electrically connected to each other to provide a more powerful battery than a single battery cell. A common type of electrical connection is a cable having terminal loops at opposite ends. Each terminal loop is bolted to one of the terminals of one of the battery cells. Another common type of electrical connection is a busbar, which is bolted to the battery cells in a manner similar to the cable.

[0005] For example, the type of battery module used in automotive applications can provide a large amount of electrical energy. It is desirable to design a system for electrically connecting and disconnecting the battery in a manner that is safe for battery module components and / or service technicians. Summary of the invention

[0006] In one exemplary embodiment, a busbar assembly mainly includes a non - conductive terminal cover, which is configured to be fixed to a conductive terminal via an attachment feature. The terminal cover has a slot configured to expose a terminal portion of the terminal in an assembled state. The busbar has an end configured to be received in the slot in the assembled state, wherein the end is in electrical contact with the terminal portion of the terminal. A non - conductive shield encloses the busbar. The end extends through the shield.

[0007] In another embodiment of any of the above, the attachment feature includes at least one snap - fitting configured to be fixed to the periphery of a terminal pad provided by the terminal.

[0008] In another embodiment of any of the above, the assembly includes a bolt that extends through a first hole in the end of the busbar and a second hole in the shield. The terminal cover includes a third hole configured to align with a threaded member of the terminal. The third hole is finger - guarded, and the threaded member is configured to receive the bolt in the assembled state.

[0009] In another embodiment of any of the above, the shield includes a first shield portion and a second shield portion that are fixed to each other around the busbar. The second hole is provided in the second shield portion. The first shield portion includes an access hole that is finger - guarded and aligned with the bolt and configured to receive a tool that cooperates with the head of the bolt.

[0010] In another embodiment of any of the above, the terminal cover includes a pair of slots. The slots are finger-proof, and the end of the bus bar has a U-shape provided by legs. The legs are configured to be received in the slots and include bolts that extend through the end and are configured to fix the bus bar to the terminal.

[0011] In another embodiment of any of the above, the bolts are arranged between the legs.

[0012] In another embodiment of any of the above, the slots are finger-proof and have a first arcuate hook shape. The terminal cover includes a post arranged internally relative to the slots. The end of the bus bar has a second arcuate hook shape that is configured to be received in the slots and around the post in the assembled state, and includes bolts that extend through the end of the bus bar and are configured to fix the bus bar to the terminal.

[0013] In another embodiment of any of the above, the bolts are configured to be received in the posts in the assembled state.

[0014] In another exemplary embodiment, a battery module mainly includes battery cells that have terminals provided by terminal pads with threaded members. A non-conductive terminal cover is fixed to the terminals via attachment features. The terminal cover has slots that expose the terminal portions of the terminal pads in the assembled state. The bus bar has ends that are received in the slots in the assembled state, where the ends are in electrical contact with the terminal pads. A non-conductive shroud encloses the bus bar. The ends extend through the shroud. The bolt has a first bolt portion and a second bolt portion. The first bolt portion is contained within the shroud. The second bolt portion is fixed to the threaded member to clamp the end of the bus bar into engagement with the terminal pad.

[0015] In another embodiment of any of the above, the battery cell is a first battery cell and includes a second battery cell. The end is a first end, and the bus bar has a second end. The bolt is a first bolt and includes a second bolt that fixes the second end to the second battery cell.

[0016] In another embodiment of any of the above, except that the slots are finger-proof and expose the terminal portions, the terminal cover encloses the terminal pads. A hole in the terminal cover exposes the threaded member. The hole is finger-proof.

[0017] In another embodiment of any of the above, the attachment features include at least one snap fitting that is fixed to the periphery of the terminal pad.

[0018] In another embodiment of any of the above, the bolts extend through a first hole in the end of the bus bar and a second hole in the shroud. The terminal cover includes a third hole corresponding to the holes.

[0019] In another embodiment of any of the above, the shroud includes a first shroud portion and a second shroud portion that surround the bus bar and are fixed to each other. A second hole is provided in the second shroud portion. The first shroud portion includes an access hole that is finger-safe and aligned with the first bolt portion and is configured to receive a tool that mates with the head of the first bolt portion.

[0020] In another embodiment of any of the above, the terminal cover includes a pair of slots. The slots are finger-safe, and the end of the bus bar has a U-shape provided by legs. The legs are configured to be received in the slots, and a bolt extends through the end and is configured to fix the bus bar to the terminal. The bolt is disposed between the legs.

[0021] In another embodiment of any of the above, the slots are finger-safe and have a first arcuate hook shape. The terminal cover includes a post disposed internally relative to the slots. The end of the bus bar has a second arcuate hook shape that is configured to be received in the slots and around the post in the assembled state. The bolt is received in the post in the assembled state.

[0022] In another exemplary embodiment, a method of electrically connecting battery cells mainly includes: fixing a non-conductive terminal cover above a conductive battery cell terminal. The terminal cover includes a hole and a slot that exposes the terminal portion of the terminal. The bus bar assembly is provided with a bus bar and a non-conductive shroud that encloses the bus bar, and the bus bar has an end, and the end extends through the shroud. The bolt is captured by the shroud in the end. The end is located in the slot. The bolt is fixed to the terminal through the hole to clamp the end to engage with the terminal.

[0023] In another embodiment of any of the above, the fixing step includes snap-fitting the terminal cover onto the periphery of the terminal.

[0024] In another embodiment of any of the above, the terminal cover includes a pair of slots. The slots are finger-safe, and the end of the bus bar has a U-shape provided by legs. The positioning step b) includes positioning the legs in the slots. The bolt extends through the end between the legs.

[0025] In another embodiment of any of the above, the slots are finger-safe and have a first arcuate hook shape. The terminal cover includes a post disposed internally relative to the slots. The end of the bus bar has a second arcuate hook shape. The positioning step includes surrounding the post with the end, and the bolt is received in the post.

[0026] In another embodiment of any of the above, the fixing step c) includes inserting a tool through the access hole in the shroud to engage with the head of the bolt and turning the bolt with the tool. The access hole is finger-safe. Description of the Drawings

[0027] The present disclosure can be further understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0028] Figure 1 is a schematic view of a battery module having a plurality of battery cells electrically connected to each other by busbars.

[0029] Figure 2A and 2B are a first perspective view and a second perspective view of a first busbar assembly.

[0030] Figure 2C is along Figure 2B A cross-sectional view of the first busbar assembly taken along line 2C-2C in.

[0031] Figure 3 is an exploded partial view of the first busbar assembly.

[0032] Figure 4A is a partial view of the first busbar assembly in an unassembled state relative to the terminal.

[0033] Figure 4B is along Figure 2B A cross-sectional view of the first busbar assembly taken along line 4B-4B in.

[0034] Figure 5A is along Figure 2B A cross-sectional view of the first busbar assembly taken along line 5A-5A in, wherein the first busbar assembly is connected to the terminal.

[0035] Figure 5B is along Figure 2B A cross-sectional view of the first busbar assembly taken along line 5B-5B in, wherein the first busbar assembly is connected to the terminal.

[0036] Figure 6A and 6B are a first perspective view and a second perspective view of a second busbar assembly.

[0037] Figure 6C is along Figure 6B A cross-sectional view of the second busbar assembly taken along line 6C-6C in.

[0038] Figure 7 is an exploded partial view of the first busbar assembly.

[0039] Figure 8A is a partial view of the second busbar assembly in an unassembled state relative to the terminal.

[0040] Figure 8B is along Figure 6B A cross-sectional view of the second busbar assembly taken along line 8B-8B in.

[0041] Figure 9A is a cross-sectional view of a second bus bar assembly taken along line 9A-9A in Figure 6B , wherein the second bus bar assembly is connected to a terminal.

[0042] Figure 9B is a cross-sectional view of a second bus bar assembly taken along line 9B-9B in Figure 6B , wherein the second bus bar assembly is connected to a terminal.

[0043] The foregoing paragraphs, claims, or the following description and examples of embodiments, examples, and alternatives of the drawings, including any one of their respective aspects or corresponding individual features, may be carried out independently or in any combination. Features described in connection with one embodiment apply to all embodiments unless the features are incompatible. In the various drawings, like reference numerals and designations indicate like elements. DETAILED DESCRIPTION

[0044] Figure 1 A battery module 10 or battery pack assembly is schematically shown in

[0045] Reference Figure 2A and 3 , the terminals 14 are provided by terminal pads 18 having threaded members 20. In this example, the terminal pads 18 are L-shaped copper structural members having a quadrangular outer surface 17 ( Figure 3 ), to which the bus bar assembly 16 is fixed. Other terminal pad shapes may be used. The vertical portion (as shown) of the terminal pad 18 is disposed within a protective non-conductive housing of the battery cell 12 and is not shown for simplicity.

[0046] When the outer surface 17 of the terminal 14 is exposed, there is a potential electric shock hazard. To mitigate the electric shock hazard when connecting and disconnecting the bus bar assembly 16 to and from the battery cell 12, a non-conductive terminal cover 22 is fixed to the terminal 14 via an attachment feature 24 (such as a snap fitting). In this example, the snap fitting engages the periphery 21 of the terminal pad 18 to hold the terminal cover 22 above the terminal 14. As best shown in Figure 2A , the periphery 21 is disposed within and enclosed by the terminal cover 22.

[0047] The terminal cover 22 has a finger guard (anti-electric shock) groove 54 that exposes the terminal portion 19 of the terminal pad 18 in the assembled state, i.e., when the terminal cover 22 is fixed to the terminal 14. In the present disclosure, "finger guard" refers to a construction that meets the standards in IEC 60529 titled "Degree of protection provided by enclosures" and the specification IP2XB related to finger entry protection. A "test finger" is a solid object with a diameter of 12.5 mm or longer and a capped length of 80 mm that is prevented from entering the enclosure. Additionally, if a standard test finger with a length of 80 mm and a diameter of 12 mm enters the enclosure, there will be sufficient clearance from the live part (i.e., the terminal). In this way, the disclosed finger guard terminal cover 22 prevents a technician from inadvertently contacting the terminal 14 when the terminal cover 22 is in place, for example, during the assembly and / or removal of the bus bar assembly 16 relative to the battery cell 12. The terminal cover 22 can be a separable piece that is permanently attached to the terminal 14.

[0048] An example bus bar assembly 16 is shown in Figures 2A to 5B . The bus bar assembly 16 includes a bus bar 40 that is substantially enclosed within a cavity 38 by a non-conductive shroud 26. The shroud 26 includes a first shroud portion and second shroud portions 28, 30 that are fixed around the bus bar 40. In the example shown, the attachment 32 between the first shroud portion and the second shroud portions 28, 30 is provided by snap fittings 36 that are removably received in corresponding windows 34. Other attachments can be used if desired.

[0049] The bus bar 40 includes ends 52 that extend through notches 50 provided at the ends of the second shroud portion 30 to expose a small portion of the ends 52. One such end 52 is provided at each of the opposite ends of the bus bar assembly 16. The ends 52 are sized to be received in the grooves 54 in the assembled state, where the ends 52 are in electrical contact with the terminal pads 18. The complementary shapes of the ends 52 and the grooves 54 facilitate the easy positioning of the bus bar assembly 16 relative to the battery cell 12 during assembly.

[0050] The bolt 56 extends through a first hole 42 in the end 52 of the bus bar 40 and a second hole 44 in the second shroud portion 30. The terminal cover 22 includes a third hole 46 configured to align with the threaded member 20 when the terminal cover 22 is installed above the terminal pad 18. The bolt 56 has a first bolt portion and second bolt portions 58, 59. The access hole 48 aligns with the head of the bolt 56 disposed on the first bolt portion 58. A tool such as an Allen wrench or a Torx wrench can be inserted through the through hole 48 to engage the bolt head. The second bolt portion 59 has threads that cooperate with the threaded member 20 to tightly clamp the end 52 to the terminal 14 when the bolt 56 is tightened to the design requirements for a good electrical connection.

[0051] When the bus bar assembly 16 is in the assembled state, the shroud 26 and the terminal cover 22 cooperate to enclose the end 52 such that no part of the bus bar 40 is exposed. However, with the bus bar assembly 16 removed, the slot 54 and the third hole 46 expose only a very small terminal portion 19, which is finger-protected and not easily touched by a technician.

[0052] Various bus bar assembly and terminal cover configurations can be used to provide finger protection. Figures 2A to 5B The example shown in uses a pair of rectangular spaced slots 54. The end 52 of the bus bar 40 has a U-shape provided by the legs 53. And when in the assembled state, the legs 53 are received in the slots 54 and extend through the terminal cover 22 for mechanical and electrical connection. The bolt 56 extends through the end 52 and is disposed between the legs 53.

[0053] In Figures 6A to 9B Another bus bar assembly 116 and terminal cover 122 configuration is shown. The same numbers are used to denote the same elements. The bus bar assembly 116 includes a bus bar 140 that is substantially enclosed within a cavity 138 by a non-conductive shroud. In this example, the bus bar 140 is oriented 90° relative to the bus bar 40. The shroud 126 includes a first shroud portion and a second shroud portion 128, 130 that are fixed around the bus bar 140. The first shroud portion 128 is nested within the second shroud portion 130. In the example shown, the attachment 132 between the first shroud portion and the second shroud portion 128, 130 is provided by snap fittings 136 that are removably received in corresponding windows 134.

[0054] The bus bar 140 includes an end portion 152, similar to the shroud 26, which extends through the first and second shroud portions 128, 130 and is exposed between the first and second shroud portions 128, 130 to expose a small portion of the end portion 152. One such end portion 152 is provided on each of the opposite ends of the bus bar assembly 116. The end portion 152 is sized to be received in the slot 154 and, in the assembled state, extends through the terminal cover 122, in which state the end portion 152 is in electrical and mechanical contact with the terminal pad 18.

[0055] The bolt 156 extends through a first hole in the end portion 152 provided in a scroll shape. The bolt 156 extends through a second hole 144 in the second shroud portion 30. The terminal cover 122 includes a third hole 146 configured to align with the threaded member 20 when the terminal cover 122 is installed above the terminal pad 18. The bolt 156 has a first bolt portion and a second bolt portion 158, 159. The access hole 148 is finger-protected and is aligned with the head of the bolt 156 provided on the first bolt portion 158. The second bolt portion 159 has threads that cooperate with the threaded member 20 to tightly clamp the end portion 152 to the terminal 14 when the bolt 156 is tightened to the design requirements for a good electrical connection.

[0056] With this configuration, the slot 154 has a first arcuate hook shape, and the terminal cover 122 includes a cylindrical post 160 disposed internally relative to the slot 154. The end portion 152 of the bus bar 140 has a second arcuate hook shape that is correspondingly shaped and is received in the slot 154 and surrounds the post 160 in the assembled state. The term "arcuate" includes cylindrical and partially cylindrical shapes. The bolt 156 is received in the post 160 in the assembled state.

[0057] In operation, during the assembly of the battery module 10, the non-conductive terminal cover is fixed to each conductive terminal, for example, by snap-fitting the terminal cover around the periphery of the terminal. The terminal cover includes finger-protected holes and finger-protected slots that expose a small terminal portion of the terminal. The non-conductive shroud encloses the bus bar, and the end portion extends through the shroud. One end of the bolt is captured by the shroud, the end portion is located in the slot, and the bolt is disposed in the hole. A tool is inserted into the access hole in the shroud to engage the bolt, and then the bolt is tightened to clamp the end portion to engage the terminal.

[0058] In this way, the terminal cover can be permanently fixed to the terminal, making the terminal finger-safe. Thus, even in the case where the bus bar assembly is disconnected, the battery module is finger-protected, which allows for the safe assembly and handling of the battery module during the assembly and repair of the battery module.

[0059] It should also be understood that although a specific component arrangement is disclosed in the illustrated embodiments, other arrangements will benefit from the present disclosure. Although a specific sequence of steps is shown, described, and claimed, it should be understood that the steps may be performed in any order, separately or in combination, unless otherwise indicated, and still benefit from the present invention.

[0060] Although the different examples have specific components as shown in the figures, embodiments of the present invention are not limited to those specific combinations. Some components or features of one of the examples may be used in combination with features or components of another of the examples.

[0061] Although example embodiments have been disclosed, those of ordinary skill in the art will recognize that certain modifications will fall within the scope of the claims. Accordingly, the following claims should be studied to determine their true scope and content.

Claims

1. A bus bar assembly (16) comprising: A non-conductive terminal cover (22) configured to be fixed to a conductive terminal (14) via an attachment feature (24), the terminal cover (22) having a slot (54) configured to expose a terminal portion (19) of the terminal (14) in an assembled state; A bus bar (40) having an end (52) configured to be received in the slot (54) in an assembled state, in which the end (52) is in electrical contact with the terminal portion (19) of the terminal (14); A non-conductive shroud (26) enclosing the bus bar (40), and the end (52) extending through the shroud (26), and A bolt (56) extending through a first hole (42) in the end (52) of the bus bar (40) and a second hole (44) in the shroud (26), the terminal cover (22) including a third hole (46) configured to be aligned with a threaded member (20) of the terminal (14), the third hole (46) being finger-safe, and the threaded member (20) configured to receive the bolt (56) in an assembled state, Wherein, the shroud (26) includes a first shroud portion and a second shroud portion (28, 30) fixed to each other around the bus bar (40), the second hole (44) is provided in the second shroud portion (30), and the first shroud portion (28) includes an access hole (48) that is finger-safe and aligned with the bolt (56) and configured to receive a tool that mates with the head of the bolt (56).

2. The bus bar assembly (16) according to claim 1, wherein The attachment feature (24) includes at least one snap fitting configured to be fixed to a periphery (21) of a terminal pad (18) provided by the terminal (14).

3. The bus bar assembly (16) according to claim 1, characterized in that, The terminal cover (22) includes a pair of the slots (54), wherein the slots (54) are finger-safe, and the end (52) of the bus bar (40) has a U-shape provided by legs (53) configured to be received in the slots (54), and includes a bolt (56) extending through the end (52) and configured to fix the bus bar (40) to the terminal (14).

4. The bus bar assembly (16) according to claim 3, wherein, The bolt (56) is disposed between the legs (53).

5. The bus bar assembly (16) according to claim 1, characterized in that, The slot (54) is finger-protective and has a first arcuate hook shape, and the terminal cover (22) includes a post (60) disposed internally relative to the slot (54), and the end (52) of the bus bar (40) has a second arcuate hook shape configured to be received in the slot (54) and around the post (60) in the assembled state, and includes a bolt (56) that extends through the end (52) of the bus bar (40) and is configured to fix the bus bar (40) to the terminal (14).

6. The bus bar assembly (16) according to claim 5, characterized in that, The bolt (56) is configured to be received in the post (60) in the assembled state.

7. A battery module (10) comprising: a battery cell (12) having terminals (14) provided by terminal pads (18) with threaded members (20); a non-conductive terminal cover (22) fixed to the terminals (14) via attachment features (24), the terminal cover (22) having a slot (54) that exposes a terminal portion (19) of the terminal pad (18) in the assembled state; a bus bar (40) having an end (52) received in the slot (54) in the assembled state, in which the end (52) is in electrical contact with the terminal pad (18); a non-conductive shroud (26) enclosing the bus bar (40), and the end (52) extending through the shroud (26); and a bolt (56) having a first bolt portion (58) and a second bolt portion (59), the first bolt portion (58) being contained within the shroud (26), and the second bolt portion (59) being fixed to the threaded member (20) to clamp the end (52) of the bus bar (40) in engagement with the terminal pad (18), wherein the bolt (56) extends through a first hole (42) in the end (52) of the bus bar (40) and a second hole (44) in the shroud (26), and the terminal cover (22) includes a third hole (46), wherein the shroud (26) includes a first shroud portion (28) and a second shroud portion (30) fixed to each other around the bus bar (40), the second hole (44) being provided in the second shroud portion (30), and the first shroud portion (28) includes an access hole (48) that is finger-protective and aligned with the first bolt portion (58) and is configured to receive a tool that mates with the head of the first bolt portion (58).

8. The battery module (10) according to claim 7, characterized in that, The battery cell (12) is a first battery cell (12) and includes a second battery cell (12), wherein the end (52) is a first end (52), and the bus bar (40) has a second end (52), wherein the bolt (56) is a first bolt (56) and includes a second bolt (56) that secures the second end (52) to the second battery cell (12).

9. The battery module (10) according to claim 7, characterized in that, Wherein, The terminal cover (22) encloses the terminal pad (18), except that the slot (54) is finger-safe and exposes the terminal portion (19), and a hole in the terminal cover (22) corresponding to the third hole exposes the threaded member, and the hole is finger-safe.

10. The battery module (10) according to claim 9, characterized in that, The attachment feature (24) includes at least one snap fitting that is fixed to the periphery (21) of the terminal pad (18).

11. The battery module (10) according to claim 8, characterized in that, The terminal cover (22) includes a pair of the slots (54), wherein the slots (54) are finger-safe, and the end (52) of the bus bar (40) has a U-shape provided by legs (53) configured to be received in the slots (54), the bolt (56) extends through the end (52), and is configured to fix the bus bar (40) to the terminal (14), and the bolt (56) is disposed between the legs (53).

12. The battery module (10) according to claim 8, characterized in that, The slot (54) is finger-safe and has a first arcuate hook shape, and the terminal cover (22) includes a post (60) disposed internally relative to the slot (54), and the end (52) of the bus bar (40) has a second arcuate hook shape configured to be received in the slot (54) and around the post (60) in the assembled state, and the bolt (56) is received in the post (60) in the assembled state.

13. A method of electrically connecting battery cells (12) of a battery module (10), the method comprising the steps of: a) providing a bus bar assembly (16) according to any one of claims 1 to 6; b) fixing a non-conductive terminal cover (22) to a conductive battery cell (12) terminal (14), wherein the terminal cover (22) includes a hole and a slot (54) that exposes the terminal portion (19) of the terminal (14); c) positioning the end (52) in the slot (54); and d) passing the bolt (56) through the hole and fixing it to the terminal (14) to clamp the end (52) into engagement with the terminal (14).

14. The method according to claim 13, characterized in that, The fixing step includes snap-fitting the terminal cover (22) onto the periphery (21) of the terminal (14).

15. The method according to claim 13, characterized in that, The terminal cover (22) includes a pair of said slots (54), wherein the slots (54) are finger-protective, and the end (52) of the bus bar (40) has a U-shape provided by the legs (53), and the positioning step c) includes positioning the legs (53) in the slots (54), and the bolt (56) extends between the legs (53) through the end (52).

16. The method according to claim 13, wherein The slots (54) are finger-protective and have a first arcuate hook shape, and the terminal cover (22) includes a post (60) arranged internally relative to the slots (54), and the end (52) of the bus bar (40) has a second arcuate hook shape, and the positioning step includes surrounding the post (60) with the end (52), and the bolt (56) is received in the post (60).

17. The method according to claim 13, wherein The fixing step d) includes inserting a tool through the access hole (48) in the shield (26) to engage with the head of the bolt (56), and turning the bolt (56) with the tool, wherein the access hole (48) is finger-protective.

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