Battery pack

Abstract

The present application provides a battery pack including: a battery stack; an apparatus electrically connected to the battery stack via bus bars; and a housing accommodating the battery stack and the apparatus, wherein the apparatus is disposed in an internal space covered by a second upper cover with a conductive member exposed, the bus bars include: a first bus bar connected to the battery stack; a second bus bar connected to the apparatus; and a third bus bar relaying between the battery bus bar and the apparatus bus bar, and in a case where fastening based on a fastening member is released and the upper cover is detached from the lower housing, the third bus bar is integrally detached from the lower housing with the upper cover and is not electrically connected to the first bus bar and the second bus bar.

Description

Technical Field

[0001] This invention relates to a battery pack. Background Technology

[0002] Patent Document 1 discloses a structure for a battery pack whose internal space is divided vertically by the upper and lower compartments. The upper and lower compartments are respectively sealed, with the battery modules housed in the lower compartment and the junction box and other equipment housed in the upper compartment. In the structure described in Patent Document 1, since the switch controlling the electrical connection between the battery modules is exposed on the surface of the casing, operators can disconnect the switch and perform work during maintenance or inspection.

[0003] Patent Document 1: International Publication No. 2013 / 186878 Summary of the Invention

[0004] However, the structure described in Patent Document 1 is a multi-shell structure that houses the junction box or equipment box inside the battery pack casing, resulting in an increase in the number of parts or weight. Furthermore, since the operator needs to manually turn off the switch at the start of the operation, the operation becomes cumbersome, and there is a possibility of forgetting to turn off the switch when opening the casing.

[0005] The present invention was made in view of the above circumstances, and its object is to provide a battery pack that can reduce the number of parts while ensuring high voltage safety.

[0006] The battery pack of the present invention comprises: a battery stack; a device electrically connected to the battery stack via a bus; and a housing housing the battery stack and the device, wherein the housing has: an upper cover covering the device; and a lower housing integrally formed with the upper cover by fastening members, the device being configured in an internal space covered by the upper cover with conductive components exposed, and the bus having: a first bus connected to the battery stack; a second bus connected to the device; and a third bus connected to the first bus. The third bus relays between the first and second busbars. The third busbar is housed in an insulating housing integral with the upper cover. When the upper cover is fastened to the lower housing by the fastening member, the third busbar is electrically connected to the first and second busbars. When the upper cover is removed from the lower housing due to the release of the fastening member, the third busbar is detached from the lower housing integrally with the upper cover and is not electrically connected to the first and second busbars.

[0007] Invention Effects

[0008] In this invention, the number of parts can be reduced while ensuring high voltage safety. Attached Figure Description

[0009] Figure 1 This is a schematic diagram illustrating the battery pack in the embodiment.

[0010] Figure 2 It is a diagram used to illustrate the internal structure of the shell.

[0011] Figure 3 It is a diagram used to illustrate the state of fastening by fastening components.

[0012] Figure 4 It is a diagram used to illustrate the state of a fastener being released based on the fastening of a fastening component.

[0013] Figure 5 It is a diagram used to illustrate the connection structure of the busbar. Detailed Implementation

[0014] The battery pack in the embodiments of the present invention will be described in detail below. However, the present invention is not limited to the embodiments described below.

[0015] Figure 1 This is a schematic diagram illustrating a battery pack in an embodiment. The battery pack 1 is mounted on an electric vehicle such as an electric car or a hybrid electric vehicle. The battery pack 1 includes a battery stack 2, equipment 3, and a housing 4.

[0016] Battery stack 2 has multiple battery cells. Battery stack 2 is a battery pack formed by electrically connecting multiple battery cells. For example, battery stack 2 has a stack of multiple stacked square battery cells. Battery pack 1 has multiple battery stacks 2. Battery stacks 2 are electrically connected to each other.

[0017] Device 3 is electrically connected to battery stack 2. Device 3 includes electronic components such as relays, fuses, switches, and monitoring systems. In the circuit that uses battery stack 2 as a power source, device 3 is installed between battery stack 2 and the load. The load is a motor or similar device mounted on an electric vehicle.

[0018] The housing 4 is a battery pack housing that houses the battery stack 2. Inside the housing 4, the device 3 is housed together with the battery stack 2. The internal space of the housing 4 is divided into upper and lower sections, with the battery stack 2 housed in the lower space S1 and the device 3 housed in the upper space S2. Inside the housing 4, the device 3 is positioned above the battery stack 2.

[0019] The housing 4 has an integrated structure of multiple housing components. The housing 4 includes a first lower housing 11, a first upper cover 12, a second lower housing 13, and a second upper cover 14. The first lower housing 11 and the first upper cover 12 are housing components that divide the lower space S1. The second lower housing 13 and the second upper cover 14 are housing components that divide the upper space S2.

[0020] The first lower housing 11 is the lower housing for housing the battery stack 2. The first lower housing 11 has an opening that opens upwards. The first upper cover 12 is a cover that covers the opening of the first lower housing 11. The lower space S1 is formed by integrating the first upper cover 12 with the first lower housing 11. The first lower housing 11 and the first upper cover 12 are integrated by joining them through a joint 21. The joint 21 is formed by welding or bonding. A through hole communicating between the lower space S1 and the upper space S2 is provided on the upper wall of the first upper cover 12.

[0021] The second lower housing 13 is the lower housing of the mounting device 3. The second lower housing 13 has an opening that opens upwards. The second upper cover 14 is a cover that covers the opening of the second lower housing 13. The upper space S2 is formed by the integration of the second upper cover 14 and the second lower housing 13. The second upper cover 14 is integrated with the second lower housing 13 by a fastening member. A through hole communicating between the upper space S2 and the lower space S1 is provided on the lower wall of the second lower housing 13.

[0022] In housing 4, the first upper cover 12 and the second lower housing 13 are integrally joined by a joint 22. The joint 22 is formed by welding or bonding. Device 3 is configured with conductive components exposed in the upper space S2 covered by the second upper cover 14. The conductive components include electronic parts. Device 3 is electrically connected to battery stack 2 via bus 5.

[0023] Busbar 5 is a busbar located inside the housing 4. For example... Figure 1 , Figure 2 As shown, bus 5 includes bus 1 31, bus 2 32 and bus 33.

[0024] The first busbar 31 is a busbar connected to the battery stack 2. The first busbar 31 extends within the lower space S1 and extends to the upper space S2 via a through hole in the first upper cover 12. The first busbar 31 has a terminal 31a for connection to the second busbar 32. The terminal 31a is disposed in the upper space S2.

[0025] The second bus 32 is a bus connected to the device 3. The second bus 32 extends within the upper space S2. The second bus 32 has a terminal 32a for connection to the first bus 31. The terminal 32a is disposed in the upper space S2. The second bus 32 is electrically connected to the first bus 31 via a third bus 33. Additionally, Figure 1 and Figure 2 This represents a cross-section cut at different positions along the Y direction.

[0026] The third bus 33 is a bus disposed on the housing 4. The third bus 33 is a relay bus that relays power between the first bus 31 and the second bus 32. In the circuit that powers the battery stack 2, the third bus 33 is disposed upstream of the second bus 32. The third bus 33 is electrically connected to the first bus 31 and also electrically connected to the second bus 32.

[0027] like Figure 3 , Figure 4 As shown, the third bus 33 extends along the Y direction. The third bus 33 has a first terminal 33a formed at one end in the Y direction and a second terminal 33b formed at the other end in the Y direction. The first terminal 33a is a terminal formed at one end of the third bus 33. The first terminal 33a is electrically connected to a terminal 31a of the first bus 31. The second terminal 33b is a terminal formed at the other end of the third bus 33. The second terminal 33b is electrically connected to a terminal 32a of the second bus 32. The third bus 33 is connected to the first bus 31 and the second bus 32 via a fastening member 6.

[0028] The fastening component 6 includes a first fastening component 41 for connecting the first busbar 31 and the third busbar 33, and a second fastening component 42 for connecting the second busbar 32 and the third busbar 33. The first fastening component 41 has a bolt 41a with an insulated head and a nut 41b that engages with the bolt 41a. The second fastening component 42 has a bolt 42a with an insulated head and a nut 42b that engages with the bolt 42a.

[0029] The first terminal 33a is connected to the terminal 31a of the first busbar 31 via the first fastening member 41. The first terminal 33a has a first through hole 33c for inserting a bolt 41a. The first terminal 33a has a first cylindrical portion 33d communicating with the first through hole 33c. The first cylindrical portion 33d is a cylindrical portion extending in the Z direction. The first terminal 33a and the terminal 31a are electrically connected via a first relay portion 35. The first relay portion 35 is a cylindrical conductive member. Figure 3 As shown, with the first fastening member 41 fastened, the lower end of the first cylindrical portion 33d contacts the upper end of the first relay portion 35, and the upper surface of the terminal 31a contacts the lower end of the first relay portion 35.

[0030] The second terminal 33b is connected to the terminal 32a of the second busbar 32 via the second fastening member 42. A second through hole 33e is provided on the second terminal 33b for the bolt 42a to pass through. The second terminal 33b has a second cylindrical portion 33f communicating with the second through hole 33e. The second cylindrical portion 33f is a cylindrical portion extending in the Z direction. The second terminal 33b and terminal 32a are electrically connected via a second relay portion 36. The second relay portion 36 is a cylindrical conductive member. Figure 3 As shown, with the second fastening member 42 fastened, the lower end of the second cylinder 33f contacts the upper end of the second relay 36, and the upper surface of the terminal 32a contacts the lower end of the second relay 36.

[0031] The third busbar 33 is housed in a receiving portion 50 integrated with the second upper cover 14. The receiving portion 50 is held in a state that accommodates the third busbar 33. The receiving portion 50 is made of an insulating resin material. The receiving portion 50 includes a holding portion 51 and a connecting portion 52. The holding portion 51 is a portion that extends in the Y direction in a manner that surrounds the periphery of the third busbar 33, and has an insulating structure that insulates the periphery of the third busbar 33. The connecting portion 52 is a portion that exposes the lower ends of the first cylindrical portion 33d and the second cylindrical portion 33f. The connecting portion 52 is a fastening portion based on the fastening member 6. Through the structure of the connecting portion 52, the lower end of the first cylindrical portion 33d faces the terminal 31a of the first busbar 31, and the lower end of the second cylindrical portion 33f faces the terminal 32a of the second busbar 32. Figure 4 As shown, the receiving portion 50 retains the third busbar 33 in a state in which a portion of the first terminal 33a is exposed toward the first busbar 31 and a portion of the second terminal 33b is exposed toward the second busbar 32.

[0032] like Figure 3 As shown, with the fastening component 6 fastened, the third busbar 33 is electrically connected to the first busbar 31 and the second busbar 32. Figure 4 As shown, in the released state where the fastening of the fastening component 6 is released and the second upper cover 14 is removed from the second lower housing 13, the third busbar 33 is integrally removed from the second lower housing 13 with the second upper cover 14 and is not electrically connected to the first busbar 31 and the second busbar 32.

[0033] like Figure 5 As shown, the third bus 33 includes two buses on the positive and negative sides. Similarly, the first bus 31 and the second bus 32 each include two buses on the positive and negative sides, respectively. The third bus 33 on the positive side is connected to the first bus 31 and the second bus 32 on the positive side. The third bus 33 on the negative side is connected to the first bus 31 and the second bus 32 on the negative side.

[0034] As explained above, according to the embodiment, the housing of device 3 can be omitted, thus reducing the number of parts. Furthermore, when the second top cover 14 is removed, the electrical connection is always disconnected on the upstream side of device 3, so the energized device 3 is not touched. Therefore, the number of parts can be reduced while ensuring high-voltage safety.

[0035] In electric vehicles, the demand for extended driving range powered solely by electricity is increasing, leading to a trend towards larger battery capacities in the battery pack 1. From a practical standpoint, a two-layer structure is adopted, housing the battery pack 1 within the wheelbase and track width of the electric vehicle, and housing the device 3, which includes conductive components such as relays and monitoring systems, within the housing 4. In the battery pack 1, the conductive components of the device 3 are exposed in the upper space S2, thus creating a housing structure consisting solely of the housing 4. In other words, the housing of the device 3 is integrated with the housing 4 in the battery pack 1, eliminating the need for a separate housing of the device 3 inside the housing 4, reducing the number of parts and weight. When the device 3 includes a junction box, the second upper cover 14 functions as the housing for the junction box, further significantly reducing the number of parts.

[0036] Furthermore, since the third busbar 33, located upstream of device 3, is integrally removed from the second lower housing 13 along with the second upper cover 14, high-voltage safety can be ensured even when the conductive components of device 3 are exposed in the upper space S2. During servicing and maintenance of relays and fuses included in device 3, removing the second upper cover 14 exposes the busbars and connections in the upper space S2, creating a structure where contact with conductive components is possible. In battery pack 1, the second upper cover 14 forms the current inlet of device 3, and the structure ensures that removing the second upper cover 14 from the second lower housing 13 cuts off the power supply path to downstream device 3. Therefore, it is possible to integrate the housing of device 3 with the housing 4 components while ensuring high-voltage safety.

[0037] Symbol Explanation

[0038] 1-Battery pack, 2-Battery stack, 3-Equipment, 4-Housing, 5-Bus, 6-Fasting component, 11-First lower housing, 12-First upper cover, 13-Second lower housing, 14-Second upper cover, 31-First busbar, 32-Second busbar, 33-Third busbar, 33a-First terminal, 33b-Second terminal, 33c-First insertion hole, 33d-First cylindrical part, 33e-Second insertion hole, 33f-Second cylindrical part, 41-First fastening component, 41a-Bolt, 41b-Nut, 42-Second fastening component, 42a-Bolt, 42b-Nut, 50-Receiving part.

Claims

1. A battery pack, characterized in that, It comprises: a battery stack; equipment electrically connected to the battery stack via a busbar; and a housing that accommodates the battery stack and the equipment, wherein, The housing has: A top cover that covers the device; and The lower housing is integrated with the upper cover by fastening components. The device is configured with its conductive components exposed within the internal space covered by the top cover. The bus has: The first busbar is connected to the battery stack; A second bus, which is connected to the device; and The third bus relays between the first bus and the second bus. The third busbar is housed in an insulating housing integral with the upper cover. With the upper cover fastened to the lower housing by the fastening components, the third busbar is electrically connected to the first busbar and the second busbar. When the fastening of the fastening component is released and the upper cover is removed from the lower housing, the third busbar is integrally removed from the lower housing with the upper cover and is not electrically connected to the first busbar and the second busbar.

2. The battery pack according to claim 1, characterized in that, The fastening component includes a bolt with an insulated head. The third bus has: The first terminal has a first through hole for the bolt to pass through, and is electrically connected to the first busbar; and The second terminal has a second through hole for the bolt to pass through, and is electrically connected to the second busbar. The receiving portion has an insulating structure that exposes a portion of the first terminal opposite to the first busbar and exposes a portion of the second terminal opposite to the second busbar, thereby insulating the area surrounding the third busbar.

3. The battery pack according to claim 2, characterized in that, The first terminal has a first cylindrical portion that communicates with the first insertion hole. The second terminal has a second cylindrical portion that communicates with the second insertion hole. The receiving portion exposes the lower ends of the first cylindrical portion and the second cylindrical portion.

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