Battery pack

Abstract

Disclosed in the present invention is a battery pack. The battery pack comprises a case, a battery assembly, and a battery pack disconnect unit; the case is internally provided with a battery compartment and an electrical compartment separated by a partition beam; the battery assembly is arranged in the battery compartment, and the battery pack disconnect unit is arranged in the electrical compartment; the battery pack disconnect unit comprises a housing, a circuit board, and electronic components connected to the circuit board, the circuit board is arranged in the housing, and the electronic components are arranged on board surfaces on both sides of the circuit board. By applying the present solution, the board surface area of the circuit board of the battery pack disconnect unit can be reduced, the space occupied by the battery pack disconnect unit in the battery pack can be reduced, the size of the electrical compartment can be effectively decreased, and more of the accommodating space in the case of the battery pack can be allocated to the battery compartment, thereby providing strong technical support for improving the overall battery energy density.

Description

A battery pack Technical Field

[0001] This invention relates to the field of battery pack circuit breaker technology, and more specifically to a battery pack. Background Technology

[0002] The battery disconnect unit (BDU) is an important component of new energy vehicles, used to provide charging and discharging control and circuit overload protection for the high-voltage system. Various relays are crucial components within the BDU, supporting its normal operation.

[0003] In related technologies, electrical components in the BDU are typically located on the same side of the circuit board, resulting in a more compact overall structure and a more regular outline. Due to the configuration of this BDU, the electrical compartment of the battery pack requires corresponding assembly space, directly affecting the battery energy density. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a battery pack that, through optimization, can effectively reduce the space occupied by the battery drain unit (BDU) within the battery pack and improve battery energy density.

[0005] The present invention provides a battery pack comprising a housing, a battery pack, and a battery pack circuit breaker unit. The housing includes a base plate and a housing frame, the housing frame being fixed to the base plate to enclose and form a receiving space within the housing. A partition beam is provided inside the housing, dividing the receiving space into a battery compartment and an electrical compartment. The battery pack is disposed within the battery compartment, and the battery pack circuit breaker unit is disposed within the electrical compartment. The battery pack circuit breaker unit includes a housing, a circuit board, and electronic components connected to the circuit board. The circuit board is disposed within the housing, and the electronic components are arranged on both sides of the circuit board.

[0006] Compared with existing technologies, this invention proposes a novel battery pack implementation scheme. Specifically, the electronic components are arranged on both sides of the circuit board of the battery pack circuit breaker unit. Compared with existing technologies, this scheme arranges electronic components on both sides of the circuit board, which reduces the board area and saves space occupied by the battery pack circuit breaker unit within the battery pack. Applying this scheme can effectively reduce the size of the electrical compartment, allowing more space within the battery pack housing to be allocated to one side of the battery compartment. This, in turn, allows for a corresponding increase in the volume of the battery pack, providing a strong technical guarantee for improving the overall battery energy density.

[0007] In addition, electronic components can be flexibly arranged on the top and bottom sides of the circuit board. On the one hand, this reduces the mutual influence between electrical components due to their own heat generation, which is beneficial for the heat dissipation of electronic components. On the other hand, it also helps to reduce electromagnetic interference between electronic components and ensure the effective transmission of control signals. Attached Figure Description

[0008] Figure 1 is a schematic diagram of the housing assembly relationship of the battery pack according to an embodiment of this application;

[0009] Figure 2 is an exploded view of the battery pack circuit breaker unit shown in Figure 1.

[0010] Figure 3 is a schematic diagram of a battery pack circuit breaker unit according to an embodiment of the present invention;

[0011] Figure 4 is a schematic diagram of the circuit board layout on one side of the battery pack circuit breaker unit shown in Figure 3.

[0012] Figure 5 is a schematic diagram of the layout of the other side of the circuit board of the battery pack circuit breaker unit shown in Figure 3.

[0013] Figure 6 is a schematic diagram of a layout above the circuit board in an embodiment of the present invention;

[0014] Figure 7 is a schematic diagram of a layout below the circuit board in an embodiment of the present invention;

[0015] Figure 8 is a schematic diagram of the assembly relationship between the circuit board and the BMS motherboard in an embodiment of the present invention.

[0016] In the diagram: Battery pack circuit breaker unit 10, housing 1, first housing 11, second housing 12, clearance recess 13, circuit board 2, heating fuse 31, heating relay 32, precharge relay 33, main positive relay 34, main negative relay 35, main fuse 36, precharge resistor 37, BMS main board 4, copper busbar 5, high voltage sampling connector 6, low voltage communication connector 7; enclosure 20, bottom plate 21, enclosure frame 22, partition beam 23, reinforcing beam 24. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] With the increasing demand for longer driving ranges, controlling battery pack size and effectively improving battery energy density have become key research and development directions in the industry. Typically, a battery pack housing includes a battery compartment and an electrical compartment. Please refer to Figures 1 and 2, where Figure 1 is a schematic diagram of the housing assembly relationship of a battery pack according to an embodiment of this application, and Figure 2 is an exploded view of the battery pack circuit breaker unit shown in Figure 1. For ease of description, the battery compartments shown in Figures 1 and 2 do not show functional components such as battery packs.

[0019] The battery pack includes a housing 20, a battery pack (not shown in the figure), and a battery pack circuit breaker unit 10. The housing 20 includes a base plate 21 and a housing frame 22, which are fixedly connected to the base plate 21 to enclose and form the housing space of the housing 20 for assembling internal components such as the battery pack and the battery pack circuit breaker unit 10.

[0020] As shown in Figures 1 and 2, a partition beam 23 is provided inside the housing 20, which divides the accommodating space into a battery compartment A and an electrical compartment B. The battery pack is located in battery compartment A, and the battery pack circuit breaker unit 10 is located in electrical compartment B.

[0021] Please refer to Figures 3, 4 and 5. Figure 3 is a schematic diagram of a battery pack circuit breaker unit according to an embodiment of the present invention. Figure 4 is a schematic diagram of the layout of one side of the circuit board of the battery pack circuit breaker unit shown in Figure 3. Figure 5 is a schematic diagram of the layout of the other side of the circuit board of the battery pack circuit breaker unit shown in Figure 3.

[0022] As shown in Figure 3, the battery pack circuit breaker unit 10 includes a housing 1 and a circuit board disposed within the housing 1, as well as electrical components including but not limited to various relays. The housing 1 shown in the figure includes a first housing 11 and a second housing 12 connected to each other, which are assembled to form the housing 1 that houses the various devices.

[0023] In this embodiment, electrical components are arranged on both sides of the circuit board 2. In other words, electrical components connected to the circuit board 2 are distributed on both the top and bottom surfaces. For ease of description, the first housing 11 shown in the figure is defined as the lower housing portion, and the second housing 12 is defined as the upper housing portion.

[0024] Figure 4 shows a schematic diagram of the electrical component layout on the upper part of circuit board 2. The upper surface of circuit board 2 includes electrical components such as a heating fuse 31, a heating relay 32, and a pre-charge relay 33. Figure 5 shows a schematic diagram of the electrical component layout on the lower part of circuit board 2. The lower surface of circuit board 2 includes a main positive relay 34 and a main negative relay 35, both electrically connected to the output terminal of the battery pack (not shown in the figure). The lower surface of circuit board 2 also includes electrical components such as a main fuse 36 and a pre-charge resistor 37.

[0025] Among them, the main positive relay 34 is the main relay on the positive side of the high-voltage system, and the main negative relay 35 is the main relay on the negative side of the high-voltage system. The pre-charge relay 33 is used in the pre-charge circuit as a switch to realize the on / off state and overcurrent control of the pre-charge circuit; that is, it connects the pre-charge circuit for self-test before the main relay operates. The heating relay 32 is used in the heating circuit as a switch to realize the on / off state and overcurrent control of the heating circuit. These relays, as non-manually operated mechanical switching devices, have only one rest position and can connect, carry, and disconnect current under normal circuit conditions (including overload operating conditions).

[0026] Among them, the pre-charge resistor 37 is a power resistor. When the vehicle executes the high voltage command, it first closes the pre-charge circuit to charge the X capacitor at the electric drive end. At this time, the pre-charge resistor 37 acts as a current limiting resistor to prevent the circuit from being damaged by a large current surge at the moment of power-on.

[0027] In the event of a short circuit in the heating circuit, the internal fusible element of the heating fuse 31 melts rapidly due to instantaneous heat accumulation, thus disconnecting the heating circuit and protecting other electrical components, wiring, and the battery from damage. In a specific implementation, when the current exceeds a predetermined value for a sufficiently long time, the current is interrupted by melting one or more proportionally designed fusible elements, thereby disconnecting the device connected to the circuit. The specific details can be determined based on the overall product design requirements; this application does not limit the specific implementation.

[0028] In this way, the double-sided layout of circuit board 2 reduces the board area and saves space occupied by the battery pack circuit breaker unit 10 within the battery pack. Compared with the implementation method of arranging electrical components on a single side, under roughly the same electrical performance configuration, this solution can effectively reduce the size of electrical compartment B, allowing more of the internal storage space of the housing 20 to be allocated to the battery compartment A side.

[0029] In one specific implementation, the projected area of ​​the electrical compartment B on the bottom plate 21 of the housing 20 can be 5% to 20% of the area of ​​the bottom plate 21; for example, but not limited to, the projected area of ​​the electrical compartment B on the bottom plate 21 of the housing 20 can be 6%, 12%, or 18% of the area of ​​the bottom plate 21. This allows for a corresponding increase in the volume of the battery pack, thereby improving the overall battery energy density.

[0030] In addition, electronic components are flexibly arranged on the upper and lower sides of the circuit board 2. On the one hand, this reduces the mutual influence between electrical components due to their own heat generation, which is conducive to the heat dissipation of electronic components. On the other hand, it also helps to reduce electromagnetic interference between electronic components and ensure the effective transmission of control signals.

[0031] To improve reliability, the electronic components on the upper and lower surfaces of circuit board 2 can be optimized. Optionally, the maximum height of each electronic component located on the lower surface of circuit board 2 can be greater than the maximum height of each electronic component located on the upper surface of circuit board 2. Here, "maximum height of each electronic component" refers to the height of the tallest electronic component among multiple electronic components located on the lower or upper surface of circuit board 2.

[0032] In contrast, large and heavy electrical components are arranged on the lower surface of circuit board 2. Under operating conditions, the battery pack will experience combined vibration in the XYZ directions, with the Z direction being perpendicular to the bottom plate of the battery pack. Especially when the entire pack vibrates in the Z direction, controlling the arrangement of electronic components in the BDU and placing tall (large and heavy) components on the lower surface of the circuit board can lower the overall center of gravity of the BDU and make it more stable. Furthermore, since small and light electrical components are arranged on the upper surface of circuit board 2, the possibility of damaging circuit board 2 can be reduced.

[0033] When the maximum height of each electronic component located on the upper surface of the circuit board is less than or equal to the maximum height of each electronic component located on the lower surface of the circuit board, the thickness of the circuit board 2 can be 0.5mm to 2mm; for example, but not limited to, the thickness of the circuit board 2 can be 0.6mm, 1.2mm, or 1.8mm. This configuration, while meeting the load-bearing capacity of the carrier board, allows for reasonable control of the board thickness, reduces the overall package weight, improves the overall mass energy density of the package to a certain extent, and reduces the component cost of the BDU circuit board itself.

[0034] In practical implementation, the ratio of the maximum height of each electronic component located on the upper surface of circuit board 2 to the maximum height of each electronic component located on the lower surface of circuit board 2 can be less than or equal to 1.27 and greater than or equal to 1. This allows for reasonable control of the height of the electronic components on the upper surface of circuit board 2, preventing the BDU's center of gravity from becoming too high, improving the stability of the BDU housing, and avoiding fatigue failure of the solder joints at the connection points of various electrical components under vibration conditions. In particular, the connections between the high-voltage busbar and the main positive and negative relays are generally screwed or welded. Under repeated vibration of the entire package, bolts are prone to loosening, loose connections, or fatigue failure and breakage at the welded positions, leading to increased local resistance, a sudden increase in heat generation, and potentially even thermal runaway of the entire package.

[0035] When the maximum height of the electronic components located on the upper surface of circuit board 2 is greater than the maximum height of the electronic components located on the lower surface of circuit board 2, the thickness of circuit board 2 can be 1mm to 3mm; for example, but not limited to, the thickness of circuit board 2 can be 1.2mm, 2mm, or 2.8mm. Due to external wiring and other reasons, when the maximum height of the upper electronic components is greater than the maximum height of the lower electronic components, it is necessary to control the thickness of the circuit board within an appropriate range to compensate for the decreased stability due to the increased center of gravity and the strength damage to the BDU circuit board caused by the pressure from the upper electronic components, thereby further improving the stability and reliability of the BDU.

[0036] In other specific implementations, the projections of the electronic components located on the lower surface of circuit board 2 and the electronic components located on the upper surface of circuit board 2 onto the plane of circuit board 2 at least partially overlap. In this way, the upper and lower layers of electrical components are sandwiched between the upper and lower surfaces of circuit board 2. When the entire circuit vibrates in the Z direction, the upper and lower layers of electronic components together clamp the circuit board, which helps to improve the overall strength of circuit board 2 and reduce the risk of circuit board bending and breakage.

[0037] To improve the adaptability of the BDU, the housing 1, which serves as the basis for BDU assembly, can be further optimized. As shown in Figures 2 and 3, the outer surface of the housing 1 can have a recess 13 to avoid interference with the reinforcing beam 24 inside the electrical compartment. The reinforcing beam 24 is perpendicular to the extension direction of the circuit board 2, which can enhance the overall structural strength of the electrical compartment. At least a portion of the reinforcing beam 24 inside the electrical compartment B can be housed within the recess 13. In this way, without increasing the assembly space inside the compartment, the available space inside the compartment is adapted, improving the overall space utilization of the package.

[0038] For example, the reinforcing beam 24 shown in Figure 2 is a beam structure. In a specific implementation, the recessed portion 13 can be fixedly connected to the beam structure, for example, but not limited to, adhesive fixing, or interference fit fixing, or concave-convex structure fitting fixing, to increase the stability of the BDU housing 1. Under whole-package vibration conditions, on the one hand, the through-beam 24 is equivalent to adding a fixing rib to the BDU housing, increasing the overall strength of the BDU; on the other hand, the strength of the BDU housing can also be used to improve the strength of the electrical compartment. The two work together to improve the overall integrity of the electrical compartment, thus contributing to the overall strength improvement. In addition, the specific location and size of the recessed portion 13 can be determined according to the overall product design requirements, for example, but not limited to, the layout of electrical components on the circuit board inside the housing 1 and the specific form of the reinforcing beam inside the electrical compartment. This application embodiment does not limit this.

[0039] Please refer to Figures 6 and 7 together. Figure 6 is a schematic diagram of a layout above the circuit board in an embodiment of the present invention, and Figure 7 is a schematic diagram of a layout below the circuit board in an embodiment of the present invention.

[0040] In a specific implementation, an avoidance recess 13 can be adaptively provided on the outer surface of the housing 1. For example, in the area indicated by mark C in FIG6, an avoidance recess 13 can be provided correspondingly on the lower part of the housing 1 shown in FIG3, and in the area indicated by mark D in FIG6, an avoidance recess 13 can be provided correspondingly on the upper part of the housing 1 shown in FIG3.

[0041] In a specific implementation, the projection of the recess 13 onto the plane of the circuit board 2 can be offset from the electronic components on the corresponding side panel to maximize the use of space in the vertical direction of the panel and rationally control the space occupied by the battery pack circuit breaker unit. It should be understood that the corresponding location area for arranging the recess can be determined according to the design needs of different products to obtain a housing outline with good assembly adaptability, thereby accommodating electrical compartments of various structures. This application does not limit the scope of the embodiments.

[0042] It should be noted that in practical application scenarios, the requirements for the overall strength of the battery pack are becoming increasingly stringent. Due to the complexity and numerous high-voltage wiring inside the electrical compartment, a beam structure is usually required inside the electrical compartment to obtain better structural strength. Based on the solution of this application, the avoidance recess 13 of the BDU shell 1 provides technical assurance for meeting the avoidance assembly requirements.

[0043] Optionally, the main positive relay 34 and the main negative relay 35 are located on the same side of the circuit board 2. This arrangement allows for the wiring of the high and low voltage ports of the main positive relay 34 and the main negative relay 35 to be arranged on the same side, which is beneficial for the overall layout and compactness. As shown in Figure 7, the main positive relay 34 and the main negative relay 35 are located at opposite ends of the lower surface of the circuit board 2. Based on the physical distance between them and the physical barrier formed by the beam structure after assembly, electromagnetic interference between them can be minimized.

[0044] In a practical implementation, the main fuse 36 and the pre-charge resistor 37 can be positioned between the main positive relay 34 and the main negative relay 35 to fully utilize the space on the circuit board 2. Simultaneously, the copper busbar 5 connected to the main positive relay 34 and the main negative relay 35 is arranged on the same side of the circuit board 2 as both, to further utilize the space on the lower surface of the circuit board 2.

[0045] To achieve a more compact internal structure, the battery management system (BMS) mainboard of the battery pack circuit breaker unit 10 can optionally be stacked with the circuit board 2. Please refer to Figure 8, which is a schematic diagram of the assembly relationship between the circuit board and the BMS mainboard in this embodiment of the invention.

[0046] The BMS mainboard 4 is positioned opposite the main positive relay 34 and the main negative relay 35 on the other side of the circuit board 2, which avoids interference between the BMS mainboard 4 and the copper busbar 5. Referring to Figures 4, 6, and 8, electronic components such as the heating fuse 31, heating relay 32, and pre-charge relay 33 can be centrally located on one side of the circuit board 2. The BMS mainboard 4 can be mounted on the circuit board 2 next to the heating fuse 31, heating relay 32, and pre-charge relay 33. This results in a more compact and rational overall structure, reducing the space occupied by the battery pack circuit breaker unit 10 within the battery compartment.

[0047] In a practical implementation, the projection of the BMS motherboard 4 onto the plane of circuit board 2 can at least partially coincide with circuit board 2. Of course, the projection of the BMS motherboard 4 onto the plane of circuit board 2 can also completely coincide with circuit board 2.

[0048] Correspondingly, a high-voltage sampling connector 6 can be provided on the upper surface of the circuit board 2, and a low-voltage communication connector 7 can be provided on the lower surface of the circuit board 2, and the two are respectively electrically interconnected with the BMS motherboard 4.

[0049] In other possible implementations, the upper and lower surfaces of circuit board 2 can also be configured with other functions, which will not be elaborated here.

[0050] It should be noted that the other functional components of the battery pack and battery pack circuit breaker unit 10 described in the embodiments of this application are not the core inventive points of this application, and can be implemented by those skilled in the art based on existing technology, and will not be elaborated further here. In addition, unless otherwise explicitly limited, the scope in this document includes endpoint values.

[0051] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A battery pack, characterized by, The device includes a housing, a battery pack, and a battery pack circuit breaker unit. The housing includes a base plate and a housing frame, with the housing frame fixed to the base plate to enclose and form the housing's accommodating space. A partition beam is provided inside the housing to divide the accommodating space into a battery compartment and an electrical compartment. The battery pack is located in the battery compartment, and the battery pack circuit breaker unit is located in the electrical compartment. The battery pack circuit breaker unit includes a housing, a circuit board, and electronic components connected to the circuit board. The circuit board is disposed inside the housing, and the electronic components are arranged on both sides of the circuit board.

2. The battery pack of claim 1, wherein, The maximum height of each electronic component located on the lower surface of the circuit board is greater than the maximum height of each electronic component located on the upper surface of the circuit board.

3. The battery pack of claim 1, wherein, The ratio of the maximum height of each electronic component located on the upper surface of the circuit board to the maximum height of each electronic component located on the lower surface of the circuit board is less than or equal to 1.

27.

4. The battery pack of any one of claims 1-3, wherein, The projections of each electronic component located on the lower surface of the circuit board and each electronic component located on the upper surface of the circuit board on the plane of the circuit board at least partially overlap.

5. The battery pack of claim 1, wherein, The maximum height of each electronic component located on the upper surface of the circuit board is greater than the maximum height of each electronic component located on the lower surface of the circuit board, and the thickness of the circuit board is 1mm to 3mm.

6. The battery pack of claim 1, wherein, The maximum height of each electronic component located on the upper surface of the circuit board is less than or equal to the maximum height of each electronic component located on the lower surface of the circuit board, and the thickness of the circuit board is 0.5mm to 2mm.

7. The battery pack of any one of claims 1-6, wherein, The outer surface of the housing has a relief recess.

8. The battery pack of claim 7, wherein, The projection of the recessed portion on the plane of the circuit board is offset from the electronic components on the corresponding side of the circuit board.

9. The battery pack of any one of claims 1-8, wherein, The electronic components include a main positive relay and a main negative relay, which are arranged on the lower surface of the circuit board.

10. The battery pack of claim 9, wherein, The main positive relay and the main negative relay are located at opposite ends of the lower surface of the circuit board.

11. The battery pack of claim 9 or 10, wherein, The electronic components also include a heating relay and a pre-charge relay, which are arranged on the upper surface of the circuit board.

12. The battery pack of any one of claims 9-11, wherein, The battery pack circuit breaker unit also includes a BMS main board, which is mounted on the circuit board and located on the other side of the circuit board opposite to the main positive relay and the main negative relay.

13. The battery pack of claim 7 or 8, wherein, The electrical compartment has a projected area of ​​5% to 20% of the area of ​​the base plate. The electrical compartment has a reinforcing beam, the extension direction of which is perpendicular to the extension direction of the circuit board, and at least a portion of the reinforcing beam is embedded in the clearance recess.

14. The battery pack of claim 13, wherein, The battery pack circuit breaker unit is fixedly connected to the reinforcing beam through the clearance recess.

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