BDU device and battery pack

Abstract

Disclosed in the present application are a BDU device and a battery pack. The BDU device comprises a shell, a heating element and a heat conduction plate, wherein an opening is provided in one end of the shell; the heating element is arranged in the shell; and the heat conduction plate has a first side and a second side facing away from each other, the first side being located in the opening and thermally coupled to the heating element, and the second side being located outside the shell.

Description

BDU device and battery pack

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 31, 2023, with application number 202323671457.9, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a BDU device and a battery pack. Background Art

[0003] To improve battery pack reliability, battery packs are typically equipped with a BDU (Battery Disconnect Unit) device. The BDU consists of a housing and numerous heat-generating electronic components within it, such as conductive bars, fuses, and relays. Due to space limitations within the battery pack, the components are compactly arranged. Therefore, current BDUs primarily utilize natural cooling to dissipate heat. This inefficient cooling method results in the BDU being exposed to high temperatures for extended periods, leading to lower reliability. SUMMARY OF THE INVENTION

[0004] The present application provides a BDU device and a battery pack to solve the above technical problems.

[0005] In a first aspect, an embodiment of the present application provides a BDU device, which includes a shell, a heating element and a heat conducting plate; an opening is provided at one end of the shell; the heating element is arranged in the shell; the heat conducting plate has a first side and a second side opposite to each other, the first side is located in the opening and is thermally coupled to the heating element, and the second side is located outside the shell.

[0006] In a second aspect, an embodiment of the present application provides a battery pack, which includes a box body and the aforementioned BDU device; the box body has a accommodating cavity; the BDU device is arranged in the accommodating cavity, and the second side is thermally coupled to the cavity wall of the accommodating cavity. Beneficial effects

[0007] The beneficial effects of this application are:

[0008] The BDU device provided in the present application can dissipate heat from the BDU device through the heat conducting plate by thermally coupling the heat conducting plate with the heating element of the BDU device, thereby improving the heat dissipation efficiency of the BDU device, further improving the current carrying capacity of the BDU device, and ultimately improving the reliability of the BDU device.

[0009] The battery pack provided in the present application can improve the reliability of the electrical components of the battery pack by adopting the above-mentioned BDU device, thereby improving the reliability of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a schematic structural diagram of a BDU device provided in an embodiment of the present application;

[0011] FIG2 is a schematic structural diagram of a conductive bar provided in an embodiment of the present application;

[0012] FIG3 is a schematic diagram of the conductive bar and the heat conducting plate abutting against each other according to an embodiment of the present application;

[0013] Figure 4 is an enlarged view of point A in Figure 1;

[0014] FIG5 is a schematic structural diagram of a BDU device provided in an embodiment of the present application installed in a box;

[0015] FIG6 is an enlarged view of point B in FIG5.

[0016] Description of reference numerals:

[0017] 001, BDU device; 011, shell; 111, opening; 112, ear plate; 012, heating element; 121, conductive bar; 013, heat conducting plate; 131, heat conducting plate body; 132, insulating film; 021, bottom guard plate; 031, bolt. Modes for Carrying Out the Invention

[0018] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0019] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0020] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0021] Please refer to Figure 1, which is a schematic diagram of the structure of a BDU device 001 provided in an embodiment of the present application. This embodiment of the present application provides a BDU device 001, which includes a housing 011, a heating element 012, and a heat conducting plate 013. An opening 111 is provided at one end of the housing 011. The heating element 012 is disposed within the housing 011. The heat conducting plate 013 has a first side and a second side that are opposite to each other. The first side is located in the opening 111 and is thermally coupled to the heating element 012. The second side is located outside the housing 011.

[0022] It is understood that when BDU 001 is used in a battery pack, it is installed within the battery pack housing. Specifically, BDU 001 is mounted on the battery pack's bottom shield, with its first side in contact with heating element 012 and its second side in contact with the bottom shield. Heat transfer plate 013 transfers heat from heating element 012 to the bottom shield, while the outer surface of the bottom shield is exposed to the atmosphere for heat dissipation.

[0023] The heating element 012 includes but is not limited to a conductive bus 121 , a relay, and a fuse.

[0024] The heat conducting plate 013 may be a silicone heat conducting pad, a rubber heat conducting plate, or a metal plate coated with an insulating layer.

[0025] In this embodiment, on the one hand, by thermally coupling the heat conducting plate 013 with the heating element 012 of the BDU device 001, the BDU device 001 can dissipate heat through the heat conducting plate 013, thereby improving the heat dissipation efficiency of the BDU device 001, and further improving the current carrying capacity of the BDU device 001, and ultimately improving the reliability of the BDU device 001; on the other hand, by arranging the second side outside the shell 011, a gap is provided between the side of the shell 011 close to the inner wall of the box and the box, thereby avoiding contact between the shell 011 and the box, and thereby avoiding excessive installation locking force of the BDU device 001, which may cause the shell 011 to squeeze the box and crack.

[0026] Please refer to Figure 2. Figure 2 shows an embodiment in which the heating element 012 includes a conductive bar 121. The two ends of the conductive bar 121 are connection ends. At least a portion of the conductive bar 121 except the connection ends is protruded toward the heat conducting plate 013 and abuts against the first side, as shown in Figure 3. Figure 3 is a schematic diagram of the conductive bar 121 abutting against the heat conducting plate 013 provided in an embodiment of the present application.

[0027] It can be understood that the conductive bus 121 is used to electrically connect some electrical components of the BDU device 001 , such as the electrical connection between the high-voltage input port and the high-voltage output port of the BDU device 001 .

[0028] Exemplarily, the conductive bus 121 is a copper bus.

[0029] In this embodiment, the middle portion of the conductive bar 121 is protruded toward the heat conducting plate 013 and abuts against the first side, thereby enabling the conductive bar 121 to be thermally coupled to the heat conducting plate 013 so that the heat conducting plate 013 can dissipate heat from the conductive bar 121, and also enabling the conductive bar 121 to achieve electrical connection between related components.

[0030] In one embodiment, the heat conducting plate 013 is elastic. For example, the heat conducting plate 013 is a silicone thermal pad with a thermal conductivity coefficient of more than 3 W / mK.

[0031] It can be understood that the BDU device 001 is detachably fixed in the box by bolts 031. In addition, when the BDU device 001 is installed in the box, the heat conducting plate 013 is located between the heating element 012 and the box wall and is in a compressed state.

[0032] In this embodiment, the use of an elastic heat conducting plate 013 allows for compression during installation of the BDU 001. This, on the one hand, creates a pre-tightening force on the heat conducting plate 013, preventing the bolts 031 securing the BDU 001 to the housing from loosening, thereby improving the stability of the BDU 001 installation. On the other hand, the compression of the heat conducting plate 013 allows it to better adhere to the heating element 012 and the housing, thereby improving the heat dissipation efficiency of the BDU 001.

[0033] Please refer to Figure 4, which is an enlarged view of point A in Figure 1. In one embodiment, the distance between the second side and the outer side surface of the housing 011 is d1, which satisfies 1mm≤d1≤4mm.

[0034] It will be understood that d1 includes but is not limited to 1mm, 1.5mm, 1.8mm, 2mm, 2.6mm, 3mm, 3.3mm, 3.8mm, and 4mm.

[0035] In this embodiment, by limiting the distance between the second side and the shell 011, on the one hand, it can be avoided that the distance between the second side and the shell 011 is too small, resulting in the shell 011 contacting the box body, thereby avoiding the shell 011 squeezing the box body and cracking due to the installation locking force of the BDU device 001 being too large; on the other hand, it can be avoided that the distance between the second side and the shell 011 is too large, resulting in a decrease in the thermal conductivity of the heat conducting plate 013.

[0036] Please refer to FIG. 4 . In one embodiment, the heat conducting plate 013 includes a heat conducting plate body 013 and an insulating film 132 . The heat conducting plate body 013 has a first side and a second side. The insulating film 132 covers at least the first side or the second side.

[0037] Exemplarily, the insulating film 132 completely covers the surface of the heat conducting plate 013 .

[0038] The heat conducting plate 013 is a silicone thermal pad. The insulating film 132 includes, but is not limited to, a PET insulating film 132 or a PC insulating film 132. Since the thermal conductivity of the PET insulating film 132 is higher than that of the PC insulating film 132, the insulating film 132 may be a PET insulating film 132.

[0039] In this embodiment, by covering the first side or the second side with the insulating film 132 , the insulation between the heating element 012 and the battery box can be improved, thereby ensuring the normal operation of the BDU device 001 and further improving the reliability of the BDU device 001 .

[0040] Referring to FIG. 4 , in one embodiment, the thickness of the insulating film 132 is d2 , which satisfies 0.1 mm ≤ d2 ≤ 0.2 mm.

[0041] It will be understood that d2 includes but is not limited to 0.1mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.17mm, 0.18mm, 0.19mm, and 0.2mm.

[0042] In this embodiment, by limiting the thickness of the insulating film 132, on the one hand, it is possible to avoid the insulating film 132 being scratched due to the thickness being too small, thereby ensuring the insulation between the heating element 012 and the box body; on the other hand, it is possible to avoid the insulating film 132 being too thick due to the thermal conductivity of the heat conducting plate 013 being reduced.

[0043] In one embodiment, the heat conducting plate 013 is engaged with the opening 111 .

[0044] It can be understood that the opening 111 can be interference-fitted with the heat conducting plate 013 to achieve a snap connection between the heat conducting plate 013 and the opening 111 .

[0045] In this embodiment, the heat conducting plate 013 is locked with the opening 111, thereby improving the connection stability between the heat conducting plate 013 and the housing 011, thereby preventing the heat conducting plate 013 from falling out of the opening 111 of the housing 011. This improves the convenience of installing the BDU device 001.

[0046] Please refer to Figure 5, which is a schematic diagram of the structure of a BDU device 001 provided in an embodiment of the present application, installed in a housing. Accordingly, an embodiment of the present application also provides a battery pack, comprising a housing and the aforementioned BDU device 001. The housing has a receiving cavity. The BDU device 001 is disposed in the receiving cavity. The second side is thermally coupled to the cavity wall of the receiving cavity. Specifically, the second side is thermally coupled to the bottom guard plate 021.

[0047] As can be understood, the BDU 001 is removably secured to the housing chamber via a fixing member. The fixing member includes a bolt 031. A lug is provided on the outer wall of the housing 011, and a hole for the bolt 031 is provided in the lug. The end of the rod of the bolt 031 passes through the hole and is threadedly connected to the housing. The head of the bolt 031 abuts the lug, and the axial direction of the bolt 031 is perpendicular to the heat conducting plate 013, thereby sequentially pressing the heating element 012, the heat conducting plate 013, and the bottom guard plate 021.

[0048] In this embodiment, by adopting the above-mentioned BDU device 001, the reliability of the electrical components of the battery pack can be improved, thereby improving the reliability of the battery pack.

[0049] In one embodiment, heat conducting plate 013 is in a compressed state. Specifically, the cavity wall thermally coupling the accommodating cavity to the second side is the first cavity wall, and the distance between the first cavity wall and the housing 011 is D, as shown in Figure 6, which is an enlarged view of point B in Figure 5. When heat conducting plate 013 is in its original state, the distance between the second side and the housing 011 is d1, satisfying the following: D < d1.

[0050] It is understood that the heat conducting plate 013 is elastic. The heat conducting plate 013 is in its original state when it is not deformed by any external force. In its original state, the heat conducting plate 013 is in its natural state and is not stretched, compressed, or twisted.

[0051] For example, 0.4 mm ≤ d1 - D ≤ 0.7 mm. Specifically, the difference between D and d1 includes, but is not limited to, 0.4 mm, 0.5 mm, 0.6 mm, and 0.7 mm. It is understood that if this difference is too large, it means that the thickness of the heat conducting plate 013 is too large, which, in turn, hinders heat conduction. If this difference is too small, the housing 011 may easily abut against the box body and crack when the BDU device 001 is installed.

[0052] In this embodiment, the above-mentioned limitation places the heat conducting plate 013 in a compressed state. Thus, on the one hand, a pre-tightening force can be formed at the heat conducting plate 013 to prevent the bolts 031 that lock the BDU device 001 to the box from loosening, thereby improving the installation stability of the BDU device 001. On the other hand, the heat conducting plate 013 can be squeezed to better fit with the heating element 012 and the box, thereby improving the heat dissipation efficiency of the BDU device 001.

Claims

1. A BDU device, comprising: A housing with an opening at one end; A heating element disposed within the housing; A heat conducting plate having a first side and a second side opposite to each other, the first side being located in the opening and thermally coupled to the heating element, and the second side being located outside the housing.

2. The BDU device according to claim 1, wherein, The heating element includes a conductive bar, both ends of the conductive bar being connection ends, and at least a part of the conductive bar except the connection ends protruding towards the heat conducting plate and abutting against the first side.

3. The BDU device according to claim 1, wherein, The heat conducting plate has elasticity.

4. The BDU device according to claim 3, wherein, The heat conducting plate is a silicone heat conducting pad or a rubber heat conducting plate.

5. The BDU device according to any one of claims 1-4, wherein, The distance between the second side and the outer side surface of the housing is d1, satisfying 1 mm ≤ d1 ≤ 4 mm.

6. The BDU device according to any one of claims 1-4, wherein, The heat conducting plate includes a heat conducting plate body and an insulating film, the heat conducting plate body having the first side and the second side, and the insulating film covering at least the first side or the second side.

7. The BDU device according to claim 6, wherein, The thickness of the insulating film is d2, satisfying 0.1 mm ≤ d2 ≤ 0.2 mm.

8. The BDU device according to claim 6, wherein, The insulating film is a PET insulating film.

9. The BDU device according to any one of claims 1-4, wherein, The heat conducting plate is snap-fitted with the opening.

10. A battery pack, comprising: A box body having a receiving cavity; The BDU device according to any one of claims 1-9, the BDU device being disposed in the receiving cavity, and the second side being thermally coupled to the cavity wall of the receiving cavity.

11. A battery pack according to claim 10, wherein, The heat conducting plate is in a compressed state.

12. A battery pack according to claim 11, wherein, The cavity wall of the receiving cavity thermally coupled to the second side is the first cavity wall, and the distance between the first cavity wall and the housing is D; when the heat conducting plate is in its original state, the distance between the second side and the housing is d1, satisfying: D < d1.

13. A battery pack according to claim 12, wherein, 0.4 mm ≤ d1 - D ≤ 0.7 mm.

14. A battery pack according to any one of claims 10-13, wherein, The BDU device is detachably fixed in the receiving cavity by a fixing member.

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