A battery pack and an electrical device

Abstract

This utility model discloses a battery pack and an electrical device, belonging to the field of battery technology. The battery pack includes a battery housing, a liquid cooling plate, and a buffer component. The battery housing includes a bottom protective plate, and the liquid cooling plate is disposed on one side of the bottom protective plate along the Z direction and located inside the battery housing. The Z direction is the thickness direction of the bottom protective plate. The buffer component is disposed between the bottom protective plate and the liquid cooling plate. The first surface of the buffer component along the Z direction makes conformal contact with the liquid cooling plate, and a first recess is provided on the first surface corresponding to the protruding flow channel of the liquid cooling plate. The protruding flow channel and the first recess are fitted together. The electrical device includes the aforementioned battery pack. Because the first surface of the buffer component along the Z direction makes conformal contact with the liquid cooling plate, and the protruding flow channel and the first recess are fitted together, the buffer component and the liquid cooling plate are in full contact, achieving a good vibration damping effect and preventing vibration from causing deformation of the liquid cooling plate.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery pack and an electrical device. Background Technology

[0002] In battery packs, liquid cooling plates are typically placed at the bottom of the battery modules to dissipate heat. The bottom protective plate of the battery casing is located beneath the liquid cooling plate, protecting it. In some battery packs, the bottom protective plate and liquid cooling plate are rigidly connected. Vibration is transmitted through the bottom protective plate to the liquid cooling plate, causing deformation or even leakage, affecting heat dissipation and posing a safety hazard. In other battery packs, a buffer is installed between the bottom protective plate and the liquid cooling plate. When the bottom protective plate and the liquid cooling plate are connected by bolts, the buffer is compressed to provide cushioning. This buffer is usually a simple flat foam, which does not fit well with the liquid cooling plate, resulting in poor vibration damping. Even after prolonged use, the liquid cooling plate may still deform due to vibration. Utility Model Content

[0003] This utility model provides a battery pack and an electrical device to solve the technical problem of vibration causing deformation of liquid cooling plates in the prior art.

[0004] As conceived above, the first aspect of the technical solution adopted by this utility model is:

[0005] A battery pack, comprising:

[0006] Battery housing, including bottom protective plate;

[0007] A liquid cooling plate is disposed on one side of the bottom protective plate along the Z direction and located inside the battery box, wherein the Z direction is the thickness direction of the bottom protective plate;

[0008] A buffer is disposed between the bottom protective plate and the liquid cooling plate. The first surface of the buffer along the Z direction makes conformal contact with the liquid cooling plate. A first recess is provided on the first surface corresponding to the protruding flow channel of the liquid cooling plate. The protruding flow channel is fitted with the first recess.

[0009] Preferably, the second surface of the buffer member along the Z direction makes conformal contact with the bottom guard plate, and a plurality of second recesses are formed on the second surface. The second recesses are used to accommodate the reinforcing protrusions on the bottom guard plate, and the first recesses and the second recesses form a dual-path buffer channel on the buffer member.

[0010] Preferably, the thickness of the buffer element along the Z direction is 115%-225% of the thickness of the liquid cooling plate along the Z direction, and the compression rebound rate of the buffer element is ≥90%.

[0011] Preferably, the battery housing further includes side beams, with two side beams distributed on both sides of the bottom protective plate along the X direction. One side of the side beam along the Z direction is connected to the bottom protective plate by a locking member, and the edge of the liquid cooling plate is welded to the side beam.

[0012] Preferably, the side beam includes a beam body and a first mounting part protruding along the X direction on one side of the beam body. The beam body and the bottom protective plate are connected by the locking member. The edge of the liquid cooling plate is located between the first mounting part and the bottom protective plate and is welded to the first mounting part. The depth of the weld is 70%-80% of the thickness of the first mounting part.

[0013] Preferably, the battery pack further includes a support beam disposed inside the battery housing. The bottom protective plate, the liquid cooling plate, and the support beam are connected by a first fastener. The liquid cooling plate and the support beam are connected by a second fastener. At least one second fastener is disposed between two adjacent first fasteners.

[0014] Preferably, the support beam includes a longitudinal beam and a transverse beam, with the first fastener and the second fastener provided on the longitudinal beam, and the second fastener provided on the transverse beam.

[0015] Preferably, the first fastener includes:

[0016] A rivet nut connects the liquid cooling plate and the support beam, with the head of the rivet nut located between the liquid cooling plate and the bottom protective plate;

[0017] A locking bolt is inserted through the bottom protective plate and threadedly connected to the rivet nut, with the head of the locking bolt located on the outside of the bottom protective plate.

[0018] Preferably, the distance L between the first fastener and the second fastener is 1.2-1.5 times the width D of the support beam.

[0019] Secondly, the technical solution adopted by this utility model is:

[0020] An electrical device includes a battery pack as described in the first aspect above.

[0021] The beneficial effects of this utility model are:

[0022] The battery pack proposed in this utility model has a buffer component between the bottom protective plate and the liquid cooling plate. The first surface of the buffer component in the Z direction makes conformal contact with the liquid cooling plate. The first surface has a first recess corresponding to the protruding flow channel of the liquid cooling plate. The protruding flow channel and the first recess are fitted together, so that the buffer component and the liquid cooling plate are in full contact, which achieves a good vibration reduction effect and prevents the liquid cooling plate from deforming due to vibration. Attached Figure Description

[0023] Figure 1 This is a first schematic diagram of a portion of the structure of the battery pack provided in this embodiment of the present invention;

[0024] Figure 2 This is a partial top view of the battery pack provided in an embodiment of the present invention;

[0025] Figure 3 yes Figure 2 A partial sectional view along the AA direction;

[0026] Figure 4 yes Figure 3 A magnified view of section B;

[0027] Figure 5 yes Figure 3 A magnified view of a portion at point C;

[0028] Figure 6 This is a first exploded view of a portion of the battery pack structure provided in this embodiment of the present invention;

[0029] Figure 7 This is a second exploded view of a portion of the battery pack structure provided in this embodiment of the present invention;

[0030] Figure 8 This is a first schematic diagram of the structure of the buffer component provided in this embodiment of the utility model;

[0031] Figure 9 This is a second schematic diagram of the buffer component structure provided in this embodiment of the present invention;

[0032] Figure 10 yes Figure 2 DD section view;

[0033] Figure 11 yes Figure 10 Partial structural diagram;

[0034] Figure 12 This is a second schematic diagram showing a partial structure of the battery pack provided in this embodiment of the present invention;

[0035] Figure 13 This is a third schematic diagram showing a partial structure of the battery pack provided in this embodiment of the present invention.

[0036] In the picture:

[0037] 10. Battery housing; 11. Bottom protective plate; 111. Reinforcing protrusion; 12. Side beam; 121. Beam body; 122. First mounting part; 123. Second mounting part; 13. Locking component; 14. First sealing gasket;

[0038] 20. Liquid cooling plate; 21. Protruding flow channel; 22. Cooling flow channel; 23. Upper cooling plate; 24. Lower cooling plate;

[0039] 30. Buffer element; 31. First surface; 32. First recess; 33. Second surface; 34. Second recess;

[0040] 40. Support beam; 41. Longitudinal beam; 42. Cross beam;

[0041] 50. First fastener; 51. Rivet nut; 52. Locking bolt; 53. Second sealing gasket; 54. Third sealing gasket;

[0042] 60. Second fastener. Detailed Implementation

[0043] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0044] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0047] See Figures 1 to 9This embodiment provides a battery pack, including a battery housing 10, a liquid cooling plate 20, and a buffer 30. The battery housing 10 includes a bottom protective plate 11. The liquid cooling plate 20 is disposed on one side of the bottom protective plate 11 along the Z direction and located inside the battery housing 10. The buffer 30 is disposed between the bottom protective plate 11 and the liquid cooling plate 20. The first surface 31 of the buffer 30 along the Z direction makes conformal contact with the liquid cooling plate 20. A first recess 32 is provided on the first surface 31 corresponding to the protruding flow channel 21 of the liquid cooling plate 20. The protruding flow channel 21 and the first recess 32 are fitted together, so that the buffer 30 and the liquid cooling plate 20 are in full contact, which achieves a good vibration reduction effect to prevent the liquid cooling plate 20 from deforming due to vibration.

[0048] In this context, the Z direction is the thickness direction of the bottom protective plate 11. The buffer member 30 has a first recess 32 along the first surface 31 of the Z direction, which is the surface of the buffer member 30 near the liquid cooling plate 20 in the thickness direction, which is consistent with the direction of the protruding flow channel 21. The protruding flow channel 21 of the liquid cooling plate 20 is embedded in the first recess 32. Since the first surface 31 and the liquid cooling plate 20 are in conformal contact, the protruding flow channel 21 and the first recess 32 are in surface fit, increasing the contact area and improving the vibration reduction effect.

[0049] The liquid cooling plate 20 includes an upper cooling plate 23 and a lower cooling plate 24. The upper cooling plate 23 is located on the side of the lower cooling plate 24 away from the buffer member 30. The lower cooling plate 24 has a protruding flow channel 21 facing the buffer member 30. The protruding flow channel 21 and the upper cooling plate 23 form a cooling flow channel 22, in which coolant flows. For example, the cooling flow channel 22 is tortuous to extend the flow path of the coolant, increase the effective cooling area of ​​the liquid cooling plate 20, and improve the liquid cooling effect.

[0050] The first surface 31 is in conformal contact with the liquid cooling plate 20, that is, the first surface 31 is in conformal contact with the surface of the lower cooling plate 24 that is away from the upper cooling plate 23. The two surfaces follow and adapt to each other in shape. When the shape of one surface changes, the other surface that follows it will also adjust its shape accordingly to maintain the contact relationship.

[0051] The shape of the first recess 32 is adapted to the shape of the protruding flow channel 21 so that the protruding flow channel 21 and the first recess 32 fit together surface to surface. For example, the cross-sectional shape of the protruding flow channel 21 is U-shaped and the bend is rounded, and the cross-sectional shape of the first recess 32 is U-shaped and the bend is rounded. The size of the rounded corners of the two are the same to achieve surface-to-surface fit.

[0052] Since the buffer 30 is elastic, the first recess 32 provides space for the lateral expansion of the liquid cooling plate 20. If the liquid cooling plate 20 deforms laterally, it will squeeze the first recess 32, and then squeeze the buffer 30, causing the buffer 30 to undergo elastic deformation, thus avoiding rigid contact that could lead to leakage of the liquid cooling plate 20.

[0053] The second surface 33 of the buffer member 30 along the Z direction makes conformal contact with the bottom guard plate 11. A plurality of second recesses 34 are formed on the second surface 33. The second recesses 34 are used to accommodate the reinforcing protrusions 111 on the bottom guard plate 11. The first recesses 32 and the second recesses 34 form a dual-path buffer channel on the buffer member 30.

[0054] Among them, the second surface 33 of the buffer 30 along the Z direction, that is, the surface of the buffer 30 in the thickness direction, is close to the bottom guard plate 11. The reinforcing protrusion 111 of the bottom guard plate 11 is embedded in the second recess 34. Since the second surface 33 and the bottom guard plate 11 are in conformal contact, the reinforcing protrusion 111 and the second recess 34 are in surface fit, increasing the contact area and improving the vibration reduction effect.

[0055] The first recess 32 and the second recess 34 form a dual-path buffer channel on the buffer member 30. That is, for the buffer member 30, the first recess 32 fits into the protruding flow channel 21 on the liquid cooling plate 20, and the second recess 34 fits into the reinforcing protrusion 111 on the bottom guard plate 11. Both sides of the buffer member 30 play a good vibration reduction role, and the buffer member 30 absorbs high-frequency vibration.

[0056] The shape of the second recess 34 is adapted to the shape of the reinforcing protrusion 111 so that the reinforcing protrusion 111 and the second recess 34 are in close contact. For example, the cross-sectional shape of the reinforcing protrusion 111 is U-shaped and the bend is rounded, and the cross-sectional shape of the second recess 34 is U-shaped and the bend is rounded. The size of the rounded corners of the two are the same to achieve a close contact.

[0057] Since the liquid cooling plate 20 has multiple protruding flow channels 21, the corresponding buffer member 30 has multiple first recesses 32, some of which can communicate with each other. The spacing between adjacent first recesses 32 is set according to the position of the protruding flow channels 21, which will not be described in detail here. Since the bottom protective plate 11 has multiple reinforcing protrusions 111, the corresponding buffer member 30 has multiple second recesses 34, some of which can communicate with each other. The spacing between adjacent second recesses 34 is set according to the position of the reinforcing protrusions 111, which will not be described in detail here.

[0058] For the buffer 30, a first recess 32 is provided on the first surface 31 along the Z direction, and a second recess 34 is provided on the second surface 33 along the Z direction. The first recess 32 and the second recess 34 may be directly opposite each other in the Z direction, which will reduce the thickness of the buffer 30. Therefore, the thickness of the buffer 30 needs to be set reasonably. By providing the first recess 32 and the second recess 34, the weight of the buffer 30 is reduced, and the utilization rate of the buffer 30 is improved.

[0059] The buffer 30 can be made of existing elastic materials, foam materials, or other materials. For example, the buffer 30 is a foam component, preferably a high-elasticity foam. For example, the thickness of the buffer 30 along the Z-direction is 115%-225% of the thickness of the liquid-cooled plate 20 along the Z-direction. This ensures structural strength and prevents tearing of the buffer 30 after the first recess 32 and the second recess 34 are provided. Furthermore, the thicker buffer 30 allows for greater elastic deformation, thereby absorbing more impact or vibration energy and reducing the impact force transmitted to other components. For example, the compression rebound rate of the buffer 30 is ≥90%, exhibiting strong impact resistance, extending the duration of impact force, preventing instantaneous high load damage to the structure, and improving vibration damping effect.

[0060] See Figures 1 to 5 The battery housing 10 also includes side beams 12, with two side beams 12 distributed on both sides of the bottom protective plate 11 along the X direction. One side of the side beam 12 along the Z direction is connected to the bottom protective plate 11 by a locking member 13. The edge of the liquid cooling plate 20 is welded to the side beam 12. The side beam 12 is connected to the bottom protective plate 11 by the locking member 13, which facilitates installation and disassembly. The edge of the liquid cooling plate 20 is welded to the side beam 12 to ensure structural strength and prevent displacement of the liquid cooling plate 20, thus making the liquid cooling plate 20 stable.

[0061] The locking element 13 can be made of bolts, which can withstand a large load. Preferably, the edge of the liquid cooling plate 20 is connected to the side beam 12 by laser deep penetration welding, and the weld penetration depth is ≥ 70% of the thickness of the side beam 12. Laser deep penetration welding is a high-energy-density welding process that uses a focused laser beam to instantly vaporize the metal material to form vapor pressure. The vapor pressure displaces the molten metal to form a deep and narrow hole. The laser energy is absorbed through multiple reflections in the hole, achieving a high aspect ratio weld.

[0062] For example, the side beam 12 includes a beam body 121 and a first mounting portion 122 protruding along the X direction on one side of the beam body 121. The beam body 121 is connected to the bottom guard plate 11 by a locking member 13. The edge of the liquid cooling plate 20 is disposed between the first mounting portion 122 and the bottom guard plate 11 and is welded to the first mounting portion 122. The welding depth is 70%-80% of the thickness of the first mounting portion 122. By providing the first mounting portion 122, it is easy to overlap with the liquid cooling plate 20 for easy welding. The welding depth is 70%-80% of the thickness of the first mounting portion 122, which is relatively large, ensuring structural strength and connection stability. Figure 5 The dashed line in the middle indicates the weld.

[0063] The beam body 121 extends along the Y direction, the first mounting part 122 protrudes relative to the beam body 121 along the X direction, the length of the first mounting part 122 is along the Y direction, the width of the first mounting part 122 is along the X direction, and the thickness of the first mounting part 122 is along the Z direction.

[0064] A first sealing gasket 14 is sandwiched between the side beam 12 and the bottom protective plate 11, and a locking member 13 passes through the first sealing gasket 14. By providing the first sealing gasket 14, not only is a sealing function achieved, preventing external moisture from entering the inner side of the bottom protective plate 11, but the preload of the locking member 13 is also distributed over a larger contact surface, reducing the compressive stress on the contact surface, ensuring structural stability, and improving the impact resistance of the bottom protective plate 11. For example, the preload of the locking member 13 is between 8N and 12N.

[0065] The side beam 12 also includes a second mounting portion 123, which protrudes along the X direction on the other side of the beam body 121. That is, the first mounting portion 122 and the second mounting portion 123 are distributed on opposite sides of the beam body 121. The second mounting portion 123 is used to mount the battery box 10 to the electrical device.

[0066] See Figure 1 , Figure 2 , Figures 10 to 13 The battery pack also includes a support beam 40, which is disposed inside the battery housing 10. The bottom protective plate 11, the liquid cooling plate 20, and the support beam 40 are connected by first fasteners 50, and the liquid cooling plate 20 is connected to the support beam 40 by second fasteners 60. At least one second fastener 60 is provided between two adjacent first fasteners 50. By setting the first fasteners 50 and the second fasteners 60, the bottom protective plate 11, the liquid cooling plate 20, and the support beam 40 are securely connected. The provision of at least one second fastener 60 between two adjacent first fasteners 50 reduces structural stress, resulting in a balanced load distribution and a weight reduction effect. The difference in the natural frequencies of the two types of fasteners can disrupt resonant harmonics and improve vibration reduction.

[0067] The spacing L between the first fastener 50 and the second fastener 60 is 1.2-1.5 times the width D of the support beam 40, which reduces the number of fasteners while ensuring structural strength and improving assembly efficiency. Figure 11 L and D are shown in the figure. For example, the distance L between the first fastener 50 and the second fastener 60 is 1.2 times, 1.3 times, 1.4 times or 1.5 times the width D of the support beam 40.

[0068] For example, the first fastener 50 includes a rivet nut 51 and a locking bolt 52. The rivet nut 51 connects the liquid cooling plate 20 and the support beam 40, with its head located between the liquid cooling plate 20 and the bottom protective plate 11. The locking bolt 52 passes through the bottom protective plate 11 and is threadedly connected to the rivet nut 51, with its head located on the outside of the bottom protective plate 11. After riveting, the rivet nut 51 forms a mechanical interlock, making it more resistant to pulling and vibration. The locking bolt 52 can be easily disassembled, while the rivet nut 51 remains secure, facilitating maintenance or component replacement.

[0069] The first fastener 50 also includes a second sealing gasket 53, which is disposed between the head of the locking bolt 52 and the bottom protective plate 11. By providing the second sealing gasket 53, not only is it sealed to prevent external moisture from entering the inside of the bottom protective plate 11, but it also distributes the preload of the locking bolt 52 to a larger contact surface, reducing the compressive stress on the contact surface, ensuring structural stability, and improving the impact resistance of the bottom protective plate 11.

[0070] The first fastener 50 also includes a third sealing gasket 54, which passes through the locking bolt 52 and is positioned between the head of the rivet nut 51 and the bottom guard plate 11. By providing the third sealing gasket 54, a sealing effect is further achieved, preventing external moisture from entering the inside of the bottom guard plate 11, and avoiding rigid contact between the rivet nut 51 and the bottom guard plate 11, thus reducing the compressive stress on the contact surface, ensuring structural stability, and improving the impact resistance of the bottom guard plate 11.

[0071] For example, the second fastener 60 includes a blind rivet, which eliminates the need for double-sided operation and can be installed using a rivet gun on only one side, improving assembly efficiency. After riveting, it forms a mechanical interlock, making it more resistant to pull-out and vibration.

[0072] In this embodiment, the support beam 40 includes longitudinal beams 41 and transverse beams 42, which are vertically distributed. For example, the longitudinal beams 41 extend along the Y direction, and the transverse beams 42 extend along the X direction. Multiple transverse beams 42 are provided, arranged parallel to each other and at intervals.

[0073] Since at least one second fastener 60 is provided between two adjacent first fasteners 50, the positions where at least two first fasteners 50 are provided are correspondingly provided with second fasteners 60. For example, two second fasteners 60 are provided between two adjacent first fasteners 50, and the spacing between the two second fasteners 60 can be set according to actual needs.

[0074] In some embodiments, both the longitudinal beam 41 and the transverse beam 42 are provided with a first fastener 50 and a second fastener 60. In some embodiments, only the second fastener 60 is provided on the longitudinal beam 41, and the first fastener 50 and the second fastener 60 are provided on the transverse beam 42. In this embodiment, the longitudinal beam 41 is provided with a first fastener 50 and a second fastener 60, and the transverse beam 42 is provided with a second fastener 60. Optionally, the transverse beam 42 is provided with a first fastener 50. Exemplarily, for a plurality of transverse beams 42, at least two transverse beams 42 are provided with a first fastener 50, and at least one second fastener 60 is provided between two adjacent first fasteners 50.

[0075] This embodiment also provides an electrical device, including the battery pack described above. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0076] In some embodiments, the electrical device can be a gasoline-powered vehicle or a new energy vehicle, such as a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle. The electrical device has a battery pack internally. The battery pack can be used to power the electrical device; for example, it can serve as the operating power source for the device. The electrical device may also include a controller and a motor. The controller controls the battery pack to supply power to the motor, for example, to meet the power requirements of the device during startup, navigation, and operation.

[0077] The above embodiments merely illustrate the basic principles and characteristics of this utility model. This utility model is not limited to the above embodiments. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A battery pack, characterized by, include: Battery housing (10), including bottom protective plate (11); A liquid cooling plate (20) is disposed on one side of the bottom protective plate (11) along the Z direction and located inside the battery box (10), wherein the Z direction is the thickness direction of the bottom protective plate (11); A buffer (30) is disposed between the bottom protective plate (11) and the liquid cooling plate (20). The first surface (31) of the buffer (30) along the Z direction is in conformal contact with the liquid cooling plate (20). A first recess (32) is provided on the first surface (31) corresponding to the protruding flow channel (21) of the liquid cooling plate (20). The protruding flow channel (21) is fitted with the first recess (32).

2. The battery pack of claim 1, wherein, The second surface (33) of the buffer member (30) along the Z direction makes conformal contact with the bottom guard plate (11). A plurality of second recesses (34) are formed on the second surface (33). The second recesses (34) are used to accommodate the reinforcing protrusions (111) on the bottom guard plate (11). The first recesses (32) and the second recesses (34) form a dual-path buffer channel on the buffer member (30).

3. The battery pack of claim 1, wherein, The thickness of the buffer (30) along the Z direction is 115%-225% of the thickness of the liquid cooling plate (20) along the Z direction, and the compression rebound rate of the buffer (30) is ≥90%.

4. The battery pack of claim 1, wherein, The battery box (10) also includes side beams (12), two side beams (12) are distributed on both sides of the bottom guard plate (11) along the X direction, one side of the side beam (12) along the Z direction is connected to the bottom guard plate (11) by a locking member (13), and the edge of the liquid cooling plate (20) is welded to the side beams (12).

5. The battery pack of claim 4, wherein, The side beam (12) includes a beam body (121) and a first mounting part (122) protruding along the X direction on one side of the beam body (121). The beam body (121) is connected to the bottom guard plate (11) by the locking member (13). The edge of the liquid cooling plate (20) is located between the first mounting part (122) and the bottom guard plate (11) and is welded to the first mounting part (122). The depth of the weld is 70%-80% of the thickness of the first mounting part (122).

6. The battery pack of any one of claims 1-5, wherein, The battery pack also includes a support beam (40), which is disposed inside the battery housing (10). The bottom guard plate (11), the liquid cooling plate (20) and the support beam (40) are connected by a first fastener (50). The liquid cooling plate (20) and the support beam (40) are connected by a second fastener (60). At least one second fastener (60) is disposed between two adjacent first fasteners (50).

7. The battery pack of claim 6, wherein, The support beam (40) includes a longitudinal beam (41) and a transverse beam (42). The longitudinal beam (41) is provided with the first fastener (50) and the second fastener (60), and the transverse beam (42) is provided with the second fastener (60).

8. The battery pack of claim 6, wherein, The first fastener (50) includes: A rivet nut (51) connects the liquid cooling plate (20) and the support beam (40), with the head of the rivet nut (51) located between the liquid cooling plate (20) and the bottom protective plate (11); A locking bolt (52) is inserted through the bottom guard plate (11) and threadedly connected to the rivet nut (51). The head of the locking bolt (52) is located on the outside of the bottom guard plate (11).

9. The battery pack of claim 6, wherein, The distance L between the first fastener (50) and the second fastener (60) is 1.2-1.5 times the width D of the support beam (40).

10. An electrical device, characterized by Includes the battery pack as described in any one of claims 1-9.

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