Battery box body and battery pack

Abstract

The utility model provides a battery box body and a battery pack. Wherein the battery box body comprises a liquid cooling bottom plate; the side beam is connected with the liquid cooling bottom plate, the side beam and the liquid cooling bottom plate define a containing space used for containing a battery cell, the outer side face, away from the containing space, of the side beam is provided with a reinforcing protrusion arranged in a protruding mode, the surface of the reinforcing protrusion is provided with a fixing foot arranged in a protruding mode, and a curved-surface-shaped first stress reduction part is arranged between the fixing foot and the surface of the reinforcing protrusion. According to the utility model, the problem that the service life is influenced due to stress concentration of the battery pack box body in the prior art is solved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and more specifically, to a battery housing and a battery pack. Background Technology

[0002] Current battery pack enclosure designs primarily prioritize lightweighting, which often leads to the following problems when facing harsh operating conditions:

[0003] 1. Stress Concentration Issue: When the battery pack is integrated with the vehicle chassis frame, insufficient flatness of the frame can lead to uneven stress on the battery pack housing, resulting in excessive local stress and stress concentration. This can cause structural fatigue or damage, affecting not only the battery pack's lifespan but also potential safety hazards. These issues are particularly prominent in the assembly of electric heavy-duty and light-duty trucks.

[0004] 2. Insufficient structural strength: When the battery pack casing is subjected to long-term high loads and impacts and vibrations from complex road conditions, it is prone to structural deformation or damage, affecting the normal operation and safety of the battery pack.

[0005] 3. Insufficient impact resistance: In actual driving, vehicles often encounter sudden impacts or vibrations, such as when passing through potholes or encountering emergency braking, which may damage the internal components or housing of the battery pack. Utility Model Content

[0006] The main objective of this invention is to provide a battery housing and battery pack to solve the problem of stress concentration in the battery pack housing affecting its lifespan in the prior art.

[0007] To achieve the above objectives, according to one aspect of the present invention, a battery housing is provided, comprising: a liquid-cooled base plate; a side beam connected to the liquid-cooled base plate and forming a receiving space for accommodating battery cells, wherein the outer side of the side beam away from the receiving space has a protruding reinforcing protrusion, the surface of the reinforcing protrusion has a protruding fixing foot, and a curved first stress reduction portion is formed between the fixing foot and the surface of the reinforcing protrusion.

[0008] Furthermore, the reinforcing protrusion is located in the lower region of the outer side of the side beam, and the reinforcing protrusion is continuously arranged along the length of the side beam.

[0009] Furthermore, there are multiple fixing feet, each of which is spaced apart along the length of the reinforcing protrusion, forming a weight reduction area between each fixing foot, and a first stress reduction part is provided between the two sides of the fixing foot and the reinforcing protrusion.

[0010] Furthermore, a portion of the reinforcing protrusion protrudes from the bottom surface of the side beam, and a reinforcing part is provided between the portion of the reinforcing protrusion protruding from the bottom surface of the side beam and the bottom surface of the side beam. The reinforcing part is connected to both the reinforcing protrusion and the bottom surface of the side beam, and the reinforcing part has a second stress reduction part in the shape of a curved surface.

[0011] Furthermore, the side beam has a connecting section on its inner side facing the accommodating space, and the side beam is welded to the liquid-cooled base plate through the connecting section.

[0012] Furthermore, the side beam includes a front beam, and the battery box also includes a liquid cooling connector. The liquid cooling connector is an integral bent structure. One end of the liquid cooling connector is connected to the liquid cooling base plate, and the other end of the liquid cooling connector is connected to the front beam and extends out of the front beam.

[0013] Furthermore, a limiting structure is provided between the liquid cooling connector and the liquid cooling base plate and / or between the liquid cooling connector and the front beam. The limiting structure includes a limiting step and a limiting surface. When the liquid cooling connector is installed on the front beam and / or the liquid cooling base plate, the limiting step abuts against the limiting surface to restrict the installation position of the liquid cooling connector.

[0014] Furthermore, the liquid-cooled base plate includes: an outer shell having a liquid-cooled cavity; and multiple flow-dispersing parts disposed within the liquid-cooled cavity, forming a swirling flow channel within the liquid-cooled cavity.

[0015] Furthermore, the liquid-cooled base plate also includes a reinforcing section, which is disposed inside the liquid-cooled cavity and connected to the opposite sides of the liquid-cooled cavity to support the reinforced liquid-cooled cavity.

[0016] According to another aspect of the present invention, a battery pack is provided, including the battery housing described above.

[0017] By applying the technical solution of this utility model, reinforcing protrusions are provided on the side beams to improve their structural strength, thereby enhancing the overall structural strength of the battery box and enabling it to withstand greater stress. Simultaneously, a first stress-reducing portion is provided between the fixed feet and the surface of the reinforcing protrusions. This first stress-reducing portion acts as a buffer when the side beam is subjected to significant stress, preventing tearing at the fixed foot connection area, reducing structural fatigue or damage, and extending the service life of the battery box. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic diagram of the battery box of this utility model is shown;

[0020] Figure 2It shows Figure 1 Exploded view;

[0021] Figure 3 It shows Figure 2 Structural diagram of the middle side beam;

[0022] Figure 4 It shows Figure 3 Enlarged image in the image;

[0023] Figure 5 It shows Figure 3 Schematic diagram showing the location of the weight loss zone;

[0024] Figure 6 It shows Figure 3 Front view of the middle side beam;

[0025] Figure 7 It shows Figure 2 Schematic diagram of the structure of the liquid cooling joint;

[0026] Figure 8 It shows Figure 7 A schematic diagram of the structure in which the liquid cooling connector mates with the side beam and the liquid cooling base plate;

[0027] Figure 9 It shows Figure 2 A cross-sectional view of the liquid-cooled base plate.

[0028] The above figures include the following reference numerals:

[0029] 10. Liquid-cooled base plate; 11. Outer shell; 12. Turbulence section; 13. Reinforcing section; 20. Side beam; 21. Reinforcing protrusion; 22. Fixing foot; 23. First stress reduction section; 24. Weight reduction area; 25. Reinforcing section; 26. Second stress reduction section; 27. Connecting section; 28. Reinforcing structure; 30. Liquid-cooled joint; 40. Limiting structure; 50. Front fixing beam; 60. Rear fixing beam; 70. First flow channel plug; 80. Second flow channel plug; 90. Fire extinguishing controller bracket; 100. High-voltage cable tie; 110. Lifting lug; 120. Sealing nut; 130. Water-cooled pipe bracket. Detailed Implementation

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0032] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0033] To address the problem of stress concentration in the battery pack housing affecting its lifespan in existing technologies, this invention provides a battery housing and a battery pack. The battery pack includes the battery housing described below.

[0034] like Figures 1 to 9 The battery housing shown includes a liquid-cooled base plate 10 and a side beam 20. The side beam 20 is connected to the liquid-cooled base plate 10 and forms a receiving space for accommodating battery cells. The outer side of the side beam 20 away from the receiving space has a protruding reinforcing protrusion 21. The surface of the reinforcing protrusion 21 has a protruding fixing foot 22. There is a curved first stress reduction portion 23 between the fixing foot 22 and the reinforcing protrusion 21.

[0035] In this embodiment, a reinforcing protrusion 21 is provided on the side beam 20 to improve the structural strength of the side beam 20, thereby enhancing the overall structural strength of the battery box and enabling it to withstand greater stress. Simultaneously, a first stress-reducing portion 23 is provided between the surface of the fixing foot 22 and the reinforcing protrusion 21. This first stress-reducing portion 23 acts as a buffer when the side beam 20 is subjected to significant stress, preventing tearing at the connection area of ​​the fixing foot 22, reducing structural fatigue or damage, and extending the service life of the battery box.

[0036] like Figure 2 As shown, in this embodiment, multiple side beams 20 are provided, including a front beam, a rear beam, and two side beams. The front beam, one side beam, the rear beam, and the other side beam are sequentially connected to form the side portion of the battery box. The side portion has openings at the top and bottom, and a cover plate or other structure can be provided at the top, while a liquid-cooled base plate 10 is provided at the bottom, thereby forming a space capable of accommodating the battery cells. The front beam and the rear beam are... Figure 2 The two side beams 20 are located at the lower left and upper right, respectively. In this embodiment, the reinforcing protrusions 21 and fixing feet 22 are located on the side beams. The front and rear side beams do not have reinforcing protrusions 21 or fixing feet 22. The subsequent cavities and connecting sections 27 are also located on the side beams. Of course, the specific arrangement of the side beams 20 can be adjusted as needed, and the reinforcing protrusions 21 and fixing feet 22 can also be located on other side beams 20, such as the front and rear side beams.

[0037] like Figures 3 to 5As shown, in this embodiment, the reinforcing protrusion 21 is located in the lower region of the outer side of the side beam 20. That is, the reinforcing protrusion 21 is at the bottom side of the side beam 20. Since the bottom of the side beam 20 is the main stress-bearing area, placing the reinforcing protrusion 21 at this location adapts to the stress conditions of the side beam 20, ensuring the structural reinforcement effect. Simultaneously, in this embodiment, the reinforcing protrusion 21 is continuously arranged along the length of the side beam 20, and the length of the reinforcing protrusion 21 roughly covers the entire length of the side beam 20, thereby improving the effect of strengthening the structural strength. The specific protrusion distance of the reinforcing protrusion 21, that is, the distance between the surface of the reinforcing protrusion 21 and the outer side of the side beam 20, can be adjusted as needed. In this embodiment, the protrusion distance of the reinforcing protrusion 21 is relatively small, thus emphasizing the effect of improving structural strength while reducing the impact on space occupation and other aspects.

[0038] Optionally, the number of fixing feet 22 can be set as needed, either one or more. In this embodiment, multiple fixing feet 22 are provided, with each fixing foot 22 spaced apart along the length of the reinforcing protrusion 21. Due to the spaced arrangement, a weight reduction area 24 is naturally formed between each fixing foot 22. The weight reduction area 24 allows the side beam 20 to reduce its mass while ensuring that the structural performance meets the requirements, thereby improving the overall energy density of the battery pack. Since multiple fixing feet 22 are provided, a first stress reduction part 23 is provided on both sides of each fixing foot 22 between it and the reinforcing protrusion 21, so that the stress reduction matches the fixing foot 22, improving the stress buffering effect, further reducing stress concentration, and ensuring structural strength and impact resistance. The fixing feet 22 are the parts that fix the battery pack to the vehicle frame. The fixing feet 22 can be provided with structures such as mounting holes to achieve the connection with the vehicle frame.

[0039] like Figure 6 As shown, in this embodiment, a portion of the reinforcing protrusion 21 protrudes beyond the bottom surface of the side beam 20, meaning the lower surface of the reinforcing protrusion 21 is lower than the lower surface of the side beam 20. This creates a space between the side of the reinforcing protrusion 21 facing the accommodating space and the bottom surface of the side beam 20. A reinforcing portion 25 is provided in this space; that is, a reinforcing portion 25 is provided between the portion of the reinforcing protrusion 21 protruding beyond the bottom surface of the side beam 20 and the bottom surface of the side beam 20. The top surface of the reinforcing portion 25 connects to the bottom surface of the side beam 20, and the side surface of the reinforcing portion 25 connects to the reinforcing protrusion 21. Thus, the reinforcing portion 25 further connects the reinforcing protrusion 21 and the side beam 20, making the connection between the reinforcing protrusion 21 and the side beam 20 more stable and reliable. Simultaneously, this embodiment provides a curved second stress-reducing portion 26 at the reinforcing portion 25. The function of the second stress-reducing portion 26 is basically the same as that of the first stress-reducing portion 23; the second stress-reducing portion 26 reduces stress concentration on the side beam 20, acting as a stress buffer, thereby improving the overall structural strength of the side beam 20.

[0040] In this embodiment, both the first stress-reducing portion 23 and the second stress-reducing portion 26 are arc-shaped. The specific size of the arc is related to its position. Since the first stress-reducing portion 23 is located between the fixing foot 22 and the reinforcing protrusion 21, it serves to connect the fixing foot 22 and the reinforcing protrusion 21, thus ensuring that the arc of the first stress-reducing portion 23 smoothly transitions with the surfaces of both the reinforcing protrusion 21 and the fixing foot 22. The second stress-reducing portion 26, being located on the reinforcing portion 25, has an arc shape that protrudes away from the bottom surface of the side beam 20 and the side surface of the reinforcing protrusion 21. Of course, the specific arrangement of the first stress-reducing portion 23 and the second stress-reducing portion 26 is not limited to the form described in this embodiment; they can be adjusted as needed, as long as they can effectively buffer stress.

[0041] In this embodiment, a connecting section 27 is provided on the inner side of the side beam 20 facing the receiving space. The connecting section 27 extends into the receiving space, and the side beam 20 is connected to the liquid-cooled base plate 10 through the connecting section 27. In this embodiment, the side beams 20 are connected to each other and the side beams 20 are connected to the liquid-cooled base plate 10 by welding. The welding connection method can make the overall structural strength of the battery box higher. When the battery pack is integrated with the vehicle, even if the flatness control of the vehicle frame is poor, the battery pack can withstand this harsh condition. For example, the connecting section 27 and the liquid-cooled base plate 10 are arranged in a roughly horizontally parallel and aligned manner. The upper and lower surfaces of both can be arranged flush. During connection, the flush upper and lower surfaces of the two can be welded together by friction welding or other methods.

[0042] In this embodiment, the side beam 20 adopts a shell structure with an internal cavity. At the same time, a weight-reducing structure is also provided in the connecting section 27. The weight-reducing structure can take the form of weight-reducing holes, weight-reducing grooves, etc. The cavity and the weight-reducing structure are similar to the aforementioned weight-reducing area 24. Both can reduce the mass of the side beam 20 while ensuring that the structural performance meets the requirements, thereby improving the overall mass energy density of the package.

[0043] In this embodiment, a reinforcing structure 28 is also provided within the cavity of the side beam 20. The reinforcing structure 28 can also take the form of ribs or other structures. By reinforcing the structure 28, the structural strength of the side beam 20 can be improved, thereby reducing the impact of the cavity on the structural strength of the side beam 20 and ensuring that the structural strength of the side beam 20 meets the requirements. When the battery pack is subjected to destructive conditions such as impact, the side beam 20 can withstand greater forces. At the same time, the cavity also acts as a buffer, absorbing most of the force, ensuring that the battery pack is protected from damage to the internal cells when impacted, thereby reducing the risk of fire and explosion.

[0044] like Figure 7and Figure 8 As shown, in this embodiment, the battery housing also includes a liquid-cooled connector 30. The liquid-cooled connector 30 is an integrally bent structure. One end of the liquid-cooled connector 30 is connected to the liquid-cooled base plate 10, and the other end of the liquid-cooled connector 30 is connected to and extends through the side beam 20. It should be noted that in this embodiment, the side beam 20 that cooperates with the liquid-cooled connector 30 is the front beam, and the liquid-cooled connector 30 extends out from the front beam on the front end face of the battery housing. Through the integrally bent liquid-cooled connector 30, the liquid-cooled connector 30 has both connection and conveying functions, ensuring the reliability of connection and conveying.

[0045] Optionally, a limiting structure 40 is provided between the liquid cooling connector 30 and the liquid cooling base plate 10 and / or between the liquid cooling connector 30 and the front beam. In this embodiment, a limiting structure 40 is provided between the liquid cooling connector 30 and the liquid cooling base plate 10 and between the liquid cooling connector 30 and the front beam, so that the liquid cooling connector 30 can be accurately installed when it is installed on the liquid cooling base plate 10 and the front beam. Then, the connection and fixation between the liquid cooling connector 30 and the liquid cooling base plate 10 and the front beam can be achieved by welding, ensuring the reliability of the connection.

[0046] The limiting structure 40 in this embodiment includes a limiting step and a limiting surface. When the liquid-cooled connector 30 is installed on the side beam 20 and / or the liquid-cooled base plate 10, the limiting step abuts against the limiting surface. The installation position of the liquid-cooled connector 30 is limited by the fit between the step surface of the limiting step and the limiting surface to ensure accurate docking and facilitate welding operations. Specifically, in this embodiment, a limiting step is provided on the liquid-cooled connector 30, and a limiting surface is provided on the side beam 20 and the liquid-cooled base plate 10. The limiting step can be formed in various ways. A radially extending protrusion can be provided on the circumferential side of the liquid-cooled connector 30 to form the limiting step. Alternatively, an annular groove can be provided on the circumferential side of the liquid-cooled connector 30 to form the limiting step. The limiting surface can be naturally formed by the surfaces of the side beam 20 and the liquid-cooled base plate 10, or a stepped hole can be provided on the side beam 20 and the liquid-cooled base plate 10 to form the limiting surface. In this embodiment, a protrusion is provided at one end of the liquid-cooled connector 30 facing the side beam 20, and an annular groove is provided at the other end facing the liquid-cooled base plate 10. The edge portion of the through hole of the side beam 20 facing the accommodating space serves as a limiting surface, and the upper surface of the liquid-cooled base plate 10 serves as a limiting surface. This allows the limiting step to abut against the limiting surface when the liquid-cooled connector 30 is installed on the liquid-cooled base plate 10 and passes through the side beam 20, thereby ensuring the accuracy of the position during docking and the accuracy of welding. At the same time, it can also prevent the weld seam from tearing and causing leakage when the liquid-cooled connector 30 is under stress.

[0047] like Figure 9As shown, in this embodiment, the liquid cooling base plate 10 is manufactured by profile extrusion process. The liquid cooling base plate 10 includes a shell 11 and multiple flow-dispersing parts 12. The shell 11 has a liquid cooling cavity, and the flow-dispersing parts 12 are disposed in the liquid cooling cavity. The flow-dispersing parts 12 can adopt structural forms such as ribs or partitions. The arrangement of the flow-dispersing parts 12 in the liquid cooling cavity makes the liquid cooling cavity form S-shaped, M-shaped and other swirling flow channels. Cooling medium such as cooling water can flow in the flow channels, thereby realizing the heat dissipation and cooling effect of the battery cell.

[0048] Meanwhile, when machining the flow-dissipating part 12, it can be first machined to extend the flow-dissipating part 12 to both ends opposite to the liquid cooling cavity, and then the ends of the flow-dissipating part 12 can be CNC machined and removed. Figure 9 The shaded portion at the end of the middle turbulence section 12 is CNC machined to remove the shaded portion, thereby further dividing the flow channel into multiple parallel sub-flow channels. This machining can make the flow distribution in the flow channel more uniform through a specific shape, ensuring the consistency of flow in each flow channel, reducing the pressure drop, thereby improving the cooling performance and achieving better temperature uniformity of the battery pack.

[0049] The liquid-cooled base plate 10 in this embodiment also includes a reinforcing portion 13. The reinforcing portion 13 is disposed inside the liquid-cooling cavity and connected to the opposite sides of the liquid-cooling cavity to support it. In this embodiment, the reinforcing portion 13 and the flow-disrupting portion 12 are arranged in a generally parallel manner. The reinforcing portion 13 is connected to the upper and lower inner wall surfaces of the liquid-cooling cavity, thereby providing support and reinforcement for the liquid-cooling cavity. At the same time, the width of the reinforcing portion 13 is greater than or equal to the width of the flow-disrupting portion 12. The width referred to here is also the thickness of the reinforcing portion 13 and the flow-disrupting portion 12, which helps to improve the structural strength of the liquid-cooled base plate 10, prevents the flow channels from collapsing, and enables the liquid-cooled base plate 10 to withstand high loads, further improving the overall structural strength of the battery box. Similar to the flow-disrupting portion 12, the reinforcing portion 13 can also adopt a rib or partition structure. Of course, the arrangement of the liquid-cooled base plate 10 is not limited to the arrangement described in this embodiment, and other arrangements can also be adopted, such as directly forming multiple parallel flow channels.

[0050] like Figure 2As shown, the battery housing in this embodiment also includes components such as a front fixed beam 50, a rear fixed beam 60, a first flow channel plug 70, a second flow channel plug 80, a fire extinguishing controller bracket 90, a high-voltage cable tie 100, a lifting lug 110, a sealing nut 120, and a water-cooled pipe bracket 130. The battery housing manufacturing process is as follows: First, the liquid-cooled base plate 10 is friction-stirred with the first flow channel plug 70 and the second flow channel plug 80 to seal the openings on both sides of the liquid-cooled cavity. Next, the liquid-cooled connector 30 is welded to the liquid-cooled base plate 10. At this time, the limiting step of the liquid-cooled connector 30 plays a role in ensuring the positional accuracy and height of the liquid-cooled connector 30 during welding. Then, the two side beams are welded to the liquid-cooled base plate 10 through the connecting section 27 using friction-stirring welding. Next, weld the front beam and the rear beam onto the liquid-cooled base plate 10. Then weld the front fixed beam 50 and the rear fixed beam 60 onto the liquid-cooled base plate 10. Next, weld the fire extinguishing controller bracket 90, the high-voltage cable tie 100, the lifting lug 110, and the water-cooled pipe bracket 130. Finally, install the sealing nut 120.

[0051] It should be noted that "multiple" in the above embodiments refers to at least two.

[0052] As can be seen from the above description, the embodiments of this utility model achieve the following technical effects:

[0053] 1. This technology solves the problem of stress concentration in the battery pack housing affecting its lifespan in existing technologies;

[0054] 2. The overall structural strength of the battery box can be improved, and it can withstand greater stress;

[0055] 3. The stress reduction section will act as a buffer when the side beam is subjected to large stress, thereby preventing tearing in the connection area, reducing structural fatigue or damage, and extending the service life of the battery box.

[0056] 4. The overall structural strength of the battery pack is higher. When the battery pack is integrated with the vehicle, even if the flatness of the vehicle frame is poor, the battery pack can withstand this harsh working condition.

[0057] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0058] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0059] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0060] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A battery case characterized by comprising: The battery box body comprises: a liquid cooling bottom plate (10); a side beam (20) connected with the liquid cooling bottom plate (10) and surrounding the liquid cooling bottom plate (10) to form a containing space for containing an electric core, the side beam (20) has a reinforcing protrusion (21) protruding outward from an outer side of the containing space, a surface of the reinforcing protrusion (21) has a fixing foot (22) protruding outward, and the fixing foot (22) and the surface of the reinforcing protrusion (21) have a first stress reduction part (23) in a curved shape.

2. The battery pack of claim 1, wherein The reinforcing protrusion (21) is located at a lower region of the outer side of the side beam (20) and is continuously arranged along a length direction of the side beam (20).

3. The battery pack of claim 2, wherein, The fixing foot (22) is in a plurality, each fixing foot (22) is arranged at intervals along a length direction of the reinforcing protrusion (21), a weight reduction region (24) is formed between each fixing foot (22), and the first stress reduction part (23) is arranged between both sides of the fixing foot (22) and the reinforcing protrusion (21).

4. The battery pack of claim 1, wherein, A part of the reinforcing protrusion (21) protrudes from a bottom surface of the side beam (20), a reinforcing part (25) is arranged between the part of the reinforcing protrusion (21) protruding from the bottom surface of the side beam (20) and the bottom surface of the side beam (20), the reinforcing part (25) is connected with the reinforcing protrusion (21) and the bottom surface of the side beam (20), and the reinforcing part (25) has a second stress reduction part (26) in a curved shape.

5. The battery pack of claim 1, wherein, The side beam (20) is provided with a connecting section (27) toward an inner side of the containing space, and the side beam (20) is welded to the liquid cooling bottom plate (10) through the connecting section (27).

6. The battery pack of claim 1, wherein, The side beam (20) comprises a front beam, and the battery box body further comprises a liquid cooling connector (30) in an integrated bending structure, one end of the liquid cooling connector (30) is connected with the liquid cooling bottom plate (10), and the other end of the liquid cooling connector (30) is connected with the front beam and penetrates through the front beam.

7. The battery pack of claim 6, wherein, A limiting structure (40) is arranged between the liquid cooling connector (30) and the liquid cooling bottom plate (10) and / or between the liquid cooling connector (30) and the front beam, the limiting structure (40) comprises a limiting step and a limiting surface, and when the liquid cooling connector (30) is installed on the front beam and / or the liquid cooling bottom plate (10), the limiting step and the limiting surface abut to limit the installation position of the liquid cooling connector (30).

8. The battery pack of claim 1, wherein, The liquid cooling bottom plate (10) comprises: an outer shell (11) having a liquid cooling cavity; a plurality of turbulence parts (12) arranged in the liquid cooling cavity and forming a spiral flow channel in the liquid cooling cavity.

9. The battery pack of claim 8, wherein, The liquid cooling bottom plate (10) further comprises a reinforcing part (13) arranged in the liquid cooling cavity and connected with both sides of the liquid cooling cavity to support and reinforce the liquid cooling cavity.

10. A battery pack, characterized by, The battery box body comprises any one of claims 1 to 9.

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