Battery box and battery device

Abstract

The utility model provides a kind of battery box and battery device, wherein, battery box includes bottom plate and the frame of setting in bottom plate edge, bottom plate and frame are integrally formed, and form the containing space containing battery, frame includes two oppositely arranged side edge beams and two oppositely arranged end edge beams, side edge beam is formed cavity after bending, end edge beam is single-layer plate structure, between adjacent end edge beam and side edge beam by welding connection, in along the arrangement direction of two side edge beams, side edge beam includes first side and second side, first side is close to containing space, second side is away from containing space, end edge beam and side edge beam first side or second side are welded.In processing, only need to weld adjacent side edge beam and end edge beam, so the number of connection weld of battery box is less, and the length of weld is shorter, it is favorable to guarantee the sealing performance in battery box.

Description

Technical Field

[0001] This utility model relates to the field of secondary battery technology, specifically to a battery box and battery device. Background Technology

[0002] The battery pack is a core component of new energy vehicles. The battery pack includes a battery box, which consists of a base plate and a frame, forming a space to house the battery. In existing technologies, the battery box is typically formed by welding profiles along the edges of sheet metal. However, this method requires welding between the profiles and sheet metal, and between adjacent profiles, resulting in numerous weld seams and making it difficult to guarantee the sealing performance within the battery box. Utility Model Content

[0003] Therefore, the technical problem to be solved by this utility model is to overcome the defect that the battery box in the prior art has many welds and it is difficult to guarantee the sealing performance, thereby providing a battery box and battery device.

[0004] To address the aforementioned problems, this utility model provides a battery box, comprising a base plate and a frame disposed along the edge of the base plate. The base plate and the frame are integrally formed, enclosing a storage space for accommodating batteries. The frame includes two opposing side beams and two opposing end beams. The side beams are bent to form cavities, and the end beams are single-layer plate structures. Adjacent end beams and side beams are connected by welding. Along the arrangement direction of the two side beams, each side beam includes a first side and a second side. The first side is close to the storage space, and the second side is away from the storage space. The end beams are welded to the first side of the side beams that is close to the storage space; and / or, the end beams are welded to the second side of the side beams that is away from the storage space.

[0005] This utility model has the following advantages: The battery box using the technical solution of this utility model includes a base plate and a frame, which are integrally formed. The frame includes side beams and end beams. The side beams are bent to form cavities, thereby ensuring the structural strength of the battery box. The end beams are single-layer plate structures. During processing, only adjacent side beams and end beams need to be welded together. Therefore, the number of welds in the battery box is small, and the weld length is short, which helps to ensure the sealing performance inside the battery box. Therefore, the technical solution of this utility model solves the defect of existing battery boxes having many welds, making it difficult to ensure sealing performance. Attached Figure Description

[0006] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0007] Figure 1 A schematic diagram of the structure of a first embodiment of the battery box of this utility model is shown; Figure 2 It shows Figure 1 A schematic diagram of the connection between the side beams and end beams of the middle battery box; Figure 3 It shows Figure 1 A schematic diagram of the cavity structure of the battery box; Figure 4 Also released Figure 1 A schematic diagram of a structure where the height of the cavity in the middle battery box is less than the height of the side beams; Figure 5 It shows Figure 1 A schematic diagram showing the connection between the side beam of the middle battery box and the first reinforcing beam; Figure 6 It shows Figure 1 A schematic diagram of the end beam of the middle battery box; Figure 7 It shows Figure 1 A schematic diagram of the connection between the side beams and end beams of the middle battery box from the bottom view; Figure 8 It shows Figure 1 A structural diagram showing the first, second, and third reinforcing beams installed in the central battery box; Figure 9 It shows Figure 1 Cross-sectional view of the middle battery box at the third reinforcing beam; Figure 10 A schematic diagram of the structure of a second embodiment of the battery box of this utility model is shown; Figure 11 It shows Figure 10 Cross-sectional view of the battery box at the third reinforcing beam.

[0008] Explanation of reference numerals in the attached figures: 10. Base plate; 20. Frame; 21. Side beam; 211. First side; 212. Second side; 22. End beam; 221. First flange; 222. Second flange; 2221. Through hole; 223. Third flange; 224. Protrusion; 30. Cavity; 301. Folded edge; 302. Cavity body; 303. Tail end; 31. First sub-cavity; 32. Second sub-cavity; 40. First weld; 50. First reinforcing beam; 60. Second weld; 70. Third weld; 80. First arc transition section; 90. Second arc transition section; 100. Second reinforcing beam; 110. Third reinforcing beam; 111. Bending part; 120. Electrical compartment. Detailed Implementation

[0009] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0010] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0011] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0012] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0013] Example 1 like Figure 1 and Figure 2As shown, according to an embodiment of the battery box of this application, a base plate 10 and a frame 20 disposed along the edge of the base plate 10 are included. The base plate 10 and the frame 20 are integrally formed, enclosing a space for accommodating the battery. The frame 20 includes two opposing side beams 21 and two opposing end beams 22. The side beams 21 are bent to form cavities 30, and the end beams 22 are single-layer plate structures. Adjacent end beams 22 and side beams 21 are connected by welding.

[0014] Using the technical solution of this embodiment, the battery box includes a base plate 10 and a frame 20, which are integrally formed. The frame 20 includes side beams 21 and end beams 22. The side beams 21 are bent to form cavities 30, thereby ensuring the structural strength of the battery box. The end beams 22 are single-layer plate structures. During processing, only adjacent side beams 21 and end beams 22 need to be welded together. Therefore, the number of welds in the battery box is small, and the length of the welds is short, which is beneficial to ensuring the sealing performance inside the battery box. Therefore, the technical solution of this embodiment solves the defect of existing battery boxes having many welds, making it difficult to ensure sealing performance.

[0015] It should be noted that the "single-layer plate structure" mentioned above refers to the fact that the end beam 22 does not have a cavity and is a plate structure, or it can be called an end plate.

[0016] Combination Figure 1 and Figure 2 As can be seen, in the battery box of this embodiment, the junction of the side beam 21 and the bottom plate 10, as well as the junction of the end beam 22 and the bottom plate 10, are all integral structures. Therefore, these two junctions do not need to be connected by welding, which ensures the sealing performance of these two junctions.

[0017] Furthermore, the side beams 21 and end beams 22 are relatively low in height, so the weld length at the connection point of the side beams 21 and end beams 22 is shorter, which also helps to ensure the sealing performance at the side beams 21 and end beams 22.

[0018] Furthermore, in this embodiment, cavities 30 are provided in a pair of side beams 21, which can ensure the structural strength of the battery box sides. The other pair of end beams 22 are single-layer plate structures, so they can be fixed to the side beams 21 with a single weld, thereby reducing the number of welding operations and improving sealing performance while ensuring strength. At the same time, since the end beams 22 are single-layer plate structures, the internal space of the box is guaranteed, improving the space utilization rate of the box.

[0019] like Figure 2As shown, in the technical solution of this embodiment, the end beam 22 is welded to the first side 211 of the side beam 21 near the accommodating space.

[0020] Specifically, with Figure 2 For example, the content shown below, Figure 2 The side of the side beam 21 shown that is closest to the accommodating space refers to its right-hand side, that is... Figure 2 The first side 211 is shown in the figure.

[0021] This design ensures that after the end beam 22 is welded to the side beam 21, the end beam 22 does not cover the cavity 30. This prevents welding slag from falling into the cavity 30 during welding and also makes it easier to remove welding slag and other foreign objects from the cavity 30. Therefore, it can reduce the risk of foreign objects entering the battery pack.

[0022] Optionally, the outer surface of the end beam 22 is flush with the end of the side beam 21, so as to maximize the capacity inside the battery box.

[0023] In one embodiment not shown, the end beam 22 may also be welded to the second side 212 of the side beam 21 on the side away from the receiving space.

[0024] by Figure 2 The contents shown are explained below. The end beam 22 can also be extended so that the end beam 22 and... Figure 2 The side of the side beam 21 shown is away from the receiving space, that is... Figure 2 The second side 212 is shown as welded.

[0025] This configuration allows the end beam 22 and the side beam 21 to be welded together to enclose the cavity 30. The cavity 30 is a closed cavity and exists inside the battery box. Therefore, the cavity 30 can serve as an exhaust channel to facilitate the exhaust of the battery box in case of thermal runaway.

[0026] like Figure 3 As shown, in the technical solution of this embodiment, the ratio of the width a of the cavity 30 to the thickness b of the plate of the side beam 21 along the arrangement direction of the two side beams 21 is in the range of 15 to 30.

[0027] First, it should be noted that the "ratio of the width a of the cavity 30 to the thickness b of the plate of the side beam 21" in this embodiment refers to the former being the latter, that is, the value of a / b. Other similar expressions in this document have the same meaning and will not be repeated hereafter.

[0028] It should be noted that the width 'a' of cavity 30 refers to Figure 3The dimensions in the left and right directions. Furthermore, the greater the thickness b of the plate of the side beam 21, the higher the strength of the side beam 21. Therefore, the requirement for the width a of the cavity 30 can be appropriately reduced, thereby increasing the battery box capacity.

[0029] Furthermore, when a and b are within a suitable range, the strength and sealing of the side beam 21 of the battery box can be guaranteed while ensuring a light weight. When the plate thickness b of the side beam 21 is large, the width a of the cavity 30 inside the side beam 21 needs to be supplemented by a certain value. However, the width a of the cavity 30 needs to be a reasonable value. If the width b of the cavity 30 is too wide, the cavity 30 will occupy a large volume of the box, affecting the number of batteries that can be placed, thereby reducing the energy density of the box. If the width a of the cavity 30 is too small, on the one hand, the strength of the side beam 21 will be reduced, and on the other hand, because the width a is too small, the plane between the top of the cavity 30 and the sealing surface of the box cover will be narrow, making sealing more difficult and thus resulting in poor sealing performance.

[0030] Optionally, the ratio of the width a of the cavity 30 to the thickness b of the plate of the side beam 21 can be selected as 15, 20, 25 or 30, etc., or any value between the two values.

[0031] Furthermore, the width a of the cavity 30 is in the range of 22mm to 35mm.

[0032] For example, the width 'a' of cavity 30 can be selected as 22mm, 24mm, 28mm, 30mm, 32mm, or 35mm, or any value between two values.

[0033] Preferably, the width a of the cavity 30 is 25 mm.

[0034] Furthermore, the thickness b of the plate of the side beam 21 ranges from 0.8 mm to 2 mm.

[0035] For example, the thickness b of the plate of the side beam 21 can be selected as 0.8 mm, 1 mm, 1.2 mm, 1.5 mm or 2 mm, etc., or any value between the two values.

[0036] Preferably, the thickness b of the plate of the side beam 21 is 1.2 mm.

[0037] like Figure 1 and Figure 3 As shown, in the technical solution of this embodiment, the ratio of the width a of the cavity 30 to the length c of the side beam 21 along the arrangement direction of the two side beams 21 is in the range of 15 to 125.

[0038] Specifically, the longer the length c of the side beam 21, the wider the corresponding cavity 30 width a, the easier it is to seal, resulting in better battery box sealing.

[0039] For example, the ratio of the width of the cavity 30 to the length of the side beam 21 can be 15, 30, 50, 100 or 125, etc., or any value between the two.

[0040] Furthermore, the length c of the side beam 21 ranges from 500mm to 2500mm.

[0041] For example, the length c of the side beam 21 can be selected as 500mm, 700mm, 1000mm, 1500mm, 2000mm or 2500mm, etc., or any value between two values.

[0042] Preferably, the length c of the side beam 21 is 2000mm.

[0043] like Figure 3 As shown, in the technical solution of this embodiment, the ratio of the height h1 of the cavity 30 to the height h2 of the side beam 21 is in the range of 0.1 to 1.

[0044] The height direction is the direction perpendicular to the plane where the base plate 10 is located.

[0045] Specifically, if the height h1 of the cavity 30 is too low, it will not effectively reinforce the side beam 21, or its reinforcing effect will be limited. However, if the height h1 of the cavity 30 is too high, the cavity 30 will occupy a large volume, which will affect the volumetric energy density of the battery box.

[0046] Figure 3 The diagram shows a case where the height h1 of the cavity 30 is basically the same as the height h2 of the side beam 21 (there is a difference of two profile thicknesses between them).

[0047] Figure 4 The diagram shows the case where the height h1 of the cavity 30 is lower than the height h2 of the side beam 21.

[0048] For example, the ratio of the height h1 of the cavity 30 to the height h2 of the side beam 21 can be selected as 0.1, 0.3, 0.5, 0.7 or 1, or any value between the two values.

[0049] Optionally, the height h1 of the cavity 30 is in the range of 15mm to 150mm.

[0050] For example, the height h1 of cavity 30 can be selected as 15mm, 30mm, 50mm, 70mm, 100mm or 150mm, etc., or any value between two values.

[0051] Optionally, the height h2 of the side beam 21 is in the range of 30mm to 150mm.

[0052] For example, the height h2 of the side beam 21 can be selected as 30mm, 50mm, 70mm, 100mm or 150mm, etc., or any value between the two values.

[0053] like Figure 4 As shown, in the technical solution of this embodiment, the cavity 30 includes a first sub-cavity 31 and a second sub-cavity 32 arranged along a direction perpendicular to the base plate 10. The first sub-cavity 31 is located on the side of the second sub-cavity 32 away from the base plate 10, and along the direction perpendicular to the base plate 10, the ratio of the height h11 of the second sub-cavity 32 to the height h1 of the cavity 30 is in the range of 0.05 to 0.95.

[0054] Specifically, from Figure 3 As can be seen, two layers of plates are installed at the position corresponding to the side beam 21 of the second sub-cavity 32. Therefore, the larger the proportion of the height h11 of the second sub-cavity 32, the larger the proportion of the two layers of plates, and the higher the strength of the side beam 21. However, the proportion of the height h11 of the second sub-cavity 32 should not be too large, as this would make the battery box too heavy.

[0055] For example, the ratio of the height of the second sub-cavity 32 to the height h1 of the h11 cavity 30 can be selected as 0.05, 0.1, 0.3, 0.5, 0.7, 0.9 or 0.95, etc., or any value between the two values.

[0056] The height of the second sub-cavity 32 and h11 are in the range of 10mm to 140mm.

[0057] For example, the height of the second sub-cavity 32 and h11 can be selected as 10mm, 20mm, 50mm, 70mm, 100mm or 140mm, etc., or any value between the two values.

[0058] like Figure 3 As shown, in the technical solution of this embodiment, on the side of the second sub-cavity 32 near the receiving space, there are at least two layers of plates between the second sub-cavity 32 and the receiving space, and the two adjacent layers of plates are welded and fixed.

[0059] This design can further improve the strength of cavity 30.

[0060] In this embodiment, the second sub-cavity 32 and the receiving space include two layers of plates. Of course, in some embodiments not shown, the second sub-cavity 32 and the receiving space may also include more than two layers of plates.

[0061] Furthermore, in this embodiment, three methods can be used to weld the two layers of plates described above.

[0062] The first method involves welding between the two bottom layers, which is a relatively easy welding process, but its strength is weaker. The second method is to perform penetration welding on the side inside the box, which results in higher welding strength. However, the weld will leave weld marks on the side beam 21 facing the inner surface of the box, affecting the installation of the battery. The third method involves welding inside the cavity 30, which results in higher strength, but the welding process is difficult to implement.

[0063] In this embodiment, the second method is preferred for welding the two layers of plates.

[0064] like Figure 3 As shown, in the technical solution of this embodiment, the relationship between the weld width d1 of the weld between two adjacent layers of plates and the ratio of the height h11 of the second sub-cavity 32 to the height h1 of the cavity 30 satisfies the following relationship: 3≤d1 / (h11 / h1)≤20.

[0065] Specifically, the higher the height h11 of the second sub-cavity 32, the larger the surface that needs to be fixed by welding, and the larger the total width d1 of the weld also needs to be, in order to improve the fixing effect of the second sub-cavity 30.

[0066] For example, the weld width d1 of the two plates, the height h11 of the second sub-cavity 32 and the height h1 of the cavity 30 can be 3, 5, 10, 15 or 20, or any value between the two values, based on the above relationship.

[0067] Furthermore, the weld width d1 between adjacent layers of plates is within the range of 1mm to 6mm. Specifically, the weld width d1 cannot be too large or too small. If the weld width d1 is too large, the weld area will be too large, increasing the risk of air leakage and sealing failure. If the weld width d1 is too small, the weld strength between the two layers of plates will be low, making it easy for the weld position of the second sub-cavity 32 to break and detach outward.

[0068] For example, the weld width d1 of the two adjacent plates can be selected as 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, etc., or any value between the two values.

[0069] Further, the ratio of the height h11 of the second sub-cavity 32 to the height h1 of the cavity 30 represents the magnitude of the height h11 of the second sub-cavity 32. If the ratio of the height h11 of the second sub-cavity 32 to the height h1 of the cavity 30 is larger, it indicates that the height h11 of the second sub-cavity 32 is relatively larger, and at this time, the weld width d1 should be appropriately increased to ensure the welding strength between the two layers of plates inside the second sub-cavity 32. If the ratio of the height h11 of the second sub-cavity 32 to the height h1 of the cavity 30 is smaller, it indicates that the height h11 of the second sub-cavity 32 is relatively smaller, and at this time the requirement for welding strength between the two layers of plates inside the second sub-cavity 32 is relatively reduced, so the weld width d1 can be appropriately reduced to meet the airtightness requirement of the battery case.

[0070] It can thus be seen that the above value of d1 / (h11 / h1) is a parameter optimization made out of consideration for the airtightness of the battery pack and the connection strength of the second sub-cavity 32.

[0071] The applicant carried out relevant experiments on the weld width d1 of the welding of adjacent two layers of plates, the height h11 of the second sub-cavity 32 and the height h1 of the cavity 30, and the experimental results are as follows:

[0072] As shown in the above table, the experimental data include eleven examples and four comparative examples, and the detected data are the airtightness of the battery pack and whether there is weld cracking at the welding point between the two layers of plates.

[0073] Further, the detection method for airtightness is: the battery case obtained in the examples and comparative examples is sealingly connected with the case cover to form a battery pack. The weld width d1, the cavity height h1, and the height h11 of the second sub-cavity of each obtained battery pack are as shown in the above table, and all battery packs are the same except for these parameters. After placing each battery pack in an environment with a temperature of 23±5°C and a humidity of 20~70% for 4 hours, gas is introduced into the battery case until the pressure reaches 3.65±0.15Kpa, and the pressure is maintained for 60s. TC-MF520-20K-50C is used to test the air leakage amount in the weld area, the test lasts 60S. If the air leakage amount is <6.5mL / min, it is qualified; if the air leakage amount ≥6.5mL / min, it is unqualified.

[0074] Furthermore, the method for detecting whether there is weld cracking at the welding point between the two layers of plates is as follows: The battery box obtained in the example and comparative example are sealed and connected to the box cover, and the battery is placed inside the battery box. Structural adhesive is applied between the battery and the bottom plate of the box for fixation to form a battery pack. The weld width d1, cavity height h1, and height h11 of the second sub-cavity of each battery pack are shown in the table above. All other aspects of each battery pack are the same. The battery pack is placed in a vibration testing instrument and subjected to random vibration in the Z / Y / X directions and sinusoidal fixed-frequency vibration in accordance with standard GB / T 38031-2020. The random vibration in each direction is continued for 12 hours and the sinusoidal fixed-frequency vibration for 2 hours. After the vibration test, the weld between the two adjacent layers of plates is observed to see if there is cracking. If there is cracking, it is unqualified; otherwise, it is qualified.

[0075] The preferred ranges for each parameter are as follows: the weld width (d1) of the two adjacent plates is in the range of 1 mm to 6 mm; the height h1 of the cavity 30 is in the range of 15 mm to 150 mm; the height h11 of the second sub-cavity 32 is in the range of 10 mm to 140 mm; and the value of d1 / (h11 / h1) is in the range of 3 to 30.

[0076] As can be seen from the table above, in the battery packs of Examples 1 to 11, since the values ​​of d1 / (h11 / h1) are all within the preferred range, the battery packs of Examples 1 to 11 meet the testing standards for airtightness and the welds do not show any cracking.

[0077] In the battery pack of Example 1, since the ratio of h11 / h1 is relatively small, the value of d1 is set relatively small. As mentioned above, this ensures that the weld will not crack and that the battery pack has good airtightness. Furthermore, experimental data shows that, while ensuring the weld does not crack, the battery pack of Example 1 exhibits the best airtightness.

[0078] In the battery packs of Examples 10 and 11, although the ratio of h11 / h1 is relatively small, the value of d1 can be appropriately increased to ensure welding strength, as long as d1 / (h11 / h1) is within the preferred range. Furthermore, experimental data shows that the airtightness requirements of the battery packs in Examples 10 and 11 are within the acceptable range.

[0079] In the battery packs of Examples 3, 5, 6, 7, and 8, the ratio of h11 / h1 is relatively large. Therefore, the value of d1 needs to be appropriately increased to ensure the strength of the weld and prevent cracking. At the same time, the value of d1 should not be too large to prevent the airtightness of the battery pack from failing. Experimental data shows that the ratio of h11 / h1 is the largest in the battery pack of Example 8; therefore, the value of d1 is adjusted to be close to the upper limit of the preferred value. Furthermore, in the battery packs of Examples 3, 5, 6, 7, and 8, d1 / (h11 / h1) is within the preferred range, meaning that the airtightness meets the requirements while ensuring that the weld does not crack.

[0080] In the battery packs of Examples 2, 4, and 9, the ratio of h11 / h1 is moderate. Therefore, adjusting the value of d1 within the preferred range is sufficient, ensuring that the value of d1 / (h11 / h1) is within the preferred range. This means that the airtightness meets the acceptable requirements while ensuring that the weld does not crack. Experimental data shows that as d1 increases, the airtightness of the battery pack decreases slightly, but it remains within the acceptable range.

[0081] In the battery packs of Comparative Examples 1 to 3, the weld strength was insufficient due to the small value of d1, resulting in weld cracking during the test. In Comparative Examples 1 and 2, although the value of d1 was within the preferred range, the ratio of h11 / h1 was relatively large, so the weld strength could not support the connection of the second sub-cavity 32, and weld cracking still occurred. The experimental data also show that in the battery packs of Comparative Examples 1 to 3, the value of d1 / (h11 / h1) was below the lower limit of the preferred range.

[0082] In the battery pack of Comparative Example 4, the excessively large value of d1 led to severe air leakage, thus the airtightness of the battery pack did not meet the requirements. The experimental data also shows that in the battery pack of Comparative Example 4, the value of d1 / (h11 / h1) was above the upper limit of the preferred range.

[0083] like Figure 3 As shown, in the technical solution of this embodiment, the cavity 30 includes a folded edge 301, which is integrally formed with the base plate 10. The cavity 30 is connected to the folded edge 301, and the cavity 30 is located on the side of the folded edge 301 away from the base plate 10.

[0084] With this configuration, the side beam 21 is rolled outwards, which facilitates the rolling process and improves production efficiency.

[0085] The following combination Figure 3 The molding method of cavity 30 in this embodiment is described in detail.

[0086] 1. The side beam 21 is bent in a direction perpendicular to the bottom plate 10, which forms the folded edge 301; 2. The side beam 21 bends horizontally outward; 3. The side beam 21 bends vertically downwards; 4. The side beam 21 bends horizontally inward to form the first sub-cavity 31; 5. The side beam 21 is bent vertically downwards and fits into the folded edge 301 (welded connection). 6. Side beam 21 bends horizontally outward; 7. The side beam 21 bends vertically upward to form the second sub-cavity 32; 8. The side beam 21 is bent horizontally inward, and the bent part is connected to the lower side of the first sub-cavity 31.

[0087] like Figure 3 and Figure 5 As shown, in the technical solution of this embodiment, the cavity 30 includes a cavity body 302 and a tail end 303. The tail end 303 is fixedly connected to the cavity body 302 through a first weld 40, and the extension length d2 of the tail end 303 is in the range of 2mm to 10mm.

[0088] Combination Figure 3 As will be understood by those skilled in the art, steps 1 to 7 above form the cavity body 302, and step 8 above forms the tail end 303.

[0089] Furthermore, from Figure 3 As can be seen, the extension length d2 of the end 303 does not include the transition arc region.

[0090] Furthermore, if the extension length of the tail end 303 is too long, the rolling process becomes more difficult to implement, and the tail end 303 cannot fit well against the inner wall of the cavity 30. If the extension length of the tail end 303 is too short, the fixing strength between the tail end 303 and the cavity body 302 is weak, resulting in lower strength of the entire side beam 21.

[0091] For example, the extension length d2 of the end 303 can be selected as 2mm, 4mm, 6mm, 8mm or 10mm, etc., or any value between the two values.

[0092] like Figure 5 As shown, in this embodiment, the battery box further includes a first reinforcing beam 50, which is disposed on the outer side of the side beam 21, that is, on the side of the side beam 21 opposite to the accommodating space. The first reinforcing beam 50 is welded and fixed to the side beam 21 by a second weld 40 and a third weld 70, and the first weld 40 is spaced apart from the second weld 60 and the third weld 70.

[0093] Specifically, the first reinforcing beam 50 is arranged in parallel with the side beam 21 and is located outside the side beam 21.

[0094] This configuration avoids the overlap of the first weld 40, the second weld 60, and the third weld 70, which could lead to the failure of the first weld 40.

[0095] like Figure 5 As shown, in the technical solution of this embodiment, the second weld 60 and the third weld 70 are located on both sides of the first weld 40. For example, in Figure 5 In the diagram, the second weld 60 is located outside the first sub-cavity 31, and the third weld 70 is located outside the second sub-cavity 32.

[0096] In an embodiment not shown, the second weld 60 and the third weld 70 may both be located on one side of the first weld 40. For example, the second weld 60 and the third weld 70 may both be located outside the first sub-cavity 31, or the second weld 60 and the third weld 70 may both be located outside the second sub-cavity 32.

[0097] Furthermore, the ratio of the distance d3 between the first weld 40 and the second weld 60 or the third weld 70 to the height h1 of the cavity is in the range of 0.2 to 0.5.

[0098] For example, the ratio of the distance d3 between the first weld 40 and the second weld 60 or the third weld 70 to the height h1 of the cavity can be selected as 0.2, 0.3, 0.4 or 0.5, etc., or any value between the two values.

[0099] Furthermore, the distance d3 between the first weld 40 and the second weld 60 or the third weld 70 is in the range of 7mm to 68mm.

[0100] For example, the distance d3 between the first weld 40 and the second weld 60 or the third weld 70 can be selected as 7mm, 10mm, 20mm, 50mm, 60mm or 68mm, etc., or any value between the two values.

[0101] This configuration further avoids the situation where the first weld 40, the second weld 60, and the third weld 70 overlap, leading to the failure of the first weld 40.

[0102] like Figure 6As shown, in this embodiment, the end beam 22 includes a first flange 221 and a second flange 222. The first flange 221 and the second flange 222 are welded and fixed to the side beam 21. One end of the first flange 221 is connected to the base plate 10, and the other end of the first flange 221 is connected to the second flange 222. The extending direction of the second flange 222 is parallel to the plane of the base plate 10. Along the arrangement direction of the two end beams 22, the ratio of the width d4 of the second flange 222 to the width a of the cavity 30 is in the range of 1 to 3.

[0103] like Figure 2 , Figure 6 and Figure 9 As shown, the outer surface of the first flange 221 is flush with the end of the side beam 21, and the second flange 222 is folded in the direction toward the receiving space.

[0104] Furthermore, when the end beam 22 is provided with a first flange 221 and a second flange 222, the end beam 22 is welded to the first side 211 of the side beam 21 near the receiving space.

[0105] Specifically, if the width d4 of the second flange 222 is too small relative to the width a of the cavity 30, it will not be able to achieve a sealing effect when the lid is closed on the box. If the width d4 of the second flange 222 is too large relative to the width a of the cavity 30, it will compress the internal space of the box and reduce the volumetric energy density of the box.

[0106] For example, the ratio of the width d4 of the second flange 222 to the width a of the cavity 30 can be selected as 1, 1.5, 2, 2.5 or 3, etc., or any value between the two values.

[0107] Optionally, the width d4 of the second flange 222 is in the range of 25mm to 50mm.

[0108] For example, the width d4 of the second flange 222 can be in the range of 25mm, 305mm, 355mm, 405mm, 455mm or 50mm.

[0109] like Figure 2 and Figure 6 As shown, in the technical solution of this embodiment, the end beam 22 further includes a third flange 223. The third flange 223 is connected to the second flange 222, and the extension direction of the second flange 222 is perpendicular to the plane where the base plate 10 is located. The ratio of the extension length d5 ​​of the third flange 223 to the height d6 of the first flange 221 is in the range of 0.015 to 1.

[0110] from Figure 6 As can be seen, the extension length of the third flange 223 includes the arc-shaped transition area.

[0111] Specifically, the larger the ratio of the extension length d5 ​​of the third flange 223 to the height d6 of the first flange 221, the higher the strength of the end beam 22. However, if the ratio of the extension length d5 ​​of the third flange 223 to the height d6 of the first flange 221 is too large, it will cause the third flange 223 to interfere more with the interior of the box and affect the bending process during bending. The smaller the ratio of the extension length d5 ​​of the third flange 223 to the height d6 of the first flange 221, the lower the strength of the end beam 22.

[0112] For example, the ratio of the extension length of the third flange 223 to the height of the first flange 221 can be selected as 0.015, 0.05, 0.1, 0.3, 0.6, 0.9 or 1, etc., or any value between the two values.

[0113] Furthermore, the extension length d5 ​​of the third flange 223 is in the range of 3mm to 150mm.

[0114] Optionally, the extension length d5 ​​of the third flange 223 can be selected as 3mm, 10mm, 20mm, 50mm, 10mm or 150mm, etc., or any value between the two values.

[0115] Furthermore, from Figure 6 As can be seen, a through hole 2221 is provided on the second flange 222. The ratio of the distance d7 between the through hole 2221 and the weld line between the end edge beam 22 and the side edge beam 21 to the diameter d8 of the through hole 2221 is in the range of 1 to 15.

[0116] Specifically, the through hole can be used to connect to the cover of the battery box.

[0117] If the distance between the through hole 2221 and the weld line is too close, the strength of the end beam 22 will decrease, and the weld will have a significant impact on the flatness when fixing the cover, thus affecting the seal. If the distance between the through hole 2221 and the weld line is too far, the downward pressure of the cover at the weld will be insufficient, which will also affect the seal of the cover.

[0118] For example, the ratio of the distance d7 between the through hole 2221 and the weld line between the end beam 22 and the side beam 21 to the diameter d8 of the through hole 2221 can be selected as 1, 3, 5, 10, 13 or 15, etc., or any value between the two values.

[0119] Furthermore, such as Figure 6 As shown, when the second flange 222 is welded to the side beam 21, the product of the weld width d10 and the width d4 of the second flange 222 is 70mm. 2 Up to 220mm 2 The range.

[0120] Specifically, the wider the width d4 of the second flange 222, the smaller the width d10 of the weld can be, while still achieving good fixing strength. Conversely, if the width d4 of the second flange 222 is narrower, the width d10 of the weld needs to be appropriately increased to meet strength requirements.

[0121] For example, the product of the weld width and the width of the second flange 222 can be selected as 70 mm. 2 100 mm 2 150 mm 2 200 mm 2 Or 220 mm 2 And so on, as well as any value between two values.

[0122] Furthermore, the width d10 of the weld is in the range of 2mm to 10mm.

[0123] For example, the width d10 of the weld can be selected as 2, 4, 6, 8 or 10, or any value between two values.

[0124] Furthermore, when the second flange 222 is welded to the side beam 21, the product of the weld width d10 and the thickness d9 of the second flange 222 is 3.2 mm. 2 Up to 10.5mm 2 Within the range.

[0125] It should be noted that the thickness d9 of the second flange 222 refers to the thickness of the material at the location of the second flange 222.

[0126] Specifically, the thicker the second flange 222 (d9), the smaller the weld width (d10) can be, while still achieving good fixing strength. Conversely, if the thickness of the second flange 222 (d9) is smaller, the weld width (d10) needs to be appropriately increased to meet strength requirements.

[0127] For example, the product of the weld width d10 and the thickness d9 of the second flange 222 can be chosen as 3.2 mm. 2 4mm 2 6mm 2 8mm 2 10mm 2 Or 10.5mm 2 And so on, as well as any value between two numbers.

[0128] Furthermore, the thickness d9 of the second flange 222 is in the range of 0.8 mm to 2.0 mm.

[0129] For example, the thickness d9 of the second flange 222 can be selected as 0.8mm, 1mm, 1.2mm, 1.5mm or 2mm, etc., or any value between two values.

[0130] Optionally, in this embodiment, the base plate 10 and the frame 20 are both made of stainless steel, and the tensile strength of the base plate 10 and the frame 20 is in the range of 590MPa to 1180MPa.

[0131] For example, the tensile strength of the base plate 10 and the frame 20 can be selected as 590MPa, 600MPa, 800MPa, 1000MPa, 1100MPa or 1180MPa, etc., or any value between two values.

[0132] like Figure 8 and Figure 9 As shown, in this embodiment, the battery box further includes a second reinforcing beam 100, which is disposed on the inner side of the frame 20. The extension direction of the second reinforcing beam 100 is parallel to the arrangement direction of the two side beams 21, that is, the extension direction of the second reinforcing beam 100 is the same as that of the end beam 22. Specifically, the second reinforcing beam 100 can further strengthen the structural strength of the side beams 21.

[0133] Optionally, in this embodiment, there are two second reinforcing beams 100, which are arranged parallel to each other and spaced apart. Of course, those skilled in the art can also determine the specific number of second reinforcing beams 100 according to actual needs.

[0134] like Figure 7 As shown, in the technical solution of this embodiment, the side beam 21 is connected to the bottom plate 10 through a first arc-shaped transition section 80, and the end beam 22 is connected to the bottom plate 10 through a second arc-shaped transition section 90. The first arc-shaped transition section 80 and the end beam 22 are spaced apart and have a first gap, and the second arc-shaped transition section 90 and the side beam 21 are spaced apart and have a second gap, the second gap being smaller than the first gap.

[0135] Specifically, by making the second spacing smaller than the first spacing, the suspension distance of the side beam 21 is shortened, which can further improve the structural strength of the side beam 21.

[0136] Furthermore, the gap formed by the end of the first arc-shaped transition section 80 and the end of the second arc-shaped transition section 90 will be filled by welding during subsequent processing.

[0137] like Figure 8 and Figure 9As shown, in this embodiment, the battery box further includes a third reinforcing beam 110, which is located within the accommodating space. One side of the third reinforcing beam 110 is connected to the base plate 10, and the other side is connected to the end side beam 22. Furthermore, along a cross-section perpendicular to the extending direction of the third reinforcing beam 110, the third reinforcing beam 110 has at least one bent portion 111.

[0138] Specifically, since the end beam 22 is a single-layer plate structure, its strength is slightly less than that of the side beam 21. Therefore, in this embodiment, a third reinforcing beam 110 is provided to enhance the structural strength of the end beam 22.

[0139] like Figure 8 and Figure 9 As shown, the extension direction of the third reinforcing beam 110 is flush with the extension direction of the end side beam 22, with one side connected to the base plate 10 and the other side connected to the end side beam 22. More specifically, the other side of the third reinforcing beam 110 is connected to the inner surface of the first flange 221. This arrangement serves two purposes: firstly, the third reinforcing beam 110 strengthens the structural strength of the end side beam 22; secondly, when the end side beam 22 collides, the third reinforcing beam 110 can transfer the impact force to the base plate 10, thereby increasing the overall impact strength of the battery box.

[0140] like Figure 9 As shown, the cross-section of the third reinforcing beam 110 reveals multiple bends 111, with adjacent bends 111 bending in opposite directions. In this embodiment, the third reinforcing beam 110 has three bends 111, resulting in a W-shaped cross-section. This allows the surfaces on both sides of the third reinforcing beam 110 to connect to the first flange 221 and the base plate 10, respectively; furthermore, the three bends 111 increase the overall structural strength of the third reinforcing beam 110.

[0141] Of course, those skilled in the art can determine the number of bends 111 in the third reinforcing beam 110 and the specific bending direction of each bend 111 according to actual needs.

[0142] Furthermore, a third reinforcing beam 110 can be provided on the inner side of one end beam 22, or a third reinforcing beam 110 can be provided on the inner side of both end beams 22.

[0143] In an embodiment not shown, a third reinforcing beam 110 may also be provided on the inner side of the side beam 21. In this case, one side of the third reinforcing beam 110 is connected to the base plate 10, and the other side of the third reinforcing beam 110 is connected to the inner surface of the side beam 21. In this embodiment, the third reinforcing beam 110 may be provided on the inner side of one side beam 21, or it may be provided on the inner side of both side beams 21. In this embodiment, the third reinforcing beam 110 may also be provided only on the inner side of the side beams 21, while the inner side of the end beams 22 may not have a third reinforcing beam 110.

[0144] like Figure 8 and Figure 9 As shown, the accommodating space includes an electrical compartment 120, and the other side of the third reinforcing beam 110 is connected to the end side beam 22 near the electrical compartment 120.

[0145] Specifically, since the internal structure of the electrical compartment 120 is relatively weak and contains a large number of electrical components, the end beams 22 near the electrical compartment 120 need to have high structural strength to prevent the electrical compartment 120 from deforming and catching fire after the battery box is hit.

[0146] Therefore, in this embodiment, a third reinforcing beam 110 is provided, and the aforementioned third reinforcing beam 110 is provided on the inner side of the end side beam 22 near the electrical compartment 120, thereby enhancing the collision strength of the electrical compartment 120.

[0147] As described above, it is also a feasible implementation method to provide a third reinforcing beam 110 on the inner side of both end beams 22.

[0148] like Figure 8 and 9 As shown, in the technical solution of this embodiment, a protrusion 224 is provided on the surface of the end beam 22 near the electrical compartment 120 that faces away from the accommodating space. From Figure 9 As can be seen, in the end side beam 22 near the electrical compartment 120, the upper part of it protrudes upward as a whole, that is, the first flange 221, the second flange 222 and the third flange 223 all protrude upward, thus forming the protrusion 224.

[0149] Specifically, an output interface needs to be installed on the end beam 22 near the electrical compartment 120. The output interface is used to output current. Since the output interface needs to pass through the end beam 22, it will weaken the strength of the plate material of the end beam 22 near the output interface. In particular, the width of the plate material in the vertical direction of the output interface is relatively narrow, which can easily affect the overall structural strength of the battery box.

[0150] In this embodiment, by providing a protrusion 224 on the end beam 22 near the electrical compartment 120, a larger mounting surface is provided at the position of the corresponding protrusion 224 on the first flange 221. After the output interface is installed, the plate material near the output interface of the first flange 221 can have a larger width, thus reducing the impact of installing the output interface on the structural strength of the battery box.

[0151] Example 2 like Figure 10 and Figure 11 As shown, the difference between Embodiment 2 of the battery box according to the application and Embodiment 1 above is that the first flange 221 of the end side beam 22 in Embodiment 2 is not flush with the end of the side side beam 21.

[0152] Specifically, as seen in section 11, the outer surface of the first flange 221 of the end beam 22 is recessed inward by a certain distance relative to the end of the side beam 21, meaning that the first flange 221 and the end of the side beam 21 have a distance x. Simultaneously, the second flange 222 is folded away from the receiving space, meaning that the second flange 222 is folded outward. The third flange 223 is folded downward, and the outer surface of the third flange 223 is flush with the end of the side beam 21.

[0153] In Embodiment 2, since there is no base plate 10 material below the second flange 222, the battery box in Embodiment 2 uses less material and has a relatively lower cost compared to Embodiment 1.

[0154] Furthermore, in Embodiment 2, the two end beams 22 have the same form, that is, the first flange 221 of the two end beams are spaced x from the end of the side beam 21.

[0155] Furthermore, in the end beam 22 near the electrical compartment 120, the outer surface of the first flange 221, the lower surface of the second flange 222, and the inner surface of the side beam 21 ( Figure 11 Within the range shown in x), the three together form a containment space, which can be used to accommodate the joint.

[0156] The other structural forms of the battery box in Embodiment 2 are the same as those in Embodiment 1 above, so they will not be described again.

[0157] This application also provides a battery device, an embodiment of which includes a battery box, a cover, and a battery pack. The battery box is the aforementioned battery box, the cover is disposed on the battery box, and the cover is connected to a side beam 21 and an end beam 22. The battery pack is disposed within the receiving space of the battery box.

[0158] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A battery box characterized by, The device includes a base plate (10) and a frame (20) disposed along the edge of the base plate (10). The base plate (10) and the frame (20) are integrally formed and enclose a space for accommodating the battery. The frame (20) includes two opposing side beams (21) and two opposing end beams (22). The side beams (21) are bent to form cavities (30). The end beams (22) are single-layer plate structures. Adjacent end beams (22) and side beams (21) are connected by welding. Along the arrangement direction of the two side beams (21), each side beam (21) includes a first side (211) and a second side (212), the first side (211) being closer to the receiving space and the second side (212) being farther away from the receiving space. Wherein, the end beam (22) is welded to the first side (211) of the side beam (21) near the receiving space; and / or, the end beam (22) is welded to the second side (212) of the side beam (21) away from the receiving space.

2. The battery pack of claim 1, wherein, In the direction of arrangement of the two side beams (21), the ratio of the width (a) of the cavity (30) to the thickness (b) of the plate of the side beam (21) is in the range of 15 to 30. and or, In the direction of arrangement of the two side beams (21), the ratio of the width (a) of the cavity (30) to the length (c) of the side beams (21) is in the range of 15 to 125; and or, The cavity (30) includes a flange (301), the flange (301) is integrally formed with the base plate (10), the cavity (30) is connected to the flange (301), and the cavity (30) is located on the side of the flange (301) away from the base plate (10); and or, The base plate (10) and the frame (20) are both made of stainless steel, and the tensile strength of the base plate (10) and the frame (20) is in the range of 590MPa to 1180MPa. and or, The battery box also includes a second reinforcing beam disposed on the inner side of the frame (20), and the extension direction of the second reinforcing beam is parallel to the arrangement direction of the two side beams (21); and or, The side beam (21) is connected to the base plate (10) through a first arc-shaped transition section (80), and the end beam (22) is connected to the base plate (10) through a second arc-shaped transition section (90). The first arc-shaped transition section (80) and the end beam (22) are spaced apart and have a first gap. The second arc-shaped transition section (90) and the side beam (21) are spaced apart and have a second gap. The second gap is smaller than the first gap.

3. The battery pack of claim 1, wherein, The direction perpendicular to the plane of the base plate (10) is the height direction. Along the height direction, the ratio of the height (h1) of the cavity (30) to the height (h2) of the side beam (21) is in the range of 0.1 to 1.

4. The battery pack of claim 1, wherein, The cavity (30) includes a first sub-cavity (31) and a second sub-cavity (32) arranged along a direction perpendicular to the base plate (10). The first sub-cavity (31) is located on the side of the second sub-cavity (32) away from the base plate (10). The direction perpendicular to the plane of the base plate (10) is the height direction. Along the height direction, the ratio of the height (h11) of the second sub-cavity (32) to the height (h1) of the cavity (30) is in the range of 0.05 to 0.

95.

5. The battery pack of claim 4, wherein, On the side of the second sub-cavity (32) near the receiving space, at least two layers of plates are included between the second sub-cavity (32) and the receiving space, and adjacent two layers of plates are welded and fixed. The ratio of the weld width (d1) of the two adjacent plates, the height (h11) of the second sub-cavity (32), and the height (h1) of the cavity (30) satisfies the following relationship: 3≤d1 / (h11 / h1)≤20, The weld width (d1) of the two adjacent plates is in the range of 1 mm to 6 mm.

6. The battery pack of claim 1, wherein, The cavity (30) includes a cavity body (302) and a tail end (303). The tail end (303) is fixedly connected to the cavity body (302) through a first weld (40). The extension length (d2) of the tail end (303) is in the range of 2 mm to 10 mm.

7. The battery pack of claim 6, wherein, The battery box also includes a first reinforcing beam (50), which is disposed on the side of the side beam (21) away from the receiving space. The first reinforcing beam (50) is welded to the side beam (21) by a second weld (60) and a third weld (70), and the first weld (40) is spaced apart from the second weld (60) and the third weld (70). The second weld (60) and the third weld (70) are located on both sides of the first weld (40), or the second weld (60) and the third weld (70) are both located on one side of the first weld (40); and or, The ratio of the distance (d3) between the first weld (40) and the second weld (60) or the third weld (70) to the height (h1) of the cavity (30) is in the range of 0.2 to 0.

5.

8. The battery pack of claim 1, wherein, The end beam (22) is welded to the first side (211) of the side beam (21) near the receiving space. The end beam (22) includes a first flange (221) and a second flange (222). The first flange (221) and the second flange (222) are welded and fixed to the side beam (21). One end of the first flange (221) is connected to the base plate (10), and the other end of the first flange (221) is connected to the second flange (222). The extension direction of the second flange (222) is parallel to the plane of the base plate (10). Along the arrangement direction of the two end beams (22), the ratio of the width (d4) of the second flange (222) to the width (a) of the cavity (30) is in the range of 1 to 3.

9. The battery pack of claim 8, wherein, The end beam (22) further includes a third flange (223), which is connected to the second flange (222). The extension direction of the second flange (222) is perpendicular to the plane of the base plate (10). The ratio of the extension length (d5) of the third flange (223) to the height (d6) of the first flange (221) is in the range of 0.015 to 1. and or, The second flange (222) is provided with a through hole (2221), and the ratio of the distance (d7) of the through hole (2221) from the weld line between the end side beam (22) and the side side beam (21) to the diameter (d8) of the through hole (2221) is in the range of 1 to 15. and or, When the second flange (222) is welded to the side beam (21), the product of the weld width (d10) and the width (d4) of the second flange (222) is 70 mm. 2 Up to 220mm 2 Within the range; and or, The product of the weld width (d10) and the thickness (d9) of the second flange (222) is in the range of 3.2 mm 2 to 10.5 mm 2 when the second flange (222) is welded to the side rail (21).

10. The battery pack of claim 1, wherein, The end beam (22) is welded to the first side (211) of the side beam (21) near the receiving space. The end beam (22) includes a first flange (221) and a second flange (222). The first flange (221) and the second flange (222) are welded and fixed to the side beam (21). One end of the first flange (221) is connected to the base plate (10), and the other end of the first flange (221) is connected to the second flange (222). The first flange (221) is flush with the end of the side beam (21), and the second flange (222) is folded in the direction toward the receiving space; or, The first flange (221) has a distance (x) between the end of the side beam (21) and the second flange (222) is folded in a direction away from the receiving space.

11. The battery box according to claim 1, characterized in that, The battery box also includes a third reinforcing beam (110) located within the accommodating space. One side of the third reinforcing beam (110) is connected to the base plate (10), and the other side of the third reinforcing beam (110) is connected to the side beam (21) or the end beam (22). In a cross section perpendicular to the extension direction of the third reinforcing beam (110), the third reinforcing beam (110) has at least one bend (111).

12. The battery pack of claim 11, wherein, The accommodating space includes an electrical compartment (120), and the other side of the third reinforcing beam (110) is connected to the end side beam (22) near the electrical compartment (140).

13. The battery pack of claim 1, wherein, The accommodating space includes an electrical compartment (120), and a protrusion (224) is provided on the surface of the end side beam (22) near the electrical compartment (120) facing away from the accommodating space.

14. A battery device characterized by comprising: Includes a battery box as described in any one of claims 1 to 13, a cover over the battery box, and a battery pack disposed within a receiving space, the cover being connected to the side beam (21) and the end beam (22).

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