Battery pack

Abstract

In order to solve the problems that an existing battery pack is complex in preparation process and high in manufacturing cost, the utility model provides a battery pack which comprises a box body, a cover plate assembly, a fixing plate assembly and a connecting piece, the box body is provided with a containing cavity, a maintenance opening communicated with the containing cavity is formed in the side wall of the box body, and the cover plate assembly is installed on the outer side face of the maintenance opening. The fixing plate assembly is installed on the inner side face of the maintenance opening, the cover plate assembly comprises a cover plate and an outer sealing gasket, the outer sealing gasket is arranged between the cover plate and the maintenance opening, the fixing plate assembly comprises a fixing plate and an inner sealing gasket, the inner sealing gasket is arranged between the fixing plate and the maintenance opening, and the fixing plate and the cover plate are connected through the connecting piece; according to the utility model, the cover plate is fixed with the connecting piece, so that the cover plate assembly is mounted outside the battery pack maintenance port; the cover plate is separated from the connecting piece, so that the cover plate assembly is disassembled outside the battery pack maintenance opening; the battery pack is simple in structure, few in parts and convenient to install, and the internal space of the battery pack is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, in particular to a battery pack. Background Art

[0002] The current lithium-ion battery pack has a high requirement for sealing performance, generally IP56 and above. The upper cover of the battery pack is generally designed with a maintenance port, which is covered and sealed by a cover plate. The cover plate can be removed from the outside of the battery pack to facilitate maintenance and charging inside the battery pack.

[0003] In the prior art, the battery box includes a cover plate and a fixed plate. The cover plate has a first recess, a first limit portion surrounding the first recess, and a reinforcement portion. The first recess is used to accommodate an outer sealing gasket, the first limit plays a limiting role to prevent the sealing gasket from being over-compressed, and the reinforcement portion plays a reinforcing role; the fixed plate has a second recess, a second limit portion surrounding the second recess, and a connector. Similarly, the second recess is used to accommodate an inner sealing gasket, the second limit plays a limiting role to prevent the sealing gasket from being over-compressed, and the connector passes through the upper box cover and the cover plate to achieve a fastened connection. There are also rivet holes on the fixed plate for pre-assembly of the fixed plate assembly.

[0004] This design has the following defects: (1) The recesses of the cover plate and the fixed plate require stamping dies to be manufactured, which increases the cost of the battery pack; (2) The limit structures at the edges of the cover plate and the fixed plate extend outward, increasing the size; (3) When the stamping depth of the cover plate limit structure is within the positive tolerance, the limit structure may contact the upper box cover, but the inner surface of the first recess has not yet contacted the step surface of the step bolt. In this way, after tightening the nut, the cover plate will deform under the action of the locking force; (4) The connector is riveted to the fixed plate, penetrating the upper box cover and the cover plate, but the meshing point between the riveted stud and the plate is not sealed, so the structure has a risk of leakage. Therefore, how to overcome the above-mentioned technical problems and defects has become a key issue that needs to be solved. Utility Model Content

[0005] In view of the problems of complex preparation process and high manufacturing cost of existing battery packs, the utility model provides a battery pack.

[0006] The technical solution adopted by the utility model to solve the above technical problems is as follows:

[0007] The utility model provides a battery pack, comprising a box body, a cover plate assembly, a fixed plate assembly and a connector, the box body having a accommodating cavity, the side wall of the box body being provided with a maintenance port communicating with the accommodating cavity, the cover plate assembly being installed on the outer side surface of the maintenance port, the fixed plate assembly being installed on the inner side surface of the maintenance port, the cover plate assembly comprising a stacked cover plate and an outer sealing gasket, the outer sealing gasket being arranged between the cover plate and the maintenance port, the fixed plate assembly comprising a fixing plate and an inner sealing gasket, the inner sealing gasket being arranged between the fixing plate and the maintenance port, and the connector connecting the fixing plate and the cover plate.

[0008] Optionally, the fixing plate is provided with a first through hole at a position corresponding to the maintenance port, the inner sealing gasket is provided with a second through hole at a position corresponding to the maintenance port, and the outer sealing gasket is provided with a third through hole at a position corresponding to the maintenance port.

[0009] Optionally, the fixing plate is provided with a plurality of first mounting holes around the periphery of the first through hole, and the inner sealing gasket is provided with a plurality of second mounting holes around the periphery of the second through hole; the side wall of the box body is provided with a plurality of third mounting holes around the periphery of the maintenance port; the outer sealing gasket is provided with a plurality of fourth mounting holes around the periphery of the third through hole, and the cover plate is provided with a fifth mounting hole at a position corresponding to the fourth mounting hole, the first mounting hole, the second mounting hole, the third mounting hole, the fourth mounting hole and the fifth mounting hole are coaxially arranged, the first end of the connecting member is embedded in the first mounting hole, and the second end of the connecting member sequentially passes through the second mounting hole, the third mounting hole, the fourth mounting hole and the fifth mounting hole.

[0010] Optionally, the connecting member includes a step surface, a connecting rod and a nut, the first end of the step surface is embedded in the first mounting hole, the second end of the step surface passes through the second mounting hole, the third mounting hole and the fourth mounting hole in sequence, and the outer surface of the step surface contacts the inner surfaces of the first mounting hole, the second mounting hole, the third mounting hole and the fourth mounting hole; the first end of the connecting rod is connected to the surface of the second end of the step surface, the connecting rod extends in a direction perpendicular to the plane where the second end of the step surface is located, the second end of the connecting rod passes through the fifth mounting hole and extends to the outside of the fifth mounting hole, the outer surface of the connecting rod contacts the inner surface of the fifth mounting hole, and the second end of the connecting rod is threadedly connected to the nut.

[0011] Optionally, the thickness of the step surface, the thickness of the fixed plate, the thickness of the outer sealing gasket, the thickness of the side wall of the box body and the thickness of the inner sealing gasket satisfy the relationship: thickness of the step surface = thickness of the fixed plate + thickness of the outer sealing gasket after compression + thickness of the side wall of the box body + thickness of the inner sealing gasket after compression.

[0012] Optionally, the first end of the step surface is embedded in the first mounting hole and forms a meshing area with the first mounting hole, and the meshing area is coated with a sealant for sealing the meshing area.

[0013] Optionally, a flange strip is extended from the edge of the first through hole toward one side of the maintenance port, the flange strip is parallel to the longer side of the maintenance port, and the angle between the flange strip and the fixing plate is α, and α satisfies the relationship: 0°<α≤90°.

[0014] Optionally, a bonding layer is provided on a side of the inner sealing gasket facing the fixing plate, and the inner sealing gasket is connected to the fixing plate through the bonding layer.

[0015] Optionally, the cover plate includes a reinforcing portion, a mounting portion and an equipotential point, one end of the cover plate protrudes in a direction away from the accommodating cavity to form the reinforcing portion; the other end of the cover plate is recessed in a direction toward the accommodating cavity to form the mounting portion, along a direction perpendicular to the maintenance port, the projections of the reinforcing portion and the mounting portion both fall within the maintenance port, and a plurality of equipotential points are provided on the periphery of the cover plate.

[0016] Optionally, a bottom plate is also included, and the bottom plate is used to seal the box body.

[0017] According to the battery pack provided by the utility model, the cover plate assembly is installed outside the maintenance port of the battery pack by fixing the cover plate and the connecting piece; the cover plate assembly is disassembled outside the maintenance port of the battery pack by separating the cover plate from the connecting piece; the battery pack of the present application has a simple structure, fewer components, is easy to install, and increases the internal space of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of a battery pack provided by an embodiment of the utility model;

[0019] Figure 2 is a cross-sectional schematic diagram of a battery pack provided by an embodiment of the utility model;

[0020] Figure 3 yes Figure 2 A is a partial enlarged schematic diagram;

[0021] Figure 4 It is a structural schematic diagram of a cover plate in a battery pack provided by an embodiment of the utility model;

[0022] Figure 5 It is a front view schematic diagram of a fixing plate assembly in a battery pack provided by an embodiment of the utility model;

[0023] Figure 6 It is a rear view schematic diagram of a fixing plate assembly in a battery pack provided by an embodiment of the utility model;

[0024] Figure 7 This is a schematic diagram of the route of humid air entering the battery pack;

[0025] The reference numerals in the drawings of the specification are as follows:

[0026] 1-housing; 11-maintenance port; 12-third mounting hole; 2-cover assembly; 21-cover; 211-fifth mounting hole; 212-reinforcement portion; 213-mounting portion; 2131-sixth mounting hole; 214-equipotential point; 22-outer sealing pad; 221-third through hole; 222-fourth mounting hole; 3-fixing plate assembly; 31-fixing plate; 311-first through hole; 312-first mounting hole; 313-flanging strip; 32-inner sealing pad; 321-second through hole; 322-second mounting hole; 33-engaging area; 34-sealant; 4-connector; 41-step surface; 42-connecting rod; 43-nut; 5-bottom plate. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0028] In the description of the present invention, it should be understood that the terms "side", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] like Figure 1-3As shown, in one embodiment, the utility model provides a battery pack, including a box body 1, a cover plate assembly 2, a fixed plate assembly 3 and a connector 4, the box body 1 has a accommodating cavity, the side wall of the box body 1 is provided with a maintenance port 11 connected to the accommodating cavity, the cover plate assembly 2 is installed on the outer side of the maintenance port 11, the fixed plate assembly 3 is installed on the inner side of the maintenance port 11, the cover plate assembly 2 includes a stacked cover plate 21 and an outer sealing gasket 22, the outer sealing gasket 22 is arranged between the cover plate 21 and the maintenance port 11, the fixed plate assembly 3 includes a fixed plate 31 and an inner sealing gasket 32, the inner sealing gasket 32 ​​is arranged between the fixed plate 31 and the maintenance port 11, and the connector 4 connects the fixed plate 31 and the cover plate 21.

[0031] Specifically, a connector 4 is installed on the fixing plate 31, and the connector 4 is connected to the maximum surface of the fixing plate 31 close to the cover plate 21 and extends in a direction perpendicular to the maximum surface of the fixing plate 31. The cover plate 21 is fixed to the connector 4 to achieve the installation of the cover plate assembly 2 outside the battery pack maintenance port 11; the cover plate assembly 2 can be disassembled outside the battery pack maintenance port 11 by separating the cover plate 21 from the connector 4; the battery pack of the present application has a simple structure, fewer components, is easy to install, and increases the internal space of the battery pack.

[0032] Specifically, the connecting member 4 is a self-clinching screw.

[0033] like Figure 3 As shown, in one embodiment, the fixing plate 31 has a first through hole 311 at a position corresponding to the maintenance port 11 , the inner sealing gasket 32 ​​has a second through hole 321 at a position corresponding to the maintenance port 11 , and the outer sealing gasket 22 has a third through hole 221 at a position corresponding to the maintenance port 11 .

[0034] In some embodiments, the maintenance opening 11 is rectangular, the first through hole 311 , the second through hole 321 , and the third through hole 221 are all rectangular, and the cover plate 21 is used to close the maintenance opening 11 to achieve good sealing of the battery pack.

[0035] In some embodiments, when the battery pack needs to be inspected, the interior of the battery pack can be inspected by simply opening the cover 21 .

[0036] In some embodiments, the fixing plate 31 is used to remove or install the cover plate 21 and the battery pack maintenance port 11 .

[0037] In some embodiments, the inner sealing gasket 32 ​​is used to fill the gap between the fixing plate 31 and the side wall of the box body 1, thereby improving the sealing performance between the fixing plate 31 and the side wall of the box body 1, and reducing the force between the fixing plate 31 and the side wall of the box body 1, thereby avoiding deformation of the side wall of the box body 1 when the fixing plate 31 is connected to the cover plate 21, thereby affecting the sealing performance of the battery pack.

[0038] In some embodiments, the outer sealing gasket 22 is used to fill the gap between the cover plate 21 and the side wall of the box body 1, thereby improving the sealing performance between the cover plate 21 and the side wall of the box body 1, and reducing the force between the cover plate 21 and the side wall of the box body 1, thereby avoiding deformation of the side wall of the box body 1 when the cover plates 21 are connected to the cover plates 21, thereby affecting the sealing performance of the battery pack.

[0039] like Figure 3-6 As shown, in one embodiment, the fixing plate 31 is provided with a plurality of first mounting holes 312 around the outer periphery of the first through hole 311, and the inner sealing gasket 32 ​​is provided with a plurality of second mounting holes 322 around the outer periphery of the second through hole 321; the side wall of the box body 1 is provided with a plurality of third mounting holes 12 around the outer periphery of the maintenance port 11; the outer sealing gasket 22 is provided with a plurality of fourth mounting holes 222 around the outer periphery of the third through hole 221, and the cover plate 21 is provided with a fifth mounting hole 211 at a position corresponding to the fourth mounting hole 222, the first mounting hole 312, the second mounting hole 322, the third mounting hole 12, the fourth mounting hole 222 and the fifth mounting hole 211 are coaxially arranged, the first end of the connecting member 4 is embedded in the first mounting hole 312, and the second end of the connecting member 4 sequentially passes through the second mounting hole 322, the third mounting hole 12, the fourth mounting hole 222 and the fifth mounting hole 211.

[0040] Specifically, the first mounting hole 312 , the second mounting hole 322 , the third mounting hole 12 , the fourth mounting hole 222 and the fifth mounting hole 211 are all circular holes, and the diameters of the first mounting hole 312 , the second mounting hole 322 , the third mounting hole 12 and the fourth mounting hole 222 are the same and larger than the diameter of the fifth mounting hole 211 .

[0041] like Figure 3 As shown, in one embodiment, the connecting member 4 includes a step surface 41, a connecting rod 42 and a nut 43, the first end of the step surface 41 is embedded in the first mounting hole 312, the second end of the step surface 41 passes through the second mounting hole 322, the third mounting hole 12 and the fourth mounting hole 222 in sequence, the outer surface of the step surface 41 contacts the inner surfaces of the first mounting hole 312, the second mounting hole 322, the third mounting hole 12 and the fourth mounting hole 222; the first end of the connecting rod 42 is connected to the surface of the second end of the step surface 41, the connecting rod 42 extends in a direction perpendicular to the plane where the second end of the step surface 41 is located, the second end of the connecting rod 42 passes through the fifth mounting hole 211 and extends to the outside of the fifth mounting hole 211, the outer surface of the connecting rod 42 contacts the inner surface of the fifth mounting hole 211, and the second end of the connecting rod 42 is threadedly connected to the nut 43.

[0042] Specifically, the step surface 41 and the connecting rod 42 are both cylindrical, the diameter of the step surface 41 is larger than the diameter of the connecting rod 42, the diameter of the step surface 41 is the same as the diameter of the first mounting hole 312, the second mounting hole 322, the third mounting hole 12 and the fourth mounting hole 222, the diameter of the connecting rod 42 is the same as the diameter of the fifth mounting hole 211, the second end of the step surface 41 passes through the second mounting hole 322, the third mounting hole 12 and the fourth mounting hole 222 in sequence, and the second end of the step surface 41 of the connecting member 4 is fitted with the inner surface of the cover plate 21 to form a limiting structure, and the compression of the outer sealing gasket 22 and the inner sealing gasket 32 ​​can be controlled by controlling the thickness of the step surface 41, thereby effectively preventing the service life of the outer sealing gasket 22 and / or the inner sealing gasket 32 ​​from being reduced due to excessive compression.

[0043] Compared with the prior art, due to the limiting effect of the step surface 41, the first recess and the first limiting portion in the prior art are eliminated on the cover plate 21, and the second recess and the second limiting portion are also eliminated on the fixed plate 31, thereby saving the cost of the stamping die, reducing the manufacturing difficulty of the cover plate assembly 2 and the fixed plate assembly 3, and reducing the manufacturing cost of the battery pack; in addition, the size of the cover plate assembly 2 and the fixed plate assembly 3 is reduced, and the space utilization rate of the battery pack is improved; and the problem of possible depression of the cover plate 21 after the connecting rod 42 and the nut 43 are locked is also solved.

[0044] like Figure 3 As shown, in one embodiment, the thickness of the step surface 41, the thickness of the fixed plate 31, the thickness of the outer sealing gasket 22, the thickness of the side wall of the box body 1 and the thickness of the inner sealing gasket 32 ​​satisfy the relationship: the thickness of the step surface 41 = the thickness of the fixed plate 31 + the thickness of the outer sealing gasket 22 after compression + the thickness of the side wall of the box body 1 + the thickness of the inner sealing gasket 32 ​​after compression.

[0045] Specifically, the compression amount of the outer sealing gasket 22 and the inner sealing gasket 32 ​​can be controlled by controlling the thickness of the step surface 41, thereby effectively preventing the service life of the outer sealing gasket 22 and / or the inner sealing gasket 32 ​​from being shortened due to excessive compression.

[0046] Since the force is mutual, the clamping force on the inner and outer sealing gaskets 32 and 22 is the same. Therefore, the compression of the two inner and outer sealing gaskets can be controlled simultaneously by the limiting effect of the step surface 41 alone, without the need to design the first limiting structure and the second limiting structure to control the compression of the inner and outer sealing gaskets 32 and 22 respectively.

[0047] Therefore, the thickness of the stepped surface 41 = the thickness of the fixing plate 31 + the thickness of the outer gasket 22 after compression + the thickness of the inner gasket 32 ​​after compression.

[0048] In some embodiments, the thickness of the inner sealing gasket 32 ​​and the outer sealing gasket 22 can be the same or different, and the material of the inner sealing gasket 32 ​​and the outer sealing gasket 22 can also be the same or different, as long as the compression amount of the inner sealing gasket 32 ​​and the outer sealing gasket 22 is within the acceptable range of the material and can achieve good sealing function.

[0049] In a preferred embodiment, the inner sealing gasket 32 ​​and the outer sealing gasket 22 have the same thickness and are made of the same material, thereby saving material preparation time and reducing costs.

[0050] like Figure 3 and Figure 6 As shown, in one embodiment, the first end of the step surface 41 is embedded in the first mounting hole 312 and forms a meshing area 33 with the first mounting hole 312 . The meshing area 33 is coated with a sealant 34 for sealing the meshing area 33 .

[0051] Specifically, since the meshing area 33 between the step surface 41 and the first mounting hole 312 is in an unsealed state, in this state, moist air will enter the battery pack along the gap between the connecting rod 42 and the nut 43, the gap between the cover plate assembly 2 and the connecting rod 42, the gap between the fixing plate assembly 3 and the connecting rod 42, and finally through the meshing area 33, thereby causing corrosion inside the battery pack.

[0052] Therefore, the sealant 34 is coated on the inner side surface of the fixing plate 31 , the first end of the step surface 41 and the meshing area 33 thereof. After the sealant 34 is coated on the meshing area 33 , the battery pack can be effectively well sealed.

[0053] like Figure 5-6 As shown, in one embodiment, a flange strip 313 is extended from the edge of the first through hole 311 toward one side of the maintenance port 11, and the flange strip 313 is parallel to the longer side of the maintenance port 11. The angle between the flange strip 313 and the fixing plate 31 is α, and α satisfies the relationship: 0°<α≤90°.

[0054] In some embodiments, the flange strip 313 is parallel to the longer side of the maintenance opening 11, the length of the flange strip 313 is less than the longer side of the maintenance opening 11, and the angle between the flange strip 313 and the fixing plate 31 is 0°-90°.

[0055] In some embodiments, the angle between the flange strip 313 and the fixing plate 31 is 60°-90°. Since a wire harness passes through the first through hole 311 , the flange strip 313 is provided on the edge of the first through hole 311 to prevent the wire harness from being cut or damaged.

[0056] In one embodiment, a bonding layer is provided on a side of the inner sealing gasket 32 ​​facing the fixing plate 31 , and the inner sealing gasket 32 ​​is connected to the fixing plate 31 through the bonding layer.

[0057] Specifically, the present application eliminates the riveting hole in the prior art, and provides an adhesive layer on the side of the inner sealing gasket 32 ​​facing the fixed plate 31, and the inner sealing gasket 32 ​​and the fixed plate 31 are connected through the adhesive layer, so that the inner sealing gasket 32 ​​and the fixed plate 31 are fixedly bonded;

[0058] In some preferred embodiments, an adhesive layer is provided on the side of the inner sealing gasket 32 ​​facing the side wall of the battery pack, and the other side of the inner sealing gasket 32 ​​is installed on the outer periphery of the maintenance port 11 through the adhesive layer, so that the inner sealing gasket 32 ​​and the fixing plate 31 are both fixed on the inner side of the box body 1, so that the cover plate assembly 2 can be installed and removed outside the battery pack.

[0059] Compared with the prior art, the manufacturing cost of the fixing plate 31 after eliminating the riveting holes is lower.

[0060] like Figure 4 As shown, in one embodiment, the cover plate 21 includes a reinforcing portion 212, a mounting portion 213 and an equipotential point 214. One end of the cover plate 21 is convex in a direction away from the accommodating cavity to form a reinforcing portion 212; the other end of the cover plate 21 is recessed in the direction of the accommodating cavity to form a mounting portion 213. Along the direction perpendicular to the maintenance port 11, the projections of the reinforcing portion 212 and the mounting portion 213 both fall within the maintenance port 11, and a plurality of equipotential points 214 are provided on the periphery of the cover plate 21.

[0061] In some embodiments, one end of the cover plate 21 is protruded in a direction away from the accommodating cavity to form a reinforcement portion 212, and the reinforcement portion 212 is used to accommodate devices such as a BMS circuit board, and also plays a reinforcing role, so that the cover plate 21 is not easily deformed.

[0062] In some embodiments, the other end of the cover plate 21 is recessed toward the accommodating cavity to form a mounting portion 213, and a sixth mounting hole 2131 is opened on the bottom surface of the mounting portion 213. The sixth mounting hole 2131 is used to install a longer connector, which can reduce the envelope size of the entire battery pack, thereby improving the space utilization of the electrical cabinet.

[0063] In some embodiments, a plurality of equipotential points 214 are provided on the periphery of the cover plate 21 . Specifically, two equipotential points 214 are provided and located at both ends of the diagonal of the cover plate 21 to meet safety requirements.

[0064] like Figure 1 As shown, in one embodiment, a bottom plate 5 is further included, and the bottom plate 5 is used to seal the box body 1.

[0065] Specifically, the bottom plate 5 and the box body 1 are sealed by threaded connection or welding.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery pack, characterized in that: It includes a box body, a cover plate assembly, a fixed plate assembly and a connecting piece, the box body has a accommodating cavity, the side wall of the box body is provided with a maintenance port connected to the accommodating cavity, the cover plate assembly is installed on the outer side of the maintenance port, the fixed plate assembly is installed on the inner side of the maintenance port, the cover plate assembly includes a stacked cover plate and an outer sealing gasket, the outer sealing gasket is arranged between the cover plate and the maintenance port, the fixed plate assembly includes a fixing plate and an inner sealing gasket, the inner sealing gasket is arranged between the fixing plate and the maintenance port, and the connecting piece connects the fixing plate and the cover plate.

2. The battery pack according to claim 1, characterized in that: The fixing plate is provided with a first through hole at a position corresponding to the maintenance port, the inner sealing gasket is provided with a second through hole at a position corresponding to the maintenance port, and the outer sealing gasket is provided with a third through hole at a position corresponding to the maintenance port.

3. The battery pack according to claim 2, characterized in that: The fixing plate is provided with a plurality of first mounting holes around the outer circumference of the first through hole, and the inner sealing gasket is provided with a plurality of second mounting holes around the outer circumference of the second through hole; the side wall of the box body is provided with a plurality of third mounting holes around the outer circumference of the maintenance port; the outer sealing gasket is provided with a plurality of fourth mounting holes around the circumference of the third through hole, and the cover plate is provided with a fifth mounting hole at a position corresponding to the fourth mounting hole, the first mounting hole, the second mounting hole, the third mounting hole, the fourth mounting hole and the fifth mounting hole are coaxially arranged, the first end of the connecting member is embedded in the first mounting hole, and the second end of the connecting member passes through the second mounting hole, the third mounting hole, the fourth mounting hole and the fifth mounting hole in sequence.

4. The battery pack according to claim 3, characterized in that: The connecting member includes a step surface, a connecting rod and a nut, the first end of the step surface is embedded in the first mounting hole, the second end of the step surface passes through the second mounting hole, the third mounting hole and the fourth mounting hole in sequence, and the outer surface of the step surface contacts the inner surfaces of the first mounting hole, the second mounting hole, the third mounting hole and the fourth mounting hole; the first end of the connecting rod is connected to the surface of the second end of the step surface, the connecting rod extends in a direction perpendicular to the plane where the second end of the step surface is located, the second end of the connecting rod passes through the fifth mounting hole and extends to the outside of the fifth mounting hole, the outer surface of the connecting rod contacts the inner surface of the fifth mounting hole, and the second end of the connecting rod is threadedly connected to the nut.

5. The battery pack according to claim 4, characterized in that: The thickness of the step surface, the thickness of the fixed plate, the thickness of the outer sealing gasket, the thickness of the side wall of the box body and the thickness of the inner sealing gasket satisfy the relationship: thickness of the step surface = thickness of the fixed plate + thickness of the outer sealing gasket after compression + thickness of the side wall of the box body + thickness of the inner sealing gasket after compression.

6. The battery pack according to claim 4, characterized in that: The first end of the step surface is embedded in the first mounting hole and forms a meshing area with the first mounting hole. The meshing area is coated with a sealant for sealing the meshing area.

7. The battery pack according to claim 1, characterized in that: A bonding layer is provided on a side of the inner sealing gasket facing the fixing plate, and the inner sealing gasket is connected to the fixing plate through the bonding layer.

8. The battery pack according to claim 2, characterized in that: A flange strip is provided on the edge of the first through hole extending toward one side of the maintenance opening. The flange strip is parallel to the longer side of the maintenance opening. An angle α is formed between the flange strip and the fixing plate. α satisfies the relationship: 0°<α≤90°.

9. The battery pack according to claim 1, characterized in that: The cover plate includes a reinforcing portion, a mounting portion and an equipotential point. One end of the cover plate is convex in a direction away from the accommodating cavity to form the reinforcing portion; the other end of the cover plate is concave in a direction toward the accommodating cavity to form the mounting portion. Along the direction perpendicular to the maintenance port, the projections of the reinforcing portion and the mounting portion both fall within the maintenance port, and a plurality of equipotential points are provided on the periphery of the cover plate.

10. The battery pack according to claim 1, characterized in that: A bottom plate is also included, and the bottom plate is used to seal the box body.

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