Lower box body assembly and battery pack with same

Abstract

The utility model discloses a lower box body assembly and a battery pack with the lower box body assembly, and the lower box body assembly comprises a frame, an upper box body and a lower box body, the peripheral edge of the cooling plate is in welded connection with the bottom of the frame; and the peripheral edge of the bottom protection plate is connected with the bottom of the frame in a welded mode, the bottom protection plate is arranged on the side, away from the frame, of the cooling plate, and the bottom protection plate is connected with the cooling plate in a bonded mode. According to the lower box body assembly, the cooling plate and the bottom protection plate are arranged, the cooling plate is connected with the bottom of the frame in the frame in a welded mode, the bottom protection plate is connected with the bottom of the frame in a welded mode, the bottom protection plate can play a good sealing role, operation of the cooling plate is more stable, and the cooling plate and the bottom protection plate are more convenient and easier to connect and assemble with the frame. Therefore, the production cost can be well reduced, the production efficiency can be improved, and the width of the frame can be set to be smaller, so that the overall size of the frame is smaller, the weight is reduced, and the energy density of the battery pack can be effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a lower box assembly and a battery pack having the same. Background Art

[0002] With the improvement of living conditions, improving the quality of life has gradually become the pursuit of many people. People's requirements for living environment are becoming higher and higher. At the same time, environmental pollution has become more and more serious with the development of society and the advancement of science and technology. Therefore, reducing environmental pollution and improving the living environment have become factors that need to be considered in the development process of all walks of life.

[0003] Electric vehicles driven by electricity can provide people with a green and environmentally friendly way of travel, and therefore are becoming more and more popular. The energy of electric vehicles comes from the battery pack. Existing battery packs are generally designed with cooling plates and bottom guards. The cooling plates provide heating and cooling for the battery cells and modules; the bottom guards are arranged at the bottom of the battery pack to protect the internal parts of the battery pack, have the functions of anti-collision and anti-stone impact, and also help improve the thermal insulation of the battery pack.

[0004] In the related art, when the cooling plate and the bottom guard plate are assembled in the battery pack, the cooling plate and the bottom guard plate are connected and fixed to the battery pack by fasteners, so that the frame structure used to cooperate and fix with the cooling plate and the bottom guard plate needs to be set to a larger width to meet the assembly requirements of the fasteners, resulting in a larger volume and heavier weight of the frame structure, which in turn reduces the energy density of the battery pack. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a lower box assembly, which can well reduce the width of the frame structure, effectively reduce the volume and weight of the frame structure in the battery pack, thereby well improving the energy density of the battery pack.

[0006] The utility model also provides a battery pack having the lower box assembly.

[0007] According to the first aspect of the utility model, the lower box assembly includes: a frame, which includes a frame; a cooling plate, the peripheral edge of the cooling plate is welded to the bottom of the frame; a bottom guard plate, the peripheral edge of the bottom guard plate is welded to the bottom of the frame, the bottom guard plate is arranged on the side of the cooling plate away from the frame, and the bottom guard plate is adhesively connected to the cooling plate.

[0008] According to the lower box assembly of the utility model, by arranging a cooling plate and a bottom guard plate, the cooling plate is welded to the bottom of the frame in the frame, and the bottom guard plate is welded to the bottom of the frame. The bottom guard plate can play a good sealing role, making the operation of the cooling plate more stable, and the cooling plate and the bottom guard plate are more convenient and easy to connect and assemble with the frame, which can greatly reduce production costs and improve production efficiency, and the width of the frame can be set smaller, so that the overall volume of the frame is smaller and the weight is reduced, thereby effectively improving the energy density of the battery pack.

[0009] In some embodiments of the present invention, the frame further includes: a cross beam and a longitudinal beam, the cross beam extends along a first direction and is connected to the frame and / or the longitudinal beam, the longitudinal beam extends along a second direction and is connected to the frame and / or the cross beam, the cooling plate is welded to the cross beam and the longitudinal beam, respectively, and the first direction is perpendicular to the second direction.

[0010] In some embodiments of the present invention, the cooling plate has a plurality of cooling channels, the plurality of cooling channels extend along the first direction and / or the second direction, the plurality of cooling channels are arranged at intervals, and the cooling channels protrude in the thickness direction of the cooling plate so that the cooling plate forms a rib structure.

[0011] In some embodiments of the present invention, the cooling plate cooperates with the frame to define a receiving cavity, and there is no channel structure on the cooling plate that connects the spaces on the upper and lower sides of the cooling plate.

[0012] In some embodiments of the utility model, a welding portion is formed on one side surface of the cooling plate facing the frame, the cooling plate is welded to the bottom of the frame through the welding portion, and an insulating layer is provided in the non-welding portion area of ​​the one side surface.

[0013] In some embodiments of the utility model, a reinforcing rib is provided on the side of the bottom guard plate facing the cooling plate, and the reinforcing rib protrudes toward the cooling plate. The lower box assembly also includes an adhesive, and the reinforcing rib is adhesively connected to the cooling plate via the adhesive.

[0014] In one embodiment of the utility model, a plurality of the reinforcing ribs are provided, and the plurality of the reinforcing ribs extend along the first direction or the second direction, and the plurality of the reinforcing ribs are arranged at intervals along the first direction or the second direction. The frame also includes: a cross beam and a longitudinal beam, and in the up and down directions, the plurality of the reinforcing ribs are respectively arranged relative to the cross beam and the longitudinal beam, and the first direction and the second direction are both perpendicular to the up and down directions.

[0015] In some embodiments of the present invention, the bottom guard plate cooperates with the cooling plate to define a buffer cavity, and there is no channel structure on the bottom guard plate that connects the spaces on the upper and lower sides of the bottom guard plate.

[0016] In one embodiment of the present invention, the lower box assembly further includes a buffer component, which is disposed in the buffer cavity and abuts against the cooling plate and the bottom guard plate.

[0017] The battery pack according to the second aspect of the utility model includes the lower box assembly according to the first aspect of the utility model.

[0018] According to the battery pack of the utility model, by setting the lower box assembly of the first aspect mentioned above, the lower box assembly is provided with a cooling plate and a bottom guard plate, the cooling plate is welded to the bottom of the frame in the frame, and the bottom guard plate is welded to the bottom of the frame. The bottom guard plate can play a good sealing role, so that the operation of the cooling plate is more stable, and the cooling plate and the bottom guard plate are more convenient and easy to connect and assemble with the frame, which can greatly reduce the production cost and improve the production efficiency, and the width of the frame can be set smaller, so that the overall volume of the frame is smaller and the weight is reduced, thereby the energy density of the battery pack can be effectively improved.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an exploded view of a battery pack according to an embodiment of the utility model;

[0021] Figure 2 is an exploded view of the lower box assembly according to an embodiment of the utility model;

[0022] Figure 3 It is a schematic diagram of the lower box assembly according to an embodiment of the utility model after the bottom guard plate is removed;

[0023] Figure 4 yes Figure 3 The cross-sectional view at AA shown in FIG.

[0024] Figure 5 yes Figure 4 A schematic diagram of a partial enlargement of point B shown in FIG.

[0025] Figure 6 yes Figure 4 A locally enlarged schematic diagram of the C shown in FIG.

[0026] Figure 7 is a schematic diagram of a cooling plate and an insulating layer according to an embodiment of the utility model;

[0027] Figure 8 is an exploded view of the lower box assembly according to another embodiment of the utility model;

[0028] Fig. 9 is a schematic diagram of a lower box assembly according to an embodiment of the utility model;

[0029] Fig.10 yes Fig. 9 The cross-sectional view at DD shown in ;

[0030] Fig.11 yes Fig.10 A locally enlarged schematic diagram of E shown in FIG.

[0031] Fig.12 yes Fig.10 A locally enlarged schematic diagram of point F shown in FIG.

[0032] Reference numerals:

[0033] 10. frame; 11. frame; 12. crossbeam; 13. longitudinal beam;

[0034] 20. Cooling plate; 21. Cooling channel; 22. Welding part;

[0035] 30. Bottom guard plate; 31. Reinforcement rib; 40. Buffer; 50. Adhesive; 60. Insulation layer;

[0036] 100, lower box assembly; 101, accommodating chamber; 102, buffer chamber; 200, upper box assembly; 300, battery module; 1000, battery pack. DETAILED DESCRIPTION

[0037] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0038] First reference Figure 1-Figure 12 A battery pack 1000 according to an embodiment of the second aspect of the present invention is briefly described. The battery pack 1000 may include an upper box assembly 200, a battery module 300, and a lower box assembly 100 according to an embodiment of the first aspect of the present invention. The lower box assembly 100 may cooperate with the upper box assembly 200 to define a receiving cavity 101, and the battery module 300 is disposed in the receiving cavity 101.

[0039] Reference below Figure 1-Figure 12 The lower box assembly 100 according to the first embodiment of the utility model is described.

[0040] like Figure 1-Figure 12 As shown, the lower box assembly 100 according to the first embodiment of the utility model comprises: a frame 10, a cooling plate 20 and a bottom guard plate 30. The frame 10 comprises a frame 11; the periphery of the cooling plate 20 is welded to the bottom of the frame 11; the periphery of the bottom guard plate 30 is welded to the bottom of the frame 11, the bottom guard plate 30 is arranged on the side of the cooling plate 20 away from the frame 10, and the bottom guard plate 30 is bonded to the cooling plate 20.

[0041] In this embodiment, a cooling plate 20 is provided, and the periphery of the cooling plate 20 is welded to the bottom of the frame 11. Specifically, the cooling plate 20 can form a continuous weld with the frame to close the bottom of the frame 11. The cooling plate 20 and the frame 11 can cooperate with the upper box assembly 200 to define a accommodating cavity 101. The battery module 300 can be arranged in the accommodating cavity 101. The cooling plate 20 can have a good cooling or heat dissipation effect on the battery module 300. The cooling plate 20 can have a good sealing effect on the accommodating cavity 101, so that the battery pack 1000 can operate stably and well.

[0042] In this embodiment, the periphery of the bottom guard plate 30 is welded to the bottom of the frame 11, and the bottom guard plate 30 is disposed on the side of the cooling plate 20 that is away from the frame 10. The bottom guard plate 30 can provide good protection for the cooling plate 20, preventing the cooling plate 20 from contacting the external environment and causing corrosion risks, making the cooling plate 20 more stable and controllable during operation, and improving the thermal management performance of the battery pack 1000 to a certain extent. The periphery of the bottom guard plate 30 is welded to the bottom of the frame 11, so that the bottom guard plate 30 can reliably seal the bottom of the frame 11, so that after the lower box assembly 100 is assembled in the battery pack 1000, the battery pack 1000 can have good airtightness.

[0043] In this embodiment, the bottom guard plate 30 and the cooling plate 20 are bonded together, which has a simple structure and can make the connection and fixation between the bottom guard plate 30 and the cooling plate 20 convenient and reliable, making the overall structure of the bottom guard plate 30 and the cooling plate 20 more compact and better integrated.

[0044] It is understandable that in the related art, when the cooling plate 20 and the frame 11 as well as the bottom guard plate 30 and the frame 11 are assembled, fasteners are usually used for connection and fixation. For example, the cooling plate 20 and the frame 11 are connected and fixed by using hot-melt self-tapping screws in combination with sealant, and the bottom guard plate 30 and the frame 11 are connected and fixed by bolts. When the cooling plate 20 and the frame 11 are connected and fixed, a large number of hot-melt self-tapping screws are used and glue is required. When the bottom guard plate 30 and the frame 11 are connected and fixed, a large number of parts such as bolts, rivet nuts, and sealing rings are used, and bolt tightening and torque verification are required. As a result, a large number of parts and processes are used when the cooling plate 20 and the bottom guard plate 30 are assembled with the frame 11, resulting in high production difficulty and cost, slowing down the production rhythm of the battery pack 1000, and reducing the production efficiency of the battery pack 1000.

[0045] In the present embodiment, by welding the cooling plate 20 to the frame 11 and the bottom guard plate 30 to the frame 11, the number of parts used can be greatly reduced, and the process of assembling the cooling plate 20 and the bottom guard plate 30 to the frame 11 is simplified, making the lower box assembly 100 easier and more convenient to produce and assemble at a lower cost, thereby greatly improving the production rhythm and production efficiency of the lower box assembly 100.

[0046] It is understandable that the method of connection and fixation using fasteners requires the arrangement of more components in the lower box assembly 100, which increases the overall weight of the cooling plate 20 and the bottom guard plate 30 after being connected and assembled with the frame 11, thereby reducing the energy density of the battery pack 1000.

[0047] In this embodiment, the cooling plate 20 is welded to the frame 11, and the bottom guard plate 30 is welded to the frame 11, which effectively avoids the use of fasteners. As a result, the overall weight of the cooling plate 20 and the bottom guard plate 30 is lower after being connected and assembled with the frame 11, thereby greatly improving the energy density of the battery pack 1000.

[0048] It can be understood that when the cooling plate 20 and the bottom guard plate 30 are connected and fixed to the frame 11 by fastener connection assembly, the frame 11 needs to be set to a larger width to provide a sufficient assembly connection surface for the fasteners, so that the fasteners can stably and reliably connect and fix the cooling plate 20 and the bottom guard plate 30 and form a good seal, and the bottom guard plate 30 can be stably and reliably connected and fixed to the frame 11 and form a good seal. The width of the frame 11 is relatively large, so that the overall volume of the frame 11 is larger and the weight is heavier, so that the frame 11 occupies a larger space in the battery pack 1000, so that the energy density of the battery pack 1000 is lower.

[0049] In this embodiment, by welding the cooling plate 20 to the frame 11, and welding the bottom guard plate 30 to the frame 11, the width of the frame 11 can be set to be smaller while meeting the requirements of a good and stable connection with the cooling plate 20 and the bottom guard plate 30, thereby reducing the overall volume and weight of the frame 11, thereby effectively improving the energy density of the battery pack 1000.

[0050] According to the lower box assembly 100 of the embodiment of the utility model, by setting the cooling plate 20 and the bottom guard plate 30, the cooling plate 20 is welded to the bottom of the frame 11 in the frame 10, and the bottom guard plate 30 is welded to the bottom of the frame 11. The bottom guard plate 30 can play a good sealing role, so that the operation of the cooling plate 20 is more stable, and the cooling plate 20 and the bottom guard plate 30 are more convenient and easy to connect and assemble with the frame 11, which can greatly reduce the production cost and improve the production efficiency, and the width of the frame 11 can be set smaller, so that the overall volume of the frame 10 is smaller and the weight is reduced, thereby the energy density of the battery pack 1000 can be effectively improved.

[0051] In some embodiments of the present invention, the cooling plate 20 and the frame 11 may be connected by friction stir welding, and the bottom guard plate 30 and the frame 11 may be connected by friction stir welding.

[0052] Stir friction welding utilizes a rotating stirring head to rotate at high speed between the welded parts, and the friction heat is used to soften the materials of the welded parts and combine them, which has higher welding quality. There are no welding defects such as pores or cracks during the welding process, and welding deformation is not easy to occur. In this embodiment, the cooling plate 20 and the frame 11 are connected by stir friction welding, and the bottom guard plate 30 and the frame 11 are connected by stir friction welding. The welding connection between the cooling plate 20 and the bottom guard plate 30 and the frame 11 can be firm and reliable, and the cooling plate 20 and the frame 11 can form a good sealing effect. The bottom guard plate 30 and the frame 11 can also form a good sealing effect, so that the bottom guard plate 30 can better play a protective role, and the battery pack 1000 can operate more stably.

[0053] In some embodiments of the present invention, Figure 2 As shown, the frame 10 may further include: a cross beam 12 and a longitudinal beam 13, the cross beam 12 is along a first direction (such as Figure 2 The longitudinal beam 13 extends in a second direction (such as the left and right direction shown in FIG. Figure 2 The first direction extends in the front-to-rear direction (as shown) and is connected to the frame 11 and / or the crossbeam 12. The cooling plate 20 is welded to the crossbeam 12 and the longitudinal beam 13 respectively. The first direction is perpendicular to the second direction.

[0054] In this embodiment, the frame 10 is further provided with a crossbeam 12 and a longitudinal beam 13, which can make the overall structural strength of the frame 10 higher and the stability better, so that the frame 10 can better play the role of supporting and protecting the various components in the battery pack 1000. The crossbeam 12 extends along the first direction and is connected to the frame 11 and / or the longitudinal beam 13. Both ends of the crossbeam 12 can be connected to the frame 11, and both ends of the crossbeam 12 can also be connected to the longitudinal beam 13. Both ends of the crossbeam 12 can also be connected to the frame 11 and the longitudinal beam 13, respectively. The longitudinal beam 13 extends along the second direction and is connected to the frame 11 and / or the crossbeam 12. Both ends of the longitudinal beam 13 can be connected to the frame 11, and both ends of the longitudinal beam 13 can also be connected to the crossbeam 12. Both ends of the longitudinal beam 13 can also be connected to the frame 11 and the crossbeam 12, respectively.

[0055] In this embodiment, the cooling plate 20 is welded to the cross beam 12 and the longitudinal beam 13 respectively, so that the cooling plate 20 can be fixed more stably and securely in the lower box assembly 100. The cross beam 12 and the longitudinal beam 13 can divide the cooling plate 20 into a plurality of small areas, so that the overall structural strength of the cooling plate 20 and the frame 10 is higher, and the overall structure of the lower box assembly 100 is more stable and reliable, so that the lower box assembly 100 can cooperate with the upper box assembly 200 to better protect the battery module 300 and other components, thereby improving the safety of the battery pack 1000.

[0056] In this embodiment, the cooling plate 20 is connected to the cross beam 12 and the longitudinal beam 13 by welding, which has a simple structure, convenient and firm connection, and the width of the cross beam 12 and the longitudinal beam 13 can be set smaller as needed, so that the cross beam 12 and the longitudinal beam 13 can occupy a smaller volume in the battery pack 1000 and have a lighter weight, so that the space in the battery pack 1000 can be more fully utilized, for example, more battery cells or battery modules 300 can be arranged, so that the energy density of the battery pack 1000 can be further improved. Optionally, the cross beam 12 and the longitudinal beam 13 can be welded to the cooling plate 20 by penetrating friction stir welding.

[0057] In one embodiment of the present invention, reference Figure 2 As shown, the lower box assembly 100 may further include an insulating sheet, which is bonded to the side surface of the cross beam 12 and / or the longitudinal beam 13. The insulating sheet can provide good insulation for the cross beam 12 and the longitudinal beam 13, so that the battery module 300 can operate stably in the accommodating cavity 101. Optionally, the insulating sheet may be a mica sheet, a polycarbonate sheet, or an epoxy sheet, etc., so that the insulating sheet has a good insulation and heat insulation effect, thereby providing good insulation, heat insulation and heat preservation in the battery pack 1000.

[0058] In some embodiments of the present invention, Figure 3As shown, the cooling plate 20 may have a plurality of cooling channels 21, which extend along the first direction and / or the second direction, are arranged at intervals, and protrude in the thickness direction of the cooling plate 20 so that the cooling plate 20 forms a rib structure.

[0059] In this embodiment, a plurality of cooling channels 21 are arranged on the cooling plate 20, and the plurality of cooling channels 21 extend along the first direction and / or the second direction. For example, the plurality of cooling channels 21 may extend along the first direction, and the plurality of cooling channels 21 may also extend along the second direction. The plurality of cooling channels 21 may also extend along the first direction and then along the second direction, or extend along the second direction and then along the first direction. The arrangement of the plurality of cooling channels 21 may be reasonably arranged according to the needs of use, and the arrangement positions and arrangement quantities of the plurality of cooling channels 21 on the cooling plate 20 may also be reasonably set according to the needs.

[0060] In this embodiment, multiple cooling channels 21 are arranged at intervals. Specifically, multiple cooling channels 21 can be arranged at intervals in the first direction, multiple cooling channels 21 can also be arranged at intervals in the second direction, multiple cooling channels 21 can also be partially arranged at intervals in the first direction, and partially arranged in the second direction. The arrangement direction of the multiple cooling channels 21 can also form a certain angle with the first direction or the second direction.

[0061] In this embodiment, the cooling channel 21 is raised in the thickness direction of the cooling plate 20 and forms a convex rib structure, which can make the cooling plate 20 have a good heat exchange capacity to meet the heat exchange needs of the battery pack 1000, and can increase the structural rigidity of the cooling plate 20, and the structural strength of the cooling plate 20 is higher, so that the overall structural strength of the cooling plate 20 and the frame 10 is better, and the cooling plate 20 can better play the role of lifting and supporting the battery module 300, so that the cooling plate 20 is more stable during operation. For example, the cooling channel 21 can be provided with five, eight, ten, fifteen, thirty, etc.

[0062] In one embodiment of the present invention, Figure 4 and Figure 6 As shown, the convex rib structure can be raised along the thickness direction toward the side away from the frame 10. In this way, the surface of the cooling plate 20 facing the frame 10 can be kept flat, so that it can be in good contact with the battery module 300 for heat exchange when the battery pack 1000 is assembled, and the cooling plate 20 can stably support the battery module 300.

[0063] In some embodiments of the present invention, reference Figure 4 and Figure 7 As shown, the cooling plate 20 can cooperate with the frame 10 to define a receiving cavity 101 , and there is no channel structure on the cooling plate 20 that connects the spaces on the upper and lower sides of the cooling plate 20 .

[0064] In this embodiment, the cooling plate 20 cooperates with the frame 10 to define a receiving cavity 101. Specifically, the cooling plate 20 and the frame 10 cooperate with the upper box assembly 200 to define the receiving cavity 101, which can facilitate the accommodation and arrangement of battery cells or battery modules 300. The structure is simple, and the cooling plate 20 can cooperate with the frame 11 to play a good sealing role in the receiving cavity 101 that accommodates the battery module 300. In this embodiment, the cooling plate 20 is set as a channel structure without connecting the upper and lower spaces of the cooling plate 20, that is, the cooling plate 20 is a whole plate structure, so that when the cooling plate 20 is manufactured, the mold development is simpler and more convenient, the production cost is lower, and the risk of airtight failure caused by the hole structure can be well avoided, so that the battery pack 1000 can operate more stably and well.

[0065] In some embodiments of the present invention, Figure 7 As shown, a welding portion 22 may be formed on one side surface of the cooling plate 20 facing the frame 10 , and the cooling plate 20 is welded to the bottom of the frame 11 via the welding portion 22 , and an insulating layer 60 is provided in the non-welding portion 22 area of ​​the one side surface.

[0066] In this embodiment, an insulating layer 60 is provided on the surface of the cooling plate 20 on one side facing the frame 10 , which can provide good electrical insulation between the cooling plate 20 and the battery module 300 in the accommodating cavity 101 and other electrical components, thereby making the battery pack 1000 safer during operation and allowing the battery module 300 in the battery pack 1000 to stably dissipate heat through the cooling plate 20 .

[0067] In this embodiment, a welding portion 22 is provided on one side surface of the cooling plate 20, and the welding portion 22 is welded to the frame 11, the cross beam 12 and the longitudinal beam 13. An insulating layer 60 is provided in the non-welding portion 22 area, which can effectively prevent the insulating layer 60 from causing adverse effects on the welding connection between the cooling plate 20 and the frame 10, so that the cooling plate 20 and the frame 10 can be stably and well welded with high quality, and the connection and fixation of the cooling plate 20 and the frame 10 can be more secure and stable. Optionally, the insulating layer 60 can be formed on one side surface of the cooling plate 20 by spraying. Optionally, the welding portion 22 can be formed to be connected to the bottom of the frame 11, the cross beam 12 and the longitudinal beam 13 in the up and down directions (such as Figure 2 The weld bead structure relative to the upper and lower directions (as shown).

[0068] In some embodiments of the present invention, Figure 2 and Fig.12 As shown, a side of the bottom guard plate 30 facing the cooling plate 20 may be provided with a reinforcing rib 31 , which protrudes toward the cooling plate 20 . The lower box assembly 100 also includes an adhesive 50 , and the reinforcing rib 31 is adhesively connected to the cooling plate 20 via the adhesive 50 .

[0069] In this embodiment, reinforcing ribs 31 are provided on the bottom guard plate 30, which can increase the structural rigidity of the bottom guard plate 30 and improve the structural strength, so that the bottom guard plate 30 can better play a protective role. The reinforcing ribs 31 protrude toward the cooling plate 20 and are bonded to the cooling plate 20. The protrusion of the reinforcing ribs 31 toward the cooling plate 20 can reduce the distance between it and the cooling plate 20, thereby facilitating the connection between the bottom guard plate 30 and the cooling plate 20. The bottom guard plate 30 and the cooling plate 20 are bonded together, which has a simple structure, is flexible to use, and is conveniently and firmly connected and fixed. The adhesive 50 can play a certain buffering effect, so that the overall structure of the lower box assembly 100 has better mechanical strength and impact resistance, and the battery pack 1000 has better stability during use.

[0070] In this embodiment, the bottom guard plate 30 and the cooling plate 20 are bonded and connected by the adhesive 50, which can reduce the use of parts, thereby improving the space utilization rate in the battery pack 1000 to a certain extent, reducing the weight of the battery pack 1000, and further improving the energy density of the battery pack 1000. Optionally, the adhesive 50 can be a thermally conductive sealant or a structural sealant.

[0071] In one embodiment of the present invention, Figure 2 and Fig. 9 As shown, the reinforcing ribs 31 may be provided in plurality, the plurality of reinforcing ribs 31 extend along the first direction or the second direction, and the plurality of reinforcing ribs 31 are arranged at intervals along the first direction or the second direction. The frame 10 further includes: a cross beam 12 and a longitudinal beam 13, which are arranged in the vertical direction (such as Figure 2 In the up-down direction shown in FIG. 1 , a plurality of reinforcing ribs 31 are arranged opposite to the cross beam 12 and the longitudinal beam 13 respectively, and the first direction and the second direction are both perpendicular to the up-down direction.

[0072] In this embodiment, a plurality of reinforcing ribs 31 are provided, and the plurality of reinforcing ribs 31 can separate the bottom guard plate 30 into a plurality of small areas, and the reinforcing ribs 31 are bonded and connected with the cooling plate 20, so that the bottom guard plate 30 can have higher rigidity and better structural strength, so that the bottom guard plate 30 can better play a protective role.

[0073] A plurality of reinforcing ribs 31 are arranged relative to the cross beam 12 and the longitudinal beam 13 in the vertical direction. When the bottom guard plate 30 is subjected to external impact, the impact force can be quickly transmitted to the cross beam 12 and the longitudinal beam 13 of the frame 10 along the reinforcing ribs 31, so that the bottom guard plate 30 can cooperate well with the structure of the frame 10 to resist external impact, so that the bottom guard plate 30 has better resistance to stone impact and collision, better protection effect, and more stable operation of the battery pack 1000. For example, the reinforcing ribs 31 can be provided with two, three, four, five, six, seven, eight, nine, ten, eleven, etc. The number, extension length and arrangement position of the reinforcing ribs 31 can be reasonably set according to the arrangement of the cross beam 12 and the longitudinal beam 13 in the frame 10 and the reinforcement needs of the bottom guard plate 30.

[0074] In some embodiments of the present invention, Figure 10-12 As shown, the bottom guard plate 30 can cooperate with the cooling plate 20 to define a buffer cavity 102 , and there is no channel structure on the bottom guard plate 30 that connects the spaces on the upper and lower sides of the bottom guard plate 30 .

[0075] In this embodiment, the bottom guard plate 30 and the cooling plate 20 cooperate to define a buffer cavity 102, so that when the bottom guard plate 30 is subjected to external impacts such as stone strikes, the buffer cavity 102 can provide an escape space for deformation buffering of the bottom guard plate 30, thereby reducing the impact of the impact force on the cooling plate 20, and can effectively reduce the risk of corrosion of the cooling plate 20, so that the operation of the cooling plate 20 is more stable. The buffer cavity 102 is formed between the cooling plate 20 and the bottom guard plate 30, which can effectively isolate the external environment and heat sources, and effectively avoid the external temperature from having a greater impact on the operation of the cooling plate 20, so that the battery pack 1000 can have better thermal management performance.

[0076] In the present embodiment, there is no channel structure on the bottom guard plate 30 connecting the spaces on the upper and lower sides of the bottom guard plate 30, so that the mold development and production costs of the bottom guard plate 30 can be low during processing and manufacturing, and the risk of airtight failure caused by setting holes can be effectively avoided, so that the sealing of the bottom guard plate 30 is better, thereby improving the safety of the battery pack 1000.

[0077] In one embodiment of the present invention, Figure 8 and Fig.12 As shown, the lower box assembly 100 may further include a buffer member 40 . The buffer member 40 is disposed in the buffer cavity 102 , and the buffer member 40 abuts against the cooling plate 20 and the bottom guard plate 30 .

[0078] In this embodiment, a buffer member 40 is arranged in the buffer cavity 102, which can better buffer external impacts and make the cooling plate 20 run more stably. The buffer member 40 can play a good supporting role for the cooling plate 20 and the bottom guard plate 30, so that the overall structural stability of the bottom guard plate 30 and the cooling plate 20 is better, and the bottom guard plate 30 can have better resistance to stone impact and bump. Optionally, the buffer member 40 can be an expanded polypropylene member, a modified polypropylene member or a buffer foam.

[0079] In one embodiment of the present invention, reference Fig. 9 As shown, the surface of the bottom guard plate 30 on the side facing away from the cooling plate 20 may have a rubber coating. In this embodiment, the rubber coating layer is provided to provide good corrosion protection, insulation protection, and sealing and moisture-proofing for the bottom guard plate 30, which facilitates the assembly and bonding of the battery pack 1000 in the vehicle. The rubber coating layer can play a certain role in vibration reduction and buffering, so that the bottom guard plate 30 can have better resistance to stone impact and bump, thereby making the battery pack 1000 operate more stably. Optionally, the rubber coating layer is a polyvinyl chloride primer.

[0080] In some examples of the present invention, micro-spherical particles can be compounded in the adhesive layer, which can enhance the buffering and energy absorption effect of the adhesive layer, so that the bottom guard plate 30 can have better impact resistance, and the adhesive layer can have greater viscosity, so that the battery pack 1000 is more firmly assembled and fixed.

[0081] Reference below Figure 1-Figure 12 A battery pack 1000 according to an embodiment of the second aspect of the utility model is described.

[0082] like Figure 1-Figure 12 As shown, the battery pack 1000 according to the embodiment of the utility model includes the lower box assembly 100 according to the embodiment of the second aspect of the utility model.

[0083] According to the battery pack 1000 of the embodiment of the utility model, by setting the lower box assembly 100 of the above-mentioned first aspect embodiment, the lower box assembly 100 is provided with a cooling plate 20 and a bottom guard plate 30, the cooling plate 20 is welded to the bottom of the frame 11 in the frame 10, and the bottom guard plate 30 is welded to the bottom of the frame 11, the bottom guard plate 30 can play a good sealing role, so that the operation of the cooling plate 20 is more stable, the cooling plate 20 and the bottom guard plate 30 are more convenient and easy to connect and assemble with the frame 11, which can greatly reduce the production cost and improve the production efficiency, and the width of the frame 11 can be set smaller, so that the overall volume of the frame 10 is smaller and the weight is reduced, thereby the energy density of the battery pack 1000 can be effectively improved.

[0084] In some embodiments of the present invention, Figure 1As shown, the battery pack 1000 may further include an upper box assembly 200 and a battery module 300. The upper box assembly 200 cooperates with the lower box assembly 100 to define a receiving cavity 101, and the battery module 300 may be disposed in the receiving cavity 101. This can provide good protection for the battery module 300, so that the battery pack 1000 can operate stably and reliably.

[0085] The following will refer to Figure 1-Figure 12 A battery pack 1000 according to a specific embodiment of the present invention is described.

[0086] like Figure 1-Figure 12 As shown, the battery pack 1000 includes an upper box assembly 200 , a battery module 300 and a lower box assembly 100 .

[0087] The lower box assembly 100 includes a frame 10, a cooling plate 20, a bottom guard plate 30, an adhesive 50 and a buffer 40. The frame 10 includes a frame 11, a crossbeam 12 and a longitudinal beam 13. The crossbeam 12 extends along a first direction, and the longitudinal beam 13 extends along a second direction. The crossbeam 12 and the longitudinal beam 13 are arranged in an area surrounded by the frame 11. There are three crossbeams 12, and the three crossbeams 12 are arranged at intervals in the second direction. The two ends of the two crossbeams 12 are respectively connected to the frame 11, and the two ends of one crossbeam 12 are respectively connected to the two longitudinal beams 13. There are three longitudinal beams 13, and the two ends of the longitudinal beam 13 are respectively connected to the frame 11 and the crossbeam 12. The frame 11 in the frame 10 is welded with the crossbeam 12 and the longitudinal beam 13 to form an integral part. The surfaces of the crossbeam 12 and the longitudinal beam 13 are pasted with mica sheets for insulation, heat insulation and heat preservation.

[0088] The cooling plate 20 is a whole plate and is arranged at the bottom of the frame 10. The periphery of the cooling plate 20 is connected to the frame 11 of the frame 10 by seam-type friction stir welding to form a continuous closed-loop weld. The cooling plate 20 is connected to the cross beam 12 and the longitudinal beam 13 by penetration-type friction stir welding. A welding portion 22 is formed on the surface of the cooling plate 20 facing the frame 10. The welding portion 22 is a weld bead. The welding portion 22 is welded to the bottom of the frame 10. The non-welding portion 22 of the cooling plate 20 is sprayed with an insulating layer 60. The cooling plate 20 is formed with a plurality of cooling channels 21. The multi-compartment cooling channels 21 protrude away from the frame 10 in the thickness direction to form a convex rib structure. The cooling channels 21 are arranged in an area where the battery pack 1000 has a large amplitude when vibration occurs.

[0089] The bottom guard plate 30 is a whole plate and is arranged at the bottom of the cooling plate 20. The periphery of the bottom guard plate 30 is connected to the frame 11 of the frame 10 by seam-type stir friction welding. A reinforcing rib 31 is formed on the bottom guard plate 30. The reinforcing rib 31 is provided with a plurality of reinforcing ribs and protrudes toward the cooling plate 20. The reinforcing rib 31 is arranged opposite to the cross beam 12 and the longitudinal beam 13 in the vertical direction. The end surface of the reinforcing rib 31 facing the cooling plate 20 is bonded and fixed to the cooling plate 20 by an adhesive 50, and the adhesive 50 is a structural adhesive. The buffer 40 is arranged in a buffer cavity 102 formed between the cooling plate 20 and the bottom guard plate 30. The surface of the bottom guard plate 30 facing away from the cooling plate 20 is coated with a polyvinyl chloride primer, and the primer is compounded with microspherical particles.

[0090] When the insulating layer 60 is sprayed on the cooling plate 20 , the spraying operation can be performed after shielding the welding portion 22 of the cooling plate 20 .

[0091] When assembling the lower box assembly 100, the cooling plate 20 is welded to the frame 11, the cross beam 12 and the longitudinal beam 13, the buffer member 40 is arranged between the bottom guard plate 30 and the cooling plate 20, the bottom guard plate 30 is bonded to the cooling plate 20 by the adhesive 50, and the periphery of the bottom guard plate 30 is welded to the frame 11. The assembled lower box assembly 100 can be assembled with the upper box assembly 200, and the battery module 300 is arranged in the accommodating cavity 101 on the upper side of the cooling plate 20. In this embodiment, by adopting the welding connection method, the width of the frame 11, the cross beam 12 and the longitudinal beam 13 can be set to be smaller, and the width requirement of the battery pack 1000 for the frame 11, the cross beam 12 and the longitudinal beam 13 can be reduced to greater than or equal to 8 mm.

[0092] According to the battery pack 1000 of the embodiment of the utility model, a cooling plate 20 and a bottom guard plate 30 are arranged in the lower box assembly 100, the cooling plate 20 is welded to the bottom of the frame 11 in the frame 10, and the bottom guard plate 30 is welded to the bottom of the frame 11. The bottom guard plate 30 can play a good sealing role, so that the operation of the cooling plate 20 is more stable, and the cooling plate 20 and the bottom guard plate 30 are more convenient and easy to connect and assemble with the frame 11, which can greatly reduce the production cost and improve the production efficiency, and the width of the frame 11 can be set smaller, so that the overall volume of the frame 10 is smaller and the weight is reduced, thereby the energy density of the battery pack 1000 can be effectively improved.

[0093] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0094] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0095] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like 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, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0097] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A lower box assembly, characterized in that: include: a frame, the frame comprising a border; A cooling plate, wherein the periphery of the cooling plate is welded to the bottom of the frame; A bottom guard plate, the periphery of which is welded to the bottom of the frame, the bottom guard plate is arranged on a side of the cooling plate away from the frame, and the bottom guard plate is adhesively connected to the cooling plate.

2. The lower box assembly according to claim 1, characterized in that: The frame also includes: a crossbeam and a longitudinal beam, the crossbeam extends along a first direction and is connected to the frame and / or the longitudinal beam, the longitudinal beam extends along a second direction and is connected to the frame and / or the crossbeam, the cooling plate is welded to the crossbeam and the longitudinal beam respectively, and the first direction is perpendicular to the second direction.

3. The lower box assembly according to claim 1, characterized in that: The cooling plate has a plurality of cooling channels, the plurality of cooling channels extend along a first direction and / or a second direction, the plurality of cooling channels are arranged at intervals, and the cooling channels protrude in a thickness direction of the cooling plate so that the cooling plate forms a rib structure.

4. The lower box assembly according to claim 1, characterized in that: The cooling plate cooperates with the frame to define a containing cavity, and the cooling plate is free of a channel structure connecting the spaces on the upper and lower sides of the cooling plate.

5. The lower box assembly according to claim 1, characterized in that: A welding portion is formed on one side surface of the cooling plate facing the frame, and the cooling plate is welded to the bottom of the frame through the welding portion. An insulating layer is provided in a non-welding portion area of ​​the one side surface.

6. The lower box assembly according to any one of claims 1 to 5, characterized in that: A reinforcing rib is provided on one side of the bottom guard plate facing the cooling plate, and the reinforcing rib protrudes toward the cooling plate. The lower box assembly also includes an adhesive component, and the reinforcing rib is adhesively connected to the cooling plate via the adhesive component.

7. The lower box assembly according to claim 6, characterized in that: There are multiple reinforcing ribs, and the multiple reinforcing ribs extend along the first direction or the second direction. The multiple reinforcing ribs are arranged at intervals along the first direction or the second direction. The frame also includes: a crossbeam and a longitudinal beam. In the up and down directions, the multiple reinforcing ribs are arranged opposite to the crossbeam and the longitudinal beam respectively, and the first direction and the second direction are both perpendicular to the up and down directions.

8. The lower box assembly according to claim 1, characterized in that: The bottom guard plate cooperates with the cooling plate to define a buffer cavity, and the bottom guard plate is free of a channel structure connecting the spaces on the upper and lower sides of the bottom guard plate.

9. The lower box assembly according to claim 8, characterized in that: It also includes a buffer component, which is arranged in the buffer cavity and abuts against the cooling plate and the bottom guard plate.

10. A battery pack, characterized in that: include: A lower box assembly according to any one of claims 1 to 9.

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