Battery lower box body, battery pack and vehicle

Abstract

The invention discloses a battery lower box body, a battery pack and a vehicle. The battery lower box body comprises a hollow frame and a liquid cooling plate, the hollow frame comprises a front frame, a rear frame and two side frames, the side frames are connected with the front frame and the rear frame, and the front frame, the rear frame and the two side frames are integrated into an integrated structure; the liquid cooling plate is fixedly connected with the bottom of the hollow frame, and the liquid cooling plate blocks the bottom opening of the hollow frame. According to the battery lower box body, through structural optimization, the number of parts can be greatly reduced, the assembly complexity can be reduced, and the structural performance can be improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery lower housing, a battery pack, and a vehicle. Background Technology

[0002] The powertrain of a new energy vehicle includes a battery pack, which comprises a battery housing, battery cell components, a thermal management system, an electrical system, and other accessories. The lower housing of the battery housing supports the battery cell components, thermal management system, and electrical system, and is a key structural component of the battery pack.

[0003] Currently, the lower casing of battery boxes mostly adopts an extruded aluminum alloy welded structure. That is, the individual parts are formed by extrusion and then welded together to form the lower casing. The lower casing generally has more than 20 parts, the welding process is complex, and the parts are prone to deformation during the welding process, which affects the structural performance of the lower casing. Summary of the Invention

[0004] The purpose of this application is to provide a battery lower housing, a battery pack, and a vehicle. The battery lower housing, through structural optimization, can significantly reduce the number of parts, thereby reducing assembly complexity and improving structural performance.

[0005] To address the aforementioned technical problems, this application provides a lower battery housing, which includes a hollow frame and a liquid cooling plate.

[0006] The hollow frame includes a front frame, a rear frame, and two side frames. The side frames connect the front frame and the rear frame, and the front frame, the rear frame, and the two side frames are integrated into a single structure.

[0007] The liquid cooling plate is fixedly connected to the bottom of the hollow frame, and the liquid cooling plate seals the bottom opening of the hollow frame.

[0008] In one feasible embodiment, the side frame includes a first side plate, a second side plate, a third side plate, a top side plate, and a bottom side plate integrated into a single structure. The first side plate, the second side plate, and the third side plate are arranged along the width direction of the lower battery housing. The first side plate is located outside the second side plate, the second side plate is located outside the third side plate, the top side plate connects the top of the first side plate and the second side plate, and the bottom side plate connects the bottom of the second side plate and the third side plate.

[0009] In one feasible embodiment, a plurality of first side stiffeners are connected between the first side plate and the second side plate, and a plurality of second side stiffeners are connected between the second side plate and the third side plate.

[0010] In one feasible embodiment, the hollow frame further includes a crossbeam connecting the two side frames, the crossbeam being integrated with the side frames into a single structure.

[0011] In one feasible embodiment, diagonal stiffeners are connected between the two beam sidewalls of the crossbeam and the side frame.

[0012] In one feasible embodiment, the crossbeam passes through a third side plate of the side frame and connects to a second side plate of the side frame. The third side plate has a clearance notch for the crossbeam to pass through. The diagonal stiffener connects to the wall portion forming the clearance notch between the beam sidewall of the crossbeam and the second side plate and connects to the crossbeam or the diagonal stiffener.

[0013] In one feasible embodiment, the crossbeam includes two crossbeam base plates and a plurality of crossbeam stiffeners, the crossbeam stiffeners being connected between the two crossbeam base plates.

[0014] In one feasible solution, the outer wall of the side frame is provided with a plurality of hoisting structures, the hoisting structures are integrated with the side frame as a whole structure, and one of the hoisting structures is provided at the position where the side frame is connected to the crossbeam.

[0015] In one feasible embodiment, the hoisting structure includes a hoisting base plate and a plurality of hoisting stiffeners. The hoisting base plate extends outward from the outer wall of the side frame along the width direction of the lower battery housing, and the hoisting stiffeners connect the hoisting base plate and the side frame.

[0016] In one feasible solution, the liquid cooling plate has an integrally integrated liquid inlet channel and a liquid outlet channel. The liquid inlet channel is connected to the liquid inlet of the liquid cooling plate, and the liquid outlet channel is connected to the liquid outlet of the liquid cooling plate. The liquid inlet channel and the liquid outlet channel are disposed adjacent to the front frame and are located on the side of the front frame facing the rear frame.

[0017] In one feasible embodiment, the lower battery housing further includes a bottom protective plate located below the liquid cooling plate, and the bottom protective plate is fixedly connected to the hollow frame.

[0018] This application also provides a battery pack, including a battery cover and a lower battery housing as described in any of the above embodiments, wherein the battery cover covers the lower battery housing.

[0019] This application also provides a vehicle, including a frame and a battery pack mounted on the frame, wherein the battery pack is the battery pack described above.

[0020] The battery lower housing provided in this application embodiment is applied to vehicles and can serve as part of the battery pack housing. The front frame, rear frame, and two side frames of the battery lower housing are integrated into a single structure and then assembled with a liquid cooling plate. Compared with the welded structure in related technologies, this effectively reduces the number of parts. There are no separate connection structures between the front and side frames and the front and rear frames, which reduces the assembly complexity of the battery lower housing and effectively improves the production efficiency of the battery lower housing. In addition, due to the reduction in the number of parts, the number of connection points is also reduced, which reduces the probability of deformation caused by assembly connections and helps to improve the overall structural performance of the battery lower housing. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the lower battery housing provided in one embodiment of this application;

[0022] Figure 2 for Figure 1 An exploded view of the lower battery housing shown.

[0023] Figure 3 for Figure 1 A partial sectional view of the lower battery housing shown.

[0024] Figure 4 for Figure 1 A partial structural diagram of the lower battery housing at the connection point between the crossbeam and one side frame;

[0025] Figure 5 for Figure 2 A schematic diagram of the hollow frame of the lower battery box from a downward viewing angle;

[0026] Figure 6 for Figure 1 The diagram shows a partial structural diagram of the lower battery housing near the front frame.

[0027] Explanation of reference numerals in the attached figures:

[0028] Battery lower casing 1, hollow frame 2, liquid cooling plate 3, cooling channel 301, liquid inlet channel 302, liquid outlet channel 303, bottom protective plate 4;

[0029] Front frame 10, front wall panel 11, front stiffener 12, first front stiffener 121, second front stiffener 122, front top panel 13;

[0030] Rear frame 20, rear wall panel 21, rear stiffening plate 22, rear top plate 23;

[0031] Side frame 30, first side plate 31, second side plate 32, third side plate 33, first side stiffener 34, second side stiffener 35, diagonal stiffener 36, side top plate 37, side bottom plate 38;

[0032] Horizontal beam 40, horizontal beam base plate 41, horizontal beam stiffening plate 42;

[0033] Lifting structure 50, lifting base plate 51, lifting hole 511, lifting stiffener 52, first lifting stiffener 521, second lifting stiffener 522;

[0034] Inlet pipe 61, outlet pipe 62. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Without loss of generality, this embodiment uses the battery lower casing, whose outer contour is generally rectangular as shown in the illustration, as the main subject of description, to explain the specific implementation scheme in detail. It should be understood that the outer contour of the battery lower casing and the dimensional proportions shown in the illustration do not constitute a substantial limitation on the battery lower casing for which protection is claimed in this application.

[0037] The ordinal numbers "first," "second," etc., used in this article are for distinguishing different components with the same name and do not indicate a specific order or hierarchy. "Multiple" in this article refers to two or more, while "several" includes one, two, or three or more.

[0038] For ease of understanding and description, this document defines three directions for the lower battery housing: the first direction x is the length direction of the lower battery housing, the second direction y is the width direction of the lower battery housing, and the third direction z is the thickness direction of the lower battery housing, which can also be understood as the height direction of the lower battery housing. In this document, the front-back direction is the first direction x, the left-right direction is the second direction y, and the up-down direction (or top-bottom direction) is the third direction z. The directional terms used in this document refer to directions relatively close to the center of the lower battery housing, and correspondingly, the directional terms refer to directions relatively far from the center of the lower battery housing. The use of these directional terms is merely for clarity and convenience in describing the technical solution and does not constitute a limitation on the scope of protection.

[0039] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the lower battery housing provided in one embodiment of this application. Figure 2 for Figure 1 An exploded view of the lower battery casing shown.

[0040] The battery lower housing 1 provided in this embodiment can be used in a battery pack, serving as part of the battery box structure of the battery pack. The battery lower housing 1 includes a hollow frame 2 and a liquid cooling plate 3.

[0041] The hollow frame 2 of the battery lower housing 1 includes a front frame 10, a rear frame 20, and two side frames 30, with the side frames 30 connecting the front frame 10 and the rear frame 20. It can be understood that the side frames 30 connect the front frame 10 and the rear frame 20 on the same side in the second direction y. Specifically, one side frame 30 connects the left side of the front frame 10 and the left side of the rear frame 20, and the other side frame 30 connects the right side of the front frame 10 and the right side of the rear frame 20. The front frame 10, the rear frame 20, and the two side frames 30 are integrated into a single structure.

[0042] The liquid cooling plate 3 of the lower battery housing 1 is fixedly connected to the bottom of the hollow frame 2, and the liquid cooling plate 3 is used to seal the bottom opening of the hollow frame 2. In this way, the liquid cooling plate 3 and the hollow frame 2 form an open receiving space, which can be used to install the battery cell assembly of the battery pack, as well as electrical components and related accessories (such as wiring harnesses) that are electrically connected to the battery cell assembly.

[0043] By adopting the above solution, the front frame 10, rear frame 20, and two side frames 30 of the lower battery housing 1 are integrated into a single structure and then assembled with the liquid cooling plate 3. Compared with the welded structure in related technologies, this method can effectively reduce the number of parts. There is no separate connection structure between the front side frame 30 and the front frame 10 and rear frame 20, which can reduce the assembly complexity of the lower battery housing 1 and effectively improve the production efficiency of the lower battery housing 1. In addition, due to the reduction in the number of parts, the number of connection points is also reduced accordingly, which can reduce the probability of deformation caused by assembly and connection, and is conducive to improving the overall structural performance of the lower battery housing 1.

[0044] The battery lower housing 1 provided in this embodiment can be used in vehicles as the main load-bearing structural component of the vehicle's battery pack. When applied to a vehicle, the battery lower housing 1 has its front edge 10 close to the front of the vehicle and its rear edge 20 close to the rear of the vehicle. In this way, the extension direction (length direction) of the side edge 30 of the battery lower housing 1 is approximately the same as the vehicle length direction.

[0045] Please refer to this as well. Figure 3 and Figure 4 , Figure 3 for Figure 1 A partial sectional view of the lower casing of the battery shown. Figure 4 for Figure 1 The diagram shows a partial structural schematic of the lower battery housing at the connection point between the crossbeam and one side frame.

[0046] In this embodiment, the side frame 30 of the hollow frame 2 includes a first side plate 31, a second side plate 32, and a third side plate 33, which are arranged along the second direction y (i.e., the width direction of the lower battery housing 1). The first side plate 31 is located outside the second side plate 32, and the second side plate 32 is located outside the third side plate 33, that is, the second side plate 32 is located between the first side plate 31 and the third side plate 33. The first side plate 31 is farther away from the center of the lower battery housing 1 relative to the third side plate 33. The side frame 30 also includes a top side plate 37 and a bottom side plate 38. The top side plate 37 connects the top of the first side plate 31 and the second side plate 32, and the bottom side plate 38 connects the bottom of the second side plate 32 and the third side plate 33. The first side plate 31, the second side plate 32, the third side plate 33, the top side plate 37, and the bottom side plate 38 are integrated into a single structure.

[0047] With the above configuration, the side frame 30 has a double-layer structure, forming a cavity between the first side plate 31 and the second side plate 32, and another cavity between the second side plate 32 and the third side plate 33, which provides good side protection performance when subjected to side impact.

[0048] In a specific implementation, the side frame 30 also includes a plurality of first side stiffeners 34 and a plurality of second side stiffeners 35. The first side stiffeners 34 are connected between the first side plate 31 and the second side plate 32, and the second side stiffeners 35 are connected between the second side plate 32 and the third side plate 33.

[0049] With the above configuration, the side frame 30 of the hollow frame 2 has a double-layer beam structure. Through the setting of the side stiffeners, the structural stability of the side frame 30 is better. When the battery lower box 1 is subjected to a side impact, a two-level protection structure can be formed. The first-level protection structure is an outer beam structure composed of the first side plate 31, the second side plate 32, and the first side stiffener 34 between them. The second-level protection structure is an inner beam structure composed of the second side plate 32, the third side plate 33, and the second side stiffener 35 connected between them. Each beam structure consists of two side plates and a side stiffener connected between the two side plates. The arrangement of the side stiffeners forms multiple chamber structures between the two side plates, which improves the structural strength of the side frame 30 and gives the side frame 30 better side protection performance. In the case of a side collision of the whole vehicle, the safety protection performance of the battery pack can be improved.

[0050] In some examples, two adjacent first side stiffeners 34, together with the first side plate 31 and the second side plate 32, can form a triangular or trapezoidal cavity structure. Similarly, two adjacent second side stiffeners 35, together with the second side plate 32 and the third side plate 33, can form a triangular or trapezoidal cavity structure. This triangular and trapezoidal cavity structure design allows the side frame 30 to have higher structural strength, which is beneficial for improving its impact resistance.

[0051] In this embodiment, the hollow frame 2 also includes a crossbeam 40, which is connected to the two side frames 30. The crossbeam 40 and the side frames 30 are integrated into a single structure.

[0052] The crossbeam 40 extends along the second direction y. The crossbeam 40 divides the accommodating space of the lower battery housing 1 into two or more sections. This improves the structural strength of the lower battery housing 1 and facilitates the layout of battery cells, electrical components, and other related accessories within the accommodating space. Integrating the crossbeam 40 with the side frame 30 into a single structure further reduces the number of parts in the lower battery housing 1, thereby reducing assembly complexity.

[0053] In the illustrated example, the hollow frame 2 has two crossbeams 40, which divide the housing space of the lower battery box 1 into three spaces. The first space is formed between the front frame 10 and a crossbeam 40, the second space is formed between the two crossbeams 40, and the third space is formed between another crossbeam 40 and the rear frame 20. The first space can be used to install electrical components and related accessories that are electrically connected to the battery cell assembly, and the second and third spaces can be used to install the battery cell assembly respectively.

[0054] In other embodiments, the number of crossbeams 40 and the division of the storage space of the lower battery housing 1 can be determined according to application needs and are not limited to those shown in the figure.

[0055] In this embodiment, diagonal stiffeners 36 are connected between the two side walls of the crossbeam 40 and the side frame 30. This arrangement enhances the structural strength at the connection point between the crossbeam 40 and the side frame 30.

[0056] In specific implementation, such as Figure 3 and Figure 4 As shown, the side end of the crossbeam 40 passes through the third side plate 33 of the side frame 30 and is connected to the second side plate 32. The third side plate 33 has a clearance notch for the crossbeam 40 to pass through. Both beam side walls of the crossbeam 40 are connected to the second side plate 32 by diagonal stiffeners 36. The wall portion of the third side plate 33 that forms the clearance notch can be connected to the crossbeam 40 or the diagonal stiffeners 36. The diagonal stiffeners 36 form a certain angle with the first direction x or the second direction y.

[0057] With the above settings, the connection position between the crossbeam 40 and the side frame 30 is roughly triangular or trapezoidal, which can improve the structural strength of the connection position between the crossbeam 40 and the side frame 30, and also help improve the side collision protection capability of the battery lower box 1.

[0058] In some examples, the third side plate 33 may include two or more side plate segments, with the aforementioned clearance gap formed between the two side plate segments. Thus, the side plate segments of the third side plate 33 may be connected to the beam sidewall of the crossbeam 40, or may be connected to the diagonal stiffening plate 36.

[0059] In this embodiment, the crossbeam 40 includes two crossbeam base plates 41 and multiple crossbeam stiffeners 42, with the stiffeners 42 connected between the two crossbeam base plates 41. Thus, the crossbeam 40 has a multi-cavity beam structure, and the crossbeam 40 itself has good structural strength, which is beneficial for improving the structural strength of the lower battery housing 1 and its side impact protection capability.

[0060] In some examples, two adjacent crossbeam stiffeners 42 and two crossbeam base plates 41 form a triangular cavity structure or a trapezoidal cavity structure. That is, multiple crossbeam stiffeners 42 can divide the space between two crossbeam base plates 41 into multiple triangular or trapezoidal cavities. This helps to improve the structural strength of the crossbeam 40, and it can better absorb collision energy when it is hit, thus having a high collision protection capability.

[0061] In this embodiment, a plurality of lifting structures 50 are provided on the outer wall surface of the side frame 30 (i.e., the outer wall surface of the first side plate 31), and the lifting structures 50 are integrated with the side frame 30 into a single structure. The lifting structures 50 facilitate the installation of the lower battery housing 1 on the vehicle body and also facilitate the transfer of the lower battery housing 1 during routine inspection and maintenance. Integrating the lifting structures 50 with the side frame 30 into a single structure helps to further reduce the number of parts in the lower battery housing 1 and further reduce assembly complexity.

[0062] After the side frame 30 of the battery lower housing 1 integrates the lifting structure 50, the battery lower housing 1 has a three-level protection structure at the location of the lifting structure 50 when subjected to a side impact. The first level of protection is the lifting structure 50, and the second and third levels of protection are the outer and inner beam structures of the side frame 30. Since the lifting structure 50 protrudes from the outer wall of the side frame 30, it first absorbs the side impact force when subjected to a side impact, and then the side frame 30 absorbs and transmits the energy of the side impact force. The three-level protection structure formed by the lifting structure 50 and the side frame 30 can further improve the side impact protection capability of the battery lower housing 1.

[0063] In this embodiment, a hoisting structure 50 is provided at the connection between the side frame 30 and the crossbeam 40. In this way, when subjected to a side collision, the side impact force can be transmitted sequentially through the hoisting structure 50 at the crossbeam 40 and the side frame 30 to the crossbeam 40. The lower battery housing 1 forms a four-level protection structure at the location of the crossbeam 40, consisting of the hoisting structure 50, the outer beam structure of the side frame 30, the inner beam structure, and the crossbeam 40, forming a stepped protection layer, which can further improve the side collision protection capability of the lower battery housing 1.

[0064] In practice, the number of lifting structures 50 on the two side frames 30 of the lower battery housing 1 is the same and their positions correspond. In this way, the structure of the lower battery housing 1 is symmetrical, which ensures the balance of the vehicle body weight after installation.

[0065] In the illustrated example, each side frame 30 is provided with five lifting structures 50, which are arranged along the length direction (first direction x) of the side frame 30. A lifting structure 50 is provided at each connection point between the side frame 30 and each crossbeam 40. In other embodiments, the number and layout of the lifting structures 50 provided on the side frame 30 can be set according to actual lifting needs and are not limited to those shown in the figure.

[0066] Please refer to this as well. Figure 5 , Figure 5 for Figure 2 A schematic diagram of the hollow frame of the lower battery compartment from a downward viewing angle.

[0067] The hoisting structure 50 includes a hoisting base plate 51 and several hoisting stiffeners 52. The hoisting base plate 51 extends outward from the outer wall surface of the first side plate 31 along the second direction y. The hoisting stiffeners 52 connect the hoisting base plate 51 and the first side plate 31. Thus, the hoisting base plate 51 can serve as a hoisting point, and hoisting holes 511 can be provided on it. The hoisting stiffeners 52 connect the hoisting base plate 51 and the first side plate 31, which can reinforce the hoisting base plate 51 and give the hoisting structure 50 good overall structural strength.

[0068] In specific implementation, the lifting base plate 51 has a certain length in the first direction x. The lifting base plates 51 of different lifting structures 50 can have the same or different lengths in the first direction x, depending on the application requirements.

[0069] Multiple lifting stiffeners 52 can be provided between the lifting base plate 51 and the first side plate 31, and the multiple lifting stiffeners 52 are arranged at intervals along the first direction x.

[0070] The hoisting stiffeners 52 of the hoisting structure 50 can be divided into first hoisting stiffeners 521 and second hoisting stiffeners 522. In the first direction x, the two end edges of the hoisting base plate 51 are respectively connected to the first side plate 31 through two first hoisting stiffeners 521, and the second hoisting stiffeners 522 are located between the two first hoisting stiffeners 521.

[0071] In some examples, in two adjacent hoisting structures 50, two adjacent first hoisting stiffeners 521 can be connected as one unit.

[0072] In some examples, the hoisting stiffener 52 can be a triangular stiffener structure.

[0073] like Figure 5As shown, in one embodiment, the rear frame 20 includes two rear wall panels 21 and multiple rear stiffeners 22, with the rear stiffeners 22 connecting the two rear wall panels 21. Thus, the rear frame 20 also has a multi-cavity beam structure, which helps to improve the overall structural strength of the lower battery housing 1.

[0074] In some examples, a lifting structure 50 is also provided at the connection point between the side frame 30 and the rear frame 20. In this way, the area where the rear frame 20 is located also has good protection when the side frame 30 is subjected to a side impact.

[0075] In some examples, two adjacent rear stiffeners 22 and two rear wall panels 21 form a triangular or trapezoidal chamber structure, that is, multiple rear stiffeners 22 divide the space between two rear wall panels 21 into multiple triangular or trapezoidal chambers. In this way, the rear frame 20 has better structural strength and can better absorb collision energy when subjected to a collision, thereby improving its collision protection capability.

[0076] Please refer to this as well. Figure 6 , Figure 6 for Figure 1 The diagram shows a partial structural diagram of the lower battery housing near the front frame.

[0077] like Figure 5 and Figure 6 As shown, in one embodiment, the front frame 10 of the battery lower housing 1 includes a front wall panel 11 and a plurality of front stiffeners 12. The plurality of front stiffeners 12 are disposed on the front wall panel 11 to improve the structural strength of the front wall panel 11. The structural configuration of the front frame 10 facilitates the provision of insertion holes on the front wall panel 11, thereby facilitating the insertion of connectors into the insertion holes for electrical connection between the electrical components inside the battery lower housing 1 and the external electrical equipment.

[0078] In some examples, the front stiffener 12 includes a first front stiffener 121 and a second front stiffener 122, which extend in different directions to improve the structural strength of the front frame 10. In the illustrated example, the first front stiffener 121 extends approximately along the second direction y, and the second front stiffener 122 extends approximately along the third direction z.

[0079] In some examples, the side frame 30 of the lower battery housing 1 may also be provided with a plug hole for inserting a connector. The side frame 30 may not be provided with a first side stiffener 34 or a second side stiffener 35 at the corresponding position of the plug hole, so as to avoid the connector.

[0080] In this embodiment, the hollow frame 2 of the lower battery housing 1 also includes a top edge plate so that the lower battery housing 1 can be connected and cooperate with the battery cover plate. The battery cover plate can seal the opening of the lower battery housing 1, so that the cell assembly and electrical components and other related accessories are in a relatively closed space.

[0081] The top edge panel includes a front top panel 13, a rear top panel 23, and two side top panels 37. The front frame 10 includes the aforementioned front top panel 13, the rear frame 20 includes the aforementioned rear top panel 23, the rear top panel 23 is connected between two rear wall panels 21, and the side frame 30 includes the aforementioned side top panels 37, the side top panels 37 are connected between a first side panel 31 and a second side panel 32. The top edge panel is parallel to the plane formed by the first direction x and the second direction y, and is located at the top of the lower battery housing 1.

[0082] The hollow frame 2 of the lower battery housing 1 is an integral structure, which can significantly reduce the number of parts of the lower battery housing 1, thereby reducing the number of connection points and improving the overall structural performance of the lower battery housing 1.

[0083] In some examples, the hollow frame 2 is formed by integral die casting. Die casting allows for customization of structural dimensions to meet the specific needs of different parts, ensuring structural performance while avoiding material waste.

[0084] In this embodiment, the liquid cooling plate 3 of the lower battery housing 1 serves as the liquid cooling structure of the battery pack, used to dissipate heat from the battery cell assembly installed inside the lower battery housing 1 to ensure the normal operation of the battery cell assembly. The liquid cooling plate 3 also serves to seal the bottom opening of the hollow frame 2, which simplifies the structural design of the lower battery housing 1.

[0085] The connection between the liquid cooling plate 3 and the hollow frame 2 can be achieved by friction stir welding, which provides good sealing and robustness. Of course, other welding methods can also be used, such as brazing or laser welding, or adhesive bonding. Without affecting the cooling channels 301 inside the liquid cooling plate 3, the liquid cooling plate 3 and the hollow frame 2 can also be fixed using bolts or riveting.

[0086] See again Figure 3 The liquid cooling plate 3 has multiple cooling channels 301, in which coolant can flow to exchange heat with the battery cell assembly installed in the lower battery housing 1.

[0087] In specific implementation, the multiple cooling channels 301 of the liquid cooling plate 3 extend in one direction. These cooling channels 301 can be divided into at least two parallel channel regions. Each channel region includes multiple cooling channels 301. The arrangement of the channel regions allows the coolant to flow through each channel region in sequence, making the flow of the coolant in the liquid cooling plate 3 a serpentine or S-shaped flow path. This can prolong the flow time of the coolant and increase the heat exchange time between the coolant and the battery cell assembly, which is beneficial to improving the cooling efficiency of the battery cell assembly.

[0088] In this embodiment, the liquid cooling plate 3 is integrally integrated with a liquid inlet channel 302 and a liquid outlet channel 303. The liquid inlet channel 302 is connected to the liquid inlet of the liquid cooling plate 3, and the liquid outlet channel 303 is connected to the liquid outlet of the liquid cooling plate 3. Both the liquid inlet channel 302 and the liquid outlet channel 303 are located inside the hollow frame 2, that is, both the liquid inlet channel 302 and the liquid outlet channel 303 are located on the side of the front frame 10 facing the rear frame 20, and both the liquid inlet channel 302 and the liquid outlet channel 303 are arranged adjacent to the front frame 10.

[0089] The liquid inlet channel 302 and liquid outlet channel 303 facilitate the introduction or exit of coolant into or out of the liquid cooling plate 3. The liquid inlet channel 302 and liquid outlet channel 303 are integrated on the liquid cooling plate 3, which eliminates the need for the connection point between the coolant connection pipe and the liquid cooling plate 3, thus helping to ensure sealing.

[0090] In the specific implementation, an inlet pipe 61 and an outlet pipe 62 are connected to the front frame 10. One end of the inlet pipe 61 extends outside the lower battery housing 1, and the other end of the inlet pipe 61 is connected to the inlet channel 302. One end of the outlet pipe 62 extends outside the lower battery housing 1, and the other end of the outlet pipe 62 is connected to the outlet channel 303. In this way, coolant can be easily introduced into or led out of the liquid cooling plate 3 through the inlet pipe 61 and the outlet pipe 62.

[0091] In some examples, the inlet pipe 61 and the outlet pipe 62 can be integrated with the front frame 10 as a single structure. This reduces the number of parts and avoids the need for connection points between the inlet pipe 61 and the outlet pipe 62 and the front frame 10, which helps ensure the sealing of the relevant passages for coolant flow.

[0092] Generally, the air conditioning and other structures in a vehicle are located on the front side. The liquid cooling plate 3 of the lower battery housing 1 can be connected to the heat exchanger in the air conditioning system to form a cooling medium circulation loop. The liquid inlet channel 302 and the liquid outlet channel 303 are arranged near the front frame 10 to facilitate the pipeline connection between the lower battery housing 1 and the air conditioning system. This application also provides a battery pack, which includes a battery cover and a lower battery housing 1, wherein the lower battery housing 1 is the lower battery housing described in the aforementioned embodiments. This battery pack has the same technical effects as the aforementioned lower battery housing, which will not be repeated here.

[0093] See again Figure 2 and Figure 3 The lower battery housing 1 also includes a bottom protective plate 4, which is located below the liquid cooling plate 3 and is fixedly connected to the hollow frame 2.

[0094] The bottom protective plate 4 and the hollow frame 2 can be fixedly connected by welding or gluing. The welding method can be friction stir welding, brazing, or laser welding.

[0095] The bottom guard plate 4 is designed to protect the liquid cooling plate 3 from being broken by impact or splashing of external objects (such as stones).

[0096] like Figure 3 As shown, in this embodiment, the lower battery housing 1 includes an integral hollow frame 2, a liquid cooling plate 3, and a bottom protective plate 4. The lower battery housing 1 is mainly composed of three parts. Compared with more than twenty parts in related technologies, the number of parts is greatly reduced, which can reduce the cost of parts management. At the same time, it effectively reduces the assembly complexity and improves production efficiency.

[0097] This application also provides a vehicle, which includes a frame on which the battery pack of the aforementioned embodiments can be mounted. In some application scenarios, the battery pack can be mounted on the underframe of the frame, and the mounting position can be close to the location of the front seat.

[0098] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery lower casing, characterized in that, The lower battery housing includes a hollow frame and a liquid cooling plate; The hollow frame includes a front frame, a rear frame, and two side frames. The side frames connect the front frame and the rear frame, and the front frame, the rear frame, and the two side frames are integrated into a single structure. The liquid cooling plate is fixedly connected to the bottom of the hollow frame, and the liquid cooling plate seals the bottom opening of the hollow frame.

2. The battery lower housing according to claim 1, characterized in that, The side frame includes a first side plate, a second side plate, a third side plate, a top side plate, and a bottom side plate integrated into a single structure. The first side plate, the second side plate, and the third side plate are arranged along the width direction of the lower battery housing. The first side plate is located outside the second side plate, and the second side plate is located outside the third side plate. The top side plate connects the top of the first side plate and the second side plate, and the bottom side plate connects the bottom of the second side plate and the third side plate.

3. The lower battery housing according to claim 2, characterized in that, A plurality of first side stiffeners are connected between the first side plate and the second side plate, and a plurality of second side stiffeners are connected between the second side plate and the third side plate.

4. The lower battery housing according to claim 1, characterized in that, The hollow frame also includes a crossbeam, which is connected between the two side frames and is integrated with the side frames into a single structure.

5. The lower battery housing according to claim 4, characterized in that, The two side walls of the crossbeam are connected to the side frame by diagonal stiffening plates.

6. The lower battery housing according to claim 4, characterized in that, The crossbeam passes through the third side plate of the side frame and connects to the second side plate of the side frame. The third side plate has a clearance notch for the crossbeam to pass through. The diagonal stiffener is connected between the beam side wall of the crossbeam and the second side plate. The wall portion forming the clearance notch is connected to the crossbeam or the diagonal stiffener.

7. The lower battery housing according to claim 4, characterized in that, The crossbeam includes two crossbeam base plates and a plurality of crossbeam stiffeners, the crossbeam stiffeners being connected between the two crossbeam base plates.

8. The lower battery housing according to claim 1, characterized in that, The outer wall of the side frame is provided with several hoisting structures, and the hoisting structures are integrated with the side frame as a whole structure. One of the hoisting structures is provided at the position where the side frame is connected to the crossbeam.

9. The lower battery housing according to claim 8, characterized in that, The hoisting structure includes a hoisting base plate and several hoisting stiffeners. The hoisting base plate extends outward from the outer wall of the side frame along the width direction of the lower battery box. The hoisting stiffeners connect the hoisting base plate and the side frame.

10. The battery lower casing according to any one of claims 1-9, characterized in that, The liquid cooling plate has an integrally integrated liquid inlet channel and a liquid outlet channel. The liquid inlet channel is connected to the liquid inlet of the liquid cooling plate, and the liquid outlet channel is connected to the liquid outlet of the liquid cooling plate. The liquid inlet channel and the liquid outlet channel are located adjacent to the front frame and are located on the side of the front frame facing the rear frame.

11. The battery lower casing according to any one of claims 1-9, characterized in that, The lower battery housing also includes a bottom protective plate, which is located below the liquid cooling plate and is fixedly connected to the hollow frame.

12. A battery pack, characterized in that, It includes a battery cover and a lower battery housing as described in any one of claims 1-11, wherein the battery cover covers the lower battery housing.

13. A vehicle, characterized in that, It includes a frame and a battery pack mounted on the frame, the battery pack being the battery pack of claim 12.

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