Lower case of power battery system

Abstract

The present application relates to the technical field of power battery, especially to a power battery system lower box, which comprises a box body, the box body has a hollow containing cavity, the containing cavity is used for storing inhibition medium; detection injection modules are fixedly arranged on the inner side of the box body, the detection injection modules are communicated with the containing cavity, and the detection injection modules can be pushed to open when the box body is impacted and deformed, so that the inhibition medium sprays the battery monomer; a medium filling one-way valve is fixedly arranged on the box body, and the gas outlet of the medium filling one-way valve is communicated with the containing cavity; and a waterproof pressure relief valve is fixedly arranged on the box body. The present application can improve the integration, reduce the space occupation, reduce the cost and ensure the reliability.

Description

Technical Field

[0001] This invention relates to the field of power battery technology, and in particular to a lower housing for a power battery system. Background Technology

[0002] With the widespread adoption of new energy vehicles, frequent car safety accidents caused by thermal runaway of power batteries due to improper external operation have resulted in severe consequences. High safety has gradually become the primary indicator for power battery development. System-level efficiency improvement and cost reduction, along with the development of power battery products that balance safety and performance density, have become the focus of enterprises. As a core component of the power battery system, the lower casing of the power battery system primarily serves a mechanical load-bearing function and must meet basic design requirements such as mechanical strength, equipotential bonding, corrosion resistance, sealing, and lightweighting, making it the most complex structural component within the power battery.

[0003] Power batteries are composed of multiple individual cells connected in series and parallel. When a power battery is overcharged, exposed to external heat sources, short-circuited, deformed, impacted, or vibrated, it is prone to thermal runaway of individual cells, generating large amounts of smoke, or even igniting and exploding, causing the fire to spread and seriously threatening life and property. Current technologies for improving power battery safety involve a monitoring module (temperature and smoke sensors) inside the power battery detecting high temperatures or smoke. In this case, a suppression medium stored in an externally located battery pack is sprayed through pipes and nozzles mounted on the battery casing to suppress the fire inside the battery. However, this approach has several drawbacks: low integration (the externally located battery packs, pipes, and nozzles occupy significant space in the vehicle); high cost (requiring a separate fire suppression system outside the battery system); and insufficient reliability (relying on electronic sensors for thermal runaway monitoring means the fire suppression function will fail in extreme situations such as signal transmission harness failure due to external impact).

[0004] Therefore, a new type of battery pack enclosure is needed to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a housing for a power battery system that can improve integration, reduce space occupation, reduce costs, and ensure reliability.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] The lower housing of the power battery system includes:

[0008] The housing body has a hollow accommodating cavity for storing the suppression medium;

[0009] The detection spray module is fixedly and spaced apart inside the housing body, and the detection spray module is connected to the accommodating cavity. When the housing body is impacted and deformed, it can push the detection spray module to open, so that the suppression medium can spray onto the battery cell.

[0010] A medium filling check valve is fixedly installed on the housing body, and the outlet of the medium filling check valve is connected to the accommodating cavity, so that the suppressing medium can be unidirectionally filled into the accommodating cavity through the medium filling check valve.

[0011] A waterproof pressure relief valve is fixedly installed on the main body of the enclosure.

[0012] Furthermore, the box body includes a bottom plate, a left side plate and a right side plate are fixedly arranged on the left and right sides of the bottom plate, and a front side plate and a rear side plate are fixedly arranged on the front and rear sides of the bottom plate. The front side plate, the left side plate, the rear side plate and the right side plate are sequentially connected to form a U-shaped frame. The left side plate, the rear side plate and the right side plate are all provided with the receiving cavity.

[0013] Furthermore, a first partition is provided in the accommodating cavity of the left side plate along the extending direction of the left side plate, a second partition is provided in the accommodating cavity of the rear side plate along the extending direction of the rear side plate, and a third partition is provided in the accommodating cavity of the right side plate along the extending direction of the right side plate. The first partition, the second partition, and the third partition are not at the same height.

[0014] Furthermore, a first mounting portion is provided at the lower end of the left side plate along the extending direction of the left side plate, a second mounting portion is provided at the lower end of the rear side plate along the extending direction of the rear side plate, and a third mounting portion is provided at the lower end of the right side plate along the extending direction of the right side plate. The bottom plate is connected to the first mounting portion, the second mounting portion, and the third mounting portion.

[0015] Furthermore, the first mounting part, the second mounting part, and the third mounting part all have hollow cavities. A first through hole communicating with the first mounting part is provided on the left side plate, a second through hole communicating with the second mounting part is provided on the rear side plate, and a third through hole communicating with the third mounting part is provided on the right side plate.

[0016] Furthermore, the detection spray module includes a mounting frame and a sealing component. The mounting frame is fixedly disposed inside the housing body, and the mounting frame has a spray hole communicating with the accommodating cavity. The sealing component is slidably disposed on the mounting frame and can block the spray hole. When the housing body is subjected to impact deformation, the sealing component can move relative to the mounting frame, thereby opening the spray hole.

[0017] Furthermore, the sealing assembly includes a seal, an elastic element, and a fixing bolt. A detection probe is fixedly disposed on one side of the seal, the detection probe passes through the mounting frame, and one end of the detection probe extends out relative to the mounting frame. The fixing bolt passes through the mounting frame and connects to the seal. The elastic element is disposed between the mounting frame and the fixing bolt, and one end of the elastic element abuts against the mounting frame, while the other end of the elastic element abuts against the fixing bolt.

[0018] Furthermore, a fixing connector is fixedly provided on the side of the sealing member facing the mounting frame, and the fixing bolt is connected to the fixing connector. The melting point of the fixing connector is equal to the thermal runaway critical point of the power battery.

[0019] Furthermore, a first sealing ring is provided between the sealing element and the mounting frame, and a second sealing ring is provided between the mounting frame and the housing body.

[0020] Furthermore, multiple connecting lugs are spaced apart along the circumference of the mounting frame, and fasteners pass through the connecting lugs to connect with the housing body.

[0021] The beneficial effects of this invention are:

[0022] This invention provides a lower casing for a power battery system. The casing body has a hollow accommodating cavity for storing suppression medium. Multiple detection and spraying modules are fixedly installed inside the casing body, communicating with the accommodating cavity. A one-way valve for medium filling is installed on the casing body to achieve one-way filling of the suppression medium. A waterproof pressure relief valve is also fixedly installed on the casing body. When the casing body is impacted and deformed, it can push the detection and spraying modules to spray the suppression medium onto the individual battery cells. Through the above configuration, a mechanical sensing method is used to promptly respond to external impacts and compressions to the lower casing of the power battery. This differs from traditional fire prevention and control systems that use internal smoke or temperature sensors for monitoring. This monitoring method has no electronic components or signal transmission harnesses, effectively avoiding monitoring failures caused by electronic component failures or broken signal transmission harnesses in extreme situations. It has stronger adaptability to extreme environments and higher reliability. Moreover, using the casing body as a storage space for the fire extinguishing medium, unlike the traditional method of storing the medium in external containers, reduces space occupation and costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the lower housing of a power battery system according to the present invention;

[0024] Figure 2 This is an exploded view of the lower housing of a power battery system according to the present invention;

[0025] Figure 3 This is a schematic diagram of a detection injection module in the lower housing of a power battery system according to the present invention;

[0026] Figure 4 This is an exploded view of the detection injection module in the lower housing of a power battery system according to the present invention;

[0027] Figure 5 This is an exploded view of the main body of the housing in the lower housing of a power battery system according to the present invention;

[0028] Figure 6 yes Figure 5 A magnified view of a portion of point A in the middle.

[0029] In the picture:

[0030] 1. Container body; 11. Front side panel; 12. Left side panel; 121. First mounting part; 122. First partition plate; 123. First through hole; 13. Rear side panel; 131. Second mounting part; 14. Right side panel; 15. Bottom plate; 2. Detection spray module; 21. Mounting frame; 211. Spray hole; 212. Connecting ear plate; 22. Seal; 221. Fixed connector; 23. Detection probe; 24. Elastic element; 25. Fixing bolt; 26. Second sealing ring; 27. First sealing ring; 28. Fixing element; 3. Medium filling check valve; 4. Waterproof pressure relief valve. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown in the accompanying drawings, not all of them.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0034] When designing and manufacturing the lower casing of a power battery system, in order to improve integration, reduce space occupation, lower costs, and ensure reliability, such as... Figures 1-6 As shown, the present invention provides a lower housing for a power battery system. The lower housing for the power battery system includes a housing body 1, a detection injection module 2, a medium filling check valve 3, and a waterproof pressure relief valve 4.

[0035] The enclosure body 1 has a hollow cavity for storing the suppression medium. Multiple detection injection modules 2 are fixedly arranged at intervals inside the enclosure body 1 and are connected to the cavity. When the enclosure body 1 is deformed by impact, it can push the detection injection modules 2 to open, so that the suppression medium can be injected onto the battery cells. A medium filling check valve 3 is fixedly arranged on the enclosure body 1 and its outlet is connected to the cavity. The suppression medium can be unidirectionally filled into the cavity through the medium filling check valve 3. A waterproof pressure relief valve 4 is fixedly arranged on the enclosure body 1.

[0036] Through the above-described configuration, a mechanical sensing method is used to promptly respond to external impacts and compressions to the lower casing of the power battery. This differs from traditional fire suppression systems that rely on internal smoke or temperature sensors. This monitoring method eliminates electronic components and signal transmission wiring, effectively preventing monitoring failures caused by electronic component malfunctions or broken signal transmission wiring in extreme situations. It offers stronger adaptability to extreme environments and higher reliability. Furthermore, utilizing the casing itself as a storage space for the extinguishing medium, unlike traditional methods that use external storage bottles for the power battery, reduces space occupancy and costs.

[0037] By employing a medium-filling one-way valve 3, a high-pressure fire-suppressing medium (such as gaseous heptafluoropropane) is injected from outside the lower housing through the medium-filling one-way valve 3. This high-pressure gas fire-suppressing medium can only enter in one direction and cannot flow out in the opposite direction after injection. After injection, it is stored under high pressure within the accommodating cavity of the lower housing. By installing a waterproof pressure relief valve 4, when the internal gas pressure of the power battery system reaches a threshold, the waterproof pressure relief valve 4 opens, and the suppressing medium flows out through the pressure relief port, preventing the power battery housing from bulging and exploding due to overpressure.

[0038] Furthermore, the enclosure body 1 includes a base plate 15. A left side plate 12 and a right side plate 14 are fixedly disposed on the left and right sides of the base plate 15, and a front side plate 11 and a rear side plate 13 are fixedly disposed on the front and rear sides of the base plate 15. The front side plate 11, left side plate 12, rear side plate 13, and right side plate 14 are sequentially connected to form a U-shaped frame. Each of the left side plate 12, rear side plate 13, and right side plate 14 is provided with a receiving cavity. Specifically, the front side plate 11, left side plate 12, rear side plate 13, and right side plate 14 are all made of profiles, and the inherent structure of the profiles themselves can be used as receiving cavities. By storing the suppressing medium through the receiving cavities of the left side plate 12, rear side plate 13, and right side plate 14, the space utilization rate can be improved.

[0039] Furthermore, a first partition 122 is provided in the accommodating cavity of the left side plate 12 along the extending direction of the left side plate 12, a second partition is provided in the accommodating cavity of the rear side plate 13 along the extending direction of the rear side plate 13, and a third partition is provided in the accommodating cavity of the right side plate 14 along the extending direction of the right side plate 14. The first partition 122, the second partition, and the third partition are not at the same height. Through the above arrangement, on the one hand, the structural strength of the left side plate 12, the rear side plate 13, and the right side plate 14 is ensured, and on the other hand, the accommodating cavities of the left side plate 12, the rear side plate 13, and the right side plate 14 are interconnected, thereby ensuring the amount of storage suppression medium. All outer gaps at the joints of the left side plate 12, the right side plate 14, and the rear side plate 13 of the lower housing are continuously welded by gas metal arc welding or non-gas metal arc welding to achieve sealing. The uppermost ends of the left side panel 12, right side panel 14, and rear side panel 13 of the lower housing are provided with aligned mating surfaces, which can be sealed by applying structural adhesive or welding. In summary, the left side panel 12, right side panel 14, and rear side panel 13 of the lower housing form a fully sealed cavity, which functions similarly to a sealed container. The interior is fully conductive and has the capacity to store a large amount of high-pressure gas.

[0040] Furthermore, a first mounting portion 121 is provided at the lower end of the left side plate 12 along the extending direction of the left side plate 12, a second mounting portion 131 is provided at the lower end of the rear side plate 13 along the extending direction of the rear side plate 13, and a third mounting portion is provided at the lower end of the right side plate 14 along the extending direction of the right side plate 14. The base plate 15 is connected to the first mounting portion 121, the second mounting portion 131, and the third mounting portion. By providing the first mounting portion 121, the second mounting portion 131, and the third mounting portion, the installation of the base plate 15 is facilitated.

[0041] Furthermore, the first mounting portion 121, the second mounting portion 131, and the third mounting portion all have hollow cavities. A first through hole 123 communicating with the first mounting portion 121 is provided on the left side plate 12, a second through hole communicating with the second mounting portion 131 is provided on the rear side plate 13, and a third through hole communicating with the third mounting portion is provided on the right side plate 14. Through this arrangement, the space of the first mounting portion 121, the second mounting portion 131, and the third mounting portion can be fully utilized, further increasing the storage space for the suppression medium.

[0042] Furthermore, the detection injection module 2 includes a mounting frame 21 and a sealing assembly. The mounting frame 21 is fixedly disposed inside the housing body 1, and has an injection hole 211 communicating with the accommodating cavity. The sealing assembly is slidably disposed on the mounting frame 21 and can seal the injection hole 211. When the housing body 1 is impacted and deformed, the sealing assembly can move relative to the mounting frame 21, causing the injection hole 211 to open. Because the housing body 1 deforms after being impacted, it pushes the sealing assembly to move, causing the injection hole 211 on the mounting frame 21 to open, and the suppressing medium can then be ejected through the injection hole 211.

[0043] Furthermore, the sealing assembly includes a seal 22, an elastic element 24, and a fixing bolt 25. A detection probe 23 is fixedly mounted on one side of the seal 22, passing through the mounting frame 21 with one end protruding relative to the mounting frame 21. The fixing bolt 25 passes through the mounting frame 21 and connects to the seal 22. The elastic element 24 is positioned between the mounting frame 21 and the fixing bolt 25, with one end of the elastic element 24 abutting against the mounting frame 21 and the other end abutting against the fixing bolt 25. Specifically, the elastic element 24 is a compression spring. After the sealing assembly is installed on the mounting frame 21, the elastic element 24 is in a compressed state. Under the elastic force of the elastic element 24, the mounting frame 21 and the seal 22 fit tightly together, thereby ensuring that the seal 22 stably seals the injection hole 211. The detection probe 23 has a certain gap with the inner wall surface of the housing body 1. When the power battery environment is abnormal, such as when the power battery is subjected to external collision and squeezing, the outer surface of the lower housing will be concave and deformed inward. When the battery environment is normal, there is a safe gap between the detection probe 23 and the inner surface of the lower housing. The collision and squeezing cause the lower housing to contact the collision detection probe 23 and generate a thrust inward, which is much greater than the pre-pressure generated by the elastic element 24. This causes the spring to be compressed, the seal 22 to separate from the mounting frame, and the spray port to open, so that the suppression medium can be sprayed.

[0044] Furthermore, a fixing connector 221 is fixedly installed on the side of the seal 22 facing the mounting frame 21. The fixing bolt 25 is connected to the fixing connector 221. The melting point of the fixing connector 221 is equal to the thermal runaway critical point of the power battery. If the internal temperature of the power battery reaches the thermal runaway critical point, the fixing connector 221 reaches its melting point. At this time, the fixing connector 221 deforms and fails, the fixing bolt 25 disengages from the fixing connector 221, the seal 22 breaks free, and the injection port is fully opened.

[0045] Furthermore, a first sealing ring 27 is provided between the sealing element 22 and the mounting frame 21, and a second sealing ring 26 is provided between the mounting frame 21 and the housing body 1. By providing the first sealing ring 27, the sealing performance between the sealing element 22 and the mounting frame 21 can be guaranteed, and by providing the second sealing ring 26, the sealing performance between the mounting frame 21 and the housing body 1 can be guaranteed.

[0046] Furthermore, multiple connecting lugs 212 are spaced apart along the circumference of the mounting frame 21, and fasteners 28 pass through the connecting lugs 212 to connect with the housing body 1. This arrangement facilitates the installation of the mounting frame 21 on the housing body 1.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A lower housing for a power battery system, characterized in that, include: The box body (1) has a hollow accommodating cavity for storing the suppression medium; The detection spray module (2) is fixedly arranged at intervals on the inner side of the housing body (1), and the detection spray module (2) is connected to the accommodating cavity. When the housing body (1) is deformed by impact, it can push the detection spray module (2) to open, so that the suppression medium sprays onto the battery cell. Medium filling check valve (3) is fixedly installed on the housing body (1), and the outlet of the medium filling check valve (3) is connected to the accommodating cavity. The suppressing medium can be unidirectionally filled into the accommodating cavity through the medium filling check valve (3). Waterproof pressure relief valve (4), which is fixedly installed on the main body of the box (1); The detection spray module (2) includes a mounting frame (21) and a sealing component. The mounting frame (21) is fixedly disposed on the inner side of the housing body (1), and the mounting frame (21) is provided with a spray hole (211) communicating with the accommodating cavity. The sealing component is slidably disposed on the mounting frame (21) and can seal the spray hole (211). When the housing body (1) is impacted and deformed, the sealing component can move relative to the mounting frame (21), so that the spray hole (211) opens. The sealing assembly includes a seal (22), an elastic element (24), and a fixing bolt (25). A detection probe (23) is fixedly disposed on one side of the seal (22). The detection probe (23) passes through the mounting frame (21), and one end of the detection probe (23) protrudes from the mounting frame (21). The fixing bolt (25) passes through the mounting frame (21) and is connected to the seal (22). The elastic element (24) is disposed between the mounting frame (21) and the fixing bolt (25), and one end of the elastic element (24) abuts against the mounting frame (21), and the other end of the elastic element (24) abuts against the fixing bolt (25).

2. The lower housing of the power battery system according to claim 1, characterized in that, The box body (1) includes a bottom plate (15). A left side plate (12) and a right side plate (14) are fixedly arranged on the left and right sides of the bottom plate (15). A front side plate (11) and a rear side plate (13) are fixedly arranged on the front and rear sides of the bottom plate (15). The front side plate (11), the left side plate (12), the rear side plate (13) and the right side plate (14) are connected in sequence to form a U-shaped frame. The left side plate (12), the rear side plate (13) and the right side plate (14) are all provided with the receiving cavity.

3. The lower housing of the power battery system according to claim 2, characterized in that, A first partition (122) is provided in the accommodating cavity of the left side plate (12) along the extending direction of the left side plate (12), a second partition is provided in the accommodating cavity of the rear side plate (13) along the extending direction of the rear side plate (13), and a third partition is provided in the accommodating cavity of the right side plate (14) along the extending direction of the right side plate (14). The first partition (122), the second partition, and the third partition are not at the same height.

4. The lower housing of the power battery system according to claim 2, characterized in that, A first mounting part (121) is provided at the lower end of the left side plate (12) along the extending direction of the left side plate (12), a second mounting part (131) is provided at the lower end of the rear side plate (13) along the extending direction of the rear side plate (13), and a third mounting part is provided at the lower end of the right side plate (14) along the extending direction of the right side plate (14). The bottom plate (15) is connected to the first mounting part (121), the second mounting part (131) and the third mounting part.

5. The lower housing of the power battery system according to claim 4, characterized in that, The first mounting part (121), the second mounting part (131) and the third mounting part all have hollow cavities. The left side plate (12) has a first through hole (123) communicating with the first mounting part (121). The rear side plate (13) has a second through hole communicating with the second mounting part (131). The right side plate (14) has a third through hole communicating with the third mounting part.

6. The lower housing of the power battery system according to claim 1, characterized in that, The sealing element (22) is fixedly provided with a fixing connector (221) on the side facing the mounting frame (21), and the fixing bolt (25) is connected to the fixing connector (221). The melting point of the fixing connector (221) is equal to the thermal runaway critical point of the power battery.

7. The lower housing of the power battery system according to claim 1, characterized in that, A first sealing ring (27) is provided between the sealing element (22) and the mounting frame (21), and a second sealing ring (26) is provided between the mounting frame (21) and the housing body (1).

8. The lower housing of the power battery system according to claim 1, characterized in that, Multiple connecting ear plates (212) are spaced apart on the mounting frame (21) along the circumference of the mounting frame (21), and the fastener (28) passes through the connecting ear plates (212) and is connected to the housing body (1).

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