Explosion-proof valves and battery packs

Abstract

This utility model relates to an explosion-proof valve and a battery pack. The explosion-proof valve includes a valve body, a piston, and a sealing assembly. The piston is elastically connected to the valve body, and a chamber is provided inside the piston, communicating with the valve body. An air vent is provided on the wall of the chamber, communicating with the outside. The sealing assembly is disposed within the chamber and selectively blocks the air vent. By placing the sealing assembly within the chamber and selectively blocking the air vent, the vent can be closed promptly when the air humidity exceeds the standard, thereby controlling the air humidity inside the battery pack within a suitable range, reducing the risk of condensation, and preventing internal electrical components from becoming damp due to condensation, thus improving the safety performance of the battery pack.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an explosion-proof valve and a battery pack. Background Technology

[0002] Explosion-proof valves are crucial safety components in battery packs, primarily divided into primary and secondary types. Primary explosion-proof valves are mainly installed on the battery cells. When a cell requires pressure relief, the high-temperature, high-pressure mixture inside the cell is discharged through the primary valve. Secondary explosion-proof valves are mainly installed on the battery pack casing. The high-temperature, high-pressure mixture discharged from the primary valve is transported to the secondary valve through a pressure relief channel, and finally discharged to the outside of the battery pack through the secondary valve. During battery pack operation, to maintain pressure balance inside and outside the pack, the secondary explosion-proof valve is usually equipped with vents, allowing gas to circulate between the inside and outside of the battery pack. In high-humidity environments, where ambient humidity increases dramatically, a large amount of humid gas entering the battery pack can easily condense and accumulate inside when the ambient temperature drops. This can lead to moisture absorption by various electrical components inside the battery pack, potentially causing metal corrosion, short circuits, and other adverse conditions. Utility Model Content

[0003] The purpose of this invention is to provide an explosion-proof valve and a battery pack that can adjust the airflow according to the ambient humidity, thereby improving the safety performance of the battery pack.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] An explosion-proof valve is provided, comprising a valve body, a piston, and a sealing assembly. The piston is elastically connected to the valve body, and a chamber is provided inside the piston. The chamber is connected to the valve body, and an air hole communicating with the outside is provided on the wall of the chamber. The sealing assembly is disposed in the chamber and selectively blocks the air hole.

[0006] In one embodiment, the sealing assembly includes a sealing block and a driving mechanism. The sealing block is slidably disposed on the cavity wall of the chamber so as to block the air hole. The driving mechanism is connected to the sealing block and is used to drive the sealing block to slide on the cavity wall of the chamber.

[0007] In one embodiment, the drive mechanism includes a motor, a mounting plate, and a support rod. The output end of the motor is connected to the mounting plate, and the motor is used to drive the mounting plate to rotate about its own axis. The two ends of the support rod are respectively connected to the mounting plate and the sealing block.

[0008] In one embodiment, there are multiple air holes, which are spaced apart along the circumference of the chamber, and each air hole is provided with a corresponding sealing block.

[0009] In one embodiment, the piston includes a base and a cover plate disposed on one side of the base, forming the chamber between the base and the cover plate. The sealing block includes a first sealing surface and a second sealing surface that are perpendicular to each other and in contact with each other. The first sealing surface abuts against the cavity wall of the chamber and is used to block the air hole. The second sealing surface abuts against the end face of the base facing the cover plate.

[0010] In one embodiment, the piston further includes a sleeve, one end of which is connected to the side of the base away from the cover plate. The sleeve communicates with the chamber. The valve body is provided with a drain hole penetrating its opposite sides. The other end of the sleeve passes through the valve body and extends in a direction away from the base. A spring is fitted on the sleeve, and the sleeve and the valve body are connected by the spring. The spring is used to drive the base to abut against the valve body so that the base can block the drain hole.

[0011] In one embodiment, a protective sleeve is also included, which is disposed on the side of the valve body opposite to the base. The protective sleeve covers the outside of the sleeve and the spring, and the sleeve communicates with the drain hole through the protective sleeve.

[0012] In one embodiment, a humidity sensor is also included, which is electrically connected to the sealing assembly.

[0013] In one embodiment, a first sealing ring is provided between the valve body and the piston.

[0014] A battery pack is also provided, including a housing, battery cells, a pressure relief channel, and an explosion-proof valve. The explosion-proof valve is installed on the side wall of the housing. A plurality of battery cells are disposed inside the housing, and all of the battery cells are connected to the explosion-proof valve through the pressure relief channel.

[0015] The advantages of this utility model compared to the prior art are:

[0016] This invention relates to an explosion-proof valve and battery pack. A chamber is provided within the piston, and vents are provided on the chamber wall for air circulation, enabling air exchange between the inside and outside of the pack and maintaining pressure balance. A sealing component is installed within the chamber to selectively block the vents. This allows for timely closure of the vents when air humidity exceeds the acceptable level, thereby controlling the internal humidity within the pack to a suitable range. This reduces the risk of condensation and prevents moisture damage to internal electrical components, thus improving the battery pack's safety performance. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the explosion-proof valve from a first-view perspective according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the explosion-proof valve from a second perspective according to an embodiment of the present invention.

[0020] Figure 3 This is an exploded view of the explosion-proof valve according to an embodiment of the present invention.

[0021] Figure 4 This is an exploded view of the piston in an embodiment of the present invention.

[0022] Figure 5 for Figure 4 Enlarged view of point A in the middle.

[0023] In the picture:

[0024] 1. Valve body; 11. Mounting surface; 12. Mounting hole; 13. Drain hole; 14. Second sealing groove; 2. Piston; 21. Base; 210. First sealing groove; 22. Cover plate; 23. Chamber; 24. Sleeve; 25. Limit nut; 26. Air hole; 3. Sealing assembly; 31. Mounting plate; 32. Support rod; 33. Sealing block; 331. First sealing surface; 332. Second sealing surface; 4. First sealing ring; 5. Second sealing ring; 6. Spring; 7. Humidity sensor; 8. Protective sleeve. Detailed Implementation

[0025] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] like Figures 1 to 4As shown, this utility model provides an explosion-proof valve applied in a battery pack, which serves to protect the battery pack from pressure relief. When the battery cells inside the battery pack experience pressure relief, the high-temperature, high-pressure mixture discharged from the pressure relief holes on the cells is transported to the explosion-proof valve through the pressure relief channel, and finally discharged to the outside of the battery pack through the explosion-proof valve. The explosion-proof valve includes a valve body 1, a piston 2, and a sealing assembly 3. The valve body 1 is the main structure of the explosion-proof valve and is installed on the battery pack housing. A drain hole 13 is provided on the valve body 1, connecting the inside and outside of the housing. The piston 2 is installed on the valve body 1, and the piston 2 is elastically connected to the valve body 1. Under the action of elastic force, the piston 2 can tightly abut against the valve body 1 and close the drain hole 13. When the battery pack experiences pressure relief, the high-temperature, high-pressure mixture inside the housing is discharged outward through the drain hole 13, and the high-temperature, high-pressure mixture can overcome the elastic force and push the piston 2 away. Piston 2 has a hollow structure with a chamber 23 inside. Chamber 23 is connected to valve body 1 and also connects to the inside of the battery pack through valve body 1. A vent 26 is provided on the wall of chamber 23, through which chamber 23 connects to the outside. This structure allows air to flow sequentially through vent 26, chamber 23, and valve body 1, facilitating air exchange between the inside and outside of the battery pack. Because air can be exchanged between the inside and outside of the battery pack through vent 26, pressure balance is maintained, ensuring optimal operation of the entire battery pack. A sealing assembly 3, located within chamber 23, controls the opening and closing of vent 26 and selectively seals it. When vent 26 needs to be closed, the sealing assembly 3 seals the end of vent 26 facing chamber 23.

[0027] Understandably, the explosion-proof valve is in a normally open state, allowing air exchange between the inside and outside of the enclosure through the vent 26 to maintain pressure balance. The size of the vent 26 is much smaller than the size of the drain hole 13 on the valve body 1. The vent 26 can only be used for gas exchange under normal pressure. When pressure is released, the high-temperature, high-pressure mixture can only be discharged by pushing open the piston 2. Due to the influence of ambient humidity, the humidity inside the enclosure needs to be controlled to avoid condensation. Therefore, when the humidity inside the enclosure exceeds a set threshold, the vent 26 is sealed using the sealing component 3 to prevent high-humidity air from entering the enclosure. When the humidity is below the set threshold, the vent 26 is opened, allowing air to continue circulating between the inside and outside of the enclosure. In this embodiment, a chamber 23 is provided inside the piston 2, and the chamber wall of the chamber 23 is provided with vents 26 for air circulation to achieve air exchange between the inside and outside of the enclosure and maintain pressure balance. By installing a sealing component 3 inside the chamber 23, the sealing component 3 selectively blocks the air vent 26 so that the air vent 26 can be closed in time when the air humidity exceeds the standard, thereby controlling the air humidity inside the box within a suitable range, reducing the risk of condensation, and thus preventing the internal electrical components from getting damp due to condensation, thereby improving the safety performance of the battery pack.

[0028] Specifically, refer to Figure 1 and Figure 3 As shown, the valve body 1 has a circular structure and a mounting surface 11 for connecting to the housing. The mounting surface 11 has multiple mounting holes 12, which are threaded holes for threading screws to secure the valve body 1 to the housing. Multiple support pillars are spaced apart on one side of the inner ring of the valve body 1, with the gap between adjacent support pillars forming a drain hole 13. To ensure a tight seal between the valve body 1 and the housing, the explosion-proof valve also includes a second sealing ring 5, which is sandwiched between the valve body 1 and the housing. Correspondingly, a second sealing groove 14 is provided on the mounting surface 11 for mounting the second sealing ring 5. The second sealing ring 5 surrounds the outer area of ​​the drain hole 13 and is positioned close to the periphery of the valve body 1.

[0029] Specifically, refer to Figure 3 and Figure 4As shown, piston 2 includes a base 21, a cover plate 22, and a sleeve 24. The base 21 has a disc-shaped structure, and the cover plate 22 covers one side of the base 21, forming a chamber 23 between the base 21 and the cover plate 22. Multiple vents 26 are provided on the wall of the chamber 23, spaced apart along the circumference of the chamber 23. In this embodiment, there are four vents 26, evenly spaced along the circumference of the chamber 23. The vents 26 are square, making their structure narrower, ensuring air permeability while reducing the risk of external debris entering the chamber 23 through the vents 26. To prevent external liquid water from entering the explosion-proof valve, a waterproof and breathable membrane is also provided over the vents 26 to block external liquid water. The side of the base 21 facing away from the cover plate 22 is used to abut against the valve body 1. The side of the base 21 facing away from the cover plate 22 abuts against the valve body 1 to seal the drain hole 13. The sleeve 24 connects the base 21 and the valve body 1. One end of the sleeve 24 is fixedly connected to the side of the base 21 facing away from the cover plate 22, and the sleeve 24 is located at the center of the base 21. The other end of the sleeve 24 passes through the valve body 1 and extends in a direction away from the base 21. Specifically, the sleeve 24 is mounted on a support column on the valve body 1. The sleeve 24 communicates with the chamber 23, allowing air in the chamber 23 to flow through the sleeve 24 to the side of the valve body 1 facing the housing. To achieve an elastic connection between the piston 2 and the valve body 1, the explosion-proof valve also includes a spring 6, which is sleeved around the periphery of the sleeve 24. A limit nut 25 is provided at the end of the sleeve 24 facing away from the base 21, and the limit nut 25 is threadedly connected to the sleeve 24. One end of the spring 6 abuts against the limiting nut 25, and the other end abuts against the mounting surface 11 of the valve body 1. By tightening the limiting nut 25, the compression length of the spring 6 can be adjusted, thereby adjusting the elastic force between the valve body 1 and the piston 2. During pressure relief, the high-temperature and high-pressure mixture is ejected outward through the drain hole 13. The high temperature and pressure push the piston 2 open and further compress the spring 6. After pressure relief is completed, the spring 6 rebounds to drive the piston 2 to close the drain hole 13.

[0030] The explosion-proof valve also includes a first sealing ring 4 and a protective sleeve 8. The first sealing ring 4 seals the valve body 1 and the base 21. Since the piston 2 and valve body 1 have both sealed and separated states, a first sealing ring 4 is provided between them to ensure airtightness. Correspondingly, a first sealing groove 210 is provided on the side of the base 21 facing away from the cover plate 22, and the first sealing ring 4 is installed within the first sealing groove 210, surrounding the periphery of the base 21. Alternatively, in some embodiments, the first sealing groove 210 can be located on the valve body 1. The protective sleeve 8 protects the sleeve 24 and spring 6. The protective sleeve 8 is installed on the side of the valve body 1 facing away from the base 21 and is fitted over the sleeve 24 and spring 6. By providing the protective sleeve 8, the high-temperature, high-pressure mixture can be prevented from adhering to the spring 6 during discharge, thus ensuring the piston 2 can open and close normally. The open end of the protective sleeve 8 faces the mounting surface 11 of the valve body 1, allowing the open end of the protective sleeve 8 to communicate with the drain hole 13. The end of the sleeve 24 facing away from the base 21 extends into the sleeve 24, allowing the sleeve 24 to communicate with the drain hole 13 through the protective sleeve 8. In this embodiment, the specific flow path of external air into the housing is as follows: external air first enters the chamber 23 through the air hole 26, then enters the protective sleeve 8 through the sleeve 24, and finally enters the drain hole 13 from the open end of the protective sleeve 8, ultimately entering the housing.

[0031] Specifically, refer to Figure 4 and Figure 5 As shown, the sealing assembly 3 is installed inside the chamber 23. The sealing assembly 3 includes a drive mechanism and a sealing block 33. The sealing block 33 is slidably disposed on the cavity wall of the chamber 23 so that it can block the air hole 26. The drive mechanism is connected to the sealing block 33 and is used to drive the sealing block 33 to slide on the cavity wall of the chamber 23. The drive mechanism includes a motor, a mounting plate 31, and a support rod 32. The motor is located at the center of the base 21, and the output shaft of the motor is coaxial with the chamber 23. The output end of the motor is connected to the mounting plate 31, and the motor is used to drive the mounting plate 31 to rotate around its own axis. The support rod 32 serves to mount the sealing block 33. One end of the support rod 32 is connected to the mounting plate 31, and the other end is connected to the sealing block 33. By rotating the motor, the sealing block 33 is driven to rotate in the circumferential direction of the chamber 23, thereby closing or opening the air hole 26 on the cavity wall. The number of sealing blocks 33 is matched with the number of air holes 26, with one sealing block 33 corresponding to each air hole 26. All sealing blocks 33 are mounted on the mounting plate 31 via corresponding support rods 32, so as to achieve synchronous driving of all sealing blocks 33.

[0032] The sealing block 33 has an "L"-shaped structure and includes a first sealing surface 331 and a second sealing surface 332. The first sealing surface 331 and the second sealing surface 332 are perpendicular to each other and are in contact. The first sealing surface 331 abuts against the cavity wall of the chamber 23 to seal the air hole 26. The second sealing surface 332 abuts against the end face of the base 21 facing the cover plate 22. By having the two perpendicular sealing surfaces abut against the base 21, the contact area between the sealing block 33 and the base 21 is increased, making the movement of the sealing block 33 more stable.

[0033] Specifically, refer to Figure 1 As shown, the explosion-proof valve also includes a humidity sensor 7, which is installed at the end of the protective sleeve 8 away from the valve body 1, allowing the humidity sensor 7 to be located inside the enclosure. The humidity sensor 7 is used to detect the air humidity inside the enclosure. The humidity sensor 7 is electrically connected to the motor in the sealing assembly 3; correspondingly, both the humidity sensor 7 and the motor are connected to a circuit board. The motor rotation is controlled based on the detection data from the humidity sensor 7. The sealing assembly 3 is controlled to close or open the vent 26 according to the air humidity range inside the enclosure.

[0034] like Figure 1 As shown, this utility model also provides a battery pack (not shown in the figure), including a housing, battery cells, a pressure relief channel, and an explosion-proof valve. Several battery cells are installed inside the housing, and each battery cell is equipped with an explosion-proof structure (i.e., a primary explosion-proof valve). A pressure relief channel is provided inside the housing, and the explosion-proof structures on all battery cells are connected to the pressure relief channel. When a battery cell experiences thermal runaway, the cell releases pressure through its respective explosion-proof structure, and the high-temperature, high-pressure mixture is discharged into the pressure relief channel. The outlet end of the pressure relief channel is connected to the outside of the housing. The explosion-proof valve is installed on the side wall of the housing and is connected to the outlet end of the pressure relief channel. The high-temperature, high-pressure mixture in the pressure relief channel is discharged through the explosion-proof valve.

[0035] In this embodiment, by setting a sealing component 3 in the explosion-proof valve, when the air humidity in the pressure relief channel is lower than the set threshold, the sealing component 3 is used to block the air hole 26 so that the explosion-proof valve is in a sealed state. The high humidity air outside cannot enter the pressure relief channel through the explosion-proof valve, thereby avoiding condensation inside the pressure relief channel due to excessive air humidity and ensuring the safe operation of the entire battery pack.

[0036] The above description is only a preferred embodiment of this utility model. For those skilled in the art, there will be changes in the specific implementation method and application scope based on the idea of ​​this utility model. The content of this specification should not be construed as a limitation of this utility model.

Claims

1. An explosion-proof valve, characterized in that, The device includes a valve body, a piston, and a sealing assembly. The piston is elastically connected to the valve body. A chamber is provided inside the piston and communicates with the valve body. An air hole communicating with the outside is provided on the wall of the chamber. The sealing assembly is disposed in the chamber and selectively blocks the air hole.

2. The explosion-proof valve according to claim 1, characterized in that, The sealing assembly includes a sealing block and a driving mechanism. The sealing block is slidably disposed on the cavity wall of the chamber so that it can block the air hole. The driving mechanism is connected to the sealing block and is used to drive the sealing block to slide on the cavity wall of the chamber.

3. The explosion-proof valve according to claim 2, characterized in that, The driving mechanism includes a motor, a mounting plate, and a support rod. The output end of the motor is connected to the mounting plate, and the motor is used to drive the mounting plate to rotate around its own axis. The two ends of the support rod are respectively connected to the mounting plate and the sealing block.

4. The explosion-proof valve according to claim 2, characterized in that, There are multiple air holes, which are spaced apart along the circumference of the chamber, and each air hole is provided with a corresponding sealing block.

5. The explosion-proof valve according to claim 2, characterized in that, The piston includes a base and a cover plate disposed on one side of the base, forming the chamber between the base and the cover plate. The sealing block includes a first sealing surface and a second sealing surface that are perpendicular to each other and connected. The first sealing surface abuts against the cavity wall of the chamber and is used to block the air hole. The second sealing surface abuts against the end face of the base facing the cover plate.

6. The explosion-proof valve according to claim 5, characterized in that, The piston also includes a sleeve, one end of which is connected to the side of the base away from the cover plate. The sleeve communicates with the chamber. The valve body is provided with a drain hole penetrating its opposite sides. The other end of the sleeve passes through the valve body and extends in a direction away from the base. A spring is fitted on the sleeve, and the sleeve and the valve body are connected by the spring. The spring is used to drive the base to abut against the valve body so that the base can block the drain hole.

7. The explosion-proof valve according to claim 6, characterized in that, It also includes a protective sleeve, which is disposed on the side of the valve body away from the base. The protective sleeve covers the outside of the sleeve and the spring, and the sleeve communicates with the drain hole through the protective sleeve.

8. The explosion-proof valve according to any one of claims 1 to 7, characterized in that, It also includes a humidity sensor, which is electrically connected to the sealing assembly.

9. The explosion-proof valve according to any one of claims 1 to 7, characterized in that, A first sealing ring is provided between the valve body and the piston.

10. A battery pack, characterized in that, The device includes a housing, battery cells, a pressure relief channel, and an explosion-proof valve as described in any one of claims 1 to 9. The explosion-proof valve is installed on the side wall of the housing. A plurality of battery cells are disposed inside the housing, and all of the battery cells are connected to the explosion-proof valve through the pressure relief channel.

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