Explosion-proof ventilation valve with function of monitoring working state of battery pack

Abstract

The utility model relates to an explosion-proof ventilation valve with a function of monitoring the working state of a battery pack, which comprises an upper protective cover, a lower protective cover and an explosion-proof valve main body, a clamp spring and a magnet are fixedly arranged at the bottom end of the lower protective cover, and a reed switch, a mounting rib and a clamping groove are arranged at the top end of the explosion-proof valve main body. The magnet is close to the reed pipe and is used for magnetizing the reed pipe, current flows in the reed pipe, and the automobile battery management system judges that the battery pack is in a normal working state by sensing a current signal in the reed pipe; when the battery pack is in thermal runaway, a large amount of gas is generated to separate the snap spring from the mounting rib, the magnet is far away from the reed pipe, no current passes through the reed pipe, and an automobile battery management system cannot sense a current signal in the reed pipe to judge that the battery pack is in a thermal runaway state. The state (thermal runaway or normal working state) of the battery pack is detected by monitoring whether current flows in the explosion-proof valve product through the battery management system, and mistaken opening of the explosion-proof ventilation valve is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an explosion-proof vent valve with the function of monitoring the working state of a battery pack. Background Art

[0002] At present, electric vehicles have a problem of internal and external pressure difference in the battery pack due to the altitude and the temperature difference between the inside and outside. If the internal and external pressures are not balanced in time, the battery pack will be at risk of compression deformation and expansion and bursting under the action of the pressure difference; at the same time, in some cases, a large amount of gas will be released when the internal battery chip unit fails. If these gases are not discharged to the outside in time, the internal pressure will increase sharply in a short period of time, causing the battery pack to burst or even explode, affecting the personal safety of passengers.

[0003] Therefore, an explosion-proof vent valve must be installed on the outside of the battery pack to connect the air inside the battery pack and the outside air for pressure balance, reduce the effect of condensed water in the battery pack, and provide explosion-proof function in emergency situations.

[0004] In the prior art, it is not possible to monitor whether the battery pack is in a normal working pressure balance state or an emergency pressure relief state through the explosion-proof valve. In addition, the driving environment of the car may be muddy, dusty, and waterlogged, so it is necessary to have waterproof and dustproof functions. The existing explosion-proof valves all use a single overall ventilation area and an explosion-proof function area. This type of explosion-proof vent valve is easy to block the waterproof vent membrane in an environment covered by muddy, dusty, waterlogged, etc., thus losing the venting function. Utility Model Content

[0005] The purpose of the utility model is to overcome the defects of the above-mentioned prior art and provide an explosion-proof vent valve with the function of monitoring the working status of the battery pack.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] An explosion-proof vent valve with a function of monitoring the working status of a battery pack, comprising an upper protective cover, a lower protective cover and an explosion-proof valve body, wherein one end of the lower protective cover is connected to the upper protective cover, and the connection method is selected from any one of welding, clamping, riveting or bonding; the other end of the lower protective cover is connected to the explosion-proof valve body, and the bottom end of the explosion-proof valve body is connected to the battery pack, and the connection method is selected from any one of clamping, threaded connection, bolt connection or plastic lock connection;

[0008] A retaining spring and a magnet are fixedly disposed at the bottom end of the lower protective cover, and the retaining spring is fixed to the outside of the magnet;

[0009] A reed switch, mounting ribs and a slot are provided at the top of the explosion-proof valve body. A reed switch is fixed in the slot. Both ends of the reed switch are connected to the battery pack through wires. A mounting rib is provided above the slot.

[0010] When the battery pack is working normally, the clamping spring is clamped with the mounting rib, the magnet is close to the reed switch, the magnet is used to magnetize the reed switch, and current flows in the reed switch. The vehicle battery management system determines that the battery pack is in a normal working state by sensing the current signal in the reed switch;

[0011] When the battery pack is in thermal runaway, a large amount of gas is generated to separate the retaining spring from the mounting rib, the magnet is away from the reed switch, no current flows through the reed switch, and the vehicle battery management system cannot sense the current signal in the reed switch to determine that the battery pack is in thermal runaway.

[0012] In one embodiment of the utility model, a waterproof breathable membrane is provided between the lower protective cover and the upper protective cover, a welding groove is provided at the top of the lower protective cover, and the waterproof breathable membrane is welded in the welding groove.

[0013] In one embodiment of the utility model, a mounting plate is provided at the bottom end of the lower protective cover, and the retaining spring and the mounting rib are fixed to the mounting plate by pre-embedding.

[0014] In one embodiment of the utility model, two springs are provided in the reed switch, and the two springs are connected to the battery pack through a first wire and a second wire respectively.

[0015] When the magnet approaches the reed switch, the two springs in the reed switch connect, causing current to flow in the reed switch.

[0016] When the magnet is away from the reed switch, the two springs in the reed switch are not connected, so that no current flows through the reed switch.

[0017] In one embodiment of the utility model, a claw is provided on the outer side of the top end of the lower protective cover, and a groove is provided on the bottom end of the upper protective cover, and the groove is fixedly connected to the claw.

[0018] In one embodiment of the utility model, a compressible seal is provided at the bottom end of the lower protective cover, the seal is connected to the top of the explosion-proof valve body, the sealing cross-section of the seal is selected from any one of circular, square, conical or elliptical shapes, and the seal is used for waterproofing and dustproofing.

[0019] In one implementation of the utility model, a sealing groove is further provided at the top of the explosion-proof valve body, and the sealing groove is used to fix a sealing member.

[0020] In one embodiment of the utility model, the bottom end of the explosion-proof valve body is connected to the battery pack through a sealing gasket to play a sealing role.

[0021] In one implementation of the utility model, a mounting groove is provided at the bottom end of the explosion-proof valve body, and the mounting groove is used to fix the sealing gasket.

[0022] In one embodiment of the present invention, the explosion-proof valve body is integrally injection molded.

[0023] Compared with the prior art, the utility model has the following beneficial effects:

[0024] (1) The utility model connects the reed switch and the spring to the car battery pack through a wire to achieve the function of current circulation. The car battery management system determines whether the battery pack is in an emergency pressure relief state by monitoring the electrical signal. When the battery pack is in an emergency pressure relief state, the lower protective cover, the retaining spring and the magnet will fly out together under the action of high pressure. In this state, no current flows through the reed switch, the car ECU signal light turns on, and the explosion-proof vent valve can monitor in real time whether the battery pack is in a thermal runaway state.

[0025] (2) The utility model connects the reed switch and the spring to the car battery pack through a wire to achieve the function of current circulation. When the battery pack is in normal working condition, the pressure of the explosion-proof vent valve is balanced. In this state, current flows through the reed switch and the wire, the car ECU signal light goes out, and the explosion-proof vent valve can monitor in real time whether the battery pack is in normal working condition.

[0026] (3) The magnet and reed switch can be installed at different positions of the lower protective cover to monitor the current.

[0027] (4) The waterproof breathable membrane is welded to the lower protective cover instead of the original one on the main body of the waterproof breathable valve. When the battery pack runs away from heat, the waterproof breathable membrane can fly out together with the lower protective cover, and a large amount of gas can be discharged in a short time. The exhaust volume per unit time is larger than that of the original traditional explosion-proof valve, and the pressure relief speed is faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the explosion-proof vent valve in the utility model;

[0029] Figure 2 This is a cross-sectional view of the explosion-proof vent valve of the utility model in a normal working state;

[0030] Figure 3 It is a cross-sectional view of the explosion-proof vent valve in the utility model in the emergency pressure relief working state;

[0031] Figure 4 This is a cross-sectional view of the explosion-proof vent valve of the utility model in a normal working state (the magnet and the reed switch are installed on the left side of the lower protective cover);

[0032] Explanation of the accompanying figures: 1. Upper protective cover, 2. Waterproof breathable membrane, 3. Lower protective cover, 4. Retaining spring, 5. Seal, 6. Explosion-proof valve body, 7. Sealing gasket, 8. Reed switch, 9. Shrapnel, 10. First wire, 11. Second wire, 12. Mounting groove, 13. Mounting rib, 14. Welding groove, 15. Sealing groove, 16. Claw, 17. Magnet, 18. Mounting plate, 19. Slot. DETAILED DESCRIPTION

[0033] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0035] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0038] Example

[0039] See also Figure 1The present embodiment provides an explosion-proof vent valve with a function of monitoring the working status of a battery pack, comprising an upper protective cover 1, a lower protective cover 3 and an explosion-proof valve body 6, wherein one end of the lower protective cover 3 is connected to the upper protective cover 1, and the connection method is selected from any one of welding, clamping, riveting or bonding; the other end of the lower protective cover 3 is connected to the explosion-proof valve body 6, and the bottom end of the explosion-proof valve body 6 is connected to the battery pack, and the connection method is selected from any one of clamping, threaded connection, bolt connection or plastic lock connection;

[0040] A clamping spring 4 and a magnet 17 are fixedly disposed at the bottom end of the lower protective cover 3, and the clamping spring 4 is fixed to the outside of the magnet 17;

[0041] The top of the explosion-proof valve body 6 is provided with a reed switch 8, a mounting rib 13 and a slot 19, the slot 19 is provided with a reed switch 8, both ends of the reed switch 8 are connected to the battery pack through a wire, and the slot 19 is provided with a mounting rib 13 above the slot 19;

[0042] When the battery pack is working normally, the clamping spring 4 is clamped with the mounting rib 13, the magnet 17 is close to the reed switch 8, the magnet 17 is used to magnetize the reed switch 8, and current flows in the reed switch 8. The vehicle battery management system determines that the battery pack is in a normal working state by sensing the current signal in the reed switch 8;

[0043] When the battery pack is in thermal runaway, a large amount of gas is generated to separate the retaining spring 4 from the mounting rib 13, the magnet 17 is away from the reed switch 8, no current flows through the reed switch 8, and the vehicle battery management system cannot sense the current signal in the reed switch 8 to determine that the battery pack is in thermal runaway.

[0044] In this embodiment, a waterproof breathable membrane 2 is provided between the lower protective cover 3 and the upper protective cover 1 , a welding groove 14 is provided at the top of the lower protective cover 3 , and the waterproof breathable membrane 2 is welded in the welding groove 14 .

[0045] In this embodiment, a mounting plate 18 is provided at the bottom end of the lower protective cover 3 , and the clamping spring 4 and the mounting rib 13 are fixed on the mounting plate 18 by pre-embedding.

[0046] In this embodiment, two springs 9 are provided in the reed switch 8, and the two springs 9 are connected to the battery pack through a first wire 10 and a second wire 11 respectively.

[0047] When the magnet 17 is close to the reed switch 8, the two springs 9 in the reed switch 8 are connected, so that current flows in the reed switch 8;

[0048] When the magnet 17 is away from the reed switch 8 , the two springs 9 in the reed switch 8 are not connected, so that no current flows in the reed switch 8 .

[0049] In this embodiment, a claw 16 is provided on the outer side of the top end of the lower protective cover 3 , and a groove is provided on the bottom end of the upper protective cover 1 , and the groove is fixedly connected to the claw 16 .

[0050] In this embodiment, a compressible seal 5 is provided at the bottom end of the lower protective cover 3, and the seal 5 is connected to the top of the explosion-proof valve body 6. The sealing cross-section of the seal 5 is selected from any one of circular, square, conical or elliptical shapes, and the seal 5 is used for waterproofing and dustproofing.

[0051] In this embodiment, a sealing groove 15 is further provided at the top of the explosion-proof valve body 6 , and the sealing groove 15 is used to fix the sealing member 5 .

[0052] In this embodiment, the bottom end of the explosion-proof valve body 6 is connected to the battery pack through a sealing gasket 7 to play a sealing role.

[0053] In this embodiment, a mounting groove 12 is provided at the bottom end of the explosion-proof valve body 6 , and the mounting groove 12 is used to fix the sealing gasket 7 .

[0054] In this embodiment, the explosion-proof valve body 6 is integrally formed by injection molding.

[0055] In addition, this embodiment also provides a method for using an explosion-proof vent valve with a function of monitoring the working status of a battery pack, and the specific steps are as follows:

[0056] like Figure 2 As shown, under normal working conditions, when the pressure inside the battery pack is less than the explosion value set by the explosion-proof vent valve, it is in a breathing state. In this working state, the gas inside and outside the battery pack passes through the waterproof vent membrane 2 welded on the lower protective cover 3 to balance the pressure difference between the inside and outside of the battery pack.

[0057] The retaining spring 4 is engaged with the mounting rib 13, and the magnet 17 is close to the reed switch 8. The magnet 17 magnetizes the reed switch 8, and the current in the battery pack enters the reed switch 8 through the first wire 10 and flows through the spring 9 in the reed switch 8. At this time, the spring 9 is in a closed state, the current will continue to flow, and the car ECU signal light will go out, so it can be monitored in real time whether the battery pack is in a normal working state.

[0058] like Figure 3 As shown, when the battery pack's cells experience thermal runaway and generate a large amount of gas, the pressure inside the battery pack box is greater than the explosion value set by the explosion-proof vent valve, which indicates an explosion-proof state.

[0059] At this time, under the pressure of a large amount of gas inside the battery pack, the retaining spring 4 fixed on the mounting rib 13 of the explosion-proof valve body 6, the lower protective cover 3 and the upper protective cover 1 are pushed open together, so that the lower protective cover 3, the retaining spring 4, the waterproof breathable membrane 2, the magnet 17 and the upper protective cover 1 are separated from the explosion-proof valve body 6 together;

[0060] In this state, a large amount of gas in the battery pack will be quickly discharged in a short time. Since the magnet 17 has been separated from the explosion-proof valve body 6, the reed switch 8 has no magnetic field, and the shrapnel 9 in the reed switch 8 will be disconnected. In this way, the current in the battery pack will not enter through the first wire 10 and flow to the second wire 11. Since there is no current flowing, the signal light of the automobile battery management system lights up, and it can monitor in real time whether the battery pack is in a state of emergency pressure relief thermal runaway, thereby protecting the battery pack and personnel safety.

[0061] The above description of the embodiments is to facilitate the understanding and use of the utility model by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the utility model is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the utility model without departing from the scope of the utility model should be within the scope of protection of the utility model.

Claims

1. An explosion-proof vent valve with the function of monitoring the working status of the battery pack, It is characterized in that The device comprises an upper protective cover (1), a lower protective cover (3) and an explosion-proof valve body (6), wherein one end of the lower protective cover (3) is connected to the upper protective cover (1) by a connection method selected from any one of welding, clamping, riveting or bonding; the other end of the lower protective cover (3) is connected to the explosion-proof valve body (6), and the bottom end of the explosion-proof valve body (6) is connected to the battery pack by a connection method selected from any one of clamping, threaded connection, bolt connection or plastic lock connection; A retaining spring (4) and a magnet (17) are fixedly provided at the bottom end of the lower protective cover (3), and the retaining spring (4) is fixed to the outside of the magnet (17); The top of the explosion-proof valve body (6) is provided with a reed switch (8), a mounting rib (13) and a slot (19); the reed switch (8) is fixed in the slot (19); both ends of the reed switch (8) are connected to the battery pack via a wire; and a mounting rib (13) is provided above the slot (19); When the battery pack is working normally, the clamping spring (4) is clamped with the mounting rib (13), the magnet (17) is close to the reed switch (8), the magnet (17) is used to magnetize the reed switch (8), and current flows in the reed switch (8); When the battery pack is in thermal runaway, a large amount of gas is generated to separate the retaining spring (4) from the mounting rib (13), the magnet (17) is away from the reed switch (8), and no current flows through the reed switch (8).

2. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that A waterproof and breathable membrane (2) is provided between the lower protective cover (3) and the upper protective cover (1), a welding groove (14) is provided at the top of the lower protective cover (3), and the waterproof and breathable membrane (2) is welded in the welding groove (14).

3. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that A mounting plate (18) is provided at the bottom end of the lower protective cover (3), and the retaining spring (4) and the mounting rib (13) are fixed on the mounting plate (18) by pre-embedding.

4. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that The reed switch (8) is provided with two springs (9), and the two springs (9) are connected to the battery pack via a first wire (10) and a second wire (11), respectively. When the magnet (17) is close to the reed switch (8), the two springs (9) in the reed switch (8) are connected, so that current flows in the reed switch (8); When the magnet (17) is away from the reed switch (8), the two springs (9) in the reed switch (8) are not connected, so that no current flows in the reed switch (8).

5. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that A claw (16) is provided on the outer side of the top end of the lower protective cover (3), and a groove is provided on the bottom end of the upper protective cover (1), wherein the groove is fixedly connected to the claw (16).

6. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that A sealing member (5) is provided at the bottom end of the lower protective cover (3), and the sealing member (5) is connected to the top end of the explosion-proof valve body (6). The sealing cross section of the sealing member (5) is selected from any one of circular, square, conical or elliptical shapes.

7. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 6, It is characterized in that A sealing groove (15) is also provided at the top of the explosion-proof valve body (6), and the sealing groove (15) is used to fix the sealing element (5).

8. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that The bottom end of the explosion-proof valve body (6) is connected to the battery pack via a sealing gasket (7).

9. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 8, It is characterized in that The bottom end of the explosion-proof valve body (6) is provided with a mounting groove (12), and the mounting groove (12) is used to fix the sealing gasket (7).

10. The explosion-proof vent valve having the function of monitoring the working status of a battery pack according to claim 1, It is characterized in that The explosion-proof valve body (6) is integrally injection-molded.

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