Drain valve for power battery pack

Abstract

The utility model discloses a drain valve for a power battery pack, which comprises a base, a cavity is arranged in the base, the base is provided with a static contact leading-out terminal extending from the inside of the cavity to the outer side of the base, and a movable contact component positioned above the static contact leading-out terminal is arranged in the cavity. The movable contact assembly comprises a liquid absorption expansion body which is tightly embedded in the cavity, a movable contact piece is arranged below the liquid absorption expansion body, and the liquid absorption expansion body absorbs liquid to expand and deform and enables the movable contact piece to make contact with the static contact leading-out terminal. By means of the mode, the drain valve for the power battery pack is sensitive in triggering and capable of rapidly sending out electric signals of major faults of coolant leakage, the phenomena of short circuit or thermal runaway and the like of the power battery pack are avoided, and use safety of the power battery pack is guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of explosion-proof valves, in particular to a liquid discharge valve for a power battery pack. Background Art

[0002] Power battery liquid cooling uses coolant (such as ethylene glycol) as a heat exchange medium. Generally, there are multiple different heat exchange circuits. However, when the ethylene glycol in the coolant is oxidized at high temperature, the hydroxyl groups will be acidified. When it is cycled at 80°C and -90°C for a long time, the ethylene glycol will be oxidized into glycolic acid and then oxidized into oxalic acid. Oxalic acid and ethylene glycol oxalic acid will corrode the equipment and liquid cooling pipes, especially when the liquid cooling pipes are welded with aluminum foil or copper foil. The surface defects of the welds or liquid cooling pipes are easily corroded and leak. If the leaked ethylene glycol coolant cannot be discharged from the battery pack in time, it will cause the battery pack to fail, short circuit or thermal runaway.

[0003] Therefore, it is necessary to provide a drain valve for a power battery pack that can quickly detect and send a signal when there is a cooling plate leak in the power battery pack. Summary of the invention

[0004] The main technical problem solved by the utility model is to provide a drain valve for a power battery pack. The drain valve is sensitive to triggering and can quickly send out an electrical signal of a major coolant leakage fault, thereby avoiding short circuit or thermal runaway in the power battery pack and ensuring the safe use of the power battery pack.

[0005] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a liquid discharge valve for a power battery pack, including a base, the base having a cavity therein, the base being provided with a static contact lead-out terminal extending from the cavity to the outside of the base, the cavity being provided with a moving contact assembly located above the static contact lead-out terminal, the moving contact assembly comprising a liquid absorbing expansion body embedded in the cavity, a moving contact piece being provided below the liquid absorbing expansion body, the liquid absorbing expansion body absorbing liquid, expanding and deforming and causing the moving contact piece to contact the static contact lead-out terminal.

[0006] In a preferred embodiment of the present invention, a conical interference fit is formed between the side surface of the liquid-absorbing expansion body and the inner wall of the cavity.

[0007] In a preferred embodiment of the present invention, the moving contact assembly further comprises a fixing rod, the fixing rod is inserted into the liquid-absorbing expansion body, the moving contact piece is fixed on the fixing rod, and the moving contact piece is a moving contact spring.

[0008] In a preferred embodiment of the present invention, the lower end of the fixing rod is inserted into the housing to position the moving contact assembly.

[0009] In a preferred embodiment of the present invention, the static contact lead-out terminal is connected to the vehicle-mounted ECU control unit, and sends a signal to the vehicle-mounted ECU control unit after the moving contact spring contacts the static contact lead-out terminal.

[0010] In a preferred embodiment of the present invention, the base and the static contact lead-out terminal are integrally formed by injection molding.

[0011] In a preferred embodiment of the utility model, a bolt is threadedly connected to the opening of the cavity, and a drainage hole for the drain valve to flow into the cavity is provided on the bolt, and the bolt abuts against the upper end of the liquid absorption expansion body.

[0012] In a preferred embodiment of the present invention, the base is threadedly connected to the bottom shell of the power battery pack, and an O-ring is provided between the base and the bottom shell.

[0013] The beneficial effects of the utility model are as follows: the utility model power battery pack discharge valve, the liquid absorption expansion body can quickly push the moving contact spring to undergo elastic deformation after the liquid absorption expansion, so that the moving contact spring contacts the static contact lead-out terminal and sends out an alarm signal, and the triggering reaction is sensitive.

[0014] The utility model discloses a drain valve for a power battery pack, wherein the liquid suction expansion body and the cavity form a conical interference fit, and the moving contact spring is fixedly connected to the fixing rod, thereby ensuring that the liquid suction expansion body and the moving contact spring are firmly positioned when the coolant is not leaked, thereby avoiding the false triggering of the alarm signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0016] Figure 1 It is a schematic diagram of the structure of the drain valve for the power battery pack of the utility model;

[0017] The markings of the components in the accompanying drawings are as follows: 1. base, 2. static contact lead-out terminal, 3. liquid absorption expansion body, 4. moving contact spring, 5. fixing rod, 6. bolt, 7. drainage hole, 8. bottom shell, 9. O-ring. DETAILED DESCRIPTION

[0018] The technical scheme in the embodiment of the utility model will be described clearly and completely below. The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification, so that people familiar with this technology can understand and read them, and are not used to limit the limiting conditions that can be implemented in the utility model, so they have no substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effect that can be produced by the utility model and the purpose that can be achieved, should still fall within the scope that the technical content disclosed in the utility model can cover. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of narration, and are not used to limit the scope that can be implemented. The change or adjustment of the relative relationship, without substantial change of the technical content, should also be regarded as the scope that can be implemented in the utility model.

[0019] See also Figure 1 A drain valve for a power battery pack includes a base 1, wherein the base 1 has a cavity, and the base 1 is provided with a static contact lead-out terminal 2 extending from the cavity to the outside of the base 1. The base 1 and the static contact lead-out terminal 2 are integrally formed by injection molding.

[0020] A moving contact assembly is provided in the cavity and is located above the static contact lead-out terminal 2. The moving contact assembly includes a liquid-absorbing expansion body 3 embedded in the cavity, and a moving contact piece is provided below the liquid-absorbing expansion body 3. The liquid-absorbing expansion body 3 absorbs liquid and expands and deforms to make the moving contact piece contact with the static contact lead-out terminal 2. The static contact lead-out terminal 2 is connected to the vehicle-mounted ECU control unit, and sends a signal to the vehicle-mounted ECU control unit after the moving contact spring piece 4 contacts the static contact lead-out terminal 2. The moving contact assembly also includes a fixing rod 5, which is inserted into the liquid-absorbing expansion body 3, and the moving contact piece is fixed on the fixing rod 5. The moving contact piece is the moving contact spring piece 4. First, the liquid-absorbing expansion body 3, the moving contact spring piece 4 and the fixing rod 5 are connected into a whole, and the moving contact spring piece 4 is firmly fixed to the fixing rod 5 by welding or spring clamping, and the moving contact assembly is loaded into the cavity, and the fixing seat is inserted into the base 1 to realize the positioning of the moving contact assembly. The side of the liquid-absorbing expansion body 3 and the inner wall of the cavity are in a conical interference fit, and the moving contact spring 4 is fixedly connected to the fixing rod 5, ensuring that the moving contact spring 4 and the liquid-absorbing expansion body 3 will not be displaced when there is no leakage of the discharge valve, thereby avoiding false triggering of the alarm signal. The liquid-absorbing expansion body 3 is made of existing sodium polyacrylate fiber / polyethylene terephthalate fiber mixed fiber or sodium polyacrylate fiber / polytetrafluoroethylene fiber mixed fiber, which belongs to the prior art.

[0021] The opening of the cavity is threadedly connected with a bolt 6, and the bolt 6 is provided with a drainage hole 7 for the drain valve to flow into the cavity. The base 1 is threadedly connected to the bottom shell 8 of the power battery pack, and an O-ring 9 is provided between the base 1 and the bottom shell 8. When the coolant inside the power battery pack leaks, the coolant enters the cavity along the drainage channel, and the coolant flows to the liquid absorption expansion body 3. The liquid absorption expansion body 3 expands and deforms after absorbing the coolant. Since the bolt 6 is against the upper end of the liquid absorption expansion body 3, the liquid absorption expansion body 3 will squeeze the moving contact spring 4 below. The moving contact spring 4 is elastically deformed downward after being compressed, so that the moving contact spring 4 contacts the static contact lead-out terminal 2 to form a passage, and the static contact lead-out terminal 2 sends an electrical signal to the on-board ECU control unit, and the on-board ECU control unit then sends a coolant alarm signal.

[0022] Different from the prior art, the drain valve for the power battery pack of the utility model is sensitive to triggering and can quickly send out an electrical signal of a major coolant leakage fault, thereby avoiding short circuit or thermal runaway in the power battery pack and ensuring the safe use of the power battery pack.

[0023] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A drain valve for a power battery pack, comprising a base, characterized in that: The base has a cavity inside, and the base is provided with a static contact lead-out terminal extending from the cavity to the outside of the base. The cavity is provided with a moving contact assembly located above the static contact lead-out terminal. The moving contact assembly includes a liquid-absorbing expansion body embedded in the cavity, and a moving contact piece is provided below the liquid-absorbing expansion body. The liquid-absorbing expansion body expands and deforms when it absorbs liquid and makes the moving contact piece contact with the static contact lead-out terminal.

2. The drain valve for a power battery pack according to claim 1, characterized in that: There is a conical interference fit between the side surface of the liquid-absorbing expansion body and the inner wall of the cavity.

3. The drain valve for a power battery pack according to claim 1, characterized in that: The moving contact assembly also includes a fixing rod, the fixing rod is inserted into the liquid-absorbing expansion body, the moving contact piece is fixed on the fixing rod, and the moving contact piece is a moving contact spring.

4. The drain valve for a power battery pack according to claim 3, characterized in that: The lower end of the fixing rod is inserted into the housing to position the moving contact assembly.

5. The drain valve for a power battery pack according to claim 1, characterized in that: The static contact lead-out terminal is connected to the vehicle-mounted ECU control unit, and sends a signal to the vehicle-mounted ECU control unit after the moving contact spring is in contact with the static contact lead-out terminal.

6. The drain valve for a power battery pack according to claim 1, characterized in that: The base and the static contact lead-out terminal are integrally formed by injection molding.

7. The drain valve for a power battery pack according to any one of claims 1 to 6, characterized in that: A bolt is threadedly connected at the opening of the cavity, and a drainage hole for the discharge valve to flow into the cavity is provided on the bolt, and the bolt abuts against the upper end of the liquid absorption expansion body.

8. The drain valve for a power battery pack according to claim 7, characterized in that: The base is threadedly connected to the bottom shell of the power battery pack, and an O-ring is provided between the base and the bottom shell.

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