Automatic drain valve and battery pack

Abstract

The application provides an automatic drain valve and a battery pack. The drain valve is arranged in the battery pack. The drain valve comprises a base, an umbrella valve, a baffle and a valve core which are assembled in sequence. The umbrella valve, the baffle and the valve core are arranged in the base. The base is internally provided with a water storage cavity for storing liquid. The umbrella valve is arranged on the upper surface of the base and functions as a one-way valve, so that the accumulated water can flow into the water storage cavity with low resistance / usually. When a certain amount of liquid is accumulated in the water storage cavity, the liquid further flows into the valve core and wets the expansion body in the valve core. After the expansion body absorbs water and expands, the accommodation space of the valve core becomes larger, so that the drain valve is opened, and the accumulated water in the water storage cavity is discharged to the outside. The umbrella valve has a sealing effect during the drainage process, so that the sealing state of the battery pack can be maintained, external water / foreign matters can be prevented from entering the inside of the battery pack through the drain valve, and the reliability of the battery pack is improved. In addition, the drain valve can realize automatic drainage without electric assistance, and can be automatically closed after drainage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy vehicle battery, in particular, to an automatic drain valve and a battery pack. BACKGROUND

[0002] The battery pack in the new energy vehicle is usually provided with a relatively sealed shell, and is provided with a breather valve to balance the pressure inside and outside the shell. The external water vapor can enter the inside of the battery pack through the breather valve and condense to generate liquid water. The liquid water can reduce the insulation performance of the high-voltage device in the battery pack, and even cause short circuit. The battery pack is usually also provided with a liquid cooling circuit. In the case of seal failure of the liquid cooling circuit, the cooling liquid leaks into the inside of the shell. Too much accumulation of the cooling liquid can cause short circuit of the high-voltage components. On the other hand, the accumulated water can accelerate the corrosion of the structural parts and the conductor material, resulting in reduced structural strength and increased contact resistance. The accumulation of conductive liquid in the battery pack can reduce the reliability of the battery pack, and drainage measures are needed to keep the inside of the box dry. The desired effect is that a certain amount of liquid is automatically drained to avoid the conductors and battery cells in the battery pack being submerged by the liquid. At the same time, the process of draining the liquid can avoid the entry of external foreign matter / liquid into the inside of the shell.

[0003] Under the prior art, the battery pack and electrical equipment such as motor are usually only provided with a breather valve without a drainage device. In the case of excessive accumulation of condensed water or cooling liquid leakage in the electrical equipment, the high-voltage components of the electrical equipment can be short-circuited. The disclosed drainage valves include electrically operated valves, spring check valves and expansion body liquid drainage valves. The electrically operated valve has the characteristics of complex structure, high cost and the need for power supply, and has poor adaptability. The spring check valve is opened to drain liquid under the action of liquid pressure when a certain amount of liquid is accumulated. After the liquid level drops, the spring force is closed. There is a problem that part of the liquid cannot be completely drained. The accumulated liquid can reduce the reliability of the electrical equipment. The check valve can be opened repeatedly in a short time, increasing the gap for foreign matter to enter. The expansion body liquid drainage valve is opened to drain liquid after absorbing water and expanding. The valve is closed after the expansion body dries and shrinks. There is no sealing effect during the opening of the valve, which can cause water and foreign matter to enter the electrical equipment. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide a drainage valve and a battery pack, which can automatically drain the liquid accumulated in the electrical equipment to the outside, and solve the problem of excessive accumulation of liquid in the electrical equipment leading to insulation / short circuit.

[0005] To achieve the above technical effects, the present application adopts the following technical solutions:

[0006] According to the first aspect of the present application, an automatic drain valve is provided, comprising a base, a umbrella valve, a baffle and a valve core which are assembled in sequence; the base is a cavity with an open lower end face, the umbrella valve, the baffle and the valve core are arranged in the base, and a water storage cavity is further arranged in the base for storing liquid; the baffle is fixedly installed below the water storage cavity of the base and serves as the bottom plate of the water storage cavity; a plurality of drain holes are arranged on the baffle, and a valve core mounting hole is arranged at the center of the baffle for fixedly installing the valve core;

[0007] A plurality of grooves are arranged on the upper end face of the base, and an umbrella valve is arranged in each groove, which is used to realize one-way flow of liquid from the groove into the water storage cavity;

[0008] The valve core comprises a valve seat, a spring, a plurality of expansion bodies and a sealing plate; the valve seat and the sealing plate are connected by the spring, the sealing plate comprises a bottom plate, a fence arranged on the bottom plate, and a fence inner cavity surrounded by the fence; the plurality of expansion bodies are arranged in the fence inner cavity; a water inlet hole is arranged at the top end of the valve seat, liquid flows into the fence inner cavity from the water inlet hole, and the expansion bodies in the fence inner cavity absorb water to expand, causing the sealing plate to move away from the valve seat; a third sealing element is arranged on the sealing plate and can move up and down with the sealing plate; a plurality of elastic claws are arranged on the outer side wall of the valve seat;

[0009] When the valve core is installed, the elastic claws cooperate with the valve core mounting hole to enable the valve core to pass through the valve core mounting hole of the baffle and be fixed, and the third sealing element is arranged below the drain hole of the baffle; when the expansion bodies are not expanded, the third sealing element blocks the drain hole on the baffle; when the expansion bodies are expanded, the third sealing element moves downward with the sealing plate, and the drain hole is opened;

[0010] When liquid in the water storage cavity flows into the valve core through the water inlet hole at the top end of the valve seat, the expansion bodies absorb water to expand, the third sealing element moves away from the valve seat with the sealing plate, and the liquid is discharged from the drain hole on the baffle; when the expansion bodies dry and shrink, the third sealing element moves toward the valve seat with the sealing plate to block the drain hole on the baffle.

[0011] Preferably, a first sealing element is arranged around the upper end face of the base to provide sealing between the drain valve and the installation interface.

[0012] Preferably, the baffle is connected to the inner wall of the base by screwing, buckling or adhesion, so that the periphery of the baffle is in a sealed state with the base, and the liquid in the water storage cavity can only flow downward through the drain hole on the baffle.

[0013] Preferably, the spring has an upper hook at its upper end and a lower hook at its lower end, a bracket at the top of the valve seat, and a connecting rod with a fixing hole at the center of the bottom plate of the sealing plate. When assembling the valve core, the upper hook of the spring is connected to the bracket, and the lower hook of the spring is inserted into the fixing hole of the sealing plate to achieve a mechanical connection between the spring and the sealing plate.

[0014] Preferably, the expandable body passes through and is fixed to the spring. The expandable body is ring-shaped or hollow disc-shaped. The expandable body is made of a material that expands after absorbing liquid. The thickness of the expandable body increases after absorbing liquid, and the total thickness of multiple stacked expandable bodies increases. The expandable body is made of one or more materials selected from water-absorbing foam, water-absorbing resin, or water-absorbing fiber. After drying, the expandable body shrinks to a smaller volume, which is reflected in the decrease in the total thickness of multiple stacked expandable bodies.

[0015] Preferably, the valve core mounting hole is provided with multiple grooves around it. When the valve core is inserted into the valve core mounting hole of the baffle, the elastic claw of the valve seat corresponds to the groove of the baffle. The elastic claw is guided to shrink during the insertion process by the groove. After the elastic claw passes through the valve core mounting hole, the elastic force of the elastic claw causes it to open automatically. The opened elastic claw abuts against the upper surface of the baffle, so that the valve seat is fixed on the baffle.

[0016] Preferably, the settling tank is provided with an umbrella valve fixing hole. The umbrella valve is made of an elastic material and includes an umbrella valve skirt and a snap-fit ​​connector on its upper part. The snap-fit ​​connector passes through the umbrella valve fixing hole and is snapped onto the upper surface of the settling tank, so that the umbrella valve skirt elastically fits against the lower surface of the settling tank. The accumulated liquid in the settling tank can flow into the water storage chamber from the drain, but the accumulated liquid in the water storage chamber will not flow back into the settling tank due to the presence of the umbrella valve.

[0017] Preferably, the valve seat has a flange at the bottom, and a second sealing element is provided in the groove of the flange; the second sealing element is placed between the baffle and the flange of the valve seat, and the second sealing element is compressed by the lower surface of the baffle to seal the valve core mounting hole.

[0018] According to a second aspect of the present invention, a battery pack is provided, including the above-mentioned automatic drain valve, and the battery pack further includes a housing, a cover, and battery cells, with a plurality of battery cells installed inside the housing;

[0019] The bottom of the housing is provided with a drainage groove, which is lower than the mounting surface of the battery cell. The drain valve is fixed to the bottom of the drainage groove by multiple bolts. The drainage groove has multiple water leakage holes, which are aligned with the sink in the drain valve. When liquid is generated inside the battery pack, the liquid will collect in the drainage groove. The liquid contained in the drainage groove will further flow into the sink through the water leakage holes. The liquid is discharged to the outside of the battery pack through the drain valve. During the drainage process, the drain valve maintains the airtightness of the battery pack, and external water will not enter the inside of the battery pack through the drain valve.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] 1. The automatic drain valve provided by the present application can automatically realize drainage without power supply and detection device, and automatically reset the seal after drainage, and the overall device is simple and practical.

[0022] 2. The automatic drain valve provided by the present application can keep the seal state during the drainage process, avoid the battery pack from being waterlogged due to the vehicle wading during the drainage process, and improve the reliability of the electrical equipment.

[0023] 3. The automatic drain valve provided by the present application will trigger the expansion of the expansion body and the opening of the sealing plate only after the water storage cavity accumulates a certain amount of liquid, thereby avoiding frequent opening of the drainage in humid weather, and the sealing plate will remain open for a period of time after being opened, so that the water in the battery pack can be fully drained. BRIEF DESCRIPTION OF DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, made with reference to the accompanying drawings:

[0025] Figure 1 FIG. 1 is a structural schematic diagram of the drain valve described in the first embodiment;

[0026] Figure 2 FIG. 2 is an exploded view of the drain valve described in the first embodiment;

[0027] Figure 3 FIG. 3 is a structural schematic diagram of the base of the drain valve described in the first embodiment;

[0028] Figure 4 FIG. 4 is a structural schematic diagram of the baffle of the drain valve described in the first embodiment;

[0029] Figure 5 FIG. 5 is an exploded view of the valve core of the drain valve described in the first embodiment;

[0030] Figure 6 FIG. 6 is a cross-sectional schematic diagram of the sealing plate of the drain valve described in the first embodiment;

[0031] Figure 7 FIG. 7 is a cross-sectional schematic diagram of the valve seat of the drain valve described in the first embodiment;

[0032] Figure 8 FIG. 8 is a structural schematic diagram of the valve core of the drain valve described in the first embodiment;

[0033] Figure 9 FIG. 9 is a cross-sectional view of Figure 8 ;

[0034] Figure 10 FIG. 10 is a cross-sectional view of the drain valve described in the first embodiment;

[0035] Figure 11 The state of liquid entering the drain valve described in the first embodiment is shown;

[0036] Figure 12 The schematic diagram of the drain state of the drain valve described in the first embodiment;

[0037] Figure 13 、 Figure 14 The schematic diagram of the battery pack structure described in the second embodiment;

[0038] Figure 15 The partial enlarged view of Figure 14 ;

[0039] Figure 16 The schematic diagram of the drain state of the drain valve on the battery pack.

[0040] The figure shows:

[0041] 1-drain valve 3-valve seat 7-battery pack

[0042] 11-base 31-flange 71-box body

[0043] 12-umbrella valve 32-claw 72-box cover

[0044] 13-shutter 33-bracket 73-cell

[0045] 14-valve core 3a-valve seat inner cavity 711-box body bottom plate

[0046] 111-mounting hole 3b-water inlet 71a-cell mounting surface

[0047] 112-sink groove 4-spring 712-drainage groove

[0048] 113-umbrella valve fixing hole 41-spring upper hook 713-leakage hole

[0049] 114-leakage port 42-spring lower hook 74-bolt

[0050] 131-drainage hole 5-expansion body 731-pole

[0051] 132-valve core mounting hole 6-sealing plate 121-umbrella valve skirt

[0052] 133-groove 61-water outlet hole

[0053] 21-first sealing element 62-fence

[0054] 22-second sealing element 63-linkage

[0055] 23-third sealing element 64-fixing hole

[0056] 11a-Water storage cavity; 6a-Inner cavity of the fence Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0059] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indication will also change accordingly. Furthermore, descriptions involving "first," "second," etc., in this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0060] Example 1

[0061] This embodiment provides an automatic drain valve, such as Figure 1 , Figure 2 As shown, the drain valve 1 is provided with a base 11, an umbrella valve 12, a baffle 13 and a valve core 14; wherein, the base 11 is a receiving cavity with an opening at one end face, the umbrella valve 12, the baffle 13 and the valve core 14 are all disposed in the receiving cavity of the base 11, and a water storage cavity 11a is also provided inside the receiving cavity of the base 11 for storing liquid.

[0062] like Figure 3 As shown, the upper surface of the base 11 is provided with mounting holes 111, multiple sinks 112, and umbrella valve fixing holes 113 and drain outlets 114. Multiple umbrella valves 12 are installed inside the base 11 and fixed through the umbrella valve fixing holes 113. One umbrella valve 12 is installed below each sink 112.

[0063] The umbrella valve 12 functions as a one-way valve. The umbrella valve 12 can be made of an elastic material such as rubber or silicone. The umbrella valve 12 includes a skirt 121 and a clamping joint on the upper part of the umbrella valve. The clamping joint passes through the umbrella valve fixing hole 113 and is clamped on the upper surface of the sink 112, so that the umbrella valve skirt 121 is elastically attached to the lower surface of the sink 112. Fluid can flow from the sink 112 to the water storage cavity 11a in the base 11 at low resistance. Conversely, fluid flows from the water storage cavity 11a to the sink 112 through the umbrella valve 12 at high resistance. Water cannot pass through the umbrella valve 12 from the water storage cavity 11a to the sink 112 at a pressure of 10 kPa, i.e., the umbrella valve 12 seals the lower part of the sink 112 to meet the IPX7 protection level. The accumulated water in the sink 112 can flow into the water storage cavity 11a through the water leakage hole 114, but the water in the water storage cavity 11a cannot flow back into the sink 112 due to the umbrella valve 12. Even if the drain valve 1 is immersed in water to a depth of 1 meter, the umbrella valve 12 can prevent the water in the water storage cavity 11a from flowing back into the sink 112.

[0064] In addition, the upper end surface of the base 11 is provided with a first sealing member 21, which provides a sealing function between the drain valve 1 and the installation interface. The inside of the base 11 is also provided with a baffle 13, as shown in Figure 4 The baffle 13 is provided with a plurality of drainage holes 131. The center of the baffle 13 is provided with a valve core mounting hole 132. The periphery of the valve core mounting hole 132 is provided with a plurality of grooves 133. The baffle 13 is fixed on the valve core 14 through the valve core mounting hole 132 and the plurality of grooves 133 on the periphery, as shown in Figure 10 , Figure 11 The baffle 13 is installed below the water storage cavity 11a of the base 11 and is configured as the bottom plate of the water storage cavity 11a. The baffle 13 can be connected to the inner wall of the base 11 by thread / catch / adhesion and the like. After connection, the periphery of the baffle 13 is in a sealed state with the base 11. The liquid in the water storage cavity 11a can only flow out through the drainage holes 131;

[0065] As shown in Figure 5 The valve core 14 is provided with a valve seat 3, a spring 4, a plurality of expansion bodies 5, and a sealing plate 6. The valve seat 3 and the sealing plate 6 both have corresponding accommodation cavities, which are the valve seat inner cavity 3a and the fence inner cavity 6a, respectively. The valve seat 3 and the sealing plate 6 are connected by the spring 4. The upper end of the spring 4 is provided with a spring upper hook 41, and the lower end is provided with a spring lower hook 42. The expansion body 5 passes through and is fixed on the spring 4. The expansion body 5 is in the shape of a circular ring or a hollow pie. The expansion body 5 is made of a material that expands after absorbing water / liquid, i.e., the volume of the expansion body 5 increases after absorbing liquid, which is manifested as an increase in the thickness of the expansion body 5. The total thickness of the plurality of stacked expansion bodies 5 increases. The expansion body 5 can be made of one or more materials such as water-absorbing foam, water-absorbing resin, or water-absorbing fiber. The expansion body 5 shrinks to a smaller volume after drying, which is manifested as a decrease in the total thickness of the plurality of stacked expansion bodies 5;

[0066] As Figure 7 shown, the bottom of the valve seat 3 is provided with a flange 31, the outer wall of the valve seat 3 is provided with a plurality of clamping claws 32, and the top of the valve seat 3 is provided with a support 33 and a water inlet 3b; the groove of the flange 31 is provided with a second sealing element 22; the support 33 is used to fix the spring upper hook 41 of the spring 4, and the water inlet 3b provides an operating space for the spring upper hook 41 to pass through the support 33;

[0067] As Figure 6 shown, the sealing plate 6 includes a bottom plate, a fence 62 on the bottom plate, a water outlet hole 61 on the bottom plate, a connecting rod 63 arranged at the center of the bottom plate, and a fixing hole 64 arranged on the connecting rod 63; the fixing hole 64 is used to fix the spring lower hook 42 of the spring 4; the fence 62 surrounds the periphery of the connecting rod 63 to form a fence inner cavity 6a and prevent liquid from entering the fence inner cavity 6a; at the same time, a third sealing element 23 is arranged on the upper surface of the bottom plate of the sealing plate 6, and the third sealing element 23 aligns with the plurality of drain holes 131 of the baffle 13 and seals the drain holes 131;

[0068] When assembling the valve core 14, as Figure 8 、 Figure 9 shown, the spring lower hook 42 of the spring 4 is passed through the fixing hole 64 of the sealing plate 6 to realize the mechanical connection between the spring 4 and the sealing plate 6; the plurality of expansion bodies 5 are passed through the spring 4 and are loaded into the fence inner cavity 6a of the sealing plate 6, further making the expansion bodies 5 enter the valve seat inner cavity 3a of the valve seat 3, and the spring upper hook 42 of the spring 4 is passed through the support 33 of the valve seat 3; the two ends of the spring 4 are respectively constrained by the support 33 and the fixing hole 64, the spring 4 is elongated, the elastic force of the spring 4 connects the sealing plate 6 and the valve seat 3, and constitutes the valve core 14 assembly, and at the same time, the expansion bodies 5 are in a clamped state in the fence inner cavity 6a by the sealing plate 6 and the valve seat 3.

[0069] Furthermore, the valve core 14 passes through the valve core mounting hole 132 of the baffle 13 and is connected to the baffle 13 through multiple claws 32. The claws 32 of the valve seat 3 correspond to the grooves 133 of the baffle 13. The claws 32 are elastic. During the insertion process, the claws 32 are guided to contract by the grooves 133. After the claws 32 pass through the valve core mounting hole 132, the rebound force of the claws 32 causes them to automatically open. The opened claws 32 abut against the upper surface of the baffle 13, fixing the valve seat 3 to the baffle 13. The second sealing element 22 is placed between the baffle 13 and the flange 31 of the valve seat 3. The second sealing element 22 is compressed by the lower surface of the baffle 13, and the second sealing element 22 seals the valve core mounting hole 132; the valve core 14 is fixed by the baffle 13. At the same time, a third sealing element 23 is provided between the baffle 13 and the bottom plate of the sealing plate 6. The third sealing element 23 is compressed by the sealing plate 6 and the baffle 13. The third sealing element 23 seals the multiple drain holes 131 of the baffle 13 so that when the drain valve 1 is in the closed state, the liquid in the water storage chamber 11a cannot be discharged through the drain holes 131, and the external liquid cannot enter the water storage chamber 11a through the drain holes 131.

[0070] The working principle of the automatic drain valve is as follows: water in the electrical equipment flows into the settling tank 112, and the accumulated water in the settling tank 112 further flows into the water storage chamber 11a through the drain port 114 and the umbrella valve 12. The S-path in the figure illustrates the liquid flowing from the settling tank 112 into the water storage chamber 11a. The liquid can pass through the umbrella valve skirt 121 with low resistance into the water storage chamber 11a. When there is a small amount of water in the water storage chamber 11a, the water will remain in the water storage chamber 11a and will not be discharged from the drain hole 131. Under the one-way sealing action of the umbrella valve 12, it will not flow back into the settling tank 112. The settling tank 112 and the water inlet 3b of the valve seat 3 are offset. During the process of the liquid in the settling tank 112 flowing into the water storage chamber 11a from the drain port 114, no liquid will directly enter the inner cavity 6a of the fence. Figure 10 As shown, when the water level in the water storage chamber 11a reaches position H1, some water will flow from the water storage chamber 11a through the inlet 3b of the valve seat 3 into the inner cavity 6a of the fence along the path indicated by arrow U. Multiple expansion bodies 5 will be wetted by the water, or in other words, the expansion bodies 5 will absorb the water flowing into the inner cavity 6a of the fence and expand. The increased thickness of the multiple expansion bodies 5 simultaneously stretches the spring 4, pushing the sealing plate 6 to move the third seal 23 towards the direction of K1. When the third seal 23 separates from the baffle 13, the drain hole 131 opens, and the liquid in the water storage chamber 11a can be discharged from the multiple drain holes 131. The expansion bodies 5 will not be directly wetted by water; only when a certain amount of liquid accumulates in the water storage chamber 11a will the expansion bodies 5 expand and the sealing plate 6 open, avoiding frequent opening of the drainage system in humid weather.

[0071] like Figure 12As shown, as the sealing plate 6 moves towards the K1 direction, the plurality of drainage holes 131 are opened; the liquid in the water storage cavity 11a is discharged from the plurality of drainage holes 131 along the Q schematic path, and further discharged to the outside along the X1 and X2 schematic paths, the X1 path is the outer ring drainage through the third sealing element 23, and the X2 path is the inner ring drainage through the water outlet hole 61 along the third sealing element 23; during the drainage, the umbrella valve 12 keeps the drainage valve 1 in a sealed state, so that even if the drainage valve 1 is in a water immersion state, the water in the water storage cavity 11a cannot flow into the sump 112 through the umbrella valve 12, that is, the water outside cannot flow back to the inside of the electrical equipment.

[0072] When the liquid in the water storage cavity 11a of the drainage valve 1 is discharged, the wet expansion body 5 will gradually dry, further shrink and become smaller in volume, which is manifested as the total thickness of the plurality of stacked expansion bodies 5 decreases; the sealing plate 6 moves in the direction opposite to the K1 under the elastic force of the spring 4, and the third sealing element 23 blocks the drainage hole 131, and the drainage valve 1 returns to the closed state.

[0073] Second embodiment

[0074] As shown in Figure 13 , Figure 14 , Figure 15 and Figure 16 , the present embodiment provides a battery pack 7, which comprises the automatic drainage valve 1 described in the first embodiment, the battery pack 7 is provided with a box body 71, a box cover 72, and a cell 73, a plurality of cells 73 are installed on the cell mounting surface 71a, and the inside of the box body bottom plate 711 can be integrated with a liquid cooling channel, which can take away the excess heat generated by the cell 73 during operation and maintain the cell 73 at a suitable temperature.

[0075] The bottom of the box body 71 is provided with a drainage groove 712, which is lower than the cell mounting surface 71a; the drainage valve 1 is fixed below the drainage groove 712 through a plurality of bolts 74; the drainage groove 712 is provided with a plurality of water leakage holes 713, the positions of which are aligned with the sump 112; the first sealing element 21 provides sealing between the drainage valve 1 and the bottom surface of the battery pack 7; the top of the cell 73 is provided with a plurality of pole columns 731, and the cell 73 transmits electric energy through the pole columns 731; if condensate water is generated inside the battery pack 7 or the cooling liquid of the box body bottom plate 711 leaks, the liquid will gather in the relatively low drainage groove 712; the liquid contained in the drainage groove 712 further flows into the sump 112 through the water leakage holes 713; further, the liquid is discharged to the outside of the battery pack 7 through the drainage valve 1, and the drainage valve 1 maintains the sealing of the battery pack 7 during the drainage process, so that the water outside cannot enter the inside of the battery pack 7 through the drainage valve 1;

[0076] After the expansion body 5 dries and shrinks, the spring 4 drives the sealing plate 6 to move to the closed state of the drain valve 1; the drain valve 1 can automatically drain the liquid in the battery pack 7, avoid the interference of the liquid to the battery cell 73, and maintain the sealing of the battery pack 7 during the whole drainage process. The sealing plate remains open for a period of time after opening, which can fully drain the water in the battery pack.

[0077] The specific embodiments of the present application are described above, and through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application.

Claims

1. An automatic drain valve characterized by, The automatic drainage valve comprises a base, an umbrella valve, a baffle and a valve core which are sequentially assembled; the base is a cavity with an open lower end face, the umbrella valve, the baffle and the valve core are arranged in the base, and a water storage cavity is further arranged in the base for storing liquid; the baffle is fixedly installed below the water storage cavity of the base and serves as a bottom plate of the water storage cavity; a plurality of drainage holes are arranged on the baffle, and a valve core mounting hole is arranged at the center of the baffle for fixedly mounting the valve core; a plurality of grooves are arranged on the upper end face of the base, and an umbrella valve is arranged in each groove, and the umbrella valve is used for realizing one-way flow of liquid from the groove into the water storage cavity; the valve core comprises a valve seat, a spring, a plurality of expansion bodies and a sealing plate; the valve seat and the sealing plate are connected by the spring; the sealing plate comprises a bottom plate, a fence arranged on the bottom plate and a fence inner cavity surrounded by the fence; the plurality of expansion bodies are arranged in the fence inner cavity; a water inlet hole is arranged at the top end of the valve seat, liquid flows into the fence inner cavity from the water inlet hole, the expansion bodies in the fence inner cavity absorb water to expand, and the sealing plate moves away from the valve seat; a third sealing element is arranged on the sealing plate and can move up and down with the sealing plate; a plurality of elastic claws are arranged on the outer side wall of the valve seat; when the valve core is installed, the elastic claws are matched with the valve core mounting hole to enable the valve core to pass through the valve core mounting hole of the baffle and be fixed, and the third sealing element is arranged below the drainage hole of the baffle; when the expansion bodies are not expanded, the third sealing element blocks the drainage hole on the baffle; when the expansion bodies are expanded, the third sealing element moves downward with the sealing plate, and the drainage hole is opened; the expansion bodies are expanded and the sealing plate is opened only after the water storage cavity of the automatic drainage valve accumulates a preset amount of liquid, so that the drainage is not frequently opened in humid weather, and the sealing plate remains opened for a preset time after being opened, so that water in the battery pack is fully drained; when liquid in the water storage cavity flows into the valve core through the water inlet hole at the top end of the valve seat, the expansion bodies absorb water to expand, the third sealing element moves away from the valve seat with the sealing plate, and the liquid is drained from the drainage hole on the baffle; when the expansion bodies are dried and shrink, the third sealing element moves towards the valve seat with the sealing plate to block the drainage hole on the baffle.

2. The automatic drain valve of claim 1, wherein, a first sealing element is arranged around the upper end face of the base to provide a sealing effect between the automatic drainage valve and a mounting interface.

3. The automatic drain valve of claim 1, wherein, the baffle is connected with the inner wall of the base by threads, buckles or adhesion, so that the periphery of the baffle is in a sealed state with the base, and liquid in the water storage cavity can only flow downward through the drainage hole on the baffle.

4. The automatic drain valve of claim 1, wherein, the upper end of the spring is provided with a spring upper hook, and the lower end is provided with a spring lower hook; the top of the valve seat is provided with a support; a connecting rod is arranged at the center of the bottom plate of the sealing plate, and a fixing hole is arranged on the connecting rod; when the valve core is assembled, the spring upper hook of the spring is connected with the support, and the spring lower hook penetrates into the fixing hole of the sealing plate, so as to realize mechanical connection of the spring and the sealing plate.

5. The automatic drain valve of claim 1, wherein, The expansion body passes through and is fixed on the spring, the expansion body is circular or hollow pie-shaped, the expansion body is made of a material that expands after absorbing liquid, the thickness of the expansion body increases after absorbing liquid, and the total thickness of the multiple stacked expansion bodies increases; the expansion body is made of one or more materials of water-absorbing foam, water-absorbing resin or water-absorbing fiber, and the expansion body shrinks to a smaller volume after drying, which is manifested as a decrease in the total thickness of the multiple stacked expansion bodies.

6. The automatic drain valve of claim 1, wherein, The periphery of the valve core mounting hole is provided with a plurality of grooves, when the valve core penetrates into the valve core mounting hole of the baffle, the elastic clamping jaws of the valve seat correspond in position with the grooves of the baffle, the process of being clamped by the elastic clamping jaws is guided and contracted by the grooves, when the elastic clamping jaws pass through the valve core mounting hole, the elastic clamping jaws are automatically opened by the elastic force, the opened elastic clamping jaws abut against the upper surface of the baffle, and the valve seat is fixed on the baffle.

7. The automatic drain valve of claim 1, wherein, The sink is provided with a valve fixing hole, the umbrella valve is made of an elastic body material, including an umbrella valve skirt and a clamping joint on the upper part, the clamping joint is clamped on the upper surface of the sink through the umbrella valve fixing hole, and the umbrella valve skirt is elastically attached to the lower surface of the sink; the accumulated liquid in the sink can flow into the water storage cavity from the water leakage hole, but the accumulated liquid in the water storage cavity cannot flow back into the sink due to the presence of the umbrella valve.

8. The automatic drain valve of claim 1, wherein, The bottom of the valve seat is provided with a flange, and a second sealing element is arranged in the groove of the flange; the second sealing element is arranged between the baffle and the flange of the valve seat, and the second sealing element is compressed by the lower surface of the baffle to seal the valve core mounting hole.

9. A battery pack, characterized by, The battery pack is provided with a box body, a box cover, and battery cells, and a plurality of battery cells are installed in the box body; The bottom of the box body is provided with a drainage groove, which is lower than the installation surface of the battery cells; the automatic drainage valve is fixed below the drainage groove by a plurality of bolts; the drainage groove is provided with a plurality of water leakage holes, and the positions of the water leakage holes are aligned with the sink in the automatic drainage valve; when liquid is generated inside the battery pack, the liquid will gather in the drainage groove; the liquid contained in the drainage groove will further flow into the sink through the water leakage holes; the liquid is discharged to the outside of the battery pack through the automatic drainage valve, and the automatic drainage valve maintains the sealing property of the battery pack during the drainage process, and water outside will not enter the inside of the battery pack through the automatic drainage valve.

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