Drain valve, battery pack and electric device

Abstract

The embodiment of the application provides a kind of drain valve, battery pack and electrical equipment, it is related to fluid control technical field, for the safety protection of new energy battery pack, the drain valve includes valve body, valve cover, valve core, elastic member and liquid suction assembly, liquid suction assembly is connected in parallel in the containing cavity of valve body, valve core is connected between valve cover and valve body, for transmitting driving force;Wherein, liquid suction assembly includes the liquid suction structure that physical expansion occurs when meeting water and the heat generation structure that chemical heat generation occurs when meeting water;The drain valve can generate driving force by physical expansion and chemical heat generation cooperation, improve the opening sensitivity and the response speed of drainage.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a drain valve, a battery pack, and an electrical device. Background Technology

[0002] Heating components are widely used in the safety protection system of new energy battery packs. As a key safety component, the drain valve plays an emergency draining role in electric vehicles, energy storage systems and other equipment when coolant leaks or internal water enters, in order to prevent safety accidents such as short circuits and thermal runaway.

[0003] In related technologies, spring-loaded drain valves that use liquid-absorbing materials to expand and open the valve cover are widely used. These valves include: a compression spring providing sealing force, a guide groove for the liquid-absorbing material to avoid expansion and blockage, and an inlet on the side of the valve body to introduce liquid. This solution uses the expansion of the liquid-absorbing material after absorbing water to generate thrust, which overcomes the spring preload and causes the valve cover to detach from the drain port, thereby establishing a drain channel.

[0004] However, the drain valves in the aforementioned technologies lack rapid response capabilities, affecting the timeliness of the draining action and system safety. Summary of the Invention

[0005] This application provides a drain valve, a battery pack, and an electrical device to solve the technical problem in the above-mentioned related technologies that the drain valve lacks rapid response capability, affecting the timeliness of the draining action and the safety of the system.

[0006] A first aspect of this application provides a drain valve, comprising:

[0007] The valve body is provided with an inlet and an outlet, and the valve body has a receiving cavity;

[0008] A valve cover is provided over the drain port;

[0009] The valve core passes through the valve body and is connected to the valve cover;

[0010] The elastic element acts on the valve body and the valve core at both ends respectively, and presses and seals the valve cover to the drain port through the valve core;

[0011] A liquid-absorbing assembly includes a liquid-absorbing structure and a heat-generating structure. The liquid-absorbing structure physically expands upon contact with water, and the heat-generating structure generates heat upon contact with water.

[0012] When the liquid comes into contact with the liquid-absorbing component through the inlet, the heat-generating structure reacts to generate heat and the physical expansion of the liquid-absorbing structure together generate a driving force to drive the valve cover to overcome the elastic force of the elastic element and open the drain port.

[0013] The drain valve provided in this application embodiment achieves the following: In the initial stage when liquid enters from the inlet and contacts the liquid suction component, the rapid exothermic reaction of the heat-generating structure causes local air to be heated and pressurized. This, together with the physical expansion of the liquid suction structure, applies an axial driving force to the valve core. This allows the valve cover to obtain a net upward resultant force before the pre-tightening force of the elastic element is completely overcome, thereby significantly shortening the drain response time and effectively improving the opening sensitivity and safety response capability of the drain valve in emergency scenarios such as battery pack thermal runaway or electrolyte leakage.

[0014] In one possible implementation, the liquid-absorbing structure has a through-hole extending through its thickness direction, and the heat-generating structure is at least partially disposed within the through-hole.

[0015] In one possible implementation, the total projected area of ​​the through holes on the cross-section of the liquid-absorbing structure accounts for 20% to 80% of the area enclosed by the outer contour of the cross-section of the liquid-absorbing structure.

[0016] In one possible implementation, the volume of the heat-generating structure is 5% to 100% of the volume of the through-hole cavity in which it is located.

[0017] In one possible implementation, the drain valve includes multiple layers of the suction assembly stacked along the thickness direction.

[0018] In one possible implementation, the heat-generating structure is a powder or bonded molded structure, and the material of the heat-generating structure includes at least one of calcium oxide, anhydrous magnesium chloride, iron powder, salt, activated carbon, or magnesium powder.

[0019] In one possible implementation, the liquid-absorbing structure is made of dry cellulose, sodium polyacrylate gel, or polyvinyl alcohol gel.

[0020] In one possible implementation, the valve core includes a core body and an abutment plate connected to the core body, the core body passing through the valve body and the liquid suction assembly, and connected to the valve cover;

[0021] The valve body has a first groove on the surface facing the abutment plate, and the abutment plate has a corresponding second groove on the surface facing the valve body. The first groove and / or the second groove are used to guide the valve core during the valve opening process.

[0022] In one possible implementation, the liquid inlet is located on the side wall of the valve body and corresponds to the position of the liquid suction structure.

[0023] In one possible implementation, the outer edge of the liquid-absorbing structure has a notch.

[0024] In one possible implementation, there is a gap of 0.2 mm to 2 mm between the inner wall of the valve body and the outer periphery of the liquid suction assembly.

[0025] A second aspect of this application provides a battery pack that includes a drain valve as described above.

[0026] A third aspect of this application provides an electrical device, which includes an electrical device and a battery pack as described above. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 An exploded view of a drain valve provided in an embodiment of this application;

[0029] Figure 2 A cross-sectional view of a drain valve provided in an embodiment of this application;

[0030] Figure 3 This is a schematic diagram of the structure of a valve body provided in an embodiment of this application;

[0031] Figure 4 This is a schematic diagram of the structure of a liquid absorption assembly provided in an embodiment of this application;

[0032] Figure 5 This is a schematic diagram of a liquid absorption structure provided in an embodiment of this application;

[0033] Figure 6 This is a schematic diagram of another liquid absorption assembly provided in an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100. Valve body;

[0036] 110. Liquid inlet; 120. Liquid outlet; 130. Receiving cavity; 140. First settling tank; 150. Gap;

[0037] 200. Valve cover;

[0038] 300. Valve core;

[0039] 310. Core; 320. Abutment plate;

[0040] 321. Second settling tank;

[0041] 400. Elastic components;

[0042] 500. Liquid suction assembly;

[0043] 510. Liquid absorption structure; 520. Heat generation structure;

[0044] 511. Through hole; 512. Notch;

[0045] 600. First sealing ring;

[0046] 700. Second sealing ring.

[0047] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0048] As described in the background section, the drain valves in the aforementioned related technologies lack rapid response capabilities, affecting the timeliness of the draining action and system safety.

[0049] The reason for this problem is that existing spring-loaded drain valves generally use liquid-absorbing materials such as electrical insulating paperboard, which rely on capillary action to slowly absorb water and expand to overcome the spring preload, resulting in an excessively long drain response time (usually 60~300s), which makes it difficult to meet the battery pack's rapid emergency response requirements for liquid leakage.

[0050] This application provides a drain valve, a battery pack, and an electrical device. The drain valve achieves the following: In the initial stage when liquid enters from the inlet and contacts the liquid-absorbing component, the rapid exothermic reaction of the heat-generating structure causes local air to be heated and pressurized. This, combined with the physical expansion of the liquid-absorbing structure, applies an axial driving force to the valve core. This allows the valve cover to obtain a net upward resultant force before the pre-tightening force of the elastic element is completely overcome, thereby significantly shortening the drain response time and effectively improving the opening sensitivity and safety response capability of the drain valve in emergency scenarios such as battery pack thermal runaway or electrolyte leakage.

[0051] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0052] refer to Figure 1 , Figure 2 and Figure 3This application provides a drain valve, which may include a valve body 100, a valve cover 200, a valve core 300, an elastic element 400, and a liquid suction assembly 500.

[0053] The valve body 100 has an inlet 110 and a outlet 120, and also has a receiving cavity 130. A valve cover 200 is placed over the outlet 120, and a valve core 300 passes through the valve body 100 and connects to the valve cover 200. An elastic element 400 acts on both ends of the valve body 100 and the valve core 300 respectively, and the valve core 300 presses and seals the valve cover 200 against the outlet 120. The liquid-absorbing assembly 500 includes a liquid-absorbing structure 510 and a heat-generating structure 520. The liquid-absorbing structure 510 physically expands upon contact with water; the heat-generating structure 520 generates heat upon contact with water.

[0054] When the liquid comes into contact with the liquid suction assembly 500 through the liquid inlet 110, the heat generation structure 520 reacts to generate heat and the physical expansion of the liquid suction structure 510 together generate a driving force to drive the valve cover 200 to overcome the elastic force of the elastic element 400 and open the drain port 120.

[0055] The valve body 100 refers to a hollow cylindrical support with a receiving cavity 130, and its material can be engineering plastics (such as polypropylene, polycarbonate) or lightweight metals (such as aluminum alloy). The liquid inlet 110 is located on the side wall of the valve body 100, and can be one or more, for example, a single rectangular hole, an annular groove, or a multi-row micropore array. Its position corresponds to the projected area of ​​the liquid suction assembly 500 in the thickness direction to ensure that the liquid can uniformly wet the liquid suction structure 510 and the heat generation structure 520 after entering. The liquid outlet 120 is located at the center of the top of the valve body 100, and has a circular opening. Its inner diameter can be set according to the actual liquid discharge flow requirements.

[0056] The valve cover 200 refers to a disc-shaped sealing structure, the bottom of which is provided with a first sealing ring 600 that matches the drain port 120. The first sealing ring 600 can be made of silicone rubber, fluororubber, or thermoplastic elastomer. The valve cover 200 is connected to the top of the valve core 300 by means of threads, snaps, or interference fit.

[0057] The valve core 300 is a rigid force-transmitting component that passes through the valve body 100 and connects to the valve cover 200. The valve core 300 as a whole is responsible for accurately transmitting the axial driving force generated by the liquid suction assembly 500 to the valve cover 200. Its degree of freedom of movement is constrained by the guide structure to ensure that the valve opening action is performed along a predetermined axis.

[0058] The elastic element 400 refers to a compression helical spring whose two ends act on the valve body 100 and the valve core 300, respectively, with its two ends abutting between the bottom of the valve body 100 and the valve core 300. The core function of the elastic element 400 is to provide an adjustable and stable initial sealing clamping force and serve as a mechanical benchmark for the driving force response. Its preload threshold is set to be slightly higher than the minimum net driving force generated by the combined action of the liquid suction structure 510 and the heat generation structure 520, thereby ensuring the sensitivity and certainty of the valve opening action.

[0059] The liquid-absorbing component 500 is a functional integrated unit located within the valve body 100, above the elastic element 400, and within the through-path of the valve core 300. Its overall shape is adapted to the cross-section of the receiving cavity 130 and can be circular, square, or annular. The liquid-absorbing structure 510 undergoes physical expansion upon contact with water, and its material can be dry cellulose, sodium polyacrylate gel, or polyvinyl alcohol gel. The heat-generating structure 520 undergoes a heat-generating reaction upon contact with water. This reaction is a strongly exothermic process, which can raise the local air temperature by 30°C to 120°C within seconds, thereby causing a significant increase in gas pressure within the confined microspace. The heat-generating structure 520 can be a loose powder accumulation or a sheet or columnar body cured with a binder (such as a polyvinyl alcohol aqueous solution). Its combination with the liquid-absorbing structure 510 can be embedded, sandwiched, or blended.

[0060] When the liquid comes into contact with the liquid-absorbing component 500 through the inlet 110, the heat-generating structure 520 generates heat and the physical expansion of the liquid-absorbing structure 510 together generate a driving force to drive the valve cover 200 to overcome the elastic force of the elastic element 400 and open the drain port 120. This describes a complete liquid-heat-force three-level coupling response process: the liquid first enters the receiving cavity 130 through the inlet 110, diffuses laterally along the gap between the valve body 100 and the liquid-absorbing component 500, or the interlayer gap between multiple liquid-absorbing components 500, and then penetrates longitudinally through the micropores or through holes 511 of the liquid-absorbing structure 510 itself. After absorbing water, the liquid-absorbing structure 510 expands isotropically or anisotropically along its thickness and radial direction, generating a continuous and gradually increasing axial thrust. At the same time, the heat-generating structure 520 quickly initiates an exothermic reaction upon contact with water, and the heat is conducted to the air in the micro-gap inside and around the liquid-absorbing structure 510, causing the local gas to expand due to heat and form an instantaneous positive pressure. This pressure acts on the back surface of the liquid-absorbing structure 510 and the bottom of the valve core 300, forming a pulsed auxiliary thrust. The combined driving forces generated by the two cause the total driving force to exceed the preload of the elastic element 400 in the initial stage, driving the valve core 300 to move upward and causing the valve cover 200 to detach from or partially detach from the drain port 120, thus achieving rapid valve opening. After the valve is opened, the liquid-absorbing component 500 is connected to the external environment, and the thermo-pressure effect decreases, but the liquid-absorbing structure 510 continues to expand in the confined space, maintaining the valve cover 200 in the open state until the liquid is drained.

[0061] Through the above technical solution, this application achieves the following: In the initial stage when the liquid enters from the inlet 110 and contacts the liquid suction assembly 500, the rapid exothermic reaction of the heat-generating structure 520 causes the local air to be heated and pressurized. This, together with the physical expansion of the liquid suction structure 510, applies an axial driving force to the valve core 300. This allows the valve cover 200 to obtain a net upward resultant force before the pre-tightening force of the elastic element 400 is completely overcome by the liquid suction structure 510. This significantly shortens the liquid discharge response time and effectively improves the opening sensitivity and safety response capability of the drain valve in emergency scenarios such as battery pack thermal runaway or electrolyte leakage.

[0062] refer to Figure 2 , Figure 4 and Figure 5 In some embodiments, the liquid absorption structure 510 is provided with a through hole 511 extending through its thickness direction, and the heat generation structure 520 is at least partially disposed within the through hole 511.

[0063] The liquid-absorbing structure 510 is provided with through holes 511 that penetrate its thickness direction. These are channels that are opened inside the liquid-absorbing structure 510 body along a direction perpendicular to its unfolded plane. The number, shape, size, and distribution of these through holes 511 can be set according to the actual liquid discharge response speed and structural strength requirements. For example, it can be a single circular through hole 511, or multiple fan-shaped, square, or irregular polygonal through holes 511 arranged in a ring array or staggered.

[0064] The heat-generating structure 520 is at least partially disposed within the through hole 511, and can be a powdered deposit, a granular filler, or a bonded molded body; the filling method of the heat-generating structure 520 can be: completely filling the cavity of the through hole 511, or only filling the bottom area, middle area, or top area of ​​the through hole 511.

[0065] The through hole 511 not only serves as the installation space for the heat-generating structure 520, but also as a flow channel for liquid inside the liquid-absorbing structure 510. After the liquid enters through the liquid inlet 110, it can quickly penetrate to the surface of the heat-generating structure 520 through the through hole 511, triggering a heat-generating reaction. At the same time, the micro gaps formed between the inner wall of the through hole 511 and the heat-generating structure 520 can also form an auxiliary capillary channel to improve the liquid transfer efficiency.

[0066] Through the above technical solution, this application achieves the following: by utilizing the structural features of the liquid absorption structure 510 to form an internal mounting cavity, the heat generation structure 520 is embedded therein, thereby improving the functional integration of the liquid absorption assembly 500 without increasing the external volume; the through hole 511 has three functions: structural support, heat generation and containment, and internal flow guidance, so that the liquid can contact the heat generation material more evenly and quickly, thereby superimposing a gas pressurization effect on the physical expansion of the liquid absorption structure 510, significantly shortening the liquid discharge response time; and because the heat generation structure 520 is wrapped inside the liquid absorption material, its reaction process is dynamically modulated by the swelling state of the liquid absorption material, avoiding instantaneous and violent gas generation that could cause the valve cover 200 to shake or be accidentally opened, thus improving the stability and controllability of the valve opening action.

[0067] refer to Figure 4 and Figure 5 In some embodiments, the total projected area of ​​the through hole 511 on the cross-section of the liquid absorption structure 510 accounts for 20% to 80% of the area enclosed by the outer contour of the cross-section of the liquid absorption structure 510.

[0068] The total projected area of ​​the through holes 511 on the cross-section of the liquid-absorbing structure 510 refers to the sum of the orthogonal projected areas of all through holes 511 on a plane perpendicular to the thickness direction of the liquid-absorbing structure 510; the area enclosed by the outer contour of the cross-section of the liquid-absorbing structure 510 refers to the area of ​​the closed region enclosed by its outermost edge in the same projection direction. This ratio range is adaptively adjusted according to the material, thickness, expected expansion amount of the liquid-absorbing structure 510 and the reaction rate of the heat-generating structure 520.

[0069] The through-hole 511 can be any of the following shapes: circular, elliptical, rectangular, fan-shaped, or polygonal, or it can be an irregular shape. Multiple through-holes 511 are arranged in an array, ring, radial, or random distribution on the liquid absorption structure 510. The dimensions of each through-hole 511 can be the same or different. The spacing between the through-holes 511 is set according to the mechanical continuity requirements of the liquid absorption structure 510 to ensure the structural integrity and assembly stability of the liquid absorption structure 510 in the non-water-absorbing state.

[0070] The 20% to 80% ratio range is understood as an opening ratio constraint: when the ratio is below 20%, the total projected area of ​​the through hole 511 is too small, which restricts the space available for the heat generation structure 520, making it difficult to provide sufficient gas pressurization auxiliary driving force and affecting the liquid discharge response speed; when the ratio is above 80%, the remaining load-bearing skeleton area of ​​the liquid absorption structure 510 is significantly reduced, its dry compressive strength and wet expansion stress transmission capacity decrease, resulting in local collapse or uneven expansion, weakening the main driving force of physical expansion, and reducing the cyclic durability of the liquid absorption structure 510 in the process of repeated water absorption and discharge.

[0071] The total projected area of ​​the through hole 511 on the cross-section of the liquid absorption structure 510 accounts for 20%, 30%, 40%, 50%, 60%, 70%, or 80% of the area enclosed by the outer contour of the cross-section of the liquid absorption structure 510.

[0072] Through the above technical solution, this application achieves the goal of reserving sufficient accommodation space and reaction environment for the heat generation structure 520 integrated inside the liquid absorption structure 510 while ensuring that the liquid absorption structure 510 has sufficient structural strength and physical expansion driving force. This allows the physical expansion force of the liquid absorption structure 510 and the gas pressurization auxiliary force of the heat generation structure 520 to form a stable synergy, thereby improving the opening sensitivity of the drain valve in the initial stage of liquid contact and the consistency of the overall drain response.

[0073] refer to Figure 4 and Figure 5 In some embodiments, the volume of the heat-generating structure 520 is 5% to 100% of the volume of the cavity in the through hole 511 in which it is located.

[0074] The volume of the heat-generating structure 520 filling the cavity of the through-hole 511 is 5% to 100%. This refers to the proportion of space occupied by the solid portion of the heat-generating structure 520 within the through-hole 511, which extends through the thickness of the liquid-absorbing structure 510. This proportion can be set according to the actual liquid drainage response speed requirements, ambient temperature conditions, battery pack installation posture, and safety redundancy level. For example, it can be 5%, 10%, 20%, 30%, 50%, 70%, 85%, or 100%.

[0075] The cavity volume of the through hole 511 refers to the geometric volume formed by the through hole 511 inside the liquid absorption structure 510. Its shape can be circular, elliptical, square, fan-shaped or polygonal, and its cross-sectional profile can be similar to or different from the outer profile of the liquid absorption structure 510. When the through hole 511 is a multi-hole array, the cavity volume is the sum of the cavities of each individual hole. The cavity volume can be designed to match the size of the liquid absorption structure 510, the liquid absorption rate of the material, and the kinetic parameters of the heat generation reaction.

[0076] Through the above technical solution, this application achieves the following: after the liquid contacts the liquid-absorbing component 500, the heat-generating structure 520 undergoes a water-reacting reaction within the through-hole 511, and its filling volume ratio directly determines the amount of substances participating in the reaction and the gas pressure increase within the sealed space; when the filling volume is 5%, it can ensure that a trace amount of heat-generating material can still trigger an initial pressure jump, enabling the valve cover 200 to obtain effective auxiliary driving force near the spring preload critical point, significantly improving the valve opening sensitivity; when the filling volume is 100%, it can maximize the release of reaction heat and gas volume within a limited space, providing the strongest instantaneous thrust, suitable for scenarios with stringent requirements for drainage response time (such as early emergency drainage in the thermal runaway of power batteries); this wide filling range takes into account performance redundancy, cost control, and process tolerance, supporting flexible adaptation and stable mass production under different operating conditions.

[0077] refer to Figure 4 and Figure 5 In some embodiments, the drain valve includes a multi-layered liquid suction assembly 500 stacked along the thickness direction.

[0078] The liquid absorption assembly 500 comprises two, three, four, or more layers stacked along its thickness direction. Each layer is independently arranged, non-adhesive, and non-fused, maintaining its relative position only through assembly constraints. The gap between adjacent liquid absorption assemblies 500 is 0 mm to 5 mm, for example, 0.3 mm, 0.5 mm, 1.0 mm, 1.5 mm, or 2.0 mm. Alternatively, the gap between adjacent liquid absorption assemblies 500 can be zero, allowing the adjacent layers to contact each other. This gap refers to the minimum vertical distance between the surfaces of adjacent liquid absorption structures 510, and it can be formed by natural stacking with gaps, or by providing limiting bosses or grooves at the edges of the liquid absorption structures 510 for mechanical limiting.

[0079] The heat-generating structure 520 is distributed in the same way in each layer of liquid-absorbing structure 510, or it is set differently layer by layer. For example, the bottom layer focuses on rapid effect (high proportion of highly active calcium oxide), while the upper layer focuses on continuous heat release (increased ratio of magnesium powder and activated carbon).

[0080] The multi-layer liquid suction assembly 500 is arranged in parallel stacks along the thickness direction within the receiving cavity 130 of the valve body 100. The number of stacked layers can be 2 to 20, for example, 2, 3, 5, 8, or 12 layers. Each layer of the liquid suction assembly 500 has the same structural parameters (such as the number, size, and projected area ratio of through holes 511), or it can be designed differently according to the flow channel requirements. For example, the projected area ratio of through holes 511 in the bottom liquid suction structure 510 is 20%, and that in the top layer is 60%, to match the liquid permeation gradient from bottom to top.

[0081] The stacked structure of the multilayer liquid absorption assembly 500 corresponds to the position of the liquid inlet 110 on the side wall of the valve body 100; the liquid inlet 110 is a single rectangular opening, or multiple circular micropores evenly distributed along the circumference. After the liquid enters from the liquid inlet 110, it preferentially diffuses laterally along the interlayer gaps between adjacent liquid absorption structures 510, and then penetrates longitudinally through the micropores or through-holes 511 of each liquid absorption structure 510 itself, thereby realizing a dual-path penetration mode of first spreading laterally and then wetting longitudinally; this mode significantly shortens the time for the liquid to reach the internal heat-generating structure 520, enabling the heat-generating reaction to be triggered earlier.

[0082] The interlayer gaps not only serve as liquid inlet channels, but also constitute an additional liquid discharge flow section after the drain valve is opened. When the valve cover 200 is opened, the liquid can flow out through the main drain channel between the valve cover 200 and the drain port 120 under the pressure difference, or it can be discharged through the interlayer gaps of the liquid suction component 500, the through hole 511 of the liquid suction structure 510, and the gap between the valve body 100 and the outer periphery of the liquid suction component 500, forming a multi-path liquid discharge mechanism to avoid a sudden drop in the liquid discharge rate due to blockage of a single channel.

[0083] Through the above technical solution, this application achieves the following: Since the multi-layer liquid absorption components 500 are stacked along the thickness direction to form interlayer gaps, the liquid can preferentially diffuse laterally along the interlayer gaps after entering the valve body 100, which greatly shortens the time required for the liquid to penetrate into the heat generation structure 520 inside each layer, so that the heat generation reaction is triggered earlier and the expansion driving force accumulates faster; at the same time, the interlayer gaps are connected in parallel with the main liquid discharge channel after the valve is opened, which expands the total liquid discharge flow area and increases the liquid discharge volume per unit time.

[0084] refer to Figure 4 and Figure 5 In some embodiments, the heat-generating structure 520 is a powder or a bonded molded body, and the material of the heat-generating structure 520 includes at least one of calcium oxide, anhydrous magnesium chloride, iron powder, salt, activated carbon, or magnesium powder.

[0085] The heat-generating structure 520 can be in powder form, such as a dry powder with a particle size range of 50 μm to 500 μm obtained by sieving calcium oxide particles. This form facilitates uniform filling within the through-hole 511 of the liquid-absorbing structure 510 and enables rapid, large-area contact reaction in the initial stage of liquid wetting, thereby quickly increasing the air temperature and pressure within the local confined space. The packing density and filling height of the powder-based heat-generating structure 520 can be set according to actual conditions, for example, the filling volume can be 5% to 100% of the cavity volume of the through-hole 511, to adapt to different response speeds and liquid discharge requirements.

[0086] The heat-generating structure 520 can also be a bonded molded body. For example, calcium oxide powder can be mixed with a water-soluble binder (such as a polyvinyl alcohol aqueous solution), molded, and then dried at low temperature to obtain a cylindrical or ring-shaped block; or iron powder, salt, and activated carbon can be mixed, a thermoplastic binder (such as EVA resin) can be added, and then extruded, granulated, and cooled to obtain a granular molded body. The bonded molded body can effectively prevent the heat-generating material from shifting or leaking during assembly or transportation. At the same time, by controlling the binder content and molding pressure, its dissolution rate and heat release rhythm after contact with water can be adjusted. Its shape, size, and density can be adapted to the actual through-hole 511 structure. For example, it can be made into a circular, square, or polygonal cross-section that matches the cross-sectional profile of the through-hole 511.

[0087] The material for the heat-generating structure 520 can be any one of calcium oxide, anhydrous magnesium chloride, iron powder, salt, activated carbon, or magnesium powder; or it can be a combination of two or more of these materials. For example, the combination of calcium oxide and anhydrous magnesium chloride can balance the initial heat release intensity and the duration of heat release; the ternary combination of iron powder, salt, and activated carbon constitutes the microenvironment of a galvanic cell, forming an electrochemical corrosion circuit in water to achieve stable heat generation over a long period of time; the mixture of magnesium powder and a small amount of salt can enhance the initial reaction activity. All of the above materials have a clear water-reacting exothermic chemical mechanism: calcium oxide (CaO) reacts with water to produce calcium hydroxide and releases approximately 65 kJ / mol of heat; the hydration process of anhydrous magnesium chloride (MgCl2) is a strongly exothermic process.

[0088] Magnesium powder reacts slowly with water at room temperature, but under salt catalysis, the reaction can be accelerated to produce magnesium hydroxide and exotherm. All materials used do not produce toxic gases, and the reaction products are solid or soluble, harmless salts, meeting the safety requirements for use inside battery packs.

[0089] Through the above technical solution, this application achieves that after the liquid contacts the liquid-absorbing component 500, the heat-generating structure 520 releases heat in a controllable manner according to the selected material type and physical form, heating the air in the through hole 511 and the surrounding closed cavity to form an instantaneous positive pressure; the positive pressure and the physical expansion of the liquid-absorbing structure 510 work together to push the valve core 300 upward and the valve cover 200 open, significantly shortening the liquid discharge response time; at the same time, different material combinations and form selections can cover a wide range of working condition adaptability requirements, ensuring the functional stability and consistency of the liquid discharge valve under high and low temperatures, different humidity and multiple batch manufacturing conditions.

[0090] refer to Figure 4 and Figure 5 In some embodiments, the liquid absorption structure 510 is made of dry cellulose, sodium polyacrylate gel, or polyvinyl alcohol gel.

[0091] The liquid-absorbing structure 510 can be made of any one of dry cellulose, sodium polyacrylate gel, or polyvinyl alcohol gel, or a composite of two or three of the above materials. For example, a composite liquid-absorbing layer can be formed by blending dry cellulose and sodium polyacrylate gel in a mass ratio of 1:1 to 5:1. Dry cellulose refers to a natural cellulose material that is loose and porous after drying. Its microstructure contains a large number of hydroxyl groups, which can quickly adsorb and lock in water through hydrogen bonding when it comes into contact with water, resulting in significant volume expansion.

[0092] Sodium polyacrylate gel is a superabsorbent polymer with a large number of sodium carboxylate hydrophilic groups on its main chain. When it comes into contact with water, it ionizes and generates an osmotic pressure difference, which drives water molecules to quickly enter the network and achieves water absorption and expansion of up to 30 to 500 times its own dry weight. In the liquid absorption component 500, it can be in the form of sheet, granular dispersion embedded or integral molding structure.

[0093] Polyvinyl alcohol gel is a hydrogel formed by physical or chemical cross-linking of polyvinyl alcohol (PVA). Its water absorption and swelling behavior has good reversibility and mechanical stability. The time required for the cross-linked PVA gel to reach 90% equilibrium swelling in water at 25℃ is 30 s to 300 s. Its wet compressive strength is 0.1 MPa to 1.5 MPa.

[0094] All three materials can complete their initial effective expansion within a few seconds to tens of seconds after contact with the liquid, providing a stable and controllable physical driving force; their water absorption process does not depend on external energy input, and the reaction products are non-toxic and environmentally friendly; all three can have through holes 511, and work in conjunction with heat-generating structures 520 such as calcium oxide, anhydrous magnesium chloride, iron powder / salt / activated carbon, and magnesium powder.

[0095] Through the above technical solution, this application achieves the following: when liquid contacts the liquid absorption component 500 through the liquid inlet 110, dry cellulose, sodium polyacrylate gel, or polyvinyl alcohol gel, as the main body of the liquid absorption structure 510, rapidly absorbs water and undergoes macroscopic volume expansion due to their inherent strong hydrophilicity and network expansion ability; the physical expansion force and the gas pressurization in the closed space caused by the reaction of the heat-generating structure 520 with water work together to drive the valve cover 200 to overcome the elastic force of the elastic element 400 and open the drain port 120; since the differences in water absorption rate, expansion ratio and mechanical response characteristics of different materials can be complementaryly configured, the drain valve can maintain good opening sensitivity and drain stability under different temperature and humidity, liquid composition and pressure conditions.

[0096] refer to Figure 1 and Figure 2 In some embodiments, the valve core 300 includes a core 310 and an abutment plate 320 connected to the core 310. The core 310 passes through the valve body 100 and the liquid suction assembly 500 and is connected to the valve cover 200. The surface of the valve body 100 facing the abutment plate 320 is provided with a first recess 140, and the surface of the abutment plate 320 facing the valve body 100 is provided with a corresponding second recess 321. The first recess 140 and / or the second recess 321 are used to guide the valve core 300 during the valve opening process.

[0097] The core 310 is a rigid rod-shaped structure with a cylindrical, prismatic, or polygonal cross-section, made of stainless steel, brass, engineering plastic, or aluminum alloy. It can withstand the axial pressure applied by the elastic element 400 and transmit the driving force to the valve cover 200. One end of the core 310 is provided with an external thread or snap-fit ​​structure for detachable connection with the internal threaded hole or groove at the bottom of the valve cover 200; the other end extends through the center hole of the liquid suction assembly 500 and is fixedly connected to the abutment plate 320. The connection method is welding, riveting, integral injection molding, or interference fit.

[0098] The abutment plate 320 has a ring, square or disc-shaped structure, and its outer contour dimension is larger than the cross-sectional dimension of the core 310 to provide sufficient force-bearing area. The thickness of the abutment plate 320 is set according to the preload of the elastic element 400 and the material strength, and is 0.5 mm to 3 mm, or 1 mm, 1.5 mm or 2 mm.

[0099] The first recess 140 is located on the outer surface of the valve body 100 facing the abutment plate 320, and its shape is an annular groove, a rectangular groove, or a multi-segment arc groove. The second recess 321 is located on the surface of the abutment plate 320 facing the valve body 100, and its contour matches the first recess 140, forming a fitting guide pair. When the abutment plate 320 moves axially with the valve core 300, the second recess 321 slides along the first recess 140, restricting the displacement of the abutment plate 320 in the direction perpendicular to the axis, thereby constraining the entire valve core 300 to move only along the predetermined axis. The first recess 140 and the second recess 321 are provided on only one side, or simultaneously, to balance processing convenience and guiding accuracy; if only the first recess 140 is provided, a guide flange is provided on the edge of the abutment plate 320, which slides within the first recess 140. If only the second recess 321 is provided, a guide boss is correspondingly provided on the surface of the valve body 100, which cooperates with the second recess 321.

[0100] Under normal conditions, the valve core 300 is in an axially compressed state by the elastic element 400, which is a compression spring. One end of the elastic element 400 abuts against the upper surface of the abutment plate 320, and the other end abuts against the limiting step or spring seat at the top of the valve body 100. After the liquid contacts the liquid suction assembly 500 and triggers synergistic expansion, the physical expansion of the liquid suction structure 510 and the heat generation structure 520 together push the valve cover 200 upward, thereby driving the core 310 and the abutment plate 320 to rise synchronously. At this time, the elastic element 400 moves along the depth direction of the second settling groove 321 or the first settling groove 140, effectively suppressing the lateral sway caused by uneven heat generation, uneven liquid suction, or assembly deviation, and ensuring that the movement trajectory of the valve core 300 is highly coaxial.

[0101] Through the above technical solution, this application achieves the following: During the movement of the valve core 300, the mechanical guide pair formed by the first groove 140 and the second groove 321 constrains the degree of freedom of the valve core 300 to a single axial translation, significantly reducing the risk of skewing during the valve opening process; thereby ensuring the stable transmission path of the elastic force of the elastic element 400, improving the repeatability positioning accuracy of the valve cover 200 opening and closing action and the consistency of the sealing surface; at the same time, it reduces the probability of local friction wear and jamming caused by skewing, and extends the service life and response reliability of the drain valve under the long-term service conditions of the battery pack.

[0102] refer to Figure 1 and Figure 2In some embodiments, the liquid inlet 110 is located on the side wall of the valve body 100 and corresponds to the position of the liquid suction structure 510.

[0103] The inlet 110 is located on the side wall of the valve body 100. It can be a through hole or slot opened at any position on the circumferential side wall of the valve body 100, with its axis perpendicular to the central axis of the valve body 100. The number of inlets 110 can be one or more, such as 1, 2, 3 or 4 to 8 evenly distributed in a ring. The shape of the inlet 110 can be circular, elliptical, elongated or rectangular, and its size can be set according to the actual discharge flow requirements and the structural space of the valve body 100.

[0104] The position of the liquid inlet 110 corresponds to that of the liquid suction structure 510. Specifically, the center projection of the liquid inlet 110 falls within the orthogonal projection area of ​​the liquid suction structure 510 on the cross-section of the valve body 100. Furthermore, when the liquid suction assembly 500 is a multi-layer stacked structure, the position of the liquid inlet 110 along the height direction of the valve body 100 should be aligned with the thickness area of ​​at least one layer of liquid suction structure 510, and can be aligned with the middle area of ​​the outermost or middle layer of liquid suction structure 510. When the liquid suction structure 510 is provided with a through hole 511 penetrating the thickness direction, the position of the liquid inlet 110 can also correspond to the lateral projection area of ​​the through hole 511, so that the liquid preferentially enters the interior of the through hole 511 through the liquid inlet 110, thereby accelerating the wetting of the heat-generating structure 520 and the start-up of the reaction.

[0105] The valve body 100 has multiple spaced liquid inlets 110 on its side wall. Each liquid inlet 110 is evenly arranged in the circumferential direction, and the radial projection of each liquid inlet 110 covers the outer peripheral area of ​​the corresponding liquid absorption structure 510.

[0106] Through the above technical solution, this application achieves the following: Since the liquid inlet 110 is located on the side wall of the valve body 100 and corresponds to the position of the liquid suction structure 510, the liquid can enter synchronously and uniformly from the side or outer peripheral area of ​​the liquid suction structure 510, avoiding the problems of liquid accumulation in the upper layer and delayed wetting of the lower layer due to top liquid inlet, or local oversaturation and blockage of the channel due to gravity sedimentation caused by bottom liquid inlet; This layout significantly shortens the time required for liquid to penetrate to the heat generation structure 520, and accelerates the start-up speed of the heat generation reaction and the gas pressurization process; At the same time, the lateral liquid inlet path is orthogonal or intersects the expansion direction of the liquid suction structure 510 at a large angle, reducing the impact of liquid impact on the guiding stability of the valve core 300, and ensuring the linearity and repeatability of the valve cover 200 opening action.

[0107] refer to Figure 2 and Figure 6 In some embodiments, the outer edge of the liquid absorption structure 510 has a through notch 512 along the thickness direction, and the through notch 512 forms a gap with the inner wall of the receiving cavity 130.

[0108] The liquid-absorbing structure 510 has a through-hole 512 along its thickness direction on its outer edge. This refers to a strip-shaped, arc-shaped, serrated, or irregularly shaped opening that extends along the overall thickness direction at the circumferential edge of the annular or sheet-like body of the liquid-absorbing structure 510. The through-hole 512 can be single or multiple, and multiple through-holes 512 are evenly or non-uniformly distributed along the outer periphery of the liquid-absorbing structure 510. The width of the through-hole 512 is 0.1 mm to 5 mm, or 0.3 mm to 2 mm. The depth of the through-hole 512 is equal to the thickness of the liquid-absorbing structure 510, achieving complete penetration. The cross-sectional shape of the through-hole 512 is rectangular, trapezoidal, V-shaped, or arc-shaped, and its specific shape is selected according to the molding process of the liquid-absorbing structure 510 and the requirements for expansion and deformation coordination.

[0109] A gap is formed between the through-hole 512 and the inner wall of the receiving cavity 130. This gap serves as the initial preset gap for the liquid-absorbing structure 510 in its unexpanded state, or as a dynamically maintained stable flow channel during the expansion of the liquid-absorbing structure 510 through water absorption. The size range of this gap is determined comprehensively based on the material of the liquid-absorbing structure 510, its expansion rate, the inner diameter tolerance of the receiving cavity 130 of the valve body 100, and the required drainage rate. This gap remains between 0.1 mm and 3 mm, or between 0.2 mm and 1.5 mm, even after the liquid-absorbing structure 510 has fully expanded. The function of this gap is that when the liquid-absorbing structure 510 physically expands upon contact with water, its main body expands radially outward and tends to conform to the inner wall of the receiving cavity 130. However, due to the presence of the through-hole 512, the local area corresponding to the through-hole 512 cannot form a continuous contact surface, thus maintaining a communication path for liquid and gas to pass through between the through-hole 512 and the inner wall of the receiving cavity 130.

[0110] Furthermore, the location of the through-gap 512 corresponds to or is offset from the location of the liquid inlet 110. When it corresponds to the liquid inlet 110, it facilitates the rapid diffusion of liquid into the interior and interlayer of the liquid absorption structure 510 after it flows in through the liquid inlet 110. When it is offset, it can extend the liquid flow path, allowing the liquid to more fully wet the liquid absorption structure 510 body and the heat generation structure 520, thereby improving the uniformity of the reaction.

[0111] Through the above technical solution, this application achieves the following: a through notch 512 along the thickness direction is provided on the outer edge of the liquid absorption structure 510, and a stable gap is formed between it and the inner wall of the receiving cavity 130. This ensures that after the liquid absorption structure 510 has fully expanded by absorbing water, its edge will not completely adhere to the inner wall of the receiving cavity 130 and block the drainage path. This gap serves as a permanent flow channel, continuously conducting liquid and gas throughout the entire valve opening process, avoiding internal pressure accumulation and drainage rate attenuation caused by edge sealing. This ensures that the drainage valve still has stable and efficient drainage capacity under high expansion conditions, effectively improving drainage response speed and long-term reliability.

[0112] refer to Figure 2 In some embodiments, there is a gap 150 of 0.2 mm to 2 mm between the inner wall of the valve body 100 and the outer periphery of the liquid suction assembly 500.

[0113] The gap 150 between the inner wall of the valve body 100 and the outer periphery of the suction assembly 500 refers to the minimum straight-line distance measured radially between the inner wall surface of the valve body 100 receiving cavity 130 and the outermost contour surface of the suction assembly 500, when the drain valve is in its assembled state. This gap 150 can be 0.2mm, 0.5mm, 1.0mm, 1.5mm, or 2.0mm, or any continuous value within the range of 0.2mm to 2mm, such as 0.8mm, 1.2mm, or 1.7mm.

[0114] The slit 150 provides radial free deformation space for the physical expansion of the liquid-absorbing structure 510 upon contact with water, preventing stress concentration, local compression, or expansion obstruction caused by rigid contact with the inner wall of the valve body 100 in the initial stage of liquid absorption. If the slit 150 is less than 0.2 mm, jamming will occur in the early stage of liquid absorption, resulting in a decrease in effective expansion force and a delay in valve opening. If the slit 150 is greater than 2 mm, the liquid-absorbing assembly 500 is prone to displacement or shaking in the unexpanded state, affecting the penetration positioning accuracy of the valve core 300 and the force symmetry of the elastic element 400, thereby reducing the repeatability of the valve opening action and the sealing reliability.

[0115] The gap 150 can also serve as an auxiliary drainage channel, allowing liquid to flow to the drainage port 120 area through the annular gap 150 between the outer periphery of the liquid suction assembly 500 and the inner wall of the valve body 100 before or during the opening of the valve cover 200. Especially in the multi-layer liquid suction assembly 500 stacked structure, the gap 150 and the interlayer gap 150 work together to form a three-dimensional interconnected flow channel network, improving the liquid permeation efficiency and drainage rate.

[0116] Through the above technical solution, this application achieves the following: after the liquid contacts the liquid suction assembly 500 through the inlet 110, the liquid suction structure 510 undergoes controllable expansion synchronously in the axial and radial directions. The radial expansion is provided by the 0.2mm to 2mm gap 150, which ensures that the liquid suction structure 510 fully releases the physical expansion driving force and avoids weakening the local sealed environment on which the heat generation structure 520 depends due to excessive constraint. At the same time, the gap 150 itself participates in forming the drainage path, and together with the internal through hole 511, interlayer gap 150 and through notch 512 of the liquid suction structure 510, it forms a multi-stage flow guidance-pressurization-discharge synergistic mechanism, thereby significantly improving the overall opening sensitivity and dynamic drainage capacity of the drainage valve without changing the pre-tightening force of the elastic element 400.

[0117] refer to Figure 1 and Figure 2 This application embodiment also provides a battery pack, which may include a battery module, a housing, and a drain valve disposed on the housing; wherein, the drain valve is as described above, specifically including a valve body 100, a valve cover 200, a valve core 300, an elastic element 400, and a liquid suction assembly 500. The valve body 100 is provided with an inlet 110 and a outlet 120, and has a receiving cavity 130; the valve cover 200 is placed over the outlet 120; the valve core 300 passes through the valve body 100 and is connected to the valve cover 200; the two ends of the elastic element 400 act on the valve body 100 and the valve core 300 respectively, and the valve cover 200 is pressed and sealed to the outlet 120 by the valve core 300; the liquid suction assembly 500 includes a liquid suction structure 510 and a heat generation structure 520. The liquid suction structure 510 undergoes physical expansion when it comes into contact with water, and the heat generation structure 520 undergoes a heat generation reaction when it comes into contact with water; when the liquid comes into contact with the liquid suction assembly 500 through the inlet 110, the heat generation structure 520 reacts to generate heat and the physical expansion of the liquid suction structure 510 together generate a driving force to drive the valve cover 200 to overcome the elastic force of the elastic element 400 and open the outlet 120.

[0118] The battery pack housing has a mounting hole, and the valve body 100 of the drain valve is fixed in the mounting hole by the second sealing ring 700. The inlet 110 is set towards the internal space of the battery pack and is used to receive liquid that seeps in from the gap between the battery modules, the interface of the cooling pipe or the failure of the housing seal. The drain outlet 120 is set towards the external environment of the battery pack and is used to discharge the intruded liquid to a designated drainage path or collection chamber.

[0119] The location of the drain valve in the battery pack can be adjusted according to the battery pack structure layout. For example, it can be set at the lowest point of the bottom of the battery pack, in the area corresponding to the gap 150 on the side of the module, in the liquid collection tank below the liquid cooling plate, or multiple drain valves can be distributed in an array along the circumference / bottom of the shell. The sealing method between the drain valve and the shell can be rubber O-ring compression seal, silicone gasket embedded seal, or laser welding seal. The drain port 120 is connected to an external guide pipe or hydrophobic and breathable membrane to prevent backflow of external dust and rainwater, while ensuring that internal gas can escape and liquid can be discharged in one direction.

[0120] Through the above technical solution, this application achieves the following: when a liquid intrusion event occurs in the battery pack, the inherent composite driving force of the drain valve, namely the synergistic effect of the physical expansion force of the liquid absorption structure 510 and the thermal pressurization of the heat generation structure 520, enables the drain valve to automatically open in a very short time, significantly shortening the drain response time.

[0121] refer to Figure 1 and Figure 2 This application also provides an electrical device, which may include an electrical device and the battery pack described above.

[0122] The electrical device can be any one of the following: a drive motor for an electric vehicle, an energy storage inverter, a robot joint servo controller, an outdoor communication base station power module, a drone flight control system, or a portable medical testing instrument. The electrical device and the battery pack are electrically connected and interact with each other via a high-voltage connector and a low-voltage communication bus. The battery pack includes a housing, cell modules, a battery management system, and a drain valve as described in the above embodiment. The drain valve is located at the bottom or low point of the side wall of the battery pack housing and communicates with the interior of the housing. The inlet 110 of the drain valve faces the interior of the housing, the outlet 120 faces the external environment, and the receiving cavity 130 of the drain valve is in fluid communication with the internal space of the battery pack.

[0123] The heat, vibration, or electromagnetic interference generated during the operation of the electrical device does not change the mechanical structure integrity or chemical reactivity of the drain valve. When the battery pack encounters coolant leakage, rainwater intrusion, or condensate accumulation, the liquid enters its receiving cavity 130 through the drain valve inlet 110 and contacts the liquid suction component 500, triggering the physical expansion of the liquid suction structure 510 and the exothermic reaction of the heat generation structure 520. The two work together to generate a driving force, driving the valve cover 200 to overcome the elastic force of the elastic element 400 and open the drain port 120, realizing the rapid discharge of liquid.

[0124] Through the above technical solution, this application realizes the deep integration of a battery pack with rapid response drainage capability into the terminal electrical equipment: because the electrical equipment includes the battery pack as described in the above embodiment, and the battery pack is embedded with the composite driving force drainage valve as defined in the above embodiment, when the equipment is in abnormal working conditions such as dampness, tilting, inversion or sealing failure, the battery pack can autonomously identify liquid intrusion and instantly start the drainage action to avoid liquid stagnation in the gap between cells or on the surface of the circuit board, thereby significantly reducing the risk of insulation breakdown, local overheating and fire and explosion, and improving the safety redundancy and service reliability of the whole machine in complex environments.

[0125] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0126] It should be noted that phrases such as "in specific implementations," "in some embodiments," "in this embodiment," and "exemplarily" in the specification indicate that the described embodiments may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0127] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0128] It should be readily understood that “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest manner, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on something” but also “on something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0129] Furthermore, for ease of explanation, spatially relative terms such as "below," "below," "under," "above," and "above" may be used to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation other than those shown in the figures. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A drain valve, characterized in that, include: The valve body (100) is provided with an inlet (110) and a outlet (120), and the valve body (100) has a receiving cavity (130); A valve cover (200) is provided over the drain port (120); A valve core (300) passes through the valve body (100) and is connected to the valve cover (200); The elastic element (400) acts on the valve body (100) and the valve core (300) at both ends respectively, and presses and seals the valve cover (200) to the drain port (120) through the valve core (300); The liquid absorption assembly (500) includes a liquid absorption structure (510) and a heat generation structure (520), wherein the liquid absorption structure (510) physically expands upon contact with water; and the heat generation structure (520) generates heat upon contact with water. When the liquid comes into contact with the liquid suction assembly (500) through the liquid inlet (110), the heat-generating structure (520) reacts to generate heat and the physical expansion of the liquid suction structure (510) together generate a driving force to drive the valve cover (200) to overcome the elastic force of the elastic element (400) and open the liquid outlet (120).

2. The drain valve according to claim 1, characterized in that, The liquid absorption structure (510) is provided with a through hole (511) extending through its thickness direction, and the heat generation structure (520) is at least partially disposed within the through hole (511).

3. The drain valve according to claim 2, characterized in that, The total projected area of ​​the through hole (511) on the cross-section of the liquid absorption structure (510) accounts for 20% to 80% of the area enclosed by the outer contour of the cross-section of the liquid absorption structure (510).

4. The drain valve according to claim 2, characterized in that, The volume filled by the heat-generating structure (520) accounts for 5% to 100% of the volume of the cavity of the through hole (511) in which it is located.

5. The drain valve according to claim 1, characterized in that, The drain valve includes multiple layers of the liquid suction assembly (500) stacked along the thickness direction.

6. The drain valve according to any one of claims 1 to 5, characterized in that, The heat-generating structure (520) is a powder or bonded molded structure, and the material of the heat-generating structure (520) includes at least one of calcium oxide, anhydrous magnesium chloride, iron powder, salt, activated carbon or magnesium powder.

7. The drain valve according to any one of claims 1 to 5, characterized in that, The liquid absorption structure (510) is made of dry cellulose, sodium polyacrylate gel or polyvinyl alcohol gel.

8. The drain valve according to any one of claims 1 to 5, characterized in that, The valve core (300) includes a core body (310) and an abutment plate (320) connected to the core body (310). The core body (310) passes through the valve body (100) and the liquid suction assembly (500) and is connected to the valve cover (200). The valve body (100) has a first groove (140) on the surface facing the abutment plate (320), and the abutment plate (320) has a corresponding second groove (321) on the surface facing the valve body (100). The first groove (140) and / or the second groove (321) are used to guide the valve core (300) during the valve opening process.

9. The drain valve according to any one of claims 1 to 5, characterized in that, The liquid inlet (110) is located on the side wall of the valve body (100) and corresponds to the position of the liquid suction structure (510).

10. The drain valve according to any one of claims 1 to 5, characterized in that, The outer edge of the liquid absorption structure (510) has a notch (512).

11. The drain valve according to any one of claims 1 to 5, characterized in that, There is a gap (150) of 0.2 mm to 2 mm between the inner wall of the valve body (100) and the outer periphery of the liquid suction assembly (500).

12. A battery pack, characterized in that, Includes the drain valve as described in any one of claims 1 to 11.

13. An electrical appliance, characterized in that, It includes an electrical device and a battery pack as described in claim 12.

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