Explosion-proof ventilation valve device

Abstract

An explosion-proof vent valve (100) for a battery pack, comprising: a top cover (1) comprising a cover hole (12); a valve body (3) detachably mounted to the top cover (1), the valve body (3) comprising a first mounting portion (36) and a second mounting portion (136); a water-impermeable and gas-permeable membrane (2) arranged between the valve body (3) and the top cover (1); a first intake valve assembly (110) mounted to the first mounting portion (36) in a first mounting direction (210); a second vent valve assembly (120) mounted to the second mounting portion (136) in a second mounting direction (220) opposite the first mounting direction (210); and the filter assembly is detachably mounted on the valve body (3). A battery pack is also provided.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to an explosion-proof ventilation valve device, and more particularly to an explosion-proof ventilation valve device for a battery pack used in, for example, an electric vehicle. BACKGROUND

[0002] Currently, due to the changes in altitude and ambient temperature during the driving of an electric vehicle, there is a significant pressure difference between the inside and outside of the battery pack. If the pressure difference between the inside and outside of the battery pack is not balanced in time, the battery pack will have the risk of compression deformation and bulging or even rupture under the action of the pressure difference. In some cases, a large amount of gas is released in the case of thermal runaway of the battery cells in the inside of the battery pack, and if these gases are not discharged to the outside of the battery pack in time, the internal pressure of the battery pack will rise sharply in a short time, causing the battery pack to rupture or even explode, which will affect the safety of the passengers.

[0003] Therefore, it is necessary to install an explosion-proof ventilation valve at the outer end of the battery pack to balance the pressure, reduce the impact of water condensation on the battery pack, and provide an explosion-proof function in an emergency. The existing explosion-proof ventilation valve adopts a single area integrating ventilation and explosion-proof functions, however, contaminants such as mud, dust, and water accumulation of the cover film easily block the film and thereby lose the air permeability function.

[0004] A battery releases a large amount of heat during a thermal runaway event. There is a chemical reaction between the positive and negative electrodes inside the battery, and when the battery is short-circuited or overcharged, the reaction becomes abnormally intense, causing the temperature inside the battery to rise sharply. Once the heat tolerance limit of the battery is exceeded, the battery will burn and release a large amount of heat. At the same time, the electrolyte in the battery usually contains substances such as organic solvents and fluorides, which decompose to produce toxic gases such as fluorides, cyanides, carbon monoxide, etc. These toxic gases are harmful to human health and can cause poisoning or even suffocation if inhaled in excess by the human body. The materials inside the battery include potassium salt, lithium manganese oxide, etc., which, when burned, produce a large amount of smoke. The smoke contains a large amount of fine particulate matter and organic matter, which pollutes the air quality and increases the risk of fire spreading. The housing of the battery pack is usually made of metal materials such as aluminum, cobalt, manganese, etc., and when the battery bursts, the housing can break and release metal fragments. These metal fragments not only can cause human injury, but also can cause secondary fires. The existing explosion-proof valve cannot adsorb harmful gases and filter other harmful substances when the battery is in an emergency abnormal ventilation, and cannot achieve smoke invisibility.

[0005] Therefore, it is necessary to develop an explosion-proof ventilation valve with a simple structure, integrated filtering function, and reliable operation under different operating conditions. SUMMARY

[0006] One object of this disclosure is to provide an explosion-proof ventilation valve that has a simple structure, integrated filtration function, and can operate reliably under different operating conditions.

[0007] In one aspect, an explosion-proof ventilation valve is provided. The explosion-proof ventilation valve includes: a top cover including a cover hole; a valve body detachably mounted to the top cover, the valve body including a first mounting portion and a second mounting portion; and a water-impermeable and gas-permeable membrane disposed between the valve body and the top cover. The explosion-proof ventilation valve further includes: a first air inlet valve assembly mounted to the first mounting portion in a first mounting direction; a second ventilation valve assembly mounted to the second mounting portion in a second mounting direction opposite to the first mounting direction; and a filter assembly detachably mounted to the valve body, the filter assembly including: a filter housing defining a filter space; a filter cover detachably mounted to the filter housing; a first filter element disposed in the filter space; a second filter element disposed on the first filter element in the filter space; and a third filter element disposed on the second filter element in the filter space.

[0008] The first filter element may include a first mesh having a first mesh size, the second filter element may include a second mesh having a second mesh size smaller than the first mesh size, and the third filter element may include a third mesh having a third mesh size smaller than the second mesh size, and may include an adsorbent for adsorbing harmful gases.

[0009] The membrane may include a hydrophobic coating thereon.

[0010] The top cover may include a plurality of resilient lugs extending downward from the top cover, each of the plurality of resilient lugs including a through hole; the valve body may include a plurality of corresponding protrusions corresponding to the plurality of resilient lugs; and the plurality of resilient lugs may slide on the plurality of protrusions on the valve body respectively and then cause each of the plurality of protrusions to engage into the through hole of the corresponding lug of the plurality of resilient lugs, thereby holding the top cover and the valve body in place.

[0011] The second ventilation valve assembly may be larger than the first intake valve assembly.

[0012] The first intake valve assembly may include a first upper component, a first lower component, and a first compression spring disposed between the first upper component and the first lower component.

[0013] The first upper component may include: a first valve plate, a first circumferential groove for receiving a first valve seal, a plurality of first upper guide portions extending radially outward from the first upper component, and a first upper cylindrical portion extending downward from the first valve plate. The first lower component may include: a first support plate having at least one air inlet, a first lower cylindrical portion extending upward from the first support plate, and a plurality of first lower guide portions extending upward around the outer edge of the first support plate, the first lower cylindrical portions defining an axially extending first central hole for receiving the first upper cylindrical portions, and the plurality of first upper guide portions and the plurality of first lower guide portions being arranged circumferentially staggered with each other. The first mounting portion may include: a first valve seat having a first valve orifice, and a plurality of pairs of first axial guide fins extending radially inward from the inner wall of the first mounting portion; a first compression spring for biasing the first valve plate to fit against the first valve seat in a fluid-impermeable manner, each of the plurality of first upper guide portions being axially slidable between a corresponding pair of first axial guide fins along a first upper guide gap, and each of the plurality of first lower guide portions being axially slidable between adjacent pairs of first axial guide fins along a first lower guide gap.

[0014] The first lower component may further include a first circumferential resilient lip extending radially outward around the outer edge of the first support plate, and the first mounting portion includes a first circumferential protrusion extending radially inward from the bottom of the inner wall of the first mounting portion.

[0015] The second ventilation valve assembly may include a second upper member, a second lower member, and a second compression spring disposed between the second upper member and the second lower member.

[0016] The second lower component may include: a second valve plate, a second circumferential groove for receiving a second valve seal, a plurality of second lower guide portions extending radially outward from the second lower component, and a second lower cylindrical portion extending upward from the second valve plate. The second upper component may include: a second support plate having at least one vent hole, a second upper cylindrical portion extending downward from the second support plate, and a plurality of second upper guide portions extending downward around the outer edge of the second support plate, the second upper cylindrical portion defining an axially extending second central hole for receiving the second lower cylindrical portion, and the plurality of second upper guide portions and the plurality of second lower guide portions being arranged circumferentially staggered with each other. The second mounting portion may include: a second valve seat having a second valve orifice, and a plurality of pairs of second axial guide fins extending radially inward from the inner wall of the second mounting portion; a second compression spring for biasing the second valve plate to fit against the second valve seat in a fluid-impermeable manner, each of the plurality of second lower guide portions being axially slidable between a corresponding pair of second axial guide fins along a second lower guide gap, and each of the plurality of second upper guide portions being axially slidable between adjacent pairs of second axial guide fins along a second upper guide gap.

[0017] The second upper member may further include a second circumferential resilient lip extending radially outward around the outer edge of the second support plate, and the second mounting portion includes a second circumferential protrusion extending radially inward from the top of the inner wall of the second mounting portion.

[0018] The filter cover may include: a grid cover body including a plurality of filter cover orifices, and a circumferential filter groove including the circumferential outer surface of the cover body and for receiving filter seals.

[0019] The valve body may include a circumferential valve body groove disposed on the bottom surface of the valve body for receiving a valve body seal, the circumferential valve body groove being further disposed at a certain distance outward from the filter assembly.

[0020] The valve body seal may include: an annular body, an inner circumferential lip extending radially inward from the annular body, and an outer circumferential lip extending radially outward from the annular body.

[0021] In another aspect, a battery pack is provided, comprising: a battery housing, at least one battery cell disposed in the battery housing, and an explosion-proof ventilation valve device as described above and installed in the battery housing.

[0022] With the help of the filter components, toxic gases, particulate matter and / or metal fragments can be reliably filtered out in the event of a thermal runaway event in the battery pack.

[0023] The filter assembly comes pre-installed as a module and can be easily installed onto the valve body, facilitating the assembly and replacement of the filter assembly.

[0024] By utilizing the multi-stage filtration of the filter assembly, particles, liquids, and / or harmful gases of different sizes can be reliably filtered out or adsorbed. Larger particles can be intercepted in the first filter element of the filter assembly to prevent the second or third filter element from becoming clogged, ensuring that the exhaust gas flows unimpeded during a thermal runaway event and thus preventing the battery pack from exploding.

[0025] With the help of the filter components, the mesh size of the first filter element, the second filter element and the third filter element can be flexibly adjusted according to the different volumes of exhaust gas generated by different types of battery packs, and the quantity, nature and size of the particulate matter contained in the exhaust gas.

[0026] The elastic constants of the first compression spring and / or the second compression spring can be adjusted according to different application scenarios and emergency release requirements of internal pressure, thus exhibiting excellent scalability.

[0027] The hydrophobic coating prevents moisture from the ambient air from entering the filter assembly, thereby extending the filter assembly's lifespan.

[0028] The second ventilation valve assembly, which is used as a ventilation valve, is larger than the first intake valve assembly, which is used as an intake valve, thereby saving the overall cost of the explosion-proof ventilation valve while ensuring its normal operation.

[0029] By means of a first axial guide fin shared by the first lower guide portion and the first upper guide portion, the first intake valve assembly can be reliably positioned and guided in the valve body with a simple structure, and saves costs compared to having separate guide fins for the first lower guide portion and the first upper guide portion.

[0030] With the help of a second axial guide fin shared by the second lower guide portion and the second upper guide portion, the second ventilation valve assembly can be reliably positioned and guided in the valve body with a simple structure, and saves costs compared to having separate guide fins for the second lower guide portion and the second upper guide portion.

[0031] Other suitable areas of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0032] This disclosure will be more fully understood from the detailed description and accompanying drawings.

[0033] Figure 1 This is a schematic exploded view of an example explosion-proof ventilation valve according to an embodiment, wherein the first intake valve assembly and the second ventilation valve assembly are omitted for clarity.

[0034] Figure 2 for Figure 1 A schematic cross-sectional view of an explosion-proof ventilation valve, wherein the explosion-proof ventilation valve is neither in intake mode nor in ventilation mode, the first intake valve assembly is in the closed state, and the second ventilation valve assembly is in the closed state.

[0035] Figure 3 This is a schematic exploded view of an example first intake valve assembly according to an embodiment.

[0036] Figure 4 This is a schematic exploded view of an example second ventilation valve assembly according to an embodiment.

[0037] Figure 5 This is a schematic perspective view of an example valve body according to an embodiment.

[0038] Figure 6 for Figure 5 A schematic top view of the valve body.

[0039] Figure 7 for Figure 1 A schematic cross-sectional view of an explosion-proof ventilation valve, wherein the explosion-proof ventilation valve is in ventilation mode, the first air inlet valve assembly is in the closed state, and the second ventilation valve assembly is in the open state.

[0040] Figure 8 for Figure 1 A schematic cross-sectional view of an explosion-proof ventilation valve, wherein the explosion-proof ventilation valve is in the air intake mode, the first air intake valve assembly is in the open state, and the second ventilation valve assembly is in the closed state. Detailed Implementation

[0041] The following description is exemplary in nature and is not intended to limit the scope, application, or use of this disclosure. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features. Furthermore, the drawings are generally schematic and not necessarily drawn to scale. Certain features may be enlarged or reduced to show detail of specific components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but rather as a representative basis for instructing those skilled in the art to implement this disclosure in diverse ways.

[0042] Some terms used in the following description are for illustrative purposes only and are therefore not intended to be limiting. For example, terms such as "above" and "below" refer to directions in the accompanying drawings. Terms such as "front," "rear," "front part," "rear part," "left part," "right part," "behind," "side part," "upward," "downward," "horizontal," "vertical," "top," and "bottom" are used to describe the orientation and / or position of portions of a part or element within a consistent but arbitrary frame of reference, as can be clearly understood by referring to the text and accompanying drawings describing the parts or elements discussed below.

[0043] Furthermore, terms such as "first," "second," and "third" may be used to describe individual components. Such terms are used for descriptive purposes in the accompanying drawings and do not represent a limitation on the scope of this disclosure as defined by the appended claims.

[0044] Referring now to the accompanying drawings, the same reference numerals refer to the same features in several views. Figure 1 This is a schematic exploded view of an example explosion-proof ventilation valve 100 according to an embodiment. The explosion-proof ventilation valve 100 is used, for example, in a battery pack in an electric vehicle. However, those skilled in the art will understand that the explosion-proof ventilation valve 100 can be used as needed in any other suitable application without departing from the scope of this disclosure.

[0045] According to one example, the explosion-proof ventilation valve 100 may include: a top cover 1; a valve body 3 engaged with the top cover 1; a membrane 2; a first inlet valve assembly 110; a second ventilation valve assembly 120; and a filter assembly.

[0046] Membrane 2 is impermeable to water but permeable to gas. Membrane 2 is disposed on top of valve body 3 and below top cover 1. According to one example, membrane 2 may be disposed on the top surface 34 of valve body 3; those skilled in the art will understand that membrane 2 may be disposed in any other suitable location without departing from the scope of this disclosure. Membrane 2 may be fixed to valve body 3 by any suitable means, such as by adhesive. Membrane 2 may be made of a microporous material. The micropores in the material allow gas to pass through membrane 2 but prevent water vapor from passing through membrane 2. Specifically, membrane 2 may be made of, for example, perfluorosulfonic acid; however, those skilled in the art will understand that membrane 2 may be formed from any other suitable material as needed without departing from the scope of this disclosure. A hydrophobic coating may be disposed thereon on membrane 2. This hydrophobic coating prevents water vapor in ambient air from entering the filter assembly, thereby extending the service life of the filter assembly.

[0047] The top cover 1 may include a top wall and a cover hole 12 extending through the top wall. According to one example, the top cover 1 may be provided with one cover hole 12; however, those skilled in the art will understand that, without departing from the scope of this disclosure, the top cover 1 may be provided with any suitable number of cover holes 12 (such as 2, 3, 4, etc.). Furthermore, the multiple cover holes 12 may be arranged in any suitable pattern.

[0048] The valve body 3 is detachably mounted to the top cover 1. According to one example, the top cover 1 may be provided with a plurality of resilient lugs 11 extending downward from the top cover 1, and the valve body 3 may be provided with a corresponding plurality of protrusions 31. Each resilient lug 11 may include a through hole 14. The resilient lug 11 may slide on a corresponding protrusion 31 on the valve body 3, and then cause the protrusion 31 to engage with the through hole 14, thereby holding the top cover 1 and the valve body 3 in place. Those skilled in the art will understand that the valve body 3 may be detachably mounted to the top cover 1 by any other suitable means without departing from the scope of this disclosure.

[0049] The valve body 3 is provided with a plurality of fastening holes 32. According to one example, the valve body 3 is provided with two fastening holes 32 at its opposite ends. However, those skilled in the art will understand that the valve body 3 may be provided with any other suitable number of fastening holes 32 without departing from the scope of this disclosure.

[0050] The filter assembly is detachably mounted below the valve body 3. The filter assembly includes: a filter housing 10 defining a filter space, a filter cover 6 detachably mounted on the filter housing 10, a first filter element 9 disposed in the filter space, a second filter element 8 disposed above the first filter element 9 in the filter space, and a third filter element 7 disposed above the second filter element 8 in the filter space.

[0051] The filter cover 6 may include a grid cover body having a plurality of filter cover orifices 62, and a circumferential filter groove 61 disposed in the circumferential outer surface of the cover body and configured to receive the filter seal 5. The filter housing 10 may also include a grid base plate having a plurality of filter housing orifices 102 to allow gas to pass through the filter assembly.

[0052] The first filter element 9 may include a first mesh with a first mesh size, the second filter element 8 may include a second mesh with a second mesh size, and the third filter element 7 may include a third mesh with a third mesh size, wherein the second mesh size is smaller than the first mesh size, and the third mesh size is smaller than the second mesh size. The third filter element 7 may include an adsorbent for adsorbing harmful gases. Those skilled in the art will understand that, without departing from the scope of this disclosure, the filter assembly may include any other suitable number of filter elements (e.g., 2, 4, etc.) as needed. Furthermore, the relative positions of the first filter element 9, the second filter element 8, and the third filter element 7 may be adjusted; for example, the positions of the first filter element 9 and the second filter element 8 may be interchanged, or the filter element 7 may be disposed below the first filter element 9 and the second filter element 8.

[0053] With the help of a filtration component, toxic gases, particulate matter and / or metal fragments can be reliably filtered out in the event of a thermal runaway event in the battery pack.

[0054] The filter assembly is pre-installed as a module and can be easily installed onto the valve body 3, thus facilitating the assembly and replacement of the filter assembly.

[0055] By means of multi-stage filtration of the filter assembly, particles, liquids and / or harmful gases of different sizes can be reliably filtered out or adsorbed, and larger particles can be intercepted in the first filter element 9 of the filter assembly to prevent the second or third filter element from clogging, ensuring that the exhaust gas flows unimpeded during thermal runaway events and thus avoiding the explosion of the battery pack.

[0056] With the help of the filter assembly, the mesh size of the first filter element 9, the second filter element 8 and the third filter element 7 can be flexibly adjusted according to the different volumes of exhaust gas generated by different types of battery packs, and the quantity, nature and size of the particulate matter contained in the exhaust gas.

[0057] Figure 2 for Figure 1 A schematic cross-sectional view of the explosion-proof ventilation valve 100, wherein the explosion-proof ventilation valve 100 is neither in the air intake mode nor in the ventilation mode, the first air intake valve assembly 110 is in the closed state, and the second ventilation valve assembly 120 is also in the closed state. Figure 3 This is an exploded schematic view of an example first intake valve assembly 110 according to an embodiment. Figure 4 This is an exploded schematic view of an example second ventilation valve assembly 120 according to an embodiment.Figure 5 This is a schematic perspective view of an example valve body 3 according to an embodiment. Figure 6 for Figure 5 A schematic top view of valve body 3.

[0058] The valve body 3 is provided with a first mounting portion 36 and a second mounting portion 136. The first intake valve assembly 110 is mounted to the first mounting portion 36 in a first mounting direction 210, and the second ventilation valve assembly 120 is mounted to the second mounting portion 136 in a second mounting direction 220 opposite to the first mounting direction 210.

[0059] The second ventilation valve assembly 120 can be used as a ventilation valve, and the first air intake valve assembly 110 can be used as an air intake valve. The second ventilation valve assembly 120 can be larger than the first air intake valve assembly 110. Therefore, while ensuring the normal operation of the explosion-proof ventilation valve 100, the overall cost of the explosion-proof ventilation valve 100 is saved.

[0060] The valve body 3 may be provided with a circumferential valve body groove 33 located on the bottom surface of the valve body 3 and configured to receive the valve body seal 4, wherein the circumferential valve body groove 33 is located at a certain distance from the filter assembly outward.

[0061] The valve body seal 4 may include an annular body, an inner circumferential lip 41 extending radially inward from the annular body, and an outer circumferential lip 42 extending radially outward from the annular body. Those skilled in the art will understand that the valve body seal 4 may be any other suitable structure without departing from the scope of this disclosure.

[0062] Based on an example, such as Figure 3 As shown, the first intake valve assembly 110 may include a first upper member 111, a first lower member 119, and a first compression spring 118 disposed between the first upper member 111 and the first lower member 119. Those skilled in the art will understand that the first intake valve assembly 110 may be any other suitable structure without departing from the scope of this disclosure.

[0063] The elastic constant of the first compression spring 111 can be adjusted according to different application scenarios and the need for emergency release of internal pressure, thus exhibiting excellent scalability.

[0064] The first upper member 111 may include: a first valve plate, a first circumferential groove 112 for receiving a first valve seal 115, a plurality of first upper guide portions 114 extending radially outward from the first upper member 111, and a first upper cylindrical portion 113 extending downward from the first valve plate.

[0065] The first lower member 119 may include: a first support plate 215 having at least one air inlet 141, a first lower cylindrical portion 216 extending upward from the first support plate 215, and a plurality of first lower guide portions 117 extending upward around the outer edge of the first support plate 215, the first lower cylindrical portion 216 defining an axially extending first central hole 116 for receiving a first upper cylindrical portion 113. The plurality of first upper guide portions 114 and the plurality of first lower guide portions 117 are arranged circumferentially staggered with each other.

[0066] The first mounting portion 36 includes: a first valve seat 161 having a first valve orifice 162, and a plurality of pairs of first axial guide fins (not shown) extending radially inward from the inner wall of the first mounting portion; a first compression spring 118 is configured to bias a first valve plate into contact with the first valve seat 161 in a fluid-impermeable manner; each first upper guide portion 114 is axially slidable between a corresponding pair of first axial guide fins along a first upper guide gap; and each first lower guide portion 117 is axially slidable between an adjacent pair of first axial guide fins along a first lower guide gap.

[0067] With the help of the first axial guide fin shared by the first lower guide portion 117 and the first upper guide portion 114, the first intake valve assembly 110 can be reliably positioned and guided in the valve body 3 with a simple structure, and saves costs compared to having guide fins on the upper and lower guide portions.

[0068] The first lower member 119 may further include a first circumferential resilient lip 151 extending radially outward around the outer edge of the first support plate 215; the first mounting portion 36 includes a first circumferential protrusion extending radially inward from the bottom of the inner wall of the mounting portion 36. In this respect, the first intake valve assembly 110 can be reliably mounted to the first mounting portion 36. Those skilled in the art will understand that the first intake valve assembly 110 can be mounted to the first mounting portion 36 by any other suitable means without departing from the scope of this disclosure.

[0069] The second ventilation valve assembly 120 may have a structure similar to that of the first intake valve assembly 110, for example, as Figure 4 As shown, the second ventilation valve assembly 120 may include a second upper member 129, a second lower member 219, and a second compression spring 128 disposed between the second upper member 129 and the second lower member 219. Those skilled in the art will understand that the second ventilation valve assembly 120 may be any other suitable structure without departing from the scope of this disclosure.

[0070] The elastic constant of the second compression spring 128 can be adjusted according to different application scenarios and emergency release requirements of internal pressure, thus exhibiting excellent scalability.

[0071] The second lower member 219 may include: a second valve plate 121, a second circumferential groove 122 for receiving a second valve seal 125, a plurality of second lower guide portions 124 extending radially outward from the second lower member 219, and a second lower cylindrical portion 123 extending upward from the second valve plate 121.

[0072] The second upper member 129 may include: a second support plate 225 having at least one ventilation hole 142, a second upper cylindrical portion 226 extending downward from the second support plate 225, and a plurality of second upper guide portions 127 extending downward around the outer edge of the second support plate 225, the second upper cylindrical portion 226 defining an axially extending second central hole 126 for receiving a second lower cylindrical portion 123, the plurality of second upper guide portions 127 and the plurality of second lower guide portions 124 being arranged circumferentially staggered with each other.

[0073] The second mounting portion 136 may include: a second valve seat 39 having a second valve orifice 160, and a plurality of pairs of second axial guide fins 237 extending radially inward from the inner wall of the second mounting portion 136, a second compression spring 128 configured to bias a second valve plate 121 into contact with the second valve seat 39 in a fluid-impermeable manner, each second lower guide portion 124 being axially slidable between a corresponding pair of second axial guide fins 237 along a second lower guide gap 37, and each second upper guide portion 127 being axially slidable between an adjacent pair of second axial guide fins 237 along a second upper guide gap 35.

[0074] With the help of the second axial guide fin 237 shared by the second lower guide portion 124 and the second upper guide portion 127, the second ventilation valve assembly 120 can be reliably positioned and guided in the valve body 3 with a simple structure, saving costs compared to having separate guide fins for the second lower guide portion 124 and the second upper guide portion 127.

[0075] The second upper member 129 may further include a second circumferential resilient lip 152 extending radially outward around the outer edge of the second support plate 225, and the second mounting portion 136 includes a second circumferential protrusion 38 extending radially inward from the top of the inner wall of the second mounting portion 136. In this respect, the second ventilation valve assembly 120 can be reliably mounted to the second mounting portion 136. Those skilled in the art will understand that the second ventilation valve assembly 120 can be mounted to the second mounting portion 136 by any other suitable means without departing from the scope of this disclosure.

[0076] Figure 7 for Figure 1 A schematic cross-sectional view of the explosion-proof ventilation valve 100, wherein the explosion-proof ventilation valve 100 is in ventilation mode, the first air inlet valve assembly 110 is in the closed state, and the second ventilation valve assembly 120 is in the open state.

[0077] When the internal pressure of the battery pack is higher than the ambient pressure by a first threshold, the pressure difference will overcome the force of the second compression spring 128, thereby pushing the second valve plate 121 away from the second valve seat 39, and thus putting the explosion-proof ventilation valve 100 into ventilation mode. This first threshold depends on the elastic constant of the second compression spring 128. In ventilation mode, the gas inside the battery pack flows out to the environment along the arrow, specifically, the gas flows through the filter housing orifice 102, the first filter element 9, the second filter element 8, the third filter element 7, the filter cover orifice 62, the ventilation hole 142 of the second ventilation valve assembly 120, the space 13 between the top cover 1 and the membrane 2, and thus flows out to the environment through the cover hole 12.

[0078] Figure 8 for Figure 1 A schematic cross-sectional view of the explosion-proof ventilation valve 100, wherein the explosion-proof ventilation valve 100 is in the air intake mode, the first air intake valve assembly 110 is in the open state, and the second ventilation valve assembly 120 is in the closed state.

[0079] When the internal pressure of the battery pack is lower than the ambient pressure by a second threshold, the pressure difference will overcome the force of the first compression spring 118, thereby pushing the first valve plate away from the first valve seat 161, and thus putting the explosion-proof ventilation valve 100 into the intake mode. This second threshold depends on the elastic constant of the first compression spring 118. In the intake mode, ambient air flows into the battery pack along the arrow, specifically, through the cover hole 12, the space 13 between the top cover 1 and the membrane 2, the intake hole 141 of the first intake valve assembly 110, the filter cover orifice 62, the third filter element 7, the second filter element 8, the first filter element 9, the filter housing orifice 102, and thus into the battery pack.

[0080] In another aspect, a battery pack is provided. The battery pack includes: a battery housing; at least one battery cell disposed in the battery housing; and an explosion-proof ventilation valve device 100 mounted to the battery housing.

[0081] This disclosure has been described in detail with reference to illustrated embodiments; however, those skilled in the art will understand that numerous modifications can be made thereto without departing from the scope of this disclosure. This disclosure is not limited to the precise construction and composition disclosed herein; any modifications, variations, and variants apparent from the foregoing description are within the scope of the disclosure defined by the appended claims. Furthermore, this disclosure expressly includes all combinations and sub-combinations of the foregoing elements and features.

Claims

1. An explosion-proof ventilation valve (100) comprising: a top cover (1) comprising a cover hole (12); a valve body (3) detachably mounted to the top cover (1), the valve body (3) comprising a first mounting portion (36) and a second mounting portion (136); a water-impermeable and gas-permeable membrane (2) disposed between the valve body (3) and the top cover (1); a first air inlet valve assembly (110) mounted to the first mounting portion (36) in a first mounting direction (210); a second ventilation valve assembly (120) mounted to the second mounting portion (136) in a second mounting direction (220) opposite to the first mounting direction (210); and a filter assembly detachably mounted to the valve body (3), the filter assembly comprising: a filter housing (10) defining a filter space; a filter cover (6) detachably mounted to the filter housing (10); a first filter element (9) disposed in the filter space; a second filter element (8) disposed on the first filter element (9) in the filter space; and a third filter element (7) disposed on the second filter element (8) in the filter space.

2. The explosion-proof ventilation valve (100) according to claim 1, wherein the first filter element (9) comprises a first mesh having a first mesh size, the second filter element (8) comprises a second mesh having a second mesh size smaller than the first mesh size, and the third filter element (7) comprises a third mesh having a third mesh size smaller than the second mesh size and comprising a sorbent for adsorbing harmful gases.

3. The explosion-proof ventilation valve (100) according to claim 1, wherein the membrane (2) comprises a hydrophobic coating thereon.

4. The explosion-proof ventilation valve (100) according to claim 1, wherein the top cover (1) comprises a plurality of resilient lugs (11) extending downwardly from the top cover (1), each of the plurality of resilient lugs (11) comprising a through hole (14), the valve body (3) comprises a plurality of protrusions (31) corresponding to the plurality of resilient lugs (11), and the plurality of resilient lugs (11) are respectively slidable on the plurality of protrusions (31) on the valve body (3), and then each of the plurality of protrusions (31) is snapped into the through hole (14) of a corresponding one of the plurality of resilient lugs (11) and holds the top cover (1) and the valve body (3) in place.

5. The explosion-proof ventilation valve (100) according to claim 1, wherein the second ventilation valve assembly (120) is larger than the first air inlet valve assembly (110).

6. The explosion-proof ventilation valve (100) according to claim 5, wherein the first air inlet valve assembly (110) comprises: a first upper member (111); a first lower member (119); and a first compression spring (118) disposed between the first upper member (111) and the first lower member (119). ​ ​ 7. The explosion vent valve (100) of claim 6, wherein the first upper member (111) includes a first valve plate, a first circumferential slot (112) for receiving a first valve seal (115), a plurality of first upper guide portions (114) extending radially outward from the first upper member, and a first upper cylindrical portion (113) extending downward from the first valve plate; the first lower member (119) includes a first support plate (215) having at least one air inlet aperture (141), a first lower cylindrical portion (216) extending upward from the first support plate (215), and a plurality of first lower guide portions (117) extending upward around an outer periphery of the first support plate (215), the first lower cylindrical portion (216) defining an axially extending first central aperture (116) for receiving the first upper cylindrical portion (113), and the plurality of first upper guide portions (114) and the plurality of first lower guide portions (117) are circumferentially interleaved with each other; and the first mounting portion (36) includes a first valve seat (161) having a first valve orifice (162), and a plurality of pairs of first axial guide fins extending radially inward from an inner wall of the first mounting portion (36), the first compression spring (118) for biasing the first valve plate in fluid-tight abutment with the first valve seat (161), each of the plurality of first upper guide portions (114) is axially slidable along a first upper guide gap between a respective pair of the first axial guide fins, and each of the plurality of first lower guide portions (117) is axially slidable along a first lower guide gap between an adjacent pair of the first axial guide fins.

8. The explosion vent valve (100) of claim 7, wherein the first lower member (119) further includes a first circumferential resilient lip (151) extending radially outward around an outer periphery of the first support plate (215), the first mounting portion (36) includes a first circumferential protrusion extending radially inward from a bottom of the inner wall of the first mounting portion (36).

9. The explosion vent valve (100) of claim 5, wherein the second vent valve assembly (120) includes: a second upper member (129); a second lower member (219); and a second compression spring (128) disposed between the second upper member (129) and the second lower member (219).

10. The explosion vent valve (100) of claim 9, wherein: the second lower member (219) includes a second valve plate (121), a second circumferential slot (122) for receiving a second valve seal (125), a plurality of second lower guide portions (124) extending radially outward from the second lower member, and a second lower cylindrical portion (123) extending upward from the second valve plate (121); ​ The second upper member (129) includes a second support plate (225) having at least one vent hole (142), a second upper tubular portion (226) extending downwardly from the second support plate (225), the second upper tubular portion (226) defining an axially extending second central bore (126) to receive the second lower tubular portion (123), and a plurality of second upper guide portions (127) extending downwardly around an outer periphery of the second support plate (225), the plurality of second upper guide portions (127) and the plurality of second lower guide portions (124) being circumferentially interleaved with each other; and The second mounting portion (136) includes a second valve seat (39) having a second valve orifice (160), and a plurality of pairs of second axial guide fins (237) extending radially inwardly from an inner wall of the second mounting portion (136), the second compression spring (128) biasing the second valve plate (121) to sealingly abut the second valve seat (39), each of the plurality of second lower guide portions (124) being axially slidable along a second lower guide gap (37) between a respective pair of the second axial guide fins (237), and each of the plurality of second upper guide portions (127) being axially slidable along a second upper guide gap (35) between adjacent pairs of the second axial guide fins (237).

11. The explosion venting valve (100) of claim 10, wherein the second upper member (129) further includes a second circumferential resilient lip (152) extending radially outwardly around an outer periphery of the second support plate (225), the second mounting portion (136) includes a second circumferential protrusion (38) extending radially inwardly from a top of an inner wall of the second mounting portion (136).

12. The explosion venting valve (100) of claim 1, wherein the filter cover (6) includes: a grid cover body including a plurality of filter cover orifices (62); and a circumferential filter groove (61) including a circumferential outer surface of the grid cover body and configured to receive a filter seal (5).

13. The explosion venting valve (100) of claim 1, wherein the valve body (3) includes a circumferential valve body groove (33) disposed at a bottom surface of the valve body (3) and configured to receive a valve body seal (4), the circumferential valve body groove (33) being further disposed at a distance outwardly from the filter assembly.

14. The explosion venting valve (100) of claim 13, wherein the valve body seal (4) includes: an annular body; an inner circumferential lip (41) extending radially inwardly from the annular body; and an outer circumferential lip (42) extending radially outwardly from the annular body.

15. A battery pack comprising: a battery housing; at least one battery cell disposed in the battery housing; and the explosion venting valve device (100) of claim 1 and mounted to the battery housing. ​ ​ ​

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