An exhaust valve and an electric vehicle

Abstract

This invention provides an exhaust valve for venting and depressurizing equipment, comprising a valve body, a valve seat, a spring, a piston, and a cylinder. The valve body includes an umbrella-shaped valve and a one-way valve. The umbrella-shaped valve has a breathable membrane and a hollow guide rod. The side wall of the hollow guide rod has several vent holes. The end of the hollow guide rod has a one-way valve fixing hole and an air inlet hole. The valve seat has an exhaust hole, a valve body mounting hole, a first spring support surface, and a valve body support surface. The umbrella-shaped valve is located on the valve body support surface. The hollow guide rod passes through the valve body mounting hole and is connected to the piston. The piston has a cylinder air inlet hole and a second spring support surface. The spring is located between the first spring support surface and the second spring support surface. The cylinder has a single-opening structure. The open end of the cylinder is fixedly connected to the valve seat. The spring and the piston are located inside the cylinder. The side wall of the cylinder near the valve seat has several air guide holes.

Description

Technical Field

[0001] This invention relates to the field of electric vehicles, and more specifically to an exhaust valve and an electric vehicle. Background Technology

[0002] Electric vehicles (BEVs) are vehicles that use onboard power sources to drive their wheels with electric motors and meet all road traffic and safety regulations. The body of an electric vehicle can accommodate multiple battery cells, which are further isolated from the occupants by a sealed cover. The sealed cover and the battery compartment of the vehicle body are relatively sealed, usually meeting the IP67 protection level. The purpose is to prevent the battery cells from being affected by external dust and liquids. However, the sealing also limits the ventilation rate between the battery compartment and the outside.

[0003] During charging and driving of electric vehicles, battery cells may overheat, be impacted, or compressed, potentially leading to thermal runaway. Thermal runaway involves the release of large amounts of gas and heat, causing a rise in pressure within the battery compartment. Excessive pressure on the sealed cover or the inflow of harmful gases into the passenger compartment can pose a hazard to occupants. To prevent the sealed battery compartment from experiencing excessive pressure and potentially exploding or leaking gas from the sealed cover, an active pressure relief valve is required to safely vent the gas from the battery compartment to the outside of the vehicle. Based on the structural characteristics and safety requirements of the battery compartment, the pressure relief valve must meet the following criteria: sealing performance, appropriate opening pressure, sufficiently large pressure relief cross-section, and automatic closure after the battery cell pressure relief is complete.

[0004] Currently, battery compartments mostly use spring-loaded or pin-type vent valves. The characteristic of spring-loaded vent valves is that the pressure relief cross-section increases with the valve opening stroke. As the opening stroke increases, the spring force that needs to be overcome also increases, resulting in higher pressure inside the battery compartment and low pressure relief efficiency. Pin-type vent valves have a larger burst pressure and poor consistency in burst pressure. After the vent membrane ruptures, the inside and outside of the compartment are connected, and a large amount of external oxygen enters the battery compartment and participates in the reaction, which can cause the battery compartment to burn again, resulting in low safety. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide an exhaust valve to solve the problems of low depressurization efficiency and low safety in the battery compartment depressurization process in the prior art.

[0006] This invention provides an exhaust valve for venting and depressurizing equipment, comprising a valve body, a valve seat, a spring, a piston, and a cylinder. The valve body includes an umbrella-shaped valve and a one-way valve. The umbrella-shaped valve has a breathable membrane and a hollow guide rod. The side wall of the hollow guide rod has several vent holes. The end of the hollow guide rod has a one-way valve fixing hole and an air inlet hole. The valve seat has an exhaust hole, a valve body mounting hole, a first spring support surface, and a valve body support surface. The umbrella-shaped valve is located on the valve body support surface. The hollow guide rod passes through the valve body mounting hole and is connected to the piston. The piston has a cylinder air inlet hole and a second spring support surface. The spring is located between the first spring support surface and the second spring support surface. The cylinder has a single-opening structure. The open end of the cylinder is fixedly connected to the valve seat. The spring and the piston are located inside the cylinder. The side wall of the cylinder near the valve seat has several air guide holes.

[0007] The beneficial effects of this invention are as follows: By configuring a valve body, valve seat, spring, piston, and cylinder, when the gas pressure inside the equipment changes within a normal range, the equipment can exchange gas with the outside through the air guide hole, vent hole, and breathable membrane; when the gas pressure inside the equipment abnormally increases drastically, the gas inside the equipment can exchange gas with the outside through the air guide hole, vent hole, and breathable membrane. Furthermore, the high-pressure gas inside the equipment applies a thrust to the inner surface of the valve body, overcoming the tension of the spring, causing the spring to stretch and separating the umbrella-shaped valve from the valve body support surface, creating a gap. The high-pressure gas inside the equipment then exchanges gas with the outside through the exhaust hole and the gap. The high-pressure gas is discharged at a faster rate. Furthermore, the high-pressure gas inside the equipment can enter the cylinder between the cylinder barrel and the piston through the air guide hole, air vent, one-way valve, air inlet, and cylinder air inlet. Through convection and thermal radiation, the gas temperature inside the cylinder rises, and the gas inside the cylinder expands due to heat, further pushing the piston to move. This increases the gap between the umbrella valve and the valve body support surface, increasing the flow cross-section of the gas inside the equipment and further accelerating the discharge rate of the high-pressure gas. After the high-pressure gas is discharged, under the action of the spring, the umbrella valve and the valve body support surface gradually close, the gap disappears, and the system returns to normal gas exchange state.

[0008] Preferably, the valve body further includes a protective cover, and the umbrella-shaped valve is also provided with an upper sealing surface, a lower sealing surface, a limiting surface, and a flange; the vent membrane is provided on the upper sealing surface, the limiting surface is in contact with the valve body support surface to limit the stroke of the valve body, the protective cover is provided on the flange, and the flange is provided with a plurality of vent holes along the circumference.

[0009] Preferably, the one-way valve includes a fixed post and a diaphragm disposed at one end of the fixed post. The fixed post is interference-fitted with the one-way valve fixing hole. A stop extends from the other end of the fixed post. The cross-sectional dimension of the stop is larger than that of the one-way valve fixing hole, and the cross-sectional dimension of the diaphragm is larger than that of the air inlet.

[0010] Preferably, the valve seat is further provided with a first sealing element receiving groove, a second sealing element receiving groove, and a fixing hole. A first sealing element is provided in the first sealing element receiving groove, and a second sealing element is provided in the second sealing element receiving groove. The first sealing element is in contact with the lower sealing surface, and the valve seat is fixed on the equipment through the fixing hole.

[0011] Preferably, the piston has an annular groove on its outer side wall, the cylinder inlet port has a coaxial mounting drive hole with a different cross-sectional shape at its end away from the valve seat, and a third seal is provided in the annular groove, the third seal being slidably connected to the inner wall of the cylinder.

[0012] Preferably, the surface of the third seal is provided with a lubricant, which is used to reduce the friction between the third seal and the inner wall of the cylinder.

[0013] Preferably, the hollow guide rod has an external thread, the cylinder inlet has an internal thread, and the hollow guide rod is connected to the piston by a thread.

[0014] Preferably, the outer wall of the cylinder near the closed end is provided with a plurality of heat dissipation fins along the circumferential direction.

[0015] Preferably, the one-way valve is made of silicone.

[0016] Another aspect of the present invention provides an electric vehicle including the above-described exhaust valve.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] Figure 1 This is an exploded structural diagram of the exhaust valve according to the first embodiment of the present invention;

[0019] Figure 2 This is a schematic cross-sectional view of the valve body of the exhaust valve according to the first embodiment of the present invention;

[0020] Figure 3 This is a first-view structural diagram of the valve body of the exhaust valve according to the first embodiment of the present invention;

[0021] Figure 4 This is a second-view structural diagram of the valve body of the exhaust valve according to the first embodiment of the present invention;

[0022] Figure 5 This is a schematic diagram of the piston structure of the exhaust valve according to the first embodiment of the present invention;

[0023] Figure 6 This is a first-view structural schematic diagram of the valve seat of the exhaust valve according to the first embodiment of the present invention;

[0024] Figure 7 This is a second-view structural schematic diagram of the valve seat of the exhaust valve according to the first embodiment of the present invention;

[0025] Figure 8 This is a schematic cross-sectional view of the valve seat of the exhaust valve according to the first embodiment of the present invention;

[0026] Figure 9 This is a partially enlarged cross-sectional view of the exhaust valve body according to the first embodiment of the present invention;

[0027] Figure 10 This is a partially enlarged cross-sectional view of the one-way valve intake state of the exhaust valve according to the first embodiment of the present invention;

[0028] Figure 11 This is a schematic diagram of the gas exchange profile of the exhaust valve under normal operating conditions according to the first embodiment of the present invention;

[0029] Figure 12 This is a schematic diagram of the gas exchange profile under abnormal operating conditions of the exhaust valve in the first embodiment of the present invention;

[0030] Figure 13 The curves showing the changes in gas temperature, valve body opening stroke, and pressure inside the cylinder of the internal exhaust valve in the first embodiment of the present invention are shown.

[0031] Figure 14 This is a schematic diagram of the exhaust valve according to the second embodiment of the present invention;

[0032] Figure 15 This is a cross-sectional schematic diagram of the exhaust valve according to the second embodiment of the present invention;

[0033] Figure 16 A schematic diagram of the structure of the device for which the exhaust valve of the present invention is installed;

[0034] Figure 17 A partial cross-sectional structural diagram of the device for which the exhaust valve of the present invention is installed;

[0035] Figure 18 A schematic diagram of an electric vehicle equipped with an exhaust valve according to the present invention;

[0036] Figure 19 A partial cross-sectional view of an electric vehicle equipped with an exhaust valve according to the present invention;

[0037] Explanation of key component symbols:

[0038]

[0039]

[0040] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0041] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0042] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] like Figures 1 to 13 As shown, the exhaust valve 1 of the first embodiment of the present invention is used to exhaust and relieve pressure on the device 2. The exhaust valve 1 includes: a valve body 11, a valve seat 12, a spring 13, a piston 14, and a cylinder 15; as shown Figure 2 , Figure 3 , Figure 4 and Figure 9 As shown, the valve body 11 includes an umbrella-shaped valve 111, a breathable membrane 112, a protective cover 113, and a one-way valve 114. The umbrella-shaped valve 111 has a hollow guide rod 1111, an upper sealing surface 1112, a lower sealing surface 1113, a limiting surface 1114, a flange 1115, and a vent hole 1116. The wall surface of the hollow guide rod 1111 of the umbrella-shaped valve 111 has one or more vent holes 1117. The umbrella-shaped valve 111 has a one-way valve fixing hole 1118 and an air inlet 1119, which cooperate with the one-way valve 114 to achieve a one-way air intake function. The one-way valve 114 has a fixing post 1142 and a diaphragm 1141. The fixing post 1142 cooperates with the one-way valve fixing hole 1118 of the umbrella-shaped valve 111 to fix the one-way valve 114 to the umbrella-shaped valve 111.

[0045] The one-way valve 114 can be constructed from a high-temperature resistant, flexible material; alternatively, the one-way valve 114 can be constructed from silicone, which has a temperature resistance of up to 350°C. This helps prevent the exhaust valve 114 from melting or sticking to the umbrella valve 111 in high-temperature environments. On the other hand, the elastomeric properties of silicone facilitate the interference fit of the fixing post 1142 into the one-way valve fixing hole 1118 of the umbrella valve 111. It is easy to understand that although the diameter of a portion of the fixing post 1142 is larger than the diameter of the one-way valve fixing hole 1118, the easily deformable fixing post 1142 can still be easily inserted into the one-way valve fixing hole 1118 and fixed. Figure 10 When air is introduced through the air inlet 1119, the diaphragm 1141 of the one-way valve 114 can swing open to reduce the intake resistance. Figure 10 Figure A2 illustrates the air intake path when the diaphragm 1141 of the one-way valve 114 is open. When air is not entering through the air intake port 1119, the diaphragm 1141 of the one-way valve 114 adheres to the bottom surface of the umbrella valve 111, increasing the resistance to gas discharge from the air intake port 1119. Figure 9 Figure A1 illustrates the path of gas exiting from the inlet port 1119. At this point, the diaphragm 1141 of the one-way valve 114 is closed. Although the one-way valve 114 and the umbrella valve 111 do not form an absolute seal, the tight fit between the diaphragm 1141 and the umbrella valve 111 results in a small gas flow cross-section and correspondingly high exhaust resistance. This means that gas can only pass through the one-way valve 114 at a very small flow rate. It should be understood that the prior art supports various construction methods for the one-way valve 114; the above is only one implementation method.

[0046] A breathable membrane 112 is installed on the upper sealing surface 1112 of the umbrella valve 111. After the exhaust valve 1 is installed in the equipment, the internal space 111a of the umbrella valve 111 can exchange with the external gas through the breathable membrane 112. At the same time, the breathable membrane 112 prevents external liquid from entering the internal space 111a of the umbrella valve 111. The internal space 111a is connected to the vent hole 1117 on the wall of the hollow guide rod 1111. That is, the gas in the vent hole 1117 can be discharged to the outside of the exhaust valve 1 through the breathable membrane 112, and the gas outside the exhaust valve 1 can also enter the vent hole 1117 through the breathable membrane 112. The inflow or outflow of gas is driven by the pressure difference on both sides of the breathable membrane 112. Preferably, the breathable membrane 112 is made of expanded polytetrafluoroethylene (ePTFE) membrane, which has good air permeability and can block liquid water and oil from passing through; alternatively, the breathable membrane 112 is fixed to the upper sealing surface 1112 of the umbrella valve 111 by bonding or welding.

[0047] The protective cover 113 is installed on the flange 1115 of the umbrella valve 111. The connection between the protective cover 113 and the flange 1115 can be welding, bonding, etc. The protective cover 113 is used to prevent the breathable membrane 112 from being disturbed by unexpected foreign objects or impact forces, such as water flow impact or puncture by sharp objects. The protective cover 113 prevents the external high-pressure water flow from directly impacting the breathable membrane 112, thereby preventing the breathable membrane 112 from being ruptured during the high-pressure water gun impact test, and further facilitating the exhaust valve 1 to pass the IPX9K protection level test. The flange 1115 is provided with one or more vent holes 1116 to enable communication between the cavity 113a between the protective cover 113 and the breathable membrane 112 and the outside of the umbrella valve 111. Figure 11 The dashed arrow K1 in the middle indicates the gas flow path in the breathable state. It is easy to understand that the gas can also flow in the opposite direction of the dashed arrow K1, which depends on the pressure difference on both sides of the breathable membrane 112.

[0048] like Figure 6 , Figure 7 and Figure 8 As shown, the valve seat 12 is provided with an exhaust hole 121, a valve body mounting hole 122, a first sealing element receiving groove 123, a second sealing element receiving groove 124, a first sealing element 125, a second sealing element 126, a fixing hole 127, a first spring support surface 128, and a valve body support surface 129; the first sealing element 125 is installed in the first sealing element receiving groove 123, and the second sealing element 126 is installed in the second sealing element receiving groove 124.

[0049] like Figure 5 , Figure 12 The piston 14 includes a piston body 141 and a third seal 142. The piston body 141 has an annular groove 1411, a cylinder inlet port 1412, a mounting drive part 1413, and a second spring support surface 1414. The third seal 142 is mounted in the annular groove 1411 of the piston body 141. Optionally, the mounting drive part 1413 can be a hexagonal hole, which can cooperate with an Allen wrench and be driven to rotate by the Allen wrench.

[0050] like Figure 11The outer surface of the hollow guide rod 1111 of the umbrella-shaped valve 111 mates with the valve body mounting hole 122 on the valve seat 12, forming a slidable connection. Preferably, the hollow guide rod 1111 and the valve body mounting hole 122 are clearance-fitted. The hollow guide rod 1111 has a first fixing port at the end away from the limiting surface 1114, and the first fixing port is connected to the piston 14. The hollow guide rod 1111 and the piston 14 can be connected by means of bonding, snap-fit, or threaded connection. For example, the first fixing port has an external thread, and the cylinder inlet hole 1412 of the piston body 141 of the piston 14 has an internal thread, that is, the cylinder inlet hole 1412 is partially constructed as a nut. The piston 14 is further driven to rotate by an Allen wrench and the piston 14 is tightened onto the hollow guide rod 1111; that is, the piston 14 and the valve body 11 are fixedly connected.

[0051] Combination Figure 11 Spring 13 is located between valve seat 12 and piston 14. The two ends of spring 13 are in contact with the first spring support surface 128 of valve seat 14 and the second spring support surface 1414 of piston 14, respectively. After piston 14 is connected to valve body 11, spring 13 is in a compressed state. The first rebound force F1 of the spring 13 is applied to the second spring support surface 1414 of the piston 14 and further pushes the limiting surface 1114 of the umbrella valve 111 to fit against the valve body support surface 129 of the valve seat 12 through the hollow guide rod 1111 fixedly connected to the piston 14. As defined by the geometric dimensions of the umbrella valve 111 and the valve seat 12, when the limiting surface 1114 of the umbrella valve 111 fits against the valve body support surface 129 of the valve seat 12, the lower sealing surface 1113 of the umbrella valve 111 cooperates with the first seal 125 and compresses the first seal 125 to a suitable size, for example, compressing the height of the first seal 125 by 30%, further satisfying the sealing requirements of the first sealing surface constructed by the lower sealing surface 1113 of the umbrella valve 111 and the first seal 125, for example, no water seepage after immersion in 1 meter of water for 24 hours. Preferably, the first sealing element 125 is made of an elastomer material such as rubber or silicone, meaning that the first sealing element 125 is easily compressed and deformed, and after being compressed and deformed, it generates a continuous rebound force on the lower sealing surface 1113. Under the action of the above-mentioned rebound force, the first sealing element 125 tightly fits the lower sealing surface 1113, thereby achieving a sealing function. It should be understood that the first rebound force F1 should be large enough to prevent the valve body 11 from separating from the valve seat under the action of vibration and impact. For example, if the mass of the valve body 11 is 40 grams, and the valve body 11 may be subjected to vibration and impact with an acceleration of 30 m / s², then the first rebound force F1 should be greater than 1.2 N.

[0052] like Figure 11 , Figure 12 As shown, the cylinder 15 moves along the axis of the hollow guide rod 1111 towards the opening direction of the valve body 11. Figure 12The piston 14 is installed (in the direction shown in X1) and placed inside the cylinder 15. The inner wall of the cylinder 15 is press-fitted with the third seal 142 of the piston 14, forming a slidable connection between them, i.e., the third seal 142 is in a compressed state inside the cylinder 15; preferably, the third seal 142 is made of silicone material. Optionally, the third seal 142 is compressed by 20% inside the cylinder 15 to ensure that the piston 14 slides relative to the cylinder 15 with less frictional resistance, while avoiding air leakage between the third seal 142 and the inner wall of the cylinder 15. The piston 14, the one-way valve 114, and the inner wall of the cylinder 15 are configured as a cylinder 15a. The one-way valve 114 makes the intake resistance of the cylinder 15a small and the exhaust resistance large, i.e., the cylinder 15a has a small leakage flow. Preferably, the inner wall of the cylinder 15 has a small surface roughness, i.e., the inner wall of the cylinder 15 is smooth to reduce the frictional resistance of the piston 14 sliding relative to the cylinder 15. Preferably, a suitable amount of lubricant is applied to the surface of the third seal 142 to reduce the frictional resistance of the piston 14 sliding relative to the cylinder 15. On the other hand, the lubricant helps to improve the sealing performance between the third seal 142 and the inner wall of the cylinder 15, which is beneficial to improving the sealing performance of the cylinder 15a. The wall of the cylinder 15 is provided with one or more air guide holes 151, which are located outside the range of the piston 14's stroke. That is, the piston 14 will not contact the air guide holes 151 when sliding relative to the cylinder 15, thus preventing air leakage from the cylinder 15a. It is easy to understand that the normal sliding stroke of the piston 14 is limited by the structure of the spring 13, the piston 14, the valve body 11, and the valve seat 12. The open end of the cylinder 15 is connected to the valve seat 12. Optionally, the open end of the cylinder 15 is welded to the first spring support surface 128 of the valve seat 12, thereby fixing the cylinder 15 and the valve seat 12 together.

[0053] In this embodiment, the device 2 is constructed into a sealed space by a housing 21 and a cover 22. The exhaust valve 1 is fixed to the housing 21 of the device 2 using a second fastener 25 through a fixing hole 127 on the valve seat 12. The second sealing member 126 and the housing 21 of the device 2 form a second sealing surface. The geometric dimensions of the second sealing member receiving groove 124 limit the installation state of the exhaust valve 1. The second sealing member 126 is compressed to a suitable size, for example, the height of the second sealing member 126 is compressed by 30%. Furthermore, the second sealing surface meets the waterproof sealing requirements. Specifically, in this embodiment, the device 2 is submerged in 1 meter of water for 24 hours without water seeping in from the second sealing surface. The breathable membrane 112, the first sealing surface, and the second sealing surface all meet the waterproof sealing requirements, thereby ensuring that the device 2 with the exhaust valve 1 installed will not suffer waterproof performance damage due to the exhaust valve 1. For example, the battery pack equipped with the exhaust valve 1 is required to be submerged in 1 meter of water for 24 hours without water seepage.

[0054] The housing 21 is equipped with an exhaust valve 1. When the gas pressure inside the equipment 2 changes within the normal range due to temperature changes, altitude changes, or other factors, the gas inside the equipment 2 exchanges gas with the outside of the equipment 2 through the air guide hole 151 of the cylinder 15 of the exhaust valve 1, then through the air vent 1117 of the hollow guide rod 1111, and further through the breathable membrane 112 and the breathable hole 1116. That is, gas flows into or out of the equipment 2 under the pressure difference between the inside and outside of the equipment 2, thereby ensuring that the pressure inside and outside of the equipment 2 is equal and preventing deformation or damage such as bulging or denting of the housing 21 or the cover 22 of the equipment 2. Specifically, in this embodiment, the internal and external pressure difference of device 2 is 1 kPa, and the air permeability rate of breathable membrane 112 is 0.5 L / min. As the internal and external pressure difference of device 2 increases, the air permeability rate of breathable membrane 112 increases. The air permeability characteristics of breathable membrane 112 can be described by the pressure-flow curve. The air permeability characteristics of breathable membrane 112 are determined by the microscopic characteristics of the material itself. Existing technology allows for the customization of breathable membrane 112 with different air permeability characteristics through the process. Figure 11 The dashed arrow K1 in the middle indicates the gas flow path in the breathable state. It is easy to understand that the gas can also flow in the opposite direction of the dashed arrow K1, which depends on the pressure difference on both sides of the breathable membrane 112.

[0055] Specifically, in this embodiment, the device 2 contains multiple battery cells 3, which are ternary lithium batteries. The battery cells 3 may experience thermal runaway due to overheating, mechanical abuse, short circuits, etc. The device 2 can be installed on an electric vehicle to provide power for the operation of the electric vehicle. The overheating may occur during the fast charging of the electric vehicle, the mechanical abuse may occur when the electric vehicle is bumped or mechanically penetrated during driving, and the short circuit may occur when the electric vehicle is squeezed or when a conductive medium enters the device 2. Thermal runaway of cell 3, accompanied by the release of a large amount of gas and heat, further increases the pressure inside device 2. For example, after thermal runaway of a 150Ah ternary lithium battery, 200L of gas is released within 15 seconds, and the temperature of the released gas may exceed 1000℃. When a rapid increase in temperature occurs inside device 2, which is equipped with exhaust valve 1, causing gas volume expansion or the generation of a large amount of gas, for example, at a gas generation rate of 800L / min, it is easy to understand that although the venting membrane 112 plays a role in venting, its venting rate is much lower than its gas generation rate, for example, at this time, the venting rate of the venting membrane 112 is 0.5L / min. The venting rate of the venting membrane 112 is insufficient to timely discharge the gas generated inside device 2, and correspondingly, the pressure inside device 2 will increase rapidly. Figure 11 , Figure 12 The pressure inside device 2 is applied to the inner surface of valve body 11, generating a first pushing force F2. The direction of the first pushing force F2 is opposite to the direction of the first rebound force F1 applied by spring 13 to piston 14. Specifically, the equivalent area S of the inner surface of valve body 11 that bears the air pressure is 5 cm².2 If the pressure P inside device 2 is 4 kPa, then the first pushing force F2 = S * P = 2 N. When the first pushing force F2 is greater than the first restoring force F1 of spring 13, for example, F2 is 2 N and F1 is 1.2 N, the first pushing force F2 overcomes the first restoring force F1 of spring 13 and pushes the valve body 11 to... Figure 12 The indicated movement in the X1 direction means that the lower sealing surface 1113 of the umbrella valve 111 moves away from the first seal 125, creating a gap of H1 between the lower sealing surface 1113 and the first seal 125, thus opening the pressure relief path of the exhaust valve 1. Figure 12 Arrow K2 indicates the gas flow path in the depressurized state. During the aforementioned movement, valve body 11 further compresses spring 13 via piston 14, and the further compressed spring 13 generates a second restoring force F3. That is, when the pressure inside device 2 reaches the opening threshold of exhaust valve 1, valve body 11 of exhaust valve 1 opens, allowing the gas inside device 2 to be discharged. This gas flows through the exhaust port 121 of valve seat 12 and further along the lower sealing surface 1113 of umbrella valve 111 to the outside of device 2; as... Figure 12 As shown, the gap height H1 between the lower sealing surface 1113 of the umbrella valve 111 and the first sealing element 125 restricts the flow cross section of gas discharge. The larger the gap height H1 between the lower sealing surface 1113 of the umbrella valve 111 and the first sealing element 125, the larger the flow cross section of gas discharge, that is, the greater the pressure relief rate under the same pressure conditions inside the device 2; conversely, the smaller the gap height H1, the smaller the flow cross section of gas discharge, that is, the smaller the pressure relief rate under the same pressure conditions inside the device 2. Based on the safety and cost requirements of the device 2, the desired effect is that the exhaust valve 1 has a sufficient pressure relief rate so that the housing 21 and the cover 22 of the device 2 can withstand the smallest possible pressure, because the design of the housing 21 and the cover 22 to be thinner and lighter is conducive to cost reduction and weight reduction.

[0056] The movement of the lower sealing surface 1113 of the umbrella-shaped valve 111 of the valve body 11 away from the first seal 125 causes the piston 14 to further compress the spring 13. This further compression of the spring 13 generates a second rebound force F3. When the first pushing force F2 and the second rebound force F3 are equal, the valve body 11 maintains its relative position to the valve seat 12 and no longer moves; that is, the valve body 11 is in a state of force equilibrium and remains stationary. In one embodiment, the stiffness coefficient μ of the spring 13 is 0.8 N / mm, the first pushing force F2 is 2 N, and the first rebound force F1 in the initial compressed state of the spring is 1.2 N. When the spring 13 generates the second rebound force F3 relative to the first rebound force F1, the compression is L. According to Hooke's Law, F3 = F1 + μ*L, meaning that when the spring 13 generates a compression of L of 1 mm, the first pushing force F2 and the second rebound force F3 are equal. Figure 12At this point, the displacement of the umbrella valve 111 is the same as the compression L generated by the spring 13, i.e., the gap height H1 = L. It should be understood that the gas / heat generation and pressure relief / exhaust inside the equipment 2 are a dynamic equilibrium process. As the pressure inside the equipment 2 changes, the first pushing force F2 changes accordingly. Under the combined action of the first pushing force F2 and the second rebound force F3, the valve body 11 will move relative to the valve seat 12 to a new relative position, i.e., the first pushing force F2 and the second rebound force F3 are equal. It is easy to understand that the compression L generated by the spring 13 changes during the movement of the valve body 11. The second rebound force F3 of the spring 13 restricts the movement position of the valve body 11, further restricting the gap height H1, i.e., restricting the pressure relief flow section of the exhaust valve 1.

[0057] like Figure 9 , Figure 10 , Figure 12 and Figure 17 As shown, during the opening process of the valve body 11, the piston 14 slides relative to the cylinder 15 along the opening direction of the valve body 11, that is, the piston 14 slides along the direction indicated by X1; during the movement of the piston 14, the gas passes through the air guide hole 151 of the cylinder 15, the air vent 1117 on the wall of the hollow guide rod 1111, further through the one-way valve 114, and then through the cylinder inlet hole 1412 in the middle of the piston 14 into the cylinder 15a; during the air intake process of the cylinder 15a, the diaphragm 1141 of the one-way valve 114 is as follows: Figure 10The indicated state is open, allowing gas to flow into cylinder 15a with low flow resistance. During the hot gas discharge process within device 2, the cylinder 15 is heated through convection and radiation heat exchange paths, further increasing the gas temperature within cylinder 15a. The heated gas expands, increasing the pressure within cylinder 15a, which in turn pushes piston 14 to slide relative to cylinder 15 along the opening direction of valve body 11. Valve body 11, connected to piston 14, also moves along the opening direction, meaning the gas expansion within cylinder 15a pushes valve body 11 further along the direction indicated by X1. Clearly, the process of the heated gas expanding within cylinder 15a and pushing piston 14 increases the gap between the lower sealing surface 1113 of the umbrella-shaped valve 111 of valve body 11 and the first sealing element 125, increasing the gas discharge flow cross-section. In other words, the pressure relief rate increases under the same pressure conditions within device 2, further reducing the gas discharge resistance within the outer casing 2 and / or increasing the gas discharge velocity, thereby preventing the casing 21 and cover 22 of device 2 from being subjected to excessive pressure and potentially exploding. On the positive side, the cylinder 15 heated by the hot airflow causes the gas inside the cylinder 15a to expand, which in turn pushes the valve body 11 through the piston 14 to increase the flow cross section for gas discharge. Under the constraint of the limited pressure relief rate, it is possible to reduce the pressure resistance requirements of the housing 21 and the cover 22 of the equipment 2. That is, the housing 21 and the cover 22 of the equipment 2 can be designed to be thinner and lighter while meeting the pressure resistance requirements. Therefore, it brings greater design freedom to the housing 21 and the cover 22 of the equipment 2 in terms of materials and thickness, thereby reducing weight and cost.

[0058] like Figure 9 , Figure 10 , Figure 12 , Figure 13 , Figure 16 and Figure 17As shown, device 2 is constructed as a sealed space by a housing 21 and a cover 22. The housing 21 and the cover 22 can be connected by multiple first fasteners 23. Preferably, a sealing medium is provided between the housing 21 and the cover 22. The housing 21 is provided with an exhaust valve 1. Optionally, the housing 21 is provided with a connector 24 for energy / signal transmission. The housing of device 2 contains multiple battery cells 3. Each battery cell 3 is provided with an explosion-proof valve 31. The multiple battery cells 3 form a high-voltage circuit in series / parallel configuration and transmit energy to the power-consuming / power-supplying equipment through the connector 24. For example, device 2 is installed on an electric vehicle to output electrical energy for the operation of the electric vehicle. After the energy stored in device 2 is consumed, it is replenished by a charging pile. The battery cells 3 may experience thermal runaway due to overheating, mechanical abuse, short circuit, etc. Thermal runaway of battery cells 3 is accompanied by the release of a large amount of gas and heat, which further increases the pressure inside the housing. The above-mentioned overheating may occur during the fast charging of electric vehicles. Mechanical abuse may occur when the electric vehicle is bumped or mechanically penetrated during driving. Short circuit may occur when the electric vehicle is squeezed or when a conductive medium enters device 2. When the pressure inside device 2 reaches the opening threshold of exhaust valve 1, the valve body 11 of exhaust valve 1 opens, allowing the gas inside device 2 to escape. The stiffness coefficient μ of the spring 13 of exhaust valve 1 is 0.8 N / mm, the initial rebound force F1 of spring 13 is 1.2 N, and the equivalent area S of the inner surface of valve body 11 that bears the air pressure is 5 cm². 2 Device 2 contains multiple battery cells 3, which are ternary lithium batteries. These cells experience thermal runaway due to overheating, mechanical abuse, or short circuits. After thermal runaway, the average gas production rate of a single cell within 25 seconds is 800 L / min. When the pressure inside device 2 reaches the opening threshold of exhaust valve 1, the valve body 11 of exhaust valve 1 opens, allowing the hot gas inside device 2 to escape. Figure 12 The middle arrow K2 indicates the flow path of the hot gas. Figure 17The diagram illustrates the process of gas being discharged from device 2 through exhaust valve 1; hot gas flows through the exhaust port 121 of valve seat 12 and further along the gap between the lower sealing surface 1113 of umbrella valve 111 and the first sealing element 125 to the outside of device 2; in the flow path of high-temperature gas flow, it exchanges heat with the cylinder 15 of exhaust valve 1 through convection and radiation, thereby heating the cylinder 15 of exhaust valve 1, further increasing the temperature of the gas in cylinder 15a; the gas in cylinder 15a expands due to heat, increasing the pressure in cylinder 15a, thereby pushing piston 14 to slide relative to cylinder 15 along the opening direction of valve body 11, and valve body 11 connected to piston 14 also moves along the opening direction of valve body, that is, the expansion of gas in cylinder 15a pushes valve body 11 to move further along the direction indicated by X1. Obviously, the process of the gas in cylinder 15a expanding due to heat and pushing the piston 14 to move increases the gap between the lower sealing surface 1113 of the umbrella valve 111 of valve body 11 and the first sealing element 125, thereby increasing the flow cross section of the gas discharge; that is, the pressure relief rate increases under the same pressure conditions in equipment 2, further reducing the gas discharge resistance and / or increasing the gas discharge velocity in equipment 2, thereby preventing the housing 21 and the cover 22 of equipment 2 from being subjected to too much pressure and causing an explosion.

[0059] Figure 13 Curve T illustrates the temperature change of the gas inside cylinder 15a. In this embodiment, the gas temperature inside cylinder 15a is heated from 35°C to a maximum of 177°C, which in turn causes the pressure inside cylinder 15a to increase. Curve P illustrates the pressure change inside cylinder 15a. The pressure inside cylinder 15a reaches 17 kPa. The diameter of piston 14 is 15 mm. At this time, the thrust F4 of piston 14 is 3 N, that is, the stroke h = F4 / μ = 3.75 mm is driven by the thermal expansion of the gas inside cylinder 15a to push piston 14. Figure 15 Curve L1 illustrates the valve body stroke in the comparative example. The difference between the comparative example and the embodiment is that the end of the hollow guide rod 1111 in the comparative example is sealed, without a one-way valve fixing hole 1118, and the air inlet 1119 does not contain a one-way valve 11. In the comparative example, the stroke of the piston 14 is only limited by the spring's restoring force. L2 illustrates the stroke of the valve body 11 in the embodiment. At time t1, the valve body stroke in the comparative example is h1, and the stroke of the valve body 11 in the embodiment is h2, where h2 = h1 + h. The process of the gas in the cylinder 15a expanding due to heat and pushing the piston 14 increases the stroke of the valve body 11, that is, it increases the gap between the lower sealing surface 1113 of the umbrella valve 111 and the first sealing member 125, thereby increasing the flow cross section for gas discharge. Figure 15 Curve S1 illustrates the pressure inside the comparative device, and curve S2 illustrates the pressure inside the device 2 of the embodiment. Since the valve body 11 of the embodiment has a larger stroke, the flow cross section for gas discharge is increased, which further reduces the gas discharge resistance inside the device 2, thereby reducing the pressure inside the device 2.

[0060] The device 2, which contains multiple battery cells 3, experiences thermal runaway and pressure relief for a single battery cell 3 for approximately 25 seconds. After the pressure relief of a single battery cell 3 ends, there is no longer a high-temperature airflow heating the cylinder 15 of the exhaust valve 1. Due to heat conduction and heat convection, the temperature of the cylinder 15 gradually decreases, further reducing the gas temperature inside the cylinder 15a. This results in a decrease in the pressure of the cylinder 15a, which in turn causes the piston 14 to slide relative to the cylinder 15 in the direction of valve body 11 closing. The valve body 11, connected to the piston 14, also moves in the direction of valve body 11 closing. Simultaneously, the one-way valve 114 causes a small flow of gas leakage in the cylinder 15a. Under the combined effects of cooling and leakage, the pressure inside the cylinder 15a gradually decreases. Spring 13 pushes piston 14 to slide relative to cylinder 15 along the closing direction of valve body 11, and valve body 11 connected to piston also moves along the closing direction of valve body 11; until the limiting surface 1114 of umbrella valve 111 fits against the valve body support surface 129 of valve seat 12, piston 14 and valve body 11 stop moving; the first rebound force F1 of spring 13 is applied to the second spring support surface 1414 of piston 14, at which time the lower sealing surface of umbrella valve 111 cooperates with the first sealing element 125 of 1113 and compresses the first sealing element 125 by a set ratio, for example, compressing the first sealing element 125 by 30%, that is, the valve body 11 of exhaust valve 1 is closed, further restoring the sealing performance of exhaust valve 1. The closure of valve body 11 of exhaust valve 1 can prevent external oxygen from entering the interior of equipment 2, and can prevent the airflow containing oxygen from entering the interior of equipment 2 and causing high-temperature combustibles to reignite, delaying or preventing heat spread between multiple battery cells 3, providing longer operation time for personnel evacuation and fire fighting, and improving the safety of equipment. It is easy to understand that after the pressure relief and venting of a single battery cell 3, the internal cavity of device 2 is filled with high-temperature combustible gas. The combustible gas may contain carbon monoxide, ethane, propane, etc., but lacks a certain proportion of oxygen. Therefore, the combustible gas does not meet the conditions for combustion or explosion inside device 2. It should be understood that after the pressure relief and venting of a single battery cell 3, the high-temperature combustible gas filling the internal cavity of device 2 exchanges heat with the outside through the housing 21 and the housing cover 22. At the same time, the high-temperature combustible gas filling the internal cavity of device 2 exchanges heat with multiple battery cells 3 that have not experienced thermal runaway, which leads to a decrease in the temperature of the high-temperature combustible gas filling the internal cavity of device 2. This further reduces the pressure inside device 2. If the valve body 11 of the exhaust valve 1 is not closed, outside air will flow into device 2 through the pressure relief channel. If the valve body 11 of the exhaust valve 1 is closed, outside air can only flow into device 2 through the breathable membrane 112. As can be seen from the above description, the permeability rate of the breathable membrane 112 is relatively slow.

[0061] The second embodiment of the present invention also provides an exhaust valve, which differs from the exhaust valve provided in the first embodiment in that:

[0062] like Figure 14 , Figure 15 As shown, the cylinder 15 is provided with multiple heat dissipation fins 152 around its perimeter. The heat dissipation fins 152 can increase the convective heat exchange area between the hot airflow and the cylinder 15 during the exhaust and depressurization process, thereby heating the cylinder 15 at a faster temperature rise rate. This allows the gas in the cylinder 15a to be heated more quickly, causing it to expand and further push the piston 14 to move. Consequently, the stroke of the valve body 11 is increased in a shorter time to obtain a larger gas discharge flow cross section, thus improving the depressurization effect.

[0063] The present invention also provides an electric vehicle 4, the electric vehicle 4 including an exhaust valve 1, such as Figure 18 and Figure 19As shown, the electric vehicle 4's body 41 houses multiple battery modules 42, each battery module 42 housing multiple battery cells 3. Each battery cell 3 is equipped with an explosion-proof valve 31. Multiple battery modules 42 are connected in series / parallel to form a high-voltage circuit, providing electrical energy for the electric vehicle 4's operation. After the energy stored in the battery modules 42 is consumed, it is replenished through a charging station. A sealing cover 43 further isolates the battery modules 42 from the occupants. The sealing cover 43 and the body 41 form a relatively sealed battery compartment 41a. Optionally, the battery compartment 41a meets the IP67 protection rating, thereby preventing the battery modules 42 / cells 3 from being affected by external dust and liquids. Under conditions such as overheating, mechanical abuse, or short circuits, the battery cells 3 may experience thermal runaway. This thermal runaway, accompanied by the release of a large amount of gas and heat, further increases the pressure within the battery compartment 41a. Overheating may occur during fast charging of the electric vehicle 4; mechanical abuse may occur when the electric vehicle 4 is subjected to impacts or mechanical penetration during driving; and short circuits may occur when the electric vehicle 4 is subjected to collisions or pressure, or when conductive media enters the battery compartment 41a. When the pressure inside the battery compartment 41a reaches the opening threshold of the exhaust valve 1, the valve body 11 of the exhaust valve 1 opens, allowing the gas inside the battery compartment 41a to be discharged. The high-temperature airflow heats the cylinder 15 of the exhaust valve 1, further increasing the temperature of the gas inside the cylinder 15a. The gas inside the cylinder 15a expands due to heat, increasing the pressure inside the cylinder 15a, which in turn pushes the piston 14 to slide relative to the cylinder 15 along the opening direction of the valve body 11. The valve body 11, connected to the piston 14, also moves along the opening direction of the valve body 11. It is easy to understand that the process of the gas inside the cylinder 15a expanding due to heat and pushing the piston 14 increases the gap between the lower sealing surface 1113 of the umbrella-shaped valve 111 of the valve body 11 and the first sealing element 125, increasing the flow cross section for gas discharge. That is to say, the pressure relief rate increases under the same pressure conditions inside the battery compartment 41a, further reducing the gas discharge resistance and / or increasing the gas discharge velocity inside the battery compartment 41a. This avoids the sealing cover 43 from being subjected to too much pressure, which could lead to gas leakage or explosion, thus improving the safety of the occupants.After the pressure relief and exhaust of cell 3 are completed, there is no longer a high-temperature airflow heating the cylinder 15 of exhaust valve 1. Due to heat conduction and heat convection, the temperature of cylinder 15 gradually decreases, further reducing the gas temperature inside cylinder 15a. This means the pressure in cylinder 15a decreases, causing piston 14 to slide relative to cylinder 15 along the closing direction of valve body 11. Valve body 11, connected to piston 14, also moves along the closing direction. Simultaneously, check valve 114 causes a small flow of gas leakage in cylinder 15a. Under the combined effects of cooling and leakage, the pressure inside cylinder 15a gradually decreases. Spring 13 pushes piston 14 along the closing direction of valve body 11. Sliding relative to cylinder 15, valve body 11 connected to piston also moves in the closing direction of valve body 11; until the limiting surface 1114 of umbrella valve 111 abuts against valve body support surface 129 of valve seat 12, piston 14 and valve body 11 stop moving; the first return force F1 of spring 13 is applied to the second spring support surface 1414 of piston 14, at which time the lower sealing surface of umbrella valve 111 cooperates with the first seal 125 of 1113 and compresses the first seal 125 by a set ratio, for example, compressing the first seal 125 by 30%, that is, the valve body 11 of exhaust valve 1 closes, further restoring the sealing performance of exhaust valve 1. The closing of valve body 11 of exhaust valve 1 prevents external oxygen from entering the battery compartment 41a, which can prevent the airflow containing oxygen from entering the battery compartment 41a and causing high-temperature combustibles to reignite, delaying or preventing heat spread between multiple cells 3, and improving the safety of electric vehicle 4.

[0064] It should be noted that the above implementation process is only to illustrate the feasibility of this application, but it does not mean that the exhaust valve of this application is limited to the above implementation process. On the contrary, as long as the exhaust valve of this application can be implemented, it can be included in the feasible implementation scheme of this application.

[0065] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An exhaust valve for venting and relieving pressure in equipment, characterized in that: The device includes a valve body, a valve seat, a spring, a piston, and a cylinder. The valve body includes an umbrella-shaped valve and a one-way valve. The umbrella-shaped valve has a breathable membrane and a hollow guide rod. The side wall of the hollow guide rod has several vent holes. The end of the hollow guide rod has a one-way valve fixing hole and an air inlet hole. The valve seat has an exhaust hole, a valve body mounting hole, a first spring support surface, and a valve body support surface. The umbrella-shaped valve is located on the valve body support surface. The hollow guide rod passes through the valve body mounting hole and is connected to the piston. The piston has a cylinder air inlet hole and a second spring support surface. The spring is located between the first spring support surface and the second spring support surface. The cylinder has a single-opening structure. The open end of the cylinder is fixedly connected to the valve seat. The spring and the piston are located inside the cylinder. The side wall of the cylinder near the valve seat has several air guide holes.

2. The exhaust valve according to claim 1, characterized in that: The valve body also includes a protective cover, and the umbrella-shaped valve is provided with an upper sealing surface, a lower sealing surface, a limiting surface, and a flange; the vent membrane is provided on the upper sealing surface, the limiting surface is in contact with the valve body support surface, and is used to limit the stroke of the valve body; the protective cover is provided on the flange, and the flange is provided with a plurality of vent holes along the circumference.

3. The exhaust valve according to claim 2, characterized in that: The one-way valve includes a fixed post and a diaphragm disposed at one end of the fixed post. The fixed post is interference-fitted with the one-way valve fixing hole. A stop extends from the other end of the fixed post. The cross-sectional dimension of the stop is larger than that of the one-way valve fixing hole, and the cross-sectional dimension of the diaphragm is larger than that of the air inlet.

4. The exhaust valve according to claim 2, characterized in that: The valve seat is also provided with a first sealing element receiving groove, a second sealing element receiving groove, and a fixing hole. A first sealing element is provided in the first sealing element receiving groove, and a second sealing element is provided in the second sealing element receiving groove. The first sealing element is in contact with the lower sealing surface, and the valve seat is fixed on the equipment through the fixing hole.

5. The exhaust valve according to claim 1, characterized in that: The piston has an annular groove on its outer side wall. The cylinder inlet port has a coaxial mounting drive hole with a different cross-sectional shape at its end away from the valve seat. A third seal is provided in the annular groove and is slidably connected to the inner wall of the cylinder.

6. The exhaust valve according to claim 5, characterized in that: The surface of the third seal is provided with a lubricant, which is used to reduce the friction between the third seal and the inner wall of the cylinder.

7. The exhaust valve according to claim 5, characterized in that: The hollow guide rod has an external thread, the cylinder inlet hole has an internal thread, and the hollow guide rod is connected to the piston by a thread.

8. The exhaust valve according to claim 1, characterized in that: The outer wall of the cylinder near the closed end is provided with several heat dissipation fins along the circumferential direction.

9. The exhaust valve according to claim 1, characterized in that: The one-way valve is made of silicone.

10. An electric vehicle, characterized in that, Includes the exhaust valve as described in any one of claims 1-9.

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