Coalescing filter element with directional drainage function and breather valve

Abstract

This invention relates to a coalescing filter element and a vent valve with directional drainage function. The coalescing filter element comprises multiple stacked coalescing filter layers, with the pore size increasing sequentially from the gas inlet to the gas outlet direction. Each coalescing filter layer includes connected oleophobic and oleophilic regions. From the gas inlet to the gas outlet direction, the area of ​​the oleophobic region in each coalescing filter layer increases sequentially, while the area of ​​the oleophilic region decreases sequentially. The oleophilic region exhibits oleophobic wettability, and an oleophilic wetting layer is formed on the gas inlet side of the oleophilic region. From the gas outlet to the gas inlet direction, the oleophilic wettability of the oleophilic wetting layer in each coalescing filter layer increases sequentially. This invention solves the technical problems of porous coalescing filter elements in vent valve products being prone to saturation, clogging, and low filtration efficiency.

Description

Technical Field

[0001] This invention relates to the field of filtration technology, and further to a coalescing filter element and a vent valve with directional drainage function, particularly to a coalescing filter element and a vent valve with directional drainage function that can be applied to the internal transmission system of new energy vehicles. Background Technology

[0002] During continuous vehicle operation, the vent valve element primarily relies on its membrane material to prevent external water and other impurities from entering the power transmission system. Meanwhile, air carrying a significant amount of oil within the system also exchanges air with the external environment through the vent valve element. Therefore, a porous coalescing filter element (a multi-layered fiber filter material within the vent valve that allows droplet coalescence, typically made of materials such as glass fiber, polypropylene fiber, or cotton fiber) is usually installed in the vent valve to separate the oil from the air. The porous material in the porous coalescing filter element can be made of various materials such as glass fiber, polypropylene fiber, and cotton fiber. The filter layer mainly ensures that air carrying oil does not damage the waterproof and breathable membrane of the vent valve, extending its service life.

[0003] In the vent valve, airflow passes from bottom to top through a porous filter element and a waterproof breathable membrane (both core components of the vent valve). The main function of the waterproof breathable membrane is to intercept water droplets and solid impurities in the gas, ensuring gas cleanliness. The porous filter element removes oil droplets entrained in the gas. Currently, oil removal methods using porous filters are mainly divided into two types: oleophilic adsorption and oleophobic coalescence. Oleophilic adsorption refers to using oleophilic porous materials to adsorb and store oil droplets in the air, achieving oil-liquid separation and removal. Oleophobic coalescence mainly refers to using oleophobic porous materials to capture oil droplets in the gas, causing small droplets to collide and merge within the fibers, forming larger droplets. Gravity then gradually discharges the oil back into the power transmission system components, achieving the purpose of removing oil droplets from the air. However, the above-mentioned porous coalescing filter element has the following problems during operation:

[0004] 1. For oleophilic porous coalescing filter elements, the filter media has a strong adsorption capacity for oil. However, the liquid absorption capacity of this type of oleophilic material has a certain saturation value. When the saturation is reached, the filter media fails and no longer has the ability to remove oil. Therefore, the vent valve needs to be replaced frequently, resulting in high operating costs.

[0005] 2. For oleophobic porous coalescing filter elements, after droplets coalesce through the material, they gradually accumulate and drain back into the system. When the gas velocity is low, as the amount of accumulated droplets increases, the gravity of the accumulated liquid gradually exceeds the drag force of the airflow, causing the liquid to penetrate downwards into the material, clogging the pores of the porous material and reducing the air permeability of the porous coalescing filter element. When the gas velocity is high, the coalesced liquid cannot drain back into the power transmission system by gravity and will accumulate on the upper surface of the porous coalescing filter element. When the droplets accumulate to a certain amount, they will contaminate the waterproof and breathable membrane, affecting its effectiveness and performance, and thus affecting the normal use of the entire breathable valve.

[0006] Third, for some existing breather valve products using oleophobic materials, the path or area through which the liquid flows through the porous coalescing filter element block when it is discharged back to the power transmission system is relatively random and without selectivity. As a result, the clean area within the porous filter block gradually decreases, the air permeability and filtration efficiency gradually decrease, and the performance and lifespan of the breather valve are affected.

[0007] There is currently no effective solution to the problems of porous coalescing filter elements in breather valve products being prone to saturation, clogging, and low filtration efficiency in related technologies.

[0008] Therefore, based on years of experience and practice in related industries, the inventor proposes a coalescing filter element and a vent valve with directional drainage function to overcome the defects of the prior art. Summary of the Invention

[0009] The purpose of this invention is to provide a coalescing filter element and a vent valve with directional drainage function, which can achieve the effect of separating oil droplets from gas and draining liquid in one direction. This effectively solves the problem that when a vehicle is running for a long time, it cannot drain oil droplets back to the power transmission system in time, resulting in excessive liquid accumulation, affecting the air permeability and contaminating the waterproof and breathable membrane, and effectively extending the service life of the vent valve.

[0010] The objective of this invention can be achieved through the following methods:

[0011] This invention provides a coalescing filter element with directional drainage function, which is used to filter out oil droplets contained in gas and directionally discharge the oil droplets. It includes multiple coalescing filter layers stacked together, from the gas inlet to the gas outlet direction, and the pore size of each coalescing filter layer increases sequentially.

[0012] Each of the coalescing filter layers includes connected oleophobic and oleophilic regions. From the direction of gas entry to gas exit, the area of ​​the oleophobic region in each of the coalescing filter layers increases sequentially, and the area of ​​the oleophilic region in each of the coalescing filter layers decreases sequentially.

[0013] The oleophilic region is oleophobic and wettable. An oleophilic and wettable layer is formed on the surface of the gas entry side in the oleophilic region. From the gas discharge direction to the gas entry direction, the oleophilic and wettable properties of the oleophilic and wettable layer in each of the coalescing filter layers increase sequentially.

[0014] In a preferred embodiment of the present invention, the oleophobic regions in each of the coalescing filter layers are stacked in opposite positions, and the oleophilic regions in each of the coalescing filter layers are stacked in opposite positions, so that the gas containing oil droplets passes through each of the oleophobic regions in sequence, and the oil droplets that are adsorbed and coalesced pass through each of the oleophilic regions in sequence in the opposite direction to the gas.

[0015] In a preferred embodiment of the present invention, a protrusion is formed on the coalescing filter layer located at the gas discharge position and in the oleophobic region, in the direction from the gas discharge to the gas inlet, so as to guide the oil droplets adsorbed and coalesced in the oleophobic region to the oleophilic region.

[0016] In a preferred embodiment of the present invention, the thickness of the oleophilic wetting layer is 3 / 5 to 4 / 5 of the thickness of the oleophilic region.

[0017] In a preferred embodiment of the present invention, an oleophilic modifier is sprayed onto the surface of the gas entry side in the oleophilic region to form the oleophilic wetting layer.

[0018] This invention provides a breathable valve, including a valve body and the aforementioned coalescing filter element with directional drainage function. The valve body has a first chamber and a second chamber, and a drainage hole is provided between the first chamber and the second chamber. The coalescing filter element with directional drainage function is disposed in the valve body, and the oleophobic region and the oleophilic region of the coalescing filter element with directional drainage function are respectively connected to the first chamber and the second chamber.

[0019] When the gas containing oil droplets in the first chamber passes through the coalescing filter element with directional drainage function, the oil droplets are adsorbed by the coalescing filter element with directional drainage function and sequentially converge into the second chamber through the oleophobic region and the oleophilic region.

[0020] In a preferred embodiment of the present invention, the second chamber is filled with a filler through which oil can pass.

[0021] In a preferred embodiment of the present invention, the valve body is provided with a channel communicating with the first chamber, so that gas containing oil droplets enters the first chamber through the channel, and oil flowing from the second chamber into the first chamber is discharged through the channel.

[0022] In a preferred embodiment of the present invention, a third chamber is formed inside the valve body, and the coalescing filter element with directional drainage function separates the third chamber from the first chamber and the second chamber. The valve body is provided with an air hole that communicates with the third chamber so that the gas inside the valve body can be exchanged with the outside.

[0023] In a preferred embodiment of the present invention, a filter screen and a breathable membrane are sequentially disposed between the coalescing filter element with directional drainage function and the third chamber.

[0024] As described above, the coalescing filter element and vent valve with directional drainage function in this invention have the following characteristics and advantages: From the gas inlet to the gas outlet direction, the coalescing filter element with directional drainage function has the following structure:

[0025] 1. The pore size of the multiple coalescing filter layers stacked in sequence increases sequentially;

[0026] 2. The area of ​​the oleophobic region in each coalescing filter layer increases sequentially, and the area of ​​the oleophilic region in each coalescing filter layer decreases sequentially.

[0027] Third, in the oleophilic region of each coalescing filter layer, an oleophilic wetting layer with oleophilic wettability is formed on the surface of the gas entry side, and the oleophilic wettability of the oleophilic wetting layer in each coalescing filter layer increases sequentially.

[0028] The combination of the above three structures facilitates oil droplet coalescence and enhances the drainage speed of the coalesced oil droplets in the oleophilic region. In addition, an oleophilic wetting layer is formed on the gas-entry side of the oleophilic region, which prevents oil droplets passing through the oleophilic region from flowing back. This achieves the purpose of oil droplet coalescence and directional drainage, avoiding the blockage of channels and contamination of the waterproof and breathable membrane that may occur due to oil droplets not being discharged in time in the vent valve. It effectively solves the problem of excessive liquid accumulation caused by the inability to drain oil droplets back to the power transmission system in time during long-term vehicle operation, which affects the air permeability and contaminates the waterproof and breathable membrane, and effectively extends the service life of the vent valve. Attached Figure Description

[0029] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0030] in:

[0031] Figure 1 : This is a perspective view of the coalescing filter element with directional drainage function of the present invention.

[0032] Figure 2 : This is a top view of the coalescing filter element with directional drainage function of the present invention.

[0033] Figure 3 :for Figure 2 Cross-sectional view along the AA direction.

[0034] Figure 4 : This is a front view of the vent valve of the present invention.

[0035] Figure 5 : This is an exploded view of the vent valve of the present invention.

[0036] Figure 6 :for Figure 4 Cross-sectional view at position BB in the middle.

[0037] The reference numerals in the accompanying drawings of this invention are:

[0038] 1. Valve body; 101. First chamber;

[0039] 102. Second chamber; 103. Drainage hole;

[0040] 104. Passageway; 105. Third chamber;

[0041] 2. End cap; 201. Vent;

[0042] 3. Coalescing filter element with directional drainage function; 301. Coalescing filter layer;

[0043] 3011, Oleophobic area; 3012, Oleophilic area;

[0044] 30121. Oleophilic wetting layer; 4. Sealing ring;

[0045] 5. Filler; 6. Filter screen;

[0046] 7. Breathable membrane. Detailed Implementation

[0047] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0048] Implementation Method 1

[0049] like Figures 1 to 3As shown, a coalescing filter element with directional drainage function is used to filter out oil droplets contained in gas and directionally discharge the oil droplets. This coalescing filter element with directional drainage function includes multiple coalescing filter layers 301 stacked together. From the gas inlet to the gas outlet direction, the pore size of each coalescing filter layer 301 increases sequentially (because the coalescing filter layer 301 is made of porous material, it has several pores for gas passage; the sequential increase in pore size means that the pore size of all pores in the porous material of each coalescing filter layer 301 increases sequentially). Each coalescing filter... Each layer 301 includes connected oleophobic regions 3011 and oleophilic regions 3012. From the gas inlet to the gas outlet direction, the area of ​​the oleophobic regions 3011 in each coalescing filter layer 301 increases sequentially, and the area of ​​the oleophilic regions 3012 in each coalescing filter layer 301 decreases sequentially. The oleophilic regions 3012 are oleophobic and wettable. An oleophilic and wettable layer 30121 is formed on the gas inlet side of the oleophilic region 3012. From the gas outlet to the gas inlet direction, the oleophilic and wettable properties of the oleophilic and wettable layers 30121 in each coalescing filter layer 301 increase sequentially.

[0050] In this invention, the coalescing filter element with directional drainage function in the direction from gas inlet to gas outlet has the following structure: the pore size of the multiple coalescing filter layers 301 stacked in sequence increases; the area of ​​the oleophobic region 3011 in each coalescing filter layer 301 increases in sequence, and the area of ​​the oleophilic region 3012 in each coalescing filter layer 301 decreases in sequence; an oleophilic wetting layer 30121 with oleophilic wettability is formed on the surface of the oleophilic region 3012 on the gas inlet side in each coalescing filter layer 301, and the oleophilic wettability of the oleophilic wetting layer 30121 in each coalescing filter layer 301 increases in sequence. By combining the above three gradient structures, it is beneficial to the coalescence of oil droplets and can enhance the drainage speed of the coalesced oil droplets in the oleophilic region 3012. In addition, the setting of the oleophilic wetting layer 30121 can prevent the backflow of oil droplets passing through the oleophilic region 3012, thereby achieving the purpose of coalescence and directional drainage of oil droplets. This avoids the situation where oil droplets in the vent valve cannot be discharged in time, which may cause blockage of the channel and contamination of the waterproof and breathable membrane. It effectively solves the problem that when the vehicle runs for a long time, it cannot discharge oil droplets back to the power transmission system in time, resulting in excessive liquid accumulation, affecting the air permeability and contaminating the waterproof and breathable membrane, and effectively extends the service life of the vent valve.

[0051] In this invention, the pore size of the multiple coalescing filter layers 301 stacked in the direction from gas inlet to gas outlet increases sequentially, which facilitates the gradual coalescence of oil droplets in the gas along the direction of gas flow and the formation of larger oil droplets, which is beneficial to the coalescence of oil droplets.

[0052] In this invention, from the gas inlet to the gas outlet direction (gas enters from the bottom coalescing filter layer 301 and exits from the top coalescing filter layer 301), the area of ​​the oleophobic region 3011 in each coalescing filter layer 301 increases sequentially, and the area of ​​the oleophilic region 3012 in each coalescing filter layer 301 decreases sequentially. This can enhance the rapid drainage of oil droplets after coalescing in the top coalescing filter layer 301 under the action of gravity in a vertically downward direction.

[0053] In this invention, from the direction of gas entry to gas exit (gas enters from the bottom coalescing filter layer 301 and exits from the top coalescing filter layer 301), the oleophilic wettability of the oleophilic wetting layer 30121 in each coalescing filter layer 301 increases sequentially, which can effectively prevent the oil entering the oleophilic region 3012 from flowing back from bottom to top and ensure the smooth discharge of the oil.

[0054] In an optional embodiment of the present invention, such as Figure 3 As shown, the oleophobic regions 3011 in each coalescing filter layer 301 are stacked in relative positions, and the oleophilic regions 3012 in each coalescing filter layer 301 are stacked in relative positions, so that the gas containing oil droplets passes through each oleophobic region 3011 in sequence, and the oil droplets that are adsorbed and coalesced pass through each oleophilic region 3012 in sequence in the opposite direction to the gas.

[0055] In an optional embodiment of the present invention, such as Figure 1 , Figure 3 As shown, from the gas discharge direction to the gas inlet direction, a protrusion is formed on the coalescing filter layer 301 located at the gas discharge position and in the oleophobic region 3011. The protrusion creates a potential energy difference between the oleophobic region 3011 and the oleophilic region 3012, thereby guiding oil droplets adsorbed in the oleophobic region 3011 to the oleophilic region 3012. The thickness of the oleophobic region 3011 can be increased by electrospinning nanofiber coating on its surface, thus forming the aforementioned protrusion at the oleophobic region 3011.

[0056] Furthermore, the height difference between the location of the protrusion and the location of the oleophilic region 3012 is 1 mm to 3 mm (that is, the thickness of the oleophobic region 3011 in the coalescing filter layer 301 is greater than the thickness of the oleophilic region 3012, and the thickness difference is about 1 mm to 3 mm).

[0057] Furthermore, the coalescing filter layer 301 is entirely made of oleophobic filter material (oleophobic glass fiber material). An oleophilic modifier is sprayed onto predetermined positions on the surface of each coalescing filter layer 301, thereby forming oleophilic regions 3012 on the coalescing filter layer 301. Of course, other methods can also be used to achieve superoleophilic modification of the coalescing filter layer 301; specific methods are not limited here.

[0058] Furthermore, the thickness of the oleophilic wetting layer 30121 is 3 / 5 to 4 / 5 of the thickness of the oleophilic region 3012.

[0059] Furthermore, an oleophilic modifier is sprayed onto the surface of the oleophilic region 3012 on the side where the gas enters, so that the oleophilic region 3012 faces the side where the oil droplets enter (i.e.: Figure 3 The upper surface of the region 3012 is oleophilic and wettable (of course, a superoleophilic modifier can also be sprayed to make the side of the oleophilic region 3012 facing the oil droplet entry superoleophilic and wettable), while the side of the oleophilic region 3012 facing away from the oil droplet entry (i.e.: Figure 3 The lower surface of the filter media (3012) is oleophobic and wettable, which gives the upper surface of the oleophilic region 3012 a strong ability to capture and adsorb oil droplets, while the lower surface of the oleophilic region 3012 can act as an oleophobic draining agent. Thus, by treating each coalescing filter layer 301, a unidirectional circulation effect of capturing, adsorbing, and draining oil droplets can be achieved. Wettability refers to the degree of wettability of the filter media by the liquid, usually expressed as the contact angle between the liquid and the filter media. It can be divided into three categories: superoleophilic or oleophilic (contact angle less than 90°), oleophobic (contact angle greater than 90° and less than 150°), and superoleophobic (contact angle greater than 150°).

[0060] Specifically, the number of coalescing filter layers 301 can be, but is not limited to, 2-8 layers.

[0061] The features and advantages of the coalescing filter element with directional drainage function of the present invention are as follows:

[0062] 1. In this coalescing filter element with directional drainage function, the pore size of the multiple coalescing filter layers 301 stacked in sequence increases sequentially; the area of ​​the oleophobic region 3011 in each coalescing filter layer 301 increases sequentially, and the area of ​​the oleophilic region 3012 in each coalescing filter layer 301 decreases sequentially; an oleophilic wetting layer 30121 with oleophilic wettability is formed on the gas entry side surface in the oleophilic region 3012 of each coalescing filter layer 301, and the oleophilic wettability of the oleophilic wetting layer 30121 in each coalescing filter layer 301 increases sequentially. By adopting the above three gradient change structures in combination, it is conducive to the coalescence of oil droplets, and the oil droplets can be easily absorbed by the filter material and moved downward by capillary force and gravity, which can enhance the drainage speed of the coalesced oil droplets in the oleophilic region 3012.

[0063] Second, in this coalescing filter element with directional drainage function, the setting of the oleophilic wetting layer 30121 can prevent oil droplets passing through the oleophilic region 3012 from flowing back, thereby achieving the purpose of coalescing oil droplets and directional drainage.

[0064] Third, in this coalescing filter element with directional drainage function, a protrusion is formed on the coalescing filter layer 301 and located in the oleophobic region 3011. This can create a potential energy difference between the oleophobic region 3011 and the oleophilic region 3012, which can guide the oil droplets in the oleophobic region 3011 to the oleophilic region 3012. This makes the path of the oil flow when it is drained back to the power transmission system of the vehicle selective, so that the coalesced oil droplets will not contaminate the oleophobic region 3011. This ensures that the coalescing filter element has a high filtration efficiency over a long period of time, thereby extending the service life of the vent valve.

[0065] Fourth, the coalescing filter element with directional drainage function can prevent the oil droplets in the vent valve from being blocked in time and contaminating the waterproof and breathable membrane. It effectively solves the problem that the oil droplets cannot be drained back to the power transmission system in time during long-term vehicle operation, resulting in excessive liquid accumulation, affecting the air permeability and contaminating the waterproof and breathable membrane, and effectively extending the service life of the vent valve.

[0066] Implementation Method 2

[0067] like Figures 1 to 6 As shown, the present invention provides a vent valve, which includes a valve body 1 and the aforementioned coalescing filter element 3 with directional drainage function. A first chamber 101 and a second chamber 102 are formed in the valve body 1, and a drainage hole 103 is provided between the first chamber 101 and the second chamber 102. The coalescing filter element 3 with directional drainage function is disposed in the valve body 1. The oleophobic region 3011 of the coalescing filter element 3 with directional drainage function is connected to the first chamber 101, and the oleophilic region 3012 of the coalescing filter element 3 with directional drainage function is connected to the second chamber 102. When gas containing oil droplets in the first chamber 101 passes through the coalescing filter element 3 with directional drainage function, the oil droplets are adsorbed by the coalescing filter element 3 with directional drainage function and sequentially pass through the oleophobic region 3011 and the oleophilic region 3012 to converge into the second chamber 102.

[0068] The present invention forms a first chamber 101 and a second chamber 102 within the valve body 1. When gas containing oil droplets in the first chamber 101 passes through the coalescing filter element 3 with directional drainage function, the oil droplets coalesce in the oleophobic region 3011 to form larger oil droplets. Due to the strong adsorption force of the oleophilic region 3012 on the oil droplets, the oil droplets coalescing in the oleophobic region 3011 are absorbed into the interior by the oleophilic region 3012. When the oleophilic region 3012 reaches saturation, the oil droplets absorbed in the oleophilic region 3012 will form oil. Under the influence of gravity, the oil flows into the second chamber 102, where it can be collected and discharged. This process achieves real-time separation and one-way drainage of oil droplets mixed in the gas, preventing the oil droplets in the vent valve from clogging the channel and contaminating the waterproof and breathable membrane. It effectively solves the problem of excessive liquid accumulation, affecting air permeability and contaminating the waterproof and breathable membrane, caused by the inability to discharge oil droplets back to the power transmission system during long-term vehicle operation, thus extending the service life of the vent valve.

[0069] In an optional embodiment of the present invention, such as Figure 5 As shown, the second chamber 102 is filled with a filler 5 that allows oil to pass through. The main purpose of the filler 5 is to increase the damping coefficient in the second chamber 102, allowing oil to enter while also blocking some gas. This prevents the gas separated from the oil droplets from entering the second chamber 102, instead allowing selective ventilation to the outside. Simultaneously, the filler 5 can also cooperate with the coalescing filter element 3, which has a directional drainage function, to adsorb and guide the oil separated by the coalescing filter element 3 and located in the oleophilic region 3012. This facilitates the smooth entry of the oil in the oleophilic region 3012 into the second chamber 102, so that the oil can be drained back into the vehicle's power transmission system through the second chamber 102.

[0070] Furthermore, the filler 5 is preferably a material that allows oil to pass through and has a certain oil adsorption capacity. The filler 5 can be, but is not limited to, porous oil-absorbing materials such as sponge or glass fiber cotton. The shape and volume of the filler 5 can be set according to the second chamber 102 so that the filler 5 can be adapted to the second chamber 102. It is best if the filler 5 can fill the entire second chamber 102, but the specific shape and volume of the filler 5 are not limited here.

[0071] In an optional embodiment of the present invention, such as Figure 6As shown, the valve body 1 is provided with a channel 104 communicating with the first chamber 101. A drain hole 103 is provided between the first chamber 101 and the second chamber 102. Through the drain hole 103, the oil collected in the second chamber 102 can flow into the first chamber 101. Since the first chamber 101 is connected to the channel 104, the channel 104 can serve as a gas inlet. Gas mixed with oil droplets in the vehicle's power transmission system can enter the first chamber 101 through the channel 104. At the same time, the channel 104 can also serve as an oil outlet. The oil that flows into the first chamber 101 through the drain hole 103 can be discharged back into the vehicle's power transmission system through the channel 104.

[0072] Specifically, there are multiple drainage holes 103, and each drainage hole 103 is spaced apart and evenly distributed along the circumference of the first chamber 101 at the lower position between the first chamber 101 and the second chamber 102.

[0073] Furthermore, such as Figure 6 As shown, a third chamber 105 is formed inside the valve body 1. The third chamber 105 is located above the first chamber 101 and the second chamber 102. A coalescing filter element 3 with directional drainage function separates the third chamber 105 from the first chamber 101 and the second chamber 102. A vent 201 connected to the third chamber 105 is provided on the valve body 1. After the oil droplets and gas are separated by the coalescing filter element 3 with directional drainage function, the gas enters the third chamber 105 and can be exchanged with the outside through the vent 201.

[0074] In one specific embodiment of the present invention, such as Figure 5 , Figure 6As shown, the first chamber 101 is located in the middle of the valve body 1, and the second chamber 102 is annular and surrounds the outer periphery of the first chamber 101. The top of the first chamber 101 and the top of the second chamber 102 are provided with openings. The coalescing filter element 3 with directional drainage function is sealed at the top openings of the first chamber 101 and the second chamber 102. Correspondingly, the oleophilic region 3012 is annular and surrounds the outer ring of the oleophobic region 3011, so that the oleophobic region 3011 is located in the middle of the coalescing filter element 3 with directional drainage function and is vertically opposite to the first chamber 101, and the oleophilic region 3012 is vertically opposite to the second chamber 102. Gas mixed with oil droplets enters the first chamber 101 from bottom to top through the top opening of the first chamber 101 into the oleophobic region 3011 of the coalescing filter element 3 with directional drainage function. The oil droplets that coalesce in the oleophobic region 3011 are absorbed by the oleophilic region 3012 surrounding the oleophobic region 3011 and transported into the oleophilic region 3012. When the oleophilic region 3012 reaches saturation, the oil droplets absorbed in the oleophilic region 3012 will form oil and converge in the second chamber 102 under the action of gravity. The oil in the second chamber 102 flows into the first chamber 101 through the drain hole 103 and is discharged back to the vehicle's power transmission system through the channel 104 connected to the first chamber 101, thereby realizing the real-time drainage function of the vent valve.

[0075] Furthermore, such as Figure 4 , Figure 6 As shown, channel 104 is located at the bottom of valve body 1, and channel 104 is vertically connected to the first chamber 101.

[0076] In an optional embodiment of the present invention, such as Figure 5 , Figure 6 As shown, a filter screen 6 and a breathable membrane 7 are sequentially arranged between the coalescing filter element 3 with directional drainage function and the third chamber 105. The filter screen 6 and the breathable membrane 7 can block oil droplets, ensuring that only gas can enter the third chamber 105, thereby further ensuring sufficient collection of oil droplets. Furthermore, the ventilation channel and drainage channel in the vent valve do not interfere with each other, realizing the unidirectional drainage function of the vent valve. The filter screen 6 can be, but is not limited to, a stainless steel filter screen.

[0077] Furthermore, the inner wall of the valve body 1 is provided with a groove, which can be used to secure the edge of the filter screen 6 and the edge of the breathable membrane 7, thereby fixing the filter screen 6 and the breathable membrane. Of course, other structures or methods can also be used to fix the filter screen 6 and the breathable membrane, and the specific structure and method are not limited here.

[0078] In an optional embodiment of the present invention, such as Figures 4 to 6As shown, the valve body 1 is provided with an end cap 2 on the top, and the end cap 2 is sealed to the valve body 1. The third chamber 105 is located between the inner wall of the end cap 2 and the breathable membrane 7, and the air hole 201 is opened on the end cap 2.

[0079] Specifically, such as Figures 4 to 6 As shown, there are multiple vents 201, and each vent 201 is spaced apart and evenly distributed along the circumference of the end cap 2.

[0080] In an optional embodiment of the present invention, such as Figures 4 to 6 As shown, a sealing ring 4 is provided at the bottom of the valve body 1 at the interface position of the channel 104.

[0081] The working principle of the vent valve of the present invention is as follows: Gas containing oil droplets in the power transmission system of the vehicle enters the first chamber 101 through the channel 104. The gas in the first chamber 101 flows upward and enters the coalescing filter element 3 with directional drainage function through the coalescing filter layer 301 located at the bottom of the coalescing filter element 3 with directional drainage function. The oil droplets contained in the gas will coalesce in the oleophobic region 3011 to form larger oil droplets. Since the oleophilic region 3012 has a strong adsorption force on the oil droplets, the oil droplets after coalescing in the oleophobic region 3011 will be absorbed into the interior by the oleophilic region 3012. When the oleophilic region 3012 reaches saturation, the oil droplets absorbed in the oleophilic region 3012 will form oil and also converge into the second chamber 102 under the action of gravity. All the oil that converges in the second chamber 102 is discharged back to the power transmission system of the vehicle through the drain hole 103, the first chamber 101 and the channel 104 in sequence, realizing the collection and return of oil.

[0082] The features and advantages of the vent valve of the present invention are as follows:

[0083] I. Existing vent valves use porous coalescing filter elements formed by oleophobic materials. Since most oleophobic materials are fiber materials with only single wettability, the coalesced oil droplets cannot drain in time, adversely affecting the performance of the vent valve. In the vent valve of this invention, an oleophobic material with an oleophilic region 3012 is used as the filter element for separating coalesced oil droplets. The oleophilic region 3012 has a strong adsorption force on oil droplets. Therefore, after oil droplets coalesce in the oleophobic region 3011, they are absorbed by the oleophilic region 3012. When the oleophilic region 3012 reaches saturation, the oil in the oleophilic region 3012 moves downward and enters the filler 5 in the second chamber 102, and then flows sequentially through the drain hole 103, the first chamber 101, and the channel 104 back to the vehicle's power transmission system. This avoids the phenomenon of oil droplets not draining in time, which may cause blockage of the channel and contamination of the waterproof and breathable membrane, effectively extending the service life of the vent valve.

[0084] Second, in the vent valve of the present invention, a filler 5 is provided in the second chamber 102, and a drain hole 103 is provided between the second chamber 102 and the first chamber 101. The filler 5 can provide a certain suction force for the oil and play a certain blocking role for the gas, so that the oil in the oleophilic area 3012 can smoothly enter the second chamber 102, so that the oil can be drained back to the power transmission system of the vehicle through the second chamber 102. By cooperating with the coalescing filter element 3 with directional drain function, the directional drain capability of the vent valve is effectively improved, and the accumulation of oil droplets inside the vent valve is avoided.

[0085] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A coalescing filter element with directional drainage function, used to filter out oil droplets contained in gas and directionally discharge the oil droplets, characterized in that, It includes multiple coalescing filter layers stacked together, with the pore size of each coalescing filter layer increasing sequentially from the direction of gas entry to the direction of gas exit; Each of the coalescing filter layers includes connected oleophobic and oleophilic regions. From the direction of gas entry to gas exit, the area of ​​the oleophobic region in each of the coalescing filter layers increases sequentially, and the area of ​​the oleophilic region in each of the coalescing filter layers decreases sequentially. The oleophilic region is oleophobic and wettable. An oleophilic and wettable layer is formed on the surface of the gas entry side in the oleophilic region. From the gas discharge direction to the gas entry direction, the oleophilic and wettable properties of the oleophilic and wettable layer in each of the coalescing filter layers increase sequentially. The oleophobic regions in each of the coalescing filter layers are stacked in relative positions, and the oleophilic regions in each of the coalescing filter layers are stacked in relative positions, so that the gas containing oil droplets passes through each of the oleophobic regions in sequence, and the oil droplets that are adsorbed and coalesced pass through each of the oleophilic regions in sequence in the opposite direction to the gas. A protrusion is formed on the coalescing filter layer located at the gas discharge position and in the oleophobic region, in the direction from the gas discharge to the gas inlet, so as to guide the oil droplets adsorbed and coalesced in the oleophobic region to the oleophilic region.

2. The coalescing filter element with directional drainage function as described in claim 1, characterized in that, The thickness of the oleophilic wetting layer is 3 / 5 to 4 / 5 of the thickness of the oleophilic region.

3. The coalescing filter element with directional drainage function as described in claim 1, characterized in that, An oleophilic modifier is sprayed onto the surface of the gas-entry side in the oleophilic region to form the oleophilic wetting layer.

4. A vent valve, characterized in that, The device includes a valve body and a coalescing filter element with directional drainage function as described in any one of claims 1 to 3. The valve body has a first chamber and a second chamber, and a drainage hole is provided between the first chamber and the second chamber. The coalescing filter element with directional drainage function is disposed in the valve body, and the oleophobic region and the oleophilic region of the coalescing filter element with directional drainage function are respectively connected to the first chamber and the second chamber. When the gas containing oil droplets in the first chamber passes through the coalescing filter element with directional drainage function, the oil droplets are adsorbed by the coalescing filter element with directional drainage function and sequentially converge into the second chamber through the oleophobic region and the oleophilic region.

5. The vent valve as described in claim 4, characterized in that, The second chamber is filled with a filler material that allows oil to pass through.

6. The vent valve as described in claim 4, characterized in that, The valve body is provided with a channel communicating with the first chamber, so that gas containing oil droplets can enter the first chamber through the channel, and oil flowing from the second chamber into the first chamber can be discharged through the channel.

7. The vent valve as described in claim 6, characterized in that, The valve body has a third chamber inside, and the coalescing filter element with directional drainage function separates the third chamber from the first chamber and the second chamber. The valve body has an air hole that communicates with the third chamber so that the gas inside the valve body can be exchanged with the outside.

8. The vent valve as described in claim 7, characterized in that, A filter screen and a breathable membrane are sequentially arranged between the coalescing filter element with directional drainage function and the third chamber.

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