Multi-stage coupled breather valve

Abstract

The application discloses a multistage coupling type breather valve, comprising a breather valve body and a pressure expansion cyclone separation structure, wherein the breather valve body is internally provided with a filter layer structure, the pressure expansion cyclone separation structure is provided with a pressure expansion piece and a cyclone separation piece connected with each other, the cyclone separation piece is connected with the breather valve body, and the cyclone separation piece is internally provided with a rotating guide vane structure. The breather valve can realize super interception of oil mist aerosol during the operation of an electric vehicle, maximally improve the toughness and the air permeability of a membrane material, effectively improve the oil-proof air permeability characteristics and the service life of the breather valve, and improve the operation safety of the electric vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of breather valves, and particularly relates to a multi-stage coupled breather valve. BACKGROUND

[0002] With the proposal of the "carbon neutralization and carbon peak" target, various industries are actively joining the energy-saving and emission-reduction team through product optimization transformation. As a near-zero-emission energy-saving product, electric vehicles gradually enter the public's field of vision. The most concerned is the safety performance of electric vehicles, which requires electric vehicles to have high protection levels. The gear box, oil-cooled motor, and electric control equipment of the vehicle must ensure that no liquid droplets and dust and other pollutants enter the box, otherwise it will cause damage to electronic components or rotating parts, thereby reducing their service life. Some equipment such as engine electronic controllers are often affected by external environmental temperature and pressure fluctuations during use. When the protective box is in an absolutely closed condition, there will be a problem of unbalanced internal and external pressure. The internal electronic components of the equipment generate heat during operation, causing the air in the shell to heat and expand. If the gas cannot be discharged in time, the pressure in the box will continue to increase and gather on the weakest part of the shell. When the equipment stops working or the temperature drops, the internal pressure will drop due to the breathing effect, which will adversely affect the performance of the equipment. To solve the above problems, a waterproof breather valve is often introduced into the equipment to prevent water, prevent pollution, and balance the internal and external pressure. In addition, many internal parts of the vehicle need to add lubricating oil to prevent wear and tear. However, during equipment operation, the impact and friction between parts and the high-speed operation of the equipment can cause lubricating oil droplets to splash, or the oil mist can be suspended in the air in the box due to the increase in equipment operating temperature and high-speed operation of the equipment. In order to prevent these oil droplets from entering the external equipment through the breather valve, the breather valve also needs to have excellent oil-proof performance.

[0003] At present, the traditional breather valve mainly achieves the purposes of waterproof, air permeability and oil-proof through the waterproof and air permeable membrane and the filter membrane material in the internal. However, the traditional breather valve has the following problems: (1) poor oil-proof performance, which cannot capture and intercept the oil mist in time, causing oil mist leakage and affecting the safe operation of the equipment; (2) poor oil discharge performance, which can capture a large amount of oil mist but cannot discharge the liquid in time, causing the oil-proof performance of the membrane material to deteriorate or the service life of the membrane material to decrease due to the collapse of the membrane material; (3) in order to achieve a high filtering effect, the traditional breather valve often uses multiple single membrane materials, which has poor air permeability; (4) the membrane material has low strength, poor pressure resistance and poor high-temperature resistance; (5) the air permeation hole is directly in contact with the outside, which is easy to cause dust and other impurities in the air to enter and contaminate the membrane material, and even affect the operation of the equipment; (6) the screw thread cooperation mode is single, which cannot meet the installation of non-threaded design equipment. SUMMARY

[0004] The application provides a multi-stage coupled breather valve, which can realize super interception of oil mist aerosol during operation of an electric vehicle, maximally improve toughness and air permeability of a membrane material, effectively improve oil-proof and air-permeable properties and service life of the breather valve, and improve operation safety of the electric vehicle.

[0005] A multi-stage coupled breather valve comprises:

[0006] A breather valve body is internally provided with a filter layer structure.

[0007] A pressure expansion and cyclone separation structure is provided with a pressure expansion part and a cyclone separation part connected with each other, the cyclone separation part is connected with the breather valve body, and a rotating guide vane structure is arranged in the cyclone separation part.

[0008] The multi-stage coupled breather valve as described above, wherein the rotating guide vane structure comprises a central shaft and first and second guide vane structures connected to the central shaft, the first guide vane structure is provided with a plurality of first blades arranged in a first rotation direction, the second guide vane structure is provided with a plurality of second blades arranged in a second rotation direction, and the rotation direction of the first blades is opposite to that of the second blades.

[0009] The multi-stage coupled breather valve as described above, wherein the pressure expansion part is provided with a pressure expansion channel, and the pressure expansion channel is arranged in a radial tapering manner towards the cyclone separation part.

[0010] The multi-stage coupled breather valve as described above, wherein an inner wall surface of the pressure expansion channel comprises a strong oil-repellent ring surface and a strong oil-wetting ring surface, and the strong oil-wetting ring surface and the strong oil-repellent ring surface are arranged in sequence towards the cyclone separation part; wherein an oil droplet contact angle of the strong oil-repellent ring surface is greater than or equal to 150°, and an oil droplet contact angle of the strong oil-wetting ring surface is 0°-10°.

[0011] The multi-stage coupled breather valve as described above, wherein the filter layer structure comprises a metal filter layer, a non-metal filter layer and an oil-repellent and water-repellent membrane layer arranged in sequence, and the metal filter layer is located at the bottom of the breather valve body and connected with the rotating guide vane structure.

[0012] The multi-stage coupled breather valve as described above, wherein the metal filter layer comprises a central circular area at a central position, and a sawtooth inner ring area and a sawtooth outer ring area at edge positions, and a sawtooth structure is arranged at the joint of the sawtooth inner ring area and the sawtooth outer ring area.

[0013] The multi-stage coupled breather valve as described above, wherein the central circular area and the sawtooth outer ring area are super oil-repellent and water-repellent areas, and the sawtooth inner ring area is a super oil-wetting and water-wetting area.

[0014] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the non-metallic filter layer is composed of a plurality of non-metallic fiber filter layers stacked together; wherein the non-metallic fiber filter layer comprises a sawtooth inner region at a central position and a sawtooth outer ring region at an edge position, and a sawtooth structure is arranged at the joint of the sawtooth inner region and the sawtooth outer ring region.

[0015] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the sawtooth inner region is a super oil-repellent and water-repellent region, and the sawtooth outer ring region is a super oil-wettable and water-wettable region, and the oil droplet contact angle of the sawtooth outer ring region of each non-metallic filter layer increases in turn in a direction away from the metallic filter layer.

[0016] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the area of the sawtooth outer ring region of the non-metallic filter layer is greater than the area of the sawtooth outer ring region of the metallic filter layer.

[0017] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the sawtooth inner region of the non-metallic filter layer and / or the central circular region of the metallic filter layer is provided with at least one liquid-wettable strip.

[0018] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the edge of the liquid-wettable strip is provided with a sawtooth structure.

[0019] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the edge of the sawtooth structure of the non-metallic filter layer and / or the edge of the sawtooth structure of the metallic filter layer is provided with an outer sawtooth structure.

[0020] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein a film placement platform is arranged between the non-metallic filter layer and the oil-repellent and water-repellent film layer, the film placement platform comprises an open hole region at a central position and a ring region at an edge position, and the oil-repellent and water-repellent film layer is arranged on the open hole region.

[0021] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein the breather valve body comprises a valve body and a valve cap buckled together, the open edge of the valve body is provided with a plurality of grooves along the circumferential direction thereof, and the top of the valve cap is provided with a plurality of bosses along the circumferential direction thereof, and in the state that the valve cap is buckled on the valve body, the bosses are embedded in the grooves.

[0022] The multi-stage coupled breather valve as claimed in any one of the preceding claims, wherein at least one breather hole is arranged on the side wall of the valve body along the circumferential direction thereof, and the valve cap has an outer ring wall extending towards the valve body, and at least one breather hole is shielded by the outer ring wall.

[0023] The multi-stage coupled breather valve as described above, wherein a retainer is arranged in the breather valve body, and the retainer is configured to press and fix the metal filter layer and the non-metal filter layer in the breather valve body.

[0024] Compared with the prior art, the technical scheme of the present application has the following beneficial effects:

[0025] (1) The multi-stage coupled breather valve has excellent oil droplet capturing capacity. The bottom diffuser and the rotating guide vane structure can realize primary cyclone separation and capture of oil droplets, the metal filter layer can realize secondary filtration and capture of oil droplets, the upper non-metal filter layer can realize tertiary filtration and capture of oil droplets, and the oil-repellent and water-repellent film at the top can realize fourth-level interception of oil droplets. The multi-stage coupling design effectively enhances the interception and capture effect of the breather valve on oil mist.

[0026] (2) The multi-stage coupled breather valve has excellent liquid discharge capacity. The non-uniform modification treatment of the bottom diffuser can realize automatic liquid discharge of droplets under the action of gravity, the opposite rotation direction of the blades of the rotating guide vane and the slit design in the middle can realize reverse liquid discharge of the two guide vanes respectively, effectively improving the liquid discharge speed, and the metal filter layer and the non-metal filter layer above form a liquid discharge channel from top to bottom under the sawtooth structure and reasonable modification area, further enhancing the liquid discharge capacity of the breather valve, and effectively reducing the phenomenon that the captured liquid droplets re-enter the upstream with the airflow due to the delayed discharge of the traditional breather valve.

[0027] (3) The multi-stage coupled breather valve has excellent pressure resistance and high temperature resistance. The metal filter layer is used as a pressure-bearing filter component, which has excellent high temperature resistance and pressure-bearing capacity, thereby further improving the overall pressure resistance and high temperature resistance of the breather valve.

[0028] (4) The multi-stage coupled breather valve has excellent air permeability. The rotating guide vane and the multi-layer filter layer coupling replace the traditional multi-layer single filter layer design, effectively avoiding the reduction of air permeability caused by too many filter layers, and the multi-stage coupling design realizes timely liquid discharge of the filter layer, effectively reducing the problem of reduced air permeability caused by oil droplets blocking the pores between fibers. Therefore, the present application significantly improves the air permeability of the breather valve without reducing the filtering effect.

[0029] (5) The multi-stage coupled breather valve can realize long-period stable operation under multiple working conditions. The diffuser cyclone separation structure and the filter layer structure are coupled to realize rapid liquid droplet separation and capture and discharge, avoiding the problem of material collapse caused by delayed discharge of the filter layer. The design of the metal filter layer can realize normal operation of the breather valve under high pressure and high temperature conditions. In addition, the present application also provides corresponding optimization schemes under different degrees of oil mist concentration. Therefore, the present application can operate safely and stably for a long period under multiple harsh conditions.

[0030] (6) The multi-stage coupled breather valve of the present application has excellent anti-pollution and anti-dust performance. The present application adopts a composite buckle type cap design, which can not only ensure that the gas passes through the breather hole smoothly to maintain the pressure balance between the inside and outside, but also prevent the breather hole from being directly exposed to the external environment, avoiding the pollution of dust and other particles in the air through the breather hole, and even affecting the normal operation of the equipment.

[0031] (7) The multi-stage coupled breather valve of the present application has strong installation applicability. The present application adopts three different matching modes of cyclone cylinders, and the corresponding breather valve has three installation forms. Different matching modes of breather valves can be selected according to the needs of the installed equipment, so the present application has a wide application scenario and strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort. In the drawings:

[0033] Figure 1 It is a schematic diagram of the overall structure of the multi-stage coupled breather valve of the present application;

[0034] Figure 2 It is a schematic diagram of the overall cross-sectional structure of the multi-stage coupled breather valve of the present application;

[0035] Figure 3 It is a schematic diagram of the cross-sectional structure of the diffuser of the multi-stage coupled breather valve of the present application;

[0036] Figure 4 It is a schematic diagram of the rotating guide vane structure of the multi-stage coupled breather valve of the present application;

[0037] Figure 5 It is a schematic diagram of the structure of a single guide vane of the multi-stage coupled breather valve of the present application;

[0038] Figure 6 It is a schematic diagram of the guide vane projection function of the multi-stage coupled breather valve of the present application;

[0039] Figure 7 It is a schematic diagram of the local modified metal fiber felt structure of the multi-stage coupled breather valve of the present application;

[0040] Figure 8 It is a schematic diagram of the cross-sectional structure of the non-metallic fiber filter layer of the multi-stage coupled breather valve of the present application;

[0041] Figure 9A non-metallic fiber filter layer structure diagram of the multi-stage coupled breather valve of the present application;

[0042] Figure 10 A longitudinal and horizontal composite sawtooth structure diagram of the multi-stage coupled breather valve of the present application;

[0043] Figure 11 A liquid-wettable strip structure diagram of the multi-stage coupled breather valve of the present application;

[0044] Figure 12 A sawtooth structure diagram on the liquid-wettable strip of the multi-stage coupled breather valve of the present application;

[0045] Figure 13 A membrane placement table structure diagram of the multi-stage coupled breather valve of the present application;

[0046] Figure 14 A valve cap structure diagram of the multi-stage coupled breather valve of the present application;

[0047] Figure 15 A cross-sectional structure diagram of the valve body of the multi-stage coupled breather valve of the present application;

[0048] Figure 16 A screw thread fitting type cyclone cylinder structure diagram of the multi-stage coupled breather valve of the present application;

[0049] Figure 17 A double sealing ring fitting type cyclone cylinder structure diagram of the multi-stage coupled breather valve of the present application;

[0050] Figure 18 A buckle fitting type cyclone cylinder structure diagram of the multi-stage coupled breather valve of the present application.

[0051] BRIEF DESCRIPTION OF THE DRAWINGS

[0052] 10, air vent valve body; 11, valve body; 111, air vent hole; 112, groove; 113, retainer; 12, valve cap; 121, boss; 13, filter layer structure; 131, metal filter layer; 1311, central circular area; 1312, inner sawtooth ring area; 1313, outer sawtooth ring area; 1314, sawtooth structure; 132, non-metal filter layer; 132a, first non-metal fiber filter layer; 132b, second non-metal fiber filter layer; 132c, third non-metal fiber filter layer; 132d, fourth non-metal fiber filter layer; 1321, inner sawtooth area; 1322, outer sawtooth ring area; 1323, sawtooth structure; 133, film placement platform; 1331, annular area; 1332, open hole area; 134, oil and water repellent film layer; 135, outer sawtooth structure; 14, liquid-philic strip; 141, sawtooth structure; 20, pressure expansion cyclone separation structure; 21, pressure expansion piece; 211, strong oil-repellent ring surface; 212, strong oil-philic ring surface; 22, cyclone separation piece; 221, cyclone cylinder; 23, rotating vane structure; 231, central shaft; 232, first vane structure; 233, second vane structure; 234, first blade; 235, second blade; A, first rotation direction; B, second rotation direction; D1, diameter; D2, diameter; H, blade height; K, pressure expansion channel; L1, length; L2, length; L3, length; L4, length; N, inner wall surface; R3, blade outer diameter; a, height; b, wall thickness; c, spacing; d, diameter; d1, necked end diameter; d2, flared end diameter; e, spacing; f, blade thickness; g, width; h, height; sawtooth angle; sawtooth angle; sawtooth angle. DETAILED DESCRIPTION

[0053] In order to make personnel in the technical field better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work should belong to the scope of protection of the present application.

[0054] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or there can be an intervening element. The terms "vertical", "horizontal", "left", "right", and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0055] 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 application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. The use herein of the terms "and / or" includes a set of one or more associated listed items.

[0056] As shown in Figure 1 and Figure 2 The application provides a multi-stage coupled breather valve, comprising a breather valve body 10 and a pressure expansion and cyclone separation structure 20; wherein the breather valve body 10 is provided with a filter layer structure 13; the pressure expansion and cyclone separation structure 20 has a pressure expansion piece 21 and a cyclone separation piece 22 connected together, the cyclone separation piece 22 is connected with the breather valve body 10, and the cyclone separation piece 22 is provided with a rotating vane structure 23.

[0057] The multi-stage coupled breather valve can realize primary cyclone separation and capture of oil droplets and has excellent liquid discharge capacity, the filter layer structure 13 in the breather valve body 10 can perform multi-stage filtration and capture of oil droplets, and the escape of oil droplets is minimized. The application effectively solves the problems of poor oil mist interception performance, low strength of the breather membrane material and poor breathability in the prior art. The multi-stage coupled breather valve can be applied in electric vehicles, can realize super-strong interception of oil mist aerosol during the operation of the electric vehicle, maximizes the toughness and breathability of the membrane material, and effectively improves the oil-proof and breathable characteristics and service life of the breather valve, and improves the operation safety of the electric vehicle.

[0058] Specifically, the bottom of the breather valve body 10 is connected with the pressure expansion and cyclone separation structure 20, and the two can be an integral structure or connected together by welding or other ways. In the embodiment, the breather valve body 10 is cylindrical, and the filter layer structure 13 is located in the cylindrical breather valve body 10; the pressure expansion and cyclone separation structure 20 is located at the bottom end of the breather valve body 10, and its main function is to preliminarily separate and capture liquid droplets. The pressure expansion piece 21 and the cyclone separation piece 22 of the pressure expansion and cyclone separation structure 20 can be an integral structure or connected together by welding or other ways, wherein the cyclone separation piece 22 is cylindrical and directly connected with the breather valve body 10, and the cyclone separation piece 22 comprises a cyclone cylinder 221 and a rotating vane structure 23 arranged in the cyclone cylinder 221. In the embodiment, the inner diameter of the cyclone cylinder 221 is 5mm-9mm, the wall thickness is 1mm-3mm, and the height is 10mm-14mm.

[0059] When the vent valve works, the gas carrying oil droplets first enters the diffuser cyclone separation structure 20, the diffuser 21 in the diffuser cyclone separation structure 20 realizes the preliminary collection of large oil droplets and flows back into the device along the diffuser 21, and then the gas enters the inside of the cyclone separation piece 22, the rotating vane structure 23 in the cyclone separation piece 22 can realize further capture and separation of oil droplets, the captured oil droplets flow back into the device through the diffuser 21, and the gas passing through the diffuser cyclone separation structure 20 enters the filter layer structure 13 in the vent valve body 10, and the filter layer structure 13 can realize multi-layer separation and capture of oil droplets, and the captured oil droplets flow back into the device through the lower cyclone separation piece 22.

[0060] According to one embodiment of the present application, as shown in Figure 3 The diffuser 21 has a diffuser channel K, which is radially tapered in the direction towards the cyclone separation piece 22. This part can realize the rapid acceleration of the liquid-containing gas flow into the upper rotating vane structure 23, and the liquid droplets can be preliminarily captured after impacting the wall surface of the diffuser 21.

[0061] Further, the inner wall surface N of the diffuser channel K includes a strong oil-repellent ring surface 211 and a strong oil-attracting ring surface 212, which are sequentially arranged in the direction towards the cyclone separation piece 22; wherein the oil droplet contact angle of the strong oil-repellent ring surface 211 is greater than or equal to 150°, and the oil droplet contact angle of the strong oil-attracting ring surface 212 is 0°-10°, and by arranging ring surfaces with different oil droplet contact angles, the backflow effect of intercepting liquid droplets can be improved.

[0062] Specifically, in the present embodiment, the diffuser 21 is designed in a narrow-top-wide-bottom type, wherein the height a of the diffuser 21 is 5mm-8mm, the wall thickness b is 1mm-3mm, the necked end diameter d1 is 3mm-5mm, the flared end diameter d2 is 8mm-10mm, and the flow rate increase multiple value is determined by the following formula:

[0063]

[0064] Wherein, M is the flow rate increase multiple value; R1 and R2 are the radii of the flared end and the necked end respectively, with the unit of m; λ is the resistance coefficient, with the value of 0.01-0.05; The diffuser port angle is 20°-70°.

[0065] Active drainage of the diffuser 21 is achieved by the asymmetric distribution of the strongly oil-repellent annular surface 211 and the strongly oleophilic annular surface 212. The lower portion of the inner wall surface N of the diffuser 21, i.e., about 3 / 4 to 4 / 5 of the height a of the diffuser 21, is made into the strongly oleophilic annular surface 212 by using a mask and a needle to spray a modifying solution. The upper portion of the inner wall surface N of the diffuser 21, i.e., about 1 / 5 to 1 / 4 of the height a of the diffuser 21, is made into a strongly oleophilic annular surface 212 by using a needle to spray a modifying solution and a sharp scratching method. The oil-repellent annular surface 211 and the oil-repellent annular surface 211 have an oil drop contact angle of not less than 150°, wherein the strongly oleophilic annular surface 212 helps to prevent oil droplets splashed in the box or running at high speed with the airflow from adhering, and the strongly oleophilic annular surface 211 helps to form a liquid flow barrier at the intersection of the two areas, so that the liquid captured by the strongly oleophilic annular surface 212 cannot continue to flow upward with the airflow, and continuously gathers at the intersection of the two areas and then automatically drains and refluxes downward due to the action of gravity, thereby improving the interception and reflux effect of the droplets.

[0066] According to one embodiment of the present invention, Figure 4 As shown, the rotating guide vane structure 23 includes a central shaft 231 and a first guide vane structure 232 and a second guide vane structure 233 connected to the central shaft 231. The first guide vane structure 232 has a plurality of first blades 234 arranged along a first rotation direction A, and the second guide vane structure 233 has a plurality of second blades 235 arranged along a second rotation direction B. The first rotation direction A is opposite to the second rotation direction B.

[0067] The rotating guide vane structure 23 utilizes the centrifugal force generated during the rotation of the high-speed airflow formed by the diffuser 21 along the multiple blades to separate the droplets from the airflow; the first blade 234 and the second blade 235 are set to opposite rotation directions, which can force the airflow to form a cross-flow reversal, and suddenly change from reverse steady flow rotation to forward steady flow rotation, thereby achieving double inertial acceleration and accelerating the inertial capture of droplets.

[0068] Specifically, such as Figure 1 and Figure 5 As shown, the second guide vane structure 233 and the first guide vane structure 232 with opposite rotation directions are fixed at the upper and lower positions on the central shaft 231 and are built into the cyclone separator 22. In this embodiment, the height h of the central shaft 231 is 10mm~14mm, and the diameter d is 1mm~1.5mm. The first rotation direction A of the first guide vane structure 232 can be counterclockwise, and the second rotation direction B of the second guide vane structure 233 is clockwise. The spacing c between the first guide vane structure 232 and the second guide vane structure 233 is 0.1mm~0.5mm, and the number of blades of the two (that is, the first blade 234 and the second blade 235) is 6~9, and the blades are arranged at equal distances, the spacing e is about 0.4mm, and the thickness f of the blades is about 0.1mm.

[0069] Wherein, the blade function in the first guide vane structure 232 and the second guide vane structure 233 is special, can effectively prevent the large size lubricating oil droplet from being carried by the airflow to escape phenomenon caused by the sudden increase of exhaust volume during the engine starting and sudden acceleration, the specific manufacturing parameters of the blade are determined by the following formula:

[0070] y = σ -1 x 2 + [σ (1-R3ε -1 sinβ) -0.1H]x + 0.9H

[0071] Wherein, σ = 0.1H [1-9 (R3 sinα) -1 ]

[0072] ε = (ω 2 -R3ωsinα) -1

[0073] ω = 0.1H cotα

[0074] As Figure 5 shown, wherein R3 is the outer diameter of the blade, 2mm-4mm; H is the blade height, 4mm-6mm; α is the blade outlet angle, 40°-70°; β is the blade wrap angle, 80°-120°; σ, ω, ε have no specific meaning.

[0075] As Figure 6As shown, the blade function is calculated based on the projection of the blade into the two-dimensional plane of the central axis 231, in the projection plane, the y-axis positive direction is vertically upward, and the x-axis positive direction is horizontally left. The three-dimensional figure obtained by stretching the function curve along the vertical projection plane direction by R3 length is the required blade. The blade function given here is for the first guide vane structure 232. The blade function of the second guide vane structure 233 is symmetric to it along the y-axis, and therefore will not be described again. During operation of the device, the high-speed liquid-containing gas stream first enters the first guide vane structure 232, and under the action of centrifugal force, the liquid droplets are subjected to a first inertial separation. The separated liquid droplets then flow back along the cylinder wall of the cyclone separation piece 22 and then enter the second guide vane structure 233 for a second separation. The second blades 235 of the second guide vane structure 233, which rotate in the opposite direction to the first guide vane structure 232, force the gas stream to form a cross-flow reversal, and the reverse steady-flow rotation changes to forward steady-flow rotation, thereby achieving double inertial acceleration and speeding up the inertial capture of the liquid droplets. In addition, the existence of the small gap c between the first guide vane structure 232 and the second guide vane structure 233 enables the gas stream to quickly change from reverse flow to forward flow, and at the moment of change, the liquid-containing gas stream hits the underside of the second guide vane structure 233 due to inertia, thereby further enhancing the capture of liquid droplets. At the same time, the liquid droplets captured by the first blades 234 and the second blades 235 can flow back under the action of their own gravity and the blade chamfer, thereby accelerating the inertial capture of the liquid droplets and reducing the upward secondary flow of the captured liquid droplets due to the action of the gas stream drag force.

[0076] According to one embodiment of the present application, as shown in Figure 1 and Figure 2 The filter layer structure 13 includes a metal filter layer 131, a non-metal filter layer 132, and an oil and water repellent membrane layer 134 arranged in sequence. The metal filter layer 131 is located at the bottom of the breather valve body 10 and is connected to the rotating guide vane structure 23.

[0077] The metal filter layer 131 can achieve two-stage filtering and capture of oil droplets passing through the above-mentioned pressure-increasing cyclone separation structure 20. The non-metal filter layer 132 located at the upper part of the metal filter layer 131 can achieve three-stage filtering and capture of oil droplets. The oil and water repellent membrane layer 134 located at the top can achieve four-stage interception of oil droplets. The multi-stage coupling design of the present application effectively enhances the interception and capture effect of the breather valve on oil mist.

[0078] According to one embodiment of the present application, as shown in Figure 7As shown, the metal filter layer 131 includes a central circular area 1311 at the center, and a serrated inner ring area 1312 and a serrated outer ring area 1313 at the edges. A serrated structure 1314 is provided at the junction of the serrated inner ring area 1312 and the serrated outer ring area 1313. The metal filter layer 131 is built into the valve body 11, with its bottom welded to the rotating guide vane structure 23. This metal filter layer 131 strengthens the filter membrane material and the rotating guide vane structure 23 above it, improving the pressure and high temperature resistance of the breathable valve while effectively enhancing the droplet interception effect.

[0079] Furthermore, the central circle area 1311 and the sawtooth outer ring area 1313 are super oil-repellent and water-repellent areas, and the sawtooth inner ring area 1312 is a super oleophilic and hydrophilic area.

[0080] Specifically, such as Figure 2 As shown, the metal filter layer 131 in this embodiment is a partially modified metal fiber felt, which is made of metal fiber and has high pressure resistance and high temperature resistance. Its metal texture is easy to connect with the central axis 231 of the rotating guide vane structure 23 at the bottom in the form of spot welding. After the connection is completed, it can be directly inverted on the bottom valve port area of ​​the valve body 11, which not only ensures the strength of the swirl element under high gas velocity conditions, but also has the characteristics of simple welding and quick installation.

[0081] In this embodiment, the locally modified metal fiber felt is a circular element with a diameter D1 of 16 mm to 18 mm, and a commonly used size of 17.5 mm. According to different functions, the element is divided from the inside into a central circle area 1311, a serrated inner ring area 1312 and a serrated outer ring area 1313. A serrated structure 1314 is provided at the intersection of the serrated inner ring area 1312 and the serrated outer ring area 1313. Among them, the diameter of the central circle area 1311 is 85% to 95% of the inner diameter of the cyclone separator 22. This area is treated into a super oil-repellent and water-repellent area using methods such as electrochemical spraying or vapor deposition, which can effectively prevent the upward impact and penetration of droplets impacted by the inertia of high-speed airflow. The serrated inner ring area 1312 is a super oleophilic and hydrophilic treatment area, whose inner diameter is equal to the diameter of the central circle area 1311, and its outer diameter is the diameter of the circumscribed circle of the sawtooth.

[0082] The diameter of the metal filter layer 131 is D1, and the number of teeth of the sawtooth structure 1314 is n1, which is determined by the following formula:

[0083]

[0084] Wherein, D1 is the diameter of the circumscribed circle of the sawtooth, in mm; L1 is the length of the hypotenuse of the sawtooth, which is 1 to 3 mm; is the sawtooth angle, which is 15° to 60°; the calculated value n1 is rounded down to ensure that the sawtooth is evenly distributed and has no overlap.

[0085] The sawtooth outer ring area 1313, i.e., the locally modified metal fiber felt, is the area other than the central circular area 1311 and the sawtooth inner ring area 1312. This area is treated in the same way as the central circular area 1311 to be super oil-repellent and water-repellent. Droplets entering this area will enter the super oil-wetting and water-wetting area under the action of the gradient force caused by the difference in wettability between this area and the adjacent area. This effectively prevents the accumulation of liquid in the corners of the locally modified metal fiber felt, causing local collapse of the filter material and poor drainage.

[0086] The locally modified metal fiber felt is also used to support the non-metallic filter layer 132 above it. When the droplet concentration is high or the equipment runs for a long time, the non-metallic filter layer 132 is prone to reach a state of over-saturation or wetness. The locally modified metal fiber felt can effectively prevent the non-metallic filter layer 132 from being damaged and deformed due to negative pressure conditions in this state, thereby effectively improving the strength and service life of the filter membrane material.

[0087] According to one embodiment of the present application, as shown in Figure 8 and Figure 9 , the non-metallic filter layer 132 is composed of multiple layers of non-metallic fiber filter layers arranged in layers. The non-metallic fiber filter layer includes a sawtooth inner area 1321 located at the center and a sawtooth outer ring area 1322 located at the edge. The intersection of the sawtooth inner area 1321 and the sawtooth outer ring area 1322 is provided with a sawtooth structure 1323.

[0088] Further, the sawtooth inner area 1321 is a super oil-repellent and water-repellent area, and the sawtooth outer ring area 1322 is a super oil-wetting and water-wetting area. In the direction away from the metal filter layer 131, the oil droplet contact angle of the sawtooth outer ring area 1322 of each non-metallic fiber filter layer increases in turn. The non-metallic filter layer 132 is mainly used to capture small droplets that are not filtered and intercepted by the pressure-increasing cyclone separation structure 20 and the metal filter layer 131, further enhancing the filtering performance of the gas valve for droplets of different sizes in different size ranges. Furthermore, the area of the sawtooth outer ring area 1322 of the non-metallic filter layer 132 is greater than the area of the sawtooth outer ring area 1313 of the metal filter layer 131.

[0089] Specifically, in this embodiment, the non-metallic filter layer is composed of four layers of non-metallic fiber filter elements with different modification treatments, which are tightly stacked and built-in the valve body 11. The non-metallic fiber filter elements are the same in diameter D1 as the locally modified metal fiber felt and are placed in turn from bottom to top. First, the first non-metallic fiber filter layer is the main capture layer for droplets, as shown in Figure 9 , which is divided into a sawtooth inner area 1321 and a sawtooth outer ring area 1322. The sawtooth inner area 1321 has the same number and angle of sawteeth as the metal filter layer 131, and the length L2 of the sawtooth hypotenuse is determined by the following formula:

[0090]

[0091] Wherein, D1, L1 and D2, L2 are the diameter of the outer edge of the sawtooth and the length of the sawtooth hypotenuse of the metal filter layer 131 and the first non-metal fiber filter layer, respectively, in mm, the area is modified to be a super oil-repellent and water-repellent area (droplet contact angle not less than 150°), and the area with a gap of 0.2mm-1.0mm between the sawtooth outer edges, i.e. the sawtooth outer ring area 1322, is treated as a super oil-wetting and water-wetting area (super-hydrophobic area, droplet contact angle of 0°-10°). When the liquid droplets enter the metal filter layer 131 with the airflow, the sawtooth inner area 1321 will intercept most of the liquid droplets outside, and the sawtooth outer ring area 1322 becomes an outer annular communication area, which not only can absorb and capture the liquid droplets entering this area, but also facilitates the mutual penetration of liquid in different sawtooth areas, avoiding the phenomenon of excess liquid accumulation in a small number of sawtooth areas.

[0092] As described above, the area of the sawtooth outer ring area 1322 of the first non-metal fiber filter layer is greater than that of the sawtooth outer ring area 1313 of the metal filter layer 131, i.e. the range of the oil-wetting area of this layer is greater than that of the outer oil-repellent area of the metal fiber layer at the bottom of this layer. Since the number and angle of the sawtooth of the two filter layers are the same, there is a sawtooth inner strong liquid-wetting overlapping area between this filter layer and the metal filter layer 131 at the bottom, which forms a liquid transport channel. Under the sawtooth tip effect and the difference in plane wettability, the large amount of liquid absorbed and captured in the sawtooth outer ring area 1322 can quickly flow to the sawtooth inner ring area 1312 of the metal filter layer 131, and then be quickly discharged back to the box from the bottom air inlet.

[0093] Wherein, the sawtooth tip effect is that the sawtooth type tip has a shape gradient in the plane. After the liquid droplet enters the sawtooth area, the part close to the tip has a small pattern area, so the liquid droplet is not easy to spread, resulting in a larger contact angle. The part relatively far from the tip has a larger pattern area, so the liquid droplet is easy to spread, resulting in a relatively smaller contact angle. The difference in contact angles of the liquid droplet before and after causes a Laplace pressure F L directed from the tip to the bottom, which promotes the movement of the liquid droplet from the tip to the bottom. The Laplace pressure F L is determined by the following formula:

[0094]

[0095] Wherein, F L is the Laplace pressure, in N; Г is the surface tension of the liquid droplet, in N / m; S is the contact area of the liquid droplet with the plane, in m 2 ; R4 and R5 represent the radii of the liquid droplet relatively far from the tip and close to the tip, respectively, in m.

[0096] The planar wetting difference effect refers to that the contact angles of liquid drops in different regions of a plane are greatly different due to different wettabilities of the same plane, the greater the contact angle value, the higher the surface energy of the liquid drop, and the more easily the liquid drop migrates to a region (more easily wetted region) in which the surface energy is reduced. The force generated by the different wettabilities of the plane to promote the migration of the liquid drop is the wettability gradient force F L * determined by the following formula:

[0097]

[0098] wherein F L * is the wettability gradient force, the unit is N; Г is the surface tension of the liquid drop, the unit is N / m; R6 is the base radius of the contact between the liquid drop and the plane, the unit is m; θ1 and θ2 respectively represent the contact angles of the liquid drop in the strongly wetted region and the weakly wetted region, the unit is °.

[0099] Under the cooperation of the Laplace pressure F L and the wettability gradient force, the directional migration of the liquid drop will be accelerated. The sawtooth inner region 1321 of the second non-metallic fiber filter layer 132b and the first non-metallic fiber filter layer 132a are modified in the same way, but the sawtooth outer ring region 1322 is a strongly wetted region (liquid contact angle is 10°-30°). The sawtooth inner region 1321 of the third non-metallic fiber filter layer 132c and the first non-metallic fiber filter layer 132a are modified in the same way, but the sawtooth outer ring region 1322 is a moderately wetted region (liquid contact angle is 30°-50°). The sawtooth inner region 1321 of the fourth non-metallic fiber filter layer 132d and the first non-metallic fiber filter layer 132a are modified in the same way, but the sawtooth outer ring region 1322 is a weakly wetted region (liquid contact angle is 50°-70°), as shown in the specific embodiment. Figure 8

[0100] As a further preferred embodiment of the present application, in another embodiment of the present application, the non-metallic filter layer 132 can increase the number of non-metallic fiber filter layers as needed, which are modified in the same way as the sawtooth inner region 1321 of the first non-metallic fiber filter layer, but the sawtooth outer ring region 1322 is a weakly wetted region (liquid contact angle is 50°-70°).

[0101] The arrangement of the non-metallic fiber filter element from bottom to top, with the wettability of the sawtooth inner region 1321 decreasing layer by layer, on the one hand, can realize that most of the liquid drops are captured and intercepted in the lower filter layer, which not only ensures the filtering efficiency of the liquid drops, but also improves the cleanliness of the upper filter layer, so that the air permeability of the filter layer is improved. On the other hand, the liquid drops can be drained and returned downward under the action of the wettability gradient.

[0102] ​According to one embodiment of the present application, serrated structures 135 are arranged at the edges of the serrated structures of the non-metallic filter layer 132 and / or the serrated structures of the metallic filter layer 131. Specifically, as shown in Figure 10 Fig. 2, the serrated structures of the metallic filter layer 131 and the non-metallic filter layer 132 can be further improved into longitudinal and transverse combined serrated structures, i.e. the linear tooth edges of the serrated structures are replaced by uniformly distributed serrated structures 135, the length L3 of the serrated inclined edges is 0.8mm-1.0mm, the serrated angle is 15°-60°, and the liquid collection and drainage capacity is further increased under the effect of the combined serrated tips.

[0103] According to one embodiment of the present application, as shown in Figure 11 Fig. 3, at least one liquid-philic strip 14 is arranged at the inner serrated region 1321 of the non-metallic filter layer 132 and / or the central circular region 1311 of the metallic filter layer 131, which can be applied in high-speed gearboxes or in situations where the oil mist content is obviously higher. Further, as shown in Figure 12 Fig. 4, serrated structures 141 are arranged at the edges of the liquid-philic strip 14.

[0104] Specifically, in the case of higher oil mist concentration, liquid-philic strips 14 (the number of pairs of liquid-philic strips 14 can be 1, 2 or 3 according to the need) can be arranged inside the non-metallic filter layer 132 and / or the metallic filter layer 131, as shown in Figure 11 Fig. 5, the strips are arranged in pairs, in this embodiment, the width g of the liquid-philic strip 14 is 0.2mm-1.0mm, and the liquid-philic strip 14 is a pair of strips arranged perpendicularly at an angle of 90°, of course, only one pair of liquid-philic strips 14 is shown in this embodiment, and multiple groups of liquid-philic strips 14 can be arranged according to the actual need, when two groups of liquid-philic strips 14 are arranged, the angle between the liquid-philic strips 14 is 45°, and when three pairs of liquid-philic strips 14 are arranged, the angle between the liquid-philic strips 14 is 30°, which is not limited. The arrangement of the liquid-philic strips 14 relieves the single region drainage pressure, and the liquid droplets can not only move towards the liquid-philic edge region, but also move towards the liquid-philic strip 14 region, and follow the principle of "drainage as close as possible", therefore, the arrangement of the liquid-philic strips 14 helps the liquid in the circular inner region to be quickly collected and directionally guided and drained.

[0105] Further, in the case of extremely high oil mist concentration and harsh working conditions, as shown in Figure 12 Fig. 6, serrated structures 141 can be arranged at both edges of each liquid-philic strip 14, wherein the serrated angle is 15°-60°, and the length L4 of the serrated inclined edges is 1mm-1.5mm, which further promotes the collection of the liquid in the strip under the effect of the serrated tips.

[0106] According to one embodiment of the present application, as shown in Figure 1As shown, a film placing platform 133 is arranged between the non-metal filter layer 132 and the oil and water repellent film layer 134, and the film placing platform 133 includes an annular region 1331 at an edge position and an open region 1332 at a central position, and the oil and water repellent film layer 134 is arranged on the open region 1332.

[0107] Specifically, as shown in Figure 2 and Figure 13 , the film placing platform 133 in the embodiment is circular, mainly used for placing the top oil and water repellent film layer 134, and has the same diameter as the inner diameter of the valve body 11, and is arranged in the valve body 11 at a position about 2 mm higher than the total height of the metal filter layer and the non-metal filter layer, and has a thickness of 0.8 mm. The film placing platform 133 is composed of the annular region 1331 with a ring width of about 0.5 mm and the open region 1332 with uniformly spaced circular holes with a diameter of 1 mm to 2 mm and a spacing of 0.1 mm to 0.3 mm. The annular region 1331 is designed to facilitate the connection of the film placing platform 133 and the valve body 11 by ultrasonic welding or other methods. The circular holes in the open region 1332 are mainly used to achieve rapid passage of gas and reduce the impact on the air permeability of the multi-stage coupled breather valve.

[0108] The oil and water repellent film layer 134 is fixed on the film placing platform 133 by ultrasonic welding, adhesive bonding or other methods, and has the same size as the non-metal filter layer 132, and is mainly used to prevent liquid droplets and dust impurities in the air from entering the breather valve and affecting the normal operation of the equipment. The oil and water repellent film layer 134 is generally an ePTFE film or other dense polymer material film.

[0109] According to one embodiment of the present application, as shown in Figure 1 , the breather valve body 10 further includes a valve body 11 and a valve cap 12 clamped together, and the opening edge of the valve body 11 is provided with a plurality of grooves 112 along the circumferential direction thereof, and the top of the valve cap 12 is provided with a plurality of bosses 121 along the circumferential direction thereof, and in the state that the valve cap 12 is clamped on the valve body 11, the bosses 121 are embedded in the grooves 112.

[0110] Further, as shown in Figure 14 and Figure 15 , at least one air permeable hole 111 is formed in the side wall of the valve body 11 along the circumferential direction thereof, and the valve cap 12 has an outer ring wall extending towards the valve body 11, and the at least one air permeable hole 111 is blocked by the outer ring wall.

[0111] Specifically, as shown in Figure 15As shown, the valve body 11 in the embodiment is cylindrical, with an inner diameter of 16mm-18mm and a wall thickness of 1mm-3mm. The height of the valve body 11 is 8mm-10mm higher than the total height of the metal filter layer 131 and the non-metal filter layer 132 inside it. Four to six evenly distributed grooves 112 are opened on the upper edge of the valve body 11, with a groove depth of 0.5mm-1mm and a length of 4mm-6mm. Two symmetrically distributed rectangular air vents 111 are opened at a position about 1mm below the lower edge of the grooves 112, facilitating the balance of the pressure inside and outside the box, with a width of 1mm-1.5mm and a length of 15mm-20mm. As described above, there is a space of 2.5mm-5.5mm in height between the air vent 111 and the oil and water repellent film layer 134, which is mainly used to buffer the airflow entering through the air vent 111, preventing impact damage to the filter element due to excessive flow rate.

[0112] As shown in Figure 2 and Figure 14 , the outer diameter of the valve cap 12 in the embodiment is 2mm-4mm larger than that of the valve body 11, with a thickness of 1mm-2mm. The brim of the cap extends downward to exceed the air vent by 0.8mm-1.2mm. The valve cap 12 is embedded with a boss 121, which is connected in cooperation with the grooves 112 on the valve body 11. The valve cap 12 covers the top of the protective shell, and the design of the brim can prevent large particulate pollutants in the air from entering the breather valve through the air vent and affecting the normal operation of the equipment in the non-working state of the equipment, and can also ensure that the air enters the breather valve normally to maintain the balance of the pressure inside and outside the equipment in the working state of the equipment. Specifically, the valve cap 12 is made of nylon or metal material and is prepared into a composite buckle type by using 3D printing technology or turning and pinning processing.

[0113] According to one embodiment of the present application, as shown in Figure 2 , the breather valve body 10 is provided with a retaining sheet 113, which is configured to be pressed and fixed inside the breather valve body 10 together with the metal filter layer 131 and the non-metal filter layer 132.

[0114] Specifically, as shown in Figure 15 , in the embodiment, four retaining sheets 113 with a length and width of 0.5mm and a thickness of 0.2mm-0.5mm are installed equidistantly inside the valve body 11, with an installation height equal to the total height of the metal filter layer 131 and the non-metal filter layer 132. This design can realize the fixation of the filter layer structure 13 and prevent the filter layer structure 13 from moving upward and being dislocated due to pressure changes or violent vibration.

[0115] According to the multi-stage coupled breather valve, when the breather valve is installed, the cyclone cylinder 221 in the pressure expansion cyclone separation structure 20 is connected in cooperation with the workpiece to be installed, as shown in Figure 16 , Figure 17 and Figure 18As shown, the application gives three kinds of cooperation forms of the cyclone cylinder 221, which are thread cooperation type, double sealing ring cooperation type and buckle cooperation type, can meet the installation needs of different equipment, increase the practicability of the breather valve.

[0116] The above-described specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the application, and it should be understood that the above-described is only a specific embodiment of the application and is not used to limit the protection scope of the application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A multi-stage coupled breather valve characterized by, The application relates to a vent valve body, which comprises a filter layer structure, an expansion pressure cyclone separation structure, a rotating guide vane structure, a metal filter layer, a non-metal filter layer and an oil and water repellent membrane layer. The expansion pressure cyclone separation structure comprises an expansion pressure part and a cyclone separation part, and the cyclone separation part is connected with the vent valve body. The expansion pressure part has an expansion pressure channel, which is radially tapered towards the cyclone separation part. The inner wall surface of the expansion pressure channel comprises an oil-repellent ring surface and an oil-attracting ring surface, which are sequentially arranged towards the cyclone separation part. The oil droplet contact angle of the oil-repellent ring surface is greater than or equal to 150 degrees, and the oil droplet contact angle of the oil-attracting ring surface is 0-10 degrees.

2. The multi-stage coupled vent valve of claim 1, wherein, The rotating guide vane structure comprises a central shaft, a first guide vane structure and a second guide vane structure connected with the central shaft.

3. The multi-stage coupled breather valve of claim 1, wherein, The first guide vane structure has a plurality of first blades arranged in a first rotation direction, and the second guide vane structure has a plurality of second blades arranged in a second rotation direction.

4. The multi-stage coupled breather valve of claim 3, wherein, The first rotation direction is opposite to the second rotation direction.

5. The multi-stage coupled breather valve of claim 4, wherein, The filter layer structure comprises a metal filter layer, a non-metal filter layer and an oil and water repellent membrane layer which are sequentially stacked.

6. The multi-stage coupled vent valve of claim 3, wherein, The metal filter layer is located at the bottom of the vent valve body and is connected with the rotating guide vane structure.

7. The multi-stage coupled breather valve of claim 6, wherein, The metal filter layer comprises a central circular area at a central position, a sawtooth inner ring area and a sawtooth outer ring area at an edge position.

8. The multi-stage coupled breather valve of claim 4 or 6, wherein, The central circular area and the sawtooth outer ring area are super oil-repellent and water-repellent areas, and the sawtooth inner ring area is a super oil-attracting and water-attracting area.

9. The multi-stage coupled breather valve of claim 4 or 6, wherein, The non-metal filter layer is composed of a plurality of non-metal fiber filter layers which are stacked.

10. The multi-stage coupled breather valve of claim 9, wherein, The non-metal fiber filter layer comprises a sawtooth inner area at a central position and a sawtooth outer ring area at an edge position.

11. The multi-stage coupled breather valve of claim 4 or 6, wherein, The sawtooth inner area is a super oil-repellent and water-repellent area, and the sawtooth outer ring area is a super oil-attracting and water-attracting area.

12. The multi-stage coupled vent valve of claim 3, wherein, The oil droplet contact angle of the sawtooth outer ring area of each non-metal filter layer increases sequentially away from the metal filter layer. The area of the sawtooth outer ring area of the non-metal filter layer is greater than that of the metal filter layer. At least one liquid-attracting strip is arranged on the sawtooth inner area of the non-metal filter layer and / or the central circular area of the metal filter layer. A sawtooth structure is arranged at the edge of the liquid-attracting strip. An outer sawtooth structure is arranged at the edge of the sawtooth structure of the non-metal filter layer and / or the edge of the sawtooth structure of the metal filter layer. A film placing table is arranged between the non-metal filter layer and the oil and water repellent membrane layer. The film placing table comprises an opening area at a central position and a ring area at an edge position, and the oil and water repellent membrane layer is arranged on the opening area.

13. The multi-stage coupled vent valve of claim 1, wherein, The air permeable valve body comprises a valve body and a valve cap buckled together, the opening edge of the valve body is provided with a plurality of grooves along the circumferential direction thereof, and the top of the valve cap is provided with a plurality of bosses along the circumferential direction thereof, and in the state that the valve cap is buckled on the valve body, the bosses are embedded in the grooves.

14. The multi-stage coupled vent valve of claim 13, wherein, At least one air permeable hole is formed in the side wall of the valve body along the circumferential direction thereof, and the valve cap has an outer ring wall extending towards the valve body, and at least one air permeable hole is blocked by the outer ring wall.

15. The multi-stage coupled air vent valve of claim 3, wherein, A retaining sheet is arranged in the air permeable valve body, and the retaining sheet is configured to press and fix the metal filter layer and the non-metal filter layer in the air permeable valve body.

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