A bionic range hood flue check valve with reduced viscosity and noise

Abstract

The present invention discloses a bionic viscosity-reducing and noise-reducing range hood flue check valve, comprising a valve body, a valve disc, and a hinge shaft. Two upper and lower annular ridge segments, concentric with the cylinder but not on the same plane, are provided in the hollow cylinder of the valve body to prevent the valve disc from opening the valve in reverse and preventing oil smoke from flowing back. The edges of the ridge segments are serrated, and an oleophobic coating is prepared on the surface of the ridge segments. The valve disc is a stainless steel disc, and the periphery of the outer edge of the valve disc is serrated. A hemispherical convex unit array is machined on the front of the valve disc, and an oleophobic coating is prepared on the surface of the valve disc. The hinge shaft horizontally passes through the shaft groove on the valve disc and two circular holes on the cylindrical wall of the valve body to eccentrically fix the valve disc in the valve body. The valve disc rotates around the hinge shaft to close or open the check valve. The check valve can avoid the problem of the valve disc being unable to open due to oil adhesion, has low noise, and a simple structure. It has high application and promotion value in civil, large-scale ship, and military fields.

Description

Technical Field

[0001] The present invention relates to a bionic range hood flue check valve with reduced viscosity and noise, belonging to the technical field of kitchenware manufacturing. Specifically, the invention relates to a method for fabricating a bionic non-smooth raised structure, an oleophobic coating, and a serrated edge on the surface of a range hood flue check valve component. This method addresses the problem of oil stains adhering to the check valve over time, which can cause adhesion between the valve cover and valve seat, preventing the valve cover from opening and preventing the range hood from exhausting fumes. It also addresses the issue of high exhaust noise. Background Art

[0002] Range hood flue check valves, also known as non-return valves, are typically installed at the interface between the range hood exhaust pipe and the building's flue. They automatically open and close based on the force of the fumes flowing through the pipe and gravity. Their primary function is to prevent the backflow of fumes from the building's common flue, preventing fumes and toxic exhaust from neighboring homes from entering the home and polluting the indoor air, thus protecting family health. They also prevent flying insects such as mosquitoes and flies, as well as reptiles such as geckos, from entering the home through the flue. Consequently, these valves are increasingly widely used in modern building construction. However, existing range hood flue check valves, after a period of use, can become greasy and sticky due to the surface contact with fumes. This can cause the valve cover to stick to the valve seat, making it difficult to open, resulting in a blocked exhaust duct and preventing the exhaust of hot kitchen fumes. Frequent disassembly and cleaning are essential, causing significant inconvenience. Furthermore, when the range hood is in operation, the interaction between the fumes and the check valve components creates a loud noise, which can seriously impact family health and negatively impact neighborhood relationships. Therefore, it is very necessary to reduce the viscosity and noise of the range hood flue check valve.

[0003] A Chinese patent (authorization publication number CN212429800U) discloses a flue check valve, comprising a fixed frame, an exhaust pipe disposed in the center of the fixed frame, a fixed disk disposed at one end of the exhaust pipe, an exhaust hole disposed in the center of the fixed disk, a stepped ring disposed concentrically with the exhaust hole of the fixed disk, and an iris-type opening and closing door mechanism disposed on the stepped ring to close and block the central through hole. The flue check valve uses an electric motor to drive a balancing gear to rotate clockwise, which drives the stepped ring to rotate counterclockwise, causing several groups of fan-shaped blades to open, ensuring the flue is unobstructed and achieving smoke exhaust. When the electric motor is driven in reverse, the flue is closed. The flue check valve avoids the problem of the valve disc and the aged leather ring of the traditional flue check valve adhering to each other, and has a good smoke exhaust effect. A Chinese patent (authorization publication number CN210034547U) discloses a double-opening metal flue check valve, which includes a metal valve body connected to the chimney, a flapper-type metal valve core inclined in the closing direction, a rubber sealing ring on the edge of the flapper-type valve core, and multiple quick-install torsion springs evenly distributed along the valve body mounting edge. A longitudinal double shaft inclined in the closing direction is provided in the middle of the metal valve body. The flapper-type metal valve core is a double-leaf semicircular metal flapper symmetrically arranged in the valve body via the dual shafts. The rubber sealing ring has a sealing ridge on the crimping surface. The check valve uses the sealing ridge on the edge to press against the metal valve body stop, forming an anti-sticking seal structure that can prevent viscous substances formed by oil smoke from sticking and preventing the valve core from opening. A Chinese patent (authorization publication number CN202937846U) discloses a drooping check valve for laboratory ventilation systems that is easily disassembled and cleaned, and has good sealing properties. The valve comprises a valve body, a valve disc, and a valve stem. The valve body has a hollow chamber that serves as an exhaust passage. The valve stem is laterally and detachably connected to the hollow chamber of the valve body. The valve disc is disposed within the hollow chamber and is used to block the exhaust passage. A one-way check structure is provided between both sides of the valve disc and the inner wall of the valve body to prevent reverse flow of smoke and air. The valve disc is connected to the valve stem via a hinged connection structure. When air is admitted, the valve disc opens the exhaust passage or closes it under its own weight. The check valve and its components, such as the valve disc, are easily disassembled and cleaned, preventing problems such as increased valve disc weight, adhesion of dirt, and poor sealing after prolonged use in the flue.

[0004] In summary, various measures have been adopted to prevent the long-term sticking of range hood check valves, which can lead to the valve cover being unable to open and exhaust fumes being blocked. These include electric valve opening and closing systems, anti-sticking sealing structures, valve disc removable and cleaning mechanisms, and even manual valve opening and closing devices. Electric check valves offer relatively reliable opening and closing performance, but they require additional energy consumption during use. While check valves with easy-to-remove and clean valve discs and manual valve opening and closing mechanisms can also address the issue of valve disc sticking and preventing opening, they are cumbersome to operate and do not fundamentally address the problem of oil and dirt adhesion. Furthermore, noise reduction in range hood check valves has received insufficient attention, with few reports available. Therefore, it is necessary to develop a range hood check valve with a simple, practical structure, easy operation, and effective performance to achieve both stickiness and noise reduction.

[0005] This invention applies bionic technology to the design and fabrication of a range hood flue check valve. By applying a bionic structure and an oleophobic coating to the surface of key components of the check valve, a bionic range hood flue check valve with reduced viscosity and noise is achieved. This check valve has a simple structure and fabrication method, is easy to operate, and can reduce both adhesion and noise, providing user convenience. It has broad application prospects in civilian applications, large ships, and military applications. Summary of the Invention

[0006] The present invention aims to develop a bionic viscosity-reducing and noise-reducing range hood flue check valve. The key parts of the valve body and valve plate of the check valve are oil-free and produce low noise, thus avoiding the phenomenon that the valve plate and the valve body are adhered to each other by oil after long-term use, resulting in the valve plate being difficult to open and making high noise.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A bionic viscosity-reducing and noise-reducing range hood flue check valve comprises a valve body, a valve plate and a hinge shaft.

[0009] The valve body is made of PVC and primarily serves to connect the check valve to the exhaust pipe and flue. A square mounting structure is installed on the outside of the valve body to secure the valve body to the flue wall. The valve body is hollow, with a cylindrical hollow portion. Exhaust gas flows through this hollow cylinder into the building's public flue. Two annular ribs, concentric with the cylinder but not on the same plane, are provided within the hollow cylinder of the valve body. These ribs are used to block the valve disc and prevent the backflow of oil smoke and exhaust gas. The vertical gap between the two ribs is exactly equal to the thickness of the valve disc. When the range hood is not in operation, the valve disc is in a vertically closed state and is located exactly between the two ribs. The ribs are flanked by the air inlet and outlet, respectively. The upper rib is located on the outside of the valve disc, and the lower rib is located on the inside of the valve disc. The projections of the two ribs on a plane perpendicular to the axis of the valve body form a circular ring with a gap on each side. The size of the gap is preferably such that it does not hinder the installation and rotation of the valve disc. A serrated structure with a side length of 1.5 to 2 mm and a height of 1.3 to 1.7 mm is machined on the edges of the two ribs. An oleophobic coating is also applied to the surfaces of the two ribs. Two circular holes with a diameter of 2 mm are machined on the hollow cylindrical wall between the two ribs of the valve body for mounting the hinge shaft.

[0010] The valve disc is made of 304 stainless steel plate with a thickness of 1 to 1.5 mm and is disc-shaped. A serrated structure with a side length of 1.5 to 2 mm and a height of 1.3 to 1.7 mm is processed around the outer edge of the valve disc. A semi-cylindrical positive and negative groove with an inner radius of 1 mm is punched out on the valve disc at a position 1 / 2 to 2 / 3 of the outer circle radius away from the center of the circle. This groove serves as an axis groove for installing the hinge axis. The axis groove divides the valve disc into upper and lower parts. The upper part of the valve disc is smaller than the lower part of the valve disc. An array of hemispherical raised units with a diameter of 2 to 4 mm and a center distance of 4 to 10 mm are punched out on the front of the valve disc, and are neatly arranged vertically and horizontally. An oleophobic coating is prepared on the surface of the valve disc.

[0011] The hinge shaft is made of stainless steel or carbon steel with a diameter of 2mm. The hinge shaft passes horizontally through the shaft groove in the valve disc and two circular holes in the cylindrical wall of the valve body, securing the valve disc within the hollow cylinder of the valve body with the smaller semicircle on top and the larger semicircle on the bottom. The inner radius of the two annular ridges within the hollow cylinder of the valve body is smaller than the outer radius of the valve disc. Excluding the two ridges and the serrated structure on the edge of the valve disc, the valve disc and the sides of the two ridges have an annular contact surface 3-6mm wide. This ensures that the installed valve disc remains in a vertical position when the range hood is shut down and no exhaust gas is being discharged. The edges of the valve disc tightly fit with the ridges, blocking the exhaust channel and preventing the reverse flow of exhaust gas, thus acting as a one-way check.

[0012] Since the height of the hinge axis is above the center of the valve plate and the distance from the center of the valve plate is 1 / 2 to 2 / 3 of the radius of the outer circle of the valve plate, when the range hood starts to exhaust smoke, the wind force area below the valve plate is larger than that above the valve plate. The lower part of the valve plate opens outward around the hinge axis, and the upper part of the valve plate opens inward around the hinge axis, and the smoke exhaust channel is opened; when the range hood is stopped, the valve plate falls under the action of its own weight, closing the smoke exhaust channel.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The two ridge sections in the valve body and the surface of the valve plate of the present invention are treated with oil repellent treatment, which avoids the phenomenon that oil stains adhere to the surface of the valve plate after the check valve is used for a long time, and adhere to the ridge section in the valve body, resulting in difficulty in opening the valve plate. The smoke exhaust is smooth, the service life is long, and maintenance and cleaning are unnecessary, which is convenient for users and has important significance for purifying indoor air and protecting the health of family members.

[0015] (2) Based on the principle of bionics, the present invention processes a serrated structure on the inner edges of the two ridge sections in the valve body and around the outer edge of the valve plate, and processes a hemispherical unit array on the surface of the valve plate, which changes the flow state of the gas, reduces the volume of the airflow vortex, and greatly reduces the airflow noise during the exhaust process of the range hood, which is of great significance to protecting the health of family members and neighbors in the same building.

[0016] (3) The present invention uses the gravity of the valve plate to close the valve plate, has a simple structure, and the valve plate is easier and more fully opened. It has high application and promotion value in the fields of civil, large ships and military industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a three-dimensional front view of the check valve.

[0018] Figure 2 This is a three-dimensional view of the back of the check valve.

[0019] Figure 3 Check valve edge Figure 1 Vertical section along line AA.

[0020] Figure 4 This is a three-dimensional view of the front of the check valve disc. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] The purpose of the present invention is to develop a bionic viscosity-reducing and noise-reducing range hood flue check valve. In order to achieve the above-mentioned purpose, the present invention performs oil-repellent treatment on the two annular ridge sections inside the valve body and the surface of the valve plate to avoid the phenomenon that oil stains adhere to the surface of the components after long-term use of the check valve, the valve plate and the ridge sections adhere to each other, and the valve plate is difficult to open; at the same time, according to the principle of bionics, a serrated structure is processed on the inner edge of the two annular ridge sections inside the valve body and the periphery of the valve plate, and a hemispherical unit array is stamped on the surface of the valve plate to reduce noise pollution during the exhaust process of the range hood.

[0023] Example 1:

[0024] A bionic viscosity-reducing and noise-reducing range hood flue check valve, the check valve comprises a valve body 1, a valve plate 2 and a hinge shaft 3 ( Figure 1 and Figure 2 ).

[0025] The valve body 1 is made of PVC material and its main function is to connect the check valve to the exhaust pipe and flue. The valve body 1 is equipped with a square fixing structure 11 on the outside, which is used to fix the valve body 1 to the wall of the flue. The valve body 1 is a hollow structure with a cylindrical hollow part. The oil smoke exhaust gas is discharged into the public flue of the building through the hollow cylinder. Two annular convex ridges 12 and 13 are arranged in the hollow cylinder of the valve body 1. They are concentric with the cylinder but not on the same plane. Figure 3 ), used to block the valve plate 2 to prevent the backflow of oil smoke and exhaust gas, the vertical gap size of the two rib sections 12 and 13 is exactly equal to the thickness of the valve plate 2, when the range hood is not working, the valve plate 2 is in a vertical closed state and is just located between the two rib sections 12 and 13, the rib sections 12 and 13 are on both sides of the air inlet and the air outlet respectively, the upper rib section 13 is located on the outside of the valve plate 2, and the lower rib section 12 is located on the inside of the valve plate 2, and the two rib sections 12 and 13 are on a plane perpendicular to the axial direction of the valve body 1. The projection is a circular ring with a gap on each side. The size of the gap is appropriate so as not to hinder the installation and rotation of the valve disc 2. A serrated structure with a side length of 1.5 mm and a height of 1.3 mm is processed on the edges of the two convex ridge segments 12 and 13 to play a bionic noise reduction role; an oleophobic coating is prepared on the surface of the two convex ridge segments 12 and 13; two circular holes 14 with a diameter of 2 mm are processed on the hollow cylindrical wall between the two convex ridge segments 12 and 13 of the valve body 1 for installing the hinge shaft 3.

[0026] The valve plate 2 ( Figure 4) is made of 1mm thick 304 stainless steel plate and is disc-shaped. A serrated structure with a side length of 1.5mm and a height of 1.3mm is processed around the outer edge of the valve plate 2; a semi-cylindrical positive and negative groove with an inner radius of 1mm is punched out at a position 1 / 2 of the outer circle radius deviating from the center of the circle on the valve plate 2, which serves as the axis groove 22 for installing the hinge axis 3; and a hemispherical raised unit array 21 with a diameter of 3mm and a center distance of 5mm is punched on the front of the valve plate 2 to reduce noise pollution during the exhaust process of the range hood; an oleophobic coating is prepared on the surface of the valve plate 2.

[0027] The hinge shaft 3 is made of 304 stainless steel with a diameter of 2 mm. The hinge shaft 3 horizontally passes through the shaft groove 22 in the valve disc 2 and two circular holes 14 in the hollow cylindrical wall, securing the valve disc 2 to the hollow cylindrical wall of the valve body 1 with the smaller semicircle on top and the larger semicircle on the bottom. The inner radius of the two annular ridges 12 and 13 within the hollow cylindrical portion of the valve body 1 is smaller than the outer radius of the valve disc 2. Besides the ridges 12 and 13 and the serrated structure on the edge of the valve disc 2, the valve disc 2 has a 5 mm wide annular contact surface around its perimeter with the sides of the ridges 12 and 13. This ensures that the installed valve disc 2 remains in a vertical position when the range hood is shut down and no exhaust is being discharged. Its edges closely contact the ridges 12 and 13, sealing the exhaust passage and preventing the reverse flow of exhaust, thus acting as a one-way check valve. Since the height position of the hinge axis 3 is above the center of the valve plate 2 and the distance from the center of the valve plate 2 is 1 / 2 of the outer radius of the valve plate 2, when the range hood starts to exhaust smoke, the wind force area below the valve plate 2 is larger than that above the valve plate 2, the lower part of the valve plate 2 opens outward around the hinge axis 3, and the upper part of the valve plate 2 opens inward around the hinge axis 3, and the smoke exhaust channel is opened; and when the range hood is stopped, the lower part of the valve plate 2 falls around the hinge axis 3 under the action of gravity, and the upper part of the valve plate 2 moves up around the hinge axis 3, returns to its original position, and closes the smoke exhaust channel.

[0028] The method for preparing an oleophobic coating on the surface of the valve disc 2 is as follows: the surface of the stainless steel valve disc 2 is cleaned with anhydrous ethanol and acetone, and dried for later use; polyacrylonitrile, epoxy resin and N,N-dimethylformamide are mixed to obtain a polyacrylonitrile epoxy resin composite solution, which is sprayed onto the surface of the stainless steel valve disc 2, and the stainless steel valve disc 2 is dried at a temperature of 80°C for 2 hours; a polytetrafluoroethylene particle dispersion is applied to the surface of the stainless steel valve disc 2, and dried at 100°C for 2 hours; finally, the surface of the stainless steel valve disc 2 is rinsed with anhydrous ethanol to obtain an oleophobic surface coating.

[0029] The method for preparing an oleophobic coating on the surfaces of the two circular ridge segments 12 and 13 of the valve body 1 is as follows: using anhydrous ethanol to clean the surfaces of the two circular ridge segments 12 and 13 of the valve body 1, and drying them for later use; mixing polyacrylonitrile, epoxy resin and N,N-dimethylformamide to obtain a polyacrylonitrile epoxy resin composite solution, spraying the solution onto the surfaces of the two circular ridge segments 12 and 13 of the valve body 1, and drying the valve body 1 at a temperature of 80°C for 2 hours; applying a polytetrafluoroethylene particle dispersion to the surfaces of the two circular ridge segments 12 and 13 of the valve body 1, and then drying the valve body 1 at 80°C for 2 hours; finally, rinsing the surfaces of the two circular ridge segments 12 and 13 of the valve body 1 with anhydrous ethanol to obtain an oleophobic surface coating.

[0030] Alternatively, the two annular rib sections 12 and 13 may not be made into one piece with the valve body 1, but may be fixed in the cylindrical inner cavity of the valve body 1 by gluing.

[0031] Example 2:

[0032] A bionic viscosity-reducing and noise-reducing range hood flue check valve, the check valve comprises a valve body 1, a valve plate 2 and a hinge shaft 3 ( Figure 1 and Figure 2 ).

[0033] The valve body 1 is made of PVC material and its main function is to connect the check valve to the exhaust pipe and flue. The valve body 1 is equipped with a square fixing structure 11 on the outside, which is used to fix the valve body 1 to the wall of the flue. The valve body 1 is a hollow structure with a cylindrical hollow part. The oil smoke exhaust gas is discharged into the public flue of the building through the hollow cylinder. There are two circular rib sections 12 and 13 (which are concentric with the cylinder but not on the same plane) in the hollow cylinder of the valve body 1. Figure 3 ), which is used to block the valve plate 2 to prevent the backflow of oil smoke and exhaust gas. The vertical gap size of the two convex rib sections 12 and 13 is exactly equal to the thickness of the valve plate 2. When the range hood is not working, the valve plate 2 is in a vertical closed state and is just located between the two convex rib sections 12 and 13. The two sides of the two convex rib sections 12 and 13 are respectively the air inlet and the air outlet. The upper convex rib section 13 is located on the outside of the valve plate 2, and the lower convex rib section 12 is located on the inside of the valve plate 2. The projections of the two convex rib sections 12 and 13 on the plane perpendicular to the axial direction of the valve body 1 are circular rings with a gap on each side. The size of the gap is suitable for not hindering the installation and rotation of the valve plate 2. A serrated structure with a side length of 2mm and a height of 1.7mm is processed on the edges of the two convex rib sections 12 and 13, and an oleophobic coating is prepared on the surfaces of the two convex rib sections 12 and 13; two circular holes 14 with a diameter of 2mm are processed on the cylindrical wall between the two convex rib sections 12 and 13 of the valve body 1 for installing the hinge shaft 3.

[0034] The valve plate 2 ( Figure 4) is made of 1.5mm thick 304 stainless steel plate and is disc-shaped. A serrated structure with a side length of 2mm and a height of 1.7mm is processed around the outer edge of the valve plate 2; a semi-cylindrical positive and negative groove with an inner radius of 1mm is punched out at a position 2 / 3 of the outer circle radius deviating from the center of the circle on the valve plate 2, which serves as the axis groove 22 for installing the hinge axis 3; and a hemispherical raised unit array 21 with a diameter of 2mm and a center distance of 4mm is punched on the front of the valve plate 2 to reduce noise pollution during the exhaust process of the range hood; an oleophobic coating is prepared on the surface of the valve plate 2.

[0035] The hinge shaft 3 is made of 304 stainless steel with a diameter of 2 mm. The hinge shaft 3 horizontally passes through the shaft groove 22 on the valve disc 2 and the two circular holes 14 in the hollow cylindrical wall, securing the valve disc 2 within the hollow cylinder of the valve body 1 with the smaller semicircle on top and the larger semicircle on the bottom. The inner radius of the two annular ridges 12 and 13 within the hollow cylinder of the valve body 1 is smaller than the outer radius of the valve disc 2. Besides the ridges 12 and 13 and the serrated structure on the edge of the valve disc 2, the periphery of the valve disc 2 forms a 6 mm wide annular contact surface with the sides of the ridges 12 and 13. This ensures that the valve disc 2, after installation, remains in a vertical position when the range hood is shut down and no exhaust is being discharged. The periphery of the valve disc 2 closely contacts the ridges 12 and 13, blocking the exhaust passage and preventing the reverse flow of exhaust, thus acting as a one-way check valve. Since the height position of the hinge axis 3 is above the center of the valve plate 2 and the distance from the center of the valve plate 2 is 2 / 3 of the outer radius of the valve plate 2, when the range hood starts to exhaust smoke, the wind force area below the valve plate 2 is larger than that above the valve plate 2. The lower part of the valve plate 2 opens outward around the hinge axis 3 and the upper part of the valve plate 2 opens inward around the hinge axis 3, and the smoke exhaust channel is opened; when the range hood is stopped, the lower part of the valve plate 2 falls around the hinge axis 3 under the action of gravity, and the upper part of the valve plate 2 moves up around the hinge axis 3, closing the smoke exhaust channel.

[0036] The method for preparing an oleophobic coating on the surface of the valve disc 2 is as follows: SiC sand particles with a particle size of about 1 mm are impacted on the surface of the stainless steel valve disc 2 by a sandblasting machine for 5 minutes to give the surface a uniform roughness. A hydrochloric acid solution with a concentration of 6 mol / L is prepared, and the surface of the sandblasted stainless steel valve disc 2 is chemically etched for 5 hours. The valve disc 2 is then cleaned in deionized water and anhydrous ethanol for 10 minutes using an ultrasonic cleaner to remove surface reaction products and residual hydrochloric acid solution, and then dried with a hair dryer. A perfluorooctanoic acid anhydrous ethanol solution with a concentration of 0.015 mol / L is prepared, and the chemically etched stainless steel valve disc 2 is placed in the solution and soaked at room temperature for 10 days. The stainless steel valve disc 2 is then taken out and dried to obtain an oleophobic surface with a contact angle of more than 140° with peanut oil.

[0037] The method for preparing an oleophobic coating on the surfaces of the two circular rib segments 12 and 13 is as follows: using anhydrous ethanol and acetone to clean the surfaces of the two circular rib segments 12 and 13 of the valve body 1, and drying them for later use; mixing polyacrylonitrile, epoxy resin and N,N-dimethylformamide to obtain a polyacrylonitrile epoxy resin composite solution, spraying it onto the surfaces of the two circular rib segments 12 and 13, and drying the two circular rib segments 12 and 13 at a temperature of 100°C for 2 hours; applying a polytetrafluoroethylene particle dispersion to the surfaces of the two circular rib segments 12 and 13, and drying them at 100°C for 3 hours; finally, rinsing the surfaces of the two circular rib segments 12 and 13 with anhydrous ethanol to obtain an oleophobic surface coating.

[0038] Alternatively, the two annular rib sections 12 and 13 may not be made into one piece with the valve body 1, but may be fixed in the cylindrical inner cavity of the valve body 1 by gluing.

[0039] Example 3:

[0040] A bionic viscosity-reducing and noise-reducing range hood flue check valve, the check valve comprises a valve body 1, a valve plate 2 and a hinge shaft 3 ( Figure 1 and Figure 2 ).

[0041] The valve body 1 is made of oleophobic PVC material containing polytetrafluoroethylene. Its main function is to connect the check valve to the exhaust pipe and flue. The valve body 1 is equipped with a square fixing structure 11 outside, which is used to fix the valve body 1 to the wall of the flue. The valve body 1 is a hollow structure with a cylindrical hollow part. The oil smoke exhaust gas is discharged into the public flue of the building through the hollow cylinder. Two annular rib sections 12 and 13 are arranged inside the hollow cylinder of the valve body 1. They are concentric with the cylinder but not on the same plane. Figure 3 ), used to block the valve plate 2 to prevent the backflow of oil smoke and exhaust gas, the vertical gap size of the two convex rib sections 12 and 13 is exactly equal to the thickness of the valve plate 2, when the range hood is not working, the valve plate is in a vertical closed state and is just located between the two convex rib sections 12 and 13, the two sides of the two convex rib sections 12 and 13 are the air inlet and the air outlet respectively, the upper convex rib section 13 is located on the outside of the valve plate 2, and the lower convex rib section 12 is located on the inside of the valve plate 2, the projections of the two convex rib sections 12 and 13 on the plane perpendicular to the axial direction of the valve body are circular rings with a gap on each side, the size of the gap is suitable for not hindering the installation and rotation of the valve plate 2, a serrated structure with a side length of 2mm and a height of 1.7mm is processed on the edges of the two convex rib sections 12 and 13; two circular holes 14 with a diameter of 2mm are processed on the cylindrical wall between the two convex rib sections 12 and 13 of the valve body 1 for installing the hinge shaft 3.

[0042] The valve plate 2 ( Figure 4) is made of 1.5mm thick 304 stainless steel plate and is disc-shaped. A serrated structure with a side length of 2mm and a height of 1.7mm is processed around the outer edge of the valve plate 2; a semi-cylindrical positive and negative groove with an inner radius of 1mm is punched out at a position 2 / 3 of the outer circle radius deviating from the center of the circle on the valve plate 2, which serves as the axis groove 22 for installing the hinge axis 3; and a hemispherical raised unit array 21 with a diameter of 2mm and a center distance of 4mm is punched on the front of the valve plate 2; an oleophobic coating is prepared on the surface of the valve plate 2.

[0043] The hinge shaft 3 is made of 45# carbon steel with a diameter of 2mm. The hinge shaft 3 horizontally passes through the shaft groove 22 in the valve disc 2 and two circular holes 14 in the hollow cylindrical wall, securing the valve disc 2 to the hollow cylinder of the valve body 1 with the smaller semicircle on top and the larger semicircle on the bottom. The inner radius of the two annular ridges 12 and 13 within the hollow cylinder of the valve body 1 is smaller than the outer radius of the valve disc 2. Besides the ridges 12 and 13 and the serrated structure on the edge of the valve disc 2, the valve disc 2 has a 4mm wide annular contact surface around the sides of the ridges 12 and 13. This ensures that the valve disc 2, after installation, remains in a vertical position when the range hood is shut down and no exhaust is being discharged. The edges of the valve disc 2 tightly contact the ridges 12 and 13, blocking the exhaust passage and preventing the reverse flow of exhaust, thus acting as a one-way check. Since the height position of the hinge axis 3 is above the center of the valve plate 2 and the distance from the center of the valve plate 2 is 2 / 3 of the outer radius of the valve plate 2, when the range hood starts to exhaust smoke, the wind force area below the valve plate 2 is larger than that above the valve plate 2. The lower part of the valve plate 2 opens outward around the hinge axis 3 and the upper part of the valve plate 2 opens inward around the hinge axis 3, and the smoke exhaust channel is opened; when the range hood is stopped, the lower part of the valve plate 2 falls around the hinge axis 3 under the action of gravity, and the upper part of the valve plate 2 moves up around the hinge axis 3, closing the smoke exhaust channel.

[0044] The method for preparing an oleophobic coating on the surface of the valve disc 2 is as follows: using anhydrous ethanol and acetone to clean the surface of the stainless steel valve disc 2, and drying it for later use; mixing polyacrylonitrile, epoxy resin and N,N-dimethylformamide to obtain a polyacrylonitrile epoxy resin composite solution, spraying it onto the surface of the stainless steel valve disc 2, and baking the stainless steel valve disc 2 at a temperature of 120°C for 5 hours; applying a polytetrafluoroethylene particle dispersion to the surface of the stainless steel valve disc 2, and drying it at 110°C for 4 hours; finally, rinsing the surface of the stainless steel valve disc 2 with anhydrous ethanol to obtain an oleophobic surface coating.

[0045] Alternatively, the two annular rib sections 12 and 13 may not be made into one piece with the valve body 1, but may be fixed in the cylindrical inner cavity of the valve body 1 by gluing.

Claims

1. A bionic viscosity-reducing and noise-reducing range hood flue check valve, comprising a valve body, a valve plate, and a hinge shaft. The valve body is made of PVC material, and a square fixing structure is provided on the valve body for fixing the valve body to the wall of the flue. The valve body is a hollow cylindrical structure with an air inlet and an air outlet at its two ends. The exhaust gas is discharged into the public flue of the building through the hollow cylinder. The valve body is characterized by: Two upper and lower annular rib sections are provided in the hollow cylinder of the valve body, which are concentric with the cylinder but not on the same plane, and are used to block the valve disc and prevent the backflow of oil smoke and exhaust gas. The vertical gap size of the two rib sections is exactly equal to the thickness of the valve disc. When the range hood is not working, the valve disc is in a vertically closed state and is just located between the upper and lower rib sections. The upper rib section is located on the outside of the valve disc, and the lower rib section is located on the inside of the valve disc. The projections of the two rib sections on a plane perpendicular to the axial direction of the valve body are circular rings with a gap on each side. The size of the gap is preferably not to hinder the installation and rotation of the valve disc. A serrated structure is machined on the edges of the two rib sections, and an oleophobic coating is prepared on the surface of the two rib sections. Two circular holes with a diameter of 2 mm are machined on the hollow cylindrical wall between the two rib sections of the valve body for installing the hinge shaft; The valve disc is made of stainless steel plate and is disc-shaped. A serrated structure is machined around the outer edge of the valve disc. A semi-cylindrical groove with an inner radius of 1 mm is punched on the valve disc, offset from the center of the circle, to serve as an axis groove for installing the hinge axis. The axis groove divides the valve disc into upper and lower parts. The upper part of the valve disc is smaller than the lower part of the valve disc. An array of hemispherical raised units arranged neatly in vertical and horizontal directions is punched on the front of the valve disc. An oleophobic coating is prepared on the surface of the valve disc. The hinge shaft is made of stainless steel or carbon steel with a diameter of 2mm. The hinge shaft horizontally passes through the shaft groove on the valve disc and the two circular holes on the cylindrical wall of the valve body to fix the valve disc in the hollow cylinder of the valve body with the small semicircle on the top and the large semicircle on the bottom. The inner radius of the two annular convex ridge sections in the hollow cylinder of the valve body is smaller than the outer radius of the valve disc. In addition, excluding the two convex ridge sections and the serrated structure part of the valve disc edge, there is a 3-6mm wide annular fitting surface around the valve disc and the side surfaces of the two convex ridge sections, so that the valve disc after installation is in a vertical position when the range hood is stopped and there is no exhaust gas discharged. The edges are tightly fitted with the two convex ridge sections to block the exhaust channel and prevent the exhaust gas from flowing in the opposite direction, thus playing a one-way check role. The height position of the hinge axis is above the center of the valve plate. When the range hood starts to exhaust smoke, the wind force area below the valve plate is larger than that above the valve plate, so the lower part of the valve plate opens outward around the hinge axis, and the upper part of the valve plate opens inward around the hinge axis, and the smoke exhaust channel is opened; when the range hood is stopped, the valve plate falls under the action of its own weight, closing the smoke exhaust channel.

2. The bionic viscosity-reducing and noise-reducing range hood flue check valve according to claim 1 is characterized in that: The edges of the two annular convex ridge segments are processed into a sawtooth structure with a side length of 1.5 to 2 mm and a height of 1.3 to 1.7 mm.

3. The bionic viscosity-reducing and noise-reducing range hood flue check valve according to claim 1 is characterized in that: The valve plate is made of 304 stainless steel plate with a thickness of 1 to 1.5 mm and is disc-shaped. A serrated structure with a side length of 1.5 to 2 mm and a height of 1.3 to 1.7 mm is processed around the outer edge of the valve plate. A semi-cylindrical axis groove with an inner radius of 1 mm is stamped on the valve plate at a position 1 / 2 to 2 / 3 of the outer circle radius away from the center of the circle. An array of hemispherical raised units with a diameter of 2 to 4 mm and a center distance of 4 to 10 mm are stamped on the front of the valve plate and arranged neatly in vertical and horizontal directions.

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