Check valve

Abstract

The utility model discloses a check valve which comprises a valve body, an inner air duct is formed in the valve body, the inner air duct is divided into an air inlet section and an air exhaust section, the inner diameter of the air inlet section is smaller than that of the air exhaust section, a table top is formed at the joint of the air exhaust section and the air inlet section, and a connecting structure detachably connected with an air pipe is formed on one side of the air inlet section; the edge of the check valve plate is opened towards the air duct outlet, when the check valve plate is closed, the edge of the check valve plate covers the table top and the valve body base, and the check valve plate is detachably connected with the valve body; compared with the prior art, according to the check valve, when the check valve plate breaks down in the long-term use process, the air inlet section of the valve body is detached from the air pipe of the range hood, the air exhaust section of the valve body is detached from the valve body base, and then the valve body can be detached, so that the check valve plate can be maintained or replaced, maintenance is convenient, and the maintenance cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of check valves, and specifically, to a check valve. Background Art

[0002] When a newly built building is handed over, a common smoke prevention check valve will be installed in the smoke inlet of the public flue. When the household moves in and decorates, the ceiling will be used to cover the smoke inlet of the public flue, that is, the installation position of the smoke prevention check valve is above the ceiling. If the ceiling is an integrated ceiling or a gypsum board ceiling that cannot be disassembled, the ceiling basically completely encloses the smoke prevention check valve above the ceiling. The installation position of the ceiling lamp is the opening to open the ceiling, and the user's operable space is very small. When the smoke prevention check valve needs to be repaired, if the smoke inlet of the public flue is far from the installation position of the ceiling lamp, the ceiling must be removed, resulting in a very high maintenance cost for the check valve. Content of the Utility Model

[0003] The purpose of the utility model is to provide a check valve, which is used to solve the above technical problems.

[0004] A check valve is used to connect the air duct of a range hood and an external ventilation duct, and includes:

[0005] A valve body forms an inner air duct, which is divided into an air inlet section and an air outlet section. The inner diameter of the air inlet section is smaller than that of the air outlet section. The air inlet section has an air duct inlet, and the air outlet section has an air duct outlet. One side of the air inlet section forms a connection structure for connecting the air duct. The connection structure includes a fixing groove arranged on the outer side of the valve body, and fixing holes are formed around the fixing groove. The connection structure is used for detachable connection with the air duct. A table surface is formed at the junction of the air outlet section and the air inlet section;

[0006] A check valve plate is arranged in the inner air duct. The edge of the check valve plate opens towards the air duct outlet, and when the check valve plate is closed, the edge of the check valve plate covers the table surface;

[0007] A valve body base has a connection section, which is a straight pipe and forms at least two symmetrical guide rails. The guide rails are used for guiding and connecting the valve body. The connection section has a fitting surface that fits with the outer surface of the air outlet section of the valve body. Guide posts corresponding to the guide rails are arranged on the outer surface of the air outlet section, and the guide posts are slidably connected with the guide rails, so that the air outlet section of the valve body is detachably connected with the valve body base.

[0008] According to an embodiment of the utility model, the range of the angle formed by the table surface formed at the junction and the center line of the valve body is 45 degrees to 90 degrees. An elastic member is arranged at the joint where the edge of the check valve plate fits with the table surface, and the table surface or the edge of the check valve plate has a flange that abuts against the elastic member.

[0009] According to an embodiment of the present utility model, the elastic member is located on the side of the check valve flap edge facing the tabletop, and is fixed by snap-fitting through a receiving groove or fixed by adhesive or process bonding; or the elastic member is arranged on one side of the tabletop and fixed by a snap structure or adhesive.

[0010] According to an embodiment of the present utility model, an oil drain hole communicating with the inner air duct of the valve body is formed on the lower side of the fixing groove.

[0011] According to an embodiment of the present utility model, the air inlet section has a smooth straight inner wall, and the ratio of the ventilation area of the air inlet section to the ventilation area of the air outlet section is 0.89 - 0.98.

[0012] According to an embodiment of the present utility model, a cross beam is arranged in the air inlet section. The side of the cross beam facing the air duct inlet is a smooth arc surface, and a fixing part is formed on the side of the cross beam facing the air duct outlet. Two shaft clamps are formed at the positions corresponding to both sides of the cross beam on the tabletop. The shaft clamps are used to snap-fit the rotating shafts arranged at both ends of the check valve flap. The check valve flap has two pieces, each of which is a semi-circular sheet structure. The two semi-circular sheet structures are symmetrically arranged on both sides of the cross beam with the cross beam as the axis of symmetry. When the check valve flap seals the connection between the air inlet section and the air outlet section, the straight line segment parts of the edges of the two semi-circular sheet structures extend to the lower side of the side of the cross beam facing the air outlet section and abut against the surface of the cross beam facing the air outlet section. A torsion spring is installed on the fixing part of the cross beam. The two acting ends of the torsion spring respectively act on the two semi-circular sheet structures from the side of the two semi-circular sheet structures facing the air outlet section, applying a force towards the air inlet section to the semi-circular sheet structures.

[0013] According to an embodiment of the present utility model, the check valve flap has wind guiding ribs arranged on the windward side.

[0014] According to an embodiment of the present utility model, the valve body base and the valve body have a sealing and fixing structure. The sealing and fixing structure includes an elastic sealing ring. The elastic sealing ring is squeezed and arranged between the valve body base and the valve body. A groove for accommodating the elastic sealing ring is arranged on the inner surface of the connection section or the outer surface of the air outlet section.

[0015] According to an embodiment of the present utility model, the valve body base has a convex edge extending outward from the connection section. The convex edge is formed with fixing holes evenly distributed around the connection section. The valve body base is connected to the wall surface of the building by passing fasteners through the fixing holes.

[0016] According to an embodiment of the present utility model, the fixing surface of the valve body base is provided with an installation beam crossing the connection section. The installation beam is integrally formed with the valve body base; further includes a fixing bracket. The fixing bracket is hung on the air outlet of the ventilation duct and fixed inside the ventilation duct; the installation beam and the fixing bracket are respectively provided with corresponding installation holes. A bracket fastener passes through the corresponding installation holes to connect the installation beam and the fixing bracket to the ventilation duct.

[0017] Compared with the prior art, the check valve of the present utility model has the following advantages:

[0018] 1. For the check valve of the present utility model, when a failure occurs to the check valve piece during long-term use, the ceiling lamp can be removed, and one can reach above the ceiling to disassemble the air inlet section of the valve body from the air duct of the range hood, and then disassemble the air exhaust section of the valve body from the valve body base, so that the valve body can be disassembled to repair or replace the check valve piece inside the valve body. Users do not need to reach into the smoke inlet of the common flue to disassemble the smoke prevention check valve, which is convenient for maintenance and has low maintenance cost.

[0019] 2. For the check valve of the present utility model, when it is used on a range hood, the air inlet section is connected to the air duct of the range hood, the valve body base is fixed to the kitchen wall surface, and the air exhaust section is connected to the valve body base. When the range hood exhausts oil fumes, the oil fumes flow from the air inlet section to the air exhaust section, pushing open the check valve piece, entering the air exhaust section, and being discharged from the air exhaust section. After the oil fumes enter the air exhaust section from the air inlet section, since the inner diameter of the air exhaust section is larger than that of the air inlet section, the oil fumes enter the air exhaust section with a larger inner diameter from the air inlet section with a smaller inner diameter, the wind speed becomes smaller, the wind pressure becomes larger, the wind resistance becomes smaller, and the generated noise is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is an exploded view of the check valve of the present utility model;

[0021] Figure 2 is a sectional view of the check valve of the present utility model;

[0022] In the figures: 1. Valve body, 11. Air inlet section, 12. Air exhaust section, 121. Guide post, 13. Table top, 14. Fixed groove, 141. Fixed hole, 15. Cross beam, 151. Shaft clamp, 2. Check valve piece, 21. Air guide rib, 22. Rotating shaft, 3. Elastic member, 4. Torsion spring, 5. Valve body base, 51. Connection section, 52. Guide rail, 53. Convex edge, 54. Fastening hole, 55. Installation beam, 56. Elastic packing, 6. Elastic sealing ring, 7. Fixed bracket

[0023] The realization and advantages of the functions of the present utility model will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will disclose multiple embodiments of the present utility model in the form of diagrams. For the sake of clarity, many practical details will be described together in the following narrative. However, it should be understood that these practical details are not used to limit the present utility model. That is to say, in some embodiments of the present utility model, these practical details are not necessary. In addition, for the purpose of simplifying the diagrams, some conventional structures and components will be shown in a simple schematic manner in the diagrams.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain specific posture (as shown in the attached drawings). If this specific posture changes, the directional indications will also change accordingly.

[0026] In addition, in the present utility model, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the meaning of order or sequence, nor are they used to limit the present utility model. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0027] In order to further understand the content, characteristics and effects of the present utility model, the following embodiments are exemplified and described in detail in conjunction with the attached drawings:

[0028] In existing commercial housing, a smoke prevention check valve is installed in the smoke inlet of the common flue. When the smoke prevention check valve in the smoke-free port of the common flue needs to be repaired, the user needs to reach into the common flue to disassemble the smoke prevention check valve from the common flue, and then install a new smoke prevention check valve into the smoke inlet of the common flue, which requires a relatively large operating space. When the user's kitchen uses an integrated ceiling or a gypsum board ceiling, the installation position of the ceiling lamp is the opening of the ceiling. Since the size of the installation opening of the ceiling lamp is relatively small, the space for the user to operate above the ceiling is relatively small. When the smoke prevention check valve in the smoke inlet needs to be replaced, the ceiling needs to be removed, resulting in a very high maintenance cost for the check valve.

[0029] The present utility model discloses a check valve. Please refer to Figure 1 and Figure 2, the check valve disclosed by the utility model is used to connect the air duct of the range hood and the external ventilation duct, and includes a valve body 1, a check valve flap 2 and a valve body base 5. The valve body 1 forms an inner air duct, which is divided into an air inlet section 11 and an air outlet section 12. The inner diameter of the air inlet section 11 is smaller than that of the air outlet section 12. The air inlet section 11 has an air duct inlet, and the air outlet section 12 has an air duct outlet. A connecting structure for connecting the air duct is formed on one side of the air inlet section 11. The connecting structure includes a fixing groove 14 provided on the outer side of the valve body 1, and fixing holes 141 are formed around the fixing groove 14. The connecting structure is used for detachable connection with the air duct. A table surface 13 is formed at the junction of the air outlet section 12 and the air inlet section 11; the check valve flap 2 is installed in the inner air duct of the valve body 1, and the edge of the check valve flap 2 opens towards the air duct outlet. When the check valve flap 2 is closed, the edge of the check valve flap 2 covers the table surface 13. The valve body base 5 has a connecting section 51, and the connecting section 51 is a straight pipe, which is formed with at least two symmetric guide rails 52. The guide rails 52 are used for guiding and connecting the valve body 1. The connecting section 51 has a fitting surface that fits with the outer surface of the air outlet section 12 of the valve body 1. Guide posts 121 corresponding to the guide rails 52 are provided on the outer surface of the air outlet section 12. The guide posts 121 are slidably connected with the guide rails 52, so that the air outlet section 12 of the valve body 1 is detachably connected with the valve body base 5. When the check valve of the utility model is in use, the valve body base 5 is fixed to the kitchen wall surface. The air inlet section 11 of the valve body 1 is detachably connected and communicated with the air duct of the range hood. The air outlet section 12 of the valve body 1 is detachably connected with the valve body base 5. After the check valve connects the air duct of the range hood and the ventilation duct, when the exhaust fan of the range hood is started, the exhaust fan extracts the cooking fumes generated by the user into the exhaust air duct of the range hood, and then discharges the fumes entering the exhaust air duct of the range hood outwards. When the fumes in the exhaust air duct enter the kitchen ventilation duct, the fumes have to pass through the check valve. The fumes in the exhaust air duct enter the air duct inlet of the valve body 1 from the outlet of the exhaust air duct, enter the air inlet section 11 through the air duct inlet, and then flow from the air inlet section 11 to the air outlet section 12. When flowing from the air inlet section 11 to the air outlet section 12, the fumes pass through the check valve flap 2. The pressure of the fumes opens the check valve flap 2, and enters the air outlet section 12 from the junction of the air outlet section 12 and the air inlet section 11, flows along the air outlet section 12 and enters the ventilation duct through the air duct outlet, and finally is discharged along the ventilation duct. After the range hood stops working, the exhaust fan of the range hood is turned off. Since the exhaust fan discharges the fumes in the air inlet section 11 to the air outlet section 12 when the exhaust fan is working, after the suction of fumes stops starting, the air pressure in the air outlet section 12 is greater than the air pressure in the air inlet section 11. The air pressure in the air outlet section 12 acts on the check valve flap 2, so that the check valve flap 2 resets and the edge of the check valve flap 2 covers the table surface 13, so that the check valve flap 2 seals the junction of the air outlet section 12 and the air inlet section 11, avoiding the fumes in the air outlet section 12 from flowing back into the exhaust air duct of the range hood through the air inlet section 11, and then flowing back into the kitchen through the exhaust air duct of the range hood, resulting in fumes in the user's kitchen and affecting the air quality of the user's living space.For the check valve of the present utility model, the inner diameter of the air inlet section 11 is smaller than that of the air exhaust section 12. When the cooking fume flows from the air inlet section 11 to the air exhaust section 12, the check valve piece 2 is pushed open under the action of the wind pressure, enters the air exhaust section 12, and is discharged from the air exhaust section 12. After the cooking fume enters the air exhaust section 12 from the air inlet section 11, since the inner diameter of the air exhaust section 12 is larger than that of the air inlet section 11, the wind resistance becomes smaller after the cooking fume enters the air exhaust section 12, and the generated noise is reduced.

[0030] For the check valve of the present utility model, when the check valve is connected to the air duct of the range hood, the air inlet section 11 of the valve body 1 is communicated with the smoke exhaust duct of the range hood through the air duct, and the air duct is connected to the air inlet section 11 through the connecting structure. A fixing groove 14 is formed between the connecting structure and the outer wall surface of the air inlet section 11. One end of the air duct connected to the air inlet section 11 is sleeved outside the air inlet section 11 and the air duct is placed in the fixing groove 14. Then, the air duct and the air inlet section 11 are fastened by a connecting piece passing through the fixing hole 141 on the connecting structure, so that the air duct and the air inlet section 11 are detachably connected, and at the same time, the air inlet section 11 is communicated with the smoke exhaust duct of the range hood through the air duct; when the valve body base 5 is connected to the valve body 1, the connecting section 51 is connected to the air exhaust section 12. The connecting section 51 is sleeved outside the air exhaust section 12. Rotate the valve body 1 so that the guide post 121 on the air exhaust section 12 enters the guide rail 52. During the process of rotating the valve body 1, the guide post 121 slides along the guide rail 52 on the connecting section 51 until the guide post 121 slides to the end of the guide rail 52 and is limited by the guide rail 52, then the valve body 1 cannot be rotated continuously, and the connecting section 51 and the air exhaust section 12 are connected together. The air inlet section 11 and the air exhaust section 12 of the valve body 1 are detachably connected to the air duct of the range hood and the valve body base 5 respectively and connect the air duct of the range hood to the ventilation duct. When the range hood is started, the cooking fume in the smoke exhaust duct of the range hood can be introduced into the ventilation duct. When the range hood is closed, the cooking fume in the ventilation duct can be prevented from flowing back into the kitchen. And when the check valve piece 2 fails during long-term use, the air inlet section 11 of the valve body 1 is detached from the air duct of the range hood, and the air exhaust section 12 of the valve body 1 is detached from the valve body base 5, then the valve body 1 can be detached to repair or replace the check valve piece, which is convenient for maintenance and has a low maintenance cost.

[0031] For the check valve of the present utility model, the range of the angle formed by the table surface 13 formed at the joint and the center line of the valve body 1 is 45 degrees to 90 degrees. An elastic member 3 is provided at the joint between the edge of the check valve piece 2 and the table surface 13, and the edge of the table surface 13 has a flange that abuts against the elastic member 3. The angle formed by the table surface 13 and the center line of the valve body 1 can increase the effective air intake area at the joint between the air intake section 11 and the exhaust section 12, and the area of the check valve piece 2 is also adapted to the effective air intake area. When the ratio of the ventilation areas of the air intake section 11 and the exhaust section 12 is fixed, the smaller the angle formed by the table surface 13 and the center line of the valve body 1, the larger the effective air intake area enclosed by the table surface 13. However, if the angle formed by the table surface 13 and the center line of the valve body 1 is too small, it will increase the length of the exhaust section 12 and is not conducive to rapid exhaust. Therefore, making the range of the angle formed by the table surface 13 formed at the joint and the center line of the valve body 1 be 45 degrees to 90 degrees can increase the effective air intake area enclosed by the table surface 13 without affecting exhaust. When the range hood is closed, the air pressure in the ventilation duct is greater than the air pressure in the exhaust duct of the range hood. When the air flow in the ventilation duct backflows into the exhaust duct of the range hood, the air flow pushes the check valve piece 2 to reset. The edge of the check valve piece 2 abuts against the table surface 13, and the elastic member 3 is squeezed by the flange on the edge of the table surface 13 and deforms, sealing the joint between the table surface 13 and the edge of the check valve piece 2, and preventing the oil fume in the ventilation duct from entering the air intake section 11 through the gap between the table surface 13 and the check valve piece 2, with a better sealing effect.

[0032] Please refer to Figure 1 and Figure 2 For the check valve of the present utility model, the elastic member 3 is located on the side of the edge of the check valve piece 2 facing the table surface 13, and is fixed by snap-fitting in a receiving groove or by adhesive or process bonding. Setting the elastic member 3 in the receiving groove and fixing it in the receiving groove by snap-fitting or by adhesive or process bonding can make the connection between the elastic member 3 and the check valve piece 2 firm and prevent the elastic member 3 from falling off the check valve piece 2.

[0033] The elastic member 3 can be provided on the check valve piece 2 or on the table surface 13. Whether it is provided on the check valve piece 2 or on the table surface 13, the purpose is to seal the contact between the check valve piece 2 and the table surface 13, and prevent the oil fume in the ventilation duct from entering the air intake section 11 through the gap between the table surface 13 and the check valve piece 2. When it is provided on one of them, a corresponding flange is provided on the other to squeeze the elastic member 3 to make the sealing effect better. In some embodiments, the width of the table surface 13 is large enough, and an elastic member 3 is provided at the joint between the edge of the check valve piece 2 and the table surface 13. The elastic member 3 is provided on one side of the table surface 13 and is fixed by a snap structure or adhesive, and the edge of the check valve piece 2 has a flange that abuts against the elastic member 3.

[0034] Please refer to Figure 1 and Figure 2, for the check valve of the present utility model, an oil drain hole communicating with the inner air duct of the valve body 1 is formed on the lower side of the fixing groove 14. When the range hood starts, the cooking fumes generated by the user are discharged through the exhaust air duct of the range hood and enter the air inlet section 11 of the valve body 1 through the air duct. During the process of the fumes entering the air inlet section 11 through the air duct, a large amount of mixture of oil and water will adhere to the inner wall surface of the air duct. This mixture of oil and water will enter the fixing groove 14 through the gap between the inner wall surface of the air duct and the outer wall surface of the air inlet section 11 and accumulate in the fixing groove 14. An oil drain hole communicating with the inner air duct of the valve body 1 is formed on the lower side of the fixing groove 14. When the mixture of oil and water accumulated in the fixing groove 14 reaches the position of the oil drain hole, the mixture of oil and water in the fixing groove 14 will enter the inner air duct of the valve body 1 through the oil drain hole, and then flow along the inner air duct of the valve body 1 towards the check valve flap 2. After the check valve flap 2 is opened, it enters the air exhaust section 12 of the valve body 1, and then enters the ventilation duct from the air exhaust section 12. The height of the oil drain hole is lower than the height of the fixing hole 141. In this way, when the mixture of oil and water in the fixing groove 14 reaches the height of the oil drain hole, it will enter the valve body 1 through the oil drain hole, which can prevent the mixture of oil and water in the fixing groove 14 from flowing towards the outer wall surface of the connection structure through the gap between the fixing hole 141 and the connecting member and dripping onto the kitchen countertop.

[0035] The check valve of the present utility model has a smooth straight inner wall in the air inlet section 11. When lampblack passes through the air inlet section 11, there will be no resistance to the flow of lampblack in the air inlet section 11, which can keep the lampblack flowing at a certain flow rate to the check valve piece 2. When it reaches the check valve piece 2, the power it stores is converted into the energy to open the check valve piece 2, and the kinetic energy of the lampblack will not be reduced due to the air resistance of the air inlet section 11, which can ensure that the check valve piece 2 is blown open by the lampblack in the air inlet section 11 and the check valve piece 2 is opened in place, so that the ventilation at the check valve piece 2 is smooth. The inner diameter of the air inlet section 11 is smaller than the inner diameter of the air exhaust section 12, and the ratio of the ventilation areas of the air inlet section 11 and the air exhaust section 12 is 0.89 - 0.98, and a table surface 13 is formed at the junction of the air exhaust section 12 and the air inlet section 11. After the lampblack in the smoke exhaust duct enters the air inlet section 11 of the valve body 1, since the air inlet section 11 extends into the air duct when connected to the air duct and is sleeved in the air duct, the inner diameter of the air inlet section 11 is smaller than the inner diameter of the air duct. After the lampblack enters the air inlet section 11 through the air duct, the air inlet section 11 throttles the air flow of the lampblack in the air duct, and the flow rate of the lampblack entering the air inlet section 11 becomes larger. When the lampblack in the air inlet section 11 flows to the junction of the air exhaust section 12 and the air inlet section 11, since the inner diameter of the air exhaust section 12 is larger than the inner diameter of the air inlet section 11, after the lampblack in the air inlet section 11 flushes open the check valve piece 2 and enters the air exhaust section 12, it expands in the air exhaust section 12. And because the inner diameter of the air inlet section 11 is smaller than the inner diameter of the air exhaust section 12, a table surface 13 is formed at the junction of the air exhaust section 12 and the air inlet section 11. After the range hood is turned off, the check valve piece 2 is closed under the action of the air flow pressure in the ventilation duct and the air exhaust section 12, and the edge of the check valve piece 2 covers the table surface 13 and forms a wind shelter with the table surface 13, which can prevent the check valve piece 2 from making the inner air duct formed by the valve body 1 not tightly sealed, so that the lampblack in the ventilation duct enters the air inlet section 11 through the air exhaust section 12, then backflows into the smoke exhaust duct of the range hood, and enters the kitchen space through the air suction port communicated with the smoke exhaust duct of the range hood. If there is no difference in the ventilation areas of the air inlet section 11 and the air exhaust section 12, that is, the inner diameters of the air inlet section 11 and the air exhaust section 12 are the same, the table surface 13 cannot be formed at the junction of the air exhaust section 12 and the air inlet section 11, and the inner wall surface of the valve body 1 cannot effectively form a sealed connection with the check valve piece 2; if the width of the table surface 13 formed at the junction of the air exhaust section 12 and the air inlet section 11 is too large, the wind resistance received by the lampblack in the smoke exhaust duct after entering the air inlet section 11 through the air duct is too large. When the lampblack is discharged by the smoke exhaust fan, the lampblack in the smoke exhaust duct cannot be effectively introduced into the air exhaust section 11 through the air inlet section 11 in time, which will cause the lampblack to be discharged not smoothly and affect the purification effect of the range hood.The ratio of the ventilation area of the air inlet section 11 to that of the air exhaust section 12 is 0.89 - 0.98, and a tabletop 13 is formed at the junction of the air exhaust section 12 and the air inlet section 11, which neither affects the effective and smooth introduction of the oil fume in the air duct into the air exhaust section 12 by the air inlet section 11, and through the throttling of the air inlet section 11, the flow rate of the oil fume entering the air inlet section 11 can be increased when it flows to the check valve piece 2, so that the oil fume can smoothly open the check valve piece 2 and enter the air exhaust section 12 through the junction of the air inlet section 11 and the air exhaust section 12; and because the inner diameter of the air exhaust section 12 expands relative to the inner diameter of the air inlet section 11, a tabletop 13 is formed at the junction of the air inlet section 11 and the air exhaust section 12 to form a sealed connection structure with the check valve piece 2 when the range hood is closed.

[0036] Please refer to Figure 1 and Figure 2, for the check valve of the present utility model, a cross beam 15 is further provided in the air inlet section 11. The side of the cross beam 15 facing the air duct inlet is a smooth arc surface, and the side of the cross beam 15 facing the air duct outlet forms a fixing part for fixing the torsion spring 4. Two shaft clamps 151 are formed at the positions corresponding to the two sides of the cross beam 15 on the table surface 13. The shaft clamps 151 are used to clamp the rotating shafts 22 provided at both ends of the check valve piece 2. The check valve piece 2 is composed of two pieces, and each piece is a semi-circular sheet structure. The two semi-circular sheet structures are symmetrically arranged on both sides of the cross beam 15 with the cross beam 15 as the axis of symmetry. The edge of the semi-circular sheet structure includes an arc segment and a straight segment. When the check valve piece 2 seals the connection between the air inlet section 11 and the exhaust section 12, the straight segment parts of the edges of the two semi-circular sheet structures extend to the lower side of the side of the cross beam 15 facing the exhaust section 12 and abut against the surface of the cross beam 15 facing the exhaust section 12. The fixing part of the cross beam 15 is installed with a torsion spring 4. The two acting ends of the torsion spring 4 respectively act on the two semi-circular sheet structures from the side of the two semi-circular sheet structures facing the exhaust section 12, applying a force towards the air inlet section 11 to the semi-circular sheet structures. When the check valve is not connected to the air duct, the two semi-circular sheet structures are unfolded under the action of the forces of the two acting ends of the torsion spring 4. The arc segments of the edges of the two semi-circular sheet structures abut against the table surface 13 at the junction of the exhaust section 12 and the air inlet section 11, and the straight segments of the edges of the two semi-circular sheet structures abut against the cross beam 15. After the check valve is connected to the air duct, when the range hood is started, the oil fume in the exhaust air duct enters the air inlet section 11 through the air duct, and then when it flows to the check valve piece 2 from the air inlet section 11, the oil fume impacts the two semi-circular sheet structures. The impact force of the oil fume overcomes the force of the torsion spring 4 acting on the two semi-circular sheet structures towards the air inlet section 11 direction. The arc segments of the edges of the two semi-circular sheet structures approach each other, and the junction between the air inlet section 11 and the exhaust section 12 is opened. The greater the impact force of the oil fume on the check valve piece 2, the closer the arc segments of the edges of the two semi-circular sheet structures approach each other. When the flow rate of the oil fume in the air inlet section 11 is large enough, the two surfaces of the two semi-circular sheet structures facing the exhaust duct 12 can also be brought together. After the range hood is turned off, the two semi-circular sheet structures are first reset under the action of the torsion spring 4. The arc segments of the edges of the two semi-circular sheet structures move away from each other and finally abut against the table surface 13 formed at the junction of the exhaust section 12 and the air inlet section 11 again. Then, due to the air pressure difference between the ventilation duct and the exhaust air duct, the two semi-circular sheet structures are squeezed towards the air inlet section 11 under the action of the air pressure difference. Finally, the arc segments of the edges of the two semi-circular sheet structures are squeezed against the table surface 13, and the straight segments of the edges of the two semi-circular sheet structures are pressed against the lower surface of the cross beam 15 to seal the junction between the exhaust section 12 and the air inlet section 11, so that the oil fume in the ventilation duct cannot flow back into the air inlet section 11.

[0037] Due to the existence of the torsion spring 4, during the long-term use of the check valve, oil dirt may adhere to both surfaces of the check valve disc 2. After the oil fume in the air inlet section 11 merges the two semi-circular sheet-like structures, the two semi-circular sheet-like structures may adhere together due to the oil dirt. The pressure difference between the exhaust section 12 and the air inlet section 11 causes the acting force of the airflow in the exhaust section 12 not to act on the side of the two semi-circular sheet-like structures facing the exhaust section 12, which is not conducive to the reset of the check valve disc 2. Due to the existence of the torsion spring 4, after the range hood is turned off and there is oil fume in the air inlet section 11 being transported to the exhaust section 12, the torsion spring 4 resets and converts the elastic potential energy it stores into the kinetic energy of the two semi-circular sheet-like structures, causing the two semi-circular sheet-like structures to separate from each other. In this way, under the action of the pressure difference between the air inlet section 11 and the exhaust section 12, the airflow in the exhaust section 12 will flow towards the air inlet section 11 and blow the two semi-circular sheet-like structures, causing the two semi-circular sheet-like structures to reset and seal the joint between the air inlet section 11 and the exhaust section 12.

[0038] Since the number of check valve discs 2 is two and the number of elastic members 3 is also two, the shape of each elastic member 3 is adapted to the contour of the semi-circular sheet-like structure. After the two semi-circular sheet-like structures are respectively in contact with the tabletop 13 and the cross beam 15, the edges of the two semi-circular sheet-like structures squeeze the elastic members 3 onto the tabletop 13 and the cross beam 15, sealing the connection.

[0039] Please refer to Figure 1 and Figure 2 For the check valve of the present utility model, the check valve disc 2 is provided with wind guiding ribs 21 on the windward side. When the oil fume in the air inlet section 11 blows towards the surface of the check valve disc 2 facing the air inlet section 11, the airflow flows along the wind guiding ribs 21, causing the two check valve discs 2 to rotate around the rotating shaft 22. The surfaces of the two check valve discs 2 facing the exhaust section 12 approach each other and open the connection between the air inlet section 11 and the exhaust section 12, allowing the oil fume in the air inlet section 11 to enter the exhaust section 12 and then enter the ventilation duct through the exhaust section 12.

[0040] Please refer to Figure 1 and Figure 2, for the check valve of the present utility model, the valve body base 5 and the valve body 1 have a sealing and fixing structure. The sealing and fixing structure includes an elastic sealing ring 6, and the elastic sealing ring 6 is disposed between the valve body base 5 and the valve body 1 in a squeezed manner. When the exhaust section 12 is connected to the valve body base 5, the connecting section 51 is connected to the exhaust section 12. The connecting section 51 is sleeved outside the exhaust section 12. Rotate the valve body 1 so that the guide post 121 on the exhaust section 12 enters the guide rail 52. During the process of rotating the valve body 1, the guide post 121 slides along the guide rail 52 on the connecting section 51 until the guide post 121 slides to the end of the guide rail 52 and is limited by the guide rail 52. Then the valve body 1 cannot be rotated continuously, and the connecting section 51 and the exhaust section 12 are connected together. The fitting surface of the connecting section 51 closely adheres to the outer surface of the exhaust section 12. At the same time, the fitting surface of the connecting section 51 and the outer surface of the exhaust section 12 squeeze the elastic sealing ring 6, causing the elastic sealing ring 6 to deform and sealing between the connecting section 51 and the exhaust section 12.

[0041] In order to have better sealing performance after the connection between the exhaust section 12 and the connecting section 51, the inner diameter of the connecting section 51 is adapted to the outer diameter of the exhaust section 12. At the same time, in order to make the sealing effect better after the two are connected, the outer diameter of the elastic sealing ring 6 is larger than the outer diameter of the exhaust section 12, and the inner diameter of the elastic sealing ring 6 is smaller than the outer diameter of the exhaust section 12. Therefore, when the exhaust section 12 is sleeved into the connecting section 51, when the exhaust section 12 passes through the elastic sealing ring 6, it will be blocked by the elastic sealing ring 6. If the exhaust section 12 is forcibly squeezed towards the wall surface of the building, the end of the exhaust section 12 facing the wall surface of the building will push the elastic sealing ring 6 to slide along the outer wall surface of the connecting section 51, which will not cause the connecting section 51 and the exhaust section 12 to be not properly connected, prevent the guide post 121 from entering the guide rail 52 on the connecting section 51, and will also affect the sealing effect between the connecting section 51 and the exhaust section 12. A groove for accommodating the elastic sealing ring 6 is provided on the inner surface of the connecting section 51. When the exhaust section 12 is sleeved into the connecting section 51, the exhaust section 12 squeezes the elastic sealing ring 6 and passes through the elastic sealing ring 6. During the process of the exhaust section 12 moving towards the direction of the wall surface of the building, the elastic sealing ring 6 will not shift. Of course, a groove for accommodating the elastic sealing ring 6 can also be provided on the outer surface of the exhaust section 12. In this way, when connecting the exhaust section 12 and the connecting section 51, first install the elastic sealing ring 6 into the groove on the outer surface of the exhaust section 12, and then sleeve the exhaust section 12 into the connecting section 51. When the exhaust section 12 moves in the connecting section 51 with the elastic sealing ring 6, the elastic sealing ring 6 will not shift.

[0042] Please refer to Figure 1 and Figure 2, for the check valve of the present utility model, the valve body base 5 has a convex edge 53 extending outward from the connecting section 51. The convex edge 53 is formed with fastening holes 54 evenly distributed around the connecting section 51. The valve body base 5 is connected to the wall surface of the building by passing fasteners through the fastening holes 54. The convex edge 53 can increase the contact area between the valve body base 5 and the wall surface of the building, making the valve body base 5 firmly installed on the wall surface of the building. When fixing the valve body base 5, the surface of the convex edge 53 away from the connecting section 51 is in contact with the wall surface of the building, and the inner air duct of the connecting section 51 is aligned with the inlet of the ventilation duct. Then, the fasteners are passed through the fastening holes 54 on the convex edge 53 to fix the convex edge 53 to the wall surface of the building, and thus the valve body base 5 can be fixed to the wall surface of the building. After the valve body base 5 is connected to the wall surface of the building, the inner air duct of the connecting section 51 of the valve body base 5 is communicated with the ventilation duct on the building. Then, the exhaust section 12 of the valve body 1 is sleeved into the connecting section 51 and the valve body 1 is rotated so that the guide post 121 on the exhaust section 12 enters the guide rail 52 on the connecting section 51. The valve body 1 is continuously rotated until the guide post 121 moves to the end of the guide rail 52 and is limited. After that, the valve body 1 cannot be rotated continuously, and the valve body 1 is successfully connected to the valve body base 5. After the range hood is installed, the air inlet section 11 of the valve body 1 is connected through an air duct, so that the air duct is sleeved into the fixing groove 14 of the air inlet section 11. Then, the connecting piece is passed through the fixing hole 141 on the connecting structure to fasten the air duct and the air inlet section 11, making the air duct and the air inlet section 11 detachably connected. The exhaust air duct of the range hood is communicated with the ventilation duct through the air duct, the valve body 1, and the valve body base 5 in sequence. During the long-term use of the check valve, if the check valve piece 2 of the check valve 2 is damaged, the connection between the check valve and the air duct can be disassembled, the air duct can be removed, and then the valve body 1 is rotated to disassemble the valve body 1 from the valve body base 5, and immediately the check valve can be removed for repair or replacement.

[0043] Please refer to Figure 1 and Figure 2, for the check valve of the present utility model, the fixed surface of the valve body base 5 is provided with a mounting beam 55 that crosses the connecting section 51, and the mounting beam 55 is integrally formed with the valve body base 5; further includes a fixed bracket 7, the fixed bracket 7 is hung on the air outlet of the ventilation duct and fixed inside the ventilation duct; the mounting beam 55 and the fixed bracket 7 are respectively provided with corresponding mounting holes, and the bracket fastener passes through the corresponding mounting holes to connect the mounting beam 55 and the fixed bracket 7 with the ventilation duct. Before the convex edge 53 of the valve body base 5 is fixedly connected to the wall surface of the building, first align the mounting beam 55 with the fixed bracket 7 hung inside the air outlet of the ventilation duct, and align the mounting holes on the mounting beam 55 with the mounting holes on the fixed bracket 7, then make the bracket fastener pass through the mounting holes on the mounting beam 55 and the fixed bracket 7 in sequence, and the mounting beam 55 and the fixed bracket 7 can be connected together to preliminarily fix the valve body base 5. After preliminarily fixing the valve body base 5, while the mounting beam 55 and the fixed bracket 7 are aligned and connected, the inner air duct of the connecting section 51 of the valve body base 5 can be aligned with the ventilation duct. When connecting the convex edge 53 to the wall surface of the building, it can play a positioning role to avoid misalignment between the inner air duct of the connecting section 51 and the ventilation duct. When fixing the convex edge 53 of the valve body base 5, make the surface of the convex edge 53 away from the connecting section 51 contact the wall surface of the building, and align the inner air duct of the connecting section 51 with the inlet of the ventilation duct, then make the fastener pass through the fastening hole 54 on the convex edge 53 to fix the convex edge 53 to the wall surface of the building, and the valve body base 5 can be fixed to the wall surface of the building, increasing the firmness of the connection between the valve body base 5 and the wall surface of the building.

[0044] For the check valve of the present utility model, a fixed surface is formed on one side of the convex edge 53 facing away from the building, and the fixed surface is used to fix the valve body base 5 to the wall surface of the building. A sealing groove is provided on the side of the fixed surface facing the wall surface of the building, and an elastic packing 56 is arranged in the sealing groove. When the fixed surface fits the wall surface of the building, the elastic packing 56 is squeezed and deformed. After the valve body base 5 is connected to the fixed wall surface of the building, the fixed surface of the valve body base 5 is closely attached to the wall surface of the building and squeezes the elastic packing 56 in the sealing groove, so that the fixed surface of the valve body base 5 is closely attached to and sealed with the wall surface of the building. When the range hood is started, the exhaust fan of the range hood inhales the cooking fumes generated by the user into the exhaust air duct. The fumes in the exhaust air duct activate the check valve and flow from the inner air duct of the valve body of the check valve to the inner air duct of the valve body base 5, and flow into the ventilation duct through the inner air duct of the valve body base 5. When the fumes flow from the inner air duct of the valve body base 5 to the ventilation duct, due to the sealing effect of the elastic packing 56, the fumes cannot flow out from the gap between the fixed surface of the valve body base 5 and the wall surface of the building.

[0045] The following will specifically show the influence on the exhaust air volume of the range hood when using the check valve with a ring-shaped retaining ring and the check valve of the present application with 4 groups of data.

[0046] Table 1:

[0047]

[0048] Please refer to Table 1. Table 1 shows the comparison of the rotational speed and power of the exhaust fan of the range hood when there is no check valve, when using a check valve with an annular retaining ring, and when using the check valve of the present application, while ensuring that the difference in air volume is not significant:

[0049] Taking the range hood without a check valve as a reference, when the exhaust fan of the range hood discharges oil fume into the kitchen ventilation duct, the air volume discharged by the exhaust fan without a check valve will not change due to the influence of the check valve. Please refer to Table 1. If the exhaust port of the range hood is connected to the kitchen ventilation duct with a check valve using an annular retaining ring, when the air volume discharged from the exhaust port of the range hood is 0.11 m³ / min more than that of the range hood without a check valve, the power of the range hood needs to increase by 60.92 W, and the rotational speed of the exhaust fan increases by 206 RPM. It can be seen that the check valve with an annular retaining ring will form a relatively large wind resistance and loss. For the check valve of the present application, when the power of the range hood increases by 1.01 W, the rotational speed increases by 5 RPM, and the air volume decreases by 0.3 m³ / min. It can be known that the check valve of the present application forms a relatively small wind resistance and has a relatively small power loss to the range hood.

[0050] Table 2:

[0051]

[0052] Please refer to Table 2. Table 2 shows the comparison of the rotational speed and air volume of the exhaust fan of the range hood when there is no check valve, when using a check valve with an annular retaining ring, and when using the check valve of the present application, while ensuring that the difference in the power of the exhaust fan of the range hood is not significant:

[0053] Taking the range hood without a check valve as a reference, when the exhaust fan of the range hood discharges oil fume into the kitchen ventilation duct, the air volume discharged by the exhaust fan without a check valve will not change due to the influence of the check valve. Please refer to Table 2. If the exhaust port of the range hood is connected to the kitchen ventilation duct with a check valve using an annular retaining ring, when the power of the exhaust fan of the range hood increases by 0.36 W, the air volume discharged from the exhaust port of the range hood is 1.68 m³ / min less than that of the range hood without a check valve, and the rotational speed of the exhaust fan increases by 63 RPM. It can be seen that the check valve with an annular retaining ring will form a relatively large wind resistance and loss. For the check valve of the present application, when the power of the range hood increases by 0.19 W, the air volume decreases by 0.35 m³ / min, and the rotational speed increases by 12 RPM. It can be known that the check valve of the present application forms a relatively small wind resistance and has a relatively small power loss to the range hood.

[0054] Table 3:

[0055]

[0056] Please refer to Table 3. Table 3 shows the comparison of the rotational speed and air volume of the exhaust fan of the range hood when there is no check valve, when using a check valve with an annular retaining ring, and when using the check valve of the present application, under the condition that the power difference of the exhaust fan of the range hood is not significant:

[0057] Please compare Table 2 with Table 3. As shown in Table 2 and Table 3, in Table 3, if the range hood does not use a check valve, when its power increases from 101.44 W to 157.05 W, with a power increase of 56.61 W, the rotational speed of the exhaust fan of the range hood increases from 1046 RPM to 1212 RPM, with a rotational speed increase of 176 RPM, and the exhaust air volume increases from 11.09 m³ / min to 12.92 m³ / min, with an air volume increase of 1.83 m³ / min; when there is a check valve with an annular retaining ring, when the power of the range hood increases from 101.8 W to 157.42 W, with a power increase of 56.62 W, the rotational speed of the exhaust fan of the range hood increases from 1109 RPM to 1280 RPM, with a rotational speed increase of 171 RPM, and the exhaust air volume increases from 9.41 m³ / min to 11.38 m³ / min, with an air volume increase of 1.97 m³ / min. Compared with the case without a check valve, the air volume decreases by 1.54 m³ / min; when using the check valve of the present application, when the power of the range hood increases from 101.63 W to 156.53 W, with a power increase of 54.9 W, the rotational speed of the exhaust fan of the range hood increases from 1058 RPM to 1220 RPM, with a rotational speed increase of 162 RPM, and the exhaust air volume increases from 10.74 m³ / min to 12.61 m³ / min, with an air volume increase of 1.97 m³ / min; comparing Table 2 and Table 3, when the air volume increases by 1.97 m³ / min, compared with the case without a check valve, the air volume decreases by 0.31 m³ / min. When there is a check valve with an annular retaining ring, more power needs to be increased, and the air volume decreases more. Therefore, using a check valve with an annular retaining ring will cause a greater wind resistance and loss.

[0058] Table 4:

[0059]

[0060] Please refer to Table 4. Table 4 shows the comparison of the rotational speed and air volume of the exhaust fan of the range hood when there is no check valve, when using a check valve with an annular retaining ring, and when using the check valve of the present application, on the basis of Table 3, with further increasing the power of the exhaust fan while ensuring that the power difference of the exhaust fan of the range hood is not significant:

[0061] Please compare Table 3 with Table 4. As shown in Table 3 and Table 4, in Table 4, if the range hood does not adopt a check valve, when its power increases from 157.05 W to 196.97 W, with a power increase of 39.92 W, the rotational speed of the exhaust fan of the range hood increases from 1212 RPM to 1306 RPM, with a rotational speed increase of 94 RPM, and the exhaust air volume increases from 12.92 m³ / min to 14.02 m³ / min, with an air volume increase of 1.1 m³ / min; while when there is a check valve with an annular retaining ring, when the power of the range hood increases from 157.42 W to 197.59 W, with a power increase of 40.17 W, the rotational speed of the exhaust fan of the range hood increases from 1280 RPM to 1373 RPM, with a rotational speed increase of 93 RPM, and the exhaust air volume increases from 11.38 m³ / min to 12.43 m³ / min, with an air volume increase of 1.05 m³ / min. Compared with the case without a check valve, the air volume decreases by 1.59 m³ / min; while for the check valve of the present application, when the power of the range hood increases from 156.53 W to 197.07 W, with a power increase of 40.54 W, the rotational speed of the exhaust fan of the range hood increases from 1220 RPM to 1317 RPM, with a rotational speed increase of 97 RPM, and the exhaust air volume increases from 12.61 m³ / min to 13.65 m³ / min, with an air volume increase of 1.04 m³ / min. Compared with the case without a check valve, the air volume decreases by 0.37 m³ / min; By comparing Table 3 and Table 4, it can be seen that when the power of the range hood is relatively high, which belongs to the high-speed operation and large exhaust of the exhaust fan of the range hood, the wind resistance and loss formed when there is a check valve with an annular retaining ring are still relatively large.

[0062] From the comparison of Table 1 to Table 4, it can be seen that the wind resistance and loss formed when the check valve of the present application exists are small.

[0063] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, or improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A check valve used to connect the air duct of a range hood with an external ventilation duct, characterized in that: include: A valve body (1) is formed with an inner air duct, the inner air duct being divided into an air inlet section (11) and an air outlet section (12), the inner diameter of the air inlet section (11) being smaller than the inner diameter of the air outlet section (12), the air inlet section (11) having an air duct inlet, the air outlet section (12) having an air duct outlet, a connection structure for connecting to an air duct being formed on one side of the air inlet section (11), the connection structure comprising a fixing groove (14) arranged on the outer side of the valve body (1), a fixing hole (141) being formed on the outer periphery of the fixing groove (14), the connection structure being used for being detachably connected to the air duct, and a table surface (13) being formed at the junction of the air outlet section (12) and the air inlet section (11); a check valve plate (2) disposed in the inner air duct, the edge of the check valve plate (2) opening toward the air duct outlet, and when the check valve plate (2) is closed, the edge of the check valve plate (2) covers the table top (13); A valve body base (5) having a connecting section (51), wherein the connecting section (51) is a straight tube and is formed with at least two symmetrical guide rails (52), wherein the guide rails (52) are used to guide and connect the valve body (1), wherein the connecting section (51) has a fitting surface that fits with the outer surface of the exhaust section (12) of the valve body (1), wherein the outer surface of the exhaust section (12) is provided with a guide column (121) corresponding to the guide rail (52), wherein the guide column (121) is slidably connected to the guide rail (52), so that the exhaust section (12) of the valve body (1) and the valve body base (5) can be detachably connected.

2. The check valve according to claim 1, characterized in that: The included angle formed by the table (13) formed at the joint and the center line of the valve body (1) is in the range of 45 degrees to 90 degrees, an elastic member (3) is provided at the place where the edge of the check valve plate (2) and the table (13) are in contact, and the edge of the table (13) or the check valve plate (2) has a flange that abuts against the elastic member (3).

3. The check valve according to claim 2, characterized in that: The elastic member (3) is located on the side of the edge of the check valve plate (2) facing the table top (13), and is fixed by clamping in the receiving groove or by gluing or gluing; or the elastic member (3) is arranged on one side of the table top (13) and is fixed by a clamping structure or gluing.

4. The check valve according to claim 1, characterized in that: An oil drain hole communicating with the inner air passage of the valve body (1) is formed on the lower side of the fixing groove (14).

5. The check valve according to claim 1, characterized in that: The air inlet section (11) has a smooth straight inner wall, and the ratio of the ventilation area of ​​the air inlet section (11) to the ventilation area of ​​the air exhaust section (12) is 0.89-0.

98.

6. The check valve according to claim 5, characterized in that: The air inlet section (11) is provided with a crossbeam (15), the side of the crossbeam (15) facing the air duct inlet is a smooth arc surface, the side of the crossbeam (15) facing the air duct outlet is formed with a fixing portion, the table top (13) is formed with two shaft clamps (151) at positions corresponding to the two sides of the crossbeam (15), the shaft clamps (151) are used to clamp the rotating shafts (22) provided at both ends of the check valve plate (2), the check valve plate (2) is composed of two plates, each of which is a semicircular plate-shaped structure, and the two semicircular plate-shaped structures are symmetrically arranged on the crossbeam (15) with the crossbeam (15) as the symmetry axis. On both sides, when the check valve plate (2) seals the connection between the air inlet section (11) and the air outlet section (12), the straight sections of the edges of the two semicircular sheet-like structures extend below the side of the cross beam (15) facing the air outlet section (12), and abut against the surface of the cross beam (15) facing the air outlet section (12). A torsion spring (4) is installed on the fixed part of the cross beam (15). The two acting ends of the torsion spring (4) act on the two semicircular sheet-like structures from the side of the two semicircular sheet-like structures facing the air outlet section (12), respectively, to apply a force toward the air inlet section (11) to the semicircular sheet-like structures.

7. The check valve according to claim 1, characterized in that: The check valve plate (2) has a wind guide rib (21) arranged on the windward side.

8. The check valve according to claim 7, characterized in that: The valve body base (5) and the valve body (1) have a sealing fixing structure, the sealing fixing structure comprising an elastic sealing ring (6), the elastic sealing ring (6) being extruded and arranged on the valve body base (5) and the valve body (1), and a groove for accommodating the elastic sealing ring (6) is arranged on the inner surface of the connecting section (51) or the outer surface of the exhaust section (12).

9. The check valve according to claim 1, characterized in that: The valve body base (5) has a convex edge (53) extending outward from the connecting section (51), and the convex edge (53) is formed with fastening holes (54) evenly distributed around the connecting section (51), and the valve body base (5) is connected to the wall of the building by fasteners passing through the fastening holes (54).

10. The check valve according to claim 1, characterized in that The fixing surface of the valve body base (5) is provided with a mounting beam (55) which crosses the connecting section (51), and the mounting beam (55) is integrally formed with the valve body base (5); it also includes a fixing bracket (7), the fixing bracket (7) is hung at the air outlet of the ventilation duct and fixed on the inner side of the ventilation duct; the mounting beam (55) and the fixing bracket (7) are respectively provided with corresponding mounting holes, and bracket fasteners pass through the corresponding mounting holes to connect the mounting beam (55) and the fixing bracket (7) to the ventilation duct.

Images