Check valve assembly

By designing a reset column within the deformation cavity in the check valve assembly, the problem of difficulty in resetting the deformation cavity under negative pressure is solved, achieving rapid reset and good sealing of the sealing sheet, and preventing backflow of oil fumes.

CN224433503UActive Publication Date: 2026-06-30GUANGDONG CHENGYI TECH CO LTD

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
GUANGDONG CHENGYI TECH CO LTD
Filing Date
2025-06-25
Publication Date
2026-06-30

AI Technical Summary

Technical Problem

When the negative pressure in the common flue is too high, the deformation chamber of the existing check valve assembly is squeezed and deformed, making it difficult to reset and affecting the sealing effect, which leads to backflow of oil fumes.

Method used

Design a check valve assembly including a seat, a check valve plate, a sealing plate, and a torsion spring assembly. A reset post is provided in the deformation cavity. A deformation cavity is formed between the sealing plate and the check valve plate. The reset post is in the deformation cavity and provides deformation space when the support surface contacts the sealing plate. The reset post reduces the adhesion between the bottom surface of the deformation cavity and the check valve plate, ensuring that the sealing plate is reset.

Benefits of technology

The backflow prevention effect of the check valve assembly is improved, and the sealing plate can quickly reset when the negative pressure disappears, maintaining good sealing performance.

✦ Generated by Eureka AI based on patent content.

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  • Figure CN224433503U_ABST
    Figure CN224433503U_ABST
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Abstract

This utility model discloses a check valve assembly, including a base, two check valve plates, a sealing plate, and a torsion spring assembly. The base has an inlet section and an outlet section arranged sequentially along the exhaust direction of the range hood. A connecting rod is provided at the inlet end of the outlet section, dividing the inlet surface of the outlet section into a first and a second symmetrical inlet surface. A support surface is provided around the first and second inlet surfaces at the inlet end of the outlet section. Both check valve plates are rotatably connected to the inlet end of the outlet section. The sealing plate is positioned around the edge of the check valve plates facing the inlet section, forming a deformation cavity between the sealing plate and the check valve plates. The deformation cavity is aligned with the support surface, and a reset post is provided within the deformation cavity. The torsion spring assembly includes a spring pin and a torsion spring. The spring pin is mounted on the connecting rod, and the two acting ends of the torsion spring act on the two surfaces of the two check valve plates away from the inlet section. Due to the presence of the reset post, the deformation cavity of this utility model's check valve assembly is easily reset, ensuring the sealing effect of the sealing plate.
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Description

Technical Field

[0001] This utility model relates to the field of smoke hood technology, specifically to a check valve assembly. Background Technology

[0002] The backflow preventer assembly is installed in the common flue of the range hood to prevent cooking fumes from flowing back into the kitchen. When no airflow passes through the base, the backflow preventer plates rest against the support edge of the base under their own weight and the action of a torsion spring. During range hood exhaust, the exhaust airflow passes through the inlet section of the backflow preventer base and flows towards the exhaust section. As the airflow flows towards the exhaust section, it impacts the backflow preventer plates, causing the two plates to move closer together and open the exhaust section of the base, allowing the airflow entering the inlet section to flow towards the exhaust section and be discharged into the common flue. After the range hood is turned off, if cooking fumes flow back into the common flue, the airflow from the common flue will enter the outlet section of the base. The airflow will then impact the backflow preventer plates in the direction of the inlet section. Due to the restraint of the support edge, the sealing plates on the two backflow preventer plates are tightly pressed against the support edge, and the deformation cavity between the backflow preventer plates and the sealing plates deforms, preventing backflow of cooking fumes. However, when the negative pressure in the common flue is too high, the deformation cavity is squeezed and deformed by a large amount. The bottom surface of the deformation cavity will be concave and stick to the check valve plate. When there is no negative pressure in the common flue, the deformation cavity is difficult to reset, which affects the subsequent sealing effect. Utility Model Content

[0003] The purpose of this invention is to provide a check valve assembly that solves the aforementioned technical problems.

[0004] The check valve assembly proposed in this utility model includes a base, two check valve plates, a sealing plate, and a torsion spring assembly. The base is provided with an air inlet section and an air outlet section in sequence along the exhaust direction of the flue. The air inlet end of the air outlet section is provided with a connecting rod, which divides the air inlet surface of the air outlet section into a first air inlet surface and a second air inlet surface that are symmetrical to each other. The air inlet end of the air outlet section is provided with a support surface around the first air inlet surface and the second air inlet surface. The two check valve plates are rotatably connected to the air inlet end of the air outlet section. The sealing plate is provided around the edge of the check valve plate on the side facing the air inlet section. A deformation cavity is formed between the sealing plate and the check valve plate. The deformation cavity is aligned with the support surface. A reset post is provided in the deformation cavity. The torsion spring assembly includes a spring pin and a torsion spring. The spring pin is provided on the connecting rod. The two working ends of the torsion spring act on the two surfaces of the two check valve plates away from the air inlet section, respectively.

[0005] According to one embodiment of the present invention, the edge of the check valve plate is provided with a first groove, the edge of the sealing plate is provided with a second groove, the sealing plate is connected to the check valve plate, the outer edge of the sealing plate forms the outer annular wall of the second groove, the outer annular wall of the second groove is embedded in the first groove and abuts against the outer annular wall of the first groove, and the reset post is provided in the second groove.

[0006] According to one embodiment of the present invention, the inner edge of the support surface extends away from the air inlet section and has a sealing edge, which is aligned with the portion of the sealing sheet that has a second groove.

[0007] According to one embodiment of the present invention, the surface of the check valve plate facing the air inlet section includes a first surface, a second surface and a third surface. The second surface is arranged around the first surface, and the third surface is arranged around the second surface. The first surface protrudes from the air inlet section relative to the second surface, and the second surface protrudes from the air inlet section relative to the third surface. An extension wall extends from the edge of the third surface toward the air inlet section. The outer wall of the second surface, the third surface and the extension wall form a first groove.

[0008] According to one embodiment of the present invention, the sealing sheet has a connecting portion corresponding to the second surface, a second groove is provided around the connecting portion, the connecting portion is connected to the second surface, the second groove is aligned with the third surface, and the outer edge of the sealing sheet abuts against the inner wall surface of the extension wall.

[0009] According to one embodiment of the present invention, the outer edge of the sealing sheet forms the outer ring wall of the second groove, the height of the outer ring wall is greater than the height of the inner ring wall of the second groove, and the height of the outer ring wall is adapted to the height of the extension wall.

[0010] According to one embodiment of the present invention, a plurality of connecting posts are provided on the second surface, and a connecting hole is provided on the sealing sheet, the connecting hole being connected to the connecting post.

[0011] According to one embodiment of the present invention, a plurality of reinforcing ribs are provided on the first surface.

[0012] According to one embodiment of the present invention, the check valve plate is provided with rotating shafts at both ends, and the connecting rod is provided with first bearing seats at both ends, with the rotating shafts rotatably connected to the first bearing seats.

[0013] According to one embodiment of the present invention, the connecting rod has a V-shaped cross-section, with the protrusion facing the air inlet section. A second bearing seat is provided in the groove of the V-shaped structure, and a spring pin is connected to the second bearing seat.

[0014] Compared with the prior art, the check valve assembly of this utility model has the following advantages:

[0015] The backflow preventer assembly of this invention features a deformation cavity formed between the sealing plate and the backflow preventer plate. When oil fumes flow back into the common flue, the airflow exerts a force on the backflow preventer plate towards the air inlet section. The backflow preventer plate is pressed against the sealing edge, causing the deformation cavity to deform. This seals the gap between the sealing plate and the sealing edge, preventing the backflowing oil fumes from entering the air inlet section, thus improving the backflow prevention effect of the backflow preventer assembly. A reset post is installed inside the deformation cavity. When the deformation cavity deforms under pressure, the presence of the reset post prevents the bottom surface of the deformation cavity from easily sticking to the backflow preventer plate. When there is no negative pressure in the common flue, the deformation cavity easily resets, continuing to ensure the sealing effect of the sealing plate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the check valve assembly of this utility model;

[0017] Figure 2 This is a schematic diagram of the check valve assembly of this utility model from another direction;

[0018] Figure 3 This is an exploded view of the check valve assembly of this utility model;

[0019] Figure 4 This is a structural cross-sectional view of the check valve assembly of this utility model;

[0020] Figure 5 for Figure 4 A magnified view of a section at point A in the middle;

[0021] Figure 6 for Figure 4 A magnified view of a section at point B in the middle;

[0022] Figure 7 This is a schematic diagram of the structure of the stop valve plate of this utility model.

[0023] In the diagram: a. Deformation cavity, 1. Seat, 11. Air inlet section, 12. Air outlet section, 121. Support surface, 122. Sealing edge, 13. Connecting rod, 131. First bearing seat, 132. Second bearing seat, 2. Check valve plate, 21. First surface, 211. Reinforcing rib, 22. Second surface, 221. Connecting column, 23. Third surface, 24. Extension wall, 25. Rotating shaft, 3. Sealing plate, 31. Second groove, 311. Reset column, 32. Connecting part, 33. Outer ring wall, 34. Connecting hole, 4. Torsion spring assembly, 41. Spring pin, 42. Torsion spring.

[0024] The implementation and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The following drawings will disclose several embodiments of this utility model. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit this utility model. That is, in some embodiments of this utility model, these practical details are not essential. In addition, for the sake of simplicity, some conventional structures and components will be shown in the drawings in a simple schematic manner.

[0026] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] Furthermore, in this utility model, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the utility model. They are merely used to distinguish components or operations described with the same technical terms and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0028] To further understand the content, features, and effects of this utility model, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0029] This utility model discloses a check valve assembly for use in a range hood. Please refer to [link / reference]. Figures 1 to 7 The check valve assembly proposed in this utility model includes a seat 1, two check valve plates 2, a sealing plate 3, and a torsion spring assembly 4. The seat 1 is provided with an air inlet section 11 and an air outlet section 12 in sequence along the exhaust direction of the flue. The air inlet end of the air outlet section 12 is provided with a connecting rod 13, which divides the air inlet surface of the air inlet end of the air outlet section 12 into a first air inlet surface and a second air inlet surface that are symmetrical to each other. The air inlet end of the air outlet section 12 is provided with a support surface 121 around the first air inlet surface and the second air inlet surface. The two check valve plates Both are rotatably connected to the air inlet end of the air outlet section 12; the sealing plate 3 is arranged around the edge of the check valve plate 2 facing the air inlet section 11, and a deformation cavity is formed between the sealing plate 3 and the check valve plate 2. The deformation cavity is aligned with the support surface 121, and a reset column 311 is provided in the deformation cavity; the torsion spring assembly 4 includes a spring pin 41 and a torsion spring 42. The spring pin 41 is arranged on the connecting rod 13, and the two working ends of the torsion spring 42 act on the two surfaces of the two check valve plates 2 away from the air inlet section 11, respectively.

[0030] In this embodiment, the backflow preventer assembly is installed at the air outlet of the range hood and then connected to the flue pipe or common flue in the kitchen to connect the range hood with the flue pipe or common flue. Thus, the fumes drawn by the range hood can flow through the backflow preventer assembly to the flue pipe or common flue, and then be discharged outdoors through the flue pipe or common flue.

[0031] The base 1 is tubular or cylindrical. The air inlet section 11 of the base 1 connects to the air outlet of the range hood, while the air outlet section 12 connects to the common flue. A connecting rod 13 is located inside the base 1. Two check valves 2 are rotatably connected to the connecting rod 13. The two check valves 2 and the connecting rod 13 together divide the flow channel of the base 1 into the air inlet section 11 and the air outlet section 12. The two check valves 2 can rotate away from the air inlet section 11 to open the air inlet end of the air outlet section 12, or they can return to their original position towards the air inlet section 11 to close the air inlet end of the air outlet section 12. When the two check valves 2 close the air inlet end of the air outlet section 12, they respectively cover the first and second air inlet surfaces.

[0032] The support surface 121 is connected to the inner peripheral wall of the base 1 and extends circumferentially along the base 1. When the two check valves 2 close the air inlet end of the air outlet section 12, they abut against the support surface 121. Thus, the support surface 121 can support and limit the two check valves 2, preventing them from continuing to rotate away from the air outlet section 12. The sealing plate 3 is connected to the side of the two check valves 2 facing away from the air outlet section 12. When the two check valves 2 close the air inlet end of the air outlet section 12, the sealing plate 3 contacts and engages with the support surface 121. The position of the sealing plate 3 abutting against the support surface 121 corresponds exactly to the deformation cavity. The deformation cavity provides deformation space for the sealing plate 3, allowing it to deform into the deformation cavity under the squeezing action of the support surface 121. This deformation of the sealing plate 3 improves the tightness of the contact between the sealing plate 3 and the support surface 121, preventing gaps between them.

[0033] Spring pin 41 is used to mount torsion spring 42 on connecting rod 13. The two working ends of torsion spring 42 abut against two check valve plates 2 respectively, thereby providing a reset driving force for the two check valve plates 2 and pressing the two check valve plates 2 against the support surface 121.

[0034] As the fumes flow from the air inlet section 11 of the seat 1 to the air outlet section 12, they overcome the resistance caused by the torsion spring 42, causing the torsion spring 42 to deform and push the two check valve plates 2 toward the air outlet section 12, thereby creating a gap between the sealing plate 3 and the support surface 121, allowing the fumes to flow through the gap to the air outlet section 12.

[0035] After the force of the oil fumes is removed, the torsion spring 42 returns to its original shape to reset the two check valve plates 2 and press the sealing plate 3 back onto the support surface 121.

[0036] When fumes from the flue or common flue flow back into the seat 1, the airflow will press the sealing plate 3 against the support surface 121. At this time, the sealing plate 3 deforms under the pressure of the support surface 121, specifically at the deformation cavity. The deformation of the reset column 311 after being subjected to force is small, and the diameter of the reset column 311 is small, so it will not affect the overall deformation of the sealing plate 3. The reset column 311 is installed in the deformation cavity. When the deformation cavity deforms under pressure, due to the presence of the reset column 311, the top surface of the deformation cavity is not easily stuck to the check valve plate 2. When there is no negative pressure in the common flue, the deformation cavity can easily reset, continuing to ensure the sealing effect of the sealing plate 3.

[0037] The check valve assembly of this utility model, such as Figures 4 to 7 As shown, the edge of the check valve plate 2 is provided with a first groove, and the edge of the sealing plate 3 is provided with a second groove 31. The sealing plate 3 is connected to the check valve plate 2. The outer edge of the sealing plate 3 forms the outer ring wall of the second groove 31. The outer ring wall of the second groove 31 is embedded in the first groove and abuts against the outer ring wall of the first groove. The reset post 311 is provided in the second groove 31.

[0038] The first groove and the second groove 31 together form a deformation cavity, which increases the depth of the deformation cavity, thus increasing the space available for the sealing sheet 3 to deform after being pressed by the support surface 121. This allows the sealing sheet 3 to deform more fully after being pressed by the support surface 121, thereby further improving the tightness of the contact between the sealing sheet 3 and the support surface 121. The outer annular wall of the second groove 31 is embedded in the first groove and abuts against the outer annular wall of the first groove, so that the first groove can play a positioning role for the sealing sheet 3, thereby making the installation of the sealing sheet 3 on the check valve plate 2 more compact and stable.

[0039] The check valve assembly of this utility model, such as Figures 5 to 6 As shown, the inner edge of the support surface 121 extends away from the air inlet section 11 and has a sealing edge 122. The sealing edge 122 is aligned with the part of the sealing sheet 3 that has the second groove 31.

[0040] After the sealing sheet 3 abuts against the sealing edge 122, there is a gap between the support surface 121 and the sealing sheet 3, which reduces the contact area between the sealing sheet 3 and the connecting rod 13 and other parts of the seat body 1, thereby increasing the pressure exerted by the sealing edge 122 on the sealing sheet 3, allowing the sealing sheet 3 to deform to a greater extent, thus ensuring the tightness of the contact between the sealing sheet 3 and the sealing edge 122.

[0041] The check valve assembly of this utility model, such as Figures 3 to 4As shown, the surface of the check valve plate 2 facing the air inlet section 11 includes a first surface 21, a second surface 22, and a third surface 23. The second surface 22 is arranged around the first surface 21, and the third surface 23 is arranged around the second surface 22. The first surface 21 protrudes towards the air inlet section 11 relative to the second surface 22, and the second surface 22 protrudes towards the air inlet section 11 relative to the third surface 23. An extension wall 24 extends from the edge of the third surface 23 towards the air inlet section 11. The outer wall of the second surface 22, the third surface 23, and the extension wall 24 form a first groove.

[0042] The second surface 22 is encircled by the first surface 21, and the third surface 23 is encircled by the second surface 22. The first surface 21, the second surface 22, and the third surface 23 together form a stepped structure. The sealing sheet 3 is installed on the second surface 22 and the third surface 23, that is, between the outer wall surface of the first surface 21 and the extension wall 24. In this way, the sealing sheet 3 does not need to cover the first surface 21, which saves material for the sealing sheet 3.

[0043] The check valve assembly of this utility model, such as Figure 5 As shown, the sealing sheet 3 has a connecting portion 32 corresponding to the second surface 22, a second groove 31 is provided around the connecting portion 32, the connecting portion 32 is connected to the second surface 22, the second groove 31 is aligned with the third surface 23, and the outer edge of the sealing sheet 3 abuts against the inner wall surface of the extension wall 24.

[0044] The connecting part 32 is connected to the second surface 22 to ensure that the sealing plate 3 and the check valve plate 2 have sufficient connection area, thereby improving the connection stability between the sealing plate 3 and the check valve plate 2. The outer edge of the sealing plate 3 abuts against the inner wall surface of the extension wall 24, so that the extension wall 24 can play a positioning role for the sealing plate 3, thereby making the installation state of the sealing plate 3 on the check valve plate 2 more compact and stable.

[0045] The check valve assembly of this utility model, such as Figure 5 As shown, the outer edge of the sealing sheet 3 forms the outer ring wall 33 of the second groove 31. The height of the outer ring wall 33 is greater than the height of the inner ring wall of the second groove 31, and the height of the outer ring wall 33 is adapted to the height of the extension wall 24. In this way, the contact area between the outer ring wall 33 of the sealing sheet 3 and the extension wall 24 can be increased to improve the contact stability; at the same time, the inner ring wall of the second groove 31 can be prevented from occupying the space of the first groove, thereby ensuring that the deformation cavity formed between the sealing sheet 3 and the check valve plate 2 has sufficient volume.

[0046] The check valve assembly of this utility model, such as Figure 5As shown, the second surface 22 is provided with several connecting posts 221, and the sealing plate 3 is provided with connecting holes 34. The connecting holes 34 are connected to the connecting posts 221, which can improve the connection strength between the sealing plate 3 and the check valve plate 2 and simplify the connection method between the sealing plate 3 and the check valve plate 2. The multiple connecting posts 221 are arranged at intervals along the circumference of the first surface 21, and the number and position of the connecting holes 34 correspond to the connecting posts 221. In this way, the connection positions between the sealing plate 3 and the check valve plate 2 can be increased, further improving the connection stability.

[0047] The check valve assembly of this utility model, such as Figure 3 As shown, the first surface 21 is provided with several reinforcing ribs 211. The reinforcing ribs 211 can improve the overall structural strength of the check valve plate 2 and prevent the check valve plate 2 from deforming or being damaged after being subjected to various forces for a long time, thereby ensuring the stability of the anti-oil fume backflow effect of the check valve assembly.

[0048] The check valve assembly of this utility model, such as Figures 1 to 7 As shown, the check valve plate 2 has rotating shafts 25 at both ends, and the connecting rod 13 has first bearing seats 131 at both ends. The rotating shafts 25 are rotatably connected to the first bearing seats 131. The rotating shafts 25 and the first bearing seats 131 are rotatably engaged, so that the check valve plate 2 can rotate around the connecting rod 13, thereby simplifying the rotational installation method of the check valve plate 2 in the seat body 1.

[0049] The check valve assembly of this utility model, such as Figures 4 to 6 As shown, the cross-section of the connecting rod 13 is V-shaped, with the protrusion facing the air inlet section 11. The groove of the V-shaped structure is provided with a second bearing seat 132, and the spring pin 41 is connected to the second bearing seat 132.

[0050] The connecting rod 13 has a V-shaped cross-section, which can divert the oil fumes rushing towards it. This allows the fumes to be diverted to both sides after impacting the connecting rod 13, flowing along the check valve plate 2 to the gap between the sealing plate 3 and the sealing edge 122 before reaching the outlet section 12. This improves the flow and discharge effect of the check valve assembly. The groove opening of the connecting rod 13 faces the outlet section 12, and this groove provides installation space for the torsion spring assembly 4, thereby improving the ease of installation of the torsion spring assembly 4 on the connecting rod 13.

[0051] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A check valve assembly, characterized by, include: The base (1) is provided with an air inlet section (11) and an air outlet section (12) in sequence along the exhaust direction of the smoke machine. The air inlet end of the air outlet section (12) is provided with a connecting rod (13). The connecting rod (13) divides the air inlet surface of the air inlet end of the air outlet section (12) into a first air inlet surface and a second air inlet surface that are symmetrical to each other. The air inlet end of the air outlet section (12) is provided with a support surface (121) around the first air inlet surface and the second air inlet surface. Two check valve plates (2), both of which are rotatably connected to the air inlet end of the air outlet section (12); A sealing plate (3) is provided around the edge of the check valve plate (2) on the side facing the air inlet section (11). A deformation cavity (a) is formed between the sealing plate (3) and the check valve plate (2). The deformation cavity (a) is aligned with the support surface (121). A reset column (311) is provided in the deformation cavity (a). The torsion spring assembly (4) includes a spring pin (41) and a torsion spring (42). The spring pin (41) is located on the connecting rod (13), and the two working ends of the torsion spring (42) act on the two surfaces of the two check valve plates (2) away from the air inlet section (11).

2. The check valve assembly of claim 1, wherein The edge of the check valve plate (2) is provided with a first groove, and the edge of the sealing plate (3) is provided with a second groove (31). The sealing plate (3) is connected to the check valve plate (2). The outer edge of the sealing plate (3) forms the outer annular wall of the second groove (31). The outer annular wall of the second groove (31) is embedded in the first groove and abuts against the outer annular wall of the first groove. The reset post (311) is provided in the second groove (31).

3. The check valve assembly of claim 2, wherein, The inner edge of the support surface (121) extends away from the air inlet section (11) and has a sealing edge (122), which is aligned with the portion of the sealing sheet (3) where the second groove (31) is provided.

4. The check valve assembly of claim 2, wherein The check valve plate (2) facing the air inlet section (11) includes a first surface (21), a second surface (22), and a third surface (23). The second surface (22) is arranged around the first surface (21), and the third surface (23) is arranged around the second surface (22). The first surface (21) protrudes towards the air inlet section (11) relative to the second surface (22), and the second surface (22) protrudes towards the air inlet section (11) relative to the third surface (23). An extension wall (24) extends from the edge of the third surface (23) toward the air inlet section (11). The outer wall of the second surface (22), the third surface (23), and the extension wall (24) form the first groove.

5. The check valve assembly of claim 4, wherein, The sealing sheet (3) has a connecting portion (32) corresponding to the second surface (22), the second groove (31) is provided around the connecting portion (32), the connecting portion (32) is connected to the second surface (22), the second groove (31) is aligned with the third surface (23), and the outer edge of the sealing sheet (3) abuts against the inner wall surface of the extension wall (24).

6. The check valve assembly of claim 4, wherein, The outer edge of the sealing sheet (3) forms the outer ring wall (33) of the second groove (31), the height of the outer ring wall (33) is greater than the height of the inner ring wall of the second groove (31), and the height of the outer ring wall (33) is adapted to the height of the extension wall (24).

7. The check valve assembly of claim 4, wherein The second surface (22) is provided with a plurality of connecting posts (221), and the sealing sheet (3) is provided with connecting holes (34), which are connected to the connecting posts (221).

8. The check valve assembly of claim 4, wherein, The first surface (21) is provided with several reinforcing ribs (211).

9. The check valve assembly of claim 1, wherein, The check valve plate (2) has a rotating shaft (25) at both ends, and the connecting rod (13) has a first bearing seat (131) at both ends. The rotating shaft (25) is rotatably connected to the first bearing seat (131).

10. The check valve assembly of claim 1, wherein The connecting rod (13) has a V-shaped cross section with the protrusion facing the air inlet section (11). The groove of the V-shaped structure is provided with a second bearing seat (132), and the spring pin (41) is connected to the second bearing seat (132).