Air damper, ventilation device and cabinet

Abstract

The utility model provides a kind of air valve, ventilation device and cabinet.The ventilation device includes fan and air valve.The air valve includes shell and multiple first blades.The shell has first end and second end, first end is provided with air inlet, and second end is provided with air outlet.The first blade is rotatably connected in the edge area of air inlet, and has opening position and closing position, and is configured to be able to switch to closing position under the action of gravity, or under the joint action of gravity, low air pressure outside air inlet and high air pressure inside air inlet;It can also switch to opening position under the action of airflow, and airflow is generated due to high air pressure outside air inlet and low air pressure inside air inlet.The blade of air valve no longer relies on motor drive, but can automatically open with the opening of fan, and automatically close with the stop of fan, which greatly reduces the manufacturing cost and structural complexity of air valve, ventilation device and cabinet, reduces fault points and improves reliability.

Description

Technical Field

[0001] This utility model relates to the field of ventilation equipment technology, and in particular to a wind valve, a ventilation device, and a cabinet. Background Technology

[0002] In air-cooled high-voltage frequency converters, the fan, as a core heat dissipation component, plays a crucial role in removing heat from the converter's interior. Its performance and reliability directly affect the converter's stable operation and lifespan. However, during long-term operation, the fan is susceptible to failure due to various factors such as dust accumulation and mechanical wear. To reduce the impact of fan failure on the normal operation of the frequency converter and ensure product reliability throughout its entire lifecycle, a redundant fan system is typically employed. This system includes a primary fan and a backup fan, with the backup fan maintaining the cooling function when the primary fan fails.

[0003] Currently, most redundant fan systems on the market use motor-driven dampers to switch air ducts. However, this has significant drawbacks: First, the operation of motor-controlled dampers requires numerous detection devices, such as position sensors and current sensors, to monitor the damper's status in real time. Simultaneously, complex control logic is needed to accurately determine when to open and close the damper, ensuring accurate and timely airflow switching. This not only significantly increases manufacturing costs but also complicates the product structure. Numerous detection devices and control circuits become new points of failure; any malfunction will affect the reliability of the entire redundant fan system, thereby jeopardizing the inverter's normal heat dissipation.

[0004] Secondly, the damper is usually installed near the air inlet of the fan, and its blades will largely block the air inlet when closed. Taking a centrifugal fan as an example, when the airflow passes through the damper, the obstruction of the blades will cause the airflow to be blocked, generating eddies and pressure loss, which will significantly reduce the actual output air volume of the fan and weaken the heat dissipation redundancy advantage brought by the fan's redundant design.

[0005] The content of the background section is merely the technology known to the inventor and does not necessarily represent the prior art in this field. Utility Model Content

[0006] To address one or more deficiencies in the prior art, this utility model provides an air valve, comprising: The outer casing has a first end and a second end, wherein the first end is provided with an air inlet and the second end is provided with an air outlet; Multiple first blades are rotatably connected to the edge region of the air inlet. Each first blade has an open position and a closed position and is configured to switch to the closed position under the action of gravity, or under the combined action of gravity, low air pressure outside the air inlet, and high air pressure inside the air inlet; it can also switch to the open position under the action of airflow, which is generated by the high air pressure outside the air inlet and the low air pressure inside the air inlet. When all the first blades are in the closed position, they can essentially seal the air inlet; when all the first blades are in the open position, an airflow channel is formed between them.

[0007] According to one aspect of the present invention, the housing comprises: A frame, configured as a ring structure, wherein the air inlet is formed on the inner circumferential surface of the frame; and Multiple side plates are arranged around the skeleton.

[0008] According to one aspect of the present invention, the air valve further includes a first positioning structure disposed inside the housing and configured to position the corresponding first blade in the open position.

[0009] According to one aspect of the present invention, the air valve further includes a first rotating shaft or a first hinge, wherein the first blade is hinged to the edge region of the air inlet via the first rotating shaft or the first hinge.

[0010] According to one aspect of the present invention, the air inlet is configured as a rectangle; There are four first blades, which are respectively connected to the four edge areas of the air inlet. The first blades are configured as isosceles trapezoids or isosceles triangles.

[0011] According to one aspect of the present invention, when all of the first blades are in the closed position, an unclosed area is formed in the middle of the air inlet; The air valve also includes: An inner shell, disposed in the unclosed area, the inner shell having an air duct; A fastener, connecting the inner shell and the outer shell; and Multiple second blades are rotatably disposed inside the inner shell. The second blades have an open position and a closed position and are configured to switch to the closed position under the action of gravity, or under the combined action of gravity, low air pressure outside the air inlet, and high air pressure inside the air inlet; and can also switch to the open position under the action of the airflow. When all of the second blades are in the closed position, the second blades can close the air duct.

[0012] According to one aspect of the present invention, the air valve further includes a second positioning structure disposed inside the inner shell and configured to position the corresponding second blade in the open position.

[0013] According to one aspect of the present invention, the air valve further includes a second rotating shaft or a second hinge, wherein the second blade is hinged inside the inner shell via the second rotating shaft or the second hinge.

[0014] According to one aspect of the present invention, the inner shell is configured as a rectangular annular structure; There are two second blades, which are respectively connected to two opposite side walls of the inner shell. The second blades are rectangular.

[0015] This utility model also provides a ventilation device, including: The air valve as described above; and A fan includes a fan ring having an air inlet and an air outlet, wherein the air inlet of the fan ring is connected and communicates with a second end of the outer casing.

[0016] According to one aspect of the present invention, the effective ventilation area of ​​the wind ring is less than or equal to the effective ventilation area of ​​the airflow channel.

[0017] This utility model also provides a cabinet, including: Cabinet; and The ventilation device described above is located at the top of the cabinet, and the air inlet of the outer shell communicates with the interior of the cabinet.

[0018] Compared with existing technologies, the embodiments of this utility model provide a damper, a ventilation device, and a cabinet. The damper blades no longer rely on a motor drive, but automatically open when the fan starts and automatically close when the fan stops. This significantly reduces the manufacturing cost and structural complexity of the damper, ventilation device, and cabinet, reduces potential failure points, and improves reliability. Furthermore, the damper blades are located away from the fan, and the effective ventilation area of ​​the damper's airflow channel is greater than or equal to the effective ventilation area of ​​the fan (fan coil), allowing airflow to pass smoothly through the damper and greatly reducing the negative impact of the damper on the fan's ventilation efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the following description of the embodiments will be introduced as examples. The drawings described below are merely embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort. The drawings are used to provide a further understanding of this utility model and constitute a part of the specification. They are used together with the embodiments of this utility model to explain this utility model and do not constitute a limitation on this utility model. In the drawings: Figure 1 A schematic diagram of a damper according to an embodiment of the present invention is shown; Figure 2 Another schematic diagram of a damper according to an embodiment of the present invention is shown; Figure 3 A cross-sectional view of a damper according to an embodiment of the present invention is shown; Figure 4 A bottom view of a damper according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of a ventilation device according to an embodiment of the present invention is shown; Figure 6 A cross-sectional view of a ventilation device according to an embodiment of the present invention is shown; Figure 7 A schematic diagram of a cabinet according to an embodiment of the present invention is shown; Figure 8 Another schematic diagram of a cabinet according to one embodiment of the present invention is shown.

[0020] In the diagram: 100, air valve; 110, outer casing; 111, air inlet; 112, air outlet; 113, frame; 114, side panel; 115, through hole; 120, first blade; 130, first rotating shaft; 140, first positioning structure; 150, inner shell; 151, flange; 160, fastener; 170, second blade; 180, second positioning structure; 190, second rotating shaft; 200, ventilation device; 210, fan; 211, fan ring; 300, cabinet; 310, cabinet body. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this invention. Therefore, the drawings and description are considered exemplary in nature and not restrictive.

[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "coupling" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] The following provides many different embodiments or examples for implementing various structures of this invention. To simplify the invention, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] Figure 1 A schematic diagram of a damper 100 according to an embodiment of the present invention is shown. Figure 2 Another schematic diagram of a damper 100 according to an embodiment of the present invention is shown below, in conjunction with... Figure 1 and Figure 2 Provide a detailed description.

[0028] like Figure 1 and Figure 2 As shown, the damper 100 includes a housing 110. The housing 110 is generally annular in shape and has a first end ( Figure 1 and Figure 2 (lower end) and second end ( Figure 1 and Figure 2 The damper 100 includes a first end with an air inlet 111 and a second end with an air outlet 112. The damper 100 also includes multiple first blades 120, which are rotatably connected to the edge region of the air inlet 111 and can flexibly switch between a closed position and an open position. In the closed position, the first blades 120 are approximately horizontal; in the open position, the first blades 120 are tilted. The first blades 120 rotate approximately 30-85° when switching between the closed and open positions.

[0029] Specifically, these first blades 120 can automatically switch to the closed position under the influence of gravity. Furthermore, when the air pressure outside the air inlet 111 is lower than the air pressure inside the air inlet 111, these first blades 120 can automatically switch to the closed position and remain stable under the combined action of gravity, the low air pressure outside the air inlet 111, and the high air pressure inside the air inlet 111. The outside of the air inlet 111 refers to... Figure 1 and Figure 2The area located below the air inlet 111; the interior of the air inlet 111 refers to... Figure 1 and Figure 2 The area located above the air inlet 111 is also located inside the housing 110. When all the first blades 120 are in the closed position, they can substantially seal the air inlet 111 of the housing 110. "Substantially sealed" here means that, except for the necessary fitting gaps between the first blades 120 and the housing 110, the necessary fitting gaps between adjacent first blades 120, and the deliberately reserved areas (such as the unsealed areas mentioned later), the other parts of the air inlet 111 are effectively blocked by the first blades 120, thereby achieving a near-complete seal of the air inlet 111.

[0030] In addition, such as Figure 2 As shown, these first blades 120 can also overcome the influence of gravity and automatically switch to the open position under the action of airflow. The airflow is generated by the high air pressure outside the air inlet 111 and the low air pressure inside the air inlet 111, and the airflow direction is as follows: Figure 2 As indicated by the arrows in the diagram. When all of these first blades 120 are in the open position, an airflow channel is formed between these first blades 120 for the airflow to pass through.

[0031] According to one embodiment of the present invention, such as Figure 1 As shown, the damper 100 also includes a plurality of first rotating shafts 130, and the first blade 120 is hinged to the edge region of the air inlet 111 via one or more of the first rotating shafts 130. Those skilled in the art will readily understand that in other embodiments, a first hinge may be used instead of the first rotating shafts 130 to connect the first blade 120 to the housing 110.

[0032] Figure 3 A cross-sectional view of a damper 100 according to an embodiment of the present invention is shown, as follows: Figure 2 and Figure 3 As shown, the housing 110 may include a frame 113 and multiple side plates 114. The frame 113 is a flat, annular structure, with its inner circumferential surface forming the aforementioned air inlet 111. Multiple side plates 114 are arranged around the frame 113 and fixedly connected to it, forming a semi-enclosed structure that is open at both the top and bottom. Optionally, the frame 113 and the side plates 114 can be fixed by one or more of the following methods: screw connection, bolt connection, riveting, snap-fit ​​connection, and welding. Optionally, through holes 115 are provided at the first and / or second ends of some of the side plates 114 (corresponding to the first and second ends of the housing 110). Using these through holes 115 and suitable connectors, the air valve 100 can be easily connected to other equipment (such as the cabinet 300, fan 210, etc., described later).

[0033] According to one embodiment of the present invention, such as Figure 1 and Figure 3 The damper 100 further includes a first positioning structure 140, which is disposed inside the housing 110 and is used to position the first blade 120 in the open position, effectively preventing excessive movement of the first blade 120 during the opening process. Specifically, the first positioning structure 140 may be multiple baffles mounted on the upper surface of the frame 113. When the first blade 120 moves to the open position, the baffles abut against the inner surface of the first blade 120, thereby preventing further movement of the first blade 120.

[0034] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the outer casing 110 is configured as a rectangular annular structure. Correspondingly, the air inlet 111 and the air outlet 112 are also rectangular. Meanwhile, the first blade 120 is configured as an isosceles trapezoid, and four first blades 120 are provided, each connected to one of the four inner edges of the frame 113 (i.e., the four edge regions of the air inlet 111). In other embodiments, the first blade 120 may also be configured as an isosceles triangle or other shapes; this invention is not limited to these.

[0035] Figure 4 A bottom view of a damper 100 according to an embodiment of the present invention is shown. Figure 3 and Figure 4 As shown, when all the first blades 120 are in the closed position, an unclosed area (not closed by the first blades 120) is formed in the middle of the air inlet 111. Simultaneously, the damper 100 may also include an inner shell 150, a fixing member 160, and multiple second blades 170. The inner shell 150 is located in the unclosed area and has upper and lower permeable air ducts; the fixing member 160 connects the inner shell 150 and the outer shell 110 to fix the inner shell 150 and the outer shell 110 relatively. The multiple second blades 170 are rotatably disposed inside the inner shell 150 and can flexibly switch between open and closed positions. Specifically, these second blades 170 can automatically switch to the closed position under the action of gravity. Furthermore, when the air pressure outside the air inlet 111 is lower than the air pressure inside the air inlet 111, these second blades 170 can automatically switch to the closed position and remain stable under the combined action of gravity, the low air pressure outside the air inlet 111, and the high air pressure inside the air inlet 111. When all these second blades 170 are in the closed position, they can seal the channel. Additionally, these second blades 170 can also overcome the influence of gravity and automatically switch to the open position under the action of the airflow. When all these second blades 170 are in the open position, the channel is opened.

[0036] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the damper 100 may further include a second positioning structure 180, which is disposed inside the inner shell 150 and is used to position the second blade 170 in the open position to prevent excessive movement of the second blade 170 during the opening process. Specifically, the second positioning structure 180 may be multiple protrusions disposed on the side wall of the inner shell 150. When the second blade 170 moves to the open position, the protrusions abut against the inner surface of the corresponding second blade 170, thereby preventing the second blade 170 from moving further.

[0037] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the damper 100 may further include a plurality of second rotating shafts 190, and the second blade 170 is hinged to the interior of the inner housing 150 via one or more second rotating shafts 190. Those skilled in the art will readily understand that in other embodiments, a second hinge may be used instead of a second rotating shaft 190 to achieve the connection between the second blade 170 and the inner housing 150.

[0038] According to one embodiment of the present invention, such as Figure 1 and Figure 2 As shown, the inner shell 150 is configured as a rectangular annular structure. Correspondingly, the second blade 170 is also rectangular, and two second blades 170 are provided, each connected to one of the opposite sidewalls of the inner shell 150. Those skilled in the art will readily understand that in other embodiments, the inner shell 150 and the second blade 170 may also be configured with other shapes; for example, the inner shell 150 may be configured as a circular annular structure, and the second blade 170 may be configured as a semi-circular shape. This invention is not limited to these embodiments.

[0039] According to one embodiment of the present invention, such as Figure 2 and Figure 4 As shown, two fasteners 160 can be provided and configured as rod-shaped structures. These two fasteners 160 are respectively connected to two opposite sidewalls of the housing 110. Figure 4 The inner shell 150 is fixedly connected to two fasteners 160 between the left and right side walls of the inner shell 150. Preferably, a flange 151 is provided on the outer side of the inner shell 150. When the first blade 120 is in the closed position, the first blade 120 can overlap the flange 151, which not only improves the stability of the first blade 120, but also enhances the airtightness of the damper 100.

[0040] Figure 5 A schematic diagram of a ventilation device 200 according to an embodiment of the present invention is shown. Figure 6A cross-sectional view of a ventilation device 200 according to an embodiment of the present invention is shown below, in conjunction with... Figure 5 and Figure 6 Provide a detailed description.

[0041] like Figure 5 and Figure 6 As shown, the ventilation device 200 mainly includes a damper 100 and a fan 210. The fan 210 can be a centrifugal fan 210, an axial flow fan 210, a mixed flow fan 210, etc., and the specific type can be determined comprehensively based on factors such as the application scenario, required air volume, air pressure, and spatial layout of the ventilation device 200. The fan 210 includes a fan ring 211, which has an inlet end and an outlet end. The inlet end of the fan ring 211 is connected and communicates with the second end of the outer casing 110. When the fan 210 is working, it draws gas from the outlet 112 of the damper 100, causing the internal air pressure of the damper 100 to be lower than the external air pressure, thereby generating airflow and opening the first blade 120 of the damper 100 under the action of the airflow. When the fan 210 stops working, the internal and external air pressures of the damper 100 are basically balanced, and the first blade 120 can close under the action of gravity. Preferably, the effective ventilation area of ​​the wind ring 211 is less than or equal to the effective ventilation area of ​​the airflow channel, so that the airflow can pass smoothly through the air valve 100, reducing the negative impact of the air valve 100 on the ventilation efficiency of the fan 210.

[0042] Figure 7 A schematic diagram of a cabinet 300 according to an embodiment of the present invention is shown. Figure 8 Another schematic diagram of a cabinet 300 according to an embodiment of the present invention is shown below, in conjunction with... Figure 7 and Figure 8 Provide a detailed description.

[0043] like Figure 7 and Figure 8 As shown, the rack 300 may include a cabinet 310 and one or more ventilation devices 200. The following description uses two ventilation devices 200 as an example. The two ventilation devices 200 are arranged side-by-side on the top of the rack 300, and the air inlet 111 of the outer casing 110 communicates with the interior of the cabinet 310. The ventilation devices 200 can be independently controlled and operated, for example in… Figure 7 In the illustrated state, both ventilation devices 200 are operational. At this time, the two ventilation devices 200 extract air from the cabinet 300, effectively dissipating heat from the cabinet 300. For example, in… Figure 8In the illustrated state, one ventilation device 200 is in operation, while the other ventilation device 200 is in shutdown. For the operating ventilation device 200, the fan 210 draws gas from the outlet 112 of the damper 100, causing the air pressure inside the damper 100 (inlet 111) to be lower than the air pressure outside the damper 100 (inlet 111), thus generating airflow. This causes the first blade 120 of the damper 100 to open under the action of the airflow. At this time, the airflow flows from inside the cabinet 300 to the outside (e.g., Figure 7 (As shown by the arrow in the image), it effectively removes heat from the cabinet 300, achieving heat dissipation for the cabinet 300. For the ventilation device 200 in a stopped state, the air pressure outside the air valve 100 (air inlet 111) is lower than the air pressure inside the air valve 100 (air inlet 111). Under the combined action of gravity, the low air pressure outside the air inlet 111, and the high air pressure inside the air inlet 111, the first blade 120 of the air valve 100 is stably kept in the closed position.

[0044] Compared with the prior art, the embodiments of this utility model provide a damper 100, a ventilation device 200, and a cabinet 300. The blades of the damper 100 no longer rely on a motor drive, but can automatically open when the fan 210 is turned on and automatically close when the fan 210 is stopped. This significantly reduces the manufacturing cost and structural complexity of the damper 100, the ventilation device 200, and the cabinet 300, reduces potential failure points, and improves reliability. Furthermore, the blades of the damper 100 are far from the fan 210, and the effective ventilation area of ​​the airflow channel of the damper 100 is greater than or equal to the effective ventilation area of ​​the fan 210 (wind ring 211), allowing airflow to pass smoothly through the damper 100 and greatly reducing the negative impact of the damper 100 on the ventilation efficiency of the fan 210.

[0045] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An air valve, characterized in that, include: The outer casing has a first end and a second end, wherein the first end is provided with an air inlet and the second end is provided with an air outlet; Multiple first blades are rotatably connected to the edge region of the air inlet. Each first blade has an open position and a closed position and is configured to switch to the closed position under the action of gravity, or under the combined action of gravity, low air pressure outside the air inlet, and high air pressure inside the air inlet; it can also switch to the open position under the action of airflow, which is generated by the high air pressure outside the air inlet and the low air pressure inside the air inlet. When all the first blades are in the closed position, they can essentially seal the air inlet; when all the first blades are in the open position, an airflow channel is formed between them.

2. The air valve according to claim 1, characterized in that, The outer casing includes: A frame, configured as a ring structure, wherein the air inlet is formed on the inner circumferential surface of the frame; and Multiple side plates are arranged around the skeleton.

3. The air valve according to claim 1, characterized in that, The air valve further includes a first positioning structure, which is disposed inside the housing and configured to position the corresponding first blade in the open position.

4. The air valve according to claim 1, characterized in that, The air valve also includes a first rotating shaft or a first hinge, and the first blade is hinged to the edge region of the air inlet via the first rotating shaft or the first hinge.

5. The air valve according to claim 1, characterized in that, The air inlet is designed to be rectangular; There are four first blades, which are respectively connected to the four edge areas of the air inlet. The first blades are configured as isosceles trapezoids or isosceles triangles.

6. The air valve according to any one of claims 1-5, characterized in that, When all the first blades are in the closed position, an unclosed area is formed in the middle of the air inlet; The air valve also includes: An inner shell, disposed in the unclosed area, the inner shell having an air duct; A fastener, connecting the inner shell and the outer shell; and Multiple second blades are rotatably disposed inside the inner shell. The second blades have an open position and a closed position and are configured to switch to the closed position under the action of gravity, or under the combined action of gravity, low air pressure outside the air inlet, and high air pressure inside the air inlet; and can also switch to the open position under the action of the airflow. When all of the second blades are in the closed position, the second blades can close the air duct.

7. The air valve according to claim 6, characterized in that, The air valve also includes a second positioning structure, which is disposed inside the inner shell and configured to position the corresponding second blade in the open position.

8. The air valve according to claim 6, characterized in that, The air valve also includes a second rotating shaft or a second hinge, and the second blade is hinged to the inside of the inner shell via the second rotating shaft or the second hinge.

9. The air valve according to claim 6, characterized in that, The inner shell is configured as a rectangular ring structure; There are two second blades, which are respectively connected to two opposite side walls of the inner shell. The second blades are rectangular.

10. A ventilation device, characterized in that, include: The air valve according to any one of claims 1-9; and A fan includes a fan ring having an air inlet and an air outlet, wherein the air inlet of the fan ring is connected and communicates with a second end of the outer casing.

11. The ventilation device according to claim 10, characterized in that, The effective ventilation area of ​​the wind ring is less than or equal to the effective ventilation area of ​​the airflow channel.

12. A server rack, characterized in that, include: Cabinet; as well as The ventilation device according to claim 10 or 11, wherein the ventilation device is disposed on the top of the cabinet, and the air inlet of the outer shell is in communication with the interior of the cabinet.

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