Air valve and adjusting method

Abstract

The invention relates to the technical field of pipeline ventilation, in particular to an air valve and an adjusting method.The air valve comprises a valve shell, and a ventilation channel is formed in the middle of the valve shell; the valve further comprises a wind blocking set, the wind blocking set is arranged in the valve shell, the wind blocking set comprises a cross-shaped supporting piece installed in the valve shell, the supporting piece divides the ventilation channel into four ventilation areas, and a plurality of wind blocking parts used for sealing the ventilation areas are arranged in the ventilation areas. According to the air valve, the air volume adjusting set is matched with the air blocking part, the passing air volume of the air valve can be changed in a small range, the passing air volume of the air valve can also be rapidly changed, the operation flexibility of the air valve is improved, and the use occasions of the air valve are increased.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline ventilation, and particularly relates to a wind valve and an adjustment method thereof. Background Art

[0002] A wind valve is an important component in air conditioning and ventilation systems, mainly used to control the direction, speed, and flow rate of air flow. They are usually installed in pipeline systems to help achieve effective control of temperature and air quality in different areas.

[0003] Existing wind valves include active wind valves, passive wind valves, etc. Passive wind valves do not rely on an external power source during operation and only automatically adjust their opening and closing states according to the natural pressure difference of air flow. They have a simple structure. However, the application range of passive wind valves is limited, and they can only be used in working environments with large air flow. Moreover, the blades of passive wind valves frequently collide with the valve body, reducing the service life of passive wind valves; Active wind valves are operated by an external power source, can control the size of the air volume, and limit the adjusted blades. They are applicable to many occasions. However, multiple blades in active wind valves can only be adjusted simultaneously, and the range of each air volume adjustment is large, reducing the accuracy of air volume adjustment of the wind valve.

[0004] Therefore, there is an urgent need to provide a wind valve that can improve the accuracy of air volume adjustment and increase the application occasions. Summary of the Invention

[0005] Based on this, it is necessary to provide a wind valve and an adjustment method thereof, aiming to solve the problems that occur when existing wind valves are used.

[0006] To achieve the above object, the present invention adopts the following technical solutions: A wind valve, comprising: a valve housing, and a ventilation passage is provided in the middle of the valve housing.

[0007] It further includes a wind blocking group, the wind blocking group is arranged in the valve housing, the wind blocking group includes a support member installed inside the valve housing and in a cross shape, the support member divides the ventilation passage into four ventilation areas, and a plurality of wind blocking parts for closing the ventilation areas are arranged in the ventilation areas.

[0008] It further includes an air volume adjustment group, the air volume adjustment group is arranged on the valve housing, the air volume adjustment group includes an overall adjustment part arranged on the valve housing, a plurality of individual adjustment parts are connected to both the left and right sides of the overall adjustment part, the plurality of individual adjustment parts are connected to a plurality of corresponding wind blocking parts, and the overall adjustment part simultaneously adjusts the plurality of individual adjustment parts, so that the plurality of wind blocking parts are simultaneously changed and the air volume of the ventilation passage is changed.

[0009] The individual adjustment part includes a lifting rod that slides through the upper shell wall of the valve housing. A plurality of positioning openings are provided on the lifting rod. The lower end of the lifting rod is hinged with a traction rod, and a rotating sleeve is installed at the lower end of the traction rod. A fixed connecting piece is connected to the rotating sleeve, and the fixed connecting piece is connected to the corresponding wind blocking part. The vertically moving lifting rod drives the traction rod and the rotating sleeve to move. The moving rotating sleeve drives the corresponding single wind blocking part to change through the fixed connecting piece, so as to change the air volume of the ventilation channel. A limiting piece connected to the overall adjustment part is arranged in any one of the positioning openings.

[0010] Preferably, the wind blocking part includes a plurality of blades located in the ventilation area. Both ends of the blades are rotatably connected to the vertical section of the support piece and the side wall of the valve housing through rotating shafts at the same time. A connecting seat is installed on the blade, an ear seat plate is hinged on the connecting seat, and a linkage rod is commonly installed on a plurality of ear seat plates.

[0011] Preferably, the overall adjustment part includes two guide rods symmetrically installed at the upper end of the valve housing. A lifting plate is slidably sleeved on the two guide rods together. A regulating screw is threadedly connected to the middle of the lifting plate, and the lower end of the regulating screw is rotatably connected to the upper shell wall of the valve housing.

[0012] Preferably, the fixed connecting piece includes a connecting rod sleeved in the rotating sleeve and rotatably connected to it. A fixing plate is installed at the end of the connecting rod, and the fixing plate is fixedly connected to the corresponding linkage rod.

[0013] Preferably, the limiting piece includes two sliding grooves symmetrically opened at the upper end of the lifting plate. A sliding block is slidably connected in the sliding grooves. An installation piece is installed at the upper end of the sliding block, and a limiting rod matched with the corresponding positioning opening is commonly installed between the front and rear installation pieces.

[0014] Preferably, the wind blocking group further includes a plurality of baffle plates respectively installed at the inner ends of the two vertical side walls of the valve housing and the left and right ends of the vertical section of the support piece. The baffle plates are used to limit the rotation angle of the blades.

[0015] Preferably, a limiting plate for restricting the descending distance of the lifting rod is installed at a position near the upper end of the lifting rod.

[0016] Preferably, the structures of the plurality of connecting rods in the same ventilation area are the same only in length, and the directions of installation of the connecting rods between the upper and lower two ventilation areas on the same side and the fixing plate are opposite.

[0017] Preferably, the traction rods in the plurality of individual adjustment parts on the same side have the same structure only in length.

[0018] In addition, the present invention also provides a method for adjusting a wind valve, which specifically includes the following steps: S1: The valve housing is detachably installed on the ventilation duct. In the initial state, a plurality of wind blocking parts seal the ventilation channel.

[0019] S2: According to the required air volume passing through, move one or more lifting rods. The lifting rods drive the traction rods and the rotating sleeves to move. The moving rotating sleeves drive the corresponding wind blocking parts to change through the fixed connectors, so as to change the air volume of the ventilation channel.

[0020] S3: Or drive multiple lifting rods to move simultaneously through the overall adjustment part. The multiple lifting rods drive multiple traction rods and multiple rotating sleeves to move. The multiple moving rotating sleeves drive multiple corresponding wind blocking parts to change through multiple fixed connectors, so as to quickly change the air volume of the ventilation channel.

[0021] S4: The air valve for changing the air volume works on the ventilation duct.

[0022] In summary, the present invention has the following beneficial effects: 1. The air volume adjustment group adopted by the present invention cooperates with the wind blocking part, which can realize a small-range change in the air volume passing through the air valve and can also realize a quick change in the air volume passing through the air valve, improving the flexibility of the air valve operation and increasing the usage occasions of the air valve.

[0023] 2. The multiple individual adjustment parts adopted by the present invention can respectively control the states of multiple wind blocking parts, flexibly control the opening and closing states of different areas of the air valve, realize a small-range change in the air passing volume of the air valve, and improve the accuracy of the air valve in adjusting the air volume.

[0024] 3. The overall adjustment part adopted by the present invention cooperates with multiple individual adjustment parts, which can realize the adjustment of multiple wind blocking parts by multiple individual adjustment parts simultaneously, and further realize the function of quickly adjusting the air volume of the air valve.

[0025] 4. The air volume adjustment group adopted by the present invention cooperates with the wind blocking part, which can limit the wind blocking part after adjustment, avoid the phenomenon of frequent collision of the wind blocking part, and effectively improve the service life of the air valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the drawings and embodiments.

[0027] Figure 1 The three-dimensional structure diagram of the first perspective of the present invention is shown.

[0028] Figure 2 The three-dimensional structure diagram of the second perspective of the present invention is shown.

[0029] Figure 3 The front view of the present invention is shown.

[0030] Figure 4 The left view of the present invention is shown.

[0031] Figure 5 Shows Figure 3 The cross-sectional view taken along A-A in

[0032] Figure 6 shows Figure 5 an enlarged view of region C in

[0033] Figure 7 shows Figure 4 a cross-sectional view taken along B-B in

[0034] Figure 8 shows Figure 7 an enlarged view of region D in

[0035] Figure 9 shows a schematic three-dimensional structure diagram of a partial valve housing, a partial lifting plate and a separate adjustment part of the present invention.

[0036] Among them, the above-mentioned drawings include the following reference numerals: 1, valve housing; 10, ventilation channel; 100, ventilation area; 11, circular pipe; 2, wind shielding group; 20, support member; 21, wind shielding part; 210, blade; 211, connecting seat; 212, ear seat plate; 213, linkage rod; 22, baffle; 3, air volume adjustment group; 30, overall adjustment part; 300, guide rod; 301, lifting plate; 302, adjusting screw; 31, separate adjustment part; 310, lifting rod; 311, positioning opening; 312, traction rod; 313, rotating sleeve; 314, fixed connecting member; 3140, connecting rod; 3141, fixing plate; 315, limiting member; 3150, chute; 3151, sliding block; 3152, mounting member; 3153, limiting rod; 316, limiting plate. Detailed Embodiment

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be made with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0038] Refer to Figure 1 , Figure 2 and Figure 5 , a wind valve includes a valve housing 1, a ventilation channel 10 is arranged in the middle of the valve housing 1, and circular pipes 11 communicating with the ventilation channel 10 are installed at both the front and rear ends of the valve housing 1.

[0039] During specific operation, the valve housing 1 is transported to the installation position. A plurality of installation holes for installation and connection are provided on the circular pipe 11, and then the two circular pipes 11 are respectively fixedly connected to two existing ventilation pipes through bolts.

[0040] Refer to Figures 1 - 5, the air valve further includes a wind blocking group 2, the wind blocking group 2 is arranged inside the valve housing 1, the wind blocking group 2 includes a support member 20 installed inside the valve housing 1 and in a cross shape, the support member 20 divides the ventilation passage 10 into four ventilation areas 100, and a plurality of wind blocking parts 21 for closing the ventilation area 100 are arranged in the ventilation area 100.

[0041] Refer to Figure 2 , Figure 6 and Figure 7 , the wind blocking part 21 includes a plurality of blades 210 located in the ventilation area 100, both ends of the blade 210 are rotatably connected to the vertical section of the support member 20 and the side wall of the valve housing 1 through a rotating shaft at the same time, a connecting seat 211 is installed on the blade 210, an ear seat plate 212 is hinged on the connecting seat 211, and a linkage rod 213 is commonly installed on a plurality of ear seat plates 212.

[0042] Refer to Figure 1 and Figure 6 , the wind blocking group 2 further includes a plurality of baffles 22 respectively installed at the inner ends of the two vertical side walls of the valve housing 1 and the left and right ends of the vertical section of the support member 20, and the baffles 22 are used to limit the rotation angle of the blade 210.

[0043] During specific operation, the support member 20 divides the ventilation passage 10 into four ventilation areas 100, and plays a role in supporting and limiting the installation of the subsequent blade 210. The support member 20 can be a rod-shaped structure or a frame-shaped structure, which is not uniquely limited here. During the installation of the valve housing 1 and the ventilation duct, ensure that the end of the blade 210 away from the linkage rod 213 faces the air inlet direction. In the initial state, the blade 210 is in a vertical state due to its own gravity. The ends of two adjacent blades 210 in the same ventilation area 100 are staggered to avoid air leakage caused by gaps between two adjacent blades 210. At the same time, the two blades 210 at the uppermost and lowermost positions in the same ventilation area 100 are in contact with the inner wall of the valve housing 1, so as to ensure that a plurality of blades 210 can seal the ventilation area 100. The blades 210 in the four ventilation areas 100 realize the function of closing the ventilation passage 10. A plurality of baffles 22 are used to limit the clockwise rotation of the blade 210 to avoid the phenomenon that the adjacent blades 210 have gaps due to excessive rotation of the blade 210.

[0044] Refer to Figure 1 , Figure 2 and Figure 5, the air damper further includes an air volume adjustment group 3, the air volume adjustment group 3 is arranged on the valve housing 1, the air volume adjustment group 3 includes an overall adjustment part 30 arranged on the valve housing 1, and a plurality of individual adjustment parts 31 are connected to both the left and right sides of the overall adjustment part 30. The plurality of individual adjustment parts 31 are connected to a plurality of corresponding wind blocking parts 21. The overall adjustment part 30 adjusts the plurality of individual adjustment parts 31 simultaneously, so that the plurality of wind blocking parts 21 change simultaneously and change the air volume of the ventilation channel 10.

[0045] Refer to Figure 1 , Figure 2 , Figure 8 and Figure 9 , the individual adjustment part 31 includes a lifting rod 310 that slidably penetrates the upper shell wall of the valve housing 1. A plurality of positioning openings 311 are formed on the lifting rod 310. A traction rod 312 is hinged to the lower end of the lifting rod 310. A rotating sleeve 313 is installed at the lower end of the traction rod 312. A fixed connecting piece 314 is connected to the rotating sleeve 313. The fixed connecting piece 314 is connected to the corresponding wind blocking part 21. The vertically moving lifting rod 310 drives the traction rod 312 and the rotating sleeve 313 to move. The moving rotating sleeve 313 drives the corresponding single wind blocking part 21 to change through the fixed connecting piece 314, so that the air volume of the ventilation channel 10 changes. A limiting piece 315 connected to the overall adjustment part 30 is arranged in any one of the positioning openings 311. A limiting plate 316 for limiting the descending distance of the lifting rod 310 is installed at a position near the upper end of the lifting rod 310.

[0046] During specific operation, after the valve housing 1 and the ventilation pipe are installed, in the initial state, a plurality of limiting pieces 315 cooperate with the corresponding positioning openings 311 on a plurality of lifting rods 310 to realize the function of limiting a plurality of lifting rods 310. Furthermore, the wind blocking parts 21 are limited through the traction rod 312, the rotating sleeve 313 and the fixed connecting piece 314, avoiding the state that a plurality of blades 210 rotate under the action of wind force, enabling it to be used under the working conditions where the air damper needs to be closed, increasing the usage occasions of the air damper. The limiting plate 316 limits the descending distance of the lifting rod 310, preventing the lifting rod 310 from entering the valve housing 1 due to its own gravity.

[0047] Refer to Figure 2 , Figure 5 , Figure 7 and Figure 9 , the fixed connecting piece 314 includes a connecting rod 3140 sleeved in the rotating sleeve 313 and rotatably connected to it. A fixing plate 3141 is installed at the end of the connecting rod 3140. The fixing plate 3141 is fixedly connected to the corresponding linkage rod 213.

[0048] Refer to Figure 1 , Figure 2 , Figure 7 and Figure 9, the overall adjustment part 30 includes two guide rods 300 symmetrically installed at the upper end of the valve housing 1. A lifting plate 301 is slidably sleeved on the two guide rods 300 together. The limiting member 315 includes two sliding grooves 3150 symmetrically opened at the upper end of the lifting plate 301. A sliding block 3151 is slidably connected in the sliding groove 3150. An installation member 3152 is installed at the upper end of the sliding block 3151. A limiting rod 3153 that cooperates with the corresponding positioning opening 311 is installed between the two installation members 3152 at the front and back.

[0049] During specific operation, if the air valve needs to ventilate, according to the required ventilation air volume, lift the corresponding lifting rod 310. The lifting rod 310 drives the rotating sleeve 313 to rise through the traction rod 312. The rotating sleeve 313 drives the connecting rod 3140 and the fixing plate 3141 to rise. The fixing plate 3141 drives the linkage rod 213 to rise. The linkage rod 213 drives multiple blades 210 to rotate around the rotating shaft through multiple ear seat plates 212 and multiple connecting seats 211, thereby opening the ventilation area 100 to achieve the ventilation function. When the lifting rod 310 rises to the required height, push the two corresponding sliding blocks 3151. The two sliding blocks 3151 drive the limiting rod 3153 to move into the corresponding positioning opening 311 through the two installation members 3152, realizing the function of limiting the lifting rod 310, and further realizing the function of limiting the rotated blades 210, avoiding the function of repeated collision of the blades 210, improving the service life of the air valve. The installation member 3152 can be a plate-like structure, a rod-like structure or a frame-like structure, which is not uniquely limited here. Multiple lifting rods 310 can respectively control the states of multiple wind shielding parts 21, so as to flexibly control the opening and closing states of different areas of the ventilation channel 10, slightly change the air volume of the air passing through the air valve, effectively improving the flexibility of the air valve to control the air volume, and improving the accuracy of the air valve to adjust the air volume.

[0050] Refer to Figure 7 and Figure 9 , the structures of the multiple connecting rods 3140 in the same ventilation area 100 are the same except for the lengths. The directions of installation of the connecting rods 3140 and the fixing plate 3141 in the upper and lower two ventilation areas 100 on the same side are opposite.

[0051] Refer to Figure 1 and Figure 7 , the traction rods 312 in the multiple individual adjustment parts 31 on the same side have the same structure except for the lengths.

[0052] During specific operation, the drawbars 312 of different lengths can achieve the function of adjusting the windshield parts 21 at different heights. The connecting rods 3140 within the same ventilation area 100 have the same structure but different lengths, and the connecting rods 3140 in the upper and lower two ventilation areas 100 on the same side are installed in opposite directions in cooperation with the fixing plates 3141, so that multiple installed drawbars 312 can be laid flat without affecting the movement of the drawbars 312 and the rotation of the blades 210.

[0053] Refer to Figure 7 In the middle of the lifting plate 301, an adjusting screw 302 is threadedly connected, and the lower end of the adjusting screw 302 is rotatably connected to the upper shell wall of the valve housing 1.

[0054] During specific operation, when the air volume of the air valve is changed, the adjusting screw 302 can also be rotated. The adjusting screw 302 drives the lifting plate 301 to rise along the guide rod 300. At the same time, the lifting plate 301 drives multiple lifting rods 310 to rise through multiple limiting plates 316 and multiple limiting members 315, thereby realizing the simultaneous rotation of all the blades 210 in multiple ventilation areas 100, so as to quickly change the air volume of the ventilation channel 10 and effectively improve the efficiency of changing the air volume of the air valve.

[0055] In addition, the present invention also provides a method for adjusting an air valve, which specifically includes the following steps: S1: The valve housing 1 is detachably installed on the ventilation duct, and multiple windshield parts 21 in the initial state seal the ventilation channel 10.

[0056] S2: According to the magnitude of the required air volume to pass through, move a single or multiple lifting rods 310. The lifting rods 310 drive the drawbars 312 and the rotating sleeves 313 to move. The moving rotating sleeves 313 drive the corresponding windshield parts 21 to change through the fixed connecting members 314, so as to change the air volume of the ventilation channel 10.

[0057] S3: Or drive multiple lifting rods 310 to move simultaneously through the overall adjusting part 30. The multiple lifting rods 310 drive multiple drawbars 312 and multiple rotating sleeves 313 to move. The multiple moving rotating sleeves 313 drive multiple corresponding windshield parts 21 to change through multiple fixed connecting members 314, so as to quickly change the air volume of the ventilation channel 10.

[0058] S4: The air valve with the changed air volume operates on the ventilation duct.

[0059] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more than two.

[0060] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0061] The embodiments of the specific implementation manners are all preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A damper, characterized in that: include: A valve housing, wherein a ventilation passage is provided in the middle of the valve housing; A wind shielding group is arranged in the valve housing, the wind shielding group includes a cross-shaped support member installed inside the valve housing, the support member divides the ventilation channel into four ventilation areas, and a plurality of wind shielding parts for closing the ventilation areas are arranged in the ventilation areas; An air volume adjustment group is arranged on the valve housing, the air volume adjustment group comprises an integral adjustment part arranged on the valve housing, a plurality of individual adjustment parts are connected to both left and right sides of the integral adjustment part, the plurality of individual adjustment parts are connected to a plurality of corresponding wind shielding parts, the integral adjustment part adjusts the plurality of individual adjustment parts simultaneously, so that the plurality of wind shielding parts are transformed and the air volume of the ventilation channel is changed simultaneously; The separate adjustment part includes a lifting rod that slides through the upper shell wall of the valve shell, and a plurality of positioning openings are opened on the lifting rod. A traction rod is hinged at the lower end of the lifting rod, and a rotating sleeve is installed at the lower end of the traction rod. A fixed connecting piece is connected to the rotating sleeve, and the fixed connecting piece is connected to the corresponding wind shield part. The vertically moving lifting rod drives the traction rod and the rotating sleeve to move, and the moving rotating sleeve drives the corresponding single wind shield part to change through the fixed connecting piece, so that the air volume of the ventilation channel changes, and a limit piece connected to the overall adjustment part is arranged in any one of the positioning openings.

2. A damper according to claim 1, characterized in that: The wind shield includes a plurality of blades located in the ventilation area, both ends of the blades are rotatably connected to the vertical section of the support and the side wall of the valve housing through a rotating shaft, a connecting seat is installed on the blade, an ear seat plate is hinged on the connecting seat, and a linkage rod is commonly installed on the plurality of ear seat plates.

3. The air valve according to claim 1, characterized in that: The integral adjustment part comprises two guide rods symmetrically mounted on the upper end of the valve housing, a lifting plate is slidably sleeved on the two guide rods, an adjusting screw is threadedly connected to the middle of the lifting plate, and the lower end of the adjusting screw is rotatably connected to the upper shell wall of the valve housing.

4. The air valve according to claim 2, characterized in that: The fixed connection member comprises a connection rod which is sleeved in the rotating sleeve and rotatably connected thereto, a fixing plate is installed at the end of the connection rod, and the fixing plate is fixedly connected to the corresponding linkage rod.

5. The air valve according to claim 3, characterized in that: The limiting member comprises two slide grooves symmetrically arranged on the upper end of the lifting plate, a sliding block is slidably connected in the slide groove, a mounting member is installed on the upper end of the sliding block, and a limiting rod cooperating with the corresponding positioning opening is installed between the front and rear mounting members.

6. The air valve according to claim 2, characterized in that: The wind shielding group also includes a plurality of baffles respectively installed on the inner ends of the side walls of the two vertical sections of the valve housing and the left and right ends of the vertical section of the support member, and the baffles are used to limit the rotation angle of the blades.

7. The air valve according to claim 1, characterized in that: A limit plate for limiting the descending distance of the lifting rod is installed near the upper end of the lifting rod.

8. The air valve according to claim 4, characterized in that: The multiple connecting rods in the same ventilation area have the same structure but different lengths. The connecting rods in the upper and lower ventilation areas on the same side are installed in opposite directions to the fixing plates.

9. The air valve according to claim 1, characterized in that: The traction rods in the plurality of separate adjustment parts on the same side have the same structure and only differ in length.

10. A method for adjusting a damper, characterized in that: The method is completed by using the air valve as claimed in claim 1, comprising the following steps: S1: The valve housing is detachably mounted on the ventilation duct, and the multiple wind shielding parts in the initial state seal the ventilation duct; S2: According to the required air volume, a single or multiple lifting rods are moved, and the lifting rods drive the traction rod and the rotating sleeve to move, and the moving rotating sleeve drives the corresponding wind shield to change through the fixed connecting piece, so that the air volume of the ventilation channel changes; S3: or the overall adjustment part drives multiple lifting rods to move at the same time, the multiple lifting rods drive multiple traction rods and multiple rotating sleeves to move, and the multiple moving rotating sleeves drive multiple corresponding wind shielding parts to change through multiple fixed connecting parts, so that the air volume of the ventilation channel changes quickly; S4: The air valve that changes the air volume works on the ventilation duct.

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