A noise reduction and reinforcement structure for the pipe wall

Abstract

The present invention relates to the technical field of air duct noise reduction and reinforcement, and discloses a pipe wall noise reduction and reinforcement structure, including a supporting mechanism, wherein the supporting mechanism includes a first fixing frame, an outer wall of the first fixing frame is fixedly connected with an elastic component, an outer wall of the first fixing frame on a side away from the elastic component is fixedly connected with a second fixing frame, a first sliding frame is arranged on the top of the second fixing frame, an inner wall of the first sliding frame is rotatably connected with a screw, and an outer wall of the second fixing frame is fixedly connected with a fixed shaft. When the fan is running, the rectangular air duct is reinforced by the supporting mechanism, the vibration generated by the fan is absorbed by the elastic component, and the sound insulation sponge is reinforced by the adjusting component, so that the sound insulation sponge is more closely fitted to the outer wall of the rectangular air duct, thereby increasing its noise blocking effect.

Description

Technical Field

[0001] The present invention relates to the technical field of air duct noise reduction and reinforcement, and specifically provides a noise reduction and reinforcement structure for the pipe wall. Background Technique

[0002] Rectangular air ducts are a common type of ventilation duct, widely used in the ventilation systems of buildings. In order to reduce the noise and vibration during the operation of rectangular air ducts, it is usually necessary to perform noise reduction and reinforcement treatments on them.

[0003] The patent application with the application number CN202323229330.1 discloses a reinforcement system for ventilation duct supports and hangers, including a duct composed of multiple sections of rectangular air ducts. Right-angle reinforcement ribs are provided at the middle position of the rectangular air ducts; a heat insulation layer is provided on the duct. The horizontal part of the duct is fixed by horizontal brackets, and the vertical part is fixed by vertical brackets. Steel plates and anti-corrosion wooden pads are provided between the duct and both the horizontal brackets and the vertical brackets.

[0004] In summary, when rectangular air ducts are applied to environments with strict noise requirements, during the operation of the fan, if effective vibration isolation treatment is not implemented for the rectangular air ducts, the vibration generated by the fan will be directly transmitted to the air ducts, resulting in the vibration and noise emission of the air ducts. In the traditional method, adding sound insulation sponges to the outer wall of rectangular air ducts has problems such as cumbersome reinforcement operations and inconvenient replacement. Moreover, if the sound insulation sponges cannot be completely attached to the outer wall of the rectangular air ducts, their noise blocking effect will be significantly weakened.

[0005] Therefore, we have proposed a noise reduction and reinforcement structure for the pipe wall. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides a noise reduction and reinforcement structure for the pipe wall to solve the problems raised in the above background technique.

[0007] To achieve the above object, the present invention provides the following technical solution: A noise reduction and reinforcement structure for the pipe wall, including a support mechanism. The support mechanism includes a first fixing frame, an elastic component is fixedly connected to the outer wall of the first fixing frame, a second fixing frame is fixedly connected to the outer wall of the first fixing frame away from the elastic component, a first sliding frame is provided at the top of the second fixing frame, a screw rod is rotatably connected to the inner wall of the first sliding frame, a fixed shaft is fixedly connected to the outer wall of the second fixing frame, and further includes:

[0008] Adjusting assembly, including a second sliding frame slidably connected to a fixed shaft, the inner wall of the second sliding frame is provided with a second connecting rod, the outer wall of the second sliding frame close to the second fixed frame is fixedly connected with a second spring, and one end of the second spring away from the second sliding frame is fixedly connected with the second fixed frame. One end of the second sliding frame close to the inner wall of the second fixed frame is rotatably connected to a first connecting rod through a rotating shaft.

[0009] According to the above technical solution, the outer wall of the first sliding frame is rotatably connected to a first rotating rod through a rotating shaft. One end of the first rotating rod away from the first sliding frame is rotatably connected to a second rotating rod through a rotating shaft. One end of the second rotating rod away from the first rotating rod is rotatably connected to the second fixed frame. The number of the first rotating rods is two, and the two first rotating rods are symmetrically arranged with the central axis of the first sliding frame as the center. The first sliding frame approaches the side of the second fixed frame under the action of the screw, so that the first sliding frame simultaneously presses the second rotating rod through the first rotating rod.

[0010] According to the above technical solution, the inner wall of one side of the second connecting rod away from the second sliding frame is rotatably connected to the second fixed frame. A second through hole is provided in the inner wall of the second connecting rod. The outer wall of one side of the second connecting rod away from the second fixed frame is rotatably connected to a pressing plate through a rotating shaft. The inner wall of the second through hole is slidably connected to the second sliding frame. The pressing plate applies different forces to the sound insulation sponge according to the different distances between the second sliding frame and the second fixed frame.

[0011] According to the above technical solution, a third through hole is provided in the inner wall of one side of the pressing plate close to the second fixed frame. A connecting shaft is fixedly connected to the outer wall of one side of the pressing plate close to the second fixed frame. The number of the connecting shafts is two, and the two connecting shafts are symmetrically arranged with the central axis of the limiting plate as the center.

[0012] According to the above technical solution, one end of the connecting shaft away from the pressing plate penetrates through the second connecting rod and is fixedly connected with a limiting plate. A third spring is fixedly connected to the outer wall of one side of the limiting plate close to the second connecting rod. One end of the third spring away from the limiting plate is fixedly connected with the second connecting rod. The third spring is used for the reset function of the pressing plate.

[0013] According to the above technical solution, one end of the fixed shaft away from the second fixed frame is fixedly connected with a fixed block. An arc-shaped rod is fixedly connected to the inner wall of the fixed block. A first through hole is provided in the inner wall of the arc-shaped rod. The inner wall of the first through hole is slidably connected to the second sliding frame. The number of the fixed shafts is two, and the two fixed shafts are symmetrically arranged with the central axis of the second fixed frame as the center.

[0014] According to the above technical solution, one end of the arc-shaped rod away from the fixed block is rotatably connected to a clamping rod through a rotating shaft. A first spring is fixedly connected to the outer wall of the clamping rod close to the arc-shaped rod. One end of the first spring away from the clamping rod is fixedly connected to the arc-shaped rod. The clamping rod adjusts its angle through the first spring, so that it can be more convenient to fix the sound insulation sponge on the outer wall of the connecting pipe.

[0015] A rectangular air duct includes: a connecting pipe, the outer wall of the connecting pipe is fixedly connected to a first fixing frame, a flange is fixedly connected to the outer wall of the connecting pipe, a sealing ring is fixedly connected to one end of the flange away from the connecting pipe, and a sound-absorbing board is fixedly connected to the inner wall of the connecting pipe.

[0016] Compared with the prior art, the present invention provides a noise reduction and reinforcement structure for the pipe wall, having the following beneficial effects:

[0017] 1. By setting a noise reduction and reinforcement structure for the pipe wall in the present invention, during the operation of the fan, the rectangular air duct is reinforced through the support mechanism, the vibration generated by the fan is absorbed through the elastic component, and the sound insulation sponge is reinforced through the adjustment component, so that the sound insulation sponge fits more closely with the outer wall of the rectangular air duct, thereby increasing its noise blocking effect.

[0018] 2. By setting the support mechanism in the present invention, with the synchronous push of the screws on both sides, the first sliding frame moves towards the second fixing frame, and then the first sliding frame exerts a squeezing effect on the second rotating rod by virtue of the first rotating rod, so that the second sliding frame can slide along the fixed shaft towards the fixed block side. Through the second sliding frame, the pressing plate and the clamping rod can clamp and fix the sound insulation sponge at the same time.

[0019] 3. By setting the arc-shaped rod and the clamping rod in the present invention, with the sliding of the second sliding frame towards the fixed block side, one end of the arc-shaped rod away from the fixed block flips towards the connecting pipe side, so as to clamp and fix the sound insulation sponge on the outer wall of the connecting pipe through the clamping rod, thereby improving the convenience of reinforcing the sound insulation sponge.

[0020] 4. By setting the adjustment component in the present invention, when the second sliding frame slides towards the fixed block side, the second connecting rod rotates around the second fixing frame. After the pressing plate presses the sound insulation sponge, the pressing plate is adjusted at a certain angle through the connecting shaft, thereby increasing the contact area between the pressing plate and the sound insulation sponge and improving the pressing force of the pressing plate on the sound insulation sponge, so that the sound insulation sponge fits more closely with the outer wall of the rectangular air duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation to the present invention. In the drawings:

[0022] Figure 1 is a schematic front view of the overall structure of the present invention;

[0023] Figure 2 is a schematic front sectional view of the overall structure of the present invention;

[0024] Figure 3 is a schematic view of the support mechanism and adjustment assembly structure of the present invention;

[0025] Figure 4 is of the present invention Figure 2 enlarged schematic view of A therein;

[0026] Figure 5 is a schematic view of the support mechanism structure of the present invention;

[0027] Figure 6 is a schematic view of the support mechanism structure of the present invention;

[0028] Figure 7 is a schematic view of the adjustment assembly structure of the present invention;

[0029] Figure 8 is a schematic view of the adjustment assembly structure of the present invention.

[0030] In the figure: 1, support mechanism; 101, first fixing frame; 102, elastic component; 103, second fixing frame; 104, first sliding frame; 105, first rotating rod; 106, screw rod; 107, fixed shaft; 108, second rotating rod; 109, fixed block; 110, arc rod; 111, first through hole; 112, clamping rod; 113, first spring; 2, adjustment assembly; 201, second sliding frame; 202, first connecting rod; 203, second spring; 204, second connecting rod; 205, second through hole; 206, pressing plate; 207, third through hole; 208, connecting shaft; 209, limiting plate; 210, third spring; 301, connecting pipe; 302, flange; 303, sealing ring; 304, sound absorption board. Detailed implementation manners

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0032] Examples of the described embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as a limitation to the present invention.

[0033] In the present invention, unless otherwise clearly specified and defined, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. 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.

[0034] Embodiment 1: Refer to Figures 1 - 6 , the present invention provides a technical solution: a noise reduction and reinforcement structure for a pipe wall, including a support mechanism 1. The support mechanism 1 includes a first fixing frame 101. An elastic component 102 is fixedly connected to the outer wall of the first fixing frame 101. The elastic component 102 is made of rubber and has a certain vibration damping and noise reduction effect. A second fixing frame 103 is fixedly connected to the outer wall of the first fixing frame 101 away from the elastic component 102. The outer wall of the second fixing frame 103 away from the first fixing frame 101 is fixedly connected to a flange 302, thereby improving the stability of the second fixing frame 103. A first sliding frame 104 is arranged at the top of the second fixing frame 103. A screw rod 106 is rotatably connected to the inner wall of the first sliding frame 104. One end of the screw rod 106 away from the first sliding frame 104 is rotatably connected to the outer wall of a connecting pipe 301. By rotating the screw rod 106, the distance between the first sliding frame 104 and the connecting pipe 301 can be adjusted. A fixed shaft 107 is fixedly connected to the outer wall of the second fixing frame 103. It further includes:

[0035] An adjusting component 2, including a second sliding frame 201 slidably connected to the fixed shaft 107. A second connecting rod 204 is arranged on the inner wall of the second sliding frame 201. A second spring 203 is fixedly connected to the outer wall of the second sliding frame 201 close to the second fixing frame 103. One end of the second spring 203 away from the second sliding frame 201 is fixedly connected to the second fixing frame 103. A first connecting rod 202 is rotatably connected to the inner wall of the second sliding frame 201 close to the second fixing frame 103 through a rotating shaft. During the operation of the fan, the support mechanism 1 is used to reinforce the rectangular air duct. With the elastic component 102 between the first fixing frame 101 and the second fixing frame 103, the vibration generated during the operation of the fan is absorbed. The sound insulation sponge is reinforced through the adjusting component 2, so that the sound insulation sponge fits more closely to the outer wall of the rectangular air duct, thereby enhancing its noise blocking effect.

[0036] The outer wall of the first sliding frame 104 is rotatably connected to a first rotating rod 105 through a rotating shaft. One end of the first rotating rod 105 away from the first sliding frame 104 is rotatably connected to a second rotating rod 108 through a rotating shaft. The first sliding frame 104 approaches one side of the second fixed frame 103 under the action of the screw rod 106. Thus, the first sliding frame 104 simultaneously exerts extrusion on the second rotating rod 108 through the first rotating rod 105. One end of the second rotating rod 108 away from the first rotating rod 105 is rotatably connected to the second fixed frame 103.

[0037] One end of the fixed shaft 107 away from the second fixed frame 103 is fixedly connected to a fixed block 109. The inner wall of the fixed block 109 is fixedly connected to an arc-shaped rod 110. A first through hole 111 is formed in the inner wall of the arc-shaped rod 110. The inner wall of the first through hole 111 is slidably connected to the second sliding frame 201. Since the second sliding frame 201 slides towards the fixed block 109, one end of the arc-shaped rod 110 away from the fixed block 109 flips towards the connecting pipe 301. Furthermore, the sound insulation sponge on the outer wall of the connecting pipe 301 is clamped and fixed by the clamping rod 112, thereby improving the convenience of the reinforcement operation for the sound insulation sponge.

[0038] One end of the arc-shaped rod 110 away from the fixed block 109 is rotatably connected to a clamping rod 112. A first spring 113 is fixedly connected to the outer wall of the clamping rod 112 on the side close to the arc-shaped rod 110. The clamping rod 112 adjusts its angle through the first spring 113, so that it can more conveniently fix the sound insulation sponge on the outer wall of the connecting pipe 301. One end of the first spring 113 away from the clamping rod 112 is fixedly connected to the arc-shaped rod 110. Driven by the synchronous force application of the screw rods 106 on both sides, the first sliding frame 104 displaces towards the second fixed frame 103. Thus, the first sliding frame 104 exerts an extrusion effect on the second rotating rod 108 through the first rotating rod 105, and further enables the second sliding frame 201 to slide along the fixed shaft 107 towards the fixed block 109. Through the second sliding frame 201, the pressing plate 206 and the clamping rod 112 can simultaneously clamp and fix the sound insulation sponge.

[0039] The working principle of this embodiment is as follows: when the sound insulation sponge is used to reinforce the outer wall of the connecting tube 301, the sound insulation sponge is first completely wrapped around the outer wall of the connecting tube 301. Then, the screws 106 on both sides are rotated in the same direction at the same time. Driven by this action, the first sliding frame 104 begins to slide slowly toward one side of the connecting tube 301. As the first sliding frame 104 gradually descends, its outer wall exerts a strong squeeze on the second rotating rod 108 through the tightly connected first rotating rod 105. This squeeze is transmitted. When the second rotating rod 108 squeezes the first connecting rod 202, a chain reaction is triggered, so that the second sliding frame 201 slides smoothly along the fixed axis 107 toward one side of the fixed block 109. During the entire sliding process of the second sliding frame 201, the second spring 203 is continuously stretched and a certain amount of elastic potential energy is accumulated. When the second sliding frame 201 continues to slide toward the side of the fixed block 109, the arc rod 110 moves away from the first rotating rod 108. One end of the fixing block 109 is flipped toward the side of the connecting pipe 301. At this time, the sound insulation sponge on the outer wall of the connecting pipe 301 can be effectively clamped and fixed by the clamping rod 112. When the clamping rod 112 and the sound insulation sponge are in contact with each other, the clamping rod 112 will cause a certain degree of extrusion on the first spring 113. By means of this extrusion, the angle of the clamping rod 112 can be flexibly adjusted by the first spring 113. In this way, the contact area of ​​the clamping rod 112 on the sound insulation sponge is greatly improved, so that the sound insulation sponge can fit more closely with the outer wall of the rectangular air duct to achieve excellent sound insulation effect. When the sound insulation sponge needs to be replaced later, it is only necessary to rotate the screws 106 on both sides to cause the first sliding frame 104 to slide upward. In this way, the fixing state of the clamping rod 112 on the sound insulation sponge can be released, so that the sound insulation sponge can be replaced smoothly to ensure that the sound insulation device is always in good working condition.

[0040] Example 2: Please refer to Figures 7 - 8 On the basis of the first embodiment, the present invention provides a technical solution: the inner wall of the second connecting rod 204 away from the second sliding frame 201 is rotatably connected to the second fixed frame 103, the inner wall of the second connecting rod 204 is provided with a second through hole 205, the outer wall of the second connecting rod 204 away from the second fixed frame 103 is rotatably connected with a pressure plate 206 through a rotating shaft, the inner wall of the second through hole 205 is slidably connected to the second sliding frame 201, and the pressure plate 206 applies different forces to the sound insulation sponge according to the different distances between the second sliding frame 201 and the second fixed frame 103.

[0041] A third through hole 207 is formed on the inner wall of the pressing plate 206 close to the second fixing frame 103, and a connecting shaft 208 is fixedly connected to the outer wall of the pressing plate 206 close to the second fixing frame 103. The connecting shaft 208 makes the pressing plate 206 close to the second fixing frame 103 more stable during movement.

[0042] One end of the connecting shaft 208 away from the pressing plate 206 penetrates through the second connecting rod 204 and is fixedly connected with a limiting plate 209. A third spring 210 is fixedly connected to the outer wall of the side of the limiting plate 209 close to the second connecting rod 204. The third spring 210 is used for the reset of the pressing plate 206. One end of the third spring 210 away from the limiting plate 209 is fixedly connected with the second connecting rod 204. When the second sliding frame 201 slides towards the fixed block 109, the second connecting rod 204 rotates around the second fixing frame 103 as the axis. After squeezing the sound-absorbing sponge through the pressing plate 206, the pressing plate 206 is adjusted by a certain angle through the connecting shaft 208, so as to increase the contact area between the pressing plate 206 and the sound-absorbing sponge, enhance the pressing force of the pressing plate 206 on the sound-absorbing sponge, and further make the sound-absorbing sponge fit more closely to the outer wall of the rectangular air duct.

[0043] The working principle of this embodiment is as follows: During the process of the second sliding frame 201 moving towards the fixed block 109, a sliding connection is formed between the outer wall of the second sliding frame 201 and the second through hole 205 on the inner wall of the second connecting rod 204. Under this action, the second connecting rod 204 can rotate around the first fixing frame 101 as the center point. Then, the sound-absorbing sponge on the outer wall of the connecting pipe 301 is squeezed and fixed by the pressing plate 206 at the bottom of the second connecting rod 204. When the second connecting rod 204 continues to rotate towards the connecting pipe 301, the side of the pressing plate 206 close to the first fixing frame 101 will come into contact with the sound-absorbing sponge first. With the continuous action of the second connecting rod 204, the pressing plate 206 gradually expands the contact area with the sound-absorbing sponge. This gradually increasing contact area effectively enhances the pressing force of the pressing plate 206 on the sound-absorbing sponge, and further promotes the sound-absorbing sponge to fit more closely to the outer wall of the rectangular air duct, achieving a better sound insulation effect. However, when the pressing of the pressing plate 206 on the sound-absorbing sponge is excessive, the side of the pressing plate 206 close to the first fixing frame 101 will slide through the connecting shaft 208. This sliding action can skillfully avoid excessive pressing of the side of the pressing plate 206 close to the first fixing frame 101 on the sound-absorbing sponge, thus protecting the sound-absorbing sponge from damage, and at the same time ensuring the rationality and stability of the entire pressing and fixing process, so that the sound-absorbing sponge can achieve a good fitting effect without being affected by excessive pressing in terms of its performance and service life.

[0044] A rectangular air duct, comprising: a connecting pipe 301, the outer wall of the connecting pipe 301 is fixedly connected with a first fixing frame 101, a flange 302 is fixedly connected to the outer wall of the connecting pipe 301, a sealing ring 303 is fixedly connected to the end of the flange 302 away from the connecting pipe 301, and a sound-absorbing plate 304 is fixedly connected to the inner wall of the connecting pipe 301.

[0045] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device.

[0046] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention 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 perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A pipe wall noise reduction and reinforcement structure, comprising a support mechanism (1), the support mechanism (1) comprising a first fixed frame (101), the outer wall of the first fixed frame (101) being fixedly connected to an elastic component (102), the outer wall of the first fixed frame (101) being fixedly connected to a second fixed frame (103) on a side away from the elastic component (102), a first sliding frame (104) being arranged on the top of the second fixed frame (103), a screw (106) being rotatably connected to the inner wall of the first sliding frame (104), and a fixed shaft (107) being fixedly connected to the outer wall of the second fixed frame (103), characterized in that: Also included are: The adjustment assembly (2) comprises a second sliding frame (201) slidably connected to the fixed shaft (107); a second connecting rod (204) is arranged on the inner wall of the second sliding frame (201); a second spring (203) is fixedly connected to the outer wall of the second sliding frame (201) on one side close to the second fixed frame (103); an end of the second spring (203) away from the second sliding frame (201) is fixedly connected to the second fixed frame (103); and a first connecting rod (202) is rotatably connected to the inner wall of the second sliding frame (201) on one side close to the second fixed frame (103) via a rotating shaft; The outer wall of the first sliding frame (104) is rotatably connected to a first rotating rod (105) via a rotating shaft, one end of the first rotating rod (105) away from the first sliding frame (104) is rotatably connected to a second rotating rod (108) via a rotating shaft, and one end of the second rotating rod (108) away from the first rotating rod (105) is rotatably connected to the second fixed frame (103); The inner wall of the second connecting rod (204) on one side away from the second sliding frame (201) is rotatably connected to the second fixed frame (103), and a second through hole (205) is formed on the inner wall of the second connecting rod (204); The outer wall of the second connecting rod (204) at one side away from the second fixed frame (103) is rotatably connected to a pressing plate (206) via a rotating shaft, and the inner wall of the second through hole (205) is slidably connected to the second sliding frame (201); A third through hole (207) is provided on the inner wall of the pressing plate (206) close to the second fixing frame (103), and a connecting shaft (208) is fixedly connected to the outer wall of the pressing plate (206) close to the second fixing frame (103); One end of the connecting shaft (208) away from the pressing plate (206) passes through the second connecting rod (204) and is fixedly connected to the limiting plate (209); A third spring (210) is fixedly connected to an outer wall of one side of the limiting plate (209) close to the second connecting rod (204); an end of the third spring (210) away from the limiting plate (209) is fixedly connected to the second connecting rod (204); One end of the fixed shaft (107) away from the second fixed frame (103) is fixedly connected to a fixed block (109), the inner wall of the fixed block (109) is fixedly connected to an arc-shaped rod (110), the inner wall of the arc-shaped rod (110) is provided with a first through hole (111), and the inner wall of the first through hole (111) is slidably connected to the second sliding frame (201); One end of the arc-shaped rod (110) away from the fixed block (109) is rotatably connected to a clamping rod (112) via a rotating shaft; an outer wall of the clamping rod (112) close to the arc-shaped rod (110) is fixedly connected to a first spring (113); and one end of the first spring (113) away from the clamping rod (112) is fixedly connected to the arc-shaped rod (110).

2. A rectangular air duct having the function of pipe wall noise reduction and reinforcement structure according to claim 1, characterized in that: include: A connecting pipe (301), the outer wall of the connecting pipe (301) is fixedly connected to the first fixing frame (101), the outer wall of the connecting pipe (301) is fixedly connected to a flange (302), one end of the flange (302) away from the connecting pipe (301) is fixedly connected to a sealing ring (303), and the inner wall of the connecting pipe (301) is fixedly connected to a sound absorbing plate (304).

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