Silencing and noise reduction equipment for building ventilating duct

Abstract

The invention discloses building ventilating duct noise elimination and reduction equipment, and relates to the technical field of ventilating duct noise elimination and reduction, the building ventilating duct noise elimination and reduction equipment comprises a mounting cabinet, one end of the mounting cabinet is fixedly communicated with a plurality of groups of fixed pipelines, every two adjacent fixed pipelines are fixedly communicated through bolts, and inner cavities of the fixed pipelines are provided with noise elimination and reduction mechanisms; according to the noise elimination and reduction equipment for the building ventilation pipeline, by arranging the replacement unit, when sound-absorbing cotton is replaced, a protective shell and a clamping assembly are dismounted, pressing on the sound-absorbing cotton is canceled through an expansion unit, and at the moment, one end of new sound-absorbing cotton and one end of old sound-absorbing cotton are clamped through the clamping assembly; and at the moment, the other end of the old sound-absorbing cotton is dragged, so that the clamping assemblies and the new sound-absorbing cotton are dragged into the inner cavity of the fixed pipeline, and when the clamping assemblies are dragged out of the through holes, the new sound-absorbing cotton completely enters the fixed pipeline, so that the sound-absorbing cotton is replaced, and the fixed pipeline does not need to be disassembled.

Description

Technical Field

[0001] This invention relates to the field of noise reduction technology for building ventilation ducts, specifically to a noise reduction device for building ventilation ducts. Background Technology

[0002] To reduce noise problems caused by ventilation and refrigeration systems, improve the consumer experience, and reduce noise pollution, silencers are usually installed in ventilation and refrigeration systems. A silencer is an engineering product installed in a ventilation and refrigeration system. Considering market demand and space constraints, the design of ventilation systems requires very high airflow rates.

[0003] During air circulation, moisture will be absorbed onto the sound-absorbing cotton of the silencer. Over time, this can cause the sound-absorbing material to become damp and moldy, leading to bacterial growth and polluted air, which affects indoor and outdoor air quality. The existing solution is to disassemble the silencer and replace the sound-absorbing cotton inside. However, this process is time-consuming, and removing the silencer will cause noise from the air circulation, thus affecting the normal operation of the ventilation system. Therefore, we propose a noise reduction device for building ventilation ducts. Summary of the Invention

[0004] The purpose of this invention is to provide a noise reduction device for building ventilation ducts to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a noise reduction device for building ventilation ducts, comprising an installation cabinet, one end of which is fixedly connected to several sets of fixed pipes, two adjacent fixed pipes being fixedly connected by bolts, the inner cavity of the fixed pipes being provided with a noise reduction mechanism, the noise reduction mechanism comprising a replacement unit and an expansion unit, the expansion unit and the replacement unit being used in conjunction, and an installation mechanism being provided on one side of the fixed pipes, the installation mechanism being used in conjunction with the noise reduction mechanism.

[0006] Preferably, the replacement unit includes a through hole on one side of the fixed pipe, the inner cavity of the fixed pipe is provided with sound-absorbing cotton, the sound-absorbing cotton is arranged in a ring and both ends of the sound-absorbing cotton extend to the outside of the through hole, one end of the sound-absorbing cotton is provided with a clamping component, and one side of the fixed pipe is provided with a protective shell that cooperates with the clamping component.

[0007] Preferably, the clamping assembly includes a first clamping plate and a second clamping plate, one end of the sound-absorbing cotton is located between the first clamping plate and the second clamping plate, a pin is fixedly connected to the bottom of the first clamping plate, and the number of pins is several. The top of the second clamping plate is provided with a insertion hole for cooperating with the pin. A first threaded rod is rotatably connected to the inner cavity of the first clamping plate, and one end of the first threaded rod passes through the sound-absorbing cotton and is threadedly connected to the inner cavity of the second clamping plate.

[0008] Preferably, the expansion unit includes four L-plates disposed in the inner cavity of the fixed pipe. The inner wall of each L-plate has several fixing holes. Sliding rods are fixedly connected to both sides of each L-plate. A fixing block is disposed between two adjacent sliding rods. A first telescopic rod is fixedly connected to both sides of each fixing block. The telescopic end of the first telescopic rod is fixedly connected to the sliding rod. A pulling assembly that cooperates with the fixing block is disposed on the inner wall of the fixed pipe.

[0009] Preferably, a second telescopic rod is fixedly connected to the bottom of the fixing block, the telescopic end of the second telescopic rod is fixedly connected to the inner wall of the fixing pipe, a first spring is sleeved on the surface of the second telescopic rod, one end of the first spring is fixedly connected to the fixing block, and the other end of the first spring is fixedly connected to the inner wall of the fixing pipe.

[0010] Preferably, an inclined block is fixedly connected to each of the two sliding rods on opposite sides, and an extrusion block that cooperates with the inclined block is fixedly connected to the inner wall of the fixed pipe.

[0011] Preferably, the pulling assembly includes a pull rope slidably connected to the inner wall of the fixed pipe, one end of the pull rope being fixedly connected to the bottom of the fixed block, and a winding shaft being rotatably connected to the inner wall of the fixed pipe, the surface of the winding shaft being fixedly connected to the other end of the pull rope.

[0012] Preferably, the installation mechanism includes a baffle plate fixedly connected to one side of the protective shell, a rack fixedly connected to one side of the baffle plate, a gear that cooperates with the rack fixedly connected to one side of the winding shaft, and a guide groove that cooperates with the rack on the surface of the fixed pipe.

[0013] Preferably, the top and bottom of the protective shell are threaded with adjusting rods, and one end of each adjusting rod is rotatably connected to a clamping rod, with both ends of the clamping rod in contact with the inner wall of the protective shell.

[0014] Preferably, a first sealing gasket is fixedly connected to one side of the shield, and a second sealing gasket is fixedly connected to the side of the protective shell near the fixed pipe. A movable hole is opened on one side of the shield, and an installation rod is movably connected to the inner cavity of the movable hole. One end of the installation rod is threadedly connected to the inner wall of the fixed pipe.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, by setting up a replacement unit, removes the protective shell and clamping assembly when replacing the sound-absorbing cotton. The expansion unit releases the pressure on the sound-absorbing cotton. At this time, the clamping assembly clamps one end of the new sound-absorbing cotton and one end of the old sound-absorbing cotton. Then, the other end of the old sound-absorbing cotton is pulled, so that the clamping assembly and the new sound-absorbing cotton are pulled into the inner cavity of the fixed pipe. When the clamping assembly is pulled out from the through hole, the new sound-absorbing cotton is completely inside the fixed pipe, thereby realizing the replacement of the sound-absorbing cotton without removing the fixed pipe.

[0016] 2. By setting an expansion unit, the present invention eliminates the expansion of the L-plate when the sound-absorbing cotton is replaced, thereby eliminating the compression of the sound-absorbing cotton. After the sound-absorbing cotton is replaced, the fixing block is moved closer to the inner wall of the fixed pipe, causing the L-plate to move closer to the inner wall of the fixed pipe. At this time, the first telescopic rod is extended, allowing the L-plate to compress the sound-absorbing cotton in the horizontal direction, thereby achieving the effect of limiting the position of the sound-absorbing cotton.

[0017] 3. By setting up an installation mechanism, when the baffle is installed, the baffle will drive the rack to move in the inner cavity of the guide groove. When the rack moves to mesh with the gear, it will continue to move and drive the gear to rotate, so that the winding shaft will rotate and wind up the pull rope, thereby achieving the effect of pulling the pull rope. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the structure of the fixed pipe and the baffle plate of the present invention; Figure 3 This is a schematic diagram of the structure of the fixed pipe and L-plate of the present invention; Figure 4 For the present invention Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a schematic diagram of the structure of the shielding plate and protective shell of the present invention; Figure 6 This is a schematic diagram of the structure of the sound-absorbing cotton of the present invention; Figure 7 For the present invention Figure 6 A magnified view of a section at point B in the middle; Figure 8 This is a schematic diagram of the structure of the sliding rod, the inclined block, and the first telescopic rod of the present invention; Figure 9 This is a schematic diagram of the structure of the sound-absorbing cotton and the first clamping plate of the present invention; Figure 10 This is an exploded view of the first clamping plate and the second clamping plate of the present invention; Figure 11 This is a cross-sectional schematic diagram of the fixed pipe of the present invention.

[0019] In the diagram: 1. Mounting cabinet; 11. Fixed pipe; 2. Noise reduction mechanism; 21. Replacement unit; 2101. Through hole; 2102. Sound-absorbing cotton; 2103. Protective shell; 2104. First clamping plate; 2105. Second clamping plate; 2106. Pin; 2107. Insertion hole; 2108. First threaded rod; 22. Expansion unit; 2201. L-plate; 2202. Fixing hole; 2203. Sliding rod; 2204. Fixing block; 22 05. First telescopic rod; 2206. Second telescopic rod; 2207. First spring; 2208. Inclined block; 2209. Pressing block; 2210. Pull rope; 2211. Rewinding shaft; 3. Mounting mechanism; 301. Baffle plate; 302. Rack; 303. Gear; 304. Guide groove; 305. Adjusting rod; 306. Clamping rod; 307. First sealing gasket; 308. Second sealing gasket; 309. Movable hole; 310. Mounting rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: Please refer to Figures 1-11 This invention provides a technical solution: a noise reduction device for building ventilation ducts, including an installation cabinet 1. One end of the installation cabinet 1 is fixedly connected to several sets of fixed pipes 11. Two adjacent fixed pipes 11 are fixedly connected by bolts. The inner cavity of the fixed pipe 11 is provided with a noise reduction mechanism 2. The noise reduction mechanism 2 includes a replacement unit 21 and an expansion unit 22. The expansion unit 22 and the replacement unit 21 are used in conjunction. An installation mechanism 3 is provided on one side of the fixed pipe 11. The installation mechanism 3 is used in conjunction with the noise reduction mechanism 2. The installation cabinet 1 is used to cover the air conditioner fan. The fixed pipes 11 are used to guide the air. The multiple fixed pipes 11 are sealed with sealing rings. The above are all prior art and will not be described in detail.

[0022] The replacement unit 21 includes a through hole 2101 on one side of the fixed pipe 11. Sound-absorbing cotton 2102 is installed inside the fixed pipe 11. The sound-absorbing cotton 2102 is annular, with both ends extending to the outside of the through hole 2101. A clamping component is installed at one end of the sound-absorbing cotton 2102. A protective shell 2103, which cooperates with the clamping component, is installed on one side of the fixed pipe 11. By providing the replacement unit 21, when replacing the sound-absorbing cotton 2102, the protective shell 2103 and the clamping component are removed, and the expansion unit 22 is used to remove the sound-absorbing cotton 2102. The clamping assembly is used to clamp one end of the new sound-absorbing cotton 2102 and one end of the old sound-absorbing cotton 2102. At this time, the other end of the old sound-absorbing cotton 2102 is pulled, so that the clamping assembly and the new sound-absorbing cotton 2102 are pulled into the inner cavity of the fixed pipe 11. When the clamping assembly is pulled out from the through hole 2101, the new sound-absorbing cotton 2102 is completely inside the fixed pipe 11, and at this time, both ends of the new sound-absorbing cotton 2102 are located outside the through hole 2101, thereby realizing the replacement of the sound-absorbing cotton 2102 without removing the fixed pipe 11.

[0023] The clamping assembly includes a first clamping plate 2104 and a second clamping plate 2105. One end of the sound-absorbing cotton 2102 is located between the first clamping plate 2104 and the second clamping plate 2105. A pin 2106 is fixedly connected to the bottom of the first clamping plate 2104, and the number of pins 2106 is several. The top of the second clamping plate 2105 has an insertion hole 2107 for cooperating with the pin 2106. A first threaded rod 2108 is rotatably connected to the inner cavity of the first clamping plate 2104. One end of the first threaded rod 2108 passes through the sound-absorbing cotton 2102 and is connected to the second clamping plate 2105. The inner cavity of plate 2105 is threaded. By setting a clamping assembly, when clamping, the sound-absorbing cotton 2102 is placed between the first clamping plate 2104 and the second clamping plate 2105. Then, the pin 2106 is aligned with the insertion hole 2107, and the pin 2106 and the first threaded rod 2108 are passed through the sound-absorbing cotton 2102. Then, the first threaded rod 2108 is rotated. Since the first threaded rod 2108 is threadedly connected to the inner cavity of the second clamping plate 2105, the first clamping plate 2104 and the second clamping plate 2105 are fixed.

[0024] The specific implementation method of this embodiment is as follows: When replacing the sound-absorbing cotton 2102, the protective shell 2103 and the clamping assembly are removed, and the compression of the sound-absorbing cotton 2102 is released through the expansion unit 22. At this time, the clamping assembly is used to clamp one end of the new sound-absorbing cotton 2102 and one end of the old sound-absorbing cotton 2102. At this time, the other end of the old sound-absorbing cotton 2102 is pulled, so that the clamping assembly and the new sound-absorbing cotton 2102 are pulled into the inner cavity of the fixed pipe 11. When the clamping assembly is pulled out from the through hole 2101, the new sound-absorbing cotton 2102 is completely inside the fixed pipe 11, and at this time, both ends of the new sound-absorbing cotton 2102 are located outside the through hole 2101, thereby realizing the replacement of the sound-absorbing cotton 2102 without removing the fixed pipe 11.

[0025] Example 2: Please refer to Figures 1-11 The present invention provides a technical solution: a noise reduction device for building ventilation ducts. The present invention makes corresponding improvements to the technical problems mentioned in the background art.

[0026] The expansion unit 22 includes four L-plates 2201 disposed within the inner cavity of the fixed pipe 11. Each L-plate 2201 has several fixing holes 2202 on its inner wall. Sliding rods 2203 are fixedly connected to both sides of each L-plate 2201. A fixing block 2204 is disposed between two adjacent sliding rods 2203. First telescopic rods 2205 are fixedly connected to both sides of each fixing block 2204. The telescopic ends of the first telescopic rods 2205 are fixedly connected to the sliding rods 2203. A pulling assembly that cooperates with the fixing blocks 2204 is provided on the inner wall of the fixed pipe 11. By setting the expansion unit 22, when the sound-absorbing cotton 2102 is replaced, the expansion of the L plate 2201 is canceled, thereby canceling the compression of the sound-absorbing cotton 2102. After the sound-absorbing cotton 2102 is replaced, the fixing block 2204 is moved to the side closer to the inner wall of the fixing pipe 11, so that the L plate 2201 is moved to the side closer to the inner wall of the fixing pipe 11. At this time, the first telescopic rod 2205 is extended, so that the L plate 2201 can compress the sound-absorbing cotton 2102 in the horizontal direction, thereby achieving the effect of limiting the sound-absorbing cotton 2102.

[0027] A second telescopic rod 2206 is fixedly connected to the bottom of the fixed block 2204. The telescopic end of the second telescopic rod 2206 is fixedly connected to the inner wall of the fixed pipe 11. A first spring 2207 is sleeved on the surface of the second telescopic rod 2206. One end of the first spring 2207 is fixedly connected to the fixed block 2204, and the other end of the first spring 2207 is fixedly connected to the inner wall of the fixed pipe 11. By setting the first spring 2207 and the second telescopic rod 2206 to work together, when the four L-plates 2201 are expanded outward, the first spring 2207 will be compressed. When the fixed block 2204 is moved to the side closer to the inner wall of the fixed pipe 11, the four L-plates 2201 will converge towards the center under the action of the first spring 2207. It should be noted that a tension spring is sleeved on the surface of the first telescopic rod 2205. One end of the tension spring is fixedly connected to the fixed block 2204, and the other end of the tension spring is fixedly connected to the surface of the sliding rod 2203.

[0028] Two sliding rods 2203 are fixedly connected to opposite sides of each other with inclined blocks 2208. The inner wall of the fixed pipe 11 is fixedly connected with a pressing block 2209 that works in conjunction with the inclined blocks 2208. By setting the inclined blocks 2208 and the pressing block 2209 to work together, when the L plate 2201 is moved closer to the inner wall of the fixed pipe 11, the L plate 2201 will drive the sliding rods 2203 to move, which in turn drives the inclined blocks 2208 to move. During the movement of the inclined blocks 2208, they will be pressed by the pressing block 2209, which will cause the two inclined blocks 2208 to move to opposite sides, thereby achieving the effect of driving the L plate 2201 to move horizontally.

[0029] The pulling assembly includes a pull rope 2210 slidably connected to the inner wall of the fixed pipe 11. One end of the pull rope 2210 is fixedly connected to the bottom of the fixed block 2204. A winding shaft 2211 is rotatably connected to the inner wall of the fixed pipe 11. The surface of the winding shaft 2211 is fixedly connected to the other end of the pull rope 2210. By setting the pull rope 2210 and the winding shaft 2211 to work together, the winding shaft 2211 is rotated, causing the winding shaft 2211 to retract the pull rope 2210, thereby pulling the fixed block 2204 and moving the L plate 2201 closer to the inner wall of the fixed pipe 11.

[0030] The specific implementation method of this embodiment is as follows: When replacing the sound-absorbing cotton 2102, the winding shaft 2211 is unwound, the expansion of the L-plate 2201 is canceled, thereby canceling the compression of the sound-absorbing cotton 2102. After replacing the sound-absorbing cotton 2102, the winding shaft 2211 is rotated, causing the winding shaft 2211 to retract the pull rope 2210, thereby causing the pull rope 2210 to pull the fixing block 2204, achieving the effect of moving the L-plate 2201 closer to the inner wall of the fixed pipe 11. At this time, the first telescopic rod 2205 is extended, allowing the L-plate 2201 to compress the sound-absorbing cotton 2102 in the horizontal direction, thereby achieving the effect of limiting the position of the sound-absorbing cotton 2102.

[0031] Example 3: Please refer to Figures 1-11 The present invention provides a technical solution: a noise reduction device for building ventilation ducts. The present invention makes corresponding improvements to the technical problems mentioned in the background art.

[0032] The installation mechanism 3 includes a baffle plate 301 fixedly connected to one side of the protective shell 2103. A rack 302 is fixedly connected to one side of the baffle plate 301, and a gear 303 that works with the rack 302 is fixedly connected to one side of the winding shaft 2211. A guide groove 304 that works with the rack 302 is opened on the surface of the fixed pipe 11. By setting the installation mechanism 3, when the baffle plate 301 is installed, the baffle plate 301 will drive the rack 302 to move in the inner cavity of the guide groove 304. When the rack 302 moves to mesh with the gear 303, it will continue to move and drive the gear 303 to rotate, so that the winding shaft 2211 rotates and winds up the pull rope 2210, thereby achieving the effect of pulling the pull rope 2210.

[0033] The top and bottom of the protective shell 2103 are threaded with adjusting rods 305. Each of the two adjusting rods 305 is rotatably connected to a clamping rod 306 at one end. Both ends of the clamping rod 306 are in contact with the inner wall of the protective shell 2103. By using the adjusting rods 305 and clamping rods 306 in cooperation, after the rack 302 is inserted into the inner cavity of the guide groove 304, both ends of the sound-absorbing cotton 2102 are located between the two clamping rods 306. At this time, the two adjusting rods 305 are rotated. Since the top and bottom of the protective shell 2103 are threaded with the adjusting rods 305, the clamping rods 306 will clamp the sound-absorbing cotton 2102, so that the two ends of the sound-absorbing cotton 2102 are in contact, preventing noise from leaking between the two ends of the sound-absorbing cotton 2102.

[0034] A first sealing gasket 307 is fixedly connected to one side of the baffle plate 301, and a second sealing gasket 308 is fixedly connected to the side of the protective shell 2103 near the fixed pipe 11. A movable hole 309 is opened on one side of the baffle plate 301, and an installation rod 310 is movably connected to the inner cavity of the movable hole 309. One end of the installation rod 310 is threaded to the inner wall of the fixed pipe 11. By setting the first sealing gasket 307 and the second sealing gasket 308, the first sealing gasket 307 is used to seal between the baffle plate 301 and the fixed pipe 11, and the second sealing gasket 308 is used to seal between the protective shell 2103 and the fixed pipe 11. When the first sealing gasket 307 contacts the surface of the fixed pipe 11, the installation rod 310 is locked in the inner cavity of the movable hole 309, and the installation rod 310 is rotated to achieve the effect of limiting the position of the baffle plate 301.

[0035] The specific implementation of this embodiment is as follows: When the baffle plate 301 is installed, the baffle plate 301 will drive the rack 302 to move within the guide groove 304. When the rack 302 moves to mesh with the gear 303, continued movement will drive the gear 303 to rotate, causing the winding shaft 2211 to rotate and wind up the pull rope 2210, thereby achieving the effect of pulling the pull rope 2210. When the first sealing gasket 307 contacts the surface of the fixed pipe 11, the mounting rod 31... The 0 is locked in the inner cavity of the movable hole 309, and the mounting rod 310 is rotated to achieve the effect of limiting the baffle 301. At this time, both ends of the sound-absorbing cotton 2102 are located between the two clamping rods 306. Then, the two adjusting rods 305 are rotated. Since the top and bottom of the protective shell 2103 are threaded to the adjusting rods 305, the clamping rods 306 will clamp the sound-absorbing cotton 2102, so that the two ends of the sound-absorbing cotton 2102 are in contact, preventing noise from leaking between the two ends of the sound-absorbing cotton 2102.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A noise reduction device for building ventilation ducts, comprising an installation cabinet (1), characterized in that: One end of the installation cabinet (1) is fixedly connected to several sets of fixed pipes (11). Two adjacent fixed pipes (11) are fixedly connected by bolts. The inner cavity of the fixed pipe (11) is provided with a noise reduction mechanism (2). The noise reduction mechanism (2) includes a replacement unit (21) and an expansion unit (22). The expansion unit (22) and the replacement unit (21) are used together. One side of the fixed pipe (11) is provided with an installation mechanism (3). The installation mechanism (3) is used in conjunction with the noise reduction mechanism (2).

2. The noise reduction and sound absorption device for building ventilation ducts according to claim 1, characterized in that: The replacement unit (21) includes a through hole (2101) opened on one side of the fixed pipe (11). The inner cavity of the fixed pipe (11) is provided with sound-absorbing cotton (2102). The sound-absorbing cotton (2102) is arranged in a ring and both ends of the sound-absorbing cotton (2102) extend to the outside of the through hole (2101). One end of the sound-absorbing cotton (2102) is provided with a clamping component. One side of the fixed pipe (11) is provided with a protective shell (2103) that works in conjunction with the clamping component.

3. The noise reduction and sound absorption device for building ventilation ducts according to claim 2, characterized in that: The clamping assembly includes a first clamping plate (2104) and a second clamping plate (2105). One end of the sound-absorbing cotton (2102) is located between the first clamping plate (2104) and the second clamping plate (2105). A pin (2106) is fixedly connected to the bottom of the first clamping plate (2104). There are several pins (2106). The top of the second clamping plate (2105) is provided with a socket (2107) for use with the pin (2106). A first threaded rod (2108) is rotatably connected to the inner cavity of the first clamping plate (2104). One end of the first threaded rod (2108) passes through the sound-absorbing cotton (2102) and is threadedly connected to the inner cavity of the second clamping plate (2105).

4. The noise reduction and sound absorption device for building ventilation ducts according to claim 2, characterized in that: The expansion unit (22) includes an L-plate (2201) disposed in the inner cavity of the fixed pipe (11). There are four L-plates (2201). The inner wall of the L-plate (2201) is provided with a plurality of fixing holes (2202). Sliding rods (2203) are fixedly connected to both sides of the L-plate (2201). A fixing block (2204) is provided between two adjacent sliding rods (2203). A first telescopic rod (2205) is fixedly connected to both sides of the fixing block (2204). The telescopic end of the first telescopic rod (2205) is fixedly connected to the sliding rod (2203). The inner wall of the fixed pipe (11) is provided with a pulling component that works in conjunction with the fixing block (2204).

5. The noise reduction and sound absorption device for building ventilation ducts according to claim 4, characterized in that: The bottom of the fixed block (2204) is fixedly connected to a second telescopic rod (2206). The telescopic end of the second telescopic rod (2206) is fixedly connected to the inner wall of the fixed pipe (11). A first spring (2207) is sleeved on the surface of the second telescopic rod (2206). One end of the first spring (2207) is fixedly connected to the fixed block (2204), and the other end of the first spring (2207) is fixedly connected to the inner wall of the fixed pipe (11).

6. The noise reduction and sound absorption device for building ventilation ducts according to claim 4, characterized in that: An inclined block (2208) is fixedly connected to one side of each of the two sliding rods (2203), and an extrusion block (2209) that cooperates with the inclined block (2208) is fixedly connected to the inner wall of the fixed pipe (11).

7. The noise reduction and sound absorption device for building ventilation ducts according to claim 4, characterized in that: The pulling assembly includes a pull rope (2210) slidably connected to the inner wall of the fixed pipe (11). One end of the pull rope (2210) is fixedly connected to the bottom of the fixed block (2204). A winding shaft (2211) is rotatably connected to the inner wall of the fixed pipe (11). The surface of the winding shaft (2211) is fixedly connected to the other end of the pull rope (2210).

8. The noise reduction and sound absorption device for building ventilation ducts according to claim 7, characterized in that: The installation mechanism (3) includes a baffle plate (301) fixedly connected to one side of the protective shell (2103), a rack (302) fixedly connected to one side of the baffle plate (301), a gear (303) that cooperates with the rack (302) fixedly connected to one side of the winding shaft (2211), and a guide groove (304) that cooperates with the rack (302) is provided on the surface of the fixed pipe (11).

9. The noise reduction and sound absorption device for building ventilation ducts according to claim 8, characterized in that: The top and bottom of the protective shell (2103) are threaded with adjusting rods (305), and the opposite ends of the two adjusting rods (305) are rotatably connected with clamping rods (306). Both ends of the clamping rods (306) are in contact with the inner wall of the protective shell (2103).

10. A noise reduction and sound absorption device for building ventilation ducts according to claim 8, characterized in that: A first sealing gasket (307) is fixedly connected to one side of the shield (301), and a second sealing gasket (308) is fixedly connected to the side of the protective shell (2103) near the fixed pipe (11). A movable hole (309) is opened on one side of the shield (301), and an installation rod (310) is movably connected to the inner cavity of the movable hole (309). One end of the installation rod (310) is threadedly connected to the inner wall of the fixed pipe (11).

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