Sliding duct system for exhaust gas extraction in mobile paint booths

Abstract

The present invention relates to the field of waste gas treatment systems, and discloses a sliding air duct system for exhaust gas extraction in a mobile spray paint room, which solves the technical problem that the exhaust pipe cannot be moved along the length direction of the air duct, resulting in the exhaust pipe being too long and being dragged on the ground in a messy manner. The system includes a movable spray paint room, an air duct, and an exhaust pipe connected between the spray paint room and the air duct. A through groove is provided on the side of the air duct facing the spray paint room along the length direction, and a group of elastic seals are provided on both sides of the through groove along the length direction. A section of a connecting shell is connected to one end of the exhaust pipe away from the spray paint room, and the connecting shell extends into the air duct through the through groove and connects the exhaust pipe and the air duct, and the connecting shell and the air duct are slidingly arranged, and the two sides of the connecting shell along the length direction are respectively in conflict with the elastic seals. Under the premise of ensuring the sealing of the through groove notch, the exhaust pipe moves along the length direction of the air duct through the connecting shell as the spray paint room moves, and there is no need to drag the exhaust pipe on the ground.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment systems, and in particular to a sliding air duct system for exhaust gas extraction in a mobile paint spraying room. Background Art

[0002] A Chinese patent with announcement number CN208810405U discloses an environmentally friendly mobile paint spraying room, including a mobile system, which includes a mobile room, a track, a pulley and an electric control device. The mobile room includes several connectable paint spraying rooms, and a paint spraying workbench is provided in the paint spraying room; a pulley is provided at the bottom of the paint spraying room, the pulley is placed in the track, and the electric control device is placed on the outer wall of the paint spraying room. The electric control device is connected to the pulley, and the rotation of the pulley can be controlled by the electric control device, so that the pulley drives the paint spraying room to move along the track.

[0003] like Figure 1 The top of the mobile paint spraying room 1 is connected with an exhaust pipe 13 for discharging exhaust gas, and an air duct 3 is set above the paint spraying room 1. The end of the exhaust pipe 13 away from the paint spraying room 1 is connected with the air duct 3. When the operator performs paint spraying operation in the paint spraying room 1, the exhaust gas generated during the painting process is discharged through the exhaust pipe 13 and the air duct 3 and then processed, thereby reducing the possibility of excessive exhaust gas concentration in the paint spraying room 1 causing harm to the operator's body.

[0004] However, during the painting process, the paint spraying room will slide along the track, and the end of the exhaust pipe away from the paint spraying room is fixedly connected to the air duct, so it is necessary to reserve an exhaust pipe of sufficient length. When the paint spraying room moves, the exhaust pipe is dragged along the ground, causing the ground to be messy. If the paint spraying room and the branch pipe are directly connected through an exhaust pipe, and a driving mechanism is set to drive the air duct to move synchronously with the paint spraying room in the horizontal direction, there is a problem of high manufacturing cost. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a sliding duct system for exhaust gas extraction in a mobile paint spraying room. The exhaust pipe can move along the length direction of the air duct as the paint spraying room moves. There is no need to reserve an exhaust pipe that is larger than the distance between the air duct and the exhaust pipe, thereby reducing the possibility of messy placement of the exhaust pipe on the ground.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions: a sliding duct system for exhaust gas extraction in a mobile paint spraying room, comprising a paint spraying room, a track and a driving mechanism for driving the paint spraying room to move along the track, a duct with a rectangular cross-section is fixedly mounted above the paint spraying room, an exhaust pipe is connected to the top of the paint spraying room, a through groove is provided on the side of the air duct facing the paint spraying room along the length direction, the through groove and the track of the track are symmetrically parallel in the vertical direction, a group of elastic seals are provided on both sides of the through groove along the length direction, and the opposite sides of the two groups of elastic seals are in conflict with each other, a section of a connecting shell is connected to the end of the exhaust pipe away from the paint spraying room, and the end of the connecting shell away from the exhaust pipe is set as an open end, the open end of the connecting shell extends into the air duct through the through groove, and extension blocks are fixedly connected to both sides of the open end along the length direction, the two extension blocks are set in opposite directions, the extension block is slidingly arranged with the inner wall of the air duct, and the two sides of the connecting shell along the length direction are respectively in conflict with the elastic seals.

[0007] Through the above technical solution, when in use, the paint spraying room is connected with the air duct through the exhaust pipe and the connecting shell, and the exhaust gas in the paint spraying room enters the air duct through the exhaust pipe and the connecting shell and is discharged. The paint spraying room moves along the track and drives the exhaust pipe and the connecting shell to move along the length direction of the air duct. There is no need to reserve a longer exhaust pipe to be placed on the ground, nor is there any need to move the air duct with the paint spraying room. When the connecting shell moves to the corresponding position of the through groove, the connecting shell will expand the elastic sealing member at the corresponding position, and the elastic sealing member expanded by the connecting shell will elastically recover, thereby re-blocking the notch of the through groove, reducing the possibility of air leakage at the notch of the through groove.

[0008] The present invention is further configured as follows: the elastic sealing member comprises a sealing strip, the sealing strip is fixed in the through groove, two opposite sides of the sealing strips are in contact with each other and a connecting shell is passed between the two sealing strips.

[0009] Through the above technical scheme, the sealing strip is made of high-quality random polypropylene as the raw material to form a base plate, which is synthesized with siliconized polypropylene yarn and polypropylene film. It has good performance and can separate the inside and outside of the air duct, reducing the possibility of air leakage in the groove.

[0010] The present invention is further configured as follows: both ends of the connection shell along the length direction are configured as cones, the top of the cone is configured toward a direction away from the connection shell, and the two sealing strips are both in contact with the outside of the cone.

[0011] Through the above technical solution, when the connecting shell moves along the length direction of the through groove, the top of the cone first stretches the sealing strip in front of the moving direction, and as the connecting shell moves, the stretched angle of the sealing strip gradually increases. This arrangement has an increasing and buffering effect on the stretched angle of the sealing strip, which is beneficial to reducing the possibility of damage to the sealing strip in the process of the connecting shell stretching the sealing strip.

[0012] The present invention is further configured as follows: a mounting plate is provided along the length direction of one side of the sealing strip facing the through slot, the sealing strip is bonded to the mounting plate, and the mounting plate is detachably connected to the air duct via a connecting piece.

[0013] Through the above technical solution, the mounting plate can be detachably connected to the air duct, so that the operator can replace the sealing strips regularly, thereby ensuring the sealing effect of the two sealing strips on the through grooves.

[0014] The present invention is further configured as follows: the connecting member includes an installation frame, a groove is provided on the side of the installation frame facing the installation plate, a protrusion is detachably connected to the side of the installation plate facing the groove, the protrusion extends into the groove, and a compression spring is fixed between the bottom of the groove and the protrusion, the two sides of the protrusion along the length direction are fitted with the groove wall of the groove, an extension plate is fixedly connected to the side of the installation frame facing away from the air duct, and the extension plate is threadedly connected to the outside of the air duct by a first screw.

[0015] Through the above technical solution, when the connecting shell squeezes and stretches the sealing strip at the corresponding position in the horizontal direction, the mounting plate drives the convex block to move toward the groove. At this time, the compression spring is compressed, and the compression spring plays a buffering role for the thrust on the convex block, the mounting plate and the sealing strip, thereby reducing the possibility of damage caused by the large squeezing force of the connecting shell on the sealing strip, which is beneficial to extending the service life of the sealing strip. When the sealing strip needs to be replaced, the operator first unscrews the first screw from the extension plate, removes the mounting frame together with the sealing strip from between the through grooves, disassembles the mounting plate and the convex block, and then replaces the new sealing strip. The operation is simple and convenient.

[0016] The present invention is further configured as follows: a connecting groove with two through ends is provided on the side of the mounting plate facing the protrusion, a connecting block is fixedly connected to the side of the protrusion facing the mounting groove, the connecting block is slidably connected in the connecting groove from one end of the connecting groove, and a pressure plate is provided at both ends of the mounting plate along the length direction, the pressure plate spans the notch of the connecting groove and is threadedly connected to the end of the mounting plate through a second screw.

[0017] With the above technical solution, the operator can unscrew the second screw at one end of the mounting plate and remove the pressing block from the end of the mounting plate. Then, the operator slides the mounting plate through the connecting groove and the connecting block until the mounting plate and the protrusion are separated, thereby realizing the disassembly of the sealing strip. During installation, the operator then slides the mounting plate with the new sealing strip bonded thereto through the connecting groove and the connecting block to connect the mounting plate and the protrusion together. Finally, the connecting block is confined in the connecting groove by the pressing block. The operation is simple and convenient.

[0018] The present invention is further configured as follows: both sides of the protrusion along the length direction are fixedly connected with sliders, a sliding groove is provided on the groove wall of the groove facing the slider, and the slider is embedded in the sliding groove and slidably cooperates with the sliding groove.

[0019] Through the above technical solution, when the mounting plate pushes the protrusion to move into the groove, the slide groove on the protrusion always moves along the slider. The coordinated setting of the slider and the slide groove guides the moving direction of the protrusion, which is beneficial to ensure the stability of the moving direction of the protrusion.

[0020] The present invention is further configured as follows: a rubber layer is bonded to one side of the mounting plate away from the air duct along the length direction, the rubber layer is arranged in the horizontal direction and extends toward the through groove, and opposite sides of the rubber layers on the two mounting plates are in contact with each other.

[0021] Through the above technical solution, the rubber layer is arranged to form a seal on the layer of the sealing strip away from the through groove, which further seals the notch of the through groove and further reduces the possibility of air leakage at the notch of the through groove.

[0022] The present invention is further configured as follows: a vertical plate is fixedly connected to the inner side of the extension block toward the air duct, the vertical plate is kept perpendicular to the inner wall of the air duct, a roller is provided at one end of the vertical plate toward the inner wall of the air duct, a slide rail is fixedly connected to the inner wall of the air duct along the length direction, and the sliding movement of the roller is restricted within the slide rail.

[0023] Through the above technical solution, when the connecting shell moves along the length direction of the through groove, the roller slides along the slide rail. This arrangement allows the slide rail friction between the extension block and the inner wall of the air duct to be converted into rolling friction, which is beneficial to reducing friction resistance.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. The paint room moves along the track while the exhaust pipe also moves along the length of the air duct, and the air tightness of the slot is ensured;

[0026] 2. The sealing strip and the notch of the through groove are connected in a detachable manner, which is convenient for the operator to replace the aged sealing strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram used to reflect the connection structure of the existing exhaust pipe, paint spray room and air duct.

[0028] Figure 2 It is a schematic diagram of the overall structure of this embodiment.

[0029] Figure 3 yes Figure 2 Cross-sectional view along direction A.

[0030] Figure 4 yes Figure 3 Enlarged view of part A in the middle.

[0031] Figure 5 yes Figure 2 Enlarged view of part B in the middle.

[0032] Figure 6 yes Figure 2 Enlarged view of part C in the middle.

[0033] 1. Spray paint room; 11. Track; 12. Driving mechanism; 121. Servo motor; 122. Pulley; 123. Linkage shaft; 124. First gear; 125. Second gear; 13. Exhaust pipe; 2. Connecting shell; 21. Open end; 22. Extension block; 23. Vertical plate; 24. Roller; 25. Conical body; 3. Air duct; 31. Through groove; 32. Slide rail; 4. Elastic seal; 41. Sealing wool strip; 42. Mounting plate; 421. Connecting groove; 422. Pressing plate; 423. Second screw; 424. Rubber layer; 5. Connecting piece; 51. Mounting frame; 511. Groove; 5111. Slide groove; 512. Extension plate; 513. First screw; 52. Bump; 521. Connecting block; 522. Sliding block; 53. Compression spring. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0035] Example:

[0036] Reference Figure 2, is a sliding air duct system for exhaust gas extraction in a mobile spray painting room disclosed in the present invention, comprising a spray painting room 1, a track 11, and a driving mechanism 12 for driving the spray painting room 1 to move along the track 11, the driving mechanism 12 comprises pulleys 122 installed at both sides of the bottom of the spray painting room 1 along the length direction, the pulleys 122 are rotatably connected with the track 11, and a linkage shaft 123 is coaxially connected between the two opposite pulleys 122, and the linkage shaft 123 is coaxially connected with a first gear 124, and a servo motor 121 is arranged at the bottom of the spray painting room 1, and the output end of the servo motor 121 is coaxially connected with a second gear 125, and the output end of the second gear 125 is coaxially connected with a second gear 125, and the first gear 124 and the second gear 125 are meshed and connected. When working, the servo motor 121 works, and the first gear 124 is meshed and transmitted through the second gear 125, and the linkage shaft 123 is driven to rotate the pulley 122, so that the pulley 122 drives the spray painting room 1 to slide along the track 11.

[0037] Reference Figure 3 and Figure 4 An exhaust pipe 13 for discharging exhaust gas is connected to the outside of the top of the paint spraying room 1. An air duct 3 is fixedly mounted above the paint spraying room 1. The cross-section of the air duct 3 is rectangular. One end of the exhaust pipe 13 away from the paint spraying room 1 is connected to the air duct 3. A through groove 31 is provided on one side of the air duct 3 facing the paint spraying room 1 along the length direction, and the through groove 31 is symmetrically parallel to the trajectory of the track 11 in the vertical direction. A section of the connecting shell 2 is connected to the end of the exhaust pipe 13 away from the paint spraying room 1, and the end of the connecting shell 2 away from the exhaust pipe 13 is set as an open end 21. The open end 21 of the connecting shell 2 extends into the air duct 3 through the through groove 31, and both sides of the open end 21 along the length direction are integrally connected with extension blocks 22, and the two extension blocks 22 are set in opposite directions. A vertical plate 23 is bonded to the extension block 22 toward the inner side of the air duct 3, and the vertical plate 23 is kept perpendicular to the inner wall of the air duct 3. A roller 24 is provided on the end of the vertical plate 23 facing the inner wall of the air duct 3, and a slide rail 32 is bonded to the inner wall of the air duct 3 along the length direction, and the sliding of the roller 24 is limited in the slide rail 32.

[0038] Reference Figure 3 The exhaust pipe 13 is arranged between the spray booth 1 and the air duct 3 in the vertical direction. The spray booth 1 is connected to the air duct 3 through the exhaust pipe 13 and the connecting shell 2. When working, the spray booth 1 slides along the track 11, and drives the exhaust pipe 13 and the connecting shell 2 to move along the length direction of the air duct 3. In this way, there is no need to reserve a long exhaust pipe 13 between the spray booth 1 and the air duct 3 to cooperate with the movement of the spray booth 1, which reduces the possibility of the exhaust pipe 13 dragging along the ground to cause a messy feeling.

[0039] Reference Figure 3 and Figure 4, a set of elastic seals 4 are provided on both sides of the through groove 31 along the length direction. The elastic seal 4 includes a sealing strip 41. Both sealing strips 41 are located in the through groove 31, and one side of the two sealing strips 41 facing each other abuts. One side of the sealing strip 41 facing the notch of the through groove 31 is provided with a mounting plate 42 along the length direction. The sealing strip 41 is adhesively bonded to the side of the mounting plate 42背离 the groove wall of the through groove 31. A rubber layer 424 is adhesively bonded to the side of the mounting plate 42背离 the air duct 3 along the length direction. The rubber layer 424 is arranged horizontally and extends towards the through groove 31. One side of the rubber layers 424 on the two mounting plates 42 facing each other fits together. The rubber layer 424 and the sealing strip 41 form two barriers at the notch of the through groove 31, achieving a double sealing effect on the through groove 31.

[0040] Refer to Figure 3 and Figure 4 , the mounting plate 42 is detachably connected to the air duct 3 through a connecting member 5. The connecting member 5 includes a mounting frame 51. A groove 511 is provided on the side of the mounting frame 51 facing the mounting plate 42. The cross-section of the mounting frame 51 is in a C shape. An extension plate 512 is adhesively bonded to the side of the mounting frame 51背离 the air duct 3. The extension plate 512 is threadedly connected to the outside of the air duct 3 through a first screw 513.

[0041] Refer to Figure 1 and Figure 5 , a convex block 52 matching the groove 511 is provided on the side of the mounting plate 42 facing the groove 511. A connecting groove 421 is opened along the length direction on the side of the mounting plate 42 facing the convex block 52. Both ends of the connecting groove 421 are through. A connecting block 521 is integrally connected to the side of the convex block 52 facing the mounting groove. The connecting block 521 slides into the connecting groove 421 from one end of the connecting groove 421. Pressing plates 422 are provided at both ends of the mounting plate 42 along the length direction. The pressing plates 422 straddle the notch of the connecting groove 421. The pressing plates 422 press on the end of the connecting block 521, restricting the connecting block 521 in the connecting groove 421, and the pressing plates 422 are threadedly connected to the end of the mounting plate 42 through second screws 423.

[0042] Refer to Figure 3 and Figure 4 , the convex block 52 extends into the groove 511, and a compression spring 53 is fixedly provided between the bottom of the groove 511 and the convex block 52. Both ends of the compression spring 53 are adhesively fixed to the opposite sides of the convex block 52 and the groove 511. Both sides of the convex block 52 along the length direction are in contact with the groove wall of the groove 511. Sliding blocks 522 are integrally connected to both sides of the convex block 52 along the length direction. A sliding groove 5111 is opened on the side of the groove wall of the groove 511 facing the sliding block 522. The sliding block 522 is embedded in the sliding groove 5111 and is slidably matched with the sliding groove 5111.

[0043] Refer to Figure 3 and Figure 4 When working, the two sealing strips 41 and the two rubber layers 424 respectively contact the outside of the connecting shell 2. At this time, the sealing strips 41 and the two rubber layers 424 at the position of the connecting shell 2 are stretched open by the connecting shell 2. The sealing strips 41 are squeezed and push the protrusions 52 to move along the slide groove 5111 toward the groove 511 through the slider 522. The compression spring 53 is compressed to provide a buffer force for the force on the sealing strips 41, thereby reducing the possibility of damage to the sealing strips 41 due to the large squeezing force.

[0044] Reference Figure 4 and Figure 5 When the sealing strip 41 ages after long-term use and needs to be replaced, the operator first unscrews the first screw 513 from the extension plate 512 and the air duct 3, and then removes the mounting frame 51 and the sealing strip 41 as a whole from between the through grooves 31. Then, the operator unscrews the second screw 423 at one end of the mounting plate 42, and removes the pressing plate 422 from the end of the mounting plate 42. Then, the operator slides the mounting plate 42 through the connecting groove 421 and the connecting block 521, so that the connecting block 521 slides out of the connecting groove 421. The sealing strip 41 is removed by pressing the extension plate 512 onto the air duct 3. Then, the operator presses the extension plate 512 onto the air duct 3 and fixes the extension plate 512 onto the air duct 3. The installation is then completed.

[0045] Reference Figure 2 and Figure 6 Both ends of the connecting shell 2 along the length direction are set as cones 25, the top of the cone 25 is set in a direction away from the connecting shell 2, and the two sealing strips 41 are both against the outside of the cone 25.

[0046] Reference Figure 4 and Figure 6 When the spray paint room 1 drives the connection shell 2 to slide along the length direction of the air duct 3 through the exhaust pipe 13, the top of the cone 25 first opens the sealing strip 41 in the front of the moving direction. As the connection shell 2 moves, the opening angle of the sealing strip 41 gradually increases until the sealing strip 41 is completely opened by the connection shell 2. In this way, the sealing strip 41 is gradually opened, which is conducive to reducing the possibility of damage to the sealing strip 41 during the process of the connection shell 2 directly opening the sealing strip 41, and is conducive to extending the service life of the sealing strip 41.

[0047] The implementation principle of this embodiment is as follows: when working, the servo motor 121 works and drives the second gear 125 to rotate. At this time, the second gear 125 and the first gear 124 are meshed and transmitted, so that the linkage shaft 123 drives the pulley 122 to rotate, so that the pulley 122 drives the paint booth 1 to slide along the track 11. At this time, the paint booth 1 drives the connection shell 2 to slide along the length direction of the air duct 3 through the exhaust pipe 13. During the sliding process of the connection shell 2, a cone 25 consistent with the moving direction of the connection shell 2 first gradually opens the front sealing wool strip 41 and rubber layer 424. As the connection shell 2 moves, the connection shell 2 completely opens the sealing wool strip 41 and rubber layer 424 at the position. In addition, after the connection shell 2 is removed, the sealing wool strip 41 and rubber layer 424 at the position where the connection shell 2 slides through will return to the initial state under the action of its own elastic restoring force, thereby re-blocking the notch of the through groove 31. At this time, the exhaust gas in the paint spraying room 1 enters the air duct 3 through the exhaust pipe 13 and the connecting shell 2, and is then discharged and collected, so as to achieve the effect of post-discharge treatment of the exhaust gas in the paint spraying room 1.

[0048] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A sliding air duct system for exhaust gas extraction in a mobile paint spraying room, comprising a paint spraying room (1), a track (11), and a driving mechanism (12) for driving the paint spraying room (1) to move along the track (11), an air duct (3) with a rectangular cross section is fixedly mounted above the paint spraying room (1), and an exhaust pipe (13) is connected to the top of the paint spraying room (1), characterized in that: A through slot (31) is provided on one side of the air duct (3) facing the spray paint room (1) along the length direction, and the through slot (31) is symmetrically parallel to the track (11) in the vertical direction. A set of elastic sealing members (4) are provided on both sides of the through slot (31) along the length direction, and the opposite sides of the two sets of elastic sealing members (4) are in contact with each other. The end of the exhaust pipe (13) away from the spray paint room (1) is connected to a section of a connecting shell (2), and the connecting shell (2) away from the exhaust pipe (13) is connected to a section of a connecting shell (2). One end of the air pipe (13) is set as an open end (21), the open end (21) of the connecting shell (2) extends into the air pipe (3) through the through groove (31), and the two sides of the open end (21) along the length direction are fixedly connected with extension blocks (22), the two extension blocks (22) are arranged in opposite directions, the extension blocks (22) and the inner wall of the air pipe (3) are slidably arranged, and the two sides of the connecting shell (2) along the length direction are respectively in contact with the elastic sealing member (4); The elastic sealing member (4) comprises a sealing strip (41), the sealing strip (41) being fixed in the through groove (31), the two opposite sides of the sealing strips (41) being in contact with each other and the connecting shell (2) passing through the space between the two sealing strips (41); Both ends of the connection shell (2) along the length direction are arranged as cones (25), the top end of the cone (25) is arranged in a direction away from the connection shell (2), and the two sealing strips (41) are both in contact with the outside of the cone (25); A mounting plate (42) is provided along the length direction of one side of the sealing strip (41) facing the notch of the through groove (31), the sealing strip (41) is bonded to the mounting plate (42), and the mounting plate (42) is detachably connected to the air duct (3) via a connecting piece (5); The connecting member (5) comprises a mounting frame (51), a groove (511) being provided on a side of the mounting frame (51) facing the mounting plate (42), a protrusion (52) being detachably connected to a side of the mounting plate (42) facing the groove (511), the protrusion (52) extending into the groove (511), and a compression spring (53) being fixedly provided between the groove bottom of the groove (511) and the protrusion (52), the protrusion (52) being in contact with the groove wall of the groove (511) on both sides along the length direction, an extension plate (512) being fixedly connected to a side of the mounting frame (51) facing away from the air duct (3), and the extension plate (512) being threadedly connected to the outer side of the air duct (3) by means of a first screw (513); A connecting groove (421) with two through ends is provided on one side of the mounting plate (42) facing the protrusion (52); a connecting block (521) is fixedly connected to the side of the protrusion (52) facing the mounting groove; the connecting block (521) is slidably connected in the connecting groove (421) from one end of the connecting groove (421); and a pressing plate (422) is provided at both ends of the mounting plate (42) along the length direction; the pressing plate (422) spans the notch of the connecting groove (421) and is threadedly connected to the end of the mounting plate (42) through a second screw (423); The protrusion (52) is fixedly connected with a slider (522) on both sides along the length direction, and a slide groove (5111) is provided on the groove wall of the groove (511) on one side facing the slider (522), and the slider (522) is embedded in the slide groove (5111) and slides with the slide groove (5111); A rubber layer (424) is bonded to the side of the mounting plate (42) facing away from the air duct (3) along the length direction, the rubber layer (424) is arranged in the horizontal direction and extends toward the through groove (31), and the opposite sides of the rubber layers (424) on the two mounting plates (42) are in contact with each other; The extension block (22) is fixedly connected to a vertical plate (23) on the inner side of the air duct (3); the vertical plate (23) is kept perpendicular to the inner wall of the air duct (3); a roller (24) is provided at one end of the vertical plate (23) facing the inner wall of the air duct (3); a slide rail (32) is fixedly connected to the inner wall of the air duct (3) along the length direction; the roller (24) is limited in sliding movement within the slide rail (32).

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