Exhaust pipe fan convenient to disassemble

Abstract

The invention discloses an exhaust pipe fan convenient to disassemble, and belongs to the field of workshop fans, the exhaust pipe fan comprises a mounting box, an air inlet pipe and an air outlet pipe are communicated with two symmetrical side walls of the mounting box respectively, a drawer fan is placed in the mounting box, a filter box is connected to the air inlet pipe, a filter screen is slidably connected to the interior of the filter box, and the filter screen is connected to the air outlet pipe. Pull ropes are fixedly connected to the two sides of the filter screen; a mounting seat is fixedly connected to the mounting box, a rotating rod is rotatably connected to the mounting seat, two second bevel gears are symmetrically and fixedly connected to the rotating rod, a first bevel gear is fixedly connected to the end of the rotating shaft, the two pull ropes are stored at the two ends of the rotating rod respectively, and the first bevel gear can be meshed with one of the second bevel gears so as to drive the rotating rod to rotate forwards or backwards; one pull rope is stored, and the other pull rope is released, so that the filter screen slides in the filter box; according to the fan, the filter screen can be automatically cleaned when the box door is opened for maintenance, and the influence of the filter screen on subsequent maintenance verification is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of workshop fans, in particular to an exhaust duct fan which is easy to disassemble. Background Art

[0002] In the field of ventilation, exhaust duct fans are widely used as key equipment for air circulation. Traditional exhaust duct fans have many problems in actual use. On the one hand, in order to ensure the cleanliness of the air entering the room, a filter is usually installed at the air inlet duct. However, when the filter surface is clogged with too much dust, it often needs to be manually disassembled and cleaned. The operation is cumbersome, time-consuming and labor-intensive, which greatly affects the efficiency of equipment use. On the other hand, the internal structure of the fan is complex. When a fault occurs and maintenance or replacement of parts is required, the disassembly process is difficult, which not only increases the maintenance cost, but also may cause damage to the equipment due to frequent disassembly and shorten the service life of the equipment. In addition, the fan needs to be tested after maintenance. If the filter permeability is poor before the test, resulting in a small air volume, it may affect the subsequent test results. In the existing technology, the filter cleaning and fan maintenance of exhaust duct fans have shortcomings such as inconvenient operation and low efficiency, which are not convenient to meet actual use needs. Summary of the Invention

[0003] The purpose of the present invention is to provide an exhaust duct fan that is easy to disassemble, thereby solving the problems of inconvenience in cleaning the filter and repairing the fan in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solution: an exhaust duct fan that is easy to disassemble, comprising an installation box, wherein two symmetrical side walls of the installation box are respectively connected to an air inlet duct and an air outlet duct, a drawer fan is placed in the installation box, the air inlet duct is connected to a filter box, a filter screen is slidably connected to the filter box, and pull ropes are fixedly connected to both sides of the filter screen;

[0005] The installation box is hinged with a box door, the installation box is rotatably connected to a rotating shaft, and a pull wire is connected between the box door and the rotating shaft;

[0006] The mounting box is fixedly connected to a mounting base, and the mounting base is rotatably connected to a rotating rod, and two second bevel gears are symmetrically fixedly connected to the rotating rod, and the end of the rotating shaft is fixedly connected to the first bevel gear. The two pull ropes are respectively received at both ends of the rotating rod, and the first bevel gear can be engaged with one of the second bevel gears, thereby driving the rotating rod to rotate forward or reverse, so that one of the pull ropes is received and the other pull rope is released, and then the filter screen slides in the filter box.

[0007] Preferably, both ends of the rotating rod are fixedly connected to the mounting rods, the two mounting rods are slidingly connected to the storage wheels, the two storage wheels are rotatably connected to the mounting seat, and the two pull ropes are respectively stored in the two storage wheels.

[0008] Preferably, the middle of the mounting seat is slidably connected to a slide seat, the rotating rod is rotatably connected to the slide seat through a bearing, the bottom of the mounting seat is fixedly connected to a small cylinder, and the output end of the small cylinder is fixedly connected to the slide seat.

[0009] Preferably, the drawer fan includes a middle tube, both ends of the middle tube are fixedly connected to limit plates, a hole is opened in the middle of the limit plate to cooperate with the middle tube, the middle of the middle tube is fixedly connected to a motor, and the output end of the motor is fixedly connected to a blade.

[0010] Preferably, a pressure measuring cylinder is fixedly connected to the side wall of the middle cylinder, and two limiting rings are symmetrically connected inside the pressure measuring cylinder. A circular plate is slidably connected between the two limiting rings, and a first spring is connected between the circular plate and one of the limiting rings. The first spring can resist the pressure difference generated when the blades are running and the filter is not blocked, so that the circular plate does not slide.

[0011] Preferably, a mounting plate is rotatably connected to the outer wall of the mounting box, two push switches for controlling the extension or shortening of the small cylinder are provided on the mounting plate, an extension rod is fixedly connected to the circular plate, and a pressure plate is fixedly connected to the end of the extension rod;

[0012] When the filter is blocked to increase the pressure difference between the inside and outside of the middle cylinder, the circular plate can slide into the middle cylinder so that the pressure plate presses one of the push switches, thereby meshing one of the second bevel gears with the first bevel gear.

[0013] Preferably, an L-shaped frame is fixedly connected to the installation box, an active hydraulic rod is fixedly connected to the L-shaped frame, a passive hydraulic rod is fixedly connected to the installation box, an oil pipe is connected between the active hydraulic rod and the passive hydraulic rod, the installation plate is rotatably connected to the installation box through a round rod, a cylindrical gear is connected to the round rod through a one-way bearing, the output end of the passive hydraulic rod is fixedly connected to a rack meshing with the cylindrical gear, and when the box door is opened, the active hydraulic rod can be pressed to shorten, thereby causing the installation plate to rotate in one direction, so that the two press switches are alternately in the pressing range of the pressure plate.

[0014] Preferably, the small cylinder is connected to a pressure relief pipe, a pressure relief valve is provided on the pressure relief pipe, a first rectangular plate is fixedly connected to the L-shaped frame, a second rectangular plate is fixedly connected to the box door, the pressure relief pipe and the pressure relief valve are both fixedly connected to the first rectangular plate, and when the box door is opened, the second rectangular plate presses the pressure relief valve to shorten the small cylinder and drive the first bevel gear not to engage with any of the second bevel gears.

[0015] Preferably, two scraping strips are symmetrically fixedly connected in the filter box, and both of the scraping strips are in contact with the air inlet surface of the filter screen.

[0016] Preferably, the edge of the filter screen is fixedly connected to a mounting frame, and the mounting frame slides in the filter box. A first through groove is provided on the bottom frame of the mounting frame, and a second through groove is provided on the bottom wall of the filter box. The first through groove is connected to the second through groove before the mounting frame slides to both ends of its stroke.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] When there is too much dust on the filter and the filter is blocked, the pressure difference generated when the drawer fan is running will increase, so that the pressure difference drives the rotating rod to slide axially, so that one of the second bevel gears is engaged with the first bevel gear, so that when the box door is subsequently opened, the first bevel gear can drive the rotating rod to rotate synchronously. At this time, one of the pull ropes is stored and the other pull rope is released, which can drive the filter to slide in the filter box, so that other parts of the filter take over the air filtration. Through the above-mentioned structural arrangement, when the filter is blocked and the air volume is reduced, the maintenance personnel can improve the permeability of the filter by opening the box door, which is more convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The overall structure of the present invention is shown in FIG. Figure 1 ;

[0020] Figure 2 The overall structure of the present invention is shown in FIG. Figure 2 ;

[0021] Figure 3 It is a structural schematic diagram of the filter screen of the present invention;

[0022] Figure 4 This is a schematic structural diagram of the drawer fan of the present invention;

[0023] Figure 5 This is a schematic structural diagram of the mounting base of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the small cylinder of the present invention;

[0025] Figure 7 It is a structural schematic diagram of the active hydraulic rod of the present invention.

[0026] In the figure: 100, installation box; 110, air outlet pipe; 120, air inlet pipe; 130, box door; 131, plug rod; 140, L-shaped frame; 150, rotating shaft; 160, first bevel gear; 170, pull wire; 180, torsion spring; 200, middle cylinder; 210, limit plate; 220, handle; 230, motor; 231, blade; 240, pressure measuring cylinder; 250, circular plate; 260, limit ring; 270, first spring; 280, extension rod; 281, pressure plate; 290, installation plate; 291, cylindrical gear; 300, filter box; 301, second through slot; 310, installation frame; 320, filter screen; 321, filter screen; 1. First through groove; 330, scraper strip; 340, pull rope; 341, guide wheel; 350, mounting seat; 360, rotating rod; 370, second bevel gear; 380, mounting rod; 390, storage wheel; 400, active hydraulic rod; 410, active cylinder rod; 420, oil pipe; 430, passive hydraulic rod; 440, passive cylinder rod; 450, rack; 460, push switch; 470, slide; 480, gas rod; 481, piston cylinder; 482, second spring; 490, small air pump; 491, air pump tube; 492, pressure relief tube; 493, second rectangular plate; 494, first rectangular plate; 495, pressure relief valve. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0028] Reference Figure 1-Figure 7, this embodiment provides a technical solution: an exhaust duct fan that is easy to disassemble, including an installation box 100, the two symmetrical side walls of the installation box 100 are respectively connected to an air inlet pipe 120 and an air outlet pipe 110, a drawer fan is placed in the installation box 100, the air inlet pipe 120 is connected to a filter box 300, a filter screen 320 is slidably connected to the filter box 300, and both sides of the filter screen 320 are fixedly connected to a pull rope 340; a box door 130 is hinged on the installation box 100, a rotating shaft 150 is rotatably connected to the installation box 100, and a pull wire 1 is connected between the box door 130 and the rotating shaft 150. 70; A mounting base 350 is fixedly connected to the mounting box 100, and a rotating rod 360 is rotatably connected to the mounting base 350. Two second bevel gears 370 are symmetrically fixedly connected to the rotating rod 360. The end of the rotating shaft 150 is fixedly connected to the first bevel gear 160. Two pull ropes 340 are respectively received at both ends of the rotating rod 360. The first bevel gear 160 can engage with one of the second bevel gears 370, thereby driving the rotating rod 360 to rotate forward or reverse, so that one of the pull ropes 340 is received and the other pull rope 340 is released, and then the filter screen 320 slides in the filter box 300.

[0029] The installation box 100 is customized according to the size of the drawer fan. If the drawer fan is large, it is hoisted on the installation box 100 with ropes. The two symmetrical walls of the installation box 100 are respectively connected to the air inlet pipe 120 and the air outlet pipe 110. When the drawer fan is running, the outside air enters through the air inlet pipe 120 and is discharged into the room through the air outlet pipe 110. The drawer fan in the installation box 100 can be inspected or replaced by opening the box door 130.

[0030] The filter 320 is provided to isolate dust contained in the air entering from the outside. When the filter 320 is blocked by too much dust, the pressure difference generated by the operation of the drawer fan will increase, thereby driving the rotating rod 360 to slide axially, so that one of the second bevel gears 370 is engaged with the first bevel gear 160. When the door 130 is subsequently opened, the first bevel gear 160 can drive the rotating rod 360 to rotate synchronously. At this time, one of the pull ropes 340 is stored and the other pull rope 340 is released, thereby driving the filter 320 to slide inside the filter box 300, so that other parts of the filter 320 take over the air filtering.

[0031] With the above-mentioned structural arrangement, when the filter 320 is blocked and the air volume is reduced, the maintenance personnel can improve the permeability of the filter 320 by simply opening the door 130, which is more convenient to use. At the same time, if the drawer fan is damaged, the permeability of the filter 320 after later maintenance will not affect the post-repair test.

[0032] In addition, the two second bevel gears 370 can alternately mesh with the first bevel gear 160 , so that after the filter screen 320 slides in one direction, if the filter screen 320 is subsequently blocked again, the filter screen 320 can slide in the other direction.

[0033] The door 130 is connected with an insertion rod 131, and the pull wire 170 is fixedly connected to the insertion rod 131. If the drawer fan is to be removed, the door 130 can be opened and the insertion rod 131 can be pulled out to avoid obstruction caused by the pull wire 170.

[0034] A torsion spring 180 is further connected between the end of the rotating shaft 150 and the installation box 100 . When the box door 130 is closed, the torsion spring 180 elastically recovers, so that the pull wire 170 is stored again.

[0035] Both ends of the rotating rod 360 are fixedly connected to the mounting rods 380, and the two mounting rods 380 are slidingly connected to the storage wheels 390. The two storage wheels 390 are both rotatably connected to the mounting seat 350, and the two pull ropes 340 are respectively stored in the two storage wheels 390.

[0036] The storage wheel 390 is rotatably connected to the mounting seat 350, but the storage wheel 390 does not move axially. When the rotating rod 360 slides and drives the two second bevel gears 370 to move, the mounting rods 380 at both ends of the rotating rod 360 slide synchronously. Since the mounting rods 380 are slidably connected to the storage wheel 390, the axial movement of the rotating rod 360 is not interfered with, and the storage wheel 390 is driven to rotate normally.

[0037] A plurality of guide wheels 341 are rotatably connected to the filter box 300 , and the guide wheels 341 are used to change the pulling direction of the pull rope 340 .

[0038] The middle of the mounting seat 350 is slidably connected to a slide seat 470 , the rotating rod 360 is rotatably connected to the slide seat 470 through a bearing, the bottom of the mounting seat 350 is fixedly connected to a small cylinder, and the output end of the small cylinder is fixedly connected to the slide seat 470 .

[0039] The small cylinder operates alternately by extending and shortening. When the small cylinder extends and contracts, it can drive the mounting seat 350 to slide back and forth in a straight line. The rotating rod 360 is rotatably connected to the mounting seat 350 but does not slide axially relative to the mounting seat 350. When the small cylinder is in operation, it drives the two second bevel gears 370 to alternately engage with the first bevel gear 160.

[0040] The drawer fan includes a middle tube 200, both ends of which are fixedly connected to a limit plate 210. A hole is opened in the middle of the limit plate 210 to match the middle tube 200. A motor 230 is fixedly connected to the middle of the middle tube 200, and a blade 231 is fixedly connected to the output end of the motor 230.

[0041] The middle tube 200 is on the same axis as the air inlet duct 120 and the air outlet duct 110. When the motor 230 is running, the blades 231 rotate, thereby allowing external air to enter the room. The two limit plates 210 are arranged so that after the box door 130 is closed, the four sides of the limit plates 210 fit with the inner wall of the installation box 100 and the inner wall of the box door 130, so that the drawer fan can be firmly fixed in the installation box 100. A handle 220 is also fixedly connected to the side wall of the middle tube 200, and the drawer fan can be easily taken in and out by pulling the handle 220.

[0042] A pressure measuring cylinder 240 is fixedly connected to the side wall of the middle cylinder 200, and two limiting rings 260 are symmetrically connected inside the pressure measuring cylinder 240. A circular plate 250 is slidably connected between the two limiting rings 260, and a first spring 270 is connected between the circular plate 250 and one of the limiting rings 260. The first spring 270 can resist the pressure difference generated when the blade 231 is running and the filter screen 320 is not blocked, so that the circular plate 250 does not slide.

[0043] The pressure measuring cylinder 240 is connected to the space between the filter screen 320 and the blade 231. When the blade 231 rotates, the air pressure at the air inlet end of the blade 231 is lower than the atmospheric pressure. When the filter screen 320 is not blocked, the pressure difference generated by this part can be offset by the elastic force of the first spring 270, so that the circular plate 250 does not slide. When the filter screen 320 is blocked, the pressure difference will increase and exceed the elastic force of the first spring 270. At this time, the circular plate 250 can slide toward the axial direction of the middle cylinder 200, which indicates that the filter screen 320 is blocked.

[0044] A mounting plate 290 is rotatably connected to the outer wall of the mounting box 100. Two push switches 460 for controlling the extension or shortening of the small cylinder are provided on the mounting plate 290. An extension rod 280 is fixedly connected to the circular plate 250, and a pressure plate 281 is fixedly connected to the end of the extension rod 280. When the filter screen 320 is blocked to increase the pressure difference between the inside and outside of the middle cylinder 200, the circular plate 250 can slide toward the inside of the middle cylinder 200 so that the pressure plate 281 presses one of the push switches 460, thereby engaging one of the second bevel gears 370 with the first bevel gear 160.

[0045] Each time the door 130 opens and closes, it drives the mounting plate 290 to rotate 180 degrees, causing the two push switches 460 to alternately be within the pressing range of the pressure plate 281. When the pressure difference between the inside and outside of the middle cylinder 200 increases, the pressure plate 281 approaches the push switch 460 within its pressing range. When the pressure difference reaches a sufficiently large value, the pressure plate 281 presses the push switch 460, causing the small cylinder to extend or contract, thereby driving one of the second bevel gears 370 to engage with the first bevel gear 160.

[0046] The small cylinder includes a piston cylinder 481, an air rod 480 that slides inside the piston cylinder 481 through a second spring 482, a small air pump 490, and an air pump tube 491 connected to the small air pump 490 and the piston cylinder 481. The air rod 480 is fixedly connected to the slide 470, and the two press switches 460 respectively control the small air pump 490 to inject or exhaust air into the piston cylinder 481 through the air pump tube 491, thereby causing the small cylinder to extend or shorten.

[0047] An L-shaped frame 140 is fixedly connected to the installation box 100, an active hydraulic rod 400 is fixedly connected to the L-shaped frame 140, a passive hydraulic rod 430 is fixedly connected to the installation box 100, an oil pipe 420 is connected between the active hydraulic rod 400 and the passive hydraulic rod 430, the installation plate 290 is rotatably connected to the installation box 100 through a round rod, a cylindrical gear 291 is connected to the round rod through a one-way bearing, the output end of the passive hydraulic rod 430 is fixedly connected to a rack 450 meshing with the cylindrical gear 291, and when the box door 130 is opened, the active hydraulic rod 400 can be pressed to shorten, thereby causing the installation plate 290 to rotate in one direction, so that the two press switches 460 are alternately in the pressing range of the pressure plate 281.

[0048] After the box door 130 is opened, the box door 130 can press the active cylinder rod 410 of the active hydraulic rod 400, so that the hydraulic oil in the active hydraulic rod 400 enters the passive hydraulic rod 430 through the oil pipe 420, so that the passive cylinder rod 440 extends, thereby moving the rack 450 and driving the cylindrical gear 291 to rotate 180 degrees. At this time, the cylindrical gear 291 drives the mounting plate 290 to rotate 180 degrees through the one-way bearing, so that the other pressing switch 460 is in the pressing range of the pressure plate 281, and the active hydraulic rod 400 and the active cylinder are in contact. A spring is also connected between the rods 410. When the box door 130 is closed, the box door 130 no longer applies pressure to the active cylinder rod 410. The spring drives the active cylinder rod 410 to slide in the cylinder body of the active hydraulic rod 400. At this time, the hydraulic oil flows back, and the rack 450 slides back. The rack 450 still drives the cylindrical gear 291 to rotate, but the cylindrical gear 291 rotates relative to the round rod on the mounting plate 290, and the mounting plate 290 does not move at this time, thereby ensuring that the two press switches 460 can be alternately in the pressing range of the pressure plate 281.

[0049] The small cylinder is connected to a pressure relief pipe 492, and a pressure relief valve 495 is provided on the pressure relief pipe 492. A first rectangular plate 494 is fixedly connected to the L-shaped frame 140, and a second rectangular plate 493 is fixedly connected to the box door 130. The pressure relief pipe 492 and the pressure relief valve 495 are both fixedly connected to the first rectangular plate 494. When the box door 130 is opened, the second rectangular plate 493 presses the pressure relief valve 495, so that the small cylinder shortens and drives the first bevel gear 160 not to engage with any second bevel gear 370.

[0050] After the box door 130 is opened, it can contact the L-shaped frame 140. At the same time, the second rectangular plate 493 on the box door 130 is close to the first rectangular plate 494 on the L-shaped frame 140. At this time, the second rectangular plate 493 can press the pressure relief valve 495, and then the pressure relief pipe 492 makes the internal space of the piston cylinder 481 connected to the outside world. The second spring 482 elastically recovers to make the gas rod 480 slide and reset, so that any second bevel gear 370 is not engaged with the first bevel gear 160, ensuring that when the subsequent small air pump 490 extracts or discharges air into the piston cylinder 481, the other second bevel gear 370 can engage with the first bevel gear 160, and at the same time, when the box door 130 is closed, it will not drive the filter 320 to slide in the opposite direction.

[0051] Two scraping strips 330 are symmetrically fixedly connected in the filter box 300 , and both scraping strips 330 are in contact with the air inlet surface of the filter screen 320 .

[0052] When the filter 320 slides, the scraper 330 can scrape the surface of the filter 320 , thereby causing dust and other debris attached to the filter 320 to fall off.

[0053] The edge of the filter screen 320 is fixedly connected to the mounting frame 310, and the mounting frame 310 slides in the filter box 300. A first through groove 321 is provided on the bottom frame of the mounting frame 310, and a second through groove 301 is provided on the bottom wall of the filter box 300. Before the mounting frame 310 slides to the two ends of its stroke, the first through groove 321 is connected to the second through groove 301.

[0054] After the box door 130 is fully opened, it can drive the installation frame 310 to slide to any end of the interior of the filter box 300. In this state, the first through slot 321 is not connected to the second through slot 301, ensuring that external air does not enter through the first through slot 321 and the second through slot 301, so that the first through slot 321 and the second through slot 301 are not easily blocked. During the sliding process of the installation frame 310, the scraper 330 scrapes the filter 320. At this time, the first through slot 321 is in a state of communication with the second through slot 301, so that the dust and other debris scraped off can be discharged from the filter box 300 through the first through slot 321 and the second through slot 301, ensuring that the filter 320 can still have good permeability when the position of the filter 320 is changed next time.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An exhaust duct fan that is easy to disassemble, comprising an installation box (100), wherein two symmetrical side walls of the installation box (100) are respectively connected to an air inlet duct (120) and an air outlet duct (110), characterized in that: A drawer fan is placed in the installation box (100), a filter box (300) is connected to the air inlet pipe (120), a filter screen (320) is slidably connected in the filter box (300), and both sides of the filter screen (320) are fixedly connected with a pull rope (340); The installation box (100) is hinged with a box door (130), the installation box (100) is rotatably connected to a rotating shaft (150), and a pull wire (170) is connected between the box door (130) and the rotating shaft (150); A mounting seat (350) is fixedly connected to the mounting box (100), and a rotating rod (360) is rotatably connected to the mounting seat (350). Two second bevel gears (370) are symmetrically fixedly connected to the rotating rod (360). The end of the rotating shaft (150) is fixedly connected to the first bevel gear (160). The two pull ropes (340) are respectively received at the two ends of the rotating rod (360). The first bevel gear (160) can be engaged with one of the second bevel gears (370), thereby driving the rotating rod (360) to rotate forward or reverse, so that one of the pull ropes (340) is received and the other pull rope (340) is released, and then the filter screen (320) slides in the filter box (300).

2. The easily disassembled exhaust duct fan according to claim 1, characterized in that: Both ends of the rotating rod (360) are fixedly connected to the mounting rods (380), and the two mounting rods (380) are slidably connected to the storage wheels (390), and the two storage wheels (390) are rotatably connected to the mounting seat (350), and the two pull ropes (340) are respectively stored in the two storage wheels (390).

3. The easily disassembled exhaust duct fan according to claim 1, characterized in that: The middle of the mounting seat (350) is slidably connected to a slide seat (470), the rotating rod (360) is rotatably connected to the slide seat (470) via a bearing, the bottom of the mounting seat (350) is fixedly connected to a small cylinder, and the output end of the small cylinder is fixedly connected to the slide seat (470).

4. The easily disassembled exhaust duct fan according to claim 3, characterized in that: The drawer fan comprises a middle cylinder (200), both ends of the middle cylinder (200) are fixedly connected to a limit plate (210), a hole is provided in the middle of the limit plate (210) for matching with the middle cylinder (200), a motor (230) is fixedly connected to the middle of the middle cylinder (200), and a blade (231) is fixedly connected to the output end of the motor (230).

5. The easily disassembled exhaust duct fan according to claim 4, characterized in that: A pressure measuring cylinder (240) is fixedly connected to the side wall of the middle cylinder (200), and two limiting rings (260) are symmetrically connected inside the pressure measuring cylinder (240). A circular plate (250) is slidably connected between the two limiting rings (260), and a first spring (270) is connected between the circular plate (250) and one of the limiting rings (260). The first spring (270) can resist the pressure difference generated when the blade (231) is in operation and the filter screen (320) is not blocked, so that the circular plate (250) does not slide.

6. The easily disassembled exhaust duct fan according to claim 5, characterized in that: A mounting plate (290) is rotatably connected to the outer wall of the mounting box (100), and two push switches (460) for controlling the extension or shortening of the small cylinder are provided on the mounting plate (290). An extension rod (280) is fixedly connected to the circular plate (250), and a pressure plate (281) is fixedly connected to the end of the extension rod (280); When the filter (320) is blocked to increase the pressure difference between the inside and outside of the middle cylinder (200), the circular plate (250) can slide toward the inside of the middle cylinder (200) so that the pressure plate (281) presses one of the press switches (460), thereby meshing one of the second bevel gears (370) with the first bevel gear (160).

7. The easily disassembled exhaust duct fan according to claim 6, characterized in that: An L-shaped frame (140) is fixedly connected to the installation box (100), an active hydraulic rod (400) is fixedly connected to the L-shaped frame (140), and a passive hydraulic rod (430) is fixedly connected to the installation box (100). An oil pipe (420) is connected between the active hydraulic rod (400) and the passive hydraulic rod (430). The installation plate (290) is rotatably connected to the installation box (100) via a round rod, a cylindrical gear (291) is connected to the round rod via a one-way bearing, and a rack (450) meshing with the cylindrical gear (291) is fixedly connected to the output end of the passive hydraulic rod (430). When the box door (130) is opened, the active hydraulic rod (400) can be pressed to shorten it, thereby causing the installation plate (290) to rotate in one direction, so that the two press switches (460) are alternately in the pressing range of the pressing plate (281).

8. The easily disassembled exhaust duct fan according to claim 7, characterized in that: The small cylinder is connected to a pressure relief pipe (492), and a pressure relief valve (495) is provided on the pressure relief pipe (492). A first rectangular plate (494) is fixedly connected to the L-shaped frame (140), and a second rectangular plate (493) is fixedly connected to the box door (130). The pressure relief pipe (492) and the pressure relief valve (495) are both fixedly connected to the first rectangular plate (494). When the box door (130) is opened, the second rectangular plate (493) presses the pressure relief valve (495), so that the small cylinder shortens and drives the first bevel gear (160) to not mesh with any of the second bevel gears (370).

9. The easily disassembled exhaust duct fan according to claim 1, characterized in that: Two scraping strips (330) are symmetrically fixedly connected in the filter box (300), and both of the scraping strips (330) are in contact with the air inlet surface of the filter screen (320).

10. The easily disassembled exhaust duct fan according to claim 9, characterized in that: The edge of the filter screen (320) is fixedly connected to a mounting frame (310), and the mounting frame (310) slides in the filter box (300). A first through slot (321) is provided on the bottom frame of the mounting frame (310), and a second through slot (301) is provided on the bottom wall of the filter box (300). Before the mounting frame (310) slides to both ends of its travel, the first through slot (321) is connected to the second through slot (301).

Images