Dust cleaning and absorbing type blackboard eraser and using method thereof
Technical Field
The invention belongs to the technical field of teaching aids, and particularly relates to an ash-cleaning dust-absorbing blackboard eraser and a using method thereof.
Background
In primary and secondary school teaching, a blackboard is widely used, characters on the blackboard are erased by using a blackboard eraser generally, but the blackboard eraser is limited in dust absorption capacity, so that dust flies when the blackboard eraser is saturated, and a large amount of dust is absorbed into lungs after the blackboard eraser is used for a long time, so that diseases such as pneumonia and pulmonary tuberculosis are caused, and the health of teachers is seriously damaged. In addition, in the process of erasing the blackboard, the blackboard eraser can generate larger raised dust at the moment of being lifted away from the blackboard, and if the raised dust can be adsorbed at the moment, most of the raised dust in the process of erasing the blackboard can be solved.
Disclosure of Invention
The invention aims to provide an ash-cleaning and dust-absorbing blackboard eraser and a using method thereof.
The invention relates to an ash-cleaning dust-absorbing blackboard eraser which comprises a box body, an erasing component and an ash-cleaning component. The bottom of the box body is opened; the erasing component comprises a brush conveyor belt, a conveyor belt rotating shaft and a roller. Two conveyor belt rotating shafts are respectively arranged at two sides of the bottom of the inner cavity of the box body. The rotary shafts of the two conveyor belts are respectively fixed with a roller; the two rollers are connected by a brush conveyor belt. When the brush conveyor belt slides on the blackboard, the friction force generated does not drive the conveyor belt rotating shaft to rotate. The ash removal component comprises a scraping plate, a drawer box, an ash removal driving component and a drawer inlet opening and closing component. The middle part of one end of the box body is provided with a drawer hole or the middle parts of the two ends are provided with drawer holes; the drawer hole is positioned between the two conveyor belt rotating shafts; a drawer box is inserted into the drawer hole; the inner side edge of the scraper is fixed with the middle part of the sliding plate; inside the squeegee brush conveyor belt. The dust attached to the brush conveyor belt is scraped off in the moving process of the brush conveyor belt; the inner side surface of the drawer box is provided with an opening; the ends of the scrapers are close to the openings of the two drawer boxes. The end part of the box body inner cavity installed on the drawer inlet opening and closing assembly is positioned at the opening of the drawer box, and the opening of the drawer box can be opened or closed.
The ash removal driving component comprises an air storage bag, a roller and an annular air bag; the air storage bag is fixed at the top of the box body; and rollers are fixed at two ends of each conveyor belt rotating shaft. The outer circumference of each roller is fixed with an annular air bag; each annular air bag is connected to the annular air bag through a ventilation rotary joint and an air pipe. In an initial state, the outer diameter of the annular air bag is smaller than the diameter of the roller.
Preferably, the dust cleaning and absorbing type blackboard eraser further comprises a dust absorbing assembly. The dust collection assembly comprises a filter screen, a sliding plate, a return spring, an inner cover plate and an outer cover plate. The sliding plate is arranged in the box body in a vertically sliding manner; the inner side of the sliding plate forms a dust suction cavity; the filter screen is fixed in the box body and is positioned on the inner side of the sliding plate. The filter screen divides the dust suction cavity into a dust storage cavity and an exhaust cavity. A plurality of reset springs are arranged between the filter screen and the sliding plate; a plurality of air suction holes are formed in the two sides of the box body; one or more exhaust holes are formed in the side part or the end part of the box body; the exhaust hole is communicated with the exhaust cavity; the air suction hole is communicated with the dust storage cavity; the inner side of each air suction hole is hinged with an inner cover plate; the inner cover plate is propped against the inner side of the air suction hole. The outer cover plate is propped against the outer side of the exhaust hole. The two conveyor belt rotating shafts are supported on the outer side of the sliding plate and slide along with the sliding plate, so that the brush conveyor belt drives the sliding plate to slide when being pressed.
Preferably, the dust cleaning and absorbing type blackboard eraser further comprises a dust hood. The two dust hoods are respectively arranged at two sides of the box body. The suction hole is positioned at the inner side of the dust hood.
Preferably, the box body is provided with an ash outlet communicated with the dust storage cavity; an ash discharging cover is detachably arranged on the ash discharging port.
Preferably, only one drawer box is arranged at one end of the box body. The drawer inlet opening and closing assembly comprises a first cover plate, a second cover plate, a closing spring and a telescopic air bag. The first cover plate and the second cover plate are arranged at the opening of the drawer box side by side and form sliding pairs with the inner cavity of the box body through the sliding rod and the sleeve. The back side edges of the first cover plate and the second cover plate are connected with the box body through a closing spring; the closing spring enables the opposite side surfaces of the first cover plate and the second cover plate to be abutted together, and the opening of the drawer box is closed. Two ends of the telescopic air bag are fixed with the outer side surfaces of the first cover plate and the second cover plate; the telescopic air bag is communicated with the air storage bag through an air pipe.
Preferably, the drawer inlet opening and closing assembly comprises a first cover plate, a permanent magnet, a second cover plate, an electromagnet, a storage battery and an electromagnet switch. The first cover plate and the second cover plate are arranged side by side and form sliding pairs with the inner cavity of the box body. The opposite side edges of the first cover plate and the second cover plate are respectively provided with a permanent magnet and an electromagnet; when the electromagnet is electrified, the adjacent side magnetic poles of the permanent magnet and the electromagnet are the same and mutually repel, so that the opening of the drawer box is opened; when the electromagnet is powered off, the permanent magnet and the electromagnet attract each other, so that the opening of the drawer box is closed. The electromagnet is electrically connected with the storage battery through an electromagnet switch. The electromagnet switch is arranged at the end part of the box body.
Preferably, the drawer inlet opening and closing assembly comprises a baffle plate and a push-pull rod. The baffle is located the opening part of drawer box, and constitutes sliding pair with the box body. The inner end of the push-pull rod is fixed with the baffle plate, and the outer end of the push-pull rod extends out of the box body and the dust cover. When the push-pull rod is not driven, the baffle keeps static; the baffle can be driven to block the opening of the drawer box or leave the opening of the drawer box by pushing or pulling the push-pull rod.
Preferably, one or more limiting blocks are fixed at the edge of the filter screen.
Preferably, the box body is provided with a rotating rod for locking the drawer box at a position close to the drawer hole.
Preferably, a plurality of salient points are arranged on the outer circumferential surface of the annular air bag.
The use method of the dust cleaning and absorbing blackboard eraser comprises the following steps:
a user holds the blackboard eraser by hand, a brush conveyor belt of the blackboard eraser is pressed on the blackboard, bristles on the conveyor belt contact the blackboard, the conveyor belt is extruded, the conveyor belt pushes a sliding plate to move upwards through a fixed rod, a return spring is compressed, a dust absorption cavity is compressed, so that gas in an exhaust cavity impacts an outer cover plate, the outer cover plate is opened outwards, and the gas is exhausted through an exhaust hole; when one erasing action is finished, a user lifts the blackboard eraser, the sliding plate resets under the action of the plurality of reset springs, the volume of the dust suction cavity is increased to form negative pressure, the inner cover plate in the dust storage cavity is inwards opened, and raised dust generated when the blackboard eraser is lifted enters the dust storage cavity through the dust suction cover and the air suction hole. In the whole blackboard erasing process, dust is absorbed once when one erasing action is finished.
When the brush conveyor belt of the blackboard eraser contains excessive dust on the outward side surface; the user erects the blackboard eraser so that one drawer box is positioned at the bottom of the box body, and the opening of the drawer box is opened through the drawer inlet opening and closing assembly. Then, the user squeezes the gas storage bag at the top of the box body by the palm of the hand, gas in the gas storage bag flows into the annular gas bag to inflate the annular gas bag, and the outer circumferential surface of the annular gas bag is contacted with the blackboard surface; then, a user transversely slides the blackboard eraser, the roller and the conveyor belt rotating shaft are driven to rotate due to the friction rolling of the annular air bag and the blackboard, so that the brush conveyor belt rotates, and when the part with the dust on the brush conveyor belt rotates to contact with the scraper, the scraper scrapes the dust on the brush conveyor belt; the dust scraped off by the scraper falls into a drawer box positioned below the box body; after the part stained with the dust on the brush conveyor belt is scraped, a user closes the opening of the drawer box through the drawer inlet opening and closing assembly and loosens the air storage bag, so that the opening of the drawer box positioned below the box body is closed, and the annular air bag is separated from the blackboard. After the dust remover is used for multiple times, the drawer box can be drawn out, and the dust in the drawer box can be poured.
The invention has the beneficial effects that:
1. in the erasing process, the chalk dust adhered to the brush conveying belt can be scraped in the sliding blackboard eraser process by pressing the air storage bag by the palm of the hand, so that the blackboard eraser can be continuously used, and the dust pollution caused by manually beating the blackboard eraser is reduced.
2. According to the invention, through the displacement of the sliding plate generated in the process of pressing the blackboard eraser, a negative pressure is generated when a user lifts the blackboard eraser, so that chalk dust is sucked into the box body, and dust emission is greatly reduced.
3. The invention utilizes the inner cover plate, the outer cover plate and the telescopic air bag structure, and can avoid the leakage of dust under the condition of not using any power supply.
4. According to the invention, through the design of the filter screen, the inner cover plate and the outer cover plate, in the process of air inlet and outlet of the dust suction cavity, dust can only enter the dust suction cavity but cannot be discharged out of the dust suction cavity, so that the dust suction effect is greatly improved.
5. According to the invention, the detachable drawer box is arranged, so that dust can be intensively dumped after being scraped for many times, and the efficiency of blackboard cleaning is greatly improved.
Drawings
FIG. 1 is a front view of embodiment 1 of the present invention;
FIG. 2 is a top view of embodiment 1 of the present invention;
FIG. 3 is a side view of embodiment 1 of the present invention;
FIG. 4 is a cross-sectional view A-A of FIG. 1;
FIG. 5 is a cross-sectional view B-B of FIG. 4;
FIG. 6 is a cross-sectional view C-C of FIG. 4;
FIG. 7 is a cross-sectional view D-D of FIG. 4;
FIG. 8 is a cross-sectional view of E-E in FIG. 4;
fig. 9 is a schematic structural view of a drawer inlet opening/closing assembly according to embodiment 1 of the present invention.
Fig. 10 is a schematic structural view of a drawer inlet opening/closing assembly according to embodiment 3 of the present invention.
In the figure: 1. a box body; 11. a sliding plate; 111. a dust storage chamber; 112. a suction hole; 113. a limiting column; 114. a return spring; 115. an exhaust chamber; 116. an exhaust hole; 117. an outer cover plate; 118. an inner cover plate; 12. an air bag; 13. a drawer hole; 14. rotating the rod; 2. a conveyor belt; 21. a conveyor belt shaft; 22. a roller; 221. an annular air bag; 23. fixing the rod; 24. a brush; 3. a squeegee; 4. a drawer box; 5. a dust hood; 6. a slide bar; 61. a sleeve; 7. a first cover plate; 71. a permanent magnet; 8. a second cover plate; 81. an electromagnet; 811. an electromagnet switch; 812. a battery cavity; 813. a storage battery; 9. filtering with a screen; 91. an ash outlet; 92. discharging the ash cover; 71. a closing spring; 72. a telescopic air bag.
Detailed Description
The invention is further described below with reference to the accompanying drawings.
Example 1
A dust-cleaning and dust-absorbing blackboard eraser comprises a box body 1, a dust-absorbing cover 5, an erasing component, a dust-absorbing component and a dust-cleaning component. The box body 1 is in a cuboid shape, and the lower side surface of the box body is arranged in an open mode to form a main body of the blackboard eraser; two long edge side surfaces of the box body 1 are used as the left side and the right side of the box body, and two short edge side surfaces are used as the front end and the rear end of the box body; the two dust hoods 5 are respectively arranged at the left side and the right side of the box body 1. The erasing component, the dust collection component and the ash removal component are all arranged inside the box body; the erasing component is positioned at the bottom of the box body (namely the opening of the box body 1) and is used for erasing chalk characters on the blackboard; the dust collection assembly is positioned at the top of the box body.
The suction assembly comprises a filter screen 9, a slide plate 11, a return spring 114, an inner cover plate 118, an outer cover plate 117 and a dust cover 92. The sliding plate 11 is arranged in the box body 1 in a vertically sliding manner; the inner side of the sliding plate 11 and the inner cavity of the box body form a dust suction cavity; the filter screen 9 is fixed in the box body 1 and is positioned inside the sliding plate 11. The screen 9 divides the dust chamber into a dust storage chamber 111 near the bottom of the inner chamber of the housing 1 and an exhaust chamber 115 near the slide plate 11. One or more stop blocks 113 are fixed at the edge of the screen 9 for limiting the inner limit position of the slide plate 11. By the sliding of the sliding plate 11, the total volume of the exhaust chamber 115 and the dust storage chamber 111 can be adjusted. A plurality of return springs 114 are arranged between the filter screen 9 and the sliding plate 11; the left side and the right side of the box body 1 are provided with a plurality of air suction holes 112, and the front end and the rear end are provided with a plurality of air exhaust holes 116; the exhaust hole 116 is communicated with the exhaust cavity 115; the air suction hole 112 is communicated with the dust storage cavity 111; the suction hole 112 is located inside the dust hood 5. The inner side of each air suction hole 112 is hinged with an inner cover plate 118; the inner cover plate 118 is urged against the inside of the suction hole 112 by the torsion spring. Gas can push out of the box body through the inner cover plate 118 into the box and cannot be blown out of the box through the suction holes 112. The outer cover plate 117 is pressed against the outside of the exhaust hole 116 by the torsion spring. The gas can be pushed out of the box by pushing the outer cover plate 117 inside the box, and cannot be blown out of the box through the exhaust hole 116. Therefore, the air exhaust chamber 115 can only exhaust air to the outside of the cartridge, and the dust storage chamber 111 can only suck air from the outside of the cartridge. The exhaust chamber 115 communicates with the dust storage chamber 111, but the dust is divided up and down by the screen 9. The top of the box body 1 is provided with an ash outlet 91; the dust outlet 91 is detachably provided with a dust outlet cover 92 for regularly cleaning dust in the dust storage cavity 111.
The wiping assembly includes the brush belt 2, the belt rotating shaft 21, the roller, and the fixing lever 23. Fixed bars 23 are fixed to four corners of the outer side surface of the slide plate 11. The two conveyor belt rotating shafts 21 are respectively arranged at the left side and the right side of the inner cavity of the box body 1. The length direction of the conveyor belt rotating shaft 21 is consistent with the long side direction of the box body 1. Two ends of the conveyor belt rotating shaft 21 and a fixed rod 23 respectively form a rotating pair with resistance (realized by interference fit of the conveyor belt rotating shaft 21 penetrating through a rubber hole). Rollers are fixed on the two conveyor belt rotating shafts 21; the two rollers are connected by a brush conveyor belt 2. The outer side surface of the brush conveyor belt 2 is provided with dense brush hairs 24 for erasing chalk characters and temporarily storing dust. The friction force between the brush 24 and the blackboard is small; so that the roller can not be driven to rotate in the normal blackboard erasing process. When the brush belt 2 slides to the inner limit position, a part is still outside the case 1, so that effective erasing is performed.
When a user presses the brush conveyor belt 2 onto the blackboard, the sliding plate is driven to slide inwards to compress the volume of the dust collection cavity, so that the air in the dust collection cavity is exhausted by pushing the outer cover plate 117 away from the exhaust hole 116 of the exhaust cavity 115; since the filter 9 blocks dust from entering the exhaust chamber 115, the exhaust gas does not cause dust to be discharged. When a user finishes an erasing action and lifts the blackboard eraser to separate the brush conveyor belt 2 from the blackboard, the sliding plate is pushed out and reset under the action of the reset spring 114, so that the volume of the dust suction cavity is increased to generate negative pressure, and air around each suction hole 112 carries dust generated when the blackboard eraser is lifted to push the inner cover plate 118 to be sucked into the dust storage cavity 111, so that raised dust is reduced.
The ash cleaning component comprises a scraping plate 3, a drawer box 4, an ash cleaning driving component and a drawer inlet opening and closing component. The middle parts of the front end and the rear end of the box body 1 are provided with drawer holes 13; the drawer hole 13 is positioned between the two conveyor belt rotating shafts 21; the two drawer boxes 4 are respectively inserted into the two drawer holes 13; the drawer box 4 is located at the outer side of the sliding plate 11. The front end and the rear end of the box body 1 are provided with rotating rods 14 close to the drawer holes; the drawer box can be locked in the box body 1 by rotating the turning lever 14. The edge of the inner side of the scraper 3 is fixed with the middle part of the sliding plate 11, and the edge of the outer side extends into the bristles 24 on the inward side of the brush conveyor 2, so that dust attached to the bristles 24 is scraped off in the moving process of the brush conveyor 2; the inner side surfaces of the two drawer boxes 4 are provided with openings; the two ends of the scraping plate 3 are respectively close to the inner sides of the two drawer boxes 4, so that the scraped dust is conveniently guided into the drawer boxes 4.
The two ends of the inner cavity of the box body 1, where the two drawer inlet opening and closing assemblies are respectively installed, are respectively located at the opening of the drawer box 4 and are used for opening or closing the opening of the drawer box 4, so as to avoid dust in the drawer box 4 from falling out in the process of cleaning the blackboard. The drawer inlet opening and closing assembly includes a first cover 7, a permanent magnet 71, a second cover 8, an electromagnet 81, a storage battery 813, and an electromagnet switch 811. The first cover plate 7 and the second cover plate 8 are arranged side by side, and both form sliding pairs with the inner cavity of the box body 1 through the sliding rod 6 and the sleeve 61, and both have two limit positions. The permanent magnet 71 and the electromagnet 81 are respectively arranged at the opposite side edges of the first cover plate 7 and the second cover plate 8; when the electromagnet 81 is electrified, the adjacent side magnetic poles of the permanent magnet 71 and the electromagnet 81 are the same, so that repulsive force is generated, and the permanent magnet 71 and the electromagnet 81 are mutually pushed away, so that the opening of the drawer box 4 is opened; when the electromagnet 81 is deenergized, the permanent magnet 71 and the electromagnet 81 attract each other, so that the opening of the drawer box 4 is closed. Electromagnet 81 is electrically connected to battery 813 via electromagnet switch 811, thereby controlling the on/off operation of electromagnet 81. The electromagnet switches 811 in the two drawer inlet opening and closing components are respectively arranged at the two ends of the box body 1; when the user presses the electromagnet switch 811 at one end of the box, the drawer inlet opening/closing assembly at the corresponding end is turned on.
The ash cleaning driving component comprises an air storage bag 12, a roller 22 and an annular air bag 221; the air storage bag 12 is fixed on the top of the box body 1; rollers are fixed at both ends of each conveyor belt rotating shaft 21. The outer circumference of each roller 22 is fixed with an annular air bag 221; each annular air cell 221 is connected to the annular air cell 221 through a ventilation rotary joint and an air tube. In an initial state, the outer diameter of the annular air bag 221 is smaller than that of the roller, and the annular air bag cannot be in contact with the blackboard; when the user extrudes the air storage bag 12, the air in the air storage bag 12 enters the annular air bag 221, the annular air bag 221 expands, the outer diameter of the annular air bag is increased to be in contact with a blackboard, at the moment, the blackboard eraser slides on the blackboard along the width direction, the annular air bag 221 and the roller 22 can be driven to rotate through friction force, so that the conveyor belt starts to move, and dust on the bristles 24 of the brush conveyor belt 2 is scraped off by the scraper.
As a preferable technical solution, a plurality of protrusions are provided on the outer circumferential surface of the annular bladder 221 to increase the frictional force.
The use method of the dust cleaning and absorbing blackboard eraser comprises the following steps:
a user holds the blackboard eraser by hand, the brush conveyor belt 2 of the blackboard eraser is pressed on the blackboard, the bristles 24 on the conveyor belt 2 contact the blackboard, the conveyor belt 2 is extruded, the conveyor belt 2 pushes the sliding plate 11 to move upwards through the fixed rod 23, the plurality of reset springs 114 are compressed, the dust absorption cavity is compressed, so that gas in the exhaust cavity 115 impacts the outer cover plate 117, the outer cover plate 117 is opened outwards, and the gas is exhausted through the exhaust hole 116; after an erasing action is finished, a user lifts the blackboard eraser, the sliding plate 11 is reset under the action of the plurality of reset springs 114, the volume of the dust suction cavity is increased to form negative pressure, the outer cover plate 117 is adsorbed on the box body 1, the inner cover plate 118 in the dust storage cavity 111 is opened inwards, raised dust generated when the blackboard eraser is lifted enters the dust storage cavity 111 through the dust suction cover 5 and the air suction hole 112, and the raised dust generated when the blackboard eraser is erased is reduced. In the whole blackboard erasing process, dust is absorbed once when one erasing action is finished.
When the brush conveyor belt 2 of the blackboard eraser contains too much dust on the outward side; the user erects the blackboard eraser and turns on the electromagnet 81 through the electromagnet switch 811, so that the opening of the drawer box 4 positioned below the box body is opened; the palm of a user presses the air storage bag 12 at the top of the box body 1, the air in the air storage bag 12 flows into the annular air bag 221, so that the annular air bag 221 is inflated and expanded, and the wheel surface of the annular air bag 221 contacts the blackboard surface; then, the user slides the blackboard eraser transversely, the roller 22 and the conveyor belt rotating shaft 21 rotate due to the friction action of the annular air bag 221 and the blackboard, so that the brush conveyor belt 2 rotates, and when the bristles 24 with dust rotate to contact with the scraper 3, the scraper 3 scrapes off the dust on the bristles 24; the dust scraped off by the scraper 3 falls into a drawer box 4 positioned below the box body 1; after the bristles stained with dust are scraped, the user closes the electromagnet switch 811 to turn on the electromagnet 81 and releases the air storage bag, so that the opening of the drawer box 4 positioned below the box body is closed, and the annular air bag 221 is separated from the blackboard. After repeated use, the drawer box 4 can be drawn out, the dust in the drawer box can be dumped, and the operation is simple and convenient.
Example 2
This example differs from example 1 in that: the structures of the drawer inlet opening and closing components are different;
the drawer inlet opening and closing assembly in the embodiment comprises a baffle plate and a push-pull rod. The baffle is positioned at the opening of the drawer box 4 and forms a sliding pair with resistance with the box body. The baffle plate is kept static when not acted by external force except gravity; the inner end of the push-pull rod is fixed with the baffle plate, and the outer end of the push-pull rod extends out of the box body and the dust cover. The user can open and close the opening of the drawer box 4 by pushing or pulling the push-pull rod. The embodiment realizes the switching of the opening and the closing of the opening of the drawer box 4 in a mechanical mode, reduces the cost and avoids the complexity of battery replacement.
Example 3
As shown in fig. 10, the present embodiment is different from embodiment 1 in that: the structures of the drawer inlet opening and closing components are different; the drawer box 4 is only one and is located at one end of the box body.
The drawer inlet opening and closing assembly comprises a first cover plate 7, a second cover plate 8, a closing spring 71 and a telescopic air bag 72. The first cover plate 7 and the second cover plate 8 are arranged at the opening of the drawer box 4 side by side, and both form sliding pairs with the inner cavity of the box body 1 through a sliding rod and a sleeve, and both have two limit positions. The opposite side edges of the first cover plate 7 and the second cover plate 8 are connected with the box body 1 through a closing spring 71; the closing spring 71 causes the opposite sides of the first and second covers 7 and 8 to abut together, closing the opening of the drawer box 4.
Two ends of the telescopic air bag 72 are fixed with the outer side surfaces of the first cover plate 7 and the second cover plate 8; the telescopic airbag 72 is in a bellows shape and extends when being inflated, so that the first cover plate 7 and the second cover plate 8 are pushed open, and the opening of the drawer box 4 is opened; the telescopic air bag 72 is communicated with the air storage bag 12 through an air pipe; when the air reservoir 12 is depressed, the bellows 72 expands to open the opening of the drawer case 4.
The use method of the dust cleaning and absorbing blackboard eraser comprises the following steps:
a user holds the blackboard eraser by hand, the brush conveyor belt 2 of the blackboard eraser is pressed on the blackboard, the bristles 24 on the conveyor belt 2 contact the blackboard, the conveyor belt 2 is extruded, the conveyor belt 2 pushes the sliding plate 11 to move upwards through the fixed rod 23, the plurality of reset springs 114 are compressed, the dust absorption cavity is compressed, so that gas in the exhaust cavity 115 impacts the outer cover plate 117, the outer cover plate 117 is opened outwards, and the gas is exhausted through the exhaust hole 116; after an erasing action is finished, a user lifts the blackboard eraser, the sliding plate 11 is reset under the action of the plurality of reset springs 114, the volume of the dust suction cavity is increased to form negative pressure, the outer cover plate 117 is adsorbed on the box body 1, the inner cover plate 118 in the dust storage cavity 111 is opened inwards, raised dust generated when the blackboard eraser is lifted enters the dust storage cavity 111 through the dust suction cover 5 and the air suction hole 112, and the raised dust generated when the blackboard eraser is erased is reduced. In the whole blackboard erasing process, dust is absorbed once when one erasing action is finished.
When the brush conveyor belt 2 of the blackboard eraser contains too much dust on the outward side; a user vertically places the blackboard eraser, so that the drawer box 4 is positioned at the bottom of the box body 1; the palm of a user presses the air storage bag 12 at the top of the box body 1, the air in the air storage bag 12 flows into the annular air bag 221, so that the annular air bag 221 is inflated and expanded, and the wheel surface of the annular air bag 221 contacts the blackboard surface; at the same time, the gas in the gas storage bag 12 flows into the bellows 72, so that the bellows 72 is extended to open the opening of the drawer case 4. Then, the user slides the blackboard eraser transversely, the roller 22 and the conveyor belt rotating shaft 21 rotate due to the friction action of the annular air bag 221 and the blackboard, so that the brush conveyor belt 2 rotates, and when the bristles 24 with dust rotate to contact with the scraper 3, the scraper 3 scrapes off the dust on the bristles 24; the dust scraped off by the scraper 3 falls into a drawer box 4 positioned below the box body 1; after the bristles stained with dust are scraped, the user loosens the air storage bag, so that the opening of the drawer box 4 positioned below the box body is closed, and the annular air bag 221 is separated from the blackboard. After repeated use, the drawer box 4 can be drawn out, the dust in the drawer box can be dumped, and the operation is simple and convenient.