CN117818240A - Automatic blackboard erasing device - Google Patents

Abstract

The invention relates to the technical field of teaching aids, in particular to an automatic blackboard erasing device, which comprises a sliding rail fixed in the middle of a support, wherein a moving platform is connected in the sliding rail in a sliding manner, an automatic blackboard eraser is arranged in the moving platform, the sliding rail comprises a sliding groove plate, the sliding groove plate is fixedly connected with the support, one end of the outer side wall of the sliding groove plate is fixedly connected with a first motor, the output end of the first motor is in transmission connection with a first threaded rod, and the first threaded rod is in screwing connection with a first sliding square. According to the invention, the change of the positions of the mobile platform on different height layers is realized through the motor, so that the mobile platform can deliver the automatic blackboard eraser for four blackboards in the bracket, thereby being convenient for wiping blackboards at different positions across a plane, realizing automatic wiping of the blackboards without manual work, and realizing wiping of one automatic blackboard eraser in the case of four-sided blackboards in university class, thereby improving the utilization rate of equipment.

Description

Automatic blackboard erasing device

Technical Field

The invention relates to the technical field of teaching aids, in particular to an automatic blackboard erasing device.

Background

The wiping of blackboard is a time consuming and cumbersome task, especially for large blackboard used in classrooms and conference rooms. For some university classes, a large number of operation formulas are usually written for the calculation of the formulas related to the classes of the students, so that the students can conveniently understand that the utilization rate of four blackboards is higher, but a classroom of a general university is not provided with a fixed classroom, so that the blackboard cannot be erased timely after the blackboard is written, thus, the students or teachers can generally arrange the students or the teachers to erase the blackboard, the progress of the lessons is influenced, and meanwhile, for some blackboard contents with larger operation amount, the written blackboard contents need to be erased and rewritten, the student erasing influences the picking of the notes of the students, and the teacher erasing influences the progress of the lessons of the teachers, so that an automatic blackboard erasing device is needed.

Disclosure of Invention

In order to overcome the technical problems, the invention aims to provide the automatic blackboard erasing device, the position of the mobile platform on different height layers is changed through the motor, so that the mobile platform can deliver the automatic blackboard erasing for four blackboards in the bracket, thereby being convenient for erasing blackboards at different positions across a plane, realizing the automatic erasing of the blackboards without manual work, and realizing the erasing of one automatic blackboard erasing in the four-sided blackboard in a university class, thereby improving the utilization rate of equipment; the whole mobile platform can be overturned left and right, and the concave plate I can be completely attached to the surface of the blackboard during overturning, so that the automatic blackboard eraser can be delivered for the blackboard positioned at the two sides of the sliding track; through the rotation of two motor four control pulleys, realize that the shell can go straight and rotate on the blackboard, the circular slot is seted up to the shell bottom, and top surface embedding fixedly connected with electro-magnet in the circular slot produces suction between electro-magnet and the blackboard to avoid automatic blackboard eraser to drop on the vertically blackboard.

The aim of the invention can be achieved by the following technical scheme:

an automatic blackboard erasing device comprises a sliding rail fixed in the middle of a bracket, wherein a moving platform is connected in the sliding rail in a sliding manner, and an automatic blackboard eraser is arranged in the moving platform;

the sliding track comprises a sliding groove plate, the sliding groove plate is fixedly connected with a support, one end of the outer side wall of the sliding groove plate is fixedly connected with a first motor, an output end of the first motor is in transmission connection with a first threaded rod, the first threaded rod is in screwed connection with a first sliding square, the first threaded rod is in rotary connection with the inner bottom of the sliding groove plate, the first sliding square is fixedly connected with a moving platform, the position of the moving platform on different height layers is changed through the first motor, and therefore the moving platform can deliver automatic blackboard erasers for four blackboards in the support, so that the blackboard at different positions can be conveniently wiped across a plane, and automatic wiping of the blackboard is achieved without manual implementation.

Further in, moving platform includes rotating block one, rotating block one bottom and sliding square one fixed connection, rotating block one middle part rotates and is connected with rotating block three, rotating block one lateral wall one end fixedly connected with motor two, motor shaft and rotating block three fixed connection of motor two, rotating block three top surface and concave board two fixed connection, concave board two both sides are all connected with concave board one through the hinge rotation, concave board two middle part sets up recess one, an inner wall of recess one is connected with concave board three through the hinge rotation, gear groove has all been seted up to concave board one, concave board two and concave board three interior bottom surface, through such setting, whole moving platform can realize controlling the upset, and can realize that concave board one is close to the blackboard surface's completion, can be for the blackboard delivery automatic blackboard eraser that is in sliding track both sides like this.

Further, a groove II is formed in the concave plate II, a fixer is arranged in the groove II, the concave plate III is fixed in the concave plate II through the fixer, a groove IV is formed on the outer side wall of the concave plate III, the groove IV is in sliding connection with the fixer, and the concave plate III can be clamped and fixed through the fixer, so that when the automatic blackboard eraser is positioned in the concave plate II, the automatic blackboard eraser is quickly taken down by the turnover concave plate III for daily maintenance.

The fixing device comprises a first fixing device, wherein the first fixing device comprises a first reset spring, one end of the first reset spring is fixedly connected with a second groove, the other end of the first reset spring is fixedly connected with a second sliding block, the second sliding block is in sliding connection with the fourth groove, the center of the outer side of the second sliding block is fixedly connected with a lock tongue, the lock tongue is in sliding connection with the fourth groove, the outer side wall of the second sliding block is fixedly connected with an anti-sliding block, and the outer side of the second groove is fixedly connected with a shielding plate.

Further in, automatic blackboard eraser includes the shell, shell both ends rotate and are connected with gear one, through gear one and gear groove meshing transmission, make things convenient for automatic blackboard eraser to smoothly remove in concave plate one and concave plate two, the inboard fixedly connected with motor three of shell, gear one and motor three's motor shaft fixed connection, the recess three has been seted up to the shell bottom surface, is provided with the cloth strip in the recess three, the equal fixedly connected with electric telescopic handle's in four corners of cloth strip one end, electric telescopic handle's the other end is fixed inside the shell, through electric telescopic handle control cloth strip's reciprocates, avoid in the in-process of blackboard eraser at the removal like this, erase the characters of route to guarantee to erase characters that can be aimed at, two square grooves are seted up to the shell bottom, square groove internal connection has motor four, motor shaft fixedly connected with pulley, pulley and square groove inner wall rotate through two motor four control pulleys, realize that the shell can go straight line and rotate on the shell, the top surface is seted up to the shell bottom, thereby avoid the electro-magnet to embed in the automatic round groove that drops perpendicularly with the blackboard eraser on the blackboard.

Further, four bull's eye wheels are fixedly connected to the bottom of the shell, and the automatic blackboard eraser can conveniently and smoothly move on the blackboard through the bull's eye wheels.

Further, the automatic blackboard eraser is provided with a marking pen in a matched mode, the marking pen comprises a pen cover, a second rotating block is fixedly connected with the inner portion of the pen cover in an embedded mode, a pen shell is connected to the bottom of the pen cover in a rotating mode, three second round holes are formed in the second rotating block, pen cores are connected to the second round holes in a sliding mode, pen points are fixedly connected to the bottoms of the pen cores, the pen points can write on a blackboard through the pen points, a fixing block is fixedly connected to the outer wall of the bottom of the pen cores in a sleeved mode, a convex column is fixedly connected to the outer wall of the fixing block, a hollow cylinder is connected to the outer wall of the bottom of the pen shell in a rotating mode, an oblique pen point is fixedly connected to the bottom of the hollow cylinder, through holes are formed in the end portion of the oblique pen point, a guide groove is formed in an annular mode, the position of the corresponding oblique pen point through holes is arranged to be of a V-shaped structure inclined to the downward through holes, and when the hollow cylinder is rotated, the hollow cylinder can be driven to extend to the outside the through holes, and writing is achieved.

The pen is characterized in that a second reset spring is arranged between the inner top of the pen shell and the pen core, and the strength of the pen point and the blackboard during writing is enhanced by arranging the second reset spring.

And further, three erasable inks of red, black and blue are respectively poured into the three pen cores, so that the pen cores with different colors can be switched to write according to the needs, and the lecture efficiency is improved.

The invention has the beneficial effects that:

1. the sliding rail in the middle of the support of the blackboard is then connected with a moving platform in a sliding way, an automatic blackboard eraser is arranged in the moving platform, a sliding groove plate of the sliding rail is fixedly connected with the support, one end of the outer side wall of the sliding groove plate is fixedly connected with a motor I which is in transmission connection with a threaded rod I, then the threaded rod I is screwed with a sliding square block I, the sliding square block I is fixedly connected with the moving platform, the position of the moving platform on different height layers is changed through the motor I, the automatic blackboard eraser can be delivered to four blackboards in the bracket by the mobile platform, so that the blackboards at different positions can be conveniently wiped across the plane, the automatic wiping of the blackboards is realized without manual work, and therefore, the wiping of one automatic blackboard eraser can be realized under the condition of four-sided blackboards in university class, thereby improving the utilization rate of equipment and ensuring the effective utilization of the classroom time of teachers and students;

2. through the bottom and the first fixed connection of slip square of moving platform dwang, then rotate the first middle part of dwang and be connected with the dwang three, motor two at the three fixed connection of dwang one lateral wall one end fixedly connected with motor shaft and dwang, three top surfaces and concave template two fixed connection of dwang, all be connected with concave template through the hinge rotation in concave template two both sides, then set up recess first with concave template second middle part, be connected with concave template three through the hinge rotation at an inner wall of recess first, and the gear groove has all been seted up at concave template first, concave template second and concave template three interior bottom surface, through such setting, whole moving platform can realize controlling the upset, and when overturning, can realize that concave template first is close to with the completion of blackboard surface, can deliver automatic blackboard eraser for the blackboard that is in slip track both sides like this.

3. The two ends of the shell of the automatic blackboard eraser are rotationally connected with the first gear, the inner side of the shell is fixedly connected with the third motor, the first gear is fixedly connected with the motor shaft of the third motor, and the first gear is meshed with the gear groove for transmission, so that the automatic blackboard eraser can smoothly move in the first concave plate and the second concave plate, the bottom surface of the shell is provided with the third groove, the third groove is internally provided with the cloth strip driven by four electric telescopic rods, the up-and-down movement of the cloth strip is controlled by the electric telescopic rods, and the phenomenon that the automatic blackboard eraser moves in the moving process is avoided, the characters in the way are erased, so that the characters can be erased in a targeted manner, two square grooves are formed in the bottom of the shell, a motor IV is fixedly connected with a motor shaft of the motor IV, the pulley is rotationally connected with the inner wall of the square groove, the pulley is rotationally controlled to rotate through the four motor control pulleys, the shell can move straight and rotate on a blackboard, a round groove is formed in the bottom of the shell, an electromagnet is fixedly connected to the inner top surface of the round groove, and suction is generated between the electromagnet and the blackboard, so that the automatic blackboard eraser is prevented from falling off on the vertical blackboard.

Drawings

The invention is further described below with reference to the accompanying drawings.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of a sliding track structure in accordance with the present invention;

FIG. 3 is a schematic diagram of a mobile platform according to the present invention;

FIG. 4 is a schematic view of the present invention in a partially enlarged configuration at A of FIG. 3;

FIG. 5 is a schematic view of the structure of an automatic blackboard eraser in the present invention;

FIG. 6 is a schematic view of the overall structure of the marker of the present invention;

FIG. 7 is a schematic view of the internal structure of the marker of the present invention;

fig. 8 is a schematic view of the internal structure of the hollow cylinder of the present invention.

In the figure: 100. a blackboard; 200. a bracket; 300. a sliding rail; 310. a first motor; 320. sliding the first square; 330. a chute plate; 340. a first threaded rod; 400. a mobile platform; 410. a second motor; 420. a first rotating block; 430. a holder; 431. a shielding plate; 432. a first reset spring; 433. an anti-skid block; 434. a bolt; 435. sliding square II; 440. concave plate I; 450. a gear groove; 460. concave plate II; 470. concave plate III; 500. an automatic blackboard eraser; 510. a first gear; 520. a housing; 530. a pulley; 540. a bullseye wheel; 550. an electromagnet; 560. a cloth wiping strip; 570. a telescopic rod; 600. marking pen; 610. a pen cap; 620. a second rotating block; 630. a pen shell; 640. a pen point; 650. a hollow cylinder; 651. a guide groove; 652. a beveled nib; 660. a fixed block; 670. and (3) a pen refill.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1-8, an automatic blackboard erasing device includes a sliding rail 300 fixed in the middle of a bracket 200, wherein a moving platform 400 is slidably connected in the sliding rail 300, and an automatic blackboard eraser 500 is arranged in the moving platform 400;

the sliding track 300 comprises a sliding groove plate 330, the sliding groove plate 330 is fixedly connected with the support 200, one end of the outer side wall of the sliding groove plate 330 is fixedly connected with a first motor 310, the output end of the first motor 310 is in transmission connection with a first threaded rod 340, the first threaded rod 340 is in screwed connection with a first sliding block 320, the first threaded rod 340 is in rotary connection with the inner bottom of the sliding groove plate 330, the first sliding block 320 is fixedly connected with the moving platform 400, the position of the moving platform 400 on different height layers is changed through the first motor 310, and therefore the moving platform 400 can deliver the automatic blackboard eraser 500 for four blackboards 100 in the support 200, and therefore the blackboards 100 at different positions can be wiped conveniently across planes, and automatic wiping of the blackboards 100 can be achieved without manual work.

The moving platform 400 comprises a first rotating block 420, the bottom of the first rotating block 420 is fixedly connected with a first sliding block 320, the middle of the first rotating block 420 is rotationally connected with a third rotating block 410, one end of the outer side wall of the first rotating block 420 is fixedly connected with a second motor 410, a motor shaft of the second motor 410 is fixedly connected with the third rotating block, the three top surfaces of the third rotating block are fixedly connected with a second concave plate 460, two sides of the second concave plate 460 are rotationally connected with a first concave plate 440 through hinges, the middle of the second concave plate 460 is provided with a first groove, one inner wall of the first groove is rotationally connected with a third concave plate 470 through hinges, the inner bottoms of the first concave plate 440, the second concave plate 460 and the third concave plate 470 are respectively provided with a gear groove 450, through the arrangement, the whole moving platform 400 can realize left-right overturning, and when overturning, the first concave plate 440 can be completely attached to the surface of the blackboard 100, and the blackboard 100 positioned at two sides of the sliding track 300 can deliver an automatic blackboard eraser 500.

The concave plate II 460 is internally provided with the groove II, the groove II is internally provided with the fixer 430, the concave plate III 470 is fixed in the concave plate II 460 through the fixer 430, the outer side wall of the concave plate III 470 is provided with the groove IV, the groove IV is in sliding connection with the fixer 430, the concave plate III 470 can be clamped and fixed through the fixer 430, thus when the automatic blackboard eraser 500 is positioned in the concave plate II 460, the automatic blackboard eraser 500 can be quickly taken down by the turnover concave plate III 470 for daily maintenance, the fixer 430 comprises the first reset spring 432, one end of the first reset spring 432 is fixedly connected with the groove II, the other end of the first reset spring 432 is fixedly connected with the second sliding block 435, the second sliding block 435 is in sliding connection with the inner side of the groove IV, the outer side wall of the second sliding block 435 is fixedly connected with the anti-sliding block 433, and the outer side wall of the second sliding block 435 is fixedly connected with the anti-blocking plate 431.

The automatic blackboard eraser 500 comprises a shell 520, two ends of the shell 520 are rotatably connected with a first gear 510, the first gear 510 is meshed with a gear groove 450 for transmission, the automatic blackboard eraser 500 can smoothly move in a first concave plate 440 and a second concave plate 460, a third motor is fixedly connected to the inner side of the shell 520, the first gear 510 is fixedly connected with a motor shaft of the third motor, a third groove is formed in the bottom surface of the shell 520, a cloth strip 560 is arranged in the third groove, four corners of the cloth strip 560 are fixedly connected with one ends of an electric telescopic rod 570, the other ends of the electric telescopic rod 570 are fixed inside the shell 520, the up-and-down movement of the cloth strip 560 is controlled by the electric telescopic rod 570, so that the automatic blackboard eraser 500 can erase characters in the way in the moving process, thereby guarantee can the targeted erasing characters, two square grooves are offered to shell 520 bottom, square inslot fixedly connected with motor four, motor shaft fixedly connected with pulley 530 of motor four, pulley 530 rotates with square groove inner wall to be connected, through two motor four control pulley 530 rotations, realize that shell 520 can go straight and rotate on blackboard 100, the circular slot is offered to shell 520 bottom, the embedded fixedly connected with electro-magnet 550 of top surface in the circular slot, produce suction between through electro-magnet 550 and blackboard 100, thereby avoid automatic blackboard eraser 500 to drop on vertically blackboard 100, four bull's eye wheel 540 of shell 520 bottom fixedly connected with, make things convenient for automatic blackboard eraser 500 smooth movement on blackboard 100 through bull's eye wheel 540.

The automatic blackboard eraser 500 is provided with the marking pen 600 in a matched mode, the marking pen 600 comprises a pen cover 610, a rotating block two 620 is fixedly connected to the inner portion of the pen cover 610, a pen shell 630 is rotatably connected to the bottom of the pen cover 610, three round holes two are formed in the rotating block two 620, a pen core 670 is slidably connected to the inner portion of the round holes two, a pen point 640 is fixedly connected to the bottom of the pen core 670, the pen point 640 can write on the blackboard 100 through the pen point 640, a fixing block 660 is fixedly sleeved on the outer wall of the bottom of the pen core 670, a convex column is fixedly connected to the outer wall of the fixing block 660, a hollow cylinder 650 is rotatably connected to the outer wall of the bottom end of the pen shell 630, an inclined pen point 652 is fixedly connected to the bottom of the hollow cylinder 650, a through hole is formed in the end portion of the inclined pen point 652, a guide groove 651 is formed in the inner wall of the hollow cylinder 650, the convex column is in annular shape with the guide groove 651, the through hole position of the guide groove 651 is arranged into a V-shaped structure inclined downwards through the through hole, when the hollow cylinder 650 is rotated, the hollow cylinder 640 can be driven to extend to the outside the through hole, and writing can be performed, a reset spring two is arranged between the top of the pen core 670 and the inner wall of the pen core 670, the bottom is fixedly connected to the hollow cylinder 670, the inclined through the fixing spring and the rotary pen point 640, when the black pen point and the black pen point 100, the black pen core can be written, and the black pen core and the black ink can be different from the black to the black and the black pen core.

The four corners of the blackboard 100 are all fixed with electromagnetic induction plates, induction coils are arranged in the electromagnetic induction plates, electromagnetic elements are arranged in the marking pen 600, when a required wiping area needs to be marked, the induction coils in the electromagnetic induction plates are utilized to record the signal size of the position of the marking pen 600, then the same signal is recorded according to the characteristics of electromagnetic coils along with the attenuation of the distance, circles with the electromagnetic induction plates as the center of circles are drawn, the positions of the marking pen 600 are determined through the intersection points of the circles at the four positions, when the marking pen 600 is wiped, the automatic blackboard eraser 500 wipes the appointed marking area according to the position signals, meanwhile, when a daily blackboard writing is carried out, writing contents can be directly converted into picture text information through the electromagnetic elements of the electromagnetic induction plates and the marking pen 600, and recording of the daily teaching contents is convenient.

Working principle: when a teacher fills all the blackboard and needs to wipe the blackboard to take a new position, as the marker pen 600 is provided with an electromagnetic element, a switch of the electromagnetic element is turned on, the switch is embedded and fixed on the outer wall of the pen shell 630, then the erasing area selected by the frame is written, electromagnetic signals are induced by electromagnetic induction plates at four corners of the blackboard 100, so that the position of the marker pen 600 above the blackboard 100 is determined, when the information of the area needing to be erased on the blackboard 100 is obtained, the automatic blackboard erasing device starts to operate, the first threaded rod 340 is driven to rotate by the first motor 310, because the first threaded rod 340 is screwed and connected with the first sliding block 320, when the first threaded rod 340 rotates, the first sliding block 320 moves up and down along with the movement of the first sliding block, so that the movable platform 400 also moves up and down, when the designated position is reached, the first motor 310 stops rotating by controlling the first gears 510 at both sides of the housing 520, the motor III in the automatic blackboard eraser 500 is controlled to rotate, the motor III in the automatic blackboard eraser 500 drives the gear I510 to rotate, the first concave plate 440, the second concave plate 460 and the third concave plate 470 are provided with the gear grooves 450, when the gear I510 rotates, the automatic blackboard eraser 500 is driven to move outwards, when the motor II moves into the first concave plate 440, the motor II starts to drive the rotating block III to rotate, the rotating block III is fixedly connected with the second concave plate 460, the second concave plate 460 also rotates along with the first concave plate 460 which is rotationally connected with the second concave plate 460 through a hinge, the first concave plate 440 starts to contact with the blackboard 100 along with the continuous rotation of the second concave plate 460, the first concave plate 440 is stressed to rotate upwards until the second concave plate 460 contacts with the blackboard 100, the motor II stops driving the rotating block III to rotate, at the moment, the first concave plate 440 is attached to the blackboard 100, the gear I510 is continuously rotated, the automatic blackboard eraser 500 reaches the surface of the blackboard 100, the electromagnet 550 is used for adsorbing the blackboard 100, the automatic blackboard eraser 500 can be fixed on the blackboard 100, the motor four driving pulleys 530 rotate, the four bull's eye wheels 540 at the bottom of the automatic blackboard eraser 500 are used for assisting in moving the automatic blackboard eraser 500, the two motors four can control the rotating speed difference to realize left and right movement of the automatic blackboard eraser 500, when reaching a positioning place, the electric telescopic rod 570 extends outwards to drive the wiping cloth strip 560 to extend outwards, and at the moment, the automatic blackboard eraser 500 moves back and forth to perform wiping work.

After the wiping operation is completed, the automatic blackboard eraser 500 returns to the initial position, the automatic blackboard eraser 500 is moved into the concave plate one 440 by rotating the gear one 510, the motor two 410 drives the rotating block to rotate to the original position, and when the rotating block rotates back to the original position, the automatic blackboard eraser 500 is continuously rotated by the gear one 510, so that the automatic blackboard eraser 500 is moved to the center position of the concave plate two 460. In this way, all positions on the blackboard 100 can be easily wiped, so that time waste of teachers on wiping the blackboard 100 is avoided, and the teaching arrangement of the teachers is disturbed.

In the description of the present specification, the descriptions of the terms "one embodiment," "example," "specific example," and the like, mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is merely illustrative and explanatory of the invention, as various modifications and additions may be made to the particular embodiments described, or in a similar manner, by those skilled in the art, without departing from the scope of the invention or exceeding the scope of the invention as defined in the claims.

Claims (9)

1. The automatic blackboard erasing device is characterized by comprising a sliding rail (300), wherein a moving platform (400) is connected inside the sliding rail (300) in a sliding way, and an automatic blackboard eraser (500) is arranged in the moving platform (400);

the sliding track (300) comprises a sliding groove plate (330), the sliding groove plate (330) is fixedly connected with a support (200), one end of the outer side wall of the sliding groove plate (330) is fixedly connected with a first motor (310), the output end of the first motor (310) is in transmission connection with a first threaded rod (340), the first threaded rod (340) is in screwed connection with a first sliding block (320), the first threaded rod (340) is in rotary connection with the inner bottom of the sliding groove plate (330), and the first sliding block (320) is fixedly connected with a mobile platform (400).

2. The automatic blackboard erasing device according to claim 1, wherein the moving platform (400) comprises a first rotating block (420), the bottom of the first rotating block (420) is fixedly connected with a first sliding block (320), a third rotating block (420) is rotatably connected to the middle of the first rotating block, one end of the outer side wall of the first rotating block (420) is fixedly connected with a second motor (410), a motor shaft of the second motor (410) is fixedly connected with the third rotating block, the top surface of the third rotating block is fixedly connected with a second concave plate (460), two sides of the second concave plate (460) are rotatably connected with a first concave plate (440) through hinges, a first groove is formed in the middle of the second concave plate (460), an inner wall of the first groove is rotatably connected with a third concave plate (470) through hinges, and gear grooves (450) are formed in the inner bottom surfaces of the first concave plate (440), the second concave plate (460) and the third concave plate (470).

3. The automatic blackboard erasing device according to claim 2, wherein the second concave plate (460) is internally provided with a second groove, the second groove is internally provided with a fixer (430), the third concave plate (470) is fixed in the second concave plate (460) through the fixer (430), the outer side wall of the third concave plate (470) is provided with a fourth groove, and the fourth groove is in sliding connection with the fixer (430).

4. An automatic blackboard erasing device according to claim 3, wherein the fixer (430) includes a first return spring (432), one end of the first return spring (432) is fixedly connected with a second groove, the other end of the first return spring (432) is fixedly connected with a second sliding block (435), the second sliding block (435) is slidably connected with a fourth groove, a lock tongue (434) is fixedly connected with the center of the outer side of the second sliding block (435), the lock tongue (434) is slidably connected with the fourth groove, an anti-slip block (433) is fixedly connected with the outer side wall of the second sliding block (435), and a shielding plate (431) is fixedly connected with the outer side of the second groove.

5. The automatic blackboard erasing device according to claim 4, wherein the automatic blackboard erasing device (500) comprises a housing (520), a first gear (510) is rotatably connected to two ends of the housing (520), a third motor is fixedly connected to the inner side of the housing (520), the first gear (510) is fixedly connected to a motor shaft of the third motor, a third groove is formed in the bottom surface of the housing (520), a cloth erasing strip (560) is arranged in the third groove, one end of an electric telescopic rod (570) is fixedly connected to four corners of the cloth erasing strip (560), the other end of the electric telescopic rod (570) is fixed inside the housing (520), two square grooves are formed in the bottom of the housing (520), a fourth motor is fixedly connected to a fourth motor shaft of the fourth motor, a pulley (530) is rotatably connected to the inner wall of the square grooves, a round groove is formed in the bottom of the housing (520), and an electromagnet (550) is fixedly connected to the top surface of the round groove in an embedded mode.

6. An automatic blackboard erasing device according to claim 5, wherein the bottom of the casing (520) is fixedly connected with four bullseye wheels (540).

7. The automatic blackboard erasing device according to claim 6, wherein the automatic blackboard erasing device (500) is provided with a marking pen (600) in a matching way, the marking pen (600) comprises a pen cover (610), a second rotating block (620) is fixedly connected to the inner portion of the pen cover (610), a second pen shell (630) is rotatably connected to the bottom portion of the pen cover (610), three second round holes are formed in the second rotating block (620), a pen core (670) is slidably connected to the second round holes, a pen point (640) is fixedly connected to the bottom portion of the pen core (670), a fixing block (660) is fixedly connected to the outer wall of the bottom portion of the pen core (670) in a sleeved mode, a convex column is fixedly connected to the outer wall of the fixing block (660), a hollow cylinder (650) is rotatably connected to the outer wall of the bottom end portion of the pen shell (630), a diagonal pen head (652) is fixedly connected to the bottom portion of the hollow cylinder (650), a through hole is formed in the end portion of the diagonal pen head (652), a guide groove (651) is formed in the inner wall of the hollow cylinder (650), and the convex column is slidably connected to the guide groove (651).

8. The automatic blackboard erasing device according to claim 7, wherein a second return spring is provided between the inner top of the pen case (630) and the pen core (670).

9. An automatic blackboard erasing device according to claim 7, characterized in that the three pen cores (670) are respectively filled with three erasable inks of red, black and blue.