CN110802971B

CN110802971B - Automatic reversing dust collecting blackboard eraser

Info

Publication number: CN110802971B
Application number: CN201911129961.1A
Authority: CN
Inventors: 张帆; 韩丁锐; 薛超凡; 田俊梅
Original assignee: Shanxi University
Current assignee: Shanxi University
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2024-08-27
Anticipated expiration: 2039-11-18
Also published as: CN110802971A

Abstract

The invention belongs to the technical field of blackboard erasers, and particularly relates to an automatic reversing dust collection blackboard eraser, which comprises a shell, a working mechanism and a dust collection box, wherein the working mechanism comprises a first rotating shaft, a second rotating shaft and a second fixed shaft, two ends of the first rotating shaft are respectively and rotatably arranged on a top plate and a bottom plate of the shell, a second swinging rod and a first swinging rod are respectively and fixedly arranged on the upper part and the lower part of the first rotating shaft, and the other end of the second swinging rod penetrates through the front wall of the shell and is rotatably connected with a mounting plate; the invention is provided with the baffle which can extend or retract along with automatic reversing, so as to assist dust to fall into the bearing piece, thereby improving the dust collection effect.

Description

Automatic reversing dust collecting blackboard eraser

Technical Field

The invention belongs to the technical field of blackboard eraser, and particularly relates to a dust collection blackboard eraser capable of automatically reversing.

Background

In China, chalk is still a necessary tool for teaching teachers, almost all teachers use the traditional chalk for teaching, and the damage caused by dust of the chalk is not negligible. The chalk consists of calcium carbonate and calcium sulfate, and a great amount of chalk dust is generated when a teacher uses the chalk. Because the dust can not be dispersed as soon as possible, the dust floats in the air, and the health of teachers and students is endangered. Meanwhile, the manufacturing and the use of chalks also cause a plurality of environmental pollution problems, so that the design of the blackboard eraser capable of collecting dust is an urgent requirement.

Based on the above, a large number of dust-removing blackboard erasers, such as electric blackboard erasers, electrostatic dust-removing blackboard erasers, etc., are now on the market. However, it requires battery consumption energy and causes "battery pollution", which causes more serious damage to the environment and requires higher cost. The collection effect is not good through specific use, and the principle of the dust collector utilizes wind power to generate negative pressure so as to achieve the purpose of absorbing dust. The collection effect is not good because of its small negative pressure.

Patent number 201821799665.3 discloses a mechanical dust collection type different-side transfer blackboard eraser, which can carry out mechanical dust collection, but the blackboard eraser on the left side and the right side can not continuously carry out blackboard erasing work because a handle is required to be stirred for changing the direction each time, and great inconvenience is caused.

Disclosure of Invention

The invention provides a dust collecting blackboard eraser capable of automatically reversing according to the problems.

The invention adopts the following technical scheme to achieve the aim:

The utility model provides an automatic reversing dust collecting blackboard eraser, includes casing, operating mechanism and dust collecting box, operating mechanism includes a pivot, no. two pivots and No. two dead axles, the both ends of a pivot are rotatable respectively and are set up on the roof and the bottom plate of casing the upper portion and the lower part of a pivot are fixed respectively and are provided with No. two swinging arms and No. one swinging arm, the other end of No. two swinging arms is passed the rotatable mounting panel that is connected with of the front wall of casing be provided with the silver on the mounting panel, the other end of No. one swinging arm is hollow structure, is provided with a slide bar in the hollow structure of No. one swinging arm, the other end of No. one slide bar articulates the middle part at No. one U type spare, no. two pivot run through No. two tip settings of U type spare No. two spacing rings are provided with in No. two pivots, the U-shaped piece is limited to move relative to the second rotating shaft, two ends of the second rotating shaft are rotatably arranged on the left side wall and the right side wall of the supporting piece, the bottom of the supporting piece is obliquely arranged, the supporting piece is arranged at the bottom of the front surface of the shell, the second fixed shaft is fixedly arranged on the front surface of the shell, the second fixed shaft is positioned below the mounting plate, a first bevel gear is rotatably arranged on the second fixed shaft, the edge of the first bevel gear is aligned with the front surface of the cotton sliver, two second bevel gears corresponding to the first bevel gear are fixedly arranged on the second rotating shaft, the two second bevel gears are oppositely arranged, brushes are fixedly arranged on two sides of the second rotating shaft, the dust collecting box is a box body with an open front surface, the dust collecting box is positioned at the front end of the inner side of the bottom plate of the shell and communicated with the supporting piece, an opening for the movement of the second swing rod and the first slide rod is arranged on the front wall of the shell.

Further, the inside dead axle that still fixedly is provided with of casing the rotatable T type connecting piece that is provided with of dead axle the front portion of T type connecting piece is provided with a spout be provided with No. two U type spare in the spout, no. two U type spare's both ends and a pivot fixed connection, the left and right sides both ends of T type connecting piece are hollow structure be provided with No. two slide bars in the hollow structure of T type connecting piece, no. two the other end of slide bar articulates on the baffle, the baffle sets up in No. two spouts on the lateral wall about the casing for stop the dust so that the dust falls on the receiver.

Still further, a positioning plate is arranged on the inner side of the second chute to limit the baffle plate to move in the second chute only; the part of the second slide bar, which is close to the baffle, is provided with a limiting block, the second slide bar is sleeved with a first spring, and the first spring is positioned between the limiting block and the T-shaped connecting piece to assist the second slide bar to extend out.

Furthermore, the cotton cloth is arranged on the front side edge of the baffle plate so as to prevent the hard contact friction between the baffle plate and the blackboard from damaging the blackboard, and the blackboard can be wiped for the second time.

Further, a rubber edge is arranged on the front side edge of the bearing piece so as to prevent the hard friction between the bearing piece and the blackboard from damaging the blackboard.

Still further, the back fixedly connected with No. three pivots of mounting panel be provided with the shaft hole that is used for installing No. three pivots on the swinging arms No. two the opening of 20 degrees has been seted up on the shaft hole for No. three pivots are connected with the mounting panel, and restrict the rotation angle of mounting panel.

Still further the inside of dust collection box is provided with the ejector pad, the both sides opening of dust collection box sets up limiting plate and storage device respectively in both sides opening part still be provided with the case on the casing the activity is provided with the push rod in the case, the push rod can pass the limiting plate and be connected with the ejector pad to control the ejector pad is with the dust propelling movement in the dust collection box to storage device in.

Furthermore, a cross limiting piece is arranged at the front end of the push rod, the push block sequentially consists of a cotton cloth layer, a plastic layer and an iron block layer, the cotton cloth layer is used for being in direct contact with dust, a limiting opening is arranged at the outer side of the iron block layer, a rotating cavity communicated with the limiting opening is arranged at the inner side of the iron block layer, and a through hole for accommodating the end head of the cross limiting piece is formed in the plastic layer; the limiting plate is a magnet.

Still further, storage device includes storage box, transition box, support, control panel, push pedal and sliding door, transition box and support are fixed on the casing lateral wall, just transition box communicates with each other with the dust collection box, the storage box activity is placed on the support, and communicates with transition box threaded connection has the screw on one of them lateral wall of support for fix the transition box the position that is close to the storage box on the transition box is provided with No. three spouts be provided with the sliding door in the No. three spouts, the sliding door can slide into inside the casing one side that the casing was kept away from to the sliding door upper surface is provided with the spliced pole be provided with the gyro wheel on the spliced pole transition box upper surface is provided with No. four spouts, the control panel sets up in the top of transition box, the width of control panel is the same with the width of transition box, and the side of control panel control spliced pole is the slope setting, the setting is in the transition box be connected with and L type pole on the push pedal, L type pole passes No. four spouts and is connected with the control panel the top of control panel.

Still further be provided with spacing strip in the casing inside, form the spacing groove that carries out spacing to the sliding door between spacing strip and the back wall of dust collection box the sliding door is close to one side of casing and is provided with No. two springs, no. two spring's the other end and casing internal connection to reset the sliding door.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, the automatic reversing is realized through the relative displacement of the shell relative to the cotton sliver and the mounting plate, and the left-right automatic reversing is realized on the basis of mechanical dust collection, so that the blackboard erasing efficiency is increased;

2. The invention is provided with the baffle which can extend or retract along with automatic reversing, so as to assist dust to fall into the bearing piece, thereby improving the dust collection effect.

Drawings

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

FIG. 2 is a schematic view of the structure of the invention without the housing and dust box;

FIG. 3 is a schematic view of the structure of the invention without the housing and dust box;

FIG. 4 is a schematic view of the structure of the present invention with the top, rear and right side walls of the housing removed;

FIG. 5 is a schematic illustration of the connection of a second swing arm and a mounting plate of the present invention;

FIG. 6 is an enlarged view of a portion of circle B of FIG. 4 in accordance with the present invention;

FIG. 7 is a schematic diagram of a push block according to the present invention;

FIG. 8 is a schematic diagram of a storage device according to the present invention;

FIG. 9 is a schematic diagram of a storage device according to the present invention;

FIG. 10 is an enlarged view of a portion of circle A of FIG. 4 in accordance with the present invention;

FIG. 11 is a schematic view of a putter in accordance with the present invention;

Wherein the shell-1, the dust collecting box-2, the first rotating shaft-3, the second rotating shaft-4, the second fixed shaft-5, the second swinging rod-6, the first swinging rod-7, the mounting plate-8, the cotton sliver-9, the first sliding rod-10, the first U-shaped piece-11, the L-shaped rod-12, the ring-13, the bearing piece-14, the limiting block-15, the first bevel gear-16, the second bevel gear-17, the brush-18, the first fixed shaft-19, the T-shaped connecting piece-20, the first sliding groove-21, the second U-shaped piece-22, the second sliding rod-23, the baffle-24, the second sliding groove-25, the positioning plate-26, the first spring-27, the third rotating shaft-28, the shaft hole-29 push block-30, limit plate-31, storage device-32, storage box-33, push rod-34, cross limit piece-35, cotton cloth layer-36, plastic layer-37, iron block layer-38, limit opening-39, rotary cavity-40, through hole-41, storage box-42, transition box-43, bracket-44, control panel-45, push plate-46, sliding door-47, screw-48, runner-49, connecting column-50, roller-51, runner-52, control block-53, limit bar-54, limit groove-55, spring-56, plug-57, plunger rod-58, cylinder-59, sensing bump-60, pushing hand-61.

Detailed Description

In order to further illustrate the technical scheme of the invention, the invention is further illustrated by the following examples.

As shown in fig. 1 to 11, an automatic reversing dust collecting blackboard eraser comprises a shell 1, a working mechanism and a dust collecting box 2, wherein the working mechanism comprises a first rotating shaft 3, a second rotating shaft 4 and a second fixed shaft 5, two ends of the first rotating shaft 3 are respectively and rotatably arranged on a top plate and a bottom plate of the shell 1, a second swinging rod 6 and a first swinging rod 7 are respectively and fixedly arranged on the upper part and the lower part of the first rotating shaft 3, the other end of the second swinging rod 6 penetrates through the front wall of the shell 1 and is connected with a mounting plate 8, the back surface of the mounting plate 8 is fixedly connected with a third rotating shaft 28, a shaft hole 29 for mounting the third rotating shaft 28 is arranged on the second swinging rod 6, The third rotating shaft 28 is disposed in the shaft hole 29, and an opening of 20 degrees is formed in the shaft hole 29, so that the third rotating shaft 28 is connected with the mounting plate 8, and the rotation angle of the mounting plate 8 is limited. The cotton sliver 9 is arranged on the mounting plate 8, the other end of the first swinging rod 7 is of a hollow structure, a first sliding rod 10 is arranged in the hollow structure of the first swinging rod 7, the other end of the first sliding rod 10 is hinged to the middle of a first U-shaped piece 11, the second rotating shaft 4 penetrates through two end parts of the first U-shaped piece 11, two limiting rings 13 are arranged on the second rotating shaft 4 to limit the first U-shaped piece 11 to move relative to the second rotating shaft 4, two ends of the second rotating shaft 4 are rotatably arranged on the left side wall and the right side wall of a supporting piece 14, the bottom of the supporting piece 14 is obliquely arranged, the supporting piece 14 is arranged at the bottom of the front surface of the shell 1, The front side of the supporting piece 14 is provided with a rubber edge, the second fixed shaft 5 is fixedly arranged on the front surface of the shell 1, the second fixed shaft 5 is positioned below the mounting plate 8, the second fixed shaft 5 is rotatably provided with a first bevel gear 16, the edge of the first bevel gear 16 is aligned with the front surface of the cotton sliver 9, the second rotating shaft 4 is fixedly provided with two second bevel gears 17 corresponding to the first bevel gear 16, the two second bevel gears 17 are oppositely arranged, the two sides of the second rotating shaft 4 are fixedly provided with brushes 18, the dust collecting box 2 is a box body with an open front surface, the dust collecting box 2 is positioned at the front end of the inner side of the bottom plate of the shell 1, And communicates with the receiving member 14, a pushing block 30 is arranged in the dust collecting box 2, two sides of the dust collecting box 2 are opened, a limiting plate 31 and a storage device 32 are respectively arranged at the openings of the two sides, a storage box 33 is also arranged on the shell 1, a pushing rod 34 is movably arranged in the storage box 33, the pushing rod 34 comprises a cylinder 59, a plunger rod 58, a plug 57 and a pushing handle 61, the plug 57 and the pushing handle 61 are respectively arranged at two ends of the plunger rod 58, the plug 57 is positioned in the cylinder 59, a cross limiting piece 35 is arranged at the front end of the cylinder 59, the end of the cross limiting piece 35 is an injection hole, The plunger rod 58 is uniformly provided with a plurality of sensing protruding points 60, a circle of corresponding sensing protruding points 60 are annularly arranged in the middle of the inner wall of the cylinder wall, the sensing protruding points 60 are made of elastic materials, such as rubber, and the cross limiting piece 35 of the push rod 34 can penetrate through the limiting plate 31 to be connected with the push block 30. The front end of the push rod 34 is provided with a cross limiting piece 35, the push block 30 sequentially comprises a cotton cloth layer 36, a plastic layer 37 and an iron block layer 38, the cotton cloth layer 36 is used for being in direct contact with dust, a limiting opening 39 is formed in the outer side of the iron block layer 38, a rotating cavity 40 communicated with the limiting opening 39 is formed in the inner side of the iron block layer 38, and a through hole 41 for accommodating the end head of the cross limiting piece 35 is formed in the plastic layer 37; the limiting plate 31 is a magnet. The storage device 32 comprises a storage box 42, a transition box 43, a bracket 44, a control board 45, a push plate 46 and a sliding door 47, wherein the transition box 43 and the bracket 44 are fixed on the side wall of the shell 1, the transition box 43 is communicated with the dust collection box 2, the storage box 42 is movably arranged on the bracket 44 and is communicated with the transition box 43, one side wall of the bracket 44 is in threaded connection with a screw 48 for fixing the transition box 43, a third sliding chute 49 is arranged on the transition box 43 near the storage box 42, the sliding door 47 is arranged in the third sliding chute 49, the sliding door 47 can slide into the shell 1, The sliding door 47 upper surface is provided with the spliced pole 50 far away from one side of casing 1 be provided with gyro wheel 51 on the spliced pole 50 the transition box 43 upper surface is provided with No. four spout 52, control panel 45 sets up the top at transition box 43, the width of control panel 45 is the same with the width of transition box 43, and the side of control panel 45 control spliced pole 50 is the slope setting, push pedal 46 sets up in transition box 43, and passes No. four spout 52 and be connected with control panel 45 the top of control panel 45 is provided with control block 53. A limit bar 54 is arranged in the shell 1, a limit groove 55 for limiting the sliding door 47 is formed between the limit bar 54 and the rear wall of the dust box 2, a second spring 56 is arranged on one side, close to the shell 1, of the sliding door 47, and the other end of the second spring 56 is connected with the interior of the shell 1 so as to reset the sliding door 47. An opening for allowing the second swing rod 6 and the first slide rod 10 to move is arranged on the front wall of the shell 1. A first fixed shaft 19 is fixedly arranged in the shell 1, a T-shaped connecting piece 20 is rotatably arranged on the first fixed shaft 19, a first sliding groove 21 is arranged at the front part of the T-shaped connecting piece 20, a second U-shaped piece 22 is arranged in the first sliding groove 21, two ends of the second U-shaped piece 22 are fixedly connected with a first rotating shaft 3, the left end and the right end of the T-shaped connecting piece 20 are hollow structures, a second sliding rod 23 is arranged in the hollow structure of the T-shaped connecting piece 20, the other end of the second sliding rod 23 is hinged on a baffle 24, the baffle 24 is arranged in a second sliding groove 25 on the left side wall and the right side wall of the shell 1, For blocking dust so that it falls onto the receptacle 14. A cotton cloth is arranged on the front side of the baffle 24 to prevent the hard contact friction between the baffle 24 and the blackboard from damaging the blackboard, and the blackboard can be wiped for the second time. A positioning plate 26 is arranged on the inner side of the second chute 25 to limit the baffle 24 to move only in the second chute 25; the second slide bar 23 is provided with a limiting block 15 at a position close to the baffle 24, the second slide bar 23 is sleeved with a first spring 27, and the first spring 27 is positioned between the limiting block 15 and the T-shaped connecting piece 20 to assist the second slide bar 23 to extend out.

Working principle: when the cotton sliver is used for erasing a blackboard, the first rotating shaft 3 is rotatably arranged in the shell 1, so that the shell 1 rotates relative to the mounting plate 8 until the second swinging rod 6 contacts the side edge of the opening, meanwhile, the first swinging rod 7 rotates along with the first rotating shaft 3 and finally drives the corresponding second bevel gear 17 to be meshed with the first bevel gear 16, specifically, when the mounting plate 8 is deflected to the right side of the shell 1, the second swinging rod 6 simultaneously drives the left second bevel gear 17 to be meshed with the first bevel gear 16, the first bevel gear 16 is rotated clockwise from right to left, the first bevel gear 16 is driven to rotate by the second bevel gear 17, finally, the brush 18 is driven to brush dust into the dust collecting box 2, the push rod 34 is taken out to stretch into the push block 30 when the dust is collected, the push rod 34 can push out of the push block 30, the push rod 58 is pushed back to move a distance of an induction bump, a certain cotton cloth soaking layer 36 is driven from the right, then the push block 30 is pushed to push the push block 30, the push block is pushed back to be in a transition state, the push block 45 is pushed back to the push block 45, the push block 45 is pushed back to the dust collecting box, and then the push block 45 is pushed back to the dust box 45 is pushed to the dust collecting box 45, and then the dust box is pushed to be compressed to the dust box 45 is pushed to the dust box 45, and the dust box is stored in the control plate 45 is pushed 45, and then the control plate 45 is pushed to the dust box is pushed 45 to 45.

While the principal features and advantages of the present invention have been shown and described, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing exemplary embodiments, but that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims

1. An automatic reversing dust collecting blackboard eraser is characterized in that: the dust collector comprises a shell (1), a working mechanism and a dust collection box (2), wherein the working mechanism comprises a first rotating shaft (3), a second rotating shaft (4) and a second fixed shaft (5), two ends of the first rotating shaft (3) are respectively and rotatably arranged on a top plate and a bottom plate of the shell (1), a second swinging rod (6) and a first swinging rod (7) are respectively and fixedly arranged at the upper part and the lower part of the first rotating shaft (3), the other end of the second swinging rod (6) penetrates through a front wall of the shell (1) and is rotatably connected with a mounting plate (8), a third rotating shaft (28) is fixedly connected to the back surface of the mounting plate (8), a shaft hole (29) for mounting the third rotating shaft (28) is arranged on the second swinging rod (6), an opening of 20 degrees is formed in the shaft hole (29) so that the third rotating shaft (28) is connected with the mounting plate (8), the rotating angle of the mounting plate (8) is limited, a second swinging rod (9) is arranged on the 8), the other end of the first swinging rod (7) penetrates through the front wall of the shell (1), a hollow part (10) is arranged in the middle part (11) of the second sliding rod (4), a hollow part (11) is arranged at the other end part of the second sliding rod (11), two limiting rings (13) are arranged on the second rotating shaft (4) to limit the first U-shaped part (11) to move relative to the second rotating shaft (4), two ends of the second rotating shaft (4) are rotatably arranged on the left side wall and the right side wall of the supporting part (14), the bottom of the supporting part (14) is obliquely arranged, the supporting part (14) is arranged at the bottom of the front surface of the shell (1), the front side edge of the supporting part (14) is provided with a rubber edge to prevent the hard friction between the supporting part (14) and a blackboard from damaging a blackboard, the second fixed shaft (5) is fixedly arranged on the front surface of the shell (1), the second fixed shaft (5) is positioned below the mounting plate (8), a first bevel gear (16) is rotatably arranged on the second fixed shaft (5), the edge of the first bevel gear (16) is aligned with the front surface of the cotton sliver (9), two second bevel gears (17) corresponding to the first bevel gears (16) are fixedly arranged on the second rotating shaft (4), the second bevel gears (17) are fixedly arranged on the second bevel gears (16) and are opposite to the front surface of the shell (1), the second bevel gears (17) are arranged on the front end of the second fixed shaft (2) and are opposite to the front end of the first dust collecting box (2), the front wall of the shell (1) is provided with an opening for the movement of a second swinging rod (6) and a first sliding rod (10).

2. An automatically commutated dust collecting blackboard eraser according to claim 1, characterized in that: the novel dust collector is characterized in that a fixed shaft (19) is fixedly arranged inside the shell (1), a T-shaped connecting piece (20) is rotatably arranged on the fixed shaft (19), a first sliding groove (21) is formed in the front portion of the T-shaped connecting piece (20), a second U-shaped piece (22) is arranged in the first sliding groove (21), two ends of the second U-shaped piece (22) are fixedly connected with a first rotating shaft (3), the left end and the right end of the T-shaped connecting piece (20) are hollow structures, a second sliding rod (23) is arranged in the hollow structures of the T-shaped connecting piece (20), the other end of the second sliding rod (23) is hinged to a baffle (24), and the baffle (24) is arranged in the second sliding groove (25) on the left side wall and the right side wall of the shell (1) and used for blocking dust to fall on the bearing piece (14).

3. An automatically commutated dust collecting blackboard eraser according to claim 2, characterized in that: a positioning plate (26) is arranged on the inner side of the second chute (25) so as to limit the baffle (24) to move in the second chute (25); a limiting block (15) is arranged on the second sliding rod (23) close to the baffle plate (24), a first spring (27) is sleeved on the second sliding rod (23), and the first spring (27) is located between the limiting block (15) and the T-shaped connecting piece (20) to assist the second sliding rod (23) to extend out.

4. An automatically commutated dust collecting blackboard eraser according to claim 2, characterized in that: the front side of the baffle plate (24) is provided with cotton cloth so as to prevent the blackboard from being damaged by hard contact friction between the baffle plate (24) and the blackboard, and the blackboard can be wiped secondarily.

5. An automatically commutated dust collecting blackboard eraser according to claim 1, characterized in that: the dust collecting box is characterized in that a pushing block (30) is arranged in the dust collecting box (2), two sides of the dust collecting box (2) are provided with openings, a limiting plate (31) and a storage device (32) are respectively arranged at the openings of the two sides, a storage box (33) is further arranged on the shell (1), a pushing rod (34) is movably arranged in the storage box (33), the pushing rod (34) can penetrate through the limiting plate (31) to be connected with the pushing block (30), and the pushing block (30) is controlled to push dust in the dust collecting box (2) into the storage device (32).

6. An automatically commutated dust collecting blackboard eraser according to claim 5, characterized in that: the front end of the push rod (34) is provided with a cross limiting piece (35), the push block (30) sequentially consists of a cotton cloth layer (36), a plastic layer (37) and an iron block layer (38), the cotton cloth layer (36) is used for being in direct contact with dust, a limiting opening (39) is formed in the outer side of the iron block layer (38), a rotating cavity (40) communicated with the limiting opening (39) is formed in the inner side of the iron block layer (38), and a through hole (41) for accommodating the end head of the cross limiting piece (35) is formed in the plastic layer (37); the limiting plate (31) is a magnet.

7. An automatically commutated dust collecting blackboard eraser according to claim 5, characterized in that: the storage device (32) comprises a storage box (42), a transition box (43), a bracket (44), a control board (45), a push plate (46) and a sliding door (47), wherein the transition box (43) and the bracket (44) are fixed on the side wall of the shell (1), the transition box (43) is communicated with the dust collecting box (2), the storage box (42) is movably placed on the bracket (44) and communicated with the transition box (43), one side wall of the bracket (44) is in threaded connection with a screw (48) for fixing the transition box (43), a third sliding groove (49) is arranged at the position, close to the storage box (42), of the transition box (43), the sliding door (47) is arranged in the third sliding groove (49), a connecting column (50) is arranged on one side, far away from the shell (1), of the upper surface of the sliding door (47), a roller (51) is arranged on the connecting column (50), a fourth sliding groove (52) is arranged on the upper surface of the transition box (43), the width of the transition box (43) is equal to the width of the control board (45), the side edge of the control connecting column (50) of the control board (45) is obliquely arranged, the push plate (46) is arranged in the transition box (43) and penetrates through the fourth sliding groove (52) to be connected with the control board (45), and a control block (53) is arranged above the control board (45).

8. An automatically commutated dust collecting blackboard eraser according to claim 7, characterized in that: a limit strip (54) is arranged inside the shell (1), a limit groove (55) for limiting the sliding door (47) is formed between the limit strip (54) and the rear wall of the dust box (2), a second spring (56) is arranged on one side, close to the shell (1), of the sliding door (47), and the other end of the second spring (56) is connected with the inside of the shell (1) so as to reset the sliding door (47).