CN115320275A

CN115320275A - Blackboard chalk groove

Info

Publication number: CN115320275A
Application number: CN202211043491.9A
Authority: CN
Inventors: 刘耕
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2022-11-11
Anticipated expiration: 2042-08-29
Also published as: CN115320275B

Abstract

The utility model relates to a teaching aid technical field specifically discloses blackboard chalk groove, including installing the chalk groove in the blackboard bottom, the middle part disconnection in chalk groove installs the collection box that is used for collecting chalk dust and vertical setting in two chalk groove disconnection departments, collects the one side that the box is close to the chalk inslot outside and installs the guard plate that is higher than the chalk groove, collects the box and comprises broken case and the liquid reserve tank of having placed water in advance, install the cross slab in broken case, open at the center around the cross slab and have the sieve mesh that is used for through chalk dust, have the blade group that is used for smashing the chalk point at the mid-mounting of cross slab, the blade group is installed in blade axle both sides, is equipped with in the bottom of blade axle and is used for driving blade axle pivoted power unit. The utility model discloses an aim at solves when carrying out the reutilization to the chalk head, the extrusion grinding of chalk end is too the problem that wastes time and energy.

Description

Blackboard chalk groove

Technical Field

The invention relates to the technical field of teaching aids, in particular to a blackboard chalk groove.

Background

In the campus, the blackboard is one of the most used teaching aids, and after the chalk writes the time on the blackboard for a long time, more chalk dust can be piled up in the chalk groove of blackboard bottom installation, and the chalk dust is piled up too much and can cause the harm to students' breathing health, so when doing daily cleaning work in the campus, the chalk dust in the chalk groove is one of clean object, and the clean mode to the chalk dust is in clearing up the garbage bin with the rag now. With the recent call of the action of 'green campus', students can make secondary use of waste, for example, waste paper is made into artwork ornaments, which not only exercises the practical ability of students, but also decorates the campus.

At the present stage, the secondary utilization of the chalk dust is little and little, and the discovery of the same students is that the chalk dust is collected, then the chalk dust is classified according to colors, a plurality of small bottle covers or pigment discs are found, the chalk dust is put in, a little water is poured, then the chalk dust is stirred and finally blended into thick paste, and the chalk dust is dried in the air, so that the self-made environment-friendly pigment is completed; or when the chalk dust is placed on a piece of paper and then blown to a required place during drawing, the effect of smoking can be achieved.

Students find that the collection majority of chalk dust can only be collected at the chalk inslot, there are more chalk ends in the chalk inslot, chalk end and chalk dust mix together, students need pick up the chalk end and take out, grind into chalk dust with the extrusion of chalk end again, when students grind the chalk end, put the chalk end in abandonment paper or abandonment pigment dish, use stone or hard billet extrusion chalk end, be powdered until the chalk end, the process that the chalk end ground is too strenuous to students, the finger can be damaged carelessly, the chalk dust that is infected with on the finger simultaneously can get into students's respiratory track, cause the damage to students's health.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a blackboard chalk groove which solves the problem that the extrusion grinding of a chalk end is too time-consuming and labor-consuming when the chalk end is secondarily utilized.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

the utility model provides a blackboard chalk groove, is including installing the chalk groove in the blackboard bottom, the middle part disconnection in chalk groove installs the collection box that is used for collecting chalk dust and vertical setting in chalk groove disconnection department, collects the box and installs the guard plate that is higher than the chalk groove near the one side in the chalk groove outside, collects the box and comprises broken case and the liquid reserve tank of having placed water in advance, install the cross slab in broken case, open at the center around the cross slab and have the sieve mesh that is used for through chalk dust, have the blade group that is used for smashing the chalk end at the mid-mounting of cross slab, the blade group is installed in blade axle both sides, is equipped with in the bottom of blade axle and is used for driving blade axle pivoted power unit.

The principle of the scheme is as follows: when chalk dust is too much in the chalk groove, use the rag to push into in the collection box body chalk end and chalk dust, then start the blade group, the blade group cuts up the chalk end of segment, the structure of the hand pulper of blade group formula of cutting up chalk end is similar, the chalk dust that the breakage finishes enters into the liquid reserve tank that is equipped with water in advance through the sieve mesh on the horizontal pole board, at this in-process, avoid classmates direct contact chalk end to carry out broken process, when having guaranteed operation safety, also avoided being stained with chalk dust on hand simultaneously, cause dirty.

The beneficial effect that this scheme produced is:

1. compared with the prior art that the chalk heads are ground by using stones or hard wood blocks, the grinding effect of the chalk heads is not good, the situation of uneven grinding can occur, and meanwhile, in the grinding process, the hand muscle is sour and swollen along with long-time grinding, so that the grinding efficiency is influenced; and now through setting up blade set in this application file, blade set can accomplish the breakage to the chalk in rotatory, has promoted the efficiency that the chalk end ground greatly, and can guarantee that the particle diameter of the back chalk of grinding is roughly the same through setting up the filter screen, and the inhomogeneous phenomenon of granule can not appear and produce.

2. The chalk dust is collected and then filled with water, and the mixture is uniformly stirred by using a wood stick, and the mixture needs to be continuously stirred for a long time when the mixture is uniformly stirred in the prior art; and at present through setting up the liquid reserve tank in this application file, can directly mix chalk dust and water in the liquid reserve tank, after mixing, can directly take off the liquid reserve tank, pour the liquid after will mixing and dry in the sun, saved the process that needs oneself to mix the stirring, avoid classmates oneself when mixing chalk dust and water, mix inhomogeneous phenomenon and produce, also promoted the efficiency of stirring simultaneously.

Further, a bobbin is connected to the center of the bottom of the transverse partition plate, the bobbin is a power mechanism, the bottom end of the bobbin and the bottom end of the blade shaft are mutually connected, meanwhile, a torsion spring is installed in the middle of the bobbin and the center of the bottom surface of the transverse partition plate, a pull rope is wound on the bobbin, a through pull wire hole is formed in one side wall of the crushing box, the pull rope penetrates through the pull wire hole and extends towards the outside of the side wall of the crushing box, a pull block is fixed to one end, extending out of the crushing box, of the pull rope, the pull block drives the pull rope to further drive the bobbin to rotate, the bobbin drives the blade group to rotate while rotating, when the pull rope is loosened, the bobbin returns the pull rope to an initial position under the action of the torsion spring, the blade group intermittently rotates through one pull, chalk dust can enter the liquid storage box through a sieve hole after the rotation of the blade group is stopped, the effect of driving through the pull rope is that the blade group intermittently rotates, the chalk head is crushed, and meanwhile, a brush can be driven to remove the chalk dust on the baffle, and the accumulation of the chalk dust can be collected when the pull rope is needed; chalk dust is when passing through the filter screen, and more dust can be piled up on the surface of filter screen, and through intermittent type nature's rotation, the brush can fall the dust brush on filter screen surface.

Further, there is the protecting wire cover at the lateral wall joint in stay cord hole, and the aperture that the stay cord hole is close to broken incasement portion one side is less than the aperture of keeping away from broken incasement portion one side simultaneously, and when the pulling stay cord, the chalk dust on the stay cord can scrape the chalk dust on the stay cord and fall in collecting the box under the effect in protecting wire cover and reducing hole.

Further, install on the top of blade axle because the flabellum that the guide chalk dust got into broken case, when the flabellum rotated, the air current from the outside entered into broken incasement, and the exhaust hole that is used for ventilating is installed at the lateral wall of broken case simultaneously, had the filter screen through bolted connection in the one side that the exhaust hole is close to broken incasement wall, through the rotation of flabellum, use the flabellum to inhale the chalk dust in collecting box, the exhaust hole can be got rid of the air current in the broken incasement, the filter screen avoids the chalk dust to be taken over out broken case.

Further, the bottom welding of broken case has the annular baffle of circle, and the middle part of baffle is to the bottom slope of broken case, and the baffle forms the circular cone tube-shape, and the chalk dust after the breakage can fall on the baffle, simultaneously because the exhaust effect is undertaken to the exhaust hole, the chalk dust can remove along with the air current, so can pile up a large amount of chalk dust at exhaust hole department ash, and the chalk dust can drop on the baffle at gravity, then in the liquid reserve tank along the inclined plane landing of baffle.

Further, bottom fixedly connected with connecting rod at the spool, install the brush that is used for cleaning baffle surface chalk dust in the both sides of connecting rod, the brush is parallel with the inclined plane of baffle, there is the chalk dust that has the difficult landing of part to adhere to on the baffle, need use the brush to brush away the chalk dust, the water in the liquid reserve tank can be avoided down to the baffle simultaneously and splashes to the surface of broken case under the effect of external force, in case there is moisture on the surface of broken case, the chalk dust can glue on the lateral wall, long time, along with the evaporation of moisture, the chalk dust can harden, more and more chalk dust is piled up to chalk dust on the chalk dust surface after the sclerosis, make the chalk dust volume that gets into in the liquid reserve tank will reduce.

Further, be used for stirring the stirring leaf of chalk dust and water in the bottom fixedly connected with of connecting rod, when the pulling stay cord, the connecting rod rotates, and the rotation that the connecting rod was followed to the stirring leaf mixes chalk dust and water in getting into the liquid reserve tank, through the speed of stay cord pulling, controls the slew velocity of stirring leaf, avoids stirring leaf speed too fast, produces the phenomenon that liquid splashes.

Further, pass through bolted connection in the bottom of broken case at the liquid reserve tank, install the transparent plastic panel that is used for observing the chalk dust and the water stirring condition on one side lateral wall of liquid reserve tank, can observe the mixed condition of chalk dust and water in the liquid reserve tank through transparent plastic panel, can observe the capacity of the mixed back liquid in the liquid reserve tank simultaneously, and then take off the liquid reserve tank, pour out the liquid that finishes mixing and sun-dry.

Furthermore, two transverse plates are welded on two sides of the top of the collecting box, holes for penetrating bolts are formed in the transverse plates, the collecting box is connected with the chalk groove through the bolts, the collecting box can be separated from the chalk groove after the bolts are taken down, and normal use of the chalk groove is not affected.

Drawings

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

FIG. 2 is an enlarged view of FIG. 1 (A) according to the present invention;

FIG. 3 is an enlarged view of FIG. 1 (B) according to the present invention;

FIG. 4 is a schematic diagram of a second embodiment of the present invention.

Reference numerals in the drawings of the specification include:

the chalk box comprises a chalk groove 1, a transverse plate 1-1, a protective plate 2, a crushing box 3, a liquid storage box 4, a blade shaft 5, a blade group 5-1, a transverse partition plate 5-2, fan blades 5-3, sieve holes 5-4, a thread shaft 6, a pull rope 6-1, a pull block 6-2, a pull rope hole 6-3, a filter screen 7, an exhaust hole 7-1, a connecting rod 8, a hairbrush 8-1, a baffle 8-2, a stirring blade 8-3 and a plastic panel 8-4.

Detailed Description

The following is further detailed by way of specific embodiments:

the pull block is arranged on the left side of the collecting box, and the exhaust hole is formed in the right side of the collecting box and is used as a direction reference.

The embodiment is basically as shown in the attached figure 1:

the first embodiment is as follows: the chalk grooves 1 are arranged at the bottoms of the blackboards, the middles of the blackboard grooves 1 are disconnected, a collecting box for collecting chalk dust is arranged at the disconnected part of the two blackboard grooves 1 through bolts, and the top of the collecting box is open; the left side and the right side of the collecting box are welded with transverse plates 1-1, bolt holes are formed in the transverse plates 1-1 on the two sides, holes which can be aligned with the bolt holes are formed in the bottoms of the two chalk grooves 1, and the collecting box is arranged at the broken positions of the chalk grooves 1 by penetrating and binding bolts in the bolt holes; the protection plate 2 is welded on the outer side face, close to the chalk groove 1, of the collecting box, the top of the protection plate 2 is arc-shaped, the height of the protection plate 2 is higher than that of the chalk groove 1, the protection plate 2 can avoid that chalk dust overflows to the ground and is polluted when the chalk dust is pushed into the collecting box, the top of the baffle plate 8-2 is arranged to be arc-shaped, and the situation that students are injured when touching the protection plate 2 can be avoided.

The collection box is whole for cylindrical, the top of collecting the box is uncovered form, collect the box and constitute by the broken case 3 and the liquid reserve tank 4 of vertical setting, the inner wall of liquid reserve tank 4 is provided with the internal thread that accounts for 4 high 1/3 of liquid reserve tank, it has the external screw thread that accounts for 3 high 1/3 of broken case to open on the lateral wall of broken case 3, liquid reserve tank 4 passes through bolted connection in the lower part of broken case 3, use bolted connection to conveniently take off liquid reserve tank 4 from the bottom of broken case 3.

A transverse partition plate 5-2 is welded in the crushing box 3 at a position accounting for 2/3 of the height of the box body, the transverse partition plate 5-2 is disc-shaped, and circular sieve holes 5-4 distributed around the circle center of the transverse partition plate 5-2 are formed in the surface of the transverse partition plate 5-2. The center of the circle of the diaphragm plate 5-2 is slidably sleeved with the blade shaft 5, two groups of blade sets 5-1 are welded on the left side and the right side of the blade shaft 5, the two groups of blade sets 5-1 are arranged in a staggered mode, the blade sets 5-1 arranged in a staggered mode can cut small sections of chalk ends into powder, and the powder enters the liquid storage tank 4 through the sieve holes 5-4 penetrating through the diaphragm plate 5-2.

The top end of the blade shaft 5 is fixedly connected with a fan blade 5-3, a one-way bearing is fixedly connected between the blade shaft 5 and the fan blade 5-3, the one-way bearing is movably sleeved at the bottom end of the fan blade 5-3, the fan blade 5-3 is driven by the blade shaft 5 to rotate, the rotating fan blade 5-3 generates suction at the top of the collecting box, and the finely-divided chalk dust is sucked into the crushing box 3; an exhaust hole 7-1 for exhausting is formed in the side wall of the right side of the middle of the crushing box 3, a filter screen 7 is connected to the position, close to the exhaust hole 7-1 of the inner wall of the crushing box 3, of the exhaust hole through a bolt, the filter screen 7 is made of fibers, the material of the filter screen is similar to that of a filter element of a dust collector, chalk dust is sucked into the crushing box 3 through the fan blades 5-3 and is exhausted from the exhaust hole 7-1, and the chalk dust carried in air flow stays in the crushing box 3 through the filter screen 7.

The lower part inside the crushing box 3 is welded with a circular baffle 8-2, the middle part of the baffle 8-2 inclines towards the center of the bottom of the crushing box 3, so that the baffle 8-2 forms a conical barrel shape, chalk dust formed after being crushed by the blade group 5-1 and the chalk dust originally in the chalk groove 1 fall onto the inclined plane of the baffle 8-2 through the sieve holes 5-4, and the chalk dust falls into the liquid storage box 4 along the inclined plane of the baffle 8-2 under the action of gravity; due to the fact that the filter screen 7 is located at the position of the vent hole, more chalk dust can be accumulated on the surface of the inner side of the filter screen 7, the inclined baffle 8-2 is used, the chalk dust on the lower portion of the filter screen 7 can fall into the liquid storage box 4 along the inclined surface of the baffle 8-2, and the chalk dust on the lower portion of the filter screen 7 is prevented from being accumulated for a long time.

The bottom end of the blade shaft 5 is fixedly connected with a bobbin 6, the bobbin 6 is transversely arranged, a pull rope 6-1 is wound on the bobbin 6, a torsion spring is arranged at the central line of the interior of the bobbin 6, two ends of a spiral elastic metal wire of the torsion spring are respectively fixed on the diaphragm plate 5-2 and the top surface of the blade shaft 5 and the central line of the diaphragm plate 5-2, a pull rope hole 6-3 for penetrating the pull rope 6-1 is formed in the side wall of the left side of the crushing box 3, the pull rope 6-1 penetrates through the pull rope hole 6-3 and extends to the exterior of the crushing box 3, a pull block 6-2 is fixedly connected to the end part of the pull rope 6-1 extending out of the crushing box 3, and the width of the pull block 6-2 is larger than the aperture of the pull rope hole 6-3; the pull rope 6-1 is pulled to the left side of the crushing box 3, the bobbin 6 is driven to rotate clockwise under the action of the pull rope 6-1, the blade shaft 5 is further driven to combine with the blade group 5-1 to rotate clockwise, the blade group 5-1 is enabled to crush the chalk head, when the pull block 6-2 is loosened, the bobbin 6 returns to the initial position under the action of the torsion spring, the pull rope 6-1 is continuously wound on the bobbin 6, at the moment, the blade group 5-1 and the blade shaft 5 rotate anticlockwise to further crush the chalk head, and due to clockwise and anticlockwise rotation, when the chalk head rotates anticlockwise, the fan blade 5-3 can reversely discharge airflow, so that the fan blade 5-3 is connected with the blade shaft 5 through a one-way bearing, and the periphery of the fan blade 5-3 is rotationally connected with the side wall of the box body; the pulling and loosening of the pull rope 6-1 enables the blade group 5-1 to be in a stop stage for a short time, and chalk dust meeting the crushing particle size enters the lower part of the crushing box 3 through the sieve holes 5-4; simultaneously through intermittent type nature pulling stay cord 6-1, can control the speed of spool 6, and then control blade group 5-1, blade axle 5 and connecting rod 8's speed, owing to leave a certain amount of water in advance in liquid reserve tank 4, connecting rod 8's speed is too fast, can lead to stirring leaf 8-3's speed too fast, and then lead to the water in the liquid reserve tank 4 to splash to broken 3 inner walls of case, the inside chalk dust of broken case 3 is the adhesion at the inner wall of broken case 3 under that of water, and as long as one's time, the chalk dust of adhesion on the inner wall can dry out and form blocky, influences the trafficability characteristic of chalk dust in broken case 3.

The stay cord hole 6-3 is a diameter-variable hole, and the aperture of the stay cord hole 6-3 close to the inner wall of the crushing box 3 is smaller than the aperture close to the outer wall of the crushing box 3; when the chalk dust falls to the lower part of the crushing box 3 through the sieve holes 5-4, a small part of chalk dust is carried on the pull rope 6-1, and when the pull rope 6-1 is pulled out of the crushing box 3, the chalk dust on the pull rope 6-1 is scraped off at one end with a smaller hole diameter, so that the chalk dust is left in the crushing box 3; meanwhile, the wire protecting sleeve is nested in the controllable part of the pull rope 6-1, the wire protecting sleeve is not drawn in the attached drawing, the pull rope 6-1 can be abraded with the inside of the pull rope hole 6-3 in long-term use, and the abrasion of the pull rope 6-1 can be reduced by using the wire protecting sleeve.

A vertically arranged connecting rod 8 is fixedly welded at the bottom end of the bobbin 6, rod-shaped brushes 8-1 are welded at the 3/4 positions of the connecting rod 8, the brushes 8-1 are welded at the left side and the right side of the connecting rod 8, the brushes 8-1 are inclined, the inclined brushes 8-1 are parallel to the inclined surface of the baffle plate 8-2, and bristles of the inclined brushes 8-1 are tightly attached to the inclined surface of the baffle plate 8-2; as the chalk dust slides down into the liquid storage tank 4 under the action of gravity, part of the chalk dust can remain on the inclined surface of the baffle 8-2, the connecting rod 8 drives the hairbrush 8-1 to rotate clockwise along the circle center of the connecting rod 8 while the spool 6 rotates clockwise, and the rotating hairbrush 8-1 brushes the chalk dust remaining on the inclined surface of the baffle 8-2 into the liquid storage tank 4.

As shown in the attached drawing 3, the right side of the brush 8-1 is fixed with the vertical brush which extends upwards, the filter screen 7 is provided with a place for adsorbing more dust and is not easy to automatically separate, the adsorption of the dust is too much, the air permeability of the filter screen 7 can be influenced, the dust on the surface of the filter screen 7 can be brushed away through the vertical brush, and the air permeability of the filter screen 7 is ensured.

The chalk dust accumulated on the surface of the baffle 8-2 is removed by driving the brush 8-1 through intermittent rotation when the pull rope 6-1 is pulled and the pull rope 6-1 is loosened, and meanwhile, the chalk dust on the surface of the filter screen 7 is removed; brush 8-1 is in intermittent type nature pivoted, and stirring leaf 8-3 also can stir the mixed liquid of chalk dust and water, when clockwise stirring solution, then when stirring to solution in the reverse time, the water of clockwise stirring can produce and collide under inertial effect, through intermittent type nature's stirring, more even with the mixture of chalk dust and water.

2/3 of the bottom end of the connecting rod 8 is fixedly welded with a stirring blade 8-3, and the stirring blade 8-3 can mix chalk dust entering the liquid storage tank 4 with water which is placed in the liquid storage tank 4 in advance; meanwhile, a transparent plastic panel 8-4 is arranged on the right side wall of the liquid storage box 4, the stirring condition of chalk dust rainwater can be observed through the plastic panel 8-4, whether the liquid storage box 4 needs to be taken down or not is judged according to the height of liquid mixed by chalk dust and water, and the mixed liquid is poured out and dried.

Example two: the difference from the above embodiment is that the sieve holes 5-4 on the surface of the diaphragm 5-2 are rectangular sieve holes 5-4, and the rectangular sieve holes 5-4 are not easy to be blocked compared with the circular sieve holes 5-4.

The specific implementation process is as follows:

the college students install the collecting box at the disconnection position of two sections of chalk grooves 1 through bolts, take down the liquid storage tank 4, fill water into the liquid storage tank 4, the height of the water accounts for 1/2 of the height of the liquid storage tank 4, then screw in the liquid storage tank 4 filled with water along the direction of screw thread, so that the crushing tank 3 is connected with the liquid storage tank 4; when chalk dust and chalk ends are accumulated in the chalk groove 1, the chalk dust and the chalk ends are pushed into the top of the crushing box 3 by using cleaning cloth; at the moment, one hand holds the outer shell of the collecting box, the other hand pulls the pull block 6-2, the pull rope 6-1 is pulled to loosen, the fan blade 5-3 rotates at the moment, chalk dust in the chalk groove 1, which is close to the collecting box, is sucked into the crushing box 3, meanwhile, the blade group 5-1 crushes the chalk head, the broken chalk dust enters the lower part of the crushing box 3 through a sieve hole 5-4 formed in the transverse partition plate 5-2, the brush 8-1 is driven by pulling the pull block 6-2 to sweep the chalk dust on the inclined surface of the baffle 8-2 into the liquid storage box 4, and at the moment, the stirring blade 8-3 mixes the chalk dust and water entering the liquid storage box 4; the students observe and discover that the chalk dust and the water are uniformly stirred according to the transparent plastic panel 8-4, then the pulling block 6-2 is released, the pulling block 6-2 returns under the action of the torsion spring, the stirring blades 8-3, the connecting rod 8, the blade group 5-1 and the fan blades 5-3 stop working, at the moment, the liquid storage tank 4 is unscrewed along the reverse direction of the thread, and the stirred solution is poured into a pigment disc and is placed under the sun for drying.

The above description is only an example of the present invention, and the common general knowledge of the known specific structures and characteristics in the schemes is not described herein. It should be noted that, for those skilled in the art, without departing from the structure of the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims

1. The utility model provides a blackboard chalk groove, is including installing the chalk groove in the blackboard bottom, its characterized in that: the chalk groove is divided in the middle, a collection box used for collecting chalk dust and vertically arranged is installed at the position of the division of the two chalk grooves, a protection plate higher than the chalk grooves is installed on one surface, close to the outer side of the chalk grooves, of the collection box, the collection box is composed of a crushing box and a liquid storage box in which water is placed in advance, a transverse partition plate is installed in the crushing box, sieve holes used for passing through the chalk dust are formed in the center of the transverse partition plate, a blade group used for crushing chalk ends is installed in the middle of the transverse partition plate, the blade group is installed on two sides of a blade shaft, and a power mechanism used for driving the blade shaft to rotate is arranged at the bottom of the blade shaft.

2. The blackboard chalk holder of claim 1, characterized in that: the bottom center department at the cross slab is connected with the spool, and the bottom of spool and the bottom of blade axle are each other, installs the torsional spring in spool middle part and the bottom surface center department of cross slab simultaneously, and the winding has the stay cord on the spool, opens the stay cord hole that has run through on one side lateral wall of broken case, and the stay cord passes the stay cord hole and extends to the lateral wall outside of broken case, is fixed with the piece that draws at the one end that the stay cord extends broken case.

3. The blackboard chalk groove of claim 2, characterized in that: the side wall joint in stay cord hole has the protecting wire cover, and the aperture that the stay cord hole is close to inside one side of broken case is lighter than the aperture of keeping away from inside one side of broken case simultaneously.

4. The blackboard chalk holder of claim 1, characterized in that: the top end of the blade shaft is provided with fan blades for guiding chalk dust to enter the crushing box, the side wall of the crushing box is provided with an exhaust hole for ventilation, and one side of the exhaust hole close to the inner wall of the crushing box is connected with a filter screen through a bolt.

5. The blackboard chalk groove of claim 2, characterized in that: the bottom of the crushing box is welded with a circular baffle, the middle of the baffle inclines towards the bottom of the crushing box, and the baffle forms a conical cylinder shape.

6. The blackboard chalk groove of claim 2, characterized in that: the bottom end of the bobbin is fixedly connected with a connecting rod, two sides of the connecting rod are provided with brushes for cleaning chalk dust on the surface of the baffle, and the brushes are parallel to the inclined plane of the baffle.

7. The blackboard chalk groove of claim 6, characterized in that: and the bottom of the connecting rod is fixedly connected with a stirring blade for stirring chalk dust and water.

8. The blackboard chalk groove of claim 1, characterized in that: the liquid storage tank is connected to the bottom of the crushing tank through a bolt, and a transparent plastic panel for observing the stirring condition of chalk dust and water is installed on the side wall of one side of the liquid storage tank.

9. The blackboard chalk holder of claim 1, characterized in that: two transverse plates are welded on two sides of the top of the collecting box, and holes for penetrating and binding bolts are formed in the transverse plates.