CN112918164A

CN112918164A - Calculus curve modeling is with drawing instrument convenient to use

Info

Publication number: CN112918164A
Application number: CN202110460395.3A
Authority: CN
Inventors: 张伟; 张纪凤; 汪忠圆
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2021-06-08
Anticipated expiration: 2041-04-27
Also published as: CN112918164B

Abstract

The invention belongs to the technical field of drawing tools, and particularly relates to a drawing tool for conveniently used calculus curve modeling, which comprises a drawing blackboard, drawing compasses and a fixed frame, wherein the drawing blackboard is fixed on a wall surface through bolts, and the fixed frame is arranged on the drawing compasses; the drawing compasses comprise compass supporting legs, an extension rod, a pen cap, a connecting sleeve, a handle and a first sucker; according to the compasses support leg, the end part of the compasses support leg is fixed by enabling the first sucker to be adsorbed on the surface of a drawing blackboard, and the end part of the compasses support leg is prevented from sliding in the drawing process; and make the compasses landing leg receive limiting displacement through fixed cover, avoid changing in the angle between drawing in-process compasses landing leg and the drawing blackboard, and then avoid the curve that will draw to appear crooked, influenced the accuracy of calculus curve model to lead to the teaching effect to receive the influence.

Description

Calculus curve modeling is with drawing instrument convenient to use

Technical Field

The invention belongs to the technical field of drawing tools, and particularly relates to a drawing tool for conveniently modeling a calculus curve.

Background

Calculus is a mathematical concept, which is the branch of mathematics on the differentiation, integration and related concepts and applications of research functions in higher mathematics. It is a basic discipline of mathematics, and the contents mainly include limit, differential, integral and their applications. Differential chemistry, which involves the computation of derivatives, is a set of theories about the rate of change. It allows functions, velocities, accelerations, slopes of curves, etc. to be discussed using a common set of symbols. Integration, including integration operations, provides a general method for defining and calculating areas, volumes, etc. On college class, when mr taught the calculus correlation knowledge, often need model building to the calculus curve, but the calculus curve often is not regular circular arc, but comprises a plurality of circular arcs, need draw on the blackboard with the help of the compasses when needing to draw comparatively accurate curve, but the compasses volume of drawing on the blackboard of current is great, the slip appears easily in the operation process, be difficult to draw comparatively accurate curve graph fast, the efficiency of study has been influenced.

The technical scheme that a patent relates to compasses for teaching also appears in the prior art, and as the compasses for teaching, a chinese patent with application number CN2014207692795 discloses a compasses for teaching, wherein the lower end of one of the compasses poles is a sucking disc, the lower end of the other compasses pole is a pen cap capable of containing chalk, a manual adjusting button is arranged above the two compasses poles, and an operation disc is arranged at the top. When the compasses are used for teaching, the compasses can be stably positioned on the blackboard through the sucker at the lower end of the compass rod, the problem that the traditional compasses are difficult to position on the blackboard is solved, and the compasses are more convenient to use when being beneficial to teachers give lessons. However, the compasses used for drawing on the blackboard for teaching still have defects, and the compasses are difficult to be fixed on the blackboard only by virtue of the adsorption effect between the sucker below the gauge rod and the blackboard, so that the sucker is easy to fall off when a teacher applies great force in the operation process, and the graph to be drawn is damaged; in the drawing process, the angle between the gauge rod and the surface of the blackboard is difficult to limit only by the aid of the sucker below the gauge rod, and in the rotating process of the compasses, the angle between the gauge rod and the surface of the blackboard is changed, so that the pen cap is easy to slide and deviate from a movement track, a curve to be drawn is inclined, and the teaching effect is influenced; so that the technical solution is limited.

In view of the above, the present invention provides a drawing tool for modeling a calculus curve, which is convenient to use, so as to solve the above technical problems.

Disclosure of Invention

In order to make up the defects of the prior art, the problem that when the existing drawing tool for modeling the calculus curve works and compasses are selected to draw on a blackboard, the stable limiting effect of a gauge rod serving as a fulcrum on the blackboard is difficult to ensure is solved; when the compasses rotate, the compasses are large in size and inconvenient to operate, so that the angle between the compass rod serving as a fulcrum and a blackboard is easy to change, and the graph to be drawn is inclined; the invention provides a drawing tool for modeling a calculus curve, which is convenient to use.

The technical scheme adopted by the invention for solving the technical problems is as follows: the drawing tool for modeling the calculus curve convenient to use comprises a drawing blackboard, drawing compasses and a fixing frame, wherein the drawing blackboard is fixed on a wall surface through bolts, and the fixing frame is installed on the drawing compasses; the drawing compasses comprise compasses supporting legs, an extension rod, a pen sleeve, a connecting sleeve, a handle and a first sucker, wherein the compasses supporting legs and the extension rod are rotatably connected through the connecting sleeve; the compass supporting leg is of a cylindrical structure, a first sucker is nested at the end part of the compass supporting leg, and the first sucker is in contact with the surface of the drawing blackboard; the fixing frame comprises a fixing plate, a fixing sleeve and a second sucker, the fixing plate is of a semicircular structure, the second sucker is uniformly arranged on the surface of the fixing plate, and the second sucker is in close contact with the surface of the drawing blackboard; the surface of the fixing plate, which is far away from the drawing blackboard, is uniformly provided with angle scales; the compasses supporting leg is characterized in that a fixing sleeve is arranged above the fixing plate, the fixing sleeve is fixedly connected with the fixing plate through a connecting rod uniformly arranged on the outer surface of the fixing sleeve, the compasses supporting leg penetrates through the fixing sleeve, and the compasses supporting leg is in close contact with the inner surface of the fixing sleeve.

When the drawing device works in a school classroom, when a teacher teaches students the related knowledge of the calculus curve, in order to facilitate the understanding of the students, the graphics of the related calculus curve model are often required to be drawn on a drawing blackboard, and the circular arc curve and the part similar to the circular arc curve in the calculus curve can be drawn more accurately by means of drawing compasses; therefore, after relevant coordinate points of the calculus curve modeling are determined in advance, the drawing compasses are installed on the fixing frame, the end parts of the supporting legs of the drawing compasses are enabled to coincide with the circle centers of circles opposite to curves to be drawn on the drawing blackboard, the angles between the supporting legs of the compasses and the extension rod are adjusted during drawing, the pen cap on the end part of the extension rod is enabled to move to the corresponding coordinate points, chalk is pushed to slide in the pen cap, the end part of the chalk is enabled to be in contact with the drawing blackboard, then the drawing compasses are rotated by holding the handle with the supporting legs of the compasses as pivots, and the chalk at the end part of the extension rod is enabled to draw the corresponding; before drawing, the first sucker on the end part of the compass support leg is in contact with a corresponding part on the surface of a drawing blackboard, the first sucker is pressed to deform and air in a gap part between the first sucker and the drawing blackboard is extruded to form negative pressure, so that the first sucker is adsorbed on the surface of the drawing blackboard, the end part of the compass support leg is fixed, and the phenomenon that the end part of the compass support leg slides in the drawing process to cause the drawn curve to incline is avoided; meanwhile, a second sucker on the fixing plate is in contact with the drawing blackboard and is adsorbed on the surface of the drawing blackboard under the pressing action of a user, so that the fixing plate is fixed on the surface of the drawing blackboard; the fixed plate enables the compass supporting legs to be limited through the fixed sleeve arranged in the middle, so that the compass supporting legs are kept perpendicular to the drawing blackboard in the process of rotating the drawing compass to draw, and the phenomenon that the end parts of the extension rods move along with the change of the angle between the compass supporting legs and the drawing blackboard in the process of drawing is avoided, so that the drawn curve is inclined, the accuracy of a calculus curve model is influenced, and the teaching effect is influenced; in addition, the angle scale arranged on the fixing plate is convenient for a user to determine the angle corresponding to the drawn arc curve, so that the drawing accuracy is further improved; therefore, through the action of the invention, a teacher can conveniently draw a more accurate curve on the drawing blackboard in the teaching process, and the teaching effect is improved.

Preferably, the first sucker comprises a sucker body and a first sleeve, and the end part of the leg of the compass is embedded into an inner hole of the first sleeve; the first sleeve consists of two half sleeves, the sucker body is fixedly connected on one half sleeve, and the half sleeves are connected through bolts; the positions of the half sleeves, which are close to the side faces of the compass support legs, are uniformly provided with fixing blocks, and the fixing blocks are embedded into annular grooves formed in the corresponding positions of the side faces of the compass support legs.

When the drawing compass works, the first sucker is fixed on a drawing blackboard in the drawing process, and the compasses supporting leg on the drawing compass rotates in the first sleeve on the first sucker; the fixing block in the first sleeve is embedded into the annular groove on the compass supporting leg, so that the compass supporting leg is fixed in the direction perpendicular to a drawing blackboard while rotating relative to the first sleeve, and the phenomenon that the compass supporting leg shakes up and down in the drawing process to influence the drawing stability is avoided; and when the mr does not need the mount, unpack a cover apart into two and half covers for a sucking disc and the separation of compasses landing leg, can take the compasses landing leg out from fixed cover during use this moment, realized the separation of drawing compasses and mount, the corner position of convenient to use person on the blackboard of drawing is drawn, also makes the compasses of drawing more convenient at transportation and deposit in-process.

Preferably, the drawing blackboard is a magnetic blackboard, the outer surface of the sucker body is uniformly provided with air outlet grooves, the air outlet grooves are provided with air outlet holes, and the air outlet holes are communicated with a gap part between the inner surface of the sucker body and the drawing blackboard; the air outlet groove is internally provided with an electromagnet, the electromagnet is connected with the air outlet groove in a sliding manner through a spring, and an electrifying switch of the electromagnet is arranged on the outer surface of the first sleeve.

When the suction disc is in close contact with the surface of the drawing blackboard and is pressed to deform, air in an area surrounded by the contact part of the suction disc and the surface of the drawing blackboard is pressed and discharged from the air outlet hole, and air in a gap between the suction disc and the drawing blackboard is further reduced, so that the negative pressure effect on the suction disc is enhanced, and the suction disc and the drawing blackboard are more tightly adsorbed; then, a user starts a power-on switch of the electromagnet, so that the electromagnet generates magnetic force and attracts the magnetic drawing blackboard mutually, and at the moment, the electromagnet is in close contact with the surface of the air outlet groove under the attraction effect of the magnetic force, so that on one hand, the sucker is extruded by the electromagnet and is in closer contact with the surface of the drawing blackboard, and the stability of the compass support leg in the drawing process is further ensured; on the other hand, after the electromagnet is tightly contacted with the surface of the air outlet groove, the air outlet hole is blocked, so that the situation that the outside air enters a gap between the first sucking disc and the drawing blackboard through the air outlet hole and the adsorption effect between the first sucking disc and the drawing blackboard is influenced is avoided; after drawing, close the circular telegram switch, the electro-magnet outage magnetic force disappears and resets under the effect of linking to each other spring, and during the outside air flowed into the venthole this moment, the negative pressure effect that a sucking disc received was relieved, has made things convenient for drawing compasses's removal this moment to carry out drawing of next section circular arc curve.

Preferably, the position that the fixed block is close to the ring channel surface is equipped with a groove, be equipped with the live-rollers in the groove, the live-rollers excircle position stretches out a groove and with ring channel internal surface in close contact with, the live-rollers rotates through pivot and a inslot internal surface and is connected.

When the compass support leg rotates in the first sleeve, the side face of the rotating roller in the fixed block is in close contact with the inner surface of the annular groove of the compass support leg, so that the compass support leg is uniformly stressed by pressure pointing to the center and keeps stable rotation; and the rotating roller rotates under the action of friction force, so that one part of sliding friction between the compass supporting leg and the inner surface of the first sleeve is converted into rolling friction, the friction resistance received when the compass supporting leg rotates is reduced, the abrasion between the inner surface of the first sleeve and the compass supporting leg is also reduced, the drawing compass rotates more conveniently and stably, and the operation of a user is more labor-saving.

Preferably, a first channel is arranged in the middle of the second sucker, which is close to the drawing blackboard, extends upwards and penetrates through the fixing plate to be communicated with the outside; a position that the passageway is close to the external world is equipped with the bell mouth, the bell mouth is embedded to have the toper piece, the toper piece is the elastic block, the toper piece contacts through elasticity rope and bell mouth internal surface, just the elasticity rope is in tensile state.

When the suction disc type blackboard works, when the suction disc type II is in contact with the surface of the drawing blackboard and is pressed to deform, air in a gap between the suction disc type II and the drawing blackboard flows out through the channel type I under the pressure; the flowing air impacts the conical block when passing through the conical hole, so that the conical block is impacted and moves, the gap between the conical block and the inner surface of the conical hole is enlarged, and the air flows out in an accelerated manner; after the air flows out fully, the negative pressure action of the gap between the second sucker and the drawing blackboard enables the conical block to be in close contact with the inner surface of the conical hole, so that the external air is prevented from flowing in through the conical hole, and the negative pressure action of the gap between the second sucker and the drawing blackboard is prevented from being influenced; through the effect of a passageway for the air outflow in clearance between No. two sucking discs and the drawing blackboard is more abundant, and the negative pressure in clearance between No. two sucking discs and the drawing blackboard also obtains strengthening, adsorbs between No. two sucking discs and the drawing blackboard more inseparabler, has further guaranteed that the fixed plate obtains fixedly, has also guaranteed the stability when the compasses landing leg rotates, makes the curve of drawing more stable accurate.

Preferably, the surface of keeping away from the drawing blackboard on the fixed plate is equipped with No. two grooves, No. two inslots are embedded to have a number board, a board upper surface is equipped with the handle, toper piece tip links firmly with a number board.

When the drawing compass works, when the drawing compass needs to move for drawing a next section of curve, in order to avoid that the fixed plate and the drawing blackboard are adsorbed too tightly to cause the drawing compass to be difficult to move and even damage the drawing compass when the drawing compass moves forcibly, the first plate is pulled by the handle to separate the conical block on the first plate from the conical hole, at the moment, the external air flows into the conical hole at an accelerated speed, so that the negative pressure effect of the gap between the second sucker and the drawing blackboard is relieved, at the moment, the fixed plate can move smoothly, and a user saves more labor; when the user releases the handle, a first plate resets under the effect of the elastic rope connected with the conical block, and the first plate can normally play a role.

The invention has the following beneficial effects:

1. according to the drawing tool for modeling the calculus curve, which is convenient to use, the fixing plate, the fixing sleeve, the first sucker and the second sucker are arranged, so that the first sucker is adsorbed on the surface of a drawing blackboard in the drawing process, the end part of the compass supporting leg is fixed, and the end part of the compass supporting leg is prevented from sliding in the drawing process; and make the compasses landing leg receive limiting displacement through fixed cover for the compasses landing leg rotates the state that the drawing process kept the perpendicular to drawing blackboard at the drawing compasses, avoids changing in the angle between drawing in-process compasses landing leg and the drawing blackboard, and then avoids the curve that will draw to appear crooked, has influenced the accuracy of calculus curve model, thereby leads to the teaching effect to receive the influence.

2. According to the drawing tool for modeling the calculus curve, which is convenient to use, air in an area surrounded by a contact part of the first sucker and the surface of the drawing blackboard is discharged from the air outlet hole by arranging the air outlet groove, the air outlet hole and the electromagnet, so that the negative pressure effect on the first sucker is enhanced, and the first sucker and the drawing blackboard are more tightly adsorbed; and through starting the electromagnet, make the sucker receive the extrusion of electromagnet and contact inseparabler with drawing blackboard surface, further guaranteed the stability of drawing in-process compasses landing leg.

Drawings

The invention will be further explained with reference to the drawings.

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

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a half sectional view of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 at B;

FIG. 5 is an enlarged view of a portion of FIG. 3 at C;

FIG. 6 is a perspective view of suction cup number one of FIG. 2;

in the figure: the drawing blackboard comprises a drawing blackboard 1, drawing compasses 2, compass support legs 21, an annular groove 211, an extension rod 22, a pen cap 23, chalk 231, a connecting sleeve 24, a handle 25, a first suction cup 26, a suction cup body 261, a first sleeve 262, a half sleeve 263, a fixing block 264, an air outlet groove 265, an electromagnet 266, an air outlet hole 267, a first groove 27, a rotating roller 271, a rotating shaft 272, a fixing frame 3, a fixing plate 31, a second groove 311, a first plate 312, a handle 313, a fixing sleeve 32, a second suction cup 33, a first channel 331, a tapered hole 332, a tapered block 333 and an elastic rope 334.

Detailed Description

In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further described with the specific embodiments.

As shown in fig. 1 to 6, the drawing tool for modeling a calculus curve, which is convenient to use, comprises a drawing blackboard 1, drawing compasses 2 and a fixing frame 3, wherein the drawing blackboard 1 is fixed on a wall surface through bolts, and the fixing frame 3 is installed on the drawing compasses 2; the drawing compass 2 comprises compass supporting legs 21, an extension rod 22, a pen cap 23, a connecting sleeve 24, a handle 25 and a first sucker 26, wherein the compass supporting legs 21 and the extension rod 22 are rotatably connected through the connecting sleeve 24, the pen cap 23 is installed at the end part of the extension rod 22, chalk 231 is embedded in the pen cap 23, the connecting sleeve 24 is provided with the handle 25, and the surface of the handle 25 is uniformly provided with anti-skidding grooves; the compasses supporting leg 21 is of a cylindrical structure, a first sucker 26 is nested at the end part of the compasses supporting leg 21, and the first sucker 26 is in contact with the surface of the drawing blackboard 1; the fixing frame 3 comprises a fixing plate 31, a fixing sleeve 32 and a second suction cup 33, the fixing plate 31 is of a semicircular structure, the second suction cup 33 is uniformly arranged on the surface of the fixing plate 31, and the second suction cup 33 is tightly contacted with the surface of the drawing blackboard 1; the surface of the fixing plate 31 far away from the drawing blackboard 1 is uniformly provided with angle scales; the fixing sleeve 32 is arranged above the fixing plate 31, the fixing sleeve 32 is fixedly connected with the fixing plate 31 through a connecting rod uniformly arranged on the outer surface of the fixing sleeve 32, the compass supporting leg 21 penetrates through the fixing sleeve 32, and the compass supporting leg 21 is in close contact with the inner surface of the fixing sleeve 32.

When the drawing device works in a school classroom, when a teacher teaches students the related knowledge of the calculus curve, in order to facilitate the understanding of the students, the graphics of the related calculus curve model are often required to be drawn on the drawing blackboard 1, and the circular arc curve and the part approximate to the circular arc curve in the calculus curve can be drawn more accurately by the drawing compasses 2; therefore, after a relevant coordinate point of the calculus curve modeling is determined in advance, the drawing compass 2 is installed on the fixing frame 3, the end part of the compass supporting leg 21 of the drawing compass 2 is enabled to coincide with the circle center of a circle opposite to a curve to be drawn on the drawing blackboard 1, the angle between the compass supporting leg 21 and the extension rod 22 is adjusted during drawing, the pen cap 23 on the end part of the extension rod 22 is enabled to move to the corresponding coordinate point, the chalk 231 is pushed to slide in the pen cap 23, the end part of the chalk 231 is enabled to be in contact with the drawing blackboard 1, then the hand-held handle 25 rotates the drawing compass 2 with the compass supporting leg 21 as a pivot, and the chalk 231 on the end part of the extension rod 22 is enabled to draw; before drawing, the first sucker 26 on the end of the compass supporting leg 21 is in contact with a corresponding part on the surface of the drawing blackboard 1, at the moment, the first sucker 26 is pressed to deform, air in a gap part between the first sucker 26 and the drawing blackboard 1 is extruded to form negative pressure, and the first sucker 26 is adsorbed on the surface of the drawing blackboard 1, so that the end of the compass supporting leg 21 is fixed, and the phenomenon that the end of the compass supporting leg 21 slides to cause the drawn curve to incline is avoided; meanwhile, the second suction cup 33 on the fixing plate 31 is in contact with the drawing blackboard 1 and is adsorbed on the surface of the drawing blackboard 1 under the pressing action of the user, so that the fixing plate 31 is fixed on the surface of the drawing blackboard 1; the fixing plate 31 enables the compass supporting leg 21 to be limited through the fixing sleeve 32 arranged in the middle, so that the compass supporting leg 21 is kept perpendicular to the drawing blackboard 1 in the rotation drawing process of the drawing compass 2, and the phenomenon that the end part of the extension rod 22 moves along with the change of the angle between the compass supporting leg 21 and the drawing blackboard 1 in the drawing process is avoided, so that the drawn curve is inclined, the accuracy of a calculus curve model is influenced, and the teaching effect is influenced; in addition, the angle scale arranged on the fixing plate 31 facilitates the user to determine the angle corresponding to the drawn arc curve, and further improves the drawing accuracy; therefore, through the action of the invention, a teacher can conveniently draw a more accurate curve on the drawing blackboard 1 in the teaching process, and the teaching effect is improved.

As an embodiment of the invention, the first sucker 26 comprises a sucker body 261 and a first sleeve 262, and the end of the compass leg 21 is embedded in the inner hole of the first sleeve 262; the first sleeve 262 consists of two half sleeves 263, the sucker 261 is fixedly connected to one of the half sleeves 263, and the half sleeves 263 are connected through bolts; fixing blocks 264 are uniformly arranged on the parts, close to the side faces of the compass support legs 21, of the half sleeves 263, and the fixing blocks 264 are embedded into annular grooves 211 formed in the corresponding parts of the side faces of the compass support legs 21.

During operation, in the drawing process, the first sucker 26 is fixed on the drawing blackboard 1, and the compass support leg 21 on the drawing compass 2 rotates in the first sleeve 262 on the first sucker 26; the fixing block 264 in the first sleeve 262 is embedded into the annular groove 211 on the compass supporting leg 21, so that the compass supporting leg 21 is fixed in the direction perpendicular to the drawing blackboard 1 while rotating relative to the first sleeve 262, and the phenomenon that the compass supporting leg 21 shakes up and down in the drawing process to influence the drawing stability is avoided; and when the mr does not need mount 3, unpack a cover 262 apart into two and half covers 263 for a sucking disc 26 separates with compasses landing leg 21, can take out compasses landing leg 21 from fixed cover 32 during use this moment, realized drawing compasses 2 and mount 3's separation, the corner position of convenient to use person on drawing blackboard 1 is drawn, also makes drawing compasses 2 more convenient at transportation and deposit in-process.

As an embodiment of the present invention, the drawing blackboard 1 is a magnetic blackboard, the outer surface of the suction cup 261 is uniformly provided with air outlet grooves 265, the air outlet grooves 265 are provided with air outlet holes 267, and the air outlet holes 267 are communicated with the gap between the inner surface of the suction cup 261 and the drawing blackboard 1; an electromagnet 266 is installed in the air outlet groove 265, the electromagnet 266 is in sliding connection with the air outlet groove 265 through a spring, and an electrified switch of the electromagnet 266 is installed on the outer surface of the first sleeve 262.

When the first sucker 26 is in close contact with the surface of the drawing blackboard 1 and is pressed to deform, air in an area surrounded by the contact part of the first sucker 26 and the surface of the drawing blackboard 1 is pressed and discharged from the air outlet 267, and air in a gap between the first sucker 26 and the drawing blackboard 1 is further reduced, so that the negative pressure effect on the first sucker 26 is enhanced, and the first sucker 26 and the drawing blackboard 1 are adsorbed more tightly; then, the user starts the power-on switch of the electromagnet 266, so that the electromagnet 266 generates magnetic force and attracts the magnetic drawing blackboard 1, and at the moment, the electromagnet 266 is in close contact with the surface of the air outlet groove 265 under the attraction effect of the magnetic force, so that on one hand, the suction cup 261 is squeezed by the electromagnet 266 and is in closer contact with the surface of the drawing blackboard 1, and the stability of the compass support leg 21 in the drawing process is further ensured; on the other hand, after the electromagnet 266 is in close contact with the surface of the air outlet groove 265, the air outlet 267 is blocked, so that the external air is prevented from entering a gap between the first suction cup 26 and the drawing blackboard 1 through the air outlet 267 and the adsorption effect between the first suction cup 26 and the drawing blackboard 1 is influenced; after drawing, close the circular arc switch, electro-magnet 266 outage magnetic force disappears and resets under the effect of linking to each other spring, and during the outside air flowed into venthole 267 this moment, the negative pressure effect that a sucking disc 26 received was relieved, has made things convenient for drawing compasses 2's removal this moment to carry out the drawing of next section circular arc curve.

As an embodiment of the invention, a first groove 27 is arranged at a position of the fixed block 264 close to the surface of the annular groove 211, a rotating roller 271 is arranged in the first groove 27, the outer circle part of the rotating roller 271 extends out of the first groove 27 and is tightly contacted with the inner surface of the annular groove 211, and the rotating roller 271 is rotatably connected with the inner surface of the first groove 27 through a rotating shaft 272.

When the compass support leg 21 rotates in the first sleeve 262, the side surface of the rotating roller 271 in the fixed block 264 is in close contact with the inner surface of the annular groove 211 of the compass support leg 21, so that the compass support leg 21 is uniformly stressed by the pressure pointing to the center and keeps rotating stably; and the rotating roller 271 rotates under the action of friction force, so that a part of sliding friction between the compass supporting leg 21 and the inner surface of the first sleeve 262 is converted into rolling friction, the friction resistance borne by the compass supporting leg 21 during rotation is reduced, the abrasion between the inner surface of the first sleeve 262 and the compass supporting leg 21 is also reduced, the rotation of the drawing compass 2 is more convenient and stable, and the operation of a user is more labor-saving.

As an embodiment of the present invention, a first channel 331 is disposed on the second suction cup 33 near the middle of the drawing blackboard 1, and the first channel 331 extends upward and penetrates through the fixing plate 31 to communicate with the outside; the position that a passageway 331 is close to the external world is equipped with bell mouth 332, the internal tapered block 333 that has inlayed of bell mouth 332, bell mouth 333 is the elastic block, bell mouth 333 contacts through elastic cord 334 with bell mouth 332 internal surface, just elastic cord 334 is in tensile state.

When the device works, when the second suction cup 33 is in contact with the surface of the drawing blackboard 1 and is pressed to deform, air in a gap between the second suction cup 33 and the drawing blackboard 1 is pressed to flow out through the first channel 331; the flowing air impacts the tapered block 333 while passing through the tapered hole 332, so that the tapered block 333 is impacted and moves, and at this time, the gap between the tapered block 333 and the inner surface of the tapered hole 332 increases, and the air is accelerated to flow out; after the air flows out sufficiently, the negative pressure action of the gap between the second suction cup 33 and the drawing blackboard 1 enables the conical block 333 to be in close contact with the inner surface of the conical hole 332, so that the external air is prevented from flowing in through the conical hole 332, and the negative pressure action of the gap between the second suction cup 33 and the drawing blackboard 1 is influenced; through the effect of a passageway 331 for the air outflow in clearance between No. two sucking discs 33 and the blackboard 1 of drawing obtains more abundant, and the negative pressure in clearance between No. two sucking discs 33 and the blackboard 1 of drawing also obtains strengthening, adsorbs between No. two sucking discs 33 and the blackboard 1 of drawing more inseparabler, has further guaranteed that fixed plate 31 obtains fixedly, has also guaranteed the stability when compasses landing leg 21 rotates, makes the curve of drawing more stable accurate.

In an embodiment of the present invention, a second groove 311 is formed on a surface of the fixing plate 31, which is away from the drawing blackboard 1, a first plate 312 is embedded in the second groove 311, a handle 313 is arranged on an upper surface of the first plate 312, and an end of the tapered block 333 is fixedly connected to the first plate 312.

When the drawing compass 2 is in operation, when the drawing compass 2 needs to move for drawing a next section of curve, in order to avoid that the fixing plate 31 and the drawing blackboard 1 are adsorbed too tightly to cause the drawing compass 2 to be difficult to move and even damage the drawing compass 2 when the drawing compass 2 moves forcibly, the first plate 312 is pulled through the handle 313, so that the conical block 333 on the first plate 312 is separated from the conical hole 332, at the moment, the external air flows into the conical hole 332 at an accelerated speed, so that the negative pressure effect of the gap between the second suction cup 33 and the drawing blackboard 1 is relieved, at the moment, the fixing plate 31 can move smoothly, and a user saves more labor; when the user releases the handle 313, the first dial 312 is reset by the elastic string 334 connected to the tapered block 333, ensuring that the first dial 312 functions properly.

The specific working process is as follows:

in a class of school, when a teacher teaches students the related knowledge of the calculus curve, in order to facilitate the understanding of the students, the graphics of the related calculus curve model are often required to be drawn on the drawing blackboard 1, and the circular arc curve and the part approximate to the circular arc curve in the calculus curve can be drawn more accurately by means of the drawing compasses 2; therefore, after a relevant coordinate point of the calculus curve modeling is determined in advance, the drawing compass 2 is installed on the fixing frame 3, the end part of the compass supporting leg 21 of the drawing compass 2 is enabled to coincide with the circle center of a circle opposite to a curve to be drawn on the drawing blackboard 1, the angle between the compass supporting leg 21 and the extension rod 22 is adjusted during drawing, the pen cap 23 on the end part of the extension rod 22 is enabled to move to the corresponding coordinate point, the chalk 231 is pushed to slide in the pen cap 23, the end part of the chalk 231 is enabled to be in contact with the drawing blackboard 1, then the hand-held handle 25 rotates the drawing compass 2 with the compass supporting leg 21 as a pivot, and the chalk 231 on the end part of the extension rod 22 is enabled to draw; before drawing, the first sucker 26 on the end of the compass supporting leg 21 is in contact with a corresponding part on the surface of the drawing blackboard 1, at the moment, the first sucker 26 is pressed to deform, air in a gap part between the first sucker 26 and the drawing blackboard 1 is extruded to form negative pressure, and the first sucker 26 is adsorbed on the surface of the drawing blackboard 1, so that the end of the compass supporting leg 21 is fixed, and the phenomenon that the end of the compass supporting leg 21 slides to cause the drawn curve to incline is avoided; meanwhile, the second suction cup 33 on the fixing plate 31 is in contact with the drawing blackboard 1 and is adsorbed on the surface of the drawing blackboard 1 under the pressing action of the user, so that the fixing plate 31 is fixed on the surface of the drawing blackboard 1; the fixing plate 31 enables the compass supporting leg 21 to be limited through the fixing sleeve 32 arranged in the middle, so that the compass supporting leg 21 is kept perpendicular to the drawing blackboard 1 in the rotation drawing process of the drawing compass 2, and the phenomenon that the end part of the extension rod 22 moves along with the change of the angle between the compass supporting leg 21 and the drawing blackboard 1 in the drawing process is avoided, so that the drawn curve is inclined, the accuracy of a calculus curve model is influenced, and the teaching effect is influenced; in addition, the angle scale arranged on the fixing plate 31 facilitates the user to determine the angle corresponding to the drawn arc curve, and further improves the drawing accuracy; therefore, through the action of the invention, a teacher can conveniently draw a more accurate curve on the drawing blackboard 1 in the teaching process, and the teaching effect is improved; when the first suction cup 26 is in close contact with the surface of the drawing blackboard 1 and is pressed to deform, air in an area surrounded by the contact part of the first suction cup 26 and the surface of the drawing blackboard 1 is pressed and discharged from the air outlet 267, and air in a gap between the first suction cup 26 and the drawing blackboard 1 is further reduced, so that the negative pressure effect on the first suction cup 26 is enhanced, and the first suction cup 26 and the drawing blackboard 1 are adsorbed more tightly; then, the user starts the power-on switch of the electromagnet 266, so that the electromagnet 266 generates magnetic force and attracts the magnetic drawing blackboard 1, and at the moment, the electromagnet 266 is in close contact with the surface of the air outlet groove 265 under the attraction effect of the magnetic force, so that on one hand, the suction cup 261 is squeezed by the electromagnet 266 and is in closer contact with the surface of the drawing blackboard 1, and the stability of the compass support leg 21 in the drawing process is further ensured; on the other hand, after the electromagnet 266 is in close contact with the surface of the air outlet groove 265, the air outlet 267 is blocked, so that the external air is prevented from entering a gap between the first suction cup 26 and the drawing blackboard 1 through the air outlet 267 and the adsorption effect between the first suction cup 26 and the drawing blackboard 1 is influenced; after drawing is finished, the power-on switch is turned off, the electromagnet 266 is powered off, the magnetic force disappears, and the electromagnet resets under the action of the connected spring, at the moment, outside air flows into the air outlet 267, the negative pressure effect on the first sucker 26 is relieved, the drawing compasses 2 can move conveniently, and the next section of arc curve can be drawn; when the compass supporting leg 21 rotates in the first sleeve 262, the side surface of the rotating roller 271 in the fixed block 264 is tightly contacted with the inner surface of the annular groove 211 of the compass supporting leg 21, so that the compass supporting leg 21 is uniformly stressed by the pressure pointing to the center and keeps stable rotation; the rotating roller 271 rotates under the action of friction force, so that a part of sliding friction between the compass support leg 21 and the inner surface of the first sleeve 262 is converted into rolling friction, the friction resistance borne by the compass support leg 21 during rotation is reduced, the abrasion between the inner surface of the first sleeve 262 and the compass support leg 21 is also reduced, the rotation of the drawing compass 2 is more convenient and stable, and the operation of a user is more labor-saving; when the second suction cup 33 is in contact with the surface of the drawing blackboard 1 and is pressed to deform, air in a gap between the second suction cup 33 and the drawing blackboard 1 is pressed to flow out through the first channel 331; the flowing air impacts the tapered block 333 while passing through the tapered hole 332, so that the tapered block 333 is impacted and moves, and at this time, the gap between the tapered block 333 and the inner surface of the tapered hole 332 increases, and the air is accelerated to flow out; after the air flows out sufficiently, the negative pressure action of the gap between the second suction cup 33 and the drawing blackboard 1 enables the conical block 333 to be in close contact with the inner surface of the conical hole 332, so that the external air is prevented from flowing in through the conical hole 332, and the negative pressure action of the gap between the second suction cup 33 and the drawing blackboard 1 is influenced; through the effect of a passageway 331 for the air outflow in clearance between No. two sucking discs 33 and the blackboard 1 of drawing obtains more abundant, and the negative pressure in clearance between No. two sucking discs 33 and the blackboard 1 of drawing also obtains strengthening, adsorbs between No. two sucking discs 33 and the blackboard 1 of drawing more inseparabler, has further guaranteed that fixed plate 31 obtains fixedly, has also guaranteed the stability when compasses landing leg 21 rotates, makes the curve of drawing more stable accurate.

The front, the back, the left, the right, the upper and the lower are all based on figure 1 in the attached drawings of the specification, according to the standard of the observation angle of a person, the side of the device facing an observer is defined as the front, the left side of the observer is defined as the left, and the like.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the scope of the present invention.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A drawing tool for calculus curve modeling convenient to use, characterized in that: the wall-mounted drawing board comprises a drawing blackboard (1), drawing compasses (2) and a fixing frame (3), wherein the drawing blackboard (1) is fixed on a wall surface through bolts, and the fixing frame (3) is installed on the drawing compasses (2); the drawing compass (2) comprises compass supporting legs (21), an extension rod (22), a pen sleeve (23), a connecting sleeve (24), a handle (25) and a first sucker (26), the compass supporting legs (21) and the extension rod (22) are rotatably connected through the connecting sleeve (24), the pen sleeve (23) is installed at the end part of the extension rod (22), chalk (231) is embedded in the pen sleeve (23), the connecting sleeve (24) is provided with the handle (25), and the surface of the handle (25) is uniformly provided with anti-skidding grooves; the compasses supporting leg (21) is of a cylindrical structure, a first sucker (26) is nested at the end part of the compasses supporting leg (21), and the first sucker (26) is in contact with the surface of the drawing blackboard (1); the fixing frame (3) comprises a fixing plate (31), a fixing sleeve (32) and a second suction cup (33), the fixing plate (31) is of a semicircular structure, the second suction cup (33) is uniformly arranged on the surface of the fixing plate (31), and the second suction cup (33) is tightly contacted with the surface of the drawing blackboard (1); the surface of the fixing plate (31) far away from the drawing blackboard (1) is uniformly provided with angle scales; fixed plate (31) top is equipped with fixed cover (32), fixed cover (32) link firmly with fixed plate (31) through the connecting rod that the surface was evenly equipped with, just compasses landing leg (21) pass fixed cover (32), and compasses landing leg (21) and fixed cover (32) internal surface in close contact with.

2. A convenient plotting tool for modeling a calculus curve as claimed in claim 1, wherein: the first sucker (26) comprises a sucker body (261) and a first sleeve (262), and the end part of the compass supporting leg (21) is embedded into an inner hole of the first sleeve (262); the first sleeve (262) consists of two half sleeves (263), the sucker body (261) is fixedly connected to one half sleeve (263), and the half sleeves (263) are connected through bolts; fixing blocks (264) are uniformly arranged on the inner surface of the half sleeve (263) close to the side face of the compass supporting leg (21), and each fixing block (264) is embedded into an annular groove (211) formed in the corresponding position of the side face of the compass supporting leg (21).

3. A convenient plotting tool for modeling a calculus curve as claimed in claim 2, wherein: the drawing blackboard (1) is a magnetic blackboard, air outlet grooves (265) are uniformly formed in the outer surface of the suction cup body (261), air outlet holes (267) are formed in the air outlet grooves (265), and the air outlet holes (267) are communicated with the gap between the inner surface of the suction cup body (261) and the drawing blackboard (1); an electromagnet (266) is installed in the air outlet groove (265), the electromagnet (266) is in sliding connection with the air outlet groove (265) through a spring, and an electrifying switch of the electromagnet (266) is installed on the outer surface of the first sleeve (262).

4. A convenient plotting tool for modeling a calculus curve as claimed in claim 3, wherein: the position that fixed block (264) is close to ring channel (211) surface is equipped with a groove (27), be equipped with live-rollers (271) in a groove (27), live-rollers (271) excircle position stretches out a groove (27) and with ring channel (211) internal surface in close contact with, live-rollers (271) are connected through pivot (272) and a groove (27) internal surface rotation.

5. A convenient plotting tool for modeling a calculus curve as claimed in claim 4, wherein: a first channel (331) is arranged at the middle part of the second sucker (33) close to the drawing blackboard (1), and the first channel (331) extends upwards and penetrates through the fixing plate (31) to be communicated with the outside; no. one passageway (331) is equipped with bell mouth (332) near external position, bell mouth (332) are embedded to have a toper piece (333), toper piece (333) are the elastic block, toper piece (333) contact through elasticity rope (334) and bell mouth (332) internal surface, just elasticity rope (334) are in tensile state.

6. The convenient drawing tool for modeling a calculus curve as defined in claim 5 wherein: keep away from drawing blackboard (1) on fixed plate (31) the surface be equipped with No. two groove (311), No. two groove (311) are embedded to have a number board (312), a number board (312) upper surface is equipped with handle (313), toper piece (333) tip links firmly with a number board (312).