CN108961940B

CN108961940B - Discrete random variable demonstration device for mathematics

Info

Publication number: CN108961940B
Application number: CN201811030960.7A
Authority: CN
Inventors: 倪晋波
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2018-09-05
Filing date: 2018-09-05
Publication date: 2020-07-14
Anticipated expiration: 2038-09-05
Also published as: CN108961940A

Abstract

The invention belongs to the technical field of mathematical teaching equipment, in particular to a discrete random variable demonstration device for mathematics, which comprises a box body, a first partition plate, a second partition plate, a distribution unit, a blocking plate, a knocking unit, an arc-shaped plate, a support, a first collection frame and a second collection frame; the second partition plate is positioned below the first partition plate; the distribution unit is arranged between the first partition plate and the second partition plate and is used for enabling only one sphere to pass through the second through hole of the second partition plate each time; the blocking plate is used for preventing the ball penetrating through the second partition plate from falling from a ball outlet of the box body, is made of elastic materials, and is internally sealed with gas; the knocking unit is used for knocking the ball body blocked by the blocking plate, so that the ball body smoothly passes through the blocking plate to vertically fall; the arc-shaped plate is arranged at the center below the outlet of the ball body of the box body through the support, and the left side and the right side of the arc-shaped plate are symmetrically provided with a first collecting frame and a second collecting frame. The invention improves the practicability of the demonstration device and is convenient to operate.

Description

Discrete random variable demonstration device for mathematics

Technical Field

The invention belongs to the technical field of mathematical teaching equipment, and particularly relates to a discrete random variable demonstration device for mathematics.

Background

Mathematics is a subject of studying concepts such as quantity, structure, variation, space, and information, and belongs to a form science from a certain point of view. In human historical development and social life, mathematics also plays an irreplaceable role and is an essential basic tool for learning and researching modern science and technology.

The random variables are divided into discrete random variables and continuous random variables, and the function of the random variables is still the random variables. Some random variables, which may all take different values, are finite or may be listed as infinite, or probabilities are distributed on each possible value with a certain rule. Such random variables are referred to as "discrete random variables".

The discrete random variable device in the prior art has the disadvantages of high manufacturing cost, low randomness and unreasonable design, so that the development of a mathematical discrete random variable demonstration device with low manufacturing cost, high randomness and reasonable design is urgently needed.

Patent documents: a discrete random variable demonstration device for mathematics teaching, application number: 2016210253699

In the patent documents, the opening of the bottom opening of the mixing box is realized by driving the connecting rod and the baffle plate to move through the rotation of the disc, so that the balls fall, but the randomness of the experiment is influenced by the falling of a plurality of balls at the same time; meanwhile, the discharge port moves left and right to enable the falling ball body to pass through the discharge port and cannot fall to the highest point of the arc plate, so that the ball body cannot fall to the first collecting frame or the second collecting frame randomly, and the device is poor in practicability.

Disclosure of Invention

The invention provides a discrete random variable demonstration device for mathematics, which is low in cost and high in randomness. The invention adopts the distribution unit to ensure that only one sphere falls down at a time; simultaneously, the design of stopping block makes the spheroid card on stopping block to hit the spheroid through knocking the board and make the spheroid pass through stopping block, stopping block that the board warp all around unanimously, thereby guarantee that the spheroid is in the center that the spheroid exported and falls down, thereby guaranteed to fall first collection frame or second collection frame and have the randomness, improved presentation device's practicality, convenient operation.

The technical scheme adopted by the invention for solving the technical problems is as follows: the invention relates to a discrete random variable demonstration device for mathematics, which comprises a box body, a first partition plate, a second partition plate, a distribution unit, a blocking plate, a knocking unit, an arc-shaped plate, a support, a first collection frame and a second collection frame, wherein the top of the box body is provided with a spherical input port, the bottom of the box body is of a funnel structure, and the bottom of the funnel structure is provided with a spherical outlet; the first partition plate is horizontally fixed in the box body, a mixing cavity is formed by the first partition plate and the space above the box body, the ball is stored in the mixing cavity, and a first through hole for the ball to pass through is formed in the first partition plate; the second partition plate is horizontally fixed in the box body and positioned below the first partition plate, a second through hole for the ball to pass through is formed in the second partition plate, and the positions of the first through hole and the second through hole are deviated; the distribution unit is arranged between the first partition plate and the second partition plate and is used for enabling only one sphere to pass through the second through hole of the second partition plate at each time, the distribution unit comprises a limiting plate, a push rod, a push head and a first spring, the limiting plate is arranged between the first partition plate and the second partition plate, the upper end and the lower end of the limiting plate are respectively contacted with the first partition plate and the second partition plate, a temporary storage cavity penetrating through the upper surface and the lower surface is vertically arranged at a part, close to the left side, of the limiting plate, and the temporary storage cavity is used for storing one sphere; the pushing rod is horizontally fixed on the right end face of the limiting plate, a sliding groove for the pushing rod to penetrate through is horizontally arranged on the right side wall of the box body, and the pushing rod penetrates through the sliding groove of the box body and extends out of the box body; the pushing head is fixed at the right end of the pushing rod, the pushing head is positioned on the outer side of the box body, the first spring is arranged on the pushing rod, and the first spring is positioned between the box body and the pushing head; the blocking plate is arranged at the position of a sphere outlet at the bottom of the box body and used for preventing the sphere passing through the second partition plate from falling from the sphere outlet of the box body, the blocking plate is made of elastic materials, and gas is sealed in the blocking plate; the knocking unit is used for knocking the ball body blocked by the blocking plate to enable the ball body to smoothly pass through the blocking plate to achieve vertical falling, and comprises a knocking plate, an elastic rope and a first gear; the upper surface of the second partition board is provided with a sink groove, the first gear is installed in the sink groove of the second partition board through a rotating shaft, the bottom of the limiting plate is provided with a tooth-shaped structure, and the first gear is meshed with the tooth-shaped structure of the limiting plate; one end of the elastic rope is fixed on the knocking plate, and the other end of the elastic rope is wound on the rotating shaft; the arc-shaped plate is arranged at the center of the lower part of the outlet of the ball body of the box body through a support, and the left side and the right side of the arc-shaped plate are symmetrically provided with a first collecting frame and a second collecting frame. When teaching needs to be performed, firstly, two spheres with the same material size and different colors are placed into the box body, then the pushing head is pushed by a hand to move towards the interior of the box body, the limiting plate carries one sphere to move to the position of the through hole II of the partition plate II, the sphere in the limiting plate smoothly passes through the through hole II to fall down, at the moment, the right entity part of the limiting plate is positioned below the through hole of the partition plate I, the falling of the sphere in the mixing cavity is prevented, only one sphere is allowed to pass through the through hole II at a time, and therefore the randomness of the experiment is guaranteed; then the pushing head is loosened by hand, the limiting plate is pushed back to the initial position under the elastic force of the first spring, the temporary storage cavity is located right below the first through hole, a ball in the mixing cavity randomly falls into the temporary storage cavity of the limiting plate, the limiting plate drives the first gear to rotate clockwise to enable the elastic rope to be loosened from the rotating shaft in the process that the limiting plate moves rightwards, the knocking plate rotates anticlockwise under the action of the torsion spring to knock the ball on the blocking block, the ball smoothly passes through the blocking block to fall from the ball outlet under the impact force, the falling ball randomly falls into the first collecting frame or the second collecting frame after impacting the arc-shaped plate, and the operation is repeated, so that the balls fall one by one; then, the operator can observe the number of the spheres which are made of the same materials and have different sizes and different colors in the first collecting frame or the second collecting frame, and statistical analysis is carried out.

The stirring unit is arranged in the box body and used for stirring the spheres in the mixing cavity, so that the disorder degree of the spheres in the mixing cavity is increased, and the randomness of an experiment is ensured; the lower end of the deflector rod is fixed on the pushing head, and the upper end of the deflector rod is provided with a fixed pin which is positioned in the spiral groove of the transmission shaft; the rotary table is positioned in the box body and fixed at the left end of the transmission shaft; the number of the stirring rods is at least two, the right end of each stirring rod is fixed on the left end face of the turntable, and the stirring rods are inclined to the horizontal plane; the stirring plate is fixed on the stirring rod and used for stirring the ball in the mixing cavity. When promoting the promotion head to box inside motion, the driving lever is along with promoting the head and remove left, because the fixed pin in the transmission shaft is along with driving lever horizontal migration, thereby promotes the transmission shaft and rotates, and the rotation of transmission shaft drives the carousel and rotates, makes the stirring rod rotate at the hybrid chamber, stirs the spheroid of board in to the hybrid chamber and carries out abundant stirring, increases spheroidal chaotic degree and spheroid and from the randomness of a through-hole whereabouts, guaranteed the effect of experiment.

The baffle plate is of a block type structure, the baffle plate is made of elastic materials, the baffle plate is divided into at least three blocks along the radial direction, movable rods are horizontally arranged on the outer side of the baffle plate along the radial direction of the box body, the number of the movable rods is the same as that of the baffle plates, a second spring is sleeved on each movable rod and is positioned between each baffle plate and the inner wall of the box body, a through groove for the movable rods to horizontally pass through is formed in the box body, each movable rod penetrates through the through groove of the box body and extends outwards, and a second gear is arranged at one end, outside the box body, of each movable; the axis of the second gear coincides with the axis of the movable rod, the second gear is rotatably installed on the outer side wall of the box body through the hollow rotating shaft, the center of the second gear is provided with a unthreaded hole along the axis direction, the diameter of the unthreaded hole is larger than that of the movable rod, the inner wall of the unthreaded hole is provided with a spiral chute, and the movable rod penetrates through the hollow rotating shaft and the unthreaded hole of the second gear; a poke rod is arranged on the surface of the movable rod and is positioned in a spiral chute of the second gear, and a fluted disc is coaxially arranged above the second gear and the box body; the fluted disc is rotatably installed on the box body, a tooth-shaped structure is arranged on the lower surface of the fluted disc, and the fluted disc is meshed with the gear two phases below the fluted disc. The spheroid falls the back from through-hole two under the action of gravity, on falling the stopper, the stopper blocks the spheroid, after loosening the promotion head, along with the limiting plate moves right, strike the board and hit the spheroid fast, the impact force makes the spheroid push down the stopper, the stopper moves along with the movable rod level outwards, the motion of movable rod makes two rotations of gear, two rotations of gear drive gear rotate, thereby make two equal simultaneous rotations of every gear, the even expansion that has realized the stopper, the spheroid has been guaranteed to fall from the center of the spheroid export of box, thereby random effect has been reached.

An elastic air bag is arranged between the first partition plate and the second partition plate and is fixed on the left side of the box body. The existence of the elastic air bag avoids the direct impact of the limiting plate on the inner wall of the left side of the box body on the one hand, and on the other hand, the elastic air bag is beneficial to the rapid reset of the limiting plate after being compressed, thereby improving the demonstration efficiency of the device.

The radian of the arc-shaped plate is 60 degrees. The design of the arc-shaped plate can enable the ball to fall into the first collecting frame or the second collecting frame randomly after falling.

Sponge pads are arranged in the first collecting frame and the second collecting frame, rebound of a ball body is avoided due to the existence of sponge, and smooth proceeding of demonstration is guaranteed.

The invention has the following beneficial effects:

1. the invention relates to a discrete random variable demonstration device for mathematics, which adopts a distribution unit to ensure that only one sphere falls down at a time; simultaneously, the design of stopping block makes the spheroid card on stopping block to hit the spheroid through knocking the board and make the spheroid pass through stopping block, stopping block that the board warp all around unanimously, thereby guarantee that the spheroid is in the center that the spheroid exported and falls down, thereby guaranteed to fall first collection frame or second collection frame and have the randomness, improved presentation device's practicality, convenient operation.

2. According to the discrete random variable demonstration device for mathematics, the distribution unit drives the stirring plate in the mixing cavity to rotate to stir the ball in the mixing cavity during movement, so that the ball falling on the distribution unit has randomness, and the accuracy of an experiment is improved.

3. According to the discrete random variable demonstration device for mathematics, the blocking blocks are divided into a plurality of blocks, the blocking blocks are made of elastic materials, and the blocking blocks are uniformly expanded through the meshing motion of the second gear and the fluted disc, so that a sphere is always positioned at the center of the sphere outlet when passing through the blocking blocks, and the randomness of an experiment is guaranteed again.

Drawings

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

FIG. 2 is a cross-sectional view A-A of FIG. 1 of the present invention;

FIG. 3 is a cross-sectional view B-B of FIG. 1 of the present invention;

in the figure: the device comprises a box body 1, a first partition plate 11, a second partition plate 12, a distribution unit 2, a blocking plate 3, a knocking unit 4, an arc-shaped plate 5, a support 6, a first collection frame 7, a second collection frame 8, a sphere outlet 13, a mixing cavity 14, a first through hole 111, a second through hole 121, a limiting plate 21, a push rod 22, a push head 23, a temporary storage cavity 211, a knocking plate 41, an elastic rope 42, a first gear 43, a stirring unit 9, a transmission shaft 91, a shifting rod 92, a rotary disc 93, a stirring rod 94, a stirring plate 95, a fixing pin 96, a movable rod 31, a second gear 32, a hollow rotating shaft 33, a fluted disc 34 and an elastic air bag 10.

Detailed Description

A mathematical discrete random variable demonstration apparatus according to an embodiment of the present invention will be described below with reference to fig. 1 to 3.

As shown in fig. 1 and 2, the discrete random variable demonstration device for mathematics comprises a box body 1, a first partition plate 11, a second partition plate 12, a distribution unit 2, a blocking plate 3, a knocking unit 4, an arc-shaped plate 5, a support 6, a first collection frame 7 and a second collection frame 8, wherein the top of the box body 1 is provided with a spherical input port, the bottom of the box body 1 is of a funnel structure, and the bottom of the funnel structure is provided with a spherical outlet 13; the first partition plate 11 is horizontally fixed inside the box body 1, a mixing cavity 14 is formed by the first partition plate 11 and the space above the box body 1, the balls are stored in the mixing cavity 14, and a first through hole 111 for the balls to pass through is formed in the first partition plate 11; the second partition plate 12 is horizontally fixed in the box body 1, the second partition plate 12 is positioned below the first partition plate 11, a second through hole 121 for the ball to pass through is formed in the second partition plate 12, and the positions of the first through hole 111 and the second through hole 121 are deviated; the distribution unit 2 is arranged between the first partition plate 11 and the second partition plate 12, the distribution unit 2 is used for enabling only one sphere to pass through the second through hole 121 of the second partition plate 12 at a time, the distribution unit 2 comprises a limiting plate 21, a push rod 22, a push head 23 and a first spring, the limiting plate 21 is arranged between the first partition plate 11 and the second partition plate 12, the upper end and the lower end of the limiting plate 21 are respectively contacted with the first partition plate 11 and the second partition plate 12, a temporary storage cavity 211 penetrating through the upper surface and the lower surface is vertically arranged at a part, close to the left side, of the limiting plate 21, and the temporary storage cavity 211 is used for; the push rod 22 is horizontally fixed on the right end face of the limiting plate 21, a sliding groove for the push rod 22 to penetrate through is horizontally arranged on the right side wall of the box body 1, and the push rod 22 penetrates through the sliding groove of the box body 1 and extends out of the box body 1; the pushing head 23 is fixed at the right end of the pushing rod 22, the pushing head 23 is positioned on the outer side of the box body 1, the first spring is arranged on the pushing rod 22, and the first spring is positioned between the box body 1 and the pushing head 23; the blocking plate 3 is arranged at the position of a sphere outlet 13 at the bottom of the box body 1, the blocking plate 3 is used for preventing a sphere passing through the second partition plate 12 from falling from the sphere outlet 13 of the box body 1, the blocking plate 3 is made of elastic materials, and gas is sealed in the blocking plate 3; the knocking unit 4 is used for knocking a ball blocked by the blocking plate 3 to enable the ball to smoothly pass through the blocking plate 3 to achieve vertical falling, the knocking unit 4 comprises a knocking plate 41, an elastic rope 42 and a first gear 43, the knocking plate 41 is hinged inside the box body 1, the knocking plate 41 is in contact with the highest point of the ball on the blocking plate 3 when being in a horizontal position, and a torsion spring is arranged at the hinged position of the knocking plate 41; the upper surface of the second partition plate 12 is provided with a sunken groove, the first gear 43 is installed in the sunken groove of the second partition plate 12 through a rotating shaft, the bottom of the limiting plate 21 is provided with a tooth-shaped structure, and the first gear 43 is meshed with the tooth-shaped structure of the limiting plate 21; one end of the elastic rope 42 is fixed on the knocking plate 41, and the other end of the elastic rope 42 is wound on the rotating shaft; the arc-shaped plate 5 is arranged at the center of the lower part of the sphere outlet 13 of the box body 1 through a support 6, and the left side and the right side of the arc-shaped plate 5 are symmetrically provided with a first collecting frame 7 and a second collecting frame 8. When teaching needs to be performed, two spheres with the same material size and different colors are put into the box body 1, then the pushing head 23 is pushed by hand to move towards the interior of the box body 1, the limiting plate 21 carries a ball to move to the position of the through hole II 121 of the partition plate II 12, the ball in the limiting plate 21 smoothly passes through the through hole II 121 to fall down, at the moment, the right entity part of the limiting plate 21 is positioned below the through hole I111 of the partition plate I11, the falling of the ball in the mixing cavity 14 is prevented, only one ball is allowed to pass through the through hole II 121 at a time, and the randomness of the experiment is ensured, in the process that the limiting plate 21 moves leftwards, the limiting plate 21 drives the first gear 43 to rotate anticlockwise so that the elastic rope 42 is wound on the rotating shaft, the knocking plate 41 is turned up, and the ball body is prevented from being blocked by the knocking plate 41 after falling from the second through hole 121, so that the ball body smoothly falls onto the blocking block; then the pushing head 23 is released by hand, the limiting plate 21 is pushed back to the initial position under the elastic force of the first spring, the temporary storage cavity 211 is positioned under the first through hole 111, a ball in the mixing cavity 14 randomly falls into the temporary storage cavity 211 of the limiting plate 21, in the process that the limiting plate 21 moves rightwards, the limiting plate 21 drives the first gear 43 to rotate clockwise to enable the elastic rope 42 to be loosened from the rotating shaft, the knocking plate 41 rotates anticlockwise under the action of the torsion spring to knock the ball on the blocking block, the ball smoothly passes through the blocking block to fall from the ball outlet 13 under the impact force, the falling ball impacts the arc-shaped plate 5 and then randomly falls into the first collecting frame 7 or the second collecting frame 8, and the operation is repeated to enable the ball to fall one by one; then, the operator can observe the number of the spheres with the same material and different sizes and colors in the first collecting frame 7 or the second collecting frame 8 for statistical analysis.

As shown in fig. 1, a stirring unit 9 is further arranged in the box body 1, the stirring unit 9 is used for stirring the spheres in the mixing chamber 14, so that the degree of disorder of the spheres in the mixing chamber 14 is increased, and the randomness of the experiment is ensured, the stirring unit 9 comprises a transmission shaft 91, a deflector rod 92, a rotary disc 93, a stirring rod 94 and a stirring plate 95, the transmission shaft 91 is horizontally arranged on the right side wall of the box body 1, the outer circumferential surface of the transmission shaft 91 is provided with a spiral groove, and the transmission shaft 91 is positioned above the first partition plate 11; the lower end of the deflector rod 92 is fixed on the pushing head 23, the upper end of the deflector rod 92 is provided with a fixing pin 96, and the fixing pin 96 is positioned in the spiral groove of the transmission shaft 91; the turntable 93 is positioned in the box body 1, and the turntable 93 is fixed at the left end of the transmission shaft 91; the number of the stirring rods 94 is at least two, the right end of each stirring rod 94 is fixed on the left end face of the turntable 93, and the stirring rods 94 are inclined with the horizontal plane; the stir plate 95 is attached to the stir rod 94, and the stir plate 95 is used to stir the spheres in the mixing chamber 14. When promoting pushing head 23 to box 1 internal motion, driving lever 92 is along with pushing head 23 and removing left, because fixed pin 96 in the transmission shaft 91 is along with driving lever 92 horizontal migration, thereby promote transmission shaft 91 and rotate, the rotation of transmission shaft 91 drives carousel 93 and rotates, make stirring rod 94 at the internal rotation of hybrid chamber 14, stir board 95 and carry out abundant stirring to the spheroid in the hybrid chamber 14, increase spheroid chaotic degree and the spheroid and follow the randomness of a 111 whereabouts of through-hole, the effect of experiment has been guaranteed.

As shown in fig. 3, as another embodiment of the present invention, the blocking plate 3 is a block-type structure, the blocking plate 3 is made of elastic material, the blocking plate 3 is divided into at least three blocks along the radial direction, the outer side of the blocking plate 3 is horizontally provided with movable rods 31 along the radial direction of the box body 1, the number of the movable rods 31 is the same as that of the blocking blocks, a second spring is sleeved on the movable rod 31, the second spring is positioned between the blocking block and the inner wall of the box body 1, the box body 1 is provided with a through groove for the movable rod 31 to horizontally pass through, the movable rod 31 passes through the through groove of the box body 1 and extends outwards, and one end of the movable rod 31 outside the box body 1 is provided with a; the axis of the second gear 32 is overlapped with the axis of the movable rod 31, the second gear 32 is rotatably installed on the outer side wall of the box body 1 through a hollow rotating shaft 33, the center of the second gear 32 is provided with a unthreaded hole along the axis direction, the diameter of the unthreaded hole is larger than that of the movable rod 31, the inner wall of the unthreaded hole is provided with a spiral chute, and the movable rod 31 penetrates through the hollow rotating shaft 33 and the unthreaded hole of the second gear 32; a poke rod is arranged on the surface of the movable rod 31 and is positioned in a spiral chute of the second gear 32, and a fluted disc 34 is coaxially arranged above the second gear 32 and the box body 1; the fluted disc 34 is rotatably installed on the box body 1, a tooth-shaped structure is arranged on the lower surface of the fluted disc 34, and the fluted disc 34 is meshed with the two lower gears 32. The spheroid falls on the stopper from the back that falls from through-hole two 121 under the action of gravity, the stopper blocks the spheroid, after loosening pushing head 23, along with limiting plate 21 moves right, strike board 41 and hit the spheroid fast, the impact force makes the spheroid push down the stopper, the stopper moves outwards along with movable rod 31 level, the motion of movable rod 31 makes gear two 32 rotate, gear two 32 rotates and drives the gear rotation, thereby make every gear two 32 all rotate simultaneously, the even expansion of stopper has been realized, the spheroid has been guaranteed to fall from the center of the spheroid export 13 of box 1, thereby random effect has been reached.

As shown in fig. 1, an elastic airbag 10 is disposed between the first partition 11 and the second partition 12, and the elastic airbag 10 is fixed to the left side of the box 1. The existence of the elastic air bag 10 avoids the direct impact of the limiting plate 21 on the inner wall of the left side of the box body 1 on the one hand, and on the other hand, the elastic air bag 10 is beneficial to the rapid reset of the limiting plate 21 after being compressed, thereby improving the demonstration efficiency of the device.

As shown in fig. 1, the arc of the arc plate 5 is 60 °. The design of the curved plate 5 enables the balls to fall randomly into the first collection frame 7 or the second collection frame 8 after falling.

As shown in fig. 1, sponge pads are arranged in the first collecting frame 7 and the second collecting frame 8, and the rebound of the ball is avoided due to the existence of the sponge, so that the smooth proceeding of the demonstration is ensured.

The specific process is as follows:

when teaching needs to be performed, two spheres with the same material size and different colors are put into the box body 1, then the pushing head 23 is pushed by hand to move towards the interior of the box body 1, the limiting plate 21 carries a ball to move to the position of the through hole II 121 of the partition plate II 12, the ball in the limiting plate 21 smoothly passes through the through hole II 121 to fall down, at the moment, the right entity part of the limiting plate 21 is positioned below the through hole I111 of the partition plate I11, the falling of the ball in the mixing cavity 14 is prevented, only one ball is allowed to pass through the through hole II 121 at a time, and the randomness of the experiment is ensured, in the process that the limiting plate 21 moves leftwards, the limiting plate 21 drives the first gear 43 to rotate anticlockwise so that the elastic rope 42 is wound on the rotating shaft, the knocking plate 41 is turned up, and the ball body is prevented from being blocked by the knocking plate 41 after falling from the second through hole 121, so that the ball body smoothly falls onto the blocking block; then the pushing head 23 is released by hand, the limiting plate 21 is pushed back to the initial position under the elastic force of the first spring, the temporary storage cavity 211 is positioned under the first through hole 111, a ball in the mixing cavity 14 randomly falls into the temporary storage cavity 211 of the limiting plate 21, in the process that the limiting plate 21 moves rightwards, the limiting plate 21 drives the first gear 43 to rotate clockwise to enable the elastic rope 42 to be loosened from the rotating shaft, the knocking plate 41 rotates anticlockwise under the action of the torsion spring to knock the ball on the blocking block, the ball smoothly passes through the blocking block to fall from the ball outlet 13 under the impact force, the falling ball impacts the arc-shaped plate 5 and then randomly falls into the first collecting frame 7 or the second collecting frame 8, and the operation is repeated to enable the ball to fall one by one; then, the operator can observe the number of the spheres with the same material and different sizes and colors in the first collecting frame 7 or the second collecting frame 8 for statistical analysis.

When promoting pushing head 23 to box 1 internal motion, driving lever 92 is along with pushing head 23 and removing left, because fixed pin 96 in the transmission shaft 91 is along with driving lever 92 horizontal migration, thereby promote transmission shaft 91 and rotate, the rotation of transmission shaft 91 drives carousel 93 and rotates, make stirring rod 94 at the internal rotation of hybrid chamber 14, stir board 95 and carry out abundant stirring to the spheroid in the hybrid chamber 14, increase spheroid chaotic degree and the spheroid and follow the randomness of a 111 whereabouts of through-hole, the effect of experiment has been guaranteed.

The spheroid falls on the stopper from the back that falls from through-hole two 121 under the action of gravity, the stopper blocks the spheroid, after loosening pushing head 23, along with limiting plate 21 moves right, strike board 41 and hit the spheroid fast, the impact force makes the spheroid push down the stopper, the stopper moves outwards along with movable rod 31 level, the motion of movable rod 31 makes gear two 32 rotate, gear two 32 rotates and drives the gear rotation, thereby make every gear two 32 all rotate simultaneously, the even expansion of stopper has been realized, the spheroid has been guaranteed to fall from the center of the spheroid export 13 of box 1, thereby random effect has been reached.

The existence of the elastic air bag 10 avoids the direct impact of the limiting plate 21 on the inner wall of the left side of the box body 1 on the one hand, and on the other hand, the elastic air bag 10 is beneficial to the rapid reset of the limiting plate 21 after being compressed, thereby improving the demonstration efficiency of the device.

While one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention.

Industrial applicability

According to the discrete random variable demonstration device for mathematics, only one sphere falls down at a time by adopting a distribution unit; simultaneously, the design of stopping block makes the spheroid card on stopping block to hit the spheroid through knocking the board and make the spheroid pass through stopping block, stop block board deformation all around unanimous, thereby guarantee that the spheroid is in the center that the spheroid exported and falls down, thereby guaranteed that it has the randomness to fall to first collection frame or second collection frame, improved presentation device's practicality, convenient operation, thereby this discrete random variable presentation device for mathematics is useful in the mathematical education equipment field.

Claims

1. A discrete random variable demonstration device for mathematics is characterized in that: the device comprises a box body (1), a first partition plate (11), a second partition plate (12), a distribution unit (2), a blocking plate (3), a knocking unit (4), an arc-shaped plate (5), a support (6), a first collecting frame (7) and a second collecting frame (8), wherein a spherical feeding port is formed in the top of the box body (1), the bottom of the box body (1) is of a funnel structure, and a spherical outlet (13) is formed in the bottom of the funnel structure; the first partition plate (11) is horizontally fixed inside the box body (1), a mixing cavity (14) is formed by the first partition plate (11) and the space above the box body (1), the spheres are stored in the mixing cavity (14), and a first through hole (111) for the spheres to pass through is formed in the first partition plate (11); the second partition plate (12) is horizontally fixed in the box body (1), the second partition plate (12) is located below the first partition plate (11), a second through hole (121) for a ball to pass through is formed in the second partition plate (12), and the positions of the first through hole (111) and the second through hole (121) are deviated; the distribution unit (2) is arranged between the first partition plate (11) and the second partition plate (12), only one sphere passes through the second through hole (121) of the second partition plate (12) at a time, the distribution unit (2) comprises a limiting plate (21), a push rod (22), a push head (23) and a first spring, the limiting plate (21) is arranged between the first partition plate (11) and the second partition plate (12), the upper surface and the lower surface of the limiting plate (21) are respectively contacted with the first partition plate (11) and the second partition plate (12), a temporary storage cavity (211) penetrating through the upper surface and the lower surface is vertically arranged at a part, close to the left side, of the limiting plate (21), and the temporary storage cavity (211) is used for storing one sphere; the push rod (22) is horizontally fixed on the right end face of the limiting plate (21), a sliding groove for the push rod (22) to penetrate through is horizontally arranged on the right side wall of the box body (1), and the push rod (22) penetrates through the sliding groove of the box body (1) to extend out of the box body (1); the pushing head (23) is fixed at the right end of the pushing rod (22), the pushing head (23) is positioned on the outer side of the box body (1), the first spring is arranged on the pushing rod (22), and the first spring is positioned between the box body (1) and the pushing head (23); the blocking plate (3) is arranged at the position of a sphere outlet (13) at the bottom of the box body (1), the blocking plate (3) is used for preventing a sphere passing through the second partition plate (12) from falling from the sphere outlet (13) of the box body (1), the blocking plate (3) is made of elastic materials, and gas is sealed in the blocking plate (3); the knocking unit (4) is used for knocking a ball blocked by the blocking plate (3) to enable the ball to smoothly pass through the blocking plate (3) to achieve vertical falling, the knocking unit (4) comprises a knocking plate (41), an elastic rope (42) and a first gear (43), the knocking plate (41) is hinged inside the box body (1), the knocking plate (41) is in contact with the highest point of the ball on the blocking plate (3) when being in a horizontal position, and a torsion spring is arranged at the hinged position of the knocking plate (41); the upper surface of the second partition plate (12) is provided with a sunken groove, the first gear (43) is installed in the sunken groove of the second partition plate (12) through a rotating shaft, the bottom of the limiting plate (21) is provided with a tooth-shaped structure, and the first gear (43) is meshed with the tooth-shaped structure of the limiting plate (21); one end of the elastic rope (42) is fixed on the knocking plate (41), and the other end of the elastic rope (42) is wound on the rotating shaft; the arc-shaped plate (5) is arranged at the central position below a sphere outlet (13) of the box body (1) through a support (6), and a first collecting frame (7) and a second collecting frame (8) are symmetrically arranged on the left side and the right side of the arc-shaped plate (5).

2. The discrete random variable demonstration apparatus for mathematics as claimed in claim 1, wherein: the stirring device is characterized in that a stirring unit (9) is further arranged in the box body (1), the stirring unit (9) is used for stirring spheres in the mixing cavity (14), so that the disorder degree of the spheres in the mixing cavity (14) is increased, the randomness of an experiment is ensured, the stirring unit (9) comprises a transmission shaft (91), a deflector rod (92), a rotary table (93), a stirring rod (94) and a stirring plate (95), the transmission shaft (91) is horizontally arranged on the right side wall of the box body (1), a spiral groove is formed in the outer circumferential surface of the transmission shaft (91), and the transmission shaft (91) is located above the first partition plate (11); the lower end of the deflector rod (92) is fixed on the pushing head (23), the upper end of the deflector rod (92) is provided with a fixing pin (96), and the fixing pin (96) is positioned in a spiral groove of the transmission shaft (91); the rotary table (93) is positioned in the box body (1), and the rotary table (93) is fixed at the left end of the transmission shaft (91); the number of the stirring rods (94) is at least two, the right end of each stirring rod (94) is fixed on the left end face of the turntable (93), and the stirring rods (94) are inclined with the horizontal plane; the stirring plate (95) is fixed on the stirring rod (94), and the stirring plate (95) is used for stirring the spheres in the mixing cavity (14).

3. The discrete random variable demonstration apparatus for mathematics as claimed in claim 1, wherein: the baffle plate (3) is of a block type structure, the baffle plate (3) is made of elastic materials, the baffle plate (3) is divided into at least three blocks along the radial direction, movable rods (31) are horizontally arranged on the outer side of the baffle plate (3) along the radial direction of the box body (1), the number of the movable rods (31) is the same as that of the baffle plates, springs II are sleeved on the movable rods (31), the springs II are located between the baffle plates and the inner wall of the box body (1), through grooves for the movable rods (31) to horizontally pass through are formed in the box body (1), the movable rods (31) penetrate through the through grooves of the box body (1) and extend outwards, and gears II (32) are arranged at one ends of the movable rods (31) outside the box body (1); the axis of the second gear (32) is overlapped with the axis of the movable rod (31), the second gear (32) is rotatably installed on the outer side wall of the box body (1) through a hollow rotating shaft (33), a unthreaded hole is formed in the center of the second gear (32) along the axis direction, the diameter of the unthreaded hole is larger than that of the movable rod (31), a spiral chute is formed in the inner wall of the unthreaded hole, and the movable rod (31) penetrates through the hollow rotating shaft (33) and the unthreaded hole of the second gear (32); a poke rod is arranged on the surface of the movable rod (31), the poke rod is positioned in a spiral chute of the second gear (32), and a fluted disc (34) is coaxially arranged above the second gear (32) and the box body (1); the fluted disc (34) is rotatably arranged on the box body (1), the lower surface of the fluted disc (34) is provided with a tooth-shaped structure, and the fluted disc (34) is meshed with the gear II (32) below.

4. The discrete random variable demonstration apparatus for mathematics as claimed in claim 1, wherein: an elastic air bag (10) is arranged between the first partition plate (11) and the second partition plate (12), and the elastic air bag (10) is fixed on the inner wall of the left side of the box body (1).

5. The discrete random variable demonstration apparatus for mathematics as claimed in claim 1, wherein: the radian of the arc-shaped plate (5) is 60 degrees.

6. The discrete random variable demonstration apparatus for mathematics as claimed in claim 1, wherein: sponge pads are arranged in the first collecting frame (7) and the second collecting frame (8).