CN210271388U

CN210271388U - Discrete random variable distribution function demonstration and image drawing instrument

Info

Publication number: CN210271388U
Application number: CN201920080972.4U
Authority: CN
Inventors: 王书营
Original assignee: Nanjing Institute of Industry Technology
Current assignee: Nanjing Institute of Industry Technology
Priority date: 2019-01-18
Filing date: 2019-01-18
Publication date: 2020-04-07
Anticipated expiration: 2029-01-18

Abstract

The utility model discloses an appearance is drawn to discrete random variable distribution function demonstration and image, the utility model aims at providing an can be through the distribution law that liquid level height in a plurality of liquid measuring cups shows discrete random variable fast and gets arbitrary data, can be with liquid in all measuring cups in order of sequence accumulation together show that distribution function is the orderly accumulation nature and the right continuity of probability, can draw the image of distribution function etc.. The drawing board comprises a support, a transverse plate slide way, a sliding block baffle, a drawing board, a probability display, a function accumulator, a piston painting brush, a communicating conduit, a control rod and a counterweight box. This demonstration appearance has: the operation is simple, all demonstration and graph drawing can be completed only by pushing the control rod, and the applicability is strong; the device can be used for calculation, demonstration and drawing in various occasions and at any visual angle, and is suitable for teacher teaching, student learning and science popularization.

Description

Discrete random variable distribution function demonstration and image drawing instrument

Technical Field

The utility model relates to a teaching model, especially a discrete random variable distribution function demonstration and image drawing appearance.

Background

The probability theory plays a key role in the big data era, wherein the distribution function of the random variable is the core of the random variable, and students lack practical problems and visual performance to master the probabilistic problems, and are simply expressed by commonly used real variables and corresponding functions in understanding, especially, the students are difficult to form a complete and clear systematic concept when learning or training the distribution of the discrete random variables, and the classroom efficiency and the sharing are poor. For example, a high school mathematics random variable teaching aid is provided in the patent application No. 201620584403X, and comprises a support, a spring I, a semicircular box, a clamping device, a roller, an electromagnet I, an iron plate, an electromagnet II, an electric push rod, a swing cylinder, a top bracket, a pulley, an electric reel I, a pull rope I, a weight, a balance block and a swing plate. The main function is to separate the black ball and the white ball into two groups after mechanical mixing, which solves the problem of authenticity test in the classical general model, can not demonstrate the distribution column of discrete random variables and can not draw the image of the distribution function; the patent application number of CN201510167393.X provides a method for judging equipment faults by normal distribution, wherein when equipment normally operates, first data of operation of a plurality of pieces of equipment are collected within a set first time interval, and a curve of the first data of the operation of the plurality of pieces of equipment, which changes along with time, is established; and calculating the first showing times of the first data of the same equipment running in a set first time interval, and establishing a normal distribution relation curve to obtain a 95% credible interval. The defects are that the distribution column of the discrete random variable cannot be demonstrated, and the image of the distribution function cannot be drawn. The document with the patent application number of CN201220704817.3 discloses a "normal probability distribution demonstrator", which includes a demonstration board, a ball barrel, n layers of hexagonal prisms, a ball box, etc., and can only be used for demonstrating an experiment complying with normal probability distribution, but cannot demonstrate a distribution column of general discrete random variables, and cannot draw an image of a distribution function.

Disclosure of Invention

For solving the technical problem, the utility model discloses the technical scheme who adopts as follows:

discrete random variable distribution function demonstration and image drawing instrument, including support, diaphragm slide, slider plate washer, drawing board, probability display, function accumulator, counter weight box, its characterized in that: the device comprises a piston painting brush, a communicating conduit and a control rod, wherein a sliding block baffle and a transverse plate slideway are respectively arranged in a support, a drawing board is arranged behind the support, a probability display is arranged on the sliding block baffle, a function accumulator is arranged on the transverse plate slideway, the piston painting brush is arranged in the function accumulator, the communicating conduit mutually communicates the probability display, the function accumulator and the piston painting brush, the control rod is arranged on the probability display and the function accumulator, and a counterweight box is connected to the piston painting brush;

according to a further technical scheme, the probability display, the communicating conduit and the counterweight box are made of transparent materials.

According to a further technical scheme, a buffer spring is arranged between the piston painting brush holder and the pen point.

According to the further technical scheme, the slide block with the lock is fixed with the slide block base plate through the spring lock.

According to a further technical scheme, the communication conduit is connected with the function accumulator through a hose.

Compared with the prior art, the utility model has the advantages that:

1. the utility model discloses a discrete random variable distribution function demonstration and image drawing appearance, easy operation as long as promote the control lever and just can accomplish all demonstrations and figure drawing.

2. The utility model discloses a discrete random variable distribution function demonstration and image drawing appearance, it is multiple functional: the discrete random variable display device can complete the demonstration of a distribution law, an accumulation probability, distribution function properties, the drawing of a distribution function image and the like formed by a finite number of discrete random variables; the structure is compact, the cost is low, and the carrying is convenient; the applicability is strong: can be used for calculation, demonstration and drawing in various occasions and at any visual angle. The device is suitable for teacher teaching, student learning, science popularization and the like.

3. At present, no product exists in the market, and the discrete random variable distribution function demonstration and image drawing instrument is low in cost, safe, reliable, light and handy.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of the middle support of the present invention.

Fig. 3 is a schematic structural view of the horizontal plate slideway of the present invention.

Fig. 4 is a schematic structural diagram of the middle slide block baffle of the present invention.

Fig. 5 is a schematic structural diagram of the middle drawing board of the present invention.

Fig. 6 is a schematic structural diagram of the middle probability display of the present invention.

Fig. 7 is a schematic diagram of the structure of the medium function accumulator according to the present invention.

Fig. 8 is a schematic diagram of a piston brush according to the present invention.

Fig. 9 is a schematic structural view of the middle communicating conduit of the present invention.

Fig. 10 is a schematic structural diagram of a control lever according to the present invention.

Fig. 11 is a schematic structural diagram of the counterweight box of the present invention.

In the figure: 1-a bracket, 11-a bottom plate, 12-a first vertical plate, 13-a second vertical plate, 14-a threaded rod, 15-a positioning nut, 16-a prismatic table base, 17-a rectangular wedge hole and 18-an elliptical wedge hole; 2-transverse plate slide way, 21-slide way base plate, 22-groove, 23-slide way, 24-rectangular slide plate, 25-first disk seat, 26-oval notch, 27-scale, 28-first oval wedge block and 29-second oval wedge block; 3-a slide block baffle, 31-a slide block base plate, 32-a groove, 33-a slideway, 34-a slide block with a lock, 35-a second disk seat, 36-a guide wedge opening, 37-a spring lock, 38-a cylindrical slide rod, 39-a circular ring, 310-a scale, 311-a first wedge block, 312-a slide rod supporting leg and 313-a second wedge block; 4-drawing board, 41-rectangular flat plate, 42-parting line, 43-paper clamping device, 44-fixing card, 45-upper layout and 46-lower layout; 5-probability display, 51-first square tube, 53-round tube hole, 54-first round tube, 55-positioning valve, 56-output branch tube, 57-pressing valve, 58-first interface, 59-scale; 6-function accumulator, 61-second square tube, 63-tube hole, 64-second round tube, 65-liquid valve, 66-round tube, 67-control valve, 68-second interface, 69-scale bar, 611-rectangular rod hole, 612-directional wedge, 613-pipe hoop, 614-insert rod lock, 615-positioning pin; 7-piston painting brush, 71-painting brush holder, 72-pen holder, 73-pen head, 74-spring, 77-groove, 78-square plate piston, 79-color sealing strip, 710-air vent, 711-air vent plug cover; 8-communicating conduit, 81-main pipe, 82-horizontal straight pipe, 83-branch hose, 84-third interface, 85-output hose, 86-fourth interface, 87-pipe orifice plug, 88-first pipe hoop and 89-second pipe hoop; 9-a control rod, 91-a rectangular plate frame, 92-a circular tube handle, 93-a circular ring plate, 94-a circular straight rod, 95-a circular disc button, 96-a spiral spring, 97-a cylindrical surface clamp, 98-a square jack, 99-a conical contact, 910-an elliptical positioning groove and 911-a positioning knob; 10-weight box, 101-water tank, 102-wire loop, 103-water filling port, 104-thin soft rope, 105-scale mark. .

The specific implementation mode is as follows:

the technical solution of the present invention will be further explained with reference to the following specific embodiments, but the present invention is not limited to the embodiments.

As shown in fig. 1-11, the discrete random variable distribution function demonstration and image drawing instrument includes a support 1, a horizontal plate slide 2, a slider baffle 3, a drawing board 4, a probability display 5, a function accumulator 6, a piston painting brush 7, a communicating conduit 8, a control rod 9, and a weight box 10, where the slider baffle 3 and the horizontal plate slide 2 are respectively disposed inside the support 1, the drawing board 4 is disposed behind the support 1, the probability display 5 is disposed on the slider baffle 3, the function accumulator 6 is disposed on the horizontal plate slide 2, the piston painting brush 7 is disposed in the function accumulator 6, the communicating conduit 8 connects the probability display 5, the function accumulator 6, and the piston painting brush 7 to each other, the control rod 9 is disposed on the probability display 5 and the function accumulator 6, and the weight box 10 is connected to the piston painting brush 7;

as shown in fig. 1-2, the bracket 1 includes a bottom plate 11, a first vertical plate 12, a second vertical plate 13 and a terrace with edge base 16, the bottom plate 11, the first vertical plate 12 and the second vertical plate 13 are 3 rectangular plates with the same size, the first vertical plate 12 and the second vertical plate 13 are of a symmetrical structure, the first vertical plate 12 is provided with a rectangular wedge hole 17 and an elliptical wedge hole 18, the first vertical plate 12 and the second vertical plate 13 are respectively fixedly connected to the left side and the right side of the bottom plate 11, four corners of the lower bottom surface of the bottom plate 11 are respectively provided with a threaded rod 14 fixedly connected thereto, the threaded rod 14 is sleeved with a positioning nut 15, the lower end of the positioning nut 15 is provided with the terrace with edge base 16, a threaded hole matched with the threaded rod is arranged in the terrace with edge base 16, and the lower surface is provided with.

As shown in fig. 1 and 3, the transverse plate slideway 2 comprises a slideway base plate 21, a sliding rail 23 and a moving unit, wherein the slideway base plate 21 is a rectangular cuboid hard plate, the right side surface of the slideway base plate is provided with a first elliptical wedge 28, the left side surface of the slideway base plate is provided with a second elliptical wedge 29, the middle part of the slideway base plate is provided with a groove 22, the side wall of the groove 22 is provided with the sliding rail 23, the moving unit comprises a rectangular sliding plate 24 and a first disk seat 25, the upper surface of the rectangular sliding plate 24 is provided with the first disk seat 25 fixedly connected with the rectangular sliding plate, the rectangular sliding plate 24 is matched with the sliding rail 23, the left side of the moving unit is provided with an elliptical notch. The slide way cross plate 2 is formed by sequentially inserting a first elliptic wedge 28 and a second elliptic wedge 29 into an elliptic wedge hole 18 on a second vertical plate 13 of a first vertical plate 12 of the bracket 1.

As shown in fig. 1 and 4, the slider baffle 3 includes a slider base plate 31, a slideway 33, a moving block, a cylindrical sliding rod 38 and a circular sleeve 39, the slider base plate 31 is a rectangular cuboid hard plate, a first wedge 311 is arranged on the right side surface, a second wedge 313 is arranged on the left side surface, a groove 32 is arranged in the middle of the slider base plate 31, a gap is arranged in the middle of the groove 32, the slideway 33 is arranged on the inner wall around the groove 32, the moving block includes a block 34 with lock and a second disk seat 35, the block 34 with lock is a rectangular hard plate, a through hole is arranged on the upper surface of the right upper corner, a latch 37 matched with the through hole is arranged in the through hole, the position of the moving block is fixed by the rotation of the latch, the second disk seat 35 fixedly connected with the block 34 with the block is arranged on the upper surface of the block 34 with the slideway 33, a conduit wedge 36 is arranged in the, the upper end of the front surface of the slider base plate 31 is provided with a scale 310, the left end and the right end of the front surface of the slider base plate 31 are provided with slide bar support feet 312, the two slide bar support feet 312 are fixedly connected with a cylindrical slide bar 38, a circular sleeve 39 is sleeved outside the cylindrical slide bar 38, a first wedge block 311 and a second wedge block 313 are sequentially inserted into rectangular wedge holes 17 on a first vertical plate 12 and a second vertical plate 13 on the support 1, and a plurality of moving blocks can be provided.

As shown in fig. 1 and 5, the drawing board 4 includes a rectangular flat plate 41, a paper jam device 43, and a fixing clip 44, where the rectangular flat plate 41 is a hard thin plate, a separation line 42 is drawn in the middle of the front of the rectangular flat plate 41, the separation line 42 divides the layout of the rectangular flat plate 41 into an upper layout 45 and a lower layout 46, the paper jam devices 43 are respectively disposed at four corners of the upper layout and four corners of the lower layout, and the fixing clip 44 is respectively disposed at the upper end and the lower end of the left and right sides of the rectangular flat plate 41. The drawing board 4 is fixed on the rear side surfaces of the first vertical plate 12 and the second vertical plate 13 by passing through the fixing clamp 44 through screws, and the drawing board 4 is used for representing probability distribution and drawing a distribution function curve.

As shown in fig. 4 and 6, the probability display 5 includes a first square pipe 51, a first T-shaped connecting pipe, a first round pipe 54 and a control valve 57, the first square pipe 51 is a transparent square container, and the inner wall is smooth, the lower end of the first square pipe 51 is provided with a round pipe hole 53, the front wall of the first square pipe 51 is provided with a scale 59, the first T-shaped connecting pipe includes a first round pipe 54 and an output branch pipe 56, the first round pipe 54 is a round pipe, one end of the first round pipe 54 is connected with the round pipe hole 53, the other end is sleeved with a connecting pipe with a diameter smaller than that of the first round pipe, a positioning valve 55 is arranged in the connecting pipe, a round notch is arranged in the middle of the first round pipe 54, the round notch is connected with the output branch pipe 56, a pressing valve 57 is arranged in the output branch pipe 56, the end of the output branch pipe 56 is sleeved with a first interface 58 with a diameter smaller than that of the first T-shaped connecting pipe, the first T, the pressing valves 57 are turned on when the switch is pressed, the pressing valves stop to be closed, and the pressing valves 57 can automatically restore the original position probability displays 5 which are respectively arranged in the second disk seats 35 on the slide block baffle 3. The probability display 5 is a container reflecting the magnitude of the probability value of the occurrence of an event.

As shown in fig. 3 and 7, the function accumulator 6 includes a second square pipe 61, a square bottom plate 62, a square cover plate 610, and a pipe clamp 613, the second square pipe 61 is a transparent container having the same size as the first square pipe 51 and a smooth inner wall, a rectangular rod hole 611 is formed in the middle of the upper surface of the second square pipe 61, a positioning wedge 612 and a positioning pin 615 are disposed on the inner wall of the lower end of the rectangular rod hole 611, the pipe clamp 613 is an iron sheet with a width of 1 is disposed on the periphery of the outer wall of the second square pipe 61, an insertion rod lock 614 is disposed on the right side of the outer wall, a pipe hole 63 is disposed at the lower end of the second square pipe 61, a scale bar 69 is disposed on the front wall of the second square pipe 61, the second T-shaped connecting pipe includes a second round pipe 64 and a round branch pipe 66, the second round pipe 64 is a round pipe, one end of the second round pipe 64 is connected to the pipe hole 63, establish liquid valve 65 in the connecting pipe, be equipped with circular breach in the middle of the second pipe 64, circular breach is connected with circle branch pipe 66, establish in the circle branch pipe 66 and press valve 57, the second interface 68 that is less than the diameter is established to the end cover of circle branch pipe 66, and second T shape connecting pipe appearance is the same with the square mouth of first disk seat 25 on diaphragm slide 2, and function accumulator 6 is arranged in first disk seat 25 on diaphragm slide 2. The function accumulator 6 is a container representing the magnitude of the cumulative probability values.

As shown in fig. 7-8, the piston-type painting brush 7 includes a painting brush rod holder 71, a pen rod 72, a pen head 73, a square plate piston 78, and a color sealing strip 79, the square plate piston 78 is square, the side length is smaller than the side length of the second square tube 61, the side edge is connected with the upper end of the side surface of the color sealing strip 79, the lower end of the right color sealing strip 79 is provided with an elastic air hole plug 711, the upper surface of the square plate piston 78 is provided with an air hole 710, the center of the upper surface of the square plate piston 78 is provided with the pen rod holder 71, the pen rod holder 71 is a U-shaped cardboard strip, the upper surface of the pen rod holder 71 is provided with a pipe 77, the end of the painting brush rod holder 71 is connected with the horizontally arranged pen rod 72, the pen head 73 is arranged at the end of the pen rod 72, a buffer spring 74 is arranged between the pen rod 72 and the pen head 73, brush holder 71 is inserted through rectangular rod hole 611 and directional wedge 612 is wedged in groove 77, pistoning brush 7 is used to plot the distribution function curve.

As shown in fig. 1 and 9, the communicating conduit 8 includes a main pipe 81, a horizontal straight pipe 82, a branch hose 83, and an output hose 85, the main pipe 81 is a rigid straight circular pipe vertically disposed, a second pipe hoop 89 is sleeved on an outer wall of the main pipe 81, an upper end of the main pipe 81 and the horizontal straight pipe 82 horizontally disposed in a reverse direction are provided, a first pipe hoop 88 is sleeved on a right end of an outer wall of the horizontal straight pipe 82, a pipe orifice plug 87 is provided at the other end of the horizontal straight pipe 82, the branch hose 83 is provided on the horizontal straight pipe 82, a third interface 84 is provided at an end of the branch hose 83, the lower end of the main pipe 81 is connected to the output hose 85, the output hose 85 is horizontally disposed, a fourth interface 86 is provided at an end of the output hose 85, the communicating conduit 8 is fixed to the first vertical plate 12 through the second pipe hoop 89 and the first pipe hoop 88, the fourth interface 86 is connected to the second interface 68 on the function, the third interface 84 is in turn connected to the first interface 58 on the probability display 5. The communication conduit 8 is for connecting the flow of liquid between the probability indicator 5 and the function accumulator 6.

As shown in fig. 4, 7, and 10, the control rod 9 includes a rectangular plate frame 91, a circular tube handle 92, a circular straight rod 94, and a circular tube button 95, the rectangular plate frame 91 is a hard plate, a vertical elliptical positioning groove 910 is provided in the middle of the rectangular plate frame 91, the circular tube handle 92 is provided in the elliptical positioning groove 910, a positioning knob 911 is provided in the middle of the circular tube handle 92, a circular ring plate 93 is provided on the front opening of the circular tube handle 92, the circular straight rod 94 is provided in the center of the circular ring plate 93, the circular straight rod 94 is provided at the front end of the circular straight rod 94, a coil spring 96 is provided between the circular ring button 95 and the circular ring plate 93, a conical contact 99 is provided at the rear end of the circular straight rod 94, the conical contact 99 of the circular ring button 95 can extend out of the circular tube handle 92, and can. Cylindrical surface clamps 97 and square insertion holes 98 are sequentially arranged at the upper and lower ends of the rectangular plate frame 91. The control rod 9 is used for buckling the square insertion hole 98 at the lower end of the rectangular plate frame 91 on the insertion rod 614 with a lock of the function accumulator 6, and the cylindrical surface clamp 97 is clamped on the circular ring sleeve 39 of the slide block baffle 3. A control rod 9 is used to control the movement of the function accumulator 6 for pistoning the brush 7 and the flow of liquid in the probability display 5.

As shown in fig. 8, 10 and 11, the weight box 10 includes a water tank 101 and a string cord 104, the water tank 101 is a transparent sealed cuboid, a water injection port 103 is arranged at the upper right lower corner of the upper top surface of the water tank 101, a wire loop 102 is arranged at the central point of the upper top surface of the water tank 101, the wire loop 102 is connected with the string cord 104, and a scale mark 105 is arranged at the left end of the front side surface of the water tank 101. Weight cartridge 10 is attached to brush holder 71 of plunger brush 7 by a round tube handle 92 of a thin flexible cord 104 that passes over control rod 9. Weight cartridge 10 is intended to supplement the fluid pressure less than the friction on plunger brush 7.

The working principle is as follows:

X	X₁	X₂	…	X_n
					p	p₁	p₂	…	p_n

the operation steps are as follows:

firstly, assembling the instrument, 1, placing a terrace with edge base 16 of the bracket 1 on a stable horizontal plane, and screwing a positioning nut 15 to enable the bracket 1 to be in a stable state. 2. The first elliptical wedge 28 and the second elliptical wedge 29 of the slide way cross plate 2 are sequentially inserted into the elliptical wedge holes 18 on the first vertical plate 12 and the second vertical plate 13 of the bracket 1. 3. The first wedge block 311 and the second wedge block 313 of the slide block baffle 3 are inserted into the rectangular wedge holes 17 on the first vertical plate 12 and the second vertical plate 13 on the bracket 1 in sequence. 4. The separation lines 42 of the drawing board 4 with the paper clamping device 43 are aligned with the inner side of the slide block base plate 31 on the slide block baffle plate 3, and are fixed on the back of the bracket 1 by screws penetrating through the fixing clamps 44. 5. Taking n probability indicators 5, putting the inner plug bottom plate 52 in the second disk seat 35 after passing the first round tube 54 through the conduit wedge 36 on the slide block baffle 3. 6. The square base plate 62 is placed in the first seat 25 by passing the second circular tube 64 of the function accumulator 6 through the oval cutout 26 in the cross plate runner 2. 7. The square cover 610 on the function accumulator 6 is removed, the pen tip 73 in the pistoning brush 7 is retracted, the square plunger 78 on the brush holder 71 is removed, the square cover 610 is fitted over the brush holder 71 along the rectangular rod hole 611 and the directional wedge 612, the square plunger 78 is mounted on the brush holder 71, the square plunger 78 is inserted into the second square tube 61 on the function accumulator 6, and the square cover 610 is fixed in the upper opening of the second square tube 61. 8. The first pipe clamp 88 and the second pipe clamp 89 of the communication conduit 8 are fixed on the second vertical plate 13 and the first vertical plate 12 of the bracket 1 in sequence, the fourth interface 86 is connected with the second interface 68 on the function accumulator 6, and more than one third interface 84 is connected with the first interface 58 on the probability displayer 5 in sequence. 9. The square insertion hole 98 at the lower end of the rectangular plate frame 91 on the control rod 9 is buckled on the insertion rod 614 with a lock of the function accumulator 6, and the cylindrical surface clamp 97 is clamped on the circular ring sleeve 39 of the slide block baffle 3. 10. One end of a flexible cord 104 of weight cartridge 10 is connected to brush holder 71 of plunger brush 7 after passing over barrel grip 92 of lever 9.

Adjusting the initial position: 1. drawing a rectangular plane coordinate system on two pieces of paper respectively, marking the value-taking point positions X1, X2, … and xn of a discrete random variable X on a horizontal axis, fixing one of the value-taking point positions on an upper plate 45 of a drawing board 4 by a paper clamping device 43, making the horizontal axis be the same as the zero scale of a first square tube 51 in a probability display 5, marking corresponding probability values p1, p2, … and pn on the vertical axes of the value-taking points X1, X2, … and xn, and marking the graph as a distribution law coordinate system and marking the graph as O1 xy; fixing another paper clamping device 43 on the lower printing surface 46 of the drawing board 4, and making the vertical axis and the vertical axis of the distribution law image on the same straight line, and the horizontal axis and the zero scale of the second square tube 61 on the function accumulator 6 the same, which is called a distribution function coordinate system and is marked as O2 xy; 2. the latch 37 on the leftmost lock slider 34 on the slider shutter 3 is opened, the lock slider 34 is moved to be fixed by the latch 37 when the center position of the first tube 51 reaches x1 of O1xy, the probability indicator 5 is denoted as x1-p1, and in order to move the rest to the corresponding positions of x2, … and xn, the probability indicators 5 in each place are denoted as xi-pi in sequence. 3. Pushing the round tube handle 92 on the control lever 9 moves the center position of the second square tube 61 on the function accumulator 6 to an arbitrary position to the left of x1 in O2xy and stops it. 4. According to the friction force between the pen point in the piston painting brush 7 and O2xy and between the inner walls of the second square tubes 61 of the square plate pistons 78 and the pressure of liquid on the square plate pistons 78, a proper amount of water is injected into the water tank 101 from the water injection port 103 of the counterweight box 10, so that the piston painting brush 7 can float up freely under the pressure of normal flowing of the liquid in the communication conduit 8; 5. opening a positioning pin 615 on the function accumulator 6, lifting the square plate piston 78 in the piston brush 7 to a position which is scaled by more than one degree on the second square tube 61, and fixing the square plate piston by using the positioning pin 615; 6. opening a positioning knob 911 on the control rod 9, pressing the disc button 95 to move the circular tube handle 92 on the control rod 9 to the position that the conical contact 99 is aligned with the pressed valve 57 on the probability display 5, loosening the disc button 95, and fixing by using the positioning knob 911; 7. closing all the positioning valves 55 and the pressing valves 57 on the probability display 5, and closing the liquid valves 65 and the control valves 67 on the function accumulator 6; 8. the water exceeding one unit height is injected into the first square pipe 51 in all probability displays 5, the press valve 57 on the x1-p1 is opened, the water exceeding the p1 height flows into the communicating conduit 8, the press valve 57 is closed when the liquid level reaches the p1 height, then the liquid level on the x2-p2 is adjusted to the p2 height, the water level is adjusted to the xn-1-p n-1 by imitating, if the communicating conduit 8 is full of liquid, only the positioning valve 55 on the probability display 5 is opened to adjust the water level, when the liquid level of the xn-pn is adjusted, the control valve 67 is opened at the same time of opening the press valve 57, the redundant liquid flows into the second square pipe 61, when the liquid level in the second square pipe 61 exceeds the zero-crossing scale, the control valve 67 and the press valve 57 are closed, the positioning valve 55 on the xn-pn is opened to adjust the water level to the pn and then is closed, reopen the liquid valve 65 on the function accumulator 6 to close when the water level is adjusted to zero.

And thirdly, demonstrating the cumulative probability P (X ≦ xi) ═ P1+ P2+ … + pi: 1. the control valve 67 on the function accumulator 6 is opened. 2. The round tube handle 92 on the control rod 9 is held to push the function accumulator 6 to move right, the movement is stopped when the center position of the second square tube 61 reaches the position x1 in O2xy, the disc button 95 is pressed by the thumb to extend the conical contact 99 and touch the press valve 57, the liquid level in the function accumulator 6 is lowered by the liquid level in the x1-p1, and the thumb is released when the liquid level in the x1-p1 reaches the zero scale. 3. Holding the round tube handle 92 on the control rod 9 to push the function accumulator 6 to move to the position x2-p2 continuously right, the method is the same as 2, the rest is continuously completed until xn-1-p n-1, 4, the function accumulator 6 is pushed to the position xn-pn, the disc button 95 is pressed, the liquid level in the xn-pn is reduced to zero, the liquid level in the function accumulator 6 is increased to the scale, and the press valve 57 and the control valve 67 are closed at the same time.

Fourthly, ending the demonstration and recovering the initial state: 1. opening liquid valves in the function accumulator 6 and the probability display 5 to drain all liquid, and 2, closing the liquid valves; 3. restoring the function accumulator 6 to the leftmost position; 4. and finishing the demonstration.

The utility model discloses a discrete random variable distribution function demonstration and image drawing appearance has the drawing analysis function: the image of the distribution function F (X) can be drawn according to the occurrence probability P (X is less than or equal to X) of the discrete random variable X, namely the relation: f (X) P (X ≦ X); demonstration and analysis of the characteristics of the distribution function f (x): f (— ∞) ═ 0, F (x0+) ═ F (x0), and F (+ ∞) ═ 1. The operation steps are as follows:

firstly, assembling the instrument,

And secondly, adjusting the initial position and the demonstration function.

Drawing an image F (x): 1. opening a locating pin 615 on the function accumulator 6, lowering the square plate piston 78 in the piston brush 7 to the zero-scale position on the second square tube 61, fixing the square plate piston by using the locating pin 615, and ejecting and aligning the pen head 73 in the piston brush 7 to the horizontal axis in O2 xy; 2. opening the control valve 67 on the function accumulator 6; 3. holding the round tube handle 92 on the control rod 9 to push the function accumulator 6 to move right, drawing a horizontal straight line along the transverse axis in O2xy by the pen point 73, stopping moving when the center position of the second square tube 61 reaches the position x1 in O2xy, pressing the disc button 95 with the thumb to extend the conical contact 99 and touch the press valve 57, raising the liquid level in the function accumulator 6 with the liquid level dropping in x1-p1, drawing a straight line along the vertical direction at x1 in O2xy by the pen point 73, releasing the thumb when the liquid level reaches zero scale in x1-p1, and stopping the pen point 73 at the height p 1; 4. holding the barrel handle 92 to push the function integrator 6 to move the pen point 73 to the right draws a horizontal straight line y ═ p1 in the direction of the horizontal axis in O2xy, and the processing method is the same as that in the positions x2-p2, and the pen point 73 is raised to p1+ p 2. The remainder up to xn-1-p n-1 is continued, the nib 73 finally staying at the height p1+ p2+ … + pn-1. 5. Pushing function accumulator 6 to move right to xn-pn, holding disk button 95, when the liquid level in xn-pn drops to zero, closing press valve 57 and control valve 67, the liquid level in function accumulator 6 rises to one, and pen point 73 stays at one unit height, i.e. p1+ p2+ … + pn 1. 6. The push function accumulator 6 is moved to the right to a position to stop at xn, and the pen point 73 draws a horizontal straight line y in the direction of the horizontal axis to 1.

Fourthly, analyzing the characteristics of the distribution function F (x): at x < x1, f (x) 0; when x is not less than xn, F (x) is 1; x is respectively at x1, x2, … and xn, and F (x) rises in a jumping way, and after rising, the F (x) is a horizontal straight line segment and shows right continuity.

Fifthly, ending the demonstration and recovering the initial state: 1. retracting the pen tip 73 in the piston brush 7; 2. opening liquid valves in the function accumulator 6 and the probability display 5 to drain all liquid, and 3, closing the liquid valves; 4. taking down the drawing; 5. restoring the function accumulator 6 to the leftmost position; 6. and finishing drawing and demonstration.

The foregoing is only a preferred embodiment of the present invention and is not intended to limit the invention in any way. Various equivalent changes and modifications can be made by those skilled in the art based on the above embodiments, and all equivalent changes and modifications within the scope of the claims should fall within the protection scope of the present invention.

Claims

1. Discrete random variable distribution function demonstration and image drawing instrument, including support, diaphragm slide, slider plate washer, drawing board, probability display, function accumulator, counter weight box, its characterized in that: piston painting brush, intercommunication pipe and control lever, the inside of support is arranged respectively in to slider plate washer and diaphragm slide, and the back of support is arranged in to the drawing board, and the probability display is arranged in on the slider plate washer, and the diaphragm slide is arranged in to the function accumulator, and in the function accumulator was arranged in to the piston painting brush, the intercommunication pipe was put through probability display, function accumulator, piston painting brush each other, and on probability display and function accumulator were arranged in to the control lever, the counter weight box was connected on the piston painting brush.

2. The discrete random variable distribution function demonstration and image drawing instrument according to claim 1, wherein: the probability display, the communicating conduit and the counterweight box are made of transparent materials.

3. The discrete random variable distribution function demonstration and image drawing instrument according to claim 1, wherein: and a buffer spring is arranged between the piston painting brush holder and the pen point.

4. The discrete random variable distribution function demonstration and image drawing instrument according to claim 1, wherein: the communication conduit is connected with the function accumulator through a hose.