CN210535137U - Magnetic induction line drawing gauge - Google Patents

Magnetic induction line drawing gauge Download PDF

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Publication number
CN210535137U
CN210535137U CN201921204688.XU CN201921204688U CN210535137U CN 210535137 U CN210535137 U CN 210535137U CN 201921204688 U CN201921204688 U CN 201921204688U CN 210535137 U CN210535137 U CN 210535137U
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positioning
round hole
compass
base
magnetic induction
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CN201921204688.XU
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石明吉
丁淑娟
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Nanyang Institute of Technology
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Nanyang Institute of Technology
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Abstract

The utility model discloses a magnetic induction line drawing gauge, which comprises a base, a small compass and a compass-shaped double positioning needle, wherein a round hole is drilled in the center of the base, two positioning holes are arranged at the bilateral symmetry positions of the round hole on the base, the distance between the positioning holes is larger than the diameter of the round hole, the centers of the round hole and the positioning holes are on a straight line, and an indicating line is arranged on the connecting line of the positioning holes; the diameter of the round hole of the base is equal to that of the small compass, the depth of the round hole is equal to that of the small compass, and the small compass can be placed into the round hole to be fixed, so that the axis of the small compass is enabled to be coincided with the center of the round hole; the compass-shaped positioning needle comprises a handle and two positioning needles, the positioning needles are respectively arranged on two sides of the handle, and the positioning needles penetrate through positioning holes in the base from top to bottom and are exposed by 3-5 mm. The novel magnetic induction line distribution pattern of the steady magnetic field is quickly, conveniently and accurately depicted.

Description

Magnetic induction line drawing gauge
Technical Field
The utility model relates to a teaching instrument field is tested to the line is felt to magnetism, especially relates to a line drawing rule is felt to magnetism for physical experiment teaching.
Background
The existing magnetic field description experiment instrument mainly has two types, the first type is to use a detection coil to research the magnetic fields of a circular coil and a Helmholtz coil, and the second type is to use a Hall effect probe to research the magnetic fields of the circular coil and the Helmholtz coil.
The first is to measure the alternating magnetic field generated by a circular coil and a Helmholtz coil which are electrified with alternating current by adopting an electromagnetic induction method. When the current passing through the circular coil and the Helmholtz coil is alternating current, the generated magnetic field is an alternating magnetic field, the alternating magnetic field can be measured by a closed loop consisting of a detection coil and an alternating current digital millivoltmeter, the detection coil is arranged in the measured magnetic field, induced electromotive force is induced in the loop by the alternating magnetic flux of the detection coil according to the Faraday's law of electromagnetic induction, the magnitude and the direction of magnetic induction intensity B can be calculated by measuring the magnitude of the induced electromotive force, the device can complete two experimental tasks, the first is to research the distribution rule of the magnetic induction intensity of each point on the axis of the coil, the second is to determine the direction of the magnetic field and draw a magnetic induction line.
The central base of the detection coil is provided with a small hole which can be used for determining the position of a point to be measured in a magnetic field by matching with a transparent gasket with a positioning pin. When the reading of the millivolt meter is the minimum value, the number of the magnetic lines of force passing through the coil is the minimum, and the connecting line of the two measuring holes at the two sides of the coil can indicate the direction of the magnetic field. In the experiment, firstly, a piece of coordinate paper is covered in an area where the magnetic induction lines need to be drawn, and a point is marked on the coordinate paper every 2 cm along the radial direction of the coil (vertical to the axis) by taking a central point 0 as a starting point and is used as a starting point for drawing the magnetic lines. The experiment requires that 3 lines of magnetic force are measured and drawn in the quadrant of 1/4, the distribution among lines is as uniform as possible and can cover the plane of 1/4 drawings.
When drawing magnetic lines, a detection coil is placed on the coordinate paper, a pen-shaped positioning needle is inserted into a first measuring hole in the radial direction of the coil through a small hole of the detection coil, and the magnetic lines of force of the measuring hole are drawn. The method is that the detection coil is rotated by taking the hole as the center until the millivolt meter is a minimum value, the pen-shaped positioning pin is pulled out (the position of the detection coil cannot be changed) and inserted into the measurement hole opposite to the detection coil, and a second hole is punched on the coordinate paper. Then the current second hole is used as the center to rotate the detection coil to find the minimum value of the induced electromotive force, and the pen-shaped positioning pin is pulled out and pricked to the opposite side to find the third hole by taking the millivoltmeter as the minimum value. Repeating the steps, and continuously doing the steps repeatedly and repeatedly to leave a series of small needle holes on the drawing. The center of the connecting line of every two needle eyes is the geometric center of the detection coil, namely the tangent points of the magnetic lines of force, and the tangent points are smoothly connected to draw one magnetic line of force. However, since the pitch of the needle holes of the detection coil is much smaller than the radius of curvature of the magnetic lines, when drawing, the needle holes are connected smoothly, and several magnetic lines passing through other points can be drawn by the same method.
The method has the advantages that: (1) the distribution rule of the magnetic induction intensity of each point on the coil axis along with the position can be researched; (2) the magnetic field direction can be determined and the lines of magnetic induction traced.
The disadvantages of this method are: (1) the average magnetic field is measured by a common detection coil, and in order to measure the true value of the magnetic field of each point, the smaller the volume of the detection coil is, the better the detection coil is, but the smaller the coil area is, the induced electromotive force is weak, and the measurement is difficult. (2) Because the magnetic field is an alternating magnetic field, the probing coil and the millivolt meter form a closed loop, and alternating current in the loop causes the probing coil to generate self-induced electromotive force, which affects the induced electromotive force. (3) The detection coil is frequently used, the wire diameter of the detection coil is too thin, the detection coil is frequently touched by hands, the lead of the coil is easily broken, and the lead of the coil is broken and welding is difficult. (4) When drawing magnetic induction lines, the pen-shaped positioning pin penetrates through a positioning hole to be inserted into coordinate paper, the pen-shaped positioning pin is used as an axis to slowly rotate the detection coil until the induced electromotive force displayed by the alternating-current millivoltmeter is minimum, the pen-shaped positioning pin is pulled out (the position of the detection coil cannot be changed), the pen-shaped positioning pin is inserted into a measurement hole opposite to the detection coil, and a second hole is formed in the coordinate paper. Then the current second hole is used as the center to rotate the detection coil to find the minimum value of the induced electromotive force, and the pen-shaped positioning pin is pulled out and pricked to the opposite side to find the third hole by taking the millivoltmeter as the minimum value. And repeating the steps. In the process, students need to complete the extraction and the insertion of the positioning needle by hands, and need to keep the position of the detection coil unchanged, so that the operation is difficult and laborious.
The second is to use Hall effect probe to measure the steady magnetic field generated by circular coil and Helmholtz coil. When the current passing through the circular coil and the Helmholtz coil is constant current, the generated magnetic field is a constant magnetic field. The steady magnetic field can not be measured by a closed loop consisting of the detection coil and the alternating current digital millivoltmeter, and can be measured by a Hall sensor. The working principle of the Hall sensor is Hall effect, when the working current of the Hall element is kept unchanged, the Hall voltage is in direct proportion to the magnetic induction intensity, and accordingly the magnetic induction intensity is measured. The magnetic field plotter which is used in the laboratory at present and is used for measuring by using the Hall effect probe can only measure the magnetic induction intensity of each point at different positions in a magnetic field along the axis direction, and can research and study the distribution rule of the magnetic induction intensity of each point on the axis of the coil, namely, the task 1 is completed; however, the conventional apparatus cannot determine the direction of the magnetic field and cannot draw the magnetic lines.
The method has the advantages that: (1) the Hall element is adopted to measure the magnetic induction intensity, so that the sensitivity and stability are realized, and the reading is convenient; (2) the position of the measuring point can be accurately positioned by utilizing the screw rod, and the distribution rule of the magnetic induction intensity of each point at different positions along the axis direction in the plane where the axis of the coil is located can be researched.
The disadvantages of this method are: (1) the Hall element needs to be moved by manually rotating the screw rod, the screw pitch of the screw rod is only 1 mm, the measuring range can reach dozens of centimeters, the number of turns of rotation is extremely large, and students are hard to measure; (2) the magnetic field direction cannot be determined and the magnetic induction lines cannot be traced.
In summary, the two methods have a common disadvantage that the magnetic induction line is difficult to draw or cannot be realized, so that a new magnetic induction line drawing device which is convenient to operate, visual, durable and low in cost is needed to be designed. As is well known, a small magnetic needle can flexibly and accurately indicate the direction of a magnetic field where the small magnetic needle is located, and based on the inspiration, a magnetic induction line drawing gauge is designed.
SUMMERY OF THE UTILITY MODEL
In order to overcome the above shortcoming of prior art, the utility model provides a magnetism is felt line and is described rule, quick, convenient, accurately depicts the magnetism of steady magnetic field and feels line distribution pattern, solves the inconvenience and the difficulty that current laboratory utilized detecting coil to confirm the magnetic field direction.
In order to achieve the above purpose, the utility model adopts the technical scheme that: a magnetic induction line drawing gauge comprises a base, a small compass and compass-shaped double positioning needles, wherein the base is made of a transparent acrylic plate, a round hole is drilled in the center, two positioning holes are symmetrically formed in the two sides of the round hole in the base, the distance between the positioning holes is larger than the diameter of the round hole, the centers of the round hole and the positioning holes are on the same straight line, and an indicating line is arranged on the connecting line of the positioning holes; the diameter of the round hole of the base is equal to that of the small compass, the depth of the round hole is equal to that of the small compass, and the small compass can be placed into the round hole to be fixed, so that the axis of the small compass is enabled to be coincided with the center of the round hole; the compass-shaped positioning needle comprises a handle and two positioning needles, the positioning needles are respectively arranged on two sides of the handle, and the positioning needles penetrate through positioning holes in the base from top to bottom and are exposed by 3-5 mm.
Furthermore, the indication line is formed by carving a thin and shallow groove on the connecting line of the positioning holes of the base, and the groove is filled with striking red pigment to ensure that the pigment cannot fall off due to friction.
Furthermore, the base is made of a transparent acrylic plate with the thickness of 10-15 mm and can be round or square.
Furthermore, the diameter of the round hole of the base is 10-18 mm, and the depth is 5-8 mm.
Furthermore, the diameter of the positioning hole is 1-2 mm, and the distance between the two positioning holes is 2 cm.
Furthermore, the positioning needle is a thin copper rod, the end part of the positioning needle is ground into a needle point which is separated at two sides of the handle, and two ends of the thin copper rod with the needle point are bent towards the same side to form a positioning needle in a compass shape.
Further, the handle is 2.5 centimeters long, can utilize the processing of the copper post of diameter 10 millimeters, is close to the bottom and transversely beats a penetrating hole of diameter 2 millimeters with the electric drill, at the bottom along the tapping of copper post axis, utilizes the screw to fix pilot pin and handle together. The diameter of the thin copper rod is 2 millimeters, the length of the thin copper rod is 15 centimeters, the length of the positioning needle is 6.5 centimeters, and the distance between the two needles is 2 centimeters.
Compared with the prior art, the beneficial effects of the utility model are that: utilize the ya keli base, the organic combination of two positioning pins of small-size compass and copper compasses shape utilizes little magnet to instruct magnetic field direction, utilizes two positioning pin alternate movement of compasses shape, has realized the accurate drawing of line is felt to magnetism, has to instruct nimble, convenient high efficiency, vivid directly perceived, the low price, advantages such as easily popularization, can realize drawing of line is felt to steady magnetic field magnetism well, makes the student can be fast, conveniently accomplish the drawing of line is felt to magnetism, deepens the understanding to the line distribution condition is felt to magnetism.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below.
Fig. 1 is a schematic structural diagram of the present invention;
fig. 2 is a schematic structural view of an acrylic chassis.
Detailed Description
The following will be described in detail with reference to the technical solutions in the embodiments of the present invention:
referring to fig. 1 and 2, the magnetic induction line tracing compass provided by the present invention mainly comprises a base 1, a small compass 2 and a compass-shaped double positioning needle 3. The base 1 is made of a transparent acrylic plate with the thickness of 10-15 mm and can be circular or square, a round hole 4 with the diameter of 10-18 mm and the depth of 5-8 mm is drilled in the center of the base 1, two positioning holes 5 are symmetrically drilled in the position, on a certain diameter of the round hole 4, of which the distance from the center of the hole is slightly larger than the radius of the hole, the diameter of each positioning hole 5 is 1-2 mm, the distance between every two positioning holes 5 is about 2 cm, finally, polishing treatment is carried out, the center of each round hole 4 and the center of each positioning hole 5 are transparent, the centers of the round holes 4 and the positioning holes 5 are on the same straight line, and an indicating line is arranged on the connecting line; the small compass 2 with the diameter of 10-18 mm and the thickness of 5-8 mm is placed into the round hole 4 at the center of the base 1 with the right side up and fixed, the shaft of the compass 2 is ensured to be exactly coincided with the center of the round hole 4, a thin and shallow groove 6 is carved along the connecting line of the two positioning holes 5 by a cutter, and is filled with striking red pigment, so that the pigment is ensured not to be separated due to friction, and the formed red line is an indicating line; the compasses-shaped positioning needle 3 comprises two positioning needles 7 and a handle 8, the positioning needles 7 penetrate through a positioning hole 5 of the base from top to bottom and expose 3-5 mm, the positioning needles 7 are thin copper rods, the end parts of the positioning needles are ground into needle points, the needle points are arranged on two sides of the handle 8, two ends of each thin copper rod with the needle points are bent to the same side to form the compasses-shaped positioning needle 7, the handle is 2.5 cm long, the diameter of each thin copper rod is 2 mm, the length of each thin copper rod is 15 cm, the length of each positioning needle is 6.5 cm, and the distance between the two needles is 2 cm.
The testing process comprises the following steps:
1) referring to fig. 2, the acrylic base 1 of the present invention is made of transparent acrylic material, and is machined into a cylinder with a diameter of 31 mm by a lathe, and a circular hole 4 with a diameter of 18 mm and a depth of 7 mm is machined in the center of the center; along the diameter, at a position 11 mm away from the center, symmetrically drilling two through positioning holes 5 with the diameter of 2 mm; and carrying out high-temperature polishing treatment on the base to make the base glittering and translucent.
2) Referring to fig. 1, after the base 1 is processed, a small compass 2 with the diameter of 18 mm and the thickness of 7 mm is embedded into a round hole 4 in the center of the acrylic base 1, gaps are coated with glue and fixed on the periphery of the small compass 2, the compass 2 is flexible to rotate, and when the base is slightly inclined, the compass can still normally indicate the direction; a penetrating hole with the diameter of 2 mm is transversely drilled in the handle 8 through an electric drill, a thin copper rod with the diameter of 2 mm and the length of about 15 cm is taken, needle points are ground at two ends of the thin copper rod, the thin copper rod penetrates through a small hole perpendicular to the handle 8, the two sides of the thin copper rod are equal in length, the bottom of the thin copper rod is glued and fastened through a glue gun, then two ends of the copper rod with the needle points are bent towards the same side to form a compass-shaped positioning needle 7, the length of each positioning needle 7 is about 6.5 cm, and the distance between the two positioning needles is.
Example (b):
the magnetic induction line drawing gauge of the invention is used for drawing the magnetic induction lines of a current-carrying circular coil, the exciting current of the coil is 350 milliampere direct current, a white soft foam board is firstly laid in the area needing to draw the magnetic induction lines, and coordinate paper with the width of 17 centimeters and the length of 28 centimeters is symmetrically covered on the white soft foam board and is fixed by an adhesive tape. A point O close to the center of the coil on the central axis of the coil is found by utilizing the scale of the coordinate paper, points 2,4 and 6 are found in sequence in the radial direction of the coil at intervals of 2 centimeters, and a magnetic induction line is respectively formed by the point O, the point 2, the point 4 and the point 6. When the compass is operated, the pencil rotating shaft at the upper end of the magnetic induction line drawing gauge is pinched by the right hand, one positioning needle point is firstly pricked at the O point, the other needle point is tightly attached to the paper surface, the compass is basically parallel to the paper surface, the magnetic induction line drawing gauge is slightly rotated by taking the positioning needle passing the O point as the shaft, the direction of the compass can flexibly rotate when the eyes look down, when the direction of the compass is overlapped with the red line connected with the two limit holes on the magnetic induction line drawing gauge, the magnetic induction line drawing gauge slightly inclines towards the other positioning needle and pricks down the positioning needle, the first positioning needle is lifted up, the second positioning needle is taken as the shaft and slowly rotates, when the direction of the compass is overlapped with the connecting line between the two positioning needles again, the rotation is stopped, the magnetic induction line drawing gauge is slightly inclined towards the other side integrally, the first positioning needle in the compass-shaped double positioning needles is taken as the shaft, the slow rotation … is repeatedly carried out, a series of needle holes are left on, by connecting the pinholes smoothly, a magnetic induction line passing through the O point can be described. Then, the magnetic induction lines of the point 2, the point 4 and the point 6 are drawn in this order, the magnetic induction lines draw holes left on the coordinate paper, the holes are smoothly connected by a pencil to obtain the magnetic induction line distribution of the current-carrying circular coil, and the distribution of the magnetic induction lines in the entire space can be inferred from the symmetry of the magnetic induction line distribution of the current-carrying circular coil.
Significant results of the invention compared with the background art
The magnetic induction line tracing gauge of the invention is used for tracing the distribution condition of the magnetic induction lines of the current-carrying circular coil, and the compass is used for indicating the direction of a magnetic field, so that the compass is flexible to rotate and has no problem of difficult measurement; a detection coil and an alternating current millivoltmeter are not used, so that the problems of thin and easy-to-break detection coil wire, poor contact and hand-pinch sensitivity are avoided; the compass-shaped double-positioning needle is used for overcoming the complexity and difficulty in frequently pulling and inserting the positioning needle and holding the detection coil to fix the position in the traditional experiment; the magnetic induction line drawing gauge is convenient to use, accurate and rapid in measurement, capable of guaranteeing experiment precision and greatly improved in experiment efficiency, can be used for drawing tasks which can be completed only within 30-40 minutes by using a detection coil in the traditional method, can be easily completed within 10 minutes by using the magnetic induction line drawing gauge, and is obvious in effect. The magnetic induction line drawing gauge is simple to manufacture, convenient to use, accurate in measurement and low in cost, has important significance in the aspects of measurement, teaching and research of a stable and constant magnetic field, and has certain popularization value.
The utility model discloses a theory of operation:
the utility model discloses mainly by the base, small-size compass and two positioning pins of compasses shape constitute, lay a cork board or rubber pad in advance in the region that needs to draw the line of magnetic induction, above-mentioned cover paper. The direction of the magnetic induction line is indicated by adopting a small compass, the whole magnetic induction line tracing gauge slightly inclines to one side, and slowly rotates by taking one positioning needle in the compass-shaped double positioning needles as an axis, the compass stops rotating when the direction of the compass is overlapped with the connecting line between the double positioning needles, the whole magnetic induction line tracing gauge slightly inclines to the other side, and slowly rotates by taking the other positioning needle in the compass-shaped double positioning needles as an axis, the compass stops rotating when the direction of the compass is overlapped with the connecting line between the double positioning needles again, the whole magnetic induction line tracing gauge slightly inclines to the other side, and the magnetic induction line tracing gauge slowly rotates … by taking the other positioning needle in the compass-shaped double positioning needles as an axis, and the operation is repeated, so that a series of pinholes are left on paper, and the pinholes are smoothly connected, and the magnetic induction line can be traced. The invention does not need to use a detection coil and an alternating current millivoltmeter, the magnetic field direction is judged quickly, the efficiency of magnetic induction line drawing is greatly improved, the cost is low, the measuring speed is high, the precision is high, the operation is simple, and the popularization value is very high.
The foregoing is directed to embodiments of the present application and it is understood that various modifications and enhancements may be made by those skilled in the art without departing from the principles of the application and are intended to be included within the scope of the application.

Claims (7)

1. A magnetic induction line drawing gauge is characterized in that: the compass comprises a base, a small compass and a compass-shaped double positioning needle, wherein the base is made of a transparent acrylic plate, a round hole is drilled in the center of the base, two positioning holes are symmetrically arranged on two sides of the round hole in the base, the distance between the positioning holes is larger than the diameter of the round hole, the center of the round hole and the center of the positioning hole are on the same straight line, and an indicating line is arranged on a connecting line of the positioning holes; the diameter of the round hole of the base is equal to that of the small compass, the depth of the round hole is equal to that of the small compass, and the small compass can be placed into the round hole to be fixed, so that the axis of the small compass is enabled to be coincided with the center of the round hole; the compass-shaped positioning needle comprises a handle and two positioning needles, the positioning needles are respectively arranged on two sides of the handle, and the positioning needles simultaneously penetrate through two positioning holes in the base from top to bottom to expose for 3-5 mm.
2. A magnetic induction line tracing gauge as claimed in claim 1, wherein: the indicating line is formed by carving a thin and shallow groove on the connecting line of the positioning holes of the base, and the groove is filled with striking red pigment to ensure that the pigment cannot fall off due to friction.
3. A magnetic induction line tracing gauge as claimed in claim 1, wherein: the base is made of a transparent acrylic plate with the thickness of 10-15 mm and can be round or square.
4. A magnetic induction line tracing gauge as claimed in claim 1, wherein: the diameter of the round hole of the base is 10-18 mm, and the depth is 5-8 mm.
5. A magnetic induction line tracing gauge as claimed in claim 1, wherein: the diameter of the positioning hole is 1-2 mm, and the distance between the two positioning holes is 2 cm.
6. A magnetic induction line tracing gauge as claimed in claim 1, wherein: the positioning needle is a thin copper rod, the end part of the positioning needle is ground into a needle point which is respectively arranged at two sides of the handle, and two ends of the thin copper rod with the needle point are bent towards the same side to form a positioning needle in a compass shape.
7. A magnetic induction line drawing gauge according to claim 5, wherein: the handle is 2.5 cm long, the diameter of the thin copper rod is 2 mm, the length of the thin copper rod is 15 cm, the length of the positioning needle is 6.5 cm, and the distance between the two needles is 2 cm.
CN201921204688.XU 2019-07-29 2019-07-29 Magnetic induction line drawing gauge Active CN210535137U (en)

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CN201921204688.XU CN210535137U (en) 2019-07-29 2019-07-29 Magnetic induction line drawing gauge

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Application Number Priority Date Filing Date Title
CN201921204688.XU CN210535137U (en) 2019-07-29 2019-07-29 Magnetic induction line drawing gauge

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112116853A (en) * 2020-09-10 2020-12-22 燕山大学 Rotating magnetic field experimental device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112116853A (en) * 2020-09-10 2020-12-22 燕山大学 Rotating magnetic field experimental device

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