JP2010054490A - Magnetic field intensity and magnetic force measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting the generation and characteristics of a magnetic field intensity by visualizing the magnetic field intensity as a force acting on a needle attached with a micro magnet and at the same time by quantitatively measuring the force to solve a problem in measuring or learning the magnetic field intensity that by using iron powder, the aspect of the force at the moment when the magnetic field acts, and the force cannot be measured, it is insufficient to understand the magnetic force and the characteristics of the current flowing in a coil, and also the magnetic field intensity cannot be measured quantitatively. <P>SOLUTION: The device includes: an electrically insulative plastic cylinder 1; an electromagnetic coil 5 for generating a magnetic field consisting of a coil in which an electric wire coated with an insulative coat is wound by a plurality of turns around the plastic cylinder 1; a fixing plate 2 for fixing the one end of two elastic bodies 15a, 15b having an equal value of Poisson ratio as an elastic coefficient; and an electrically insulated needle 4 attached with a micro magnet 16 at the lower part being hanged from the fixing plate 2 by the 2 elastic bodies protected by 2 straw-like cylinders 3, wherein the position of the needle is measured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic force measuring apparatus that can visually understand the presence of a magnetic force and the strength of a magnetic field, and can be used in a scientific experiment that can measure the strength of a magnetic force or a magnetic field. It is.

  To visualize the strength and appearance of magnetic fields in science experiments that measure magnetic and magnetic field strengths, we used fine iron powder such as iron sand to observe patterns with magnetic lines of force.

  The conventional method is to make a slightly abstract understanding of the magnetic field distribution and magnetic force by sprinkling fine iron powder such as iron sand on a plastic plate, etc., bringing the magnet close to the iron powder, and observing the pattern. Was in a situation to do. There is no affordable experimental device that visualizes the magnetic force and the strength of the magnetic field and at the same time quantitatively measures it.

  On the other hand, as a specific example of a tool that visualizes the movement of magnetic force, Japanese Patent Publication No. 2005-10051 discloses a handle, an insertion needle fixed to the handle and inserted into a detection site such as a wall surface, and the difference. A guide body having a needle exit hole through which the insertion needle projects and a contact portion capable of contacting the detection site at the front end portion, and urging the guide body in the forward sliding direction so that the insertion needle is moved to the needle An elastic body that is immersed in the outlet hole, and a magnet having a passage hole for the insertion needle is provided in the front end portion of the guide body so as to be slidable back and forth, and the magnet is provided so as to be visible from the outside of the guide body. A base material detector has been proposed.

Patent Publication 2005-10051

  In the conventional method using fine iron powder, the action of the magnetic field can be understood as a distribution, but the state of the force at the moment when the magnetic field is applied and the magnetic force cannot be measured. It was not enough to understand.

  Moreover, the movement of sand iron is slow due to the friction between fine iron powder such as iron sand and a plastic plate, which is insufficient to understand the characteristics of magnetic force and current flowing in the coil.

  Furthermore, in order to quantitatively measure the magnetic force and magnetic field generated by a coil or the like, measurement including temporal variation is necessary, and the conventional method is not sufficient for quantitative measurement, There was a lack of visualizing the changes.

  The present invention is to solve such a conventional problem, and visualizes the strength of the magnetic field as a force acting on an electrically insulating needle with a micro magnet, and the electrically insulating needle operates in the space. It is possible to visually understand the generation of force, and at the same time to provide a device for generating the strength of a magnetic field and detecting features by quantitatively measuring the force. To do.

  The present invention provides a first magnetic field generation for generating a magnetic field composed of an electrically insulating plastic cylinder having two elongated holes and a coil in which an electric wire having an insulating coating is wound around the coil cylinder. Means, fixing means for fixing upper ends of two elastic bodies having Poisson's ratios having the same value as an elastic coefficient at the upper part of the plastic cylinder, and protection for protecting the elastic body by two straw-shaped cylinders And a second magnetic field for generating a constant magnetic field made of a micro magnet provided at a lower portion of the electrically insulating needle, an indicating means for indicating a position by an electrically insulating needle fixed to the other lower end of the elastic body The present invention solves the above-mentioned problems by comprising generating means and position reading means for detecting and measuring the position of the electrically insulated needle on which the scale is written.

  At the moment when the current flows through the electromagnetic coil 5, a large magnetic field is generated and a strong magnetic force is generated, and a state in which the micro magnet 16 is greatly lowered downward can be visually grasped, and a strong inrush current acting on the electromagnetic coil 5. It is possible to understand the generation of a large magnetic field, which is one of the natural phenomena.

  Moreover, the electrical insulating needle 4 with the micro magnet 16 attenuates while vibrating up and down, and can be observed to stop at a slightly higher position, and understand the attenuation due to energy dissipation. Can do.

  Further, it is possible to visualize the generation of a large magnetic field due to the inrush current at the moment when the current flows through the electromagnetic coil 5, and to measure the strength of the magnetic field in a steady state, and to grasp the change in the magnetic field numerically and visually.

  Furthermore, the position (height) of the wooden needle can be measured when the wooden needle, which is the electrically insulating needle 4 to which the micro magnet 16 is attached, indicates the scale, and the magnetic force generated in the electromagnetic coil 5 due to the inrush current. , And the magnetic force and magnetic field strength generated by the electromagnetic coil 5 in a steady state of current flow can be quantitatively measured.

  On the other hand, the current flowing through the electromagnetic coil 5 is cut off by the switch 13, so that the electrical insulation needle 4 returns to the original position (height) and the magnetic field by the electromagnetic coil 5 disappears visually. be able to.

  In the present invention, an electrically insulating plastic cylinder 1 having two long holes 20 and a coil 19 in which an electric wire 18 having an insulating coating such as an enameled wire is wound around the plastic cylinder 1 a plurality of times are used. Is generated.

  The length of the plastic tube 1 is longer than that of the coil 19, and the upper portion of the plastic tube 1 protrudes outside the coil 19.

  FIG. 3 shows an external view of the electromagnetic coil 5 in which the coil 19 is wound around the plastic cylinder 1 a plurality of times and the iron core 17 is placed inside the plastic cylinder 1. The iron core 17 is shorter than the plastic cylinder 1 and has a length until it is positioned at the lowermost part of the two long holes 20 provided in the plastic cylinder 1.

FIG. 4 is an external view of the plastic cylinder 1, and FIG. 5 is an external view of the two long holes 20 provided in the plastic cylinder 1.
In addition, elongated holes 20 are provided on the upper end side of the coil 19 through the center of the plastic cylinder 1 and on both sides at 180 degrees.

  A fixing plate 2 is attached to the uppermost portion of the plastic cylinder 1 above the electromagnetic coil 5 in which an enameled wire 18 with an insulating coating is wound on the plastic cylinder 1, and plays a role of a sensor inside the plastic cylinder 1. A micro magnet 16 made of neodymium or the like is suspended by two elastic bodies 15 a and 15 b having the same Poisson ratio so as to hang in the vertical direction inside the plastic cylinder 1, and the elastic bodies 15 a and 15 b are suspended on the fixing plate 2. Is fixed with elastic body stoppers 14a and 14b.

  The elastic bodies 15 a and 15 b are outside the coil plastic cylinder 1 and are covered with a straw-shaped cylinder 3 as a protective member that prevents the elastic bodies 15 a and 15 b from being wrapped around the plastic cylinder 1.

  The elastic bodies 15a and 15b are preferably small in Poisson's ratio, and may be tension springs or rubber.

  FIG. 2 shows a state in which the electrically insulating needle 4 is hung on the fixed base 2 by an elastic body covered with a straw-shaped tube 3. The straw-like tube 3 is preferably made of transparent and thin plastic. Below the electrically insulating needle 4 is attached a micro magnet 16 as means for generating a constant magnetic field made of neodymium or the like.

  The reason for using the micro magnet 16 as a means for generating a constant magnetic field is to enable detection of the magnetic force and the strength of the magnetic field and improve the measurement resolution even when the magnetic force and magnetic field generated by the electromagnetic coil 5 are weak. is there.

  The two elastic bodies 15a and 15b have the same Poisson's ratio. When the Poisson's ratio is a small value, the movement of the micro magnet 16 becomes large.

  The micro magnet 16 is fixed to a lower portion of an electrically insulating needle 4 made of a wooden needle or the like, and both ends of the needle are exposed to the outside through two elongated holes 20 provided in the plastic cylinder 1, thereby The insulating needle 4 points to the scale plate 6. The scale plate 6 is a means for detecting and measuring the position of the electrically insulating needle.

  The scales of the scale plate 6 are equally spaced, and values are engraved so that the value is larger as it goes downward in the vertical direction and smaller as it goes upward.

  At the moment when the current is passed through the coil 19, the electrical insulation needle 4 is greatly lowered, the scale shows a large value, shakes slightly upward due to the reaction, repeats vibration while decreasing the amplitude, and finally stops at a fixed position. .

  The generation of a large magnetic field due to the inrush current at the moment when the current flows through the coil 19 can be visualized, the strength of the magnetic field in a steady state can be measured, and changes in the magnetic field can be captured.

  The circuit of the current that flows through the coil 19 is shown in FIG. 1. A circuit with a resistor 8 and a circuit without a resistor are prepared. It is possible to compare that the scale values indicated by the needles 4 are different.

  It can be seen that in the circuit without the resistor 8, the current flowing through the electromagnetic coil 5 is large, the value indicated by the electrically insulating needle 4 is large, and the strength of the magnetic field is large.

  In the circuit having the resistor 8, the current flowing through the electromagnetic coil 5 is small, and the value indicated by the electrically insulating needle 4 is small. It can be seen that the strength of the magnetic field is small.

The power source used for the circuit is a DC power source 9 and may be a dry battery or the like.
Further, a switch 13 for turning on / off the current and a switch 7 for switching the circuit are connected to the circuit as shown in FIG.

  A support column 10 is used for gripping the scale plate, and a support column 11 having a large diameter is attached to the support column 10 for fixing the support column 10.

  In order to hold the electromagnetic coil 5, a rubber base 12 having a hole is used and inserted into a central hole. The electromagnetic coil 5 is fixed to the rubber stand 12 so as to stand vertically.

  The coil 20 is 4Ω (1500 turns), the plastic tube 1 is 10 mm in diameter, the resistor 8 is 3Ω, the neodymium micromagnet 16 is 4.5 mm in diameter, and the single dry battery 1.5V is four (6V) DC power supply 9. When a thin household rubber is used for the elastic body 15, the insulation needle 4 can be shaken by about 2 mm on the scale plate 6 and about 6 mm if the resistance 8 is 0Ω.

  In the production of electromagnetic coils, it can be used for coil disconnection inspection and coil winding number inspection, and is useful as an inspection device. On the other hand, it can also be used as an apparatus for measuring the strength of a magnet.

  Moreover, it is effective in the educational industry as an electromagnetic coil science experiment device in a school or school, and is excellent as a device for visually understanding the influence of magnetic force and the action of an electromagnet.

  Furthermore, the time variation of the magnetic force can be observed from the scale provided on the device, and since it can be measured as a value, the influence of the inrush current generated in the coil, the dissipation of energy including elastic energy, the steady state The magnetic field strength and magnetic force of the coil can be measured, and it is effective as an experimental device and a learning device.

It is an external view of a magnetic field strength and magnetic force measuring device. An electrically insulating needle 4 with a micro magnet 16 is suspended from a fixed plate 2 that fixes one upper end of two elastic bodies having the same Poisson's ratio, and the other end below the elastic body. FIG. It is an external view of an electromagnetic coil. 1 is an external view of a plastic cylinder 1. FIG. 1 is an external view of a long hole 20 provided in a plastic cylinder 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Plastic cylinder 2 ... Fixed board 3 ... Straw-shaped cylinder 4 ... Electrical insulation needle 5 ... Electromagnetic coil 6 ... Scale plate 7 ... Switch for switching a circuit It is.
8 ... Resistance 9 ... DC power supply 10 ... Post 11 ... Post base 12 ... Rubber base 13 ... A switch for turning on / off the current.
14a ... Elastic body stop a
14b ... Elastic body stop b
15a ... elastic body a
15b ... elastic body b
16 ... Micro magnet 17 ... Iron core 18 ... Electric wire 19 with insulating coating ... Coil 20 ... Long hole

Claims (4)

  A first magnetic field generating means for generating a magnetic field comprising an electrically insulating plastic cylinder having two elongated holes and a coil in which an electric wire having an insulating coating is wound around the coil cylinder; and The position is fixed by fixing means for fixing one upper end of two elastic bodies having an equal Poisson's ratio as an elastic coefficient at the upper part of the coil cylinder, and an electrically insulating needle fixed to the other lower end of the elastic body. A magnetic field strength and magnetic force measuring device comprising: indicating means for indicating; and second magnetic field generating means for generating a constant magnetic field made of a micro magnet provided below the electrically insulating needle.   2. The magnetic field strength and magnetic force measuring device according to claim 1, further comprising a protective means for protecting the elastic body with two straw-shaped tubes.   2. A magnetic field strength and magnetic force measuring apparatus according to claim 1, further comprising position reading means for detecting and measuring the position of the electrically insulating needle on which a scale is written.   3. A magnetic field strength and magnetic force measuring device according to claim 2, further comprising position reading means for detecting and measuring a position of the electrically insulating needle on which a scale is written.

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