JP2014054129A - Magnetic driving apparatus and magnetic driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more easily perform movement control on a diamagnetic substance which is levitating magnetically.SOLUTION: In a magnet array 20, a plurality of permanent magnets with longitudinal and lateral widths of 3×3 mm shorter than 10 mm that is a diameter (full length) of a diamagnetic substance 10 are arrayed in a lattice shape so as to alternate N poles and S poles, respectively. The diamagnetic substance 10 formed from graphite levitates magnetically by resiliency of a magnetic field formed by the magnet array 20. When a portion of the magnetically levitating diamagnetic substance 10 is irradiated with laser light by a laser light irradiation device 30, a temperature in the portion irradiated with laser light rises, an absolute value of magnetic susceptibility is reduced, and a levitation distance is shortened just in that portion. As a result, power moving to the side irradiated with laser light acts on the diamagnetic substance 10, thereby performing an optical induction for guiding the magnetically levitating diamagnetic substance 10 in a direction irradiated with light.

Description

  The present invention relates to a magnetic drive device and a magnetic drive method for controlling movement of a diamagnetic body levitated in a magnetic field as a drive target.

  A diamagnetic material having a negative magnetic susceptibility generates a repulsive force in a magnetic field space, and it is known that magnetic levitation can be achieved by placing such a diamagnetic material in a specific magnetic field space. Since the diamagnetic material levitated in this way does not have a contact surface, there is little friction and it can be moved efficiently with a slight force. ing.

  For example, in Patent Document 1, a temperature-sensitive magnetic material array is placed on a magnet array composed of a plurality of permanent magnets arranged so as to form a potential wall of a magnetic field, and this temperature-sensitive magnetic material array is selectively used. A magnetic drive device for a diamagnetic material is disclosed in which a diamagnetic material, which is an object to be driven, is magnetically levitated or driven by heating and changing a magnetic field.

JP 2010-68603 A

  However, in the magnetic drive device described in Patent Document 1 shown above, it is necessary to selectively heat the temperature-sensitive magnetic material array placed on the magnet array to drive the diamagnetic material that is the object to be driven. Therefore, there is a problem that it is difficult to know how and how much the thermosensitive magnetic material is heated to drive the diamagnetic substance.

  Further, in the magnetic drive device described in Patent Document 1, it is possible to drive the diamagnetic material only within the potential wall of the magnetic field, so that the diamagnetic material can be freely moved to a desired position. I can't do that.

  Accordingly, an object of the present invention is to provide a magnetic drive device and a magnetic drive method that can more easily perform motion control of a magnetically levitated diamagnetic material.

[Magnetic drive]
The present invention includes a diamagnetic material to be driven,
A magnetic field generator for generating a magnetic field for levitating the diamagnetic material;
It is a magnetic drive apparatus provided with the light irradiation means for irradiating light to a part of said diamagnetic body.

  In the present invention, a part of the diamagnetic material is irradiated with light by the light irradiation means, and a part of the diamagnetic material is heated by photothermal conversion to partially change the magnetic susceptibility, thereby driving the diamagnet that is the driving object. The body movement can be controlled. Therefore, according to the present invention, it is possible to realize operations such as light induction and rotational motion of the diamagnetic material by directly irradiating light to the diamagnetic material to be driven. Motion control can be easily performed.

  In the present invention, the magnetic field generator may generate a magnetic field in which valleys of magnetic potential are formed with a period shorter than the total length of the diamagnetic material.

  Furthermore, in the present invention, the magnetic field generator has a plurality of permanent magnets arranged in a lattice pattern so that the permanent magnets whose one side is shorter than the entire length of the diamagnetic material are in close contact with other adjacent permanent magnets. You may make it make it the magnet arrangement | sequence arranged alternately.

  According to the present invention, since the valley of the magnetic potential is formed with a period shorter than the entire length of the diamagnetic material to be driven, the diamagnetic material can easily move and is reflected by the light irradiation means. By irradiating a part of the magnetic body with light, light induction for guiding the diamagnetic body in the direction of light irradiation can be performed.

Further, in the present invention, the shape of the diamagnetic material is a disk shape,
The magnetic field generator may generate a magnetic field that forms a wall of a magnetic potential that covers the periphery of the diamagnetic material.

  Furthermore, in the present invention, the magnetic field generator has a cylindrical first permanent magnet having a diameter shorter than the diameter of the diamagnetic body, and a shape covering the periphery of the first permanent magnet, You may make it comprise from the 2nd permanent magnet which has a magnetic pole different from the magnetic pole of the said 1st permanent magnet in the side facing the said diamagnetic body.

  According to the present invention, since the wall of the magnetic potential that covers the periphery of the diamagnetic material to be driven is configured, the diamagnetic material cannot be easily moved, and the irradiating means does not move the diamagnetic material. It is possible to rotate the diamagnetic material by irradiating a part thereof with light.

[Magnetic drive method]
In addition, the present invention magnetically levitates a diamagnetic material to be driven by generating a magnetic field with a magnetic field generator,
In this magnetic driving method, the movement of the diamagnetic material is controlled by irradiating a part of the magnetically levitated diamagnetic material with light.

  According to the present invention, since the motion control can be performed by directly irradiating the diamagnetic material to be driven with light, the magnetic drive device capable of performing the motion control of the magnetically levitated diamagnetic material more easily. And a magnetic driving method can be provided.

FIG. 3 is a diagram illustrating a state in which a diamagnetic body 10 is magnetically levitated by a magnetic field generated by a magnet array 20. FIG. 2 is a side view of a state in which the diamagnetic body 10 is levitated by the magnetic field generated by the magnet array 20 as shown in FIG. It is a figure which shows the relationship between the magnetic susceptibility of graphite which is a diamagnetic material, and temperature. It is a figure which shows the relationship between the flying distance of the diamagnetic body 10 shown in FIG. 2, and temperature. It is a figure which shows the structure of the magnetic drive device of the 1st Embodiment of this invention. It is a figure which shows a mode at the time of seeing the magnetic pole arrangement | sequence of the magnet arrangement | sequence 20 shown in FIG. 5 from the top. It is a figure which shows the mode of the magnetic field produced | generated by the magnet arrangement | sequence 20 at the time of seeing the magnetic drive device of the 1st Embodiment of this invention from the side. It is a figure which shows a mode that a laser beam irradiation apparatus 30 irradiates a part of magnetically levitated diamagnetic body 10 with a laser beam. It is a figure which shows a mode that it saw from the side at the time of irradiating a laser beam to a part of diamagnetic body 10 with the laser beam irradiation apparatus 30. FIG. FIG. 2 is a diagram illustrating a state in which light induction of the diamagnetic body 10 is performed by irradiating a part of the diamagnetic body 10 with laser light in the magnetic drive device according to the first embodiment of the present invention. It is a figure which shows another structure of the magnetic drive device of the 1st Embodiment of this invention. It is a figure which shows the structure of the magnetic drive device of the 2nd Embodiment of this invention. It is a figure for demonstrating the structure of the cylindrical magnet 40 shown in FIG. 3 is a cross-sectional view when a diamagnetic body 10 is placed in a magnetic field formed by a columnar magnet 40. FIG. It is sectional drawing at the time of irradiating a part of diamagnetic body 10 shown in FIG. 14 with the laser beam by the laser beam irradiation apparatus 30. FIG. In the magnetic drive device of the 2nd Embodiment of this invention, it is a figure which shows a mode that the diamagnetic body 10 rotates by irradiating a part of diamagnetic body 10 with a laser beam.

[background]
First, in order to help understanding of the present invention, magnetic levitation of a diamagnetic material will be described.

  FIG. 1 is a diagram illustrating a state in which the diamagnetic body 10 is magnetically levitated by the magnetic field generated by the magnet array 20.

  The magnet array 20 has a configuration in which a plurality of permanent magnets are alternately arranged in a lattice pattern so that magnetic poles different from other adjacent permanent magnets are in close contact with each other. That is, in the magnet arrangement | sequence 20, as FIG. 1 shows, the N pole and the S pole are arranged alternately.

  The diamagnetic body 10 is an object made of a material having a negative magnetic susceptibility. Here, the diamagnetic body 10 is made of graphite having a thickness of 25 μm and a diameter of 10 mm.

  As shown in FIG. 1, the diamagnetic body 10 having a negative magnetic susceptibility generates a repulsive force in a magnetic field space. Therefore, by placing such a diamagnetic body 10 in a specific magnetic field space, magnetic levitation can be achieved. It becomes possible.

  Next, FIG. 2 shows a side view of how the diamagnetic body 10 is levitated by the magnetic field generated by the magnet array 20 as shown in FIG. As shown in FIG. 2, the diamagnetic body 10 floats at a position where the repulsive force Fmag due to the magnetic field generated by the magnet array 20 and the gravity mg are balanced (Fmag = mg).

Here, m is the mass (kg) of the diamagnetic body 10, and g is the gravitational acceleration (m / s ² ).

Further, the repulsive force Fmag is calculated by the following equation.

  Here, dB / dz indicates the gradient of the magnetic flux density B in the vertical direction.

  That is, as can be seen by referring to the above formula, the magnitude of the repulsive force Fmag is proportional to the magnetic susceptibility χ, so the larger the absolute value of the magnetic susceptibility χ, the larger the magnitude of the repulsive force Fmag.

  Here, it is known that the magnetic susceptibility of the diamagnetic material changes with temperature. FIG. 3 shows the relationship between the magnetic susceptibility and temperature of graphite, which is a diamagnetic material. FIG. 4 shows the relationship between the flying distance of the diamagnetic body 10 shown in FIG. 2 and the temperature.

  Although the magnetic susceptibility increases as the temperature increases, the magnetic susceptibility of the diamagnetic material takes a negative value. As can be seen from FIG. 3, the absolute value of the magnetic susceptibility of the diamagnetic material increases as the temperature increases. It is getting smaller.

  That is, as the temperature increases, the magnitude of the repulsive force Fmag shown in FIG. 2 decreases. Therefore, as shown in FIG. 4, the flying distance of the diamagnetic body 10 becomes shorter as the temperature of the diamagnetic body 10 becomes higher.

  It can be seen that the levitation distance of the diamagnetic material levitating above a certain magnetic field can be controlled by temperature. Referring to FIG. 4, it can be seen that the flying distance of the diamagnetic body 10 is changed by about 10% by light irradiation.

[Embodiment]
Next, embodiments of the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 5 is a diagram showing the configuration of the magnetic drive device according to the first embodiment of the present invention.

  As shown in FIG. 5, the magnetic drive device of the present embodiment includes a diamagnetic body 10 to be driven, a magnet array 20 that is a magnetic field generator that generates a magnetic field for floating the diamagnetic body 10, and The laser beam irradiation device 30 is a light irradiation means for irradiating a part of the diamagnetic material 10 with laser light.

  The diamagnetic material 10 in this embodiment is the same material as that shown in FIG. 1, and is made of graphite having a thickness of 25 μm and a diameter of 10 mm. In the present embodiment, the case where the diamagnetic body 10 has a disk shape will be described. However, the shape of the diamagnetic body 10 does not have to be a disk shape, and may be a square or rectangular plate shape. It may be other shapes.

  The magnet array 20 is composed of a plurality of permanent magnets whose vertical and horizontal widths are 3 × 3 mm shorter than 10 mm which is the diameter (full length) of the diamagnetic body 10 and whose height is 10 mm. The plurality of permanent magnets are alternately arranged in a lattice pattern so that magnetic poles different from other adjacent permanent magnets are in close contact with each other. That is, the plurality of permanent magnets are arranged in a lattice shape so that the N poles and the S poles are alternately arranged.

  With such a configuration, the magnet array 20 generates a magnetic field in which valleys of the magnetic potential are formed with a period shorter than the entire length of the diamagnetic body 10.

  The laser irradiation apparatus 30 is an apparatus that can irradiate laser light having an irradiation light wavelength of 405 nm and an irradiation light intensity of 300 mW. In the present embodiment, the laser irradiation device 30 irradiates the diamagnetic body 10 with laser light, and changes the temperature of the diamagnetic body 10 by photothermal conversion.

  Next, FIG. 6 shows a view of the magnetic pole array of the magnet array 20 as viewed from above. In FIG. 6, the diamagnetic material 10 is shown transparent so that the arrangement of the magnetic poles can be easily seen.

  Referring to FIG. 6, it can be seen that in the magnet array 20, the S poles and the N poles are alternately arranged so that the same magnetic poles are not arranged between adjacent permanent magnets.

  Next, FIG. 7 shows the state of the magnetic field generated by the magnet array 20 when the magnetic drive device of this embodiment is viewed from the side. In the present embodiment, since the diameter of the diamagnetic body 10 is 10 mm and the width and the vertical width of each permanent magnet constituting the magnet array 20 are 3 mm, in the magnetic field generated by the magnet array 20, As shown in FIG. 7, it can be seen that valleys of the magnetic potential are formed with a period shorter than the entire length of the diamagnetic body 10.

  Therefore, in the magnetic drive device of the present embodiment, the diamagnetic body 10 can be easily moved only by applying a minute force in the horizontal direction.

  In the magnetic drive device of the present embodiment, when the motion control of the diamagnetic body 10 that is magnetically levitated in this way is performed, as shown in FIG. Is irradiated with laser light.

  FIG. 9 shows a state seen from the side when the laser beam is irradiated to a part of the diamagnetic material 10 by the laser beam irradiation device 30.

  Referring to FIG. 9, in the diamagnetic body 10, when a laser beam is irradiated on a part, the temperature of the part rises and the absolute value of the magnetic susceptibility decreases, and only the part irradiated with the laser beam floats. The distance is getting shorter. Therefore, the direction of the repulsive force Fmag that the diamagnetic body 10 receives from the magnetic field is inclined with respect to the vertical direction. Therefore, as shown in FIG. 9, as can be seen by resolving the repulsive force Fmag in the vertical direction and the horizontal direction, the diamagnetic body 10 is subjected to a force that moves to the side irradiated with the laser beam. . As a result, by irradiating a part of the diamagnetic body 10 with laser light as in the magnetic drive device of the present embodiment, the diamagnetic body 10 moves to the side irradiated with the laser light. And if the irradiation position of a laser beam is as it is, if the diamagnetic body 10 moves until the irradiation position of a laser beam becomes the center, the diamagnetic body 10 will stop moving.

  When the laser beam irradiation device 30 is operated and the laser beam irradiation position is continuously moved, the diamagnetic body 10 continues to move following the movement of the irradiation position as shown in FIG. That is, according to the magnetic drive device of the present embodiment, it is possible to perform light guidance that guides the diamagnetic body 10 that has been magnetically levitated in the direction of light irradiation.

  Furthermore, another configuration of the magnetic drive device of this embodiment will be described with reference to FIG. The magnetic drive device of the present embodiment having the configuration shown in FIG. 11 has a configuration in which the magnet array 20 is replaced with a magnet array 20a with respect to the configuration shown in FIG.

  In this magnet arrangement 20a, three long and narrow rectangular parallelepiped permanent magnets are arranged so that different magnetic poles are adjacent to each other. In the configuration shown in FIG. 11, the diamagnetic body 10 cannot freely move on the magnet array 20a, and the central permanent magnet sandwiched between two other permanent magnets by the repulsive force of the magnetic potential. It is possible to reciprocate only in the longitudinal direction.

  For this reason, in the configuration as shown in FIG. 11, by irradiating a part of the diamagnetic body 10 with the laser light irradiation device 30, the diamagnetic body 10 can be light-induced to slide on the rail. it can.

  In FIG. 11, the case where the diamagnetic body 10 is moved to the back side of the magnet array 20a is shown. However, by irradiating the opposite side of the diamagnetic body with laser light, the diamagnetic body 10 is moved to the magnet array 20a. It moves to the near side of.

  As described above, according to the magnetic drive device of the present embodiment, it is possible to perform the light induction of the magnetically levitated diamagnetic body 10 only by irradiating a part of the diamagnetic body 10 with laser light. Motion control of the levitated diamagnetic body 10 can be easily performed.

  In the magnetic drive device of the present invention, the magnetically levitated diamagnetic material can be guided by the irradiation position of the laser beam, so that it can be applied to a manipulation or an actuator for controlling the position of an object, It can also be applied to various toys that are driven by magnetically levitated diamagnetic materials. In addition, the present invention can be applied to material transport by placing an object to be transported on a levitated diamagnetic material. Furthermore, the present invention can also be applied to various types of sensing using the movement of a diamagnetic material depending on the presence or absence of light irradiation.

[Second Embodiment]
Next, a magnetic drive device according to a second embodiment of the present invention will be described.

  FIG. 12 is a diagram showing the configuration of the magnetic drive device according to the second embodiment of the present invention.

  As shown in FIG. 12, the magnetic drive device of the present embodiment includes a diamagnetic body 10 to be driven, and a columnar magnet 40 that is a magnetic field generator that generates a magnetic field for floating the diamagnetic body 10. The laser beam irradiation device 30 is a light irradiation means for irradiating a part of the diamagnetic body 10 with laser light.

  The magnetic drive device of this embodiment rotates a disk-shaped diamagnetic material 10 that has been magnetically levitated. The diamagnetic material 10 and the laser beam irradiation device 30 in this embodiment are the same as those in the magnetic drive device of the first embodiment shown in FIG. That is, the diamagnetic body 10 in the present embodiment is also made of graphite having a disk shape, a thickness of 25 μm, and a diameter of 10 mm.

  And the cylindrical magnet 40 in this embodiment becomes a structure as shown by FIG. The cylindrical magnet 40 has a cylindrical first permanent magnet having a diameter of 8 mm, which is slightly shorter than 10 mm, which is the diameter of the diamagnetic body 10, and a shape covering the periphery of the first permanent magnet. It is comprised from the 2nd permanent magnet which has a magnetic pole (S pole) different from the magnetic pole (N pole) of a 1st permanent magnet in the side which faces the magnetic body 10. FIG. In the example shown in FIG. 13, the first magnet embedded in the central portion of the columnar magnet 40 has an N pole on the side facing the diamagnetic body 10 and covers the periphery of the first magnet. The second magnet that faces the diamagnetic body 10 has an S pole.

  With such a configuration, the cylindrical magnet 40 has a magnetic potential that covers the periphery of the diamagnetic body 10 as shown in FIG. 14 when the diamagnetic body 10 is placed on the upper side. Generates a magnetic field that constitutes a wall.

  FIG. 14 is a cross-sectional view when the diamagnetic body 10 is placed in a magnetic field formed by the columnar magnet 40. However, the shape of the magnetic potential shown in FIG. 14 is conceptual and is different from the actual shape.

  FIG. 15 is a cross-sectional view when a portion of the diamagnetic material 10 shown in FIG. 14 is irradiated with a laser beam by the laser beam irradiation device 30.

  Referring to FIG. 15, in the diamagnetic material 10, when a part of the diamagnetic material 10 is irradiated with the laser light, the temperature of the part rises and the absolute value of the magnetic susceptibility decreases, and only the part irradiated with the laser light floats. The distance is getting shorter. Therefore, the direction of the repulsive force Fmag that the diamagnetic body 10 receives from the magnetic field is inclined with respect to the vertical direction. Therefore, as shown in FIG. 15, as can be understood from resolving the repulsive force Fmag in the vertical direction and the horizontal direction, a force that moves to the side irradiated with the laser beam acts on the diamagnetic body 10. .

  However, in the magnetic drive device according to the present embodiment, since the wall of the magnetic potential is provided around the diamagnetic body 10, the diamagnetic body 10 cannot move, and the diamagnetic body 10 is in the horizontal direction. The force to be moved is changed in direction by the wall of the magnetic potential and rotates the diamagnetic body 10.

  As a result, in the magnetic drive device of this embodiment, as shown in FIG. 16, the diamagnetic body 10 rotates on the columnar magnet 40 by irradiating a part of the diamagnetic body 10 with laser light. become.

  As described above, according to the magnetic drive device of the present embodiment, the magnetically levitated diamagnetic body 10 can be rotated only by irradiating a part of the diamagnetic body 10 with laser light. Thus, the motion control of the diamagnetic body 10 can be easily performed.

  In this embodiment, a part of the diamagnetic material 10 that has been magnetically levitated is irradiated with laser light to rotate the diamagnetic material 10, but by using sunlight instead of the laser light, It can also be applied to photovoltaic power generation.

  In other words, by adopting a configuration in which sunlight is irradiated to a part of the magnetically levitated diamagnetic material, the light energy of sunlight is converted into the rotational motion of the diamagnetic material, and power is generated by this rotational motion. If this is done, solar power generation can be realized.

  Specifically, for example, solar energy can be obtained by converting light energy into rotational motion by using a magnetically levitated diamagnetic material as a planetary gear in a planetary gear mechanism and rotating the generator by this rotational motion. It is possible to realize power generation. However, in order to realize such a configuration, it is naturally necessary to make the shape of the diamagnetic material considerably large.

[Modification]
In the first and second embodiments, the case where graphite is used as the diamagnetic body 10 has been described. Since graphite is black, it has high conversion efficiency during photothermal conversion. Therefore, the time from the start of light irradiation to the desired temperature is short. Graphite also has a high thermal conductivity, so it quickly returns to its original temperature when light irradiation is stopped. For these reasons, graphite is a suitable material when motion control of a diamagnetic material is performed using photothermal conversion as in the present invention.

  However, the present invention is not limited to the case where graphite is used as the diamagnetic material, and can be similarly applied to the case where another material having a negative magnetic susceptibility such as bismuth is used as the diamagnetic material. is there.

  In addition to graphite and bismuth, various materials such as polycarbonate, polystyrene, and polyethylene are known as diamagnetic materials, and these materials can be used as diamagnetic materials.

  Moreover, although the said 1st and 2nd embodiment demonstrated using the case where a laser beam was irradiated to a part of diamagnetic body 10 by the laser beam irradiation apparatus 30, this invention is limited to such a structure. Instead, the movement of the diamagnetic body 10 may be controlled by irradiating a part of the diamagnetic body 10 with light from another light source such as a light emitting diode. Of course, the present invention can also be realized by irradiating a part of the diamagnetic body 10 with sunlight as described above.

DESCRIPTION OF SYMBOLS 10 Diamagnetic material 20, 20a Magnet arrangement | sequence 30 Laser beam irradiation apparatus 40 Cylindrical magnet

Claims (6)

A diamagnetic material to be driven, and
A magnetic field generator for generating a magnetic field for levitating the diamagnetic material;
A light irradiation means for irradiating a part of the diamagnetic material;
A magnetic drive device comprising:   2. The magnetic drive device for a diamagnetic material according to claim 1, wherein the magnetic field generator generates a magnetic field such that a valley of a magnetic potential is formed with a period shorter than the total length of the diamagnetic material.   The magnetic field generator includes a magnet in which a plurality of permanent magnets are alternately arranged in a lattice pattern so that a permanent magnet whose one side is shorter than the entire length of the diamagnetic material is in close contact with other adjacent permanent magnets. 3. The magnetic drive device according to claim 2, which is an array. The shape of the diamagnetic material is a disk shape,
The magnetic drive unit according to claim 1, wherein the magnetic field generator generates a magnetic field that forms a wall of a magnetic potential that covers the periphery of the diamagnetic material.   The magnetic field generator has a cylindrical first permanent magnet having a diameter shorter than the diameter of the diamagnetic material and a shape covering the periphery of the first permanent magnet, and faces the diamagnetic material. The magnetic drive unit according to claim 4, further comprising a second permanent magnet having a magnetic pole different from the magnetic pole of the first permanent magnet on the closed side. A magnetic field is generated by a magnetic field generator to levitate a diamagnetic material to be driven,
A magnetic drive method for controlling the movement of the diamagnetic material by irradiating a part of the diamagnetic material with magnetic levitation to light.

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