JPWO2019069990A1 - Ferrofluid controller - Google Patents

Abstract

To make the raised part of the magnetic fluid where the spike phenomenon occurs visible without obstructing the field of view. The magnetic fluid control device 1 includes a pedestal 10 having a magnet 12 and an inclusion body 20 which is arranged on the gantry 10 and is formed in a hollow shape and in which the magnetic fluid 221 is enclosed. The main body 21 is made of a transparent material and has an opening 211 for inserting the magnetic fluid 221 and a lid 23 that closes the opening 211 of the main body 21. The main body 10 is formed in a dome shape that bulges in the direction opposite to the direction in which the bottom surface is formed, with the portion formed on the bottom surface as the bottom surface.

Description

The present invention relates to a ferrofluid control device.

Conventionally, the spike phenomenon is known as an interface phenomenon of a magnetic fluid. In the spike phenomenon, the magnetic fluid rises along the magnetic field lines generated from the magnet, deforms to a position where the repulsion between the raised magnetic fluids and the surface tension are balanced, and finally forms a spike shape and is stable. It is a phenomenon that occurs.

As a device for visually recognizing such a spike phenomenon, a magnetic fluid composite for exhibition containing a magnetic fluid, a container having a lid on the upper side and containing the magnetic fluid composite for exhibition inside, and a magnetic field generating member are provided. A magnetic fluid composite exhibiting device has been proposed in which a magnetic field generating member exerts a magnetic force on the ferrofluid composite for display housed in the container (Patent Document 1).
According to the magnetic fluid composite display device of Patent Document 1, a delicate shape caused by the spike phenomenon can be visually recognized.

International Publication No. 2016/02753

However, since the magnetic fluid composite display device of Patent Document 1 is provided with a thick lid on the upper side, the shape of the magnetic fluid in which the spike phenomenon occurs is visually recognized from the direction in which the lid is provided. Can't.

In view of the above problems, it is an object of the present invention to make the raised portion of the magnetic fluid in which the spike phenomenon occurs visible without obstructing the field of view.

(1) A mount with a magnet and
An inclusion body which is arranged so as to be in contact with the gantry, is formed in a hollow shape, and has a magnetic fluid enclosed therein.
The inclusion body is
A main body made of a transparent material and having an opening for inserting the magnetic fluid,
It has a lid that closes the opening of the main body, and
The opening is formed on the bottom surface of the main body or a side surface near the bottom surface.
A magnetic fluid control device in which the main body is in contact with the gantry on the bottom surface and is formed in a dome shape that bulges in a direction opposite to the direction in which the bottom surface is formed.

According to the configuration of (1), the magnetic fluid control device includes a gantry and an inclusion body.
The gantry has a magnet. The inclusion body is arranged so as to be in contact with the gantry, is formed in a hollow shape, a magnetic fluid is enclosed inside, and has a main body and a lid. The main body is made of a transparent material and has an opening for inserting a magnetic fluid. The lid closes the opening of the main body.
The opening is formed on the bottom surface of the main body or a side surface near the bottom surface.
Further, the main body is formed in a dome shape that is in contact with the gantry on the bottom surface and bulges in the direction opposite to the direction in which the bottom surface is formed.

As a result, the magnetic fluid is inserted into the main body, and the enclosure in which the opening formed on the bottom surface or the side surface near the bottom surface is closed by the lid is placed on the pedestal having a magnet so that the bottom surface is in contact with the enclosure. Then, the magnetic fluid causes a spike phenomenon inside the main body. At this time, the magnetic fluid rises upward from the bottom surface along the magnetic flux line of the magnet inside the inclusion body made of a transparent material.
Therefore, the raised portion of the magnetic fluid in which the spike phenomenon occurs can be visually recognized without obstructing the field of view.

That is, in the case of a magnetic fluid placed in a bottle as in the prior art, the lid blocks the line of sight, and even when the bottle is turned upside down, the optical distortion due to the shape of the bottle makes it difficult to see the magnetic fluid inside. There is an angle. However, according to the present invention, since the main body has a transparent dome shape, the beautiful shape of the thorns of the magnetic fluid in which the spike phenomenon occurs can be seen from any direction.

In addition, as in the prior art, all commercially available products such as magnetic fluids placed in bottles are devices in which a small magnet is manually brought close to the bottle to splinter the magnetic fluid and play. In this device, in order to maintain the shape in which the thorns of the magnetic fluid are widely spread, it is necessary to hold the magnet in the position where the thorns are spread, so the hand holding the magnet must be kept still. It is difficult to watch for a long time, and it is necessary to move the magnet to search for the position where beautiful thorn flowers appear. According to the present invention, the amount of magnetic fluid and transparent liquid inside the gantry, and from the magnet to the magnetic fluid in the transparent container, so that the thorn shape of the magnetic fluid that spreads beautifully like a flower can be reliably formed and held. The distance between the magnets and the ferrofluid can be adjusted according to the characteristics of the magnet and the ferrofluid to be incorporated, so that the shape of the ferrofluid can be reliably formed as if the flowers were wide open.

(2) The magnetism according to (1), wherein the shape formed by the magnetic fluid encapsulated inside the inclusion body can be changed by changing the position of the inclusion body with respect to the magnet of the gantry. Fluid control device.

As a result, it is possible to change the shape of the spike formed by the magnetic fluid by changing the position of the inclusion body with respect to the magnet of the gantry and changing the distance between the magnet and the magnetic fluid.

(3) The gantry has a gantry body in which the magnet is arranged inside.
A plurality of contact surfaces that can come into contact with the inclusion body are formed on the gantry main body when the inclusion body is arranged on the gantry.
The magnetic fluid control device according to (1), wherein the plurality of contact surfaces have different distances to the magnet.

As a result, the magnetic force that affects the magnetic fluid is generated when the inclusion body is arranged so as to abut on a certain contact surface of the gantry body and when the inclusion body is arranged so as to abut on another contact surface. Since they are different, it is possible to visually recognize the spike shape of the magnetic fluid having a different shape in each case.

(4) The inclusion body is
Multiple pieces of information are displayed on the bottom surface.
Movable with respect to the gantry
The magnetic fluid control device according to (1), wherein when the magnet is arranged at a position that overlaps with any one of the plurality of information, the magnetic fluid is arranged at a position that overlaps with the information.

As a result, the magnetic fluid is moved from the state where the magnetic fluid is placed at a position that overlaps with any of the information displayed on the bottom surface of the inclusion body to the position where the magnetic fluid overlaps with other information by moving the inclusion body with respect to the gantry. Can be made to. Therefore, for example, it is possible to change from a state in which certain information cannot be visually recognized and another information to be visible to a state in which certain information can be visually recognized and other information cannot be visually recognized.

According to the present invention, the raised portion of the magnetic fluid in which the spike phenomenon occurs can be visually recognized without obstructing the field of view.

It is a figure explaining the structure of the magnetic fluid control device 1 which concerns on 1st Embodiment of this invention. It is sectional drawing of the gantry 10 which concerns on 1st Embodiment of this invention. It is sectional drawing of the inclusion body 20 which concerns on 1st Embodiment of this invention. It is an enlarged sectional view around the opening 211 of the inclusion body 20 which concerns on 1st Embodiment and a modification of this invention. FIG. 4A is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the first embodiment of the present invention, and FIG. 4B is the opening of the inclusion body 20 according to the first modification of the present invention. FIG. 4 (c) is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the second modification of the present invention. FIG. 4D is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the third modification of the present invention. From the example shown in FIG. 1, it is a photograph of the magnetic fluid control device 1 when the distance from the magnetic pole of the magnet 12 arranged inside the gantry 10 to the contact surface with the inclusion body 20 is large. It is a photograph which imaged the magnetic fluid control device 1 shown in FIG. 1 from above. It is a table which shows the result of an experimental example. FIG. 7A shows the magnetic force (kG) at the center of the magnetic pole surface, the number of thorn shapes at the center of the magnetic fluid 221, and the number of thorn shapes around it when magnets of different sizes are brought into close contact with the inclusion body 20. And the result of measuring the height of the thorn shape in the center is shown. FIG. 7B shows the center of the magnetic fluid 221 when the distance (GAP) from the inclusion body 20 is increased with the same neodymium magnet (diameter 10 mm, height 16 mm, central magnetic field 4.3 kG). The results of measuring the number of thorn shapes and the number of surrounding thorn shapes are shown. FIG. 7 (c) shows the magnetic fluid 221 when the distance (GAP) from the inclusion body 20 is increased with the same neodymium magnet (diameter 10 mm, height 10.8 mm, central magnetic field 4.4 kG). The results of measuring the number of thorn shapes in the center and the number of thorn shapes around the center are shown. FIG. 7 (d) shows the magnetic force (kG) at the center of the magnetic pole surface and the magnetic fluid 221 when neodymium magnets having the same diameter (10 mm) and a height of 1.8 mm are stacked and the height is changed. The results of measuring the number of thorn shapes in the center, the number of thorn shapes around the center, and the height of the thorn shapes in the center are shown. It is a figure which shows a part of the result of this experimental example schematically. FIG. 8A is a diagram schematically showing an aspect of the thorn shape of the magnetic fluid 221 when a magnet having a diameter of 10 mm and a height of 14.4 mm is brought into contact with the inclusion body 20. FIG. 8B is a diagram schematically showing an aspect of the thorn shape of the magnetic fluid 221 when a magnet having a diameter of 10 mm and a height of 3.6 mm is brought into contact with the inclusion body 20. It is a figure explaining the structure of the magnetic fluid control device 1A which concerns on 2nd Embodiment of this invention. FIG. 9A is a diagram showing a first aspect of the magnetic fluid control device 1A, and FIG. 9B is a diagram showing a second aspect of the magnetic fluid control device 1A. It is sectional drawing of the magnetic fluid control apparatus 1A shown in FIG. 10 (a) is a cross-sectional view taken along the line AA'shown in FIG. 9, and FIG. 10 (b) is a cross-sectional view taken along the line BB'shown in FIG.

Hereinafter, embodiments for carrying out the present invention (hereinafter, embodiments) will be described in detail with reference to the accompanying drawings. In the description of the embodiment, the same components are designated by the same reference numerals, and the description thereof will be omitted or simplified.

[First Embodiment]
FIG. 1 is a diagram illustrating a configuration of a magnetic fluid control device 1 according to a first embodiment of the present invention. FIG. 1 is a photograph of the magnetic fluid control device 1.
The ferrofluid control device 1 includes a gantry 10 having a magnet and an inclusion body 20 arranged on the gantry 10. The magnetic fluid control device 1 is a device that makes it possible to visually recognize the shape formed by the magnetic fluid 221 enclosed inside the inclusion body 20 in which the spike phenomenon is caused by the magnet of the gantry 10. In the magnetic fluid control device 1, for example, by arranging the inclusion body 20 on a frame 10 placed on an exhibition stand or the like, the spike shape formed by the magnetic fluid 221 enclosed inside the inclusion body 20 is in a constant state. It is possible to appreciate the spike phenomenon of magnetic fluid.

FIG. 2 is a cross-sectional view of the gantry 10 according to the first embodiment of the present invention.
The gantry 10 has a gantry main body 11 and a magnet 12 arranged inside the gantry main body 11.
The gantry main body 11 forms the outer shape of the gantry, and is made of, for example, wood or resin, and the magnet 12 is arranged in the space formed inside. Further, the gantry main body 11 is formed with a plurality of contact surfaces 111 that come into contact with the inclusion bodies 20 when the inclusion bodies 20 are arranged on the gantry 10. For example, in the example shown in FIG. 2, the outer surface of the gantry main body 11 is formed in a substantially spherical shape as a whole, and a part of the outer surface forms a relatively flat contact surface 111.

In the example shown in FIG. 2, the two contact surfaces 111a and 111b are arranged at positions facing each other with the magnetic pole 121 of the magnet 12 interposed therebetween. The distances L1 and L2 of the two contact surfaces 111a and 111b to the magnetic pole 121 of the magnet 12 are different from each other. As a result, the magnetic force generated by the magnet 12 differs between the contact surface 111a and the contact surface 111b. In the example shown in FIG. 2, the distance L1 is smaller than the distance L2. Therefore, the magnetic force of the contact surface 111a is larger than that of the contact surface 111b.

The difference in the strength and direction of the magnetic force on the contact surface 111 is the difference in the shape formed by the spike phenomenon of the magnetic fluid inside the arranged inclusion body 20.
FIG. 5 is a photograph of the magnetic fluid control device 1 when the distance from the magnetic pole of the magnet 12 arranged inside the gantry 10 to the contact surface with the inclusion body 20 is large from the example shown in FIG.
As shown in FIGS. 1 and 5, the magnetic fluid in the magnetic fluid control device 1 is formed with a plurality of thorn shapes that rise in a direction away from the portion in contact with the gantry 10 and the inclusion body 20 due to the spike phenomenon. Comparing the example shown in FIG. 1 with the example shown in FIG. 5, in the example shown in FIG. 5, the distance from the magnetic pole to the contact surface with the inclusion body 20 is larger than that in the example shown in FIG. 1 (contact surface). It can be confirmed that the number of thorn shapes is reduced, the height of the thorn shapes is reduced, and the width of the base end of the thorn shapes is increased.

In this way, by changing the position of the inclusion body 20 with respect to the magnet 12 installed in the gantry 10, the shape formed by the magnetic fluid 221 enclosed inside the inclusion body 20 can be changed. Specifically, the magnetic force lines from the magnet 12 determine the positional relationship between the magnet 12 having a magnetic force sufficient to give a thorn shape to the magnetic fluid 221 in the inclusion body 20 and the inclusion body 20. It is provided with a mechanism that can be controlled so as to generate magnetic force lines in a direction substantially perpendicular to the bottom surface of 20. Then, by continuously changing the positional relationship, the opening angle of the thorn shape of the magnetic fluid 221 and the number of thorn shapes are changed, so that the flower of the magnetic fluid 221 appears to open in the inclusion body 20. Can be done.

As shown in FIG. 1, the outer surface of the gantry 10 may be provided with a pattern such as a pattern or characters. When such a pattern is viewed through the inclusion body 20, the inclusion body 20 functions as a lens, so that the pattern is viewed through the lens, and the interest is improved.
FIG. 6 is a photograph of the magnetic fluid control device 1 shown in FIG. 1 taken from above.
As shown in FIG. 6, when the magnetic fluid control device 1 is viewed from above, the shape formed by the spike phenomenon of the magnetic fluid 221 viewed from above can be visually recognized, and the gantry 10 viewed through the inclusion body 20 can be visually recognized. You can see the design attached to the outer surface. As shown in FIG. 6, the pattern viewed in this way appears to be magnified due to the lens effect of the inclusion body 20.

In the first embodiment, the outer shape of the gantry 10 is formed in a substantially spherical shape, but the present invention is not limited to this, and the gantry 10 can be formed in any shape such as a polygonal shape, a cylindrical shape, and a quadrangular shape. .. Further, the contact surface 111 of the gantry 10 is not limited to two, and may be one or three or more. Further, the contact surface 111 of the gantry 10 can be formed at an arbitrary position on the outer surface if the inclusion body 20 can be arranged. Further, when two or more contact surfaces 111 of the gantry 10 are formed, it is desirable that the distances from the magnetic poles of these magnets 12 are different from each other, but the distance is not limited to this, and the distances from the magnetic poles of the magnets 12 are the same. Good.

The magnet 12 is composed of a permanent magnet, but the magnet 12 is not limited to this, and may be composed of an electromagnet whose magnetic force can be controlled. In this case, by controlling the change of the magnetic force, it is possible to continuously change the spike shape of the magnetic fluid 221 of the inclusion body 20 arranged so as to be overlapped with the contact surface of the gantry 10. As a result, the opening angle of the thorn shape and the number of thorn shapes of the magnetic fluid 221 can be changed to make it appear as if a flower is opening in the inclusion body 20.
Further, in the gantry 10, the permanent magnet is moved by incorporating mechanical parts such as gears and motors, and the relative position and angle of the permanent magnet from the inclusion body 20 are changed to continuously change the spike shape. Is also possible.

Further, in the first embodiment, the magnet 12 increases the magnetic force by stacking a plurality of permanent magnets, but if a desired magnetic force can be obtained by one permanent magnet, the magnet 12 is composed of only one permanent magnet. You may. Further, the magnet 12 is formed in a cylindrical shape, but the magnet 12 is not limited to this, and may be any shape such as a quadrangular prism shape, a donut shape, and a rod shape.

FIG. 3 is a cross-sectional view of the inclusion body 20 according to the first embodiment of the present invention.
The inclusion body 20 is formed in a hollow shape, and the magnetic fluid 221 is enclosed inside. The inclusion body 20 includes a main body 21 in which a transparent material is formed in a hollow shape and an opening 211 for inserting the magnetic fluid 221, a composite body 22 sealed inside the main body 21, and an opening 211. A lid 23 for closing the lid 23 and a sealing member 24 for covering the lid 23 are provided.

The main body 21 is made of a transparent material such as glass or resin. The inclusion body 20 is arranged so as to be overlapped with the contact surface of the gantry 10 (see FIG. 1) with the portion where the opening 211 is formed as the bottom surface. The main body 21 is formed in a dome shape that bulges in a direction opposite to the direction in which the bottom surface is formed. For example, in the example shown in FIG. 3, the outer shape of the main body 21 is formed into a substantially spherical shape. That is, it is formed in a shape that bulges in a direction orthogonal to the direction in which the bottom surface is formed, in addition to the direction opposite to the direction in which the bottom surface is formed. The main body 21 is not limited to a substantially spherical shape, and may have an arbitrary shape as long as it has a dome shape.

FIG. 4 is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the first embodiment and the modified example of the present invention. FIG. 4A is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the first embodiment of the present invention, and FIG. 4B is the opening of the inclusion body 20 according to the first modification of the present invention. FIG. 4 (c) is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the second modification of the present invention. FIG. 4D is an enlarged cross-sectional view of the periphery of the opening 211 of the inclusion body 20 according to the third modification of the present invention.

As shown in FIG. 4A, the opening 211 of the inclusion body 20 according to the first embodiment is closed by the lid 23 having a recessed portion formed in the central portion. The portion around the recessed portion of the lid 23 is locked to the side edge forming the opening 211. The lid 23 is covered with a sealing member 24 made of a waterproof material such as silicon while being attached to the opening 211.

Conventionally, since the magnetic fluid which is a nanoparticle leaks in a small gap, it has been avoided to arrange the opening of the container containing the magnetic fluid at the lower part, but according to the present embodiment, it is chemically. By covering the lid 23 with a stable sealing member 24 made of silicon resin or the like, it is possible to prevent the magnetic fluid 221 from leaking from the opening 211.

As shown in FIG. 4B, in the opening 211 of the inclusion body 20 according to the first modification, the outer side edge of the opening 211 is inclined downward toward the opening 211 inward. .. A portion around the recessed portion of the lid 23 is locked to a downwardly sloping side edge forming the opening 211.

As shown in FIG. 4C, the opening 211 according to the second modification is closed by a lid 23a formed of the same material and the same thickness as the main body 21. The side edge of the lid 23a and the side edge of the opening 211 are adhered to each other by, for example, a sealing member 24a which is an ultraviolet curable adhesive.

Regarding the opening 211, even if the lid 23 is composed of, for example, a poly stopper, a resin stopper, a glass stopper or a rubber stopper, the inner surface thereof is coated with water and oil repellency, and the magnetic fluid is repelled. Good. Further, a magnetic material such as iron may be inserted into the recessed portion of the lid 23 to enhance the magnetic force. Further, the shape of the lid 23 may be made into a three-dimensional shape such as a cone protruding inside the inclusion body 20, and a magnetic material such as iron may be put inside the three-dimensional shape.

As shown in FIG. 4D, the opening 211 according to the third modification is closed only by the silicon lid 23. As described above, when the inner diameter of the opening 211 is relatively small, a sealing member (for example, a silicon material) is applied so as to fill the opening 211. When the sealing member is cured, it functions in the same manner as the lid.

Returning to FIG. 3, the composite 22 contains a ferrofluid 221 and water 222.
The water 222 is general water, and may be tap water, pure water, or the like.
The magnetic fluid 221 is a known oil-based magnetic fluid, and is a ferrite system such as Fe ferrite (that is, magnetite), Mn ferrite, Co ferrite, Ni ferrite, Zn ferrite, Mn-Co ferrite, Mo-Ni ferrite and Mo-Zn ferrite. The magnetic particles of No. 1 are finely dispersed in an oil-based dispersion medium such as kerosine in the presence of a surfactant such as oleic acid.

Further, the composite 22 may further include a non-magnetic light-shielding piece having a known predetermined color. The non-magnetic light-shielding piece is a thin microfilm having hydrophilicity, oil affinity, low magnetism and light-shielding property. By including such a non-magnetic light-shielding piece in the composite 22, it is possible to make the interface between the water 222 and the magnetic fluid 221 covered with the non-magnetic light-shielding piece. In this case, the black color caused by the ferrite of the magnetic fluid 221 is covered with the non-magnetic light-shielding piece, and the color of the non-magnetic light-shielding piece becomes visible. That is, the black magnetic fluid 221 can be made to appear as if it were colored.

[Experimental example]
In the experimental example, the size of the magnet brought close to the inclusion body 20 (see FIG. 3) in the first embodiment and the distance between the magnet and the inclusion body 20 are changed to change the form formed by the magnetic fluid 221 (see FIG. 3). Was observed. The amount of the magnetic fluid 221 in the enclosure 20 of the experimental example was about 2 ml, and (model number DS-60) manufactured by Sigma High Chemical Co., Ltd. was used as the magnetic fluid. FIG. 7 is a table showing the results of the experimental examples.

FIG. 7A shows the magnetic force (kG) at the center of the magnetic pole surface, the number of thorn shapes at the center of the magnetic fluid 221, and the number of thorn shapes around it when magnets of different sizes are brought into close contact with the inclusion body 20. And the result of measuring the height of the thorn shape in the center is shown.
From the results shown in FIG. 7A, when the magnetic force at the center of the magnetic pole surface is substantially the same, the larger the diameter of the magnet, the more the number of thorn shapes in the center, the number of thorn shapes around it, and the height of the thorn shape in the center. Was confirmed to increase.

FIG. 7B shows the center of the magnetic fluid 221 when the distance (GAP) from the inclusion body 20 is increased with the same neodymium magnet (diameter 10 mm, height 16 mm, central magnetic field 4.3 kG). The results of measuring the number of thorn shapes and the number of surrounding thorn shapes are shown.
FIG. 7 (c) shows the magnetic fluid 221 when the distance (GAP) from the inclusion body 20 is increased with the same neodymium magnet (diameter 10 mm, height 10.8 mm, central magnetic field 4.4 kG). The results of measuring the number of thorn shapes in the center and the number of thorn shapes around the center are shown. The value of the "central magnetic field" in the experimental example is the magnetic force at the center of the magnetic pole surface.

From the results shown in FIGS. 7 (b) and 7 (c), it was confirmed that as the magnet is separated from the inclusion body 20, the center of the magnetic fluid 221 is dented and the width of the base end of the thorn shape becomes larger. It was also confirmed that the higher the height of the magnet, the larger the number of thorn shapes in the center and the number of thorn shapes in the periphery of the magnetic fluid 221.

FIG. 7 (d) shows the magnetic force (kG) at the center of the magnetic pole surface and the center of the magnetic fluid 221 when neodymium magnets having the same diameter (10 mm) and a height of 1.8 mm are stacked and the height is changed. The results of measuring the number of thorn shapes, the number of surrounding thorn shapes, and the height of the central thorn shape are shown.
From the results shown in FIG. 7 (d), as the number of magnets stacked (height) becomes less than a predetermined value, the number of central thorn shapes, the number of peripheral thorn shapes, and the height of the central thorn shape increase. However, it was confirmed that there was no change above the predetermined value. In addition, the number of thorn shapes around and the height of the thorn shape in the center are relatively low and do not change at a predetermined value (5 (9 mm) in this experimental example) or more, but the number of thorn shapes in the center is compared. It was confirmed that the change disappeared at a high predetermined value (7 pieces (12.6 mm) in this experimental example) or more.

FIG. 8 is a diagram schematically showing a part of the results of this experimental example. FIG. 8A is a diagram schematically showing an aspect of the thorn shape of the magnetic fluid 221 when a magnet having a diameter of 10 mm and a height of 14.4 mm is brought into contact with the inclusion body 20. FIG. 8B is a diagram schematically showing an aspect of the thorn shape of the magnetic fluid 221 when a magnet having a diameter of 10 mm and a height of 3.6 mm is brought into contact with the inclusion body 20.

In the example shown in FIG. 8A, the height of the magnet is higher than that in the example shown in FIG. 8B, so that the magnetic field line (dotted line in the middle of FIG. 8) rises in the vertical direction. In this case, the thorn shape also appears upward in the central portion.
On the other hand, in the example shown in FIG. 8B, since the height of the magnet is lower than that in the example shown in FIG. 8A, the magnetic field line (dotted line in the middle of FIG. 8) spreads in the horizontal direction. In this case, the thorn shape does not appear upward in the central portion, and a large number of thorn shapes appear only in the horizontal direction (see, for example, FIG. 9 described later).

[Second Embodiment]
Next, the second embodiment will be described. In the following description, the same configurations as in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted or simplified.
FIG. 9 is a diagram illustrating a configuration of a magnetic fluid control device 1A according to a second embodiment of the present invention. FIG. 9A is a diagram showing a first aspect of the magnetic fluid control device 1A, and FIG. 9B is a diagram showing a second aspect of the magnetic fluid control device 1A.

The magnetic fluid control device 1A includes a gantry 10A and an enclosure 20A arranged so as to overlap the contact surface of the gantry 10A. FIG. 9 is a view of the magnetic fluid control device 1A viewed from the inclusion body 20A side in the direction of the gantry 10A.
The inclusion body 20A displays information consisting of a plurality of characters, figures, etc. on the bottom (in the example shown in FIG. 9, the display such as “presence” shown in (a) and the display such as “absence” shown in (b)). It is movable with respect to the gantry 10.

FIG. 10 is a cross-sectional view of the magnetic fluid control device 1A shown in FIG. 10 (a) is a cross-sectional view taken along the line AA'shown in FIG. 9, and FIG. 10 (b) is a cross-sectional view taken along the line BB'shown in FIG.
The gantry 10A has a gantry main body 11A and a magnet 12 arranged inside the gantry main body 11A.
The gantry main body 11A is made of wood or resin, for example, and the magnet 12 is arranged in the space formed inside. As shown in FIG. 10B, the gantry main body 11A is formed with a groove 111A that engages with a part of the inclusion body 20A on at least a part of the side surface that is in sliding contact with the inclusion body 20A.

Similar to the inclusion body 20 (see FIG. 3), the inclusion body 20A contains a magnetic fluid 221 and includes a main body 21A, a lid (not shown) and a sealing member (not shown), but the main body 21A The outer shape is different from that of the inclusion body 20. As shown in FIG. 9, the main body 21A has a magnetic fluid control device 1A having a substantially quadrangular outer shape when viewed from the inclusion body 20A side in the direction of the gantry 10A. Further, a plurality of information (in the example shown in FIG. 9, display of "presence" or the like shown in (a), display of "absence" or the like shown in (b)) is displayed on the bottom surface of the main body 21A. Further, as shown in FIG. 10, the main body 21A is formed in a dome shape that bulges in a direction opposite to the direction in which the bottom surface is formed.

Further, as shown in FIG. 10B, the main body 21A projects toward the gantry 10A side, and a protruding portion 211A that is in sliding contact with the side surface of the gantry main body 11A is formed. The protrusion 211A is formed with a protrusion 212A that projects toward the gantry main body 11A and engages with the groove 111A of the gantry main body 11A.

The magnetic fluid control device 1A slides the inclusion body 20A along the side surface of the gantry 10A with respect to the gantry 10A by engaging the groove 111A of the gantry 10A with the protrusion 212A of the inclusion body 20A. Can be done.

According to such a configuration, the magnetic fluid control device 1A can function as an information display device. For example, the user arranges the inclusion body 20A so that one of the information of the inclusion body 20A (for example, "absence" or the like) comes at a position overlapping with the magnet 12 of the gantry 10A. Then, at the position where the magnetic fluid 221 in the inclusion body 20A overlaps with one of the information, the shape is formed by the spike phenomenon. As a result, one piece of information becomes invisible due to the magnetic fluid 221 and the other information (for example, a display such as "presence") becomes visible, and the state shown in FIG. 9A is obtained.

Next, the user moves the inclusion body 20A with respect to the gantry 10A so that the other information of the inclusion body 20A (for example, "present" or the like) comes to a position overlapping the magnet 12 of the gantry 10A. The inclusion body 20A is arranged in the. Then, at the position where the magnetic fluid 221 in the inclusion body 20A overlaps with the other information, the shape is formed by the spike phenomenon. As a result, the other information (for example, display of "presence" or the like) becomes invisible due to the magnetic fluid 221 and one information (for example, display of "absence" or the like) becomes visible, as shown in FIG. 9B. It will be in the state shown.

Such a magnetic fluid control device 1A can use the magnetic fluid 221 to selectively display information in an aesthetically pleasing manner.

The magnetic fluid control device 1A is not limited to the mode in which the inclusion body 20A can be slidably moved with respect to the gantry 10A, and if a plurality of information can be selectively displayed, for example, any movement mode such as rotational movement can be used. can do.

Although the present invention has been described above using the embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various changes or improvements can be made to the above embodiments. Further, it is clear from the description of the scope of claims that the form to which such a modification or improvement is added may be included in the technical scope of the present invention.

1,1A Magnetic fluid control device 10,10A Mount 11,11A Mount body 12 Magnet 20,20A Inclusion body 21,21A Body 22 Composite 23 Lid 24 Seal member 111 Contact surface 111A Groove 111a, 111b Contact surface 121 Magnetic pole 211 Opening 211A Protruding 212A Protruding 221 Ferrofluid 222 Water

Claims (4)

A pedestal with a magnet and
An inclusion body which is arranged so as to be in contact with the gantry, is formed in a hollow shape, and has a magnetic fluid enclosed therein.
The inclusion body is
A main body made of a transparent material and having an opening for inserting the magnetic fluid,
It has a lid that closes the opening of the main body, and
The opening is formed on the bottom surface of the main body or a side surface near the bottom surface.
A magnetic fluid control device in which the main body is in contact with the gantry on the bottom surface and is formed in a dome shape that bulges in a direction opposite to the direction in which the bottom surface is formed. The magnetic fluid control device according to claim 1, wherein the shape formed by the magnetic fluid encapsulated inside the inclusion body can be changed by changing the position of the inclusion body with respect to the magnet of the gantry. .. The gantry has a gantry body in which the magnet is arranged.
The gantry body is formed with a plurality of contact surfaces that come into contact with the inclusion bodies when the inclusion bodies are arranged on the gantry.
The magnetic fluid control device according to claim 1, wherein the plurality of contact surfaces have different distances to the magnets. The inclusion body is
Multiple pieces of information are displayed on the bottom surface.
Movable with respect to the gantry
The magnetic fluid control device according to claim 1, wherein when the magnet is arranged at a position that overlaps with any one of the plurality of information, the magnetic fluid is arranged at a position that overlaps with the information.