JPH01114381A - Actuator - Google Patents

Abstract

PURPOSE:To simplify a device and miniaturize it, by forming the combined unit of a superconductor and a magnetic unit, and by performing double-throw position change with a single magnetic source. CONSTITUTION:An actuator is provided with a superconductor 1 and a ferromagnetic unit 2, and the peripheral surface of the ferromagnetic unit 2 is covered with the superconductor 1, and one combined unit is formed with both the units. Besides, a case 3 for containing the combined unit, and a coil 4 for applying a magnetic field to said combined unit from the external side are arranged, and the combined unit is contained double-throw-displaced in the case 3, and the superconductor 1 is set in a perfect diamagnetic state in the peripheral atmosphere of a device. As a result, by the coil 4 of a single magnetic source, the double-throw positional change can be performed and is applied for switch function, breaker function, and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an actuator that performs a desired operation by displacing the position of a movable part within a case, and particularly relates to an actuator using a superconductor.

[Summary of the Disclosure] The present specification and drawings describe an actuator that performs a desired operation by displacing the position of a movable part within a case, which is capable of transitioning between two properties of complete diamagnetism and magnetism, and which has at least one property. The present invention discloses a technology that enables bidirectional positional changes by a single magnetic source by providing a movable part that is displaced by changes in the magnetic field of individual magnetic sources, thereby making it possible to simplify and downsize the device. .

[Prior Art] In recent years, technology for increasing the critical temperature of superconductors has been rapidly progressing, and some reports have even reported the possibility of superconductivity at room temperature. One of the most important properties of this superconductor is the Meissner effect, which exhibits perfect diamagnetism, and can be used in various applications including magnetic levitation. Now, a superconductor forms a single body or a group of fine particles.

In this case, it is well known that in order to have complete diamagnetic properties in a magnetic field, the particle diameter must be set larger than the magnetic field penetration distance on the surface. An example of the application of this superconducting fine particle group is, for example, when it is used as a developer in an image forming apparatus, and developer transportation and development using the Meissner effect can be considered.

Perfect diamagnetism is maintained by the Meissner effect.

Since there are upper limits to the critical temperature and magnetic flux density, it is also possible to convert between complete diamagnetism and paramagnetism by changing these parameters.

[Problems to be Solved by the Invention] As described above, superconductor fine particles and actuators using the same can be used in various applications.

However, since magnetic properties are simply the difference between being repelled by a magnetic field or not, other elements such as gravity, electric force, heat, etc. are required to create reciprocating motion using a single magnetic source. do. If this were to be done using magnetic force alone, multiple magnetic sources would be required, making the configuration complicated and large.

The present invention was devised in view of these problems.
By forming a combination of a superconductor and a magnetic material, bidirectional position change can be performed using a single magnetic source, simplifying and downsizing the device, and making it suitable for many applications such as switches, fuses, and display devices. The purpose is to provide an actuator that is capable of

[Means for solving the problem] In the present invention, the means for solving the above problem consists of a case and a movable part housed in the case, and the position of the movable part inside the case can be changed in both directions. An actuator that performs a desired operation by displacement, characterized by comprising a movable part that is capable of transitioning between two properties, complete diamagnetism and magnetism, and that is displaced by a change in the magnetic field of at least one magnetic source. It is something to do. The magnetic source has a constant static magnetic source, and the movable part is formed by a combination of a superconductor and a ferromagnetic material, the surface of a ferromagnetic material is coated with a superconductor, or a magnetic It is preferable to use a superconductor or a molded mixture of a ferromagnetic material and a superconductor, and the movable part can be a single body, a composite, a group of fine particles, or a molded body thereof. The particles may be dispersed in the particles, or the surface or the entire surface of the particles may be provided with charging characteristics.

[Function] In the present invention, by making one particle share the properties of magnetism and perfect diamagnetic property, it is possible to impart properties that enable bidirectional displacement of a single body or a fine particle even with only a single magnetic source. I have to. This is possible, for example, if one particle is a combination of a ferromagnetic material and a superconductor. Of course, assuming that the magnetic field of the ferromagnetic part is below the critical magnetic field of the superconductor, these particles can be enclosed within a certain area and a magnetic field applied to it.However, in this case, the superconductor is below the critical temperature. Assume that it exhibits perfect diamagnetism. If the particles are arranged in such a proportion that the repulsive force of the superconducting part is stronger than the attractive force towards the ferromagnetic part, the particles will move toward the wall in the opposite direction from the magnetic source.

If the strength of the applied magnetic field is further increased to exceed the critical magnetic field of the superconductor, the superconductor will transition from a completely diamagnetic state to a paramagnetic state, and the particles will return to their initial position due to the attractive force from the magnetic source exerted on the ferromagnetic part. return. That is, bidirectional displacement is possible. In order to increase the particle motion speed and improve efficiency, the surface of the magnetic material may be coated with a superconductor.

In this way, in a magnetic field weaker than the critical magnetic field, the magnetic field is repelled by the superconductor on the surface, so no external magnetic field acts on the internal magnetic material, and only the repulsive force due to the perfect diamagnetism of the superconductor acts, making it stronger than the critical magnetic field. In a large magnetic field, the superconductor is in a paramagnetic state, so the magnetic field penetrates inside and the particles behave as a magnetic material. These particles can be produced, for example, by applying fine particles of a ceramic superconductor dissolved in a solvent to the surface of ferrite particles and then heat-treating them.

Furthermore, existing ceramic superconducting materials may be used as magnetic superconducting materials by adding an appropriate amount of ferrite powder.

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

FIG. 1 is a configuration diagram showing an example of an actuator embodying the present invention. In FIG. 1, 1 is a superconductor, 2 is a ferromagnetic material, and the superconductor l covers the circumferential surface of the ferromagnetic material 2,
The two form one combined body. Reference numeral 3 denotes a case that houses the combined body, and 4 denotes a coil for applying a magnetic field to the combined body from the outside of the case 3. The combination of the superconductor 1 and the ferromagnetic material 2 is housed in a case 3 so as to be movable in both directions, and the end A (3a ), and the weaker end is defined as end B (3b). It is assumed that the superconductor l used here is in a completely diamagnetic state in the surrounding atmosphere of the device.

FIG. 2 is an explanatory diagram showing the operation of the coupled body when the magnetic field of the coil 4 is gradually strengthened in the above device.

Initially, the combined body is completely diamagnetic due to the Meissner effect of the superconductor 1, and as shown in Figure (a), it repels the magnetic field of the coil 4 and reaches the end B (3b). However, when the magnetic field is further strengthened and the magnetic field applied to the coupled body exceeds the superconductor's critical magnetic field Hc, the perfect diamagnetism of the superconductor l transitions to paramagnetism, so the superconductor 1 experiences magnetic repulsion from the coil. It no longer receives force, and the coil magnetic field enters inside. This penetrating magnetic field acts on the internal ferromagnetic body 2, and the coupled body receives an attractive force toward the coil side, and as shown in Figure (b), the end A
(3a) is reached. Bidirectional movement is thus possible by changing the strength of a single magnetic field. Of course, the thickness of the superconductor must be greater than the penetration depth of the magnetic field in perfect diamagnetism.

Now, if the magnetic field is simply erased when the bonded body reaches end B, the bonded body will remain at end B. Also, at the end A, the magnetic field is changed quickly from the ON state to the O state in a pulsed manner.
When changed to the FF state, the conjugate remains at end A. This is because a thermal transition is required for the superconductor's paramagnetism to become completely diamagnetic again, and it takes time. Therefore, as shown in FIG. 3, if the intensity H of the pulsed magnetic field is less than or equal to the critical magnetic field Hc, the position can be specified as the end B side, and if H is more than Ha, the position can be specified as the end A side. As shown in FIG. 4, the width of this pulse may be short enough that the phase transition of the combined body cannot be followed, and it is not necessarily necessary to keep the current flowing through the coil at all times.

However, if you want to reliably hold the bonded body at either end A or end B even when no current is applied, for example, a portion of the ferromagnetic material may be slightly exposed from the end face of the bonded body. All you need to do is to apply a weak magnetic field to both end faces of the case. Also, if the bond is in the form of fine particles, it will stick to the end face of the case with van der Waals force, so it can maintain its position. .

Regarding the case where the conjugate is a fine particle, the fifth
As shown in the figure, the fine particles 2' of the binder may be dispersed in a solution, or the surface of each fine particle may be coated with a resin having charging properties, and held at the edge of the case by its electrostatic attraction. You can.

In addition, as shown in Fig. 6, if the bias magnetic field generated by the magnet 5 is always kept slightly smaller than the critical magnetic field Hc, weak energy control is possible and the bonded body is always held at one end. .

FIG. 7 is a block diagram showing an application example of the present invention,
This is an example in which an image is displayed by differentiating a plurality of configuration examples of the diagram. In the figure, if the end surface 3b' of the case is made of a semipermeable material and the end portion 1b of the combined body is colored, it is possible to display the positional relationship between the combined body and the end surface B based on the magnetic field strength. In other words, when the bond is repelled by the magnetic field, the color of the bond at the end appears through the semi-permeability, and when the bond is not on the end face B side, the color of the bond is not displayed due to the semi-transparency. When the function relies only on magnetic material as in the past, coils are required at both ends, but in the present invention, only a single magnetic source is required, making the configuration extremely simple.

Furthermore, images can be written and erased by scanning each unit with the magnetic head 4' without attaching coils to each unit.

Furthermore, as shown in FIG. 8, it can also be applied as a switch or breaker that detects changes in the magnetic field and interrupts the circuit when a current of a certain level or more flows through the circuit.

The circuit is introduced into the case 3 via a coil 4 and a pair of electrodes 6, where the coupled bodies are normally repelled by the magnetic field of the coil 4 and current flows between the electrodes 6 via the superconducting surface. , if an excessive current flows, the superconductor transitions to paramagnetism, the bond is attracted to the other end, and the circuit is broken. Incidentally, if a part of the combined body is extended outside the case 3 and is made to also serve as the push switch 7, the circuit can be restored in a timely manner. Even if the combined body returns to complete diamagnetism, the magnetic field of the coil 4 has disappeared and the circuit will not recover unless the push switch 7 is turned on, so it is safe. In this case, the electrode 6 is disposed on the end face of the case. This device can also be used as a meter overcurrent protection device.

By forming a combination of a superconductor and a ferromagnetic material in this way, it is possible to change the position in both directions with a single magnetic source, and it is possible to perform switch functions, breaker functions, image display functions, etc. Many applications are possible. This combined body may be either a single body or fine particles and molded bodies thereof.

In addition, the superconductor part and the ferromagnetic part are inside the combined body.
It may be divided into regions or may be mixed. Also, when a ferromagnetic material is coated with a superconductor, the efficiency is high.

[Effects of the Invention] As explained above, according to the present invention, by forming a combination of a superconductor and a magnetic material, bidirectional positional change can be performed by a single magnetic source, and the device simplification and miniaturization can be realized. In particular, the present invention can be applied to many applications such as switches, breakers, and display devices.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the embodiment, Fig. 3 is an explanatory diagram of the positional relationship between the coupled body and the magnetic field, and Fig. 4 is an explanatory diagram of magnetic transition. , FIG. 5 and FIG. 6 are configuration diagrams of each embodiment of the present invention, FIG. 7 is a configuration diagram of an example of application of the present invention to a display device, and FIG. 8 is a configuration diagram of an example of application of the present invention to a breaker. It is a diagram. l...superconductor, 2...ferromagnetic material, 3...
...Case, 3a...End part A, 3b...
End B, 4... Coil, 5... Magnet, 6... Electrode. 7...Press switch.

Claims (8)

[Claims] (1) Consisting of a case and a movable part housed in the case,
In an actuator that performs a desired operation by displacing the position of a movable part in a case in both directions, the actuator is capable of transitioning between the two properties of complete diamagnetism and magnetism, and has at least one
An actuator comprising a movable part that is displaced by a change in the magnetic field of a magnetic source. (2) The actuator according to claim 1, wherein the movable part is formed of a combination of a superconductor and a ferromagnetic material. (3) The actuator according to claim 1, wherein the movable part is formed by coating the surface of a ferromagnetic material with a superconductor. (4) The actuator according to claim 1, wherein the movable part is formed of a magnetic superconductor or a mixed molded body of a ferromagnetic material and a superconductor. (5) The actuator according to any one of claims 1 to 4, characterized in that it includes a constant magnetostatic source. (6) The actuator according to any one of claims 1 to 5, wherein the movable part has fine particles or a molded body thereof. (7) The actuator according to claim 6, characterized in that fine particles are dispersed in a solution. (8) The actuator according to claim 6 or 7, characterized in that the surface or the entire part of the fine particles has a charging property.