JPH01302706A - Magnetic circuit - Google Patents

Abstract

PURPOSE:To improve efficiency of a magnetic device by either coating or arranging a superconducting material over the surface or on the periphery excluding both the air gap of a soft magnetic material and a magnet constituting a magnetic circuit to thereby prevent leaks of magnetic flux outside the magnetic circuit. CONSTITUTION:A superconductive material 8 is coated around the peripheries of a core 1, a yoke 2, and an auxiliary yoke 3. When an exciting current is caused to flow to an exciting coil 7, a plunger 5 is attracted toward the core 1 side. An impact wire 6 is integrally formed with the plunger 5 through an armature plate 4, whereby the impact wire 6 is moved in association with the movement of the plunger 5, and thus moves in the direction indicated by the arrow B to perform a printing operation. At this time, since the superconductive material 8, which has the Meissner effect-based magnetic shielding effect, is coated around the peripheries of the core 1, the yoke 2, and the yoke 3, magnetic flux leakage is eliminated because of this effect. Accordingly, the efficiency of a magnetic device can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic circuit for an actuator such as a motor or a plunger, a generator, or a static device such as a transformer.

[Conventional technology]

BACKGROUND ART Magnetic devices such as various magnetic actuators and magnetic recording devices that utilize magnetism have been known.

The magnetic circuit of these devices forms a closed circuit similar to an electrical circuit, and the air gap that exists within this circuit
This utilizes the attractive force generated on both end surfaces or the magnetizing force within the air gap.

[Problem that the invention seeks to solve]

The above-mentioned magnetic circuit is mainly composed of soft magnetic materials, magnets, coils, etc., but since the magnetic permeability of soft magnetic materials is at most 105 times that of air, it is as shown in 13 in Figure 2. The leakage of magnetic flux was unavoidable, and the leakage magnetic flux caused a decrease in the efficiency of the equipment.

The present invention solves the above problems, and aims to provide a magnetic circuit that can prevent or supplementally guide leakage magnetic flux and effectively utilize the generated magnetic flux for magnetic attraction or magnetization.

[Means for solving problems]

The superconducting phenomenon is a state in which the electric resistance is zero and it has diamagnetic properties, and this diamagnetic property is especially called the Meissner effect. Figure 6 is a diagram to explain the Meissner effect. When body 30 is present, superconductor 30 excludes magnetic flux. That is, the magnetic field 29 applied from the outside
creates a current in a thin layer on the surface of the superconductor 30, and this current impinges an external magnetic field 29 inside the superconductor 30.
This is to create a magnetic field large enough to erase the light. When a material with such diamagnetic properties is present on the surface of a magnetic body, magnetic flux is blocked and cannot penetrate into the inside of the magnetic body.

The present invention utilizes the properties of superconductors as described above,
In a magnetic circuit mainly composed of soft magnetic materials, magnets, coils, etc., by applying or placing superconducting material on the surface or around the air gap of the soft magnetic material and magnet, magnetic flux outside the magnetic circuit can be reduced. This is to achieve the above objective by preventing leakage of.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. FIG. 1 is a sectional view of a magnetic head of an impact dot printer using the magnetic circuit of this embodiment.

The excitation coil 7 is wound around the core 1, and the plunger 5 is disposed at a position facing the core 1 via an air gap.

An auxiliary yoke 3 is fixed to the yoke 2 and arranged around the plunger 5.

Further, an impact wire 17 is connected to the armature plate 4 fixed to the plunger 5. Further, the spring 10 is used to maintain a predetermined air gap 11 between the plunger 5 and the core 1 in a non-excited state.

The superconducting material 8 is applied around the core 1, yoke 2, and auxiliary yoke 3.

In the above configuration, when an excitation current is passed through the excitation coil 7, the core 1, yoke 2, auxiliary yoke 3, armature plate 4,
A magnetic field is generated in the magnetic circuit consisting of the plunger 5, air gap 11, etc. The plunger 5 is attracted toward the core 1 by the suction force generated at both ends of the air gap 11. Since the impact wire 6 is integrated with the granger 5 via the armature plate 4, it moves in the direction of arrow B in conjunction with the movement of the plunger 5 and performs the printing operation.At this time, the core 1, yoke 2, and auxiliary Since a superconducting material 8 is applied around the yoke 3, leakage of magnetic flux is eliminated as shown in the figure due to the magnetic shielding effect of the superconducting material due to the Meissner effect.

Although not shown, the Meissner effect can be maintained by arranging a cooling device for the superconducting material in contact with or in the vicinity of the superconducting material 8.

[Other Examples]

FIG. 3 shows a linear step motor showing another embodiment to which the magnetic circuit of the present invention is applied.

The mover 14 is composed of a yoke 15, 16 and a magnet 17, and the magnetic pole facing the stator 18 is notched and has teeth 19 formed therein. The yokes 15 and 16 each have two magnetic poles ts(a), ts(b), x6(a
), t6(b), and these two magnetic poles 15(a), 1
5(b) (or 16(a), 16(b)) (7) Tooth 19
are shifted in phase by % of the pitch of the teeth 25 of the stator 18. Also, the magnetic poles of the yokes 15 and 16 are pitch-shifted from each other. Furthermore, coils 20 and 21 are wound around the magnetic poles of each yoke to strengthen or weaken the magnetic flux of the magnet 17.

A superconducting material 22 is provided in the gap between the teeth of the mover 14 and the stator 18.
23 is embedded, and superconducting material 24 is also arranged on the magnetic poles and the side surfaces of the magnet 17.

With the above configuration, the magnetic flux 28 generated in the air gap between the mover 14 and the stator 18 is directed straight from tooth to tooth, as shown in the same figure and in FIG. 5, which is an enlarged view of the air gap. , preventing the generation of magnetic flux 26 that detours in and out of the side surfaces of the teeth as shown in FIG. It can be generated effectively and more powerful propulsive force can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, by applying or arranging the superconducting material on the surface of or around the soft magnetic material and the magnet constituting the magnetic circuit other than the air gap, leakage can be prevented due to the Meissner effect of the superconducting material. It is possible to provide a magnetic circuit that can prevent or supplementally guide magnetic flux and effectively utilize the generated magnetic flux, which has a great effect on improving the efficiency of all magnetic devices using the magnetic circuit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the magnetic circuit of the present invention, FIG. 2 is a sectional view of a conventional magnetic circuit, FIG. 3 is a sectional view of another embodiment, and FIGS. FIG. 6, an enlarged view of the gap portion, is an explanatory diagram of the Meissner effect. 1 Core 2... Yoke 3 Auxiliary yoke 4 - Amateur plate 5 - Plunger 6 - I/Pact wire 7... Excitation coil 8... Superconducting material 9 - Armature presser 10... Spring 11... Air gap 12... ... Magnetic flux 13 ... Leakage magnetic flux 14 ... Mover 15.16 ... Yoke 17 ... Magnetic flux 18 ... Stator 19.25 ... Teeth 20.21 ... Coils 22, 23.24. ...Superconducting material 26...Leakage magnetic flux 1s(a), xs(b), 1a(a), t6(b) -
...Magnetic pole 29...Magnetic field 30...Superconductor

Claims (1)

[Claims] A magnetic circuit mainly composed of a soft magnetic material, a magnet, and a coil, characterized in that a superconducting material is coated or placed on the surface or around the soft magnetic material and the magnet other than the air gap.