JPH02254704A - Magnetizing device for permanent magnet - Google Patents

Abstract

PURPOSE:To reduce leakage magnetic flux and to make it possible to conduct a magnetizing operation efficiently and more completely by a method wherein a low permeability member is inserted into the gap between the coil in a groove and the surface of a yoke. CONSTITUTION:Four magnetic poles 2 and 3 are formed on a yoke 4, coils 6 are passed in series through the groove 7 located between respective magnet poles, and a permanent magnet 8 is press into the gap G. Accordingly, when a low permeability member (permanent magnet 8) is viewed from the yoke 1, magnetic flux is in a state wherein it is hardly passed through, and as a result, the magnetic flux generated by the coil passes through the material to be magnetized from the surface of the yoke 1 without leaking, and a magnetizing operation is conducted through a material to be magnetized M. As a result, the leakage of magnetic flux is prevented, the generated magnetic flux is effectively used for magnetization without leakage, and the efficiency of magnetization can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetizing device for permanent magnets used in electromagnetic devices such as motors, stepping motors, and the like.

[Conventional technology]

A conventional magnetizing device is shown in FIGS. 3 to 6 as an example of four-pole magnetization, in which magnetized materials M are placed facing each other between substantially circular yokes 1.1, and the yoke A coil 6 is disposed in a groove 7 between the magnetic poles 2 and 3 of the magnetic pole. The magnetic flux φ generated by the excitation current flowing through the coil 6 passes through the magnetized material M, thereby causing magnetization.

In order to efficiently carry out magnetization, the material M to be magnetized and the surfaces of the magnetic poles 2 and 3 should be brought as close as possible to each other in order to allow all of the magnetic flux φ to pass through the material M to be magnetized without leaking. Generally preferred.

For this purpose, if the coil 6 protrudes from the surface of the yoke 1, the above-mentioned approach becomes difficult.

However, since variations in the processing of the groove 7 and variations in the finished height of the coil 6 cannot be avoided, the depth of the groove 7 is
It is customary to process the material with a margin greater than the finished height of the material.

When processed as described above, the coil 6 sinks by the dimension A shown in FIG. 5, forming a space G, and when an excitation current is applied to the coil 6, it becomes as shown in FIG. In addition to the magnetic flux φ1 that passes through the magnetized material M, leakage magnetic flux φ2 that directly passes through the space G in the groove 7 between the magnetic poles 2 and 3 is generated. Since this leakage magnetic flux φ2 does not pass through the magnetized material M at all, the magnetization efficiency only decreases (,
It becomes difficult to perform complete magnetization.

For this reason, in the past, after inserting the coil 6 into the groove 7, the surface of the yoke 1 was ground by the dimension A to minimize the space G, but since the finished height of the coil also differs for each groove, the coil was ground too much. The insulation coating of the wire may be scraped off, causing dielectric breakdown between the yoke 1 and the coil 6.

[Problems to be Solved by the Invention] The present invention focuses on the above-mentioned conventional circumstances, and provides a magnetizing device that can reduce leakage magnetic flux and efficiently perform more complete magnetization without requiring high accuracy in processing each part. It is about providing.

[Means to solve the problem]

The present invention is characterized in that a low magnetic permeability member is inserted into the space between the coil in the groove and the yoke surface.

Further, it is characterized in that the low magnetic permeability member is a superconductor.

Further, the low magnetic permeability member is characterized by inserting a permanent magnet having the same polarity as the adjacent magnetic pole.

It is also characterized in that a permanent magnet is press-fitted into the groove between the magnetic poles.

[Effect]

The present invention is made by inserting a low magnetic permeability member into the space between the coil and the surface of the yoke, and when looking at the low magnetic permeability member from the yoke, it becomes difficult for magnetic flux to pass through, and the magnetic flux generated by the coil eventually disappears. passes through the magnetized material from the yoke surface without leaking and performs the magnetizing action.

Furthermore, in a superconductor, magnetic flux is completely prevented from passing through due to the Messner effect, so no leakage magnetic flux occurs at all.

Furthermore, since a permanent magnet is inserted between the magnetic poles, leakage magnetic flux is almost never generated.

Furthermore, since the permanent magnet is press-fitted into the groove between the magnetic poles, the groove is closed by the permanent magnet, and the coil and the permanent magnet are held in the yoke.

〔Example〕

1 and 2 show embodiments of the present invention.
Four magnetic poles 2.3 are formed on the yoke 1 shown in the figure, and a coil 6 is passed in series through the groove 7 between each magnetic pole. Then, the permanent magnet 8 is press-fitted into the space G above the coil 6 in the groove 7. The inner groove 7 is not limited to having a bottom.

Since the permanent magnet 8 is subjected to a magnetic field in the opposite direction every time it is magnetized, a permanent magnet with a high coercive force is suitable.

The magnetic flux φ3 of the permanent magnet 8 passes through the magnetic pole 3 toward the boron material M to be adhered, thereby assisting magnetization and improving the magnetization efficiency.

In the press-fitting operation, by press-fitting the permanent magnet with the surface of the yoke 1 as a reference, the surface of the permanent magnet 8 and the surface of the yoke 10 can be easily matched.

Therefore, since the magnetized material M can be brought very close to the surface of the yoke 1, the -layer magnetization efficiency is improved.The coil 6 is also held in the yoke 1 together with the permanent magnet 8 held by press-fitting, and the coil 6 is held by the excitation current. Even if the electromagnetic repulsive force acting on the wire is strong, the coil 6 will not escape from the groove 7.

In the magnetization work, as shown in Figure 2, when magnetizing is performed by sandwiching both sides of the material M to be magnetized between the yokes 1.1, the magnetic flux φ1 penetrating between the front and back sides of the material M to be magnetized causes , a pair of N and S poles are magnetized in the front and back directions.

If only one side of the yoke 1 is used, the magnetic flux φ1 coming out of the magnetic pole 3 on the N pole side enters the surface of the magnetized material M, bends at right angles without penetrating the back, and turns the inside of the magnetized material M into a disc. The magnetic flux φ1 comes out from the front side in the direction of the magnetic pole 2 after turning at a right angle and returns to the magnetic pole 2. In this case, the magnetized state of the magnetized material M is such that the portion through which the magnetic flux φ1 enters and exits becomes a pair of N and S poles. In this way, the arrangement of the yoke 1 and the magnetized material M can be changed in various ways other than those described above depending on the magnetization mode.

Furthermore, in Fig. 1, four permanent magnets 8 are press-fitted into the groove 7, but in addition to making the strength of each permanent magnet uniform, it is necessary to vary the magnetization strength for each magnetic pole. It is also possible to vary the strength of the permanent magnets or even remove some of the permanent magnets.

Another example of attaching the permanent magnet 8 to the yoke 1 is by using adhesive or welding, or by deforming a part of the groove wall toward the permanent magnet side and caulking the permanent magnet between the deformed walls. It's okay.

Although not shown, superconductors such as ceramics and intermetallic compounds can be inserted into the grooves to create the Messner effect (completely diamagnetic material).
[Effects of the Invention] The present invention improves magnetization efficiency by effectively using all the magnetic flux generated by preventing leakage magnetic flux for magnetization.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a front view and FIG. 2 is an enlarged partially sectional view taken along line aa in FIG. 1. 3 to 6 show conventional examples, FIG. 3 is a front view, FIG. 4 is an enlarged partially sectional view taken along the line a-a in FIG. 3, and FIG. FIG. 6 is an enlarged view showing the state of magnetic flux in the state of FIG. 5; 1: York, 2, 3, 4, 5: M! Pole, 6: Coil, 7
= groove, 8: permanent magnet, φ, φ1. φ2: magnetic flux, φ2:
Leakage magnetic flux, G: Space, M: Magnetized material tube 1 @ δ Figure 3 Figure 4 fs5 Figure 2 Figure 6

Claims (4)

[Claims] (1) Consisting of a yoke with multiple magnetic poles and a coil placed in the groove between the magnetic poles, the magnetized material placed opposite the magnetic pole surface of the yoke is magnetized by magnetic flux generated by the coil's excitation current. A magnetizing device for a permanent magnet, characterized in that a low magnetic permeability member is inserted into a space between a coil in a groove and a yoke surface. (2) A permanent magnet magnetizing device according to claim 1, wherein the low magnetic permeability member is a superconductor. (3) A permanent magnet magnetizing device according to claim 1, characterized in that a permanent magnet is inserted in which the low magnetic permeability member has the same polarity as the adjacent magnetic poles. (4) A permanent magnet magnetizing device according to claim 1 or 3, characterized in that the permanent magnet is press-fitted into a groove between magnetic poles.