JPH04267508A - Magnetizing yoke - Google Patents

Abstract

PURPOSE:To enable a permanent magnet to be sufficiently magnetized by a method wherein a circular ring type magnetizing yoke is formed of a permanent magnet material while windings are made in a multitude of trenches formed inside the circular ring so as to concentrate the magnetic flux of the magnetizing yoke in the easily magnetizing direction of the permanent magnet material. CONSTITUTION:A permanent magnet 24 to be magnetized is inserted into the inner diametral part of a magnetizing yoke as shown in Fig.1 so as to magnetize the permanent magnet 21 of the magnetizing yoke while windings 23 are fed with specific current to generate magnetic flux around the windings 23 as shown in Fig.2. At this time, the magnetizing yoke 21 comprising a permanent magnetic material is also magnetized together with the permanent magnet 24. Next, when the current is shut off to remove the permanent magnet 24, N, S magnetic poles are alternately made on the surface of the part not forming the trenches due to the residual magnetism on the magnetizing yoke 21 as shown in Fig.3. Through these procedures, the permanent magnet 24 can be inserted while turning into the magnetizing yoke 21 so as to automatically align the easily magnetizing direction of the permanent magnet 24 with the part not forming the trenches due to the function of the magnetic poles made on the ends of the part not forming the trenches so that the permanent magnet 24 may be sufficiently magnetized by feeding the windings 23 with specific current.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetizing yoke, and more particularly to a magnetizing yoke for magnetizing a plurality of magnetic poles on the outer peripheral surface of a cylindrical permanent magnet having magnetic anisotropy.

0002

2. Description of the Related Art FIG. 4 is a sectional view showing the structure of a conventional magnetizing yoke, and FIG. 5 is a developed view showing the relationship between magnetic poles and windings. In FIG. 4, reference numeral 1 is formed of a soft magnetic material into an annular shape, and its inner diameter is slightly larger than the outer diameter of the cylindrical permanent magnet 4 to be magnetized. A yoke is provided with a plurality of grooves 2, and 3 is a winding. As shown in FIG. 5, the winding 3 has a single conductor arranged in a meandering manner between grooves 2 provided in the inner diameter portion of the yoke 1. When magnetizing, a cylindrical permanent magnet 4 is inserted into the inner diameter part of the magnetizing yoke 1 and a predetermined current is passed through the winding 3. Magnetic flux is generated around the winding 3 as shown by the arrow, and the permanent magnet N and S poles are alternately magnetized on the outer periphery of the permanent magnet 4, and the current in the winding 3 is stopped and the permanent magnet 4 is taken out from the magnetizing yoke 1 to complete magnetization.

0003

[Problems to be Solved by the Invention] The magnetizing yoke shown in FIG. 4 and the magnetizing process described above are common, and when the permanent magnet to be magnetized is an isotropic magnet, When inserting the permanent magnet 4 to be magnetized into the yoke 1, the permanent magnet 4
If the permanent magnet 4 is fully inserted into the magnetizing yoke 1, it will be in a newly magnetized state regardless of the remaining magnetization state of the permanent magnet 4. There is no need to pay particular attention to the magnetized position. However, if the permanent magnet to be magnetized is a magnetically anisotropic magnet whose magnetic field is oriented at the position where the magnetic pole is to be formed, the magnetic field of the permanent magnet to be magnetized is oriented as shown by the broken line in FIG. It is necessary to align the position of the magnetic pole of the magnetizing yoke with the position of the magnetic pole part of the magnetizing yoke for magnetization. If the positions of both magnetic poles are misaligned as shown by the broken line in Fig. 7, it will not be possible to easily magnetize the permanent magnet. Since the positions of the magnetic flux generated from the magnetizing yoke do not match, a problem arises in that sufficient magnetization is not achieved. The object of the present invention is to obtain a magnetizing yoke in which the easy magnetization direction of a permanent magnet oriented in a magnetic field can be made to coincide with the direction of magnetic flux of the magnetizing yoke.

0004

[Means for Solving the Problems] The magnetizing yoke of the present invention has the following features:
The structure includes an annular yoke made of a permanent magnetic material and having a plurality of grooves formed on its inner peripheral surface, and a winding wire wound within the plurality of grooves.

[0005]

[Operation] An annular magnetized yoke is formed from a permanent magnet material,
Since the windings are installed in multiple grooves inside the ring,
Even when the winding is not energized, magnetic flux is generated by the permanent magnet of the magnetizing yoke in the inner diameter part without grooves (corresponding to the magnetic pole part), and the permanent magnet to be magnetized is moved by the magnetizing yoke. When inserted into the inner diameter part of the magnetizing yoke, the magnetizing yoke is inserted while rotating so that the direction of easy magnetization of the permanent magnet to be magnetized matches the magnetic pole part of the magnetizing yoke. The magnetic flux is concentrated and sufficient magnetization can be achieved.

[0006]

[Embodiment] Fig. 1 is a cross-sectional view showing the structure of a magnetizing yoke in which the present invention is implemented, where 21 is an annular magnetizing yoke made of a permanent magnet material, and 22 is a magnetizing yoke provided on the inner circumferential surface of the magnetizing yoke. 23 is a winding, and 24 is a permanent magnet oriented in a magnetic field to be magnetized. It is best to use a strong permanent magnetic material such as a rare earth magnet for the magnetizing yoke of No. 21.
A groove 22 for storing the winding 23 is provided on the inner circumferential surface, and the inner diameter portion (corresponding to the magnetic pole portion) where the groove is not provided is formed slightly larger than the outer diameter dimension of the permanent magnet 24 to be magnetized. A winding 23 is wound around the groove 22.

The arrangement of the windings is the same as that of the prior art magnetizing yoke shown in FIG. FIG. 2 shows the state of magnetization in the energized state for magnetizing the magnetizing yoke, and FIG. 3 shows the state of magnetization in the non-energized state. In order to magnetize the permanent magnet 21 of the completed magnetizing yoke, as shown in FIG. As shown in FIG. 2, a magnetic flux is generated around the winding 23, and a magnetizing yoke 21 made of a permanent magnet material together with a permanent magnet 24 to be magnetized.
When the permanent magnet 24 is removed by stopping the current, as shown in FIG. Magnetic poles appear.

Next, when a new permanent magnet 24 to be magnetized is inserted into the inner diameter part of the magnetizing yoke 21, due to the action of the magnetic pole appearing at the tip of the part without grooves (corresponding to the magnetic pole part), If the permanent magnet 24 is rotated and inserted so that the direction of easy magnetization coincides with the part where no groove is provided, and the winding 23 is energized in this state, sufficient magnetization can be achieved.

Furthermore, even if the direction of easy magnetization of the permanent magnet 24 to be magnetized at the time of insertion does not completely match the position of the magnetic pole part, the force of the magnetic flux generated when the winding 23 is energized The permanent magnet 24 is attracted and rotated, and is magnetized with the direction of easy magnetization matching the position of the magnetic pole portion.

0010

[Effects of the Invention] Since the magnetizing yoke according to the present invention has the above-described configuration, the magnetically anisotropic permanent magnet formed of a permanent magnet material and oriented in advance in a magnetic field at a predetermined magnetic pole position is magnetized. When it is a target permanent magnet, it is automatically rotated and magnetized so that the direction of easy magnetization of the permanent magnet matches the position of the magnetic pole part of the magnetizing yoke, so that sufficient magnetization can be achieved. be.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of a magnetizing yoke according to the present invention.

FIG. 2 is a diagram showing the magnetization state of the magnetizing yoke according to the present invention when energized.

FIG. 3 is a diagram showing the state of magnetization of the magnetizing yoke according to the present invention when no current is applied.

FIG. 4 is a partial cross-sectional view of a magnetizing yoke according to the prior art.

FIG. 5 is a developed view showing the arrangement of windings of a magnetizing yoke according to the prior art.

FIG. 6 shows a state when the magnetic pole portion of the magnetizing yoke and the magnetic pole direction of the magnetic field orientation of the permanent magnet to be magnetized match when magnetizing the anisotropic magnet.

FIG. 7 shows a state in which the direction of the magnetic pole portion of the magnetizing yoke and the magnetic field orientation of the permanent magnet to be magnetized are misaligned when magnetizing an anisotropic magnet.

[Explanation of symbols]

1: Magnetizing yoke made of soft magnetic material 2: Groove 3: Winding 4: Cylindrical permanent magnet 21: Magnetizing yoke 22 made of permanent magnet material: Groove for storing the winding 23: Winding 24: Magnetized object A cylindrical permanent magnet treated with magnetic field orientation.

Claims (1)

[Claims] 1. A magnetizing yoke used to magnetize a plurality of magnetic poles on the outer peripheral surface of a cylindrical permanent magnet, the annular yoke is made of a permanent magnet material and has a plurality of grooves on its inner peripheral surface.
1. A magnetized yoke comprising: a main body; and a winding wire wound within the plurality of grooves.