JPS63308907A - Manufacture of permanent magnet - Google Patents

Abstract

PURPOSE:To obtain a permanent magnet wherein an intensive magnetic pole is formed at a specified position of a member to be magnetized, by a method wherein leakage flux is prevented from permeating into the member to be magnetized, by arranging perfect diamagnet ic material around the member to be magnetized, and the magnetic path and the direction of magnetizing flux itself are controlled. CONSTITUTION:Perfect diamagnetic members 3A-3C act so as to repel leakage flux toward a member to be magnetized, so that the magnetizing action of the member to be magnetized is increased, and the effect is remarkable in the case of manufacturing a multipole magnet. In the example wherein a ring type member 2 to be magnetized is subjected to magnetization with magnetic poles 1A-1D of one or more magnetizing yokes, the interference caused by mutual leakage flux of yokes can be prevented by inserting the perfect diamagnetic members 3A-3C between the magnetic poles of each magnetizing yoke. Further, by arranging the perfect diamagnetic member 3D on the outer periphery of the ring type member to be magnet ized, a magnet can be manufactured, wherein leakage magnetic flux from the outer periphery is pervented, magnetic poles are concentrated on the inner periphery, and the generation of magnetic poles on the outer periphery is restricted. The perfect diamagnetic member can be selected from superconducting materials. Thereby, a permanent magnet can be obtained wherein the intensity of magnetization is large, and pole position is clear.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of manufacturing a permanent magnet.

(Prior art) To create a permanent magnet 'ffd' by magnetizing a magnetic material, a magnetic path is usually formed using an excitation coil or a yoke provided in the excitation magnet, and the open circuit portion (gap) of the magnetic path is The members to be magnetized are brought into contact with each other or brought close to each other to form a closed magnetic path and are magnetized. In addition, a method for producing a permanent magnet, a so-called multipolar magnet, in which magnetic poles are formed at any part other than both ends by locally adhering a highly permeable member to the surface of the magnetized member during magnetization. is also known (Japanese Unexamined Patent Publication No. 107809/1983).

(Problem to be Solved by the Invention) The strength of the magnetic poles of a magnetized permanent magnet is determined by the residual magnetic flux density of the material, the distance between the magnetic poles, and their volume, but in practical terms, there are additional effects. The magnetic flux density at (t) and its direction are important. In conventional magnetization methods, in addition to the magnetic flux that passes through the target magnetic path, there is so-called leakage magnetic flux that passes through the space and pond members around the magnetized member, and it is necessary to prevent this interference from disturbing the purpose of magnetization. I couldn't avoid it. This effect increases as the distance between the magnetic poles becomes shorter and magnetization becomes so-called high-magnetization degree, causing a decrease in the strength of each magnetic pole and an indistinct position of the magnetic poles. Furthermore, in the production of permanent magnets, it is often required that the formed magnetic poles be strong. It is also required that the position of the magnetic pole be clear and that the transition of the magnetic field between the magnet and the box be sharp.

The present invention suppresses the generation or passage of leakage magnetic flux during magnetization, and controls the direction of the magnetic flux to eliminate the influence of leakage magnetic flux and ensure that all of the magnetizing magnetic flux is properly introduced at a predetermined position and direction. It is an object of the present invention to provide a method of manufacturing a permanent magnet in which strong magnetic poles are formed at predetermined positions of a member to be magnetized.

(Means for Solving the Problems) The present invention provides a complete diamagnetic structure around the magnetized member in order to prevent the density and direction of the predetermined magnetizing magnetic flux from being disturbed due to the influence of leakage magnetic flux during magnetization. The main idea is to block the leakage magnetic flux from entering the magnetized member by arranging and adjusting the members, and the main idea is to control the magnetic path and direction of the magnetizing magnetic flux itself.

That is, the first aspect of the present invention is a method for manufacturing a permanent magnet by inserting a magnetized member between the magnetic poles of an excitation yoke and fully magnetizing the magnetized member, in which a completely diamagnetic member is entirely disposed around the magnetized member. , -'--Also, the second aspect of the present invention is a method of sandwiching a magnetized member between the magnetic poles of an excitation yoke and magnetizing the magnetized member to create a permanent magnet. This method of manufacturing a permanent magnet is characterized in that a magnetic member and a highly permeable member are all disposed, and the member to be magnetized is magnetized.

The present invention will be explained below with reference to all the drawings. Figures 4 and 5
The figure shows a conventional method for manufacturing permanent magnets. The magnetic flux emitted from the magnetic pole IAIIB of the excitation yoke is not only an effective magnetic flux 7 that passes through the inside of the magnetized member 2, but also a leakage magnetic flux 8 that passes through the space around the magnetized member and other members. The magnetizing effect of becomes weaker. In particular, as shown in FIG. 5, a highly permeable member 4 A is locally placed around the magnetized member.
When all multipolar magnets are produced by energizing all the magnetized members by arranging +4B, the influence of leakage magnetic flux is large because the magnetic flux is moved in and out of the magnetized member, and the magnetization strength of the magnetic poles is reduced. The magnetic pole position tends to be low and the magnetic pole position becomes unclear.

On the other hand, according to the method of manufacturing a permanent magnet of the present invention shown in FIGS. 1 and 2, the completely diamagnetic member 3#3Al 38130 disposed around the magnetized member directs leakage magnetic flux to the magnetized member. Since it acts to push the magnetized member back inward, the magnetizing effect on the magnetized member becomes stronger. This effect is particularly noticeable when manufacturing the multipolar magnet shown in FIG.

FIG. 3 shows an example in which the ring-shaped magnetized member 2 is fully magnetized by the magnets ff11A to 1D of a plurality of excitation yokes.

By inserting completely diamagnetic members 38 to 3C between the magnetic poles of each excitation yoke, interference due to leakage magnetic flux between the yokes can be prevented. Furthermore, by disposing a completely diamagnetic member 3D' on the outer circumference of the ring-shaped magnetized member, magnetic flux leakage from the outer circumferential surface is completely prevented, magnetic poles are concentrated on the inner circumferential surface, and magnetic poles are prevented from appearing on the outer circumferential surface. All suppressed magnets can be manufactured.

The fully diamagnetic material can be selected from those known as superconducting materials. There are no particular limitations on the material of the completely diamagnetic member and the surroundings of the magnetized member in which it is arranged, but it is important to minimize the space in the part of the magnetized member that receives the leakage magnetic flux and the exposed area with other members. Preferably, a completely diamagnetic member is provided surrounding the magnetized member and in close contact with the magnetized member.

It is preferable that the completely diamagnetic member be disposed at a location other than the portion where the magnetic poles are formed, and it is also preferable that the completely diamagnetic member be disposed at a key local portion in consideration of the direction of the magnetic flux and the magnetic path. If necessary, processing may be performed to maintain superconductivity and complete diamagnetism, or an insulating coating may be applied to the surface. However, in the present invention, the formation of a continuous phase as a material necessary to maintain superconductivity is not essential. Therefore, other types of materials may be mixed or composited to the extent that they do not hinder the slow closing or deflection effect of the lines of magnetic force.

There are no particular restrictions on the type of magnetized member. Carbon steel, alloy magnetic materials, ferrite, rare earth magnets,
Plastic (rubber) magnets, magnetic recording materials, etc. can be selected as appropriate.

There are no particular restrictions on the type of highly permeable material, and examples include pure iron and permalloy. There are no particular limitations on the shape of the highly permeable member and the periphery of the magnetized member on which it is disposed, and the size and arrangement position of each member can be determined depending on the position of the magnetic pole formed on the magnetized member.

When adjusting the magnetic ratio, it is a matter of course that the temperature must be lower than the temperature at which the completely diamagnetic member exhibits its complete diamagnetic property. For this purpose, there are methods to bring the entire device including the excitation yoke to the above temperature, a method to bring the magnetized member, a completely diamagnetic member, and a highly permeable member to the above temperature, or a method to bring only the completely diamagnetic member to the above temperature. . Which of these methods is FL?
'Ft □"cχ may be determined by considering the size and shape of the member to be magnetized, the position where the magnetic pole is formed, etc.

(Effects of the Invention) According to the method of the present invention, there is no influence of leakage magnetic flux when the magnetized member is fully magnetized to produce a permanent magnet, and the direction and magnetic path of the magnetic flux are controlled, which is effective for the magnetized member. Since magnetic flux acts on the magnetic flux, a permanent magnet with high magnetic pole magnetization strength and a clear magnetic pole position can be obtained.

[Brief explanation of drawings]

FIGS. 1, 2, and 6 are sectional views of an apparatus and each member showing the method of manufacturing a permanent magnet of the present invention. FIGS. 4 and 5 are cross-sectional views of an apparatus and each member showing a conventional permanent magnet manufacturing method. Codes 1A, iB, 1c, 1D...Magnetic ball of excitation yoke, 2...Member to be magnetized, 3.3AP 3B, 3C, 3D
-... Completely diamagnetic member, 4 A* 4 B... Highly permeable member, 5A, 15B... Excitation yoke, 6A, 6B
... Coil, 7... Effective magnetic flux, 8... Leakage magnetic flux Patent applicant Denki Kagaku Kogyo Co., Ltd. Figure 1B Figure 2

Claims (2)

[Claims] (1) In a method of manufacturing a permanent magnet by sandwiching a magnetized member between the magnetic poles of an excitation yoke and magnetizing the magnetized member,
A method of manufacturing a permanent magnet, which comprises arranging a completely diamagnetic member around a member to be magnetized and magnetizing the member to be magnetized. (2) A method of manufacturing a permanent magnet by sandwiching a magnetized member between the magnetic poles of an excitation yoke and magnetizing the magnetized member,
A method of manufacturing a permanent magnet, which comprises arranging a completely diamagnetic member and a highly permeable member around a member to be magnetized, and magnetizing the member to be magnetized.