JPS6366908A - Magnetizer - Google Patents

Abstract

PURPOSE:To generate strong electric fields both in a magnetic pole for drive and a magnetic pole for detecting speed without generating field spots in both magnetic poles by using a magnetizer consisting of a pole magnetizing section for drive, in which several comparatively large-sized magnetic poles are arranged annularly, and a pole magnetizing section for detecting speed in which a large number of comparatively small-sized magnetic poles are disposed circularly. CONSTITUTION:An annular permanent magnet 1 to be magnetized, a cuppy yoke 4 and an auxiliary yoke 12 are placed on a magnetizer. When currents are caused to flow simultaneously through a magnetic coil 10 wound on a central-section annular yoke 8 and a magnetic coil 7 wound on an outer- circumferential section annular yoke 5, the central-section annular yoke 8 and the outer-circumferential section annular yoke 5 are each magnetized, and the contact surface of the annular permanent magnet 1 to be magnetized placed onto the magnetizer can be magnetized. Accordingly, a magnetic pole 2 for drive and a magnetic pole 3 for detecting speed are magnetized at the same time, thus generating strong magnetic fields both in the magnetic pole 2 and the magnetic pole 3 without generating field spots in both magnetic poles.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention mainly relates to an improvement of a magnetizer developed for annular permanent magnets of flat motors, and in particular, to improve magnetic field unevenness in drive magnetic poles and speed detection magnetic poles. The present invention relates to a magnetizer that can generate a strong magnetic field without generating it.

[Conventional technology]

In order to improve the characteristics of flat motors, which are widely used in audio and imaging equipment in recent years, highly accurate position and speed detection is required. It is desired not only to have a driving magnetic pole that generates power, but also to have a strong speed detection magnetic pole.

The structure of the annular permanent magnet is shown in FIG.

In the annular permanent magnet l, as shown in the figure, on the same plane, several relatively large magnets with different poles are lined up in an annular shape in the center to form a drive magnet FIi2, and relatively small magnets with different poles are arranged in an annular shape around the outer circumference. A large number of poles with different shapes are lined up to constitute a speed detection magnetic pole 3, and usually a cup-shaped yoke 4 is crowned on the other plane.

Although not shown, a flat motor has a Hall element for position detection and a tachometer generator coil for speed detection placed opposite the magnetic pole surface of this annular permanent magnet across an air gap, and below that a tachometer generator coil for driving. It can be assembled by placing the board on which the T1 machine coil etc. are attached and erecting the rotating shaft.

By the way, in order to magnetize the annular permanent magnet l for a flat motor, conventionally, a magnetizer that magnetizes the driving magnetic pole 2 and a magnetizer that magnetizes the speed detection magnetic pole 3 are separate, and the annular permanent magnet l is On one plane of the magnet, there is a driving magnetic pole 2 on the entire surface.
After magnetizing, the speed detection magnetic pole 3 is magnetized in duplicate, or the speed detection magnetic pole 3 is left unmagnetized and the driving magnetic pole 2 is magnetized first, and then the speed detection magnetic pole 3 is magnetized. Mu II
A method has been adopted in which the speed detection magnetic pole 3 is magnetized in the K magnetic part.

C Problem 3 to be Solved by the Present Invention In the former case in the above configuration, when magnetizing the speed detection magnetic pole in the portion where the driving magnetic pole and the speed detection magnetic pole overlap with each other and have different polarities. In this case, the driving magnetic poles are locally demagnetized, leading to a decrease in the driving magnetic field as a whole, and there is a possibility that magnetic field unevenness may occur.

In the latter case, the attachment riI! due to leakage magnetic flux, etc. In consideration of L bleeding, it becomes necessary to magnetize in an area narrower than the required area of the driving magnetic pole, and similarly to the former case, there is a risk that the driving magnetic field will decrease and magnetic field unevenness will occur.

Furthermore, in both cases, if the speed detection magnetic pole 3 is magnetized to such an extent that it does not affect the drive magnetic pole 2, the speed detection magnetic field will be weak and highly accurate speed detection will be difficult.

The present invention was made to solve these problems, and provides a magnetizer that can generate a strong magnetic field at both the driving magnetic pole and the speed detection magnetic pole without generating magnetic field unevenness. The purpose is to

[Means for solving problems]

In the annular permanent magnet l, in order to solve the above problem and generate a strong magnetic field in both the drive magnetic pole 2 and the speed detection magnetic pole 3, it is possible to simultaneously generate a strong magnetic field in both the drive magnetic pole 2 and the speed detection magnetic pole 3 without overlapping the drive magnetic pole and the speed detection magnetic pole. This is achieved by magnetization.

The present invention has been made based on the above findings, and is a magnetizer that can generate strong magnetic fields for both the driving magnetic pole and the speed detection magnetic pole by -times of magnetizing operation. That is, in the present invention, an electromagnetic coil is wound around a central annular yoke in which several relatively large magnetic poles are arranged in an annular manner for magnetizing a driving magnetic pole so that adjacent magnetic poles are different in polarity. A driving magnetic pole magnetized part formed by the driving magnetic pole magnetized part, and relatively small multi-magnetic poles arranged in an annular manner in proximity to or in contact with the outer periphery of the driving magnetic pole magnetized part for magnetizing the speed detection magnetic poles. It consists of an M1 scraping magnetized part for speed detection, which is formed by winding an electromagnetic coil around an annular yoke of the outer circumferential part so that adjacent magnetic poles have different polarities, and these mutually magnetized parts are fixed coaxially and integrally. This is a magnetized part of a permanent magnet for a flat motor, characterized in that a driving magnetic pole and a speed detection magnetic pole are simultaneously magnetized without overlapping them.

Hereinafter, the present invention will be explained with reference to drawings listed as examples.

FIG. 2 shows the mechanism of the magnetizer of the present invention, in which a magnetized annular permanent magnet l, a cup-shaped yoke 4, and an auxiliary yoke 12 are mounted on the magnetizer! ! FIG.

FIG. 3 is a partial plan view of the magnetic pole surface of the magnetizer of the present invention.

In the figure, 8 is a central annular yoke, the base of which is continuous in a cylindrical shape, but the upper part has an even number of notches to form relatively large magnetic poles, and there is an excitation coil lO.
is wound to form a driving magnetic pole magnetized section. The excitation coil 1O is wound so that adjacent poles are different from each other, and the magnetic pole surfaces are arranged in a ring in a relatively large sector shape as shown in FIG. magnetize. Reference numeral 5 designates an outer peripheral annular yoke, which is disposed close to or in contact with the outer periphery of the drive magnetic pole magnetized part, and has a thick crown gear with square teeth and an enlarged flat plate shaft hole. It has a shape that fits into the central annular yoke 8. The end face of the tooth shape has a relatively small square shape as shown in Fig. 3, and is composed of an even number of poles with adjacent poles arranged close to each other in a ring shape in order to serve as the magnetizing magnetic pole for the speed detection magnetic pole 3. , each magnetic pole has an excitation coil 7 wound so that adjacent poles are different from each other, thereby forming a speed detection magnetic pole magnetized section. The driving magnetic pole magnetized section and the speed detection magnetic pole magnetized section are fixed in a coaxial body using a non-magnetic material 11 as shown in FIG. 2 to constitute a magnetizer.

In the above configuration, the electromagnetic coil 10 wound around the central annular yoke 8 has a required number of turns of W4KIA having an insulating film on its surface, but the electromagnetic coil 7 wound around the outer peripheral annular yoke 5 has an attached 1aifi pole. Since the number of coils is extremely large, and the magnetized part of the drive pole is placed close to or in contact with them, the coil space is extremely small, so instead of winding a copper wire with an insulating coating, As shown in Figure 3, a thin steel plate may be used instead of the coil.

When magnetizing with the magnetizer of the present invention, in consideration of further improvement of magnetization efficiency and magnetic properties after magnetization, it is preferable to magnetize the cup-shaped yoke 4 in advance, rather than magnetizing only the annular permanent magnet. Furthermore, it is preferable to magnetize the cup-shaped yoke 4 with an auxiliary yoke 12 made of the same material as each yoke constituting the magnetized section placed on the upper surface of the cup-shaped yoke 4.

[For production]

In the above configuration, when current is simultaneously applied to the electromagnetic coil lO1 wound around the central annular yoke 8 and the electromagnetic coil 7 wound around the outer annular yoke 5, the central annular yoke 8 and the outer annular yoke 5 become magnetized, respectively. The contact surface of the magnetized annular permanent magnet l placed on the magnetizer is 4! It becomes possible to magnetize.

That is, the drive magnetic pole 2 and the speed detection magnetic pole 3 (see FIG. 1) are magnetized at the same time, and it is possible to generate a strong magnetic field together without generating magnetic field unevenness in each.

〔Example〕

Next, the effects of implementing the present invention will be described.

A cup-shaped yoke with a thickness of 0.5 m is fixed to an axially anisotropic annular ferrite stone with an outer diameter of φ6 ON, an inner diameter of φ20, and a thickness of 3 fins, and a drive magnetic pole 2 is attached using a conventional magnetizer. and the case where the speed detection magnetic pole 3 and the speed detection magnetic pole 3 are magnetized overlappingly,
A comparison was made between the case where the drive magnetic pole 2 and the speed detection magnetic pole 3 were simultaneously magnetized without overlapping them using the magnetizer of the present invention. The results are shown in Table 1. The values in Table 0 indicate the magnetic field strength of each magnetic pole part magnetized by the magnetizer of the present invention.
This is a comparison value when it is set to 0.

Table 1 As described above, according to the wearer of the present invention, the magnetic field strength at each magnetic pole portion is uniform and strong compared to the case where a conventional magnetizer is used. As described above, the magnetizer of the present invention can magnetize both the drive magnetic pole and the speed detection magnetic pole with one magnetization, and the effect of improving the performance of the flat motor and work efficiency is remarkable.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an annular permanent magnet for a flat motor, and FIG. 2 is a sectional view showing the mechanism of the magnetizer of the present invention in a state where the annular permanent magnet is magnetized. FIG. 3 is a partial plan view of the magnetizer of the present invention. l: Annular permanent magnet, 2: Drive magnetic pole, 3: Speed detection magnetic pole, 4: Cup-shaped yoke, 5: Outer peripheral annular yoke, 8:
Central annular yoke, 'r, to: electromagnetic coil, 12: auxiliary yoke. Figure 3 +0 7 Figure 1

Claims (1)

[Claims] (1) Drive formed by winding an electromagnetic coil around a central annular yoke in which several relatively large magnetic poles are arranged in a ring to magnetize the driving magnetic poles, so that adjacent magnetic poles have different polarities. an outer circumferential annular yoke in which a plurality of comparatively small magnetic poles are arranged in an annular manner to magnetize a speed detection magnetic pole in proximity to or in contact with the outer periphery of the driving magnetic pole magnetized section; It consists of a speed detection magnetic pole magnetized part formed by winding an electromagnetic coil so that adjacent magnetic poles have different polarities, and these magnetized parts are coaxially fixed integrally, and a drive magnetic pole and a speed detection A magnetizer for permanent magnets for flat motors, which is characterized by magnetizing magnetic poles simultaneously without overlapping them.