JPS63316658A - Multipolar magnetization - Google Patents

Abstract

PURPOSE:To extent the useful life of magnetized yokes, by bringing the magnetized yokes made of a gear-cut magnetic material into contact with both planes of a plate-type permanent magnet and by generating magnetic field with a field coil separately provided for multipolar magnetization. CONSTITUTION:A multipolar magnetizer is composed of a combination of a pole piece 2 with a field coil 1 attached with a DC electromagnet to cause current to flow from a DC power source separately provided, and is equipped with an upper frame 3 and a lower frame 4. To these upper and lower frames 3 and 4 upper and lower tables 6 and 7 with an upper-and-lower adjusting handle 5 are connected, at the tips of which upper and lower magnetized yokes 8 and 9 are coupled, so as to put a permanent magnet 10 between them. The teeth sections of both yokes 8 and 9 are positioned to face each other with the permanent magnet 10 put between them, while the magnet 10 can be slided with a guide table 11 and a positioning plate 12. The permanent magnet 10 is thereby moved and the sections engaged with the teeth of magnetized yokes 8 and 9 are shifted with precision for magnetization.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to a method of multipole magnetizing a plane of a flat permanent magnet.

[Conventional technology]

With the recent development of office automation equipment, the method of magnetizing a flat permanent magnet with multiple poles and using it as an element part of an IJ near step motor is increasing.

The multipolar magnetization of such a flat permanent magnet was developed by
A method of performing multi-pole magnetization using a magnetizing yoke as shown in Japanese Patent No. -8589 is widely used.

First, a soft magnetic material that matches the dimensions of the flat permanent magnet that is to be multipole magnetized is cut into grooves to match the pole width and number of poles to be magnetized, and then an insulated wire is wrapped around it. The insulated wires are heat-treated and fixed, and a set of multi-pole magnetized yokes is manufactured.

Align the grooved positions of the multi-pole magnetized yokes produced in this way, sandwich a flat permanent magnet between both magnetized yokes, and apply a large current to the wrapped insulated wire to generate magnetic lines of force. Multipole magnetization was performed using

[Problem that the invention seeks to solve]

However, recently, with the advent of highly divided type linear step motors, the following problems have been brought into focus regarding multi-pole magnetized yokes.

As the number of divisions per unit dimension increased, the area within one pole of magnetization became narrower, and the groove processing for wrapping the insulated wire became smaller and processing became difficult. ■In order to make the insulated wire thinner, the cross-sectional area of the copper wire is reduced, and therefore the magnetizing current must also be reduced, which reduces the magnetizing magnetic field and makes it impossible to completely magnetize the permanent magnet. It was also necessary to make the insulator thinner. ■The winding extension of the insulated wire became long (which increased the resistance) and the magnetizing current could not flow to the set value unless the applied voltage was increased.

As a result, the insulator became thinner, resulting in many damage to the magnetizing yoke due to leakage and damage due to melting of insulated wires.

The present invention is intended to solve these problems, and its purpose is to provide a completely different method of winding an insulated wire around a magnetizing yoke without having to wind it directly around a magnetizing yoke. The purpose of the present invention is to provide a multi-pole magnetization method that provides a magnetic yoke with a high durability and a surface magnetic flux density on the same level as the multi-pole magnetization method of the prior art.

[Means for solving problems]

The multi-pole magnetization method of the present invention involves contacting both planes of a flat permanent magnet with a magnetizing yoke made of a magnetic material and having a plurality of gears cut in the middle of one pole, and using a separate magnetic field coil. A magnetizing magnetic field is generated through a magnetizing yoke to perform multi-pole magnetization.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Generally called resin bonded rare earth permanent magnet, 2-17
A mixture of Sm-Co magnet powder and epoxy resin as a binder is pressure-molded in a magnetic field and thermally solidified to form a permanent flat plate with anisotropy in the thickness direction of 20 mm in length and 1 mm in thickness. I got a magnet.

Multipole magnetization of 50 poles was performed on a 50×20 mm surface of this flat permanent magnet at a pitch of 1 mm.

FIG. 1 is a cross-sectional view showing the current state of the multi-pole magnetizing device, and FIG. 2 is a cross-sectional view of the magnetizing yoke portion of the multi-polar magnetizing device shown in FIG. 1, viewed from the direction of the arrow.

The multi-pole magnetizing device shown in Fig. 1 uses a DC electromagnet that combines a magnetic field coil 1 with a pole piece 2 and supplies current from a separate DC power supply. Good (protrudes to one side in order to do so.

An upper table 6 with a vertical adjustment/17 dollar 5 and a lower tail 7 are connected to the upper and lower frames 3 and 4, respectively, and an upper magnetic yoke 8 and an undergarment are attached to the tips of the upper table 6 and the lower tail 7 with a permanent magnet 10 sandwiched therebetween. A magnetic yoke 9 is joined.

Figure 2 shows the permanent magnet 10 and the upper and lower magnetic yokes 8 and 9 placed in the first
FIG. 3 is a partially enlarged cross-sectional view seen from the direction of the arrow shown in the figure. The toothed portions of the upper and lower magnetic yokes 8 and 9 are positioned to face each other with a permanent magnet 10 in between, and the permanent magnet 10 is slidable left and right by a guide table 11 and a positioning plate 12. Although non-magnetic materials were used for the guide table 11 and the positioning plate 12, all other device components except the magnetic field coil 1 were made of pure iron, which is a magnetic material. The dimensions of the teeth of the upper and lower magnetic yokes 8 and 9 were 0.95 mm so as not to exceed 1 mm, which is in the magnetized pole, and the groove depth was an isosceles triangle with a depth of 1.4 mm.

Next is the adjustment of the magnetizing current.The upper and lower magnetic yokes 8 and 9
Insert a Hall probe into the space where the permanent magnet 10 of the opposing teeth will fit, and measure approximately 16,500 yen with a galaca camera.
Magnetization was started by adjusting the DC power supply connected to the separately provided magnetic field coil 1 so that a magnetic field of (Oe) was generated.

First, a set current is passed through the magnetic field coil 1 using a separate DC power supply so as to generate an N pole on the upper magnetizing yoke 8 side and an S pole on the underwear magnetic yoke 9 side, completing the first magnetization. did.

Next, loosen the vertical adjustment handle 5 until the permanent magnet 10 can be moved smoothly, slide the permanent magnet 10 by the middle of one pole using the guide table 11 and positioning plate 12, and adjust the vertical adjustment again/above the 11-pole position. A permanent magnet 10 is narrowed by a magnetizing yoke 8 and an undergarment magnetic yoke 9.

In other words, by moving the permanent magnet 10 whose upper side is magnetized with N pole and the lower side with S pole by each magnetizing yoke, the part that was in contact with the teeth of the magnetizing yoke becomes the groove part, and the part of the groove becomes The non-magnetized part was moved with high precision so that it touched the teeth.

Furthermore, the terminals of the magnetic field coil 1 are switched and the set current is again applied to the magnetic field coil 1 by the upper magnetizing yoke 8.
The second magnetization was completed by flowing so that an S pole was generated on the side of the underwear magnetic yoke 9 and an N pole was generated on the side of the underwear magnetic yoke 9. As a comparative example, the same permanent magnet was made with multiple poles magnetized using a conventional multi-pole attaching method.

The magnetizing yoke is made of 55 x 22 x 15 mm pure iron material with grooves cut by machining, copper wire diameter φ 0.4 mm insulated, finished outer diameter of φ 0.7 mm wire wrapped around it, and treated with an insulating face. A pair of magnetized yokes prepared above were sandwiched between permanent magnets to align the magnetic poles, and then a pulsed magnetizing current of about 2500 A at a peak was applied by a pulsed magnetizing power supply to perform multipolar magnetization.

Each flat permanent magnet that has been multipole magnetized by the above method is made by bonding a 50 x 20 x 1 mm thick plate made of pure iron, which is a magnetic material, to one of the multi-pole magnetized surfaces. The surface magnetic flux density of the multipolar magnetized surface was measured.

The 35th waveform A is a part of the results of measuring each multipolar magnetized permanent magnet using an X-Y table with a Hall probe and a Gauss meter.A...Multipole magnetization method according to the present invention B: This is based on the multi-pole magnetization method of the prior art, and shows almost the same values.

Next, we investigated the durability of each magnetizing yoke while magnetizing each, and found that using conventional technology, the multipolar magnetizing yoke was approximately 11.0
Damage was seen on the insulating face after 00 pieces, and when 8,500 pieces were magnetized, the magnetization yoke was destroyed due to leakage and became unusable.

In the method according to the present invention, after about 50,000 magnets were magnetized, wear was observed on the surface of the teeth of the magnetizing yoke in contact with the permanent magnet, but there was no abnormality in any part including the magnetic field coil. .

〔Effect of the invention〕

As described above, according to the multipolar magnetization method of the present invention,
In a method of multipole magnetizing opposing planes of a flat permanent magnet, a magnetizing yoke made of a magnetic material and having a plurality of gears corresponding to one pole is brought into contact with both planes of the flat permanent magnet. By using a separate magnetic field coil to generate a magnetizing magnetic field through the above-mentioned magnetizing yoke and performing multi-pole magnetization, it is possible to obtain the same level of surface magnetic flux density as the multi-pole magnetization method using conventional technology. Moreover, it has the effect of making the magnetizing yoke extremely durable.

In this example, SmCo, a resin-bonded rare earth permanent magnet, is used.
Although only the system has been described, similar effects can be obtained for Nd-Fe-B system permanent magnets and multipolar magnetization of permanent magnets using thermoplastic resin.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing the multi-pole magnetizing device completely exposed. FIG. 2 is a sectional view showing a part of the magnetizing yoke as seen from the direction of the arrow shown in FIG. FIG. 3 is a waveform diagram showing part of the measurement results of a multi-pole magnetized product. 1...Magnetic field coil 2...Pole piece 3...Upper frame 4...Lower frame 5...Vertical adjustment handle 6...Upper table 7...Lower table 8...Top magnetization Yoke 9...Underwear magnetic yoke 10...Permanent magnet 11...Guide table 12...Positioning plate A...Measurement results of multi-pole magnetization according to the present invention. B...Measurement results of multi-pole magnetization using the conventional method. that's all

Claims (1)

[Claims] In a method of multipole magnetizing opposing planes of a flat permanent magnet, a magnetizing yoke made of a magnetic material and having a plurality of gears cut in a width equivalent to one pole is brought into contact with both planes of the flat permanent magnet. A method of multi-pole magnetization, characterized in that multi-pole magnetization is performed by generating a magnetizing magnetic field via the above-mentioned magnetizing yoke using a separate magnetic field coil.