JPS6064411A - Oxide permanent magnet - Google Patents

Abstract

PURPOSE:To easily obtain an integrated sintered magnet by forming arcuated high coersive force part and high residual magnetic flux part and disposing these portions in vertical in the axial direction. CONSTITUTION:A material having a high coersive force and a material having a high residual magnetic flux density are selected from the oxide permanent magnet material indicated by the composition MOnFe2O3 (M is a mixture of a kind or more of Ba, Sr, Pb, and Ca, n=5-6). The magnetic powder of these materials are formed as a slurry and the space 4 which will become the high residual magnetic flux density part is filled with such slurry. Next, the space 5 which will become the high coersive force part at the inside is formed and is filled with the other slurry magnetic powder. An arcuated mold is formed by the wet type molding under the magnetic field. Finally, a composite permanent magnet is obtained by the sintering. Thereby, the manufacturing process can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an oxide permanent magnet comprising a composite sintered magnet used in a permanent magnet rotating machine such as a permanent magnet generator or a permanent magnet heptata.

Conventional ferrite sintered magnets have mostly been sintered magnets in which the magnetic properties of each part of the sintered body are generally the same, so to speak, consisting of a urine component.

However, as ferrite magnets are widely used in various motors such as automobile scooter motors, and the range of applications of ferrite magnets expands, ferrite magnets made of ferrite components do not sufficiently satisfy the required magnetic properties. This has become essentially difficult. Therefore, for use in scooter motors, etc., a method has been adopted in which two types of magnets are bonded together after sintering to create a composite.1 An example of this magnet is shown in Figure 1, and % is an adhesive. , 2 is on the high coercive force (high 111c) side, and 3 is on the high residual magnetic flux density (
It is on the high By) side.

A particularly high coercive force is required in order to increase the resistance to demagnetization of the magnet itself during use, that is, to improve the demagnetization resistance depending on the application of the single-rotation machine. For this reason, a composite magnet as shown in FIG. 1 is required. As shown in the figure, the high coercive force side 2 where demagnetization resistance is required is 1
The portion corresponding to approximately 30 to 50 qb of the arc segment-shaped sintered body, and the portion corresponding to the high residual magnetic flux density 3 in Figure 1 is.

This is a part where high Br is desired in order to obtain high output. However, in manufacturing a composite magnet using the adhesive method shown in Figure 1,
There is a drawback that it requires a large amount of man-hours and time, such as trowel surface polishing of the joint surfaces, alignment, and bonding.

The present invention solves the above-mentioned drawbacks and at the same time
The object of the present invention is to obtain a composite integrated oxide permanent magnet comprising a sintered portion having Hc and a sintered portion having high Br.

The oxide permanent magnet of the present invention has the general formula MO-nnFe20
s (is one of 13a, Sr, Pb and Ca
A composite integral sintered magnet comprising at least two types of oxide permanent magnet materials having different magnetic properties, each of which has different magnetic properties.

A portion having a high coercive force and a portion having a high residual magnetic flux density are formed in an arc shape, and the high coercive force portion and the high residual yield portion are arranged perpendicularly to the axial direction. .

The details of the present invention will be explained below with reference to Examples.

Example 1゜SrO/P”t20s 25.2 to 5.8 (molar ratio)
using calcined powder.

As a high Br side additive, Ca Cos, 0.8 to 1
．． 2 wt%, Siυ20.3~Q, 6urt% was added and crushed to obtain a pulverized powder, while CaCo5O, 7~1.5 wt%, 5i02 was added as a high tHc side additive.
0.4-0.9wt%, A120B t5-5. f3
wt% was added and crushed to obtain a crushed powder. The amount of the additive added above naturally depends on the pulverized particle size, desired range of magnetic properties, sintering temperature, etc. Therefore, the above range is only an example, and the amount added is within the above range. Other than these do not depart from the scope of the present invention.

The obtained magnetic powder was made into a slurry containing 50 to 70 wt%, and first, the high residual magnetic flux density Br shown in FIG.
A material is injected into the void 4 that will become the part with the .

Next, a gap 5 was formed inside where the coercive force rHc was high, a different material was injected into this area, and wet molding was performed in an Al magnetic field to obtain a 100 x 50 x 10 arc-shaped molded body. .

Next, sintering was carried out in the range of 1120 to 1200°C.

The oxide permanent magnets obtained above were measured and typical definition results are shown in Table 1.

Table 1 also shows the results in Table 1 for Bα ferrite magnets treated in the same manner.
Results showing similar trends to those in the table were obtained.

Example 2゜A slurry was obtained with the same composition as in Example 1, and material was injected into the air gap 6, which is a portion with a high residual magnetic flux density as shown in Fig. 5, and then a portion with a high coercive force was formed inside. A gap 7 is formed, a different material is injected into this part, and wet molding is performed in a magnetic field.

A molded article having an arc shape of 100 x 50 x 10 was obtained.

Sintering was then carried out in the range 1120-1200 volts.

The oxide permanent magnet obtained above was measured.

Typical measurement results are shown in Table 2.

Table 2 also shows the results in Table 2 for Bα ferrite magnets treated in the same way.
Results showing similar trends to those in the table were obtained.

As explained above, the present invention is made by integrally molding a high By material and a high It also has many effects, such as simplifying the manufacturing process and greatly improving efficiency.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing an example of a conventional composite magnet for motors.
FIG. 2 is a cross-sectional view of a composite integrally sintered magnet showing one embodiment of the present invention, and FIG. 5 is a cross-sectional view of a composite integrally sintered magnet showing another embodiment of the present invention. 4.6: High residual magnetic flux density side, 5.71 High coercive force side. %/2 2nd 3rd m

Claims (1)

[Claims] 1. General formula NO, n1g20s (M is Bα, St
, a composite integral sintered magnet containing at least two types of parts with different magnetic properties made of an oxide permanent magnet material represented by one or a mixture of two or more of PB and Ca, n = 5 to 6). , a portion having a high coercive force and a portion having a high residual magnetic flux density are formed in an arc shape with respect to the axial direction, and are arranged in a shell shape in a perpendicular direction that intersects with the axial direction. oxide permanent magnet. 2. The oxide permanent magnet according to claim 1, wherein the portion having a high coercive force is arranged inside an arc shape. 5. The oxide permanent magnet according to claim 2, which has a portion having a high coercive force and occupies the entire thickness of the arc shape.