JPH09233776A - Manufacturing method for lengthy radial anisotropic ring magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a lengthy radial anisotropic ring magnet with high maximum energy product. SOLUTION: At the time of magnetically-forming rare earth magnetic alloy powder with a magnetic forming device consisting of non-magnetic dies 11, 13, a ferromagnetic die 12, punches 21, 22, magnetic coil 41, 42 and so on, the first layer 2 divided in the axial direction is formed, on which magnetic powder 3 is charged for forming, and subsequent stacking is conducted for forming. It is thus possible to generate them for production of a lengthy radial anisotropic ring magnet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ring-shaped permanent magnet used for a rotor of a servomotor or the like.

[0002]

2. Description of the Related Art In a rotating machine using a ring magnet such as a rotor of a servo motor, a magnet having a high magnetic flux density on the surface of the magnet has a so-called radial anisotropy in which the anisotropy of magnetization is radial. Ring-shaped permanent magnets are often used. Further, a radial anisotropic ring magnet using a rare earth element-Fe-B based magnet is in great demand in the above-mentioned applications as a magnet having a large maximum energy product.

By the way, the formation of the radial anisotropic ring magnet is performed by compressing the magnet powder with a press or the like in a magnetic field. At this time, if the length of the ring magnet to be molded is long, it is not possible to apply a magnetic field of sufficient strength to the molded body when molding in a magnetic field, so it is possible to manufacture a long magnet having a high maximum energy product. could not. Therefore, a short magnet is joined with an adhesive or the like and used as a required magnet length.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to manufacture a radial anisotropic ring magnet having a long length and a high maximum energy product. By providing the method, it is possible to contribute to the improvement of the performance of the magnet and the reduction of the man-hours for assembling the magnet.

[0005]

In order to achieve the above object, the method for producing a long radial anisotropic ring magnet of the present invention is as follows: (1) Production of a radial anisotropic ring magnet made of a rare earth magnet alloy. In the above, when the magnet alloy powder is molded in a magnetic field, the magnet alloy powder is divided in the axial direction and sequentially laminated and molded to form a long ring magnet molded body. (2) In manufacturing a radial anisotropic ring magnet composed of a rare earth element-based magnet alloy and a thermosetting resin, when the powder of the magnet alloy is molded in a magnetic field, the powder is divided in the axial direction and sequentially laminated and molded. It is characterized in that a long ring magnet molded body is formed by the integration. (3) In the method for producing a long radial anisotropic ring magnet described in (1) and (2) above, the height of one layer when axially divided and molded is determined by the outer diameter of the magnet to be molded. It is characterized in that it is one-half or less.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the first embodiment of the radial anisotropic ring magnet of the present invention, a rare earth element-Fe-B based magnet alloy is used as the rare earth element based magnet alloy. As the rare earth element, Nd is mainly contained, and other rare earth elements may be contained in 90% or less by mass%. The rare earth element-based magnet alloy powder is compressed into a ring shape in a magnetic field. At this time, the length (axial length) of the molded body molded by one compression is made shorter than the final target length, magnet alloy powder is further added to this, and this additional portion is molded in a magnetic field. . By repeating the above steps, a ring molded body having a final target length and being oriented in the radial direction is obtained by laminating and integrating.

Second aspect of the radial anisotropic ring magnet of the present invention
In one embodiment, the rare earth element-based magnet alloy is Nd.
A -Fe-B system magnet alloy or a Sm-Co system magnet alloy is used. A magnet powder-resin mixture obtained by adding a thermosetting resin to the magnet alloy powder is molded into a ring shape by compression processing in a magnetic field. At this time, similarly to the above, the length (axial length) of the molded body to be molded by one compression is shorter than the final target length, and a magnet powder-resin mixture is further added thereto,
The additional portion is molded in a magnetic field. By repeating the above steps, a ring molded body having a final target length and being oriented in the radial direction is obtained by laminating and integrating.

In the first and second embodiments,
Since the effect of radial orientation in the magnetic field molding becomes more remarkable as the length of the molded body molded by one compression becomes smaller, 1
It is preferable that the length of the molded body that is molded by one compression is small. The length of the molded body molded by one compression is preferably ½ or less of the outer diameter of the molded body.

[0009]

【Example】

(Experiment 1) Nd: 32% by mass, Dy: 1% by mass, B:
A magnet alloy ingot consisting of 1.1 mass% and the balance Fe was pulverized in an argon atmosphere to obtain a powder having an average particle size of 3 μm. This magnet alloy powder was molded in a magnetic field by the following method.

The magnetic field molding is performed using an upper non-magnetic die 11, a lower non-magnetic die 13 and a ferromagnetic material made of a non-magnetic material, and arranged between the upper non-magnetic die 11 and the lower non-magnetic die 13. It was performed using the die 10 including the ferromagnetic die 12. The die 10 includes an upper non-magnetic die 11 and a ferromagnetic die 1.
2. Provided with a through hole 14 penetrating the lower non-magnetic die 13.
Each of the upper punch 21 and the lower punch 22 is a cylinder having a core hole 23 in the center thereof, and is slidably fitted in the through hole 14. The core 30 is a rod-shaped body made of a ferromagnetic material that is slidably fitted in the core hole 23. An upper magnetic field coil 41 is arranged adjacent to the upper non-magnetic die 11 and a lower magnetic field coil 42 is arranged adjacent to the lower non-magnetic die 13 with the die 10 interposed therebetween.

First, the lower punch 22 is inserted into the through hole 14 and positioned at the lower edge of the ferromagnetic die 12. Core 30
Is inserted into the core hole 23 and its upper end is positioned at the upper edge of the non-magnetic die 11. In this way the ferromagnetic die 12,
The magnet alloy powder 1 is filled in the cavity formed by the core 30 and the lower punch 22. Then, currents in opposite directions are applied to the upper magnetic field coil 41 and the lower magnetic field coil 42 to form a magnetic field so that the surfaces facing each other have the same pole, and the through hole 14
Then, the upper punch 21 is fitted into the core 30 and the upper punch 21 is inserted. The upper punch 21 presses and solidifies the magnet alloy powder 1 filled in the cavity to form the first layer compact 2.

Next, the lower punch 22 is pulled down and the upper punch 21 is pushed in, so that the upper edge of the first layer compact 2 is positioned at the upper edge of the lower non-magnetic die 13. In this state, the upper punch 21 is pulled up to the outside of the through hole 14, and the magnet alloy powder for forming the second layer molded body in the cavity formed by the ferromagnetic die 12, the core 30 and the upper surface of the first layer molded body 2. 3 is filled and the upper punch 21 is descended in the same manner as described above to pressurize and solidify the magnet alloy powder 3 to form a second layer compact. By this pressure, the second layer molded body is pressed against the first layer molded body 2 and the first layer molded body 2 and the second layer molded body are integrated. Thereafter, by laminating and molding in the same manner, a ring magnet molded body having a predetermined length was obtained.

The ring magnet compact was sintered at 1100 ° C. in an argon atmosphere and further heat-treated at 600 ° C. to produce a radial anisotropic ring magnet having an outer diameter of 26 mm × an inner diameter of 20 mm × a length of 39 mm. Table 1 shows the measurement results of the magnetic properties.

[0014]

[Table 1]

(Experiment 2) Sm: 24% by mass, Ce: 1.
5% by mass, Fe: 15% by mass, Cu: 4.5% by mass, Z
r: 2.5% by mass, 115 in the magnetic alloy ingot consisting of residual Co
After solution heat treatment at 0 ° C x 2Hr, 800 ° C x 2H
A heat treatment of r-750 ° C. × 5 Hr-550 ° C. × 10 Hr was performed. This was pulverized to obtain a magnet alloy powder having an average particle size of 10 μm. Thermosetting epoxy resin is added to the magnet alloy powder 2
Mass% was added and mixed. The magnet alloy powder-thermosetting epoxy resin mixture thus obtained was molded in a magnetic field in the same manner as in Experiment 1, and the outer diameter was 24 mm, the inner diameter was 18 mm, and the length was 24 m.
The molded body of m was further cured at 150 ° C. for 1 hour to obtain a radial anisotropic ring magnet made of a bonded magnet. Table 2 shows the magnetic property measurement results.

[0016]

[Table 2]

From Tables 1 and 2, a magnet having a large maximum energy product can be obtained even if it is long, by reducing the molding height per operation to less than half the outer diameter of the magnet. I understand.

[0018]

According to the present invention as described above,
It is possible to provide a method of manufacturing a radial anisotropic ring magnet that is long and has a high maximum energy product. As a result, the performance of the magnet can be improved and the man-hours for assembling the magnet can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state in which a first layer is formed in the example of the present invention.

[Explanation of symbols]

 1 magnet alloy powder 2 1st layer compact 3 magnet alloy powder 10 die 11 upper non-magnetic die 12 ferromagnetic die 13 lower non-magnetic die 14 through hole 21 upper punch 22 lower punch 23 core hole 30 core 41 upper magnetic field coil 42 lower Magnetic field coil

Claims (3)

[Claims] 1. In the manufacture of a radial anisotropic ring magnet made of a rare earth magnet alloy, when the powder of the magnet alloy is molded in a magnetic field, it is integrally formed by axially dividing and sequentially laminating and molding. A method for producing a long radial anisotropic ring magnet, which comprises forming a long ring magnet molded body. 2. In the manufacture of a radial anisotropic ring magnet made of a rare earth element magnet alloy and a thermosetting resin,
When the powder of the magnet alloy is molded in a magnetic field, it is divided in the axial direction and sequentially laminated and molded to be integrated to form a long ring magnet compact, which is a long radial anisotropy. Ring magnet manufacturing method. 3. The method for manufacturing a long radial anisotropic ring magnet according to claim 1, wherein the height of one layer when axially divided and molded is the outer diameter of the magnet to be molded. ½ or less of the above method for producing a long radial anisotropic ring magnet.