JPS61164215A - Manufacture of thin-walled cylindrical magnet - Google Patents

Abstract

PURPOSE:To simplify the saturation multipolar magnetization by making a rare earth magnet anisotropic in a cylindrical shape and a radial orientation, and performing extrusion molding. CONSTITUTION:As the magnet powder, an inter-rare earth metal compound alloy containing a rare earth metal such as yttrium and a transition metal such as iron is used. As the organic resin, a polyamide resin such as thermoelectric nylon 6, 12 is preferable. As to the mixing ratio of the magnetic powder and the organic resin, since the magnetic powder has a low magnetic performance if it is 50vol% or less, and extrusion molding cannot be applied it is exceeds 75vol%. Thus, the fill of the magnet powder is preferably in the range of 50vol%-75vol%. The above mixture is heated to about 80 deg.C-300 deg.C. After it becomes fluid, it is made to pass through a metal mold, simultaneously it is provided with a magnetic orientation, and then it is cooled and set to be made into a pipe. Here, the magnetic field is generated so that it becomes radial.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a cylindrical magnet having radial anisotropy, which is manufactured using a rare earth intermetallic compound as a raw material phase.

[Conventional technology 9 yen] Conventional anisotropic rare earth resin magnets, for example,
Proposals such as No. 66265 have been made.

[Problem that the invention seeks to solve]

However, (7) the above-mentioned conventional technology had the problem that only thick cylinders could be produced.

The present invention is intended to solve these problems, and its purpose is to provide a cylindrical anisotropic resin magnet having a wall thickness (1) of approximately 11 or less.

[Means for solving problems]

The method for producing a cylindrical anisotropic resin magnet of the present invention involves making a composition composed of magnet powder consisting of a rare earth end and a transition metal and an organic resin into a fluid state, and then applying a magnetic field to a cylindrical space using an extrusion molding method. %R refers to the product produced by orienting the magnet powder and cooling and solidifying the binder while adding the binder.

The specific structure of the present invention and the reason for the use of substances will be described in detail below. The object of this study is something similar to the magnetic powder used here. Yttrium (Y), Lanthonide rare earth metals Ramen (La), Cerium (Oe), Praseodymium (Pr), Neodymium (
), samarium (Sm), gadolinium (oa
,) One or more rare earth metals such as terbium (Tb) and zirconium (IJy) and iron and cobalt.

Nickel, steel, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum,
Tungsten and manganese are 44 polymetals of 1 or 2
A rare earth intermetallic compound alloy containing more than 100% is used. -f The organic resin is thermoplastic nylon 6.12. Polyamide resins such as are suitable. This is because if the mixing ratio of the magnet powder and the organic resin is less than 50 1i (vol)%, the magnetic performance will be low and it will crumble, making it impossible to put it into practical use. - If the force exceeds 75 Vol %, extrusion molding will not be possible, so the filling amount of magnet powder should be 50 Vol.
It ranges from 1 m/m to 75 VOI%. The above mixture is mixed in a screw type kneader or pressure type kneader.
The composition produced while heating at around 60°C to 500°C is called a compound.

The compound is put into an extrusion molding machine and heated to 80°C~
After being heated to about 500°C and becoming fluid, it is passed through a mold and exposed to a magnetic field, and then cooled and solidified to form a pipe. Here, the magnetic field must be generated radially. Specific methods include: ■A method of applying a magnetic field from outside the mold via a coil;
■The yJ method in which a permanent magnet is placed in a part of the mold, and ■The method in which the 4t'i& of the mold is magnetized with martenzite-based H magnets. That's fine.

The required magnetic field within the gap is approximately 5 Koθ or more.

The degree of radial orientation is preferably 80% or above, but according to our experiments, magnetic performance can be improved if it is 50% or more.

[Detailed Example-1] A conopound consisting of rare earth magnet powder 60 Vol. and the balance nylon 12 was used. Rare earth magnet powder is used as a material.
An alloy of rO,02J)ms was used for one history. The powder particle size has an average value of 25μ and a distribution between 5μ and 60μ. The magnetic alloy having this composition is generally called a 2-17 rare earth intermetallic compound. This alloy was used as a powder after being subjected to solution treatment and aging treatment as heat treatment for magnetization. The powder is nylon 12.

The mixture was mixed at a heating temperature of 260° C. with a twin-screw kneader (POM45 manufactured by Ikegu Iron Works). The kneaded compound (mixture of magnet powder and nylon 12) was hot-cut into thick-phase pellets with a diameter of 5 to 4 m x 51 z.

The thick phase compound is extruded in a magnetic field using an extrusion molding apparatus W shown in FIG. 1A. Raw material Konnok Land 8
is fed forward through the barrel 2 by the screw 3. The rotational speed of the screw is approximately 15 rpm (15 revolutions per i minute) and heated by a 1σ] nichrome heater. The heating temperature is approximately 250° C., which is a necessary condition for the compound to become fluid and oriented in the magnetic field.

According to our research, nylon 12 has a temperature of 250°C to 27°C.
0°C is preferable; below 250°C, the orientation rate is less than 50%, which tends to reduce performance; and above 270°C, oxidation of the magnet powder and deterioration of the magnet powder (nylon 12) tend to occur. . The raw stone 8 fed into the extrusion mold 9 disposed at the front is oriented in the magnetic field in the space 7. Here, the magnetic field is guided to the yoke 5-a (pure iron) by passing a current through the electromagnetic coil 4, passes through the axis 5-b (pure iron), and generates a radial orientation magnetic field. Furthermore, the cylindrical pipe solidifies in front,
I was able to create a cylindrical shape by adjusting the dimensions using 10 sizing dyes. Figure 1-B is a sectional view of section A-B.
The space portion generates a magnetic field radially toward the central axis s-b machining 5-a.

In this method, the inventors of the present application collected data using the magnetic field strength and orientation Br (residual magnetic flux density) in 7 as parameters using the method described above. The manufacturing conditions at this time were that the heating knitting temperature was 240°C, the screw 5 was 14 rpm, the product shape was 14'% in outer diameter, 12x in inner diameter, and the extrusion speed was 50 m/min. The performance of the magnet was measured using a self-recording magnetometer. The results are shown in Figure 2. That is, the orientation magnetic field preferably needs to be 6 KG or more. Now that we know the strength of the magnetic field, we investigated its relationship with wall thickness. The strength of the orientation magnetic field is 1O-1z[L5
KG, heating width 245:1:2°C, and other conditions were the same as above. Table 1 shows the results.

Table 1 Magnetic performance: The residual magnetic flux density (Br) was 1llll'ZL using a self-recording magnetometer. As can be seen from Table 1, the wall thickness is 1'1 or more, 1. S: When it crosses the line, it causes the disadvantage of density force; vomiting. However, it was found that the characteristic of the shape was also weakened, resulting in a defect that the circle 114i became worse.

[Example 2] The cylindrical magnets made in '4f' and '4f' were cut into lengths of four lengths, and the magnets were fitted into a yoke to perform multipolar magnetization. The 4-magnetic conditions were carried out using a set of oil-condensate containers. The photovoltaic voltage was 2,000 V, and each of the contours was set to i, 000 μF.

In FIG. 5-A, a thin cylindrical magnet 13 is fitted into a yoke 12 made of pure iron and fixed in place. This was set in a magnetizing yoke and magnetized to 24 poles under the above conditions. Layer line angle Q,
As shown in Figure 5-B at 15 degrees, the longitudinal direction (thickness direction)
Groove lines were placed on each side to provide 24 poles per circumference. Next, the inventive magnet t =
Table 2 shows the magnetic flux densities of 0.5 and the conventional product 7-1,5.

Table 2 6 (1j constant was measured using a Gauss meter.

FIG. 4 shows the magnetic pole positions (1 to 24 blocks) and surface magnetic flux changes of the two conventional magnets according to the present invention, and it was found that the force of the magnet according to the present invention is much more accurate. From the above, it was found that radial orientation and a slight multi-polar layer wire make it extremely easy to magnetize, and it is possible to fully bring out the boning that the moon has. The applications are PM type step motor printing machine developing Macnet roll, speaker, magnetic engine: l-ter & to VC.
It can be used.

〔Effect of the invention〕

According to the present invention, it is possible to facilitate multipolar magnetization by extruding a rare earth magnet in a circular shape with an anisotropic f-hole in radial orientation, thereby making it commercially viable. We were able to achieve both performance and high accuracy. However, due to the thin wall ratio, the cost of fabrication can be reduced to less than the conventional A, so the contribution of the product Tepais to the downfall is high.

By using the extrusion molding method in combination, shape retention can be improved, so the wall thickness can be reduced to t = 1. [Thin cylindrical magnets with a thickness of 1'% or less can be mass-produced.

[Brief explanation of drawings]

FIG. 1-A is a sectional view of a magnetic extrusion molding machine. Figure 1-B is the magnetic field extrusion molding machine magnetic field orientation part mold σ〕A-B
Cross-sectional view. FIG. 2 is a diagram showing the orientation magnetic field strength and performance of the method of the present invention. FIG. 5A is a sectional view of the jig used in the magnetization experiment, and FIG. 5B is a similar diagram showing the method of magnetization. FIG. 4 is a diagram showing the correlation between magnetic pole position and surface magnetic flux density. that's all

Claims (1)

[Claims] A molded product characterized by manufacturing a cylindrical magnet with an outer diameter of 150φm/m or less by passing a composition consisting of rare earth magnet powder and resin through a mold space using an extrusion molding method while heating the composition. A method for producing a thin cylindrical magnet having a wall thickness of 1 m/m or less.