JP3004204U - Anisotropic magnet - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to an anisotropic magnet in which a uniaxially anisotropic sintered magnet is arranged in the central portion of each magnetic pole of a cylindrical polar anisotropic magnet. An object of the present invention is to realize an anisotropic magnet in which a sintered magnet is arranged in a part of a polar anisotropic magnet to increase the packing ratio of magnetic powder and the magnetic flux density to improve the characteristics. [Arrangement] A uniaxially anisotropic sintered magnet 12 is arranged at the center of each cylindrical magnetic pole 11, and a polar anisotropic magnet 13 in which a resin is kneaded is arranged around it, and the polar anisotropic magnet 13 is oriented. It is an anisotropic magnet in which a resin is solidified while a magnetic field is applied in the direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an anisotropic magnet in which a uniaxially anisotropic sintered magnet is arranged in the central portion of each magnetic pole of a cylindrical polar anisotropic magnet.

[0002]

[Prior art]

 Conventionally, magnets often used for motors are roughly classified into sintered magnets and bonded magnets obtained by mixing magnetic powder and resin and solidifying them according to their composition. Further, it is classified into isotropic, radial anisotropy and polar anisotropy by the orientation treatment that gives out magnetic characteristics.

The polar anisotropic magnet that has been subjected to the polar anisotropic orientation treatment is widely used in stepping motors. This is because the orientation magnetic field distribution is as shown in (b-1) of FIG. 6 and the magnetic field distribution after magnetization is as shown in (b-2) of FIG. It is possible to extract a large magnetic flux as compared with the radial anisotropy of (a-1) and (a-2) of FIG. 6 and isotropicity (not shown). The manufacturing procedure will be described below with reference to the manufacturing flowchart of FIG. 7.

FIG. 7 shows a conventional manufacturing flowchart. In FIG. 7, in S21, the magnetic powder (for example, ferrite powder) and the resin are well kneaded.

In S22, the kneaded material that is well kneaded in S21 is granulated. In step S23, a magnetic pole, for example, a magnet which is a rotor of a cylindrical stepping motor is solidified by applying an orientation magnetic field distribution by injection molding while applying a magnetic field.

In S24, the magnet manufactured in S23 is magnetized.

[0007]

[Problems to be solved by the device]

 The polar anisotropic magnets shown in (b-1) and (b-2) of FIG. 6 produced according to the above-described conventional production flowchart of FIG. 7 are compared with other isotropic or radial anisotropic magnets. High magnetic flux can be obtained.

However, the polar anisotropic magnet has a problem in that it is necessary to knead a resin with a magnetic powder, the filling rate is lower than that of a sintered magnet, and there is a limit to improving the characteristics. In order to solve these problems, the present invention arranges a uniaxial anisotropic sintered magnet in a part of the polar anisotropic magnet to increase the packing ratio of the magnetic powder and the magnetic flux density to further improve the characteristics. The purpose is to realize an anisotropic magnet.

[0009]

[Means for Solving the Problems]

 Means for solving the problem will be described with reference to FIG. In FIG. 1, the magnetic pole 11 is a cylindrical magnetic pole. In the figure, one part (1/2 magnetic pole) is shown.

The sintered magnet 12 is a highly-filled sintered magnet containing no uniaxially anisotropic resin, and is disposed in a part of the polar anisotropic magnet 13. The polar anisotropic magnet 13 is obtained by kneading magnetic powder and resin and solidifying the resin in a state where a magnetic field is applied in the orientation direction.

[0011]

[Action]

 As shown in FIG. 1 showing a part of a cylindrical magnetic pole, the present invention arranges a uniaxially anisotropic sintered magnet 12 in the center of each cylindrical magnetic pole 11 and a pole mixed with a resin around it. The anisotropic magnet 13 is arranged, and the resin is solidified in a state where a magnetic field is applied in the orientation direction of the polar anisotropic magnet 13 to produce a cylindrical anisotropic magnet.

At this time, the width of the uniaxially anisotropic sintered magnet 12 is set to 0.5 to 0.8 × (Dπ / P) as a magnetizable range. Here, D represents the outer diameter of the cylindrical magnetic pole, and P represents the number of poles.

Further, a thermoplastic resin is used as a resin to be kneaded when the polar anisotropic magnet 13 is manufactured. Therefore, by arranging the uniaxially anisotropic sintered magnet 12 in a part of the polar anisotropic magnet 13, the packing ratio of the magnetic powder is increased and the magnetic flux density is increased to improve the characteristics of the cylindrical cylinder. An anisotropic magnet could be produced.

[0014]

【Example】

 Next, the configuration and operation of the embodiment of the present invention will be sequentially described in detail with reference to FIGS.

FIG. 1 shows a block diagram of an embodiment of the present invention. This is an anisotropic structure consisting of a polar anisotropic magnet 13 in which the uniaxially anisotropic sintered magnet 12 of the present invention is placed in the center of the magnetic pole by taking out a portion corresponding to 1/2 of the magnetic pole from the mold. 3 shows a procedure for producing a magnetic magnet.

In FIG. 1, a cavity 1 is a space for producing the anisotropic magnet of the present invention. . The non-magnetic sleeve 2 is a non-magnetic sleeve arranged between the permanent magnet 3 and the ferromagnetic steel 4 provided in the mold.

The permanent magnet 3 is for producing a polar anisotropic magnet 13 by applying a magnetic field to the resin and magnetic powder with which the cavity 1 is filled. The ferromagnetic steel 4 is a magnetic path of magnetic flux from the permanent magnet 3 and is for generating a magnetic field having a predetermined orientation in the cavity 1.

The non-magnetic steel 5 is used to hold the entire non-magnetic material. The magnetic pole 11 is a cylindrical magnetic pole, and represents a half magnetic pole in the figure. The sintered magnet 12 is a uniaxially anisotropic pre-sintered thin plate-shaped sintered magnet, and is disposed in a part of the polar anisotropic magnet 13. The size of the sintered magnet 12 is a magnetizable size, and according to experiments, the width is 0.5 to 0.8 × (Dπ / P), the thickness (orientation direction) is 0.2 to 0. 5 × (Dπ / P) D: outer diameter, P: number of poles are desirable. In addition, it is desirable to chamfer or make a trapezoid to prevent falling off due to centrifugal force. This sintered magnet 12 contains no resin and has a high filling rate.

The anisotropic magnet 13 is obtained by kneading magnetic powder and resin and solidifying the resin in a state where a magnetic field is applied in the orientation direction. Next, the procedure for producing the cylindrical anisotropic magnet of the present invention will be described in detail in the order of (a) to (e) of FIG.

FIG. 1A shows a half magnetic pole orientation mold diagram. This mold diagram represents 7.5 ° for 1/2 pole as shown. That is, since it is the case of 24 poles, it is 360 ÷ 24 ÷ 2 = 7.5 °. Here, the cavity 1 is a portion (1/2 magnetic pole portion) where the cylindrical anisotropic magnetic pole 11 is injection molded. The permanent magnet 3 and the ferromagnetic steel 4 are for giving a predetermined magnetic field distribution in the cavity 1 and orienting the magnetic powder to have polar anisotropy.

FIG. 1B shows a molding space (1/2 magnetic pole) surrounded by a dotted circle. FIG. 1C shows insertion of the sintered magnet. This shows a state in which the uniaxially anisotropic sintered magnet 12 is inserted and arranged in the central portion of the magnetic pole in the cavity 1. This sintered magnet 12 is arranged so as to be attracted to the central portion of the magnetic pole.

FIG. 1D shows the filling, orientation and solidification of (resin + magnetic powder). In FIG. 1 (c), the uniaxially anisotropic sintered magnet 12 is placed in the center of the magnetic pole, and then the kneaded material in which the resin and the magnetic powder are well kneaded is filled in the cavity 1 to make the permanent magnet 3 and the magnetic field distribution applied by the ferromagnetic steel 4, the magnetic powder in the kneaded material is oriented and heated to solidify the resin.

FIG. 1E shows a magnetized state. This is for a cylindrical anisotropic magnet (an anisotropic magnet consisting of a polar anisotropic magnet 13 having a sintered magnet 12 as a part) after being filled, oriented and solidified in (d) of FIG. Magnetization is performed by the coil 7 for generating a magnetic field for magnetization and the ferromagnetic steel 6 forming a magnetic path for generating a magnetic field distribution for magnetization, which are arranged as shown in the figure. By this magnetization, the cylindrical rotor having 24 magnetic poles in FIG. 4 can be manufactured.

FIG. 2 shows an example of a permanent magnet embedded type anisotropic magnet mold of the present invention. This is an overall configuration diagram of the mold having the configuration of FIG. 1, and is composed of 24 poles. Here, the permanent magnet 3 and the ferromagnetic steel 4 are used to form a magnetic field distribution so that the polar anisotropic magnet is oriented in the cavity 1.

FIG. 3 shows a manufacturing flow chart of the present invention. This is a procedure for manufacturing a cylindrical anisotropic magnet using the mold of FIG. In FIG. 3, S1 is kneading. In this, ferrite powder (for example, Sr-Ferrite powder) as magnetic powder and resin (for example, 6 nylon or 6.6 nylon) are well kneaded.

S2 is granulated. This granulates the kneaded material well kneaded in S1. In S3, placement on the die is performed. As shown in FIG. 1 (c), the sintered magnet thin plate is attached to the central portion of the magnetic pole in the cavity 1 of the mold. This is arranged by adsorbing all magnetic poles, in the case of FIG. 2, 24 magnetic poles at the central portion of each magnetic pole.

At S4, molding is performed. As shown in (d) of FIG. 1 described above, this is filled with granulated resin and magnetic powder (or liquid) and heat-molded. S5 is magnetized. As shown in (e) of FIG. 1 described above, this is performed by inserting the magnet 7 composed of the coil 7 and the ferromagnetic steel 6 into the magnet 12 and the polar anisotropic magnet 13. Magnetize with magnetic field distribution. As a result, the rotor, which is a cylindrical anisotropic magnet, as shown in FIG. 4, can be manufactured.

As described above, the uniaxially anisotropic sintered magnet 12 is arranged in the central portion of each magnetic pole, and the polar anisotropic magnet 13 of magnetic powder mixed with resin is applied to the periphery of the sintered magnet 12 so that a predetermined orientation magnetic field distribution is applied. After being solidified in this state, it was magnetized into a predetermined magnetic field distribution, and a cylindrical anisotropic magnet having a high magnetic flux density and an increased filling rate of magnetic powder could be manufactured. As a result of the experiment, a uniaxially anisotropic fan-shaped ferrite sintered magnet 12 was adsorbed and arranged in a state in which a polar magnetic field was formed with the configuration shown in FIG. Was injection molded to prepare a polar anisotropic ferrite plastic magnet (anisotropic magnet). In Experimental Example 1 of this anisotropic magnet, the following results were obtained as a result of actual measurement.

Conventional polar anisotropy magnet Anisotropic magnet of the present invention Performance index 110 130 Here, product shape: outer diameter φ18 / inner diameter φ13, width t = 11.7 mm, number of poles 24 performance index: 100 (pole (The total magnetic flux of anisotropic magnets / the total magnetic flux of general-purpose magnets) The following results were obtained as a result of measuring the magnetic flux induced in the search coil having pole teeth according to the number of magnet poles using a magnetometer. .

Conventional method: resin + magnetic powder 485 KMx. T Experimental Example 1: Resin + magnetic powder + uniaxially anisotropic sintered magnet 12 570 KMx. Experimental Example 2: Resin + uniaxially anisotropic sintered magnet 12 530 KMx. T Reference Example: Cylindrical isotropic sintered magnet 440 KMx. T. In Experimental Example 2, when the magnetic powder of Experimental Example 1 was eliminated and the uniaxially anisotropic sintered magnet 12 was attracted and arranged in the center of the magnet, only the resin was filled, solidified, and magnetized. It is a thing.

Similar results can be obtained by using the following resin and magnetic powder. -Similar results can be obtained by using the following as ferrite + polyamide resin.

-PBT (polybutylene terephthalate) -LCP (liquid crystal polymer) -PA (polyamide, nylon) -POM (polyacetal) -PC (polycarbonate) -PPE (modified polyphenylene ether) -PSF (polysulfone) -PES (polyether) Sulfone) PPS (polyphenylene sulfide) PEEK (polyether ether ketone) FIG. 4 shows an example of the rotor of the present invention. This shows an example of the cylindrical anisotropic magnet manufactured according to FIGS. 1 to 3 described above. The portions indicated by S and N are the magnetized portions of the uniaxially anisotropic sintered magnet 12 arranged in a part of the anisotropic magnet of the present invention.

FIG. 5 shows an example of the orientation / magnetization state of the present invention. This is one in which one half of the pole of the cylindrical anisotropic magnet according to the present invention is taken out. FIG. 5A shows the orientation state. The right side is the outside, and the left arrow portion is the portion where the uniaxially anisotropic sintered magnet 12 is arranged and oriented.

FIG. 5B shows a state after magnetization. The right side is the outer side, and the part indicated by the arrow pointing to the left is the part where the uniaxially anisotropic sintered magnet 12 is arranged and magnetized, and the orientation is the same in the oriented state and the state after the magnetization. It has become possible to generate magnetic flux very efficiently. As a result, the portion of the uniaxially anisotropic sintered magnet 12 contains no resin and has a high packing rate of the magnetic powder, and the orientation and the direction of the magnetic flux after magnetization are the same, so that the magnetic flux can be generated very efficiently. Can be generated. Further, the portion of the polar anisotropic magnet 13 which is a polar anisotropic bond magnet (a permanent magnet obtained by kneading and solidifying resin into magnetic powder) other than the uniaxially anisotropic sintered magnet 12 is Although it contains a resin and the filling rate becomes slightly lower, the orientation and the direction of the magnetic flux after magnetization are almost the same, and the magnetic flux can be efficiently generated.

Therefore, by arranging only the central portion corresponding to the magnetic poles of the polar anisotropic magnet 13 by replacing it with the resin-free uniaxially anisotropic sintered magnet 12, the characteristics of the polar anisotropic magnet 13 are impaired. It was possible to produce a cylindrical anisotropic magnet that can generate a high magnetic flux.

[0036]

[Effect of device]

 As described above, according to the present invention, the uniaxially anisotropic sintered magnet 12 is arranged in a part of the polar anisotropic magnet 13, and the magnetic powder is filled without impairing the characteristics of the polar anisotropic magnet. Since a structure that increases the rate is adopted, a cylindrical anisotropic magnet with higher characteristics than the polar anisotropic magnet could be manufactured.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is an example of a permanent magnet embedded type anisotropic magnet mold of the present invention.

FIG. 3 is a production flow chart of the present invention.

FIG. 4 is an example of a rotor of the present invention.

FIG. 5 is an example of an orientation / magnetization state of the present invention.

FIG. 6 is an explanatory diagram of a conventional technique.

FIG. 7 is a conventional manufacturing flowchart.

[Explanation of symbols]

 1: Cavity 2: Non-magnetic sleeve 3: Permanent magnet 4: Ferromagnetic steel 11: Magnetic pole 12: Uniaxial anisotropic sintered magnet 13: Polar anisotropic magnet

Claims (3)

[Scope of utility model registration request] 1. A uniaxially anisotropic sintered magnet (12) is arranged at the center of each cylindrical magnetic pole (11), and a polar anisotropic magnet (13) kneaded with a resin is arranged around it. An anisotropic magnet in which the resin is solidified while a magnetic field is applied in the orientation direction of the polar anisotropic magnet (13). 2. The anisotropic magnet according to claim 1, wherein the uniaxially anisotropic sintered magnet (12) has a width of 0.5 to 0.8 × (Dπ / P). .
Here, D represents the outer diameter of the cylindrical magnetic pole, and P represents the number of poles. 3. The anisotropic magnet according to claim 1, wherein the resin is a thermoplastic resin.