JPH02211032A - Composite-structured magnet member - Google Patents

Abstract

PURPOSE:To improve finishing accuracy, to promote efficiency in magnetical use and to reduce the cost in installation by fitting a composite magnet material with intense magnetic force into a base magnet material in normal magnetic force for a composite structure. CONSTITUTION:A magnet substance of a composite structure is composed of a grooved base magnet material 1 and a magnet material 2 for composite structure with intense magnetic force inserted into the groove. The N-pole is caused to face the S-pole in magnetizing radially so that the center of the compound magnet material 2 may be the center of pole of a magnetized yoke. Here, the flux density phi of the magnet substance of a composite structure increases in sinusoidal wave towards the N-pole with the illustrated angle theta as 0 deg. to 90 deg. and when it passes 90 deg., it begins to decrease. When it passes 180 deg., it turns to the increase towards S-pole. From 270 deg. it turns to decrease until it comes to 360 deg.. If it is used for the field system of a stator in a motor, cogging torque can be reduced and peak flux as required can be obtained without a necessity of forming all the magnets of expensive ones with intense magnetic force.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a composite structure magnet body, which can be widely used in the technical field of so-called mechatronics, for example, as a member of pulse motors, servo motors, actuators, etc. The present invention relates to a composite structure magnet that can be used.

[Prior art and its problems] Fig. 8 is an explanatory diagram of a conventional magnet, and Fig. 8 (A) shows a schematic configuration of a conventional single magnet, and FIG. 8(B) shows the distribution of surface magnetic flux density at the inner diameter portion of the conventional single magnet. This conventional single magnet is formed into a hollow cylindrical shape using only a suitable resin magnet material or sintered magnet material (1), and has an N
The pole and the S pole are arranged to face each other at the top and bottom of the drawing.

Now, by arranging a predetermined magnetic flux density sensor (not shown) opposite to the inner diameter of such a single magnet and rotating either of them relative to each other, the inner diameter of the single magnet can be adjusted. When the change in the surface magnetic flux density (φ) with respect to the angle (θ) is determined, the result is as shown in FIG. 8(B). In other words, the angle (θ) increases almost sinusoidally from 0 degrees to the vicinity of 90 degrees, but it actually decreases at a predetermined part around 90 degrees.This phenomenon occurs at 270 degrees. It is also recognized in the vicinity of . That is,
As the angle (θ) further increases from 180 degrees, the magnetic flux density (φ) increases sinusoidally, but it actually decreases at a predetermined portion around 270 degrees.

By the way, since the above-mentioned conventional magnets are composed of only a certain predetermined single magnet material, until now, only the materials, shapes, and manufacturing methods have been devised to obtain such magnets. It's here.

Here, looking at some types of single magnets that have been used in the past, for example, ferrite sintered magnets are considered to be inexpensive, but there are difficulties in the way they are manufactured. In other words, although the manufacturing process of this magnet includes a sintering process, the volume of the magnet shrinks significantly during this sintering process, and as a result, the dimensional accuracy of the magnet becomes extremely poor. However, it is unavoidable to rely on the required post-processing, and the only operations that can be used as such post-processing are polishing operations or slicer cutting operations, and the cost required for this becomes extremely high. Put it away.

The next option to consider is a rare earth magnet, but since the materials used to manufacture it are expensive and the manufacturing method is a fine powder anisotropic sintering method, this magnet will also be considered later. Processing is required. Furthermore, alnico magnets can also be considered, but since these magnets are obtained by casting, post-processing is also required in this case.

In addition, depending on the object, only the local magnetic force of the target magnet may be required, but conventionally, due to structural constraints, the magnet as a whole has been used to respond. , sometimes included parts that were not used effectively.

As mentioned above, conventional magnets have had the disadvantage that their finishing accuracy is dependent on required post-processing. Furthermore, it has been difficult to effectively utilize the magnetic force of the magnet as a whole.

[Means for Solving the Problems] The composite structure magnet of the present invention has a composite structure instead of the conventional single structure magnet.

By adopting such a composite structure, it is possible to improve the finishing accuracy, improve the efficiency of magnetic use, etc., and reduce the cost of the magnet itself and the necessary equipment including the magnet. By making the necessary adjustments to obtain the desired magnetic force distribution, the overall performance benefits of the composite structure magnet can be realized.

In addition, in this invention, if the desired magnetization is performed after the required device including the composite structure magnet is completed,
Its unit permeance is improved to achieve excellent demagnetization properties, magnetic operating points and magnetic flux density distribution states.

[Example] Next, the composite structure magnet of the present invention will be described based on an example thereof.

LK11 For example, as a high-magnetic-force magnet body to obtain a magnet body used in a specified motor, (1) a magnet body cut from a large block high-magnetic-force sintered magnet, (2) a simple-shaped magnet body obtained by compression molding. An appropriate one is selected from the following: (3) a high magnetic force bonded magnet obtained by magnetic field orientation extrusion molding, and the like.

Now, FIG. 1 is an explanatory diagram of a composite structure magnet body which is a first embodiment of the present invention. Here, the first figure (A) is
This figure shows a schematic configuration of the composite structure magnet according to the first embodiment, and FIG. 1(B) shows the surface magnetic flux density at the inner diameter of the composite structure magnet according to the first embodiment. 1 distribution.

First, in FIG. 1(A), grooves with a rectangular cross section are provided in the upper and lower parts of a basic magnet material made of a suitable resin magnet material or sintered magnet material (1) in a hollow cylindrical shape. . Then, a composite magnet material (2) made of a high-magnetic-force magnet material is inserted into this groove portion, or insert injection molding is performed appropriately, thereby constructing the composite structure magnet body as the first embodiment as a whole. . Then, the composite structure magnet body constructed in this way is arranged symmetrically on the inner diameter side surface (up and down in the drawing)! Composite magnet material as a high magnetic force magnet material (
Two-pole magnetization is performed in the radial direction so that the center of 2) becomes the center of the magnetic pole of the magnetizing yoke, so that the north pole and the south pole face each other at the top and bottom of the drawing.

Now, as in the case of the conventional example, by arranging a predetermined magnetic flux density sensor (not shown) opposite to the inner diameter part of such a composite structure magnet body and rotating one of them relatively, When the change in the surface magnetic flux density (φ) with respect to the angle (θ) at the inner diameter portion of the composite structure magnet is determined, it is as shown in FIG. 1(B). That is,
From 0 degrees to 90 degrees, the angle (θ) increases in a substantially sinusoidal manner toward the N pole, and after 90 degrees, it begins to decrease in a similar sinusoidal manner. This trend reverses to an increase beyond 180 degrees to the south pole. Then, from 270 degrees, it starts to decrease, and this decreasing trend continues up to 360 degrees. Since the first embodiment has the above-mentioned properties, when it is used as a stator field in a suitable motor, it has the characteristic that the cogging torque is low. In addition, the required peak magnetic flux can be obtained without making the entire magnet body of an expensive high-magnetic-force magnet material, and it can be suitably used as a field magnet for a DC micromotor, for example.

11E11 FIG. 2 is a schematic configuration diagram showing a composite structure magnet body which is a second embodiment of the present invention. In this Figure 2, the required dimensions (for example, outer diameter 22 mm, inner diameter 18 mm, height 15 m)
In order to obtain the composite magnet for a small motor (m), SmC, which is a high magnetic force magnetic material, is used.

From system anisotropic sintered magnet material, for example, 50 mm x 25 mm
A diamond with a shape of 100 mm was used. A composite magnet material (2) having a shape of 1.5 mm x 1 mm x 15 mm was created using a slicer. Separately, the basic magnet material (1) was formed into a hollow cylindrical shape by injection molding using an inexpensive ferrite-based isotropic resin magnet material. Then, grooves with a rectangular cross section are provided in the upper and lower and left and right parts of this basic magnet material (1), and the composite magnet material (2) made of the above-mentioned high magnetic force magnet material is inserted, using the required adhesive. Both were joined together to obtain a composite structure magnet as a whole as this second example. Regarding the composite structure magnet body configured in this way, the center of the composite magnet material (2) as a high magnetic force magnet material arranged 4-fold symmetrically on the inner diameter side surface is the center of the magnetic pole of the magnetizing yoke. By subjecting the magnet to four poles in the radial direction, a composite structure magnet was obtained that was inexpensive, had high magnetic force, and was easy to attach.

Looking at the magnetic force of this second example, it was found that the magnetic force is about twice that of a single magnet made of a ferrite resin magnet of the same shape. Further, by devising the shape of the composite magnet material as the high magnetic force magnet material, the motor characteristics of the motor in which the composite structure magnet body of the second embodiment is used can be improved.

FIG. 3 is a schematic configuration diagram showing a composite structure magnet body according to a third embodiment of the present invention. In FIG. 3, a pair of fan-shaped basic magnet members (1) are arranged facing each other, and a groove of a desired shape (for example, rectangular) is provided in the center of the inner diameter of the basic magnet members (1). There is.

The basic magnet material (1) is obtained by appropriately injection molding a ferrite resin magnet material.

What is inserted into the groove is an SmCO rubber magnet material (BHmax is 7MGOe) as a composite magnet material (2) created by magnetic field orientation extrusion molding. Then, after inserting this composite magnet material (2) into the basic magnet material (1), insert it into the iron housing yoke (
3) to obtain the desired high efficiency and low cogging torque motor segment.

Conventionally, since there was no effective adhesive between rubber and iron,
It is extremely difficult to fit a single rubber magnet tightly into an iron housing yoke, and even if a structure is adopted in which the ends of the single rubber magnet are sandwiched, the ends of the single rubber magnet Although there was a problem in that the mechanical strength of the parts was low and the purpose could not be achieved, this problem was solved by this third embodiment.

Fig. 4 is a schematic configuration diagram showing a composite structure magnet according to a fourth embodiment of the present invention, in which Fig. 4(A) is a plan view, and Fig. 4(B) is a plan view. is a side sectional view. In FIG. 4, the basic magnet material (1) having the required shape was obtained by injection molding a ferrite resin magnet material. Further, as the composite magnet material (2), SmCo-based sintered magnet material, which is a high magnetic force magnet material, was selected, and these were placed in a groove of a desired shape provided at a suitable location on the outer peripheral edge of the basic magnet material (1). Glued it. Then, after applying desired magnetization to this material, a shaft is press-fitted into a hollow cylindrical portion provided at the center of the basic magnet material (1), thereby obtaining an inexpensive and high-magnetic rotor magnet. did it.

FIG. 5 is a schematic configuration diagram showing a planar tweeter (treble speaker) as an application example of the embodiment of the present invention. In FIG. 5, sound holes (7) are provided at appropriate locations on a flat first ferrite magnet (5). Further, a flat second ferrite magnet (6) is arranged facing each other, and a diaphragm (9) is sandwiched between them. A diaphragm terminal (8) is provided at a suitable location on the outer circumference of this diaphragm (9).

FIG. 6 is an explanatory diagram of the planar tweeter of the above application example. Here, FIG. 6A is a plan view of the first ferrite magnet (5), FIG. 6B is a side sectional view of the first ferrite magnet (5), and FIG. 6C is a plan view of the first ferrite magnet (5).
A plan view of the magnet (6), and the sixth diagram is the second one.
It is a side sectional view of a ferrite magnet (6). In FIG. 6, (51) is a hole for attaching the terminal of the diaphragm, (52) is a hole for attaching the main body, (53) is a diaphragm fixing hole, and (54) is an assembly screw hole.

In addition, (1) is a basic magnet material made of an inexpensive ferrite-based polar anisotropic resin magnet material, (2) is a NdFeB-based high magnetic force layer magnetic resin magnet material composite magnet material, and (7) is a sound hole magnet material. It is.

In order to obtain a composite structure magnet used in such a planar tweeter, an inexpensive ferrite-based magnet is used as the basic magnet material (1), which also has the function of housing the planar tweeter and holding down the diaphragm. A desired object is created by appropriately injection molding using an anisotropic resin magnet material. In addition, as the composite magnet material (2), Nd
FeB-based high-magnetic-force layered magnetic resin magnet material This is made into a desired material by compression molding as required. By fitting these two together and coupling them together, the desired composite structure magnet can be obtained.

Next, the composite structure magnet obtained as described above is subjected to required magnetization.

When we measured the surface magnetic flux density of the composite structure magnet obtained in this way, the maximum value was 1700.
It was G. However, the maximum value of the surface magnetic flux density of a conventional single magnet body made of a ferrite-based polar anisotropic resin magnet material having the same shape as this composite structure magnet body is 1200G.
Therefore, the total flux amount is approximately 1.5 times that of the conventional method.

The graph in FIG. 7 shows the frequency characteristics of a planar tweeter constructed using a composite structure magnet as described above, in a manner in which it is compared with that of a conventional product. In FIG. 7, a solid line characteristic curve (71) represents the frequency characteristics of a planar tweeter constructed using the above-mentioned composite structure magnet, and a dotted line characteristic curve (72) represents the frequency characteristic of a conventional tweeter. It represents the quality of the product. As can be seen from FIG. 7, the planar tweeter to which the embodiment of the present invention is applied can be used in the midrange as the magnetic flux density increases.

[Effects of the Invention] As explained above, according to the present invention, it is possible to obtain a composite structure magnet having a desired magnetic flux density distribution, a desired shape, and excellent mounting properties at a relatively low cost. can.

Further, the thus obtained composite structure magnet body is expected to have a wide range of uses, for example, as a member of pulse motors, servo motors, actuators, and the like.

That is, according to the composite structure magnet according to the present invention, the unit permeance in various types of motors as described above is significantly improved, and remarkable good results are obtained in terms of functional factors such as demagnetization and magnetic flux density distribution. be beaten down, also
If you look at this from a cost perspective, by using expensive magnet materials with recessed magnetic force only in the necessary locations and using inexpensive resin magnet materials in other locations, the overall cost can be significantly reduced. becomes possible.

In addition, as mentioned above, since it is commonly used with inexpensive resin magnet materials, when the composite structure magnet according to the present invention is attached to other related parts, it is necessary to use the good resin magnet material. The mounting characteristics can be skillfully utilized to serve the purpose very well.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a composite structure magnet according to a first embodiment of the present invention, FIG. 2 is a schematic configuration diagram showing a composite structure magnet according to a second embodiment of the invention, and FIG. , a schematic configuration diagram showing a composite structure magnet according to a third embodiment of the present invention, and a fourth embodiment.
FIG. 5 is a schematic configuration diagram showing a composite structure magnet body according to a fourth embodiment of the present invention, FIG. 5 is a schematic configuration diagram showing a planar tweeter as an application example of the embodiment of the present invention, and FIG. , an explanatory diagram of the planar tweeter of the above application example, FIG.
FIG. 8, which is a graph diagram for comparing and explaining the applied example and the conventional magnet, is a schematic configuration diagram showing a conventional magnet. (1) is the basic magnet material, (2) is the composite magnet material, (3) is the iron housing/yoke, and (4) is the shaft. In addition, the same reference numerals in the drawings are engravings of the same or corresponding parts (no changes in content) Figure 1 Figure 2 Figure 3 (B) Figure 4 Figure 5 Guan 6 Figure 8 (A) (B ) Magnetic flux attainment (φ) Procedural amendment writing method) % formula % 1. Indication of the case 1999 Patent Application No. 29940 2. Name of the invention Composite structure magnet 3. Person making the amendment Relationship with the case Patent applicant Name: Tomoyuki Okumura 4, Agent: 100 Address: 4th floor, Marunouchi Building, 2-4-1 Marunouchi, Chiyoda-ku, Tokyo 6°7° Target of amendment as of May 30, 1999 (1) Drawings (full drawings) Amendment Contents (1) An engraving of the drawing originally attached to the application, as per the attached sheet (
(Changes have been made to the contents.)

Claims (1)

[Claims] (1) A basic magnet material that has a normal magnetic force and is shaped to have a required receiving part; and a composite magnet material that has a high magnetic force and is shaped so that it can fit into the receiving part; A composite structure magnet body having a configuration in which the composite magnet material is fitted into a receiving portion of the basic magnet material.