JPS5813009B2 - magnet device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnet device using a resin magnet having different magnetic poles on the same surface and capable of increasing magnetomotive force.

Generally, resin magnets are made of a composition consisting of a polymer material and a magnetic material such as ferrite powder containing at least one type of barium, strontium, or lead, which is easily magnetized by mechanical or magnetic force. It is obtained from a plate-shaped molded product whose axial direction (magnetically strong direction) is arranged perpendicular to the plate surface.

The magnetic properties of such a resin magnet are the residual magnetic flux density IB
r is 2100~2530G1 coercive force BHC is 1850~
22500e, maximum energy product BHmax is 1.04
~1.49MGOe, and has properties equivalent to or better than those of isotropic sintered ferrite.

This resin magnet is processed into a rectangular or cylindrical shape as shown in Fig. 1 a = c, so that it has a structure with an axis of easy magnetization in the direction of arrow 1, and when different magnetic poles are magnetized on the same surface, the same shape The surface magnetic flux density variation is only about 70 to 80% that of isotropic sintered ferrite magnets.

For example, a plate-shaped resin magnet 2 having an axis of easy magnetization 1 perpendicular to the plate surface as shown in FIG. 2A is wound around a stainless steel shaft 3 as shown in FIG. 2B, and the magnet is easily magnetized in the radial direction. A laminated roll magnet having a shaft 1 was manufactured, and the outer circumferential surface 4 was magnetized by a magnetizer 5 as shown in FIG. 3, and the magnetic flux density on the surface was measured to be 800 to 950G.

On the other hand, an isotropic sintered ferrite magnet having the same shape as this had a surface magnetic flux density of IOOOG.

Conventionally, a structure of a magnet device shown in FIG. 4 has been developed to increase the surface magnetic flux density.

A soft magnetic material 8 is provided as a common base for the magnets 6 and 7, which are constructed by stacking magnet sheets and have different magnetic poles, to form a closed magnetic path, and the magnets are used to prevent magnetic flux leaking from the sides of the magnets 6 and 7. A magnet 9 having a magnetic axis perpendicular to the magnetic axes 6 and 7 is arranged.

In the above explanation, the magnetic axis refers to the N,
This means the direction of magnetization of S, and the magnet 9 for leakage magnetic flux is magnetized in N and S, and this magnet 9 is joined so that the same poles as the poles of magnets 6 and 7 are brought close together, so when joining,
The magnet 9 receives a repulsive force from the magnets 6 and 7 and tends to bend over, making assembly difficult.

Furthermore, the soft magnetic material 8 for constructing the closed magnetic circuit is required, increasing the number of parts.

Furthermore, there is a gap between the magnets 6 and 7, and a magnet 9 is inserted to prevent leakage magnetic flux generated due to this gap, but the gap cannot be completely eliminated by the magnet 9.
Leakage flux was present.

The present invention seeks to eliminate the above-mentioned drawbacks of the prior art.

In other words, the gap between the roll magnet and the spacer is eliminated by using a resin magnet that can be easily cut with a knife, has high flexibility, can be bent, is easy to mold, and can be bonded with heat, pressure, adhesive, etc. The present invention relates to a magnet device that is capable of eliminating magnetic permeability reduction and loss due to leakage magnetic flux.

Hereinafter, the principle structure of the magnet device of the present invention will be explained with reference to FIGS. 5 and 6.

Roll magnet 1 having an axis of easy magnetization 10 in the radial direction
1, its peripheral surface 12 is magnetized by a magnetizer 13, and a groove 16 is provided between the magnetic poles 14 and 15 on the same surface, so that the axis of easy magnetization 10 is aligned with the magnetic flux line 17 flowing through this groove 16. The magnet device of the present invention is constructed by inserting a spacer 18 made of a plate-shaped resin magnet.

According to this configuration, the manufacturability is excellent, and the roll magnet 1
It is also possible to eliminate the existence of a gap between 1 and the spacer 18, thereby increasing magnetic permeability and significantly reducing leakage magnetic flux.

Next, the magnet device of the present invention will be specifically explained using examples.

Example 1: 6 parts by weight of chlorinated polyethylene, 5.9 parts by weight of plasticizer, 0.0 parts by weight of lubricant. Mix and knead I weight part and Ferrite 88 weight part in a Henschel type mixer at 150 rpm for 5 minutes, then take out the kneaded material and mix with a roll mill at 90 to 130 °C, 5 to 1
Kneading was carried out for 0 minutes to obtain a plate-shaped resin magnet sheet with a thickness of 0.1 to 5.0 mm in which the axis of easy magnetization of plate-shaped ferrite particles having a substantially domain size was oriented in a direction perpendicular to the plate surface. Ta.

The magnetic properties of this resin magnet sheet were as follows: residual magnetic flux density Br was 2340G, coercive force BHC was 18500e, and maximum energy product BHmax was 1.26MGOe.

After that, apply a chloroprene adhesive to one side of this resin magnet sheet, and as shown in Figure 7A, the diameter is about 7φ.
A laminated roll magnet 11 having a diameter of 19φ was obtained by winding the core material 19 around the core material 19 of the magnet.

A groove 16 having a width of 8 mm was formed in this laminated roll magnet 11 as shown in FIG. 7B.

In order to arrange the axis of easy magnetization 10 in the tangential direction of the roll magnet 11 as shown in FIG. 7C, a spacer 18 made of a plate-shaped resin magnet is inserted into this groove 16 and then glued, as shown in FIG. 7D. I made a magnet like this.

Thereafter, the outer peripheral surface is ground to obtain a laminated roll magnet having an axis of easy magnetization 10 as shown in FIGS. 5 and 6,
A magnet device was obtained by magnetizing the portion sandwiching the spacer 18 using a magnetizer.

A Hall element is brought into contact with the outer peripheral surface of this magnet device and rotated, and the maximum magnetic flux density is read on the scale of a Gaussmeter.

The surface magnetic flux density of the magnet device with this configuration is 1050~
It was IIOOG.

Example 2 Similar to Example 1 above, a resin magnet sheet was made with a diameter of about 7 mm.
The laminated roll magnet 11 is wound around a core material 19 of φ to obtain a laminated roll magnet 11 with a diameter of 26.4φ.
As shown in Fig. 8, groove 1 with a width of 3 mm and a depth of 57 nt is formed.
6 were provided at two locations, spacers 18 were inserted and bonded in the same manner as in Example 1, and magnetized with S and N poles with the spacers 18 in between to create a magnet device.

The maximum magnetic flux density on the surface of this magnet device is 1100 to 1150G at the N pole sandwiched between the insertion portions of the spacer 18.
1 and other S poles were 1050 to 1100G.

Example 3 A molding composition is prepared by mixing, cross-mixing, and granulation in a Henschel type mixer according to the formulation example shown in Example 1.

This composition was extruded using a 65φ extruder with an effective cross-sectional area of 6.3
cyj, a cylindrical magnet with an outer diameter of 29φ and an inner diameter of 10φ is obtained, a core material coated with chloroprene adhesive is inserted into this cylindrical magnet, a groove is formed with the outer peripheral surface of the cylindrical magnet, and a groove is formed in a direction perpendicular to the plate surface. A spacer made of a plate-shaped resin magnet having an axis of easy magnetization was inserted into the magnet so that the axis of easy magnetization was in the tangential direction.

Thereafter, the outer peripheral surface was ground and magnetized in the same manner as in Example 1 to obtain a magnet device.

The surface magnetic flux density of this magnet device is 900-980G
Met.

Since the above extruded product can be processed by extrusion processing so that the axis of easy magnetization is oriented in the radial direction, the same effect as the laminated roll magnet of Example 1 can be obtained.

As described above, since resin magnets contain non-magnetic materials such as polymeric materials, compared to sintered ferrite magnets, the same volume contains less magnetic energy.

However, by aligning the axes of easy magnetization of each magnetic material in a certain direction through strong processing, the magnetic properties in the aligned direction become equal to or even better than a sintered ferrite magnet that is not particularly oriented.

However, the magnetic properties in the direction perpendicular to the direction in which the resin magnet is oriented are such that Br is 500 to 800G. BHC is 50
Very low, 0-8000e.

In addition, in order to achieve orientation, extremely strong processing is required by roll processing or extrusion processing, and the shape of the axis of easy magnetization can be relatively simple, such as at right angles to the plate surface or in a direction radiating from the center point. limited to.

However, the lines of magnetic flux flowing between different magnetic poles on the same surface have a curved or bulging shape as shown in FIG. 3 and FIGS. 10A and 10B.

In a structure having the magnetization capacity axis 1 in the direction shown in Fig. 3, the magnetic flux lines pass in a direction perpendicular to the easy magnetization axis 1 in some parts, and only a low value of the magnetic energy of the material is collected. do not have.

As shown in the embodiments of the present invention, the direction of the magnetic flux lines near the magnetic poles is
It has a direction toward the inside of the magnet, but as it moves to the middle of the magnetic poles, the direction gradually changes, and at the center of the magnetic poles, it is parallel to the direction that connects the magnetic poles. This is a magnet device with a structure in which a spacer is inserted so that the axis of easy magnetization can be arranged in the direction connecting the magnetic flux lines, and the magnetic energy in the direction of the magnetic flux lines is increased in each part of the magnetic flux lines, so that a large magnetic force is generated at the magnetic poles.

In order to explain the principle of the present invention in more detail, an enlarged view of the spacer insertion portion is shown in FIG. 11.

Lines of magnetic flux 17 flow between magnetic poles 14,15 of different polarity.

The magnetic flux line vector of each part of the magnetic flux line 17 is divided into two directional components, a direction A toward the inside of the material and a direction B perpendicular to it, and the region where the component A toward the inside of the material is larger is the direction toward the inside of the material. A first resin magnet 15A and a second resin magnet 14A having easy magnetization axes 10 in opposite directions.
The structure is such that a third resin magnet 15B having an axis of easy magnetization 10 in the B direction is arranged in a region with a large component in the B direction.

That is, in FIG. 11, the first resin magnet 15A
forms the S magnetic pole, and the second resin magnet-14A forms the N magnetic pole.
In this structure, a third resin magnet 15B having an axis of easy magnetization 10 in a direction parallel to the straight line connecting the S pole and the N pole is arranged between these two resin magnets forming the magnetic poles.

Therefore, the large magnetic energy of each part of the material can be collected in the direction of the magnetic flux lines, and the accumulation of all the magnetic flux lines also has large magnetic energy.

Based on this idea, Figure 9 A, B. Figure 10A
, B can be manufactured with a structure in which the easy magnetization axes 10 are arranged.

Alternatively, the sheet-like resin magnets shown in FIGS. 10A and 10B may be wound to form magnet devices such as those shown in FIGS. 9A and 9B.

Since the magnet device of the present invention is configured as described above, the magnetomotive force can be increased, the surface magnetic flux density of the magnetic poles can be increased, and even if the same magnetomotive force is obtained, a light magnet device that is about 27 times lighter can be obtained. Although the density of the sintered ferrite magnet is 4.89l crd, the density of the resin magnet of the present invention is 3.59/crl.
＜Not only is it resistant to impact, it can be easily cut with a cutter, and it can be easily bonded with at least one of heat, pressure, and adhesives, so even laminated structures can be easily cut and bonded, and magnetic materials can be easily cut. Utilizing plasticity and applying at least one of heat and pressure to the laminated structure in one mold, it is possible to almost eliminate the air gap at the laminated interface, and prevent a decrease in magnetic permeability in the magnetic circuit. It also eliminates loss of leakage magnetic flux, making it highly productive and economically advantageous to manufacture.Furthermore, since the direction of magnetic flux is aligned with the axis of easy magnetization, In order to make the magnetic flux into a closed loop, no extra material is required, and since the resin magnet has a laminated structure, it is possible to attract or repel each other, and to remove dust. It has the advantages of not having the inconvenience of handling such as suction and being extremely easy to assemble, making it a valuable product in industry.

[Brief Description of the Drawings] Figures 1 a to c are perspective views showing the direction of the easy axis of magnetization of a conventional resin magnet, Figure 2 A is a perspective view showing the direction of the easy axis of magnetization of a plate-shaped resin magnet, and Figure 2A is a perspective view showing the direction of the easy axis of magnetization of a conventional resin magnet. Figure 2B is a perspective view showing the state in which the magnet is wound, Figure 3 is an explanatory diagram when the roll magnet is magnetized, Figure 4 is a sectional view of the main part of the conventional magnet device, Figures 5 and 6. The figures are schematic configuration diagrams showing the basic principle of the magnet device of the present invention, FIGS. 7A-D are perspective views showing the manufacturing process of the same device, FIG. 8 is a schematic configuration diagram of another embodiment, and FIG. 9A , B are schematic configuration diagrams showing still another embodiment, FIGS. 10A and B are perspective views of still another embodiment, and FIGS.
The figure is an enlarged explanatory diagram of main parts showing the basic principle of the present invention. 10...Easy magnetization axis, 11...Roll magnet, 14.15...Magnetic pole, 16...
... Groove, 17 ... Line of magnetic flux, 18 ... Spacer, 19 ... Core material.

Claims (1)

[Scope of Claims] 1. A first resin magnet that has an axis of easy magnetization in a direction substantially perpendicular to a straight line connecting magnetic poles of different polarities and forms a magnetic pole of one polarity, and a first resin magnet that has a similar axis of easy magnetization. and a second resin magnet forming a magnetic pole of the other polarity, and an axis of easy magnetization located between the first resin magnet and the second resin magnet in a direction substantially parallel to a straight line connecting the magnetic poles of different polarity. The magnetic flux line vector at each point on the line of many magnetic flux lines flowing between the magnetic poles is decomposed into two components: a component in the direction that connects the magnetic poles linearly, and a component perpendicular to the direction. When this happens, a third resin magnet is placed in an area where the former component is more than the latter component, and the first and second resin magnets are placed in an area where the latter component is more than the former component and fixed to each other. , a magnet device with magnetic poles of different polarities on the same surface. 2. The magnet device according to claim 1, which uses a plate-shaped resin magnet having an axis of easy magnetization perpendicular to the plate surface as the resin magnet.