JPH0638486A - Movable magnet type actuator - Google Patents

Abstract

PURPOSE:To obtain a movable magnet type actuator in which its thrust and an efficiency are improved by using the magnet movable element in which at least two permanent magnets are disposed oppositely at the same poles and effectively utilizing magnetic fluxes generated from the poles of the magnet. CONSTITUTION:Magnetic elements 6 are provided between at least two permanent magnets 5A and 5B opposed at the same pole to constitute a magnet movable element 3. The element 3 is movably provided inside at least three- element coils 2A, 2B, 2C, and the three-element coils are wired so as to allow a current to flow in different directions between the poles of the magnets as a boundary.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a control device, an electronic device,
The present invention relates to a movable magnet actuator that converts electric energy into reciprocating kinetic energy and the like by electromagnetic action in machine tools and the like.

[0002]

2. Description of the Related Art Conventional reciprocating devices of a movable magnet type include those having a structure of a first conventional example shown in FIG. 6 and those having a structure of a second conventional example shown in FIG.

In the first conventional example shown in FIG. 6, reference numeral 10 denotes a magnet movable body composed of a rod-shaped permanent magnet magnetized in the axial direction.
It has magnetic poles on both end faces. The coils 11A and 11B are
The magnet movable body 10 is wound so as to circulate around the outer peripheral side of the end portion in a ring shape, and the same pole is generated in adjacent portions. Although not shown, the coil 11
A and 11B are usually mounted on guide cylinders for guiding the movable magnet body 10 so as to be movable in the axial direction. Then, the magnetic flux from each end surface of the movable magnet body 10 is transferred to the coil 11 respectively.
It is linked to A and 11B.

In the second conventional example shown in FIG. 7, the movable magnet body 1 is used.
Reference numeral 5 is two rod-shaped permanent magnets 16A and 16B having the same pole facing each other.
And a rod-shaped soft magnetic body 17 fixed between these permanent magnets 16A, 16B are integrally fixed, and the coil 18 is wound so as to circulate around the outer peripheral side of the intermediate portion of the magnet movable body 15 in an annular shape. It has been turned. Although not shown, the coil 18 is usually attached to a guide cylinder body for guiding the movable magnet body 15 movably in the axial direction. The magnetic fluxes from the end faces of the permanent magnets of the magnet movable body 15 that face each other in the same pole are linked with the coil 18.

By the way, in the first conventional example and the second conventional example, the thrust generated in the magnet movable bodies 10 and 15 is basically similar to the thrust given based on Fleming's left-hand rule (Fleming. The left-hand rule of is applied to the coil, but since the coil is fixed here,
Thrust as a reaction force of the force acting on the coil is generated in the movable magnet body. ). Therefore, it is the vertical component of the magnetic flux of the permanent magnet of the magnet movable body (the component orthogonal to the axial direction of the permanent magnet) that contributes to the thrust.

Therefore, an analysis was made on how the vertical component of the magnetic flux is in the case of one permanent magnet or two permanent magnets of the same pole facing each other.

FIG. 8 shows the result of magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side surface of a single permanent magnet.
However, the permanent magnet is a rare earth permanent magnet and has a diameter of 2.5 m.
m, length 6mm, 0.25 ~ 0.45mm from the surface of the permanent magnet
The distant positions were measured.

FIG. 9 shows the results of magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side faces of the two permanent magnets when the two permanent magnets are arranged with the same poles facing each other and are directly bonded. . However, each permanent magnet was a rare earth permanent magnet, had a diameter of 2.5 mm and a length of 3 mm (two pieces were 6 mm), and measured a position apart from the surface of the permanent magnet by 0.25 to 0.45 mm.

FIG. 10 shows a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side faces of the two permanent magnets when the two permanent magnets have the same poles facing each other and the facing distance is 1 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, had a diameter of 2.5 mm and a length of 3 mm, and measured the position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 11 shows a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side faces of the two permanent magnets when the two permanent magnets have the same poles facing each other and the facing distance is 2 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, had a diameter of 2.5 mm and a length of 3 mm, and measured the position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 12 shows a magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side faces of the two permanent magnets when the two permanent magnets have the same poles facing each other and the facing distance is 3 mm. The results are shown. However, each permanent magnet was a rare earth permanent magnet, had a diameter of 2.5 mm and a length of 3 mm, and measured the position 0.25 to 0.45 mm away from the surface of the permanent magnet.

FIG. 13 shows a case where two permanent magnets are arranged so as to face each other with the same pole and a soft magnetic material having a length of 1 mm is arranged between the two permanent magnets. The result of magnetic field analysis of the vertical component of the density is shown. However, each permanent magnet was a rare earth permanent magnet, had a diameter of 2.5 mm and a length of 3 mm, and measured the position 0.25 to 0.45 mm away from the surface of the permanent magnet.

In FIG. 14, two permanent magnets are arranged with the same poles facing each other, a soft magnetic material having a length of 1 mm is arranged between the permanent magnets, and the soft magnetic material is further opposed to the outer circumferences of the two permanent magnets. The results of magnetic field analysis of the vertical component of the surface magnetic flux density along the longitudinal side surfaces of the two permanent magnets when the yoke is arranged are shown. However, each permanent magnet is a rare earth permanent magnet and has a diameter of 2.5 mm and a length of 3 mm, and the yoke has a cylindrical shape surrounding the permanent magnet and has a thickness of 0.5 mm and a length of 10 mm, and is separated from the outer circumference of the permanent magnet by 1.25 mm. The vertical component of the surface magnetic flux density was measured at a position 0.25 to 0.45 mm away from the surface of the permanent magnet.

[0014]

As described above, the thrust generated in the magnet movable body is basically similar to the thrust given based on Fleming's left-hand rule.
It is desirable that the vertical component of the magnetic flux of the permanent magnet interlinking with the coil (the component orthogonal to the axial direction of the permanent magnet) is large, but in the first conventional example of FIG. 6, the vertical component of the surface magnetic flux density is As a result, it was found that the vertical component is smaller than that in the case where the two permanent magnets shown in FIGS. Therefore, the structure of the first conventional example shown in FIG. 6 has a limit in improving the thrust. For example, the magnet movable body 10 has a diameter of 2.
Thrust F1 generated when a current of 40 mA is applied to each coil 11A, 11B so that the same pole is generated in the adjacent portions of the two coils 11A, 11B. Was 4.7 (gf).

On the other hand, in the second conventional example of FIG. 7, the movable magnet body 15 in which the soft magnetic material is arranged between two permanent magnets of the same pole facing each other is used, and the vertical component of the magnetic flux density is shown in FIG. Thus, the magnetic flux generated from the magnetic poles of the permanent magnets 16A and 16B facing each other with the same pole is larger than in the case of one permanent magnet (see FIG. 8) or the case of only two permanent magnets (see FIGS. 9 to 12). However, there is only one coil that surrounds the intermediate portion of the magnet movable body 15, and there is a dislike that the magnetic flux generated by the magnetic poles on both end surfaces of the magnet movable body 15 is not effectively used. For this reason, it was difficult to improve the thrust force in the case of the second conventional example shown in FIG. For example, in the second conventional example of FIG. 7, the magnet movable body 15 has a diameter of 2.5 m.
As shown in FIG. 6, two rare earth permanent magnets having a length of 3 mm and a length of 3 mm are used (the performance of the rare earth permanent magnet is the same as that of the first conventional example), and a soft magnetic material having a length of 1 mm is arranged between them. First of
Coil 18 created to have the same power consumption as the conventional example
The thrust force F2 generated when a current of 40 mA was applied to the same and the same power consumption as that of the first conventional example was 5.6 (gf).

In view of the above points, the present invention has at least two aspects.
To provide a movable magnet type actuator that improves thrust and efficiency by using a magnetic movable body in which individual permanent magnets are arranged with the same poles facing each other and by effectively utilizing the magnetic flux generated by the magnetic poles of the permanent magnets. With the goal.

[0017]

In order to achieve the above object, the movable magnet type actuator of the present invention comprises a magnetic body provided between at least two permanent magnets having the same poles facing each other to form a movable magnet body. The movable magnet body is movably provided inside at least three continuous coils, and the at least three continuous coils are connected so that current flows in different directions with the magnetic poles of the permanent magnets as boundaries. .

Further, a magnetic yoke may be provided on the outer peripheral side of the coil to form a magnetic circuit for increasing a magnetic flux component in a direction perpendicular to the magnetizing direction of the permanent magnet.

Further, the magnet movable body may be movably guided by a guide body, and at least one end of the guide body may be provided with a magnetic attraction body for attracting the magnet movable body.

[0020]

The operation principle of the movable magnet type actuator of the present invention will be described with reference to the schematic diagram of FIG. In FIG. 4, the magnet movable body 3 is composed of two columnar permanent magnets 5 arranged in the same pole and facing each other.
A and 5B and a columnar soft magnetic body 6 fixed between these permanent magnets 5A and 5B are integrated, as shown in FIG.
As shown in, the structure has many vertical components of the magnetic flux density (components orthogonal to the axial direction of the permanent magnet). The three continuous coils 2A, 2B, 2C are wound so as to circulate around the outer circumference of the magnet movable body 3, and the permanent magnets 5 constituting the magnet movable body 3 are wound.
The magnetic fluxes from the left end of A, the opposite ends of the same poles of the permanent magnets 5A and 5B, and the magnetic poles of the right end of the permanent magnet 5B are arranged so as to interlink with each other. These coils 2A, 2B, 2C
Are connected so that currents flow in different directions with the magnetic poles of the permanent magnets 5A and 5B as the boundary (the boundary between the magnetic poles is not necessarily at the magnetic pole intermediate position as long as it is between the magnetic poles). Although not shown, the coils 2A, 2
B and 2C are usually mounted on guide cylinders for guiding the movable magnet body 3 movably in the axial direction. Coils 2A, 2
The positional relationship between B and 2C and the magnet movable body 3 is set so that the currents flowing through the coils are opposite to each other with the permanent magnet magnetic poles as boundaries at all movable positions of the magnet movable body 3. Keep it.

The structure of the movable magnet body 3 in FIG. 4 is as shown in FIG.
As in No. 3, two permanent magnets have the same poles facing each other and a soft magnetic material is arranged between the permanent magnets. In this FIG. 13, the vertical component of the surface magnetic flux density in the region Q corresponding to the position of the soft magnetic material is superior to that in FIGS. 9 to 12 without the soft magnetic material (the width of the peak of the magnetic flux density of 0.3 T or more). Is wide and has a high peak.)

As described above, the magnet movable body 3 in which the two permanent magnets 5A and 5B are opposed to each other with the same pole and the soft magnetic body 6 is provided between the permanent magnets can contribute to the thrust based on Fleming's left-hand rule. The magnetic flux component perpendicular to the longitudinal direction of the movable body 3 can be increased, and the triple coils 2A, 2B, 2C effectively interlink with the magnetic fluxes of all the magnetic poles of the permanent magnet, so that the triple coils 2A, 2B, 2C. By alternately passing a current in a direction in which a magnetic field of opposite polarity is generated, a large thrust that cannot be reached in the conventional example can be generated. If the current of each coil is reversed, the direction of the thrust of the movable magnet body 3 is also reversed. When an alternating current is applied, it works as a vibrator that vibrates repeatedly in a fixed cycle.

In the case of FIG. 4 according to the present invention, for example, two rare earth permanent magnets having a diameter of 2.5 mm and a length of 3 mm are used as the magnet movable body 3 (the performance of the rare earth permanent magnet is the same as that of the first conventional example). ), And a triple magnetic coil 2A, 2B which is made to have the same power consumption as that of the first and second conventional examples of FIGS. , 2
The thrust F3 generated when a current of 40 mA was applied to C and the power consumption was the same was 6.7 (gf). This is about 1.42 times the thrust of the first conventional example with the same power consumption, and about 1.2 times the thrust of the second conventional example.
Also, it is understood that it is remarkably superior to the second conventional example.

The curve (a) in FIG. 5 shows the relationship between the axial displacement of the magnet movable body 3 and the thrust (gf) in the case of FIG. 4 (without yoke). However, the dimensions and characteristics of the permanent magnet are as shown in FIG. 13, and when the midpoint of the magnet movable body 3 is located at the midpoint of the central coil 2B, the displacement amount is zero, and the current of each coil is 40 mA. And

As described above, in the movable magnet type actuator of the present invention, the movable magnet body is constituted by the combined structure of permanent magnets having the same poles facing each other, and the magnetic flux perpendicular to the magnetizing direction (axial direction) of the permanent magnets. Since the density component can be made sufficiently large and the magnetic flux generated by all the magnetic poles of the permanent magnet can be effectively used,
The thrust force based on Fleming's left-hand rule between the currents flowing in at least three coils surrounding the magnet movable body can be sufficiently increased, and a large thrust force can be obtained with a small size and a small current.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a movable magnet type actuator according to the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of the present invention. In these figures, reference numeral 1 denotes a soft magnetic cylindrical yoke, and three coils 2A,
2B and 2C are arranged and fixed to the cylindrical yoke 1 by an insulating member such as an insulating resin forming a guide cylinder 4 for slidably guiding the magnet movable body 3. Magnet movable body 3
Is two columnar rare earth permanent magnets 5A, which are arranged to face each other with the same pole,
5B and a columnar soft magnetic body 6 fixed between these permanent magnets 5A and 5B.
B and the soft magnetic material 6 are integrated with each other with an adhesive or the like. The three coils 2A, 2B and 2C are permanent magnets 5.
The wires are connected so that currents flow in different directions with the magnetic poles A and 5B as a boundary. That is, the central coil 2B surrounds the ends of the soft magnetic body 6 and the permanent magnets 5A and 5B including the N pole, and the coils 2A and 2C on both sides are the permanent magnets 5A and 5B.
Each of the end portions including the S pole can be surrounded, and the direction of the current flowing through the central coil 2B is opposite to the direction of the current flowing through the coils 2A and 2C on both sides (FIG. 1). Refer to N and S attached to each coil of). In addition,
Pins 7 and the like for transmitting the thrust force to the outside are provided on the outer end surfaces of the permanent magnets 5A and 5B as needed, as indicated by the phantom lines in FIG. When used as a vibrator for a pager or the like, the pin 7 is unnecessary.

In the first embodiment, each coil 2A, 2
Since the soft magnetic cylindrical yoke 1 is provided on the outer peripheral sides of B and 2C, the vertical component of the surface magnetic flux density of the movable magnet body 3 is further increased as shown in FIG. Therefore, the magnetic flux component perpendicular to the longitudinal direction of the magnet movable body 3 that can contribute to the thrust force based on Fleming's left-hand rule can be increased, and the triple coils 2A, 2 wound around the magnet movable body 3 in an annular shape.
A larger thrust can be generated by passing a current through B and 2C in the direction of alternately generating magnetic fields of opposite polarities. For example, the magnet movable body 3 has a diameter of 2.5 m.
As shown in FIG. 6, two rare earth permanent magnets having a length of 3 mm and a length of 3 mm are used (the performance of the rare earth permanent magnet is the same as that of the first conventional example), and a soft magnetic material having a length of 1 mm is arranged between them. , Fig. 7
The thrust force F4 generated when a current of 40 mA is applied to the triple coils 2A, 2B, and 2C that are made to have the same power consumption as those of the first and second conventional examples and the power consumption is the same is 8.
It was 0 (gf). In the polarity of FIG. 1, the direction of the thrust F4 is the direction in which the magnet movable body 3 moves to the right, and if the current of each coil is reversed, the direction of the thrust of the magnet movable body 3 is also reversed. When an alternating current is applied, it works as a vibrator that vibrates repeatedly in a fixed cycle.

The curve (B) in FIG. 5 is the axial displacement of the magnet movable body 3 in the case of the first embodiment (however, the dimensions and arrangement of the permanent magnet and the yoke and the characteristics of the permanent magnet are as shown in FIG. 14). The relation with the thrust (gf) is shown when the movable magnet body moves in the direction away from the point of zero displacement. Also, the curve (C)
Shows the relationship between the axial displacement of the magnet movable body 3 and the thrust (gf) in the case of the first embodiment (with a yoke), and shows the case where the movable body 3 operates in a direction approaching the point of zero displacement. However, the displacement amount was set to zero when the midpoint of the movable magnet body 3 was located at the midpoint of the central coil 2B, and the current of each coil was set to 40 mA. As described above, the thrust differs depending on whether the magnet movable body 3 approaches or moves away from the point where the displacement amount is zero. This is because the magnet movable body 3 is displaced between the magnetic pole of the permanent magnet of the magnet movable body 3 and the yoke 1. This is because the magnetic attraction force that returns the quantity to zero is working.

FIG. 3 shows a second embodiment of the present invention. In this case, soft magnetic attraction plates 8A, 8B are fitted and fixed to both ends of the soft magnetic cylindrical yoke 1 and the guide cylinder 4. Then, a pin 9 fixed to the outer end surface of the permanent magnet 5A projects from a hole formed in one attraction plate 8A. The other structure is similar to that of the first embodiment.

In the case of this second embodiment, each coil 2A, 2
Soft magnetic attraction plate 8 when B and 2C are not energized
Adsorbed on either A or 8B. Now, when the magnet movable body 3 is in the illustrated state, the coils 2A, 2B, 2
If a thrust force in the direction of arrow R is generated by energizing C in a direction that alternately generates a magnetic field of opposite polarity, the magnet movable body 3 will move to the attraction plate 8
It departs from A, moves in the direction of arrow R, adsorbs to the adsorption plate 8B, and stops. Further, if the currents of the coils 2A, 2B, 2C are reversed to generate thrust in the opposite direction of arrow R,
The magnet movable body 3 separates from the attraction plate 8B, moves in the direction of the attraction plate 8A, attracts the magnet plate 3 and stops. In this way, the suction plate 8
By providing A and 8B, the moving range of the magnet movable body 3 can be accurately regulated.

In each of the above embodiments, the magnet movable body 3 is composed of two permanent magnets of the same pole facing each other and the soft magnetic material between the permanent magnets, but three or more permanent magnets of the same pole facing each other. The magnet movable body may be formed of a soft magnetic material between both permanent magnets, and the number of coils may be four or more in correspondence with this.

Although the soft magnetic attraction plates 8A and 8B are provided on both sides of the cylindrical yoke 1 and the guide cylinder 4 in the second embodiment, a structure in which the attraction plates are provided on only one of them may be adopted. .

Further, in each of the embodiments, the cylindrical yoke 1 and the guide cylinder 4 are used, but it is also possible to employ a square cylinder-shaped yoke and guide body. In this case, each coil also has a movable magnet body. It may be wound so as to wrap around the outer circumference of.

[0035]

As described above, according to the movable magnet type actuator of the present invention, since the magnetic movable body is constructed by providing the magnetic body between at least two permanent magnets having the same poles facing each other, it is possible to move the magnet. Longitudinal direction of body (permanent magnetizing direction)
Since the magnetic flux component perpendicular to the magnetic flux can be made sufficiently large and at least three coils are wound so as to surround the magnet movable body, the magnetic flux generated by each magnetic pole of the magnet movable body can be effectively linked. The thrust given based on Fleming's left-hand rule between the vertical magnetic flux component and the current flowing through each coil can be made sufficiently large. Therefore, it is possible to realize a small-sized movable magnet actuator having a large thrust with a small current.

[Brief description of drawings]

FIG. 1 is a first part of a movable magnet type actuator according to the present invention.
It is a right sectional view showing an example.

FIG. 2 is a side view of the same.

FIG. 3 is a front sectional view showing a second embodiment of the present invention.

FIG. 4 is a schematic configuration diagram showing a basic configuration of the present invention.

5 is a graph showing the relationship between the amount of displacement of the movable magnet body and the thrust force in the movable magnet actuator shown in FIGS. 1 and 4. FIG.

FIG. 6 is a schematic configuration diagram showing a first conventional example.

FIG. 7 is a schematic configuration diagram showing a second conventional example.

FIG. 8 is a graph showing a vertical component (a component perpendicular to a longitudinal side surface) of a surface magnetic flux density on a longitudinal side surface (a surface parallel to a magnetizing direction of the permanent magnet) of a single permanent magnet.

FIG. 9 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side face when two permanent magnets of the same pole facing each other are directly brought into contact with each other.

FIG. 10 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side face when two permanent magnets are in the same pole facing state with an air gap of 1 mm.

FIG. 11 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are in the same pole facing state with an air gap of 2 mm.

FIG. 12 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side face when two permanent magnets are in the same pole facing state with an air gap of 3 mm.

FIG. 13 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side face when two permanent magnets are in the state of opposing each other with a soft magnetic body interposed therebetween.

FIG. 14 is a graph showing the vertical component of the surface magnetic flux density on the longitudinal side surface when two permanent magnets are in the same pole facing state with a soft magnetic material interposed and a soft magnetic material yoke is arranged.

[Explanation of symbols]

 1 Cylindrical Yoke 2A, 2B, 2C Coil 3 Magnet Moving Body 4 Guide Cylindrical Body 5 Cylindrical Permanent Magnet 6 Cylindrical Soft Magnetic Body 7, 9 Pin 8A, 8B Adsorption Plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Sono 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation

Claims (3)

[Claims] 1. A magnetic movable body is formed by providing a magnetic body between at least two permanent magnets facing each other with the same pole, and the movable magnet body is movably provided inside at least three coils. A movable magnet actuator, wherein three coils are connected so that currents flow in different directions with the magnetic poles of the permanent magnets as boundaries. 2. The movable magnet type actuator according to claim 1, wherein a magnetic yoke is provided on the outer peripheral side of the coil to form a magnetic circuit for increasing a magnetic flux component in a direction perpendicular to the magnetizing direction of the permanent magnet. . 3. The movable magnet type actuator according to claim 1, wherein the movable magnet body is movably guided by a guide body, and a magnetic attraction body for attracting the movable magnet body is provided on at least one end of the guide body.