JP2001275332A - Vibrating linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assure a sufficiently large thrust. SOLUTION: A vibrating linear actuator comprises a movable element 1 having a permanent magnet 11 and a yoke 12, a stator 2 having a stator 21 and a winding 22, and a resonance spring system 3. In this case, the element 1 is vibrated in a reciprocating manner. The element 1 has permanent magnets 11, 11 which are opposed to two poles of both ends of the U-shaped stator 21. The magnets 11, 11 are magnetized in the vibrating direction. Opposed surfaces of the adjacent magnets 11, 11 are of the same polarity. Thus, since a magnetic flux operating as the thrust can be increased, a large thrust can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration type linear actuator.

[0002]

2. Description of the Related Art As a vibration type linear actuator, as shown in FIG. 11 (a), a movable element 1 composed of a permanent magnet 11 and a yoke 12, and a stator 2 composed of a stator 20 and windings 21, 21 are provided. The conventional vibration type linear actuator of this type has a permanent magnet 11 magnetized in a direction perpendicular to a surface facing the stator 2. Further, the permanent magnet 11 of the mover 1 is fixed to the U-shaped stator 2 having two poles.
Has a magnetic pole on the surface facing the stator 2 with one pole in the center and different poles on both sides in the vibration direction. FIG. 11B shows the magnetic flux passing through the magnetic circuit.

[0003]

In this case, the thrust characteristics show a substantially flat characteristic with respect to the displacement of the mover. However, since the magnetization direction is perpendicular to the stator facing surface, the magnetic flux However, there is a problem that a large suction force acts, and thus a large thrust in the vibration direction cannot be obtained. Incidentally, P1 in FIG. 4 indicates a thrust characteristic in the above-mentioned conventional example.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a vibration type linear actuator capable of securing a sufficiently large thrust.

[0005]

According to the present invention, there is provided a movable element including a permanent magnet and a yoke, a stator including a stator and a winding, and a resonance spring system. A linear actuator for performing vibration, wherein U
The mover is provided with permanent magnets facing the two poles at both ends of the letter-shaped stator, and each permanent magnet is magnetized in the vibration direction and the facing surface of the adjacent permanent magnet has the same polarity. Has features.

At this time, it is preferable that the center of the thickness in the magnetizing direction of the permanent magnet and the center of the stator pole face each other.

The thickness of the permanent magnet in the magnetizing direction may be narrower or wider than the pole width of the opposed stator, but the thickness of the permanent magnet in the magnetizing direction is opposite to the pole width of the opposed stator. The width may be narrower and wider on the stator side, or wider on the opposite side of the stator than the pole width of the opposed stator and narrower on the stator side.

The height of the permanent magnet is preferably substantially the same as the height of the yoke. At this time, the yoke may be separated by the permanent magnet.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIGS. 2 and 3 show a vibrating linear actuator used as a drive source of a reciprocating electric shaver. 1a and 1b are movers,
Yoke (back yoke) 12 made of magnetic material
And a permanent magnet 11 adhered and fixed to the yoke 12 and a frame member 10 for integrating them.

The stator 2 has a coil bobbin 23 as an insulator attached to two magnetic poles of a U-shaped yoke 21 in which a sintered body of a magnetic material or an iron plate of a magnetic material is laminated, and a winding 22 is provided thereon. And is fixed to the chassis 4.

The upper end of the connecting plate 5 is fixed to the chassis 4 by the supporting plate 40, and the lower end of the connecting plate 5 is fixed to the movers 1a and 1b by the supporting plate 41, so that the stator 2 is fixed. Mover 1 on chassis 4
a and 1b are connected to each other. At this time, the stator 2 is connected to the movers 1a and 1b by a connecting plate 5 formed of a spring material (leaf spring) that can be displaced only in the reciprocating direction of the movers 1a and 1b.
b and faces the permanent magnet 11 provided at b with a predetermined gap.

Further, between the spring receiving portion 14 of the mover 1a and the spring receiving portion 15 on the inner surface of the mover 1b,
A pair of spring members 30, 30 composed of compression coil springs are arranged in the reciprocating directions of a, 1b. This spring material 30,3
0 functions as the resonance spring system 3 of the mover 1 (1a, 1b).

In the linear actuator configured as described above, by changing the direction of the current flowing through the winding 22 of the stator 2 alternately, the permanent magnets 11, 11 provided on the movers 1a, 1b move in the reciprocating direction. Driven. In addition, mover 1
Since the arrangement of the magnetic poles of the permanent magnet 11 provided on the movable element 1a and the arrangement of the magnetic poles of the permanent magnet 11 provided on the mover 1b are reversed,
Both movers 1a and 1b perform reciprocating vibrations having a phase difference of 180 °. At this time, the spring members 30, 30 are compressed and expanded, and both the movers 1a, 1b operate as a spring vibration system.

Here, as shown in FIG. 1, in the vibration type linear actuator according to the present invention, a pair of permanent magnets 1 are arranged so as to face two magnetic poles of the U-shaped stator 18.
The permanent magnets 1 and 11 are arranged in the yoke 12, and the adjacent permanent magnets are magnetized in the amplitude direction so that the opposing surfaces are the same. The permanent magnet 11 has the same total amount of permanent magnets as the conventional one. The magnetic flux passing through the magnetic circuit in this case is shown in FIG.

Compared with the conventional magnetic circuit, the component of the magnetic flux acting in the direction of increasing the thrust is relatively increased with respect to the component of the magnetic flux acting in the direction of decreasing the thrust, and the thrust is increased. Large thrust can be obtained with the same amount of permanent magnet as.

Now, the total permanent magnet amount of the permanent magnet 11 is the same as that of the conventional example, and the outer dimensions of the yoke 12 are constituted by the yoke 12 and the permanent magnet 11 of the conventional example as shown in FIG. In the case where the outer dimensions are the same as the external dimensions of the portion, the thrust characteristic is indicated by P2 in FIG.
Further, in order to obtain a thrust equivalent to that of the conventional example, it is sufficient to use a permanent magnet amount of about 60% of the conventional permanent magnet amount.

As shown in FIG. 6, if the center of the thickness of the permanent magnet 11 in the magnetizing direction and the center of the stator pole are opposed to each other, the thrust can be further increased.

In the embodiment shown in FIG.
Is thinner than the pole width of the opposed stator 21, but the thrust characteristic in this case is indicated by P3 in FIG. The thrust is larger than before,
The thrust characteristics with respect to the displacement in the vibration direction become almost flat, and the variation in the thrust with respect to the displacement in the vibration direction is eliminated, so that a constant thrust can always be obtained regardless of the change in the position of the mover 1 in the vibration direction.

In FIG. 7, the thickness of the permanent magnet 11 in the magnetizing direction is made wider than the pole width of the opposed stator 21 and the center of the permanent magnet 11 in the magnetizing direction and the center of the stator pole are arranged. And are opposed to each other. In this case, a thrust characteristic indicated by P4 in FIG. 4 can be obtained. The thrust characteristic P4 is such that the maximum thrust obtained is large and the thrust characteristic with respect to the displacement of the mover 1 is inclined.
The thrust increases as the displacement in the vibration direction increases, and this force is used to return the mover 1 to a position where the displacement from the center of the stator 2 poles, which is the initial position, is zero. , The amplitude of the mover 1 can be increased.

As shown in FIG. 8, the thickness in the magnetizing direction of the permanent magnet 11 having the center of the thickness in the magnetizing direction and the center of the stator pole opposed to each other is larger than the pole width of the stator 21. The trapezoidal shape is narrower on the side opposite to 21 and wider on the stator 21 side. In this case, the thrust characteristic indicated by P5 in FIG. 4 can be obtained, and the inclination of the thrust characteristic with respect to the displacement of the mover 1 becomes gentler than that shown in FIG.

As shown in FIG. 9, the thickness in the magnetization direction of the permanent magnet 11 whose center in the magnetization direction and the center of the stator pole are opposed to each other is larger than the pole width of the stator 21. A trapezoidal shape that is wider on the side opposite to 21 and narrower on the stator 21 side may be used. In this case, the thrust characteristic is indicated by P6 in FIG. 4, and the thrust can be increased while flattening the thrust characteristic with respect to the displacement of the mover 1. Therefore, the advantages shown in FIG. 6 and the advantages shown in FIG. 7 are simultaneously obtained.

FIG. 10 shows a permanent magnet 11 in which the center of the thickness in the magnetization direction and the center of the stator pole are opposed to each other, and the thickness in the magnetization direction is smaller than the pole width of the opposed stator 21. Is approximately the same as the height of the yoke 12. The thrust characteristic at this time is shown by P7 in FIG. Since the magnetic flux short circuit by the yoke 12 at the upper end or the lower end of the permanent magnet 11 can be avoided, the maximum thrust can be obtained when the yoke 12 is integrated. In particular, in the case where the yoke 12 is separated by the permanent magnet 11, the permanent magnet space can be maximized in the yoke 12, so that the maximum thrust can be generated.

[0023]

As described above, according to the first aspect of the present invention, a movable element including a permanent magnet and a yoke, a stator including a stator and a winding, and a resonance spring system are provided.
In a linear actuator for causing a mover to reciprocate, a mover is provided with permanent magnets opposed to two poles at both ends of a U-shaped stator, and each permanent magnet is magnetized in the vibration direction and adjacent to each other. Since the facing surfaces of the magnets have the same polarity, it is possible to increase the magnetic flux acting as a thrust, and to obtain a large thrust.

According to the second aspect of the present invention, since the center of the thickness of the permanent magnet in the magnetizing direction and the center of the stator pole are opposed to each other, the thrust can be further increased.

According to the third aspect of the present invention, since the thickness of the permanent magnet in the magnetizing direction is smaller than the pole width of the opposed stator, the thrust characteristics with respect to displacement are made substantially flat while increasing the thrust. be able to.

According to the fourth aspect of the present invention, since the thickness of the permanent magnet in the magnetizing direction is wider than the pole width of the opposed stay, the thrust can be greatly improved, and the thrust characteristic with respect to displacement can be improved. Can be tilted so that the thrust increases as it goes to the end of the vibration, and therefore, the amplitude can be increased against the spring force for resonance.

According to the fifth aspect of the present invention, the thickness of the permanent magnet in the magnetizing direction is narrower on the side opposite to the stator than the pole width of the opposed stator and wider on the stator side. Compared with the present invention, the inclination of the thrust characteristic with respect to the displacement can be made gentler.

According to the sixth aspect of the present invention, since the thickness of the permanent magnet in the magnetizing direction is wider on the side opposite to the stator and narrower on the stator side than the pole width of the opposed stator, the thrust characteristic with respect to displacement is obtained. And a large thrust can be obtained while making the pressure flat.
The present invention can also have the advantages of the present invention.

According to the seventh aspect of the present invention, since the height of the permanent magnet is substantially equal to the height of the yoke, it is possible to avoid a magnetic flux short circuit due to the yoke at the upper end or the lower end of the permanent magnet. , A large thrust can be obtained.

According to the invention of claim 8, since the permanent magnet space can be maximized in the yoke, the maximum thrust can be generated.

[Brief description of the drawings]

FIGS. 1A and 1B show a main part of an example of an embodiment of the present invention, in which FIG. 1A is a schematic front view, and FIG. 1B is a magnetic machine circuit diagram showing a flow of a magnetic flux.

FIG. 2 is a perspective view showing the overall configuration of the above.

FIG. 3 is an exploded perspective view of the same.

FIG. 4 is a characteristic diagram showing a thrust characteristic.

FIG. 5 is a schematic front view of another example.

FIG. 6 is a schematic front view of still another example.

FIG. 7 is a schematic front view of another example.

FIG. 8 is a schematic front view of still another example.

FIG. 9 is a schematic front view of a different example.

FIG. 10 is a schematic front view of another example.

11A and 11B show a conventional example, in which FIG. 11A is a schematic front view, and FIG.
FIG. 3 is a magnetic machine circuit diagram showing the flow of magnetic flux.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mover 2 stator 3 resonance spring system 11 permanent magnet 12 yoke 21 stator 22 winding

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ryo Motohashi 1048 Kadoma Kadoma, Osaka Pref.Matsushita Electric Works, Ltd. F term (reference) 5H633 BB03 GG02 GG05 GG07 HH06 HH09 HH10 HH13 JA03 JB05 JB09

Claims (8)

[Claims] 1. A mover comprising a permanent magnet and a yoke;
A linear actuator comprising a stator consisting of a stator and windings, and a spring system for resonance, for causing a mover to perform reciprocating vibration, wherein permanent magnets respectively oppose two poles at both ends of a U-shaped stator. The permanent magnet is magnetized in the vibration direction, and the opposing surfaces of adjacent permanent magnets have the same polarity. 2. The vibration type linear actuator according to claim 1, wherein a center of a thickness of the permanent magnet in a magnetization direction and a center of the stator pole face each other. 3. The vibrating linear actuator according to claim 1, wherein the thickness of the permanent magnet in the magnetizing direction is smaller than the pole width of the opposed stator. 4. The vibration type linear actuator according to claim 1, wherein the thickness of the permanent magnet in the magnetizing direction is wider than the pole width of the opposed stays. 5. The vibrating linear device according to claim 1, wherein the thickness of the permanent magnet in the magnetizing direction is smaller on the side opposite to the stator than on the pole width of the opposed stator and wider on the stator side. Actuator. 6. The vibrating linear device according to claim 1, wherein the thickness of the permanent magnet in the magnetization direction is wider on the side opposite to the stator than on the pole width of the opposed stator and narrower on the stator side. Actuator. 7. The vibration type linear actuator according to claim 1, wherein the height of the permanent magnet is substantially equal to the height of the yoke. 8. The vibrating linear actuator according to claim 7, wherein the yoke is separated by a permanent magnet.