JP2001309632A - Vibrating-type linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibrating-type linear actuator capable of enhancing an efficiency of a magnetic circuit eliminating a usual attracting force component that acts between permanent magnets. SOLUTION: The actuator consists of a stator 1 composed of an electromagnet, needles 2 each of which comprises a permanent magnet 8 and a frame 3 that is fixed with the stator 1 and reciprocatively holds the needles 2 through a plate-spring connector 10. A plurality of the moving elements 2 is connected to a vibrating direction with a spring 14. Each mass of the moving elements 2 is almost same, and the permanent magnet 8 is mounted only at a side of the moving elements 2 that adjoin to each other. The moving elements 2 are so configured as to drive in opposite phase around the particular frequency of a vibration system by alternately changing a direction of a current that is fed to the only one electromagnet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrating linear actuator for obtaining reciprocating vibration.

[0002]

2. Description of the Related Art Conventionally, as a vibration type linear actuator of this type, there is one disclosed in Japanese Patent Application Laid-Open No. H11-285226. This is a stator consisting of electromagnets,
It consists of a plurality of movers having permanent magnets, and a frame to which the stator is fixed and which supports the mover reciprocally via a leaf-spring-like coupling body. Are connected by a spring in the vibration direction. By alternately changing the direction of the current supplied to the electromagnets, the movers each having a permanent magnet are driven in opposite phases.

[0003]

By the way, in the above-mentioned prior art, a plurality of movable elements are provided with permanent magnets respectively. In this case, the permanent magnets of the plurality of movable elements are attracted to each other. There is a problem in that a force is generated, and the attraction force is a loss in forming the magnetic circuit, and adversely affects the efficiency of the magnetic circuit. Further, when permanent magnets are arranged on adjacent movable elements, it is necessary to provide a certain gap or more between adjacent permanent magnets, so that there is a problem that the size of the actuator is increased by the gap.

The present invention has been made in view of the above description, and has as its object to provide a vibration-type linear actuator capable of improving the efficiency of a magnetic circuit by eliminating a conventional attractive force component acting between permanent magnets. I do.

[0005]

According to a first aspect of the present invention, there is provided a vibration-type linear actuator in which a stator comprising an electromagnet, a movable element having a permanent magnet, and a stator are fixed. And a frame that supports the mover in a reciprocating manner via a leaf spring-like connecting body.A plurality of movers are connected by springs in a driving vibration direction, and the mass of the plurality of movers is Permanent magnets are provided on only one of the adjacent movable elements that are substantially the same, and the directions of the current supplied to the only electromagnet are alternately changed so that the movable elements are driven in opposite phases near the natural frequency of the vibration system. It is characterized by the following. With a structure in which a permanent magnet is provided on one of the movers, a plurality of movers can be driven in opposite phases. For this reason, since there is no permanent magnet in the adjacent movable element as in the related art, no attractive force is generated between the adjacent permanent magnets, and the loss of the magnetic flux used in the magnetic circuit is eliminated, and the efficiency of the magnetic circuit is improved.

According to a second aspect of the present invention, in the vibration linear actuator according to the first aspect, the area of the permanent magnet facing the electromagnet is equal to the area when all the movable elements have the permanent magnet. It is characterized by being. Even if the total area of the permanent magnets facing the electromagnets is the same as the conventional one, the attractive force between the permanent magnets does not occur unlike the conventional one, so the output is equal to or higher than the conventional one, and a gap is provided between the adjacent permanent magnets as the conventional The actuator can be made thinner as much as it is unnecessary.

According to a third aspect of the present invention, there is provided the vibration linear actuator according to the first aspect, wherein only one movable element has a plurality of drivers. The degree of freedom of the shape and material of the mover having no driver is increased, and the degree of freedom in designing the actuator is increased even if the output is the same.

According to a fourth aspect of the present invention, there is provided a vibration linear actuator according to the first aspect, wherein a driver is not provided on a movable element having a permanent magnet constituting a magnetic circuit. Since each mover has a driver and a permanent magnet separately, mass balance design between the movers is facilitated.

According to a fifth aspect of the present invention, there is provided a vibrating linear actuator according to the first aspect, wherein a movable element is formed by connecting two movable elements into a box, and a central movable element disposed in the movable element. And wherein only one of the movers has two drivers symmetrically arranged about the center in the depth direction. Since each of the movers has a symmetrical shape with respect to the central axis in the drive direction and the vertical direction, the positions of the centers of gravity of the movers in the drive direction and the vertical direction substantially match, and vibration of the actuator can be reduced.

According to a sixth aspect of the present invention, there is provided a vibration type linear actuator according to the fourth aspect, wherein a movable member is formed in a box shape by connecting two movable members, and a central movable member provided in the movable member. Only the box-shaped mover has a permanent magnet constituting a magnetic circuit, and only the center mover has a driver. Since each mover has a driver and a permanent magnet separately, it is easy to design a mass balance between the movers, and each mover is symmetrical with respect to the center axis in the direction perpendicular to the drive direction. Therefore, the positions of the centers of gravity of the movers in the driving direction and the vertical direction substantially match, and the vibration of the actuator can be reduced.

According to a seventh aspect of the present invention, there is provided a vibration linear actuator according to the fourth aspect, wherein a movable element formed by connecting two movable elements into a box, and a central movable element disposed in the movable element. And the center mover only has permanent magnets constituting a magnetic circuit, and only the box-shaped mover has a driver. Since each mover has a driver and a permanent magnet separately, it is easy to design a mass balance between the movers, and each mover is symmetrical with respect to the center axis in the direction perpendicular to the drive direction. Therefore, the positions of the centers of gravity of the movers in the driving direction and the vertical direction substantially match, and the vibration of the actuator can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on examples shown in the accompanying drawings. The illustrated vibration type linear actuator is for a reciprocating electric shaver, and includes a stator 1, a mover 2 (two movers 2 a and 2 b in the illustrated example), and a frame 3. The stator 1 includes an E-shaped yoke 4 in which a sintered body of a magnetic material or an iron plate of a magnetic material is laminated.
And an electromagnet composed of a coil 5 wound around a central piece of the yoke 4, and is fixed to the frame 3 having a substantially U-shaped cross section by welding or screws.

Each of the two types of movers 2a and 2b is mainly composed of a frame member 6 made of a synthetic resin, and the frame member 6 of one mover 2a is provided via a back yoke 7 made of a magnetic material. The permanent magnet 8 is provided (the back yoke 7 and the permanent magnet 8 are not provided on the other movable element 2b). Of course, the back yoke 7 and the permanent magnet 8 may be provided on the mover 2b, and these may not be provided on the mover 2a. The frame member 6 of one of the movers 2a is formed in a box shape having a substantially rectangular shape in plan view, and the other mover 2b is disposed between both side pieces of the one mover 2a. A driver 9 for connecting to the movable blade of the electric razor is provided on the movable elements 2a and 2b so as to protrude upward.

Both ends of the movers 2a and 2b are connected to the frame 3 via a plate spring-shaped connecting body 10. The connecting body 10 here comprises a central leaf spring 10b connected to the mover 2b, and a pair of left and right leaf springs 10a having lower ends connected to the mover 2a. , And is fixed to the frame 3 by welding, screws, or the like. That is, the mover 2
a, 2b are suspended from the frame 3 by a leaf spring-like connecting body 10. The support plate 11 serves as a base for fixing the vibration type linear actuator and other components. A spring 14 composed of a compression coil spring is disposed between the spring receiving portion 12 on the inner surface of the mover 2a and the spring receiving portion 13 of the driver 9 of the mover 2b in the reciprocating direction of the movers 2a and 2b. Has been established.

In the vibrating linear actuator thus constructed, the permanent magnet 8 provided on the mover 2a
Is vertically opposed to the stator 1 via a gap, and is magnetized in the reciprocating direction of the mover 2a. Move 10 right and left while bending 10. The movable element 2a can be reciprocated by switching the direction of the current flowing through the coil 5 at an appropriate timing.

The masses of the movers 2a and 2b are set so as to be driven at the natural frequency of resonance of the vibration system of the vibration type linear actuator, and the respective masses are substantially the same. Therefore, each of the movers 2a and 2b makes a reciprocating motion in the left and right directions via the spring 14. That is, the movements are performed in opposite phases.

FIGS. 3A and 3B are a schematic front view and a schematic side view of a conventional movable element 2, respectively. FIGS. 4A and 4B are schematic front views of the movable element 2 of the present invention. And a schematic side view. In the present invention, the movers 2a and 2b are connected in the vibration direction by a spring 14, and the permanent magnet 8 has an area of the permanent magnet 8 facing the stator 1 made of an electromagnet. It is equivalent to the area when doing. That is, two permanent magnets 8 facing the conventional stator 1
Is equal to the area of one permanent magnet 8 which faces the stator 1 of the present invention (A + A = 2A). In the vibration type linear actuator of the present invention, a propulsive force is obtained in proportion to the area of the permanent magnet 8. The following formula 1 shows the theoretical formula of the propulsion force F.

[0018]

(Equation 1)

In Equation 1, Br: magnetic flux density, aL: magnet thickness,
Z: magnet width in the thickness direction, E: total gap, n: number of coil turns, I: current. Thus, the thrust F is proportional to the area of the magnet. Therefore, the propulsion force of the present invention and that of the conventional example can be obtained substantially the same propulsion force.
There is no flow of magnetic flux between them, and the thrust generated by the magnetic flux acts only on the propulsion component, so that the efficiency of the magnetic circuit is improved. Further, in the case of the present invention, there is no need to provide a gap in consideration of the attraction force of the permanent magnet 8 between the adjacent movers 2 as in the related art. As a result, it is possible to design a vibration-type linear actuator having a small size corresponding to the gap to obtain an output equivalent to that of the related art.

FIG. 5 shows another example. In the case of the above example, the driver 9 is disposed on each of the two movers 2a and 2b.
In the case of this example, the driver 9 is provided only on one movable element 2a. In the case of this example, the mover 2b without the driver 9
Exists, and the degree of freedom in the design of the mover 2b is improved.

FIG. 6 shows another example. In the case of the present example, the driver 9 is disposed only on the mover 2b that does not have the permanent magnet 8 and the back yoke 7. The permanent magnet 8, the back yoke 7, and the driver 9 occupy most of the mass of the mover 2.
In this example, the movable element 2a having the permanent magnet 8 and the back yoke 7 and not having the driver 9 and the movable element 2b having the driver 9 and not having the permanent magnet 8 and the back yoke 7 are separated. The mass of only the mover 2 is unlikely to become extremely large. As a result, the mass design between the movers 2a and 2b is facilitated, and there is no need to make the mover 2 heavy in order to make the mass substantially the same.

FIG. 7 shows another example. The mover 2 is composed of a mover 2a formed by connecting two movers to form a box, and a center mover 2b disposed in the box-like mover 2a. Only one of the movers 2a and 2b has the driver 9 symmetrically disposed about the center in the depth direction (the direction orthogonal to the drive direction). In the case of the example shown in the drawing, the driver 9 is provided symmetrically with respect to the mover 2a. As a result, the position of the center of gravity in the direction perpendicular to the vibration direction of the movers 2a, 2b is substantially the center of the movers 2a, 2b. That is, the center of gravity of each mover 2a, 2b is
And the vibration of the vibration type linear actuator can be reduced.

FIG. 8 shows another example. FIG. 8A shows a box-shaped movable element 2a in which only a central movable element 2b has two drivers 9 arranged symmetrically about the center in the depth direction, and two movable bodies are connected to each other. Have a permanent magnet 8 and a back yoke 7. FIG. 8 (b) shows that only the movable element 2a in the form of a box formed by connecting two movable elements has two drivers 9 symmetrically arranged about the center in the depth direction. It has a permanent magnet 8 and a back yoke 7.
With the above-described configuration, the design shown in FIG. 8 facilitates the mass design between the movers 2a and 2b, and makes the mover 2 heavy in order to make the mass substantially the same. No longer needed.

[0024]

According to the first aspect of the present invention, there is provided a stator comprising an electromagnet, a movable member having a permanent magnet, and a movable member which is fixed to the stator and which is movable via a leaf spring-like connecting member. The armature consists of a frame that supports the armature in a reciprocating manner.A plurality of armatures are connected by springs in the driving vibration direction, and the masses of the armatures are substantially the same, and only one of the adjacent armatures has a permanent magnet. Is provided, and the direction of the current supplied to the only electromagnet is alternately changed so that the movers are driven in opposite phases near the natural frequency of the vibration system, so a permanent magnet is provided on one of the movers. With the structure, it is possible to drive a plurality of movers in opposite phases.Because there is no permanent magnet in the adjacent mover as in the past, no attractive force is generated between adjacent permanent magnets, and the magnetic circuit The loss of magnetic flux used for Efficiency of road is enhanced.

[0025] The invention of claim 2 of the present invention is based on claim 1
Since the area of the permanent magnet facing the electromagnet is equal to the area when all the movers have the permanent magnet, even if the total area of the permanent magnet facing the electromagnet is equal to the conventional, As in this case, there is no attraction between the permanent magnets,
The output is equal to or higher than that of the conventional one, and the actuator can be made thinner by the amount that there is no need to provide a gap between the adjacent permanent magnets as in the conventional case.

The invention of claim 3 of the present invention is directed to claim 1
In the above, since only the mover has a plurality of drivers, the freedom of shape and material of the mover without the driver is increased, and the design freedom of the actuator is increased even if the output is the same. It is.

The invention of claim 4 of the present invention provides the method of claim 1
In the above, the driver is not provided on the mover having the permanent magnet constituting the magnetic circuit, so that each mover has the driver and the permanent magnet separately, and the mass balance between the movers is designed. Is easier.

Further, the invention of claim 5 of the present invention is directed to claim 1
In the above, a movable element is formed by connecting two movable bodies to form a box,
It consists of a central mover disposed in the mover, and only one of the movers has two drivers arranged symmetrically with respect to the center in the depth direction. The movable member has a symmetrical shape with respect to the central axis in the drive direction and the vertical direction, and the positions of the centers of gravity of the movers in the drive direction and the vertical direction are substantially the same, so that the actuator vibration can be reduced.

The invention according to claim 6 of the present invention is directed to claim 4
In the above, a movable element is formed by connecting two movable bodies to form a box,
Consisting of a central mover disposed in the mover, only a box-shaped mover constituted a magnetic circuit and had a permanent magnet, and only the central mover had a driver. Since the mover has a driver and a permanent magnet separately, it is easy to design a mass balance between the movers, and each mover has a symmetrical shape with respect to the center axis in the direction perpendicular to the drive direction. Therefore, the positions of the centers of gravity of the movers in the driving direction and the vertical direction are substantially the same, and the vibration of the actuator can be reduced.

The seventh aspect of the present invention provides the fourth aspect.
In the above, a movable element is formed by connecting two movable bodies to form a box,
Consisting of a central mover disposed in the mover, only the central mover had a permanent magnet constituting a magnetic circuit, and only a box-like mover had a driver, so each Mover has a driver and a permanent magnet separately, which facilitates mass balance design between movers,
Since each mover has a symmetrical shape with respect to the center axis in the drive direction and the vertical direction, the center of gravity of each mover in the drive direction and the vertical direction substantially coincides, and vibration of the actuator can be reduced. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a vibration type actuator according to an example of an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the same.

3 (a) is a schematic front view of a conventional mover, and FIG. 3 (b) is a schematic side view of the conventional mover.

4A and 4B are diagrams for explaining the above operation, in which FIG. 4A is a schematic front view of the mover of the present invention, and FIG. 4B is a schematic side view.

FIG. 5 is a schematic side view of a mover of another example of the above.

FIG. 6 is a schematic side view of a mover of another example of the above.

FIG. 7 is a schematic side view of a mover of another example of the above.

8A and 8B are schematic side views of another example of the above.

[Explanation of symbols]

 Reference Signs List 1 stator 2 mover 2a one mover 2b the other mover 3 frame 4 yoke 5 coil 7 back yoke 8 permanent magnet 9 driver 10 connector 14 spring

Claims (7)

[Claims] 1. A stator comprising an electromagnet, a mover having a permanent magnet, and a stator fixedly mounted and supporting the mover reciprocally via a leaf-spring-like coupling body. It consists of a frame, and a plurality of movers are connected by a spring in the driving vibration direction. The mass of the plurality of movers is almost the same, and a permanent magnet is provided on only one of the adjacent movers, and is supplied to only one electromagnet. A vibrating linear actuator wherein the movers are driven in opposite phases near the natural frequency of the vibration system by alternately changing the direction of the current. 2. The vibrating linear actuator according to claim 1, wherein the area of the permanent magnet facing the electromagnet is equal to the area when all of the movers have the permanent magnet. 3. The vibration-type linear actuator according to claim 1, wherein only one mover has a plurality of drivers. 4. A drive element is not provided on a mover having a permanent magnet constituting a magnetic circuit.
The vibration type linear actuator as described. 5. A movable element comprising two movable elements connected to each other to form a box, and a central movable element disposed in the movable element.
2. The vibration type linear actuator according to claim 1, wherein only one of the movers has two drivers arranged symmetrically with respect to a center in a depth direction. 6. A movable element which is formed by connecting two movable elements to form a box, and a central movable element disposed in the movable element.
5. The vibrating linear actuator according to claim 4, wherein only the box-shaped mover has a permanent magnet constituting a magnetic circuit, and only the center mover has a driver. 7. A box-shaped mover formed by connecting two movers, and a center mover disposed in the mover.
5. The vibrating linear actuator according to claim 4, wherein only the center mover has a permanent magnet forming a magnetic circuit, and only the box-shaped mover has a driver.