JP5096839B2 - Electromagnetic actuator and electric razor - Google Patents

Description

  The present invention relates to a vibration-type electromagnetic actuator that is suitable for application to a reciprocating electric shaver and causes a mover to reciprocate.

Conventionally, a vibration type including a stator made of an electromagnet, a plurality of movers provided with permanent magnets, and a frame portion to which the stator is fixed and supports a plurality of movers reciprocally via a spring. Are known (see Patent Documents 1 and 2). In this electromagnetic actuator, by alternately switching the direction of the current supplied to the electromagnet, the plurality of movers reciprocate in opposite phases.
JP-A-7-265560 JP-A-7-313749

  In general, the magnetic efficiency of an electromagnetic actuator is determined by the magnetic efficiency of a magnetic circuit composed of a mover and a stator, and the magnetic efficiency of the magnetic circuit is determined by the magnetic resistance of the magnetic gap between the mover and the stator. However, this magnetoresistance has a trade-off relationship with the magnetomotive force of the permanent magnet that determines the magnetic efficiency by generating the main magnetic flux (magnetization increases as magnetomotive force increases, and magnetomotive force decreases as magnetoresistance decreases). For this reason, the magnetic flux of the permanent magnet cannot be used effectively.

  Against this background, according to conventional electromagnetic actuators, magnetic flux that is not used effectively causes magnetic saturation of the back yoke (magnetic conductor) of the mover, resulting in saturation of reciprocating thrust, and magnetic efficiency is reduced. descend. In order to solve such a problem, a method of supplementing the magnetic flux of the permanent magnet with the magnetomotive force of the electromagnet of the stator can be considered, but when this method is used, the loss such as copper loss increases. The overall efficiency of the entire electromagnetic actuator is reduced.

  From such a background, it is desired to provide an electromagnetic actuator with high magnetic efficiency.

  The present invention has been made to solve the above problems, and improves the magnetic efficiency and the overall efficiency by using the magnetic flux of a permanent magnet that is not effectively used due to magnetic saturation as the thrust of the reciprocating motion of the mover. It is to provide an electromagnetic actuator and an electric razor.

  An electromagnetic actuator and an electric razor according to the present invention include a stator formed by winding a coil around a core having a plurality of magnetic poles, and a permanent magnet disposed to face the tip surface of the magnetic poles via a magnetic gap. And a plurality of movers supported so as to be able to reciprocate in a direction orthogonal to the opposing direction of the magnetic poles. These movers are reciprocatingly moved in opposite phases to each other, and at least two adjacent movers of the plurality of movers have projecting pieces protruding toward the other mover.

  According to the electromagnetic actuator and the electric razor according to the present invention, the adjacent movable element is formed by forming a projecting piece on the surface facing the other movable element of at least two adjacent movable elements among the plurality of movable elements. A magnetic path is formed between the movers when displacement occurs between them, and the magnetic flux of the permanent magnet that has not been used effectively due to magnetic saturation is used as the thrust of the reciprocating motion of the mover. Can be improved.

  Hereinafter, the configuration of an electromagnetic actuator according to an embodiment of the present invention will be described with reference to the drawings.

[Configuration of electromagnetic actuator]
As shown in FIGS. 1 (a) and 1 (b), an electromagnetic actuator according to an embodiment of the present invention includes an electromagnetic block (stator) 1 and a plurality of movable elements 2 as main components. It is formed by winding a coil 12 around a magnetic pole 11b of an E-shaped core 10 having two magnetic poles 11a, 11b, 11c. Although only one mover 2 is shown in FIGS. 1 (a) and 1 (b), a plurality of movers 2 (two in this embodiment) are actually arranged adjacent to each other (see FIG. 3). .

  Each mover 2 is disposed so as to face the end faces of the three magnetic poles 11a, 11b, and 11c via a magnetic gap, and is supported so as to reciprocate in the direction in which the magnetic poles 11a, 11b, and 11c are arranged. Each mover 2 includes a permanent magnet 21 and a magnetic conductor 22 as a back yoke. The permanent magnet 21 has different poles in the left-right direction, which is the reciprocating direction, and the arrangement of the poles of the permanent magnets 21 is different among the plurality of movers 2 so that the movers 2 reciprocate in opposite phases. Yes. As shown in FIG. 2, the width W1 of the permanent magnet 21 is smaller than the maximum width W2 of the magnetic poles 11a and 11c at the left and right ends. It is formed so as to satisfy (W2 ≧ W1 + ST).

  In this embodiment, as shown in FIGS. 3 (a) to 3 (d), the magnetic conductors 22 of the two adjacent movers 2a and 2b are projecting pieces made of a dust core on the surface facing the other mover. 31. In the conventional electromagnetic actuator not having such a protrusion 31, the magnetic path uses the permanent magnet 21 as a magnetomotive force, and the permanent magnet 21 → the magnetic gap → the electromagnetic block 1 → the magnetic gap → the permanent magnet 21 → the magnetic conductor 22 → It was composed only of a closed loop of the permanent magnet 21.

  On the other hand, when the projecting piece 31 is formed on the magnetic conductor 22, in addition to the conventional magnetic path, the closed loop magnetic path as shown in FIGS. 4 (a) to 4 (c) has the movable elements 2a and 2b. Formed between. And according to such a magnetic path between the movers 2a and 2b, it is possible to generate an attractive force and a repulsive force in the reciprocating direction of the mover 2, and to increase an effective thrust in the reciprocating direction. It is possible to improve the magnetic efficiency by effectively utilizing the magnetic flux that has not been effectively utilized due to the magnetic saturation.

  That is, according to the projecting piece 31, the magnetic force (reluctance force) using the magnetic saliency can be effectively used, and the magnetic efficiency is improved. Further, since only the projecting piece 31 is provided on the magnetic conductor 22, the cost of the electromagnetic actuator does not increase greatly. Furthermore, since the projecting piece 31 is formed of a dust core, eddy current loss can be reduced and magnetic efficiency can be further improved.

[Other Embodiments]
As shown in FIG. 5, the number of protrusions 31 formed on the opposing surface of one movable element 2a of two adjacent movable elements and the number of protrusions 31 formed on the opposing surface of the other movable element 2b. It is desirable to form at least one region having a ratio of 2: 1. According to such a configuration, the magnetic force using the magnetic saliency can be effectively used in the reciprocating direction of the movers 2a and 2b, and the magnetic efficiency can be further improved. In this case, as shown in FIG. 6, it is desirable to arrange the projecting piece 31 on the movable element side 2a and the projecting piece on the movable element 2b side so as to be nested. According to such a configuration, even when the movers 2a and 2b reciprocate like a linear actuator, the magnetic force is always effectively used regardless of the moving direction of the movers 2a and 2b. Magnetic efficiency can be improved.

  As shown in FIG. 7A, chamfering may be performed on the upper end portion 31 a of the projecting piece 31. According to such a configuration, since the magnetic flux can be generated obliquely between the opposing surfaces of the movers 2a and 2b, the thrust in the moving direction of the movers 2a and 2b is generated while changing the magnetic resistance, Magnetic efficiency can be further improved. Moreover, as shown in FIG.7 (b), you may make the upper surface of the protrusion 31 uneven | corrugated shape. According to such a configuration, the magnetic force can be applied with an arbitrary displacement by applying a magnetic saliency to the surface of the protruding piece 31, so that the thrust can be freely controlled and cogging can be reduced.

  As shown in FIG. 7 (c), the protruding piece 31 may be formed by a combination of the form shown in FIG. 7 (a) and the form shown in FIG. 7 (b). In general, the magnetic attraction force required to generate thrust works in the direction of the opposing surface as well as the direction of thrust to be used, but according to such a configuration, unnecessary attraction in the opposing surface direction is maintained while maintaining the thrust. Since the force can be reduced and the magnetic attractive force can be effectively used in the thrust direction to be used, the magnetic efficiency can be improved.

  As shown in FIG. 8 and FIGS. 9A and 9B, the upper surface of the projecting piece 31 may be inclined. According to such a configuration, since the facing area that affects the magnetic utilization rate can be increased in the limited gap between the movers 2a and 2b, the magnetic force using the magnetic saliency is further effectively utilized. , Magnetic efficiency can be improved.

  As shown in FIG. 10, of the two adjacent movable elements 2a and 2b, the opposing surface of the movable element 2a has a concave shape, and the opposing surface of the movable element 2b has a protruding shape. Good. According to such a configuration, by making the two adjacent protrusions 31 uneven, the total weight can be made equal to that of the conventional electromagnetic actuator, so that the magnetic saliency can be reduced while realizing cost reduction. The magnetic efficiency can be improved by effectively using the magnetic force used. .

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the description and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it should be added that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above embodiments are all included in the scope of the present invention.

It is the front view and perspective view of the electromagnetic actuator which become embodiment of this invention. It is a front view of the electromagnetic actuator for demonstrating the width dimension of a permanent magnet. It is the perspective view of the needle | mover for demonstrating the structure of the protrusion which becomes embodiment of this invention, a top view, and a side view (X direction, Y direction). It is a schematic diagram for demonstrating the magnetic path formed with the protrusion which becomes embodiment of this invention. It is a top view of the needle | mover for demonstrating the structure of the modification of the protrusion which becomes embodiment of this invention. It is a top view of the needle | mover for demonstrating the structure of the modification of the protrusion which becomes embodiment of this invention. It is a schematic diagram for demonstrating the shape of the modification of the protrusion which becomes embodiment of this invention. It is a schematic diagram for demonstrating the shape of the modification of the protrusion which becomes embodiment of this invention. It is the upper side figure of the needle | mover for demonstrating the structure of the modification of the protrusion used as embodiment of this invention, a side view, and the elements on larger scale. It is a top view of the needle | mover for demonstrating the structure of the modification of the protrusion which becomes embodiment of this invention.

Explanation of symbols

1: Electromagnetic block (stator)
2, 2a, 2b: Movable element 10: Core 11a, 11b, 11c: Magnetic pole 12: Coil 21: Permanent magnet 22: Conductor 31: Projection piece

Claims (9)

  A stator formed by winding a coil around a core having a plurality of magnetic poles, and a permanent magnet disposed opposite to the tip surface of the magnetic pole via a magnetic gap, and facing the magnetic pole A plurality of movers supported so as to be capable of reciprocating in orthogonal directions, the plurality of movers are arranged adjacent to each other, and the plurality of movers are in reverse phase with each other as an alternating current is applied to the coil. An electromagnetic actuator that reciprocally moves, wherein at least two adjacent movers of the plurality of movers have a projecting piece protruding toward the other mover.   2. The electromagnetic actuator according to claim 1, wherein the two adjacent movers have at least a region where a ratio of the number of protrusions of one mover to the number of protrusions of the other mover is 2: 1. An electromagnetic actuator comprising one or more.   3. The electromagnetic actuator according to claim 2, wherein the projecting piece on one of the movable elements and the projecting piece on the other movable element are arranged so as to be nested with each other.   4. The electromagnetic actuator according to claim 1, wherein an inclined surface is formed by chamfering the upper end portion of the projecting piece. 5.   5. The electromagnetic actuator according to claim 1, wherein an upper surface of the projecting piece has a concavo-convex shape. 6.   The electromagnetic actuator according to any one of claims 1 to 5, wherein an upper surface of a projecting piece facing between one movable element and the other movable element has an inclination.   2. The electromagnetic actuator according to claim 1, wherein the projecting piece on one of the movers has a convex shape, and the projecting piece on the other of the movers has a concave shape.   The electromagnetic actuator according to any one of claims 1 to 7, wherein the protruding piece is formed of a dust core. An electric razor comprising the electromagnetic actuator according to any one of claims 1 to 8 .

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