JP2009240044A - Electromagnetic actuator and electric shaver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce its parts count without deteriorating its magnetic efficiency and overall efficiency. <P>SOLUTION: Moving members 2a and 2b are composed of magnets whose directions of magnetization can be adjusted optionally at magnetization, and their opposite sides to a stator 1 are magnetized. According to such configuration, a path for magnetic flux can be formed of only a magnet, accordingly a back yoke, which is conventionally necessary as a path for magnetic flux, becomes needless, and the parts count of components and the cost can be reduced without deteriorating the magnetic efficiency and the overall efficiency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration-type electromagnetic actuator that is suitable for application to a reciprocating electric shaver, linear clipper, linear toothbrush, linear drive pump, or the like and causes a mover to reciprocate.

Conventionally, a stator composed of an electromagnet, a plurality of movers including a permanent magnet and a back yoke, and a frame portion to which the stator is fixed and reciprocally supported via a spring are supported. A vibration type electromagnetic actuator is 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

  As a method of reducing the cost of the conventional electromagnetic actuator, a method of reducing the number of parts of the electromagnetic actuator can be considered. Specifically, by omitting the back yoke of the mover, the material cost and the processing cost are reduced, and the cost of the electromagnetic actuator can be reduced. However, in the conventional electromagnetic actuator, the magnetic path is composed of a closed loop of a back yoke → magnetic gap → stator → magnetic gap → permanent magnet → back yoke with a permanent magnet as a magnetomotive force. As the magnetic resistance of the magnetic path increases, the magnetic efficiency and the overall efficiency deteriorate.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an electromagnetic actuator and an electric razor capable of reducing the number of parts without deteriorating magnetic efficiency and overall efficiency.

  An electromagnetic actuator and an electric razor according to the present invention are arranged so as to face a stator formed by winding a coil around a core having a plurality of magnetic poles, a magnetic gap with respect to a tip surface of the magnetic pole, and a magnetic pole. An electromagnetic actuator and an electric razor including a mover supported so as to be able to reciprocate in a direction orthogonal to the facing direction of, and is configured by a magnet capable of arbitrarily adjusting the direction in which the mover is magnetized. The surface of the magnet facing the stator is magnetized.

  The electromagnetic actuator and the electric razor according to the present invention can reduce the number of parts without deteriorating the magnetic efficiency and the overall efficiency.

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

  As shown in FIGS. 1 (a) and 1 (b), an electromagnetic actuator according to an embodiment of the present invention includes a stator 1 and a plurality of movers 2a and 2b as main components, and the stator 1 has three magnetic poles. It is formed by winding a coil 12 around a magnetic pole 11b of an E-shaped core 10 having 11a, 11b, 11c. The mover 2 is disposed opposite to the end faces of the three magnetic poles 11a, 11b, and 11c via a magnetic gap. The mover 2 is supported by a spring (not shown) so as to reciprocate in the direction in which the magnetic poles 11a, 11b, and 11c are arranged and to return to the vicinity of the center position of the moving range. The width W1 of the movers 2a and 2b is smaller than the maximum width W2 of the magnetic poles 311 and 11c at the left and right ends. It is formed to become.

  The movers 2a and 2b are composed of magnets capable of arbitrarily adjusting the direction of magnetization when magnetized, and the surface facing the stator 1 is magnetized. According to such a configuration, since the magnetic flux path can be formed only by the magnet, the back yoke which has been conventionally required as the magnetic flux path becomes unnecessary, and the component parts can be obtained without deteriorating the magnetic efficiency and the overall efficiency. The number of parts and cost can be reduced. Examples of magnets that can arbitrarily adjust the direction of the magnetization vector during magnetization include bond magnets and nanocomposite magnets. When a bonded magnet is used, the magnetizing operation is facilitated and the electromagnetic actuator can be configured at a low cost. When a nanocomposite magnet is used, the magnetizing operation is facilitated, and a magnet having a higher saturation magnetic flux density than that when a bonded magnet is used can be manufactured, so that the magnetic efficiency is improved. The bond magnet and the nanocomposite magnet may be isotropic or anisotropic. If it is isotropic, the direction of the magnetization vector can be arbitrarily adjusted. In the case of anisotropy, the magnetization vector can be concentrated in a certain direction, so that the saturation magnetic flux density is improved.

  In the example shown in FIG. 2, the movers 2a and 2b have two different poles in the left and right direction that is the reciprocating direction, but as shown in FIG. 3, the movers 2a and 2b have different poles in the left and right direction that is the reciprocating direction. You may have two or more. According to such a configuration, since the magnetic path is increased as compared with the conventional electromagnetic actuator, the magnetic flux utilization rate is improved and the magnetic efficiency is improved. As shown in FIGS. 4A and 4B, the stator 1 preferably has n magnetic poles, and the movers 2a and 2b preferably have (n-1) polarities. According to such a configuration, when a current is excited in the coil 12 and a displacement occurs between the stator 1 and the movers 2a and 2b, a closed magnetic circuit is formed between the stator 1 and the movers 2a and 2b. As a result, the magnetic flux can be effectively used, and the magnetic efficiency is improved. As shown in FIGS. 5A, 5B, and 5C, the stator 1 preferably has n magnetic poles, and the movers 2a and 2b preferably have (n + 1) polarities. According to such a configuration, when a current is excited in the coil 12 and displacement occurs between the stator 1 and the movers 2a and 2b, a new magnetic path that cannot be obtained by a conventional electromagnetic actuator is formed. Thus, the magnetic flux and magnetic path that have not been used can be effectively used, and the magnetic efficiency is improved.

  The movers 2a and 2b are preferably arranged adjacent to each other so as to reciprocate in opposite phases with each other when a current is applied to the coil 12. 6 (a) and 6 (b) show the thrust characteristics of a conventional electromagnetic actuator, and FIGS. 7 (a) and 7 (b) show the thrust characteristics of the electromagnetic actuator of this embodiment. As is clear from the figure, the electromagnetic actuator of this embodiment has a smaller detent than the conventional electromagnetic actuator. Therefore, by arranging the movers 2a and 2b adjacent to each other so as to reciprocate in opposite phases with each other when current is applied to the coil 12, torque fluctuation with respect to stroke fluctuation is reduced, and control is performed. It was confirmed that the property was improved.

  The stator 1 is preferably formed of a laminated steel plate. According to such a configuration, as shown in FIGS. 8A and 8B, the eddy current loss can be reduced and the efficiency can be improved. The stator 1 is preferably formed of a dust core. According to such a configuration, as shown in FIGS. 8 (c) and (d), the magnetic isotropy of the dust core is effectively utilized three-dimensionally to concentrate the magnetic flux between the magnetic gaps, Since the back yoke that has been conventionally used as the magnetic path of the magnetic flux can be eliminated, the electromagnetic actuator can be made small and inexpensive.

  The electromagnetic actuator of this embodiment can be applied to an electric razor. When applied to an electric razor, the head part that houses the actuator can be miniaturized, so that the fulcrum position approaches the skin surface when performing shave, and the followability of the head part to the skin increases. Further, the use of a highly efficient actuator has advantages such as a longer battery life.

  As mentioned above, although embodiment which applied the invention made by the present inventors was described, this invention is not limited by the description and drawing which make a part of indication of this invention by this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on the above-described 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 needle | mover. It is a perspective view which shows the modification of the electromagnetic actuator shown in FIG. It is a front view which shows the modification of the electromagnetic actuator shown in FIG. It is a front view which shows the modification of the electromagnetic actuator shown in FIG. It is a figure which shows the thrust characteristic of the conventional electromagnetic actuator. It is a figure which shows the thrust characteristic of the electromagnetic actuator used as embodiment of this invention. It is a figure which shows magnetic flux distribution of the electromagnetic actuator at the time of forming a stator with a laminated steel plate and a powder iron core.

Explanation of symbols

1: Stator (stator)
2a, 2b: Movable element 10: Core 11a, 11b, 11c: Magnetic pole 12: Coil

Claims (13)

  A stator formed by winding a coil around a core having a plurality of magnetic poles, and a reciprocating motion in a direction perpendicular to the opposing direction of the magnetic poles, arranged opposite to the tip surface of the magnetic poles via a magnetic gap An electromagnetic actuator comprising a freely supported mover, comprising a magnet capable of arbitrarily adjusting a direction in which the mover is magnetized when magnetized, and a surface of the magnet facing the stator is magnetized Electromagnetic actuator characterized by being made.   The electromagnetic actuator according to claim 1, wherein the magnet is a bonded magnet.   The electromagnetic actuator according to claim 1, wherein the magnet is a nanocomposite magnet.   The electromagnetic actuator according to claim 2, wherein the bond magnet is an isotropic bond magnet.   The electromagnetic actuator according to claim 2, wherein the bond magnet is an anisotropic bond magnet.   4. The electromagnetic actuator according to claim 3, wherein the nanocomposite magnet is an isotropic nanocomposite magnet.   The electromagnetic actuator according to claim 3, wherein the nanocomposite magnet is an anisotropic nanocomposite magnet.   The electromagnetic actuator according to any one of claims 1 to 7, wherein the stator has n magnetic poles, and the magnet has (n-1) polarities. Electromagnetic actuator to perform.   The electromagnetic actuator according to any one of claims 1 to 7, wherein the stator has n magnetic poles, and the magnet has (n + 1) polarities. Actuator. The electromagnetic actuator according to any one of claims 1 to 9, wherein a plurality of the movable elements are provided, the plurality of movable elements are arranged adjacent to each other, and an alternating current is applied to the coil. Accordingly, the electromagnetic actuator reciprocates in opposite phases.   The electromagnetic actuator according to any one of claims 1 to 10, wherein the stator is formed of a laminated steel plate.   The electromagnetic actuator according to any one of claims 1 to 10, wherein the stator is formed of a dust core.   An electric razor comprising the electromagnetic actuator according to any one of claims 1 to 12.