JP3841021B2

JP3841021B2 - Vibration type linear actuator

Info

Publication number: JP3841021B2
Application number: JP2002154789A
Authority: JP
Inventors: 渉実松; 誠藤原; 敏中山
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 2002-05-28
Filing date: 2002-05-28
Publication date: 2006-11-01
Anticipated expiration: 2022-05-28
Also published as: JP2003348813A

Description

【０００１】
【発明の属する技術分野】
本発明は、振動型リニアアクチュエータ、殊に固定子の基台と可動子とを連結する連結体の構造に関するものである。
【０００２】
【従来の技術】
振動型リニアアクチュエータの可動子を薄板の連結体により連結する従来例として図６に示すものがある。図において１０５は固定子で、磁性材料の焼結体や磁性材料の鉄板を積層したものに巻線１０６を施した電磁石により構成されている。この電磁石である固定子１０５は基台１０１に溶接により固着されている。図中１０３ａ，１０３ｂは共に可動子、１０２は薄板よりなる連結体であり、連結体１０２はその上端部が基台１０１に溶接固着され、連結体１０２の各下端部に可動子１０３ａ，１０３ｂの端部が溶着されて、固定子１０５が可動子１０３ａ、１０３ｂに設けた永久磁石１０４とエアギャップを介して対向している。
【０００３】
連結体１０２は可動子１０３ａ，１０３ｂの振動方向（図中ｘ軸方向）に対して直交する方向（ｙ軸方向）において図７に示すように、両側縁が円弧状に切り欠かれて円弧状部１０２ａを形成してあり、このことにより薄板の中央部の幅が狭く且つ基台１０１及び可動子１０３ａ，１０３ｂとの連結部分側の幅が広くなるように設定されている。
【０００４】
また、可動子１０３ａ中央突出部分の振動方向の両側と可動子１０３ｂの両端支持部の内側とにはばね受け部（図示せず）となる突部が突設されており、その間にそれぞればね１０７，１０７が配設されている。
【０００５】
このような構成の振動型リニアアクチュエータは、固定子１０５である電磁石の巻線１０６に流れる電流の方向を切り換えることで、可動子１０３ａ，１０３ｂに取り付けられた永久磁石１０４の吸引・反発によりｘ軸方向に可動子１０３ａ，１０３ｂが振動する。
【０００６】
【発明が解決しようとする課題】
上記の従来例にあっては、薄板よりなる連結体１０２は可動子１０３ａ，１０３ｂの振動方向に対して直交する方向（ｙ軸方向）においてＲ形状に切り欠かれ、薄板の中央部の幅が狭く且つ基台１０１及び可動子１０３ａ，１０３ｂとの連結部分側の幅が広くなっているため、可動子１０３ａ，１０３ｂに設けたそれぞれの永久磁石１０４のｙ軸方向の吸引力により、連結体１０２は同方向に座屈してｚ軸回りの回転変位が生じる。特に、可動子１０３ａ，１０３ｂの振動がその振幅の両端に位置するところにおいては変形量が大きくなる。
【０００７】
すなわち、図８に示すように、可動子１０３ａ，１０３ｂに設けたそれぞれの永久磁石１０４のｙ軸方向の吸引力により連結体１０２は同方向に座屈してｚ軸回りの回転変位１０２ｃが生じ、この時、可動子１０３ａ，１０３ｂのｘ軸における振幅軌道は並進運動から円弧運動になるため磁気推進力が低下し、さらには可動子同士が接触するという問題があった。
【０００８】
本発明は上記の従来例の問題点に鑑みて発明したものであり、その目的とするところは、連結体の磁石吸引力方向の高剛性化を図った連結体を用いた振動型リニアアクチュエータを提供するにある。
【０００９】
【課題を解決するための手段】
上記従来例の問題点を解決して本発明の目的を達成するため、本発明の振動型リニアアクチュエータは、固定子を備えた基台と固定子にエアギャップを介して対向する可動子とが薄板からなる連結体で連結されて基台に対して可動子が連結体により往復動自在に支持されている振動型リニアアクチュエータにおいて、薄板の肉厚方向を可動子の振動方向と同方向としている上記連結体は、薄板形成面上において可動子と固定子の連結方向と直交する方向での連結体中央部の一部又は全部が、当該中央部の幅が狭く且つ基台及び可動子との連結部分側の幅が広くなるように滑らかな曲線で切り欠かれていることに特徴を有している。
【００１０】
この時、連結体は切り欠かれた部分の左右が基台及び可動子との連結部分側において可動子と固定子の連結方向と直交する方向にブリッジ部にて繋がれているものであってもよい。
【００１２】
上記のような構成の本発明にあっては、薄板形成面上において可動子と固定子の連結方向と直交する方向での連結体中央部の一部又は全部が切り欠かれることで、基台及び可動子との連結部の幅が小さくなるため、薄板形成面上において可動子と固定子の連結方向と直交する方向の磁石吸引力による座屈作用に対する許容応力が向上し、連結方向を軸とする回転変位を低減することことが可能となる。
【００１３】
また、上記の連結体の切り欠きにより離れた側端部間が荷動子と固定子の連結方向と直交する方向にブリッジ部にて繋がれているものにおいては、連結体の上部と下部の発生応力をより均等にすることが可能となる。
【００１５】
【発明の実施の形態】
以下本発明を実施の形態の一例に基づいて詳述すると、図１は本発明に係る振動型リニアアクチュエータの組立状態の斜視図であり、図２は同上の分解斜視図である。図中２ａ，２ｂは可動子であって、永久磁石８ａ，８ｂ，９とヨーク１０（バックヨーク）と剛性を有する非磁性金属からなる可動子本体部１２とで構成されている。磁性材料のヨーク１０には永久磁石８ａと８ｂの磁極方向が永久磁石９の磁極と対極になるように接着されている。
【００１６】
図中１は固定子で磁性材料の焼結体や磁性材料の鉄板を積層したものに巻線３を施した電磁石で構成されて、基台４に固着されている。この電磁石である固定子１は可動子２に設けた永久磁石８ａ，８ｂ，９とエアギャップを介して対向する。すなわち、連結体５の上端部を連結体支持台１３にねじ具２０により固着し、さらにこれを基台４にねじ具２１により固着すると共に連結体５の下端部を可動子２にねじ具２２により固着することで、上記エアギャップが確保されている。
【００１７】
連結体５は可動子２の往復動方向に変位可能な薄板の板ばねで形成されている。本発明は該連結体５の構成に特徴を有しており、ここでの連結体５は薄板の板ばねの肉厚方向を可動子２の振動方向（ｘ方向）と同方向に設定されているとともに、この薄板の板ばねよりなる連結体５が可動子２の振動方向に対して直交する方向（すなわちｙ方向）において図３に示すように薄板のｙ軸方向の中央部が全部切り欠かれて左右に分割された２片で構成されている。
【００１８】
本例では２個の可動子２ａ，２ｂが設けられており、このために可動子２ａ，２ｂの振動方向（ｘ軸方向）の両端部にそれぞればね取り付け部１１ａ，１１ｂとなる突部が突設されており、このばね取り付け部１１ａ，１１ｂにはばね６がねじ具２３により固着されて両可動子２ａ，２ｂがばね６によって連結されている。可動子２ａ，２ｂの上面部には駆動子７が突設されている。この、駆動子７は被駆動部材を取り付けるためのものであり、例えば往復式電気かみそりとして使用する場合には、駆動子７に内刃が取付けられる。
【００１９】
このように構成された振動型リニアアクチュエータの基本動作は、固定子１である電磁石の電流方向を交番にすることで、可動子２に取り付けた永久磁石８ａ，８ｂ，９がｘ方向に往復動を行う。可動子２ａ，２ｂはそれぞれ上記のように永久磁石８ａ，８ｂ，９との吸引・反発力により移動するが、その移動方向は連結体５による往復動が許された方向になっている。固定子１を構成する電磁石の巻線３は実施例においては１本であり、往復運動の右方向運動と左方向では巻線に与える電流の向きを反転させる。つまり、移動方向に推進力が働く方向に電流を流すのである。
【００２０】
ここで、可動子２ａ，２ｂに設けたそれぞれの永久磁石８ａ，８ｂ，９の吸引により連結体５はｙ軸方向に対しそれぞれ内側に磁石吸引力を受ける。この時、連結体５は前記従来例と同様に滑らかな曲線で切り欠かれて中央幅１０２ｂが基台４及び可動子２との連結部分側の幅よりも狭くなっているのであるが、この切り欠きは図３に示すように連結体５のｙ軸方向中央部にその一部又は全部を切り欠くものとして設けられているために、ｙ軸方向の磁石吸引力による座屈作用に対する許容応力が向上し、ｚ軸回りの回転変位５ｄ（図４参照）を軽減することことが可能となる。つまり、本発明の連結体５は従来の連結体１０２と比較した時、中央幅５ａの和と中央部幅１０２ｂが等しくｚ方向の長さ且つ板厚が同じ場合では、連結体５の磁石吸引力方向の剛性が向上する。
【００２１】
図５に連結体５の他例を示す。ここでは上記の例では連結体の５が切り欠きによって分離されていたのに対して、中央部の一部のみを切り欠くことで側端部間が可動子と固定子の連結方向と直交する方向にブリッジ部５ｂにて繋がれている。このように連結体５の中央部において、切り欠きにより離れた側端部間を繋ぐブリッジ部５ｂを可動子と固定子の連結方向と直交する方向に設けた連結体５は振動方向の変位時において連結体５の上部と下部の発生応力を均等にすることができ、最大応力をさらに低減することできる。
【００２３】
【発明の効果】
本発明の請求項１記載の発明は、薄板の肉厚方向を可動子の振動方向と同方向としている上記連結体は、薄板形成面上において可動子と固定子の連結方向と直交する方向での連結体中央部の一部又は全部が、当該中央部の幅が狭く且つ基台及び可動子との連結部分側の幅が広くなるように滑らかな曲線で切り欠かれているために、両側縁を滑らかな曲線で切り欠いた従来例のものに比して座屈作用に対する許容応力が向上し、連結方向を軸とする回転変位を軽減することことが可能となる。この結果、連結体の磁石吸引力方向の剛性が向上し、且つ高性能とできる。
【００２４】
また、本発明の請求項２記載の発明にあっては上記の請求項１記載の発明の効果に加えて、請求項１の連結体の切り欠きにより離れた側端部間が基台及び可動子との連結部分側において可動子と固定子の連結方向と直交する方向にブリッジ部にて繋がれていることにより、連結体の上部と下部の発生応力をより均等にすることが可能となる。
【図面の簡単な説明】
【図１】本発明の実施の形態の一例を示すもので、(a)は斜視図、(b)は要部拡大斜視図である。
【図２】同上の分解斜視図である。
【図３】同上の連結体の正面図である。
【図４】同上の連結体の変形を示した正面図である。
【図５】連結体の他例の正面図である。
【図６】従来例の分解斜視図である。
【図７】従来例の連結体の正面図である。
【図８】従来例の連結体の変形を示した正面図である。
【符号の説明】
１固定子
２ａ，２ｂ可動子
４基台
５連結体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration type linear actuator, and more particularly to a structure of a connecting body that connects a base of a stator and a movable element.
[0002]
[Prior art]
FIG. 6 shows a conventional example in which the movable element of the vibration type linear actuator is connected by a thin plate connecting body. In the figure, reference numeral 105 denotes a stator, which is composed of an electromagnet obtained by laminating a sintered body of a magnetic material or an iron plate of a magnetic material and windings 106. This electromagnet stator 105 is fixed to the base 101 by welding. In the figure, 103a and 103b are both movable elements, and 102 is a connecting body made of a thin plate. The connecting body 102 is fixedly welded to the base 101, and the movable elements 103a and 103b are attached to the respective lower end portions of the connecting body 102. The ends are welded, and the stator 105 is opposed to the permanent magnet 104 provided on the movers 103a and 103b via an air gap.
[0003]
Connecting member 102 is movable piece 103a, the vibration direction of 103b as shown in FIG. 7 in the direction (y-axis direction) perpendicular to (in the figure the x-axis direction), the arc-shaped side edges are cut out in an arc shape A portion 102a is formed, so that the width of the central portion of the thin plate is narrow and the width of the connecting portion side between the base 101 and the movers 103a and 103b is widened.
[0004]
Further, protrusions serving as spring receiving portions (not shown) are provided on both sides of the vibration direction of the central projecting portion of the mover 103a and inside the support portions on both ends of the mover 103b. , 107 are arranged.
[0005]
The vibration type linear actuator having such a configuration switches the direction of the current flowing through the winding 106 of the electromagnet, which is the stator 105, so that the permanent magnet 104 attached to the movers 103a and 103b attracts and repels the x axis. The movers 103a and 103b vibrate in the direction.
[0006]
[Problems to be solved by the invention]
In the above-described conventional example, the connecting body 102 made of a thin plate is cut into an R shape in a direction (y-axis direction) orthogonal to the vibration direction of the movers 103a and 103b, and the width of the central portion of the thin plate is reduced. Since it is narrow and the width of the connecting portion side between the base 101 and the movers 103a and 103b is wide, the connecting body 102 is attracted by the attractive force in the y-axis direction of each permanent magnet 104 provided on the movers 103a and 103b. Will buckle in the same direction, causing rotational displacement about the z-axis. In particular, Oite where the movable element 103a, the vibration of 103b is located at both ends of the amplitude deformation amount increases.
[0007]
That is, as shown in FIG. 8 , the coupling body 102 is buckled in the same direction by the attractive force in the y-axis direction of the permanent magnets 104 provided on the movers 103a and 103b, and a rotational displacement 102c around the z-axis is generated. At this time, the amplitude trajectory on the x-axis of the movers 103a and 103b changes from a translational motion to an arc motion, so that there is a problem that the magnetic propulsive force is reduced and the movers are in contact with each other.
[0008]
The present invention was invented in view of the above-described problems of the conventional example, and the object of the present invention is to provide a vibration type linear actuator using a coupling body that is highly rigid in the direction of the magnet attractive force of the coupling body. Is in providing.
[0009]
[Means for Solving the Problems]
In order to solve the problems of the conventional example and achieve the object of the present invention, the vibration type linear actuator of the present invention includes a base having a stator and a mover facing the stator through an air gap. In a vibration type linear actuator that is connected by a thin plate connecting body and the movable element is supported by the connecting body in a reciprocating manner with respect to the base, the thickness direction of the thin plate is the same as the vibration direction of the moving element. In the connecting body, a part or all of the central portion of the connecting body in the direction orthogonal to the connecting direction of the mover and the stator on the thin plate forming surface has a narrow width at the center and the base and the mover. It is characterized by being cut out with a smooth curve so that the width of the connecting portion side becomes wide .
[0010]
At this time, the connecting body is connected at the bridge portion in the direction orthogonal to the connecting direction of the mover and the stator on the side where the cutout portion is connected to the base and the mover. Also good.
[0012]
In the present invention having the above-described configuration, the base is formed by cutting out part or all of the central portion of the connecting body in the direction orthogonal to the connecting direction of the mover and the stator on the thin plate forming surface. Since the width of the connecting portion with the mover is reduced, the allowable stress against the buckling action due to the magnet attractive force in the direction orthogonal to the connecting direction of the mover and the stator is improved on the thin plate forming surface, and the connecting direction is It is possible to reduce the rotational displacement.
[0013]
Further, in the case where the side end portions separated by the notch of the connecting body are connected by a bridge portion in a direction orthogonal to the connecting direction of the load and stator, the upper and lower portions of the connecting body are The generated stress can be made more uniform.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on an example of an embodiment. FIG. 1 is a perspective view of a vibration type linear actuator according to the present invention in an assembled state, and FIG. 2 is an exploded perspective view of the same. In the figure, reference numerals 2a and 2b denote movers, which are composed of permanent magnets 8a, 8b and 9, a yoke 10 (back yoke), and a mover main body 12 made of a rigid nonmagnetic metal. The magnetic material yoke 10 is bonded so that the magnetic pole directions of the permanent magnets 8 a and 8 b are opposite to the magnetic poles of the permanent magnet 9.
[0016]
In the figure, reference numeral 1 denotes a stator which is composed of an electromagnet obtained by laminating a sintered body of magnetic material or an iron plate of magnetic material and winding 3, and is fixed to a base 4. The stator 1, which is an electromagnet, faces the permanent magnets 8a, 8b, 9 provided on the mover 2 through an air gap. That is, the upper end portion of the connection body 5 is fixed to the connection body support base 13 with the screw tool 20, and further fixed to the base 4 with the screw tool 21, and the lower end portion of the connection body 5 is fixed to the mover 2 with the screw tool 22. The air gap is secured by being fixed by.
[0017]
The connecting body 5 is formed of a thin plate spring that can be displaced in the reciprocating direction of the mover 2. The present invention is characterized by the structure of the connecting body 5, and the connecting body 5 is configured such that the thickness direction of the thin plate spring is set in the same direction as the vibration direction (x direction) of the mover 2. In addition, as shown in FIG. 3, the central portion of the thin plate in the y-axis direction is notched in the direction in which the connecting body 5 made of the thin plate spring is orthogonal to the vibration direction of the mover 2 (that is, the y direction). It consists of two pieces that are divided into left and right sides.
[0018]
In this example, two movers 2a and 2b are provided, and for this reason, protrusions serving as spring attachment portions 11a and 11b protrude from both ends of the vibration directions (x-axis direction) of the movers 2a and 2b, respectively. A spring 6 is fixed to the spring mounting portions 11 a and 11 b by a screw tool 23, and both movable elements 2 a and 2 b are connected by the spring 6 . A driver element 7 projects from the upper surface of the movers 2a and 2b. This drive element 7 is for attaching a driven member. For example, when used as a reciprocating electric shaver, an inner blade is attached to the drive element 7.
[0019]
The basic operation of the vibration type linear actuator configured as described above is that the current direction of the electromagnet as the stator 1 is alternated so that the permanent magnets 8a, 8b, 9 attached to the mover 2 reciprocate in the x direction. I do. The movers 2a and 2b move by the attraction and repulsion force with the permanent magnets 8a, 8b, and 9 as described above, and the moving direction is a direction in which reciprocation by the connecting body 5 is allowed. The number of the electromagnet windings 3 constituting the stator 1 is one in the embodiment, and the direction of the current applied to the windings is reversed in the rightward movement and the leftward movement of the reciprocating movement. That is, a current is passed in the direction in which the driving force is applied in the moving direction.
[0020]
Here, due to the attraction of the respective permanent magnets 8a, 8b, 9 provided on the movers 2a, 2b, the coupling body 5 receives a magnet attraction force inward in the y-axis direction. At this time, the connecting body 5 is notched with a smooth curve like the conventional example, and the central width 102b is narrower than the width of the connecting portion side with the base 4 and the movable element 2, As shown in FIG. 3, the notch is provided in the central portion of the connecting body 5 in the y-axis direction so that a part or all of the notch is notched , so that the allowable stress against the buckling action by the magnet attractive force in the y-axis direction is provided. Thus, the rotational displacement 5d around the z axis (see FIG. 4) can be reduced. In other words, when the connecting body 5 of the present invention is compared with the conventional connecting body 102, when the sum of the center width 5a and the center width 102b are equal and the length in the z direction and the plate thickness are the same, the magnet attraction of the connecting body 5 The rigidity in the force direction is improved.
[0021]
FIG. 5 shows another example of the connector 5. Here, in the above example, the connecting body 5 is separated by the notch, but by cutting out only a part of the central portion, the side end portion is orthogonal to the connecting direction of the movable element and the stator. It is connected to the direction by a bridge portion 5b. Thus, in the central part of the connecting body 5, the connecting body 5 provided with the bridge portion 5 b connecting the side ends separated by the notch in a direction orthogonal to the connecting direction of the mover and the stator is The generated stresses at the upper and lower parts of the connector 5 can be made uniform, and the maximum stress can be further reduced.
[0023]
【The invention's effect】
The invention of claim 1, wherein the present invention, the connecting member to the thickness direction of the thin plate is a vibrating direction in the same direction of the movable element, in a direction perpendicular to the coupling direction of the movable element and the stator on the thin plate forming surface for some or all of the coupling body central portion, the width of the connecting portion side with and base and the movable element is narrow in the central portion is cut in a smooth curve to be wider in both sides As compared with the conventional example in which the edge is notched with a smooth curve, the allowable stress for the buckling action is improved, and the rotational displacement about the connecting direction can be reduced. As a result, the rigidity of the coupled body in the direction of the magnet attractive force can be improved and high performance can be achieved.
[0024]
In addition, in the invention according to claim 2 of the present invention, in addition to the effect of the invention according to claim 1, the base end and the movable portion between the side end portions separated by the notch of the connecting body of claim 1 are provided. By connecting the bridge part in the direction orthogonal to the connecting direction of the mover and the stator on the connecting part side with the child, it becomes possible to make the generated stress at the upper and lower parts of the connecting body more even. .
[Brief description of the drawings]
FIG. 1 shows an example of an embodiment of the present invention, in which (a) is a perspective view and (b) is an enlarged perspective view of a main part.
FIG. 2 is an exploded perspective view of the above.
FIG. 3 is a front view of the same coupling body.
FIG. 4 is a front view showing a modification of the connection body according to the embodiment.
FIG. 5 is a front view of another example of a connected body.
FIG. 6 is an exploded perspective view of a conventional example .
FIG. 7 is a front view of a connection body of a conventional example .
FIG. 8 is a front view showing a modification of a connection body of a conventional example .
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Stator 2a, 2b Movable element 4 Base 5 Connection body

Claims

A base having a stator and a mover opposed to the stator through an air gap are connected by a connecting body made of a thin plate, and the moving element is supported by the connecting body so as to be reciprocally movable with respect to the base. In the vibration type linear actuator, the connecting body in which the thickness direction of the thin plate is the same direction as the vibration direction of the mover is the central part of the connecting body in the direction perpendicular to the connecting direction of the mover and the stator on the thin plate forming surface. A vibration type linear actuator characterized in that a part or all of the actuator is cut out with a smooth curve so that the width of the central part is narrow and the width of the connecting part side with the base and the mover is widened .

The connecting body is characterized in that the left and right sides of the cut-out portion are connected by a bridge portion in a direction orthogonal to the connecting direction of the mover and the stator on the connecting part side of the base and the mover. 1. The vibration type linear actuator according to 1.