JP2007124812A - Excitation distortion actuator - Google Patents

Excitation distortion actuator Download PDF

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JP2007124812A
JP2007124812A JP2005314138A JP2005314138A JP2007124812A JP 2007124812 A JP2007124812 A JP 2007124812A JP 2005314138 A JP2005314138 A JP 2005314138A JP 2005314138 A JP2005314138 A JP 2005314138A JP 2007124812 A JP2007124812 A JP 2007124812A
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Nobutaka Hirama
宣孝 平間
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Kyocera Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an excitation distortion actuator that can eliminate the thermal expansion deformation of an excitation distortion element caused by the Joule heat of a coil generated at operating the excitation distortion actuator, and heat generation caused by an eddy current loss of the excitation distortion element, can drive a movable member and a fixed member in a manner of non-contact between them, is smooth in operation mode, and is improved in responsiveness. <P>SOLUTION: The actuator includes: a displacement generation means composed of the excitation distortion element 2 and a movable shaft 7; a magnetic field application means composed of the coil 3 that applies a magnetic field to the displacement generation means, a coil bobbin 4, and permanent magnets 5; a casing 1 that accommodates the displacement generation means and the magnetic field application means; and a magnetic circuit mechanism constituted of at least part of the casing together with the displacement generation means. An annular gap 10 is formed between the actuator and the casing 1 that surrounds the movable shaft 7, and a fluid hole that opens toward the annular gap 10 is formed at the casing, thus forming a fluid bearing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、外部磁界の印加により生じる磁歪効果を利用して位置決めを行う磁歪アクチュエータに関する。   The present invention relates to a magnetostrictive actuator that performs positioning using a magnetostrictive effect generated by application of an external magnetic field.

近年、微小位置決めシステムにおいてナノメートル、サブミクロンオーダでの要求がある。このような微小位置決めシステムでは、圧電効果や磁歪効果を利用したアクチュエータが利用されている。前者の圧電素子は現在幅広い分野で利用されている。一方後者の磁歪素子は、圧電素子に比べて発生応力が大きい、低電圧で駆動できる、キュリー温度が高いなどの利点があり注目されつつある。
磁歪アクチュエータは、磁歪素子に与える磁界を変化させると素子が変位する原理を利用しており、具体的には制御電流の供給で容易に磁界を制御できる磁気回路を有し、この磁気回路で発生させた磁界を磁歪素子に加えることで磁歪素子の変位を制御している。図４に磁歪と歪みの関係を示す。このとき、アクチュエータの発生変位の制御性を簡易にするために、制御磁界と発生変位との関係が線形部分となる磁界領域を使用するのが一般的な手法である。即ち、図５に示すように一定バイアス磁界を印加しておき、この状態で磁界の強さを制御することにより変位を制御する。 In recent years, there has been a demand on the order of nanometers and submicrons for micropositioning systems. In such a micropositioning system, an actuator using a piezoelectric effect or a magnetostrictive effect is used. The former piezoelectric element is currently used in a wide range of fields. On the other hand, the latter magnetostrictive element is attracting attention because it has advantages such as higher stress generated than piezoelectric elements, drive at a low voltage, and high Curie temperature.
The magnetostrictive actuator uses the principle that the element is displaced when the magnetic field applied to the magnetostrictive element is changed. Specifically, the magnetostrictive actuator has a magnetic circuit that can easily control the magnetic field by supplying a control current. The displacement of the magnetostrictive element is controlled by applying the applied magnetic field to the magnetostrictive element. FIG. 4 shows the relationship between magnetostriction and strain. At this time, in order to simplify the controllability of the generated displacement of the actuator, it is a general method to use a magnetic field region in which the relationship between the control magnetic field and the generated displacement is a linear portion. That is, as shown in FIG. 5, a constant bias magnetic field is applied, and the displacement is controlled by controlling the strength of the magnetic field in this state.

一般的な磁歪アクチュエータの構成を図６に示す。磁歪アクチュエータは、ケーシング１に内に設けられた磁歪素子２を備え、磁歪素子２の周辺には磁歪素子２を変位させるための駆動用磁界印加コイル３が設けられている。そしてコイル３に流す電流の向きおよび大きさによって磁界を制御している。また磁気バイアス印加用に永久磁石５、コイル３が設けられており、ケーシング１により閉磁気回路を構成している。磁歪素子２の材料としては、Ｎｉ系磁歪合金、Ｆｅ−Ａｌ系磁歪合金、フェライト系磁歪合金等が主に用いられており、さらにこれらの磁歪材料に比べて１桁以上大きな変位を発生する希土類金属−遷移金属系超磁歪合金も実用化されている。
ところで、磁歪素子２は伸縮軸方向に対して予め圧縮力を与えておいた方が、伸縮変位量が大きくなるが、圧縮力による面圧が適当な値で伸縮変位量が最大になり、それよりも大きいと伸縮変位量が減じてしまう。従って、一般的には圧縮ばね８などを用いて封じ部材６を介して磁歪素子２に予圧を与えて伸縮変位量を大きくする方法が採用されている。 A configuration of a general magnetostrictive actuator is shown in FIG. The magnetostrictive actuator includes a magnetostrictive element 2 provided inside a casing 1, and a driving magnetic field applying coil 3 for displacing the magnetostrictive element 2 is provided around the magnetostrictive element 2. The magnetic field is controlled by the direction and magnitude of the current flowing through the coil 3. A permanent magnet 5 and a coil 3 are provided for applying a magnetic bias, and the casing 1 forms a closed magnetic circuit. As the material of the magnetostrictive element 2, Ni-based magnetostrictive alloy, Fe-Al-based magnetostrictive alloy, ferrite-based magnetostrictive alloy and the like are mainly used, and further, rare earths that generate a displacement larger than one digit compared with these magnetostrictive materials. Metal-transition metal giant magnetostrictive alloys have also been put into practical use.
By the way, if the magnetostrictive element 2 has been given a compressive force in the direction of the expansion / contraction axis in advance, the amount of expansion / contraction displacement increases, but the amount of expansion / contraction displacement becomes maximum when the surface pressure due to the compression force is an appropriate value. If it is larger than this, the amount of expansion / contraction displacement is reduced. Therefore, generally, a method is employed in which a preload is applied to the magnetostrictive element 2 through the sealing member 6 using a compression spring 8 or the like to increase the amount of expansion / contraction displacement.

上記したような磁歪アクチュエータの構成は、特許文献１（特開平４−６０２８５号公報）、特許文献２（実開平６−９１６１号公報）、特許文献３（特開平５−２８２０４４号公報）、特許文献４（特開平５−３４４７６７号公報）等に開示されている。
しかしながら、これらの磁歪アクチュエータでは、アクチュエータを作動する際に発生するコイルのジュール熱や磁歪素子の過電流損失による発熱を起因として、磁歪素子が熱膨張する惧れがある。このためサブミクロン、ナノメートルオーダでの位置決めを行う際に問題となる。この問題を解消するために特許文献２ではコイルと磁歪部材の間に冷却空間を形成し、該冷却空間を大気に開放させてコイルにて発生する熱をケーシング外に放出させる構成を提案している。また、特許文献３でもケーシングに放熱孔を形成して熱を放出する構成が開示されている。 The configuration of the magnetostrictive actuator as described above is disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 4-60285), Patent Document 2 (Japanese Utility Model Laid-Open No. 6-9161), Patent Document 3 (Japanese Patent Laid-Open No. 5-282444), Patent It is disclosed in Document 4 (Japanese Patent Laid-Open No. 5-344767).
However, in these magnetostrictive actuators, there is a concern that the magnetostrictive element may thermally expand due to the Joule heat of the coil generated when the actuator is operated and the heat generation due to the overcurrent loss of the magnetostrictive element. For this reason, it becomes a problem when positioning on the order of submicron and nanometer. In order to solve this problem, Patent Document 2 proposes a configuration in which a cooling space is formed between the coil and the magnetostrictive member, and the cooling space is opened to the atmosphere so that the heat generated in the coil is released outside the casing. Yes. Patent Document 3 also discloses a configuration in which heat is released by forming a heat radiation hole in the casing.

特開平４−６０２８５号公報Japanese Patent Laid-Open No. 4-60285 実開平６−９１６１号公報Japanese Utility Model Publication No. 6-9161 特開平５−２８２０４４号公報Japanese Patent Application Laid-Open No. 5-282044 特開平５−３４４７６７号公報JP-A-5-344767

上記したような従来の磁歪アクチュエータでは、磁歪素子や可動軸からなる可動部材を支持する際に、該可動部材と固定部材とが微小間隙を介して接するようにしたすべり軸受方式を採用している。しかし、このような支持方法は軸と案内支持部材との間に固体摩擦抵抗を生じてしまい、スムーズで応答性の良い制御を行えないという問題があった。尚、特許文献４では静圧型エアーベアリングの構成が開示されているが、これはエアーベアリング自体に磁歪素子を使用してエアーベアリングのギャップを磁歪素子により制御することを目的としており、本発明の目的とは異なるものである。
また、磁歪素子の熱膨張の問題に対しては、特許文献２、３に記載される冷却機構が有効であるが、何れの場合もケーシング内に冷却空間を形成して、ケーシングに設けられた孔から外部に熱を放出する構成としており、この構成では冷却空間を冷却用流体が円滑に流れない場合には効率的に冷却が行われない惧れがある。
従って本発明においては、磁歪アクチュエータを作動する際に発生するコイルのジュール熱や磁歪素子の渦電流損失による発熱を起因とした磁歪素子の熱膨張変形を解消するとともに、可動部材と固定部材との非接触駆動が可能であり、スムーズで応答性の良い制御を可能とした磁歪アクチュエータを提供することを目的とする。 In the conventional magnetostrictive actuator as described above, when a movable member composed of a magnetostrictive element or a movable shaft is supported, a slide bearing system is adopted in which the movable member and the fixed member are in contact with each other through a minute gap. . However, such a support method has a problem that solid friction resistance is generated between the shaft and the guide support member, so that smooth and responsive control cannot be performed. In addition, although the structure of the static pressure type air bearing is disclosed by patent document 4, this aims at controlling the gap of an air bearing by a magnetostrictive element using a magnetostrictive element in the air bearing itself, and this invention. It is different from the purpose.
Moreover, although the cooling mechanism described in Patent Documents 2 and 3 is effective for the problem of thermal expansion of the magnetostrictive element, in any case, a cooling space is formed in the casing and the cooling mechanism is provided in the casing. The configuration is such that heat is released from the hole to the outside. In this configuration, if the cooling fluid does not flow smoothly through the cooling space, there is a possibility that the cooling will not be performed efficiently.
Therefore, in the present invention, the thermal expansion deformation of the magnetostrictive element due to the Joule heat of the coil generated when the magnetostrictive actuator is operated and the heat generation due to the eddy current loss of the magnetostrictive element is eliminated, and the movable member and the fixed member are An object of the present invention is to provide a magnetostrictive actuator capable of non-contact driving and capable of smooth and responsive control.

そこで、本発明はかかる課題を解決するために、磁歪を有する磁性体を含む変位発生手段と、該変位発生手段に磁界を印加するための磁界印加手段と、前記変位発生手段と前記磁界印加手段を収納するケーシングと、該ケーシングの少なくとも一部が前記変位発生手段とともに閉磁気回路を構成する磁気回路機構とを具備した磁歪アクチュエータにおいて、
前記変位発生手段の少なくとも一部を可動軸で形成するとともに、該可動軸を囲繞する囲繞部材との間にリング状間隙を設け、前記囲繞部材に前記リング状間隙へ開口する流体孔を設けて流体軸受を形成したことを特徴とする。
本発明によれば、変位発生手段の一部材である可動軸と、該可動軸を囲繞する固定された囲繞部材との間において流体を用いた軸受を形成することにより、可動軸と囲繞部材との非接触駆動が可能となり、スムーズで応答性の良い制御が可能となる。また、流体軸受が、囲繞部材の流体孔からリング状間隙に向けて流体を噴出させ可動軸に衝突させる構成であるため、簡単な構成で以って流体軸受を形成することができるとともに、衝突流により可動軸を効果的に冷却することが可能である。 Therefore, in order to solve the problem, the present invention provides a displacement generating means including a magnetic body having magnetostriction, a magnetic field applying means for applying a magnetic field to the displacement generating means, the displacement generating means, and the magnetic field applying means. A magnetostrictive actuator comprising: a casing that houses a magnetic circuit mechanism in which at least a part of the casing forms a closed magnetic circuit together with the displacement generating unit;
At least a part of the displacement generating means is formed by a movable shaft, a ring-shaped gap is provided between the movable shaft and the surrounding member surrounding the movable shaft, and a fluid hole is provided in the surrounding member to open to the ring-shaped gap. A hydrodynamic bearing is formed.
According to the present invention, the movable shaft and the surrounding member are formed by forming the bearing using the fluid between the movable shaft that is one member of the displacement generating means and the fixed surrounding member that surrounds the movable shaft. Non-contact driving is possible, and smooth and responsive control is possible. In addition, since the fluid bearing is configured to eject fluid from the fluid hole of the surrounding member toward the ring-shaped gap and collide with the movable shaft, the fluid bearing can be formed with a simple configuration, The movable shaft can be effectively cooled by the flow.

また、前記リング状間隙の開口面積が前記流体孔の開口面積より大であることを特徴とする。これにより、流体孔から噴出する流体の一部が円滑にケーシング内に流入し、また流体の噴出圧により確実に流体軸受を形成することが可能である。
さらに、前記流体孔がリング状間隙の軸対称位置に複数設けられた流体孔群であることを特徴とする。このように、複数の流体孔からなる流体孔群を軸対称位置に設けることによって、可動軸の外周囲に均一に流体が噴出し、可動軸の振動を抑制することが可能である。
さらにまた、前記囲繞部材が磁気回路機構部材であることを特徴とする。これにより、囲繞部材と変位発生部材とケーシングとにより磁気回路機構が構成されることとなり、ケーシング内部に冷却用の空間を設けた場合においても閉磁気回路を確実に形成することが可能である。 Further, the opening area of the ring-shaped gap is larger than the opening area of the fluid hole. Thereby, a part of the fluid ejected from the fluid hole smoothly flows into the casing, and the fluid bearing can be reliably formed by the fluid ejection pressure.
Furthermore, the fluid hole is a fluid hole group provided in a plurality at axially symmetrical positions of the ring-shaped gap. As described above, by providing a fluid hole group including a plurality of fluid holes in the axially symmetric position, it is possible to uniformly eject the fluid around the outer periphery of the movable shaft and to suppress the vibration of the movable shaft.
Furthermore, the surrounding member is a magnetic circuit mechanism member. As a result, a magnetic circuit mechanism is configured by the surrounding member, the displacement generating member, and the casing, and a closed magnetic circuit can be reliably formed even when a cooling space is provided inside the casing.

また、前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、該第１の空間と第２の空間の少なくとも何れか一方に偏流発生手段が設けられ、夫々の空間に均等に流体が通流するようにしたことを特徴とする。
本発明によれば、磁界印加手段であるコイル及び変位発生手段である磁歪素子の両方を効果的に冷却できる構造となるため、磁歪素子の熱膨張を防ぎ位置決め制御性の向上が図れる。 A first space formed between the displacement generating unit and the magnetic field applying unit; and a second space formed between the magnetic field applying unit and the casing. The drift generating means is provided in at least one of the two spaces so that the fluid flows evenly through each of the spaces.
According to the present invention, since both the coil as the magnetic field applying means and the magnetostrictive element as the displacement generating means can be effectively cooled, thermal expansion of the magnetostrictive element can be prevented and positioning controllability can be improved.

また、前記磁界印加手段が前記変位発生手段の周囲を取囲むごとく設けられるとともに該変位発生手段に封じ部材が固定され、該封じ部材と前記ケーシングとの間に前記流体孔からの流体が供給される流体溝が設けられた磁歪アクチュエータであって、前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、これらの２つの空間が前記流体溝に連通するとともに、前記第１の空間の半径方向幅が前記第２の空間の半径方向幅よりも大となるようにしたことを特徴とする。
本発明によれば、流体溝から直線状に連通する第１の空間より、流体溝から屈曲して連通する第２の空間の半径方向幅を大とすることにより、第２の空間への流体の流れ難さが改善され２つの空間の流体流れがほぼ均等となり、磁界印加手段と変位発生手段の両方を効果的に冷却可能となる。 Further, the magnetic field applying means is provided so as to surround the displacement generating means, and a sealing member is fixed to the displacement generating means, and fluid from the fluid hole is supplied between the sealing member and the casing. A magnetostrictive actuator provided with a fluid groove, a first space formed between the displacement generating means and the magnetic field applying means, and a second space formed between the magnetic field applying means and the casing. A space is provided, and these two spaces communicate with the fluid groove, and the radial width of the first space is larger than the radial width of the second space. .
According to the present invention, by increasing the radial width of the second space that is bent and communicated with the fluid groove from the first space that communicates linearly with the fluid groove, the fluid into the second space is obtained. Thus, the flow of fluid in the two spaces is almost uniform, and both the magnetic field applying means and the displacement generating means can be effectively cooled.

また、前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、該第１の空間と第２の空間の略中間位置に流体を供給する流体溝が設けられたことを特徴とする。
本発明によれば、磁界印加手段と変位発生手段の略中間位置に流体溝を設けることにより、２つの空間に通流する流体の流れがほぼ均等となり、磁界印加手段と変位発生手段の両方を効果的に冷却可能となる。 A first space formed between the displacement generating unit and the magnetic field applying unit; and a second space formed between the magnetic field applying unit and the casing. The present invention is characterized in that a fluid groove for supplying a fluid is provided at a substantially intermediate position between the two spaces.
According to the present invention, by providing the fluid groove at a substantially intermediate position between the magnetic field applying means and the displacement generating means, the flow of fluid flowing through the two spaces becomes substantially equal, and both the magnetic field applying means and the displacement generating means are It becomes possible to cool effectively.

さらに、前記磁気回路機構が、前記ケーシングと、前記変位発生手段と、該変位発生手段に固定された封じ部材と、前記ケーシングに固定され流体が通流する流体溝を介して前記封じ部材の延長線上に配設されたハウジングとから構成される場合に、前記ハウジングの厚さが前記変位発生手段の変位許容量以上の厚さとなるようにしたことを特徴とする。これにより、変位発生手段とともに封じ部材が変位した場合においても、ハウジングが変位許容量以上の厚さを有することから閉磁気回路を確実に形成することができる。
さらにまた、前記囲繞部材に対して前記磁界印加手段を挟んで反対側に位置するケーシング部位に流体排出孔を設けたことを特徴とする。これにより、囲繞部材に形成された流体孔より流入した流体が、発熱部位である磁界印加手段を通過した後に流体排出孔より外部へ排出するため、発熱部位の円滑な冷却が可能となり、磁歪素子の熱膨張の低減が図れる。 Further, the magnetic circuit mechanism includes the casing, the displacement generating means, a sealing member fixed to the displacement generating means, and an extension of the sealing member through a fluid groove that is fixed to the casing and through which a fluid flows. In the case where the housing is arranged on a line, the thickness of the housing is equal to or greater than the allowable displacement of the displacement generating means. As a result, even when the sealing member is displaced together with the displacement generating means, the closed magnetic circuit can be reliably formed because the housing has a thickness equal to or greater than the allowable displacement.
Furthermore, a fluid discharge hole is provided in a casing part located on the opposite side of the surrounding member with the magnetic field applying means interposed therebetween. As a result, the fluid flowing in from the fluid hole formed in the surrounding member is discharged to the outside from the fluid discharge hole after passing through the magnetic field applying means that is the heat generating part, so that the heat generating part can be cooled smoothly, and the magnetostrictive element The thermal expansion can be reduced.

以上記載のごとく本発明によれば、可動部材と固定部材が非接触となる流体軸受を備えた構成としたため、磁歪アクチュエータの伸縮にともなう固体摩擦の影響を受けることなく応答性を維持でき、制御性の向上が図れる。また、変位発生手段及び磁界印加手段を効果的に冷却できる構成としたため、磁歪素子の熱膨張変形を防止することができ、より一層の制御性向上が期待できる。   As described above, according to the present invention, since the movable member and the fixed member are provided with the fluid bearing in which the movable member and the fixed member are not in contact with each other, the responsiveness can be maintained without being affected by the solid friction accompanying the expansion and contraction of the magnetostrictive actuator. Can improve the performance. In addition, since the displacement generating means and the magnetic field applying means can be effectively cooled, thermal expansion deformation of the magnetostrictive element can be prevented, and further controllability can be expected.

以下、図面を参照して本発明の好適な実施例を例示的に詳しく説明する。但しこの実施例に記載されている構成部品の寸法、材質、形状、その相対的配置等は特に特定的な記載がない限りは、この発明の範囲をそれに限定する趣旨ではなく、単なる説明例に過ぎない。
図１は本発明の実施例１に係る磁歪アクチュエータの断面図、図２は図１の空気軸受の変形例を示す要部断面図、図３は本発明の実施例２に係る磁歪アクチュエータの断面図である。 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
1 is a cross-sectional view of a magnetostrictive actuator according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view of a principal part showing a modification of the air bearing of FIG. 1, and FIG. 3 is a cross-section of the magnetostrictive actuator according to the second embodiment of the present invention. FIG.

図１に本発明の実施例１に係る磁歪アクチュエータの断面図を示す。本実施例１において磁歪アクチュエータは、ケーシング１と、該ケーシング１内に収容された変位発生部及び磁界印加部と、ケーシング１の少なくとも一部と前記変位発生部とともに閉磁気回路を構成する磁気回路機構と、を主要構成とする。
ケーシング１は純鉄、パーマロイなどの高透磁率材により構成されている。
変位発生部は、磁歪素子２と、該磁歪素子２の軸方向の一端側に連結された可動軸７と、該可動軸７に固定された封じ部材７と、から構成されている。磁歪素子２は磁歪量が大きく、磁気異方性定数がゼロに近いＴｂ（テルビウム）Ｄｙ（ジスプロシウム）Ｆｅ（鉄）などが好ましい。磁歪素子２に予圧を与える場合は、ケーシング１内面と封じ部材７の間に圧縮ばね８を介装する。このとき、圧縮ばね８の負荷量は１０×１０６Ｎ／ｍ２程度が好ましい。 FIG. 1 shows a cross-sectional view of a magnetostrictive actuator according to Embodiment 1 of the present invention. In the first embodiment, the magnetostrictive actuator includes a casing 1, a displacement generation unit and a magnetic field application unit housed in the casing 1, a magnetic circuit that forms a closed magnetic circuit together with at least a part of the casing 1 and the displacement generation unit. The mechanism is the main component.
The casing 1 is made of a high permeability material such as pure iron or permalloy.
The displacement generating unit includes a magnetostrictive element 2, a movable shaft 7 connected to one end side in the axial direction of the magnetostrictive element 2, and a sealing member 7 fixed to the movable shaft 7. The magnetostrictive element 2 is preferably Tb (terbium) Dy (dysprosium) Fe (iron) or the like having a large magnetostriction amount and a magnetic anisotropy constant close to zero. When applying a preload to the magnetostrictive element 2, a compression spring 8 is interposed between the inner surface of the casing 1 and the sealing member 7. At this time, the load amount of the compression spring 8 is preferably about 10 × 10 6 N / m 2 .

磁界印加部は、磁歪素子２に対して駆動方向に磁界を印加するコイル３と、該コイル３を固定するコイルボビン４と、磁歪素子２の両端側に配置され磁気バイアスを印加する永久磁石５とによって構成される。コイル３は磁歪素子２を中心として該磁歪素子２の一端側から多端側に亘って所定の空隙をあけて配置された多層一様巻き構造になっており、該コイル３にて形成した磁界によって磁歪素子２及び可動軸７を変位させる。コイルボビン４は非磁性材料である樹脂やアルミニウムで形成されている。
磁気回路機構は、ケーシング１、磁歪素子２、永久磁石５、可動軸７からなり、これらがコイル３による閉磁気回路を構成している。この構成では、可動軸７を囲繞する囲繞部材、即ち可動軸７周囲のケーシング１も磁気回路機構の一部となる。
また別の磁気回路機構として、ケーシング１、磁歪素子２、永久磁石５、封じ部材６からなる閉磁気回路とすることもできる。この場合、可動軸７を囲繞する囲繞部材は磁気回路機構に該当しない。 The magnetic field applying unit includes a coil 3 that applies a magnetic field in the driving direction to the magnetostrictive element 2, a coil bobbin 4 that fixes the coil 3, and a permanent magnet 5 that is disposed on both ends of the magnetostrictive element 2 and applies a magnetic bias. Consists of. The coil 3 has a multilayered uniform winding structure with a predetermined gap from one end side to the other end side of the magnetostrictive element 2 around the magnetostrictive element 2, and the magnetic field formed by the coil 3 The magnetostrictive element 2 and the movable shaft 7 are displaced. The coil bobbin 4 is made of resin or aluminum which is a nonmagnetic material.
The magnetic circuit mechanism includes a casing 1, a magnetostrictive element 2, a permanent magnet 5, and a movable shaft 7, and these constitute a closed magnetic circuit by the coil 3. In this configuration, the surrounding member surrounding the movable shaft 7, that is, the casing 1 around the movable shaft 7 also becomes a part of the magnetic circuit mechanism.
As another magnetic circuit mechanism, a closed magnetic circuit including the casing 1, the magnetostrictive element 2, the permanent magnet 5, and the sealing member 6 can be used. In this case, the surrounding member surrounding the movable shaft 7 does not correspond to the magnetic circuit mechanism.

また、本実施例の特徴的な構成として、可動軸７の軸受に流体軸受を用いた構成としている。尚、本実施例では流体軸受として、流体に圧縮空気を用いた空気軸受につき説明するが、これに限定されるものではなく他の流体を用いる構成としてもよい。
空気軸受は、可動軸７と該可動軸７を囲繞するケーシング１との間に形成されたリング状間隙１０に設けられる。リング状間隙１０に対面するケーシング面には、該リング状間隙１０に開口する空気孔が設けられている。またケーシング１内には該空気孔に連通する空気供給路９が設けられている。圧縮空気は、空気供給路９を通流して空気孔よりリング状間隙１０に噴出し、可動軸７に略直角方向に衝突して該可動軸７を非接触にて支持するようになっている。空気孔は、圧縮空気が可動軸７の外周囲に均一に噴出するように構成される。該空気孔が複数設けられる場合には、可動軸７に対して軸対称に配置されることが好ましい。さらに、本構成において、リング状間隙１０の開口面積が空気孔の開口面積より大きくなるようにする。これにより、流体孔から噴出する流体の一部が円滑にケーシング１内に流入し、また流体の噴出圧により確実に流体軸受を形成することが可能となる。 As a characteristic configuration of the present embodiment, a fluid bearing is used as the bearing of the movable shaft 7. In the present embodiment, the fluid bearing is described as an air bearing using compressed air as a fluid. However, the present invention is not limited to this, and another fluid may be used.
The air bearing is provided in a ring-shaped gap 10 formed between the movable shaft 7 and the casing 1 surrounding the movable shaft 7. An air hole that opens to the ring-shaped gap 10 is provided on the casing surface facing the ring-shaped gap 10. An air supply path 9 communicating with the air hole is provided in the casing 1. Compressed air flows through the air supply path 9 and is ejected from the air hole to the ring-shaped gap 10 so as to collide with the movable shaft 7 in a substantially perpendicular direction to support the movable shaft 7 in a non-contact manner. . The air hole is configured so that the compressed air is uniformly ejected to the outer periphery of the movable shaft 7. When a plurality of the air holes are provided, it is preferable that the air holes are arranged symmetrically with respect to the movable shaft 7. Further, in this configuration, the opening area of the ring-shaped gap 10 is made larger than the opening area of the air holes. As a result, a part of the fluid ejected from the fluid hole smoothly flows into the casing 1, and the fluid bearing can be reliably formed by the fluid ejection pressure.

空気軸受は、流体流れが層流であっても乱流であってもよいが、層流とした場合には可動軸７が振動や騒音を起こすことなく、制御性を高めることができる。
また、空気軸受は図２に示されるように、可動軸７の外周囲に螺旋状溝７ａを設けて、該可動軸７に衝突した圧縮空気が旋回するようにしてもよい。これにより、可動軸７へ均等な空気圧が付与され、空気軸受の振動やぶれを防ぎ、安定して可動軸７を支持することが可能となる。さらにまた、ケーシング１に設けられた空気孔に絞りを設けてもよい。空気軸受における絞りは、バランスを考慮したものであればその種類、数を規定しない。絞りの例としては、自成絞り、オリフィス絞り、多孔質絞り等が挙げられるが、特に多孔性焼結体等により形成した多孔絞りが好ましく、これにより圧縮空気を可動軸７に均一に噴出させることができる。 In the air bearing, the fluid flow may be laminar or turbulent, but in the case of laminar flow, the controllability can be improved without causing the movable shaft 7 to vibrate or noise.
As shown in FIG. 2, the air bearing may be provided with a spiral groove 7 a on the outer periphery of the movable shaft 7 so that the compressed air that has collided with the movable shaft 7 swirls. Thereby, an even air pressure is applied to the movable shaft 7, and vibration and shaking of the air bearing can be prevented and the movable shaft 7 can be stably supported. Furthermore, a throttle may be provided in the air hole provided in the casing 1. The type and number of throttles in the air bearing are not specified as long as balance is taken into consideration. Examples of the restriction include a self-contained restriction, an orifice restriction, a porous restriction, and the like, but a porous restriction formed by a porous sintered body or the like is particularly preferable, whereby compressed air is uniformly ejected onto the movable shaft 7. be able to.

さらに本実施例は、磁歪アクチュエータを作動する際に発生するコイル３のジュール熱や磁歪素子２の渦電流損失による発熱を起因とした熱膨張変形を解消する構成を有する。
ここで、一例として磁歪素子の全長Ｌに対し、α／℃程度の線膨張係数を有する磁歪素子２を用いた場合、磁歪素子２の周囲の温度がｔ℃上昇すると、磁歪素子２はＬ×α×ｔだけ熱膨張することになる。一般的に磁歪素子２は鉄系材料が含まれているために熱膨張係数αが大きい。本実施例では、この熱膨張対策として、流体によってコイル３と磁歪素子２を冷却する冷却機構を有している。 Furthermore, the present embodiment has a configuration that eliminates thermal expansion deformation caused by Joule heat of the coil 3 generated when the magnetostrictive actuator is operated and heat generation due to eddy current loss of the magnetostrictive element 2.
Here, as an example, when the magnetostrictive element 2 having a linear expansion coefficient of about α / ° C. is used with respect to the total length L of the magnetostrictive element, when the temperature around the magnetostrictive element 2 increases by t ° C., the magnetostrictive element 2 becomes L × Thermal expansion will occur by α × t. In general, the magnetostrictive element 2 has a large thermal expansion coefficient α because it contains an iron-based material. In the present embodiment, as a countermeasure against this thermal expansion, a cooling mechanism for cooling the coil 3 and the magnetostrictive element 2 with a fluid is provided.

冷却機構は、前記空気孔より流入する圧縮空気が、コイル３及び磁歪素子２の少なくとも何れか一方の表面を流れる空間と、圧縮空気が排出される空気排出孔１１からなる。
好ましくは、コイル３（コイルボビン４）と磁歪素子２の間の第１の空間と、コイル３とケーシング１の間の第２の空間を設け、この両方の空間の経路ＡとＢに空気が通流するように構成する。さらに好ましくは、空気排出孔１１は空気孔に対してコイル３を挟んで反対側のケーシング部位に設ける。
空気供給路９を通って空気孔よりリング状間隙１０に噴出した空気の少なくとも一部は、ケーシング１と封じ部材６の隙間である空気溝１３から第１の空間及び第２の空間に流入する。該流入した空気は、経路ＡとＢを通流して空気排出孔１１より外部へ排出される。
本構成とすることにより、ケーシング内の空気の流れが得られ、コイル３及び磁歪素子２の高い冷却効果が得られる。従って、コイル３のジュール熱や磁歪素子２の渦電流損失による発熱を起因とした磁歪素子２の熱膨張変形を解消することができ、磁歪アクチュエータにおける制御性の向上が図れる。 The cooling mechanism includes a space in which compressed air flowing in from the air holes flows on the surface of at least one of the coil 3 and the magnetostrictive element 2, and an air discharge hole 11 through which the compressed air is discharged.
Preferably, a first space between the coil 3 (coil bobbin 4) and the magnetostrictive element 2 and a second space between the coil 3 and the casing 1 are provided, and air passes through paths A and B in both spaces. Configure to flow. More preferably, the air discharge hole 11 is provided in a casing part on the opposite side of the coil 3 with respect to the air hole.
At least part of the air jetted from the air hole into the ring-shaped gap 10 through the air supply path 9 flows into the first space and the second space from the air groove 13 which is a gap between the casing 1 and the sealing member 6. . The inflowing air flows through the paths A and B and is discharged from the air discharge hole 11 to the outside.
By setting it as this structure, the flow of the air in a casing is obtained and the high cooling effect of the coil 3 and the magnetostrictive element 2 is acquired. Therefore, the thermal expansion deformation of the magnetostrictive element 2 caused by Joule heat of the coil 3 or heat generation due to eddy current loss of the magnetostrictive element 2 can be eliminated, and controllability in the magnetostrictive actuator can be improved.

また、本実施例１において、コイル３（コイルボビン４）と磁歪素子２の間の第１の空間と、コイル３とケーシング１の間の第２の空間を設け、この両方の空間の経路ＡとＢに空気が通流するように構成した場合に、少なくとも何れかの空間に偏流発生手段を配設することが好適である。
偏流発生手段は、経路Ａ及び／又は経路Ｂ上に設けられ、経路ＡとＢに空気を均等に通流させる機能を有する。偏流発生手段としては、空気流量が大きい側の経路にオリフィスを設けて２つの経路の空気流量を均等にする手段、経路Ａ及び／又は経路Ｂ上に強制的に空気流れを決定する強制流れ板を設けて２つの経路の空気流量を均等にする手段、或いは空気排出孔１１からの空気引き出し量を調整して２つの経路の空気流量を均等にする手段などが挙げられる。 In the first embodiment, a first space between the coil 3 (coil bobbin 4) and the magnetostrictive element 2 and a second space between the coil 3 and the casing 1 are provided. When air is passed through B, it is preferable that the drift generating means is disposed in at least one of the spaces.
The drift generation means is provided on the path A and / or the path B, and has a function of allowing air to flow evenly through the paths A and B. As the uneven flow generation means, an orifice is provided in a path on the side where the air flow rate is large to equalize the air flow rate of the two paths, a forced flow plate for forcibly determining the air flow on the path A and / or the path B And means for equalizing the air flow rates of the two paths, or means for adjusting the amount of air drawn from the air discharge hole 11 to equalize the air flow rates of the two paths.

さらに、本実施例１において、コイル３（コイルボビン４）と磁歪素子２の間の第１の空間と、コイル３とケーシング１の間の第２の空間を設け、この両方の空間にて形成される経路ＡとＢに空気が通流するように構成した場合に、第１の空間の半径方向幅が第２の空間の半径方向幅よりも大となるように夫々を配置することが好適である。即ち、コイル３（コイルボビン４）と磁歪素子２の離間距離が、コイル３とケーシング１の離間距離よりも大となるようにする。これにより経路Ｂへの流体の流れ難さが改善され経路ＡとＢに流体が均等に通流し、コイル３と磁歪素子２の両方を効果的に冷却可能となる。   Further, in the first embodiment, a first space between the coil 3 (coil bobbin 4) and the magnetostrictive element 2 and a second space between the coil 3 and the casing 1 are provided and formed in both spaces. It is preferable to arrange each of the first space and the second space so that the radial width of the first space is larger than the radial width of the second space. is there. That is, the separation distance between the coil 3 (coil bobbin 4) and the magnetostrictive element 2 is made larger than the separation distance between the coil 3 and the casing 1. As a result, the difficulty in flowing the fluid to the path B is improved, the fluid flows evenly through the paths A and B, and both the coil 3 and the magnetostrictive element 2 can be effectively cooled.

さらに、本実施例１では、経路ＡとＢの流体流れが層流となるように、レイノルズ数が２０００〜３０００となるように設定することが好ましい。レイノルズ数ＲｅはＲｅ＝（ρｖｄ／μ）で表すことができる。
ここでρ：流体の密度ｖ：隙間の流速、ｄ：隙間の直径、μ：流体の粘度である。ここでレイノルズ数から分子が規則正しく一定の層をなして流れている層流から無数の不規則な渦をともなう乱流の変わり目の目安となる臨界レイノルズは約２３２０になることが分かっている。尚、この臨界レイノルズ数はあくまで目安に過ぎず、実際には２０００〜３０００程度のばらつきがあると考えられる。本実施例では流体として圧縮空気を用いるが空間内の流速は圧縮圧力がパラメータとなり、空間の長さは設計により既知であるので、レイノルズ数の概算は計算によって求められる。レイノルズ数を上記範囲内に設定するためには、空気圧若しくは空間容積を調整するとよい。 Further, in the first embodiment, it is preferable to set the Reynolds number to 2000 to 3000 so that the fluid flows in the paths A and B are laminar. The Reynolds number Re can be expressed as Re = (ρvd / μ).
Here, ρ: fluid density v: gap flow velocity, d: gap diameter, μ: fluid viscosity. Here, it is known from the Reynolds number that the critical Reynolds, which is a measure of the transition of turbulent flow with innumerable irregular vortices from laminar flow in which molecules regularly flow in a constant layer, is about 2320. Note that this critical Reynolds number is only a guide, and it is considered that there is actually a variation of about 2000 to 3000. In this embodiment, compressed air is used as a fluid. Since the flow velocity in the space is a parameter of the compression pressure and the length of the space is known by design, the Reynolds number is roughly calculated. In order to set the Reynolds number within the above range, the air pressure or the space volume may be adjusted.

図３に本実施例２に係る磁歪アクチュエータの断面図を示す。尚、本実施例２において前記実施例１と同様の構成についてはその詳細な説明を省略する。
本実施例２において磁歪アクチュエータは、ケーシング１と、該ケーシング１内に収容された変位発生部及び磁界印加部と、ケーシング１の少なくとも一部と前記変位発生部とともに閉磁気回路を構成する磁気回路機構と、を主要構成とする。変位発生部は、磁歪素子２と、該磁歪素子２の軸方向の一端側に連結された可動軸７と、該可動軸７に固定された封じ部材７と、から構成されている。磁歪素子２に予圧を与える場合は、ケーシング１内面と封じ部材７の間に圧縮ばね８を介装する。磁界印加部は、磁歪素子２に対して駆動方向に磁界を印加するコイル３と、該コイル３を固定するコイルボビン４と、磁歪素子２の両端側に配置される永久磁石５とによって構成される。磁気回路機構は、ケーシング１、磁歪素子２、永久磁石５、可動軸７からなり、これらがコイル３による閉磁気回路を構成している。即ち、可動軸７を囲繞する囲繞部材も磁気回路機構の一部となる。また別の磁気回路機構として、ケーシング１、磁歪素子２、永久磁石５、封じ部材６からなる閉磁気回路とすることもできる。この場合、可動軸７を囲繞する囲繞部材は磁気回路機構に該当しない。 FIG. 3 is a sectional view of the magnetostrictive actuator according to the second embodiment. In the second embodiment, detailed description of the same configuration as that of the first embodiment is omitted.
In the second embodiment, the magnetostrictive actuator includes a casing 1, a displacement generation unit and a magnetic field application unit accommodated in the casing 1, a magnetic circuit that forms a closed magnetic circuit together with at least a part of the casing 1 and the displacement generation unit. The mechanism is the main component. The displacement generating unit includes a magnetostrictive element 2, a movable shaft 7 connected to one end side in the axial direction of the magnetostrictive element 2, and a sealing member 7 fixed to the movable shaft 7. When applying a preload to the magnetostrictive element 2, a compression spring 8 is interposed between the inner surface of the casing 1 and the sealing member 7. The magnetic field application unit includes a coil 3 that applies a magnetic field in the driving direction to the magnetostrictive element 2, a coil bobbin 4 that fixes the coil 3, and a permanent magnet 5 that is disposed on both ends of the magnetostrictive element 2. . The magnetic circuit mechanism includes a casing 1, a magnetostrictive element 2, a permanent magnet 5, and a movable shaft 7, and these constitute a closed magnetic circuit by the coil 3. That is, the surrounding member surrounding the movable shaft 7 is also a part of the magnetic circuit mechanism. As another magnetic circuit mechanism, a closed magnetic circuit including the casing 1, the magnetostrictive element 2, the permanent magnet 5, and the sealing member 6 can be used. In this case, the surrounding member surrounding the movable shaft 7 does not correspond to the magnetic circuit mechanism.

本実施例２の磁歪アクチュエータにおいても、実施例１と同様に空気軸受及び冷却機構を備える構成とする。
冷却機構は、空気孔より流入する圧縮空気が、コイル３及び磁歪素子２の少なくとも何れか一方の表面を流れる空間と、圧縮空気が排出される空気排出孔１１からなる。好ましくは、コイル３（コイルボビン４）と磁歪素子２の間の第１の空間と、コイル３とケーシング１の間の第２の空間を設け、この両方の空間の経路ＡとＢに空気が通流するように構成する。さらに好ましくは、空気排出孔１１は空気孔に対してコイル３を挟んで反対側のケーシング部位に設けられる。 The magnetostrictive actuator of the second embodiment is also configured to include an air bearing and a cooling mechanism as in the first embodiment.
The cooling mechanism includes a space in which compressed air flowing in from the air holes flows on at least one surface of the coil 3 and the magnetostrictive element 2 and an air discharge hole 11 from which the compressed air is discharged. Preferably, a first space between the coil 3 (coil bobbin 4) and the magnetostrictive element 2 and a second space between the coil 3 and the casing 1 are provided, and air passes through paths A and B in both spaces. Configure to flow. More preferably, the air discharge hole 11 is provided in a casing part on the opposite side of the coil 3 with respect to the air hole.

さらに本実施例２の特徴的な構成として、実施例１では空気が封じ部材６とケーシング１の間を通って経路ＡとＢに流入する構成であったが、本実施例２では封じ部材６を短くし、経路ＡとＢの略中間位置に空気を流入させる空気溝１３を設けた構成としている。
空気溝１３は、可動軸７に固定された封じ部材６と、ケーシングに固定されたハウジング１２により形成される。ハウジング１２は、空気溝１３を介して封じ部材６の延長線上に配設される。
このとき、磁界印加手段である磁歪素子２の直径と変位発生手段であるコイル３の直径の差分の約１／２となる部分に空気溝１３を位置させることが好ましく、これにより流体の流れが略均等に磁歪素子表面とコイル表面に流れるため、磁歪素子２の熱膨張の低減が図れる。
本構成により、経路Ａでは磁歪素子２とコイルボビン４の隙間を圧縮空気が流れ、磁歪素子２とコイルボビン４を冷却する。経路Ｂではコイル３表面の冷却を行う。このように、主な熱源であるコイル３のみならず磁歪素子２表面を直接冷却することで、効果の大きい熱膨張対策となっている。 Further, as a characteristic configuration of the second embodiment, in the first embodiment, air flows between the sealing member 6 and the casing 1 and flows into the paths A and B. In the second embodiment, the sealing member 6 is used. And an air groove 13 for allowing air to flow into a substantially middle position between the paths A and B is provided.
The air groove 13 is formed by a sealing member 6 fixed to the movable shaft 7 and a housing 12 fixed to the casing. The housing 12 is disposed on an extension line of the sealing member 6 through the air groove 13.
At this time, it is preferable to place the air groove 13 at a portion that is about ½ of the difference between the diameter of the magnetostrictive element 2 that is the magnetic field applying means and the diameter of the coil 3 that is the displacement generating means. Since the magnetostrictive element 2 and the coil surface flow almost uniformly, the thermal expansion of the magnetostrictive element 2 can be reduced.
With this configuration, in the path A, the compressed air flows through the gap between the magnetostrictive element 2 and the coil bobbin 4 to cool the magnetostrictive element 2 and the coil bobbin 4. In the path B, the surface of the coil 3 is cooled. Thus, by directly cooling not only the coil 3 which is the main heat source but also the surface of the magnetostrictive element 2, it is a highly effective thermal expansion countermeasure.

空気溝１３付近のギャップについて注目すると、永久磁石５−封じ部材６−ケーシング２−永久磁石５−磁歪素子２により閉磁気回路を形成する場合には、空気溝１３のギャップは磁気抵抗の観点からできるだけ狭くすることが望ましい。さらにこの場合において、ハウジング１２の厚みを封じ部材６の変位許容範囲の厚みと同等若しくはこの厚みより大きくすることが好適である。これにより、封じ部材６が可動軸７とともに変位した場合であっても、確実に閉磁気回路を保持することができる。尚、閉磁気回路を可動軸７−ケーシング１、若しくは封じ部材６−ハウジング１２−ケーシング１で形成する場合には、各部品において透磁率の大きい材料を用いれば、特に変位に伴う閉磁気回路の問題はない。   When attention is paid to the gap near the air groove 13, when the closed magnetic circuit is formed by the permanent magnet 5-sealing member 6-casing 2-permanent magnet 5-magnetostrictive element 2, the gap of the air groove 13 is from the viewpoint of magnetoresistance. It is desirable to make it as narrow as possible. Furthermore, in this case, it is preferable that the thickness of the housing 12 is equal to or larger than the thickness of the allowable displacement range of the sealing member 6. Thereby, even if it is a case where the sealing member 6 is displaced with the movable axis | shaft 7, a closed magnetic circuit can be hold | maintained reliably. When the closed magnetic circuit is formed of the movable shaft 7-casing 1 or the sealing member 6-housing 12-casing 1, if a material having a high magnetic permeability is used for each part, the closed magnetic circuit is particularly affected by the displacement. No problem.

本発明の実施例１に係る磁歪アクチュエータの断面図である。It is sectional drawing of the magnetostrictive actuator which concerns on Example 1 of this invention. 図１の空気軸受の変形例を示す要部断面図である。It is principal part sectional drawing which shows the modification of the air bearing of FIG. 本発明の実施例２に係る磁歪アクチュエータの断面図である。It is sectional drawing of the magnetostrictive actuator which concerns on Example 2 of this invention. 磁歪アクチュエータの特性を示すグラフである。It is a graph which shows the characteristic of a magnetostrictive actuator. バイアス磁界を印加した場合の磁歪アクチュエータの特性を示すグラフである。It is a graph which shows the characteristic of a magnetostriction actuator at the time of impressing a bias magnetic field. 従来の磁歪アクチュエータの断面図である。It is sectional drawing of the conventional magnetostrictive actuator.

符号の説明Explanation of symbols

１ ケーシング
２ 磁歪素子
３ コイル
４ コイルボビン
５ 永久磁石
６ 封じ部材
７ 可動軸
８ 圧縮ばね
９ 空気溝
１０ リング状間隙
１１ 空気排出孔
１２ ハウジング DESCRIPTION OF SYMBOLS 1 Casing 2 Magnetostrictive element 3 Coil 4 Coil bobbin 5 Permanent magnet 6 Sealing member 7 Movable shaft 8 Compression spring 9 Air groove 10 Ring-shaped gap 11 Air discharge hole 12 Housing

Claims (9)

磁歪を有する磁性体を含む変位発生手段と、該変位発生手段に磁界を印加するための磁界印加手段と、前記変位発生手段と前記磁界印加手段を収納するケーシングと、該ケーシングの少なくとも一部が前記変位発生手段とともに閉磁気回路を構成する磁気回路機構とを具備した磁歪アクチュエータにおいて、
前記変位発生手段の少なくとも一部を可動軸で形成するとともに、該可動軸を囲繞する囲繞部材との間にリング状間隙を設け、前記囲繞部材に前記リング状間隙へ開口する流体孔を設けて流体軸受を形成したことを特徴とする磁歪アクチュエータ。 A displacement generating means including a magnetic material having magnetostriction, a magnetic field applying means for applying a magnetic field to the displacement generating means, a casing for housing the displacement generating means and the magnetic field applying means, and at least a part of the casing. In a magnetostrictive actuator comprising a magnetic circuit mechanism that constitutes a closed magnetic circuit together with the displacement generating means,
At least a part of the displacement generating means is formed by a movable shaft, a ring-shaped gap is provided between the movable shaft and the surrounding member surrounding the movable shaft, and a fluid hole is provided in the surrounding member to open to the ring-shaped gap. A magnetostrictive actuator characterized by forming a fluid bearing. 前記リング状間隙の開口面積が前記流体孔の開口面積より大であることを特徴とする請求項１記載の磁歪アクチュエータ。   The magnetostrictive actuator according to claim 1, wherein an opening area of the ring-shaped gap is larger than an opening area of the fluid hole. 前記流体孔が前記リング状間隙の軸対称位置に複数設けられた流体孔群であることを特徴とする請求項１記載の磁歪アクチュエータ。   2. The magnetostrictive actuator according to claim 1, wherein the fluid hole is a group of fluid holes provided in a plurality of axially symmetrical positions of the ring-shaped gap. 前記囲繞部材が磁気回路機構部材であることを特徴とする請求項１記載の磁歪アクチュエータ。   The magnetostrictive actuator according to claim 1, wherein the surrounding member is a magnetic circuit mechanism member. 前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、該第１の空間と第２の空間の少なくとも何れか一方に偏流発生手段が設けられ、夫々の空間に均等に流体が通流するようにしたことを特徴とする請求項１記載の磁歪アクチュエータ。   A first space formed between the displacement generating means and the magnetic field applying means; and a second space formed between the magnetic field applying means and the casing, wherein the first space and the second space 2. The magnetostrictive actuator according to claim 1, wherein a drift generation means is provided in at least one of the spaces so that the fluid flows evenly through each of the spaces. 前記磁界印加手段が前記変位発生手段の周囲を取囲むごとく設けられるとともに該変位発生手段に封じ部材が固定され、該封じ部材と前記ケーシングとの間に前記流体孔からの流体が供給される流体溝が設けられた磁歪アクチュエータであって、前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、これらの２つの空間が前記流体溝に連通するとともに、前記第１の空間の半径方向幅が前記第２の空間の半径方向幅よりも大となるようにしたことを特徴とする請求項１記載の磁歪アクチュエータ。   A fluid in which the magnetic field applying means is provided so as to surround the displacement generating means, a sealing member is fixed to the displacement generating means, and fluid from the fluid hole is supplied between the sealing member and the casing A magnetostrictive actuator provided with a groove, comprising: a first space formed between the displacement generating means and the magnetic field applying means; and a second space formed between the magnetic field applying means and the casing. And the two spaces communicate with the fluid groove, and the radial width of the first space is larger than the radial width of the second space. The magnetostrictive actuator according to 1. 前記変位発生手段と前記磁界印加手段の間に形成された第１の空間と、前記磁界印加手段と前記ケーシングの間に形成された第２の空間を備え、該第１の空間と第２の空間の略中間位置に流体を供給する流体溝が設けられたことを特徴とする請求項１記載の磁歪アクチュエータ。   A first space formed between the displacement generating means and the magnetic field applying means; and a second space formed between the magnetic field applying means and the casing, wherein the first space and the second space The magnetostrictive actuator according to claim 1, wherein a fluid groove for supplying fluid is provided at a substantially intermediate position in the space. 前記磁気回路機構が、前記ケーシングと、前記変位発生手段と、該変位発生手段に固定された封じ部材と、前記ケーシングに固定され流体が通流する流体溝を介して前記封じ部材の延長線上に配設されたハウジングとから構成される場合に、前記ハウジングの厚さが前記変位発生手段の変位許容量以上の厚さとなるようにしたことを特徴とする請求項１記載の磁歪アクチュエータ。   The magnetic circuit mechanism is on an extension line of the sealing member via the casing, the displacement generating means, a sealing member fixed to the displacement generating means, and a fluid groove fixed to the casing and through which a fluid flows. 2. The magnetostrictive actuator according to claim 1, wherein the housing has a thickness equal to or greater than a displacement allowable amount of the displacement generating means when the housing is provided. 前記囲繞部材に対して前記磁界印加手段を挟んで反対側に位置するケーシング部位に流体排出孔を設けたことを特徴とする請求項１乃至８の何れかに記載の磁歪アクチュエータ。
9. The magnetostrictive actuator according to claim 1, wherein a fluid discharge hole is provided in a casing portion located on the opposite side of the surrounding member with the magnetic field applying means interposed therebetween.
JP2005314138A 2005-10-28 2005-10-28 Excitation distortion actuator Pending JP2007124812A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103196667A (en) * 2013-04-01 2013-07-10 中国北方发动机研究所(天津) Electromagnetism energizing connecting rod fatigue test bed
CN103888017A (en) * 2014-04-21 2014-06-25 北京航空航天大学 Magnetostrictive actuator and magnetostrictive actuator test platform
CN103904935A (en) * 2014-04-14 2014-07-02 浙江理工大学 Converse magnetostriction actuator and using method
JP2018504580A (en) * 2015-01-15 2018-02-15 浙江大学Ｚｈｅｊｉａｎｇ Ｕｎｉｖｅｒｓｉｔｙ 3D standard shaking table based on hydrostatic gas floating decoupling device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103196667A (en) * 2013-04-01 2013-07-10 中国北方发动机研究所(天津) Electromagnetism energizing connecting rod fatigue test bed
CN103904935A (en) * 2014-04-14 2014-07-02 浙江理工大学 Converse magnetostriction actuator and using method
CN103904935B (en) * 2014-04-14 2016-05-18 浙江理工大学 Converse magnetostriction driver and using method
CN103888017A (en) * 2014-04-21 2014-06-25 北京航空航天大学 Magnetostrictive actuator and magnetostrictive actuator test platform
JP2018504580A (en) * 2015-01-15 2018-02-15 浙江大学Ｚｈｅｊｉａｎｇ Ｕｎｉｖｅｒｓｉｔｙ 3D standard shaking table based on hydrostatic gas floating decoupling device

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