JPH03239172A

JPH03239172A - Ultrasonic motor

Info

Publication number: JPH03239172A
Application number: JP2035869A
Authority: JP
Inventors: Kazuma Suzuki; 数馬鈴木
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-02-16
Filing date: 1990-02-16
Publication date: 1991-10-24

Abstract

PURPOSE:To make a thin-type ultrasonic motor which produces a large output by adhering two piezoelectric elements on each face of a square board-shaped basic body which is provided with drivers on four corners and by moving objects to be moved linearly. CONSTITUTION:A basic body 1 is formed in the size in which it causes a compound resonance of bend and length modes at which both ends are in opposite phase when an ultrasonic electric signal is sent to piezoelectric elements 2a, 2b or 3a, 3b which are installed on the surface and on the back of the basic body 1 symmetrically about the center of the basic body 1. In such an operation of the basic body 1, objects to be moved which are adhered by pressure to drivers 4a-4d are adhered to and released from the drivers 4a, 4b and 4c, 4d repeatedly at the bend mode while being swung longitudinally at the length mode.

Description

【発明の詳細な説明】［産業上の利用分野］この発明は、超音波モータに関し、とりわけ、圧電素子
に超音波領域の電気信号を印訓して一軸アクチュエータ
として動作させる超音波モータに関するものである。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an ultrasonic motor, and more particularly to an ultrasonic motor that operates as a uniaxial actuator by imprinting electrical signals in the ultrasonic range onto a piezoelectric element. be.

［従来の技術］第３図〜第５図は特開昭６３−２８３４７３号公報に記
載された従来の超音波モータを示し、金属、セラミック
スなどの弾性体でなる直方体状の基体（５１）の上面に
駆動子（５３）が一体に突設されている。また、基体（
５１）の側面および下面には、基体（５１）をＸ方向に
屈曲させるための圧電素子（５２ｂ）、（５２ｃ）と、
Ｙ方向に屈曲させるための圧を素子（５２ａ）がそれぞ
れ固着されている。（５４ａ）、（５４ｂ）は取付穴、
（５５）は接続リード線である。[Prior Art] Figures 3 to 5 show a conventional ultrasonic motor described in Japanese Patent Application Laid-Open No. 63-283473, in which a rectangular parallelepiped base (51) made of an elastic body such as metal or ceramics is used. A driver element (53) is integrally provided on the upper surface. In addition, the base (
Piezoelectric elements (52b) and (52c) for bending the base body (51) in the X direction are provided on the side and bottom surfaces of 51),
Pressure elements (52a) for bending in the Y direction are fixed respectively. (54a) and (54b) are mounting holes,
(55) is a connecting lead wire.

以上の儒成により、超音波領域の電気信号を圧電素子（
５２ａ）と（５２ｂ）または（５２ａ）と（５２Ｃ）　
ｉｃ加えると、基体（５１）はＸ方向成分とＹ方向成分
の両方向に同時に屈曲する。したがって、基体（５１）
には、両者の合成でめるＥＦまたはＨＧ力方向振動が発
生する。駆動子（５３）には被移動体が圧接されており
、基体（５１）がＥＦ方向の合成振動を行うようにした
場合は、被移動体は第３図で右左に移動される。また、
ＨＧ力方向場合は、被移動体は左方に移動される。Due to the above-mentioned Confucianism, electrical signals in the ultrasonic range are transferred to piezoelectric elements (
52a) and (52b) or (52a) and (52C)
ic, the base body (51) bends simultaneously in both the X direction component and the Y direction component. Therefore, the base (51)
, an EF or HG force-direction vibration is generated by the combination of both. The object to be moved is pressed against the drive element (53), and when the base body (51) is made to perform synthetic vibration in the EF direction, the object to be moved is moved to the right and left in FIG. Also,
In the case of the HG force direction, the object to be moved is moved to the left.

かようにして、被移動体に互いに逆向きの直線移動を任
意に与えることができる。In this way, it is possible to arbitrarily apply linear movements in opposite directions to the objects to be moved.

［発明が解決しようとする課題］以上のような従来の超音波モータは、Ｘ方向、Ｙ方向の
２つの成分の圧電素子を、基体の別々の面にそれぞれ設
ける必要があるため、スペースファクタが悪く、したが
って出力が制限される。また、Ｘ１Ｙ方向の各共振周波
数を揃える必要から、薄形化が困難であった。[Problems to be Solved by the Invention] In the conventional ultrasonic motor as described above, the piezoelectric elements for the two components in the X direction and the Y direction must be provided on separate surfaces of the base, so the space factor is low. poor, and therefore output limited. In addition, it was difficult to make the device thinner because it was necessary to align each resonance frequency in the X1Y directions.

この発明は上記の課題を解決しようとするもので、大出
力化、薄形化を容易に達成できる超音波モータを得るこ
とを目的とするものである。The present invention is intended to solve the above-mentioned problems, and aims to provide an ultrasonic motor that can easily achieve high output and a thin design.

［課題を解決するだめの手段］この発明に係る超音波モータは、弾性体角板でなる基体
の表面の四隅に、被移動体が圧接係合する駆動子がそれ
ぞれ突設されている。この基体の表、裏面には互いに同
極に分極された圧′Ｉｔ素子が２個づつ固着されている
。超音波領域の電気信号は、一方の面の１つの圧電素子
と、これと基体中心対称の他方の面の１つの圧！素子に
印加され、基体に、両端が逆相になる厚み方向屈曲モー
ドと長さ方向伸縮モードの複合共振を生じさせる。[Means for Solving the Problems] In the ultrasonic motor according to the present invention, drive elements, with which the moving object is press-fitted, are protrudingly provided at the four corners of the surface of the base body made of an elastic rectangular plate. Two pressure 'It elements each polarized to the same polarity are fixed to the front and back surfaces of this base body. The electrical signal in the ultrasonic region is generated by the pressure of one piezoelectric element on one surface and one pressure on the other surface that is symmetrical to the center of the base! It is applied to the element and causes a composite resonance of a thickness direction bending mode and a length direction expansion/contraction mode in which both ends are in opposite phase to each other in the base body.

［作　用］この発明においては、被移動体が、基体の両端が逆相に
なる屈曲モードの振動に対応して、両端部の駆動子への
圧接、解放を繰返し、長さ方向モードの振動に起因して
、長手方向に蹴り出され、これにより被移動体は直線移
動される。[Function] In this invention, in response to vibrations in a bending mode in which both ends of the base body are in opposite phase, the object to be moved repeatedly presses and releases both ends of the drive element against the drive element, thereby generating vibrations in a longitudinal mode. Due to this, the object is kicked out in the longitudinal direction, and the object to be moved is thereby moved in a straight line.

［実施例コ第１図、第２図はこの発明の一実施例を示し、図におい
て、矩形板状の弾性体でなる基体（１）の表面には、四
隅に駆動子（４ａ）　（４ｂ）　（４Ｃ）　（ｔｄ）が
−体に突設されている。基体（１）の表、裏面には、同
極に分極された角板状の圧電素子（２ａ）　（２ｂ）と
（３ａ）　（３ｂ）がそれぞれ基体（１）の中心対称に
固着されている。中心部の貫通孔（１ａ）は取付用のも
のである。[Embodiment] Figures 1 and 2 show an embodiment of the present invention. In the figures, the surface of the base body (1) made of a rectangular plate-like elastic body has drive elements (4a) (4b) at the four corners. ) (4C) (td) is provided protruding from the - body. Square plate-shaped piezoelectric elements (2a) (2b) and (3a) (3b) polarized to the same polarity are fixed to the front and back surfaces of the base (1), respectively, symmetrically with the center of the base (1). . The through hole (1a) in the center is for attachment.

次に動作について説明する。基体（１）は、圧電素子（
２ａ）　（２ｂ）または（３ａ）　（３ｂ）によりバイ
モルフ挙動を示し、その両端が逆相になる屈曲モードと
長さ方向伸縮モードとを同時に発生することができる。Next, the operation will be explained. The base (1) includes a piezoelectric element (
2a) (2b) or (3a) (3b) exhibits bimorph behavior, and can simultaneously generate a bending mode and a longitudinal stretching mode in which both ends are in opposite phases.

この実施例では、基体（１）の衆、裏で基体（１）の中
心対称の圧電素子（２ａ）　（２ｂ）　または（３ａ）
　（３ｂ）に超音波電気信号を印加したとさ、第１図（
ｂ）　（Ｃ）　（ｄ）係に形成されている。基体（１）
のかかる動作により、駆動子（４ａ）〜（４ｄ）に圧接
さｎているスライダ（被移動体）は、屈曲モードにより
、駆動子（４ａ）（４ｂ）と（４ｃ）　（４ｄ）に圧接
、開放が繰返さｎ、長さモードに起因して長手方向へ振
られることになる。In this embodiment, piezoelectric elements (2a) (2b) or (3a) symmetrical to the center of the base body (1) on the back side of the base body (1)
When an ultrasonic electrical signal was applied to (3b), Fig. 1 (
b) (C) It is formed in section (d). Base (1)
Due to this operation, the slider (moved object) that is in pressure contact with the drive elements (4a) to (4d) is brought into pressure contact with the drive elements (4a), (4b), (4c), and (4d) due to the bending mode. As the opening is repeated, it will be swung in the longitudinal direction due to the length mode.

いま、表裏対称の圧電素子（２ａ）　（２ｂ）に′電気
信号が印加されて第１図（ａ）の左端が同図（ｂ）の破
線のような挙動に屈曲すると、駆動子（４ａ）　（４ｂ
）は今までの零点位置より上がるので、これに圧接され
ているスライダにますます圧接され、反対側の右肩は同
極の圧電素子（２ｂ）が下側に固着さＧているため、同
図（ｅ）の破線の挙動を呈し、駆動子（４Ｃ）（４ｄ）
は、今までの位置よｐ下がるので、これに圧接されてい
たスライダから離れる。この動作と同時に長手方向には
、圧電素子（２ａ）　（２ｂ）は同極のため同図（ｄ）
の破綴のように長さ方向に収縮することになる。そのた
め、駆動子（４ａ）　（４ｂ）に圧接しているスライダ
は同図（ａ）で右方に移動する。Now, when an electric signal is applied to the front and back symmetrical piezoelectric elements (2a) and (2b) and the left end of FIG. 1(a) bends as shown by the broken line in FIG. 1(b), the driver (4a) (4b
) rises from the previous zero point position, so it is further pressed against the slider that is in pressure contact with it, and the piezoelectric element (2b) of the same polarity is fixed to the bottom of the opposite right shoulder, so the same The driver (4C) (4d) exhibits the behavior shown by the broken line in figure (e).
is lowered by p than its previous position, so it separates from the slider that was pressed against it. At the same time as this operation, the piezoelectric elements (2a) and (2b) have the same polarity in the longitudinal direction, so the same figure (d)
It will shrink in the length direction like a broken book. Therefore, the slider that is in pressure contact with the drive elements (4a) (4b) moves to the right in FIG. 4(a).

次の半サイクルでは、上記の動作が反転するので、今度
は駆動子（４ｃ）　（４ｄ）　Ｉｌｌが働らくことにな
り、第１図（ｄ）で実線の伸びになるので、スライダは
右方へ移動する。即ち、１サイクルで両端の駆動子がそ
扛ぞれ１回づつスライダの移動に関与することになる。In the next half cycle, the above operation is reversed, so the drivers (4c) (4d) Ill work this time, and the solid line in Figure 1(d) extends, so the slider moves to the right. Move to. That is, in one cycle, the drive elements at both ends are each involved in moving the slider once.

次に、スライダの左方への移動には、電気人力を別の表
裏対称の圧電素子（３ａ）　（３ｂ）側に切換えること
で行うことができる。即ち、長手方向には各圧電素子の
分極が同極のため先程と同じで、屈曲モードだけが反対
になるからである。Next, the slider can be moved to the left by switching the electric power to the other symmetric piezoelectric elements (3a) and (3b). That is, since the polarization of each piezoelectric element is the same in the longitudinal direction, it is the same as before, and only the bending mode is opposite.

以上のように、スライダの移動方向は、圧電素子（２ａ
）　（２ｂ）と（３ａ）　（３ｂ）　ヘの給１にヲ互い
に切換えればよいので、駆動回路は暑しく簡略化さｎる
。As described above, the moving direction of the slider is determined by the piezoelectric element (2a
) (2b) and (3a) (3b) Since it is only necessary to switch the inputs 1 to 1, the drive circuit is greatly simplified.

一般に駆動回路は、共振時のインピーダンス変化を横用
して自励発振させる方法と、圧１！Ｌ素子は２つのグル
ープのどちらかが空いているので、これからの発生電圧
をフィードバック信号として利用する自助発振回路が採
用される。何れも、発振が容易で、負荷の変動に対して
も安定に動作するため回路は単純になる。In general, drive circuits use a method of self-oscillation by making use of impedance changes during resonance, and a method of generating a pressure 1! Since one of the two groups of L elements is vacant, a self-help oscillation circuit is employed that uses the voltage that will be generated from now on as a feedback signal. In either case, oscillation is easy and the circuit is simple because it operates stably even with load fluctuations.

試作例を挙げると、長さモード：第１次モード基体の寸法：長さ４７１１１１、幅１６簡、厚さ２簡基
体り材質：鋼板圧　電素　子：　　１５．５ｍｍ角、厚さ０．４餌、Ｐ
ＺＴ系共振Ｈｅ　ｍ　：　５２ｋＨｚ駆動　電圧：　５Ｖ（実効値）駆　動　子：　鋼板チップを四隅にスポット溶接スライダ材質：　アラミド繊維をエポキシ樹脂で固化、
板状にしたもの圧　　接　　力　：　　２００ｇｒ　　ｆ移動スピード
：　　２３ｏｍ、４（無負荷時）なお、駆動子（４ａ）
〜（４ｄ）は、基体（１）と一体信造の場合を示したが
、軽負荷のときは、スポット溶接か接着等の手段で取着
してもよい。また、基体の両面に駆動子を設置するよう
にしてもよい。To give an example of a prototype, Length mode: 1st mode Dimensions of substrate: length 471111, width 16, thickness 2 Substrate material: steel plate Piezoelectric element: 15.5 mm square, thickness 0.4 Bait, P
ZT system resonance Hem: 52kHz Drive voltage: 5V (effective value) Drive element: Steel plate chips spot welded at the four corners Slider material: Aramid fiber solidified with epoxy resin,
Plate-shaped pressure contact force: 200gr f Movement speed: 23om, 4 (at no load) Also, drive element (4a)
- (4d) show the case of integral construction with the base (1), but when the load is light, it may be attached by means such as spot welding or adhesion. Further, drivers may be installed on both sides of the base.

組立て用の穴として、貫通孔（１ａ）は２個にしてもよ
い。There may be two through holes (1a) as holes for assembly.

また、上記の実施例では第１次の長さモードを使用した
が、これｔま第２次長さモードとの組合せでもよく、こ
の場合は一段大きいモータの設計がロエ能（′こなる。Furthermore, although the first-order length mode was used in the above embodiment, it may be combined with the second-order length mode, and in this case, the design of a motor that is one step larger will be more effective.

このときの圧電素子の分極方向は左右が互いに異極にな
り、圧電素子の結線は同一面内の２個が並列になる。動
作と移動方向の切換えは上４己実施例と同じである。At this time, the left and right polarization directions of the piezoelectric elements are different from each other, and the two piezoelectric elements are connected in parallel in the same plane. The operation and switching of the moving direction are the same as in the above four embodiments.

できる。通常、２枚の圧電素子間に金（鴫板を入れ国て接合強度の向上をＸると共に中央部両側にけみ出Ｌｋ
作って、これを取付は用とアース端子の両方ｅこ兼用す
る。このときの分極は上記実施例と同じく両面同極にす
る。アース端子の引き出しは、長手中央部側面からのは
み出しｔＰｊｌｉによってもよい。さらに駆動電圧を低
くしたい場合には、圧イ累子をｆＩＲｌｄ　ｍ潰にする
ことで可能になる。can. Usually, a gold plate is inserted between the two piezoelectric elements to improve the bonding strength, and it also oozes out on both sides of the center.
After making this, I installed it and used it both as a power supply and as a ground terminal. At this time, the polarization is the same on both sides as in the above embodiment. The ground terminal may be drawn out by protruding tPjli from the side surface of the longitudinal center portion. If it is desired to further lower the drive voltage, this can be achieved by making the insulator inflated.

［発明の効果コ以上の説明から明らかなように、この発明は、四隅に駆
動子を設けた角板状の基体の両面に各２個の、駆動用の
圧電素子を固着して基体を励振し、屈曲モードと長さ方
向先−ドの複合共振によシ被移動体を直線移動するよ“
）にしたので、被移動体の移動方向は圧電素子への給電
切換えだけで切換えることができ、薄形、軽輩化を達成
することができる。[Effects of the Invention] As is clear from the above description, the present invention has two drive piezoelectric elements fixed to each side of a square plate-shaped base with drive elements provided at the four corners to excite the base. The object to be moved is moved in a straight line by the combined resonance of the bending mode and the longitudinal direction.
), the moving direction of the object to be moved can be changed simply by switching the power supply to the piezoelectric element, making it possible to achieve a thinner and lighter design.

[Brief explanation of drawings]

第１図、第２図はこの発明の一実施例全館し、第１図は
平面図、第２図は側面図である。第３図〜第５図は従来
の超晋−波モータを示し、第３図は斜視図、第４図は正
面図、第５図は動作説明のための線図である。（１）−・・基体、（２ａ）　（２ｂ）　、（３ａ）　
（３ｂ）　−・・圧電素子、（４ａ）〜（４ｄ）・・・
駆動子。ｃｄ）２久、２ｂ、３直、３ｂ：ＩＬ電ｔ＋手続補正書（自発）平成２年１１月２２日FIGS. 1 and 2 show an entire building of an embodiment of the present invention, with FIG. 1 being a plan view and FIG. 2 being a side view. 3 to 5 show a conventional ultra-high-speed wave motor, with FIG. 3 being a perspective view, FIG. 4 being a front view, and FIG. 5 being a line diagram for explaining the operation. (1)--Base, (2a) (2b), (3a)
(3b) - Piezoelectric element, (4a) to (4d)...
drive element. cd) 2nd shift, 2b, 3rd shift, 3b: IL electronic t+ procedural amendment (voluntary) January 22, 1990

Claims

[Scope of Claims] A base made of an elastic rectangular plate and having drive elements protruding from the four corners of at least one surface for press-fitting a moving object, the front and back surfaces of the base, piezoelectric elements, two piezoelectric elements fixed to each other across the center of the back surface and polarized to the same polarity; An ultrasonic motor that applies a signal to produce complex resonance in the base body of a thickness direction bending mode and a length direction expansion/contraction mode in which both ends are in opposite phases to each other.