JPH084360B2 - Ultrasonic transducer - Google Patents
Ultrasonic transducerInfo
- Publication number
- JPH084360B2 JPH084360B2 JP61272066A JP27206686A JPH084360B2 JP H084360 B2 JPH084360 B2 JP H084360B2 JP 61272066 A JP61272066 A JP 61272066A JP 27206686 A JP27206686 A JP 27206686A JP H084360 B2 JPH084360 B2 JP H084360B2
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- ultrasonic transducer
- piezoelectric element
- vibration
- resonator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Apparatuses For Generation Of Mechanical Vibrations (AREA)
Description
【発明の詳細な説明】 発明の目的 [産業上の利用分野] 本発明は、超音波振動を効率高く発生することのでき
る超音波振動子に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an ultrasonic vibrator capable of efficiently generating ultrasonic vibration.
[従来の技術] 従来、電気的な信号を機械的な振動に変換して超音波
振動を発生させるために、電気ひずみ素子、磁気ひずみ
素子あるいは圧電素子を利用した電気機械変換素子が用
いられている。超音波振動子はこれらの電気機械変換素
子に共振器を着設し、振幅の大きな超音波振動を得るよ
うに構成されている。[Prior Art] Conventionally, an electromechanical conversion element using an electrostrictive element, a magnetostrictive element, or a piezoelectric element has been used to generate an ultrasonic vibration by converting an electric signal into a mechanical vibration. There is. The ultrasonic vibrator is configured to attach a resonator to these electromechanical conversion elements to obtain ultrasonic vibration with a large amplitude.
上記超音波振動子においては、電気機械変換素子にそ
の振動子の機械的共振周波数に一致する電気入力を与え
れば、極めて高効率の超音波振動が与えられる。In the above ultrasonic oscillator, if an electromechanical conversion element is given an electrical input that matches the mechanical resonance frequency of the oscillator, ultrasonic vibration of extremely high efficiency is given.
しかし反面、超音波振動子の温度変動や経時変化によ
り上記機械的共振周波数の変動が発生すると、その効率
は共振の鋭さ(Q)に比例して急減することになる。そ
こで、従来の超音波振動子では超音波振動子の振幅を検
出し、その振幅が極大となるように電気入力の周波数を
帰還するフィードバック制御が多用されている。However, on the other hand, when the mechanical resonance frequency fluctuates due to temperature fluctuations or temporal changes of the ultrasonic transducer, its efficiency sharply decreases in proportion to the resonance sharpness (Q). Therefore, in the conventional ultrasonic transducer, feedback control is often used in which the amplitude of the ultrasonic transducer is detected and the frequency of the electric input is fed back so that the amplitude becomes maximum.
[発明が解決しようとする問題点] しかし、上記のごとき超音波振動子にあっても未だ十
分なものではなく、次のような問題点があった。[Problems to be Solved by the Invention] However, even the ultrasonic transducer as described above is not yet sufficient, and has the following problems.
すなわち、超音波振動子の共振周波数の変動を電気入
力の周波数により調節するものにあっては、常に超音波
振動子の発生する超音波の振動周波数が定まらず、ある
範囲内で変化することになる。これでは、複数の超音波
振動子が協動するようなシステム、例えば信号波形超音
波モータにあっては所定の周波数の超音波振動を得るこ
とが不可能であった。That is, in the case where the fluctuation of the resonance frequency of the ultrasonic vibrator is adjusted by the frequency of the electric input, the vibration frequency of the ultrasonic wave generated by the ultrasonic vibrator is not always fixed, but changes within a certain range. Become. With this, in a system in which a plurality of ultrasonic transducers cooperate, for example, a signal waveform ultrasonic motor, it is impossible to obtain ultrasonic vibration of a predetermined frequency.
本発明は、上記問題点を解決するためになされたもの
で、超音波の振動周波数は常に一定であり、しかも高効
率で印加される電気入力を超音波振動に変換することの
できる優れた超音波振動子を提供することをその目的と
している。The present invention has been made to solve the above-mentioned problems, and the vibration frequency of ultrasonic waves is always constant, and an excellent ultrasonic wave capable of converting an electric input applied with high efficiency into ultrasonic vibrations. Its purpose is to provide a sound wave oscillator.
発明の構成 [問題点を解決するための手段] 上記問題点を解決するための本発明の超音波振動子の
構成は、電気信号が印加されることにより振動が励起さ
れる電気機械変換素子に対して共振器を圧着機構を用い
て所定の圧着力で圧着させ、共振器の共振作用を利用し
て大振幅の超音波振動を得る超音波振動子において、前
記電気機械変換素子と前記共振器とを圧着する圧着機構
中に前記圧着力を変化させる別の電気機械変換素子を配
置することを特徴とする。Configuration of the Invention [Means for Solving the Problems] The configuration of the ultrasonic vibrator of the present invention for solving the above problems is an electromechanical conversion element in which vibration is excited by application of an electric signal. On the other hand, in the ultrasonic transducer for crimping a resonator with a predetermined crimping force using a crimping mechanism to obtain ultrasonic vibration of large amplitude by utilizing the resonance action of the resonator, the electromechanical conversion element and the resonator Another electromechanical conversion element for changing the pressure bonding force is arranged in the pressure bonding mechanism for pressure bonding.
[作用] 本発明の超音波振動子では電気機械変換素子と共振器
とを圧着している圧着機構中に他の電気機械変換素子が
存在し、これに所望の電気信号を与えることで上記圧着
力が制御可能とされる。[Operation] In the ultrasonic vibrator of the present invention, another electromechanical transducer is present in the crimping mechanism that crimps the electromechanical transducer and the resonator, and the crimping is performed by applying a desired electric signal to the electromechanical transducer. Power is controllable.
[実施例] 以下、本発明をより具体的に説明するために実施例を
挙げて説明する。[Examples] Hereinafter, examples will be described in order to more specifically describe the present invention.
第1図は、実施例の超音波振動子2の一部を破断した
斜視図に、その駆動電気回路を略記した説明図である。
図より明らかなように本実施例の超音波振動子2はボル
ト締めランジュバン型の構成で、中央部にある円板上の
駆動用圧電素子4の両側を肉厚の弾性体6,8で挟み込
み、これらの中心軸上を貫通するボルト10と該ボルト10
に螺着されるナット12との締め付け力により、駆動用圧
電素子4と弾性体6,8とを圧着する。上記駆動用圧電素
子4に電気信号を与えるための駆動用電極板14は、駆動
用圧電素子4の上面に電気的に密に着設され、また弾性
体6と電気的に絶縁するために、該駆動用電極板14の上
方に配設される絶縁板16を介して弾性体6に当接してい
る。一方、駆動用圧電素子4の他方面には制御用電極板
18が電気的に密に着設される制御用圧電素子20が弾性体
8との間に介在している。FIG. 1 is an explanatory view in which a drive electric circuit is abbreviated in a perspective view in which a part of the ultrasonic transducer 2 of the embodiment is cut away.
As is clear from the figure, the ultrasonic transducer 2 of the present embodiment has a bolted Langevin type construction, in which both sides of the driving piezoelectric element 4 on the disc in the central portion are sandwiched by thick elastic bodies 6 and 8. , The bolt 10 that penetrates on these central axes and the bolt 10
The driving piezoelectric element 4 and the elastic bodies 6 and 8 are crimped by the tightening force of the nut 12 screwed to the. The driving electrode plate 14 for giving an electric signal to the driving piezoelectric element 4 is electrically and densely attached to the upper surface of the driving piezoelectric element 4 and is electrically insulated from the elastic body 6, It is in contact with the elastic body 6 via an insulating plate 16 arranged above the driving electrode plate 14. On the other hand, a control electrode plate is provided on the other surface of the driving piezoelectric element 4.
A control piezoelectric element 20, to which 18 is electrically and densely attached, is interposed between the elastic body 8.
換言するならば、本実施例の超音波振動子は上記した
制御用圧電素子20を除けば通常のボルト締めランジュバ
ン型の超音波振動子と差異はなく、駆動用圧電素子4に
電気入力を効率良く伝える駆動用電極板14に、交流の駆
動用電源30を整合回路32を介して接続する通常の構成で
ある。In other words, the ultrasonic vibrator of the present embodiment is the same as a normal bolted Langevin type ultrasonic vibrator except for the control piezoelectric element 20 described above, and the electric input to the driving piezoelectric element 4 is efficient. This is a normal configuration in which an AC drive power source 30 is connected to a well-transmitted drive electrode plate 14 via a matching circuit 32.
実施例の超音波振動子2に特有の制御用圧電素子20に
は、制御用電極板18に接続される電圧可変の直流電源36
から直流電圧が印加される。公知のごとく、圧電素子12
は印加される電圧に比例した伸縮作用があり、直流電圧
を印加するならば制御用圧電素子20はその印加する電圧
値に比例した値の伸びあるいは縮みが生じて超音波振動
子2全体から見たときのボルト締め付力を任意に変更す
ることができる。これは、超音波振動子2の共振周波数
を、直流電源36から印加する電圧によって可変できるこ
とを意味しており、超音波振動子2の共振周波数は直流
電源36の電圧値により制御可能となる。従って、直流電
圧を制御して駆動用電源30の交流周波数、すなわち電気
的周波数に超音波振動子2の機械的共振周波数を一致さ
せ、高効率の超音波振動の励起が達成される。In the control piezoelectric element 20 peculiar to the ultrasonic transducer 2 of the embodiment, the voltage variable DC power source 36 connected to the control electrode plate 18 is used.
DC voltage is applied from the. As is known, the piezoelectric element 12
Has an expansion / contraction effect proportional to the applied voltage, and when a DC voltage is applied, the control piezoelectric element 20 expands or contracts by a value proportional to the applied voltage value, and is seen from the entire ultrasonic transducer 2. The bolt tightening force can be changed as desired. This means that the resonance frequency of the ultrasonic vibrator 2 can be changed by the voltage applied from the DC power supply 36, and the resonance frequency of the ultrasonic vibrator 2 can be controlled by the voltage value of the DC power supply 36. Therefore, the direct-current voltage is controlled to match the alternating-current frequency of the driving power source 30, that is, the electrical resonance frequency with the mechanical resonance frequency of the ultrasonic transducer 2, and highly efficient excitation of ultrasonic vibration is achieved.
なお、上記実施例では制御用圧電素子20が超音波振動
子2のほぼ中央部に配置されているが、これは、超音波
振動子2の節点近傍に制御用圧電素子20を配置すること
により、僅かな制御用圧電素子20の伸びあるいは縮みで
も大きな共振周波数の変化を招来させるためである。従
って、この実施例の構成に限らずとも制御用圧電素子20
の圧電効果や共振周波数の制御範囲、制御精度等を考慮
して制御用圧電素子20の圧着機構中の配置位置を変更し
たり、あるいは複数並設する等適宜改変してもよい。更
には、その電気機械変換素子に使用する素子も圧電素子
に限らず、電歪あるいは磁歪素子を用いる等本発明の要
旨を逸脱しない種々の態様て実現してもよい。In the above embodiment, the control piezoelectric element 20 is arranged substantially in the center of the ultrasonic transducer 2, but this is achieved by disposing the control piezoelectric element 20 near the node of the ultrasonic transducer 2. This is because even a slight expansion or contraction of the control piezoelectric element 20 causes a large change in the resonance frequency. Therefore, the piezoelectric element for control 20 is not limited to the configuration of this embodiment.
Considering the piezoelectric effect, control range of resonance frequency, control accuracy, and the like, the arrangement position of the control piezoelectric element 20 in the crimping mechanism may be changed, or a plurality of the piezoelectric elements for control 20 may be appropriately arranged such that they are arranged in parallel. Further, the element used for the electromechanical conversion element is not limited to the piezoelectric element, and may be realized in various modes such as using an electrostrictive element or a magnetostrictive element without departing from the gist of the present invention.
第2図は、上記した実施例のように機械的共振周波数
が制御可能な超音波振動子2を複数用いて、進行波形超
音波モータを構成した応用例である。FIG. 2 is an application example in which a traveling waveform ultrasonic motor is configured by using a plurality of ultrasonic transducers 2 whose mechanical resonance frequency can be controlled as in the above-described embodiment.
2つの超音波振動子2A,2B内に配置されるそれぞれの
駆動用圧電素子4A,4Bは、同一の駆動用電源30に接続さ
れているが、一方の駆動用圧電素子4Bは位相器40により
電源30の電気信号に対して90゜の位相差を持たされた電
気信号が入力されるように構成されている。相互に90゜
の位相差を持つ電気信号は、増幅器42A,42Bおよび整合
回路32A,32Bを介して駆動用圧電素子4A,4Bに供給される
が、更にこの供給される電気信号の電圧、電流は共振検
出回路50A,50Bによってその共振状況の検出がなされ、
該共振検出回路50A,50Bの出力に基づき2つの超音波振
動子2A,2Bの制御用圧電素子20A,20Bに印加される直流電
源36A,36Bの電圧が制御される。共振検出回路50A,50Bは
共に同一構成であるため、図はその50Aについてのみ詳
細に記載している。公知のごとく、電気的な共振状態と
は回路内のリアクタンス分が零となり、その電圧、電流
が同相となる状態である。従って、共振検出回路50A,50
Bは駆動用圧電素子2A,2Bの入力電気信号を定抵抗器Rの
両端からピックアップし、両端の電位差を増幅する差動
増幅器51で電流波形を、またいずれか一端のアースから
の電位を増幅する差動増幅器52で電圧波形を、検出して
いる。そして、この両差増幅器51,52の出力波形の位相
を位相比較器53が比較することにより電気的共振状態か
らのずれ量が検出され、その検出値に応じて制御回路54
が直流電源36Aまたは36Bの電位を制御する。これによ
り、超音波振動子2A,2Bは駆動用電源30の周波数に一致
した共振周波数を有するべくフィードバック制御され、
高効率の超音波発生が行われる。前述のごとく、それぞ
れが同一周波数で高効率に駆動される超音波振動子2A,2
Bの電気信号位相は互いに90゜だけずれているため、こ
の2つの超音波振動子2A,2Bを円環状のステータ60に固
有の進行波の1/4波長間隔を隔てた位置に配設し、ステ
ータ60を励振させるならば、図示するように時計方向の
進行波を正起させることができる。従って、このステー
タ60に一定圧力で当接されるロータ70には上記進行波と
は逆方向の回転移動力が発生し、進行波形超音波モータ
が構成される。The driving piezoelectric elements 4A and 4B arranged in the two ultrasonic transducers 2A and 2B are connected to the same driving power source 30, but one driving piezoelectric element 4B is connected by the phase shifter 40. An electric signal having a phase difference of 90 ° with respect to the electric signal of the power source 30 is input. The electric signals having a 90 ° phase difference with each other are supplied to the driving piezoelectric elements 4A, 4B through the amplifiers 42A, 42B and the matching circuits 32A, 32B. Is detected by the resonance detection circuit 50A, 50B,
The voltages of the DC power supplies 36A and 36B applied to the control piezoelectric elements 20A and 20B of the two ultrasonic transducers 2A and 2B are controlled based on the outputs of the resonance detection circuits 50A and 50B. Since the resonance detection circuits 50A and 50B have the same configuration, only the 50A is described in detail in the drawing. As is well known, the electrical resonance state is a state in which the reactance component in the circuit becomes zero and the voltage and current are in phase. Therefore, the resonance detection circuit 50A, 50
B picks up the input electric signals of the driving piezoelectric elements 2A and 2B from both ends of the constant resistor R, and a current waveform is amplified by the differential amplifier 51 that amplifies the potential difference between both ends, and the potential from the ground at either one end is amplified. The differential amplifier 52 detects the voltage waveform. Then, the phase comparator 53 compares the phases of the output waveforms of the differential amplifiers 51 and 52 to detect the amount of deviation from the electrical resonance state, and the control circuit 54 according to the detected value.
Controls the potential of the DC power supply 36A or 36B. Thereby, the ultrasonic transducers 2A, 2B are feedback-controlled so as to have a resonance frequency that matches the frequency of the driving power source 30,
Highly efficient ultrasonic wave generation is performed. As mentioned above, the ultrasonic transducers 2A, 2 that are driven at the same frequency with high efficiency
Since the electric signal phase of B is deviated from each other by 90 °, these two ultrasonic transducers 2A and 2B are arranged at positions separated by a quarter wavelength interval of the traveling wave peculiar to the annular stator 60. If the stator 60 is excited, a clockwise traveling wave can be generated as shown in the figure. Therefore, a rotational movement force in the direction opposite to the traveling wave is generated in the rotor 70 that is in contact with the stator 60 at a constant pressure, and a traveling waveform ultrasonic motor is configured.
以上のように、本実施例の超音波振動子によれば、発
生する超音波振動の周波数が常に一定値に安定すること
になり、複数箇の超音波振動子を協動させるシステム等
を簡単に構築することができる。As described above, according to the ultrasonic transducer of the present embodiment, the frequency of the generated ultrasonic vibration is always stable at a constant value, and a system for cooperating a plurality of ultrasonic transducers can be simplified. Can be built into.
発明の効果 以上、実施例を挙げて詳述するように本発明の超音波
振動子は、所定の周波数で高効率の共振状態を作り出す
ことが可能となり、複数箇の超音波振動子を協動させた
り、共振周波数が一定の負荷に簡単に利用できる等、適
応範囲の広い優れた超音波振動子となる。EFFECTS OF THE INVENTION As described above in detail with reference to examples, the ultrasonic transducer of the present invention can create a highly efficient resonance state at a predetermined frequency, and cooperates with a plurality of ultrasonic transducers. It becomes an excellent ultrasonic transducer with a wide adaptable range, such as being able to be used for a load having a constant resonance frequency.
第1図は本発明の超音波振動子の基本的構成を示す基本
構成図、第2図は同実施例の超音波振動子を利用した超
音波モータの構成概略図、を示している。 2,2A,2B……超音波振動子 4,4A,4B……駆動用圧電素子 20,20A,20B……制御用圧電素子FIG. 1 is a basic configuration diagram showing a basic configuration of an ultrasonic transducer of the present invention, and FIG. 2 is a schematic configuration diagram of an ultrasonic motor using the ultrasonic transducer of the embodiment. 2,2A, 2B …… Ultrasonic transducer 4,4A, 4B …… Piezoelectric element for driving 20,20A, 20B …… Piezoelectric element for control
Claims (1)
起される電気機械変換素子に対して共振器を圧着機構を
用いて所定の圧着力で圧着させ、共振器の共振作用を利
用して大振幅の超音波振動を得る超音波振動子におい
て、 前記電気機械変換素子と前記共振器とを圧着する圧着機
構中に前記圧着力を変化させる別の電気機械変換素子を
配置することを特徴とする超音波振動子。1. A resonator is crimped with a predetermined crimping force using a crimping mechanism to an electromechanical conversion element in which vibration is excited when an electric signal is applied, and the resonance action of the resonator is utilized. In an ultrasonic transducer that obtains ultrasonic vibration of large amplitude, another electromechanical conversion element that changes the pressure bonding force is arranged in a pressure bonding mechanism that pressure bonds the electromechanical conversion element and the resonator. Ultrasonic transducer to do.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP61272066A JPH084360B2 (en) | 1986-11-14 | 1986-11-14 | Ultrasonic transducer |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP61272066A JPH084360B2 (en) | 1986-11-14 | 1986-11-14 | Ultrasonic transducer |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS63125100A JPS63125100A (en) | 1988-05-28 |
JPH084360B2 true JPH084360B2 (en) | 1996-01-17 |
Family
ID=17508619
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP61272066A Expired - Fee Related JPH084360B2 (en) | 1986-11-14 | 1986-11-14 | Ultrasonic transducer |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH084360B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0217870A (en) * | 1988-06-30 | 1990-01-22 | Honda Electron Co Ltd | Ultrasonic driving gear |
-
1986
- 1986-11-14 JP JP61272066A patent/JPH084360B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPS63125100A (en) | 1988-05-28 |
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