JP5110241B2 - Wave piezoelectric transducer - Google Patents

Description

Detailed Description of the Invention

The present invention relates to a wave piezoelectric transducer that is a part of application of a flexible material having a piezoelectric property as a polymer material, and that is used as a thin plate or a membrane surface, and that is applied to fluid movement or propulsion of a moving body.

Conventional jet engines, airplane propellers, helicopter rotors, marine screws, water turbines, various wind turbines, and blowers are almost all rotary converters.
Since ancient times, there have been spears and spears, some of which have wing fan movable systems and suction / injection pump systems. As a special case, in the case of exclusive use for seawater, there is a propulsion method using electromagnetic induction utilizing its conductivity.

In these conventional converters, most of them are a power source engine and motor, a power transmission shaft, and propeller blades for propulsion.
Naturally, weight saving is necessary for resource-saving flight at high altitudes, and weight reduction is a major problem for the weight of the aircraft itself, the transmission mechanism, the weight of the rotor blades, and so on.
JP, 2004-276614, A (Lightweight mobile body) Japanese Patent Laid-Open No. 11-124095: (High gliding body) "Basics of Aerodynamics" published by industrial books 1987 by Mitsuo Makino "Flying Mechanics" (3rd edition) Published by Yokendo 1993 Hiroshi Maeda

On the other hand, the vehicle, which is lighter than the air of very high altitude disclosed in the above [Patent Document 1], has PVDF layers disposed on both sides of the liquid crystal polymer fiber layer, and is lightweight and has high strength.
Regarding the manufacturing method and applied processing of the PVDF polymer dielectric film surface, there are the following background technologies.
Japanese Patent Publication No. 44-11656 (PVDF production method) JP-A-54-154383: (PVDF electrode deposition) JP-A-56-132533: (PVDF bending) Japanese Patent Application No. 2005-145978 (Application for relevant points of the same applicant) “Advanced Sensor Handbook” Kiyoshi Takahashi § 6.4.4 Piezoelectric polymer thin film (published by Bafukan 1994) Akio Sasaki… “Pyroelectric infrared detector using PVF 2”, NTR Vol. 26 No. 3 1980 “PVDF Infrared detector and microphone for monitoring” (THE JOURNAL of the Acoustic Society of America) (ASA Vol. 64, Supplement No. 1, s56. “Pyroelectric infrared detector” (detection by PbTiO 3) NTR Vol. No. 18 2 1972

  Many of today's aircraft use a lot of energy to carry their own propulsion engines, propellers, shafts to connect them, high-speed tires that are only used for takeoff and landing, fuel for the flight, etc. Consuming. These are common problems for aircraft.

Air pollution is a major factor in recent global changes in climate and disasters, and global warming countermeasures are also being carried out internationally. Among these, an increase in air transportation in the stratosphere and an increase in CO ₂ emissions are also major problems. These reductions are major challenges and urgent matters.

The present invention eliminates most of the conventional engine, motor, transmission mechanism, and the like. (1) By applying a piezoelectric body, the blade surface itself can be bent and propelled [wave piezoelectric surface].
(2) With the same application, attach a [ wave piezoelectric transducer ] to the glide body, etc., and fly by its own thrust. (3) The [wave piezoelectric transducer ] of the present invention is mounted on the front edge of the blade surface, and lift is obtained by blowing laminar flow.
(4) The blade upper surface other than the wave piezoelectric transducer is a solar cell, and is used as a [power source for wave propulsion].
In addition, a required secondary battery and electronic circuit are installed to enable [self-contained flight].
Here, it relates to details other than the case of the single surface described in the prior application “Patent Document 6”.

が高い。この変換の際にも誘電体損失と電流損失は発生するが、大部分は音響出力と風損である。Some ferroelectrics have sinterability such as lead titanate and have piezoelectric / pyroelectric characteristics, and some polymer dielectrics have similar characteristics such as PVDF, and the film surface Some are easy to process.
FIG. 2 is an explanatory diagram of an acoustic / electrical converter using PVDF (polyfucavinylidene). The size of the PVDF membrane surface 1 shown in FIG. 2A and the curved frame 4 having an arch-shaped curve is a basic frame made assuming an effective area of 1 cm ² and has a thickness of 20 μm. Ni-Cr thin film electrodes are vapor-deposited on both sides of the film, and the front side of the film is attached to the casing via a frame, connected to a common ground, and a signal is extracted from the back side of the film. ing.
When used as a speaker, the amplifier (Amp.) In FIG. 2B is switched in the reverse direction, and the PVDF film surface is driven by the output of the amplifier.
When the radius of the arch curve is 2 cm, the resonance frequency is about 11 kHz, and the output voltage with respect to the sound pressure is 0.4 × 10 ⁻¹ V / hPa. The input and output sound pressures and voltages are reversible.
In [Non-Patent Document 5], there is a report on a theoretical formula of an electrical output with respect to a voice input and actually measured data of frequency characteristics ranging from 20 Hz to 20 kHz in sound pressure sensitivity as an actual microphone.
The sensitivity at this resonance point varies with frequency, but the maximum sensitivity at the peak value is

Is expensive. Even during this conversion, dielectric loss and current loss occur, but most are acoustic output and windage loss.

In order to increase the size of the basic frame, if the outer shape is enlarged 100 times, the film area is 1 m ² and the radius of the arch curve is 2 m, the film thickness is 2 mm, and the output voltage as sensitivity Is 4 V / hPa. FIG. 3A is a perspective view of the upper limit when the vibrating membrane stretched on the curved frame 4 is moved upward, and FIG. 3B is a perspective view of the lower limit when the vibrating membrane is moved downward. It is .
FIG (c) is Ru amplitude der the center of the horizontal direction and the stretching. That in Figure, d: the center of the horizontal direction are shown as 1 m, and depicts the vibration status of the central portion each point in the case of the the d in the drawing → (1.5 m), in this case The resonance frequency of is about 110 Hz. The numbers in the symbol → () in this figure indicate the numbers for mounting calculation described later.
The sound pressure output in this case is due to expansion and contraction of the film surface by the voltage applied to PVDF1, and if an AC voltage of 200V is applied thereto, a sound pressure output of 50 hPa can be obtained.
As described above, the conversion efficiency of a general acoustic transducer is about a few percent, but if converted near the resonance point, the efficiency is improved, and this pressure difference between the sound pressures can be used sufficiently to generate a large airflow. It makes a difference. However, although the sound output also becomes a loud noise, the conversion using the cancellation method can be dealt with almost completely as will be described later.

As a method of sound pressure → air flow conversion, the membrane surfaces stretched on the large curved frame are arranged in a vertical line in a tunnel shape (FIG. 4A), and a multiphase AC voltage (FIG. 4 (FIG. 4 ( If the six phases shown in b) are added, the piezoelectric film contracts as depicted in (3), (4) and (5) of FIG. Move up and down as in c). Therefore, the air in the membrane is moved and discharged in the direction in which the diaphragm moves due to the up-and-down movement, and new air is sucked from the counter electrode side to form a continuous flow.
The moving speed of the suction and discharge is determined by the fluid resistance obtained from the scanning speed of the multiphase alternating current applied to the membrane surface and the shape dimension of the tunnel-like flow path with respect to the scanning speed. From the theoretical formula including the membrane surface, the flow path width is as wide as possible, and the length needs to be shorter.
Here, if the curved frame 4 is removed, the membrane surface 1 is only stretched. The side strut of the duct shape composed of support struts 4 to extend to form "walls" on both sides of the illustrated as shown in FIG. 1 (a), stretched to come illustrated wind tunnel 9 Wotsu, be added a slight tension It has natural vibration as a flat stretcher. If this is divided for each electrode as shown in FIG. 2 (1)... 2 (12) , each element has a natural vibration close to a string vibration.

If the arch radius is 3 m and the chord length is 1.5 m, the cross-sectional area of the flow path is more than double. It becomes. The channel length is about 1/4 of the most effective portion at the center of the piezoelectric film, and all the other 3/4 are omitted together with the frame, and the total length is shortened to about 1.5 m. Increase the pressure in the channel membrane slightly. If drive scanning by the same multiphase alternating current as described above is performed, the film surface is in a wave state as shown in FIGS.
This internal pressure state, that is, the state in which the internal pressure is applied to the wind tunnel 9 is a case where pressure from the inner surface is constantly applied like a paraglider or balloon, and there are many practical aspects, and the above-described wave scanning can be performed as it is.

In the following, near the resonance point where the maximum output can be obtained, the expansion and contraction of the piezoelectric surface is efficiently converted into amplitude motion, the transmission of vibration to a series of transducers is converted into waves, and the waves are complemented by two surfaces, Furthermore, it is converted into fluid movement as a four-sided cooperative operation type, pursuing increased output and efficiency . Representative examples are shown in FIGS. 1A to 1C, and application examples are shown in FIGS. 11A to 11C, following the explanatory diagrams of FIG .

The wave piezoelectric transducer of the present invention can be directly applied as a wing surface material to a wing surface of a glider or paraglider, and enables self-flight.
Further, (attached to key points configured as or complementary wave thruster having front and rear two surfaces, as shown in FIG. 1 (b)) the internal pressure surface, such as balloons or airships initially constituted by wave piezoelectric surface from the drive If it performs, active maneuvering can be performed.
The complementary cooperative wave propulsion system as shown in FIG. 1 (c) has a stronger thrust, and by this installation, the role of a conventional light aircraft or helicopter, and air transportation that does not compete for speed. It can be used for monitoring services from the sky in agriculture, forestry and fisheries, for airplanes for sightseeing, etc., and with little noise and no exhaust gas.

By installing the wave piezoelectric transducers side by side as shown in Fig. 11 (b) and expanding them in order to cover the upper surface of the aircraft wing with the laminar flow of this device , the lift of the wing surface is It increases in proportion to the area. As will be described later, the longer the blade length and the wider the blade surface, the larger the lift force is obtained. The margin for mounting the solar cell is increased, and the flexible thin-film solar cell can be bonded to the piezoelectric surface.
If this is equipped with a lightweight frame mechanism, the required secondary battery, and a driving electronic circuit, the wing surface load is relatively small, and it is possible to easily realize a large aircraft for high-level flight with lean air. it can.
FIG. 11C is an application example of this wave piezoelectric transducer, which can overcome the “problem in the case of no wind in the high sky”, which becomes a problem when using the high-rise westerly wind, and realizes long-term air suspension at high altitude. be able to.

These significant simplifications and weight savings make it easier to fly at high altitudes, allowing effective use of the southern or northern hemisphere jet stream. This specific route around the east on the westerly wind enables air transport at a speed close to that of current air transport.
That is, ( a ) an elevator using a western wind that reciprocates between the ground and the sky, ( b ) a transfer platform using the western wind, and ( c ) a wave piezoelectric transducer that travels around the important points on the western wind route. This mechanism can be constructed, such as a large machine installed.
They will be able to play a major transportation role without consuming fuel, generating loud noises, and not requiring a large airport as in the conventional aircraft.

Furthermore, the use of this device opens the way for the development and utilization of wind power and solar energy in high-rises, as a base for wind power generation by solar power generation and westerly winds in high skies, and for communications, traffic monitoring, observation, sightseeing, etc. As a base, new fields can be developed.
This high-rise westerly wind power generation base will generate new energy that has not yet been launched. Solar power generation at high altitudes that are always sunny is far more efficient than the ground, and in the winter when there is little sunshine, westerly winds This is a strong period for wind power generation. Equipped with solar power and wind power generation facilities, this machine will be able to generate power efficiently throughout the spring, summer and autumn.
Although this wave piezoelectric transducer provides a light-weight propulsion transducer that replaces some of the conventional engines and propellers, the overall effect is that we are facing energy problems and mass transport issues. In the problem of global warming gas, it greatly contributes to the reduction of CO ₂ exhaust gas.

As a method of replacing the tension with the curved frame, a curved suspension of the piezoelectric surface from the opposite direction can be considered. FIG. 6A shows a piezoelectric surface with 12 electrodes, and these two surfaces are stretched in parallel.
If these piezoelectric surfaces are suspended like a suspended ceiling, they become a pair of curved surfaces opposite to each other like the piezoelectric surfaces 1-1 and 1-2 in FIG. 6B. An auxiliary net is used for this parallel stretch and mutual suspension . From several of the linkage line 8 provided (right and left to facilitate cooperation movement of the suspension wire 7, and the electrode cross a cross-suspension to give intervals in two electrode surfaces arranged vertically as the auxiliary net The suspension line 7 is suspended in a reverse arc shape so that both sides are slightly curved ( as a linkage line 8 traversing the stretched auxiliary net 3).
Here, the polarities of the polarization of the first piezoelectric surface 1-1 and the second piezoelectric surface 1-2 are reversed. As a result, when the first piezoelectric surface expands, the second piezoelectric surface contracts. Conversely, when the first piezoelectric surface contracts, the second piezoelectric surface expands. FIGS. 6C, 6D, and 6E show the operating state of the contradictory motion.
When 12-phase AC voltage corresponding to the position of each electrode is sequentially applied to each of the 12 electrodes on each piezoelectric surface, that is, a 12-phase AC voltage having a phase difference of 30 °, the first piezoelectric surface, Each element on the piezoelectric surface 2 repeats the movement along the phase of the AC voltage, and each element forms a series of vibrators that perform a reverse movement with a phase difference of 30 °. A series of these reciprocal motions that are linked together is the basic motion of the wave propulsion motion.
This anti-reverse movement is a complementary cooperative action, and the sound pressure output in the cooperative action is the sum of both.

順次に仕切り、準閉鎖の状態を走査で移動させ、一方向への送出工程の流れとしているからであり、指向性の少ない低周波においては、振幅利用の仕切り挿入形式で気体の振動を一方向への気体の移動として方向付けができ、気流に変換することが出来るからである。
これにより電気的入力は、殆ど誘電体損失と銅損以外は音響的出力または空気の移動に変換されるが、その音響出力も殆ど気流に変換され、消音された連続流となる。Here, since the individual electrodes are driven by polyphase alternating current, the sound pressure output in the direction perpendicular to the piezoelectric surface is always one of the counter electrode outputs having a phase difference of 180 °. All acoustic outputs are always canceled by the output of either counter electrode.
That is, this even-numbered 360 ° equally phase difference is the cancellation cancellation method of all acoustic outputs itself, and some Doppler sound generated by the difference between the scanning speed and the sound speed remains in the front-rear direction of the flow path. This is due to a shift in the erase phase erased in step (b). At the same time, an air flow is generated in the moving direction of the amplitude accompanying the phase shift.
The energy conversion from the air flow accompanying the amplitude movement, that is, the movement of the gas to the momentum is performed here.

This is because partitioning is performed sequentially, and the quasi-closed state is moved by scanning, and the flow of the sending process in one direction is used. At low frequencies with little directivity, the vibration of the gas is unidirectional in the partition insertion type using amplitude. This is because it can be directed as the movement of the gas to and converted into an air current.
As a result, the electrical input is converted into an acoustic output or air movement except for the dielectric loss and copper loss, but the acoustic output is also almost converted into an air flow, resulting in a silenced continuous flow .

In this case, the expansion and contraction of the element on the piezoelectric surface is different for each electrode, and needs to be set with a degree of freedom as individual string vibration. Therefore, a certain degree of partitioning is provided for each electrode, for example, the degree of freedom of expansion and contraction of individual elements is given as necessary for frequency adjustment, and the transmission of waves is facilitated by the cooperation line.
In this case, fundamental frequency f of the string vibration of a single string vibrations as possible out by the following expression.

上記、［数１］での張力は広幅での値であり、［表１］の値は３ｃｍ幅での張力である。
張力の調整は別途仕様の圧電素子で行ない、これも電圧駆動による調整が可能である。
ここで駆動電圧の周波数は発信器の走査速度の切り替え（調整）により任意に調整することができ、最大振幅は振幅制限回路により常に一定値を越えないよう規定しておく。
これにより圧電面の振動数と駆動電圧の振動（周波）数を共振状態にすることになる。また、張架用の機構には伸縮自在の菱形枠体を用い、この伸縮を圧電体により制御する。上記の懸架分割しての張力範囲は、この制御に無理のない張力範囲で、翼面に必要な流速が得られる制御が可能なことを示している。これにより駆動電圧と振幅の位相を、帰還方式で自動調整を行うことができる。 In the practical stage, it is necessary to make the waves smoother, and it is preferable to increase the number of power sources to 48 phases and 48 vibrators. This also reduces the potential difference between adjacent elements. On the other hand, the element width of the vibrator is as narrow as 3 cm in that case, and the vibration becomes closer to the string vibration.
The resonance point shifts to the high frequency side by mutual suspension, but when suspended at 9 points and divided into 10 sections, the resonance frequency f of each part becomes 10 times, and shifts as follows due to the change in tension.

The tension in [Equation 1] is a value in a wide range, and the value in [Table 1] is a tension in a width of 3 cm.
The tension is adjusted by a piezoelectric element with a separate specification, which can also be adjusted by voltage drive.
Here, the frequency of the drive voltage can be arbitrarily adjusted by switching (adjusting) the scanning speed of the transmitter, and the maximum amplitude is defined so as not to always exceed a certain value by the amplitude limiting circuit.
Thereby, the vibration frequency of the piezoelectric surface and the vibration (frequency) of the drive voltage are brought into a resonance state. Further, a stretchable rhombus frame is used for the tension mechanism, and this expansion and contraction is controlled by a piezoelectric body. The tension range obtained by dividing the suspension described above indicates that the control can be performed so that the flow velocity necessary for the blade surface can be obtained within the tension range that is not unreasonable for this control. As a result, the drive voltage and the phase of the amplitude can be automatically adjusted by a feedback method.

As shown in FIG. 7 (a), two sets of the above-mentioned complementary piezoelectric surfaces are arranged so that the wave vibration surfaces face each other in plane symmetry, and the fluid movement is more quantitatively processed by the cooperation of both. This is a superposition method, and the output is doubled by performing a collaborative operation symmetrically with the plane, and the flow rate is processed more quantitatively.
FIG. 7B shows a stationary state with complementary superimposition / symmetric driving, FIG. 7C shows a fully open state, and FIG. 7D shows a closed state.
This is a complementary cooperative operation, which is a so-called complementary push-pull type double push-pull. In this method, an output that is about four times that of the original single-plane stretch method can be obtained.
A part (perspective view) of the waves of the piezoelectric surfaces 1-2 and 1-3 facing each other when viewed from the side surface is shown in FIG. 8A, and the change with time in the diameter of the central portion is shown in FIG. ) (C) (d) This central part is a more quantitative flow.

翼面上の実効流速（相対速度；ｖ）が離陸速度（揚力＞機体重量となる速度）
を越えれば、翼面体は滑走路を要せず離陸することができる。
この場合、圧電面の表と裏は相補対称形であり、単一面の動作では表と裏の流速は等しくなるが、周囲の状況で表裏の流速が異なれば、その差に応じた前述の［揚力同等の力］が働くため、表と裏の流速による圧力差を少なくするための構造上の配慮が必要である。
図９で、（ａ）は単１面、（ｂ）は相補形、（ｃ）は相補協働形に対応した機構で、膜面の張力調整と対称な流路、空電防護等を考慮したカバ−を備え、立体的拡張配設が容易である。 When the wave piezoelectric transducers are arranged in a horizontal row and mounted on the leading edge of a flying wing and driven by a predetermined 6n-phase AC voltage, a laminar flow covering the wing according to the AC angular velocity is applied to the wing surface. Will occur. If this laminar flow effectively acts on the blade surface, it is possible to obtain lift while the blade surface remains stationary.
The effect on the actual wing surface depends greatly on the airfoil shape. As an example, in the case of calculating the lift acting on the blade surface, the lift L is obtained by the following equation.

Effective flow velocity (relative speed; v) on the wing surface is the take-off speed (speed where lift> aircraft weight)
The wings can take off without requiring a runway.
In this case, the front and back surfaces of the piezoelectric surface are complementary and symmetrical, and the flow velocity on the front and back surfaces is equal in single-surface operation. However, if the flow velocity on the front and back surfaces is different in the surrounding conditions, the above-mentioned [ Therefore, structural considerations are necessary to reduce the pressure difference between the front and back flow velocities.
In FIG. 9, (a) is a single surface, (b) is a complementary type, and (c) is a mechanism corresponding to a complementary cooperative type, taking into account the tension adjustment of the membrane surface, a symmetrical flow path, aeroelectric protection, etc. A three-dimensional expansion arrangement is easy.

The role of the auxiliary net contributes to the tensioning of the membrane surface, mutual suspension, adjustment of the resonance point, and increase of output at that point, but it requires some man-hours in manufacturing and may increase the cost. . Especially when high-speed driving is not required, a tensioning method suitable for the application such as one-point bonding, three-point bonding, five-point honeycomb, etc. can be considered, and simple bonding is easier to manufacture. .
FIG. 10 shows three examples.

FIG. 11 is an application example thereof, and FIG. 11A is similar to a single-sided paraglider, but can fly by itself. (B) is an example in which complementary piezoelectric surfaces of doubled thrust are used in parallel, and this is also a suspension type maneuver. In (c), the main wing and tail wing are equipped with this complementary and cooperating type device to enable take-off and landing by the Coanda effect.
These examples are basic shapes such as drive electrode and axial direction, stacking and bonding, shape and surface treatment, etc. If a power supply and drive circuit are mounted on this, propulsion flight can be performed with only the blade surface, and the wing length can be increased. If it is longer, the solar cell can be installed accordingly. A self-driving and self-contained aircraft using the energy received by the wing surface can be obtained.

FIG. 1A is a perspective view of a wave piezoelectric transducer corresponding to the present invention. FIG. 1A is a complementary diagram of a wave piezoelectric transducer . FIG. Principle of acoustic / electrical conversion using PVDF (Polyfucavinylidene) piezoelectric film Fig. 2 (a) External dimensions of conversion element (b) Conversion circuit diagram (c) Equivalent circuit diagram PVDF piezoelectric surface Fig. 3 (a) External shape of piezoelectric surface (b) Same as above, at maximum signal (c) Change at amplitude Fig. 4 (a) Tunnel-like wind tunnel (b) Six-phase AC drive voltage (c) Fluctuation at the center of the film surface When the piezoelectric surface is unified to give an internal pressure and driven by six-phase alternating current FIG. 5 (a) to (d) Changes in the film surface due to changes in the driving voltages (1) to (6) Form that converts contraction of piezoelectric surface into low frequency vibration (complementary suspension drive system) Fig. 6 (a) Parallel stretch of two piezoelectric surfaces (b) Curved by suspending the two surfaces to each other Fig. 6 (c) When the upper surface contracts (d) Intermediate point (e) When the lower surface contracts Collaborative operation with superimposed complementary drive type (a) Explanatory drawing of part 1 as a perspective view (b) Initial state, no signal (c) Central wind tunnel maximum (d) Central minimum Operation of the piezoelectric surface as viewed from the side (a) Operational perspective view of the internal piezoelectric surfaces 1-2, 1-3 The same figure (b) shows the movement of inhalation, (c) closing, (d) release by → sign Show. Cover / resonance frequency control mechanism perspective view with rhombus structure FIG. 9 (a) Protective cover / extension mechanism single surface (b) Complementary form (c) Complementary cooperative form Simplification of complementary cooperating piezoelectric surface (for low speeds, the suspension line is omitted and bonding is performed) Fig. 10 (a) In case of one point bonding (b) Three point bonding (c) Five point bonding Application of wave piezoelectric transducer to moving body, perspective view of three examples Fig. 11 (a) Hang glider type, (b) Wing plane body using parallel multiple use (c) One example when mounted on aircraft wing surface, perspective view Figure

DESCRIPTION OF SYMBOLS 1 Flexible piezoelectric film / surface 2 Electrode of piezoelectric surface 3 Auxiliary net 4 Support | pillar, support frame 5 Connection wiring 6 Signal power supply 7 Suspension line 8 Coupling line 9 Wind tunnel, flow path 10 Cover
11 Single piezoelectric surface wave piezoelectric transducer 12 Complementary wave piezoelectric transducer 13 Complementary cooperative wave piezoelectric transducer

Claims (3)

6 or more even number (6n) rectangular electrode pairs are provided in parallel along the axial direction in which the piezoelectric distortion is greatest, on the front and back surfaces of the flexible piezoelectric plate or film. A flexible piezoelectric surface that performs wave motion by applying a 6n-phase multi-phase AC voltage corresponding to these electrodes to each electrode in order of phase, and individually extending and contracting each electrode portion of the piezoelectric surface by a piezoelectric effect Are arranged in parallel so that the flexible piezoelectric surfaces face each other, and the axial central portions of the electrode pairs of the respective flexible piezoelectric surfaces are joined so that they are in contact with each other. The wave piezoelectric transducer characterized in that the multiphase AC voltage is applied so that when one side of the flexible piezoelectric surface is expanded, the other side contracts. The wave piezoelectric transducer according to claim 1 is referred to as a complementary wave piezoelectric transducer,
2. The wave according to claim 1, wherein at least two sets of the complementary wave piezoelectric transducers are arranged so that the flexible piezoelectric surfaces face each other to form complementary cooperative wave piezoelectric transducers. Piezoelectric transducer. Supporting each of the flexible piezoelectric surfaces of the wave piezoelectric transducer of claim 1 or claim 2 to adjust the tension applied to each of the flexible piezoelectric surfaces,
The frequency of the multiphase AC voltage applied to each flexible piezoelectric surface and the vibration frequency of each flexible piezoelectric surface are made to be in a resonance state. Wave piezoelectric transducer.

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