JP2008148439A - Oscillation-type actuator and control method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oscillatory actuator which can improve the durability of an oscillator. <P>SOLUTION: The oscillatory actuator has an oscillator comprising a piezoelectric substance 2 and an elastic body 1 and pinches a mobile object 3 in between the oscillator and a catching member 4, and makes the mobile object 3 shift relatively with the oscillator and the catching member 4. The mobile object 3 has a projection 3a on the side of the catching member 4, and the frictional force between the mobile object 3 and the catching member 4 is set larger than the frictional force between the mobile object 3 and the oscillator. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vibration type actuator using piezoelectric vibration and a control method thereof.

  The vibration type actuator is composed of at least a vibrating body made of a piezoelectric body and a moving body pressed against the vibrating body, and moves with the vibrating body by a frictional force generated between the moving body and vibration excited by the vibrating body. The body is configured to move relatively.

  Usually, in order to control the position change due to this relative movement, a sensor for position detection such as an optical sensor is provided. The position information detected by the sensor is compared with the target position, and the vibration excited by the vibrating body is detected. The position is controlled by controlling on and off.

  In Patent Document 1, a moving body is provided with a notch, and the position of the notch is moved to the antinode position of the standing wave excited by the vibrating body, and the position of the antinode of the standing wave is moved. A piezoelectric actuator that moves the position of the moving body has been proposed.

Further, in Patent Document 2, a protrusion is provided on a moving body, the protrusion and the vibrating body are brought into contact with each other, and the concave portion between the protrusions moves to the antinode position of the standing wave excited by the vibrating body. A piezoelectric actuator that moves the position of a moving body by moving the position of the antinode of the standing wave has been proposed.
Japanese Patent No. 3044750 Japanese Patent No. 297527

  However, as shown in Patent Document 1 and Patent Document 2 described above, in the configuration in which the vibrating body and the notch or protrusion are in contact with each other, there is a problem that the vibration body is easily worn and the vibration characteristics of the vibrator are changed. It was.

  Further, since the moving body is stopped at the antinode position of the standing wave by the balance of the force to be moved to both sides with the antinode of the standing wave as the center, the wear progresses further if the vibrating body is vibrated at the time of stopping. There was a problem.

  An object of the present invention is to provide a vibration type actuator capable of improving the durability of a vibrating body and a control method thereof.

  In order to achieve the above object, a vibration type actuator according to claim 1 is configured to sandwich a moving body between a vibrating body composed of a piezoelectric body and an elastic body, and the vibrating body and the sandwiching member, and In the vibration type actuator that moves relative to the vibrating body and the holding member, the moving body has a protrusion on the holding member side, and a frictional force between the moving body and the holding member is applied to the moving body. The frictional force between the body and the vibrating body is set to be larger.

  The vibration type actuator according to claim 2 is a vibration type actuator comprising a moving body in which vibration is excited, and first and second holding members that hold the moving body and move relative to the moving body. The movable body has an uneven portion on the first clamping member side, and a frictional force between the movable body and the first clamping member is generated between the movable body and the second clamping member. It is characterized by being larger than the frictional force.

  According to a fifth aspect of the present invention, there is provided a vibration type actuator control method comprising: a movable body that is excited by vibration; and a first and second sandwiching member that sandwiches the movable body and moves relative to the movable body. An actuator control method, wherein a frictional force between the movable body and the first clamping member is set larger than a frictional force between the movable body and the second clamping member, and the second clamping member The moving body is moved by changing the position of the antinode of the vibration wave excited upward.

  The vibration type actuator holds a moving body between a vibrating body made of a piezoelectric body and an elastic body, and the vibrating body and the holding member, and moves the moving body relative to the vibrating body and the holding member. The moving body has a protrusion on the holding member side, and the frictional force between the moving body and the holding member is set larger than the frictional force between the moving body and the vibrating body.

  With such a structure, the durability of the vibrator can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is an explanatory diagram of the driving principle and operation of the vibration type actuator according to the first embodiment of the present invention.

  In FIG. 1, the vibration type actuator includes a vibrating body including an elastic body 1 and a piezoelectric body 2 bonded to the elastic body 1. The piezoelectric body 2 has electrodes 2a and 2b. By applying an AC voltage to the electrode 2a or the electrode 2b, the position of the antinode of the bending vibration formed in the elastic body 1 is moved.

  The vibration actuator includes a moving body 3. The moving body 3 is sandwiched between the sandwiching member 4 and the elastic body 1 with a constant pressure. A protrusion 3 a which is a protrusion integrally formed with the moving body 3 is in pressure contact with the clamping member 4. Further, one surface of the moving body 3 is in contact with the elastic body 1, and the moving body 3 is also vibrated in response to the vibration of the elastic body 1.

  Further, the friction coefficient between the moving body 3 and the clamping member 4 is higher than the friction coefficient between the elastic body 1 and the moving body 3, and the driving force when the moving body 3 moves is mainly It is generated by the frictional force between the protrusion 3a and the clamping member 4.

  The driving principle will be described below. When an alternating voltage is applied to the electrode 2 a of the piezoelectric body 2, bending vibration is generated on the elastic body 1 as indicated by the dotted line shown in FIG. Accordingly, since a vibration antinode of the elastic body 1 is formed on the right side of the protrusion 3a of the moving body 3, a bending vibration having an antinode of vibration in the vicinity of the electrode 3a is also generated in the moving body 3.

  Then, by pushing up the right side of the projection 3a by the pushing-up force due to this bending vibration, a counterclockwise moment is generated in the projection 3a, and the movable body 3 is relatively moved to the right in the drawing between the projection 3a and the holding member 4. A moving force is generated. Since the frictional force between the moving body 3 and the elastic body 1 is designed to be low (such as lubricating oil and Teflon (registered trademark) coating), the moving body 3 moves to the right in the drawing.

  As the protrusion 3a approaches the antinode bending vibration of the elastic body 1, the moment gradually decreases, and when the protrusion 3a reaches the bending vibration antinode of the elastic body 1, the moment is completely reduced to zero. The moving body 3 stops.

  In FIG. 1, (a) shows a state in which an AC voltage is applied only to the electrode 2a, and shows a state in which a driving force to the right side of the paper is generated as described above.

  (B) has shown the case where the same alternating voltage is simultaneously applied to electrode 2a, 2b, and the position of the antinode of the bending vibration formed on the elastic body 1 becomes an intermediate position of the electrode 2a and the electrode 2b. The moving body 3 shows a state in which the protrusion 3a moves to the antinode position of the bending vibration and receives only the vibration in the push-up direction from the elastic body 1.

  (C) has shown the state which applied the alternating voltage only to the electrode 2b, and the position of the antinode of the bending vibration formed on the elastic body 1 becomes an intermediate position of the electrode 2b. Since there is an antinode of bending vibration on the left side of the protrusion 3 a, a clockwise moment is generated in the protrusion 3 a when the bending vibration pushes up the moving body 3, and the moving body 3 is relatively between the protrusion 3 a and the holding member 4. A force is generated to move to the left in the drawing.

  As described above, the moving body 3 moves so that the position of the protrusion 3 a follows the antinode position of the elastic body 1, so that the antinode position of the bending body formed on the elastic body 1 is moved. The moving body 3 can be moved to an arbitrary position.

  FIG. 2 is an external perspective view of the rotary vibration actuator according to the first embodiment of the present invention.

  In FIG. 2, the elastic body 1, the piezoelectric body 2, the moving body 3, and the clamping member 4 are each formed in an annular shape, and a disk 5 is integrally joined to the inside of the moving body 3, and the rotation provided at the center of the disk 5. A rotational force is extracted from the shaft 6.

  The clamping member 4 is integrally formed with the elastic body 1 by a support body (not shown), and is supported so as to be rotatable relative to the moving body 3. The moving body 3 has twelve protrusions 3a on the circumference.

  FIG. 3 is a diagram showing an electrode structure formed on the piezoelectric body in FIG.

  In FIG. 3, the piezoelectric body 2 is composed of 24 electrodes. Reference numerals shown in the respective electrodes indicate the polarization directions of the individual electrodes of the piezoelectric body 2, and the respective electrodes are connected to each other by the wiring means 7a or the wiring means 7b. AC voltages VA and VB having the same frequency are applied to the wiring means 7a and 7b, so that six-wave bending vibration is formed in the elastic body 1.

  FIG. 4 shows the relationship between the amplitude of the alternating voltage VA and the alternating voltage VB in FIG. 3, the amplitude of the bending vibration (φ), and the rotational angle (θ) of the moving body when the voltage amplitude is switched stepwise. FIG.

  3 and 4, when an AC voltage having an amplitude V is applied to the AC voltage VA, the AC voltage VA is applied to the electrodes 2a and 2c of the piezoelectric body 2 connected by the wiring means 7a, and the electrodes 2a and 2c A standing wave having an antinode position of bending vibration around the center is excited.

  Further, the vibration directions of this bending vibration in the electrode 2a and the electrode 2c are opposite to each other. In FIG. 4, the positions of the antinodes are indicated by solid lines and dotted lines. Since the position of the protrusion 3a formed on the moving body 3 rotates so that the moving body 3 follows the antinode position of the bending vibration formed on the elastic body 1, the protrusion 3a is formed at the center position of the electrode 2a. Will move.

  Here, assuming that the intermediate position between the electrodes 2b and 2c of the piezoelectric body 2 is 0 degree, the 24 electrodes are arranged at equal intervals on the circumference, so the center position of the electrode 2a is 22.5 degrees.

  Next, consider the case where the AC voltage VB is also set to the amplitude V. When the AC voltages VA and VB are simultaneously applied to the wiring means 7a and 7b in the same phase, the AC voltage VB having the same voltage as the AC voltage VA is applied to the electrodes 2b and 2d simultaneously with the electrodes 2a and 2c of the piezoelectric body 2.

  Then, since the position of the antinode of the bending vibration formed on the elastic body 1 is an intermediate position between the electrode 2a and the electrode 2b, the position of the protrusion 3a of the moving body 3 is also an intermediate position between the electrode 2a and the electrode 2b. Move to the degree position.

  Next, when the AC voltage VA is set to 0, the antinode position of the bending vibration formed on the elastic body 1 moves to the center position of the electrodes 2b and 2d, so that the protrusion 3a of the moving body 3 is further 7.5 degrees. It rotates and moves to a position of 7.5 degrees which is the center position of the electrode 2b.

  Next, the amplitude of the AC voltage VA is set to −V while the AC voltage VB is generated with the amplitude V. This symbol indicates phase inversion, and indicates that the phases of the AC voltage VA and the AC voltage VB are inverted.

  Then, the antinode of the bending vibration formed on the elastic body 1 is an intermediate position between the electrode 2b and the electrode 2c. Accordingly, in the same manner as described above, the protrusion 3a of the moving body 3 rotates to a position of 0 degrees that is an intermediate position between the electrode 2b and the electrode 2c.

  In this way, the rotational position of the movable body 3 can be moved stepwise by switching the antinodes of the bending vibration formed on the elastic body 1 in a stepwise manner.

  Next, an operation when the AC voltages VA and VB are continuously switched instead of stepwise will be described.

  FIG. 5 shows the relationship between the amplitude of the alternating voltage VA and the alternating voltage VB in FIG. 3, the antinode position (φ) of the bending vibration, and the rotational angle (θ) of the moving body when the voltage amplitude is continuously switched. FIG.

  In FIG. 5, by switching the alternating voltages VA and VB sinusoidally, the antinode position of the bending vibration is continuously moved, and the moving body 3 is also moved continuously following that. The AC voltage VA and the AC voltage VB are sinusoidal shapes that are substantially 90 degrees out of phase, and the moving body 3 can be moved to an arbitrary position by calculating in advance the amplitude of the AC voltage with respect to the position. Can do.

  In this way, the movable body 3 having the surface provided with the projections and recesses 3 a is sandwiched between the elastic body 1 and the sandwiching member 4, and the movable body 3 is elastically made using the frictional force between the projection 3 a and the sandwiching member 4. It can be moved relative to the body 1 and the clamping member 4.

[Second Embodiment]
FIG. 6 is an explanatory diagram of the driving principle of the vibration type actuator according to the second embodiment of the present invention.

  In FIG. 6, a, b, c, d, and e represent how the bending vibration formed on the elastic body 1 moves in order from a while the amplitude of the wave increases and decreases. The increase / decrease in the amplitude of the wave occurs at substantially the same interval as the interval between the protrusions 3a formed on the moving body 3, and the bending vibration formed on the elastic body 1 is in contact with the moving body 3 near the largest amplitude. .

  Therefore, the movable body 3 moves following the position where the position of the protrusion 3a is always in contact with the largest amplitude of the bending vibration formed on the elastic body 1.

  (A) and (b) represent the passage of time and show how the largest amplitude position of the bending vibration formed on the elastic body 1 moves. Δθ represents the amount of movement of the largest amplitude position of the bending vibration formed on the elastic body 1 over time.

  Thus, the moving body 3 can be moved smoothly by gradually moving the position of the largest amplitude of the bending vibration formed on the elastic body 1.

  FIG. 7 is a block diagram showing an example of a control circuit for generating a bending vibration subjected to amplitude modulation in the vibration type actuator according to the second embodiment of the present invention.

  In FIG. 7, this control circuit has a comparison means 10 for detecting a difference between a speed command from a command means (not shown) and a speed detection signal from a speed detection means for detecting the speed of a moving body (not shown). . Further, there is an adding means 11 for adding a drive frequency command from a command means (not shown) and an output of the comparison means 10 to generate a second drive frequency command.

  In addition, this control circuit has AC voltage generating means 12 and 13 and inductance elements 14, 15, 16, and 17 for generating two-phase AC voltages whose phases are shifted by 90 degrees at a frequency according to the drive frequency command. .

  One of the output voltages of the AC voltage generating means 12 is applied to the electrode 2 a of the piezoelectric body 2 via the inductance element 14. The other output voltage of the AC voltage generating means 12 is 90 degrees behind in phase with respect to the other, and is applied to the electrode 2 b of the piezoelectric body 2 via the inductance element 17.

  One of the output voltages of the AC voltage generating means (phase difference AC voltage generating means) 13 is applied to the electrode 2 b of the piezoelectric body 2 via the inductance element 16. Further, the other output voltage of the AC voltage generating means 13 is delayed in phase by 90 degrees with respect to the other, and is applied to the electrode 2 a of the piezoelectric body 2 via the inductance element 15.

  As described above, when an AC voltage having a phase difference of 90 degrees is applied to the electrodes 2a and 2b of the piezoelectric body 2, the elastic body 1 can generate a progressive bending vibration that rotates around the circumference. The AC voltage generators 12 and 13 are set to have a phase difference so that progressive bending vibrations rotating in opposite directions are formed on the elastic body 1.

  Here, the reason why the progressive bending vibration in the reverse direction is generated will be briefly described. If it is possible to arbitrarily set the traveling speed of a traveling wave, it is possible to arbitrarily set the rotational speed of the moving body 3 that rotates following the wave front.

  However, in practice, the wave traveling speed is proportional to the driving frequency in a narrow band that depends on the resonance frequency of the elastic body 1 and normally moves on the elastic body 1 at a high speed. It is difficult to rotate with.

  Therefore, in the present embodiment, progressive bending vibrations of the same wave number traveling in opposite directions are generated at the same time, and a wave having a modulated amplitude that maximizes the bending vibration amplitude at the position where the wave fronts overlap is used. The protrusion 3a of the moving body 3 is caused to follow the point.

  This maximum point is generated approximately once every time the traveling bending vibration moves by one wave, and by giving a difference between the frequencies of the two traveling waves, the position where the amplitude is maximum is the difference between the frequencies. It moves at a speed proportional to. Further, the moving direction of the maximum point can be reversed if the frequency is changed, and can be stopped if the frequency is the same.

  Thus, since the maximum point of amplitude can be smoothly moved to an arbitrary position at an arbitrary speed, the rotational position of the moving body 3 can be similarly moved.

[Third Embodiment]
FIG. 8 is a configuration diagram of a vibration-type piezoelectric actuator according to the third embodiment of the present invention.

  In FIG. 8, the piezoelectric vibrators 18a, 18b, 18c, 18d, 18e, 18f, and 18g vibrate so as to push up in contact with the moving body 3 in the vertical direction of the paper.

  Although not shown in the figure, the required number of piezoelectric vibrators 18 are arranged in the horizontal direction according to the system, and any piezoelectric vibrator 18 can be vibrated independently. The figure shows a state in which the piezoelectric vibrators 18a, 18d, and 18g are vibrated in the same phase, and the protrusion 3a of the moving body 3 moves to the contact position between the piezoelectric vibrators 18a, 18d, and 18g and the moving body 3. Yes.

  When the piezoelectric vibrators 18b and 18e are vibrated, the moving body 3 moves in the right direction of the paper, and when the piezoelectric vibrators 18c and 18f are vibrated, the moving body 3 moves in the left direction of the paper and the protrusion 3a of the moving body 3 Moves to a position where each vibrating piezoelectric vibrator comes into contact with the moving body 3.

  Further, when the piezoelectric vibrators 18a, 18d, and 18g and the piezoelectric vibrators 18b and 18e are simultaneously vibrated with the same force, the protrusion 3a of the moving body 3 is located at an intermediate position between the piezoelectric vibrator 18d and the piezoelectric vibrator 18e. Moving.

  Further, when the piezoelectric vibrators 18a, 18d, and 18g and the piezoelectric vibrators 18b and 18e are vibrated simultaneously with different forces, the protrusion 3a of the moving body 3 is moved to the piezoelectric vibrator 18d and the piezoelectric vibration according to the ratio of the forces. Move to a position between the child 18e.

  In the present embodiment, a one-dimensional example is shown. However, the piezoelectric vibrator 18 and the protrusions 3a of the moving body 3 may be two-dimensionally arranged in a lattice shape.

[Fourth Embodiment]
FIG. 9 is a configuration diagram of a piezoelectric vibrator of a vibration type actuator according to the fourth embodiment of the present invention.

  In FIG. 9A, the piezoelectric body 9 is bonded to one surface of a rectangular plate-like elastic body 8. (B) has shown the electrode pattern for the electric power feeding provided in the piezoelectric material 9, and has divided the longitudinal direction into two, the electrodes 9a and 9b.

  FIG. 10 is a diagram showing a vibration shape of the piezoelectric vibrator (elastic body and piezoelectric body) of FIG.

  (A) is a figure which shows the bending vibration formed in the elastic body 8 when the alternating voltage of a negative phase is applied to the electrode 9a and the electrode 9b of the piezoelectric body 9. FIG. A bending vibration having two antinodes in the longitudinal direction is formed.

  (B) is a diagram showing bending vibration formed in the elastic body 8 when an in-phase AC voltage is applied to the electrodes 9a and 9b of the piezoelectric body 9. FIG. A bending vibration having one antinode in the short side direction is formed.

  (C) is a diagram showing bending vibration formed in the elastic body 8 when an AC voltage having a phase of 90 degrees is applied to the electrodes 9 a and 9 b of the piezoelectric body 9. A bending vibration is formed by combining the waves of (a) and (b).

  As described above, when an AC voltage is applied to the electrodes 9a and 9b with a phase difference of 90 degrees, it is possible to simultaneously generate bending vibrations having different vibration shapes. (C) shows the bending vibration of (a) and (b) superimposed, but the phase difference of (a) or (b) is reversed by setting the phase difference of 90 degrees to -90 degrees. Can be stacked.

  FIG. 11 is a diagram illustrating a vibration waveform of the piezoelectric vibrator of FIG.

  11A and 11E show the vibration of FIG. 10A, and the waveform shows the displacement amount of the maximum displacement point of the bending vibration.

  FIG. 11B shows the vibration of FIG. 10B, and similarly shows the displacement at the maximum displacement point of the bending vibration.

  (F) in FIG. 11 shows the antiphase vibration of (b) in FIG. 10, and similarly shows the displacement at the maximum displacement point of the bending vibration.

  (C) and (d) of FIG. 11 show the vibration of (c) of FIG. 10, and (c) of FIG. 11 has the same maximum value of the bending vibration of (a) and (b) of FIG. The vibration waveform of the point 8a on the elastic body 8 overlapping in the direction is shown.

  FIG. 11D shows the vibration waveform of the point 8b on the elastic body 8 where the maximum values of (a) and (b) overlap in the opposite direction. By synthesizing the vibration in this way, the vibration amplitudes of the points 8a and 8b on the elastic body 8 which are the antinode positions of the vibration can be made different.

  Further, (g) and (h) in FIG. 11 are vibrations obtained by synthesizing the vibrations in (e) and (f) of FIG. Since the vibration phase of (f) in FIG. 11 is opposite to that of (b), the amplitude relationship between points 8a and 8b on the elastic body 8 is the same as (c) and (d) in FIG. It has been replaced.

  An example in which a vibration type actuator is configured using this piezoelectric vibrator is shown below.

  FIG. 12 is an explanatory diagram (1) of the driving principle of the vibration type actuator according to the fourth embodiment.

  Specifically, a configuration in which the movable body 20 is sandwiched between the elastic body 8 whose side surfaces are hatched and the sandwiching member 19 is shown. A protrusion 20 a is formed on the moving body 20, and the protrusion 20 a is in contact with the clamping member 19.

  (A) and (b) show a state in which the phase is shifted by 180 degrees in time, and the waveforms shown by the thick solid line and the dotted line show the vibration amplitude when the elastic body 8 contacts the moving body 20. . A thick solid line and a thick dotted line show waveforms in a state where the phase is shifted by 180 degrees in time. The line indicating the center of vibration is a line substantially parallel to the moving body 20, and the thick solid line and the thick dotted line have substantially the same amplitude as indicated by the arrows.

  The positions of the antinodes of the vibrations that are shifted in phase by 180 degrees in time are the points 8a and 8b on the elastic body 8, so that the protrusion 20a of the moving body 20 is an intermediate position between the points 8a and 8b on the elastic body 8. Move to become.

  FIG. 13 is an explanatory diagram (2) of the driving principle of the vibration type actuator according to the fourth embodiment.

  Specifically, FIG. 11 is a diagram showing a contact state between the movable body 20 and the elastic body 8 in the vibration state shown in FIG. The side surface of the elastic body 8 is hatched.

  In this example, in FIGS. 11 (c) and 11 (d), the vibration amplitude of the points 8a and 8b on the elastic body 8 is larger than 8b because the vibration amplitude of the points 8a and 8b is larger than 8b. Yes. Therefore, the protrusion 18a of the moving body 18 is moved toward the point 8a on the elastic body 8 that generates a large excitation force.

  As described above, according to the present embodiment, the point 8a on the elastic body 8 is changed by changing the phase difference of the AC voltage applied to the electrodes 9a and 9b of the piezoelectric body 9 between 0 degrees and 180 degrees. It is possible to move the position of the protrusion 20a of the moving body 20 to an arbitrary position between 1 and 8b.

It is explanatory drawing of the drive principle and operation | movement of a vibration type actuator which concerns on the 1st Embodiment of this invention. 1 is an external perspective view of a rotary vibration actuator according to a first embodiment of the present invention. It is a figure which shows the electrode structure formed in the piezoelectric material in FIG. It is a figure which shows the relationship at the time of switching the voltage amplitude of AC voltage VA and AC voltage VB in FIG. 3 stepwise, the position (phi) of a bending vibration antinode, and the rotation angle (theta) of a moving body. It is a figure which shows the relationship of the amplitude at the time of switching the voltage amplitude of AC voltage VA in FIG. 3, and AC voltage VB continuously, the position (phi) of a bending vibration antinode, and the rotation angle ((theta)) of a moving body. It is explanatory drawing of the drive principle of the vibration type actuator which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the example of the control circuit for generating the bending vibration in which the amplitude modulation was applied in the vibration type actuator which concerns on the 2nd Embodiment of this invention. It is a block diagram of the vibration type piezoelectric actuator which concerns on the 3rd Embodiment of this invention. It is a block diagram of the piezoelectric vibrator of the vibration type actuator which concerns on the 4th Embodiment of this invention. It is a figure which shows the vibration shape of the piezoelectric vibrator (an elastic body and a piezoelectric body) of FIG. It is a figure which shows the vibration waveform of the piezoelectric vibrator of FIG. It is explanatory drawing (1) of the drive principle of the vibration type actuator of 4th Embodiment. It is explanatory drawing (2) of the drive principle of the vibration type actuator of 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 8 Elastic body 2, 9 Piezoelectric body 3, 20 Moving body 3a, 20a Protrusion 4, 19 Holding member 5 Disk 6 Rotating shaft 7 Wiring means 10 Comparison means 11 Addition means 12, 13 AC voltage generation means 14, 15 16, 17 Inductance element 18 Piezoelectric vibrator

Claims (7)

In a vibrating actuator comprising a piezoelectric body and an elastic body, a moving body sandwiched between the vibrating body and the clamping member, and moving the moving body relative to the vibrating body and the clamping member,
The moving body has a protrusion on the holding member side, and the frictional force between the protrusion of the moving body and the holding member is set larger than the frictional force between the moving body and the vibrating body. A vibration type actuator characterized by being.   A vibration type actuator comprising a moving body excited by vibration, and first and second holding members that sandwich the moving body and move relative to the moving body, the moving body including the first actuator A vibration characterized by having a concavo-convex portion on the side of the holding member and a frictional force between the moving body and the first holding member being larger than a frictional force between the moving body and the second holding member. Type actuator.   The vibration type actuator according to claim 2, wherein the movable body vibrates according to the vibration of the second holding member.   4. The vibration type actuator according to claim 3, wherein a piezoelectric body is bonded to the second clamping member on a surface opposite to the contact portion with the moving body. A control method of a vibration type actuator comprising a moving body excited by vibration, and first and second holding members that sandwich the moving body and move relative to the moving body. The frictional force between the first clamping member is set to be larger than the frictional force between the movable body and the second clamping member;
A control method of a vibration type actuator, wherein the moving body is moved by changing a position of an antinode of a vibration wave excited on the second holding member.   The position and amplitude of the vibration wave excited on the second clamping member are periodically changed, and the movable body is moved by changing the position that becomes the maximum point of the amplitude change that is periodically repeated. The method for controlling a vibration type actuator according to claim 5.   6. The method of controlling a vibration type actuator according to claim 5, wherein a plurality of vibrations are excited at different positions on the second holding member, and the moving body is moved by changing the balance of the amplitudes. .

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