JPH0947048A - Oscillator for ultrasonic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillator for ultrasonic actuator in which a high thrust can be obtained without limiting the profile of oscillator and the moving direction of a mover can be changed easily. SOLUTION: First and second piezoelectric bodies 3, 4 are arranged between a pair of annular resilient bodies 1 and tightened by means of a bolt 24 having a hexagonal hole and a nut 25 through a washer 26. The piezoelectric bodies 3, 4 comprise annular split piezoelectric elements 3a, 3b, 4a, 4b polarized in the opposite directions, and electrode plates 6a, 6b disposed between and arranged symmetrically on the opposite sides of a central plane extending in parallel with the axial direction of an oscillator 2. The electrode plate 6a of first piezoelectric body 3 is connected through an amplifier 27 and a phase shifter 28 with a two-phase oscillator 29 while the electrode plate 6b of second piezoelectric body 4 is connected with the two-phase oscillator 29. The resilient bodies 1 are grounded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibrator for an ultrasonic actuator using a piezoelectric element.

[0002]

2. Description of the Related Art Ultrasonic actuators are characterized in that they can provide high thrust for small size, light weight and low cost as compared with other actuators such as electromagnetic actuators. As a piezoelectric vibrator for this kind of ultrasonic actuator, Japanese Patent Laid-Open No. 63-316674 proposes a piezoelectric vibrator capable of drawing a curved closed path in an arbitrary direction at the tip of the vibrator by an electric signal. ing. As shown in FIG. 33, the piezoelectric vibrator 51 has a first piezoelectric element 51a having two regions whose polarization directions are opposite to each other and a second piezoelectric element 51b having all regions having the same polarization direction as a reference. The electrodes 52c are stacked with the electrode 52c interposed therebetween. First piezoelectric element 51
The piezoelectric element 51 faces a reference electrode 52c and
Electrodes 52a and 52b are formed so as to divide a into two regions. The second piezoelectric element 51b has a reference electrode 52c.
An electrode 52d is formed so as to face with. The vibrating body 53 is bonded to the electrodes 52a and 52b of the piezoelectric vibrator 51. Then, with the electrodes 52a and 52b short-circuited by the lead wire 54a, the lead wire 54 is connected to the first piezoelectric element 51a.
The periodic voltage is applied from the AC power supply 55a via a and 54b, and the periodic voltage is applied from the AC power supply 55b to the second piezoelectric element 51b via the lead wires 54b and 54c.

When the periodic voltage is applied only to the first piezoelectric element 51a, the piezoelectric element 51a moves to the tip portion 53 of the vibrating body 53.
A reciprocating motion of an arcuate locus is generated in a. When the periodic voltage is applied only to the second piezoelectric element 51b, the piezoelectric element 51b
Reference character b causes the tip portion 53a of the vibrating body 53 to reciprocate along a linear locus in the central axis direction of the vibrating body 53. Therefore, the vibrations generated by the first and second piezoelectric elements 51a and 51b are combined by making the cycles of the voltages applied to the two piezoelectric elements 51a and 51b different, or making the phases different at the same cycle, thereby generating vibrations. Vibration that forms a locus of a curved circuit can be generated at the tip portion 53a of the body 53.

Further, Japanese Patent Laid-Open No. 5-64465 discloses that
As a drive source, an ultrasonic transducer has been proposed which can simply switch the operation direction of an output applied to the outside of a movable body or the like, while it is sufficient to excite longitudinal vibration. As shown in FIG. 34 (a), this transducer includes a vertical excitation means 61 for outputting a vertical vibration, and a vibration direction control means for receiving the vertical vibration and outputting a bending vibration in a direction intersecting the vibration direction. And 62. The vertical-direction excitation means 61 is formed of a Langevin type vertical vibrator, and includes a vertical-direction piezoelectric element 63 that vibrates in the axial direction, and two electrodes 64a,
A drive voltage is applied by the power supply 65 via 64b.
The vibration direction control means 62 is formed by a piezoelectric element 66 having one end surface in close contact with the end surface of the vertical direction excitation means 61, and a vibrator 67 in close contact with the other end surface. Then, when the vertical vibration is output from the vertical excitation means 61, the vibration direction control means 62 which receives the vertical vibration outputs the flexural vibration vibrating in the direction intersecting the vertical vibration, and the flexural vibration and the The vertical direction vibration is combined, and the vibration direction control means 62 vibrates while drawing a Lissajous.

Further, in Japanese Unexamined Patent Publication No. 6-197572, as shown in FIG. 34 (b), a cylindrical metal block 7 is used.
1, ring-shaped piezoelectric vibrator 72, divided electrodes 73a, 73
There has been proposed a vibration type driving means (vibrator) 78 in which b, a ring-shaped piezoelectric vibrator 74, a ring-shaped electrode 75, and a metal block 76 are sequentially laminated in an abutting state and fixed by a screw 77. This vibrating drive means 78 is used for the divided electrodes 73a, 7a.
By applying a high-frequency AC voltage between any one of 3b and the ring-shaped electrode 75, longitudinal vibration and bending vibration are generated in the axial direction, and an arbitrary point on the drive surface 71a forms an elliptical locus. Exercise. The direction of movement of the elliptical locus can be changed by switching the divided electrodes 73a and 73b to which an alternating voltage is applied.

[0006]

Problems to be Solved by the Invention JP-A-63-3166
In the piezoelectric vibrator disclosed in Japanese Patent Publication No. 74, the first piezoelectric element 5
Since 1a has different left and right polarization directions, an unpolarized region exists at the boundary near the center of the piezoelectric element.
Since it is difficult to apply uniform polarization treatment to the left and right, it is difficult to match the vibration characteristics of the left and right. In addition, the first piezoelectric element 51
a causes arc-shaped reciprocating vibration at the tip portion 53a of the vibrating body 53 due to the maximum displacement of both left and right ends. Therefore, in order to increase the displacement of the arcuate reciprocating vibration, the distance between the left and right ends of the first piezoelectric element 51a is set large.

Further, the polarization directions of the first and second piezoelectric elements 51a and 51b on the upper and lower surfaces are different between the right side and the left side. As a result, as shown in FIG. 35 (a), the left side becomes a vibration in which the lower part contracts when the upper part expands and the upper part contracts when the lower part expands. Further, as shown in FIG. 35 (b), the right side expands and contracts in the same manner vertically. Therefore, the upper and lower first piezoelectric elements 5
1a has the second piezoelectric element 51b, the right and left vibrations are different, and the piezoelectric elements have an integral structure, so that they are affected by both vibration displacements, and the vibration of the entire vibrator The displacement may be suppressed to a small value, resulting in an inefficient vibrator.

Further, in order to expand the vibration displacement, it has been proposed to stack a plurality of first piezoelectric elements 51a and second piezoelectric elements 51b on the upper and lower surfaces, respectively.
First piezoelectric element 5 that produces the above-described non-uniform vibration displacement characteristics
Since the combination of 1a and the second piezoelectric element 51b is selected, the effect cannot be expected so much. Therefore, judging from the structure, this piezoelectric vibrator is effective as an actuator vibrator for relatively low thrust,
It seems that it is not suitable for actuator vibrators that are small and require large thrust.

Japanese Unexamined Patent Publication Nos. 5-64465 and 6-
In the device described in Japanese Patent Laid-Open No. 197572, the longitudinal vibration of the rod-shaped vibrator and the length resonance of the bending vibration are used, so that the vibration becomes long in the axial direction. In addition, because there is no optimal method for supporting and fixing the vibrator, it is necessary to provide a flange near the node of vibration, or to provide peripheral support and fixing parts at several points on the outer circumference, which causes the device to become large. There is. Further, since the resonance is used, there is a problem that the degree of freedom in design is small and only the vibrator having a limited size can be manufactured.

The present invention has been made in view of the above conventional problems, and a first object thereof is to provide a vibrator for an ultrasonic actuator, in which the shape of the vibrating body is less limited and a large thrust can be obtained. The second purpose is to
In addition to the above-mentioned object, it is an object of the present invention to provide a vibrator for an ultrasonic actuator, which can easily change the moving direction of a moving body.

[0011]

In order to achieve the above-mentioned object, according to the invention of claim 1, there is provided a vibrator for an ultrasonic actuator constituted by a piezoelectric element exhibiting stretching vibration, wherein the vibrator is provided in a first direction. On the other hand, piezoelectric elements are arranged in at least two layers, and at least two layers of the piezoelectric elements are divided into a first piezoelectric body and a second piezoelectric body with a plane parallel to the first direction as a boundary. The first piezoelectric body and the second piezoelectric body have polarization directions parallel to the first direction and opposite to each other on different sides with respect to a surface orthogonal to the first direction. According to a second aspect of the invention, the first piezoelectric body and the second piezoelectric body are in a state orthogonal to the first direction in the invention according to the second aspect. Third composed of a piezoelectric element that can face the body A piezoelectric body is disposed, and the third piezoelectric body has at least two polarization directions that are parallel to the first direction and opposite to each other on different sides with respect to a surface orthogonal to the first direction. It is composed of layers of piezoelectric elements.

According to a third aspect of the present invention, in the first aspect of the invention, the first direction is the axial direction of the vibrator, and the center plane of the vibrator parallel to the first direction is a boundary. Then, the first piezoelectric body and the second piezoelectric body are divided and arranged,
The fourth piezoelectric body is placed at a position where the phase is shifted by 90 ° with respect to the first piezoelectric body and the second piezoelectric body with respect to the central axis of the vibrator and does not interfere with the first piezoelectric body and the second piezoelectric body. And a fifth piezoelectric body are arranged, and the fourth piezoelectric body and the fifth piezoelectric body have their respective polarization directions on different sides with respect to a surface orthogonal to the first direction. It is composed of at least two layers of piezoelectric elements that are parallel to the direction and opposite to each other.

According to a fourth aspect of the present invention, there is provided an ultrasonic actuator oscillator comprising a piezoelectric element exhibiting stretching vibration, wherein first and second sides are provided on both sides of a plane parallel to the first direction. At least one piezoelectric element and at least one second piezoelectric element are arranged, respectively, and a third piezoelectric element that is in a state orthogonal to the first direction and that can face the first piezoelectric element and the second piezoelectric element. Are arranged, and the polarization directions of the first piezoelectric element and the second piezoelectric element and the polarization direction of the third piezoelectric element are different from each other on the sides different from each other with the plane orthogonal to the first direction as a boundary. It is set to be parallel to the direction of 1 and opposite to each other.

According to a fifth aspect of the invention, in the invention according to any one of the first to fourth aspects, the vibrator has the piezoelectric elements arranged between a pair of elastic bodies. , Is fastened and fixed by a fastener penetrating the elastic body.

According to the first, second, and fourth aspects of the invention, the end portions of the vibrator are stretched by the stretching vibrations of the piezoelectric elements arranged on both sides of the plane parallel to the first direction. Figure 1
Displacement occurs in the step shown in (a), and an arbitrary point (for example, M) on the end surface 1a of the vibrator moves along the locus Q of the curved circuit which is the displacement shown in FIG. 1 (b). In the process of (1), the one equivalent to the lateral thrust is obtained as the rotational moment of the couple, and the couple is positively generated by the expansion and contraction vibration of the piezoelectric element arranged with the plane parallel to the axial direction of the vibrator as a boundary. And a large displacement of the lateral vibration component is obtained.

The locus of the curved circuit presenting the end face of the vibrator is the curve C that allows the moving body to move in one direction.
L, for example, a perfect circle (as shown in FIG. 1, etc.), an ellipse ((a) of FIG. 36), a distorted ellipse ((b) of FIG. 36),
For example, it is an 8-shaped curve ((c) in FIG. 36). That is, as shown in FIG. 37, the moving body cannot be moved on a curve open path locus such as a curve with no internal space even if it is a curve CL, and if the curve closed path locus has an internal space, the moving body is moved. It can be moved.

In the invention described in claim 3, 90 ° to each other
The moving direction given to the moving body by the vibrator is changed to four directions depending on which one of the two piezoelectric bodies arranged with the phase difference of 2 is driven.

According to a fifth aspect of the invention, each piezoelectric element is arranged between a pair of elastic bodies and is fastened and fixed by a fastener penetrating the elastic bodies. Compared with the method of arranging (stacking) the piezoelectric elements by means of adhesive bonding, the piezoelectric elements are more likely to be displaced during driving and stable vibration characteristics are obtained when the piezoelectric elements are arranged (laminated) using a fastener. Obtainable. Further, in the case of tightening and fixing with a fastener penetrating the elastic body at the center of the vibrator, the tightening portion by the fastener becomes the center axis of the vibrator. Then, the force due to the stretching vibration generated in the piezoelectric elements arranged symmetrically with respect to the central axis makes it easy to generate the rotational moment of the couple.

In the present invention, the first direction may be any direction, and the surface parallel to the first direction may be any surface in the vibrator. Among them, it is preferable that the first direction is the axial direction of the vibrator and the plane parallel to the first direction (axial direction of the vibrator) is the center plane of the vibrator. This is because the piezoelectric elements can be evenly arranged on both sides of the center surface of the vibrator, and a well-balanced displacement can be obtained.

The vibrator may be composed of only a piezoelectric element, or may be composed of a combination of a piezoelectric element and an elastic body. Further, as the means for stacking the piezoelectric elements, any form such as a form of adhesive bonding, a form of tightening and fixing with a fastener, or the like may be used, but as described above,
A form in which the fastener is tightened and fixed is preferable.

The vibrator of the present invention does not have to take a structure using the axial length resonance of an elastic body or the like (resonance can be used),
The structure is based on the stretching vibration of the piezoelectric element. Therefore, there are many possible variations in design. For example,
If there is a thin piezoelectric element, an extremely thin vibrator can be constructed. Further, there are few special limitations on the shape of the piezoelectric element and the shape of the elastic body.

Further, the vibrator of the present invention can be easily manufactured by a mechanical coupling method such as fastening an elastic body and a piezoelectric element with screws and bolting. It should be noted that the base end of the vibrator may be a completely fixed portion to have a cantilever structure. Further, the elastic protrusion that serves as a contact portion with the moving body used in the vibrator of the present invention uses a head such as a bolt so as to have both functions of fastening the elastic body and the piezoelectric element and expanding displacement. it can.

Since the vibrator does not specially utilize the resonance of the elastic body or the like, it is not necessary to strictly control the resonance frequency. As a result, even when the actuator is configured by using a large number of vibrators, the fabrication becomes easy.

The ultrasonic actuator using the vibrator of the present invention can be used in equipments and devices which are small in size, light in weight and require low speed and high thrust. It needs to be thin and compact, and is suitable for use in areas where electromagnetic actuators cannot be used.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) The invention according to claim 1 is, for example, as shown in FIG. 2, a first piezoelectric body arranged on both sides of a center plane parallel to the axial direction of the vibrator 2. The third piezoelectric body 4 and the second piezoelectric body 4 are fastened and fixed by the fastener 5 via the pair of elastic bodies 1. The two piezoelectric bodies 3 and 4 are polarized in opposite directions (the polarization directions are parallel to the axial direction of the vibrator and opposite to each other on different sides with the plane orthogonal to the axial direction of the vibrator as a boundary). 2 layers of piezoelectric elements 3a, 3
b, 4a, 4b. This two-layer piezoelectric element 3
electrode plates 6a, 6b arranged between a, 3b, 4a, 4b
A-phase and B-phase AC drive voltages are applied to both piezoelectric bodies 3, 4 via
(Oscillator, phase shifter, amplifier, etc. are not shown). When a phase difference of + 90 ° is applied to the A phase and the B phase, the drive voltage / displacement waveform shown in FIG.
Each have the same form of displacement as the corresponding drive voltage waveform. That is, at the time of, both piezoelectric bodies 3 and 4 are expanded and
In the state of (a), at the time of, the first piezoelectric body 3
Contracts and the second piezoelectric body 4 expands to the state shown in FIG. At the time point of, both piezoelectric bodies 3 and 4 contract and become the state of FIG. 1A, and at the time point of, the first piezoelectric body 3 extends and the second piezoelectric body 4 contracts and the state of FIG.
It becomes the state of. Therefore, in the vicinity of the central axis of the tip of the vibrator 2 (point M), the elliptical locus of the counterclockwise displacement shown in FIG. 1B is obtained.

When a phase difference of −90 ° is applied to the A phase and the B phase, the drive voltage / displacement waveform shown in FIG. 3B is obtained, and the piezoelectric bodies 3 and 4 have the same drive voltage waveforms. It becomes a displacement of form. Therefore, the displacement occurs in the order of →→→, and an elliptical locus of the clockwise displacement of the point M is obtained.
That is, the phase difference between the applied voltages of the A and B phases is + 90 ° and −90.
By switching to and, the elliptical locus of displacement is redirected.

Further, as shown in FIG. 4, the structure of the vibrator 2 is almost the same as that of FIG. 2, and the protrusion Ta of the elastic body is formed at a position corresponding to the first piezoelectric body 3 and the second piezoelectric body 4. When Tb is provided, the direction of displacement is changed by switching the switch 7 in one-phase driving instead of two-phase driving. Figure 6
As shown in, the optimum position of the protrusion Ta is near the right side position (between the vibration loop (antinode) and the node (node)) with respect to the center axis Oa in the width direction of the first piezoelectric body 3, and It is near the left side position (between the vibration loop (antinode) and the node (node)) with respect to the center axis Ob in the width direction of the piezoelectric body 4.

When the piezoelectric bodies 3 and 4 expand and contract as shown in FIG. 5A, a displacement gradient is generated in the vicinity of the left and right ends thereof as shown in FIG. 5B. When an elastic protrusion is provided directly above the displacement gradient, Δx and Δy are provided at the tip of the protrusion.
The displacement of the two components of The elastic body 1 produces a displacement gradient as shown in FIG. 6 based on the stretching vibration of the piezoelectric bodies 3 and 4. Then, the projection Ta provided on the first piezoelectric body 3 side
When a displacement of Δy is produced, a displacement of + Δx is produced at the same time, and when the movable body 8 is brought into contact with the tip end of the protrusion Ta, FIG.
As shown in FIG. 5, a vibration displacement component that moves diagonally to the right is generated as a combined displacement, and the moving body 8 tries to move to the right. In addition, the protrusion Tb provided on the second piezoelectric body 4 side
When the displacement of Δy is generated, the displacement of −Δx is generated at the same time, and when the moving body 8 is brought into contact with the tip of the protrusion Tb, the state shown in FIG.
Similarly to the above, as shown in FIG. 7B, a vibration displacement component that moves diagonally leftward is generated as a combined displacement, and the moving body 8 tries to move leftward.

Therefore, by selecting the piezoelectric bodies 3 and 4 to be driven by switching the switch 7, the direction of the moving body 8 can be changed. It is more efficient to provide the protrusions Ta and Tb separately, but they may be provided integrally. At that time, it is desirable that there is no elastic mass such as a protrusion on the upper surface near the node N of the vibration of the central axis of the vibrator 2.

(Second Embodiment) In the invention described in claim 2, for example, as shown in FIG. 8, the first and second piezoelectric bodies 3 and 4 are the elastic body 1 and the third piezoelectric body 9 respectively. Is fastened and fixed by the fastener 5. First and second piezoelectric bodies 3, 4
And the third piezoelectric body 9 is provided with a ground electrode 10,
The third piezoelectric body 9 is polarized in opposite directions (the respective polarization directions are parallel to the axial direction of the oscillator and opposite to each other on different sides with the plane orthogonal to the axial direction of the oscillator as a boundary). ) An AC drive voltage is applied through the electrode plate 11 arranged between the two layers of piezoelectric elements 9a and 9b (oscillator, phaser, amplifier, etc. are not shown). First and second piezoelectric bodies 3,
An AC drive voltage is applied to 4 through the electrode plates 6a and 6b and the switch 7.

The switch 7 is connected to the terminal B ₁ on the first piezoelectric body 3 side.
9A, the oscillator becomes the same as the oscillator shown in FIG. 9A, and the expansion and contraction vibration of the first piezoelectric body 3 causes + Δ in the protrusion Ta.
Displacement of two components of x and Δy occurs. Then, when the protrusion Ta is brought into contact with the moving body, the moving body moves to the right in FIG. 9A. Further, the switch 7 is connected to the terminal B on the second piezoelectric body 4 side.
_When it is short-circuited with _2, it becomes the same as that of the vibrator shown in FIG. 9B, and the expansion and contraction vibration of the second piezoelectric body 4 causes −Δ in the protrusion Tb.
Displacement of two components of x and Δy occurs. Then, when the protrusion Ta abuts on the moving body, the moving body moves to the left in FIG. 9B. When the AC drive voltage is applied to the first piezoelectric body 3 or the second piezoelectric body 4, the same AC drive voltage is also applied to the third piezoelectric body 9, and the stretching vibration of the third piezoelectric body 9 causes ± The Δx and Δy components are expanded.

As a driving method, the third piezoelectric body 9 is connected to the A-phase power source, and the first and second piezoelectric bodies 3 and 4 are connected to the B-source.
The switching may be performed by a switch while being connected to a phase power source through a switch and applying a voltage with a phase difference of ± 90 ° between the A phase and the B phase.

(Third Embodiment) In the invention described in claim 4, for example, as shown in FIG. 10, electrode plates 6a and 6b are provided.
The first and second piezoelectric elements 12 and 13 and the third piezoelectric element 14 are laminated via the elastic body 1 and the fastener 5
Tighten and fix with. A switch 7 is provided on the electrode plates 6a and 6b.
AC drive voltage is applied via (oscillator, phaser,
(Amplifier, etc. are not shown). First and second piezoelectric elements 12, 1
The polarization directions of 3 are the same as each other, and the polarization directions of the third piezoelectric element 14 are opposite to each other on the basis of a plane orthogonal to the axial direction of the vibrator 2 (a plane orthogonal to the axial direction of the vibrator is a boundary between them). The respective polarization directions on different sides are parallel to the axial direction of the vibrator and opposite to each other).

The switch 7 is connected to the terminal A on the first piezoelectric element 12 side.
11A is the same as that of the vibrator shown in FIG. 11A, and the expansion and contraction vibration of the first piezoelectric element 12 and the third piezoelectric element 14 causes displacement of two components + Δx and Δy on the protrusion Ta. Then, when the protrusion Ta is brought into contact with the moving body, the moving body moves to the right in FIG. 11A. Also, switch 7
Is short-circuited with the terminal B on the second piezoelectric element 13 side,
The same as the vibrator shown in FIG. 1 (b), and the second piezoelectric element 13
And due to the stretching vibration of the third piezoelectric element 14, the protrusion Ta-
Displacement of two components of Δx and Δy occurs. And the protrusion Tb
When is contacted with the moving body, the moving body moves to the left in FIG. 11B.

(Fourth Embodiment) In the invention described in claim 3, for example, FIG. 12 (top view) and FIG.
As shown in (b) (side view), in addition to the first and second piezoelectric bodies 3 and 4 between the pair of elastic bodies 1, 90% with respect to the piezoelectric bodies 3 and 4 with respect to the central axis. The fourth piezoelectric body 15 and the fifth piezoelectric body 16 are arranged on the same plane that does not interfere with the first and second piezoelectric bodies 3 and 4 while phaseally shifting the phase. The first and second piezoelectric bodies 3 and 4 have an electrode plate 6 disposed between the piezoelectric elements 3a, 3b, 4a and 4b.
A-phase or B-phase AC drive voltage is applied via a and 6b (oscillator, phaser, amplifier, etc. are not shown). Piezoelectric elements 15a, 1 constituting the fourth piezoelectric body 15
The C-phase AC drive voltage is applied to the electrode plates 17a arranged between the 5b and the piezoelectric elements 16a, 1a which constitute the fifth piezoelectric body 16.
An AC driving voltage of D phase is applied to each of the electrode plates 17b arranged between 6b (oscillator, phase shifter, amplifier, etc. are not shown).

When the vibrator 2 is driven by two-phase driving by giving a phase difference of + 90 ° to the A phase and the B phase, the moving body is moved to the left side of FIG. 12 as in the case of the vibrator 2 shown in FIG. Move,
A movement of a curved closed path (a perfect circular path, an elliptical path, or the like) that is a displacement occurs counterclockwise. -90 for Phase A and Phase B
When the oscillator 2 is driven by two-phase drive with a phase difference of °,
The movement of the locus of the curved path that is the displacement that causes the moving body to move to the right in FIG. 12 occurs in the clockwise direction. Further, a phase difference of + 90 ° is given to the C phase and the D phase, and the vibrator 2 is driven by the two-phase drive.
When is driven, the movement of the locus of the curved circuit, which is a displacement, which moves the moving body to the lower side in FIG. 12, occurs counterclockwise. When the oscillator 2 is driven by the two-phase drive by giving a phase difference of −90 ° to the C phase and the D phase, the movement of the locus of the curved circuit which is the displacement that moves the moving body to the upper side in FIG. 12 is clockwise. It occurs around.

As shown in FIGS. 14A and 14B, the first and second piezoelectric bodies 3 and 4 are provided between the pair of elastic bodies 1.
In addition, 9 with respect to both piezoelectric bodies 3 and 4 based on the central axis
When the phase is shifted by 0 ° and the fourth piezoelectric body 15 and the fifth piezoelectric body 16 are arranged below the first and second piezoelectric bodies 3 and 4, the configuration is almost the same. The action is done. That is, the phase difference of ± 90 ° is given to the A phase and the B phase, and 2
When the oscillator 2 is driven by phase drive, the arrow A in FIG.
The movement of the locus of the curved circuit, which is a displacement, that causes the moving body to move in the B direction occurs on the end surface of the oscillator 2. Further, when the vibrator 2 is driven by the two-phase drive by giving a phase difference of ± 90 ° to the C phase and the D phase, the moving body is moved in the direction of the arrow CD in FIG. The motion of the locus is generated on the end face of the oscillator 2.

As a method of driving the vibrator 2, as described above, the phase A and the phase B which are opposed to each other at an angle of 180 ° are positioned.
2-phase drive in which a phase difference is provided by a combination of phase, C phase-D phase is common, but depending on the application, A phase-C phase, A phase-D
A phase, a B phase-D phase, a B phase-C phase, or a combination of facing each other at an angle of 90 ° may be adopted.

Further, elastic protrusions are provided at predetermined positions corresponding to the first, second, fourth and fifth piezoelectric bodies 3, 4, 15 and 16, and are provided at the respective terminals A, B, C and D. An AC drive voltage may be applied via a switch (oscillator, amplifier, etc. are not shown).

(Fifth Embodiment) Next, a large number of vibrators 2 are provided.
FIG. 1 shows an embodiment applied to an actuator using
5 will be described. Longitudinal direction of the long moving body 8 (see FIG.
A plurality of (3 in this embodiment) along the horizontal direction of 5)
The vibrator 2 is provided. A guide roller 18 is arranged on the side opposite to the vibrator 2 with the moving body 8 interposed therebetween. The vibrator 2 has substantially the same structure as the vibrator 2 of the first embodiment. The base end side of the vibrator 2 is attached to the support frame 19 via a pressing means 20 such as a coil spring,
Each transducer 2 is arranged so as to press the moving body 8 toward the guide roller 18 side. The electrode plate 6a of the first piezoelectric body 3 of each vibrator 2 is connected to a common AC drive source 21, and the electrode plate 6b of the second piezoelectric body 4 is connected to a common AC drive source 22. (Amplifier, phase shifter, etc. are not shown).

AC drive sources 21 and 22 with a phase difference of + 90 ° with respect to the first piezoelectric body 3 and the second piezoelectric body 4 of each vibrator 2.
When a voltage is applied from the above, a locus of a curved closed path that is a displacement in the counterclockwise direction in FIG. 15 is generated at the tip of each vibrator 2,
The moving body 8 is moved to the left in FIG. Further, when a voltage having a phase difference of −90 ° is applied to each of the piezoelectric bodies 3 and 4, a locus of a curved circuit which is a clockwise displacement in FIG. The moving body 8 is moved to the right in FIG. That is, in the actuator using the large number of vibrators 2, two AC drive sources 21, 2 are used.
By changing the phase difference of the applied voltage of 2
You can change the moving direction of.

(Sixth Embodiment) Next, a sixth embodiment applied to an actuator will be described with reference to FIG. This embodiment is different from the fifth embodiment in that an elastic body forming a vibrator is shared by a plurality of vibrators, and other parts are the same. That is, the first and second piezoelectric bodies 3 and 4 of each vibrator 2 are sandwiched between a common set of elastic bodies 23. Also in this case, when a voltage having a phase difference of + 90 ° is applied to each of the piezoelectric bodies 3 and 4, the moving body 8 is moved to the left in FIG.
When a voltage having a phase difference of ° is applied, the moving body 8 is moved to the right in FIG. 16 (amplifier, phaser, etc. are not shown). Note that only one of the elastic bodies 23 may be shared.

(Seventh Embodiment) Next, a seventh embodiment applied to an actuator will be described with reference to FIGS. This embodiment differs from the fifth and sixth embodiments in that the vibrator 2 is in contact with the moving body 8 in four directions, up, down, left, and right, and the structure of each vibrator 2 itself is basically the same. The same as the fifth embodiment. FIG.
As shown in FIG. 5, the support frame 19 is formed in an octagonal tube shape in cross section, and the vibrators 2 are arranged in pairs on the surfaces facing each other.

As shown in FIG. 18, in the vibrators 2 arranged on the upper and lower sides of the support frame 19, the first piezoelectric body 3 and the second piezoelectric body 4 are orthogonal to the moving direction of the moving body 8. It is attached to the support frame 19 at symmetrical positions with respect to the plane. In addition, the vibrators 2 arranged on both the left and right sides of the support frame 19 also have symmetrical positions with the first piezoelectric body 3 and the second piezoelectric body 4 sandwiching a plane orthogonal to the moving direction of the moving body 8. It is attached to the support frame 19 so that Each vibrator 2 includes an elastic body 1 having a boss portion 1b that abuts on the moving body 8. In addition, as shown in FIG.
The electrode plate 6a of the first piezoelectric body 3 of each vibrator 2 is connected to a common AC drive source 21, and the electrode plate 6b of the second piezoelectric body 4 is connected to a common AC drive source 22. (Amplifier, phase shifter, etc. are not shown).

AC drive sources 21 and 22 with a phase difference of + 90 ° with respect to the first piezoelectric body 3 and the second piezoelectric body 4 of each vibrator 2.
When a voltage is applied from the vibrator 2 arranged on the lower side of the support frame 19, a curved closed circuit locus that causes a counterclockwise displacement is generated at the tip of the vibrator 2, and the vibrator 2 arranged on the upper side.
A locus of a curved circuit that is a clockwise displacement is generated at the tip of the. The direction of the locus of the curved path that is the displacement is the direction in which the moving body 8 is moved to the left in FIG. Also,
At the tips of the vibrators 2 arranged on both the left and right sides of the moving body 8, curved path trajectories, which are displacements in the direction of moving the moving body 8 to the left in FIG. 18, are generated. As a result, the movable body 8 moves to the left in FIG. 18 with a high thrust due to the joint action of the vibrators 2. When a voltage is applied to each of the first and second piezoelectric bodies 3 and 4 with a phase difference of −90 ° from the AC power supplies 21 and 22, the moving body 8 moves to the right in FIG. 18. In this embodiment, as in the fifth embodiment, one of the moving bodies 8 is
Thrust that is four times as large as that of an actuator provided with a plurality of vibrators 2 that abut only on the surface is obtained.

The vibrators 2 arranged vertically and horizontally with respect to the moving body 8 do not necessarily have to be arranged at positions facing each other. Further, the vibrators 2 may be provided only above and below the moving body 8, or the vibrators 2 may be provided only at the left and right sides of the moving body 8.

In the vibrator of the present invention, vibration modes other than the stretching vibration are coupled based on the stretching vibration of the piezoelectric element depending on the structure and shape of the elastic body. It is possible to change the direction of the locus of the curved circuit in (in the first to seventh embodiments).

[0048]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 20 and 21. Vibrator 2
Is a circular ring-shaped elastic body 1 as shown in FIG.
Formed by combining the half-ring ring-shaped piezoelectric element 3a and the like and the substantially half-ring-shaped electrode plate 6a and the like, and tightening and fixing the hexagon socket bolts 24 and nuts 25 as fasteners through the washers 26. Has been done. As shown in FIG. 21, the first piezoelectric body 3 and the second piezoelectric body 4 are symmetrically arranged on both sides of the center plane parallel to the axial direction of the vibrator 2. The two piezoelectric bodies 3 and 4 are polarized in opposite directions (the polarization directions are parallel to the axial direction of the vibrator and opposite to each other on different sides with the plane orthogonal to the axial direction of the vibrator as a boundary). 2 layers of piezoelectric element 3a,
3b, 4a, 4b and electrode plates 6a, 6 arranged therebetween
b. The polarization direction of the piezoelectric element 3a and the like is indicated by an arrow.

The elastic body 1 is made of steel and has an outer diameter of 20 m.
m, an inner diameter of 8 mm, and thicknesses of 5 mm and 10 mm are prepared, and the elastic body 1 having a thickness of 10 mm is arranged on the base end side of the vibrator 2, and the side abutting the moving body (the hexagon socket head bolt 24 The elastic body 1 having a thickness of 5 mm is arranged on the head side). The piezoelectric element 3a and the like are made of PZT (polycrystal of zirconate / lead titanate type) as a material, and a circular ring-shaped one having an outer diameter of 20 mm, an inner diameter of 8 mm and a thickness of 4 mm is halved, and its divided end faces are ground. It has a different shape. Then, both piezoelectric bodies 3,
4 are arranged between the elastic bodies 1 with a gap between their end faces. As the electrode plate 6a and the like, a copper plate having a thickness of 0.1 mm formed into a shape having a protrusion on the outside of a half ring having an outer diameter of 20 mm and an inner diameter of 8 mm is used. The washer 26 has an outer diameter of 20 mm, an inner diameter of 8 mm and a thickness of 1 mm.

The vibrator 2 was fixed and supported by sandwiching the nut 25 with a plastic vise. And
The electrode plate 6 a of the first piezoelectric body 3 was connected to the two-phase oscillator 29 via the amplifier 27 and the phase shifter 28. The electrode plate 6 b of the second piezoelectric body 4 was connected to the two-phase oscillator 29 via the amplifier 27. The elastic body 1 was grounded. Since both elastic bodies 1 are electrically connected to each other by the hexagon socket head cap screw 24, the elastic body 1 on the distal end side is automatically grounded by grounding the elastic body 1 on the proximal end side.

First, in order to examine whether it can be used as an actuator vibrator, the first piezoelectric body 3 and the second piezoelectric body 3
The phase difference of the voltage is given to the piezoelectric body 4 of + 90 °,
While driving the vibrator 2 while sequentially changing the frequency between 20 and 70 kHz, with the bearing 30 pressed against the tip of the vibrator 2, that is, the head of the hexagon socket head cap bolt 24,
The rotation direction of the bearing 30 was observed. As a result, a frequency region was observed in which the frequency rotates in the left direction (counterclockwise direction) in the vicinity of 35 kHz and 50 kHz, and in the right direction (clockwise direction) in the vicinity of 40 kHz.

Next, the frequency was fixed at around 50 kHz and the voltage phase difference was changed from + 90 ° to −90 °. Vibrator 2
It was confirmed that the rotation direction of the bearing 30 pressed against the tip of the bearing was the right direction (clockwise direction) and the opposite direction to the case of the phase difference of + 90 °. From this result, both piezoelectric bodies 3,
It can be seen that by changing the phase difference of the voltage applied to 4, it is possible to change the direction of the locus of the curved closed path that is the displacement, and it is possible to change the moving direction of the moving body.

For comparison, two piezoelectric elements 3, 4 having a diameter of 20 mm, an inner diameter of 8 mm and a thickness of 4 mm are used in place of the two piezoelectric bodies 3, 4 and the other parts are shown in FIG.
The oscillator shown in FIG. 22 was constructed by using the same oscillator 2 as that of No. 0. An experiment similar to the above was conducted on this oscillator. It was confirmed that the bearing rotated at a frequency other than the above-mentioned frequency, but it was confirmed that the elliptical locus of displacement could not be redirected even if the phase difference of the voltage applied to both electrode plates 6a and 6b was changed. It was The cause is a pair of piezoelectric elements 3
When voltages with different phase differences are applied to the divided electrode plates 6a and 6b with respect to 1a and 31b, the left and right sides of the piezoelectric elements 31a and 31b are bordered by the center plane parallel to the axial direction of the vibrator. It is considered that the portions restrain the vibration displacements of the other portions to each other, so that the stretching vibration in the intended state does not occur independently on each side of the piezoelectric element.

From this result, the driving principle of the present invention is reproduced only when the first and second piezoelectric bodies 3 and 4 are arranged in a divided manner with the center plane parallel to the axial direction of the vibrator as a boundary. It is thought to be possible.

(Second Embodiment) Next, a second embodiment will be described with reference to FIG.
A description will be given according to (a) and (b). In this embodiment, the first
And piezoelectric elements 3a, 3 constituting the second piezoelectric bodies 3, 4.
The shapes of b, 4a, and 4b are different from those of the above-described embodiment, and other configurations are the same. The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The piezoelectric element 3a made of PZT is shown in FIG.
As shown in, it is formed in the shape of a rectangular parallelepiped, and the length L = 15m.
m, width W = 5 mm, and thickness 4 mm. Then, as shown in FIG. 23A, each piezoelectric element 3a, 3b, 4
The a and 4b are arranged symmetrically with respect to the center plane of the vibrator 2.

The vibrator 2 was connected to the two-phase oscillator 29 as in the first embodiment, and the rotating state of the bearing 30 was observed by the same method. As a result, also in the vibrator 2 of this example, the bearing 30 was rotated leftward (counterclockwise) at frequencies near 35 kHz and 50 kHz, and rightward (clockwise) at 40 kHz. Also, the frequency is 50 kHz
By changing the phase difference of the voltages applied to the first piezoelectric body 3 and the second piezoelectric body 4 in the vicinity to + 90 ° and −90 °, the rotation direction of the bearing 30, that is, the curved closed path that is the displacement is obtained. It was confirmed that the direction of the trajectory changed.

Therefore, even if the shape of the piezoelectric element 3a or the like is changed, the action of the vibrator 2 does not change, and the shape of the piezoelectric element does not affect the generation of a curved closed path that is the displacement of the vibrator 2. Was confirmed.

(Third Embodiment) Next, a third embodiment will be described with reference to FIG. This embodiment is largely different from the first and second embodiments in that the vibrator 2 has a cantilever structure. The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Among the constituent parts of the vibrator 2 of the first embodiment,
Instead of the elastic body 1 (thickness 10 mm) on the base end side, a base (rigid body) 32 having a length x width (100 mm x 100 mm) and a thickness of 15 mm is used, and a hole 33 of 8 mm is formed in the center thereof, A recess 34 for accommodating the nut 25 is formed on the bottom. Then, with the hexagon socket head cap bolt 24 penetrating the hole 33, the first and second piezoelectric bodies 3 and 4 are connected to the elastic body 1 (thickness 5
mm) and the base 32.

Then, this oscillator 2 was connected to the two-phase oscillator 29 as in the first embodiment, and the rotating state of the bearing 30 was observed by the same method. As a result, the bearing 30 is used at frequencies near 35 kHz, 50 kHz and 60 kHz.
Turned to the left (counterclockwise), and the right direction (clockwise) was confirmed at 38 kHz and 48 kHz. Also, frequency 5
By changing the phase difference of the voltages applied to the first piezoelectric body 3 and the second piezoelectric body 4 in the vicinity of 0 kHz to + 90 ° and −90 °, the rotational direction of the bearing 30, that is, a curved circuit that causes displacement. It was confirmed that the direction of the locus of was changed.

Therefore, it was confirmed that even when the supporting state of the piezoelectric element is cantilevered, the locus of the curved closed path which is the target displacement can be obtained and the direction thereof can be changed.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIGS. In this embodiment, the piezoelectric element 3
The third embodiment is different from the third embodiment in that the outer diameter and thickness such as a are changed. Piezoelectric element 3a etc. has an outer diameter of 30 mm and an inner diameter of 8 m
A circular ring made of PZT having a thickness of 1 mm and a thickness of 1 mm was cut in half, and the end faces of the ring were cut so that the end faces of the first and second piezoelectric bodies 3 and 4 did not come into contact with each other. As the electrode plate 6a and the like, a copper plate having a thickness of 0.1 mm formed into a shape having a protrusion on the outside of a half ring having an outer diameter of 30 mm and an inner diameter of 8 mm was used. As shown in FIG. 26, the ring-shaped elastic body 1 has a boss portion 1b formed at the center. The elastic body 1 has an outer diameter of 30.
mm, inner diameter 8 mm, large-diameter portion thickness 3 mm, and boss portion 1 b thickness 5 mm. Then, with the hexagon socket head cap bolt 24 and the nut 25, the piezoelectric elements 3a, 3b, 4a, 4b and the elastic body 1 are attached to the same base 32 as in the third embodiment.
Was fixed by tightening to form a vibrator 2 having a cantilever structure.

Then, this oscillator 2 was connected to the two-phase oscillator 29 as in the first embodiment, and the rotating state of the bearing 30 was observed by the same method. As a result, it was confirmed that the bearing 30 rotates in the vicinity of the frequency of 38 kHz. In addition, the first piezoelectric body 3 and the second piezoelectric body 3
Of the voltage applied to the piezoelectric body 4 of + 90 ° and −9
It was confirmed that the direction of rotation of the bearing 30, that is, the direction of the locus of the curved closed path, which is the displacement, was changed by changing to 0 °.

Therefore, it was confirmed that even when the outer diameter and the thickness of the piezoelectric element were changed, the locus of the curved closed path which was the target displacement was obtained and the direction thereof could be changed. (Fifth Embodiment) Next, a fifth embodiment will be described with reference to FIG. In this embodiment, a third piezoelectric body 9 is provided in addition to the first and second piezoelectric bodies 3 and 4, which is a great difference from the above-mentioned respective embodiments. Except for the parts constituting the third piezoelectric body 9, the same parts as those used for the vibrator 2 shown in FIG. 20 of the first embodiment were used. Piezoelectric element 9 constituting the third piezoelectric body 9
A piezoelectric element made of PZT having an outer diameter of 20 mm, an inner diameter of 8 mm, and a thickness of 4 mm is used for a and 9b, and a copper plate having a thickness of 0.1 mm is used for the electrode plate 11 arranged between the piezoelectric elements 9a and 9b. A ring having a diameter of 30 mm and an inner diameter of 8 mm and formed with a protrusion on the outside was used. Then, the third piezoelectric body 9 is arranged closer to the tip side of the vibrator 2 than the first and second piezoelectric bodies 3 and 4, and the set of elastic bodies 1 and the respective piezoelectric bodies 3, 4, 9 are arranged.
With a hexagon socket head cap screw 24 and nut 25.
The vibrator 2 was formed by tightening and fixing via 6.

The electrode plate 11 of the third piezoelectric body 9 is connected to the amplifier 27.
And a two-phase oscillator 29 via a phase shifter 28 (not shown). The electrode plate 6a of the first piezoelectric body 3 and the electrode plate 6b of the second piezoelectric body 4 can be connected to the two-phase oscillator 29 via the switch 7. Further, the ground electrode 10 and the elastic body 1 on the base end side were grounded. Then, the switch 7 is switched so that the combination of the first piezoelectric body 3 and the third piezoelectric body 9 and the combination of the second piezoelectric body 4 and the third piezoelectric body 9 are the same as those in the respective embodiments. The rotating state of the bearing 30 was observed by the method. As a result, frequencies 24, 39, 53k
It was confirmed that the bearing 30 rotates counterclockwise (counterclockwise) in the vicinity of Hz. Further, by changing the phase difference of the voltages applied to the piezoelectric bodies of both the combinations in the vicinity of the frequency of 39 kHz to + 90 ° and −90 °, the direction of rotation of the bearing 30, that is, the direction of the locus of the curved closed path that is the displacement is changed. It was confirmed to change.

In order to change the direction of the locus of the curved circuit which is the displacement, the contact points of the switch 7 are A and B ₁ and A and B ₂ even if the phase difference of the voltage applied to each piezoelectric body of the combination is not given.
It was also confirmed that it is possible by switching the combination of.

Therefore, the first and second piezoelectric bodies 3, which are divided and arranged with the center plane parallel to the axial direction of the vibrator as a boundary, are arranged.
It was confirmed that, even if 4 was not in direct contact with the elastic body 1, the trajectory of the curved closed path that was the target displacement was obtained and the direction thereof could be changed.

(Sixth Embodiment) Next, a sixth embodiment will be described with reference to FIG.
A description will be given according to (a) and (b). In this embodiment, the first
In addition to the second piezoelectric bodies 3 and 4, a 90 ° phase shift is made with respect to the central axes of the vibrators 2 with respect to both piezoelectric bodies 3 and 4, and the first and second piezoelectric bodies 3 and 4 are arranged. On the other hand, the fourth piezoelectric body 15 and the fifth piezoelectric body 16 are arranged on the lower side, which is a great difference from the above-mentioned embodiments. FIG. 2 of the first embodiment
In addition to the same parts used for the oscillator 2 shown in 0,
Piezoelectric element 1 forming fourth and fifth piezoelectric bodies 15 and 16
5a, 15b, 16a, and 16b use the same half ring-shaped PZT-made piezoelectric element as the piezoelectric element 3a and the like.
A half ring-shaped electrode plate having the same protrusion as the electrode plate 6a was used for a and 17b. Each piezoelectric body 3, 4, 15, 16
Was placed between a set of elastic bodies 1 and tightened and fixed by a hexagon socket head cap screw 24 and a nut 25 to form a vibrator 2.

Then, with the nut 25 fixed with a vise, the combination of the first and second piezoelectric bodies 3 and 4 and the combination of the fourth and fifth piezoelectric bodies 15 and 16 are each driven by two-phase drive. The rotating state of the bearing 30 was observed by the same method as in the first embodiment.

As a result, the frequency 3 which is almost the same as that of the fifth embodiment is obtained.
It was confirmed that the bearing 30 rotated in the vicinity of 9 kHz. Further, by changing the phase difference of the voltages applied to the piezoelectric bodies of both the combinations in the vicinity of the frequency of 39 kHz to + 90 ° and −90 °, the direction of rotation of the bearing 30, that is, the direction of the locus of the curved closed path that is the displacement is changed. It was confirmed to change.
In the case of the combination of the first and second piezoelectric bodies 3 and 4, when the phase difference of ± 90 ° is applied to the voltage applied to the A phase and the B phase, the bearing is positive in the left-right direction in FIG. 28 (a). It will be the reverse. Further, in the case of the combination of the fourth and fifth piezoelectric bodies 15 and 16, when the phase difference of ± 90 ° is applied to the voltages applied to the C phase and the D phase, the bearings move in the left and right direction of FIG. 28 (b). It will be the normal reverse.

The present invention is not limited to the above-mentioned respective embodiments and examples, and may be embodied as follows, for example. (1) To reduce the number of parts that make up the vibrator 2,
As shown in FIG. 29, the elastic body 1 has a boss portion 1b and a shaft portion 1c.
Are integrally formed, and can be attached to the base 32 by the male screw 1d formed on the shaft portion 1c. In this case, bolts, nuts and washers for tightening the elastic body that holds the piezoelectric bodies 3 and 4 are not necessary, and one elastic body can be omitted.

(2) The piezoelectric elements 3a, 3b, 4a and 4b forming the first and second piezoelectric bodies 3 and 4 arranged with the center plane parallel to the axial direction of the vibrator as a boundary are shown in FIG. (A),
It may be arranged by dividing it in the left-right direction (x direction) as shown in (b) or by dividing it in the front-rear direction (z direction) as shown in FIGS. 31 (a) and 31 (b). Also, a plurality of them may be arranged in both the x direction and the z direction.

(3) The piezoelectric elements forming the first piezoelectric body 3 and the second piezoelectric body 4 are not limited to the same shape,
Different shapes may be used. However, at that time,
It is preferable that the piezoelectric elements 3 and 4 have the same thickness. Also, in the case of the fourth piezoelectric body 15 and the fifth piezoelectric body 16, different shapes may be used as well.

(4) The shape of the vibrator 2 is not limited to a cylindrical shape or a quadrangular prism shape, and various shapes can be adopted. For example, as the elastic body 1, a plane-symmetric one having a regular triangle, a regular hexagon, a regular octagon or the like is used, and the corresponding ring-shaped piezoelectric elements are used as the first piezoelectric body 3 and the second piezoelectric body 4. Use a half-cut shape.

(5) The first piezoelectric body 3, the second piezoelectric body 4,
The piezoelectric elements forming the fourth piezoelectric body 15 and the fifth piezoelectric body 16 may be laminated in two or more pairs instead of one pair.
In this case, the displacement increases.

(6) In the fifth to seventh embodiments, when the vibrator 2 is used as an actuator, the direction of the moving body 8 is changed by changing the phase difference of the drive applied voltage. Two protrusions T that contact the body 8
Using the vibrator 2 including a and Tb, the first piezoelectric body 3
Alternatively, the moving direction may be changed by switching the supply of the voltage applied to the second piezoelectric body 4.

(7) When the vibrators 2 are used as actuators, for example, as shown in FIG. 32, a plurality of vibrators 2 are fixed in a row on the support 35, and the tip surfaces of the vibrators 2 run. The self-propelled actuator 37 may be configured by being placed on the traveling surface 36 in a state of being in contact with the surface 36. In this case, the first piezoelectric body 3 of each vibrator 2 is connected to the two-phase oscillator 29 via the amplifier 27 and the phase shifter 28,
The second piezoelectric body 4 is connected to the two-phase oscillator 29 via the amplifier 27. Then, the first piezoelectric body 3 and the second piezoelectric body 4
When an applied voltage having a phase difference is supplied to and, the actuator 37 moves to the right side or the left side in FIG. 32, and the moving direction is changed by changing the phase difference to + 90 ° and −90 °, for example.

(8) The vibrators 2 having the configurations of the second to sixth examples may be used as the vibrator 2 constituting the actuators of the fifth to sixth embodiments. In the case of the configurations of the third and fourth embodiments, the support frame 19 can also serve as the base 32, which simplifies the configuration.

Inventions other than those described in the claims that can be understood from the respective embodiments and examples will be described below along with their effects. (1) The oscillator according to claim 1 or 2 and the phase difference between the voltages applied to the first and second piezoelectric bodies constituting the oscillator can be switched within ± 90 ° or in the vicinity thereof. Ultrasonic actuator with a power supply. In this case, the moving direction of the moving body can be easily changed with a simple configuration in which the phase difference of the applied voltage is switched at ± 90 ° or in the vicinity thereof.

(2) The vibrator according to claim 3, first and second piezoelectric bodies constituting the vibrator, and fourth and fifth
An ultrasonic actuator including a changeable power supply unit capable of applying a drive voltage to the piezoelectric body and switching the phase difference of the applied voltage at ± 90 ° or in the vicinity thereof. In this case, the moving direction of the moving body can be easily changed to four directions with a simple configuration in which the phase difference of the applied voltage is switched at or around ± 90 °.

[0082]

As described in detail above, according to the invention described in claims 1 to 5, a large thrust can be obtained with less limitation on the shape of the vibrator. In addition, it is possible to easily change the moving direction of the moving body.

According to the second aspect of the invention, the displacement increases due to the presence of the third piezoelectric body. According to the invention described in claim 3, the moving direction of the moving body can be changed to four directions orthogonal to each other (for example, four directions of front, rear, left and right).

According to the invention described in claim 4, the number of parts of the vibrator is reduced. According to the fifth aspect of the present invention, the elastic body and the piezoelectric element forming the vibrator can be reliably fixed, and the force due to the stretching vibration generated in the piezoelectric element easily causes the rotational moment of the couple.

[Brief description of drawings]

FIG. 1A is a schematic diagram showing displacement of a tip of a vibrator,
(B) is a schematic diagram of an elliptic locus of displacement.

FIG. 2 is a schematic cross-sectional view of the vibrator according to the first embodiment.

FIG. 3A is a diagram showing a drive voltage and a displacement having a phase difference of 90 °, and FIG. 3B is a diagram showing a drive voltage and a displacement having a phase difference of −90 °.

FIG. 4 is a schematic cross-sectional view of another vibrator.

FIG. 5 is a schematic diagram showing a state of displacement of a piezoelectric element.

FIG. 6 is a schematic diagram showing the state of displacement of the vibrator tip elastic body projection in the same manner.

FIG. 7 is a schematic diagram showing a moving state of the moving body.

FIG. 8 is a schematic cross-sectional view of the vibrator according to the second embodiment.

FIG. 9 is a schematic diagram illustrating the same operation.

FIG. 10 is a schematic cross-sectional view of a vibrator according to a third embodiment.

FIG. 11 is a schematic diagram illustrating the same operation.

FIG. 12 is a top view of the vibrator according to the fourth embodiment.

13 (a) is a Y view of FIG. 12, and FIG. 13 (b) is an X view of FIG.

FIG. 14A is a schematic perspective view of another vibrator, FIG.
(B) is a side view seen from C ′.

FIG. 15 is a schematic diagram of an actuator using the vibrator according to the fifth embodiment.

FIG. 16 is a schematic diagram of an actuator using the vibrator according to the sixth embodiment.

FIG. 17 is a schematic cross-sectional view of an actuator using the vibrator according to the seventh embodiment.

18 is a sectional view taken along line ZZ of FIG.

FIG. 19 is a schematic exploded perspective view of FIG.

FIG. 20 is a schematic diagram of a vibrator according to the first embodiment.

21A is a perspective view of a piezoelectric element, FIG. 21B is a perspective view of an electrode plate, and FIG. 21C is a perspective view of an elastic body.

FIG. 22 is a side view of a vibrator of a comparative example.

FIG. 23A is a side view of the vibrator according to the second embodiment,
(B) is a perspective view of a piezoelectric element.

FIG. 24 is a side view of the vibrator according to the third embodiment.

FIG. 25 is a side view of the vibrator according to the fourth embodiment.

FIG. 26 is a perspective view of the same elastic body.

FIG. 27 is a side view of the vibrator according to the fifth embodiment.

28A is a side view of the vibrator of the sixth embodiment, FIG.
(B) is a front view.

FIG. 29 is a cross-sectional view of a vibrator of a modified example.

FIG. 30 (a) is a perspective view of a vibrator according to another modification,
(B) is a side view.

FIG. 31A is a perspective view of a vibrator of another modification,
(B) is a side view.

FIG. 32 is a schematic side view of a self-propelled actuator.

FIG. 33 is a schematic perspective view of a conventional device.

34A is a perspective view of another conventional device, and FIG. 34B is an exploded perspective view of another conventional device.

FIG. 35 is a schematic diagram illustrating the operation of a conventional device.

FIG. 36A is a schematic diagram of a trajectory of a curved circuit closed on the oscillator, FIG. 36B is a schematic diagram of a trajectory of a curved circuit closed on the oscillator, and FIG. 36C is a schematic diagram of a trajectory of a curved circuit closed on the oscillator. Fig.

FIG. 37 is a schematic diagram of a locus of a curved circuit.

[Explanation of symbols]

1 ... Elastic body, 2 ... Oscillator, 3 ... First piezoelectric body, 4 ... Second
Piezoelectric body, 3a, 3b. 4a, 4b ... Piezoelectric element, 5 ... Fasteners, 6a, 6b, 11, 17a, 17b ... Electrode plate, 9
... third piezoelectric body, 12 ... first piezoelectric element, 13 ... second piezoelectric element, 14 ... third piezoelectric element, 15 ... fourth piezoelectric body, 16
... Fifth piezoelectric body.

Claims (5)

[Claims] 1. A vibrator for an ultrasonic actuator comprising a piezoelectric element exhibiting stretching vibration, wherein the piezoelectric element is arranged in at least two layers in the first direction, and at least two layers of the piezoelectric elements are arranged. The first
And is divided into a first piezoelectric body and a second piezoelectric body with a plane parallel to the first piezoelectric body and the second piezoelectric body being arranged.
Of the piezoelectric elements are composed of piezoelectric elements whose polarization directions are parallel to the first direction and opposite to each other on different sides with a surface orthogonal to the first direction as a boundary. An ultrasonic actuator transducer. 2. A third piezoelectric body composed of a piezoelectric element is arranged so as to face the first piezoelectric body and the second piezoelectric body in a state orthogonal to the first direction, and the third piezoelectric body is arranged. Of the piezoelectric body is composed of at least two layers of piezoelectric elements whose polarization directions are parallel to the first direction and opposite to each other on different sides with a surface orthogonal to the first direction as a boundary. The oscillator for an ultrasonic actuator according to claim 1. 3. The first direction is an axial direction of a vibrator, and the first piezoelectric body and the second piezoelectric body are separated from each other with a center plane of the vibrator parallel to the first direction as a boundary. Positions which are divided and arranged so as to shift the phase by 90 ° with respect to the first piezoelectric body and the second piezoelectric body with respect to the central axis of the vibrator and which do not interfere with the first piezoelectric body and the second piezoelectric body. A fourth piezoelectric body and a fifth piezoelectric body are disposed in the first piezoelectric body and the fourth piezoelectric body and the fifth piezoelectric body are polarized on different sides with respect to a plane orthogonal to the first direction. The ultrasonic actuator vibrator according to claim 1, comprising at least two layers of piezoelectric elements whose directions are parallel to the first direction and opposite to each other. 4. A vibrator for an ultrasonic actuator, comprising a piezoelectric element exhibiting stretching vibration, wherein a first piezoelectric element and a second piezoelectric element are provided on both sides of a plane parallel to the first direction. At least one element is arranged respectively, and a third piezoelectric element is arranged so as to face the first piezoelectric element and the second piezoelectric element in a state orthogonal to the first direction, and The polarization directions of the piezoelectric element and the second piezoelectric element and the polarization direction of the third piezoelectric element are parallel to the first direction and are on different sides with respect to a plane orthogonal to the first direction. A vibrator for an ultrasonic actuator, which is set so as to have opposite directions. 5. The vibrator according to claim 1, wherein each of the piezoelectric elements is arranged between a pair of elastic bodies, and is fixed by a fastener penetrating the elastic bodies. The ultrasonic actuator transducer according to the item.