JPH03128683A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To improve productivity, efficiency and response by installing a longitudinal vibrator onto the nodal line of standing-wave vibrations generated by a flexing vibrator, adjusting the expansion and contraction timing of the flexing vibrator and the longitudinal vibrator and relatively displacing the vibrators and a contacting member. CONSTITUTION:A flexing vibrator 1 and longitudinal vibrators 3, 4 are driven by an AC power, phase of which is shifted at 90 deg. mutually. The first longitudinal vibrator 3 is elongated and pressure-welded to a moving body 5, and the second longitudinal vibrator is shrunk and detached from the moving body 5. The fine anticlockwise revolution P'-P of the nose P of the first longitudinal vibrator 3 centering around the node N of the flexing vibrator 1 is generated at the position of the node N of the flexing vibrator 1, where the first longitudinal vibrator 3 is arranged, while being synchronized with the pressure-welding and detaching, thus working the first longitudinal vibrator 3 so as to kick up the moving body 5 from the right to the left, then giving moving force in the horizontal direction to the moving body 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic motor, and more particularly to an ultrasonic motor that generates a driving force on a contact member by ultrasonic vibration.

[Prior Art] An ultrasonic motor that drives a moving body, which is a contact member, using nodes of standing waves is disclosed in, for example, Japanese Patent Laid-Open No. 63-69472. This is achieved by arranging protrusions protruding in the normal direction at the nodes of the standing waves on the same circumference on one side of a disc-shaped vibrator that generates standing waves of thickness bending vibration.
On the other side of this vibrator, means for vibrating every other protrusion part in the thickness direction with an opposite phase is arranged, and by pressing the rotor against this protrusion, the inclination of the protrusion in the circumferential direction is caused by a standing wave. This change causes rotational force in a fixed direction to be applied to the rotor. The above-mentioned known examples also disclose a proposal in which longitudinal oscillators utilizing a plurality of transverse effects are attached to the node positions of a disc bending oscillator.

Furthermore, in the traveling wave type linear ultrasonic motor proposed in Japanese Patent Application Laid-open No. 59-96881, it is necessary to use a closed-loop bending vibrator in order to efficiently generate a traveling wave. As it has become extremely large, the support mechanism for this vibrator has also become complicated, and the efficiency of the motor itself has decreased by a few percent.
However, this did not necessarily result in a small linear type ultrasonic motor with high efficiency.

Furthermore, in the case of a linear type ultrasonic motor that combines the bending resonance of a plate and the longitudinal resonance vibration in the longitudinal direction of the plate, as disclosed in JP-A-63-277477, the bending resonance of the plate and the longitudinal resonance vibration of the plate are combined. Unless the resonant frequencies of the longitudinal resonances match, a highly efficient motor cannot be realized, and the size and shape of the motor are limited.

Therefore, it has not been easy to downsize and increase efficiency.

Furthermore, because this motor uses the transverse effect of the piezoelectric body (the direction of vibration is perpendicular to the direction of voltage application) to generate the frictional force, it is not possible to increase the crimping force. However, it also had the disadvantage of not being able to generate a large driving force.

Problems to be Solved by Invention C] By the way, in the configuration proposed in the above-mentioned Japanese Patent Application Laid-Open No. 63-69472, the bending vibration generated in the second vibrator is generated in synchronization with the bending vibration generated in the first vibrator. The bending vibration caused must cause the protrusion placed on the top of the first vibrator to vibrate in the thickness direction. For this purpose, it is necessary to match the resonant frequency of the first vibrator and the resonant frequency of the second vibrator, and a sophisticated technique is required to manufacture the vibrator. Moreover, even if the first vibrator is vibrated, the vibration of the first vibrator is suppressed by the second vibrator disposed on the first vibrator, and conversely, the vibration of the first vibrator is suppressed by the second vibrator disposed on the first vibrator. Since the vibration of the vibrator is suppressed by the first vibrator, the loss of vibration energy is large.

In addition, the above-mentioned Japanese Patent Application Laid-Open No. 63-69472 discloses a means of using a vertical vibrator that utilizes the transverse effect of a piezoelectric material to boil a bent disk, but in this case, in order to drive a moving body, To drive with the necessary amplitude, ■Apply a high voltage signal to the longitudinal vibrator.

■Lengthen the vertical oscillator.

■Make the vertical oscillator resonate.

Possible methods include: However, there are many problems when trying to implement the above-mentioned means, so the fourteenth
The problem will be explained below using figures.

FIG. 14 is a perspective view for explaining the operation of the longitudinal vibrator. In the figure, when applying a voltage to the vertical vibrator 101 in the thickness direction to utilize the transverse effect of the piezoelectric material, the original length of the vertical vibrator is L (m).

Assuming that the thickness is T (m), the width is W (m), the piezoelectric strain constant in the length L direction is d3 (m/V), and the applied voltage is V (v), the displacement ΔL (m) is ΔL − d atTV ...... It is expressed by the relational expression (1).

Therefore, 100
Consider the case where a voltage of v is applied. In this case, since the voltage application direction is opposite to the polarization direction A1, the voltage is V--100V. Now, if the piezoelectric strain constant d3□ is set to d=-', which is the standard value of the piezoelectric element material used in ultrasonic motors, and 30X10-''' m/V1, then the displacement ΔL (m) is ΔL''-130X 10'' ”2X O°014o(
12X (100)-8,5X 10-0-8(...
......(1a). That is, even if a negative voltage of 100V is applied, the displacement ΔL (m) is at most 0.0
The elongation is only 65 μm. Therefore, means for increasing the displacement ΔL will be discussed below.

First, consider the case where the displacement ΔL is obtained by increasing the voltage as in the above item (2). For example, when trying to obtain a displacement of 1 μm, in the above equation (la), ΔL = 0.0 at V-100V
Since it was 65 μm, an extremely high applied voltage V of 1500 V, which is 110.085-15 times 100 V(7)1'5, is required.

Next, consider the case where a sufficient displacement ΔL-1 μm is obtained by lengthening the longitudinal vibrator as in the above item (2). The original length L of the longitudinal vibrator can be found by modifying the above equation (1). Therefore, by substituting the actual value into the above equation, it becomes -0,153 (m). In other words, in order to obtain a displacement of 1 μm, 15
．． This would require a longitudinal vibrator as long as 3 cm.

Furthermore, consider the case of utilizing the resonance of the above-mentioned item (■).

Now, if the frequency constant in the length direction is N2 (Hz-m) and the length is L (m), then the resonance frequency in the length direction f (
(2a ) is obtained.Then, the longitudinal frequency constant N2 is the value 1570 (H
By substituting the general driving frequency of an ultrasonic motor, 40 KHz, into the above equation (2a) with the resonant frequency f in the longitudinal direction of the longitudinal vibrator as
becomes L-1570/40000 -0.03925 (m). In other words, the length L of the longitudinal oscillator that resonates at 40 KHz is about 4 cm, which is about 1/4 of the length of 154 cm obtained in the study in section It ends up being quite long. In such a longitudinal vibrator with a length of approximately 4 cm, the resonance point of bending exists at a lower frequency, making the longitudinal vibration operation unstable and impractical, and the piezoelectric body itself is likely to break. .

In addition, when a large number of vertical oscillators are arranged on a disk, in order to effectively transmit the driving force generated by the vertical oscillators to the rotor,
The tip of each vertical vibrator must be brought into uniform contact with the rotor. Therefore, it becomes difficult to maintain the flatness of the contact surfaces of each vibrator.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an ultrasonic motor with high productivity, high efficiency, and good responsiveness.

[Means and effects for solving the problem] The ultrasonic motor of the present invention includes a plate-shaped or rod-shaped elastic body, is fixed to the elastic body, and generates a standing wave in the elastic body by applying an alternating voltage. a bending vibrator that causes bending vibration of the mold; and a bending vibrator that is provided on the surface of the elastic body on the nodal line of the bending vibration, is oscillated about the nodal line by the bending vibrator, and is applied with an alternating current voltage. A vibrating body consisting of a longitudinal vibrator that expands and contracts in the amplitude direction of the bending vibration, and a contact member that is pressed against the tip surface of the vertical vibrator, and expands and contracts the vertical vibrator in synchronization with the bending vibration. This is characterized in that the vibrating body and the contact member are moved relative to each other.

[Example] The present invention will be explained below with reference to illustrated embodiments.

First, before giving a detailed explanation of the present invention, the basic principle of the present invention will be described, and then a longitudinal vibrator formed by laminating piezoelectric elements will be explained using FIG. The structure, operation, vibration mode, etc. of the driving body consisting of a bending vibrator, a longitudinal vibrator, etc. will be explained below.

To explain the basic principle of the ultrasonic motor of the present invention, one or more piezoelectric elements are fixed to a rod-shaped or plate-shaped elastic body having both ends, and a standing wave of thickness-bending vibration is generated. A vibrator and a plurality of piezoelectric elements that utilize the longitudinal thickness effect are laminated on the nodal line of the standing wave excited by the bending vibrator and at the same height from the neutral axis to create a vertical wave that vibrates in the amplitude direction of the bending vibration. a vibrating body consisting of a vibrator, and a contact member press-welded to the end face of the vertical vibrator, and driving the bending vibrator and the vertical vibrator with an alternating current voltage having a predetermined phase difference;
The present invention is characterized in that the vibrating body and the contact member are moved relative to each other. In this ultrasonic motor, since the bending vibrator is used for resonance and the longitudinal vibrator is used for non-resonance, there is no need to match the resonance frequencies of the bending vibrator and the longitudinal vibrator, which improves productivity. Furthermore, since the bending vibrator has nodes, it can be supported with low loss. Furthermore, the fact that the longitudinal vibrator is non-resonant means that the vibration form is much more stable than when it is resonant, so that a highly efficient ultrasonic motor can be achieved.

Next, the structure and operation of a laminated longitudinal vibrator formed by laminating piezoelectric elements will be explained with reference to FIG. In the figure, the length of the laminated longitudinal vibrator when no voltage is applied is J7 (m
), the number of laminated sheets is n, and the piezoelectric strain constant in the height g direction is d3
3 (m/V) and the applied voltage is V (v), the displacement ΔD (m) when a voltage is applied to n layers of piezoelectric materials electrically stacked in parallel is generally Δg increase nd33v ・It can be expressed by the relational expression (3). When this equation (3) is transformed, it becomes. Therefore, the piezoelectric strain constant d33 is the standard value of the piezoelectric element material used in the laminated actuator d -635×10-
By substituting 12 m/V 3 and 100 V as the voltage applied to the laminated longitudinal vibrator into the above equation (3a), the number n of laminated sheets required to obtain a displacement of 1 μm becomes -15.7. . In other words, it is sufficient to use 16 piezoelectric elements to obtain a displacement of 1 μm.

For example, if a piezoelectric element with a thickness of 0.12+nm is used, it will be 16 All you have to do is apply . In this way, by stacking and using piezoelectric elements as a vertical vibrator, the external size becomes extremely small, and
An ultrasonic motor that can be driven at low voltage can be obtained.

Next, the structure, operation, and vibration mode of the drive body used in the ultrasonic motor of the present invention will be explained.

FIGS. 2(A) and 2(B) show the bending vibrator 1 including the piezoelectric element 6 and the first oscillator 1. They are a front view of a vibrating body 2 made up of second longitudinal vibrators 3 and 4, and an action diagram showing a vibration state.

In the figure, nodes N and N' are points where the bending vibrator 1 is not displaced even when the bending vibrator 1 is subjected to bending vibration, and a line drawn in a direction perpendicular to the plane of the paper passing through this node N or N' is a nodal line. Also,
The arrow in the figure indicates the polarization direction. Further, reference numeral 5 denotes a movable body which is a contact member that is pressed against the end surface of the vertical vibrator 3.4.

The bending vibrator 1 is composed of a plate-like elastic body 7 and a piezoelectric element 6 polarized in the plate thickness direction bonded to the lower surface of the plate-like elastic body 7, and is laminated on the nodal line of the bending vibrator 1 so that the polarization directions face each other. The first vertical vibrator 3 and the second vertical vibrator 4 are arranged so as to protrude from the surface of the bending vibrator.

In such a structure, when the bending vibrator 1 performs bending vibration, a minute rotational reciprocating motion is generated around the nodes N and N' at the nodes of the bending vibration, as shown in FIG. 2(B).

Therefore, the first. The second longitudinal vibrator 3.4 undergoes minute rotational reciprocating motion, that is, oscillation, in mutually different rotation directions. Further, a movable body 5 is pressed onto the vertical vibrators 3 and 4.

Then, the longitudinal vibrator 3.4 is driven so as to cause either the forward motion or the backward motion of the minute rotational reciprocating motion to act on the movable body 5, and the movable body 5 is relatively driven in one direction. It is supposed to be done.

Next, FIG. 3 shows the polarization direction, lamination method, and wiring method of the piezoelectric element 6 and the longitudinal vibrators 3 and 4.

In FIG. 3, if the alternating current voltage applied to the lower electrode of the piezoelectric element 6 is positive, the bending vibrator 1 is bent in an upward convex shape, and if it is negative, it is bent in a downward convex shape.

Moreover, if the AC voltage of the longitudinal oscillator 3.4 is positive, the first longitudinal oscillator 3 will be in an expanded state and the second longitudinal oscillator 4 will be in a contracted state. Then, if the AC voltage of the longitudinal oscillator 3.4 is negative, the first longitudinal oscillator 3 is in a contracted state, and the second
The longitudinal vibrator 4 is in an expanded state. Note that the arrow in the figure indicates the polarization direction.

Next, the operation will be explained using FIG. 2(B).

The bending vibrator 1 and the longitudinal vibrator 3.4 have a phase of 90@
Since it is driven by a shifted AC power source, the first vertical vibrator 3 expands and presses against the moving body 51, and the second vertical vibrator 4 contracts and separates from the moving body 5, in synchronization. At the position of the node N of the bending oscillator 1 where the first longitudinal oscillator 3 is arranged, there is a slight counterclockwise rotation p'-p of the tip P of the first longitudinal oscillator 3 about this node N. As a result, the first vertical vibrator 3 acts to kick up the moving body 5 from right to left, and applies a moving force to the moving body 5 in the horizontal direction. At this time, the second
At the position of the node N' of the bending vibrator 1 where the longitudinal vibrator 4 is arranged, there is a minute clockwise rotation M' about this node N'.
-M occurs, but the second longitudinal vibrator 4 contracts and the moving body 5
Since it is not in contact with the movable body 5, no force in the opposite direction is applied to the movable body 5.

Further, the first longitudinal vibrator 3 contracts and separates from the moving body 5,
In synchronization with the expansion of the second longitudinal vibrator 4 and the pressure contact with the movable body 5, at the position of the node N' of the bending vibrator 1 where the second longitudinal vibrator 4 is arranged, this node N' Since a slight counterclockwise rotation M-M' about the center occurs, the second vertical vibrator 4 acts to kick up the moving body 5 from right to left, and applies a horizontal moving force to the moving body 5. Give. At this time, at the position of the node N of the bending oscillator 1 where the first longitudinal oscillator 3 is arranged, a slight clockwise rotation pp' is generated around this node N, but the first longitudinal oscillator 3 has contracted and is not in contact with the moving body 5, so it does not apply a force in the opposite direction to the moving body 5. Therefore, by repeating this operation, the movable body 5 moves horizontally to the left.

To move the movable body 5 in the opposite direction, the first . The timing of expansion and contraction of the second longitudinal vibrators 3 and 4 may be reversed. That is, the bending vibrator 1 or the first . The signal applied to the second longitudinal oscillator 3.4 is 180° for the above case.
``By shifting the phase, the moving body 5 can be driven in the opposite direction to the above.

The above is an explanation of the structure, operation, and vibration mode of the drive body used in the ultrasonic motor of the present invention. Next, specific embodiments of the present invention will be described based on the drawings.

1, 4, and 5 are a side sectional view, a front view, and a perspective view, respectively, of an ultrasonic motor showing a first embodiment of the present invention. Moreover, FIG. 6 is a diagram showing the third-order vibration state excited in the bending vibrator in this first embodiment. In addition, in the explanation up to FIG. 3 above, it is assumed that the bending vibrator and the vertical vibrator are fixed and the movable body that is the contact member is moved, but in this first embodiment, the movable body that is the contact member is moved. The description will be made assuming that the linear rail is fixed to the motor body and moves a vibrating body such as a bending vibrator or a vertical vibrator.

In the figure, a bending vibrator 1 is constructed by integrally bonding piezoelectric elements 6 arranged at the ratio shown in FIG. 6 to the lower surface of an elastic body 7 made of stainless steel, brass, phosphor bronze, aluminum, or the like. By arranging the piezoelectric element 6 in this manner, third-order bending vibration with both ends free can be excited most efficiently, and in this case, nodes of vibration are created at positions as shown in FIG. From the position of the node of this bending vibrator 1, that is, from both sides of the elastic body 7 in the left and right longitudinal direction, (0,0944+0.2614) /1
The first . A second vertical vibrator 3.4 is bonded, and the end faces of the vertical vibrators 3, 4 are pressed in a direction perpendicular to the sliding surface 8a of the linear rail 8. Here's the first one. The second longitudinal vibration 3.4 has the same polarization structure.

Note that in this embodiment, the first. An insulating layer 9 is provided on the lower surface of the second longitudinal vibrator 3 4 , that is, on the adhesive surface with the bending vibrator 1 . This insulating layer 9 is necessary because the first layer is made of laminated piezoelectric material. This is a case where the contact portion of the upper surface of the second longitudinal vibrator 3.4 to the linear rail sliding surface 8a becomes a positive electrode. However, if the contact portion to the linear rail sliding surface 8a is a negative electrode, the linear rail 8 may be grounded, and the insulating layer 9 is not required in this case. Then, an insulating and wear-resistant friction material 27 such as a polymer material, ceramics, or composite material is pasted on the upper surface of this longitudinal vibrator 3.4, that is, the contact surface with the sliding surface 8a of the linear rail 8. For example, longitudinal oscillators 3 and 4
The voltage applied to the linear rail 8 can be prevented from leaking to the linear rail 8, and the motor can be made durable.

In addition, in this embodiment, the tip of the friction material 27 has a partially cylindrical semi-cylindrical shape, which means that when the bending vibrator 1 causes bending vibration as shown in FIG. Since the vertical vibrator 3.4 makes a slight rotational reciprocating motion around the center, the tip of the vertical vibrator 3.4 draws an arc. If the tip of the friction material 27, that is, the contact surface with the linear rail 8 is square, the linear rail 8
Since the contact point contacts one corner of the plane, the contact state becomes unstable, and unevenness occurs in the relative movement speed of the linear rail 8. Therefore, by making the tip of the friction material 27, that is, the contact surface with the linear rail 8, partially cylindrical, the tip of the friction material 27 and the linear rail 8 are always in a stable contact state. Taking FIG. 2(B) as an example, the radius of curvature R of the surface of the partially cylindrical portion of the friction material 27 is
The tip P' of the friction material, which is related to the total height of the friction material 27
(or M') to node N length P'N (or M
'N) is preferable.

Furthermore, by pasting the friction material 27, the friction material 27
By adjusting the thickness of the piezoelectric element and polishing the friction material after integrally molding the piezoelectric element and the friction material 27, the contact between the linear rail sliding surface 8a of the vertical vibrators 3 and 4 and this linear rail 8 can be made optimal. can be in the state of

At each node of the bending vibrator 1, there are four support pins 10a, 10b, 10c on both widthwise side surfaces of the elastic body, which serve as supporting parts of the bending vibrator 1.

10d is attached. FIG. 7(A), <8) is a side view and a front view of the vibrating body 2, which is composed of an elastic body 7. Piezoelectric element6. 1st. A second longitudinal vibrator 3.4 and four support pins 10a, 10b.

It is composed of 10c and 10d. Note that the arrow in the figure indicates the polarization direction.

4 protruding from the side of the elastic body 7 forming the vibrating body 2
support pins 10a, 10b, 10c.

10d is formed of a short cylindrical body so as not to impede the minute rotational reciprocating motion of the node caused by bending vibration, and is supported by a support base 12 fixed to a support base mounting plate 11.

The upper surface of this support stand 12 has support pins 10a, 1
These are the contact parts with 0b, 10c, and 10d, and like the support pins, they are V-shaped grooves because they need to be positioned and not interfere with the bending vibration of the bending vibrator. In addition, this support stand 12 has a crank-shaped thin part so that unnecessary vibrations generated by the vibrating body 2 do not leak toward the support stand mounting plate 11, and the vibrating body 2 is connected to the bending vibrator 1. The support pins 10a, 10b,
A step is provided in the short cylinder portions 10c and 10d, so that if the device tries to shift, it will come into contact with the support base 12.

A hole is provided in the center of the support mounting plate 11 through which the tip of the support bolt 18 passes. In addition, the pressure adjustment spring 15 and the spring pressure adjustment nut 17 guided by the upper and lower spring holders 14 and 16 are attached to the bolt 18.
The upper tip of the bolt 18 is fitted into a hole in the center of the support mounting plate 11. Since this spring pressure adjustment nut 17 is engaged with the threaded portion of the bolt 18, by turning this spring pressure adjustment nut 17, the pressure adjustment spring 15 can be adjusted to move upward in the figure. Then, the support base mounting plate 11 moves upward, and the ends of each of the vertical vibrators 3 and 4 attached to the moving body are
It comes into pressure contact with the sliding surface 8a of the linear rail 8.

A thread is cut in the center of the lower plate 19, and the lower part of the bolt 18 is screwed into the lower plate 19.

The lower part of the bolt 18 is disc-shaped, and since the lower surface of this disc touches the upper surface of the lower plate 19, the bolt 18
is fixed with no play. And linear rail 8
A bearing 26 inserted into the shaft 23 is mounted on the sliding surface 8b of the
A freely rotatable wheel 22 is mounted thereon.

The upper plate 21 and the lower plate 19 are fixed by left and right side plates 20, and the upper plate 21. The lower plate 199 and both side plates 20 are made of a rigid body. As shown in FIGS. 1 and 4, a shaft 23 through which the wheels 22 pass is fixed above the center of both side plates 20. One mounting plate guide bar 25 is embedded in each side of the support base mounting plate 11 on the front side and the back side in FIG. It is designed to be guided by a groove 24 bored in the vertical direction. This prevents the support mounting plate 11, which moves up and down when adjusting the contact pressure between the linear rail sliding surface 8a and the vertical vibrators 3 and 4, from wobbling.

In this first embodiment configured in this way, a method for moving objects other than the linear rail 8 to the right along the linear rail as indicated by arrow A in FIG. 1 is shown in FIGS. 8 and 9. This will be explained below.

An alternating current voltage V (, sin
(IJ t is applied. Also, the eighth
An alternating current voltage having a sine waveform fI2 whose phase is advanced by 90 degrees from the sine waveform I11 as shown in FIG. 3(B) is applied. Then, when an AC voltage of a sine waveform II3 having a phase difference of 1800 from the sine waveform ρ2 applied to the first longitudinal oscillator 3 is applied to the second longitudinal oscillator 4, as shown in FIGS. 9(A) to 9(D). As the first longitudinal oscillator 3 expands and the second longitudinal oscillator 4 contracts, the bending oscillator 1 is driven, and the longitudinal oscillators 3 and 4
undergoes a bending vibration that changes from a V-shape to an inverted V-shape. Then, the first vertical vibrator 3 is brought into pressure contact with the sliding surface 8a, and the second vertical vibrator 4 is separated. Therefore, in the vibrating body 2, the first vertical vibrator 3 kicks up the sliding surface 8a of the linear rail 8 from right to left, and as a result, the vibrating body 2 moves rightward.

Next, in FIGS. 9(E) to (H), the first longitudinal vibrator 3
The bending vibrator 1 is driven in synchronization with the contraction of the second vertical vibrator 4 and the expansion of the second vertical vibrator 4, and the vertical vibrator 3.4 performs a bending vibration that changes from an inverted V-shape to a V-shape.

Then, the sliding surface 8a and the second vertical vibrator 4 come into pressure contact, and the first
Since the vertical vibrator 3 is separated, the second vertical vibrator 4 of the vibrating body 2 kicks up the sliding surface 8a from right to left, and as a result, the vibrating body 2 moves rightward.

Then, by continuously repeating the above operation, the vibrating body 2 moves as the bending vibrator 1 bends. Along with this, the upper and lower plates 1
9. The moving object integrated with 21 moves to the right while rotating the wheels 22 on the sliding surface 8b of the linear rail 8.

Incidentally, when moving an object other than the linear rail to the left, the timing of expansion and contraction of the vertical oscillators 3 and 4 relative to the flexural oscillator may be reversed. In other words, the signal applied to the bending vibrator 1 or the longitudinal vibrator 3.4 is 1 for the above case.
If the phase is shifted by 80", the linear rail 8 in Figure 1
It is possible to drive other moving objects in the direction opposite to arrow A.

The moving speed and driving force of the moving object in this first embodiment are related to the amplitude ratio of the bending vibration amplitude of the bending vibrator 1 and the vibration amplitude of the longitudinal vibrators 3 and 4.
This will be explained using a diagram.

FIGS. 10(A) and 10(B) are action diagrams showing the operation of the vibrating body when the vibration amplitude of the longitudinal vibrator is zero and only the bending vibration of the bending vibrator is occurring. Also, Figure 10 (C)
, (D) is the bending vibration amplitude of bending vibrator 1 and longitudinal vibrator 3.
．． 10 is a diagram showing the locus of the tip T of the longitudinal vibrator 3.4 (see FIGS. 10(A) and 10'(B)) when the vibration amplitudes of 4 are combined. FIG. In this FIG. 10, (A).

(C) shows the case where the vibration amplitude of the bending vibrator 1 is large; (B
) and (D) respectively show the small cases. In FIGS. 10(C) and 10(D), the vibration amplitude UM of the longitudinal vibrator 3.4 is the same. This can be achieved by keeping the voltage amplitude applied to the longitudinal vibrator 3.4 constant. The amplitude of the longitudinal vibrator at this time needs to be greater than the surface precision of the contact surface with the contact member (linear rail 8).
Practically speaking, an amplitude of 0.1 μm or more is required. Also,
The force generated by the vertical vibrator 3.4 is proportional to the voltage applied to the vertical vibrator, and is strong enough to generate the above-mentioned necessary amplitude of 0.1 μm or more against the pressure contact force on the contact member (linear rail 8). A value is required. The pressing force applied to the linear rail 8 is proportional to the driving force of the motor, and in order to increase the driving force, the pressing force and the voltage applied to the vertical vibrator can be increased.

Next, the moving speed is proportional to the horizontal component Uvl' Uv□ caused by the bending vibration of the bending vibrator 1 in FIG.
This is proportional to the voltage applied to the piezoelectric body integrated with the bending vibrator 1. That is, when only the vertical vibrator 3.4 is driven and the bending vibrator 1 is not driven, the moving speed is zero and the contact member does not move. Therefore, the moving target also does not move. When the amplitude to the bending vibrator 1 is gradually increased from this state, the moving speed becomes faster in proportion to the amplitude. To change the amplitude of the bending vibrator 1, in addition to the method of changing the applied voltage described above, there is also a method of changing the drive frequency of the bending vibrator 1 from the resonance point, and a method of changing the high frequency voltage applied to the bending vibrator 1 as a burst signal intermittently. There are ways to make it a target. Using these methods, the speed can be changed steplessly from the speed O to the maximum speed at which no slipping occurs between the contact surfaces of the longitudinal vibrator and the contact member (linear rail 8).

Further, in this first embodiment, the width of the longitudinal vibrators 3, 4 along the length direction of the bending vibrator 1 at the bonded portion of the longitudinal vibrator 3.4 to the bending vibrator 1 is preferably small. This is because bending vibration occurs in bending vibrator 1, so longitudinal vibrator 3
, 4, the bending vibration occurring in the bending vibrator 1 will be hindered. On the other hand, longitudinal oscillator 3
．． If the width of 4 is made too narrow, the adhesive force to the bending vibrator 1 will be weakened, and the bending vibration of the bending vibrator 1 will cause damage to the bond between the longitudinal vibrators 3 and 4 and the bending vibrator 1, as well as to the longitudinal vibrator. there is a possibility. However, in this first embodiment, since a laminated vertical vibrator is used as the vertical vibrator, the height direction of the vertical vibrator can be made sufficiently low, thereby eliminating the risk of the vertical vibrator being destroyed. do not have.

In this first embodiment, the vertical vibrator 3.4 has dimensions of approximately 1.5 mm in width, 7.4 mm in length, and 2 mm in height. In this longitudinal vibrator, the resonance frequency in the longitudinal direction is around 200KHz, and the resonance frequency in the longitudinal direction is around 700K.
It exists around Hz. In addition, the resonance frequency of the bending vibration of the bending vibrator is around 40 KHz, which is less than 1/3 of the longitudinal resonance frequency of the longitudinal vibrator, so the longitudinal vibrator is affected by the bending vibration when the bending vibrator resonates. There is no.

As described in detail in FIG. 15 above, in the case of this embodiment, the longitudinal vibrator is about 2 mm in height, made by laminating 16 piezoelectric plates with a thickness of 0.12 m+s, and a voltage of 1 μm is applied to the vertical vibrator.
00V can be applied, and an ultrasonic motor that is extremely small and can be driven at low voltage can be obtained.

Furthermore, the neutral plane S1. Node N1. which is perpendicular to S2 and whose intersection line is node line 14.15. Vertical oscillator 3.4 in the plane of N2
By arranging the supporting parts, the leakage of the bending vibration generated in the bending vibrator 1 is minimized, so that the bending vibration can be excited in the best possible manner.

The supporting portions are arranged so that a pressing force acts on the cylinder surface in the same direction as the longitudinal vibration direction of the longitudinal vibrators 3 and 4. When the bending vibrator 1 performs bending vibration, the left and right portions of the neutral plane of the bending vibrator vibrate up and down on the plane of the paper with the node as the center. For this reason, if a support portion is provided at a position other than the node of bending vibration, the bending vibration of the bending vibrator will be hindered, the vibration state will become unstable, and the motor efficiency will decrease. In addition, since the longitudinal vibration direction of the vertical vibrators 3 and 4 and the direction and position of the force for supporting the support portion are approximately the same, the pressure contact force due to the longitudinal vibration is effectively applied to the contact member (linear rail 8). Because of this transmission, a highly efficient and stable motor can be realized.

In the first embodiment described above, the linear rail 8 is fixed, and the vibrating body 2 consisting of the bending vibrator 1 and the vertical vibrators 3 and 4 is
For example, a self-propelled motor is shown, which is configured to cause moving objects including objects to travel along a linear rail 8.

However, if the moving target is fixed and the linear rail 8
A modified example of the first embodiment in which the wafer is moved will be explained below with reference to FIGS. 11(A) and 11(B).

FIGS. 11(A) and 11(B) are a front view and a side view of this modification. In the figure, a bending vibrator 1a and a vertical vibrator 3 are placed on a pair of supports 12a fixed by a lower plate 19a.
A vibrating body consisting of a and 4a is mounted, and the vertical vibrator 3 of the vibrating body
A, 4a are in contact with a part of the lower surface of the movable body 29, which is a contact member. In addition, a pressure adjustment spring 15a is provided at the top.
, 15b, wheels 22a are attached to a support shaft 23a that is pulled downward. This wheel 22a is configured to be able to rotate in contact with two movable bodies, and includes a support shaft 23a of this wheel 22a and a pressure adjustment spring tSa.

15b is a frame 30 whose wheels are movable up and down.
This frame 30 is attached to the lower plate 19a. And pressure adjustment springs 15a, 15b
This adjusts the contact pressure between the moving body 29 and the vibrating body.

When an AC voltage having the same phase difference as in the first embodiment is applied to the bending vibrator 1a and the vertical vibrators 3a and 4g, only the two movable bodies move linearly. Further, in this modification, a groove 29a that is slightly wider than the width of the wheel is provided on the sliding surface 29b of the moving body 29 so that the wheel 22a does not come off in the width direction of the linear rail.

FIGS. 12(A) and 12(B) are a front view and a side view of an ultrasonic motor showing a second embodiment of the present invention, and show a case in which there is one longitudinal vibrator. While the first embodiment described above uses a third-order bending vibration mode with four nodes and free ends,
This second embodiment differs in that the second-order bending vibration mode of the one-end clamp having one node is used.

As for the vibration mode, as shown in Figure 12 (C), considering the secondary bending resonance mode with one side completely clamped, the bending vibration node of this plate is as follows, assuming the total length is 1.
It is located 0.2165 from the tip of the plate. Therefore, in this embodiment, one end of the bending vibrator IA is fixed to the side plate 21A so as to be completely clamped, and a longitudinal vibrator is placed at a node position having a ratio of (0,2185/1) from the tip of the bending vibrator IA. 3A is placed. And the longitudinal vibrator 3A
At the position of the node where is placed, as in the first embodiment above,
Support stand 12A, moving body 5A as a contact member, pressure adjustment springs 15A and 15B, wheels 22A, and a pair of frames 33
Place. In addition, the above-mentioned bending vibrator IA and longitudinal vibrator 3A
constitutes a vibrating body. Therefore, the first
If an AC voltage with the same phase difference as in the example is applied, the moving body 5
Only A will move linearly. Here, when the movable body 5A moves in the horizontal direction, a small rotatable type is mounted on two support shafts 28a and 28b horizontally suspended on the frame 33 on both sides of the wheels 22A so that the movable body 5A does not tilt. wheels 31 and 32 respectively, and these are attached to the moving body 5A.
is pressed against.

In the case of this second embodiment as well, the mobile body 5 is similar to the first embodiment described above.
A groove 29a is provided on the sliding surface SAa of A.

The above is the outline of the ultrasonic motor showing the second embodiment of the present invention. Next, these first. As an application example of the ultrasonic motor according to the second embodiment, an example in which the ultrasonic motor is applied to a lens barrel of a camera will be described with reference to FIGS. 13(A) and 13(B).

FIGS. 13(A) and 13(B) show an application example in which the ultrasonic motor is used to move an internal moving object, such as a lens support frame, inside a cylinder such as a camera lens barrel. be.

FIG. 13(A) is a cross-sectional view of the lens barrel;
Figure (B) (;i, Figure 13 (A) (7) is a sectional view taken along the , the pressure adjusting leaf spring 42 fixedly supports a piezoelectric element 43 as a vibrating body and a bending vibrator 45 to which a vertical vibrator 44 is attached,
The tip of the vertical vibrator 44 attached to the bending vibrator 45 is
Internal moving body 47 that is cylindrical and has a lens fixed inside.
The pressure is adjusted by a pressure adjusting plate spring 42 and the contact is made in contact with the pressure adjusting plate spring 42. Further, the portion of the internal movable body 47 that is a contact member that is in contact with the vertical vibrator 44 is connected to the bending vibrator 45 and the vertical vibrator 4.
It has a planar shape to efficiently transmit the driving force generated in step 4, and since it is planar, unnecessary rotation does not occur. Then, the bending vibrator 45 and the longitudinal vibrator 4
When voltages with different phases similar to those in the above embodiment are applied to 4, the internal moving body 47 to which the lens is fixed can be moved in parallel along the central axis of the outer wall 41.

In this embodiment, a lens 46 is fixed in a cylindrical shape as the internal moving body 47, and this lens 46 is moved in the direction of arrow E in FIG. 13(B). It can be anything that can be attached to a cylinder or a cylinder.

In each of the above embodiments, the support part of the bending vibrator and the longitudinal vibrator are on the same nodal line of bending vibration in the amplitude direction of bending vibration, but the support part of the bending vibrator and the longitudinal vibrator are on the WJ line of bending vibration. , and the bending vibration support portion and the longitudinal vibrator do not need to be on the same nodal line as long as they are located at symmetrical positions of the bending vibrator. In other words, the support part of the bending vibrator and the longitudinal vibrator are
They may be arranged on a straight line passing through the same or different nodes of the bending vibration and extending in the amplitude direction of the bending vibration.

Next, an ultrasonic motor showing a third embodiment of the present invention will be described. In the ultrasonic motor of this embodiment, by providing the additional mass body, the position of the first-order resonance node of the bending vibration of the longitudinal vibrator and the bending vibrator is located on the center plane in the thickness direction of the elastic body itself. This is an efficient ultrasonic motor in which bending vibration, which is minute reciprocating vibration around the nodes, is not inhibited as much as possible during driving.

In an ultrasonic motor using a conventional vibrating body composed of a bending vibrator and a longitudinal vibrator, as shown in the schematic diagram of FIG.
A vertical vibrator 84a is placed on one side of the oscillator 84a.

84b is attached. Therefore, the positions of the nodes 82b and 82c of the bending vibration of the vibrating body 82 are determined by the unbalance f of the longitudinal vibrator [depending on the amount, the nodes 81b and 81 of the bending vibrator 81 itself]
It is slightly shifted from the position of c. Furthermore, since the piezoelectric element 86 is attached only to one side of the elastic body 85, the position of the node of the bending vibrator 81 itself is not actually at the center in the thickness direction of the elastic body, but is slightly shifted toward the piezoelectric element side. . Therefore, the 21st
The unbalanced mass that causes the difference between the positions of the nodes 82b and 82c in the vibrating body 82 shown in the figure and the nodes 81b and 81c of the bending vibrator 81 itself will be explained.

First, when considering the range from the A-A plane to the B-B plane of the vibrating body 82 in FIG. Let rl be the distance to the rotation axis. Also, the vertical vibrator 8
Let m2 be the equivalent mass of the lower side to which 4a is fixed, and let r2 be the distance from the center of mass to the axis (see FIG. 22). Upper and lower rotational inertia masses 1 around the above virtual rotation axis
1゜I2 is respectively 1 -m Xr...old...(1) 11 1 -m
It becomes 2 2. Now, if the virtual axis of rotation is the node 81b on the neutral plane 81a of the bending vibrator 81 as in the conventional example, this node position is located near the center position of the elastic body 85 because the piezoelectric element 86 is lightweight. do. Therefore, the distances rt and r2 have the relationship rt<r2. Also, quality fi 1ml
, m2, since the longitudinal vibrator 84a is added to m2, m l < m 2 . Above (1), (
2) From the formula, the upper and lower rotational inertia f with node 81b as the rotation axis
The relationship between f1I and I is I1 and I2, which is an unbalanced state, and the node gtb does not become a true node of the bending vibration of the vibrating body 82.

When the vibrating body 82 is subjected to bending vibration by supporting the supporting parts 85a and 85b centered on the node 81b of the bending vibrator 81, the bending vibration is inhibited and efficient driving becomes impossible. becomes. , the true nodes on the neutral plane 82a for the bending vibration in the vibrating body 82 as described above are respectively nodes 82b.

82c (see Fig. 21), as shown in Fig. 22, the distance r1 from the rotation axis C to the position of the upper mass m1 is equal to the distance r1 to the position of the lower mass m2 where the longitudinal oscillator is located. The axis C such that the distance "2" is shorter than the above node 82b
Or it will be 82c.

However, it is extremely difficult to determine the positions of these nodes 82b and 82c by calculation or the like.

Therefore, in the ultrasonic motor of this embodiment, as described above, a vibrating body is used in which an additional mass body having a mass corresponding to the mass of the vertical vibrator is fixed to an elastic body at a position facing the vertical vibrator. Then, the above equivalent quality l1m in the vibrating body
11m2 and the distance rr to the node are each ml”
The structure has a relationship of 'm2 * r 1-1' 2 r2, and the values of the rotational inertia masses above and below the joint rotation are also balanced. Therefore, the bending vibration nodes of the vibrating body are located on the neutral plane of the elastic body. Then, the vibrating body is configured such that the nodes are used as support portions and supported by a support body. If this vibrating body is used, the vibrating body can be efficiently vibrated in a state where minute reciprocating vibrations around the nodes of bending vibration are not inhibited.

FIG. 14(A) is a vertical cross-sectional view of the essential parts of the ultrasonic motor of the third embodiment, and the vibrating body 62 in this motor is
It is composed of vertical vibrators 54a, 54b, bending vibrator 61, and additional mass bodies 65a, 65b. The bending vibrator 61 is
Thin piezoelectric elements 56a and 56b polarized in the thickness direction are bonded to the upper and lower surfaces of a relatively thick plate-shaped elastic body 55 having a rectangular planar shape. When a high frequency voltage is applied to the piezoelectric elements 56a and 56b in the polarization direction, the bending vibrator 61 generates bending vibration, and when a signal of a specific frequency is further applied, it causes resonance bending standing wave vibration. In the case of this embodiment, the bending vibrator 61 is configured so that first-order bending resonance vibration is most efficiently excited.

On the other hand, the longitudinal vibrators 54a and 54b are formed of laminated piezoelectric elements wider than the bending vibrator 61 (see FIG. 14(A)). Then, the bending vibrator 61
It is fixed to the surface of the elastic body 55 of the bending vibrator 61 on a straight line extending in the amplitude direction of the bending vibration from the position of each two nodes of the first-order bending vibration. This longitudinal vibrator 54a, 5
4b vibrates in the thickness direction of the bending vibrator 61 when a high frequency voltage is applied. Further, on the surface opposite to the surface of the elastic body 55 of the flexural oscillator to which the longitudinal oscillators 54a and 54b are fixed, at a position symmetrical with respect to the node of flexural vibration, with the same specific gravity as that of the longitudinal oscillator, shaped additional mass body 65a.

65b is fixed. Furthermore, the longitudinal vibrator 54
Sliders 54c and 54d made of a wear-resistant friction material are fixed to the tip surfaces of the sliders a and 54b, respectively.

The sliders 54c and 54d are pressed against a slide plate 52b made of wear-resistant friction material fixed to the upper surface of the rail member 52, which is a contact member shown in the figure, and frictional contact is maintained. It is assumed that the rail member 52 is fixed to another immovable member (not shown).

On the other hand, on the surface of the rail member 52 on the side to which the slide plate 52b is not fixed, there are two straight lines each having a semicircular cross section.
A row of guide grooves 52a are bored parallel to the direction in which the vibrating body 62 is driven. Further, a part of the rail member 52 and the bending vibrator 61 are disposed within a motor support frame 51, and this motor support frame 51 is attached to the rail member 5.
2 and the bending vibrator 61, it is formed of a channel-shaped member having a U-shaped cross section. This support frame 5
1 is provided with a straight, parallel ball storage groove 51a having a semicircular cross section similar to that of the guide groove 52a at a position opposite to the guide groove 52a. A plurality of bearing balls 63 are arranged in both the guide grooves 52a and the guide grooves 52a. This allows the support frame 51 to move only in the direction of the guide groove 52a of the rail member 52 while holding the ball 63 in the ball storage groove 51a.

The bending vibrator 61 is attached to the support frame 51 in the following manner. That is, at the positions of the bending vibration nodes of the bending vibrator 61, there are support pins 55a, 55b, 5 in the form of cylindrical shafts that protrude in the width direction of the bending vibrator 6.1.
5c and 55d are integrally provided on the elastic body 55 at symmetrical positions, and are provided at four locations on the center position of the elastic body 55 in the thickness direction. This support pin becomes a support part for the bending vibrator.

On the outer peripheries of the support pins 55a to 55d, support members 64a and 64b made of a material with good sliding properties are provided with flanges, respectively.
64c and 64d are fixed or fitted.

The holder 57, which is a holder for the vibrating body 62, is a channel-shaped member formed with an inverted U-shape in cross section so as to surround the bending oscillator 61 from above, and has an engagement notch 57c in its leftward portion. , 57d.

57e and 57f are drilled. The support pins 55a to 55d provided on the elastic body 55 of the bending vibrator 61 are rotatably fitted into the engagement notches 57c to 57e via the support members 64a to 64d. The holding body 57 has mounting pieces 57a and 57b that are bent upward at the middle of both left and right edges and project horizontally outward to the left and right in the width direction, and the support pins 55a ~
55d fitted into the engagement notches 57C to 57e
Mounting pieces 57a and 57b of No. 7 are placed on the upper surface of the support frame 51, and two screws 60 are passed through the mounting pieces 57a and 57b via the disc spring 58 and five spacers to attach the support frame 5.
Screw it onto the top of 1. In this way, the holding body 57 is fixed to the support frame 51. Further, the design is such that a slight gap is created between the mounting pieces 57a, 57b and the upper surface of the support frame 51 in this mounted state.

One of the spring biasing forces generated by the disc spring 58 is applied to the holder 57. The signal is transmitted to sliders 54c and 54d via vibrators 54a and 54b.

The other spring biasing force is the support frame 51. Rail member 52
and the like to the slide plate 52b.

Therefore, the urging force acts as a pressing force on the contact surfaces of the sliders 54c, 54d and the slide plate 52b. The biasing force is adjusted by changing the thickness of the five spacers. As described above, the vibrating body 62 consisting of the bending vibrator 61, the vertical vibrators 54a and 54b, and the additional mass bodies 65a and 65b can be pressed against the slide plate 52a of the rail member 52 with an appropriate pressure.

As described above, according to the ultrasonic motor of the third embodiment, first, the bending vibrator 61
On the other hand, piezoelectric elements 56a and 56b having the same shape are fixed to the upper and lower surfaces of the elastic body 55 so that the shape and mass are symmetrical. Furthermore, additional mass bodies 65a and 65b having the same shape and mass are fixed to the longitudinal vibrators 54a and 54b at symmetrical positions with respect to the neutral plane 61a. Therefore, the bending vibration nodes 62b and 62C of the vibrating body 62 are located on the neutral plane 61a. Specifically, the nodes 62b and 62c are positioned at the center of the elastic body 55 in the thickness direction.

The ultrasonic motor of the third embodiment configured as described above includes a bending vibrator 61 and a vertical vibrator 54a.

They are driven by applying phase-controlled alternating current voltages to each of the electrodes 54b. Then, the slider 54C254d fixed to the vertical vibrators 54a and 54b pressed against the slide plate 52b of the rail member 52 behaves in a circular or elliptical trajectory as shown in the first embodiment. Therefore, the support frame 51 is moved along the rail member 52, and a moving object (not shown) attached to the support frame 51 is also driven at the same time.

According to the ultrasonic motor of this embodiment, the bending vibration node of the vibrating body 62, which is the driving part, can be accurately set on the neutral plane of the elastic body, and that part is supported by the holding body 57. Therefore, the bending vibration is not inhibited, and an efficient and stable driving state is realized, and furthermore, generation of unpleasant audible sounds during driving can be prevented. Further, the design of the elastic body itself becomes easier, and furthermore, even if the position of the node is slightly shifted due to errors in the parts, it can be easily corrected by adjusting the size of the additional mass.

In the third embodiment described above, the order of bending vibration was first order, but
Of course, this can also be applied to other higher order vibrations such as second order, third order, etc. In addition, support pins 55a to 55d
is the same as the position where the longitudinal vibrator is attached, but this may of course also be a different node position. Moreover, the piezoelectric element 5
6a and 56b are attached to both sides of the elastic body 55, but they may also be attached only to one side. Furthermore, additional mass body 65
a.

65b has the same specific gravity and the same shape as the longitudinal oscillators 54a and 54b, but if the rotational inertia mass around the nodes is made equal above and below the nodes, that is, in the amplitude direction, even if they have different specific gravity or shape. Of course it's a good thing. For example, the additional mass bodies 65a, 65b and the elastic body 55 may be formed integrally.

In this case, the number of components is reduced, and the number of steps needed to attach the additional mass body to the elastic body is also eliminated.

FIG. 15 is a side view of a vibrating body 69 showing a modification of the third embodiment. The difference from the vibrating body 62 of the third embodiment is as follows.
A piezoelectric element 56a is provided on the elastic body 55.

56b1 Vertical oscillators 54 a, 54 b sAdditional mass bodies 65a, 65b are attached to grooves 55 for positioning.
e, 55f, 55g, 55h, 55i, '55j, and additional mass body 65a.

By using a material with high specific gravity for 65b, the additional mass body 65a
, 65b are made smaller.

In this way, the manufacturing error of the vibrator can be suppressed to a smaller level, so that the bending vibration becomes more stable and highly efficient due to the increased accuracy of vibration symmetry. Furthermore, it is possible to make the vibrating body 69 smaller. The material of the additional mass bodies 65a, 65b is preferably an iron-based metal, a copper-based metal, or the like. For further miniaturization, tungsten is a good choice.

FIG. 16 shows a vibrating body of another modification of the third embodiment. The vibrating body 72 of this modification does not use a special additional mass body, the mass of the vertical vibrators 74a and 74b is reduced, and the piezoelectric element 76 attached to one side acts as the additional mass. It is something. In this modification, the mass of the elastic body 75 is sufficiently larger than the mass of the longitudinal oscillators 74a and 74b, so even if no additional mass is attached, the rotational inertia mass for the nodes of bending vibration is not too large above and below the nodes. There is no difference and almost no unbalance of bending vibration occurs. Therefore, the ultrasonic motor to which the vibrator according to the present modification is applied is similar to the ultrasonic motor of the third embodiment described above, in which the bending vibration is less inhibited in driving the motor, and efficient ultrasonic waves can be generated. It becomes possible to provide motors.

FIG. 17 shows a vibrating body that is still another modification of the third embodiment described above. Similar to the above-mentioned modification, this modification does not require any special additional mass body. and,
The support parts 55a and 55b that support the vibrating body 92 are not necessarily set on the neutral plane 91a of the elastic body 95 in the vibration direction.

The neutral plane 91a is calculated or experimentally determined by considering the balance of the rotational inertia mass of the piezoelectric element 96 and the elastic body 95 or the longitudinal vibrators 94a and 94b in the bending vibration direction, or the balance of the rigidity of the elastic body. The position of the node shifted by the displacement lid is determined, and four support bins 55a and 55b (other support parts are not shown) for supporting the vibrating body 92 are arranged at that position.

The ultrasonic motor using the vibrating body of this modification has good efficiency and does not generate unpleasant audible sounds, like the motor using the above modification. In addition, in the ultrasonic motor according to the third embodiment and its modifications, the support is a moving member,
The rail member is fixedly supported. However, it is of course possible to provide an ultrasonic motor in which the support body is fixedly supported and the rail member is used as a moving member.

Next, an ultrasonic motor showing a fourth embodiment of the present invention will be described using FIG. 18.

In this embodiment, the present invention is applied to a rotary drive type ultrasonic motor in which the contact member pressed against the vibrating bodies 106 and 109 is a disk-shaped moving body 110. The moving body 110
The vibrating bodies 106 and 109 that drive the support pins 1 and
05a, 108a and longitudinal vibrators 104, 107. and,
The longitudinal vibrators 104 and 107 are pressed against the movable body 110 via supports (not shown).

Further, the movable body 110 is supported by a bearing 111 by an output shaft portion 110a that is integral with the movable body 110. In other respects, the vibrating bodies 106 and 109 have the same structure as that used in each of the embodiments described above.

To explain the operation of the ultrasonic motor of this embodiment configured as described above, first, a phase-controlled AC voltage is applied to each vibrator of the vibrating body 106 and 109 to give vibration, and the movable body 110 is rotated to the left or right to drive a moving object (not shown) as a load using the output shaft portion 110a.

According to this embodiment, it is also possible to provide a rotary ultrasonic motor having high efficiency and stable characteristics. Note that in this embodiment, two vibrating bodies 106
, 109 are used, but it is also possible to configure the ultrasonic motor using only one other vibrating body.

[Effects of the Invention] As described above, according to the present invention, the vertical vibrator is provided on the nodal line of the standing wave vibration generated by the bending vibrator, and the timing of expansion and contraction of the bending vibrator and the longitudinal vibrator is adjusted. By doing so, the contact member in contact with the tip of the vertical vibrator can be moved, so the moving direction can be adjusted by timing conversion, and the driving force can be adjusted by voltage control. Moreover, this control is easy, and since the flexural oscillator is driven in a resonant state and the longitudinal oscillator is driven in a non-resonant state, there is no need to match the resonance frequencies of the flexural oscillator and the longitudinal oscillator, making manufacturing easy. Can be done. Moreover, the vibrating body can be configured only with a bending vibrator and a thin vertical vibrator, and a number of remarkable effects such as being able to obtain a very small and thin motor are exhibited.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an ultrasonic motor showing a first embodiment of the present invention, and FIGS. 2(A) and (B) are side views of a vibrating body used in the ultrasonic motor of the present invention. FIG. 3, an action diagram showing the vibration state, shows an example of the wiring direction when applying an AC voltage to the piezoelectric element and the longitudinal vibrator in FIG. 2 (A) above, and the state of the polarization direction at this time. 4 and 5 are a front view and a perspective view of the ultrasonic motor shown in FIG. 1, and FIG. 6 shows the third-order bending vibration excited by the bending vibrator shown in FIG. 1. Diagram showing the state, Figure 7 (A), (
B) is a side view and a front view of the vibrating body in FIG. 1, FIGS. 8(A), (B), and (C) are the bending vibrator and first longitudinal vibrator in FIG. 1, Waveform diagram showing the phase of the AC voltage applied to each of the second longitudinal oscillators, FIG. 9 (A), (B), (C), (D), (
E), (P), (G), (+1) are the linear values when the AC voltage shown in Fig. 8 (A), (B), (C) is applied to the vibrating body shown in Fig. 1 above. FIGS. 10(A) and 10(B), which are action diagrams explaining the movement of the vibrating body with respect to the rail, show the case where the vibration amplitude of the longitudinal vibrator in the first embodiment is zero and only the bending vibration of the bending vibrator occurs. Action diagram showing the operation of the vibrating body when
0 (C) and (D) are diagrams showing the locus of the tip of the longitudinal vibrator. (D) is a diagram showing the case where the bending vibration amplitude is small, and FIG. 11 (A)
, (B) is a front view and a side view of a modification of the first embodiment in which the vibrating body is fixed and the linear rail is moved. FIG. 12 (C
) is an action diagram of the vibration state of this second embodiment, and Fig. 13 (A
), (B) are a cross-sectional view of a lens barrel and a cross-sectional view taken along line X-X in an application example in which the ultrasonic motor of the present invention is applied to a lens barrel of a camera, and FIG. 14 (A ) is a vertical cross-sectional view of a main part of an ultrasonic motor showing a third embodiment of the present invention, FIG. 14(B) is a cross-sectional view taken along line XX in FIG. , FIG. 14(A) above is a side view of the main part of the vibrating body showing a modification of the third embodiment shown in <8), FIG. FIG. 17, a side view of the main part of the vibrating body showing a modified example, is the same as the third part of FIG. 14(A) above.
FIG. 18 is a side view of a main part of a vibrating body showing still another modification of the embodiment, and FIGS. 19 and 20 are schematic perspective views of main parts of an ultrasonic motor showing a fourth embodiment of the present invention. 19 is a perspective view illustrating the operation of a vertical vibrator, FIG. 19 is a diagram showing a conventional vibrator, FIG. 20 is a diagram showing a laminated type vertical vibrator, and FIG. 21 is a diagram showing a conventional vibrator. A side view of the main part, FIG. 22, is a diagram showing a balanced state of the rotational inertial mass of the vibrating body shown in FIG. 21. 2, 82.89.72.92.108, 109...
... Vibrating body 1, 1 a, IA, 61.71.
105.108 =-Bending vibrator 6°6A. 6a 56b. 7B. 96...Piezoelectric element that gives bending vibration 7゜55゜75゜95...Elastic body

Claims (4)

[Claims] (1) A plate-shaped or rod-shaped elastic body, a bending vibrator that is fixed to the elastic body and causes standing wave type bending vibration in the elastic body by applying an alternating voltage, and a surface of the elastic body. a vibrating body comprising a longitudinal vibrator, which is provided on a nodal line of the bending vibration, is oscillated about the nodal line by the bending vibrator, and expands and contracts in the amplitude direction of the bending vibration when an alternating current voltage is applied; and a contact member pressed into contact with a tip end surface of the vertical vibrator, and by expanding and contracting the vertical vibrator in synchronization with the bending vibration, the vibrating body and the contact member are moved relative to each other. An ultrasonic motor featuring: (2) The supporting part of the vibrating body and the longitudinal vibrator are arranged on a straight line passing through the same or different nodes of the bending vibration and extending in the amplitude direction of the bending vibration. Ultrasonic motor as described. (3) An additional mass body is provided on the opposite side of the bending vibrator to which the longitudinal vibrator is provided, so that the neutral plane of the longitudinal vibrator and the bending vibrator coincides with approximately the center of the elastic body. The ultrasonic motor according to claim 1, characterized in that: (4) The ultrasonic motor according to claim 1, wherein the longitudinal vibrator is composed of piezoelectric elements laminated in the thickness direction of the elastic body.