JPH06169582A - Ultrasonic driving device - Google Patents

Abstract

PURPOSE:To provide an ultrasonic driving device where the abraded powder never gets jammed in a pressure-bonding part even if the contact face with an elastic body or a mobile part of a projection is worn away, and besides the propagation efficiency of driving force never drops even by the dispersion in the shape, the boding force, etc., of the contact face. CONSTITUTION:This has a mobile part which is the end face of an elastic body 1 to cause the longitudinal vibration to give floating force and the crooked vibration to give driving force and which gets driving force from an elastic body 1 at vibration, being bonded in the position other than the node of crooked vibration stationary waves, and besides either the elastic body 1 or a mover is provided with a projection 3b for transmitting driving force to the mobile part, and also the contact face with the elastic body or the mobile part of the projection 3b is made irregular.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic drive device, and more particularly, to an ultrasonic drive device for generating a levitation force due to longitudinal vibration and a driving force due to bending vibration on an end face of a single flat plate-like elastic body. Regarding the device.

[0002]

2. Description of the Related Art An ultrasonic drive device (ultrasonic motor) utilizing ultrasonic elliptical vibration has been developed with a focus on its small size, light weight and simple structure. Conventionally, an ultrasonic motor device is classified into two types, a standing wave type ultrasonic motor device using a standing wave and a traveling wave type ultrasonic motor device using a traveling wave, when classified according to the mode of vibration generated in an elastic body. It is roughly divided into types. Among the above, as a standing wave type ultrasonic motor device, a motion extractor such as a roller is pressed onto a plane (perpendicular to the thickness direction) of the elastic body to extract a driving force by longitudinal vibration. It is known to do so. In order to obtain a large torque in the ultrasonic motor configured as described above, it is necessary to select a material having a high friction coefficient as the material of the elastic body or the motion extractor and strongly press the motion extractor against the elastic body.

[0003]

However, in the above-mentioned conventional device, since the pressing force is applied in the direction perpendicular to the plane of the elastic body, the elastic body is deformed and the vibration characteristic is often abnormal. there were. For this reason, strong pressing cannot be applied, and thus a large torque cannot be obtained. Further, although the above-mentioned conventional device using the flat plate-shaped elastic body is structurally suitable for a linear motor, it has a difficulty in constructing a rotary motor. Conventionally, as a rotary ultrasonic motor, one using torsional vibration and longitudinal vibration is known, but since the excitation unit is a Langevin type,
There was a limit to miniaturization. Moreover, in order to obtain both torsional vibration and longitudinal vibration in the same manner, this type of device first applies longitudinal vibration to the first vibrating elastic body, and this longitudinal vibration is applied to the second vibrating body having the Langevan type excitation part. By adding to the vibrating elastic body, longitudinal vibration is generated in the second vibrating elastic body, and torsional vibration is generated by the longitudinal vibration. At least the first vibrating elastic body and the second vibrating elastic body are required, and the structure is complicated. is there. Further, in particular, in order to induce the torsional vibration in the second vibrating elastic body, not only the special exciting section described above is necessary, but also the first and second
However, there is a drawback that the induced characteristics of the longitudinal vibration and the torsional vibration easily vary depending on the pressure contact state of the vibrating elastic body. Therefore, Japanese Patent Application No. 2-316659 is proposed by the applicant of the present application as an application filed in view of the above circumstances. That is, this application is composed of a flat plate-shaped elastic body that induces resonance of bending vibration when a vibration is excited at a resonance frequency, and a piezoelectric body provided on the plane of the elastic body, and levitated on the end surface of the elastic body. A vibrating portion that causes a longitudinal vibration that gives a force and a bending vibration that gives a driving force, and a power source that applies an AC voltage having a frequency equal to the longitudinal vibration resonance frequency of the elastic body to the piezoelectric body, and give a levitation force A driving force is applied from the elastic body at the time of vibration by crimping to the end surface of the elastic body that causes the longitudinal vibration and the bending vibration that gives the driving force, and crimping to a position other than the node portion of the bending vibration standing wave. By providing a protrusion that transmits a driving force to the moving part on at least one of the elastic body and the moving body, the pressure resistance is improved and the elasticity by the pressure is increased. Prevents body deformation and damage Rutotomoni, it is possible to obtain high torque stably, and in a small, further, in which forward and reverse switching is to provide an ultrasonic driving device possible. However, although this device overcomes the above-mentioned drawbacks, it needs to be improved in the following points. That is, due to the abrasion of the contact surface of the protrusion with the elastic body or the moving portion, the worn powder material is caught in the crimp portion, and as a result, the driving force transmission efficiency is reduced. The transmission efficiency of the driving force also decreases due to variations in the shape of the contact surface of the protrusion with the elastic body or the moving portion, the pressure bonding force, and the like. There are drawbacks such as. The present invention has been made in view of the above circumstances,
Even if the contact surface of the protrusion with the elastic body or the moving part is worn, the worn powder material is not caught in the crimping part, and the transmission efficiency of the driving force depends on the shape of the contacting surface and the variation of the crimping force. It is an object of the present invention to provide an ultrasonic wave drive device that does not decrease.

[0004]

In order to solve the above-mentioned problems, the invention according to claim 1 is provided with a flat plate-like elastic body for inducing longitudinal vibration and bending vibration, and a flat surface of the elastic body. A piezoelectric body, a vibrating portion that causes a longitudinal vibration that gives a levitation force to the end face of the elastic body and a bending vibration that gives a driving force, and an AC voltage having a frequency equal to the longitudinal vibration resonance frequency of the elastic body. In an ultrasonic driving device consisting of a power source for applying to, in the end face of the elastic body that causes the longitudinal vibration giving the levitation force and the bending vibration giving the driving force,
And a moving part that is crimped to a position other than the node part of the bending vibration standing wave to obtain a driving force from the elastic body at the time of vibration, and at least one of the elastic body and the moving body, The ultrasonic drive device is characterized in that a projection portion for transmitting a driving force is provided on the moving portion, and a contact surface of the projection portion with the elastic body or the moving portion is formed in an uneven shape. Further, the invention according to claim 2 is characterized in that the uneven shape formed on the contact surface of the protruding portion in the ultrasonic drive device according to claim 1 with the elastic body or the moving portion is
The ultrasonic drive device is characterized by comprising a knurled surface. According to a third aspect of the present invention, in the ultrasonic drive device according to the first aspect of the present invention, the concavo-convex shape formed on the contact surface of the protrusion with the elastic body or the moving portion is parallel to the plate width direction. The ultrasonic drive device is characterized in that it is formed by slit grooves provided at a predetermined interval.

[0005]

In the above structure, when the power source is turned on to excite the piezoelectric body, a longitudinal vibration standing wave is first generated in the elastic body. Then, a bending vibration standing wave is induced. In this way, the levitation force due to the longitudinal vibration and the driving force due to the bending vibration are obtained on one end surface of the elastic body. According to the above configuration, since the pressing by the moving portion is applied in the direction perpendicular to the wide plane of the elastic body, it is possible to prevent the elastic body from being deformed or damaged by the pressing, and thus to obtain a high torque stably. It becomes possible. Further, in the structure according to the second aspect, it is possible to easily perform forward / reverse rotation by selectively applying a voltage to the first piezoelectric body and the second piezoelectric body.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1A shows a first embodiment of the present invention.
The top view which shows the structure of the ultrasonic drive device which is an Example, the same figure
(b) is a side view showing a configuration of a vibrating section which is a main body of the apparatus,
FIG. 2 is a perspective view showing the configuration of the moving part of the device, FIG.
(b) is a perspective view and a plan view showing an elastic body that constitutes the vibrating portion. First, the schematic shape of the elastic body used in the first embodiment will be described with reference to FIG. In the figure, reference numeral 1 is an elastic body, and this elastic body 1 is
Two wide planes 1a and 1b (hereinafter referred to as wide planes) facing each other in parallel to each other, and four flat planes 1c that are orthogonal to these wide planes 1a and 1b and have a narrow width (hereinafter referred to as end faces) Is formed into a flat rectangular parallelepiped shape.
The elastic body 1 is made of a piezoelectric ceramic or generally a metal plate such as stainless steel or aluminum. The elastic body 1 is formed so as to have the following vibration characteristics. That is, this elastic body 1 is generated in the z direction in FIG. 1A, and the resonance frequency of the longitudinal vibration whose vibration waveform is represented by the first equation and U _z = Asin (K _Lz ) (1) The anti-symmetric bending vibrations generated in the y-direction and having the vibration waveform represented by the second equation are formed so that the resonance frequencies are equal to or close to each other. _{U x = Bsinh (K BY)} + Dsin (K EY) ··· (2) The first equation, the second equation, Uz is, z-direction of displacement, Ux is the x direction of the displacement, K _L is the longitudinal vibration (Wave) wave number, K _E is bending vibration,
The wave number of (wave). As described above, it is possible to set the size and shape of the elastic body 1 so that the resonance frequencies of the Z-direction longitudinal vibration and the Y-direction antisymmetric bending vibration are equal to or close to each other. The rationale is shown below. As is well known, the resonance frequency f of the longitudinal vibration of the plate-shaped elastic body
_L is expressed as in the third equation. f _L = (1 / 2L _O ) √ (E / ρ) (3) Here, E is the Young's modulus of the elastic body, ρ is its density, and L _O is the length in the Z direction. On the other hand, the resonance frequency fB of the flexural vibration of the plate-shaped elastic body is expressed by the fourth equation. f _B = (t / √12) · (α ² / 2πω ² ) · √ (E / ρ) ··· (4) where w is the length of the elastic body in the Y direction and L is the length in the X direction. (Thickness of elastic body). Further, α is the root of the fifth equation, and corresponds to the order of the resonance vibration vibration mode order from the smallest value. sin (α / 2) cosh (α / 2) + sin (α / 2) sinh (α / 2) = 0 ··· (5) Now, the right side of the third equation is equal to the right side of the fourth equation (f _L = F _B ), the sixth equation is derived. ^{_{π / L O = (α 2}} / w 2) (t / √12) ··· (6) sixth equation, identical to the resonant frequency and the resonant frequency in the y direction antisymmetric bending vibration in the Z-direction longitudinal vibration Is the condition for
As is clear from the formula, the length l in the Z direction, the width w in the y direction, x
It is possible to freely set any two of the three variables of the length t in the direction. In the elastic body 1 of this example, the longitudinal vibration resonance mode is L ₁₀ (the standing wave node is one) and the antisymmetric bending vibration resonance mode is B ₃₀ (the standing wave node N is based on the theory described above.
3 is shown in FIG. 3 (b), the dimensions and shape are determined. Next, with reference to FIGS. 1 (a), 1 (b) and 2, the configuration of the ultrasonic drive device according to the first embodiment of the present invention will be described. As shown in FIGS. 1 (a) and 1 (b), piezoelectric bodies (piezoelectric vibrators) 2a and 2b are provided on the wide flat surfaces 1a and 1b of the flat elastic body 1.
Are glued to each other. These piezoelectric bodies 2a and 2b
Are arranged so as not to face each other and at the position of the abdomen of the bending vibration standing wave B ₃₀ . Further, conductive layers (not shown) are respectively formed on both surfaces of the piezoelectric bodies 2a and 2b. Further, at both ends of the end face 1c of the elastic body 1, protrusions 3a and 3b for extracting a driving force by ultrasonic vibration are formed. The elastic body 1, the piezoelectric bodies 2a and 2b, and the protrusions 3a and 3b described above roughly constitute a vibrating portion of the ultrasonic drive device. Next, 4 is a power supply for ultrasonic excitation that outputs an AC voltage having the same frequency as the resonance frequency in the longitudinal vibration resonance mode L ₁₀ of the elastic body 1. Of the two output terminals of the power source 4, one terminal is connected to the elastic body 1 via the electric line, and the other terminal is connected in parallel to the piezoelectric bodies 2a and 2b via the electric line. Reference numeral 5 denotes a disk-shaped moving portion that extracts motion from the vibrating body, and is pressed against the protrusions 3a and 3b. The elastic body 1 is a node of the longitudinal vibration standing wave and a node of the bending vibration standing wave.
A through hole 6 is provided at the center of the wide plane 1a (1b) of
By passing a support member (not shown) through the through hole 6, the frame member (not shown) is fixedly supported.
When the power source 4 is turned on and a high frequency voltage is applied to the piezoelectric bodies 2a and 2b in the ultrasonic driving device having the above-described configuration, the piezoelectric bodies 2a and 2b are excited in response to this. Along with the excitation of the piezoelectric bodies 2a and 2b, a longitudinal vibration standing wave in the excitation mode L ₁₀ occurs in the elastic body 1. And, in resonance with this longitudinal vibration standing wave,
A bending vibration standing wave of vibration mode B ₃₀ is induced. Thus, the longitudinal vibration resonance expressed by the first equation and the antisymmetric bending vibration resonance expressed by the second equation occur at the same time. Therefore, the levitation force is obtained by the longitudinal vibration, and the bending vibration causes As shown, the distribution of the driving force (arrows in the figure) in different directions is obtained with the bending vibration node as a boundary. Therefore,
Since driving forces parallel to each other and opposite to each other are generated in the protrusions 3a and 3b, the disc-shaped moving portion 5 pressed onto the protrusions 3a and 3b is given a levitation force by longitudinal vibration. The bending vibration gives a rotational force in the direction A shown in FIG. According to the above configuration, since the pressing by the moving portion 5 is applied in the direction perpendicular to the wide flat surfaces 1a and 1b of the elastic body 1, it is possible to prevent the elastic body 1 from being deformed by the pressing. Therefore, a large torque can be stably obtained. Since the vibrating part is not of Langevin type, it is easy to achieve miniaturization.

(Second Embodiment) FIG. 4A shows a second embodiment of the present invention.
The top view which shows the structure of the ultrasonic drive device which is an Example, the same figure
(b) is a side view showing a configuration of a vibrating section which is a main body of the apparatus,
FIG. 5 is a perspective view showing a configuration of a moving unit of the apparatus. In these figures, portions corresponding to the respective portions shown in FIGS. 1 (a), 1 (b) and 2 are designated by the same reference numerals and the description thereof will be omitted. This second embodiment is largely different from the first embodiment in that the piezoelectric bodies 2c and 2d having the same structure as the piezoelectric bodies 2a and 2b.
And that the switch mechanism 7 is added. The piezoelectric body 2
The c is bonded to the piezoelectric body 2a on the wide plane 1b so as to face each other. The piezoelectric body 2d is bonded to the piezoelectric body 2b on the wide plane 1a so as to face each other. These piezoelectric 2a~2d, as in the first embodiment, are disposed at positions of the abdomen of the bending vibration standing wave B _30. Next, the piezoelectric bodies 2a and 2b and the piezoelectric bodies 2c and 2d are electrically connected in parallel, respectively, and each of them operates as a pair of piezoelectric bodies. The switch mechanism 7 outputs the output voltage of the power source 4 to the piezoelectric bodies 2a and 2b or the piezoelectric bodies 2c and 2d.
It is configured such that the voltage is selectively applied to. A major difference from the first embodiment is that piezoelectric bodies 2c and 2d having the same structure as the piezoelectric bodies 2a and 2b and a switch mechanism 7 are added. The piezoelectric body 2c is bonded to the piezoelectric body 2a on the wide plane 1b so as to face each other. In addition, the piezoelectric body 2d
Are bonded to the piezoelectric body 2b on the wide plane 1a so as to face each other. These piezoelectric 2a~2d, as in the first embodiment, are disposed at positions of the abdomen of the bending vibration standing wave B _30. Next, the piezoelectric bodies 2a and 2b and the piezoelectric bodies 2c and 2d are electrically connected in parallel, respectively, and each of them operates as a pair of piezoelectric bodies. The switch mechanism 7 is configured to selectively apply the output voltage of the power source 4 to the piezoelectric bodies 2a, 2b or the piezoelectric bodies 2c, 2d.
In the ultrasonic driving device having the above configuration, first, the switch mechanism 7 is operated to electrically connect the power source 4 and the piezoelectric bodies 2a and 2b, and a high frequency voltage is applied to the piezoelectric bodies 2a and 2b. The same operation as that described in the first embodiment is performed, and the moving unit 5 shown in FIG.
Rotate in the direction. Next, when the switch mechanism 7 is operated to switch the electrically connected state of the piezoelectric bodies, the piezoelectric bodies 2a and 2b are brought into an electrically open state, and the piezoelectric bodies 2c and 2d are brought into an electrically connected state. As a result, this time the piezoelectric bodies 2c, 2
d is excited, and the longitudinal vibration standing wave of the vibration mode L ₁₀ is generated in the elastic body 1 with the excitation. Then, in resonance with this longitudinal vibration standing wave, a bending vibration standing wave of vibration mode B ₃₀ is induced. In this case, the phase of the longitudinal vibration is the same regardless of which pair of piezoelectric bodies is excited by the switching of the switch, but the phase of the flexural vibration becomes the opposite phase by the switching of the switch. Therefore, the directions in which the piezoelectric bodies 2a and 2b are excited and the piezoelectric bodies 2c and 2d are opposite to each other (directions A and B in FIG. 5).
The rotational force of can be obtained. According to the above configuration, the direction of rotation can be appropriately changed only by operating the switch mechanism 7. Further, if the non-driving side piezoelectric body is used as a vibration sensor, it is possible to detect vibration, and if the forward and reverse drive frequencies do not match, the vibration can be corrected. Further, since the non-driving side piezoelectric body is in an electrically open state, the elastic constant is different from that of the driving side piezoelectric body, and the elastic body is asymmetric. As a result, it is possible to couple the longitudinal vibration and the bending vibration, which are not coupled when they are symmetrical. If the coupling is generated, it is sufficient to drive at the resonance frequency of the longitudinal vibration, and it is not necessary to strictly match the resonance frequencies of the longitudinal vibration and the bending vibration, which is advantageous in management.

(Third Embodiment) FIG. 6 is a plan view showing the structure of an ultrasonic driving apparatus according to a third embodiment of the present invention. This third embodiment is the same as the first embodiment (FIG. 1) and the second embodiment.
A big difference from (Fig. 4) is that a power supply for two-phase excitation is used. As shown in FIG. 6, on the wide plane 1a of the elastic body 1, a piezoelectric body 2e for adhering longitudinal vibration to the elastic body 1 is bonded. On the other hand, on the wide plane 1b, a pair of piezoelectric bodies 2f, 2 for causing the elastic body 1 to generate bending vibrations.
The g's are bonded so that they are symmetrical with respect to the longitudinal centerline of the elastic body 1b and their polarizations are opposite to each other. Further, 4a is a power source for exciting the piezoelectric body 2e, and 4b is a power source for simultaneously exciting the piezoelectric bodies 2f, 2g. According to the above configuration, the longitudinal vibration and the bending vibration can be independently generated, so that a much higher torque can be obtained.

(Fourth Embodiment) FIG. 7 is a side view showing the configuration of an ultrasonic driving device according to a fourth embodiment. In this figure, reference numeral 8 is a vibrating portion, and 9 is a moving portion, which have the same configuration as shown in FIGS. 1a), (b) and FIG.
More specifically, the material of the elastic body that constitutes the vibrating portion 8 of this example is SUS304 (stainless steel), and the dimension is 31 mm.
(w) x 25.5 mm (H) x 5 (T) mm with a height of 5 m at both ends
m projections are provided. The material of the piezoelectric body is C-1 (trade name of piezoelectric ceramics manufactured by Fuji Ceramics), and the dimensions are 20 mm × 10 mm × 0.5 mm. The moving unit 9 is S
It is made of 45C (steel) and has a diameter of 35 mm. 10
Is a frame member having a U-shaped cross section, 11 is a supporting member (a screw of M2) for fixing and supporting the vibrating portion 8 to the frame member 8,
Reference numeral 12 is an adjustable pressure member for pressurizing the moving portion 9, and comprises a shaft portion 13, a pressure plate 14, a rubber member 15, a pressure spring 16 and a pressure screw 17. Reference numeral 18 is an output shaft that outputs a rotational force. These moving section 9, shaft section 13,
The output shaft 18 has a common axis. In the above configuration, the pressure member 17 is adjusted so that the pressure applied to the moving portion 9 is 750 g and the applied voltage is 10V, 20V, 30V.
A characteristic experiment was conducted with the drive frequency set to 102.6 KHz. As a result of the experiment, as shown in FIG. 8, a high torque of about 500 g was obtained. In the above-described first embodiment, the case has been described in which the dimensional shape of the elastic body 1 is determined so that the bending vibration mode occurring in the elastic body 1 becomes the antisymmetric bending vibration mode B _30.
(See FIG. 2) The present invention is not limited to the case of the above mode, and it is also possible to set the antisymmetric vibration modes to B ₁₀ and B ₆₀ as appropriate according to the mode of use, for example. . In this case, if both the longitudinal vibration resonance and the antisymmetric bending vibration resonance are set to the lowest order mode, the value of α on the right side of the fifth equation that determines the dimensional condition of the elastic body is 7.85. Further, in the above-mentioned embodiment, the case where the size and shape of the elastic body is determined so that the bending vibration mode occurring in the elastic body becomes the antisymmetric bending vibration mode has been described, but the present invention is not limited to this. Depending on the mode, even if the dimension and shape of the elastic body are determined so as to generate the symmetrical bending vibration mode, the same effect as described above can be obtained. Further, in the above-mentioned embodiment, the case where the rectangular parallelepiped elastic body is used has been described, but the present invention is not limited to the rectangular parallelepiped as long as it has a flat plate shape. Further, in the above-described embodiment, the case where the waveform of the longitudinal vibration is represented by the first equation and the waveform of the bending vibration is represented by the second equation has been described, but the present invention is not limited to this, and a relationship similar to these is provided. I wish I had it. Further, in the above-described embodiment, the case where the fifth formula is used as the dimension condition in which the resonance frequencies of the z-direction longitudinal vibration and the y-direction antisymmetric bending vibration are equal to each other has been described, but the present invention is not limited to this. Approximate formulas or empirical formulas may be used, or the dimensional conditions may be obtained by experiments or simulations. In particular, when the elastic body is not a flat rectangular parallelepiped, other approximate expressions and simulations are effective. Further, in the above-described embodiment, the disk-shaped moving unit 5
(Fig. 2) is the protrusions 3a and 3 provided on both ends of the end face 1c.
Although the case of being pressed against b has been described, as shown in FIG. 9, it may be appropriately pressed against only one of the protrusions. Further, in the above-described embodiment, the case where the elastic body 1 is provided with the protrusions 3a and 3b has been described, but instead of this, as shown in FIG.
Even if the protrusions 20a and 20b are provided on the base and the protrusions 20a and 20b are pressed against the elastic body 21, the same effect as described above can be obtained. Also,
In the above-described embodiments, the case where the protrusion is provided at the end of the end surface 1c of the elastic body 1 has been described. It is not limited. Further, in the above-described embodiment, the case where the disc-shaped moving portion 5 (FIG. 2) is used has been described, but the present invention is not limited to this. For example, as shown in FIG. 11, an annular shape having a relatively large radius is used. The moving portion 22a is pressed against the protruding portion 3a, and the annular moving portion 22b having a relatively small radius is connected to the protruding portion 3b.
It may be pressed against. By doing so, it is possible to obtain both forward and reverse driving forces at the same time. Alternatively, as shown in FIG. 12, a roller-shaped moving unit 23 may be used. Furthermore, in the above embodiment,
The case where the vibrating portion is provided with the protrusions has been described. However, if an abacus-shaped moving portion 25 is used as shown in FIG. 13, it is possible to configure the elastic body 24 having no protrusions. is there.

An embodiment of an ultrasonic driving device when the present invention is concretely experimented will be described below with reference to FIGS. 14 to 19. FIG. 14 is an overall configuration diagram showing an embodiment of an ultrasonic driving device used as an experimental machine of the present invention and a schematic diagram showing the vibration configuration of an elastic body. In particular, as shown in FIG. Of 2f and 2g, the piezoelectric bodies 2f and 2g, which are PZTs for antisymmetric bending vibration excitation, are arranged so that their polarizations are opposite to each other, as indicated by the arrow directions in the figure.
The piezoelectric body 2e, which is the PZT for exciting the contour vibration, has the same direction on the entire surface. FIG. 15 shows the applied voltage V _B (V) and the rotation speed N of the ultrasonic drive device used as the experimental machine of the present invention.
FIG. 17 is a graph showing the relationship of (rpm), showing each characteristic according to the shape of the protrusion of the elastic body shown in FIG. 16, and as a result, the one in which the slit shown in FIG. , Its applied voltage V _B (V) and rotation speed N (rpm)
The characteristic indicating the relationship of can obtain a smooth and smooth drive. FIG. 17 is a graph showing the relationship between the torque T (gcm) and the rotation speed (rpm) of the ultrasonic drive device used as the experimental machine of the present invention.
It can be seen that the drive transmission efficiency is remarkable when the slit shown in (c) is formed. It is considered that this is because the vibration was amplified by reducing the equivalent elastic constant. Also,
FIG. 18 is a front view (b), a plan view (a) and an enlarged view (A) of a portion A showing the shape of an elastic body used in the ultrasonic drive device used as the experimental machine of the present invention. Further, FIG. 19 is a front view (b) and a plan view (a) showing the shape of the moving body used in the ultrasonic drive device used as the experimental machine of the present invention.

[0012]

As described above, according to the present invention, at least one of the elastic body and the moving body is provided with the projection portion for transmitting the driving force to the moving portion, and the elastic body of the projection portion is provided. Alternatively, by forming the contact surface with the moving part in an uneven shape, even if the elastic body of the protrusion or the contact surface with the moving part is worn, the worn powder material is not caught in the crimping part, and the contact surface is It is possible to provide the ultrasonic drive device in which the transmission efficiency of the driving force does not decrease due to variations in the shape, the pressure bonding force, and the like.

[Brief description of drawings]

FIG. 1 is a plan view and a side view showing a configuration of an ultrasonic wave drive device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a moving unit of the apparatus.

FIG. 3 is a perspective view showing an elastic body forming the vibrating section and a plan view of the vibrating section.

FIG. 4 is a plan view showing a configuration of an ultrasonic wave drive device according to a second embodiment of the present invention and a side view showing a configuration of a vibrating section which is a main body of the device.

FIG. 5 is a perspective view showing a configuration of a moving unit of the apparatus.

FIG. 6 is a plan view showing a configuration of an ultrasonic wave drive device according to a third embodiment of the present invention.

FIG. 7 is a side view showing the configuration of an ultrasonic drive device according to a fourth embodiment. FIG. 8 is a graph showing characteristics of the device. FIG. 9 is a diagram showing another first modification of the present invention.

FIG. 10 is a diagram showing another second modification of the present invention.

FIG. 11 is a diagram showing another third modification of the present invention.

FIG. 12 is a diagram showing another fourth modification of the present invention.

FIG. 13 is a diagram showing another fifth modification of the present invention.

FIG. 14 is an overall configuration diagram showing an embodiment of an ultrasonic drive device used as an experimental machine of the present invention and a schematic diagram showing a vibration configuration of an elastic body.

FIG. 15 is a graph showing the relationship between the applied voltage and the rotation speed of the ultrasonic drive device used as the experimental machine of the present invention.

FIG. 16 is a partial perspective view showing the shape of the protrusion of the elastic body used in the ultrasonic drive device used as the experimental machine of the present invention.

FIG. 17 is a graph showing the relationship between the torque and the rotational speed of the ultrasonic drive device used as the experimental machine of the present invention.

18A and 18B are a front view and a plan view showing the shape of an elastic body used in the ultrasonic drive device used as the experimental machine of the present invention, and an enlarged view of part A.

19A and 19B are a front view and a plan view showing the shape of a moving body used in the ultrasonic drive device used as the experimental machine of the present invention.

[Explanation of symbols]

 1, 21, 24 ... Elastic body 2a to 2g ... Piezoelectric body, 3a, 3b, 20a, 20b ... Projection portion, 4, 4a, 4b ... Power supply 5, 9, 19 ... Disk-shaped moving portion

Claims (3)

[Claims] 1. A flat plate-shaped elastic body for inducing longitudinal vibration and bending vibration, a piezoelectric body provided on the plane of the elastic body, and a longitudinal vibration and a driving force for giving a levitation force to the end face of the elastic body. In an ultrasonic driving device comprising a vibrating portion that causes a bending vibration to be applied and a power source that applies an AC voltage having a frequency equal to a longitudinal vibration resonance frequency of the elastic body to the piezoelectric body, the longitudinal vibration that gives a levitation force A moving portion that is crimped to an end surface of the elastic body that causes the bending vibration that gives a driving force and is located at a position other than the node portion of the bending vibration standing wave to obtain the driving force from the elastic body during vibration. Further, at least one of the elastic body and the moving body is provided with a projection portion for transmitting a driving force to the moving portion, and the contact surface of the projection portion with the elastic body or the moving portion is uneven. Characterized by being made into a shape That the ultrasonic drive unit. 2. The ultrasonic drive device according to claim 1, wherein the uneven shape formed on the contact surface of the protrusion with the elastic body or the moving portion is a knurled surface. 3. The concavo-convex shape formed on the contact surface of the protrusion with the elastic body or the moving portion is parallel to the plate width direction,
The ultrasonic drive device according to claim 1, wherein the ultrasonic drive device is formed by slit grooves provided at predetermined intervals.