JPH0937577A - Ultrasonic vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic vibrator that allows two resonance frequencies in modes of different shapes to be matched with each other with precision. SOLUTION: An ultrasonic vibrator 10 has the anisotropy of the elastic constant due to the direction of its basic elastic body 11 reduced to as small a value as 5% or below. As long as the dimensions of the basic elastic body 11 are kept constant, therefore, it is possible to match two resonance frequencies of the ultrasonic vibrator 10 in modes of different shapes with each other with accuracy by forming the basic elastic body 11 using elastic bodies within a lot or between lots.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ultrasonic transducer used in an ultrasonic motor.

[0002]

2. Description of the Related Art In recent years, an ultrasonic motor has attracted attention as a new motor replacing an electromagnetic motor. This ultrasonic motor has the following advantages over a conventional electromagnetic motor.

(1) A low speed and high thrust can be obtained without a gear. (2) Large holding force. (3) Long stroke and high resolution. (4) It is extremely quiet. (5) Magnetic noise is not generated, and the influence of noise is not exerted.

As an ultrasonic linear motor which is an example of a conventional ultrasonic motor, there is one disclosed in Japanese Patent Application Laid-Open No. 6-105571 proposed by the applicant of the present application.

The conventional ultrasonic linear motor disclosed in the above publication will be described below with reference to FIG.

In FIG. 13, reference numeral 200 denotes an ultrasonic transducer of a conventional ultrasonic linear motor, which is a basic elastic body 211.
Two laminated piezoelectric elements 213 are arranged in the upper part of the above, at a portion corresponding to approximately the antinode of the second resonance bending vibration. And
It is fixed on the basic elastic body 211 by the holding elastic member 212. Although not shown, the basic elastic body 211 has three tapped screws, and the holding elastic body 212 is a screw 21.
It is fixed to the basic elastic body 211 by 4. At this time, the laminated piezoelectric element 213 is held in a state of being abutted by the holding elastic body 212.

The portion of the laminated piezoelectric element 213 that contacts the holding elastic body 212 is fixed with an epoxy adhesive, and the portion of the holding elastic body 212 that contacts the basic elastic body 211 is also epoxy-bonded. It is joined by the agent. However,
The laminated piezoelectric element 213 is prevented from coming into contact with the basic elastic body 211. Multilayer piezoelectric element 21 of basic elastic body 211
Sliding members 215 are bonded to both ends of a surface opposite to the surface on which 3 is arranged (a surface on the side in contact with the driven body) using an epoxy adhesive. Sliding member 215
Is a mixture of polyimide with carbon fiber and mica as a filler (carbon fiber: 20% by weight, mica 30% by weight).

Next, the operation of the ultrasonic transducer 200 will be described. By properly setting the dimensions of the ultrasonic transducer 200, the primary resonant longitudinal vibration and the secondary resonant bending vibration can be excited at substantially the same frequency.

The laminated piezoelectric element 213 on the left side shown in FIG.
The electrical terminals taken out from A, G (called A phase)
The electric terminals taken out from the laminated piezoelectric element 213 on the right side are B and G (referred to as B phase).

First, a DC voltage of 30 V is applied to the A phase and the B phase. Thereby, a compressive force (preload) can be applied to the laminated piezoelectric element 213. Therefore, when an alternating voltage having an amplitude of 10 Vp-p is applied to the A phase at the frequency Fr and an alternating voltage having the same frequency and the same amplitude and the same phase is applied to the B phase, a primary resonance longitudinal vibration as shown in FIG. 14 is excited. it can. Next, when an alternating voltage having an amplitude of 10 Vp-p with a frequency Fr is applied to the A phase and an alternating voltage having the same frequency and the same amplitude and an opposite phase is applied to the B phase, a secondary resonance bending vibration as shown in FIG. 15 is generated. Can be excited.

Further, the amplitude of 1 is applied to the A and B phases at the frequency Fr.
When an alternating voltage of 0 Vp-p is applied and the phase difference is set to 90 degrees or -90 degrees, clockwise or counterclockwise ultrasonic elliptical vibration can be excited at the position of the sliding member 215. When a driven body (not shown) is pressed to the position of the sliding member 215 where the ultrasonic elliptical vibration is excited, the driven body moves to the right,
Or it is driven to the left.

[0012]

However, the above-mentioned conventional ultrasonic wave oscillator 200 has the following problems.

That is, the ultrasonic wave oscillator 200 is shown in FIG.
As shown in FIG. 15, since the longitudinal primary vibration and the bending secondary vibration are excited at the same frequency to form ultrasonic elliptical vibration, the resonance frequency of the longitudinal primary vibration and the resonance frequency of the bending secondary vibration are generated. Need to match. For this purpose, the dimensions (length and height) of the basic elastic body 211 are actually adjusted so that the two resonance frequencies match.

However, even if the dimensions of the basic elastic body 211 are made constant, the basic elastic body is processed with the brass material in the lot of the brass material which is the base material of the basic elastic body 211, and the ultrasonic transducer 200 is manufactured as a prototype. In many cases, the two resonance frequencies described above do not match, and the basic elastic body 21
When the basic elastic body 211 is processed by the brass material between lots of the brass material which is the base material of No. 1 to configure the ultrasonic transducer 200, there are many cases where the both resonance frequencies do not match.

Therefore, an object of the present invention is to provide an ultrasonic transducer capable of accurately matching the resonance frequencies of two variant modes.

[0016]

An ultrasonic transducer according to a first aspect of the present invention is composed of an elastic body and an electromechanical conversion element bonded to the elastic body, and synthesizes two variant resonance modes. In the ultrasonic transducer that forms ultrasonic elliptical vibration,
The elastic body is made of a material having a small anisotropy of elastic constant depending on the direction.

An ultrasonic transducer according to a second aspect of the present invention is composed of an elastic body and an electromechanical conversion element bonded to the elastic body, and synthesizes two odd-shaped resonance modes to form ultrasonic elliptical vibration. In the ultrasonic transducer, the elastic body is
It is characterized in that it is made of a material having anisotropy of elastic constant within 5% depending on the direction.

An ultrasonic vibrator according to a third aspect of the present invention is composed of an elastic body and an electromechanical conversion element bonded to the elastic body, and synthesizes two variant resonance modes to form ultrasonic elliptical vibration. In the ultrasonic transducer, the elastic body is
It is characterized by being made of a material having anisotropy of longitudinal sound velocity and transverse sound velocity depending on the direction within 5%.

An ultrasonic transducer according to a fourth aspect of the present invention is composed of an elastic body and an electromechanical conversion element bonded to the elastic body, and synthesizes two variant resonance modes to form an ultrasonic elliptical vibration. In the ultrasonic vibrator described above, the elastic body is a metal material that has been annealed.

According to the ultrasonic transducer of the first aspect, since the elastic constant of the elastic body material has a slight anisotropy, the lot of the elastic body base material can be obtained by keeping the size of the elastic body constant. When the ultrasonic oscillator is configured by using the elastic body inside or between the lots, the resonance frequencies of the two variant resonance modes of the ultrasonic oscillator can be accurately matched.

According to the ultrasonic vibrator of the second aspect, since the anisotropy of the elastic constant depending on the direction of the elastic material is small,
As long as the dimensions of the elastic body are kept constant, when an ultrasonic oscillator is constructed using elastic bodies within the lot of the elastic body preform or between the lots, the two odd-shaped resonance modes of this ultrasonic oscillator are The resonance frequencies can be accurately matched.

According to the ultrasonic vibrator of the third aspect, since the longitudinal acoustic velocity and the transverse acoustic velocity anisotropy depending on the direction of the elastic material are small, the resonance frequencies of the longitudinal vibration and the torsional vibration are determined by the lot of the elastic material base material. When the ultrasonic oscillator is configured by using the elastic body inside or between the lots, the resonance frequencies of the two variant resonance modes of the ultrasonic oscillator can be accurately matched.

According to the ultrasonic transducer of the fourth aspect, since the elastic body is formed of the annealed metal material, the resonance frequencies of the two variant resonance modes of the ultrasonic transducer can be accurately matched. You can

[0024]

Embodiments of the present invention will be described below.

First Embodiment of the Invention (Structure) FIG. 1 shows an ultrasonic transducer 10 according to the first embodiment of the invention.
Is shown. This ultrasonic transducer 10 will be described with reference to FIG.

The ultrasonic transducer 10 is provided with a basic elastic body 11 formed in a convex shape by using a metal material such as brass material. The size of the basic elastic body 11 is 30
mm, depth 4 mm, and height 7.5 mm. The convex portions have a width of 4 mm, a depth of 4 mm, and a height of 2.5 mm.
6 mm from the bottom of the center of the basic elastic body 11 in the width direction
A pin 16 made of stainless steel and having a diameter of 2 mm is driven into the position by press fitting.

A pair of laminated piezoelectric elements 12, which are electromechanical conversion elements, are arranged on both sides of the convex portion of the basic elastic body 11. This laminated piezoelectric element 12 is formed by laminating several tens to several hundreds of electrode-treated piezoelectric elements. In the embodiment of the present invention, the laminated piezoelectric element N manufactured by Tokin Co., Ltd.
LA-2 × 3 × 9 was used. Its dimensions are 2 mm x 3.
It is 1 mm × 9 mm. Although not shown in FIG. 1, portions other than both ends of the laminated piezoelectric element 12 are covered with an epoxy resin (coating thickness: about 20 μm).

In FIG. 1, the left laminated piezoelectric element 12 is shown.
Electrical terminals taken out from A and GND (referred to as A phase) are shown in FIG. 1, and electric terminals taken out from the laminated piezoelectric element 12 on the right side in FIG. 1 are referred to as B and GND (referred to as B phase).

Multilayer piezoelectric element 12 of the basic elastic body 11
A rectangular shape at a position of 9 mm from each end of the surface opposite to the surface on which is arranged (the surface in contact with the driven body) (the position where the vibration amplitude of resonance bending vibration shows a maximum value). A pair of drivers (dimensions: width 3 mm, depth 4 mm, thickness 1 mm) (grinding stone material: resin in which abrasive grains of alumina are dispersed) 15 are joined together using an epoxy adhesive.

Next, a method of assembling the ultrasonic transducer 10 will be described. As shown in FIG. 1, the laminated piezoelectric elements 12 are arranged on both sides of the convex portion of the basic elastic body 11. Then, the elastic member for holding 13 (width 4 mm, depth 4 mm, height 2.5 m
m) is fixed on the basic elastic body 11. Although not shown, the basic elastic body 11 is tapped with screws at two positions, and the holding elastic body 13 is fixed to the basic elastic body 11 by two screws 14 as shown in FIG.

At this time, the laminated piezoelectric element 12 has a compressive force (about 5 kg) between the convex portion of the basic elastic body 11 and the holding elastic body 13.
It is held and fixed in the state of applying f). In addition, the laminated piezoelectric element 12 includes a convex portion of the basic elastic body 11 and a holding elastic body 13.
It is fixed with an epoxy adhesive. The side surface portion of the laminated piezoelectric element 12 in contact with the basic elastic body 11 and the basic elastic body 11
Is also adhered using an epoxy resin. Furthermore,
The contacting portions of the holding elastic body 13 and the basic elastic body 11 are also joined by an epoxy adhesive.

(Operation) Next, the operation of the ultrasonic transducer 10 will be described. According to the above-described dimensions and shapes, two variant resonance modes, that is, the first-order resonance longitudinal vibration in the maximum length direction and the second-order resonance bending vibration in the plane having the largest area have substantially the same frequency Fr ( It could be excited at 53 kHz to 56 kHz). The vibration state of the ultrasonic transducer 10 at this time is shown in FIG.
As shown in FIG. FIG. 2 shows the case of the first resonance longitudinal vibration, and FIG. 3 shows the case of the second resonance bending vibration. Although FIG. 2 is analyzed by a simulation using the finite element method, it was confirmed that such vibration actually occurred. Then, the frequency Fr and the amplitude 10 Vp− are applied to the A phase and the B phase.
By applying an alternating voltage of p and a phase difference of ± 90 °, clockwise or counterclockwise ultrasonic elliptical vibration could be excited at the position of the driver 15. It should be noted that a DC bias may be simultaneously applied to the alternating voltage as the applied voltage.

(Structure of Ultrasonic Linear Motor) Next, referring to FIG.
An ultrasonic linear motor using the ultrasonic transducer 10 will be described with reference to FIG.

As shown in FIG. 4, the ultrasonic transducer 10 is held from both sides by the two holding plates 21 at the pin 16 portion thereof. The holding plate 21 is provided with a hole having a diameter substantially the same as the diameter of the pin 16, and the hole is engaged with the pin 16 of the ultrasonic transducer 10. By holding the ultrasonic vibrator 10 in this manner, the ultrasonic vibrator 10 has a degree of freedom only in the rotation direction around the pin 16.

The holding plate 21 is fixed to the holding plate fixing member 22 with screws 23. In the holding plate fixing member 22,
The linear bush 24 is held. The linear bush 24 moves linearly along the shaft 25. The shaft 25 is fixed to a shaft fixing member 26, and the shaft fixing member 26 is a base 2
It is fixed to 7 by screws 36. The shaft fixing member 26 is tapped at a substantially central portion thereof, and the pressing screw 28 is screwed therein. A spring 29 is inserted between the pressing screw 28 and the holding plate fixing member 22.

Further, below the ultrasonic transducer 10, the base 27 is provided with a fixed portion 30 and a moving portion 32 which form a cross roller guide. The fixing portion 30 is fixed to the base 27 with screws 31. A sliding member holding portion 33 is fixed to the moving portion 32 by screws (not shown), and a sliding member 34, which is a driven member made of zirconia ceramics, is bonded to the sliding member holding portion 33. .

With such a configuration, it is possible to adjust the pressing force of the ultrasonic vibrator 10 on the sliding member 34 (driven member) by adjusting the pressing screw 28.

(Operation of Ultrasonic Linear Motor) Next, the operation of the ultrasonic linear motor according to the embodiment of the present invention will be described. As described above, an alternating voltage having a frequency Fr (frequency between 53 kHz to 56 kHz), an amplitude of 10 Vp-p, and a phase difference of +90 degrees or -90 degrees is applied to the A phase and the B phase of the ultrasonic transducer 10. Then, the sliding member 34 is driven rightward or leftward in FIG. At this time, 5 N was obtained as the starting thrust of the ultrasonic linear motor, and 300 mm / sec was obtained as the no-load speed.

Now, the inventors have paid attention to the elastic characteristics of the brass material, and actually used the ultrasonic transducer 1 for two types of the brass material that was annealed and the one that was not annealed.
Several 0s were produced in each lot and several in each lot, and the resonance frequencies of longitudinal vibration and bending vibration were measured.

The difference between the longitudinal acoustic velocity and the transverse acoustic velocity, which is an index of the elastic constant, was measured for the samples subjected to the annealing treatment and those not subjected to the annealing treatment. Here, the material that has been annealed is referred to as material A, and the material that has not been annealed is referred to as material B. Further, the pull-out direction of the brass base material is the X direction, and the directions orthogonal to the X direction are the Y direction and the Z direction. Further, the Y direction and the Z direction are directions orthogonal to each other.

As a result, the longitudinal sound velocity and the lateral sound velocity of the material A were within 5% within the lot and between lots depending on the anisotropy, that is, the direction (X direction, Y direction, Z direction). At this time, the ultrasonic transducer 10 made by trial using the material A was used.
The difference between the resonance frequencies of the two types of vibration including the longitudinal resonance vibration and the bending resonance vibration was within 5%. Such an ultrasonic transducer 1
The ultrasonic linear motor configured by using 0 obtained predetermined characteristics in both thrust and speed.

On the other hand, the anisotropy was about 10% at maximum in the lot and in the lot between the lot B and the transverse sonic velocity. At this time, the difference between the resonance frequencies of the longitudinal resonance vibration and the bending resonance vibration of the ultrasonic vibrator 10 prototyped using the material B was about 10% at the maximum. The ultrasonic linear motor configured by using the ultrasonic transducer 10 in which the difference between the longitudinal resonance frequency and the bending resonance frequency exceeds 5% is lower in both thrust force and speed than in the case of trial manufacture using the above-mentioned A material. It was

(Effects) According to the embodiment of the present invention, since the ultrasonic vibrator 10 is made of a material having a small elastic constant anisotropy of 5% or less depending on the direction, the longitudinal vibration and the bending vibration are suppressed. The resonance frequency can be accurately matched within and between lots of the elastic body preform.

[Second Embodiment of the Invention] Next, a second embodiment of the present invention will be described with reference to FIGS.

(Structure of Ultrasonic Transducer) FIG. 5 shows a front view of the ultrasonic vibrator 110 according to the second embodiment of the invention, FIG. 6 shows a rear view of the ultrasonic vibrator 110, and FIG. FIG. 8 shows a right side view and a left side view of the ultrasonic transducer 110.
9 is a top view of the ultrasonic transducer 110 according to the second embodiment of the invention.

FIG. 5 shows the ultrasonic transducer 110 shown in FIG.
6 is a view of the ultrasonic transducer 110 shown in FIG. 9 from the β direction, and FIG. 7 is a view of the ultrasonic transducer 110 shown in FIG. 9 from the γ direction. 8 is a view of the ultrasonic transducer 110 shown in FIG. 9 viewed from the δ direction.

The prism-shaped basic elastic body 111 made of brass which is a metal material constituting the ultrasonic transducer 110 is composed of 9
The groove 112 is formed to have a size of mm × 9 mm × 40 mm, and a groove 112 having a depth of 2 mm is provided over the entire circumference at a position 16 mm from the lower end thereof. In addition, the laminated piezoelectric element 113, which is an electromechanical conversion element, is formed on the front surface and the back surface of the basic elastic body 111.
It is sandwiched with a tilt angle of °. The electric terminals output from the respective laminated piezoelectric elements 113 are referred to as A, GND and B, GND, respectively.

The laminated piezoelectric element 113 is held and fixed in a state where a compressive stress is applied by the holding elastic body 114. The laminated piezoelectric element 113 is attached so that the front surface and the back surface are tilted in opposite directions when viewed from the front. The laminated piezoelectric element 113 has dimensions of 2 mm × 3.1 mm × 9 mm
Is formed. A sliding driving element 115 made of a grindstone in which abrasive grains of alumina ceramic are dispersed in an annular phenol resin is joined to a tip end portion of the basic elastic body 111. A through hole 116 is formed in the central portion of the holding elastic body 114.
Is provided, and a tap is cut in a part of the through hole 116.

A method of producing the ultrasonic transducer 110 will be described below with reference to FIG. The laminated piezoelectric element 1
13 is inserted into the recess 118 of the basic elastic body 111.
The holding elastic body 114 is inserted along the protrusion 117 for guiding the holding elastic body 114 on the basic elastic body 111, applied to the laminated piezoelectric element 113, and then a compressive stress of 100 N is applied. In the applied state, the screws and all the contact surfaces are adhesively fixed using an epoxy adhesive.

Further, as shown in FIG. 10, the basic elastic body 1
A through hole 119 is provided at the center of 11. Then, a tap 120 is cut at substantially the center thereof (to be exact, a node position of vertical vibration).

(Operation of Ultrasonic Transducer) Next, the operation of the ultrasonic transducer 110 described above will be described. The size of the ultrasonic transducer 110 has a primary resonance longitudinal vibration (vertical vibration shown in FIG. 5) and a primary resonance (secondary considering the twist below the groove 12) (longitudinal vibration). The vibrations of which the vibration direction is the axis of the twist) have substantially the same frequency Fr (38 kHz
It can be excited by z). The shape is designed so that the natural vibration of the bending resonance vibration does not occur in the vicinity of this frequency.

First, an amplitude of 20 at frequency Fr is applied to the A terminal.
When an alternating voltage of Vp-p was applied and an alternating voltage of the same frequency and the same amplitude and the same phase was applied to the B terminal, resonance longitudinal vibration could be excited. The node portion of the resonance longitudinal vibration exists at a substantially central position on the central axis of the basic elastic body 111. Next, when an alternating voltage having an amplitude of 20 Vp-p with a frequency Fr was applied to the A terminal and an alternating voltage having the same frequency and the same amplitude and an opposite phase was applied to the B terminal, resonance torsional vibration could be excited. In the resonance torsional vibration, all the central axes of the basic elastic body 111 are nodes.

Next, an amplitude of 20 Vp at the frequency Fr is applied to the A terminal.
When an alternating voltage of −p is applied and an alternating voltage having the same frequency, the same amplitude and a phase difference of 90 degrees is applied to the B terminal, the resonance longitudinal vibration and the resonance torsional vibration are combined, and the sliding driving element 115.
Elliptical vibration could be excited at the position. Incidentally, a DC bias voltage may be simultaneously applied as the applied voltage.

(Structure and Operation of Ultrasonic Motor) Next, referring to FIG.
An ultrasonic motor 150 using the ultrasonic transducer 110 will be described with reference to FIGS. FIG. 11 is a side view of the ultrasonic motor 150. FIG. 12 is an exploded view of the ultrasonic motor 150.

A shaft 151 is inserted into the through hole 119 of the ultrasonic transducer 110. As shown in FIG. 12, the shaft 151 is provided with screw portions 158 at the central portion and both end portions,
The screw portion 115 at the center is adhesively fixed to the tap portion of the ultrasonic transducer 110. A rotor 153 is pressed and fixed to the upper end of the ultrasonic transducer 110 by a spring 156 via a thrust bearing 154 and a spring holder 155.
The pressing force of the spring 156 is adjusted by the nut 157.
A sliding member 153a made of an annular zirconia ceramic is adhered to the lower surface of the annular rotor 153. When fixing the ultrasonic motor 150, the shaft 151 protruding from the lower portion is screwed and fixed to a base (not shown).

Next, the operation of the ultrasonic motor 150 will be described. As described above, the A terminal and the B terminal of the ultrasonic transducer 110
Frequency 38kHz, amplitude 20Vp-p, phase difference +
An alternating voltage of 90 degrees or -90 degrees is applied. Then, the rotor 153 rotated clockwise or counterclockwise.

Further, as in the case of the first embodiment of the invention, the inventors of the present invention focused on the elastic properties of the brass material and, regarding the two types, those that were annealed and those that were not annealed, Several ultrasonic transducers 110 were actually created in each lot and several in each lot, and the resonance frequencies of longitudinal vibration and torsional vibration were measured.

The difference in longitudinal acoustic velocity and transverse acoustic velocity, which is an index of the elastic constant, was measured for the samples annealed and those not annealed. Here, the material that has been annealed is referred to as material A, and the material that has not been subjected to annealing is referred to as material B. Further, the pull-out direction of the brass base material is the X direction, and the directions orthogonal to the X direction are the Y direction and the Z direction. Further, the Y direction and the Z direction are directions orthogonal to each other.

As a result, the longitudinal sound velocity and the lateral sound velocity of the material A are different in anisotropy within and between lots, that is,
The difference due to the direction (X direction, Y direction, Z direction) was within 5%. At this time, the difference between the resonance frequencies of the longitudinal resonance vibration and the torsional resonance vibration of the ultrasonic vibrator 110 prototyped using the material A was within 5%. This ultrasonic transducer 11
The ultrasonic rotary motor 150 configured by using 0
Predetermined characteristics were obtained for both rotation speeds.

On the other hand, the anisotropy of material B was about 10% at maximum in both longitudinal sound velocity and lateral sound velocity within and between lots. At this time, the difference between the resonance frequencies of the longitudinal resonance vibration and the torsional resonance vibration of the ultrasonic vibrator prototyped using the material B was about 10% at the maximum. When the difference between the longitudinal resonance frequency and the torsional resonance frequency exceeds 5%, the ultrasonic rotary motor configured by using the ultrasonic vibrator 110 has a decrease in torque rotation speed.

(Effects) According to the embodiment of the present invention, since the ultrasonic oscillator is formed by using the material having the elastically small anisotropy, the resonance frequencies of the longitudinal vibration and the torsional vibration are set to the elastic body matrix. It was possible to match within 5% within and between lots of material.

In the embodiment of the present invention, the basic elastic body has a prismatic shape, but a cylindrical shape may be partially cut to fix the laminated piezoelectric element. Further, in the embodiment of the present invention, an example in which two laminated piezoelectric elements are used has been shown, but four laminated piezoelectric elements may be arranged on each of four side surfaces.

As described in detail above, according to the ultrasonic transducers 10 and 100 of the embodiment of the present invention, the resonance frequency of the longitudinal vibration and the torsional vibration or the resonance frequency of the longitudinal vibration and the torsional vibration is set to the elastic body. It is possible to match within 5% within the lot of the base material and between lots, whereby an ultrasonic linear motor or an ultrasonic rotary motor having desired characteristics can be realized.

[0064]

According to the invention as set forth in claim 1, there is provided an ultrasonic vibrator capable of accurately matching the resonance frequencies of two variant modes consisting of the resonance frequency of longitudinal vibration and the resonance frequency of torsional vibration. be able to.

According to the second aspect of the invention, since the anisotropy of the elastic constant depending on the direction of the elastic body is small, the resonance frequencies of the two variant modes, which are the resonance frequency of the longitudinal vibration and the resonance frequency of the torsional vibration, are accurate. It is possible to provide an ultrasonic transducer that can be well matched.

According to the third aspect of the present invention, since the difference between the longitudinal sound velocity and the lateral sound velocity of the elastic body is small, the resonance frequency of the longitudinal vibration and the resonance frequency of the torsional vibration are the same as in the invention of the first aspect. It is possible to provide an ultrasonic transducer capable of accurately matching the resonance frequencies of the two different shape modes.

According to the invention described in claim 4, since the elastic body is composed of the annealed metal material,
Similar to the invention described above, it is possible to provide an ultrasonic transducer capable of accurately matching the resonance frequencies of two variant modes, which are the resonance frequency of longitudinal vibration and the resonance frequency of torsional vibration.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment of the invention of an ultrasonic transducer of the present invention.

FIG. 2 is an explanatory diagram showing primary resonance vibration in the ultrasonic transducer according to the first embodiment of the invention.

FIG. 3 is an explanatory diagram showing secondary resonance vibration in the ultrasonic vibrator according to the first embodiment of the invention.

FIG. 4 is a front view of an ultrasonic linear motor using the ultrasonic transducer according to the first embodiment of the invention.

FIG. 5 is a front view showing an ultrasonic transducer according to a second embodiment of the present invention.

FIG. 6 is a back view showing the ultrasonic transducer according to the second embodiment of the present invention.

FIG. 7 is a right side view showing the ultrasonic transducer according to the second embodiment of the present invention.

FIG. 8 is a left side view showing the ultrasonic transducer according to the second embodiment of the present invention.

FIG. 9 is a plan view showing an ultrasonic transducer according to a second embodiment of the present invention.

FIG. 10 is an exploded view showing an assembled state of the ultrasonic transducer of the second embodiment of the present invention.

FIG. 11 is a front view of an ultrasonic motor using the ultrasonic vibrator according to the second embodiment of the present invention.

FIG. 12 is an exploded view showing an assembled state of an ultrasonic motor using the ultrasonic vibrator according to the second embodiment of the present invention.

FIG. 13 is a perspective view of an ultrasonic transducer of a conventional ultrasonic linear motor.

FIG. 14 is an explanatory diagram showing primary resonance vibration in an ultrasonic oscillator of a conventional ultrasonic linear motor.

FIG. 15 is an explanatory diagram showing primary resonance vibration in an ultrasonic transducer of a conventional ultrasonic linear motor.

[Description of Reference Signs] 10 ultrasonic transducer 11 basic elastic body 12 laminated piezoelectric element 13 elastic member for holding 14 screw 15 driver 16 pin 21 holding plate 22 holding plate fixing member 23 screw 24 linear bush 25 axis 26 axis fixing member 27 Base 28 Pressing Screw 29 Spring 30 Fixed Part 34 Sliding Member

Claims (4)

[Claims] 1. An ultrasonic transducer, comprising an elastic body and an electromechanical conversion element bonded to the elastic body, which synthesizes two variant resonance modes to form an ultrasonic elliptical vibration, wherein the elastic body comprises: An ultrasonic transducer characterized by being made of a material having a small anisotropy of elastic constant depending on the direction. 2. An ultrasonic transducer, comprising an elastic body and an electromechanical conversion element bonded to the elastic body, which synthesizes two variant resonance modes to form an ultrasonic elliptical vibration, wherein the elastic body comprises: An ultrasonic transducer comprising a material having anisotropy of elastic constant within 5% depending on a direction. 3. An ultrasonic transducer, comprising an elastic body and an electromechanical conversion element bonded to the elastic body, which synthesizes two variant resonance modes to form an ultrasonic elliptical vibration, wherein the elastic body comprises: An ultrasonic transducer comprising a material having anisotropy of longitudinal acoustic velocity and lateral acoustic velocity within 5% depending on the direction. 4. An ultrasonic transducer, comprising an elastic body and an electromechanical conversion element bonded to the elastic body, which synthesizes two variant resonance modes to form an ultrasonic elliptical vibration, wherein the elastic body is annealed. An ultrasonic transducer, which is a treated metal material.