JP3311446B2 - Ultrasonic motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an ultrasonic vibrator.
It relates to 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) Quiet and quiet. (5) No magnetic noise is generated, and no influence of noise is generated. The present applicant has previously proposed a conventional ultrasonic vibrator and an ultrasonic linear motor using the vibrator in Japanese Patent Application No. 4-321096. Hereinafter, the conventional ultrasonic transducer and an ultrasonic linear motor using the transducer will be described with reference to the drawings.

FIG. 24 is a front view showing the structure of an ultrasonic vibrator in the above-mentioned conventional technical means.

[0005] As shown in FIG.
The laminated piezoelectric element 113 is disposed on the upper part of the basic elastic body 111 at a portion substantially corresponding to the antinode of the secondary resonance bending vibration. The laminated piezoelectric element 113 is provided with the holding elastic body 1.
12 fixed on the basic elastic body 111.
That is, although not shown, the basic elastic body 111 is provided with three screw taps at three locations.
1 so that the multilayer piezoelectric element 113
Is pressed and held by the holding elastic body 112 from the side.

A portion where the laminated piezoelectric element 113 contacts the holding elastic body 112 is fixed with an epoxy adhesive, and other parts of the laminated piezoelectric element 113 are covered with a resin or the like. . Further, a portion where the holding elastic 112 and the basic elastic body 111 are in contact with each other is also joined by an epoxy adhesive.

The surface of the basic elastic body 111 opposite to the surface on which the multilayer piezoelectric element 113 is arranged (the upper surface in the figure), that is, the bending vibration on the surface in contact with the driven body. A driver 116 made of amorphous carbon is joined to a portion corresponding to the antinode using an epoxy-based adhesive.

The driven member (not shown) made of stainless steel or the like is held by the sliding member of the ultrasonic vibrator having such a structure so as to be linearly movable with a certain pressing force. A sonic linear motor can be configured.

Next, the operation of the ultrasonic transducer 110 will be described.

By appropriately setting the dimensions of the ultrasonic vibrator 110, the primary resonance longitudinal vibration and the secondary resonance bending vibration can be excited at almost the same frequency. In FIG. 24, electric terminals (not shown) taken out of the left laminated piezoelectric element 113 are denoted by A and G (referred to as A phase), and electric terminals (not shown) taken out of the right laminated piezoelectric element 113 are denoted by B and B. G (called B phase). First, a DC voltage of 30 V is applied to the A phase and the B phase. By doing this,
A compression force (pressurization) of approximately 70 N can be applied to the multilayer piezoelectric element 113.

Thereafter, the phase A is applied to the phase A at a frequency Fr and an amplitude of 10
When an alternating voltage of Vp-p is applied and an alternating voltage having the same frequency, the same amplitude, and the same phase is applied to the B phase, the primary resonance longitudinal vibration can be excited. Next, in the A phase, at a frequency Fr and an amplitude of 10 Vp-
When an alternating voltage of p is applied and an alternating voltage of the same frequency, the same amplitude and the opposite phase is applied to the B phase, a secondary resonance bending vibration can be excited.

Now, the A-phase and the B-phase have an amplitude of 1 at a 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 driver 116. At this time, the driven body pressed by the driver 116 is driven rightward or leftward.

[0013]

However, the above-described conventional ultrasonic motor has a complicated manufacturing process because an elastic body such as brass and a laminated piezoelectric element are joined using an adhesive. In addition, the relative positions of the respective components are likely to be out of order, and the vibration characteristics are likely to vary. Further, there has been a problem that the adhesive is easily peeled off in a resonance state.

The present invention has been made in view of such a problem, and requires a step of bonding a laminated piezoelectric body to an elastic substrate.
No peeling of adhesive, etc.
An object is to provide a small ultrasonic motor.

[0015]

In order to achieve the above object, a first ultrasonic motor according to the present invention comprises a driven body,
First piezoelectric lamination configured by laminating piezoelectric plates in the same direction
And a second piezoelectric laminate, which are integrated via an insulating portion.
The first and second piezoelectric laminates configured as
A side face of the first and second piezoelectric laminates, wherein the driven body
A driver provided at a position of an antinode of the bending vibration on a surface in contact with the first and second piezoelectric laminates, and a first driver alternately provided on a side surface of the laminated piezoelectric plate between the first and second piezoelectric laminates.
An internal electrode having a first electrode group and a second electrode group ; a first external electrode provided on an outer surface of the first piezoelectric laminate and electrically connected to the first electrode group; A second external electrode provided on the external surface of the multilayer body and electrically connected to the second electrode group; and a third external electrode provided on the external surface of the second piezoelectric multilayer body and electrically connected to the first electrode group. An external electrode, and a fourth external electrode provided on the external surface of the second piezoelectric laminate and electrically connected to the second electrode group .
Between the first and second external electrodes and between the third and fourth external electrodes;
By applying voltages having different phases to each other between the
To excite the longitudinal and bending vibrations to move the driver elliptically.
The driven body is driven by being moved. Also,
The second ultrasonic motor according to the present invention includes the first ultrasonic motor
In the motor, the first and second piezoelectric laminates are
The piezoelectric plates laminated in the driving direction of the driven body are
By dividing into two laminates, it becomes a serial arrangement
And wherein the first electrode group and the second electrode group are
The side surface of the piezoelectric plate, provided on the opposite side to the driver
It is characterized by being. Also, a third supersonic according to the present invention
The wave motor according to the first ultrasonic motor,
The first and second piezoelectric laminates are arranged in a driving direction of the driven body.
The first and second electrode groups are stacked in a direction orthogonal to each other.
Divided into two areas by the insulating part provided in the center of the piezoelectric plate
By doing so, it is
Features.

[0016]

The ultrasonic vibrator according to the present invention applies a drive signal to the electro-mechanical energy conversion element, and in the area where the first electrode group is provided, the sign and the bending of the expansion / contraction strain component generated by the longitudinal vibration. Vibration occurs in which the sign of the stretching component generated by the vibration is the same as the sign of the stretching component, and in the area where the second electrode group is provided, the sign of the stretching component caused by the longitudinal vibration and the strain component caused by the bending vibration are Causes different vibrations.

[0017]

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

FIG. 1 is a front view of an ultrasonic vibrator according to a first embodiment of the present invention, and FIG. 2 is a top view of the ultrasonic vibrator.

As shown in the figure, a basic portion of the ultrasonic vibrator 10 of the first embodiment is configured by laminating a rectangular PZT-PMN-based piezoelectric plate 11 which has been subjected to internal electrode treatment. The two stacked piezoelectric members 18 are similarly rectangular PZs.
As shown in the figure, it is configured to be sandwiched between three T-PMN-based insulating plates 12.

FIG. 3 is an exploded perspective view showing the essential parts of the ultrasonic transducer 10 in detail. FIG.
FIG. 5 is a perspective view of relevant parts showing both side surfaces of one piezoelectric plate 11 in the ultrasonic transducer 10, and FIG. 5 shows both side surfaces of the piezoelectric plate 11 adjacent to the piezoelectric plate 11 shown in FIG. It is a principal part perspective view.

The piezoelectric plate 11 has a height of 10 mm and a depth of 4 mm.
mm, a piezoelectric element having a thickness of 100 μm,
An internal electrode 17a is provided on an upper portion of one side surface, and an internal electrode 17b is provided on an upper portion of a back surface of the internal electrode 17a.

The internal electrode 17a is a thin film electrode on which a silver-palladium alloy having a thickness of about 10 μm is applied in a rectangular shape. As shown in FIGS. About 1 mm at the back end, 1 mm at the top end,
The piezoelectric plates 11 are arranged so as to have an insulating portion at a lower portion thereof, which is approximately の of the height of the piezoelectric plate 11. On the other hand, the internal electrode 17b is connected to the internal electrode 17 on the piezoelectric plate 11.
a is a thin-film electrode having a back surface allotted to a side and similarly coated with a silver-palladium alloy having a thickness of about 10 μm.
Then, on the back surface, about 1 mm at the front end, 1 mm at the upper end, and about ／ of the height of the piezoelectric plate 11 at the bottom in the figure.
It is arranged so as to have a degree of insulation.

The internal electrodes 17a, 17a,
As shown in FIGS. 4 and 5, the application position of 17b is reversed between one side surface and the back surface of the piezoelectric plates 11 adjacent to each other. The two types of piezoelectric plates 11 (FIGS. 4 and 5) provided with such internal electrodes 17a and 17b are alternately set to one.
About 00 layers are laminated, and the piezoelectric plate laminated portion 18 of the first embodiment is laminated.
(See FIG. 1).

Returning to FIG. 1, the insulating plate 12 is a rectangular PZT-PMN-based element and has a shape of 10 mm in height, 4 mm in depth, and 3 mm in thickness. In addition, the above 2
Of the insulating plates 12 provided at three places so as to sandwich the two piezoelectric laminate portions 18, a central portion of the insulating plate 12 is provided with a perforation 15 having a diameter of 1 mm at the center from the front to the back. Have been.

The piezoelectric laminated portion 1 of the ultrasonic vibrator 10
A part of the internal electrodes 17a and 17b is exposed in the upper front part and the upper rear part in FIG. 8 to form four exposed part groups (not shown). The four exposed portions are provided with four external electrodes 14 each made of a conductive silver paste independently of each other so as to be electrically connected to the internal electrode 17a or 17b.

Lead wires extend from the external electrodes 14, respectively, and the two external electrodes 14 disposed on the front surface of the ultrasonic vibrator 10 are electrically connected as shown in FIGS. The external electrodes 14 disposed on the back of the ultrasonic transducer 10 as terminals A and B, as ground (GND) terminals,
It is connected to a drive circuit for a piezoelectric plate 11 (not shown).

On the other hand, a driver 16 having a width of 4 mm, a depth of 4 mm, and a thickness of 1 mm is joined to the bottom of the ultrasonic vibrator 10 by an adhesive at a position 9 mm from the longitudinal end. The driver 16 is formed by dispersing alumina in a polymer material. Further, a pin 19 made of a stainless steel material is penetrated and adhered to the perforation 15 of the central insulating plate 12 (see FIG. 2).

The ultrasonic vibrator 1 thus constructed
The overall dimensions of 0 are 30 mm in width, 10 mm in height, and 4 mm in depth.

Next, a method of manufacturing a basic portion of the ultrasonic transducer 10 will be described.

The above-mentioned rectangular piezoelectric plate 11 and insulating plate 12
Is made of a PZT-PMN-based material as described above. First, a method for manufacturing the piezoelectric plate 11 will be described. That is, a pre-sintered powder of the PZT-PMN-based material and a binder are mixed to prepare a slurry, and the slurry is cast into a film by a doctor blade method to form a green sheet. Then, after drying the green sheet, the green sheet is peeled off from the film to form a rectangular piezoelectric plate 11.
Create Thereafter, as described above, the internal electrodes 17a and 17b are applied to both surfaces of the piezoelectric plate 11, respectively.
On the other hand, the insulating plate 12 is formed by a method using a mold.

Next, the piezoelectric plate 11 and the insulating plate 12 are laminated as shown in FIG. 3 and pressed while applying heat. After that, main firing is performed at 1200 ° C. to form a basic portion of the ultrasonic vibrator 10. After that, the external electrodes 14 are provided as described above, and a DC voltage is applied to the electric terminals A, B, and GND for about 10 minutes to polarize the portion of the piezoelectric plate 11 on which the internal electrodes 17a and 17b are provided.

Next, the ultrasonic vibrator 10 of the first embodiment will be described.
Will be described.

When the size and shape of the ultrasonic transducer 10 of the first embodiment are set as described above, the primary resonance longitudinal vibration and the secondary resonance bending vibration have substantially the same frequency Fr (53 k
Hz to 56 kHz). In addition, the applicant has
As a result of computer analysis of these vibrations using the finite element method, a resonance longitudinal vibration state as shown in FIG. 6A and a resonance bending vibration state as shown in FIG. 6B are expected. The measurement proved it. Less than,
The vibration measurement will be described.

First, of the external electrodes 14, the frequency Fr is applied to the external electrodes 14 which are to be the electric terminals A (see FIGS.
When an alternating voltage having an amplitude of 10 Vp-p is applied to the external electrode 14 serving as the electrical terminal B, and an alternating voltage having the same frequency, the same amplitude and the same phase is applied to the external electrode 14, the primary resonance as shown in FIG. Longitudinal vibration could be excited. Next, the frequency F is applied to the electrical terminal A.
r, an alternating voltage having an amplitude of 10 Vp-p
When an alternating voltage having the same frequency, the same amplitude, and the opposite phase was applied to, a secondary resonance bending vibration as shown in FIG. 6B could be excited. Next, the electrical terminal A is applied with a frequency Fr and an amplitude of 10 Vp-p.
When an alternating voltage having the same frequency, the same amplitude, and a phase different by 90 degrees is applied to the electric terminal B, the resonance longitudinal vibration and the resonance bending vibration are combined, and the elliptical vibration is generated at the position of the driver 16. Could be excited.

Next, referring to FIG.
The ultrasonic linear motor 50 to which 0 is applied will be described.

As shown in FIG. 7, in the ultrasonic linear motor 50, the ultrasonic vibrator 10 is held on two sides by two holding plates 21 at the pin 19 thereof. The holding plate 21 is provided with a hole having substantially the same diameter as the diameter of the pin 19, and the hole is engaged with the pin 19 of the ultrasonic transducer 10. By holding the ultrasonic vibrator 10 in this manner, the ultrasonic vibrator 10 has a degree of freedom only with respect to rotation around the pin 19.

On the other hand, the holding plate 21 is fixed to the holding plate fixing member 22 by screws 23. The holding plate fixing member 22 is held by a linear bush 24, and the linear bush 24 moves linearly along a shaft 25. Further, the shaft 25 is fixed to a shaft fixing member 26, and the shaft fixing member 26 is
Are fixed by screws. Further, the shaft fixing member 2
6 has a tap at almost the center, and a pressing screw 2
8 is screwed. A spring 29 is inserted between the pressing screw 28 and the holding plate fixing member 22.

A fixing portion 30 of a cross roller guide is fixed to the base 27 with a screw 31 on a base.
Further, a sliding member holding portion 33 is fixed to the moving portion 32 of the cross roller guide with a screw (not shown), and zirconia ceramics subjected to HIP processing as a sliding member 34 is adhered to the sliding member holding portion 33. . By adjusting the pressing screw 28 in such a configuration, the pressing force of the ultrasonic vibrator 10 on the sliding member 34 (driven member) can be adjusted.

As described above, the frequency Fr (53 kHz to 56 kHz) is applied to the electric terminals A and B of the ultrasonic vibrator 10.
kHz), amplitude 10 Vp-p, phase difference +9
An alternating voltage of 0 degrees or -90 degrees is applied. Then, the driven member 34 is driven rightward or leftward.

According to the ultrasonic vibrator of the first embodiment,
Since the basic part of the ultrasonic vibrator 10 is formed without the bonding step, a highly reliable ultrasonic vibrator with small fluctuation in vibration characteristics can be obtained.

Next, an ultrasonic transducer according to a second embodiment of the present invention will be described.

FIGS. 8 to 12 are explanatory views showing an ultrasonic vibrator 60 according to a second embodiment of the present invention, and FIG. 8 is a front view of the ultrasonic vibrator 60. 9 is a top view of the ultrasonic vibrator. FIG. 10 is an exploded perspective view of a main part showing a basic part of the ultrasonic transducer 60 in detail. FIG. 11 is a perspective view of a main part showing both sides of one piezoelectric plate 11 in the ultrasonic transducer 60, and FIG. 12 is a side view of both sides of the piezoelectric plate 11 adjacent to the piezoelectric plate 11 shown in FIG. It is the principal part perspective view which showed.

The ultrasonic transducer according to the second embodiment has basically the same configuration as that of the first embodiment, and therefore, only the differences from the first embodiment will be described.

Also in the second embodiment, the piezoelectric laminated portion 18, which is a laminated body of the piezoelectric plate 11, the insulating plate 12 and the like are provided in the first embodiment.
It is configured in the same manner as the embodiment,
Are different in the number of external electrodes 14 to be joined.

As shown in FIGS. 11 and 12, the piezoelectric plate 11
Are provided in two portions on both one side and the back side. One side is in the first region (1
7c) and an insulating part of about 2 mm at the boundary between the second area (17d), an insulating part of about 1 mm at the rear end of each area, and an insulating part of 1 mm at the upper or lower end. , A silver-palladium alloy having a thickness of about 10 μm is applied, and the back surface of the side surface is covered with the first region (17e).
Leaving approximately 2 mm of insulation at the boundary between the first and second regions (17f), approximately 1 mm of insulation at the front end of each region, and 1 mm of insulation at the top or bottom surface of each region.
A silver-palladium alloy having a thickness of about 10 μm is applied.

The internal electrodes 17c and 17d of the piezoelectric plate 11
As shown in FIG. 11 and FIG. 12, the piezoelectric plates 11 adjacent to each other and the inner electrodes 17e and 17f have application positions opposite to each other on one side and the back side. About 100 layers of two types of piezoelectric plates (FIGS. 11 and 12) provided with such internal electrodes 17c to 17f are alternately laminated to form the piezoelectric plate laminated portion 18 (see FIG. 8) of the second embodiment. Be composed.

As shown in FIGS. 8 and 9, the upper and lower front and rear portions of the piezoelectric laminated portion 18 of the ultrasonic vibrator 60 have the internal electrodes 17c to 17c as in the first embodiment. Part of 17f is exposed, forming eight exposed part groups (not shown). Each of the eight exposed portions is provided with eight external electrodes 14 made of conductive silver paste, respectively, with the internal electrodes 17c, 17d, 17e or 1
7f are provided independently of each other so as to conduct with 7f.

Lead wires extend from the external electrodes 14, respectively, and the external electrodes 14 on the diagonal line are short-circuited by the lead wires at both front and back sides of the ultrasonic transducer 60. ing. In addition, four external electrodes 14 disposed on the front and back sides of the ultrasonic vibrator 60 are provided.
Are connected to a drive circuit of the piezoelectric plate 11 (not shown) as electrical terminals A and B and a ground (GND) terminal as shown in FIGS.

The other parts of the structure of the ultrasonic vibrator 60 are the same as those of the first embodiment, and the description is omitted.

The manufacturing method and operation of the basic part of the ultrasonic vibrator of the second embodiment, and the configuration and operation of the ultrasonic linear motor using the ultrasonic vibrator of the second embodiment. Is the same as that of the first embodiment, and the description is omitted here.

According to the ultrasonic vibrator of the second embodiment,
Since the volume of the portion of the piezoelectric vibrator 18 of the ultrasonic vibrator 60 is large, the output of the ultrasonic vibrator is increased and the output of the motor is increased.

Next, an ultrasonic transducer according to a third embodiment of the present invention will be described.

FIGS. 13 to 17 are explanatory views showing an ultrasonic vibrator according to a third embodiment of the present invention. FIG. 13 is a front view of the ultrasonic vibrator, and FIG. It is a top view of a child.

The ultrasonic vibrator 70 of the third embodiment is basically composed of a rectangular P which has been subjected to internal electrode treatment.
A piezoelectric laminated portion 18 on which a ZT-PMN-based piezoelectric plate 11 is laminated; and a rectangular PZT-PMN-based insulating plate 1
2 are laminated as shown in the figure.

FIG. 15 is an exploded perspective view showing the essential parts of the ultrasonic transducer 70 in detail. 16 is a perspective view showing the upper and lower surfaces of one piezoelectric plate 11 of the ultrasonic vibrator 70, and FIG. 17 is an upper and lower surface of the piezoelectric plate 11 adjacent to the piezoelectric plate 11 shown in FIG. It is the principal part perspective view which showed.

The piezoelectric plate 11 in the third embodiment has a width 3
The piezoelectric element has a thickness of 0 mm, a depth of 4 mm, and a thickness of 100 μm. On the upper surface (or lower surface) of the piezoelectric plate 11, an internal electrode 17a coated with a silver-palladium alloy having a thickness of about 10 μm as in the first embodiment is provided with a back end, left and right ends, 1m each at the center in the width direction
m insulating portions are provided, and are arranged so as to be further divided into two regions.

On the other hand, the internal electrode 1 on the piezoelectric plate 11
The back side of 7a has a silver-like thickness of about 10 μm as described above.
The internal electrodes 17b coated with a palladium alloy are 1 m each at the front end, the left and right ends, and the center in the width direction.
m insulating portions are provided, and are arranged so as to be further divided into two regions.

As shown in the figure, the inner electrodes 17a and 17b are arranged such that the electrode application positions of the piezoelectric plates 11 adjacent to each other are reversed on the upper surface and the lower surface. Such an internal electrode 17
The piezoelectric plate laminated portion 18 shown in FIG. 13 is obtained by alternately laminating about 40 layers of two types of piezoelectric plates 11 (FIGS. 16 and 17) provided with a and 17b.

In the ultrasonic vibrator 70 of the third embodiment,
The upper insulating plate 12 of the rectangular PZT-PMN system has a width of 30.
mm, a depth of 4 mm, and a thickness of 1 mm. The lower insulating plate 12 has a width of 30 mm and a depth of 4 m.
m, a thickness of 5 mm, and a perforation 15 having a diameter of 1 mm is provided on an upper portion thereof.

In FIGS. 13 and 14, a part of the internal electrodes 17a and 17b is exposed on both sides of the front and back sides of the piezoelectric layered portion 18 of the ultrasonic vibrator 70. An exposed part group is formed (not shown). In the four exposed part groups, four external electrodes 14 each made of conductive silver paste are provided with the internal electrodes 17a.
Alternatively, they are provided independently of each other so as to be electrically connected to the internal electrode 17b.

Lead wires extend from the external electrodes 14 respectively, and the two external electrodes 14 disposed in front of the ultrasonic vibrator 70 are electrically connected as shown in FIGS. The external electrodes 14 disposed on the back of the ultrasonic transducer 70 as terminals A and B are connected to a drive circuit for the piezoelectric plate 11 (not shown) as ground (GND) terminals.

On the other hand, a driver 16 having a width of 4 mm, a depth of 4 mm and a thickness of 1 mm is joined to the bottom of the ultrasonic transducer 70 at a position 9 mm from the longitudinal end by an adhesive. The driver 16 is formed by dispersing alumina in a polymer material. Further, a pin 19 made of a stainless steel material is penetrated and adhered to the perforation 15 of the central insulating plate 12 (see FIG. 2).

The overall size of the ultrasonic vibrator 70 of the third embodiment having such a configuration is 30 mm in width and 10 m in height.
m, depth 4 mm.

The method of manufacturing the basic portion of the ultrasonic vibrator 70 is the same as that of the first embodiment, and the description is omitted here. Further, the other configuration and operation of the ultrasonic vibrator 70, and the configuration and operation of the ultrasonic linear motor using the ultrasonic vibrator 70 are the same as those in the first embodiment, and thus description thereof will be omitted. .

In general, the laminated ultrasonic vibrators are easily broken by the tensile force in the laminating direction. However, according to the ultrasonic vibrator of the third embodiment, the ultrasonic vibrators of the first and second embodiments are used. Since the lamination direction is the up-down direction with respect to the transducer, an ultrasonic vibrator that is strong against the pressing force in the up-down direction can be obtained. Further, the third embodiment is advantageous when producing an ultrasonic transducer having a lower height than the ultrasonic transducers of the first and second embodiments.

As a modification of the third embodiment, as in the second embodiment with respect to the first embodiment, a piezoelectric plate 11 provided with internal electrodes may be provided in the lower half. Good.

Next, an ultrasonic transducer according to a fourth embodiment of the present invention will be described.

FIGS. 18 to 23 are explanatory views showing an ultrasonic transducer according to a fourth embodiment of the present invention.
9, FIG. 20 is a front view of the ultrasonic vibrator 80,
It is a top view and a side view.

The ultrasonic vibrator 80 of the fourth embodiment has a rectangular PZ having a basic portion treated with an internal electrode.
A piezoelectric laminate portion 18 on which a T-PMN-based piezoelectric plate 11 is laminated, and a rectangular PZT-PMN-based insulating plate 12
Are stacked as shown in the figure.

FIG. 21 is an exploded perspective view showing the essential parts of the ultrasonic transducer 80 in detail. 22 is a perspective view showing the front and rear surfaces of one piezoelectric plate 11 in the ultrasonic vibrator 80. FIG. 23 is a front and rear view of the piezoelectric plate 11 adjacent to the piezoelectric plate 11 shown in FIG. It is the principal part perspective view which showed.

The piezoelectric plate 11 according to the fourth embodiment has a width 3
A piezoelectric element having a thickness of 0 mm, a height of 10 mm, and a thickness of 100 μm, and a front surface (or a rear surface) having a thickness of 10 μm.
Internal electrode 17 coated with a silver-palladium alloy of about m
a is provided with an insulating portion of 1 mm at the upper end, 5 mm at the lower portion, and 1 mm at the center in the width direction, respectively.
It is divided into two regions and arranged.

On the other hand, on the back side of the internal electrode 17a of the piezoelectric plate 11, an internal electrode 17b has an insulating portion of 1 mm at the left and right ends, 5 mm at the lower portion, and 1 mm at the center in the width direction. Each is provided and further divided into two regions.

As shown in FIGS. 22 and 23, the piezoelectric plate 11 is provided with an internal electrode 17 between adjacent piezoelectric plates 11.
The application positions of a and 17b are reversed. Two types of piezoelectric plates 11 provided with such internal electrodes 17a and 17b
By stacking about 40 layers (FIGS. 22 and 23) alternately, the piezoelectric plate laminated portion 18 (see FIG. 18) of the fourth embodiment is formed.

In the fourth embodiment, the rectangular insulating plate 12 disposed on the front and rear surfaces of the ultrasonic vibrator 80 is an element having a width of 30 mm, a height of 10 mm, and a thickness of 0.5 mm. . Further, a part of the internal electrodes 17a and 17b is exposed on both sides of the upper surface and upper portions of both sides of the piezoelectric laminated portion 18 of the ultrasonic vibrator 80 to form four exposed portion groups. (Not shown). The four exposed portions are provided with four external electrodes 14 each made of a conductive silver paste independently of each other so as to be electrically connected to the internal electrode 17a or 17b.

Lead wires extend from the external electrodes 14, respectively. The two external electrodes 14 disposed on the upper surface of the ultrasonic vibrator 80 are electrically connected to each other as shown in FIGS. The external electrodes 14 disposed on the side surfaces of the ultrasonic vibrator 80 as terminals A and B are connected to a drive circuit for the piezoelectric plate 11 (not shown) as ground (GND) terminals.

On the other hand, a driver 16 having a width of 4 mm, a depth of 4 mm, and a thickness of 1 mm is joined to the bottom of the ultrasonic vibrator 80 at a position 9 mm from an end in the longitudinal direction by an adhesive. The driver 16 is formed by dispersing alumina in a polymer material. A hole having a diameter of φ1 mm is formed in a substantially central portion of the ultrasonic vibrator 80, and a pin 19 made of a stainless steel material is penetrated and bonded to the hole (see FIG. 19).

The ultrasonic vibrator 8 thus configured
The overall dimensions of 0 are 30 mm in width, 10 mm in height, and 4 m in depth.

The method of manufacturing the basic part of the ultrasonic vibrator 80 of the fourth embodiment is the same as that of the first embodiment, and the description thereof is omitted.

The other structure and operation of the ultrasonic vibrator 80 of the fourth embodiment, and the structure and operation of an ultrasonic linear motor using the ultrasonic vibrator 80 of the fourth embodiment are described in the above-described first embodiment. Since it is the same as the first embodiment, the description is omitted here.

According to the ultrasonic vibrator of the fourth embodiment,
An ultrasonic vibrator having a smaller depth dimension than the first, second, and third embodiments can be provided.

Further, as a modification of the fourth embodiment, a structure in which internal electrodes are provided on the lower half of the piezoelectric plate as in the second embodiment with respect to the first embodiment may be laminated.

As described above, according to the above-described embodiments, the following effects can be obtained. (1) Since the elastic body and the piezoelectric body are integrally formed at the same time, adhesion and peeling do not occur and the reliability is high. (2) For the same reason as above, variation in vibration characteristics is small. (3) The manufacturing process is simple.

Although the embodiments of the present invention have been described with reference to only the linear type ultrasonic motor, the rotary type ultrasonic motor can be used if the moving body is a rotary body using the ultrasonic vibrator of the present invention. It is also possible to apply to. In each of the above embodiments, the piezoelectric element is used as the electro-mechanical energy conversion element. However, it goes without saying that the same effect can be obtained by using the electrostrictive element.

As described above, according to the present invention, the piezoelectric
The plates are laminated to form an integral part with the insulating part, and the piezoelectric laminate is driven.
Since a moving element is formed, the laminated piezoelectric
There is no need for a step of bonding to a conductive substrate, and adhesive peeling may occur.
Provides an ultrasonic motor with less variation in vibration characteristics
I can do it.

[Brief description of the drawings]

FIG. 1 is a front view of an ultrasonic transducer according to a first embodiment of the present invention.

FIG. 2 is a front view of the ultrasonic transducer according to the first embodiment.

FIG. 3 is an exploded perspective view of a main part showing a basic part of the ultrasonic transducer in detail.

FIG. 4 is an essential part perspective view showing both side surfaces of one piezoelectric plate in the ultrasonic transducer.

FIG. 5 is a perspective view of relevant parts showing both side surfaces of the piezoelectric plate adjacent to the piezoelectric plate shown in FIG. 4;

FIG. 6 is a perspective view showing (A) a resonance longitudinal vibration state and (B) a resonance bending vibration state of the ultrasonic transducer of the first embodiment.

FIG. 7 is a front view showing an ultrasonic linear motor to which the ultrasonic transducer of the first embodiment is applied.

FIG. 8 is a front view of an ultrasonic transducer according to a second embodiment of the present invention.

FIG. 9 is a top view of the ultrasonic transducer according to the second embodiment.

FIG. 10 is an exploded perspective view of a main part showing in detail a basic part of the ultrasonic transducer of the second embodiment.

FIG. 11 is an essential part perspective view showing both side surfaces of one piezoelectric plate in the ultrasonic transducer according to the second embodiment.

12 is an essential part perspective view showing both side surfaces of the piezoelectric plate adjacent to the piezoelectric plate shown in FIG. 11;

FIG. 13 is a front view of an ultrasonic transducer according to a third embodiment of the present invention.

FIG. 14 is a top view of the ultrasonic vibrator showing the third embodiment.

FIG. 15 is an exploded perspective view of a main part showing in detail a basic part of the ultrasonic transducer of the third embodiment.

FIG. 16 is an essential part perspective view showing upper and lower surfaces of one piezoelectric plate in the ultrasonic transducer according to the third embodiment.

17 is an essential part perspective view showing upper and lower surfaces of a piezoelectric plate adjacent to the piezoelectric plate shown in FIG. 16;

FIG. 18 is a front view of an ultrasonic transducer according to a fourth embodiment of the present invention.

FIG. 19 is a top view of the ultrasonic vibrator showing the fourth embodiment.

FIG. 20 is a side view of an ultrasonic transducer according to the fourth embodiment.

FIG. 21 is an exploded perspective view of a main part showing in detail a basic part of the ultrasonic transducer of the fourth embodiment.

FIG. 22 is an essential part perspective view showing front and rear surfaces of one piezoelectric plate in the ultrasonic transducer of the fourth embodiment.

23 is an essential part perspective view showing front and rear surfaces of a piezoelectric plate adjacent to the piezoelectric plate shown in FIG. 22; FIG.

FIG. 24 is a front view showing a configuration of a conventional ultrasonic transducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Ultrasonic vibrator 11 ... Piezoelectric plate 12 ... Insulating plate 14 ... External electrode 16 ... Driver 17a-17f ... Internal electrode 18 ... Piezoelectric laminated part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-55585 (JP, A) JP-A-3-212173 (JP, A) JP-A-53-80193 (JP, A) 40294 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02N 2/00 B06B 1/06

Claims (3)

(57) [Claims] 1. A first piezoelectric laminate comprising a driven body and a piezoelectric plate laminated in the same direction.
And a second piezoelectric laminate, which are integrated via an insulating portion.
The first and second piezoelectric laminates, and the side surfaces of the first and second piezoelectric laminates, wherein
A driver provided at a position of an antinode of bending vibration on a surface in contact with the driver, and a layer between the first and second piezoelectric laminates,
An internal electrode having a first electrode group and a second electrode group alternately provided on the side surface of the piezoelectric plate; and the first electrode provided on an outer surface of the first piezoelectric laminate.
A first external electrode electrically connected to the second electrode group; a second external electrode provided on an outer surface of the first piezoelectric laminate;
A second external electrode that is electrically connected to the first electrode group; a second external electrode that is provided on an outer surface of the second piezoelectric laminate;
A third external electrode which is electrically connected to the second electrode group; and a third external electrode provided on an external surface of the second piezoelectric laminate,
A fourth external electrode which is electrically connected to the electrode group of the first and second external electrodes.
And voltages having phases different from each other are applied between the first and fourth external electrodes.
By exciting longitudinal vibration and bending vibration,
Characterized in that the driven element is driven by making the child move elliptically.
Ultrasonic motor. 2. The piezoelectric device according to claim 1, wherein the first and second piezoelectric laminates include
The piezoelectric plates laminated in the driving direction of the driving body are
Divided into two laminates to form a serial arrangement
Wherein the first electrode group and the second electrode group are
A side surface of the plate, which is provided on a side opposite to the driver.
The ultrasonic motor according to claim 1, wherein: 3. The piezoelectric device according to claim 1, wherein the first and second piezoelectric laminates are each
Stacked in a direction perpendicular to the driving direction of the driving body,
And a second electrode group formed by an insulating portion provided at the center of each piezoelectric plate.
By dividing the area into two areas,
The ultrasonic wave according to claim 1, wherein the ultrasonic wave is formed.
motor.