JP2000312490A - Piezo actuator - Google Patents

Abstract

(57) [Problem] A conventional piezoelectric actuator is composed of a vibrating body, a moving body, a pressing member, and a rotating shaft, but these components go through a highly accurate joining and assembling procedure. ,
A problem arises in that variations occur in the manufacturing process, which affects dynamic characteristics such as the driving speed of the piezoelectric actuator. SOLUTION: A supporting member 7 which extends a piezoelectric actuator in parallel with a circular tangential direction of a rotary moving member 5 and has one end fixed and the other end free, and a vibrating member 4 made of a piezoelectric member provided on the supporting member 7 are provided. By providing a substrate 8 provided, a structure in which the substrates are stacked at regular intervals, and a rotating body 5 provided with a pressurizing unit 6 for applying a pressure in the direction of the substrate provided with the vibrating body, the movement is achieved. The function to excite the movement of the body was realized. The assembly and joining steps can be reduced, the variation in the dynamic characteristics of the piezoelectric actuator due to mass production can be reduced, and the piezoelectric actuator can be simplified, thinned and reduced in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piezoelectric actuator used for a timepiece, a camera, a printer, an information storage device, and the like, and more particularly, to a piezoelectric actuator and a device using the piezoelectric actuator, for stabilizing the operation and simplifying a manufacturing process.

[0002]

2. Description of the Related Art At present, OA equipment and information processing equipment have been miniaturized, and accordingly, piezoelectric actuators have attracted attention as a power source used for driving and transporting. As an example of such a piezoelectric actuator, a micro piezoelectric motor developed by the present applicant is known (IEEJ).
15th Sensor Symposium TECHNICAL DIGEST 1
81-184, 1997). FIG. 2 shows an assembly diagram of the micro piezoelectric motor.

This micro piezoelectric motor comprises a disk-shaped rotary moving body 5 having a shaft projection, a vibrating body 4 and a base chassis 13 supporting the shaft projection. Vibrator 4
Is provided with three bending displacement mechanism sections 1 in which a piezoelectric body 2 that generates expansion and contraction motion is attached to a support 7. The bending displacement mechanism 1 has an L-shape, and a short side and a short portion of the L-shape are fixed to the center of the vibrating body 4. The bending displacement mechanism 1 is arranged in parallel with the tangential direction of the rotary moving body 5.
Note that the rotary moving body 5 is provided with a sliding portion.

In addition, the rotary moving body 5 and the base chassis 13
Is used, and the rotating body 5 and the vibrating body 4 are brought into contact with each other under a constant pressure. Further, a non-magnetic material is used for the vibrating body, particularly for the bending displacement mechanism 1, so as not to be affected by the magnetic force of the magnet material. The shaft projection of the rotary moving body 5 is supported by a hollow shaft hole of the vibrating body 4. The main body of the rotary moving body 5 is formed of a metal or a resin, and the sliding portion is subjected to an oxide film treatment. In addition, a photofabrication technique such as etching is used for forming the rotating body 5 and the vibrating body 4. FIG. 3 is an explanatory diagram showing the operation principle of the micro piezoelectric motor. By applying a drive voltage of a specific frequency to the piezoelectric body 2, the piezoelectric body 2 expands and contracts in the direction of the arrow in the figure. Due to this expansion and contraction, the bending displacement mechanism 1 fixed to one end of the support 7 vibrates in the direction of the arrow in the figure. When the bending displacement mechanism 1 vibrates, the tip of the bending displacement mechanism 1 comes into contact with the rotary moving body 5, and the rotary moving body 5 moves due to the combination of the vertical and horizontal force components.

[0005]

FIG. 4 is a block diagram showing the structure of a conventional piezoelectric actuator. The piezoelectric actuator includes a vibrating body in which a piezoelectric body is attached to a vibrator, a moving body in contact with the vibrating body, a pressing member in contact with the moving body, and a rotation axis serving as a rotation center axis of the moving body and the pressing member. Is shown. In order to stably obtain a small driving force transmitted from the vibrating body, the moving body is required to have a structure for managing the sliding surface between the moving body and the vibrating body under a constant pressurization.

FIG. 2 shows a configuration example in which a stable contact state between the moving body and the vibrating body is maintained by the attraction force of the magnetic force.
As another example, a configuration using a joining method of sandwiching a movable body supported by rotation guide between a vibrating body and a pressing member is also used.

[0007] With these configurations, it is possible to easily reduce the size of the piezoelectric actuator and obtain a desired rotation speed and movement of the movable body, which are difficult with the conventional technology.

However, since the components are formed by integration of the respective components, variations tend to occur between the component components, particularly in the high-precision joining and assembling process of the pressing member and the rotating shaft. There is a problem that the dynamic characteristics such as the driving speed of the piezoelectric actuator are affected. Furthermore,
In the future microfabrication, measures for similar issues are desired.

Accordingly, an object of the present invention is to provide a piezoelectric actuator which can eliminate the above-mentioned problems and can stabilize the operation with a simple structure.

[0010]

A first piezoelectric actuator according to the present invention is provided on a support which extends parallel to the circular tangential direction of the rotary moving body and is fixed at one end and free at one end. It comprises a substrate provided with a vibrating body made of a piezoelectric body, a structure in which the substrates are stacked at regular intervals, and a rotary moving body provided with a structure for applying a pressure to the substrate provided with the vibrating body.

As described above, by eliminating the rotation center axis and by providing the moving body with a structure for applying pressurization and reducing the number of parts, it is possible to reduce manufacturing variations due to the assembling process. And the driving of the piezoelectric actuator is stabilized.

A second piezoelectric actuator according to the present invention comprises a support extending parallel to the circular tangential direction of the rotary moving body and fixed at one end and free at the other end, and a piezoelectric body provided on the support. A substrate having a plurality of vibrators,
It is composed of a structure in which the substrates are stacked at regular intervals, and a rotary moving body having a structure for applying a pressure in the direction of the substrate provided with the vibrator.

As described above, by eliminating the central axis of rotation and adopting a structure in which the number of parts is reduced, it is possible to reduce manufacturing variations due to the assembling process as in the first piezoelectric actuator. It is expected that the driving of the piezoelectric actuator will be stable, and the use of a structure having a plurality of vibrating bodies makes it possible to increase the output of the piezoelectric actuator.

Further, a third piezoelectric actuator according to the present invention is a support which extends in parallel with the moving direction of the parallel moving body and is fixed at one end and free at the other end, and a vibrator made of the piezoelectric material provided on the support. , A structure in which the substrates are stacked at regular intervals, and a parallel moving body having a structure for applying a pressure in the direction of the substrate provided with the vibrating body.

As described above, by providing a structure for applying a pressure to the parallel moving body, the substrate provided with the vibrating body and the substrate provided with the vibrating body can be simplified without providing a pressing member. Thus, the product life of the structure in which the substrates are stacked can be extended, and the product can be downsized and the manufacturing process can be simplified.

Further, a fourth piezoelectric actuator according to the present invention comprises a support extending in parallel to the moving direction of the parallel moving body and having one end fixed and the other end free, and a plurality of vibrators comprising the piezoelectric provided on the support. It is characterized by comprising a substrate provided with a body, a structure in which the substrates are stacked at regular intervals, and a parallel moving body provided with a structure for applying a pressure in the direction of the substrate provided with the vibrating body.

According to this, by providing a plurality of vibrators, it is possible to increase the output of the piezoelectric actuator in addition to the effect of the third piezoelectric actuator.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, FIGS.
Embodiment 1 of the present invention will be described in detail with reference to FIGS. FIG. 1 is an assembly diagram showing a configuration of the piezoelectric actuator according to the first embodiment. Piezo actuators are
A substrate 8 provided with a support 7 extending parallel to the circular tangent direction of the rotary moving body 5 and fixed at one end and free at multiple ends, and a vibrator 4 formed of a piezoelectric body (not shown) provided on the support.
And a rotary moving body 5 having a pressing unit 6 for applying a pressure in the direction of the substrate provided with the vibrating body.

As the piezoelectric material, for example, barium titanate, lead titanate, lithium niobate, lithium tantalate or the like is used. Further, for example, a sine wave is used as the drive signal.

The rotary moving body 5 is inserted into the insertion frame 9 between the substrates stacked at regular intervals. Then, by applying an AC voltage to the piezoelectric body (not shown) in accordance with the natural vibration of the vibrating body 4, the vibrating body 4 generates bending, torsion, and expansion and contraction vibrations. An elliptical motion is generated on the surface of the body 4, and an appropriate pressure from the pressurizing unit 6 is applied to the vibrating body 4 and the rotary moving body 5.
The rotary moving body 5 moves.

Here, the piezoelectric body (not shown) is a vibration body 4
On the other hand, the movement of the rotary moving body 5 is not hindered by, for example, pasting it on the opposite surface to the insertion frame 9 into which the rotary moving body 5 is inserted.

As described above, the moving direction of the rotary moving body 5 is
Since it is determined by the arrangement of the vibrating body 4, a rotating shaft is not required. In other words, the elimination of the rotating shaft eliminates the need for a bonding step using a pressing member for suppressing the movement of the rotating moving body 5 in the out-of-plane direction, and reduces variation in dynamic characteristics of the piezoelectric actuator due to mass production. It is possible to Further, the piezoelectric actuator can be simplified, and furthermore, the thickness and size can be reduced. Further, the rotary moving body 5
Can be configured from desired external dimensions, and at the same time, by providing the insertion frame 9, the rotary moving body 5 can be freely taken in and out. As a new function, a conventional type such as a floppy disk or a CD can be used. It is considered that a simple recording medium can be used as a substitute for the rotary moving body 5.

FIG. 5 is a perspective view showing an example of the piezoelectric actuator according to the first embodiment having a plurality of vibrators.

FIG. 5A is a perspective view showing an example in which a single vibrating body 4 is used. Since it has a structure using a single vibrating body 4, it is possible to change the direction or rotate the moving body. FIG. 5B is a perspective view illustrating an example in which two vibrators 4 are used. Since the structure is such that two vibrators are arranged in the circumferential direction with respect to the moving body, not only can a stable rotating force be applied to the moving body, but also a higher output can be given to the moving body. .

FIG. 5C is a perspective view showing an example in which four vibrators 4 are used. The vibrator has a structure in which four vibrators are arranged in the circumferential direction with respect to the moving body.
It is possible to give a high output to a moving body as compared with a sheet. In addition, by changing the arrangement of the vibrating body 4 such that the stacked substrate having the single or plural vibrating bodies 4 can be rotated forward and reverse with respect to the surface of the moving body by reversing the surface of the moving body. It is also possible to change the moving direction of the moving body.

FIG. 6 is a perspective view showing an example in which a guide frame 10 for a moving body of the piezoelectric actuator is provided in the piezoelectric actuator according to the first embodiment.

FIG. 6A shows an example in which a hollow cylinder is vertically divided into two parts to form a guide frame 10 for guiding a moving body. The guide frame 10 is provided for both the singular and the plural vibrators 4.
It is desirable to provide at a position that is the center of rotation.

FIG. 6B is a perspective view showing an example in which the hollow prism is divided into two in the vertical direction to form a guide frame 10 for guiding the moving body. The guide frame 10 is desirably provided at a position that is the center of rotation in both the single and multiple vibrators 4. The vibrating body substrate provided with the guide frame 10 can be integrally formed by an electroforming technique or the like.

FIG. 7 is a perspective view showing an example in which the piezoelectric actuator according to the first embodiment and a gear train are combined. The piezoelectric actuator has a structure in which a substrate 8 provided with a vibrating body 4 to which a piezoelectric body (not shown) is attached is stacked, and an insertion frame (not shown) is provided between the substrates 8 so as to keep a constant interval. The first gear 11 is provided with a pressurizing section, and is configured to apply an appropriate pressure between the vibrating body 4 and the first gear 11. Thereby, the first gear 1
In 1, a frictional force acts on the vibrating body 4 and the surface of the first gear 11 by the elliptical motion of the surface of the vibrating body 4, and causes the first gear 11 to rotate. Thereby, the power of the first gear is changed to the second gear 1
The speed is transmitted to the motor 2 and the speed can be increased or decreased, the torque can be changed, and the rotation direction can be reversed.

FIG. 8 is a schematic diagram showing the operation of the gear train by the piezoelectric actuator according to the first embodiment.
The piezoelectric actuator has a structure in which a substrate 8 provided with a vibrating body 4 to which a piezoelectric body (not shown) is attached is stacked, and an insertion frame (not shown) is provided between the substrates 8 so as to keep a constant interval. A pressurizing unit (not shown) is provided on the first gear 11.
Is provided, and a suitable pressure is applied between the vibrating body 4 and the first gear 11. Thereby,
The first gear 11 exerts a frictional force on the vibrating body 4 and the surface of the first gear 11 due to the elliptical motion of the surface of the vibrating body 4, and the first gear 1
1 is rotated. Thereby, the power of the first gear is
The power is transmitted to the second gear 12, and the speed can be increased or reduced. The direction of rotation of the first gear is determined by the direction of the vibrating body 4.

As described above, the piezoelectric actuator according to the first embodiment has a structure for applying a pressure to the rotary moving body, and the moving direction of the rotary moving body is determined by the arrangement of the vibrating body. Does not require a rotating shaft. In addition, it is not necessary to perform a bonding step or the like using a pressing member, and it is possible to reduce variations in dynamic characteristics of the piezoelectric actuator due to mass production. Further, the piezoelectric actuator can be simplified, and furthermore, the thickness and size can be reduced. Furthermore, the rotary moving body can be configured from desired external dimensions, and at the same time, by providing an insertion frame, the rotary moving body can be freely taken in and out, and as a new function, a conventional floppy disk or It is considered that a recording medium such as a CD can be used as a substitute for the rotary moving body. Since such a recording medium is provided with a structure for providing pressurization, there is no need to provide a structure for providing pressurization on the drive device side. Therefore, it is not necessary to consider a failure due to the above, it is possible to extend the product life of the drive device, and it is possible to drive the recording medium stably. << Embodiment 2 >> Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to FIGS.

FIG. 9 shows a configuration diagram of a piezoelectric actuator according to the second embodiment. The piezoelectric actuator includes a support 7 having a vibrating body 4 to which a piezoelectric body 2 is attached, a structure 6 for applying pressurization, and a parallel moving body 14 having an information recording unit 15 for recording information, and a parallel moving body. Body 14
Frame 9 fixed to the upper surface of the insertion frame 9 and in contact with the structure 6 for applying pressurization, and an upper substrate fixed to the upper surface of the substrate 8 and further provided with the information reading unit 16 17, the support 7, the insertion frame 9, the substrate 8, and the upper substrate 17 are laminated.

The substrate 8 and the support 7 have a certain interval, and are dimensioned so that the parallel moving body 14 can be inserted. Further, the substrate 8 and the support 7 are suitable for the parallel moving body 14 to move. The pressure is dimensioned at such intervals from the structure 6 which provides the prestress. In order to read information from the information recording unit 15 provided in the parallel moving body 14, the parallel moving body 14 is inserted into the insertion frame 7, and the information reading unit 16 on the upper surface is read.
Read the information with. Then, when taking out the parallel moving body 14, by inputting a drive signal to the piezoelectric body 2,
The vibrating body 4 is bent, and a driving force is applied to the parallel moving body 14 in a direction opposite to the insertion direction, so that the parallel moving body 14 can be taken out.

FIG. 10 is a configuration diagram of a piezoelectric actuator according to the second embodiment. The piezoelectric actuator includes a take-out vibrator 18 to which a piezoelectric body (not shown) is attached,
A piezoelectric body (not shown) is attached, and the take-out vibrator 18 includes a support body 7 provided with a plurality of transverse-movement vibrators 19 extending in different directions, and a structure 6 for applying a pressurization. Further, a first parallel moving body 20 having a first information recording section 22 on which information is further recorded, and a structure 6 for applying a pressurizing force as in the case of the first parallel moving body 20 are provided, and further information is recorded. A second parallel moving body 21 having a second information recording section 23, an insertion frame 9 for inserting the first parallel moving body 20 and the second parallel moving body 21, and fixed to an upper surface of the insertion frame 9; A substrate 8 which is in contact with the structure 6 for applying pressurization, and an upper surface substrate 17 fixed to the upper surface of the substrate 8 and further provided with an information reading portion 16;
The support 7, the insertion frame 9, the substrate 8, and the upper substrate 17 are stacked.

The substrate 8 and the support 7 are spaced at a certain distance, and have such a size that the first parallel moving body 20 and the second parallel moving body 21 can be inserted. The body 6 is dimensioned at an appropriate pressure from the structure 6 providing the prestress for movement. In order to read information from the first information recording unit 22 provided on the first parallel moving body 20 or the second information recording unit 23 provided on the second parallel moving body 21, the first The parallel moving body 20 or the second parallel moving body 21 is inserted into the insertion frame 9, and the information is read by the information reading section 16 on the upper surface. When the first parallel moving body 20 or the second parallel moving body 21 is taken out, the taking-out vibrating body 18 is used.
By vibrating the first parallel moving body 20 or the second parallel moving body 20, a driving force is applied to the first parallel moving body 20 or the second parallel moving body 21 in a direction opposite to the inserted direction. The moving body 21 can be taken out.

Further, by providing the transverse moving vibrator 19 in a direction different from the insertion direction of the first parallel moving body 20 or the second parallel moving body 21, for example, Is inserted into the insertion frame 9, the first parallel moving body 20 is moved to a place different from immediately below the information reading unit 16, and further, the second parallel moving body 21 is inserted into the insertion frame 9, The information in the second information recording unit 23 of the two parallel moving bodies 21 can be read by the information reading unit 16.

If necessary, the second parallel moving body 2
1 is moved to the first parallel moving body 20 by the lateral moving vibrating body 19.
Then, the first parallel moving body 20 is moved to a position directly below the information reading unit 16 by using the lateral moving vibrating body 19, and the first parallel moving body 20 It is possible to read the information of the first information recording section 22 provided in the first information recording section.

That is, by providing a plurality of the laterally-moving vibrators 19 on the support body 7, application to an autochanger system or the like becomes possible. In addition, by providing the pressing member on the first parallel moving body 20 or the second parallel moving body 21, the structure on the drive device side including the information reading unit 16 can be simplified, and the manufacturing can be simplified. Thus, the size of the driving device can be reduced.

As described above, the piezoelectric actuator according to the second embodiment can simplify the piezoelectric actuator having the vibrating body by providing the structure for applying a pressure to the parallel moving body. In addition, the number of components and the number of assembling steps can be reduced, so that it is easy to shift to mass production and cost can be reduced. In addition, by using a plurality of vibrators, the parallel moving body can be moved to an arbitrary position, and the driving force of the parallel moving body can be increased.

[0040]

As described above, according to the present invention, the piezoelectric actuator extends parallel to the circular tangential direction of the rotary moving body and is fixed at one end and free at the multi-end, and the piezoelectric body provided on the support is provided. A substrate provided with a vibrating body comprising: a structure in which the substrates are stacked at a constant interval; and a rotary moving body provided with a pressurizing unit for applying a pressure in the direction of the substrate provided with the vibrating body. , As a new realizable function,
With the conventional rotary actuator, easy operation of the rotation characteristics of the rotary moving body by the pattern of the vibrator, which was difficult,
There is an effect that a desired rotational moving body shape can be selected for one actuator structure, and that it is possible to put in and out of a stacked substrate provided with a vibrating body.

As described above, according to the present invention, the piezoelectric actuator can be used as a drive source for a second hand or a minute hand of a timepiece, or applied to a disk exchangeable information storage device by combining with a gear train. it can.

Further, simplification of the shape of the constituent members, reduction of the number of constituent members and the number of assembling steps are achieved, and it is easy to shift to mass production.
Costs can be reduced.

Further, according to the present invention, the piezoelectric actuator comprises a support which extends parallel to the circular tangential direction of the rotary moving body, is fixed at one end and is free at the multi-end, and a piezoelectric member provided on the support. Since a plurality of bodies are used, the output of the piezoelectric actuator can be increased.

Further, according to the present invention, the piezoelectric actuator includes a support extending in parallel with the moving direction of the parallel moving body and fixed at one end and free at the other end, and a vibrator formed of the piezoelectric body provided on the support. And a parallel moving body having a structure in which the substrates are stacked at regular intervals and a structure for applying a pressure in the direction of the substrate provided with the vibrating body.

According to this, by providing a structure for applying a pressure to the parallel moving body, it is possible to simplify the piezoelectric actuator having the vibrating body. In addition, the number of components and the number of assembling steps can be reduced, so that it is easy to shift to mass production and cost can be reduced.

Further, according to the present invention, the piezoelectric actuator is provided with a support extending in parallel to the moving direction of the parallel moving body and fixed at one end and free at the other end, and a plurality of vibrators formed of the piezoelectric provided on the support. , A structure in which the substrates are stacked at regular intervals, and a parallel moving body having a structure for applying a pressure in the direction of the substrate provided with the vibrator.

According to this, by using a plurality of vibrators, the parallel moving body can be moved to an arbitrary position and the driving force of the parallel moving body can be increased.

[Brief description of the drawings]

FIG. 1 is an assembly diagram showing a configuration of a piezoelectric actuator according to Embodiment 1 of the present invention.

FIG. 2 is an assembly view showing a configuration of a conventional micro piezoelectric motor.

FIG. 3 is an explanatory diagram showing the operation principle of a conventional micro piezoelectric motor.

FIG. 4 is a block diagram showing a configuration of a conventional piezoelectric actuator.

FIG. 5 is a perspective view showing an example of the piezoelectric actuator according to Embodiment 1 of the present invention including a plurality of vibrators.

FIG. 6 is a perspective view showing an example of a guide frame of a moving body of the piezoelectric actuator according to the first embodiment of the present invention.

FIG. 7 is a perspective view showing an example in which the piezoelectric actuator and the gear train according to Embodiment 1 of the present invention are combined.

FIG. 8 is a schematic diagram showing an operation of the gear train by the piezoelectric actuator according to the first embodiment of the present invention.

FIG. 9 is a configuration diagram showing a piezoelectric actuator according to Embodiment 2 of the present invention.

FIG. 10 is a configuration diagram showing a piezoelectric actuator according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bending displacement mechanism part 2 Piezoelectric body 4 Vibrating body 5 Rotating moving body 6 Structure providing pressure application 7 Supporting body 8 Substrate 9 Insertion frame 10 Guide frame 11 First gear 12 Second gear 13 Base chassis 14 Parallel moving body 15 Information Recording section 16 Information reading section 17 Upper substrate 18 Vibrating body for taking out 19 Vibrating body for horizontal movement 20 First parallel moving body 21 Second parallel moving body 22 First information recording section 23 Second information recording section

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuo Tani 1-8-8 Nakase, Mihama-ku, Chiba-shi, Chiba Prefecture Inside SII RRD Center Co., Ltd. (72) Yoko Suzuki 1 Nakase, Mihama-ku, Chiba-shi, Chiba 8th Street Inside SII R.D. Center

Claims (4)

[Claims] A substrate extending in parallel to a circular tangent direction of the rotating body and having a fixed end and a free end, and a vibrating body made of a piezoelectric member provided on the support; And a rotary moving body having a structure for applying pressure in the direction of the substrate on which the vibrating body is provided. 2. A substrate provided with a support extending in parallel to a circular tangent direction of the rotary moving body and fixed at one end and free at the other end, and a plurality of vibrators made of a piezoelectric body provided on the support, A piezoelectric actuator, comprising: a structure in which substrates are stacked at regular intervals; and a rotary moving body having a structure for applying a pressure in the direction of the substrate on which the vibrating body is provided. 3. A substrate provided with a support extending in parallel with the moving direction of the parallel moving body and fixed at one end and free at the other end, and a substrate provided with a vibrator made of a piezoelectric member provided on the support, A piezoelectric actuator, comprising: a structure laminated at intervals; and a parallel moving body having a structure for applying a pressure in the direction of the substrate on which the vibrating body is provided. 4. A substrate provided with a support extending in parallel with the moving direction of the parallel moving body and fixed at one end and free at the other end, and a substrate having a plurality of vibrators made of a piezoelectric material provided on the support, And a parallel moving body having a structure for applying a pressure in the direction of the substrate on which the vibrating body is provided.