JP2012070572A - Piezoelectric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric motor selectively enabling direct-acting drive and rotating drive by a simple configuration.SOLUTION: A piezoelectric motor driving a shaft 11 by using vibration of a vibrator 13 which is a piezoelectric element having an approximately rectangular parallelepiped shape comprises: the vibrator 13 in which an extending/contracting direction thereof is a long side direction of a rectangular face opposing to the shaft 11 and at least two piezoelectric active regions are arranged in parallel in a short side direction of the rectangular face; a holding part 15 holding one end in the longitudinal direction of the vibrator 13 and fixing a relative position of the one end with respect to the shaft 11; a friction contact member 19 arranged at the other end in the longitudinal direction of the vibrator 13 and brought into contact with the shaft 11; and a pressing member 17 pressing the vibrator 13 so that the friction contact member 19 is brought into pressure contact with the shaft 11.

Description

  The present invention relates to a piezoelectric motor that uses vibration of a vibrator such as a piezoelectric element.

  Patent Document 1 discloses an ultrasonic motor that is a kind of piezoelectric motor. The ultrasonic motor disclosed in Patent Document 1 is an ultrasonic motor that uses a helical coil as a stator and rotates a rotor in a spiral direction. The basic configuration and operating principle of this ultrasonic motor are as follows.

  When a cylinder is arranged for a string vibrating with a transverse wave, the cylinder rotates at the antinode of the vibration of the string. When the string rotates at both ends like a jump rope, the cylinder rotates more. However, when only one string is used, the rotation direction of the cylinder is unstable. Therefore, in the ultrasonic motor disclosed in the cited document 1, the rotor is rotated in the propagation direction of the ultrasonic wave at the time of activation, that is, in the spiral direction, by using a thin wire or a thin plate coiled as a string.

International Publication No. 2007/126031

  Incidentally, the driving of the ultrasonic motor disclosed in the cited document 1 is limited to the rotational driving as is apparent from the above-described operation principle. Therefore, when driving such as a combination of linear motion and rotational motion is required, a separate linear motion mechanism is required, and the entire system becomes large and complicated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a piezoelectric motor capable of selectively performing linear motion driving and rotational driving with a simple configuration.

In order to achieve the above object, a piezoelectric motor according to an aspect of the present invention includes:
A piezoelectric motor that drives a driven body using vibration of a vibrator that is a substantially rectangular parallelepiped piezoelectric element,
A vibrator comprising at least two piezoelectric active regions arranged in parallel in the short side direction of the rectangular surface, wherein the long side direction of the rectangular surface facing the driven body is an expansion / contraction direction;
Holding one end in the longitudinal direction of the vibrator, and a holding part for fixing the relative position between the one end and the driven body;
A friction contact member provided at the other end in the longitudinal direction of the vibrator, and in contact with the driven body;
A pressing member that presses the vibrator so that the friction contact member is in pressure contact with the driven body;
It is characterized by comprising.

  According to the present invention, it is possible to provide a piezoelectric motor capable of selectively performing direct drive and rotational drive with a simple configuration.

The figure which shows the example of 1 structure of the piezoelectric motor which concerns on 1st Embodiment of this invention. FIG. 6 is a diagram illustrating a configuration example of a vibrator. FIG. 6 is a diagram illustrating a configuration example of a vibrator. FIG. 6 is a diagram illustrating a configuration example of a vibrator. FIG. 6 is a diagram illustrating a configuration example of a vibrator. FIG. 6 is a diagram illustrating a configuration example of a vibrator. The figure which shows operation | movement of the vibrator | oscillator in the case of rotationally driving a shaft. The figure which shows an example of the drive signal applied to the piezoelectric active area | region of a vibrator | oscillator when rotating a shaft. The figure which shows operation | movement of the vibrator | oscillator in the case of driving a shaft linearly. The figure which shows an example of the drive signal applied to the piezoelectric active area | region of a vibrator | oscillator, when driving a shaft linearly. The figure which shows the example of 1 structure of the piezoelectric motor which concerns on 2nd Embodiment of this invention. The figure which shows the example of 1 structure of the piezoelectric motor which concerns on 3rd Embodiment of this invention. The figure which shows the example of 1 structure of the piezoelectric motor which concerns on 4th Embodiment of this invention.

Hereinafter, an ultrasonic motor according to an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
FIG. 1 is a diagram illustrating a configuration example of a piezoelectric motor according to a first embodiment of the present invention.
As shown in FIG. 1, the piezoelectric motor according to the first embodiment includes a shaft 11, a vibrator 13, a holding member 15, a pressing member 17, a friction contact member 19, a case 21, and a drive unit 100. Are provided.

  The shaft 11 is a cylindrical driven body that is driven by the vibrator 13 via the frictional contact member 19 and moves linearly and rotationally. The shaft 11 is a driven body made of a material having excellent wear resistance, and is made of, for example, a ceramic material such as alumina or zirconia, or a metal material subjected to surface treatment by quenching or plating. Further, the shaft 11 is held in the case 21 by the guide mechanism 11g so as to be movable in the direction indicated by the arrow S (linear motion direction) and the direction indicated by the arrow R (rotation direction) in FIG.

The guide mechanism 11g is a guide mechanism that includes a steel ball and a retainer that is made of a material (for example, a resin material) that has a sliding property at least in contact with the shaft 11.
The guide mechanism 11g may have any configuration as long as the shaft 11 can be slidably supported in the case 21.

  The vibrator 13 is tangent to the cross section of the shaft 11 (tangent to the contact point between the frictional contact member 19 and the shaft 11 when viewed from the direction indicated by arrow A in FIG. 1; hereinafter simply referred to as the tangent to the shaft cross section). The piezoelectric element has a piezoelectric active region divided into two. The vibrator 13 has a longitudinal direction in the linear movement direction of the shaft 11.

In other words, the substantially rectangular parallelepiped-shaped vibrator 13 has two long-side directions of the rectangular surface facing the shaft 11 being the expansion / contraction direction, and two parallel-arranged in the short-side direction of the rectangular surface facing the shaft 11. A piezoelectric active region is provided.
The vibrator 13 may be a vibrator having a structure having a piezoelectric active region at least divided into two in the tangential direction of the shaft cross section as described above. Specifically, for example, a vibrator having the following configuration is used. If it is.

2 to 6 are diagrams showing an example of the configuration of the vibrator 13. 2 to 5, the arrow L indicates the tangential direction of the shaft cross section. 2 to 5 indicate the polarization direction of each piezoelectric active region of the vibrator 13.
In the vibrator 13 shown in FIG. 2, two single-plate piezoelectric elements 13A and 13B having the same shape are arranged in parallel in the same direction as the tangential direction L of the shaft cross section and integrated by bonding or the like. The piezoelectric element is polarized in a direction perpendicular to the longitudinal direction (longitudinal direction of the vibrator 13). The vibrator 13 of this example is a piezoelectric element that utilizes a so-called “longitudinal effect”. The vibrator 13 shown in FIG. 1 is a vibrator having the form shown in FIG.

  The vibrator 13 shown in FIG. 3 includes two laminated piezoelectric elements having the same shape (the lamination direction of the piezoelectric sheet is a direction perpendicular to the tangential direction L of the shaft section (longitudinal direction of the vibrator 13)) 13A ′ and 13B ′. A direction (vibration) perpendicular to the tangential direction L of the shaft cross section, which is arranged in parallel in the same direction as the tangential direction L of the shaft cross section and integrated by bonding or the like (of course, the piezoelectric sheet may be integrally fired). The piezoelectric element is polarized in the longitudinal direction of the child 13. The vibrator 13 of this example is a piezoelectric element that utilizes a so-called “longitudinal effect”. As in this example, the vibrator 13 has a laminated structure, so that low voltage driving is possible.

  The vibrator 13 shown in FIG. 4 has two identical single-plate piezoelectric elements 13A and 13B arranged in parallel in the same direction as the tangential direction L of the shaft cross section and integrated by bonding or the like. The piezoelectric element is polarized in the same direction. The vibrator 13 of this example is a piezoelectric element that utilizes a so-called “lateral effect”.

  The vibrator 13 shown in FIG. 5 has two laminated piezoelectric elements having the same shape (the lamination direction of the piezoelectric sheet is the same as the tangential direction L of the shaft cross section) 13A ″, 13B ″ is the same as the tangential direction L of the shaft cross section. It is a piezoelectric element that is arranged in parallel in the direction and integrated by bonding or the like (of course, a piezoelectric sheet may be integrally fired) and is polarized in the same direction as the tangential direction L of the shaft cross section. The vibrator 13 of this example is a piezoelectric element that utilizes a so-called “lateral effect”. As in this example, the vibrator 13 has a laminated structure, so that low voltage driving is possible.

  As shown in FIG. 6, the vibrator 13 may have a configuration in which an elastic body 13E is sandwiched between the piezoelectric element 13A and the piezoelectric element 13B. As this elastic body 13E, a metal plate etc. can be mentioned, for example. When configured in this manner, the elastic body 13E can be used for holding the vibrator 13, so that the holding structure can be further simplified.

The holding member 15 holds one end portion in the longitudinal direction of the vibrator 13 by bonding or the like, and fixes the relative position between the one end portion and the shaft 11.
The pressing member 17 is a member that presses the vibrator 13 toward the shaft 11 in order to press-contact the friction contact member 19 provided on the vibrator 13 against the shaft 11. Examples thereof include an elastic member such as a coil spring and silicon rubber.

  The friction contact member 19 is provided on the surface facing the shaft 11 in the other end portion (the end portion not held by the holding member 15) in the longitudinal direction of the vibrator 13, and the vibrator 13 by the pressing member 17. It is a driver which press-contacts with respect to the shaft 11 by press of. Examples of the material of the friction contact member 19 include a wear-resistant resin material and a ceramic material such as alumina.

The case 21 is a case that accommodates the above-described members constituting the piezoelectric motor 1.
The driving unit 100 is a driving signal output unit for applying a driving signal to the vibrator 13.
Hereinafter, the operation of the piezoelectric motor according to the first embodiment will be described.
《Rotation operation》
FIG. 7 is a diagram illustrating an operation example of the vibrator 13 when the shaft 11 is rotationally driven. FIG. 8 is a diagram illustrating an example of a drive signal applied to the piezoelectric active region of the vibrator 13 when the shaft 11 is rotationally driven. In FIG. 8, the horizontal axis of the graph shown at the top indicates time, and the vertical axis indicates the voltage value of the drive signal applied to the piezoelectric element 13A. The horizontal axis of the middle graph indicates time and the vertical axis. The axis indicates the voltage value of the drive signal applied to the piezoelectric element 13B, the horizontal axis of the lower graph indicates time, and the vertical axis indicates the amount of movement of the shaft 11.

By applying a voltage signal to the external electrodes (not shown) provided at both ends in the polarization direction of each piezoelectric active region in the vibrator 13 as follows, the vibrator 13 can be flexibly vibrated.
In other words, in order to rotate the shaft 11, an external electrode (not shown) provided in each piezoelectric active region in the vibrator 13 is used, and one piezoelectric active region (piezoelectric element 13A in the example shown in FIG. 7) is used. ) Is applied in the forward direction (in the same direction as the polarization direction) with respect to the polarization direction (drive signal (1) shown in FIG. 8), and the other piezoelectric active region (in the example shown in FIG. 7). For the piezoelectric element 13B), a voltage signal is applied in the direction opposite to the polarization direction (drive signal (2) shown in FIG. 8).

  At this time, the piezoelectric active region (piezoelectric element 13A) to which a voltage signal is applied in the forward direction (in the same direction as the polarization direction) with respect to the polarization direction is expanded and deformed in the direction indicated by the arrow G in FIG. The piezoelectric active region (piezoelectric element 13B) to which a voltage signal is applied in the opposite direction (opposite to the polarization direction) is contracted and deformed in the direction indicated by arrow S in FIG.

  Due to the deformation asymmetry of the vibrator 13 as described above, the vibrator 13 is deformed into a bent shape toward the piezoelectric active region side contracted and deformed (in the direction indicated by the arrow T in FIG. 7) as shown in FIG. Mu). When the voltage application is stopped, the vibrator 13 returns to the original shape (the shape indicated by the broken line in FIG. 7). In the piezoelectric motor according to the first embodiment, a drive signal (voltage signal) having a sawtooth waveform in which the fall of each drive signal is steeply set as shown in FIG. 8 is applied to each piezoelectric active region (piezoelectric elements 13A and 13B). Apply to.

  In other words, the drive signal gradually increases the applied voltage at the rise for deforming the vibrator 13, and the drive signal is zero at high speed at the fall. By applying such a drive signal to each piezoelectric active region via the external electrode, a force in the same direction as the shaft rotation direction R is generated by the frictional force between the friction contact member 19 and the shaft 11 at the time of rising. It is driven in addition to the shaft 11. On the other hand, at the fall, slip occurs between the frictional contact member 19 and the shaft 11, and the shaft 11 remains in place due to inertial force. Then, by repeatedly performing such signal input, the shaft 11 rotates in one rotation direction.

When the shaft 11 is rotated in the direction opposite to the rotation direction in the above example, the drive signal applied to the piezoelectric element 13A and the drive signal applied to the piezoelectric element 13B may be reversed. That is, the piezoelectric element 13A may be contracted and the piezoelectric element B may be expanded and deformed.
<Linear operation>
FIG. 9 is a diagram illustrating the operation of the vibrator 13 when the shaft 11 is linearly driven. FIG. 10 is a diagram illustrating an example of a drive signal applied to the piezoelectric active region of the vibrator 13 when the shaft 11 is linearly driven. In FIG. 10, the horizontal axis of the graph shown at the top indicates time and the vertical axis indicates the voltage value of the drive signal applied to the piezoelectric element 13A. The horizontal axis of the graph shown at the middle indicates time and the vertical axis. The axis indicates the voltage value of the drive signal applied to the piezoelectric element 13B, the horizontal axis of the lower graph indicates time, and the vertical axis indicates the amount of movement of the shaft 11.

By applying a voltage signal to external electrodes (not shown) provided at both ends of the piezoelectric active region in the polarization direction of the vibrator 13 as follows, the vibrator 13 can be expanded and contracted.
That is, in order to cause the shaft 11 to move linearly, all the piezoelectric active regions (in the example shown in FIG. 9, the piezoelectric element 13A) are utilized by using external electrodes (not shown) provided in the piezoelectric active region of the vibrator 13. , 13B), the same voltage signal is applied in the forward direction (in the same direction as the polarization direction) with respect to the polarization direction (drive signal (1) and drive signal (2) shown in FIG. 10).

At this time, the piezoelectric active regions (piezoelectric elements 13A and 13B) to which a voltage signal is applied in the forward direction (in the same direction as the polarization direction) with respect to the polarization direction extend in the polarization direction (in the direction indicated by arrow G in FIG. 9). Deform.
As described above, the vibrator 13 expands and deforms as shown in FIG. 9, and then when the voltage application is stopped, the vibrator 13 returns to the original shape (the shape indicated by the broken line in FIG. 9). In the piezoelectric motor according to the first embodiment, a sawtooth waveform in which the rising speed and the falling speed of each drive signal are set as shown in FIG. 10 is applied to each piezoelectric active region (piezoelectric elements 13A and 13B).

  In other words, the drive signal gradually increases the applied voltage at the rise for deforming the vibrator 13, and the drive signal is zero at high speed at the fall. By applying such a driving signal to each piezoelectric active region via the external electrode, a force in the same direction as the straight shaft traveling direction S is generated by the frictional force between the frictional contact member 19 and the shaft 11 at the time of rising. It is driven in addition to the shaft 11. On the other hand, at the fall, slip occurs between the frictional contact member 19 and the shaft 11, and the shaft 11 remains in place due to inertial force. By repeatedly performing such signal input, the frictional contact member 19 exerts a force in the axial direction (longitudinal direction) on the shaft 11 and advances straight in the length direction.

When the shaft 11 is moved backward, the same voltage signal may be applied to all the piezoelectric active regions (piezoelectric elements 13A and 13B in the example shown in FIG. 9) in the direction opposite to the polarization direction. That is, all the piezoelectric active regions (piezoelectric elements 13A and 13B) may be similarly contracted and deformed.
《Helix motion》
The shaft 11 can be spirally operated by changing the drive signal for the linear motion described above as follows.

  That is, the same voltage signal is applied in the forward direction (in the same direction as the polarization direction) with respect to the polarization direction in all piezoelectric active regions in the same manner as the voltage application method for the linear motion operation. A difference is provided in the voltage value of the drive signal applied to the two piezoelectric active regions. As a result, the vibrator 13 undergoes deformation of deformation and warpage at the same time, and the vibrator 13 is deformed so as to extend in an oblique direction. At this time, due to the frictional force between the friction contact member 19 and the shaft 11, a force in the same direction as the deformation direction of the vibrator 13 acts on the shaft 11.

Accordingly, the shaft 11 is driven in a spiral motion as the screw advances by repeatedly performing the above-described operation with a sawtooth drive signal as in the linear motion operation.
As described above, according to the first embodiment, it is possible to provide a piezoelectric motor that can be selectively driven in the linear motion direction and the rotational direction with a simple configuration.

  Specifically, in the piezoelectric motor according to the first embodiment, the vibrator 13 that is a piezoelectric element having a plurality of piezoelectric active regions and having one end fixed in the longitudinal direction is connected to the shaft 11 that is a driven body. Placed along the axial direction and press-contacted via a frictional contact member, applying a sawtooth waveform voltage signal with a difference between the rising and falling speeds (for example, the output of the drive signal is turned off at the falling edge) ). As a result, the shaft 11 is driven by the frictional force with the frictional contact member 19 in the rising region where the increase or decrease of the input is moderate. On the other hand, in a falling region where the increase / decrease of the input is steep, the shaft 11 stays in place due to inertial force (not frictionally driven). Specifically, the shaft 11 can be linearly driven by expanding and contracting the vibrator 13. Further, the shaft 11 can be rotationally driven by bending (warping) the vibrator 13.

The sawtooth waveform voltage signal having a difference between the rising speed and the falling speed may be a voltage signal that makes the rising edge steep and changes the falling edge gently. When driven by such a voltage signal, the shaft 11 is driven by a frictional force with the frictional contact member 19 in the falling region, and the shaft 11 stays in place by the inertial force in the rising region (not frictionally driven). ).
With the configuration described above, according to the piezoelectric motor according to the first embodiment, the shaft 11 as the driven body can be rotated, moved straight, and spiraled at one point of action by one piezoelectric motor. Therefore, a motor that can be driven in a small space with multiple degrees of freedom is realized.

In addition, the piezoelectric motor according to the first embodiment is configured by using a highly versatile and reliable part called “a piezoelectric element having a bimorph structure”. The manufacturability and reliability of piezoelectric motors are also high.
[Second Embodiment]
Hereinafter, a piezoelectric motor according to a second embodiment of the present invention will be described. In order to avoid duplication of explanation, differences from the piezoelectric motor according to the first embodiment will be described. One of the main differences is that the piezoelectric motor according to the second embodiment includes a plurality of piezoelectric elements as drive sources.

FIG. 11 is a diagram illustrating a configuration example of the piezoelectric motor according to the second embodiment. In the figure, in order to avoid complication of the drawing, the illustration of a drive unit that applies a drive signal to the vibrator is omitted.
As shown in the figure, the piezoelectric motor according to the second embodiment has a vibrator 13-1 and a vibrator 13-2 each having one end in the longitudinal direction held by a holding member 15-1, The vibrator 13-3 and the vibrator 13-4 each having one end in the longitudinal direction held by the holding member 15-2 are provided.

  The vibrator 13-1 and the 13-2 are arranged symmetrically with respect to the holding member 15-1. Similarly, the vibrator 13-3 and the 13-4 are arranged symmetrically with respect to the holding member 15-2. Further, the holding member 15-1 and the holding member 15-2 are arranged symmetrically with respect to the shaft 11.

  Of the end portions (end portions not held by the holding members 15-1 and 15-2) in the longitudinal direction of the vibrators 13-1, 13-2, 13-3, and 13-4, the surface facing the shaft 11 Are provided with frictional contact members 19-1, 19-2, 19-3, 19-4.

  Further, in order to make the frictional contact members 19-1, 19-2, 19-3, 19-4 come into pressure contact with the shaft 11, the vibrators 13-1, 13-2, 13-3, 13-4. Pressing members 17-1, 17-2, 17-3, and 17-4 that press the shaft toward the shaft 11 are provided.

The driving principle is the same as that of the piezoelectric motor according to the first embodiment described above.
As described above, according to the second embodiment, in addition to the same effects as the piezoelectric motor according to the first embodiment, a piezoelectric motor having the following effects can be provided. That is, according to the piezoelectric motor according to the second embodiment, it is possible to provide a piezoelectric motor having a larger thrust / torque than the piezoelectric motor according to the first embodiment and improved holding force when no current is supplied.

The number of vibrators provided in the piezoelectric motor is not limited to four, and may be determined as appropriate according to the thrust / torque required for the piezoelectric motor, the diameter / length of the shaft 11, and the like.
[Third Embodiment]
Hereinafter, a piezoelectric motor according to a third embodiment of the present invention will be described. In order to avoid duplication of explanation, differences from the piezoelectric motor according to the first embodiment will be described. One of the main differences is that in the piezoelectric motor according to the third embodiment, the driven body is a cylindrical hollow shaft.

FIG. 12 is a diagram illustrating a configuration example of the piezoelectric motor according to the third embodiment. In the figure, in order to avoid complication of the drawing, the illustration of a drive unit that applies a drive signal to the vibrator is omitted.
As shown in the figure, the piezoelectric motor according to the third embodiment includes vibrators 13-1, 13-2, holding members 15-1, 15-2, a pressing member 17, and a friction contact member 19-. 1, 19-2, a case 21, a pipe-shaped member 31, and a positioning member 41.

  The pipe-shaped member 31 is a cylindrical driven body inserted into the case 21, and the vibrator 13- is interposed via frictional contact members 19-1 and 19-2 that are in contact with the inner peripheral surface thereof. 1 and 13-2. Further, at the time of driving, it is the inner peripheral surface of the case 21 that functions as a guide mechanism for the pipe-shaped member 31 that is a driven body.

  One end of the vibrator 13-1 in the longitudinal direction is held by a holding member 15-1, and the relative position between the one end and the case 21 is fixed. In addition, a friction contact member 19-1 is provided on a surface facing the inner peripheral surface (inner wall surface) of the pipe-shaped member 31 in the other end portion in the longitudinal direction of the vibrator 13-1.

  Similarly, one end of the vibrator 13-2 in the longitudinal direction is held by the holding member 15-2, and the relative position between the one end and the case 21 is fixed. In addition, a friction contact member 19-2 is provided on a surface facing the inner peripheral surface (inner wall surface) of the pipe-shaped member 31 in the other end portion in the longitudinal direction of the vibrator 13-2.

The pressing member 17 presses the vibrators 13-1 and 13-2 toward the inner peripheral surface of the pipe-shaped member 31, and the friction contact members 19-1 and 19-2 are applied to the inner peripheral surface of the pipe-shaped member 31. The pressure contact is made.
The positioning member 41 is a member for positioning the vibrators 13-1 and 13-2 by pressing and holding the holding members 15-1 and 15-2 against the inner peripheral surface of the pipe-shaped member 31. is there.

By comprising as mentioned above, the hollow part of a pipe-shaped member can be utilized, and wiring, a thin catheter for drug solution transportation, etc. can be passed inside.
The driving principle is the same as that of the piezoelectric motor according to the first embodiment described above.
As described above, according to the third embodiment, in addition to the same effects as the piezoelectric motor according to the first embodiment, a piezoelectric motor having the following effects can be provided. That is, according to the piezoelectric motor according to the third embodiment, since there is no projecting portion to the outside of the piezoelectric motor, a smaller diameter motor is realized. The piezoelectric motor according to the third embodiment is particularly expected to be applied to, for example, an ultrasonic endoscope, an ultrasonic microscope, and thrombus removal.
[Fourth Embodiment]
Hereinafter, a piezoelectric motor according to a fourth embodiment of the present invention will be described. In order to avoid duplication of explanation, differences from the piezoelectric motor according to the first embodiment will be described. One of the main differences is the shape and driving direction of the driven body. Specifically, in the piezoelectric motor according to the fourth embodiment, the driven body is a plate-like member and can be driven in a biaxial direction perpendicular to each other by a single piezoelectric motor.

FIG. 13 is a diagram illustrating a configuration example of the piezoelectric motor according to the fourth embodiment. In the figure, in order to avoid complication of the drawing, the illustration of a drive unit that applies a drive signal to the vibrator is omitted.
As shown in FIG. 13, the piezoelectric motor according to the fourth embodiment includes a vibrator 13, a holding member 15, a pressing member 17, a friction contact member 19, an XY stage 50, a base 51, and a stopper 53. And a guide mechanism 55.

  One end of the vibrator 13 in the longitudinal direction is held by a holding member 15. Further, a friction contact member 19 is provided on a surface of the other end portion of the vibrator 13 in the longitudinal direction facing the XY stage 50. Further, the vibrator 13 is pressed toward the XY stage 50 by a pressing member 17 provided on the holding member 15. As a result, the frictional contact member 19 comes into pressure contact with the XY stage 50 that is the driven body.

The base 51 is a plate-like member on which the XY stage 50 is placed. Stoppers 53 for preventing the XY stage 50 from falling off are provided at the four corners of the base 51. The holding member 15 is fixed on the base 51.
The guide mechanism 55 is a guide mechanism composed of a linear guide combined so that the XY stage 50 can be moved in two directions (a direction indicated by an arrow X and a direction indicated by an arrow Y in FIG. 13).

  When the drive signal similar to the “rotation operation” in the piezoelectric motor according to the first embodiment is applied to the vibrator 13 with the above-described configuration, the XY stage 50 as the driven body is driven straight in the X direction. . On the other hand, when a drive signal similar to the “linear motion” in the piezoelectric motor according to the first embodiment is given to the vibrator 13, the XY stage 50 that is a driven body is linearly driven in the Y direction.

  As described above, according to the fourth embodiment, a single piezoelectric motor can be driven in two axial directions (X-axis direction and Y-axis direction) orthogonal to each other, and the drive member occupies it. An XY stage with a small volume is realized. In the prior art, in order to drive in two axes orthogonal to each other, a drive motor in the X-axis direction and a drive motor in the Y-axis direction are required, and the volume occupied by the drive member is somewhat large. However, with the piezoelectric motor according to the fourth embodiment, an XY stage with a small volume occupied by the drive member is realized.

As mentioned above, although this invention was demonstrated based on 1st Embodiment thru | or 4th Embodiment, this invention is not limited to each embodiment mentioned above, In the range of the summary of this invention, various deformation | transformation and Of course, application is possible.
For example, in the piezoelectric motor according to the first to third embodiments, the friction contact member 19 may be configured in such a shape that the friction contact member 19 and the shaft 11 are in line contact. With this configuration, when the shaft 11 is rotated, the friction between the friction contact member 19 and the shaft 11 when the vibrator 13 returns to the “straight state from the bent state” is further reduced. Can do.

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention can be achieved. In the case of being obtained, a configuration from which this configuration requirement is deleted can also be extracted as an invention.

    DESCRIPTION OF SYMBOLS 1 ... Piezoelectric motor, 11 ... Shaft, 11g ... Guide mechanism, 13 ... Vibrator, 13A, 13B ... Single plate piezoelectric element, 13A ', 13B' ... Laminated piezoelectric element, 13E ... Elastic body, 15 ... Holding member, 17 ... Press member, 19 ... friction contact member, 21 ... case, 31 ... pipe-like member, 41 ... positioning member, 50 ... XY stage, 51 ... base, 53 ... stopper, 55 ... guide mechanism.

Claims (9)

A piezoelectric motor that drives a driven body using vibration of a vibrator that is a substantially rectangular parallelepiped piezoelectric element,
A vibrator comprising at least two piezoelectric active regions arranged in parallel in the short side direction of the rectangular surface, wherein the long side direction of the rectangular surface facing the driven body is an expansion / contraction direction;
Holding one end in the longitudinal direction of the vibrator, and a holding part for fixing the relative position between the one end and the driven body;
A friction contact member provided at the other end in the longitudinal direction of the vibrator, and in contact with the driven body;
A pressing member that presses the vibrator so that the friction contact member is in pressure contact with the driven body;
A piezoelectric motor comprising: The driven body is a cylindrical member,
The friction contact member is in contact with the outer peripheral surface of the driven body;
The piezoelectric motor according to claim 1, further comprising a guide member that guides the driven body so as to be movable in a rotation direction and a rotation axis direction. The driven body is a cylindrical member,
The friction contact member is in contact with the inner peripheral surface of the driven body;
The piezoelectric motor according to claim 1, further comprising a guide member that guides the driven body so as to be movable in a rotation direction and a rotation axis direction. The piezoelectric motor according to claim 1, wherein the driven body is a plate-like member. The number of piezoelectric active regions is two;
One piezoelectric active region includes a driving unit that applies a voltage signal in a forward direction with respect to the polarization direction, and the other piezoelectric active region includes a voltage signal that is applied in a direction opposite to the polarization direction,
The piezoelectric motor according to any one of claims 1 to 4, wherein the voltage signal is a voltage signal having a sawtooth waveform whose falling is steeper than rising. The number of piezoelectric active regions is two;
One piezoelectric active region includes a driving unit that applies a voltage signal in a forward direction with respect to the polarization direction, and the other piezoelectric active region includes a voltage signal that is applied in a direction opposite to the polarization direction,
5. The piezoelectric motor according to claim 1, wherein the voltage signal is a voltage signal having a sawtooth waveform whose rising edge is steeper than falling. The number of piezoelectric active regions is two;
The two piezoelectric active regions each include a drive unit that applies a voltage signal in the same direction with respect to the polarization direction,
The piezoelectric motor according to any one of claims 1 to 4, wherein the voltage signal is a voltage signal having a sawtooth waveform whose falling is steeper than rising. The number of piezoelectric active regions is two;
The two piezoelectric active regions each include a drive unit that applies a voltage signal in the same direction with respect to the polarization direction,
5. The piezoelectric motor according to claim 1, wherein the voltage signal is a voltage signal having a sawtooth waveform whose rising edge is steeper than falling. The piezoelectric motor according to claim 1, wherein the contact between the friction contact member and the driven body is a line contact.

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