JPH1080164A - Rotary type driving equipment using electro-mechanical transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary type driving equipment in which the number of components is small, assembling is easy, and an electro-mechanical transducer is used. SOLUTION: This rotary type driving equipment consists of the following, a rotary shaft 11 which is rotatably retained by a frame 1, a cylindrical rotary operator 12 which is coaxially fixed to the rotary shaft 11, and piezoelectric element vibrating parts 15A, 15B arranged at positions, which are laterally symmetric interposing the cylindrical rotary operator 12, on a plane isolated in the radius direction from the center of rotation (i.e., axial center of the rotary shaft 11) of the cylindrical rotary 12. The piezoelectric element vibrating parts are composed of piezoelectric elements 16a, 16b which are stretched and displaced, chips 17a, 17b which are fixed to one side ends of the piezoelectric elements, and retaining part members 18a, 18b which are fixed to the other side ends and constituted of planar elastic members. The chips are positioned on parts adjacent to the cylinder surface of the rotary actuator, brought into contact with the surface of the rotary actuator when the pizoelectric elements are stretched, and rotates the rotary operator 12 around the rotary shaft 11 with frictional force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive using an electromechanical transducer.

[0002]

2. Description of the Related Art As a rotary actuator, an electromagnetic motor is widely used, and recently, a small and high-speed rotary actuator is widely used. On the other hand, this type of actier
Since various devices using a motor require precise position control and high resolution, that is, precise control of the rotation angle, conventionally, an electromagnetic motor has been combined with a speed reduction mechanism.

[0003] However, when the speed reduction mechanism is used, it is practically difficult not only to increase the size of the device but also to precisely control the rotation angle by using a backlash of gears constituting the speed reduction mechanism.

As means for solving this problem, the present applicant generates a telescopic displacement in an electromechanical transducer, transmits the telescopic displacement to a driving member, and drives the driven member through a moving member frictionally coupled to the driving member. (See Japanese Patent Application Laid-Open No. 6-261559).

[0005]

An actuator using the above-described electromechanical transducer transmits an expansion / contraction displacement generated in the electromechanical transducer to a drive member, and the movable member is frictionally coupled to the drive member via a moving member. The structure is such that the driven member is moved, so even though it has a small and stable driving performance, the number of parts is large and the assembling is troublesome, so the number of parts is small and the rotary actuator is easy to assemble. Was required. An object of the present invention is to solve the above problems.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an electromechanical transducer which is provided with an operating member at an end in the direction of expansion and contraction and which can be extended and contracted. And an operating member provided on the electromechanical transducer is disposed at a position that can contact the cylindrical surface of the rotary operator on a plane radially separated from a rotation center of the rotary operator. The actuating member contacts the cylindrical surface of the rotary actuator by the extension displacement of the electromechanical transducer, and presses and rotates the rotary operator in the extension direction.

The plural sets of the electromechanical transducers and the action members are arranged symmetrically with respect to the rotary actuator on a plane radially separated from the rotation center of the rotary operator, so that any set is provided. Can be rotated in the rotation direction.

Further, the electromechanical transducer and the working member are preferably supported by a flexible support member.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 and FIG. The rotary actuator 1 includes a rotary shaft 11 rotatably supported by a cylindrical frame 13, a cylindrical rotary actuator 12 fixed coaxially with the rotary shaft 11, and a rotary actuator 1.
The piezoelectric vibrating portions 15A and 15B are disposed on a plane radially distant from the center of rotation (i.e., the axis of the rotating shaft 11) in the left-right direction with respect to the rotary actuator 12.

Each of the piezoelectric element vibrating portions 15A and 15B includes a plurality of piezoelectric elements (electromechanical transducers) 16a and 16b which are formed by laminating a plurality of elements and which expand and contract in the thickness direction.
And a chip 1 made of a rigid body fixed to one end thereof
7a, 17b and a support member 18 made of a flat elastic material fixed to the other end of the piezoelectric elements 16a, 16b
a, 18b. The other ends of the support members 18a and 18b are fixed to the inner wall of the frame 13 by screws, adhesives, or other appropriate means.

The chips 17a and 17b are connected to the rotary actuator 12
On a plane radially away from the center of rotation of the rotary actuator, the piezoelectric element 16a (1)
When the extension displacement occurs in 6b), the tip 17a (17b)
Comes into contact with the surface of the rotary actuator 12, and further, the rotary operator 12 is rotated by the frictional force with the rotary operator 12.
Acts to rotate around.

When rotating the rotary actuator 12 in the direction of arrow a, the piezoelectric element vibrating section 15A is operated and the piezoelectric element vibrating section 15B is stopped.

That is, when a voltage is applied to the piezoelectric element 16a to cause an elongation displacement, the tip 17a comes into contact with the surface of the rotary actuator 12, and further, the rotary operation is performed by a frictional force with the rotary operator 12. The child 12 around the rotation axis 11 with an arrow a
Rotate in the direction. At this time, if the piezoelectric element 16a further extends, the support member 18a bends in the direction in which the tip 17a moves away from the rotary actuator 12 (downward in FIG. 2).
There is no possibility that the piezoelectric element 16a or the like is broken.

When the application of the voltage to the piezoelectric element 16a is stopped, the piezoelectric element 16a contracts to the initial state, so that the chip 17a separates from the surface of the rotary actuator 12 and returns to the initial state. By continuously applying and stopping the voltage to the piezoelectric element 16a, the rotary operator 12 can be continuously rotated in the direction of the arrow a.

The rotation of the rotary actuator 12 in the direction opposite to the arrow a can be achieved by activating the piezoelectric element vibrating section 15B and stopping the piezoelectric element vibrating section 15A.

[0016]

Embodiments of the present invention will be described below.
FIG. 1 is a perspective view showing the configuration of a rotary actuator using the electromechanical transducer of the present invention, in which a cylindrical frame is indicated by imaginary lines. FIG. 2 is a front view of the rotary actuator viewed from the end of the rotary shaft, and the frame is partially cut away.

Hereinafter, a description will be given with reference to FIGS.
The rotary actuator 1 includes a rotary shaft 11 rotatably supported by a cylindrical frame 13, a cylindrical rotary actuator 12 fixed coaxially with the rotary shaft 11, and a rotation of the rotary actuator 12. It is composed of piezoelectric element vibrating portions 15A and 15B arranged on a plane radially away from the center (that is, the axis of the rotating shaft 11) in a symmetrical manner with the rotary actuator 12 therebetween.

Each of the piezoelectric element vibrating portions 15A and 15B includes a plurality of piezoelectric elements 16a and 16b which are formed by laminating a plurality of elements and which expand and contract in the thickness direction, and a rigid chip fixed to one end thereof. 17a and 17b, and support members 18a and 18b made of a flat elastic material fixed to the other ends of the piezoelectric elements 16a and 16b. The other ends of the support members 18a, 18b
Is fixed to the inner wall by screws, adhesive, or other appropriate means.

As is apparent from FIG. 2, the piezoelectric element vibrating parts 15A and 15B have the same configuration, but the piezoelectric element vibrating parts 15A and 15B are located on a plane radially away from the center of rotation of the rotary actuator 12. Therefore, the tip of the tip 17a and the tip of the tip 17a are arranged at positions symmetrical with respect to the rotary actuator and at a position close to the cylindrical surface of the rotary operator 12.
The tip of 7b is formed in accordance with the outer shape of the rotary operator so that it contacts the rotary operator 12 on a relatively wide surface (or line).

When the piezoelectric element 16a (16b) expands and displaces, the tip 17a (17b) comes into contact with the surface of the rotary actuator 12, and further the frictional force between the rotary element 12 and the rotary element 12 causes the rotary element 12 to move. It acts to rotate around the rotation axis 11. When the piezoelectric element 16a (or 16b) is further extended, the support member 18a is bent in a direction in which the tip 17a moves away from the rotary actuator 12 (downward in FIG. 2),
Since it is configured to release the elongation, the piezoelectric element 16
There is no danger of a being destroyed.

Next, the operation will be described with reference to FIGS. 3, 4, and 5. First, when rotating the rotary actuator 12 in the direction of arrow a, the piezoelectric element vibrating section 15A is operated and the piezoelectric element vibrating section 15B is stopped. FIG. 3 shows a state where no voltage is applied to the piezoelectric element 16 of the piezoelectric element vibrating section 15A and the piezoelectric element vibrating section 15B is at rest.

When a voltage is applied to the piezoelectric element 16a of the piezoelectric element vibrating portion 15A to extend the piezoelectric element 16a in the direction of the arrow b, the state shown in FIG. 4 is reached, and the chip 17a comes into contact with the surface of the rotary actuator 12, and The rotary actuator 12 is turned around the rotary shaft 11 in the direction of arrow a by the frictional force between the rotary operator 12 and the rotary actuator 12. At this time, if the piezoelectric element 16a is further extended, the state shown in FIG. 5 is reached, and the support member 18a bends downward.

When the application of the voltage to the piezoelectric element 16a is stopped at the timing when the supporting member 18a is bent downward, the piezoelectric element 16a contracts and returns to the initial state, so that the tip 17a separates from the surface of the rotary actuator 12. , And returns to the state shown in FIG. By continuously applying and stopping the voltage to the piezoelectric element 16a, the rotary actuator 12 is continuously moved by the arrow a.
Can be rotated in any direction.

The rotation of the rotary actuator 12 in the direction opposite to the arrow a can be achieved by operating the piezoelectric element vibrating section 15B and stopping the piezoelectric element vibrating section 15A. The operation is the same as the above-described operation of rotating the rotary actuator 12 by the piezoelectric element vibrating portion 15A, and thus the description is omitted.

FIG. 6 shows the piezoelectric element vibrating sections 15A and 15B.
In this case, the piezoelectric elements 16a extend in the direction of arrow b, and the piezoelectric elements 16b extend in the direction of arrow c. In this case, the chips 17a and 17b Simultaneously contact the rotary actuator 12, and the rotation of the rotary operator 12 in either the right or left direction is braked.

FIG. 7 is a sectional view of a linear moving mechanism according to a second embodiment of the present invention. The second embodiment is a linear moving mechanism to which the rotary actuator of the first embodiment is applied. The slider 20 is supported by a frame 21 so as to be linearly movable. The rotary actuator 12 of the rotary actuator according to the first embodiment is brought into frictional contact with the rotary
0 and the slider 20 is moved linearly. In this case, the slider 20 and the frame 2
It is preferable that the surface is finished so that the coefficient of friction between the slider 20 and the rotary actuator 12 is small and the coefficient of friction between the slider 20 and the rotary actuator 12 is large.

In this embodiment, the rotary actuator 12 is brought into direct frictional contact with the slider 20, but it goes without saying that the rotary disc 13 may be brought into frictional contact with the slider 20.

FIG. 8 shows a driving circuit for the piezoelectric element of the rotary actuator described above.
The piezoelectric elements 16a and 16b are connected to the amplifiers 32 and 33, respectively. When a rotation operation command signal is input from the outside, the CPU 31 selects and drives one of the amplifiers 32 and 33 according to the commanded rotation direction, and applies a drive voltage to the piezoelectric element 16a or 16b. When a braking command signal for the rotary actuator 12 is input from the outside, the CPU 31 simultaneously drives the amplifiers 32 and 33 and applies a driving voltage to the piezoelectric elements 16a and 16b.

FIG. 9 shows an example of the circuit of the amplifiers 32 and 33 in the piezoelectric element driving circuit shown in FIG. 8, which includes three transistors Tr1, Tr2 and Tr3, an inverter In, and resistors R1, R2 and R3. Be composed. When the signal "H" is output from the CPU 31, the transistors Tr1, T
r2 is turned on, Tr3 is turned off, and the piezoelectric element 16a
The voltage Va (= VH) is applied to the terminal (16b),
The piezoelectric element causes an elongation displacement. When the signal "L" is output from the CPU 31, the transistors Tr1, Tr2
Is OFF, Tr3 is ON, and the piezoelectric element 16a (16
The terminal b) is grounded (voltage Va = 0) and the application of the voltage is stopped, so that the piezoelectric element contracts and returns to the initial state.

[0030]

As described above, the rotary driving device using the electromechanical transducer of the present invention comprises a piezoelectric element having an action member provided at an end thereof, which is capable of expanding and contracting, and a cylindrical rotary actuator. When the electromechanical conversion element is extended and displaced, the working member is brought into frictional contact with the rotary operator to rotate the rotary operator, so that the number of constituent parts is small and assembly is easy, and Since the displacement of the conversion element is directly transmitted to the rotary actuator, a highly reliable rotary actuator with high driving efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating the configuration of a rotary actuator according to the present invention.

FIG. 2 is a front view of the rotary actuator shown in FIG. 1;

FIG. 3 is a front view (part 1) for explaining the operation of the rotary actuator shown in FIG. 1;

FIG. 4 is a front view (part 2) for explaining the operation of the rotary actuator shown in FIG. 1;

FIG. 5 is a front view (part 3) for explaining the operation of the rotary actuator shown in FIG. 1;

FIG. 6 is a front view illustrating a braking operation of the rotary actuator shown in FIG. 1;

FIG. 7 is a cross-sectional view illustrating a configuration of a second embodiment of the rotary actuator.

FIG. 8 is a block diagram of a drive circuit of the rotary actuator.

9 is a circuit diagram illustrating an example of an amplifier circuit of the drive circuit illustrated in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary actuator 11 Rotary shaft 12 Rotary actuator 15A, 15B Piezoelectric element vibrating part 16a, 16b Piezoelectric element 17a, 17b Chip 18a, 18b Support member

Claims (3)

[Claims] 1. An electromechanical conversion element having an action member provided at an end in an expansion and contraction direction and capable of expanding and contracting, and a cylindrical rotary actuator rotatably supported, and provided on the electromechanical conversion element. The action member is disposed at a position that can contact the cylindrical surface of the rotary operator on a plane that is radially separated from the rotation center of the rotary operator, and the action member is rotated by an extension displacement of the electromechanical transducer. A rotary drive device using an electromechanical transducer, wherein the rotary actuator is rotated in contact with a cylindrical surface of the actuator in the extension direction. 2. The electromechanical transducer and the working member,
The rotation using the electromechanical transducer according to claim 1, wherein a plurality of sets are arranged symmetrically with respect to the rotary actuator on a plane radially separated from a rotation center of the rotary actuator. Mold drive. 3. The electromechanical transducer and the operating member,
The rotary drive device using an electromechanical transducer according to claim 1, wherein the rotary drive device is supported by a flexible support member.