JPH0541399U - Piezo actuator - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To obtain a piezoelectric actuator that can realize linear motion with a simple structure. [Structure] A piezoelectric ceramic plate 11 for obtaining longitudinal vibration is attached to a rod-shaped metal piece having a rectangular cross section, and a piezoelectric ceramic plate 12 for bending vibration is attached to the other side surface to generate two vibration modes by a driving voltage. , Cause an elliptical movement on the other side. The metal piece is accommodated in the frame body integrated with the guide 16 via the elastic body 14, and the leaf spring 17
The metal piece 10 is pressed against the rail by pressing the metal piece 10 with the lid.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a piezoelectric actuator, and more particularly to a piezoelectric actuator capable of linear driving (movement).

[0002]

[Prior Art]

 Piezoelectric motors and piezoelectric actuators are expected to be used in various fields, and piezoelectric motors and actuators with various structures have been proposed for that purpose. This is because it can be driven with a small amount of power and has the advantage that it is not affected by electromagnetic waves. However, in order to obtain a large torque or a large amount of displacement, there are problems that a complicated structure is required and manufacturing becomes difficult.

Therefore, the inventor has proposed a piezoelectric actuator as shown in FIG. FIG. 2 is a perspective view showing the shape of a metal piece serving as the vibrating piece. A rod-shaped metal piece 10 made of metal such as phosphor bronze is cut out, and one of the four side surfaces has a central portion in the longitudinal direction that is cut away to form a concave portion, and a shape having protrusions 15 at both ends is formed. There is.

Piezoelectric ceramic plates 11 are attached to the two side surfaces adjacent to the side surface provided with the protruding portion 15. In this example, two piezoelectric ceramic plates 11 are attached to each surface, but the piezoelectric ceramic plates 11 do not necessarily have to be divided into two. The piezoelectric ceramic plate 11 causes longitudinal vibration. Further, an electrode is formed on the surface of the piezoelectric ceramic plate 11 by baking silver or the like.

Piezoelectric ceramic plates 12 a and 12 b that cause bending vibration are attached to the side face between the two side faces to which the piezoelectric ceramic plate 11 is attached and the side face without the protruding portion. The piezoelectric ceramic plates 12a and 12b had the same size and thickness as above. Although the piezoelectric ceramic plates 12a and 12b are divided, they can also be formed by dividing the electrodes of a single ceramic plate.

[0006]

[Problems to be solved by the device]

 The present invention is intended to obtain a piezoelectric actuator having a simple structure and a relatively large output.

Further, it is required to efficiently convert the elliptical motion into the motion of the object. In order to meet this demand, it is necessary to transfer the motion of the vibrating piece to an object that moves integrally with the vibrating piece. The aim is to obtain a piezoelectric actuator suitable for positioning precision equipment.

[0008]

[Means for Solving the Problems]

 The present invention generates longitudinal vibration and bending vibration by displacement of a piezoelectric ceramic plate attached to the side surface of a rectangular parallelepiped metal piece, and thereby presses the surface where elliptical motion occurs via a leaf spring to contact the rail. The above problems are solved.

That is, in a piezoelectric actuator in which a guide device that is movable in both directions along a rail, a frame body that houses the piezoelectric drive device, and a lid body that is attached to the frame body are integrally moved, The driving device is a rod-shaped metal piece having a rectangular cross section, and has a piezoelectric ceramic plate that causes longitudinal vibration and a piezoelectric ceramic plate that causes bending vibration on at least two side surfaces, and a lid body is provided via a V-shaped leaf spring. The metal piece is pressed against the rail, and due to the elliptical movement that occurs on the side surface without the piezoelectric ceramic plate due to the above two vibration modes, the side surface comes into contact with the rail and moves on the rail integrally with the guide device, the frame and the lid. It is characterized by moving.

[0010]

[Action]

 The size of the metal piece should be such that it resonates at the same frequency in longitudinal vibration and bending vibration, or resonates at the resonance frequency of its higher order mode. Then, a driving voltage is applied to the electrodes of the two types of piezoelectric ceramic plates at the same frequency to generate respective vibration modes. Two vibration modes cause elliptical motion on the side without the piezoelectric ceramic plate attached. This side surface can be brought into contact with the rail to move the metal piece itself.

The voltages applied to the two types of piezoelectric ceramic plates have a phase difference. By changing the phase difference, the direction of rotation can be changed, and the moving direction can be changed accordingly.

Further, around the metal piece, a frame body and a lid body which are integrated with the guide device are arranged, and the movement of the metal piece pressed by the rail via the plate spring is surely performed. Since it is transmitted to the body, the conversion efficiency is also high.

[0013]

【Example】

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

FIG. 1 shows an embodiment of the present invention. (A) is a front sectional view and (b) is a side sectional view. The protruding portion 15 of the rod-shaped metal piece 10 made of metal such as phosphor bronze comes into contact with the rail 19, and the metal piece 10 is arranged so as to be movable on the rail 19 in both directions. There is. Piezoelectric ceramic plates 11 are attached to the two side surfaces adjacent to the side surface provided with the protruding portion 15. A piezoelectric ceramic plate 12 that causes bending vibration is attached to the side surface between the two side surfaces to which the piezoelectric ceramic plate 11 is attached, which has no protruding portion, that is, the upper surface in FIG.

The metal piece 10 is housed in a frame body 13 which has a vertically extending through portion which encloses and accommodates four side surfaces of the metal piece 10, and which is provided at the center. An elastic body 14 such as silicon rubber is arranged between the metal piece 10 and the frame body 13 in the longitudinal direction, that is, the direction in which the rail extends. The elastic body such as silicone rubber is intended to surely reach the frame without suppressing the vibration of the metal piece. When the frame such as hard plastic is brought into direct contact with the metal piece, the longitudinal vibration and bending vibration of the metal piece are pushed, and it becomes difficult to efficiently obtain the motion as an actuator.

The frame body 13 is integrated with the guide 16 and is fixed to the guide 16 by bolts or the like. The guide 16 has a structure in which the convex portions on the side surface of the rail 19 are sandwiched from both sides so that the moving frame 13 does not come off the rail 19, and the U-shaped concave portion and the convex portion of the rail 19 mesh with each other. The structure is such that it can be moved across it.

The metal piece 10 is pressed against the rail 19 by a lid 18 fixed to the frame 13 via a V-shaped leaf spring 17. If this pressure is weak, sufficient movement distance and speed cannot be obtained, so the lid 18 fixed to the frame 13 presses the metal piece 10 via the leaf spring 17 from the upper surface toward the rail surface. Is. Since the central portion of the metal piece 10 is pushed by using the V-shaped leaf spring 17, a predetermined rotational motion can be obtained without affecting longitudinal vibration and bending vibration.

As described above, the metal piece 10 has four side surfaces surrounded by the frame body 13, the lower surface is in contact with the rail 19, and the upper surface is pressed by the lid 18 via the leaf spring 17. This metal piece 10 is not fixed to any of these, and can be moved in both directions on the rail 19 by the applied voltage, and at this time, the frame body 13, the guide 16 and the lid 18 also move integrally. .

As the material of the elastic body, a commonly used elastic body such as sponge can be used in addition to the above-mentioned silicone rubber.

[0020]

[Effect of the device]

 According to the present invention, it is possible to obtain a piezoelectric actuator having a small number of piezoelectric ceramic plates, easy wiring, a simple structure, and a large momentum by connection. In addition, the direction can be easily switched by adjusting the phase difference between the applied voltages.

Further, it is possible to obtain a piezoelectric actuator which can surely contact the vibrating piece with the rail and can reliably transmit the motion of the vibrating piece with a small number of parts.

[Brief description of drawings]

FIG. 1 is a front sectional view (a) and a side sectional view (b) of an embodiment of the present invention.

FIG. 2 is a perspective view of a metal piece.

[Explanation of symbols]

 10: Metal piece 13: Frame 14: Elastic body 15: Projection 16: Guide 17: Leaf spring 18: Lid

Claims (1)

[Scope of utility model registration request] 1. A piezoelectric actuator in which a guide device movable in both directions of a rail, and a frame and a lid for housing a piezoelectric driving device are attached and move integrally.
A piezoelectric drive is a rod-shaped metal piece with a rectangular cross section,
A piezoelectric ceramic plate that generates longitudinal vibration and a piezoelectric ceramic plate that generates bending vibration are provided on at least two sides, and a metal piece is pressed against the rail by a lid via a V-shaped leaf spring, and the two vibration modes described above are used. A piezoelectric actuator characterized in that an elliptic movement generated on a side surface without a piezoelectric ceramic plate causes the side surface to come into contact with a rail and move on the rail integrally with a guide device, a frame body and a lid body.