JPH08322270A - Stator for ultrasonic driving device - Google Patents

Abstract

PURPOSE: To provide a stator for ultrasonic driving device by slightly cutting off small areas from the three vertexes of a piezoelectric vibrator having an equilateral triangular shape. CONSTITUTION: A stator for ultrasonic driving device is formed by slightly cutting off the vertexes 2, 3, and 4 of a piezoelectric vibrator 1 having a equilateral triangular shape by the same length and respectively forming supporting notches 8, 9, and 10 at the central parts of the sides 5, 6, and 7 opposite the vertexes 2, 3, and 4, and then, sticking a front end chip 2a composed of a metal or a material having a high wear resistance to the vortex 2 and respectively forming electrodes 12 and 13 on the left- and right-side parts of the surface of the vibrator 1 which are divided by forming a dividing section 11 the vertex 2 to the center of the side 6 opposite to the vortex 2. In addition, an electrode cutting-off section 9a is provided around the supporting notch 9 and an electrode is stuck to the entire surface of the vibrator 1 on the other side. Moreover, electrode cutting-off sections are formed around the supporting notches 8 and 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of an ultrasonic drive device in which a piezoelectric vibrator having an equilateral triangle is cut off.

[0002]

2. Description of the Related Art The applicant of the present invention, as an ultrasonic drive device, adheres an electrode to the entire surface of one surface of a piezoelectric vibrator of a fan-shaped or isosceles trigonometer, and from the tip to the other surface of the fan-shaped or isosceles trigonometer. We have proposed an ultrasonic drive device in which two electrodes are adhered to each other by providing divided parts on opposing arcs or sides, and a driver is brought into contact with the tip (see Japanese Patent Application No. 63-32414).

[0003]

However, in such an ultrasonic driving device, there are many resonance points, and
The impedance of the piezoelectric vibrator is as high as several hundreds of ohms, it is difficult to adjust even with the use of an automatic tracking circuit, and the high impedance of the ultrasonic vibrator requires a high driving voltage.

[0004]

According to the present invention, three tips of an equilateral triangle are cut off by slightly the same length,
A tip chip is adhered to one tip of one surface of a piezoelectric vibrator having a fixing notch provided substantially at the center of the side opposite to the three tips, and the tip is divided from the one tip to the center of the opposite side. A part is provided to bond the two electrodes, and the electrodes are bonded to the entire other surface.

[0005]

According to the present invention, by making the shape of the piezoelectric vibrator an equilateral triangle, and making it small and thin, the resonance point is limited, which facilitates automatic tracking, and because the impedance is low, it is low. It is easy to drive with voltage and can be constructed at low cost.

[0006]

1 is a structural view of one surface of a stator of an ultrasonic driving apparatus according to an embodiment of the present invention, and FIG. 2 is a structural view of the other surface of the stator shown in FIG. The three tips 2, 3, 4 of the child 1 are slightly cut off by the same length,
Supporting notches 8, 9, 10 are formed substantially in the center of sides 5, 6, 7 facing the three tips 2, 3, 4.
Further, a split portion 11 is split in the center between one tip 2 and its opposing side 6, and two electrodes 12, 1 are provided on both sides thereof.
3 is formed, an electrode cutout portion 9a is provided around the supporting notch 9, and the entire surface electrode 14 is adhered to the entire other surface of the piezoelectric vibrator 1, and the supporting notch 8 is formed. The electrode cutouts 8 a and 10 a are formed around the circumference 10 to form the stator 15.

The electrode cutout 9a is constructed so that the electrodes 12 and 13 do not come into contact with each other when the piezoelectric vibrator 1 is supported by soldering or conductive paste in the support cutout 9, and the electrode cutout 8a, When the supporting notches 8 and 10 are supported by soldering or paste, the whole surface electrode 10a of the other surface does not come into contact with the supporting notches 8 and 10. Further, the sliding tip portion 2 is made of metal or wear-resistant. The tip 2a made of a material having excellent properties is bonded.

In the stator of this embodiment having such a structure, the oscillating device is connected between one electrode 13 on one surface of the piezoelectric vibrator 1 and the whole electrode 14 on the other surface of the piezoelectric vibrator 1. When driven half-way, at a point B where the impedance of the curve A shown by the solid line in FIG. 3 in which the vertical axis represents the impedance and the horizontal axis represents the frequency, the impedance sharply decreases, the piezoelectric vibrator 1 is bent as shown in FIG. Since mode vibration 16 is generated and the tip 2a of the piezoelectric vibrator 1 moves in the direction of arrow 17 to move the contacted driving body, the driving body can be linearly moved in the direction of arrow 17.

Further, when the frequency of the voltage applied between the electrode 13 and the entire surface electrode 14 of the piezoelectric vibrator 1 is further increased, at the point C where the impedance sharply decreases next to the curve A, as shown in FIG. As shown, since the longitudinal vibration 18 and the bending secondary mode vibration 19 are generated in the piezoelectric vibrator 1, the combined vibration of the longitudinal vibration 18 and the bending secondary mode vibration 19 causes the tip end 2 of the piezoelectric vibrator 1 to move in the arrow direction 19 The elliptic vibration is generated, and the driving body contacting the tip 2 of the piezoelectric vibrator 1 can be rotated.

4 and 5, an example in which an oscillating device is connected between the electrode 13 on one surface of the piezoelectric vibrator 1 and the whole surface electrode 14 on the other surface is shown. When an oscillating device is connected between the electrode 12 on one surface and the electrode 14 on the other surface, bending one-mode vibration occurs in the opposite direction to the arrow 17 in FIG. 4, and in FIG. Inverted elliptical vibration is generated, and the driving bodies that are in contact with the tip 2a of the piezoelectric vibrator 1 can be driven in opposite directions.

Incidentally, when an oscillating device is connected between the electrodes 12 and 13 on one surface and the electrode 14 on the other surface and the piezoelectric vibrator 1 is entirely driven, the impedance of the curve D shown by the dotted line in FIG. 6, the respiratory vibrations 20, 21, 22 are generated from the center of the piezoelectric vibrator 1 toward the three tips 2, 3, 4, as shown in FIG. Reference numeral 22 denotes the tips 2, 3, 4 of the piezoelectric vibrator 1.
Only protrudes once, so that only the driving body in contact with the tip tip 2a of the piezoelectric vibrator 1 is pushed out.

FIG. 7 is a constitutional view of a stator of a piezoelectric vibrator according to another embodiment of the present invention as seen from the side 6 side, and the whole surface electrodes 14A and 14B of the two piezoelectric vibrators 1A and 1B are adhered to each other,
The stator 23 is configured such that the two electrodes 12A, 13A, 12B and 13B divided by the dividing portions 11A and 11B are on the outside.

In this embodiment thus constructed, the oscillator may be connected so that the tips (not shown) of the piezoelectric vibrators 1A and 1B generate lateral vibration or rotational vibration in the same direction. By generating the transverse vibration or the rotational vibration in the opposite directions, the torque can be doubled, or the opposing driving body can be driven in the opposite direction.

[0014]

As is apparent from the above description, in the stator of the ultrasonic driving apparatus of the present invention, two electrodes are bonded to one surface of the piezoelectric vibrator in which the tip of an equilateral triangle is slightly cut off, and the other is bonded to the other surface. By providing a full-scale electrode on the surface of the piezoelectric element and connecting an oscillating device between one of the two electrodes and the full-scale electrode, lateral vibration and rotational vibration are generated at the tip of the piezoelectric vibrator, and a driving member is provided at this tip. The actuator can be driven or rotated in a linear direction by touching with, and the shape of the piezoelectric vibrator is an equilateral triangle, which limits the resonance point and facilitates adjustment by the automatic tracking circuit. In addition, since the impedance is low, there is an advantage that the applied voltage can be low, and the amplitude is amplified by the combination of the resonance of the piezoelectric vibrator and the resonance of the tip chip.

[Brief description of drawings]

FIG. 1 is a plan view of one surface of a stator of an ultrasonic drive device according to an embodiment of the present invention.

FIG. 2 is a plan view of the other surface of the stator shown in FIG.

3 is a diagram showing the relationship between the impedance of the stator of FIG. 1 and the frequency of the applied voltage.

4 is a diagram showing a direction of vibration of a bending primary mode of the stator of FIG.

5 is a diagram showing directions of vibration in a bending secondary mode of the stator of FIG.

FIG. 6 is a diagram showing respiratory vibration of the stator of FIG.

FIG. 7 is a side view of a stator of an ultrasonic drive device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric vibrator 2, 3, 4 Tip circuit 2a Tip chip 5, 6, 7 Sides 8, 9, 10 Fixing notch 11 Dividing part 12, 13 Electrode 14 Full surface electrode 15 Stator

Claims (2)

[Claims] 1. A piezoelectric vibrator, wherein three tips of an equilateral triangle are cut off by slightly the same length, and a fixing notch is provided substantially at the center of a side facing the three tips. Ultrasonic drive, characterized in that a tip is adhered to the tip, a split portion is provided in the center of the side facing from the one tip to adhere two electrodes, and the electrodes are adhered to the entire other surface. The stator of the device. 2. The stator for an ultrasonic wave drive device according to claim 1, wherein the two electrodes of the two piezoelectric vibrators are adhered to each other to drive the two piezoelectric vibrators in parallel.