JPS63209479A - Quadrupole couple ultrasonic rotating vibrator and ultrasonic motor - Google Patents

Abstract

PURPOSE:To increase mechanical strength and to double inputs and outputs, by orientating the sense of the polarization of a disc element in the direction of its thickness, and by polarizing in the opposite direction so that a semicircle may be polarized positively while the other polarized negatively, and by overlapping one after another so that two sheets of homopolar electrodes may face each other. CONSTITUTION:For a piezoelectric element of a quadrupolar couple ultrasonic vibrator, an earth electrode is put to one side of a hollow disc 1 and to the other side a sector electrode opened in a right angle of a quadrant. Two sheets of this electrode are overlapped so that the electrodes may exactly face each other, between which four sheets of sector terminal strips are inserted and engaged with an aluminium ring 17 for integration. If sinusoidal wave voltage is applied to lead wires 9 and 10 and the frequency is coincided with the resonance frequency, it will work as an ultrasonic rotating vibrator of which the centroid rotates. If the outside diameter of the aluminium ring 17 of the vibrator above is taper-machined and a disc 18 having the same tapered inside diameter to coincide with this ring 17, the disc 18 will rotate smoothly.

Description

[Detailed Description of the Invention] C. Industrial Application Field] The present invention relates to an ultrasonic vibrator for an ultrasonic motor and its stator, and more specifically to an improvement in the electrode structure for combining two vibrators into a pair. Regarding.

[Conventional technology]

The present inventor previously developed a "center of gravity rotation type ultrasonic motor" in 1982-
No. 11374 was proposed. The ultrasonic vibrator used in this motor is the "Ultrasonic Rotating Vibrator" No. 11373 (Sho 62=11373), and the semicircular parts are polarized in the thickness direction so that the polarity is opposite to each other. It has electrodes and is constructed so that it can be deformed independently. When a perforated ring or disk is fitted around the outer periphery of this ultrasonic rotary vibrator, it rotates smoothly, so that the ultrasonic rotary vibrator is functionally itself a motor.

When viewed as a motor, the rotation of the center of gravity is due to the primary resonance mode of the element, so it is unrelated to the number of electrode divisions. A four-pole motor driven by phase power is the simplest and best. By the way, when viewed as a motor from a practical standpoint, a conventional four-pole rotary vibrator has a total of eight electrodes exposed on its surface, requiring an insulating cover, and connecting eight lead wires is complicated, leading to accidents. There are drawbacks that can be considered.

Furthermore, if the plates are made thinner in order to lower the voltage, they become mechanically weaker, so the structure becomes complicated in response to demands such as bonding two layers together or stacking two layers for the purpose of doubling the output.

[Problem that the invention seeks to solve]

This invention is useless except for the four poles that the previous application's "center of gravity rotation type ultrasonic motor" and "ultrasonic rotary vibrator" had, eight electrodes are complicated even in the case of four poles, the outside cannot be grounded, and it is easy to stack two sheets. The purpose of the present invention is to solve the drawbacks such as impossibility, and thereby provide a vibrator and motor with an excellent structure of practicality.

Note that the quadrupole pair ultrasonic rotary vibrator of the present invention includes a filter,
Not only can it be used as a sensor, actuator, etc., but it can also be used as a motor itself.

[Means to solve the problem]

The most widely used powerful ultrasonic transducer is the bolted Langevin transducer, in which the main components are metal, so the external electrodes of the piezoelectric element are short-circuited. In order to prevent this, it is usually made into a set of two, with the outer side being the ground electrode and the inner side being the high potential electrode, so that it can be insulated and protected from the ground side by itself.

In the present invention, the same method is used, and the entire outer surface is a ground electrode. In order to achieve this, the direction of polarization of the disk element is taken in the thickness direction, and the semicircle is polarized in the opposite direction so that it is positively polarized and the remaining semicircle is negatively polarized. Attach a circular fan-shaped electrode that opens at a right angle. Prepare another element made in exactly the same way, stack these two elements so that the electrodes of the same polarity face each other, and short-circuit the electrodes of each four elements arranged symmetrically with the center. A pair.

Only three lead wires are required, one for each pair and one for the ground electrode, which simplifies the wiring, and since two leads are stacked, it is also mechanically strong, and both input and output can be doubled.

〔Example〕

1 and 2 are a plan view and a bottom view showing the polarization of a piezoelectric element and the arrangement of electrodes of a quadrupole ultrasonic transducer according to the present invention, and FIGS. 3 and 4 are a diagram of a motor using the transducer. FIG. 2 is a plan view and a vertical cross-sectional view.

A ground electrode 2 is provided on one side of a hollow circular plate 1 made of Pb (Zr Ti )Os based piezoelectric ceramic, and a sector-shaped electrode 3 opened at a right angle to a quarter circle is provided on the other side as shown in FIG. .4, 5.6 are applied.

Of these electrodes, electrode 2 is grounded, positive DC high voltage is applied to electrodes 3 and 4, and negative DC high voltage is applied to electrodes 5 and 6.
When the time-applied polarization process is completed, (+) and (-) symbols are marked to clearly indicate the polarity of residual polarization.

Two electrodes with the same treatment, for example, electrodes with (+) and (-) symbols, with an outer diameter of 40a+n+, an inner diameter of 15mm, and a thickness of 2ram, are stacked so that they are exactly facing each other, and a sector-shaped terminal plate is placed between them as shown in Figure 3. Four sheets 21, 22, 23, and 24 are inserted, and these are fitted into the aluminum ring 17 and integrated.

The electrode 21 and the electrode 23 and the electrode 22 and the electrode 24 are short-circuited, the lead wire 10 and the lead wire 9 are connected to these, and the outer short-circuit electrode 12 and the short-circuit electrode 12° are further short-circuited as shown in FIG. Then, connect the lead 8 to this and ground it. When a sinusoidal voltage around 45 KHz is applied to the lead wires 9 and 10 and the frequency is made to match the resonant frequency, it functions as an ultrasonic rotary vibrator whose center of gravity rotates.

When the outer periphery of the aluminum ring 17 of the ultrasonic rotary transducer constructed in this manner was tapered at 75°, and a disk 18 with a matching taper and the same inner diameter was mounted, the disk 18 rotated smoothly. . Brass is used here as the material for the disk 18, but other metals, glass, ceramics, or other hard materials can function as a rotor and rotate well. The rotation speed increased in proportion to the voltage and exceeded 20 Orpm at about 85 volts.

If the phase relationship of the two-phase power supply is reversed, for example, the electrodes 21.
When electrodes 22 and 24 are advanced in phase with respect to 23, disk 1
8 rotates clockwise, and when the phase is delayed, it rotates counterclockwise.

As described above, by tightly fitting and integrating the ring 17 around the outer periphery of the rotary vibrator [1], the mechanical strength of the rotary vibrator 11 is greatly reinforced. Further, by stacking two rotary vibrators 11, not only the output is multiplied but also the mechanical strength is increased, and as a result, an ultrasonic motor with excellent impact resistance can be obtained.

〔Effect of the invention〕

As explained above, in the present invention, the electrodes of the ultrasonic rotary transducer are made into a quarter circle, that is, a quadrupole, with a full electric electrode on one side and a quarter circle electrode on the other side, with two adjacent electrodes having positive and negative polarization, respectively. Polarization was performed so that each semicircle was polarized in opposite directions. The structure was such that the electrodes of two polarized elements with the same polarity were placed one on top of the other so that they faced each other correctly, the four electrodes located at centrally symmetrical positions were short-circuited, and an aluminum ring was fitted around the outer periphery to integrate them.

This eliminates the need to increase the number of poles beyond the maximum pole, places the ground electrode on the outside of the two stacked electrodes, has the effect of preventing short-circuit accidents between the electrodes, and simplifies the wiring so that it can be driven with three lead wires. Moreover, since they are paired, they not only reinforce mechanical strength but also double input and output.

[Brief explanation of the drawing]

1 and 2 are a plan view and a bottom view of a quadrupole pair ultrasonic rotary vibrator according to an embodiment of the present invention, and FIGS. 3 and 4 are a plan view and a bottom view of an ultrasonic motor using the rotary vibrator. FIG. l, 11... Ultrasonic rotating transducer, 2.12... Ground electrode, 3.4.5.6... Electrode, 8,9.10...
・Lead wire, 21, 22, 23゜24...Terminal board, 1
7... Aluminum ring, ■8... Disc. Figure 1 Figure 2 Figure 3 Figure 4

Claims (2)

[Claims] (1). Two piezoelectric disks are polarized in the thickness direction so that the semicircles have opposite polarities, and have electrodes of the same polarity on one side, almost the entire surface, and the other side with quarter-circular electrodes in the positive and negative regions. A quadripolar ultrasonic rotary vibrator characterized in that the quadrupolar ultrasonic rotary vibrator is fitted into a ring of an elastic body in a stacked state so that they face each other and are in contact with each other either directly or via a terminal plate. (2). Two piezoelectric disks are polarized in the thickness direction so that the semicircles have opposite polarities, and have electrodes of the same polarity on one side, almost the entire surface, and the other side with quarter-circular electrodes in the positive and negative regions. An ultrasonic motor characterized in that the stator is a quadrupole pair of ultrasonic rotary vibrators fitted in an elastic ring in a stacked state facing each other and in contact with each other either directly or via a terminal plate.