JPS6152167A - Piezoelectric motor using cantilever beam supersonic elliptical vibrator - Google Patents

Abstract

PURPOSE:To obtain a large moving torque with light weight and compactness by press-bonding a moving element to the free end of a cantilever and applying a moving torque of the direction along the bending direction of the cantilever beam in the press-bonding surface of the moving element. CONSTITUTION:A cantilever beam 1 is of part of aluminum in the shape erected from the beam 12 in an inverted T shape on a circular base 12. Piezoelectric thickness vibrators 31, 32 for exciting the beam is formed of thickness vibrators made of doughnut-shaped Pb(Zr-Ti)O2 ceramic, and when a sinusoidal voltage is applied to the vibrators 31, 32 through leads 71, 72 connected with terminal boards 42, 43, the thickness vibrations of the vibrators 31, 32 produce deflecting vibration of the base 12, thereby causing the vibration of the end of the beam 12 to draw an elliptical motion.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application and Object of the Invention] The present invention relates to an improvement of a piezoelectric motor, and relates to a piezoelectric motor. Elliptical vibration is generated on the free end surface of a cantilever-shaped ultrasonic transducer excited by torsional vibration, and a moving torque within the crimped surface is applied to the mover crimped to the stator surface, resulting in high-speed and powerful rotation or An object of the present invention is to provide a piezoelectric motor that performs linear motion.

[Conventional technology]

Ultrasonic motors using piezoelectric materials have recently been researched and developed, and their ultrasonic vibration source uses longitudinal vibrations such as bolt-tight Langevin transducers that have been used in the ultrasonic industry. However, without moving the mover, it is necessary to convert the longitudinal vibration into moving torque, and this conversion often causes inconvenience.

Ultrasonic elliptical vibration should be used to generate moving torque, but since no ultrasonic vibrator that directly generates elliptical vibration has been found, there is no hope for a piezoelectric motor using an ultrasonic elliptical vibrator. Piezoelectric motors that utilize the elliptical vibration of surface waves, which have been attracting attention recently, have had the problem of low input/output efficiency for both rotary and linear types.

Means for Solving Problem C] This invention solves the above-mentioned drawbacks of the prior art,
By bolting and fixing a piezoelectric thickness vibrator to the fixed end of the cantilever beam, bending vibration is excited in the cantilever beam, the movement is crimped to the exit end surface of the cantilever beam, and the vibration is applied to the crimping surface of the slider. On the other hand, the above object is achieved by applying a moving torque along the bending direction of the cantilever beam within this plane.

〔Example〕

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

Embodiment 1 FIGS. 1 to 3 show an example of a cantilever-like ultrasonic elliptical vibrator used in the piezoelectric motor of the present invention. FIG. 1 is a front view, and FIG. 2 is a side view. , FIG. 3 is a plan view. Comparing these figures, i.e. cantilever 1 has a diameter of 3
On top of a circular platform 12 with a length of 5 meters and a thickness of 9 gates, a seaweed with a thickness of 7,
[It is an aluminum part with a beam part 11 about 10 inches tall standing upright in an inverted T shape. The piezoelectric thickness vibrators 5 and 62 that excite this have an outer diameter of 35 gates and an inner diameter of 15 gates.
2-gate donut shape (DPb, (Zr-Ti)O
This is a thickness vibrator made of S-based ceramic, with a phosphor bronze terminal plate 42 having the same shape and a thickness of 0.2 tm sandwiched between the positively polarized surface electrodes, and terminal plates 41 and 43 on the outside. Overlap.

Furthermore, aluminum washers 2 and 5 with an outer diameter of 35 mg, an inner diameter of 8.2 mm, and a thickness of 10 mm are stacked, and a cap bolt 6 with a diameter of 8 mm and a length of 25 mm is passed through the bolt hole of washer 5. It was screwed into the screw hole formed in the center of the base part 12 and tightened with a torque of 150 kq-f-m using a torque wrench. A groove 13 with a width of 20 mm and a depth of 2 mm is carved parallel to the beam portion 11 on the underside of the disc-shaped base portion 12 of the cantilever beam 1, so when the porthole is tightened, three grooves on both sides of the groove 18 are carved. With the legs of the shape as a fulcrum, the disc-shaped platform 12
Deflection deformation occurs.

The cantilever-shaped ultrasonic elliptical transducer is constructed as described above, and the lead M71 is connected to the terminal plate 42 and 4s.
When a sinusoidal voltage of 41.06 KH, 30 volts is applied to the piezoelectric vibrators 31 and 32 through the piezoelectric vibrators 31 and 72, the thickness vibration of the piezoelectric vibrators 3+ and 32 causes a deflection vibration of the disc-shaped platform 12, and this deflection The vibration causes bending resonance in the beam portion 11 of the cantilever beam 1. Since this bending vibration is combined with the longitudinal vibration through the deflection of the base portion 12, the end face of the beam portion 11 traces an elliptical motion as shown by the locus of vibration enlarged by the arrow 8 in FIG. When the rotor was pressed onto the end face with the rotating shaft 10 held parallel to the width direction of the beam 1, that is, in the horizontal direction, as shown in FIG. 4, the rotor rotated vigorously clockwise.

The cantilever-shaped ultrasonic elliptical transducer used in the present invention differs in groove depth and shape depending on the purpose, but its basic shape is all as described above. In FIG. 4, an elliptical vibrator is used as a stator and rotates a drum-shaped rotor 9 pressed onto a vibrating surface.

Example 2 FIG. 3 shows an example in which the vibrator is set on the rotor side. The stator 11 has a height of 50mm and a size of 100ffi+xX100
It has four circular parts with a diameter of 90 mm and a depth of 45 mm on the inside, and the inner circumferential surface of this recess is inscribed with the free end of the cantilever of the ultrasonic elliptical transducer set in the rotor, and is made of crimped foil. move. A disc-shaped rotor 12 with a diameter of 89 cm is set in the recess of the stator 11 in the form of an inner lid. That is, the ball bearing installed in the center of the disk has a diameter of 1.2 mm, which stands at the center of the four parts of the stator 11. Q Fits my rotor holding shaft. The rotor 12 has a case 1 that can accommodate two ultrasonic elliptical vibrations.
3 is fixed. This case 16 has a prismatic shape of 44 mm x 44 mm x 70 mm, and has a hole with an inner diameter of 35 mg passing through it in the length direction. Insert the disc-shaped spring 29 between the bottom parts. While pressing the two vibrators 26 into contact with each other from both sides of the case 13 so as to compress the spring 29, the stator 11 is
By inserting it into the recess and setting the center shaft in the bearing, a rotary piezoelectric motor was completed. 4 lead wires 271.
When a sinusoidal voltage of 41.06 KM was applied to the rotor 12, the rotor 12 began to rotate smoothly. The rotation speed and torque of the rotor 12 can be adjusted by adjusting the strength of the spring 22. Since the rotor disk is supported by the holding shaft of the stator 11, a heavy object of about 9 can be placed on 10.

Embodiment 3 FIG. 6 shows the operating principle of a linear motor as an embodiment of a piezoelectric motor using the cantilever-like ultrasonic elliptical vibrator of the present invention. Linear motors are essential mechanisms that are used not only for transporting objects, but also for x-y-z-direction stages that are essential for robots and the like.

The piezoelectric motor of the present invention is lightweight and compact, and has low speed and
Due to its large torque characteristics, it is ideal for linear motors for robots, and can be used not only for x-y-z direction stages, but also for arm and
It can be used for a mechanism that extends and contracts the legs. here,
The basic structure of the various linear motors mentioned above is shown. It is natural that various mechanisms can be developed by combining these.

The moving surfaces of the mover 62 are arranged opposite to each other on the wall of the stator 61 with the ball bearing 63 interposed therebetween, and the elliptical vibrator 35'E-- is crimped to the other surface of the mover 62, that is, the sliding surface. The vibrator 65 is housed in a case 64 set on the stator 61, and can slide only in the normal direction of the sliding surface. Furthermore, the sliding direction is adjusted by the coil spring 56 and the pressure adjusting screw 67 so that a predetermined pressure force is generated. Since the free end surface of the cantilever beam portion 651 is pressed against the sliding surface of the slider 62 with a considerably strong force,
The force for holding the mover 32 in a stationary state is comparable to a torque of several kp -771.

In this state, when a high frequency signal of a predetermined frequency was applied to the lead wire 38, it was possible to move the mover fully loaded with about 10 to 9 weights at a speed of about 50 m/s.

In this embodiment, the motor of the present invention is set on the stator side, but like the rotor shown in FIG. 5, it can also be set on the mover side and the same effect can be obtained.

〔Effect of the invention〕

As explained above, the present invention excites bending vibration in the cantilever beam by bolting and fixing the piezoelectric thickness vibrator to the fixed end of the cantilever beam, and crimps the movable part on the free end surface of the cantilever beam. The present invention is characterized in that a moving torque is applied to the crimp surface of the mover in a direction along the bending direction of the cantilever within this plane. Therefore, although the piezoelectric motor of the present invention is lightweight and compact, it can output a large movement torque, provide a high-precision movement at low speed, and have an extremely large static holding force at the stopped position. There are effects such as

[Brief explanation of drawings]

1, 2, and 3 are a front view, a side view, and a plan view of a cantilever-shaped ultrasonic elliptical transducer used in the present invention;
The figure is a front view of a piezoelectric motor according to Embodiment 1 of the present invention.
FIG. 6 is a partially cross-sectional plan view of a piezoelectric motor according to a second embodiment of the present invention, and FIG. 6 is a partially cross-sectional side view of a piezoelectric motor according to a third embodiment of the present invention. 1... Cantilever beam, 3s, 32... Piezoelectric vibrator, 6
...Cap bolt, 9...Rotor. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Procedure amendment meeting (spontaneous) January/7, 1980

Claims (4)

[Claims] 1. By bolting and fixing a piezoelectric thickness vibrator to the fixed end of the cantilever beam, bending vibration is excited in the cantilever beam, a slider is crimped to the free end surface of the cantilever beam, and the slider is crimped to the crimping surface of the slider. On the other hand, a piezoelectric motor is characterized in that it applies a moving torque in the direction along the bending vibration direction of the cantilever beam within this plane. 2. In the piezoelectric motor according to claim 1,
A piezoelectric motor characterized by using a rotor as a mover. 3. In the piezoelectric motor according to claim 1,
A linear motor-type piezoelectric motor characterized by a mechanism in which the mover moves back and forth linearly. 4. In the piezoelectric motor according to claim 1,
A piezoelectric motor characterized in that the relationship between the stator and the mover is swapped, an ultrasonic elliptical vibrator is attached to the mover, and the vibrator is moved together with the mover by the reaction of applying sliding torque to the crimp surface of the stator. .