JPS62225182A - Oscillatory wave motor - Google Patents

Abstract

PURPOSE:To dispense with a conversion mechanism in different constitution for converting the moving direction and to improve the efficiency by forming a screw at the contact portion of a vibrator and a moving body or a fixed body. CONSTITUTION:A vibratory ring lb is provided at an end of an electrome chanical transducer la. On the inside of the vibratory ring lb, a screw portion l0a composed of a recessed portion l0a is formed. Progressive vibratory waves are produced by impressing frequency voltage with phase difference to the electro mechanical transnsducerla arranged with phase difference. A screw portion l0b threaded with the screw portion 10a is formed to a moving body 3 which comes into contact with a vibrator l. The moving body 3 performs a spiral movement by the vibratory waves of the vibrator l.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a vibration wave motor that drives a moving body using progressive vibration waves, and particularly to a structure that converts its rotational motion into linear motion.

<Prior art> A vibration wave motor for rotating a moving body using progressive vibration waves generated in an annular elastic body is disclosed in, for example, Japanese Patent Laid-Open No. 59-20
Various structures have been proposed, as disclosed in Japanese Patent No. 1684 and the like.

By the way, in order to convert the rotational motion of this type of vibration wave motor into linear motion, a mechanism for converting the rotational motion into linear motion, that is, a screw, a rack, a gear, etc., is required. For example, in order to move a camera lens in the optical/F111 direction, a conversion using a helicoid of a different configuration that converts the rotational motion of a moving body into linear motion as disclosed in Japanese Patent Application Laid-Open No. 111117/1980 is used. A mechanism is required. Conventional devices in which a movable body is moved in a straight line through a separate conversion mechanism suffer a large amount of energy loss, and as a result, the motor output has to be increased by the amount of loss.

<Object of the Invention> The present invention provides a modification of a different configuration for changing the direction of motion as in the prior art.
In order to eliminate the j1 mechanism and reduce energy loss, in a vibration wave motor that generates circumferentially progressive vibration waves on a circular vibrating body, a spiral threaded portion is formed on the vibrating body and the threaded portion and The object is to cause the contact body to be screwed together to move relative to the vibrating body and the contact body in a direction different from the traveling direction of the progressive vibration wave, specifically, in the direction of the central axis of the circular vibrating body.

<Example> Figure 1 shows an example of the present invention, where Ia is an electro-mechanical energy conversion element, Ib is a vibrating body made of piezoelectric ceramics, for example, a vibration ring, and the vibration ring is made of aluminum alloy, iron-nickel alloy, stainless steel, or steel. The ring 1b is made of metal such as phosphor bronze, or a ring-shaped ceramic material such as alumina, and a threaded portion 10a consisting of a recess 10a1 is formed inside the photographing ring 1b. The piezoelectric ceramic Ia is fixed to the vibrating ring Ib by adhesive or the like to form a vibrating body 1. Piezoelectric ceramics 1a arranged with phase difference
By applying a frequency voltage with a phase difference (for example, 9°) to , progressive vibration waves are generated throughout the vibrating body l according to a known principle.

3 is a moving body that comes into contact with the vibrating body l, and this also has a convex portion ]Ob
, the vibrating body 1 is fixed by a fixing means (not shown), and the vibrating body 3 is a vibrating body l excited by piezoelectric ceramics. The vibrating waves cause a relative rotational movement, and at the same time, since they are in contact with each other at the threaded portions, a spiral movement occurs and also moves in the direction of the center 1IIIb100 of the vibrating body ring.

The vibration mode of the vibrating body 1 is the ring expansion/contraction mode disclosed in the Proceedings of the Acoustic Instrument Society of Japan (October 359) or Japanese Patent Application No. 60-49057, or the mode disclosed in Japanese Patent Application Laid-Open No. 60-210175. Vibrating body 1 disclosed in the publication
An in-plane bending mode that causes displacement in the radial direction is used.

Figure 2 shows an example of the electrode pattern and polarization of the piezoelectric ceramic 1a to excite the expansion/contraction mode of the ring, and the wiring method for applying a frequency voltage.The surface of the piezoelectric ceramic 1a is divided into eight equal parts. A TL pole is formed. (+) and (-) indicate polarity polarized in the direction perpendicular to the plane of the paper. The electrodes are connected every other electrode, and frequency voltages with a phase shift of 90° are applied to each group. 4 indicates a known 90° phase shifter. Figure 2 shows how to excite the second-order moat of ring expansion and contraction, or by changing the number of electrode divisions, we can also excite motes in other dimensions.
In principle, it is possible to drive a moving object in any mode higher than the first order.

Figure 3 shows a second real/one-color example of the electrode pattern and polarization of the piezoelectric ceramic 1a for exciting the in-plane bending mode of the ring, and the wiring method for applying a frequency voltage. '1' is a ceramic material, and 4 is a known 90° phase shifter. Figure 3 shows a method for exciting the fourth-order mote of in-plane bending, but as with the stretching mode, modes higher than the first-order can be excited. If so, the moving body can be driven.

The above fruit 7jf! In Example i, for example, a ring-shaped piezoelectric ceramic la is disposed only on the lower surface of the vibration ring 1b in FIG. 1, and the ring-shaped pressure '! t,h-
'Fb117) I-11-i1117kf:flu;
4JF;, l'iu! 100°view:, l-ni--))fil
E-dynamic link ring 1b waves were generated, but with this configuration, traveling waves are likely to be generated only around the joint between the vibration ring 1b and the piezoelectric ceramic Ia, and the vibration ring 1b
It is difficult to transmit traveling waves uniformly throughout the area. Therefore, in the embodiment shown in FIG.
By joining d and le and applying a frequency voltage with a phase shift of 90 degrees to each piezoelectric ceramic ld and le, a traveling wave in an expansion/contraction mode is generated in the vibration ring Ib as a whole. In this embodiment, compared to FIGS. 1 and 2, the output can be increased and the drive can be performed more efficiently.

FIG. 5 shows an embodiment in which the fourth-order mode of in-plane bending of the studs and rings in FIG. 3 is excited, and it is possible to obtain a larger output than that in FIG.

In the above embodiment, the vibrating body is formed with an external thread, but conversely, as shown in FIG. 6, the vibrating body is formed with a male thread,
It is also possible to configure the vibrating body to be a moving body, the fixed body 20 to generate a traveling wave between the female screw and the vibrating body, and the vibrating body 1 to move in the axial direction by itself due to friction with the fixed body 20. .

Furthermore, FIG. 7 is a cross-sectional view of another embodiment in which screws are provided on both the inner and outer sides of a ring-shaped vibrating body.

A stator 20 is fixed with bolts 5, is screwed together with the vibration 20, and further has a threaded portion 10d formed on the inner circumferential side of the vibration %l, and a movable body 6 that is screwed with the threaded portion 10d. It is made up of. Here, 10e is the threaded part of the stator 20, which is 10
f is a threaded portion on the inner surface of the vibrating body. Based on this configuration, by applying a frequency voltage to the piezoelectric ceramic 1a, a traveling wave is generated in the ring-shaped vibrating body 1, and the vibrating body 1 moves along the rotation Ir1lI1100 with respect to the stator 20, and further the vibrating body 1 The movable body 6 provided on the inner peripheral side of the vibrating body 1 moves in the same direction as the moving direction of the vibrating body 1 due to the vibration of the vibrating body 1. Now, if the distance between the screw threads 10c and 10d of the vibrating body 1 is equal on the outer circumferential side and the inner circumferential side, the movable body 6 will move upward along the rotation axis at twice the moving speed of the vibrating body 1. move in the direction.

However, when exciting an expansion/contraction mode in the vibrating body, the internal and external screws must be screwed in the same direction, and when exciting an in-plane bending mode, they must be screwed in opposite directions.

FIG. 8 is a sectional view of a structure for stabilizing the contact pressure of the movable body 3 in contact with the vibrating body 1. 5 is a disc spring, and if the spacing between the ridges of the threaded portion is uneven, the contact pressure between the movable body 3 and the vibrating body 1 will not be uniform, making it impossible to obtain a stable driving force. This function works so that uniform contact pressure can be obtained at all times. Alternatively, a bottle for fixing the relative position of the left and right moving bodies.In this embodiment, the cross section of the threaded portion is approximately triangular, but the point is that the moving body and the vibrating body each have a concave part and a convex part. If it has a shape that fits, it is a good fit.

<Effects> By forming a screw at the contact portion between the vibrating body and the moving body or fixed body in the annular vibration motor, (1) a conversion mechanism from rotational motion to linear motion is not required;

(2) Therefore, there is no energy loss associated with the conversion mechanism,
This is a highly efficient linear actuator.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a vibrating body and a moving body of a vibrator according to the present invention; Fig. 2 is an electrode pattern, polarization polarity, and connection diagram of a piezoelectric ceramic according to an embodiment that excites a stretching mode; Fig. 3; Figures 4 and 5 are diagrams illustrating the electrode pattern, polarization polarity, and connection diagram of the piezoelectric ceramic of the embodiment that excites the in-plane bending mode, and Figures 4 and 5 are diagrams explaining the configuration of the vibrating body in which piezoelectric ceramics are bonded to both ends of the vibrating body. , Fig. 6 is a cross-sectional view showing an embodiment in which male threads are formed on the vibrating body, Fig. 7 is a cross-sectional view showing an embodiment in which screws are formed on both the inside and outside of the vibrating body, and Fig. 8 is a cross-sectional view showing an embodiment in which screws are formed on both the inside and outside of the vibrating body, and Fig. 8 stabilizes the contact pressure. FIG. In the figure, 1 is a vibrating body, and 3.6 is a moving body.

Claims (1)

[Claims] By applying a frequency voltage to an electro-mechanical energy conversion element, a progressive vibration wave is generated in the circumferential direction of a circular vibrating body, and the vibrating body and a contact body in contact are caused to move relative to each other. In the vibration wave motor, a convex portion or a concave portion is formed on the vibrating body, the convex portion or the concave portion forms a spiral shape, and a fitting portion that fits into the convex portion or the concave portion is formed on the contact body; A vibration wave motor characterized in that the vibrating body and the contact body are caused to move relative to each other in a direction different from the circumferential direction.