JPS5893477A - Piezoelectric motor - Google Patents

Abstract

PURPOSE:To enable to arbitrarily switch the driving direction of a piezoelectric motor as required by applying a voltage output having the prescribed phase difference to a plurality of vibrators. CONSTITUTION:A vibrator section 15 has a pair of vibrator 18, 19 which are depended vertically substantially in parallel with the downward from the lower surface 17 of a stationary unit 16. Voltage outputs having the prescribed phase difference are respectively applied from a drive control circuit 25 to the electrode plates of the vibrators 18, 19. The advance and delay of the relative phase of the voltage outputs are altered by a changeover switch 26, thereby allowing the vibrating mode of a vibration piece 20 to be altered, and the driving direction of a drive output member 23 is switched by the piece 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piezoelectric motor, and particularly to a piezoelectric motor in which a drive shaft J can be arbitrarily switched as required.

The piezoelectric motor utilizes the inverse piezoelectric effect of a vibrator made of a piezoelectric material such as a piezoelectric ceramic or a piezoelectric crystal, and linearly interlocks or rotates the drive output by the expansion and contraction force generated when a voltage is applied to the vibrator. In this way, a mechanical output is generated, and the configuration shown in FIG. 1 has been conventionally considered as a configuration for switching the direction of movement of this mechanical output.

In other words, in the case of FIG. 1, two vibrators (3) and (3) made of piezoelectric ceramic are used so that they can come into contact with the surface of the drive output section (contacted) that can be interlocked with electric movement or rotation in the left-right direction.
4) It is not well established. Each vibrator (3) and (4) has one end identified as 5 (5) and (6), and is made of a plate-shaped piezoelectric material, for example, and is attached to surfaces facing each other when viewed in the thickness direction. The rowed electrode plates (3A), (3B) and (4A×(
4B) to a power source (7) and (8) delivering a sinusoidal output voltage).
is designed to extend and move in the vertical direction.

In the first garden, the oscillator (3) of the right wing is vertically imaginary 11jL1, and the driving output is from the upper left side to the lower right side (1)
Table 1fia> is arranged so that when the vibrator (3) is extended, the tip comes into contact with the surface (2) and this surface (2) and therefore the drive output section frame (1). Push it to the right, and when the vibrator (3) shortens from this extended state, the tip is separated from the table It (2) and no driving force is applied to this surface (2) (and therefore the drive output part) 1). It is done like this.

Note that the vibrator (3) supported cantilevered in this way has a surface (
When expanding and contracting in a direction oblique to oscillator (3),
) The locus of motion of the point P1 that contacts the surface (2) of the tip draws a nearly elliptical shape as shown in FIG. By the way, the vibrator (3)
When is in the IJjii contracted state, the contact point P1 is at position 1
When the vibrator (3) begins to expand, the contact point P1 moves obliquely downward through the loop a1 toward the position fItK2. Contact point P1 is l1kl
When it reaches (2), it can no longer go to the loop IL2 on the ellipse, so the contact point P1 becomes the loop &
Go through 3 and move to the right. At this time, the tip of the vibrator (3) is strongly pressed in the direction (2) at the contact point P1, and the friction forces the surface (2) to the right. When the vibrator (3) reaches its full length and begins to shorten, the contact point P
1 is separated from the surface (2) at position 3, and the vibrator (3
) passes through the loop a3 on the ellipse and returns to the original position in the upper left corner at 1.

In this way, the contact point P1 pushes the drive output part (1) to the right while it is in contact with the surface (2), and therefore the drive output part It is possible to avoid applying force to 1'(1). And the contact point P□ is a surface (2)
When stress is applied to the opening mover (3) which is in contact with and in the direction perpendicular to the Fi longitudinal vibration direction, an e vibration component is generated, which causes it to continue to vibrate along an elliptical trajectory. Become. Therefore, the drive output S (1) is driven to the right by a distance of approximately tK2 every time the vibrator (3) vibrates once.

On the other hand, the right transducer (4) L is vertically imaginary &
The transducer L2 was driven in the same manner as the above-mentioned vibrator (3), except that L2 was disposed from the upper right to the lower left in FIG. As a result, when the vibrator (4) vibrates 1-1, the drive output section G'(1) is driven to the extreme left, which corresponds to the position 2-2 in FIG.

Therefore, according to the configuration of No. 1 II, when sending the drive output part (1) to the right, the oscillator (4) is placed in a non-operating state, and the oscillator (4) is kept in a state away from the surface (2). vibrator (3
), and in contrast, when sending the drive output part (1) to the left, vibrator 0) is inactive and this vibrator (3) is kept away from surface e) and vibrated. By operating the child (4), the drive direction of the drive output sI'(1) can be switched.

However, according to the conventional configuration shown in FIG.
1) Two oscillators (3) and (4) depending on the zero motion direction
It is therefore necessary to separately prepare two sets of a related mechanism for vibration operation, and the total structure inevitably becomes 1111K in number. In addition, the two vibrators (3) and (4) must be arranged so as to face in a predetermined direction with respect to the plane @ point 02 of the drive output section W (1), so that the drive output section I"
(1) A relatively large space is required around the periphery of the vibrator in contact with the oscillator, and therefore there are certain limitations when trying to obtain a 7-1 that is compact as a whole.

The present invention has been made in consideration of the above points, and the driving direction of the drive output part can be arbitrarily changed as required by simply providing one vibrating part that contacts the surface of the drive output part. This paper attempts to propose a piezoelectric motor that can be replaced.

An embodiment of a piezoelectric motor according to the present invention will be described in detail below with reference to the drawings.

In Fig. 3, (15) is the Fi vibration part and the fixed part (1
6) has a pair of vibrators (18) and (19) supported downwardly and parallel to each other from the lower surface (17) of the vibrator. The vibrators (18) and (19) are made of pressure tIR material having the same quality, dimensions, and characteristics, and a vibrating piece (2o) is bridged at the lower roadside of each vibrator. The vibrating piece (21J) includes a bridge plate (21) that is bridged between the free ends of the vibrators (18) and (19), and a central exit piece (22) that protrudes downward from the lower surface of the O-bridge plate (21). The vibrators (18) and (19) are attached to the fixed part (16) so that the tip of the center output part (22) faces the surface (24) of the drive output part & (23) with a predetermined gap. be scattered on.

Electrode plate (18A) of vibrator (18) and (19), (1
8B) and (19A), (19B) Voltage outputs E1 and E having a phase difference of 90 degrees from each other are given from the tcIIi drive control circuit (25), and these voltage outputs E and E2
For example, the shift or delay in the relative phase of the changeover switch (2
6), and by changing the vibration mode of the vibrating element (2o), the drive output section by the vibrating element (20) can be changed. ￥ (23
) can change the driving direction.

In the above structure a, the switch (26) is connected to the pressure feeding side A.
When switched to 26L, the first vibrator (18) is connected to the circuit (
25) at time t as shown in FIG. There is a process of elongation from the natural length (time point 1), a process of shortening after reaching the maximum length (time point 12), and a process of further shortening to the natural length. ) The process of becoming shorter (time t3
), and the process of elongation after reaching the shortest length (time t
4') and f: Sequentially, at 114 t, the natural length returns to its original state lIK, and the change in length draws a sinusoidal waveform.

On the other hand, the length of the second vibrator (19) is
), the voltage outputs E and K given by
The 0° phase changes as if delayed, and at time t. The process of elongating from the state of shortening to the shortest length to the natural length (time point 11), and further elongating to the natural length (time point 11). (Time point 1.), and after reaching the longest length K, it shortens to 1i! (time point 1.) and a process of further shortening to the natural length (time point t5), and then vibrate so as to return to the shortest shortened state at time point 1s.

At this time, the vibrating element (20) is connected to the first and second vibrating elements at each time point.
Depending on the degree of elongation or shortening of the vibrators (18) and (19), the tip of the protrusion (22) of the vibrating element (@) is tilted at the center as shown in Figure 5. moves in an elliptical locus in the buried plane. That is, at time ti, the first oscillator (18) is extended and the second
The oscillator (since the oscillator is shortened, the protruding element (22) a tilts to the right in Fig. 5 and comes to the right talon position tKuK. At the subsequent time t2, the first and 20th & oscillator (18) and (
19) are both extended, the protrusion (22) is lowered downward at the center position of the vibrators (18) and (19) and comes to a position approximately below the center □2.

At the edge O time t3, the first oscillator (18) is shortened and the second oscillator (19) is extended, so the protrusion (
22) tilts to the left and comes to the right position at 1B. At the subsequent time t4, the first and second oscillators (18) and (1
9) are both shortened by Km, so the protrusion (22) is the oscillator (
It rises upward at the center position of 18) and (19) and comes to the center lower position of 14. Then, through time t, to time t. K returns to the original state described above.

Therefore, the protrusion (?2) will draw an elliptical locus rotating clockwise as shown in FIG. Therefore, the drive output section 4't' (23) is arranged so that it falls within this elliptical orbit, and the central output (22) of d1 is placed on the surface (24) of the drive output section Q- (23). When the state is reached, it moves from the right side to the left side through the loop a□2 along the surface (24') K without passing through the loop '11, and thereby the jlJk dynamic output section 'D
'(Z3) will be pushed to the left.

When the selector switch (X3) is switched to the right feed position (26R) from this operating state, the first and second vibrators (
Voltage outputs E8 and E20 for 18) and (19)
The phase relationship changes and the phase of voltage output E2 becomes voltage output E1.
The phase of the change in the position of the second oscillator (19) (FIG. 6B) or the phase of the change in the position of the first oscillator (18) (FIG. 4 ) phase is 90
It's going to be a lot of progress. However, from time t0 to t in Figure '4
Considering the states of the first and 20th oscillators (18) and (19) that die from time t0 to time t in FIG. has shortened and the second vibrator (19) has expanded, so the protrusion (
22) tilts to the left in Figure 5 and comes to 13 in the 9 left position. At a subsequent time point t, the first and second oscillators (1
8) and (19) are both extended, so the protrusion (22)
) is located approximately at the lower center position at 12.

At the subsequent time point t3, the first C) vibrator (18) has expanded and the second vibrator (19) has moved 41 degrees, so the protrusion (22) tilts to the right and comes to the right position □1. At a subsequent time t, it is the first and second oscillator' (18
) and (19) are both shortened, so the protrusion (22)
is approximately at the upper center position at 14.

Therefore, at this time, the protrusion (22) draws an elliptical locus that rotates counterclockwise, contrary to that described above with reference to FIG. will be pushed to the right.

Using the piezoelectric motor with the configuration shown in Figure 3 in this way,
By operating the changeover switch (26) as necessary, the driving direction of the drive output section 41' (D) by the vibrating section (15) can be changed accordingly, as shown in No. 7E.

In the above description, the vibrating part (15) is made of IIJIE L using two vibrators, and the protrusion is moved in a vertical plane. It is also possible to use a plurality of oscillators to move the protrusion in three-dimensional space.

In the above description, the vibrators (18) and (19) were constructed using piezoelectric bars having the same material, dimensions, and characteristics, but instead, they may be made to be different, and the structure of the vibrating pieces may be In addition to the above-described structure, the cage may be one in which a plurality of vibrators are bridged so that the protrusion can be driven in contact with the drive output section in accordance with the expansion and contraction of each vibrator.

As described above, according to the present invention, the drive direction of the drive output member can be arbitrarily switched as necessary by simply providing one vibrating part that comes into contact with the drive output member. It is possible to easily obtain a piezoelectric motor in which the configuration of the vibrator chest that contacts the output portion can be simplified and miniaturized.

[Brief explanation of the drawing]

Fig. 1 is a linear 11I8n diagram showing a conventional piezoelectric motor, and Fig. 2 is an approximately 1IiI diagram showing the vibration locus of its vibrator.
Fig. 3 is a line side view showing an embodiment of the piezoelectric motor according to the present invention, Fig. 4 is a curve diagram showing the operation of the vibrator during leftward movement, and Fig. 5 is the vibrating element at each point in time. A route map showing the operation of Figure 6, a curve diagram showing the operation of the vibrator during rightward transport,
・#171Il is a schematic side view showing the drive state of the drive output unit by the vibrating unit. Figure 3 R 26 deficiency 61 tE2 /6 +th Rfi gloss J 1 emotion) 5 -ri/p Cow 4 @ Tea 6 Garden Figure 7 Proceedings formal notice @ @ 1957 AA28B Patent H Director Haruki Shimada Incident O Indication Showa Circulation Division 轡迡证 [1g9726 1issue@O name piezoelectric rod - data correction t sui person case and O relation Applicant's address 6-7 Kanei No. 4, Kitashinyo, Tokyo Parts Co., Ltd., agent Man(
〒141) Address: Kitashina-yo 6-7, Tokyo Parts-Yo-ku 3 @

Claims (1)

[Claims] a plurality of vibrators that are cantilever-supported at a predetermined distance from each other; and a vibrating piece that is bridged between the plurality of vibrators and that can contact the drive output section beam and drive the drive output section beam. By applying voltage outputs having a predetermined phase difference to each of the plurality of vibrators to cause the vibrators to expand and contract in a predetermined vibration mode, a drive open circuit that changes the vibration mode of the vibrator and changes the direction of the main body force of the vibrating element with respect to the drive output section beam by driving the vibrator and changing the phase difference; A piezoelectric motor characterized by: