JPH06339288A - Wave circulation type actuator - Google Patents

Abstract

PURPOSE:To minimize the influence of the displacement of a bar-shaped vibrating body in its length direction on the vibrating mode required for the drive of a mobile object so as to support the vibrating body with a low supporting loss by absorbing the displacement of the vibrating body. CONSTITUTION:A mobile object 3 holds a bar-like vibrating body 1 with bodies 3a and 3b which are press-contacted with the opposite surfaces of the vibrating body 1 and have U-shaped cross sections. The length of the vibrating body 1 in its length direction at the exciting time becomes shorter than that at non- exciting time by the wavy part. The difference in length between the exciting time and non-exciting time can be absorbed by the elastic deformation of bent sections 4a and 5a and the supporting loss of the vibrating body 1 is minimized by forming the bent sections 4a and 5a in supporting means 4 and 5 by bending the means 4 and 5 in the middle by about 90 deg.. Therefore, the influence of the displacement of the vibrating body 1 on the moving mode required for the drive of the mobile body 3 can be minimized and the vibrating body 1 can be supported with a low supporting loss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wave circulation type actuator that circulates a wave in a rod-shaped vibrating body and moves the moving body by the wave.

[0002]

2. Description of the Related Art Conventionally, as an apparatus of this type, for example, there is one disclosed in JP-A-59-122385. There, a ring type shown in FIG. 9, a vibration feedback type shown in FIG. 10, an energy feedback type shown in FIG. 11 and the like are disclosed.

[0003]

However, in the above-mentioned conventional devices, there is a problem in that the size of the whole is large because a return path is required separately from the drive section. It was Therefore, it is an object of the present invention to provide a wave circulation type actuator which does not require a return path outside the drive section and has a supporting means for supporting the most efficiently.

[0004]

The present invention solves the above problems by the following means. In addition, in order to facilitate understanding, the description will be given with the reference numerals corresponding to the embodiments, but the present invention is not limited thereto. That is, the first solution means of the wave circulation type actuator according to the present invention is
A rod-shaped vibrating body (1) having two surface groups in a longitudinal direction, a first surface group consisting of two surfaces facing each other and a second surface group consisting of two surfaces facing each other different from the first surface group; An exciter (2) provided on the first surface group of the rod-shaped vibrating body and generating a wave traveling in the longitudinal direction of the first surface group, and the first surface provided on one end of the rod-shaped vibrating body. A first reflecting portion (E-face / F-face) that reflects a wave traveling in the longitudinal direction of the group and transmits it to the second surface group; and the second surface group provided on the other end of the rod-shaped vibrating body. To the first surface group by reflecting the waves transmitted to the first surface group and propagating in the longitudinal direction.
H-plane) and the rod-shaped vibrating body are supported by a fixed portion, and the rod-shaped vibrating body is coupled by an end portion thereof, and at least one position between the rod-shaped vibrating body and the fixed portion is long. The support means (4, 5) having a displacement absorbing portion for absorbing the displacement in the direction and the moving body (3) which is pressed against the rod-shaped vibrating body and moves by the traveling wave are formed.

A second solving means is the wave circulation type actuator according to the first solving means, wherein the supporting means has a rod-shaped portion extending in the longitudinal direction of the rod-shaped vibrating body. . Furthermore, the third solution is
In the wave circulation type actuator according to the second solving means, the displacement absorbing portion of the supporting means has a bent portion (4a, 5a) formed at least at one position between the rod-shaped vibrating body and the fixed portion. Is characterized in that.

[0006]

In the present invention, as described above, since the supporting means having the displacement absorbing portion for absorbing the displacement in the longitudinal direction is provided at the longitudinal end portion of the rod-shaped vibrating body, the vibration mode required for driving the moving body is provided. The impact on the product is minimized, and support with low support loss is possible.

[0007]

Embodiments will be described in more detail below with reference to the drawings and the like. FIG. 1 is a perspective view showing a first embodiment of a wave circulation type actuator according to the present invention, and FIG. 2 is a front view showing the wave circulation type actuator of the embodiment of FIG. The rod-shaped vibrating body 1 has four surfaces A to D in the longitudinal direction (see FIG. 3), the A and C surfaces face each other to form a first surface group, and the B and D surfaces are The second surface group faces each other. Further, for convenience of explaining the traveling direction of the wave, the left end in the longitudinal direction will be referred to as "N end" and the right end will be referred to as "S end" hereinafter. Details of the shape will be described later with reference to FIG. The exciter body 2 is composed of a plurality of plate-shaped piezoelectric bodies, and the polarization directions of the piezoelectric bodies are arranged in opposite directions alternately in groups of two. The details will be described later with reference to FIG.

The movable body 3 is composed of main bodies 3a having a U-shaped cross section.
The surface B and the surface D of the rod-shaped vibrating body 1 facing each other are pressed against each other by b. Connecting members 3c to 3f (3e,
3f is an urging member for pressure contact, which acts in a direction to draw the main bodies 3a and 3b toward each other. The supporting means 4 is a thin rod shape that is connected to the N-end of the rod-shaped vibrating body 1, extends in the longitudinal direction of the rod-shaped vibrating body 1, and has a bent portion 4a bent almost at a right angle from the middle, and supports the rod-shaped vibrating body 1. To do. Further, the supporting means 5 is connected to the S end of the rod-shaped vibrating body 1, extends in the longitudinal direction of the rod-shaped vibrating body 1, and has a thin bar shape having a bent portion 5a bent from the middle in the same direction as the supporting means 4 at a substantially right angle. And supports the rod-shaped vibrating body 1.

The length in the longitudinal direction of the rod-shaped vibrating body 1 becomes shorter by the amount of waviness when excited than when it is not excited. Therefore, the supporting means 4 and 5 are formed in a shape having bent portions 4a and 5a which are bent substantially at right angles from the middle, so that the difference in length between the time of excitation and the time of non-excitation can be reduced.
It is possible to absorb the elastic deformation of 5a and minimize the support loss. The supporting means 4 and 5 are respectively arranged between the rod-shaped vibrating body 1 and the fixed portions 6 and 7, and have a vibration-proof function that does not transmit the vibration of the rod-shaped vibrating body 1 to the fixed portions 6 and 7.

FIG. 3 is a detailed view of the rod-shaped vibrating body shown in FIG. 3A and 3B are drawn by the third angle method. FIG. 3A is a front view, FIG. 3B is a plan view, FIG. 3C is a left side view, and FIG. 3D is a right side view. Note that the four surfaces in the longitudinal direction are labeled A to D. The rod-shaped vibrating body 1 is composed of two triangular-shaped surfaces at the N end, and is named E and F. Further, the S end is also composed of two triangular surfaces, and the names G and H are given. Surfaces E to H are reflecting portions provided to reflect waves traveling in the longitudinal direction. Here, the reason why the G surface and the H surface are twisted by 90 ° with respect to the E surface and the F surface is that the waves can be circulated without providing a return path outside the driving unit. is there.

FIG. 4 is a diagram for explaining how the bending wave traveling in the rod-shaped vibrating body of FIG. 1 is circulated. Rod-shaped vibrating body 1
Causes a bending wave to be generated by applying a high-frequency voltage to the excitation body 2 provided on the A surface, and the bending wave is generated on the A surface and the C surface.
It vibrates in the direction perpendicular to the plane, and progresses from the S end to the N end as shown in the lower right (a) of FIG. Then, by being reflected by the E and F surfaces at the N end (b), it becomes a bending wave that oscillates in a direction perpendicular to the B and D surfaces, and as shown in the left center (c) of FIG. It progresses from the N end to the S end. Further, by being reflected by the G and H surfaces at the S end (d), a bending wave that oscillates again in a direction perpendicular to the A and C surfaces is again circulated. The bending waves oscillating in the direction perpendicular to the A-plane and the C-plane and the bending waves oscillating in the direction perpendicular to the B-plane and the D-plane are polarized in directions perpendicular to each other, so that the phases are the same. If not, it is incoherent.

FIG. 5 is a diagram for explaining the circulation of surface waves traveling in the rod-shaped vibrating body of FIG. Rod-shaped vibrating body 1
Generates a surface wave by applying a high frequency voltage to the exciter 2 provided on the A surface, and the surface wave vibrates in a direction perpendicular to the A surface, as shown in the upper left (a) of FIG. From S end to N end. Then, the E surface at the N end is reached, and E
The surface wave is reflected by the line of intersection of the surface and the F surface, reaches the B surface, becomes a surface wave that oscillates in a direction perpendicular to the B surface, and travels from the N end to the S end direction. Next, it reaches the G surface at the S edge, is reflected by the line of intersection of the G surface and the H surface (b), reaches the C surface, and becomes a surface wave that oscillates in the direction perpendicular to the C surface. Proceed to (C). Further, it reaches the F surface at the N end, is reflected by the line of intersection of the F surface and the E surface (d), reaches the D surface and becomes a surface wave oscillating in a direction perpendicular to the D surface, and from the N end to the S end direction. Proceed to (e). Then, it reaches the H surface at the S end, is reflected by the line of intersection of the H surface and the G surface (f), and again reaches the A surface and circulates (g).

FIG. 6 is a developed view of the surface of the rod-shaped vibrating body of FIG. Although the circulation of bending waves has been described with reference to FIG. 4 and the circulation of surface waves has been described with reference to FIG.
The bending wave becomes dominant when the attenuation in the deep part of is small or when the vibration amplitude of the exciter 2 is large. On the contrary, when the attenuation of the deep portion of the rod-shaped vibrating body 1 is large or the vibration amplitude of the exciter 2 is small, the surface wave becomes dominant. FIG. 6 shows both waves on the same drawing. What is important from this figure is that both the bending wave and the surface wave travel in the same direction in the planes A to D in the longitudinal direction. This confirms that the bending wave and the surface wave do not cancel each other out.

FIG. 7 is a diagram for explaining the structure of the exciter of FIG. 1 and the method of applying power. The excitation body 2 is composed of eight driving piezoelectric bodies 2a to 2h and a vibration detection piezoelectric body 2i. As shown in FIG. 7, the driving piezoelectric bodies 2a to 2h are arranged in pairs so that the polarization directions are alternately opposite. In the figure, "+" indicates that the polarization direction is from the front side to the back side of the paper, and "-" indicates that the polarization direction is from the back side to the front side of the paper. Then, the driving piezoelectric bodies 2a, 2c, 2
A high-frequency voltage V1 is applied to the surface electrodes every other e, 2g, and a high-frequency voltage V2 is applied to the surface electrodes of the remaining driving piezoelectric bodies 2b, 2d, 2f, and 2h. The high frequency voltage V2 has the same frequency as the high frequency voltage V1, and is π / 2.
Has a temporal phase difference of. Driving piezoelectric bodies 2a to 2h
The back surface of is bonded to the surface A of the rod-shaped vibrating body 1 while electrically conducting. Therefore, the rod-shaped vibrating body 1 is the common electrode "GND". By applying the high frequency voltages V1 and V2, the driving piezoelectric bodies 2a to 2h expand and contract, and a progressive wave is generated in the rod-shaped vibrating body 1. A more detailed pattern regarding the generation of waves is disclosed in Japanese Patent Application Laid-Open No. 60-24548 by the present applicant.
The description is omitted here because it is described in Japanese Patent Publication No.

The vibration detecting piezoelectric body 2i is for converting the vibration generated in the rod-shaped vibrating body 1 into a voltage, and it is possible to control the input while monitoring the magnitude and phase difference of the generated voltage. Become. For details, refer to JP-A-59-204477 and JP-A-61-251490 by the present applicant.
Since it is described in the publication, etc., the description is omitted here.

FIG. 8 is a sectional view for explaining the relationship among the rod-shaped vibrating body, the exciting body, and the moving body in FIG. Exciter 2
Is arranged on the surface A of the rod-shaped vibrating body 1, and the moving body 3 slides while sandwiching the surface B and the surface D of the rod-shaped vibrating body 1.

FIG. 12 is a front view showing a second embodiment of the wave circulation type actuator according to the present invention. In each of the embodiments described below, the parts having the same functions as those in the first embodiment are given the same reference numerals or the reference numerals at the end are unified. In the second embodiment, the supporting means 14, 1
5 are arranged between the rod-shaped vibrating body 1 and the fixed portions 16 and 17, respectively. The supporting means 14 is connected to the N end of the rod-shaped vibrating body 1, has a thin rod shape extending in the longitudinal direction of the rod-shaped vibrating body 1, and supports the rod-shaped vibrating body 1. Also, the supporting means 15
Is connected to the S end of the bar-shaped vibrating body 1, extends in the longitudinal direction of the bar-shaped vibrating body 1, and is bent at a substantially right angle from the middle thereof.
It is a thin rod shape having 5 a and supports the rod-shaped vibrating body 1. In the case of the second embodiment, since the bending portion 15a is provided in the supporting means 15, the difference in length between the excited state and the non-excited state can be absorbed by the elastic deformation of the bent portion 15a. Further, when the wall surface of one fixing portion 16 is substantially perpendicular to the rod-shaped vibrating body 1, it is sufficient to provide the bent portion 15a only on the supporting means 15 on the other end side.

FIG. 13 is a front view showing a third embodiment of the wave circulation type actuator according to the present invention. In the third embodiment, the supporting means 24 and 25 are arranged between the rod-shaped vibrating body 1 and the fixed portions 26 and 27, respectively. Support means 24
Is a thin rod shape that is connected to the N end of the rod-shaped vibrating body 1 and extends in the longitudinal direction of the rod-shaped vibrating body 1, and supports the rod-shaped vibrating body 1. Further, the supporting means 25 is connected to the S end of the rod-shaped vibrating body 1, extends in the longitudinal direction of the rod-shaped vibrating body 1, and is bent in zigzag from the middle to four bent portions 25a-1 and 25a-.
The rod-shaped vibrating body 1 is supported by a thin rod shape having 2, 25a-3 and 25a-4. In the case of the third embodiment, since the supporting means 25 is provided with the bent portions 25a-1 to 25a-4 which are bent at four places from the middle, the difference in length between the time of excitation and the time of non-excitation is The elastic deformation of the bent portion 15a enables efficient absorption. In addition, even when the wall surface of the fixed portion 27 is substantially perpendicular to the rod-shaped vibrating body 1, the bent portion 25a can be provided on the support means 25 side.

FIG. 14 is a front view showing a fourth embodiment of the wave circulation type actuator according to the present invention. In the fourth embodiment, the supporting means 34 and 35 are arranged between the rod-shaped vibrating body 1 and the fixed portions 36 and 37, respectively. Support means 34
Is a thin rod shape that is connected to the N end of the rod-shaped vibrating body 1 and extends in the longitudinal direction of the rod-shaped vibrating body 1, and supports the rod-shaped vibrating body 1. Further, the support means 35 is a thin rod shape that is connected to the S end of the rod-shaped vibrating body 1, extends in the longitudinal direction of the rod-shaped vibrating body 1, and has a displacement absorbing portion 35a that absorbs displacement in the longitudinal direction in the middle thereof. The vibrating body 1 is supported. This displacement absorbing portion 35a
Is composed of a moving member 35a-1 and a guide member 35a-2 which movably supports the moving member 35a-1 in the longitudinal direction. In the case of the fourth embodiment, since the displacement absorbing portion 35a is provided on the support means 35, the difference in length between the excited state and the non-excited state is determined by the displacement absorbing portion 35a.
Can be absorbed by moving. Also, the supporting means 34, 35
The axis of is not displaced and the rod-shaped vibrating body 1 can be stably supported.

[0020]

As described above, according to the present invention, since the supporting means having the displacement absorbing portion for absorbing the displacement in the longitudinal direction is provided at least at one end portion in the longitudinal direction of the rod-shaped vibrating body, the moving means can be moved. The influence on the vibration mode required to drive the body is minimized, and support with low support loss is possible.

[Brief description of drawings]

FIG. 1 is a first wave circulation type actuator according to the present invention.
It is a perspective view showing an example.

FIG. 2 is a front view showing the actuator of the embodiment of FIG.

FIG. 3 is a detailed view showing the rod-shaped vibrating body of FIG.

FIG. 4 is a diagram for explaining how a bending wave traveling in the rod-shaped vibrating body of FIG. 1 is circulated.

FIG. 5 is a diagram for explaining the circulation of surface waves traveling in the rod-shaped vibrating body of FIG.

6 is a developed view showing the surface of the rod-shaped vibrating body of FIG. 1. FIG.

FIG. 7 is a diagram illustrating a configuration of the exciter of FIG. 1 and a method of applying a power source.

8 is a cross-sectional view illustrating the relationship among the rod-shaped vibrating body, the exciting body, and the moving body in FIG.

FIG. 9 is a cross-sectional view showing a conventional actuator (annular type).

FIG. 10 is a sectional view showing a conventional actuator (vibration feedback type).

FIG. 11 Conventional actuator (energy feedback type)
FIG.

FIG. 12 is a perspective view showing a second embodiment of the wave circulation type actuator according to the present invention.

FIG. 13 is a perspective view showing a third embodiment of the wave circulation type actuator according to the present invention.

FIG. 14 is a perspective view showing a fourth embodiment of the wave circulation type actuator according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Rod-shaped vibrating body 2 Exciting body 3 Moving body 4,14,24,34,5,15,25,35 Supporting means 4a, 5a, 15a, 25a Bending part 35a Displacement absorption part

Claims (3)

[Claims] 1. A rod-shaped vibrating body having two surface groups in the longitudinal direction, a first surface group consisting of two surfaces facing each other and a second surface group consisting of two surfaces facing each other different from the first surface group. An exciter that is provided on the first surface group of the rod-shaped vibrating body and that generates a wave traveling in the longitudinal direction of the first surface group; and a first surface group that is provided on one end of the rod-shaped vibrating body. A first reflecting portion for reflecting a wave traveling in the longitudinal direction and transmitting it to the second surface group; provided on the other end of the rod-shaped vibrating body, transmitted to the second surface group and traveling in the longitudinal direction A second reflecting portion for reflecting waves to circulate in the first surface group; a member for supporting the rod-shaped vibrating body on a fixed portion, the rod-shaped vibrating body being joined by an end portion thereof. And a supporting means having a displacement absorbing portion that absorbs displacement in the longitudinal direction at least at one location between the fixing portion and the fixing portion. A wave circulation type actuator including a moving body that is pressed against the rod-shaped vibrating body and moves by the traveling wave. 2. The wave circulation type actuator according to claim 1, wherein the supporting means has a rod-shaped portion extending in a longitudinal direction of the rod-shaped vibrating body. 3. The wave circulation type actuator according to claim 2, wherein the displacement absorbing portion of the supporting means is a bending portion formed at least at one position between the rod-shaped vibrating body and the fixed portion. A wave circulation type actuator characterized in that