JP4046966B2 - Vibration wave drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration wave driving device capable of multi-degree-of-freedom driving.
[0002]
[Prior art]
Conventionally, an example of a vibration wave driving device such as a vibration wave motor that can be driven with multiple degrees of freedom is disclosed in Japanese Patent Application Laid-Open No. 62-141978. This multi-degree of freedom vibration wave motor is shown in FIG. As shown in FIG. 4, a large number of ring-shaped vibrating bodies M1 to M4 are pressed against a spherical moving body.
[0003]
This type of vibration wave motor requires one vibrating body for each degree of freedom, and a plurality of vibrating bodies are necessary to enable driving with multiple degrees of freedom, which is not suitable for miniaturization.
[0004]
In addition, since the vibrating body that does not contribute to driving is also pressed by the spherical moving body among the plurality of vibrating bodies, the friction force with this acts as a brake to inhibit the movement of the moving body, or to reduce the friction force. Wasteful energy was required to generate a standing wave for reduction.
[0005]
Further, the multi-degree-of-freedom vibration wave motor described in Japanese Patent Application Laid-Open No. 11-220893 presses a spherical moving body b against a rod-shaped vibrating body a as shown in FIG. However, since the shape of the vibrating body is a rod-shaped body, it is not suitable for downsizing.
[0006]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to solve such a conventional problem and to provide a vibration wave driving device such as a vibration wave motor that can move in a multi-degree of freedom with a small and simple structure. is there.
[0007]
[Means for Solving the Problems]
Configuration for realizing the object of the invention according to this application, the elastic body and the provided in the elastic body electrically - a vibration body provided with a mechanical energy conversion element, pressurized to a plurality of projections provided on the resilient member in the vibration wave driving device having a movable body that pressure contact, the electro - mechanical energy conversion element to the elastic member, vibration of even order in the in-plane direction and the odd order out-of-plane direction of the vibration, or odd the Rukoto to generate vibration of vibration and even order out-of-plane direction of the plane direction of the order, the moving body is frictionally driven, the plurality of protrusions of the in-plane direction vibration and the out-of-plane direction of the With respect to vibration, it is characterized in that it is provided at a position that becomes an antinode of these vibrations and a position that is an antinode of one vibration and becomes a node of the other vibration .
[0008]
(Delete)
[0009]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
FIG. 1 is a perspective view of a vibrating body showing a first embodiment of a vibration wave driving device according to the present invention.
[0010]
In the figure, 1 is an elastic body annular shape made of a metal or the like, the protruding portion 3 of the four locations on the surface are formed. Reference numeral 2 denotes a piezoelectric element as an electro-mechanical energy conversion element, which is bonded to the elastic body 1 to constitute a vibrating body.
[0011]
In such a vibrating body, when an alternating electric field is applied to the piezoelectric element 2, the piezoelectric element 2 expands and contracts in the circumferential direction, so that the entire vibrating body undergoes bending deformation. Further, by making the frequency of the AC electric field applied to coincide with the natural frequency of the vibrating body, an odd number order shown in FIG. 3 (a) 3-order plane vibration (bending vibration) or, in FIG. 3 (b) The displacement of the secondary out-of- plane vibration (bending vibration) that is the even order shown is enlarged. As can be seen, the surface particles of the vibration member in the abdomen of the surface vibration displaced in the radial direction in the ring plane (plane of FIG. 3 (a)), out-of-plane vibration is displaced to the ring plane outward.
[0012]
Here, if the two natural frequencies are substantially matched, in- plane vibration and out-of-plane vibration (bending vibration) can be simultaneously generated at the same frequency.
[0013]
As a result, if an elliptical motion occurs in the protrusion 3 positioned on the diameter of the vibrating body, the movable body 4 pressed against the protrusion 3 can be frictionally driven as shown in FIG.
[0014]
In FIG. 4, the protrusion 3 is formed of a member having wear resistance, which is a separate member from the main ring portion of the elastic body 1, for example, a resin or ceramic containing reinforcing fibers, and is bonded to the main ring portion with an adhesive to be elastic. The body 1 is constituted.
[0015]
FIG. 5 is a schematic diagram showing the vibration order (wave number) generated in the vibrating body and its position phase.
[0016]
In FIG. 5 , a solid line and a broken line that extend in the radial direction from the center of the circle indicate antinodes of vibration, and the vibration phase is reversed between the broken line and the straight line.
[0017]
In FIG. 5, an outer circle denoted by reference numeral 5 indicates in- plane vibration (bending vibration) and has a wave number of 3. Further, inner circle indicated by reference numeral 6 is an illustration for the out-of-plane vibration (bending vibration), the wave number 2. Further, the protrusion 3a~3d exist four positions in the position shown in FIG. The protrusions 3a, 3b, 3c, and 3d exist at antinodes of out-of-plane vibration, but the out-of-plane vibrations at the protrusions 3a and 3c and the protrusions 3b and 3d are in opposite phases.
[0018]
Moreover, regarding the phase relationship between the in-plane vibration, as shown in FIG. 5 (a), projections 3a and the projection 3c is located in the belly of the surface vibration, the phase is reversed. On the other hand, the projections 3b, 3d is located in the section of the surface vibration, displacement in the plane is not generated.
[0019]
Therefore, as shown in FIG. 6A, if a time phase difference of approximately 90 degrees is given between the displacement of the in-plane vibration and the displacement of the out-of-plane vibration, the protrusion 3a and the protrusion 3c are about the x axis. If a time phase difference of approximately -90 degrees is performed by performing a circular or elliptical motion, a reverse circular or elliptical motion is performed. However, since no in-plane displacement occurs in the protrusions 3b and 3d, a substantial axis due to out-of-plane vibration is generated. Only the linear motion in the direction (z-axis direction) (the motion associated with one of the two components causing the elliptical motion) is performed.
[0020]
Therefore, as shown in FIG. 4, lever contacting press the moving body 4 of the flat plate-like projections 3 of the vibrating body, the moving body 4 is translation in the y direction, plane vibration and the surface within the time of vibration If the phase difference is switched, it can be reciprocated in the y direction.
[0021]
On the other hand, in the configuration shown in FIG. 5 (b) the spatial phase difference between the in-plane vibration was shifted 90 degrees to the configuration shown in FIG. 5 (a), when generating the in-plane vibration, in FIG. 6 (b) as shown, the protrusion 3b, and the y-axis (axis perpendicular to the plane X-axis) of the circular or elliptical motion generated in 3d, protrusions 3a, 3c performs substantially linear motion in the axial direction. Therefore, the movable body 4 pressed by this is driven in the X direction.
[0022]
In addition, the bending vibration mode has been shown above as an example of in-plane vibration and out-of-plane vibration. However, as in-plane vibration, there are other expansion / torsional vibration and out-of-plane vibration as vibration accompanied by displacement in the in-plane direction. Can use torsional vibration or the like as being accompanied by displacement in the out-of-plane direction.
[0023]
(Second Embodiment)
FIG. 7 shows a second embodiment of the present invention. FIG. 7A is a cross-sectional view of the vibrating body, and FIG. 7B is a top view of the vibrating body.
[0024]
In the vibrating body of the present embodiment, the protrusion 3 formed by bending four outer peripheral portions of a disk-shaped thin plate having a diameter larger than that of the elastic body 1 is formed of a member separate from the elastic body 1. The elastic body 1 and the thin plate are integrated by bonding. Therefore, since the elastic body 1 can be obtained by a ring having a rectangular cross section and the protrusion 3 can be obtained by press working, it can be manufactured at low cost.
[0025]
Moreover, since the projection part 3 is a cantilever projecting from the elastic body 1 in the outer diameter direction, it has a spring property and can smoothly contact the moving body.
[0026]
(Third embodiment)
FIG. 8 shows a third embodiment of the present invention.
[0027]
The ring-shaped vibrating body of the present embodiment has four protrusions 3 on the upper surface of the inner peripheral portion of the elastic body 1. On the other hand, the moving body 4 has a spherical shape, is fitted into the inner peripheral portion of the elastic body 1, and is in press contact with the protrusion 3.
[0028]
Also, either the elastic body 1 or the spherical moving body 4 is magnetized, or a magnet is provided in the vicinity of the contact portion between the elastic body 1 and the moving body 4 so that the pressing contact is performed by magnetic force. A compact pressure mechanism can be realized.
[0029]
(Fourth embodiment)
FIG. 9 shows a fourth embodiment of the present invention.
[0030]
Although the vibrating body of the present embodiment is formed in the same external shape as that of FIG. 8, it is composed of a permanent magnet, and the stainless steel spherical shell-like moving body 4 is pressed from the lower surface of the elastic body 1 made of permanent magnet. Thus, a rotational movement is performed in three axial directions by vibrations generated in the elastic body 1.
[0031]
Further, a pin-like or flange-like support member 7 projects radially outward from the outer peripheral side surface of the elastic body 1, and the support member 7 is supported by the fixed base 8.
[0032]
On the other hand, a functional member is included in the moving body 4. In the present embodiment, the lens 9 and the image sensor 10 are arranged, and the input / output wiring 11 passes through a hole provided in a part of the moving body 4 .
[0033]
Reference numeral 12 denotes an LED that emits light toward the outer peripheral surface of the movable body 4, and reference numeral 13 denotes a CCD that receives the reflected light from the movable body 4 of the LED 12, and constitutes a position detection sensor for the spherical movable body 4. the intensity distribution pattern of the reflected light from the outer surface of the fourth spherical detects the amount of movement of the moving member 4 in the detection and signal processing to three axis directions from changing I by the movement of the movable body 4.
[0034]
(Fifth embodiment)
10 and 13 show a fifth embodiment of the present invention.
[0035]
10 shows an electrode pattern of a piezoelectric element bonded to the elastic body 1, and FIG. 13 shows an external perspective view of the vibrating body.
[0036]
The outer pattern is an electrode for in-plane vibration excitation. The electrodes 2s1, 2s2, 2c1, and 2c2 provided on the outer peripheral side are half-wavelengths of in-plane vibration, and the electrodes adjacent in the circumferential direction are polarized in the opposite direction. In addition, an alternating electric field in the same direction is applied during driving. Further, 2H1,2h2 the electrode is not used for driving, the former is a length of a quarter wavelength, the latter 3/4 wavelength.
[0037]
Therefore, the electrodes 2s1 and 2s2 and the electrodes 2c1 and 2c2 have a spatial phase difference of 90 degrees spatially.
[0038]
Further, the inner peripheral side pattern is an electrode for out-of-plane vibration excitation , and all of the electrodes 2a1 to 2a4 have a half-wavelength of out-of-plane vibration.
[0039]
In this embodiment, the electrode for in-plane vibration is provided on the outside and the electrode for out-of-plane vibration is provided on the inner peripheral side. However, the inside and outside may be reversed, and a single piezoelectric element is used for out-of-plane vibration . and without forming an electrode for plane vibration, and the piezoelectric element to the multi-layer, or provided layers for plane vibration and out-of-plane vibration, further, it is divided ones of different spatial phase to another layer good.
[0040]
The in-plane vibration due to the piezoelectric element placed on the bottom surface of the elastic body is likely to be small displacement compared to the out-of-plane vibration. Therefore, the piezoelectric element area for in-plane vibration excitation is compared with the piezoelectric element area for out-of-plane vibration excitation . The number of layers may be large.
[0041]
By the way, in the electrode pattern shown in FIG. 10, the electrodes 2s1 , 2s2 , 2c1 , 2c2 for in-plane vibration excitation on the outer peripheral side excite two in-plane vibrations having a spatial difference of 90 degrees. If a 90-degree temporal phase difference is given between both vibrations, the in-plane vibration proceeds on the vibrating body.
[0042]
At this time, as shown in FIG. 13, the protrusions have elliptical motions in the same direction on the circumference, so that the spherical moving body contacting the upper inner circumference of the ring can be frictionally driven around the axis of the vibrating body. .
[0043]
Therefore, the electrodes 2s1 , 2s2, and 2a1-2a4 are driven to rotate around the x-axis, the electrodes 2c1 , 2c2, and 2a1-2a4 are driven to rotate around the y-axis, and the electrodes 2s1 , 2s2, and By driving 2c1 and 2c2, a three-degree-of-freedom vibration wave motor that performs rotational motion about the z-axis can be realized.
[0044]
(Sixth embodiment)
FIG. 11 shows a sixth embodiment of the present invention.
[0045]
The vibrating body of the present embodiment shown in FIG. 11 is formed in an annular shape, and the protrusion 3 protrudes toward the inner circumferential direction (radially inward) on the upper surface of the annular elastic body 1. It is provided to do. The vibrator, which was intended to drive the x-direction or y-direction, but the protrusion portion 3 is a spring having elasticity, hard in the radial direction of the elastic body 1, so that the soft circumferentially configuration Has been. That is, the protrusion 3 is a spring that is hard in the driving direction and soft in the direction perpendicular thereto.
[0046]
FIG. 12 shows the displacement distribution of the in-plane vibration as viewed from above, but the displacement diameter in the circumferential direction of the elastic body at the node of the in-plane vibration is zero at the radial center of the elastic body 1, but the bending the inner peripheral portion or the outer peripheral portion of the elastic member 1 by the rotation θ with the deformation, and further, as explained in FIG. 11, when the protrusions for contacting the inner diameter direction or radially outward is flared, the surface Displacement in the circumferential direction due to internal vibration. Therefore, the spring property is given in the circumferential direction to prevent unnecessary slipping that does not contribute to driving of the moving body due to the deformation of the spring.
[0047]
(Seventh embodiment)
FIG. 14 shows a seventh embodiment of the present invention. In the present embodiment, the vibrating body is brought into contact with the moving body 4 formed in the spherical shell. Four protrusions 3 extending radially outward are provided at equal intervals in the circumferential direction on the upper surface of the elastic body 1, and the four protrusions 3 are in contact with the inner peripheral surface of the moving body 4. A flange-like support plate 14 made of a thin plate is formed on the inner peripheral side of the elastic body 1 . The support plate 14 has a hole formed at the center thereof fitted into a bolt portion of the vibrating body fixing base 15, and the nut 16 is fastened to the bolt portion to fix the vibrating body to the vibrating body fixing base 15. Yes.
[0048]
With such a configuration, it is possible to provide the thin plate flange-shaped support plate 14 on the inner diameter side of the vibrating body 1 , and the vibrating body 1 can be fixed at this central portion, so that the vibrating body can be supported in a compact manner. it can.
[0049]
(Eighth and ninth embodiments)
FIG. 15 shows the eighth and ninth embodiments.
[0050]
Figure 15 eighth embodiment shown in (a), in-plane vibration quintic to the vibrating body in the piezoelectric element 5 for longitudinal vibration is provided on the outer peripheral side, piezoelectric for out-of-plane vibration is provided on the inner peripheral side The element 6 generates a fourth-order vibration out-of-plane vibration, and the same motor as in the first embodiment can be obtained. In this case, since the phase of the in- plane vibration is reversed by the protrusions 3e and 3f, the contact with the moving body is also reversed in synchronization therewith. However, the directions of the elliptical motion are equal, and the moving body is driven in the y direction.
[0051]
In this configuration, when the ring diameter is large and low-order natural frequencies such as secondary and tertiary are in the audible range, high-order vibrations may be appropriately used as described above.
[0052]
In the ninth embodiment shown in FIG. 15B, the piezoelectric element 5 for in-plane vibration provided on the outer peripheral side is a piezoelectric element for in-plane vibration secondary provided on the vibrating body and the piezoelectric for out-of-plane vibration provided on the inner peripheral side. The element is configured to form a third-order vibration out of plane vibration, and protrusions 3i and 3j are formed in the y direction. Since there is no anti-plane vibration antinode on the x axis, driving in the x direction is not possible, but driving in the y direction is possible.
[0053]
【The invention's effect】
As described above, according to the present invention, of the plurality of protrusions, some of the protrusions are provided at positions where antinodes of vibrations in the in-plane direction and the out-of-plane direction, and the other protrusions are provided with one vibration. By providing it at a position where it becomes an antinode and a node of the other vibration, when the moving body is driven by causing a circular or elliptical motion in one projection, the other projection The suppression of driving can be reduced, and the driving efficiency of the vibration wave driving device can be improved .
[Brief description of the drawings]
1 is a perspective view of a vibrating body according to the present invention. FIG. 2 is a conventional view. FIG. 3 is a vibration mode diagram. FIG. 4 is a longitudinal sectional view of a vibration wave motor according to the present invention. FIG. 6 is a perspective view of a vibrating body according to the present invention. FIG. 7 is a longitudinal sectional view and a top view of the vibrating body according to the present invention. [Fig. 9] Other embodiment of the present invention [Fig. 10] Electrode pattern of the piezoelectric element [Fig. 11] Other embodiment of the present invention [Fig. 12] Vibration mode diagram [Fig. 13] FIG. 14 is a perspective view of a vibrating body according to the present invention. FIG. 15 is another embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Elastic body 2 Piezoelectric element 3 Protruding part 4 Moving body 7 Support member 8 Fixing base 9 Lens 10 Image sensor 11 Input / output wiring 12 LED
13 CCD
14 Support plate 15 Fixing base 16 Nut

Claims (4)

Elastic and electrically the provided elastic body - a vibrating body provided with a mechanical energy conversion element, the vibration wave driving device having a moving body in contact pressure with respect to a plurality of projections provided on the resilient member ,
The electro-mechanical energy conversion element has an even-order in-plane vibration and an odd-order out-of-plane vibration , or an odd-order in-plane vibration and an even-order out-of-plane direction with respect to the elastic body. the Rukoto to generate vibration of the moving body is frictionally driven,
The plurality of protrusions are provided at a position that becomes an antinode of these vibrations and a position that is an antinode of one vibration and a node of the other vibration with respect to the in-plane vibration and the out-of-plane vibration. The vibration wave drive device characterized by the above-mentioned . The elastic body is annular, said plurality of projections, the vibration wave driving device according to claim 1, characterized in that provided at a plurality of positions on the diametrical axis of the elastic body. Vibration wave driven apparatus according to claim 1 or 2, characterized in that for switching the moving direction of the movable body by changing the time phase difference between the vibration of the out-of-plane direction as vibration in the in-plane direction. 3. The vibration wave drive according to claim 2 , wherein at least a part of the moving body is formed in a spherical shape, and the portion formed in the spherical shape is fitted in a central hole of the annular elastic body. apparatus.

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