JP3825643B2 - Ultrasonic motor and electronic device with ultrasonic motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic motor used for driving a printer, a paper feeder, a machine tool, a zoom mechanism of a camera, and the like, and more particularly, to an ultrasonic motor that supports and pressurizes a rectangular periodic vibration member.
[0002]
[Prior art]
Recently, a drive signal having a predetermined frequency is generated by a variable oscillator, and the drive signal is applied to a piezoelectric element via a power amplifier, thereby generating a traveling wave in a vibrating body joined to the piezoelectric element, ultrasonic motor for moving the moving body in contact with a predetermined pressure is known (e.g., JP-B-62 - see 92781 JP).
[0003]
In particular, an ultrasonic drive device that uses elongation vibration and bending vibration (double mode vibrator) of a rectangular piezoelectric diaphragm can move a moving body in a linear motion, a rotational motion, or the like by a combined displacement of vibration modes. It is possible and is expected to be applied to various uses.
FIG. 13 shows an ultrasonic motor of a type using a rectangular vibrator.
That is, this apparatus includes a piezoelectric vibrating body 14 that vibrates by application of a high frequency voltage, a moving body 11 that is pressed against the vibrating body 14, a support member 26 that supports a vibration node of the vibrating body 14, and a support member 26. And pressurizing member 33 that applies pressure to press contact between vibrating body 14 and moving body 11 (Jpn. J. Appl. Phys. Vol. 31 (1992) Pt. 1, No. 9BP3079).
[0004]
According to this, the movable body 11 is rotated by a combination of the extension vibration and the bending vibration of the vibration body 14.
FIG. 14 also shows an ultrasonic motor of the same type using a rectangular vibrator.
This apparatus includes a multilayer piezoelectric element 14h, a vibrating body 14 including a vibrating portion 14i joined to the piezoelectric element 14h, a columnar support member 26 that is locked to a vibration node of the vibrating body 14, and a vibration. a protrusion 13 fixed to the underside of the body 14, and a moving body 11 abuts against the projection 13 (Jpn.J.Appl.Phys.Vol.34 (1995) pp2756 - 2759 reference).
[0005]
According to this, the movable body 11 is linearly moved in a fixed direction by the elliptical vibration of the protrusion 13 generated by the combination of the extension vibration and the bending vibration of the vibration body 14.
[0006]
[Problems to be solved by the invention]
However, according to the ultrasonic motor described above, the pressure member 33 is required in addition to the support member 26, so that the configuration of the apparatus is complicated, the entire apparatus is enlarged, and the vibration body 14 is reduced in size. There is a technical problem that it is easy to cause loss.
[0007]
Further, since the support member 26 is usually locked to the piezoelectric vibrating body 14 by a screwing or pinning structure and the structural strength is not high, the applied pressure to the support member 26 can be increased. It has a technical problem that it cannot.
Furthermore, the piezoelectric vibrating body 14 has a technical problem that the moving direction of the moving body 11 fluctuates with respect to the target direction due to a deviation at the time of incorporation, a non-uniform contact surface with the moving body 11, or the like.
[0008]
Accordingly, the present invention has been made to solve the above technical problem, and is intended to simplify and miniaturize the device configuration, strengthen the support structure of the piezoelectric vibrating body, and improve the moving direction of the moving body. An object of the present invention is to provide an ultrasonic motor that prevents fluctuations.
[0009]
[Means for Solving the Problems]
That is, a first invention that solves the above technical problem includes a periodic vibration member that periodically vibrates by application of a high-frequency voltage, and a movable body that is movable along with the periodic vibration of the periodic vibration member. An ultrasonic motor, comprising: a node support pressing member that supports a vibration node of the periodic vibration member and applies a pressing force that presses the periodic vibration member and the movable body. To do.
[0010]
The effect of the first invention, the by knuckles supporting pressure member, a periodic vibration member to support the vibration node portions, the periodic vibration member pressed causes a frictional force to the periodic oscillation member and the moving member Therefore, it is not necessary to provide a pressure member in addition to the node support pressure member.
In the above invention, the periodic vibration member includes only a piezoelectric element and includes a case where a vibrating body is joined to the piezoelectric element.
[0011]
Moreover, the case where the moving body is formed integrally with the driving object and the case where the moving body is formed as a separate member from the driving object are included.
As a second invention for solving the above technical problem, an ultrasonic wave comprising a periodic vibration member that periodically vibrates by application of a high-frequency voltage, and a movable body that is movable in accordance with the periodic vibration of the periodic vibration member. In the drive device,
And a fitting support member that is fitted at a vibration node of the periodic vibration member and reinforces the engagement strength with the periodic vibration member.
[0012]
As an action of the second invention, since the engagement strength between the fitting support member and the periodic vibration member is strengthened and a large pressing force is applied to the fitting support member, the movable body and the periodic vibration member Sufficient frictional force is generated during
In the first or second aspect of the invention, from the viewpoint of stabilizing the movable direction, the movable body is provided with a guide member for guiding the moving direction, and the movable member is movable in a pair with the guide member. It is preferable to provide a movable restricting member that restricts the direction.
[0013]
As a third invention for solving the above technical problem, a periodic vibration member that periodically vibrates by application of a high-frequency voltage, and a frictional force is applied along with the periodic vibration to move the periodic vibration member. In the ultrasonic drive device including the friction applying member to be guided, a guide member that guides the moving direction of the periodic vibration member, and a movable restriction member that pairs with the guide member and restricts the moving direction of the periodic vibration member. , Provided.
[0014]
As an action of the third invention, the periodic vibration member can be precisely moved only in the restricted direction by the guide member and the movable restricting member.
In addition, as a fourth invention for solving the above technical problem, a periodic vibration member that periodically vibrates by application of a high-frequency voltage, a movable body that is moved along with the periodic vibration of the periodic vibration member, and the periodic vibration In an ultrasonic driving device including a node support member that supports a vibration node of a member,
And a pressurizing and pressing member that applies a pressing force that presses the movable body and the periodic vibration member against the movable body.
[0015]
As an effect of the fourth invention, a pressing force is applied from the movable body side by the pressurizing and pressing member, and the movable body and the periodic vibration member are pressed together, so it is necessary to provide a member for applying pressure to the periodic vibrating member side. There is no.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
Embodiment 1
FIG. 1 shows a first embodiment in which the first invention is applied to an ultrasonic driving device.
[0017]
In the present embodiment, a vibrating body 14 as a periodic vibrating member of the present invention, a protrusion 13 fixed to the lower portion of the vibrating body 14, a rail 11a as a movable body of the present invention that abuts the protrusion 13, and a rail 11a A rotating member 12 that contacts the lower surface of the rail 11a and guides the rail 11a, a spring member 17 as a nodal support pressing member of the present invention that contacts the upper surface of the vibrating body 14, and between the spring member 17 and the vibrating body 14. , And rubber sheets 15, 16, 18 installed between the spring member 17 and the fixed plate 19.
[0018]
Furthermore, the vibrating body 14 has a rectangular plate shape, and is formed of, for example, a piezoelectric element that has been subjected to a predetermined polarization process. Moreover, you may use the type which surface-bonded the vibration part to the piezoelectric element.
The spring member 17 has a V-shaped cross section, presses the vibration node portion 14a on the vibrating body 14 with a V-shaped sharp portion through the rubber sheet 15, and the tip of the V-shaped bifurcated portion has a rubber sheet 16; 18 is brought into contact with the fixing plate 19 via
[0019]
Next, the operation of the ultrasonic drive device will be described.
The vibrating body 14 to which the high-frequency voltage is applied starts extension vibration and bending vibration, and the protrusion 13 fixed to the lower part of the vibrating body 14 contacts the rail 11a at a predetermined timing by these two combined vibrations, and horizontally moves the rail 11a. Move linearly in the direction.
At this time, the spring member 17 supports the vibration node portion 14 a so as not to move the vibration body 14, and applies a pressure force due to elastic deformation to the vibration body 14, thereby providing a sufficient frictional force between the protrusion 13 and the rail 11 a. Cause it to occur. Therefore, it is not necessary to provide a member for pressing the vibrating body 14 in addition to the spring member 17.
[0020]
As described above, according to the present embodiment, since the vibrating body 14 is supported and pressurized by one member, the member for applying pressure according to the prior art is omitted, and the apparatus configuration is simplified and miniaturized. The
FIG. 2 shows an ultrasonic driving apparatus according to a modification of the first embodiment.
[0021]
The present modification has substantially the same configuration as that of the first embodiment, but is characterized in that a columnar stopper 21 that passes through the rubber sheet 15 and the spring member 17 and is fixed to the vibrating body 14 is provided.
According to this, since the spring member 17 surely supports the vibration node 14a of the vibration body 14, the support location of the vibration body 14 may vary from the vibration node 14a due to the vibration of the vibration body 14. And the vibration of the vibrating body 14 is stabilized.
[0022]
Embodiment 2
FIG. 3 shows Embodiment 2 in which the first invention is applied to an ultrasonic drive device.
In the present embodiment, the rectangular vibrating body 14 that contacts the moving body 11b, the spring members 17a and 17b fixed by the vibration node portion 14a of the vibrating body 14, and the fixing plate that supports the spring members 17a and 17b. 19.
[0023]
Specifically, the spring members 17a and 17b are plate-like bodies, curved in a convex shape, and a fixing portion with the vibrating body 14 is bent in a letter shape.
Next, the operation of the present embodiment will be described.
The vibrating body 14 to which the high-frequency voltage is applied performs extension vibration and bending vibration at a predetermined timing, and rotates the moving body 11b by the combined displacement.
[0024]
At this time, as in the first embodiment, the spring members 17a and 17b support the vibrating body 14 and apply a pressing force that presses the vibrating body 14 and the moving body 11b together. Therefore, it is not necessary to use a member used for the purpose.
4 and 5 show a modification of the second embodiment.
As shown in FIG. 4, the first mode related to the deformation mode is substantially the same as that of the second embodiment. In particular, the locking grooves 14 b are formed at both edges of the vibration node portion 14 a of the vibrating body 14. , 14c, and the spring members 17a and 17b are bent to lock their ends.
[0025]
Further, as shown in FIG. 5, the second mode relating to the deformation mode is substantially the same as the configuration of the second embodiment. In particular, the second mode is for locking at both ends of the vibration node 14a of the vibrating body 14. The projections 14d and 14e are provided, and the spring members 17a and 17b are bent to be hooked on the opposite side of the movable projections 12 of the locking projections 14d and 14e.
Embodiment 3
FIG. 6 shows Embodiment 3 in which the second invention is applied to an ultrasonic drive device.
[0026]
In this embodiment, as shown in FIG. 6A, the vibration member 14 that contacts the moving body 11 and the fitting support member of the present invention that is fitted to the vibration node portion 14a of the vibration member 14 are fitted. The joint support member 22 is used.
Further, as shown in FIG. 6B, the vibrating body 14 has a rectangular shape, and the vibration node portion 14a has concave portions 14f and 14g that are removed in a rectangular shape from both ends toward the central portion. Yes.
[0027]
The fitting support member 22 includes a rectangular parallelepiped body portion 22a and columnar projecting portions 22b and 22c projecting from both edges of the body portion 22a.
According to this, the concave portions 14f and 14g of the fitting support member 22 and the convex portions 22b and 22c of the vibrating body 14 are fitted together to enhance the support strength, so that a large pressure is applied to the fitting support member 22. Therefore, a sufficient frictional force is generated between the vibrating body 14 and the moving body 11.
[0028]
7 (a) and 7 (b) show a modification in which the second invention is applied to a horizontal type vibrating body 14. FIG.
The present modification is characterized in that a U-shaped fitting support member 22 is fitted into the concave portion 14f at one end of the vibration node portion 14a of the vibrating body 14.
This also provides the same effect.
[0029]
Embodiment 4
FIG. 8 shows Embodiment 4 in which the moving direction of the moving body according to the first invention is improved.
In the present embodiment, the vibrating body 14, the protrusion 13 provided on the lower side of the vibrating body, the rail 11a in contact with the protrusion 13, and the guide groove 11c as the guide member of the present invention provided on the surface of the rail 11a. And a movement restricting member 23 as a movable restricting member of the present invention provided integrally with the protrusion 13.
[0030]
According to this, since the movement restricting member 23 enters the guide groove 11c and restricts the moving direction of the rail 11a, the rail 11a is not affected by the vibration shake of the vibrating body 14 and moves stably. Is called.
FIG. 9 shows a modification according to the fourth embodiment.
The present modification has substantially the same configuration as that of the fourth embodiment, but in particular, the fitting support member 22 is fitted to the vibration node portion of the vibrating body 14 and both ends of the fitting support member 22 are moved to the movement restricting member. It has the feature in the point used as 23.
[0031]
This also provides the same effect as in the fourth embodiment.
Embodiment 5
FIG. 10 shows Embodiment 5 in which the third invention is applied to an ultrasonic drive device.
In this embodiment, as shown in FIGS. 10A and 10B, the vibrating body 14, the protrusion 13 provided on the lower side of the vibrating body 14, and the friction applying member of the present invention that contacts the protrusion 13. Rail 11a, a movement restriction member 25 as a movable restriction member of the present invention fixed to the rail 11a, and a guide member 24 as a guide member of the present invention fixed to the vibration node portion 14a of the vibrating body 14. ing.
[0032]
Furthermore, the movement restricting member 25 has a plate shape and is fixed perpendicular to the rail 11a. The guide member 24 includes a plate-like vibrating body mounting portion and a U-shaped section, and the U-shaped section has a structure in which the plate-shaped movement restricting member 25 is inserted. The vibrating body 14 is loaded with a pressing force that comes into pressure contact with the rail 11a.
Next, the operation of the ultrasonic drive device will be described.
[0033]
When the periodic vibration of the vibrating body 14 is transmitted to the protrusion 13, a frictional force is generated between the protrusion 13 and the rail 11a, and the vibrating body 14 moves in the horizontal direction on the rail 11a.
At this time, the vibration body 14 is guided in the direction regulated by the guide member 24 and the movement restriction member 25 even if vibration vibration occurs in the vibration body 14.
As described above, according to the present embodiment, since the vibrating body 14 is not displaced in a direction other than the predetermined regulating direction, the vibrating body 14 moves stably in the regulating direction.
[0034]
Embodiment 6
FIG. 11 shows Embodiment 6 in which the fourth invention is applied to an ultrasonic drive device.
In the present embodiment, a vibrating body 14 as a periodic vibrating member of the present invention that vibrates periodically, a support member 26 as a node support member of the present invention that supports the vibrating body 14 by a vibration node 14a, and the vibrating body 14 A rotating body 11b as a movable body of the present invention that abuts against the pressure member, a pressure transmission shaft 28 as a pressure-contacting member passing through the rotation center of the rotation body 11b, and a pair of bearings 29 that receive the tip of the pressure transmission shaft It is composed of
[0035]
Further, as shown in FIG. 12, the pressurizing mechanism of the present embodiment includes a guide ring 31 that guides the moving direction of the bearing 29 and a spring member 32 that pressurizes the bearing 29. As described above, the pressure transmission shaft 28, the bearing 29, the guide ring 31, and the spring member 32 correspond to the pressure contact member of the present invention.
Here, the pressure transmission shaft 28 is in the form of an elongated rod, and both ends thereof are sharpened. The bearing 29 has a disc shape, and the receiving portion that receives the tip of the pressure transmission shaft 28 has a concave shape. The guide ring 31 has a horizontally long circular shape, and has a guide portion having the same shape at the center. Further, the spring member 32 has a U-shaped bent shape, and both ends thereof are fixed to the fixing member 33.
[0036]
Next, the operation of the ultrasonic drive device will be described.
The vibrating body 14 vibrates by combining elongation vibration and bending vibration periodically.
At this time, the spring member 32 applies a pressure force due to elastic deformation to the bearing 29, the bearing 29 is guided by the guide ring 31 in the direction of the vibrating body 14, and the pressure transmission shaft 28 locked to the bearing 29 rotates. A pressing force that presses the rotating body 11b and the vibrating body 14 is applied to the body 11b.
[0037]
In this state, a sufficient frictional force is generated between the vibrating body 14 and the rotating body 11b, and the rotating body 11b is stably rotated in a predetermined direction. Therefore, it is not necessary to provide a pressurizing mechanism on the vibrating body 14 side.
According to this, since the pressure is applied from the rotating body 11b side, the device configuration on the vibrating body side is simplified and miniaturized.
[0038]
◎ Embodiment 7
The present embodiment is characterized in that a predetermined groove is provided in the vibration mode displacement direction with respect to the rectangular vibration body in the double vibration mode.
According to this, when the resonance frequencies of the extension vibration and the bending vibration do not coincide with each other, the resonance frequency is made to coincide with the predetermined groove. Therefore, it is necessary to process the vibrating body with strict accuracy and make the resonance frequencies coincide with each other. In addition, the manufacturing process of the vibrator is simplified.
◎ Eighth embodiment
FIG. 15 shows a block diagram of an embodiment of an electronic apparatus with an ultrasonic motor of the present invention. A configuration in which a transmission mechanism 50 that operates integrally with the ultrasonic motor moving body 11 and an output mechanism 51 that operates based on the operation of the transmission mechanism 50 are provided using the ultrasonic motor shown in the previous embodiment. By doing so, an electronic device with an ultrasonic motor can be realized. As the transmission mechanism 50, a transmission wheel such as a gear or a friction wheel is preferably used. As the output mechanism 51, a shutter drive mechanism and a lens drive mechanism are preferably used in the camera, a pointer drive mechanism, a calendar drive mechanism, and the like are used in the electronic timepiece, and a cutting tool feed mechanism, a machining member feed mechanism, and the like are used in the machine tool.
[0039]
As the electronic apparatus with an ultrasonic motor of the present invention, an electronic timepiece, a measuring instrument, a camera, a printer, a printing machine, a machine tool, a robot, a moving device, and the like can be realized. Furthermore, if an output shaft is attached to the moving body and a power transmission mechanism for transmitting torque from the output shaft is provided, an ultrasonic motor drive mechanism can be realized.
[0040]
【The invention's effect】
As described above, according to the first invention, since the periodic vibration member is supported and pressed by the node support pressing member, there is no need to provide a pressing member as in the prior art, and the apparatus configuration is simplified and reduced in size. Is achieved.
Further, according to the second invention, since the engagement strength with the periodic vibration member is strengthened by the fitting support member, and a larger pressing force is applied to the fitting support member than in the prior art, Sufficient frictional force is generated and stable movement is achieved.
[0041]
Furthermore, if a guide member or a movable restricting member is used in the first or second invention, the movable direction is stabilized.
According to the third aspect of the invention, since the periodic vibration member is not displaced in the direction other than the restricted direction, it can be stably moved against vibration vibration.
According to the fourth aspect of the invention, since the pressurizing mechanism on the periodic vibration member side is omitted, the size and simplification of the periodic vibration member side can be achieved.
[Brief description of the drawings]
FIGS. 1A and 1B are explanatory views showing Embodiment 1 in which the first invention is applied to an ultrasonic drive device; FIGS.
FIG. 2 is an explanatory view showing a modified embodiment related to FIG. 1;
FIG. 3 is an explanatory diagram showing a second embodiment in which the first invention is applied to an ultrasonic driving device.
FIG. 4 is an explanatory view showing a modified embodiment related to FIG. 3;
FIG. 5 is an explanatory view showing a modified embodiment related to FIG. 3;
6 (a) and 6 (b) are explanatory views showing Embodiment 3 in which the second invention is applied to an ultrasonic driving device.
7 (a) and 7 (b) are explanatory views showing a modification relating to FIG.
FIG. 8 is an explanatory diagram showing a fourth embodiment in which the ultrasonic driving device according to FIG. 1 is improved.
FIG. 9 is an explanatory view showing a modified embodiment related to FIG. 8;
FIGS. 10A and 10B are explanatory views showing Embodiment 5 in which the third invention is applied to an ultrasonic drive device; FIGS.
FIGS. 11A and 11B are explanatory views showing Embodiment 6 in which the fourth invention is applied to an ultrasonic drive device; FIGS.
12A and 12B are explanatory views showing a pressurizing mechanism according to FIG.
FIG. 13 is an explanatory diagram showing a configuration of an ultrasonic drive device according to a conventional technique.
FIG. 14 is an explanatory diagram showing a configuration of an ultrasonic drive device according to a conventional technique.
FIG. 15 is a block diagram showing an embodiment of an electronic apparatus with an ultrasonic motor of the present invention.
[Explanation of symbols]
11a Rail 11b Moving body 11c Guide groove 12 Rotating member 13 Protrusion 14 Vibrating body 15 Rubber sheet 16 Rubber sheet 17 Spring member 18 Rubber sheet 19 Fixing plate 21 Column-shaped stopper 22 Fitting support member 23 Movement restricting member 24 Guide member 25 Movement restricting Member 26 support member 28 pressure transmission shaft 29 bearing 31 guide ring 32 spring member 33 fixing member

Claims (5)

A vibrating member that periodically vibrates by application of a high-frequency voltage;
In an ultrasonic motor provided with a movable body that is moved along with the periodic vibration of the vibrating member,
The vibration member is supported only by a spring member that applies a pressing force that presses the vibration member and the movable body,
The ultrasonic motor according to claim 1, wherein the vibration member is supported by the spring member at a vibration node of the vibration member.   2. The ultrasonic motor according to claim 1, wherein the spring member forms a pair to support and pressurize the vibration member.   3. The ultrasonic motor according to claim 1, wherein the movable body is a rail that moves linearly.   3. The ultrasonic motor according to claim 1, wherein the movable body is a moving body that rotates.   An electronic apparatus with an ultrasonic motor, comprising the ultrasonic motor according to any one of claims 1 to 3.

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