JP2009207339A - Piezoelectric driving device and electronic apparatus - Google Patents

Abstract

The present invention provides a piezoelectric drive device that can drive a rotated body with low power when the driven body is driven by vibration of a piezoelectric element.
A piezoelectric actuator having a vibrator and a rotor ring that rotates in contact with the vibrator, a spiral spring capable of storing rotational energy of the rotor ring as elastic energy, and storage in the spiral spring. And a second rotor transmission gear 60 that is rotated by the generated elastic energy. When the vibrator 20 moves away from the rotor ring 30 against the pressing force of the pressing means, a reverse rotation prevention mechanism 90 is provided that restricts the release of the elastic energy accumulated in the spiral spring 50. When the piezoelectric actuator 4 is started, the driving force of the piezoelectric actuator 4 is accumulated as the elastic energy of the spiral spring 50 and then the second rotor transmission gear 60 starts to rotate. Therefore, the load at the time of starting is reduced, and low power Thus, the piezoelectric actuator 4 can be driven.
[Selection] Figure 6

Description

  The present invention relates to a piezoelectric driving device and an electronic apparatus including a piezoelectric actuator.

2. Description of the Related Art Conventionally, an ultrasonic driving device using a piezoelectric element that is not easily affected by a magnetic field is known and used as a driving device that drives a timepiece of a timepiece (see, for example, Patent Document 1).
The ultrasonic drive device described in Patent Document 1 includes a vibrating body to which a piezoelectric element is bonded, a rotor body that rotates in the circumferential direction in accordance with the vibration of the vibrating body, and a pressing member that press-contacts the vibrating body and the rotor body. And a presser spring that applies pressure, and the time hand is rotated by the rotation of the rotor body.

Japanese Patent Laid-Open No. 10-290579

However, in the ultrasonic driving device described in Patent Document 1, when the ultrasonic driving device is started from a stopped state, the rotor body starts rotating when a high-frequency voltage (drive signal) is applied to the vibrating body. A certain amount of time (acceleration period) is required until the body reaches a predetermined rotational speed. This acceleration period becomes longer as the moment of inertia such as the time hand is larger. For example, when a reduction gear train for reducing the rotational speed of the rotor body is arranged between the rotor body and the time hand, the inertia moment of the train wheel and the time hand is smaller than the inertia moment of the rotor body. For example, the moment of inertia of the rotor body, the reduction gear train, and the time hand may be several tens to one hundred times or more of the moment of inertia of the rotor body alone.
In some cases, a speed increasing wheel train is provided between the rotor and the pointer, and the pointer can be moved by a predetermined angle even if the rotation angle of the rotor is small. For example, this is a case where an angle of 6 degrees for one second of the second hand is to be moved by rotating the rotor by 2 degrees. In the case of the speed increasing wheel train, the moment of inertia is larger and the acceleration time is longer than that in the case of the speed reducing wheel train.
Thus, the moment of inertia is determined by, for example, the configuration and form of the train wheel and the pointer. When the moment of inertia is large, the acceleration period of the rotor body becomes long, and the time for which the drive signal is applied to the vibrating body (vibrator) becomes long, so that the power consumption of the ultrasonic driving device increases. There is.

  An object of the present invention is to provide a piezoelectric drive device and an electronic apparatus that can drive a rotated body with low power when the driven body is driven by vibration of a vibrator.

The piezoelectric drive device of the present invention includes a vibrator having a piezoelectric element, a piezoelectric actuator having a rotor rotated by the vibrator in contact with the vibrator, and a pressing unit that presses the vibrator and the rotor together. A piezoelectric drive device comprising: an elastic device capable of storing rotational energy generated by rotation of the rotor as elastic energy; and a rotated body rotated by the elastic energy stored in the elastic device, wherein the vibrator And a release restricting means for restricting the release of the elastic energy for rotating the rotor in a direction opposite to the rotation direction of the rotor.
Here, the vibrator may be configured to vibrate when at least a drive signal is given to the piezoelectric element and to rotate the rotor by the vibration. For example, the vibrator may be configured to rotate the rotor by vibrating the piezoelectric element itself, or to rotate the rotor by vibrating a laminate of a plate-like piezoelectric element and a reinforcing plate. It may be configured. Further, the rotated body may be any member that transmits the rotation of the rotor via the elastic device and further transmits the rotation to the rotating object. For example, the rotation is transmitted from the rotor to the rotating object such as a pointer. It may be a rotor transmission gear, an escape gear, a driven vehicle, or the like disposed in the path, or a rotor transmission gear, a rotor gear, or the like that is disposed with a rotating shaft common to the rotor.
The rotational energy includes rotational force and the like, and the elastic energy includes elastic force and the like.

Here, the characteristic of the piezoelectric actuator used by this invention is demonstrated based on the graph of FIGS.
The graph of FIG. 1 shows the torque (load) and rotational speed generated by the piezoelectric actuator and a general electromagnetic motor, and the relationship between torque and electric power, respectively. As indicated by the solid line in the graph of FIG. 1, between the torque T generated by the piezoelectric actuator and the rotational speed N, the rotational speed N increases as the torque T decreases, as in a general electromagnetic motor. There is a relationship that the rotational speed N decreases as the torque T increases. Further, in an electromagnetic motor, as indicated by a dotted line in FIG. 1, the electric power W required for driving generally increases with a torque T, whereas in a piezoelectric actuator, a dashed line in FIG. As shown, the electric power W required for driving is not substantially affected by the torque T and is substantially constant. The characteristics as described above show the case where they are schematically explained, and are actually accompanied by fluctuations.
The graph of FIG. 2 shows the relationship between time t and angular velocity V when a force moment N is applied to a general rigid body that rotates about a certain axis. Here, the relationship between the moment N of the force acting on the rigid body, the angular acceleration β generated thereby, and the inertia moment I of the rigid body is generally N = I · β. That is, when the force moment N is the same, the greater the moment of inertia I, the smaller the angular acceleration β. In other words, the larger the moment of inertia I, the longer the time until the predetermined angular velocity V0 is reached. For example, when there are rigid bodies A ₀ and B ₀ having different inertia moments I and the respective inertia moments IA and IB have a relationship of IA: IB = 1: 2, the angular accelerations of the rigid bodies A ₀ and B ₀ are as follows. βA and βB have a relationship of βA: βB = 2: 1. As shown by the solid line in the graph of FIG. 2, when the inclination t of the rigid body A _{0 having} a small moment of inertia I becomes steep (the rate of change of the angular velocity V increases) and the time t until the predetermined angular velocity V0 is reached is compared. The required time tB for the rigid body B ₀ is twice the required time tA for the rigid body A ₀ . This indicates that the time required to move the predetermined distance (predetermined rotation angle) is twice as long for the rigid body B ₀ as for the rigid body A ₀ .

The present invention aims at an effect based on the characteristics of a rigid body affected by the moment of inertia I, and the effect will be described below.
As shown in FIG. 3, the basic performance of the piezoelectric actuator in the present invention is derived from the number of rotations N1 at that time and the power consumption W1, assuming a torque (load torque) T1 to be generated. FIG. 4 shows the relationship between the time t and the rotational speed N when the piezoelectric actuator is started from a stopped state. The rotation speed N starts to increase after the drive signal is supplied to the piezoelectric element of the piezoelectric actuator (signal ON), and after reaching the predetermined rotation speed N1, supply of the drive signal stops (signal OFF). . The time (acceleration period) t1 required to reach the rotational speed N1 varies depending on the moment of inertia I. For example, when a reduction gear train for reducing the rotational speed N of the rotor is arranged between the rotor and the pointer in a watch, the inertia moment of the reduction gear train and the pointer is compared with the inertia moment of the rotor. In some cases, the inertia moment of the rotor, the reduction gear train, and the pointer is several tens to one hundred times greater than the inertia moment of the rotor alone. The moment of inertia combining the rotor, the reduction gear train, and the pointer is determined by, for example, the configuration and form of the reduction gear train and the pointer. The greater the moment of inertia, the longer the acceleration period t1 of the rotor. Since the drive signal is supplied for a long time, the power consumption of the piezoelectric drive device increases.

On the other hand, according to the present invention, when the piezoelectric actuator is started from the stopped state, the elastic device is provided on the side of the rotated body from the rotor. The object is not directly rotated by the piezoelectric actuator, and the moment of inertia of the portion directly rotated by the piezoelectric actuator is reduced by the amount of the rotated body or the rotating object. That is, the elastic device starts elastic deformation simultaneously with the rotation of the rotor, and the rotational energy of the rotor is accumulated as the elastic energy of the elastic device. When the accumulated elastic energy reaches a predetermined magnitude and reaches a predetermined timing, the rotated body and the rotating object start to rotate. Therefore, it is possible to prevent the rotor from being affected by the moment of inertia of the rotating object and the rotating object until the rotor reaches a predetermined rotational speed and reaches a predetermined timing. In this way, the moment of inertia I acting on the piezoelectric actuator can be reduced, so that the acceleration period t1 of the rotor can be shortened as shown in FIG. The predetermined rotational speed N1 can be reached. Therefore, when the rotating object is rotated by a predetermined angle, the driving time of the piezoelectric actuator can be shortened, so that the time for supplying the driving signal is shortened, the startability is improved, and the driving is performed with low power. can do.
In addition, when rotating the rotating object by a predetermined angle, if the rotor is rotated by a predetermined angle, the rotated object and the rotating object are moved over a longer time than the rotation time of the rotor by the accumulated elastic energy. Since it can be rotated, even if the piezoelectric actuator is stopped when the rotor is rotated by a predetermined angle, the rotated body can be rotated to a predetermined angle.

In the present invention, as described above, by providing the elastic device, the influence of the moment of inertia of the rotated body and the rotating object after the elastic device can be eliminated from the rotor, and the startability can be improved. On the other hand, since the elastic energy of the elastic device is also applied to the stationary rotor, the force applied from the elastic device affects as a new load on the startability of the rotor. However, as will be described below, the force applied by the elastic energy of the elastic device has little influence on the rotational startability of the rotor.
That is, there are a dynamic load and a static load as loads applied to the piezoelectric actuator. Therefore, it is examined from the viewpoint of which load brings about the operational effect of “the drive time and drive signal supply time of the piezoelectric actuator can be shortened, the startability is improved, and the drive can be driven with low power consumption”. To do.
A dynamic load is generated based on the moment of inertia of an object to be driven in an environment where acceleration such as a disturbance is applied. Etc.
In the piezoelectric actuator, the influence of the dynamic load is larger than the influence of the static load. In particular, when the piezoelectric actuator drives the driving target vigorously in a short time (for example, when the pointer is driven instantaneously for one step), the influence of the inertia moment is large, and the static load caused by the elastic device or the like is large. The degree of influence is small. This has been confirmed in experiments conducted by the inventor.
Therefore, in the present invention, the effect of the above-described effect can be obtained compared with the case where the elastic device of the present invention is not used by preventing the influence of the moment of inertia after that by the elastic device from affecting the piezoelectric actuator. Can do.

The influence of the load of the elastic device on the characteristics of the piezoelectric actuator will be described with reference to FIG. FIG. 5 shows a decrease amount of the rotational speed N in the piezoelectric actuator when the torque T applied to the piezoelectric actuator is increased. The load torque T2 when the piezoelectric actuator receives the load of the elastic device needs to exceed the load torque T1 at a minimum. The load torque T2 is a necessary torque that can drive a driven body (for example, a train wheel or a pointer) that is rotated by elastic energy accumulated in the elastic device. The torque exceeding the above is α1. Further, the rotational speed at the load torque T2 is N2, and the decrease amount of the rotational speed N when the rotational speed is changed from N1 to N2 is α2. As described above, the rotation speed is decreased by α2 due to the torque increase amount α1, so that the basic characteristics of the piezoelectric actuator are deteriorated. However, such a relationship between the torque T and the rotation speed N indicates a relationship in a state where the piezoelectric actuator is stably driven. On the other hand, in the present invention, when starting the stopped piezoelectric actuator, the energy loss is reduced particularly when the piezoelectric actuator is started quickly, thereby reducing power consumption in the entire drive from start to stop. Therefore, it is necessary to make a determination by comparing both the reduction of the basic characteristic due to the reduction amount α2 of the rotational speed and the reduction of the energy loss in the starting operation.
Therefore, the load torque T2 when the elastic device is used will be described by taking the driving of the hands of the watch as an example. It is desirable that the load torque T2 is larger than the load torque T1, and the increase amount α1 of the load torque is as small as possible. However, in the present invention, in a piezoelectric actuator that is driven at predetermined intervals (step drive), an increase in load according to the deflection of the elastic device with respect to the drive for one step is important. If the increase in the load is almost zero, the load due to the elastic device applied to the piezoelectric actuator is extremely small.
For example, if the rotation angle for one step of the rotor is 20 degrees and the rotation angle corresponding to the initial deflection of the elastic device is 20 degrees, the deflection of the elastic device will increase, resulting in a deflection of 40 degrees. The load by the elastic device is twice the initial state. That is, if the initial deflection can be increased, the increase in load is reduced. When the number of windings of the initial deflection can be secured with a spring such as a “spring spring” as an elastic device, even if the rotor rotates 20 degrees, the value is 20 degrees ÷ (360 degrees × 3 windings) = 0.018. Thus, the increase in load is 2% or less. Therefore, the amount of increase in load by the elastic device can be suppressed to a very small amount, and the influence on the characteristics of the piezoelectric actuator can be almost eliminated.

Further, when the elastic device is not used, the necessary performance of the piezoelectric actuator needs to be set in consideration of the shape of the rotating object, the impact from the outside, the influence of the temperature environment, and the like.
As shown in FIG. 5, for the piezoelectric actuator, the load torque T2 is set to drive the load in the case of normal driving, whereas the maximum torque T3 is a margin for the load that occurs suddenly. Set as minutes. For example, when an unbalanced rotating object (such as a member that is supported by a cantilever such as a watch pointer) is included in the drive path, the piezoelectric actuator depends on the orientation of the rotating object. The influence of the moment of inertia to give may become temporarily large. Further, when the piezoelectric drive device is used while being attached to an arm or the like, the acceleration G due to the movement of the arm or a light impact may act on the rotating object, particularly when the rotating object has an unbalanced shape. An acceleration G several times the load in a static state is generated. For example, when applause is performed, the acceleration G may be several tens to one hundred times. When the piezoelectric actuator directly rotates the rotating body as in the conventional case, the load is overcome in order to rotate the rotating object under the moment of inertia or a sudden load as described above. It is necessary to set the maximum torque T3 of the piezoelectric actuator so that only the torque can be generated.
On the other hand, when the elastic device is used as in the present invention, the elastic device is elastically deformed to reduce the influence on the piezoelectric actuator due to the moment of inertia temporarily increased or the sudden acceleration G. be able to. That is, the sudden acceleration G is applied in a direction that blocks the rotation of the rotating body, so that even if the rotation of the rotating body temporarily stops, the rotor can continue to rotate during that time. Energy is stored as the elastic energy of the elastic device. Then, after the sudden acceleration G disappears, the rotated body can be rotated by the accumulated elastic energy. In addition, when sudden acceleration G occurs intermittently, such as applause, the rotated body can be rotated by the accumulated elastic energy while no sudden acceleration G occurs.
As described above, by providing the elastic device, the piezoelectric actuator can be set to a characteristic corresponding to the static load torque T1 (set to T2), and can respond to the sudden acceleration G as in the past. The power supplied to the piezoelectric actuator can be reduced, and the power consumption W1 can be reduced.
Considering the effect of the viscosity of the lubricating oil used for the bearing, the viscosity of the lubricating oil increases as the temperature decreases, and the viscosity increases in proportion to the speed of the rotated body. It is necessary to improve the performance. On the other hand, when the elastic device is used, the influence of the viscosity of the lubricating oil of the rotated body can be reduced by rotating the rotated body gradually by elastic energy.

When the elastic device as in the present invention is provided, a mechanism for holding the elastic deformation state of the elastic device is required so that the elastic energy accumulated in the elastic device is consumed only by the rotation of the rotated body. . For example, it is necessary to prevent the rotor from rotating in the opposite direction due to elastic energy. In the present invention, in a state where the rotor and the vibrator are in contact with each other, free rotation of the rotor itself is restricted by the mutual frictional force. However, when a disturbance such as vibration or an impact such as a collision or a drop is applied, there is a possibility that the rotor can be easily separated from the vibrator, and the elastic energy of the elastic device is released by reversing the rotor. There is.
On the other hand, the present invention is provided with a release restricting means for restricting the elastic energy accumulated in the elastic device from being released by the reverse rotation of the rotor. Therefore, for example, when an impact due to disturbance such as vibration or dropping is applied, the contact between the vibrator and the rotor is not maintained and they are separated from each other, or the pressing force between the vibrator and the rotor is weakened or the surface condition of each other is Even when the coefficient of friction decreases and the friction coefficient decreases, the rotor does not reverse so that elastic energy is maintained. The release restricting means may be any means provided with a mechanism capable of maintaining at least the elastic deformation state of the elastic device. Therefore, since it is not necessary to increase the pressing force between the rotor and the vibrator, the startability of the rotor is secured, and even when an impact or the like is applied, the accumulated elastic energy is reliably transmitted to the rotated body. Can be made.

In the piezoelectric drive device of the present invention, the elastic device accumulates elastic energy in accordance with the rotation of the rotor in the forward direction, and the release restricting means is a reverse rotation prevention mechanism that prevents the rotation of the rotor in the reverse direction. Preferably there is.
According to this configuration, when the rotor rotates in the positive direction, elastic energy is accumulated in the elastic device. On the other hand, since the reverse rotation prevention mechanism prevents the rotor from rotating in the reverse direction, the rotor does not rotate in the reverse direction and the elastic energy is not released. Thus, by preventing the rotor from rotating in the reverse direction, even when an impact or the like is applied, the elastic energy can be reliably transmitted to the rotated body.

In the piezoelectric drive device of the present invention, the reverse rotation prevention mechanism includes a locked member that is provided coaxially with the rotor and rotates integrally with the rotor, and the locked rotation with respect to the rotation of the rotor in the positive direction. A locking member that allows rotation of the rotor in the forward direction without locking the member and locks the locked member against rotation in the reverse direction of the rotor to prevent rotation in the reverse direction of the rotor; Are preferably provided.
According to this configuration, when the rotor tries to rotate in the positive direction, the locking member does not lock the locked member, allowing the rotor to rotate in the positive direction, and elastic energy is accumulated in the elastic device. . When the rotor tries to rotate in the reverse direction, the locking member locks the locked member, so that the rotation of the rotor in the reverse direction is prevented, and the release of the elastic energy of the elastic device is restricted. Therefore, only the reverse rotation of the rotor can be reliably prevented by the locking of the locking member and the locked member.
Here, as a rotational drive system using a piezoelectric actuator, a drive system that rotates the rotating body by increasing the rotational speed of the rotor with a speed increasing wheel train or the like is often used. In such a case, the rotational torque of the rotor is used. Is the largest. Therefore, the load of the reverse rotation prevention mechanism is greater when the reverse rotation prevention mechanism is provided for the rotor having the largest rotation torque than when the reverse rotation prevention mechanism is provided for the rotating body having a smaller rotation torque than the rotor. The impact can be minimized.
Further, if the rotor is provided with a reverse rotation prevention mechanism, the rotation of the rotor in the reverse direction can be prevented even when the rotational energy of the rotor is directly transmitted to the elastic device. Therefore, the number of parts can be reduced as compared with the case where a train wheel part is provided between the rotor and the elastic device.

The piezoelectric drive device of the present invention includes a base member that supports the vibrator, and a lever member that supports the rotor and is provided to be swingable about a predetermined axis with respect to the base member. The means is a rotor pressing member that presses and swings the lever member in a direction in which the rotor contacts the vibrator, and the locking member is preferably supported by the lever member.
Here, the vibrator is supported by the base member, the rotor is pivotally supported by the lever member, and the rotor is pressed in a direction in contact with the vibrator by the rotor pressing member. Thereby, the contact between the rotor and the vibrator is maintained. However, when the locking member is supported by the base member and only the locked member is supported by the lever member, when the lever member swings due to an impact or the like, the locked state between the locking member and the locked member May change and the lock may be released.
According to this configuration, since the locking member is also supported by the lever member, even if the lever member swings, the relative position of the locking member and the locked member does not change, and the locking can be performed. Since it is not released, rotation of the rotor in the reverse direction can be reliably prevented.

In the piezoelectric driving device of the present invention, a base member that supports the vibrator, a lever member that supports the rotor and is swingable about a predetermined axis with respect to the base member, and coaxial with the rotor A rotor gear that is provided on the rotor and rotates integrally with the rotor; and at least one rotor transmission gear that meshes with the rotor gear and transmits the rotational energy of the rotor to the elastic device; A rotor pressing member that presses and swings the lever member in a direction in which the rotor comes into contact with the vibrator; and a contact portion between the vibrator and the rotor and an engagement portion between the rotor gear and the rotor transmission gear. Preferably, the lever member is provided at a position sandwiching a straight line passing through the rotation shaft of the lever member and the rotation shaft of the rotor.
Here, the rotational energy of the rotor is transmitted from the rotor gear to the elastic device via the rotor transmission gear. A contact portion of the vibrator and the rotor is a contact portion A, an engagement portion of the rotor gear and the rotor transmission gear is an engagement portion B, and a straight line passing through the rotation shaft of the lever member and the rotation shaft of the rotor is a straight line C. explain.
Even if the rotation of the rotor in the reverse direction is prevented, if the engagement between the rotor gear and the rotor transmission gear is released when the lever member swings, the elastic energy of the elastic device is released. is there. On the other hand, according to the configuration of the present invention, the contact portion A and the engagement portion B are provided at positions where the straight line C is sandwiched even when the rotor is moved away from the vibrator by an impact or the like. Therefore, the moving direction of the rotor is the direction in which the engagement portion B is deeply engaged. Therefore, the disengagement between the rotor gear and the rotor transmission gear can be prevented, and the elastic energy accumulated in the elastic device can be held.

In the piezoelectric drive device of the present invention, a base member that supports the vibrator, a lever member that supports the rotor and is provided so as to be swingable about a predetermined axis with respect to the base member, and coaxial with the rotor A rotor gear that is provided on the rotor and rotates together with the rotor; and at least one rotor transmission gear that meshes with the rotor gear and transmits the rotational energy of the rotor to the elastic device; A rotor pressing member that presses and swings the lever member in a direction in which the rotor is brought into contact with the vibrator; and a contact portion between the vibrator and the rotor and an engagement portion between the rotor gear and the rotor transmission gear. The lever member is disposed on one side with respect to a straight line passing through the rotation shaft of the lever member and the rotation shaft of the rotor, and the rotor rotates in the opposite direction. In this case, there is provided a swing restricting means for restricting the lever member from swinging in a direction opposite to the direction in which the rotor is brought into contact with the vibrator, and the swing restricting means is arranged on the straight line. On the other hand, it is preferably arranged on the other side.
In this configuration, when the contact portion A and the engagement portion B are both arranged on one side with respect to the straight line C, the rotor moves away from the vibrator by an impact or the like, and the engagement portion B Will become shallower. On the other hand, in the present invention, since the rocking restricting means is disposed on the other side with respect to the straight line C, even if the lever member rocks in the direction away from the vibrator, the lever member Is restricted by the swing restricting means. Therefore, the disengagement between the rotor gear and the rotor transmission gear can be prevented, and the elastic energy accumulated in the elastic device can be held.

In the piezoelectric drive device of the present invention, the piezoelectric drive device includes a vibrator support member that is provided so as to be swingable about a predetermined axis with respect to the base member, and that supports the vibrator. A vibrator pressing member that presses and swings the vibrator support member in a direction in contact with the rotor may be used.
In this configuration, the vibrator supported by the vibrator support member presses the rotor, so that the contact between the vibrator and the rotor is maintained.
According to this configuration, a rotor pressing mechanism that presses the rotor against the vibrator is not required, and therefore, the rotating shaft of the rotor can be provided on the ground plate or the like. Therefore, compared with the case where the rotor is supported by the lever member so as to be able to swing, the position coordinates of the rotor do not change, so that the mutual disengagement is prevented.

In the piezoelectric drive device of the present invention, the rotated body is provided coaxially with the rotor and rotates separately from the rotor, and the elastic device is a spiral spring, and the rotor and the rotated body Preferably, the spiral springs are arranged coaxially between the bodies, one end of the spiral spring is engaged with the rotor, and the other end of the spiral spring is engaged with the rotated body.
According to this configuration, since the rotation shaft of the rotor and the rotation shaft of the rotated body are formed on the same axis and are provided to be rotatable separately from each other, there is no elasticity between the rotor and the rotated body. A spiral spring can be arranged as a device, and the elastic device can be stored compactly.

The piezoelectric drive device of the present invention includes a base member that supports the rotor, is provided coaxially with the rotor and rotates integrally with the rotor, and meshes with the rotor gear and transmits rotational energy of the rotor. At least one rotor transmission gear that transmits to the elastic device, and the reverse rotation prevention mechanism is provided coaxially with the rotor transmission gear and rotates integrally with the rotor transmission gear and is pivotally supported by the base member. A locked member that is supported by the base member, and allows the rotor transmission gear to rotate in the positive direction without locking the locked member with respect to the rotation of the rotor in the positive direction. It is preferable to include a locking member that locks the locked member against rotation in the opposite direction to prevent rotation of the rotor transmission gear in the reverse direction.
According to this configuration, by providing a reverse rotation prevention mechanism for the rotor transmission gear other than the rotor, the rotor can be configured as it is, and the design of the piezoelectric actuator composed of the rotor and vibrator is changed. The reverse rotation prevention mechanism can be provided without doing so.

In the piezoelectric driving device of the present invention, the locked member is a claw wheel provided so as to be rotatable around a predetermined axis in accordance with the rotation of the rotor in the positive direction, and the claw wheel is continuous along the circumferential direction. A plurality of claw teeth formed, and the locking member is a claw having a blade edge that locks with the claw teeth and supported so as to be swingable about a claw axis; An urging member for urging the blade edge toward the claw tooth is provided adjacently, and the blade edge is engaged with the claw tooth by urging the urging member against rotation in the reverse direction of the rotor. The rotation of the rotor is prevented from rotating in the reverse direction, and the claw teeth oscillate against the bias of the biasing member with respect to the rotation of the rotor in the forward direction. It is preferable to allow the rotation of.
Here, the ratchet wheel should just be formed on the same axis | shaft as the rotating shaft of either a rotor or a rotor transmission gearwheel.
According to this structure, the blade edge | tip of a nail | claw is urged | biased by the nail | claw tooth | gear of a claw wheel by the biasing member. These claws and claw wheels function as a ratchet and can prevent the rotor from rotating in the reverse direction.

In the piezoelectric drive device of the present invention, when the rotor is about to rotate in the reverse direction, the claw is moved so that the blade edge swings in a direction urged against the claw tooth by the urging member. You may arrange | position with respect to the said pinion wheel.
According to this configuration, even when the vibrator is separated from the rotor due to an impact or the like, the claw blade edge moves in a direction urged by the claw tooth of the claw wheel. The stop is maintained.

In the piezoelectric drive device of the present invention, the locked member is a rotor gear that is provided so as to be rotatable around a predetermined axis in accordance with the rotation of the rotor in the positive direction, and transmits rotational energy to the elastic device. The locking member is a leaf spring having a tip that engages with the teeth of the rotor gear, and the leaf spring is elastically deformed so as to bias the tip of the leaf spring to the teeth of the rotor gear. The tip of the leaf spring is supported by the tooth side surface against rotation of the rotor in the reverse direction to prevent the rotation of the rotor in the reverse direction and against the rotation of the rotor in the forward direction. It is preferable that the rotor is moved in a direction in which it is further elastically deformed against the biasing direction to allow the rotor to rotate in the positive direction.
According to this configuration, since the locking member is a leaf spring, the rotation of the rotor in the reverse direction can be prevented by bringing the tip of the leaf spring into contact with the rotor gear. Therefore, compared to the case where a claw wheel or the like is provided as a member to be locked, a claw wheel or the like is not necessary, and thus it is possible to reduce the rotational torque necessary for rotational driving of the rotor.

In the piezoelectric drive device of the present invention, the locked member is a rotor gear that is provided so as to be rotatable about a predetermined axis in accordance with the rotation of the rotor in the positive direction and that transmits rotational energy to the elastic device. The locking member is a brush having a plurality of bristles having tips that engage with the teeth of the rotor gear, and the brush biases the tips of the plurality of bristles against the teeth of the rotor gear. The tips of the plurality of bristles are locked to the side surfaces of the teeth against the rotation of the rotor in the reverse direction to prevent the rotation of the rotor in the reverse direction. The forward rotation of the rotor may be permitted by the teeth being moved in a direction that is further elastically deformed against the biasing direction by the teeth.
According to this configuration, since the locking member is a brush, the rotation of the rotor in the reverse direction can be prevented by bringing the tip of the brush hair into contact with the rotor gear. Therefore, compared to the case where a claw wheel or the like is provided as a member to be locked, a claw wheel or the like is not necessary, and thus it is possible to reduce the rotational torque necessary for rotational driving of the rotor.

Furthermore, in the piezoelectric drive device of the present invention, the locked member is a claw wheel provided so as to be rotatable around a predetermined axis in accordance with the rotation of the rotor in the positive direction, and the locking member is the claw wheel. A claw lever having a push claw and a pull claw provided so as to sandwich the claw, wherein the push claw and the pull claw are arranged in an elastically deformed state so as to bias the claw teeth of a claw wheel for the claw lever, The claw lever is moved in a direction in which the push claw and the pull claw are elastically deformed without being engaged with the claw teeth with respect to the rotation of the rotor in the positive direction, and permits the claw wheel to rotate in the positive direction. The pushing claw and the pulling claw may be engaged with the claw teeth to prevent the claw wheel from rotating in the reverse direction with respect to the rotation of the rotor in the reverse direction.
According to this configuration, the claw lever is used as a locking member instead of the claw in the reverse rotation prevention mechanism by the locking of the claw and the claw wheel, and the rotor claw lever is pushed and pulled by the claw lever. Since rotation in the reverse direction can be prevented, the same effect as described above can be obtained.

Further, the piezoelectric drive device of the present invention has a cam member that is driven by the rotation of the rotor, and the claw lever is swung by the cam member to rotate the claw wheel only in the forward direction, The elastic energy may be stored in the elastic device via the claw wheel.
According to this configuration, the claw lever swings by the cam member driven by the piezoelectric actuator, and the claw wheel for the claw lever is driven. Since elastic energy can be accumulated in the elastic device via the claw wheel, the claw lever can have both functions of preventing reverse rotation and driving. Therefore, the number of parts can be reduced as compared with the case where the reverse rotation prevention function and the drive function are provided in different configurations.
Further, an ankle that can be swung by a cam member and an escape gear that engages with the ankle may be provided, and the escape gear may be a rotated body. The cam member can swing the aforementioned claw lever to accumulate elastic energy in the elastic device, and can also swing the ankle to regulate the rotation angle of the escape gear that is the rotated body. Therefore, the number of parts can be reduced and the phases of the two trains are out of phase as compared with the case where the drive system for swinging the ankle and the drive system for swinging the claw lever are individually provided. Can also be prevented.

In the piezoelectric driving device of the present invention, it is preferable that the piezoelectric driving device includes a detecting unit that detects a position of the locking member, and obtains the number of movements of the locking member with respect to the rotation of the rotor in the positive direction.
According to this configuration, when the rotor rotates in the positive direction due to the accumulated elastic energy, the locking member moves. For example, when the pawl as the locked member moves due to the movement of the pawl as the locked member, or when the rotor gear as the locked member moves, The case where the leaf | plate spring as a stop member moves against a biasing direction is mentioned. In such a case, the amount of rotation of the rotor in the positive direction can be grasped by detecting the moving position of the locking member by the detecting means.

In the piezoelectric driving device of the present invention, the piezoelectric actuator rotates the rotor intermittently, the locked member has a locked portion with a predetermined pitch, and the locking member is a positive part of the rotor. The rotating portion is provided to intermittently lock the locked portion by one pitch with respect to the rotation of the direction, and the rotation angle of one step of the rotor corresponds to the pitch of the locked portion corresponding to one pitch. It is preferable that the rotation angle is set to be the same as the rotation angle of the locking member or an integral multiple of the rotation angle of the locked member corresponding to one pitch of the locked portion.
According to this configuration, when the piezoelectric actuator is driven stepwise, that is, at a constant interval, the rotation angle of the rotor for one step corresponds to the rotation angle of the locked member corresponding to one pitch of the locked portion. Or an integer multiple of the rotation angle of the locked member corresponding to one pitch of the locked portion, so that the locking position between the locking portion and the locked portion and the rotor The rotational position for one step drive can be matched, and the rotor can be prevented from stopping at a position where the locking portion and the locked portion are not sufficiently locked.

The piezoelectric drive device of the present invention preferably includes a movement restricting device that restricts the rotational movement angle of the rotated body to a predetermined angle.
Here, the movement restricting device may be, for example, a mechanism including an ankle and an escape gear, or may be a Geneva mechanism.
According to this configuration, the rotating body is rotated by the driving of the rotor, and the rotation of the rotating body is restricted at a certain angle by the movement restricting device. Even if the amount of rotation is not uniquely determined, if the rotating body rotates by a certain angle, the movement restricting device restricts the rotation angle of the rotating body to a certain angle, so that the rotation amount of the rotating body becomes constant. As a result, it is possible to prevent overrun of the rotating object rotated by the piezoelectric actuator, so that it is not necessary to strictly control the rotation angle of the rotor, and the accuracy of the rotating angle of the rotated object can be improved. The display accuracy of display means such as a pointer rotated by the body can be improved.
Note that the movement restricting device is not limited to a device that restricts the rotation angle of the rotated body at every fixed angle, but may be a movement restricting device configured to change the restricting rotation angle, such as a mechanical clock. Good. That is, the movement restricting device may be any device that restricts the rotation angle of the rotated body to a predetermined angle.

An electronic apparatus according to the present invention includes the above-described piezoelectric driving device and a driven portion driven by the piezoelectric driving device.
According to the present invention, it is possible to configure various electronic devices using a piezoelectric drive device as a drive source. At this time, the driving of the driven part by the piezoelectric driving device can be prevented from being influenced by the magnetic field, the power consumption during driving can be reduced, and further, the release of the elastic energy accumulated in the elastic device can be prevented. The rotational energy of the rotor can be reliably transmitted to the driven part.

In the electronic device according to the aspect of the invention, it is preferable that the driven unit is a time information display unit that displays time information measured by the time unit.
According to the present invention, the time information display unit such as the timepiece of the watch can be driven by the piezoelectric driving device, so that the driving of the hand etc. can be prevented from being influenced by the magnetic field, and the hand of the time information display unit can be reduced. It can be driven by electric power, and further, the release of elastic energy accumulated in the elastic device can be prevented, and the rotational energy of the rotor can be reliably transmitted to the timing information display section.

  According to the present invention, the driven member can be driven with low power when the driven member is driven by the vibration of the piezoelectric element.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
Note that, in the second and subsequent embodiments described later, the same reference numerals are given to the same structural members and structural members having the same functions as the structural members in the first embodiment described below, and the description will be simplified or omitted. .

[overall structure]
FIG. 6 is a perspective view showing a drive mechanism of the piezoelectric drive device 10 according to the present embodiment.
The piezoelectric driving device 10 is a device for rotating a pointer, for example, with the rotational driving force of the piezoelectric actuator, and the piezoelectric actuator 4 that rotates the rotor ring (rotor) 30 using the vibration of the piezoelectric element, and the rotor A rotor transmission wheel 5 that transmits the rotational drive of the ring 30 to the transmission wheel 3 while decelerating, and a reverse rotation prevention mechanism 90 that prevents the rotor ring 30 from rotating in the reverse direction are provided.

[Configuration of piezoelectric actuator]
As shown in FIG. 6, the piezoelectric actuator 4 includes a vibrator 20 having a piezoelectric element 22 and a rotor ring 30 that is rotated by the vibrator 20 in contact with the vibrator 20.
The vibrator 20 includes a substantially rectangular plate-like thin plate reinforcing plate 21 and a substantially rectangular plate-like piezoelectric element 22 bonded to both surfaces of the thin plate reinforcing plate 21, and has an overall thin plate-like laminated structure. is doing.
An arm portion 211 projecting to one side is formed at a substantially longitudinal center of the thin plate reinforcing plate 21, and the arm portion 211 is fixed to a ground plate or the like (not shown) with screws or the like. At both ends of the thin plate reinforcing plate 21 on the diagonal line, substantially semicircular abutting portions 212 protruding along the longitudinal direction of the thin plate reinforcing plate 21 are formed. One of these contact portions 212 is in contact with the side surface of the rotor ring 30.
The thin plate reinforcing plate 21 and the rotor ring 30 are made of, for example, stainless steel (SUS). In particular, if the thin plate reinforcing plate 21 and the rotor ring 30 are made of a nonmagnetic material such as stainless steel or hardened beryllium copper, the anti-magnetism of the piezoelectric actuator 4 is improved and can be driven without being affected by a magnetic field.

Piezoelectric element 22 includes lead zirconate titanate (PZT (registered trademark)), crystal, lithium niobate, barium titanate, lead titanate, lead metaniobate, polyvinylidene fluoride, lead zinc niobate, lead scandium niobate, etc. It is made of any material selected from. Drive electrodes 221 are formed on both surfaces of the piezoelectric element 22 by a plating layer (not shown).
When a voltage having a predetermined frequency is applied to the drive electrode 221 of the vibrator 20, the piezoelectric element 22 excites vibration in the longitudinal primary vibration mode in which the piezoelectric element 22 expands and contracts along the longitudinal direction. At this time, since the contact portions 212 are provided at both ends of the diagonal line of the vibrator 20, the vibrator 20 as a whole is unbalanced in weight with respect to the longitudinal center line. Due to this imbalance, the vibrator 20 excites vibrations in a bending secondary vibration mode that bends in a direction substantially orthogonal to the longitudinal direction. Therefore, the vibrator 20 excites vibrations that combine these longitudinal primary vibration mode and bending secondary vibration mode, and the contact portion 212 vibrates in a substantially elliptical orbit.

The rotor ring 30 is rotationally driven by the vibrator 20. A rotor gear 32 that transmits rotational driving to the first rotor transmission gear 40 is fixed to the rotor rotation shaft 31 of the rotor ring 30.
The rotor ring 30 and the contact portion 212 of the vibrator 20 are pressed by pressing means (not shown) so as to contact each other. As this pressing means, the rotor ring 30 may be pressed against the vibrator 20, or the vibrator 20 may be pressed against the rotor ring 30. By the pressing means, an appropriate frictional force is generated between the contact portion 212 and the side surface of the rotor ring 30, and the transmission efficiency of the driving force of the vibrator 20 is improved.
In such a piezoelectric actuator 4, when the contact portion 212 of the vibrator 20 vibrates in a substantially elliptical orbit, the rotor ring 30 and the rotor gear 32 are counteracted by pressing the rotor ring 30 with a part of the vibration orbit. It is rotationally driven only in the clockwise direction (forward rotation direction indicated by arrow A1 in FIG. 6).

[Configuration of rotor transmission wheel]
As shown in FIG. 6, the rotor transmission wheel 5 has a structure in which a spiral spring (elastic device) 50 is interposed between two gears provided on the same shaft, and rotates a pointer or the like. It is for transmitting rotational energy to the transmission wheel 3 which is a part of the train wheel. Specifically, the rotor transmission wheel 5 includes a first rotor transmission gear 40 that meshes with the rotor gear 32, a spiral spring 50 having one end locked to the first rotor transmission gear 40, and the other end of the spiral spring 50. The second rotor transmission gear 60 and the transmission wheel rotating shaft 63 are connected to each other.

The first rotor transmission gear 40 is formed in a disc shape and is rotatably supported by a transmission wheel rotating shaft 63. The first rotor transmission gear 40 is formed with a spring locking hole 41 and a positioning hole 42 penetrating in the rotation axis direction. Although not shown, an optical detection means for detecting the rotation amount of the first rotor transmission gear 40 is provided, and the first rotor transmission gear 40 is rotated by the piezoelectric actuator 4 to a predetermined rotation by this non-contact detection means. The piezoelectric actuator 4 is stopped every time it is driven by an amount, and the piezoelectric actuator 4 is started after a predetermined time. Thus, the piezoelectric actuator 4 is periodically driven by repeating starting and stopping.
When the piezoelectric actuator 4 stops, the contact portion 212 of the piezoelectric actuator 4 is pressed against the rotor ring 30 by a pressing means (not shown) and is frictionally engaged, so that the rotor ring 30 is positioned at that position. . Therefore, the rotor ring 30 does not move in the rotation direction. Therefore, the first rotor transmission gear 40 is also positioned in the rotational direction by the positioned rotor ring 30. Note that the position of the second rotor transmission gear 60 and the transmission wheel 3 in the rotational direction is determined by the positioning hole 42 and the positioning pin 61, which are release restriction portions, as will be described later. It will be.

The positioning hole 42 is a long hole formed along the outer periphery of the first rotor transmission gear 40. The dimension in the direction along the outer periphery of the first rotor transmission gear 40 at the opening of the positioning hole 42 is such that the first rotor transmission gear 40 is equivalent to one cycle of the piezoelectric actuator while the second rotor transmission gear 60 is stopped. The length dimension (dimension of the play portion) is set so as to be rotatable in the forward rotation direction (direction indicated by arrow A1 in FIG. 6) by the driving amount.
The second rotor transmission gear 60 is fixed to the transmission wheel rotation shaft 63, has the same rotation shaft as the first rotor transmission gear 40, and meshes with the transmission wheel 3. A cylindrical positioning pin 61 that protrudes toward the first rotor transmission gear 40 and is inserted through the positioning hole 42 is fixed to the second rotor transmission gear 60.

The spiral spring 50 is formed by winding a spring wire having a circular cross section in a clockwise spiral shape on a plane in FIG. The end portion on the outer peripheral side of the spiral spring 50 is engaged with the spring locking hole 41, and the end portion on the center axis side is engaged by being wound around the transmission wheel rotating shaft 63.
The spiral spring 50 is elastically deformed in a direction in which the number of windings increases as the first rotor transmission gear 40 rotates in a clockwise direction before the second rotor transmission gear 60, and is transmitted to the first rotor transmission gear 40. The rotational energy of the rotor ring 30 thus made can be stored as elastic energy.

Next, the situation where the elastic deformation in the initial stage is maintained in the spiral spring 50 will be described.
In a state where the spiral spring 50 is initially elastically deformed (about 3 turns), the end portion on the center side of the spiral spring 50 is transmitted and fixed to the wheel rotating shaft 63, and the outer end portion of the spiral spring 50 is fixed to the spring. It is locked in the locking hole 41 for use.
When the first rotor transmission gear 40 and the second rotor transmission gear 60 are assembled as shown in FIG. 6 while maintaining the initial elastic deformation, the second rotor transmission gear 60 is moved to the first by the elastic energy of the spiral spring 50. A force that rotates in the forward rotation direction (the direction of arrow A2 in FIG. 6) is applied to the rotor transmission gear 40. However, since the positioning pin 61 is disposed in the positioning hole 42, the second rotor transmission gear 60 contacts the inner surface of the positioning hole 42 on the forward rotation direction side with respect to the first rotor transmission gear 40. The contact position, that is, the state shown in FIG. 6 is maintained.
Further, the first rotor transmission gear 40 meshes with the rotor gear 32. As described above, the rotor ring 30 integrated with the rotor gear 32 is positioned by the pressure of the contact portion 212 of the piezoelectric actuator 4. Therefore, when the piezoelectric actuator 4 is stopped, the rotor ring 30 is maintained in the stopped state by the contact portion 212 of the piezoelectric actuator 4 contacting, and the first rotor transmission gear 40 meshing with the rotor gear 32 is also stopped. Maintained in a state. Further, the second rotor transmission gear 60 is positioned at a position where the positioning pin 61 contacts the positioning hole 42 with respect to the first rotor transmission gear 40. Thus, the elastic deformation (initial elastic deformation) of the spiral spring 50 is maintained.
Therefore, in the present embodiment, the spiral spring 50 constitutes an elastic device, the second rotor transmission gear 60 constitutes a rotated body, and the positioning pin 61 and the positioning hole 42 constitute a release restricting portion.

The positioning hole 42 and the positioning pin 61, which are release restriction portions, maintain the elastic deformation (initial deflection) in the initial stage of the spiral spring 50 as described above, but the piezoelectric actuator 4 further has one step. It also has a role of holding the second rotor transmission gear 60 and the transmission wheel 3 at predetermined positions when driven for minutes (one cycle).
That is, when the piezoelectric actuator 4 is driven by one step, the first rotor transmission gear 40 is rotated by one period (one step) in the clockwise direction in FIG. 6, and at the same time, the spiral spring 50 is also wound. Then, the second rotor transmission gear 60 is also rotated in the clockwise direction by the release force of the elastic energy accumulated in the spiral spring 50, but the positioning pin 61 is positioned on the inner side surface of the positioning hole 42 in the clockwise direction (positioning in FIG. 6). The second rotor transmission gear 60 is positioned in the rotational direction because the pin 61 abuts against and is pressed against the inner side surface with which the pin 61 is in contact.

  The vibrator 20 of the piezoelectric actuator 4 is fixed to the base plate, which is the base frame of the timepiece 1, by the arm portion 211. The rotor rotating shaft 31, the transmission wheel rotating shaft 63, and the rotating shaft of the transmission wheel 3 have one end. The bearing is supported by the bearing hole of the main plate, and the other end is supported and held by the train wheel bearing arranged opposite to the main plate. Note that one end of the rotation shaft of the transmission wheel 3 and the other rotation shafts of the other indicator wheels are supported by the main plate, but the other end may be supported by a receiving member other than the train wheel.

[Configuration of reverse rotation prevention mechanism]
As shown in FIG. 6, the reverse rotation prevention mechanism 90 releases the elastic energy accumulated in the spiral spring 50 when the rotor ring 30 moves away from the vibrator 20 against the pressing force due to an impact or the like. It is provided as a release restricting means for restricting the above.
Specifically, the reverse rotation preventing mechanism 90 is a claw wheel (locked member) provided so as to maintain mutual locking with respect to rotation in the reverse direction and not lock with respect to rotation in the forward direction. 91 and a claw (locking member) 92.

The claw wheel 91 is disposed on the same rotation axis as the rotor ring 30 and is provided so as to be rotatable integrally. The claw wheel 91 has claw teeth 93 that are a plurality of locked portions that are continuously formed at a predetermined pitch along the circumferential direction.
The claw 92 is supported so as to be able to swing around a shaft portion 95 that is formed to protrude from the base plate, and a cutting edge 94 provided at the tip portion of the claw 92 is provided by a biasing member such as a U-shaped spring (not shown). It is arrange | positioned with respect to the claw wheel 91 so that it may be urged | biased by the nail | claw tooth | gear 93 of this.
When the claw wheel 91 is rotated in the reverse direction, the cutting edge 94 is moved to a position where the claw tooth 93 is locked by the urging force of the urging member (locking position) and the claw wheel 91 is rotated in the forward direction. At this time, it is provided so as to be movable between a position (non-locking position) where the claw teeth 93 are not locked.

By such a reverse rotation prevention mechanism 90 provided directly with respect to the rotor ring 30, the claw teeth 93 lock the blade edge 94 against the urging force of the urging member against the forward rotation of the rotor ring 30. It is provided to move from the position to the non-locking position. That is, the claw 92 is provided so as to intermittently lock the claw teeth 93 one pitch at a time, and allows the rotor ring 30 to rotate in the positive direction.
Further, the claw teeth 93 are provided so as to maintain the engagement with the blade edge 94 against the rotation of the rotor ring 30 in the reverse direction, and prevent the rotation of the rotor ring 30 in the reverse direction.
In this embodiment, the claw 92 constitutes a locking member, and the claw wheel 91 constitutes a locked member.

  Here, the claw wheel 91 is not limited to the case where it is integrally formed on the same axis as the rotor ring 30, and for example, the first rotor transmission gear 40 that meshes with the rotor gear 32, and the rotor gear 32. You may provide with respect to the other intermediate wheel etc. which mesh. That is, the reverse rotation prevention mechanism 90 is provided for the first rotor transmission gear 40, the intermediate wheel, and the like that are provided so as to be rotatable around a predetermined axis in accordance with the rotation of the rotor ring 30, thereby preventing the reverse rotation of the rotor ring 30. You may make it prevent.

[Operation when starting the piezoelectric drive]
Next, the operation at the time of starting of the piezoelectric drive device 10 will be described.
First, when a drive voltage is applied to the vibrator 20 with the piezoelectric actuator 4 stopped, rotational energy is transmitted from the rotor ring 30 to the first rotor transmission gear 40 via the rotor gear 32, and these rotating bodies (Rotor ring 30, rotor gear 32, first rotor transmission gear 40) starts rotating, and spiral spring 50 starts elastic deformation, and the transmitted rotational energy is accumulated as elastic energy of spiral spring 50. Then, when the rotational energy applied to the second rotor transmission gear 60 reaches a predetermined magnitude by the elastic energy of the spiral spring 50, the second rotor transmission gear 60 and the transmission wheel 3 start to rotate. The rotational energy of the predetermined magnitude is the moment of inertia of each rotating body (second rotor transmission gear 60, transmission wheel 3 and pointer driven by transmission wheel 3), and the bearing load of each of these rotating bodies. Rotational energy having a magnitude equal to the total load.
Therefore, when the piezoelectric actuator 4 is driven for one cycle, the first rotor transmission gear 40 is also rotated by one cycle in the clockwise direction in FIG. 6 as described above, and the spiral spring 50 is also simultaneously wound up. Then, the second rotor transmission gear 60 is also rotated in the clockwise direction by the releasing force of the spiral spring 50. However, the positioning pin 61 is in contact with the inner surface of the positioning hole 42 in the clockwise direction (the positioning pin 61 in FIG. The second rotor transmission gear 60 and the pointer and the like are also positioned in the rotational direction.
In this way, the piezoelectric driving device 10 is activated and the pointer or the like is rotated.

[Effects of this embodiment]
According to this embodiment, the following effects can be achieved.
(1) A spiral spring 50 is provided, and when the piezoelectric actuator 4 is started, the second rotor transmission gear 60 starts rotating after the driving force of the piezoelectric actuator 4 is accumulated as elastic energy of the spiral spring 50. When the actuator 4 is driven, each moment of inertia such as the second rotor transmission gear 60, the transmission wheel 3, and the pointer does not act on the piezoelectric actuator 4, and a load applied to the piezoelectric actuator 4 at the time of activation is reduced and consumed. The starting power can be reduced.

(2) Since the spiral spring 50 is provided and the load at the time of activation applied to the piezoelectric actuator 4 is reduced, the drive speed of the piezoelectric actuator 4 can be increased to a desired speed in a short time, and the activation time is shortened. Therefore, power consumption can be further reduced.
Here, the reason why the power consumption can be reduced by reducing the load applied to the piezoelectric actuator 4 will be described with reference to FIGS.
FIGS. 7 and 8 illustrate a case where an inertial load applied to the rotor ring 30 is driven with a predetermined amount (hereinafter referred to as an inertial load of 1) and an inertial load with 10 times the inertial load (referred to as an inertial load of 10 times). The relationship between the drive elapsed time and the rotation speed of the rotor ring 30 and the relationship between the drive elapsed time and the rotation angle of the rotor ring 30 are shown.
Here, the rotational speed gradually increases when a drive signal is given to the piezoelectric actuator 4, and eventually becomes a constant speed. On the other hand, the rotation angle increases in an accelerated manner in the initial speed increase range, and when the rotation speed becomes constant, the rotation angle increases in proportion to time.
As shown in FIGS. 7 and 8, the lower the inertia load, the faster the rotation speed increases, and the shorter the time required to move by a predetermined rotation angle. For example, in the example of FIGS. 7 and 8, if the time required to rotate 10 degrees is compared, the time of about 0.0017 seconds is required when the inertial load is 1 time as shown in FIG. On the other hand, in the case of 10 times the inertia load shown in FIG. 8, a time of about 0.003 seconds, that is, about twice as long as the case of 1 time of the inertia load is required.
Therefore, when the rotor ring 30 is rotated at a constant angle, the drive time can be shortened and the power consumption can be reduced correspondingly when the inertia load applied to the rotor ring 30, that is, the piezoelectric actuator 4 is small.

(3) Since the spiral spring 50 is provided, the impact of the spiral spring 50 can be quickly reduced by the interference function of the spiral spring 50 when the impact from the outside acts on the pointer or the like when dropped, etc. Since the driving force of the piezoelectric actuator 4 is accumulated in the spiral spring 50 while the impact force is applied, the rotation of the pointer or the like is driven by the elastic energy of the spiral spring 50 when the influence of the impact disappears. Can be made. Accordingly, it is not necessary for the impact of the impact to be transmitted from the pointer or the like to the piezoelectric actuator 4, and the operation of the piezoelectric actuator 4 can be stabilized.
(4) Since the positioning pin 61 and the positioning hole 42 are provided and the initial deflection (initial strain) of the spiral spring 50 is maintained, the force due to the initial deflection is always applied to the second rotor transmission gear 60, so that the external Oscillation of the pointer or the like due to the impact of can be suppressed.

(5) Even when the moment of inertia of the rotating system on the pointer side from the second rotor transmission gear 60 is relatively large, when the piezoelectric actuator 4 is driven intermittently, the positioning pin 61 and the positioning hole 42 Since the range of the play portion is set to a range corresponding to the driving amount for one cycle of the piezoelectric actuator 4, the first rotor transmission gear 40 and the second rotor transmission gear 60 interfere with each other and are applied to the piezoelectric actuator 4. An increase in load can be avoided.

(6) Since the spiral spring 50 is provided, even if the number of turns of the spiral spring 50 is increased in order to ensure a large amount of displacement, the installation space is smaller than when a U-shaped spring or a cantilever spring is used. The spiral spring 50 can be arranged without widening.
Further, since the spiral spring 50 is provided, a large amount of displacement can be secured, and substantially constant elastic energy can be generated regardless of the amount of displacement of the spiral spring 50. Therefore, the second rotor transmission gear 60 receives substantially constant elastic energy from the spiral spring 50 regardless of the magnitude of the external impact, so that the operation of the second rotor transmission gear 60 can be stabilized.
(7) Since the piezoelectric element 22 is formed in a rectangular plate shape, the piezoelectric drive device 10 can be made thinner.

(8) If the rotor ring 30 rotates in the positive direction, elastic energy is accumulated in the spiral spring 50. On the other hand, since the reverse rotation prevention mechanism 90 prevents the rotor ring 30 from rotating in the reverse direction, the rotor ring 30 does not rotate in the reverse direction and the elastic energy is not released. In this way, by preventing the rotor ring 30 from rotating in the reverse direction, even when a disturbance such as vibration or an impact such as a drop is applied, the elastic energy is retained even if the rotor ring 30 is separated from the vibrator 20. Is done.
Therefore, since it is not necessary to increase the pressing force between the rotor ring 30 and the vibrator 20, the startability of the rotor ring 30 is ensured, and the accumulated elastic energy can be reliably ensured even when an impact or the like is applied. It can be transmitted to the second rotor transmission gear 60.

(9) When the rotor ring 30 is about to rotate in the forward direction, the ratchet wheel 91 and the pawl 92 are not locked. Therefore, the rotor ring 30 is allowed to rotate in the forward direction, and elastic energy is accumulated in the spiral spring 50. . Further, when the rotor ring 30 tries to rotate in the reverse direction, the ratchet wheel 91 and the claw 92 are locked together to prevent the rotor ring 30 from rotating in the reverse direction, and the release of the elastic energy of the spiral spring 50 is restricted. The Therefore, the claw wheel 91 and the claw 92 function as a ratchet, and it is possible to reliably prevent only the rotation of the rotor ring 30 in the reverse direction.

(10) Even when the frictional resistance of the contact surface between the rotor ring 30 and the vibrator 20 becomes small (when the contact surface becomes smooth after a certain amount of use, when oil enters the contact surface, etc.), the elastic energy Will not be released.

[Second Embodiment]
Next, a piezoelectric drive device 10A in the timepiece 1 according to the second embodiment of the present invention will be described with reference to FIGS.
[overall structure]
FIG. 9 is an overall plan view showing a drive mechanism of the minute hand 2 in the timepiece 1 according to the present embodiment. 10 and 11 are longitudinal sectional views showing the piezoelectric driving device 10A. FIG. 12 is a plan view showing FIG. 9 partially enlarged. 10 is a cross-sectional view of a transmission path connecting the piezoelectric actuator 4, the intermediate wheel 71, the cam wheel 72, and the ankle 8 in FIG. FIG. 11 is a cross-sectional view of the transmission path connecting the rotor transmission wheel 5A, the third wheel 11 and the second wheel 12 in FIG.
The timepiece 1 includes a timekeeping section inside an exterior case (not shown), a time information display section for displaying timekeeping information measured by the timekeeping section with the minute hand 2, and a driving mechanism (a mechanism for driving a plurality of hands, etc.). 11 (including the hand movement mechanism of FIG. 11), and the piezoelectric drive device 10 is used for the operation of the drive mechanism of the driven part. Here, the driven unit refers to a time information display unit that displays time information measured by the time measuring unit.

In FIG. 9, the piezoelectric driving device 10 </ b> A is provided with an escape gear 60 </ b> A corresponding to the second rotor transmission gear and is driven by an ankle 8 driven by the piezoelectric actuator 4 with respect to the piezoelectric driving device 10 of the first embodiment. The configuration in which the rotation of the escape gear 60A is restricted for each predetermined rotation angle is different, and the other configurations are substantially the same.
For example, the configuration and operation of the piezoelectric actuator 4 in the first embodiment, the configuration and operation of the spiral spring 50, the basic structure and basic operation of an unillustrated release restricting portion (positioning hole and positioning pin), the structure of the reverse rotation prevention mechanism 90, and The operation is the same in the second embodiment.

[Configuration of rotor pressing mechanism]
The piezoelectric driving device 10 </ b> A includes a vibrator 20 and a rotor pressing mechanism 35 for the rotor ring 30.
The rotor pressing mechanism 35 is provided so as to be swingable around a predetermined shaft portion 352, and is supported in a direction in which the rotor ring 30 contacts the vibrator 20 and a support arm 351 (lever member) that pivotally supports the rotor ring 30. A pressing spring 353 (rotor pressing member) that presses and swings the arm 351 is provided.
The rotor rotation shaft 31 of the rotor ring 30 is provided near one end of the support arm 351 at a predetermined distance from the shaft portion 352. The support arm 351 is supported so as to be swingable with respect to the main plate or the like around the shaft portion 352. The other end of the support arm 351 is biased by a pressing spring 353.
The pressing spring 353 is configured to press in the direction in which the rotor ring 30 and the contact portion 212 of the vibrator 20 contact each other.
Specifically, the pressing spring 353 is constituted by a torsion coil spring, and one end of the pressing spring 353 is fixed to the ground plate or the like by a support shaft 354. The other end of the pressing spring 353 urges the end of the support arm 351, and the rotor ring 30 is urged toward the vibrator 20, and is pressed against the contact portion 212 in the pressing direction F. The pressing direction F is a direction substantially orthogonal to the rotation axis of the rotor ring 30, and the pressing direction F and the vibration direction of the vibrator 20 are on the same plane.

[Configuration of Movement Control Device]
The piezoelectric drive device 10A is driven by the piezoelectric actuator 4 and the piezoelectric actuator 4, and the rotational drive of the rotor ring 30 is transferred to the wheel train (third wheel 11, second wheel 12, sun wheel 13, and hour wheel 14). A rotor transmission wheel 5A for transmission is provided. The piezoelectric drive device 10 </ b> A also swings with an intermediate wheel 71 driven by the piezoelectric actuator 4 via the rotor gear 32, a cam wheel 72 as a cam member driven by the intermediate wheel 71, and the cam wheel 72. Ankle 8 is provided.
The rotor gear 32 transmits the rotational drive to the first rotor transmission gear 40 and the intermediate wheel 71.

The rotor transmission wheel 5A includes a rotor transmission gear 40A that meshes with the rotor gear 32, a spiral spring 50 whose one end on the outer peripheral side is locked in a spring locking hole 41 (FIG. 11) of the rotor transmission gear 40A, and a spiral spring. 50, an escape gear 60 </ b> A connected to the other end on the inner peripheral side, and a transmission wheel rotating shaft 63. In this way, a first transmission path through which the driving force of the rotor ring 30 is transmitted to the spiral spring 50 is configured. Note that, among the components of the rotor transmission gear 40A, the escape gear 60A is disposed at the foremost side in FIG. 9, but in the following description, the escape gear 60A is indicated by a two-dot chain line in order to simplify the illustration. Shall be shown.
Similarly to the first embodiment, the rotor transmission gear 40A is formed with a spring locking hole 41 penetrating in the rotation axis direction and a positioning hole (not shown).
As shown in FIG. 12, the escape gear 60 </ b> A includes 15 escape teeth 62 and is supported at a position facing the ankle 8. An escape pinion 67 (FIG. 11) is fixed to the transmission wheel rotating shaft 63 together with the escape gear 60A. The escape pinion 67 rotates integrally with the escape gear 60 </ b> A and meshes with the third wheel 11. A rotor transmission gear 40A is rotatably supported on the transmission wheel rotating shaft 63. Since the other end of the spiral spring 50 is fixed to the transmission wheel rotating shaft 63, the escape gear 60 </ b> A is connected to the other end of the spiral spring 50.
Although not shown, a positioning pin that protrudes toward the rotor transmission gear 40A and is inserted into the positioning hole is fixed to the escape gear 60A, as in the second rotor transmission gear 60 of the first embodiment.
As described in the first embodiment, the positioning hole and the positioning pin are used when the rotor transmission wheel 5A is assembled and when the rotor transmission wheel 5A is assembled to the main plate (base member) 15 together with each component as shown in FIG. This is for maintaining the initial deflection of the spiral spring 50.

  The intermediate wheel 71 is a gear that meshes with the cam wheel 72, has an intermediate pinion 73 that meshes with the rotor gear 32, and is fixed to the intermediate wheel rotating shaft 74 together with the intermediate pinion 73. The intermediate wheel 71 is formed with a detection hole 75 for rotation detection around the intermediate wheel rotation shaft 74 every 60 degrees. An optical sensor (not shown) is disposed so as to penetrate the detection hole 75. This optical sensor detects the rotational position of the intermediate wheel 71 every time the intermediate wheel 71 rotates 60 degrees.

The cam wheel 72 includes a cam pinion 76 that meshes with the intermediate wheel 71, a circular cam 77 that has an eccentric outer central axis with respect to the rotation shaft, and a cam rotation shaft 78 that fixes the cam pinion 76 and the cam 77. It is prepared for.
The ankle 8 includes an ankle body 81, two ankle claws 82 and 83, a notch 84 that engages with the cam 77, and an ankle rotation shaft 85.
The ankle body 81 includes a first arm portion 811 and a second arm portion 812, which are integrally formed on both sides with the ankle rotation shaft 85 interposed therebetween, and can swing around the ankle rotation shaft 85. It is supported by. The first arm portion 811 extends from the ankle rotation shaft 85 to the side opposite to the rotor gear 32 side, and fixes an ankle claw 82 protruding to the escape gear 60A side. The second arm portion 812 extends from the ankle rotation shaft 85 to the rotor gear 32 side, and fixes an ankle claw 83 protruding to the escape gear 60A side.

The ankle body 81 is formed with two protrusions 86 extending from the ankle rotation shaft 85 toward the cam wheel 72 on the opposite side of the ankle claws 82 and 83. A notch portion 84 is formed in a portion sandwiched between the projecting portions 86, and the cam wheel 72 is disposed so that the side surface of the cam 77 is in contact with the inner side surface of the notch portion 84.
In such a configuration, when the rotor gear 32 rotates, the cam wheel 72 rotates, and the ankle 8 swings due to the eccentric cam 77. Here, when the cam wheel 72 rotates once, the ankle 8 swings by one reciprocation, and the two ankle claws 82 and 83 abut against the escape gear 60A alternately. In this way, a second transmission path through which the driving force of the rotor ring 30 is transmitted to the ankle 8 is configured.

In the movement restricting device having such a configuration, when the escape gear 60A is rotated, the two ankle claws 82 and 83 are alternately inserted between the escape teeth 62, and the rotation angle of the escape gear 60A is restricted at every predetermined angle. . That is, the ankle 8 swings in the first direction (counterclockwise direction in FIG. 12), and one ankle claw 83 of the ankle 8 is inserted between the escape teeth 62 and is driven to rotate in the clockwise direction. When it comes into contact with the escape teeth 62 of the escape gear 60A, the rotation of the escape gear 60A is restricted.
Further, when the ankle 8 swings in the second direction (the clockwise direction in FIG. 12), one of the ankle claws 83 of the ankle 8 is separated from between the escape teeth 62 and the regulation of the escape gear 60A is released. At the same time, the other ankle pawl 82 is inserted between the escape teeth 62, and the escape gear 60 </ b> A rotates by an angle corresponding to a half pitch of the escape teeth 62 by the elastic energy accumulated in the spiral spring 50. The claw 82 contacts the escape tooth 62 of the escape gear 60A. In this way, the rotation of the escape gear 60A is again restricted. Further, at the same time as the escape teeth 62 rotate by an angle corresponding to a half pitch, the rotor transmission gear 40A is rotated in the positive direction by an angle corresponding to a half pitch by the rotor gear 32 to wind up the spiral spring 50. Elastic energy is maintained.
In the present embodiment, a rotating body is configured by the escape gear 60A, and a movement restricting device is configured by the escape gear 60A and the ankle 8.
The vibrator 20 of the piezoelectric actuator 4 is fixed to the base plate 15 which is the base frame of the timepiece 1 by the arm 211, and the intermediate wheel rotation shaft 74, the transmission wheel rotation shaft 63, and the cam rotation shaft 78 of the cam wheel 72. The rotation shafts of the ankle rotation shaft 85, the third wheel 11 and the second wheel 12 are supported at one end by a bearing hole of the main plate 15 and at the other end by a train wheel bridge 16 disposed opposite to the main plate. Is held. Note that one end of the rotation shaft of the third wheel 11 and the second wheel 12 and each rotation shaft of the other indicator wheel is supported by the main plate 15, but the other end is supported by a receiving member other than the train wheel bridge 16. You may do it.
Moreover, it is preferable that each gear rotated by the escape gear 60A, the ankle 8, and the escape gear 60A is made of a nonmagnetic material. However, these materials are not limited to nonmagnetic materials.

[Configuration of reverse rotation prevention mechanism]
Similar to the first embodiment, the reverse rotation prevention mechanism 90 maintains a latch when the claw wheel 91 is coaxially and integrally provided with the rotor ring 30 and rotates in the forward direction with respect to the claw wheel 91. A pawl 92 movably provided between a latching position and a non-locking position that does not latch when rotating in the reverse direction, and a leaf spring as a biasing member that biases the pawl 92 against the pawl wheel 91. 96. In other words, the leaf spring 96 is fixed to the ground plate 15 or the like via the leaf spring fixing portion 97, and the claw 92 is swung around the shaft portion 95 protruding from the ground plate, so that the blade tip provided at the tip portion of the claw 92 is provided. It arrange | positions so that 94 may be urged | biased by the nail | claw tooth 93 (FIG. 12).

  In addition, instead of the optical sensor provided for the detection hole 75 of the intermediate wheel 71, an optical sensor capable of detecting the state in which the blade edge 94 is in the locking position and the state in which the blade edge 94 is in the non-locking position, respectively. May be provided for the nail 92. This optical sensor functions as a means for detecting the nail 92. By doing so, the cutting edge 94 moves alternately between the locking position and the non-locking position in accordance with the rotation of the rotor ring 30 in the positive direction, so that the moving position of the claw 92 is detected by the detecting means. Then, the amount of rotation of the rotor ring 30 in the positive direction can be acquired.

[Pitch of claw teeth of a claw wheel]
As shown in FIG. 12, the rotation angle for one step of the rotor ring 30 is an integral multiple of the rotation angle of the claw wheel 91 corresponding to one pitch of the claw teeth 93 formed along the outer periphery of the claw wheel 91. Is set to
As a result, when the piezoelectric actuator 4 is driven stepwise, that is, intermittently driven at regular intervals, the locking position of the blade edge 94 and the claw teeth 93 and the rotational position of the rotor ring 30 corresponding to one step drive are obtained. The rotor ring 30 does not stop at a position where the engagement between the blade edge 94 and the claw teeth 93 is insufficient. Accordingly, the reverse rotation of the rotor ring 30 can be reliably prevented while the piezoelectric actuator 4 is stopped. Further, since the engagement state between the blade edge 94 and the claw teeth 93 occurs a plurality of times during driving of the piezoelectric actuator 4 for one step, it is easy to prevent reverse rotation of the rotor ring 30 even during driving of the piezoelectric actuator 4. Become.
The rotation angle for one step of the rotor ring 30 may be set to be the same as the rotation angle of the claw wheel 91 corresponding to one pitch of the claw teeth 93.

[Arrangement of vibrator and rotor transmission wheel to support arm]
FIG. 13 is a plan view showing a part of the piezoelectric driving device 10A.
Here, a contact portion between the vibrator 20 and the rotor ring 30 is a contact portion A, an engagement portion between the rotor gear 32 and the rotor transmission gear 40A is an engagement portion B, and the center of the shaft portion 352 of the support arm 351 is connected to the rotor ring 30. A straight line passing through the center of the rotor rotation shaft 31 will be described as a straight line C.
As shown in FIG. 13, the contact portion 212 and the contact portion A of the rotor ring 30 are arranged on one side with respect to the straight line C, and the engagement portion B of the rotor gear 32 and the rotor transmission gear 40A is It is arranged on the other side with respect to the straight line C. That is, the contact portion A and the engagement portion B are provided at positions that sandwich the straight line C, respectively.

  According to this configuration, due to an impact or the like, the support arm 351 swings in the direction opposite to the pressing direction of the pressing spring 353, and the vibrator 20 can no longer hold the rotation of the rotor ring 30 in the reverse direction by a frictional force. In addition, since the contact portion A and the engagement portion B are provided at positions where the straight line C is sandwiched, the moving direction of the rotor ring 30 is a direction in which the engagement of the engagement portion B is deepened. Therefore, the disengagement between the rotor gear 32 and the rotor transmission gear 40A is prevented as long as the reverse rotation prevention mechanism (not shown) prevents the rotor ring 30 from rotating in the reverse direction. Elastic energy is maintained.

In addition, about the arrangement | positioning of the vibrator | oscillator 20 and the rotor transmission wheel 5A with respect to the support arm 351 of this embodiment, it is good also as an arrangement | positioning as shown in FIG.
FIG. 14 is a plan view showing a part of a piezoelectric driving device 10B according to a modification of the present embodiment.
In the piezoelectric driving device 10B,
The contact portion A of the vibrator 20 and the rotor ring 30 and the engagement portion B of the rotor gear 32 and the rotor transmission gear 40A pass through the center of the shaft portion 352 of the support arm 351 and the center of the rotor rotation shaft 31 of the rotor ring 30. Both are arranged on the same side with respect to the straight line C.
On the side opposite to the contact portion A and the engagement portion B with respect to the straight line C, a swing restricting means 36 is provided.
The swing restricting means 36 is configured to restrict the support arm 351 from rotating in a direction opposite to the pressing direction when the rotor ring 30 is separated from the vibrator 20 due to an impact or the like.
As the swing restricting means 36, a contact member 361 that directly contacts the support arm 351 as shown in FIG. 14 is exemplified. A predetermined gap S is provided between the contact member 361 and the support arm 351. When the support arm 351 swings due to an impact or the like, the clearance S so that the support arm 351 and the contact member 361 come into contact before the engagement amount K of the rotor gear 32 and the rotor transmission gear 40A becomes zero. Is set.

According to such a configuration, the swing restricting means 36 is disposed on the other side with respect to the straight line C, so that the support arm 351 swings in a direction in which the rotor ring 30 is away from the vibrator 20. Even so, the swing of the support arm 351 is restricted by the swing restricting means 36.
Therefore, if the swing restricting means 36 is provided, the engagement of the engagement portion B is maintained even when the contact portion A and the engagement portion B are arranged on the same side with respect to the straight line C. The elastic energy accumulated in the spiral spring 50 can be held, and the degree of freedom in arrangement can be increased.

[Circuit configuration of the watch]
Next, the circuit configuration of the timepiece 1 will be described with reference to FIG.
The driving circuit of the timepiece 1 includes an oscillation circuit 102, a frequency dividing circuit 103, and a control circuit 104 that are driven by a power source 101 composed of a primary battery or a secondary battery.
The oscillation circuit 102 has a reference oscillation source such as a crystal resonator and outputs an oscillation signal to the frequency dividing circuit 103.
The frequency divider 103 receives the oscillation signal output from the oscillation circuit 102 and outputs a clock reference signal (for example, a signal of 1 Hz) based on the oscillation signal.

The control circuit 104 counts the time based on the reference signal output from the frequency dividing circuit 103 and instructs the timepiece driving circuit 106 to output a timepiece driving signal conforming to the timepiece specification.
For example, when the timepiece 1 performs step hand movement every second as in the case where the timepiece 1 includes an hour hand, a minute hand, and a second hand, the control circuit 104 outputs a timepiece driving signal once per second. To instruct.
On the other hand, when the timepiece 1 is a two-hand timepiece having an hour hand and a minute hand and the minute hand is sent twice every 20 seconds, the control circuit 104 outputs a timepiece driving signal once every 20 seconds. 106 is instructed.

The control circuit 104 is connected to a detection circuit (detection means) 107 and controls the operation of the timepiece driving circuit 106 using a detection signal output from the detection circuit 107 as a trigger.
The detection circuit 107 detects whether the movement amount (rotation angle) of the rotor ring 30 has reached a predetermined amount, and outputs a detection signal to the control circuit 104. In the present embodiment, the rotation angle of the intermediate wheel 71 that moves directly with respect to the rotor ring 30 is detected, and the amount of movement of the rotor ring 30 is acquired indirectly. Therefore, the detection circuit 107 can use various sensors capable of detecting the amount of rotation (rotation angle) of the rotor ring 30 such as optical detection by an LED or the like, a mechanical contact by a spring, or a magnetic sensor.
Further, the detection circuit 107 may detect the rotation angle of the rotor transmission gear 40 </ b> A instead of the intermediate wheel 71. In other words, the amount of movement of a member that is provided before the spiral spring 50 from the rotor ring 30 and rotates together with the rotor ring 30 may be detected. Alternatively, the rotational angle of the rotor ring 30 or the rotor gear 32 may be directly detected without using the intermediate wheel 71 or the like.
In the present embodiment, as described above, the optical detection circuit (detection means) 107 that detects the rotation amount of the intermediate wheel 71 is provided.

When the detection signal is output from the detection circuit 107, that is, when it is detected that the rotor ring 30 has moved by a predetermined amount, the control circuit 104 controls the timepiece drive circuit 106 to stop outputting the drive signal. Control to stop the piezoelectric driving device 10A is performed.
For example, when the second hand is stepped at intervals of 1 second, the control circuit 104 instructs the timepiece drive circuit 106 to output a drive signal every second. In this case, the detection circuit 107 is set to detect that the rotor ring 30 rotates by a predetermined angle corresponding to the rotation of the second hand for one second, that is, 6 degrees. When detecting that the angle has been rotated, the control circuit 104 causes the timepiece driving circuit 106 to stop outputting the driving signal. For this reason, the piezoelectric driving device 10A is driven by an amount for moving the second hand by one second at intervals of one second.
In addition, when the minute hand is sent twice at intervals of 20 seconds as in a two-hand timepiece, the control circuit 104 instructs the timepiece drive circuit 106 to output a drive signal every 20 seconds. In this case, the detection circuit 107 is set so as to detect that the rotor ring 30 rotates by a predetermined angle corresponding to the rotation of the minute hand for 20 seconds, that is, 2 degrees. When detecting that the angle has been rotated, the control circuit 104 causes the timepiece driving circuit 106 to stop outputting the driving signal.

In addition, an operation detection unit 109 that detects an operation of the time correction mechanism 108 such as a crown or a button is connected to the control circuit 104. When the operation detection unit 109 detects a predetermined operation of the time adjustment mechanism 108, the operation detection unit 109 detects the operation and sends a predetermined signal to the control circuit 104. Based on the signal from the operation detection unit 109, the control circuit 104 outputs a driving signal to the timepiece driving circuit 106, that is, starts driving the piezoelectric driving device 10A and stops outputting the driving signal, that is, stops driving the piezoelectric driving device 10A. Instruct.
For example, when the crown is pulled out to correct the time, it is necessary to stop the hand movement of the pointer. For this reason, when the operation detection unit 109 outputs a detection signal for the operation of pulling out the crown, the control circuit 104 outputs a control signal for stopping the driving of the piezoelectric driving device 10 </ b> A to the timepiece driving circuit 106. On the other hand, when the operation detection unit 109 outputs a detection signal for pushing the crown, the control circuit 104 outputs a control signal for starting the driving of the piezoelectric driving device 10A to the timepiece driving circuit 106.

The timepiece driving circuit 106 receives a control signal from the control circuit 104 and outputs a driving signal for the piezoelectric driving device 10A. Specifically, the timepiece driving circuit 106 is driven by applying a driving voltage of a predetermined frequency to the piezoelectric element 22 of the piezoelectric driving device 10A by an AC signal (pulse signal).
The method for controlling the drive frequency of the piezoelectric drive device 10A is not particularly limited. For example, as disclosed in a patent document (Japanese Patent Laid-Open No. 2006-20445), the frequency of the drive signal supplied to the piezoelectric element 22 May be swept (changed) over a wide range including the driveable frequency range to reliably drive the piezoelectric driving device 10A, or as disclosed in a patent document (Japanese Patent Laid-Open No. 2006-33912). Method for changing the frequency of the drive signal so that the phase difference between the frequency of the drive signal supplied to the piezoelectric element 22 and the detection signal obtained from the vibration state of the piezoelectric element 22 becomes a predetermined target phase difference suitable for driving Alternatively, a method of driving at a fixed frequency preset for each temperature may be used.
In addition, a detection electrode that is not subject to voltage application is provided on the piezoelectric element 22 of the piezoelectric drive device 10A, and a detection signal output from the detection electrode is fed back to the control circuit 104 to control the frequency of the drive signal. Also good. With this detection signal, the control circuit 104 can confirm the driving state of the piezoelectric driving device 10A and feedback control the frequency of the driving signal.

The hand movement mechanism 110 includes a wheel train driven by the piezoelectric drive device 10A (the piezoelectric actuator 4 and the rotor transmission wheel 5A). In this embodiment, the third wheel 11, the second wheel 12, and the date shown in FIG. The back wheel 13 and the hour wheel 14 are provided.
The hand movement mechanism 110 converts the amount of movement obtained from the piezoelectric driving device 10A into a movement amount suitable for time display of a time display unit (hand) which is a time information display unit, and drives the time display unit. In the present embodiment, the hand movement mechanism 110 is a reduction gear train, and decelerates the movement amount of the piezoelectric drive device 10A (rotation amount of the rotor ring 30) to the rotation amount of the minute hand 2 at a predetermined reduction ratio. For example, if the reduction ratio of the hand movement mechanism 110 is 1/6, in order to rotate the minute hand 2 by 2 degrees every 20 seconds, the escape gear 60A, which is the driven body of the piezoelectric driving device 10A, is rotated by 12 degrees. Just do it. Further, in order to rotate the escape gear 60A by 12 degrees, if the speed increasing ratio from the rotor ring 30 to the escape gear 60A is 1.2, the rotor ring 30 may be rotated 10 degrees by the vibrator 20. If the speed increase ratio from the rotor ring 30 to the intermediate wheel 71 is six, the detection circuit 107 may be set so that a detection signal is output every time the intermediate wheel 71 rotates 60 degrees.

In the present embodiment, in addition to the circuit configuration as described above, the movement restricting device using the ankle 8 and the escape gear 60A is provided, so that the amount of rotation of the minute hand 2 rotated via the hand movement mechanism 110 is accurately determined. It can be controlled well. That is, when one of the ankle claws 82 and 83 of the ankle 8 is engaged with the escape tooth 62 of the escape gear 60A, the piezoelectric actuator 4 starts to drive one step and the rotor ring 30 rotates by one step. The other ankle claws 82 and 83 of the ankle 8 are engaged with the next escape tooth 62. In this way, when the rotor ring 30 rotates 10 degrees per step, the engagement of the ankle claws 82 and 83 with the escape teeth 62 is set to be switched, and one step of the escape gear 60A (that is, the minute hand 2). The rotation angle is maintained.
In consideration of the detection error of the detection circuit 107, the detection circuit 107 detects the rotation angle of the rotor ring 30 when the rotor ring 30 rotates to an angle slightly larger than 10 degrees (for example, 11 degrees). May be set to detect that the rotor ring 30 rotates at least 10 degrees or more. In this case, the rotational angle of the cam wheel 72 is also slightly increased, but as shown in FIG. 12, the amount of change in the distance from the cam rotation shaft 73 to the side surface of the cam 77 that contacts the notch 84 is small. The ankle 8 hardly moves, and the engagement state of the ankle claws 82 and 83 with the escape teeth 62 can be maintained. Further, when the rotor ring 30 is somewhat overrun, the rotor transmission gear 40A rotates with respect to the escape gear 60A that engages with the ankle claws 82 and 83 and stops, but the spiral spring 50 is wound for the rotation. And the change in the elastic energy of the spiral spring 50 is slight, so that the movement of the minute hand 2 is not affected.

[Operation of Piezoelectric Drive]
The rotor ring 30 is rotated clockwise in FIG. The rotation of the rotor ring 30 is transmitted to the intermediate wheel 71 and the rotor transmission gear 40A. The rotation of the intermediate wheel 71 is transmitted to the cam wheel 72. The rotation of the rotor transmission gear 40A is transmitted to the escape gear 60A via the elastic energy of the spiral spring 50.
Here, the train wheel from the rotor ring 30 to the rotor transmission gear 40A is set so that when the rotor ring 30 rotates 10 degrees, the rotor transmission gear 40A rotates at a speed of 12 degrees. The rotation of the rotor ring 30 is transmitted at an increased speed to the cam wheel 72. When the rotor ring 30 rotates 10 degrees, the cam wheel 72 rotates 180 degrees.
While the ankle 8 regulates the rotation of the escape gear 60A, the escape gear 60A remains stopped, the spiral spring 50 is elastically deformed, and the rotational energy of the rotor ring 30 is accumulated as elastic energy. Subsequently, when the cam wheel 72 rotates and the ankle 8 swings due to the eccentricity of the cam 77 and one of the claws of the ankle 8 engaged with the escape gear 60A is disengaged from the escape teeth 62 of the escape gear 60A, the escape gear 60 60A is rotated by the elastic energy of the spiral spring 50. At that time, the tip of the other nail of the ankle 8 is inserted between the escape teeth 62. When the other pawl of the ankle 8 is further inserted between the hook teeth 62 and the hook teeth 62 come into contact with the claws, the rotation of the hook gear 60A is restricted again. The escape gear 60A rotates one pitch (24 degrees) by one reciprocation of the ankle 8. That is, when the rotor ring 30 rotates 10 degrees, the cam wheel 72 rotates 180 degrees, whereby the ankle 8 moves in one direction, and the escape gear 60A rotates 12 degrees. At that time, since the rotor transmission gear 40A is rotated 12 degrees, the spiral spring 50 returns to the initial state. Accordingly, the escape gear 60 </ b> A is intermittently driven by the swing of the ankle 8.
That is, when the state in which one ankle claw 82 of the ankle 8 is engaged with the escape tooth 62 of the escape gear 60A is started (as shown in FIG. 12), the cam 77 starts to rotate, and the one ankle claw 82 Separated from the escape tooth 62, the other ankle claw 83 of the ankle 8 is engaged with the other escape tooth 62, the other ankle claw 83 is separated from the other escape tooth 62, and the one ankle claw 82 is again connected to the escape gear 60A. The cycle until the rotation of the cam 77 is stopped is referred to as one reciprocation of the ankle 8. Therefore, one reciprocation of the pallet fork 8 is one swing reciprocation of the pallet fork 8.

The elastic energy of the spiral spring 50 urges the escape gear 60A in a counterclockwise direction, so that the frictional force between the ankle pawls 82 and 83 increases with the escape teeth 62 in contact. Is done.
Even if a moment that the ankle 8 swings due to an external impact or the like is applied, the ankle 8 is connected to the cam wheel 72 by a cam mechanism, and the direction of the force acting on the cam 77 from the ankle 8 is changed. Since the rotation direction is substantially in the direction of the rotation center of the cam 77, rotation energy is not transmitted from the ankle 8 to the cam wheel 72. Therefore, even if a force in the direction in which the ankle 8 swings due to an impact is applied, the force for rotating the cam 77 is not transmitted, so the ankle 8 does not swing and the regulation of the escape gear 60A is not released. The position of the pointer or the like can be held.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (10), the following effects can be achieved.
(11) Similar to the effect of (1) above, the startup load applied to the piezoelectric actuator 4 by the spiral spring 50 is reduced, and the startup power consumed can be reduced.
In particular, in an analog timepiece, the rod-shaped minute hand 2 has a large moment of inertia, and the shape of the pointer changes depending on the design (model) of the timepiece. For this reason, the moment of inertia by the minute hand 2 is different for each watch model, and the power consumption is also changed in the conventional method. This means that in the case of a timepiece driven by a battery, the battery life varies depending on the model.
In contrast, in this embodiment, by providing the spiral spring 50, the moment of inertia of the minute hand 2 does not act on the piezoelectric actuator 4, so the influence of the change in the moment of inertia of the minute hand 2 can be canceled and driven with low power. In addition, changes in battery life due to models can be prevented.
In addition, a disc-shaped pointer having a large moment of inertia compared to the minute hand 2 can be used, and the design freedom of the watch can be improved.

(12) Rotational energy is applied to the escape gear 60A by driving the piezoelectric actuator 4 and the rotation of the escape gear 60A by a fixed angle is regulated by the ankle 8 so that the escape gear 60A with respect to the drive amount of the piezoelectric actuator 4 Even if the rotation amount of the escape gear is not uniquely determined, if the escape gear 60A rotates by a certain angle, the ankle 8 regulates the rotation angle of the escape gear 60A to a constant angle, so that the rotation amount of the escape gear 60A is accurately constant. Become. Therefore, since the overrun of the escape gear 60A rotated by the piezoelectric actuator 4 can be prevented, it is not necessary to strictly control the rotation angle of the rotor ring 30, and the accuracy of the rotation angle of the escape gear 60A can be improved. The display accuracy of the display means such as the minute hand 2 rotated by the escape gear 60A can be improved.

(13) By providing the ankle 8 and the escape gear 60A, the movement of the escape gear 60A, that is, the minute hand 2 can be controlled with high accuracy. For this reason, even when the detection circuit is set so as to detect the detection error and the rotor ring 30 is rotated slightly larger than the predetermined target value, the overrun is not limited to the cam wheel 72, the ankle 8, It can be absorbed by the escape teeth 62, the spiral spring 50, etc., and the escape gear 60A and the minute hand 2 can be driven accurately.
(14) Furthermore, since the ankle claws 82 and 83 mesh with the escape gear 60A, it is possible to restrict the rotation of the train wheel during the time adjustment operation by a time adjustment mechanism such as a crown. For this reason, in a general quartz timepiece, the function of a restriction lever that restricts rotation of the train wheel when the time is corrected can be realized, and in this embodiment, the restriction lever can be made unnecessary.

(15) Since the drive source of the escape gear 60A and the drive source of the ankle 8 can be shared, the number of parts can be reduced and the timepiece can be downsized.
(16) Since the ankle 8 is reciprocated by the cam 77, the piezoelectric actuator 4 as a driving source of the ankle 8 does not need to be configured to be rotatable in both directions, and can be configured to be rotatable in one direction. it can. In particular, since the rectangular plate-like vibrator 20 is used, the single-rotation type can freely select the contact position with the rotor ring 30, thereby improving the transmission efficiency of the driving force and promoting the reduction in power and torque. it can.

(17) Since the detection circuit 107 is provided to detect the movement amount of the intermediate wheel 71, that is, the rotor ring 30, the movement amount of the minute hand 2 can also be set accurately. That is, since the vibrator 20 of the piezoelectric actuator 4 and the rotor ring 30 transmit torque by friction, it is difficult to accurately set the rotation amount of the rotor ring 30 according to the driving time of the piezoelectric actuator 4. Therefore, in this embodiment, the detection circuit 107 detects the movement amount of the rotor ring 30 or the intermediate wheel 71 that is directly driven with the rotor ring 30, and the detection circuit 107 moves the rotor ring 30 by a predetermined amount. Therefore, the rotor ring 30, that is, the minute hand 2 can be accurately moved.

(18) Since the rotational speeds of the rotor transmission gear 40A and the intermediate wheel 71 are larger than the rotational speed of the rotor ring 30, the rotational torque of the rotor ring 30 is the largest. And since the reverse rotation prevention mechanism 90 is provided with respect to the rotor ring 30, the force which urges the blade edge 94 to the nail | claw tooth | gear 93 can be made as small as possible, and rotation of the rotor ring 30 in the reverse direction efficiently. Can be prevented.

[Third Embodiment]
Next, a piezoelectric driving device 10C in a timepiece according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 16 is a plan view showing a drive mechanism in the timepiece of the present embodiment.
The piezoelectric driving device 10C is different from the piezoelectric driving device 10A of the second embodiment described above in that the claw 92 is supported by the support arm 351A, and other configurations are substantially the same.
For example, the circuit configuration and operation of the timepiece according to the second embodiment, the configuration and operation of the piezoelectric actuator 4, the configuration and operation of the rotor transmission wheel 5A, the basic structure and basic operation of a release restricting portion (positioning hole and positioning pin) (not shown), The configuration and operation of the movement restricting device for the escape gear 60A are the same in the third embodiment. The basic configuration and basic operation of the rotor pressing mechanism 35 and the reverse rotation prevention mechanism 90A of the third embodiment are the same as those of the second embodiment, and the rotation amount detecting means and operation of the rotor ring 30 are the same as those of the second embodiment. The same optical operation means for detecting the amount of rotation of the intermediate wheel as in the above is used, and the same operation is performed.

As shown in FIG. 16, a shaft portion 95 of a claw 92 is fixed to a support arm 351A that is rotatably arranged on the main plate, and the claw 92 is rotatably provided around the shaft portion 95. . The blade edge 94 that is the tip of the claw 92 is urged against the claw teeth 93 by a leaf spring 96.
FIG. 17 is a plan view showing a reverse rotation prevention mechanism 90B according to a modification of the present embodiment. As shown in FIG. 17, the blade edge 94A may be formed of ruby and fixed to the tip of the claw 92A. By using ruby as the blade edge 94A, the friction coefficient of the blade edge 94A is reduced, and the load on the rotor can be reduced.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (18), the following effects can be achieved.
(19) Since the support arm 351A supports both the claw wheel 91 and the claw 92, even if the support arm 351A swings, the relative position of the claw wheel 91 and the claw 92 does not change. Since the stop is not released, the reverse rotation of the rotor ring 30 can be reliably prevented.

[Fourth Embodiment]
Next, a piezoelectric driving device 10D in a timepiece according to a fourth embodiment of the invention will be described with reference to FIG.
FIG. 18 is a plan view showing the piezoelectric driving device 10D in the timepiece of the present embodiment.
The piezoelectric driving device 10D is different from the piezoelectric driving device 10A of the second embodiment described above in the arrangement of the reverse rotation prevention mechanism 90C with respect to the rotor, and the other configurations are substantially the same.
As shown in FIG. 18, the shaft portion 95 of the claw 92 is fixed to the support arm 351 </ b> B, and the claw 92 is rotatably provided around the shaft portion 95. The blade edge 94, which is the tip of the claw 92, is urged to the claw teeth 93 by the leaf spring 96.

Here, the urging force of the leaf spring 96 is not set so large that a moment generated in the claw 92 due to an impact or the like can be suppressed. For example, at the position of the claw 92 with respect to the claw wheel 91 as shown in FIG. Since the moment acts in a direction away from the rotor ring 30, the claw 92 may be separated from the claw tooth 93.
On the other hand, in the positional relationship between the claw wheel 91 and the claw 92 shown in FIG. A moment works in the direction of biting into the claw wheel 91 around 95. Therefore, the blade edge 94 moves in a direction urged by the claw teeth 93 due to the moment, so that the engagement between the claw 92 and the claw teeth 93 is maintained. Even if the support arm 351B swings, the claw 92 is pivotally supported by the support arm 351B, so that the relative position does not change.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (19), the following effects can be achieved.
(20) Even when the rotor ring 30 moves away from the vibrator 20 due to an impact or the like, the blade edge 94 moves in the direction urged by the claw teeth 93 due to the moment generated in the claw 92. Locking of the claw 92 and the claw wheel 91 is maintained, and the rotation of the rotor ring 30 in the reverse direction is prevented.

[Fifth Embodiment]
Next, a piezoelectric driving device 10E in a timepiece according to a fifth embodiment of the invention will be described with reference to FIG.
FIG. 19 is a plan view showing the piezoelectric driving device 10E in the timepiece of the present embodiment.
The piezoelectric driving device 10E is not a rotor pressing mechanism 35 that presses the rotor ring 30 against the vibrator 20 but a vibrator that presses the vibrator 20 against the rotor ring 30 with respect to the piezoelectric driving device 10A of the second embodiment described above. The difference is that the pressing mechanism 37 is provided, and other configurations are substantially the same.
As shown in FIG. 19, the vibrator pressing mechanism 37 is provided so as to be rotatable around a predetermined rotation shaft 213, and has an arm portion 211 </ b> A as a vibrator support member that supports the vibrator 20, and the vibrator 20 is rotated. And a pressing spring 373 as a vibrator pressing member that presses and rotates the arm portion 211 </ b> A in a direction to contact the arm 30.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (18), the following effects can be achieved.
(21) By pressing the rotor ring 30 from the vibrator 20 side, the rotor rotation shaft 31 of the rotor ring 30 can be provided on the ground plate 15 and the like, and the position coordinates of the rotor ring 30 do not change. The disengagement with the rotor transmission gear 40A is prevented. Further, the engagement of the rotor transmission gear 40A and the intermediate wheel 71 with respect to the rotor gear 32 is also maintained. Therefore, the reverse rotation of the rotor ring 30 is reliably prevented, and a phase shift due to erroneous detection of the rotation angle of the rotor by the intermediate wheel 71 is also prevented.

[Sixth Embodiment]
Next, a piezoelectric driving device 10F in a timepiece according to a sixth embodiment of the invention will be described with reference to FIGS.
20 and 21 are a plan view and a longitudinal sectional view showing the piezoelectric driving device 10F in the timepiece according to this embodiment.
The piezoelectric driving device 10F is configured such that, with respect to the piezoelectric driving device 10E of the above-described fifth embodiment, the rotor ring 30 directly winds the spiral spring 50 without using the rotor transmission gear 40A. Are different, and the other configurations are substantially the same.
For example, the basic configuration and basic operation of the vibrator pressing mechanism 37, the movement restricting device for the escape gear 60A, and the reverse rotation prevention mechanism 90 in the fifth embodiment are the same in the sixth embodiment.
As shown in FIGS. 20 and 21, the escape gear 60 </ b> A is configured coaxially with the rotor ring 30. That is, in FIG. 21, the rotor ring 30, the rotor gear 32, and the claw wheel 91 are fixed to a common cylinder portion 38, and this cylinder portion 38 is rotatably supported on the outer periphery of the rotor rotation shaft 31A. An escape gear 60A is fixed to the rotor rotation shaft 31A closer to the train wheel bridge 16 than the cylindrical portion 38 (upper in the figure), and the rotor ring 30 and the escape gear 60A are connected by a spiral spring 50. . An escape hook 67 is fixed to the rotor rotation shaft 31A on the side of the base plate 15 (lower side in the drawing) with respect to the cylindrical portion 38, and the escape hook 67 is rotated integrally with the escape gear 60A.
In addition, since the reverse rotation prevention mechanism 90 is provided with respect to the rotor ring 30, even if the rotor ring 30 directly winds the spiral spring 50, the reverse rotation of the rotor ring 30 is prevented. The elastic energy of the spiral spring 50 can be maintained.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (18) and (21), the following effects can be achieved.
(22) Since the rotation shaft of the rotor ring 30 and the rotation shaft of the escape gear 60A are formed on the same axis, the spiral spring 50 is arranged between the rotor ring 30 and the escape gear 60A, and the spiral spring 50 can be stored compactly. Further, since the rotor transmission gear 40A is not necessary, it is possible to reduce the number of parts and the planar arrangement space along the main plate 15.

[Seventh Embodiment]
Next, a piezoelectric driving device 10G in a timepiece according to a seventh embodiment of the invention will be described with reference to FIG.
FIG. 22 is a plan view showing the piezoelectric driving device 10G in the timepiece of the present embodiment.
The piezoelectric drive device 10G is different from the piezoelectric drive device 10C of the third embodiment described above in that a configuration using a locking leaf spring 98 as a locking member of the reverse rotation prevention mechanism 90D is different. Are substantially the same.
As shown in FIG. 22, the reverse rotation prevention mechanism 90 </ b> D includes a rotor gear 32 and a rectangular locking leaf spring 98 that abuts against the teeth 321 of the rotor gear 32.
The longitudinal direction of the locking leaf spring 98 is arranged substantially along the tangential direction of the rotor gear 32 from the contact portion with the tooth 321 that is the locked portion. The proximal end of the locking plate spring 98 is fixed to the support arm 351B via a fixing portion 982. The locking plate spring 98 is installed in an elastically deformed state, and the tip 981 biases the teeth 321 toward the rotation center of the rotor gear 32. Further, the locking plate spring 98 is configured such that the teeth 321 are locked to the front end 981 of the locking plate spring 98 with respect to the rotation of the rotor gear 32 in the reverse direction. Here, the locking plate spring 98 has such a rigidity that it does not buckle against the reverse rotational force of the rotor gear 32 caused by the elastic energy of the spiral spring 50.

With this configuration, the tip 981 of the locking leaf spring 98 locks the inner side surface of the valley portion of the tooth 321 against rotation of the rotor ring 30 in the reverse direction, thereby preventing rotational movement of the rotor ring 30. . On the other hand, the tip 981 of the locking leaf spring 98 does not lock the teeth 321 with respect to the rotation of the rotor ring 30 in the positive direction, and allows the rotor ring 30 to rotate.
Although not shown, a brush may be used instead of the locking leaf spring 98. That is, the tips of the bristles of the brush are arranged in an elastically deformed state so as to urge the teeth 321 of the rotor gear 32, and the side surfaces of the valleys of the teeth 321 are rotated against the rotation of the rotor ring 30 in the reverse direction. It may be locked to prevent the rotor ring 30 from rotating. In this way, the same effect as in the case of the locking leaf spring 98 can be obtained.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (19), the following effects can be achieved.
(23) Since the tip 981 of the locking leaf spring 98 is locked to the teeth 321 of the rotor gear 32 with respect to the rotation of the rotor ring 30 in the reverse direction, the rotation of the rotor ring 30 in the reverse direction can be prevented. Accordingly, since the moment of inertia of the rotating system of the rotor is reduced as compared with the case where a claw wheel or the like is provided as the locked member, it is possible to reduce the rotational torque necessary for the rotational driving of the rotor ring 30. . In addition, there is an effect that the number of parts can be reduced.

[Eighth Embodiment]
Next, a piezoelectric driving device 10H in a timepiece according to an eighth embodiment of the invention will be described with reference to FIG.
FIG. 23 is a plan view showing the piezoelectric driving device 10H in the timepiece of the present embodiment.
The piezoelectric drive device 10H includes a piezoelectric actuator 4 similar to the piezoelectric drive device 10A of the second embodiment described above, an intermediate wheel 71 that meshes with the rotor gear 32, and a cam wheel 72A as a cam member that meshes with the intermediate wheel 71. The claw lever 79 is a locking member that is swung by the cam wheel 72A, and the rotor transmission wheel 5B that is rotationally driven by the claw lever 79.
The cam wheel 72A includes a cam pinion 721 that meshes with the intermediate wheel 71, and a claw lever cam 722 and an ankle cam 723 that are provided eccentrically with respect to the cam pinion 721, respectively. The pawl lever cam 722 swings the pawl lever 79, and the ankle cam 723 swings the ankle 8. The claw lever cam 722 and the ankle cam 723 may be the same.

The claw lever 79 includes a claw lever main body 791 fitted on the outer periphery of the claw lever cam 722, and two push claws 792 and a pulling claw 793 extending from the claw lever main body 791. ing.
The pushing claw 792 and the pulling claw 793 are each provided with a blade 794 at each distal end portion and sandwiching a claw wheel 40B which is a locked member provided in the rotor transmission wheel 5B. The push claws 792 and the pull claws 793 are arranged in an elastically deformed state so as to urge the teeth of the claw wheel 40B, and the blades 794 of the push claws 792 and the pull claws 793 are arranged in the teeth of the claw wheel 40B. Abut. The pushing claw 792 and the pulling claw 793 do not lock the teeth of the claw wheel 40B with respect to the rotation of the rotor ring 30 in the forward direction, while the teeth of the claw wheel 40B with respect to the rotation of the rotor ring 30 in the reverse direction. Is provided so as to be locked.

The rotor transmission wheel 5B is connected to a claw wheel 40B that is rotated only in the positive direction by a claw lever 79, a spiral spring (not shown) wound up by the claw wheel 40B, and one end of the spiral spring and intermittently connected to the ankle 8. It is configured to have an escape gear 60 </ b> A and an escape hook 67. As described above, the rotor transmission wheel 5B corresponds to the rotor transmission wheel 5A of the second embodiment in which the rotor transmission gear 40A is replaced with the claw wheel 40B.
The rotational force of the escape pinion 67 is transmitted to a wheel train composed of the transmission gear 17, the third wheel 11A, and the second wheel 12A, and rotates a pointer (not shown).
In the present embodiment, the claw lever 79 and the claw wheel 40B constitute a reverse rotation prevention mechanism 90E. In addition, the ankle 8 and the escape gear 60A constitute a movement restricting device similar to that of the second embodiment.

  With this configuration, when the pawl lever 79 is swung by the cam wheel 72A, the pawl lever 79 rotates the pawl wheel 40B only in the forward direction. When the ratchet wheel 40 </ b> B rotates in the forward direction, the spiral spring 50 is wound up, and elastic energy is accumulated in the spiral spring 50. Since the claw lever 79 prevents the claw wheel 40B from rotating in the reverse direction, the release of the accumulated elastic energy is restricted.

According to this embodiment, in addition to the effects substantially the same as the effects (1) to (18), the following effects can be achieved.
(24) The cam wheel 72A can cause the claw lever 79 to swing to accumulate elastic energy in the spiral spring 50 via the claw wheel 40B, and the ankle cam 723 can cause the ankle 8 to swing. The rotation angle of the escape gear 60A can be regulated. Accordingly, the number of parts can be reduced and the phases of the two trains of wheels can be reduced as compared with the case where a drive system for reciprocating the ankle 8 and a drive system for swinging the claw lever 79 are individually provided. It is also possible to prevent deviation.

[Modification of the present invention]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the first embodiment, the first rotor transmission gear 40 has the positioning hole 42, and the second rotor transmission gear 60 has the release restricting portion having the positioning pin 61. The rotor transmission gear 40 may have a positioning pin, and the second rotor transmission gear 60 may have a positioning hole. The release restricting portion only needs to maintain at least the initial deflection of the spiral spring 50, and can be brought into contact with each other by a method other than the engagement between the pin and the hole, for example, the first and second rotor transmission gears. A protrusion may be formed.

  In the first embodiment, the spiral spring 50 is used as the elastic device, the end in the outer peripheral direction is fixed to the first rotor transmission gear 40, the end in the center direction is fixed to the second rotor transmission gear 60, 1 When the rotor transmission gear 40 is rotated in advance of the driving direction of the piezoelectric actuator, it is attached in a direction in which the amount of deformation of the spiral spring 50 increases. The fixing method may be reversed. That is, when the end portion in the center direction of the spiral spring is fixed to the first rotor transmission gear, the end portion in the outer peripheral direction is fixed to the second rotor transmission gear, and only the first rotor transmission gear is rotated in advance. The spiral spring may be attached in a direction in which the amount of deformation increases (a direction in which a spiral spring is formed when viewed from the second rotor transmission gear side).

In each of the above embodiments, the spiral spring is used as the elastic device. However, the invention is not limited to this, and a U-shaped spring, a cantilever spring, a coil spring, or the like may be used. Moreover, although the spiral spring 50 having a circular cross-section of the spring wire is illustrated, a spiral spring having a cross-sectional shape such as a rectangle may be used.
In each of the above embodiments, the detection means for detecting the rotation amount of the intermediate wheel 71 is exemplified, but it may be a detection means for detecting the movement amount of the rotor gear 32. Or it is good also as a detection means which detects the movement position of latching members, such as a nail | claw, a latching leaf | plate spring, a brush, and a claw lever. In each embodiment, the detection means may be any method other than the optical type, and may be, for example, a magnetic type or a mechanical type (contact type, engaging / disengaging type between members). However, in consideration of the case of being affected by external magnetism, the optical detection means is more suitable.

In the second embodiment, one piezoelectric actuator is provided, and this piezoelectric actuator serves as a driving source for the second transmission path together with the first transmission path. However, the first transmission path driving first The piezoelectric actuator and the second piezoelectric actuator for driving the second transmission path may be provided separately.
For example, the intermediate wheel 71 or the rotor transmission gear 40A is driven by the vibrator 20 of the first piezoelectric actuator, and the rotor ring 30 (not to mesh with the intermediate wheel 71 is driven by the vibrator 20 of the second piezoelectric actuator. Or a rotor member separately fixed to the cam wheel 72 may be driven.
Furthermore, in the second embodiment, the cam 77 of the cam wheel 72 rotates in the notch 84 of the ankle 8 to swing the ankle 8. However, the swing structure of the ankle 8 is limited to the above. Instead, any structure may be used. For example, a bearing hole member (formed of a hard material such as a ruby) having a bearing hole formed therein is fitted and fixed in place of the notch at the position where the notch 84 of the ankle 8 is disposed, and the cam wheel 72 is fixed. Alternatively, an eccentric pin that is eccentric with respect to the center of rotation protrudes, and the eccentric pin may be inserted into the bearing hole. In this case, compared with the structure of the second embodiment, the plane area is reduced, the friction between the bearing hole and the eccentric pin is small and the contact radius is shortened, and the lubricating oil adhering to the contact portion is less likely to flow out due to surface tension. Therefore, an efficient reciprocating rocking mechanism with small mechanical loss and good efficiency can be obtained.

  In addition, the movement restricting device is not limited to a device that restricts the rotation angle of the rotated body at every fixed angle, but may be a movement restricting device configured to change the restricting rotation angle, such as a clockwork clock. Good. That is, the movement restricting device may be any device that restricts the rotation angle of the rotated body to a predetermined angle.

  In each of the embodiments described above, the minute hand 2 is used as the driving target of the piezoelectric driving device. However, as the minute hand 2, a second hand, a minute hand, a time hand, and the like can be exemplified, and a combination thereof may be used. The driving object is not limited to the minute hand 2 but may be a rotating object such as a calendar display plate of a clock.

  Further, the reverse rotation prevention mechanism 90 may not be provided for the rotor ring 30 but may be provided for the rotor transmission gear 40A or may be provided for the intermediate wheel 71 or the cam wheel 72. Accordingly, the rotor can be kept in the conventional configuration, and the reverse rotation prevention mechanism can be provided without changing the design of the piezoelectric actuator including the rotor and the vibrator. However, if the torque is provided as much as possible, the influence of the load on the reverse rotation prevention mechanism can be minimized as compared with the case where the reverse rotation prevention mechanism is provided on a rotating body having a rotational torque smaller than that of the rotor ring 30. Therefore, it is preferable to provide a reverse rotation prevention mechanism in the rotor ring 30 having the highest torque as in the above embodiment.

  Further, when the reverse rotation prevention mechanism 90 is provided in the intermediate wheel 71 or the cam wheel 72, consideration in arrangement regarding disengagement between the rotor gear 32 and the intermediate wheel 71 is necessary. If the engagement portion between the rotor gear 32 and the intermediate wheel 71 is not arranged on the same side with respect to the straight line C together with the contact portion A and the engagement portion B, disengagement due to impact or the like is prevented. Can do.

For example, the claw lever 79 of the eighth embodiment is provided instead of the claw 92 of the second embodiment, and the claw lever 79 is locked to the claw wheel 91 to prevent the rotation of the rotor ring 30 in the reverse direction. You may do it.
Further, in each of the above embodiments, the claw wheel, the gear, or the like that is the locked member is provided so as to rotate integrally with the rotor or the transmission wheel, and the claw, the leaf spring, or the like that is the locking member is connected to the base plate or the support. Although the configuration in which the arm is swingably supported has been described, the locked member is fixed to the base plate or the support arm, and the locking member is swingably supported by the rotor or the transmission wheel. Good.

In each of the embodiments described above, the rotated body is rotated by the elastic energy of the elastic device. However, the driven body driven by the elastic device may be non-rotatably driven. The non-rotational drive is, for example, linear drive, linear reciprocating drive, circular arc reciprocating drive, or the like.
For example, a pinion is integrally formed on the lower side of a rotor ring 30 that is rotationally driven by a piezoelectric vibrator, and a rack in which ratchet teeth that mesh with the pinion gears are linearly driven and disposed on the front end side of the rack. Then, elastic energy is accumulated in an elastic device (coil spring or the like) that expands and contracts in the linear direction in which the rack is driven, and the elastic energy of the elastic device is released at an appropriate timing, and the driven device is arranged on the distal end side of the elastic device May be driven linearly. The driven device returns to the original position when linearly driven to a predetermined position. At that time, when the driven device returns to the original position, the elastic device is pressed and the rack is also pushed back, the rack returns to the original position while moving so as to escape the outer peripheral side of the pinion, and the rack ratchet It may be configured such that a pinion gear meshes with the teeth and is positioned.
When the rack is linearly driven as described above, the piezoelectric vibrator may be linearly driven by directly contacting the rack without using the rotor.

The piezoelectric driving device of the present invention can be used not only as a timepiece but also as a driving source for various electronic devices. That is, the electronic device having the piezoelectric driving device of the present invention may be, for example, various instruments that drive the display needle with the piezoelectric driving device, or an electronic device that drives the driven body such as a turntable. In particular, the piezoelectric drive device of the present invention is widely used as a drive source that requires anti-magnetism because it has excellent anti-magnetic performance compared to a stepping motor or the like.

In addition, the best configuration, method and the like for carrying out the present invention have been disclosed above, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

The graph which shows the relationship between the torque and rotation speed in the piezoelectric actuator which concerns on the piezoelectric drive apparatus of this invention, and the relationship between torque and electric power. The graph which shows the relationship between time and angular velocity at the time of rotation of a general rigid body. The graph which shows the relationship between the torque and rotation speed in the said piezoelectric actuator, and the relationship between a torque and power consumption. The graph which shows the relationship between the time at the time of starting of the said piezoelectric actuator, and rotation speed. The graph which shows the relationship between the torque and rotation speed in the said piezoelectric actuator, and the relationship between a torque and power consumption. 1 is a perspective view showing a piezoelectric driving device according to a first embodiment of the present invention. The graph which shows the relationship of time, rotation speed, and rotation angle in case of inertial load 1 time. The graph which shows the relationship between time, a rotational speed, and a rotation angle in case of inertial load 10 time. The whole top view which shows the drive mechanism in the timepiece which concerns on 2nd Embodiment of this invention. The longitudinal cross-sectional view which shows the piezoelectric drive apparatus in the said drive mechanism. The longitudinal cross-sectional view which shows the said piezoelectric drive device. The top view which expands and shows the said piezoelectric drive device partially. The top view which shows a part of said piezoelectric drive device. The top view which shows a part of piezoelectric drive device which concerns on the modification of the said embodiment. The block diagram which shows the circuit structure in the timepiece of the said embodiment. The top view which shows the drive mechanism in the timepiece which concerns on 3rd Embodiment of this invention. The top view which shows a part of piezoelectric drive device which concerns on the modification of the said embodiment. The top view which shows the drive mechanism in the timepiece which concerns on 4th Embodiment of this invention. The top view which shows the drive mechanism in the timepiece which concerns on 5th Embodiment of this invention. The top view which shows the drive mechanism in the timepiece which concerns on 6th Embodiment of this invention. The longitudinal cross-sectional view which shows the piezoelectric drive device of the said timepiece. The top view which shows the drive mechanism in the timepiece which concerns on 7th Embodiment of this invention. The top view which shows the drive mechanism in the timepiece which concerns on 8th Embodiment of this invention.

Explanation of symbols

  4 ... Piezoelectric actuator 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H ... Piezoelectric drive device, 15 ... Ground plane (base member), 20 ... Vibrator, 22 ... Piezoelectric element, 30 ... Rotoring ( (Rotor), 32 ... rotor gear (locked member), 36 ... swing restricting means, 40 ... first rotor transmission gear, 40A ... rotor transmission gear, 40B ... claw wheel (locked member), 50 ... spiral spring (Elastic device), 60 ... second rotor transmission gear (rotated body), 60A ... escape gear (rotated body), 72A ... cam wheel (cam member), 79 ... claw lever (locking member), 90, 90A , 90B, 90C, 90D, 90E ... reverse rotation prevention mechanism (release restricting means), 91 ... claw wheel (locked member), 92 ... claw (locking member), 93 ... claw tooth (locked portion), 94, 94A ... blade edge, 96 ... leaf spring (biasing Material), 98 ... leaf spring for locking (locking member), 107 ... detection circuit (detecting means), 211A ... arm part (vibrator support member), 321 ... tooth (locked member), 351, 351A, 351B ... support arm (lever member), 353 ... pressing spring (rotor pressing member), 373 ... pressing spring (vibrator pressing member), 792 ... pressing claw, 793 ... pull claw, 794 ... blade.

Claims (15)

A vibrator having a piezoelectric element, and a piezoelectric actuator having a rotor rotated by the vibrator in contact with the vibrator;
Pressing means for pressing the vibrator and the rotor together;
An elastic device capable of storing rotational energy generated by rotation of the rotor as elastic energy;
A rotating body rotated by elastic energy accumulated in the elastic device, and a piezoelectric driving device comprising:
A piezoelectric drive device comprising: release restriction means for restricting release of the elastic energy for rotating the rotor in a direction opposite to the rotation direction of the rotor by the vibrator. The piezoelectric drive device according to claim 1,
The elastic device accumulates elastic energy according to the positive rotation of the rotor,
The piezoelectric drive device according to claim 1, wherein the release restricting means is a reverse rotation prevention mechanism that prevents the rotor from rotating in the reverse direction. The piezoelectric drive device according to claim 2,
The reverse rotation prevention mechanism is
A locked member provided coaxially with the rotor and rotating integrally with the rotor;
The locking member is not locked against the rotation of the rotor in the forward direction, the rotation of the rotor in the forward direction is allowed, and the locked member is locked against the rotation of the rotor in the reverse direction. A locking member for preventing reverse rotation of the rotor;
A piezoelectric drive device comprising: The piezoelectric drive device according to claim 3.
A base member for supporting the vibrator;
A lever member that supports the rotor and is provided to be swingable around a predetermined axis with respect to the base member;
The pressing means is a rotor pressing member that presses and swings the lever member in a direction in which the rotor is brought into contact with the vibrator.
The piezoelectric driving device, wherein the locking member is supported by the lever member. In the piezoelectric drive device according to claim 3 or 4,
A base member for supporting the vibrator;
A lever member that supports the rotor and is provided to be swingable around a predetermined axis with respect to the base member;
A rotor gear provided coaxially with the rotor and rotating integrally with the rotor;
Including at least one rotor transmission gear meshing with the rotor gear and transmitting rotational energy of the rotor to the elastic device;
The pressing means is a rotor pressing member that presses and swings the lever member in a direction in which the rotor is brought into contact with the vibrator.
The contact portion of the vibrator and the rotor and the engaging portion of the rotor gear and the rotor transmission gear are respectively provided at positions sandwiching a straight line passing through the rotation shaft of the lever member and the rotation shaft of the rotor. A piezoelectric drive device characterized by the above. In the piezoelectric drive device according to claim 3 or 4,
A base member for supporting the vibrator;
A lever member that supports the rotor and is provided to be swingable around a predetermined axis with respect to the base member;
A rotor gear provided coaxially with the rotor and rotating integrally with the rotor;
Including at least one rotor transmission gear meshing with the rotor gear and transmitting rotational energy of the rotor to the elastic device;
The pressing means is a rotor pressing member that presses and swings the lever member in a direction in which the rotor is brought into contact with the vibrator.
The contact portion of the vibrator and the rotor and the engagement portion of the rotor gear and the rotor transmission gear are both arranged on one side with respect to a straight line passing through the rotation shaft of the lever member and the rotation shaft of the rotor. And
When the rotor tries to rotate in the reverse direction, a swing restricting means is provided for restricting the lever member from swinging in a direction opposite to a direction in which the rotor contacts the vibrator.
The piezoelectric drive device according to claim 1, wherein the swing restricting means is disposed on the other side with respect to the straight line. In the piezoelectric drive device according to any one of claims 3 to 6,
The rotated body is provided coaxially with the rotor and rotates separately from the rotor,
The elastic device is a spiral spring, and is arranged so as to be coaxial between the rotor and the rotating body. One end of the spiral spring is engaged with the rotor, and the other end of the spiral spring is A piezoelectric driving device being engaged with a rotating body. The piezoelectric drive device according to claim 2,
A base member for supporting the rotor;
A rotor gear provided coaxially with the rotor and rotating integrally with the rotor;
Including at least one rotor transmission gear meshing with the rotor gear and transmitting rotational energy of the rotor to the elastic device;
The reverse rotation prevention mechanism is
A locked member provided coaxially with the rotor transmission gear and rotating integrally with the rotor transmission gear and pivotally supported by the base member;
While being supported by the base member, the rotor transmission gear is allowed to rotate in the forward direction without locking the locked member with respect to the forward rotation of the rotor, and against the rotation of the rotor in the reverse direction. And a locking member that locks the locked member to prevent the rotor transmission gear from rotating in the reverse direction. In the piezoelectric drive device according to any one of claims 3 to 8,
The locked member is a claw wheel provided to be rotatable around a predetermined axis according to the rotation of the rotor in the positive direction.
The claw wheel has a plurality of claw teeth continuously formed along the circumferential direction,
The locking member is a claw having a cutting edge that locks with the claw teeth and supported so as to be swingable around a claw axis,
The nail is provided adjacent to a biasing member that biases the blade edge of the nail toward the nail teeth,
The cutting edge is
Maintaining locking with the claw teeth by urging the urging member against rotation in the reverse direction of the rotor, preventing rotation in the reverse direction of the rotor,
A piezoelectric drive device that swings against the biasing force of the biasing member by the claw teeth with respect to the rotation of the rotor in the positive direction, and allows the rotor to rotate in the positive direction. In the piezoelectric drive device according to any one of claims 3 to 8,
The locked member is a rotor gear that is provided so as to be rotatable around a predetermined axis in accordance with rotation in the positive direction of the rotor, and that transmits rotational energy to the elastic device,
The locking member is a leaf spring having a tip locked with a tooth of the rotor gear,
The leaf spring is supported in an elastically deformed state so as to urge the tip of the leaf spring to the teeth of the rotor gear,
The tip of the leaf spring is
While preventing rotation of the rotor in the reverse direction by locking to the side surface of the teeth against rotation in the reverse direction of the rotor,
The piezoelectric drive device according to claim 1, wherein the rotor is moved in a direction in which it is further elastically deformed against the biasing direction by the teeth with respect to the rotation of the rotor in the positive direction, and the rotation of the rotor in the positive direction is permitted. In the piezoelectric drive device according to any one of claims 3 to 10,
A detection means for detecting the position of the locking member;
A piezoelectric driving device characterized in that the number of movements of the locking member with respect to rotation of the rotor in the positive direction is acquired. In the piezoelectric drive device according to any one of claims 3 to 11,
The piezoelectric actuator rotates the rotor intermittently,
The locked member has a locked portion with a predetermined pitch,
The locking member is provided so as to intermittently lock the locked portion pitch by pitch with respect to the positive rotation of the rotor
The rotation angle of one step of the rotor is the same as the rotation angle of the locked member corresponding to one pitch of the locked portion, or the locked surface corresponding to one pitch of the locked portion. A piezoelectric driving device characterized in that the piezoelectric driving device is set to an integral multiple of the rotation angle of the stop member. The piezoelectric drive device according to any one of claims 1 to 12,
A piezoelectric drive device comprising a movement restricting device for restricting a rotational movement angle of the rotated body to a predetermined angle.   An electronic apparatus comprising: the piezoelectric driving device according to claim 1; and a driven unit driven by the piezoelectric driving device. The electronic device according to claim 14, wherein
The electronic device according to claim 1, wherein the driven unit is a time information display unit that displays time information measured by a time measuring unit.

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