CN101257265B - Piezoelectric drive device and electronic device - Google Patents

Abstract

The invention provides a piezoelectric driving device and electronic equipment. The piezoelectric drive device can drive the object to be rotated with low power when the object to be rotated is driven by the vibration of the piezoelectric element. The piezoelectric driving device has: a piezoelectric driver (4) having a piezoelectric element (22) and a rotor ring (30) rotationally driven by the piezoelectric element (22); the driving force of the piezoelectric driver can be accumulated as elastic energy a coil spring (50); and a second rotor transmission gear (60) rotated by elastic energy accumulated in the coil spring (50). When the piezoelectric driver starts, the driving force of the piezoelectric driver is accumulated as the elastic energy of the coil spring (50), and the second rotor transmission gear (60) starts to rotate, so the piezoelectric driver (4) does not undertake the second rotor transmission. The loads generated by the moment of inertia of the gear (60), the pointer wheel (3) and the pointer (2) reduce the load at startup, so that the piezoelectric driver can be driven with low power.

Description

Piezoelectric actuators and electronics

technical field

The present invention relates to a piezoelectric drive device and electronic equipment with a piezoelectric driver.

Background technique

Conventionally, an ultrasonic drive device using a piezoelectric element that is less susceptible to magnetic fields is known and used as a drive device for driving clock hands and the like of a timepiece (for example, refer to Patent Document 1).

The ultrasonic drive device described in Patent Document 1 is configured to have: a vibrating body to which a piezoelectric element is bonded; a rotor body that rotates in the circumferential direction as the vibrating body vibrates; The pressing spring with a certain pressing force, the clock hands rotate through the rotation of the rotor body.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-290579

However, in the ultrasonic drive device described in Patent Document 1, when the ultrasonic drive device is started from a stop state, when a high-frequency voltage (drive signal) is applied to the vibrating body, the rotor body starts to rotate, but when the rotor body reaches A certain amount of time (acceleration period) is required until a predetermined rotational speed is reached. The larger the moment of inertia of the clock hands and the like, the longer the acceleration period. For example, when a reduction gear train for reducing the rotational speed of the rotor body is disposed between the rotor body and the clock hands, the moment of inertia of the gear train and the clock hands is larger than the moment of inertia of the rotor body, e.g. The combined moment of inertia of the rotor body, the reduction gear train and the hands of the clock is tens to hundreds of times more than the moment of inertia of the rotor body.

In addition, there may be a configuration in which a speed increasing gear train is provided between the rotor and the hands of the timepiece so that the hands of the timepiece can be moved by a predetermined angle even if the rotation angle of the rotor is small. For example, there is a case where the second hand traverses an angle of 6 degrees corresponding to 1 second by rotating the rotor by 2 degrees. In the case of an increasing gear train, the moment of inertia is greater than in the case of a reducing gear train, and the acceleration time is also longer.

Thus, the moment of inertia depends on, for example, the structure and configuration of the gear train and hands. Furthermore, when the moment of inertia is large, the acceleration period of the rotor body becomes longer, and the time for applying a drive signal to the vibrating body (vibrator) becomes longer. Therefore, there is a problem that the power consumption of the ultrasonic drive device increases.

Contents of the invention

An object of the present invention is to provide a piezoelectric drive device, a watch, and an electronic device capable of driving a rotating body with low power when the rotating body is driven by vibration of a vibrator.

The piezoelectric driving device of the present invention is characterized in that it has: a piezoelectric driver having: a vibrator having a piezoelectric element and a rotor rotated by the vibrator; and an elastic device capable of using the rotational energy of the rotor as The elastic energy is accumulated; and the rotated body is rotated by the elastic energy accumulated in the elastic device.

Here, the vibrator may be configured to vibrate when at least a drive signal is applied to the piezoelectric element, and the rotor is rotated by the vibration. For example, the vibrator may be configured to rotate the rotor by vibrating the piezoelectric element itself, or may be configured to rotate the rotor by vibrating a laminated plate-shaped piezoelectric element and a reinforcing plate. In addition, as the object to be rotated, as long as it is a member that transmits the rotation of the rotor through an elastic device, and then transmits the rotation to the object to be rotated, for example, it may be arranged in the rotation transmission path from the rotor to the object to be rotated such as a pointer. The rotor transmission gear, the escape wheel, the driven wheel, and the like may be a rotor transmission gear, a rotary gear, and the like arranged so as to have a common rotation axis with the rotor.

In addition, the above-mentioned rotational energy includes rotational force and the like, and elastic energy includes elastic force and the like.

Here, the characteristics of the piezoelectric actuator used in the present invention will be described based on the graphs in FIGS. 1 to 5 .

In the graph of FIG. 1, the relationship between torque (load) and rotation speed, and torque and power generated by piezoelectric actuators and ordinary electromagnetic motors are respectively shown. As shown by the solid line in the graph of Figure 1, there is a relationship between the torque T generated by the piezoelectric actuator and the rotational speed N, as in a general electromagnetic motor: the smaller the torque T, the higher the rotational speed N , the bigger the torque T is, the smaller the speed N is. In addition, in the electromagnetic motor, as shown by the dotted line in Fig. 1, the power W required for driving usually increases with the torque T. In contrast, in the piezoelectric actuator, as shown by the single-dot chain line in Fig. 1 It is shown that the power W required for driving is almost constant regardless of the influence of the torque T. The characteristics described above are schematically described, but actually vary.

In addition, the graph in FIG. 2 shows the relationship between the time t and the angular velocity V when the moment N of force acts on a general rigid body rotating around a certain axis. Here, the relationship between the torque N of the force acting on the rigid body, the angular acceleration β generated by it, and the moment of inertia I of the rigid body is generally such that the relationship of N=I·β is established. That is, when the moment N of force is the same, the larger the moment of inertia I is, the smaller the angular acceleration β is. In other words, the larger the moment of inertia I is, the longer it takes to reach the predetermined angular velocity V0. For example, when there are rigid bodies A and B with different moments of inertia I, and the respective moments of inertia IA and IB are in the relationship of IA:IB=1:2, the angular accelerations βA and βB of rigid bodies A and B are βA:βB= 2:1 relationship. As shown by the solid line in the graph of FIG. 2 , the rigid body A with a small moment of inertia I has a steep slope (the change rate of the angular velocity V becomes large), and when the time t to reach the predetermined angular velocity V0 is compared, all the rigid body B The required time tB is twice the required time tA of rigid body A. This means that the time required to move a predetermined distance (predetermined rotation angle) in rigid body B needs to be twice that of rigid body A.

In the present invention, the effect based on the characteristics of the rigid body affected by such moment of inertia I will be focused on, and the effect will be described below.

Regarding the basic performance of the piezoelectric actuator in the present invention, as shown in FIG. 3 , it is assumed that the generated torque (load torque) T1 is derived from the rotational speed N1 and power consumption W1 at that time. In addition, FIG. 4 shows the relationship between the time t and the rotational speed N when the piezoelectric actuator is started from a stop state. After the drive signal is supplied to the piezoelectric element of the piezoelectric driver (signal ON), the rotational speed N starts to increase, and when the predetermined rotational speed N1 is reached, the supply of the drive signal is stopped (signal OFF). The time (acceleration period) t1 required to reach the rotation speed N1 varies with the moment of inertia I. For example, in a timepiece, when a reduction gear train for reducing the rotational speed N of the rotor is arranged between the rotor and the pointer, the moment of inertia of the reduction gear train and the pointer is relatively large relative to the inertia moment of the rotor, and there is a difference between the rotor and the pointer. The combined moment of inertia of the reduction gear train and the pointer is only tens to hundreds of times the moment of inertia of the rotor. The combined moment of inertia of the rotor, the reduction gear train, and the pointer depends, for example, on the structure and shape of the reduction gear train and the pointer. The larger the inertia moment, the longer the acceleration period t1 of the rotor. Therefore, due to the time for supplying the drive signal to the vibrator becomes longer, so the power consumption of the piezoelectric actuator increases.

On the other hand, according to the present invention, when the piezoelectric actuator is started from a stopped state, since the elastic device is provided from the rotor to the rotated body side, the rotated object such as the rotated body with a large moment of inertia or the pointer does not pass through. The piezoelectric actuator rotates directly, and the moment of inertia of the portion directly rotated by the piezoelectric actuator reduces the amount of the object to be rotated or the object to be rotated. That is, the elastic means starts elastically deforming simultaneously with the rotation of the rotor, and the rotational energy of the rotor is accumulated as elastic energy of the elastic means. Next, when the accumulated elastic energy reaches a predetermined magnitude and at a predetermined timing, the object to be rotated and the object to be rotated start to rotate. Therefore, it is possible to prevent the influence of the moment of inertia of the object to be rotated and the object to be rotated from acting on the rotor until the rotor reaches a predetermined rotational speed and reaches a predetermined timing. In this way, since the moment of inertia I acting on the piezoelectric driver can be reduced, as shown in Figure 4, the acceleration period t1 of the rotor can be shortened, and the rotational speed N of the rotor can reach a predetermined rotational speed N1 in a short time when starting. . Therefore, when the object to be rotated is rotated by a predetermined angle, the driving time of the piezoelectric driver can be shortened, so the time for supplying the driving signal is also shortened, the startability is improved, and driving can be performed with low power.

In addition, in the case of rotating the object to be rotated by a predetermined angle, if the rotor is rotated by a predetermined angle, the object to be rotated and the object to be rotated can be rotated for a time longer than the rotation time of the rotor by virtue of the accumulated elastic energy, Therefore, even if the piezoelectric actuator is stopped when the rotor is rotated by a predetermined angle, the object to be rotated can be rotated by a predetermined angle.

Furthermore, in the present invention, by providing the elastic device as described above, the influence of the moment of inertia of the object to be rotated or the object to be rotated after the elastic device on the rotor can be eliminated, and the starting performance can be improved. On the other hand, since the elastic energy of the elastic means is also exerted on the stationary rotor, the force exerted from the elastic means acts as a new load on the startability of the rotor. However, as will be described below, the force exerted by the elastic energy of the elastic means has little influence on the rotation startability of the rotor.

That is, as loads applied to the piezoelectric actuator, there are dynamic loads and static loads. Therefore, it is studied from the viewpoint of which load has the above-mentioned effects of "shortening the driving time of the piezoelectric driver and the supplying time of the driving signal, improving the startability, and being able to drive with low power consumption".

The dynamic load is a load generated based on the moment of inertia of the driven object in an acceleration environment such as disturbance, and the static load is a load generated by the friction of the driven object, air resistance, and the reaction force of the elastic device as in the present invention.

In piezoelectric actuators, the influence of the above-mentioned dynamic load is greater than that of static load. Especially when the piezoelectric actuator drives the driven object with good momentum in a short period of time (for example, when the pointer is driven by one step in an instant), the influence of the above-mentioned moment of inertia is large, and it is generated by the above-mentioned elastic device, etc. The influence degree of the static load is small. This was confirmed in experiments conducted by the present inventors.

Therefore, in the present invention, the elastic device prevents the influence of the moment of inertia downstream from affecting the piezoelectric actuator, and compared with the case where the elastic device of the present invention is not used, the above-mentioned effects can be exhibited.

In addition, the effect of the load on the elastic device on the characteristics of the piezoelectric actuator will be described with reference to FIG. 5 . FIG. 5 shows the amount of decrease in the rotation speed N of the piezoelectric actuator when the torque T applied to the piezoelectric actuator increases. The load torque T2 in a state where the piezoelectric actuator receives the load of the elastic device must at least exceed the load torque T1. The aforementioned load torque T2 is a necessary torque capable of driving a driven body (for example, a wheel train or a pointer) that is rotated by the elastic energy accumulated in the elastic device. Let the excess torque mentioned above be α1. Also, let N2 be the rotational speed at the time of the load torque T2, and let α2 be the amount of decrease in the rotational speed N when the rotational speed changes from N1 to N2. In this way, the rotational speed decreases by α2 by increasing the torque by α1, so the basic characteristics of the piezoelectric actuator are degraded. However, such a relationship between the torque T and the rotational speed N represents a relationship in a state in which the piezoelectric actuator is stably driven. On the other hand, in the present invention, by reducing the energy loss when the stopped piezoelectric actuator is started, especially when the start operation is performed quickly, the power reduction in the entire drive from start to stop is realized. The reduction of the basic characteristics due to the reduction amount α2 of the rotation speed is compared with the reduction of energy loss during the starting operation, and is judged.

Then, the load torque T2 in the case of using the elastic device will be described by taking the driving of the hands of the timepiece as an example. Preferably, 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 the piezoelectric actuator that is driven at predetermined intervals (step driving), the amount of increase in load corresponding to the deflection of the elastic device for one-step driving becomes important. If the amount of increase in this load is almost zero, the load applied by the elastic device to the piezoelectric actuator becomes extremely small.

For example, if the rotation angle of the rotor in one step 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 increases to a value of 40 degrees. deflection, so the load generated by the elastic device becomes twice the initial state. That is, if the initial deflection can be increased, the amount of increase in load becomes small. If the number of turns of the initial deflection can be ensured to be 3 turns by a spring like a "hairspring" as an elastic device, even if the rotor rotates 20 degrees, the value is 20 degrees ÷ (360 degrees × 3 coils) = 0.018, and the increase in load The amount is below 2%. Therefore, the amount of increase in load caused by the elastic device can be suppressed to an extremely small amount, and the influence on the characteristics of the piezoelectric actuator can be substantially eliminated.

In addition, when the elastic device is not used, the required performance of the piezoelectric actuator needs to be set in consideration of the shape of the object to be rotated, the impact from the outside, the influence of the temperature environment, and the like.

As shown in Fig. 5, for the piezoelectric driver, the load torque T2 is set to drive the load during normal driving, while the maximum torque T3 is set as a margin for sudden loads And set. For example, when an unbalanced rotating object (a member supported by a cantilever such as a watch pointer, etc.) is included in the drive path, the moment of inertia given to the piezoelectric actuator may vary depending on the direction of the posture of the rotating object. The impact will suddenly increase. In addition, when the piezoelectric drive device is worn on the wrist, etc., the acceleration G generated by the movement of the wrist or a slight impact may act on the rotating object, especially when the rotating object has an unbalanced shape. In the case of , an acceleration G that is several times that of the load in a static state is generated. For example, in the case of clapping hands, an acceleration G that is tens to hundreds of times is sometimes generated. When the piezoelectric actuator directly rotates the object to be rotated as in the past, in order to rotate the object to be rotated under the sudden increase in the moment of inertia or sudden load as described above, it is necessary to set the maximum generated rotation of the piezoelectric actuator. torque T3 in order to be able to generate a torque capable of overcoming these loads.

On the other hand, when an elastic device is used as in the present invention, the influence of suddenly large moment of inertia or sudden acceleration G on the piezoelectric actuator can be reduced by the elastic deformation of the elastic device. That is, by causing sudden acceleration G to act in the direction of cutting off the rotation of the rotating body, even if the rotation of the rotating body stops suddenly, the inner rotor can continue to rotate during this period, and the rotation of the rotor can act as the elasticity of the elastic device. can accumulate. Furthermore, after the sudden acceleration G disappears, the object to be rotated can be rotated by the accumulated elastic energy. In addition, even when the sudden acceleration G is generated intermittently such as clapping hands, the object to be rotated can be rotated by the accumulated elastic energy without generating the sudden acceleration G.

In this way, by having the elastic device, the piezoelectric actuator can be set to have characteristics corresponding to the static load T1 (set to T2), and it is not necessary to set the characteristics to correspond to the sudden acceleration G as in the past. The power supplied to the piezoelectric driver can be reduced, and the power consumption W1 can be reduced.

In addition, if the influence of the viscosity of the lubricating oil used in the shaft support is considered, the lower the temperature, the more the viscosity of the lubricating oil increases, and the viscosity increases in proportion to the speed of the rotated body, so it is necessary to increase the piezoelectric actuator accordingly. performance. On the other hand, when the elastic device is used, if the object to be rotated is gradually rotated using elastic energy, the influence of the viscosity of the lubricating oil on the object to be rotated can be reduced.

In the piezoelectric drive device of the present invention, it is preferable to include a rotation restricting means for restricting the rotation angle of the above-mentioned to-be-rotated body to a predetermined angle.

Here, when a piezoelectric driver is used to drive the pointer of a watch or the like, it is very important to move the pointer at a constant interval. Therefore, if the piezoelectric driver using the piezoelectric driver cannot realize the stepping motion of a constant angle, the pointer's The position will shift, which is a big problem.

According to the present invention, the object to be rotated is rotated by the drive of the rotor, and the rotation of the object to be rotated is regulated by a constant angle each time by the rotation restricting device, so even if the amount of driving of the piezoelectric driver is not uniformly determined, the object to be rotated The amount of rotation of the body, because if the rotated body is rotated by a constant angle, the rotation limiting device will limit the rotation angle of the rotated body to a constant angle, so the amount of rotation of the rotated body is constant. Thus, since the overrunning of the rotating body rotated by the piezoelectric actuator can be prevented, it is not necessary to strictly control the rotation angle of the rotor, the accuracy of the rotation angle of the rotating body can be improved, and the rotation speed of the rotating body can be improved. The display accuracy of the pointer and other display units.

In addition, the rotation restricting device is not limited to restricting the rotation angle of the rotating body at a constant angle each time, and may be a rotation restricting device configured to restrict changes in the rotation angle like a mechanical clock. That is, the rotation limiting device may be any device that limits the rotation angle of the rotating body to a set predetermined angle.

In the piezoelectric driving device of the present invention, preferably, the piezoelectric driving device has: a first transmission path that transmits the rotational energy of the rotor to the rotation limiting device without passing through the elastic device; and a second transmission path that transmits the rotational energy of the rotor to the elastic device.

According to the present invention, since the piezoelectric driving device has: a first transmission path which transmits the rotational energy of the rotor to the rotation restricting means; and a second transmission path which transmits the rotational energy of the rotor to the elastic means, it can be Since the drive source of the rotating body and the drive source of the rotation restricting device are shared, the number of parts can be reduced and the device can be miniaturized.

In the piezoelectric drive device according to the present invention, it is preferable that the rotation restricting device is engaged with the rotating body.

According to the present invention, the rotation restricting device only needs to be engaged so as to restrict the rotation of the rotated body at least. The rotation restricting means and the rotated body may be configured in such a manner that the rotation angles of other rotating bodies that are transmitted and driven from the rotated body are restricted by the rotation restricting means. Alternatively, the rotation angle of the rotating body configured coaxially with the rotating body may be restricted by the rotation restricting device. Therefore, the degree of freedom in the arrangement of the rotation restricting device and the object to be rotated can be increased.

In the piezoelectric drive device of the present invention, the object to be rotated is an escape wheel, and the rotation limiting device is a pallet fork.

According to the present invention, an escapement machine can be constituted by an escape wheel and a pallet fork, and when the escape wheel is driven by a piezoelectric actuator, the escape wheel can be rotated with a correct driving amount.

In the piezoelectric driving device of the present invention, preferably, the piezoelectric driving device has a cam member, the cam member engages with the pallet fork and is driven by the piezoelectric driver, and the cam member is configured as When the cam member rotates one revolution, the pallet fork performs one reciprocating action.

According to the present invention, since the pallet fork is reciprocated by the cam member driven by the piezoelectric driver, the pallet fork can be reciprocated once by rotating the cam member once in at least one direction. Therefore, it is not necessary to rotate the driver as a driving source in two directions, but it can be rotated in one direction. For example, in the case of a piezoelectric actuator with a rectangular plate-shaped vibrator, since the unidirectional rotation type can freely select the contact position with the rotor, the transmission efficiency of the driving force is improved, and it is possible to promote low power and high torque.

In addition, when rotating in both directions, there is a protruding portion substantially in the center of the short side of the rectangular plate-shaped piezoelectric element, and the protruding portion is arranged toward the center of the rotor. On the other hand, in the case of unidirectional rotation, the projection can be deviated from the direction toward the center of the rotor, so that a large torque can be generated on the rotor in response to the operation of the piezoelectric element. That is, the driving force can be efficiently transmitted only in a certain direction.

In the piezoelectric drive device according to the present invention, it is preferable that the rotating body and the rotation restricting device are constituted by an Oldham wheel mechanism.

According to the present invention, when the object to be rotated is operated intermittently, the pointer and the like can be driven at an accurate rotation angle of one step without being affected by fluctuations in the rotation angle of the rotor.

In the piezoelectric driving device of the present invention, preferably, the elastic device is a coil spring.

Here, as the coil spring, a hairspring or a power spring used in a watch or the like can be used.

According to the present invention, since the coil spring is used as the elastic device, even if the number of turns of the coil spring is increased in order to ensure a large displacement, the installation space can be reduced compared with the case of using a U-shaped spring or a cantilever spring. The coil spring is configured in the case. Furthermore, if a large amount of displacement is ensured, substantially constant elastic energy can be generated regardless of the amount of displacement of the elastic means. Therefore, since the object to be rotated receives substantially constant elastic energy from the elastic device regardless of the magnitude of the external impact, the motion of the object to be rotated can be stabilized.

In the piezoelectric drive device of the present invention, preferably, the piezoelectric drive device has a rotor drive wheel to which the rotation of the rotor is transmitted, and the rotor drive wheel and the rotated body are disposed on On the same rotating shaft, one end of the elastic device is engaged with the rotor drive wheel, and the other end of the elastic device is engaged with the rotated body.

Here, examples of the elastic means include spring members called coil springs, U-shaped springs, cantilever springs, and coil springs. In addition, a member made of rubber may also be used as the elastic means. In addition, the elastic device may be installed so as to be elastically deformable at least by the driving force of the rotor.

According to the present invention, since the elastic device can be arranged between the rotor transmission wheel and the rotating body arranged on the same axis, the elastic device can be arranged compactly.

In addition, when the elastic device is arranged between the gear (rotor pinion) arranged coaxially with the rotor and the rotated body, the rotor, the rotor pinion, the elastic device, and the rotated body overlap in the axial direction, so the thickness The size also becomes larger. In contrast, in the present invention, the rotor driving wheel can be arranged on a different shaft from the rotor, so only the rotor driving wheel, the elastic device, and the rotated body overlap, and thinning can be achieved because there is no laminated rotor.

In the piezoelectric drive device of the present invention, preferably, the rotor and the rotated body are disposed on the same rotating shaft, one end of the elastic device engages with the rotor, and the other end of the elastic device One end is engaged with the rotated body.

According to the present invention, since the rotating shaft of the rotor and the rotating shaft of the rotated body are formed on the same shaft, the other rotating body that transmits the driving force of the rotor to the elastic device is arranged between the rotor and the elastic device, and is passed through Compared with the case where the other rotating body transmits the driving force to the rotated body, the load applied to the rotor can be reduced by an amount equivalent to the moment of inertia of the other rotating body. Therefore, the rotor can be rotated at a high speed with a reduced amount of moment of inertia, and the power input time when the rotor is driven by a predetermined amount can be shortened, and power reduction can be promoted.

In the piezoelectric driving device of the present invention, preferably, the elastic device has an initial deflection, and a A release restriction that maintains the initial deflection.

According to the present invention, since the release restricting portion is provided, the elastic device can maintain the elastically deformed state (the state having the initial deflection) in the initial state. The performance of the rotor and the object to be rotated will be described. At the time of starting, the rotor starts to rotate first, and the object to be rotated delays the start of rotation due to the influence of the moment of inertia. In such a structure, if there is a release regulation part, the force by the said initial deflection will always act on a to-be-rotated body. Therefore, it is possible to suppress the swing of the rotating body due to external impact, and prevent the indicated position of the hands and the like of the timepiece connected to the rotating body from moving. In addition, the magnitude of the force generated by the initial deflection of the elastic means is preferably greater than or equal to the magnitude capable of rotating the object to be rotated.

As a specific example, when the release restricting portion is constituted by a pin as an engaging portion fixed to the rotated body, and a long hole formed on the rotor as the engaged portion and long in the relative movement direction of the pin , the body to be rotated is rotated by the elastic energy of the elastic device until the pin abuts against the inner side wall of the long hole, and this state is maintained. Thereby, swinging of the object to be rotated can be reliably suppressed. For example, if there is no elastic device, and the rotor and the object to be rotated are formed of gears and mesh with each other, the body to be rotated will wobble as much as the gap between the teeth of the gear. Therefore, when the hands of the timepiece and the like are attached to the rotating body, there is a problem that the display positions of the hands are incorrect. On the other hand, if the rotor and the rotated body are connected by an elastic device, and the initial elastic deformation (initial deflection) of the elastic device is maintained by releasing the restricting part, the shaking of the rotor and the rotated body disappears, and the timepiece can be displayed correctly. pointer etc.

In addition, compared with the case where the rotor and the rotating body are meshed with gears, if there is an elastic device, the unevenness of the gap between the meshing parts of the gears due to fluctuations in the machining accuracy of the tooth spacing dimensions of the gears will disappear, and the rotor And the rotated body will not be affected by fluctuations in the machining accuracy of the parts.

In addition, even with the elastic device, in the absence of initial elastic deformation, even if the rotation of the rotor is restricted when the piezoelectric actuator is stopped, since the elastic energy of the elastic device is not applied to the rotated body, the rotated body is relatively easy Vibration due to external impact, etc. On the other hand, if the initial elastic deformation is maintained, the force due to the initial elastic deformation is applied to the object to be rotated, and the object to be rotated can be prevented from swinging due to external impact or the like. In addition, even if the magnitude of the external shock is such that the elastic device is elastically deformed, if the elastic device returns to its original state and returns to the state in which the force generated by the original initial elastic deformation acts on the rotated body, then No problem either.

In the piezoelectric drive device of the present invention, preferably, the release restriction portion has a play that allows the rotor drive wheel or the rotor to rotate only in a direction that increases the deflection of the elastic device, and the The maximum amount of deflection of the elastic device is set according to the amount of play of the release restricting portion.

If the amount of deflection of the elastic device is not limited, if the elastic energy accumulated in the elastic device is too large, the object to be rotated that is rotated by the elastic energy may rotate beyond a predetermined rotation angle. On the other hand, according to the present invention, since the maximum amount of deflection of the elastic device is set according to the amount of play of the release limiting means, it is possible to prevent accumulation of elastic energy exceeding the requirement, and to suppress overrunning of the rotatable body.

Furthermore, if the amount of play is set to an amount corresponding to a predetermined amount of rotation of the rotor, the rotation of the object to be rotated starts at least when the rotor has rotated a predetermined amount regardless of the magnitude of the moment of inertia of the body to be rotated, Therefore, the maneuverability of the object to be rotated can be improved.

In the piezoelectric driving device according to the present invention, it is preferable that the piezoelectric driver is configured to perform step-by-step driving, and the play of the release restriction part corresponds to at least one-step driving of the piezoelectric driver. The amount of rotation of the rotor drive wheel or the rotor.

In the case of driving the rotor with a piezoelectric driver, if the object to be rotated is directly mounted on the rotated body, and the moment of inertia of the rotating system after the rotated body is small, since the rotated body is also linked with the rotation of the rotor And start spinning, so it won't cause a big problem. However, in cases where the moment of inertia of the rotating system after the object to be rotated is large, such as when the object to be rotated after the object to be rotated is large, or when the transmission path after the object to be rotated is constituted by a plurality of objects to be rotated Next, there may be a problem that the rotation of the rotatable body with respect to the rotor is not immediately interlocked.

On the other hand, according to the configuration of the present invention, when the piezoelectric actuator is driven step by step, that is, is driven at a constant interval, the range of the play portion of the release control portion is set to be at least as large as one cycle of the rotor. Corresponding range, so even if the moment of inertia after the rotating body is large, the situation that the rotor and the rotating body interfere and cause the load on the rotor to increase can be avoided.

That is, when the range of the backlash portion is set smaller than the range corresponding to the rotation amount of one cycle, it takes time from rotating the rotor until the rotating body follows the rotation of the rotor. Therefore, even if the rotor has reached the rotation amount of one cycle, if the object to be rotated has not yet started to rotate, the elastic device cannot be elastically deformed until the rotation amount of one cycle of the rotor is reached. Inertial force of the rotating body. On the other hand, as in the present invention, it is possible to prevent an increase in the load applied to the rotor by setting a clearance corresponding to at least one cycle of the piezoelectric actuator.

It should be noted that one cycle of the piezoelectric driver means from the start of driving to the time when the driving is stopped once and the next driving is started in the intermittently driven piezoelectric driver. That is, one-step driving of the piezoelectric driver is one-cycle driving of the piezoelectric driver. In addition, the rotation amount of one cycle of the rotor means the amount of rotation of the rotor when the piezoelectric actuator that rotationally drives the rotor is driven by one step, that is, one cycle.

In the piezoelectric driving device of the present invention, preferably, the piezoelectric driving device has: a swing unit that is alternately rocked in first and second directions by the rotated body; and a second rotated body , whenever the swing unit swings to the first and second directions, the second rotated body is rotated in a constant direction by the swing unit, and the swing unit has the ability to limit the The rotation restricting part of the rotation angle of the second to-be-rotated body.

Here, the mechanism constituted by the swing unit and the second rotated body is a so-called reverse escapement. In this reverse escapement, there is a problem that the load on the piezoelectric actuator is large. That is, the reverse escapement, unlike the escapement of a mechanical timepiece, transmits the driving force from the pallet fork to the escape wheel, so the transmission efficiency of the driving force is significantly lower than that of gears and the like. The mechanism reason is that the angle of intersection between the direction of the force when the claw of the pallet fork abuts against the teeth of the escape wheel and the direction of rotation of the escape wheel is large. Therefore, the load on the piezoelectric actuator increases, the driving speed decreases, and the time required to advance at a desired pace becomes longer.

On the other hand, according to the present invention, by providing the elastic device, the load on the piezoelectric actuator is reduced, the rotation speed of the rotor can be increased, the time required to advance at a desired pace can be shortened, and the power consumption can be reduced.

In the piezoelectric drive device according to the present invention, it is preferable that the vibrator is formed in a plate shape and has a contact portion that contacts the outer peripheral surface of the rotor, and that the piezoelectric drive device has a pressing unit that A pressing unit presses one of the vibrator and the rotor toward the other of the vibrator and the rotor.

Here, the vibrator should only be formed in at least a plate shape, for example, it may be formed in a rhombus, trapezoid, parallelogram, or the like. In addition, the abutting portion only needs to be provided so as to contact at least the outer peripheral surface of the rotor, for example, may have a shape protruding from the end of the plate-shaped vibrator, or may be formed by using a corner of the plate-shaped vibrator. In addition, the rotor can be pressed against the vibrator by the pressing unit, and the vibrator can be pressed against the rotor. The pressing direction of the pressing unit is substantially perpendicular to the rotation axis of the rotor, and the pressing direction and the vibration direction of the vibrator are preferably on the same plane.

According to the present invention, since the vibrator is formed in a plate shape, it is possible to promote thinning of the piezoelectric drive device. In addition, since the pressing means is provided, the frictional force between the abutting portion and the outer peripheral surface of the rotor can be increased, and the driving force when the rotor is rotated by the vibration of the vibrator can be reliably transmitted.

An electronic device according to the present invention is characterized in that the electronic device includes: the piezoelectric drive device described above; and a driven portion driven by the piezoelectric drive device.

According to the present invention, it is possible to configure various electronic devices that use the piezoelectric drive device as a drive source. In this case, the driving of the driven part by the piezoelectric driving device can be prevented from being affected by the magnetic field, and the power consumption during driving can be reduced.

In the electronic device according to the present invention, preferably, the driven unit is a timekeeping information display unit that displays timekeeping information measured by the timekeeping unit.

According to the present invention, since the timing information display unit such as the hands of the clock can be driven by the piezoelectric drive device, the driving of the hands and the like can be prevented from being affected by the magnetic field, and the hands of the timing information display unit can be driven with low power.

According to the present invention, there is an effect that when the object to be rotated is driven by vibration of the piezoelectric element, the object to be rotated can be driven with low power.

Description of drawings

FIG. 1 is a graph showing the relationship between torque and rotation speed and the relationship between torque and power in a piezoelectric driver of the piezoelectric driving device according to the present invention.

FIG. 2 is a graph showing the relationship between time and angular velocity during rotation of a general rigid body.

FIG. 3 is a graph showing the relationship between torque and rotational speed, and the relationship between torque and power consumption in the piezoelectric actuator.

FIG. 4 is a graph showing the relationship between time and rotational speed at the start of the piezoelectric actuator.

FIG. 5 is a graph showing the relationship between torque and rotational speed, and the relationship between torque and power consumption in the piezoelectric actuator.

6 is a perspective view showing a piezoelectric drive device in the timepiece according to the first embodiment of the present invention.

Fig. 7 is a plan view showing the above piezoelectric drive device.

Fig. 8 is a block diagram showing a circuit configuration of the timepiece according to the first embodiment of the present invention.

9 is a graph showing the relationship between time, rotation speed, and rotation angle when the inertial load is doubled.

10 is a graph showing the relationship between time, rotation speed, and rotation angle when the inertial load is 10 times larger.

Fig. 11 is a plan view showing a piezoelectric drive device according to a second embodiment of the present invention.

Fig. 12 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 13 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 14 is a longitudinal sectional view showing the above-mentioned piezoelectric drive device.

15 is a plan view showing a piezoelectric drive device according to a third embodiment of the present invention.

Fig. 16 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 17 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 18 is a plan view showing the above piezoelectric drive device.

Fig. 19 is a plan view showing a piezoelectric drive device according to a fourth embodiment of the present invention.

Fig. 20 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 21 is a longitudinal sectional view showing the above piezoelectric drive device.

Fig. 22 is a plan view showing a piezoelectric drive device according to a fifth embodiment of the present invention.

Fig. 23 is a perspective view showing a main part of the piezoelectric drive device.

Label description

1: Clock; 4, 4A, 4B, 4C: Piezoelectric drive; 7: Cam gear (cam member); 8: Pallet (rotation limiting device); 8A: Reverse escapement pallet (oscillating unit) ;9: driving wheel (rotation limiting device); 10, 10A, 10B, 10C, 10D: piezoelectric drive device; 20, 20A, 20B: vibrator; 22, 22A: piezoelectric element; 30, 30A, 30B, 30C: Rotor ring (rotor); 33B: first rotor gear (rotated body); 33C: second rotor gear (rotated body); 34: rotor transmission gear (rotated body); 40: first rotor transmission gear (rotor transmission wheel); 40A: rotor transmission gear (rotor transmission wheel); 42: positioning hole (release restriction part); 43: positioning plate (release restriction part); 50, 50B, 50C, 50D: coil spring (elastic device); 60: second rotor transmission gear (rotated body); 60A: escape wheel (rotated body); 60B: driven wheel (rotated body); 60C: reverse escapement escape wheel (second rotated body ); 61: positioning pin (release restricting part); 63: positioning hole (release restricting part); 82A, 83A: pawl (rotation restricting part); 212, 212A: contact part; 335: positioning cutout (release restricting part ); 342: positioning protrusion (release restriction).

Detailed ways

(first embodiment)

A first embodiment of the present invention will be described below with reference to the drawings.

In addition, after the second embodiment described later, the same components and components having the same functions as those in the first embodiment described below are assigned the same reference numerals, and descriptions thereof are simplified or omitted.

(the whole frame)

6 and 7 are a perspective view and a plan view showing a driving mechanism of the hands 2 in the timepiece 1 of the present embodiment. The timepiece 1 is equipped with a timing unit inside an unshown exterior case; a timing information display unit for displaying timing information obtained by timing the timing unit with hands 2; mechanism, etc., including the movement mechanism in FIG. 8), the piezoelectric drive device 10 is used for the action of the drive mechanism of the pointer 2. That is, the pointer wheel 3 on which the pointer 2 as the object to be driven is attached is rotatable by the piezoelectric drive device 10 .

As shown in Figures 6 and 7, the piezoelectric drive device 10 has: a piezoelectric driver 4 that rotates the rotor ring by vibration of the piezoelectric element; Wheel 5 (rotation transfer wheel).

(Structure of piezoelectric actuator)

Next, the configuration of the piezoelectric actuator 4 will be described. The piezoelectric actuator 4 is configured to include a vibrator 20 and a rotor ring 30 .

The vibrator 20 includes a substantially rectangular thin plate reinforcing plate 21 and substantially rectangular plate piezoelectric elements 22 bonded to both surfaces of the thin plate reinforcing plate 21 , and the vibrator 20 has a laminated thin plate structure as a whole.

An arm portion 211 protruding to one side is formed substantially at the center in the longitudinal direction of the thin-plate reinforcing plate 21, and the arm portion 211 is fixed to a bottom plate, not shown, or the like with screws or the like. Approximately semicircular contact portions 212 protruding in the longitudinal direction of the thin-plate reinforcing plate 21 are respectively formed at both ends on the diagonal line of the thin-plate reinforcing plate 21 . One of these abutting portions 212 abuts against the side surface of the rotor ring 30 .

In addition, 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 non-magnetic materials such as stainless steel and hardened beryllium copper alloy (Bertllium Copper), the piezoelectric actuator 4 will have improved magnetic resistance and can be driven without being affected by a magnetic field. .

The piezoelectric element 22 is made of any material selected from the following materials: lead zirconate titanate (PZT (registered trademark)), quartz, lithium niobate, barium titanate, lead titanate, lead metaniobate, polybias Vinyl fluoride (polyfluoroethylene), zinc lead niobate, scandium lead niobate, etc. Driving electrodes 221 are formed on both surfaces of the piezoelectric element 22 by plating (not shown).

When a voltage of a predetermined frequency is applied to the driving electrodes 221 of the vibrator 20 , the piezoelectric element 22 is excited to vibrate in the longitudinal primary vibration mode in which the piezoelectric element 22 expands and contracts in 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 weight of the vibrator 20 as a whole is unbalanced with respect to the centerline in the longitudinal direction. Due to this unbalance, the vibrator 20 is excited to vibrate in a bending secondary vibration mode in which the vibrator 20 bends in a direction substantially perpendicular to the longitudinal direction. Therefore, the vibrator 20 excites vibrations in which the longitudinal primary vibration mode and the bending secondary vibration mode are combined, and the abutting portion 212 vibrates so as to draw a substantially elliptical orbit.

The rotor ring 30 is rotationally driven by the vibrator 20 . On the rotor rotating shaft 31 of the rotor ring 30 , a rotor pinion 32 that transmits rotational drive to the first rotor transmission gear 40 is fixed. The rotor rotating shaft 31 is rotatably supported at one end of the support arm 35 . The support arm 35 is supported so as to be rotatable about the arm rotation shaft 351 relative to the base plate or the like. The other end of the support arm 35 is urged by a pressing spring 36 as a pressing unit.

The pressing spring 36 is configured to press the contact portion 212 of the rotor ring 30 and the vibrator 20 to contact each other.

Specifically, the pressing spring 36 is constituted by a torsion coil spring, and one end of the pressing spring 36 is fixed to the bottom plate or the like by the supporting member 361 . The other end of the pressing spring 36 urges the end of the support arm 35 , and the rotor ring 30 is urged toward the vibrator 20 to press the abutting portion 212 in the pressing direction F. As shown in FIG. The pressing direction F is a direction substantially perpendicular 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. Accordingly, 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 becomes good.

In such a piezoelectric actuator 4, when the contact portion 212 of the vibrator 20 vibrates to describe a substantially elliptical orbit, the rotor ring 30 and the rotor pinion 32 are only reversed by pressing the rotor ring 30 on a part of the vibration orbit. Rotational drive is performed in the clockwise direction (direction of arrow A). Therefore, in this embodiment, the rotor of the present invention is constituted by the rotor ring 30 and the rotor pinion 32 .

(Structure of the rotor drive wheel)

Next, the structure of the rotor transmission wheel 5 will be described. The rotor drive wheel 5 is configured to have:

For example, when the crown is pulled out to correct the time, it is necessary to stop the operation of the hands. Therefore, when the operation detection unit 109 outputs a detection signal of the pull-out operation of the crown, the control circuit 104 outputs a control signal for stopping the driving of the piezoelectric drive device 10 to the timepiece drive circuit 106 . On the other hand, when the operation detection unit 109 outputs a detection signal of the push-in operation of the crown, the control circuit 104 outputs a control signal for starting the driving of the piezoelectric drive device 10 to the timepiece drive circuit 106 .

The watch drive circuit 106 receives the control signal from the control circuit 104 and outputs a drive signal for the piezoelectric drive device 10 . Specifically, the watch driving circuit 106 applies a driving voltage of a predetermined frequency to the piezoelectric element 22 of the piezoelectric driving device 10 using an AC signal (pulse signal) for driving.

In addition, the method of controlling the driving frequency of the piezoelectric driving device 10 is not particularly limited, and for example, as disclosed in the patent document (Japanese Patent Application Laid-Open No. 2006-20445), the driving signal supplied to the piezoelectric element 22 may be set to The frequency sweeps (changes) in a wide range including the drivable frequency range, and the method of reliably driving the piezoelectric drive device 10; it may also be changed as disclosed in the patent document (Japanese Patent Application Laid-Open No. 2006-33912). The frequency of the driving signal, so that the phase difference between the frequency of the driving signal supplied to the piezoelectric element 22 and the detection signal obtained from the vibration state of the piezoelectric element 22 is a predetermined target phase difference suitable for driving, and also A method of driving at a fixed frequency set in advance according to temperature may be used.

In addition, detection electrodes not to be applied with voltage may be provided on the piezoelectric element 22 of the piezoelectric drive device 10, and detection signals output from the detection electrodes may be fed back to the control circuit 104 to control the frequency of the drive signal. Through the detection signal, the control circuit 104 can confirm the driving state of the piezoelectric driving device 10 and perform feedback control on the frequency of the driving signal.

The movement mechanism 110 is constituted by a gear train driven by the piezoelectric driver 10 (the piezoelectric driver 4 and the rotor drive wheel 5 ), and has the pointer wheel 3 in the present embodiment.

The movement mechanism 110 converts the movement amount obtained from the piezoelectric drive device 10 into a movement amount suitable for time display, and transmits the movement amount to the time display unit (hand) 2 as a timekeeping information display unit. In this embodiment, since the movement mechanism 110 is a reduction gear train, the movement amount (rotation amount of the rotor) of the piezoelectric drive device 10 is changed to the movement amount displayed at time with a predetermined reduction ratio. The first rotor transmission gear 40 meshed with the rotor pinion 32; the coil spring 50 with one end locked on the first rotor transmission gear 40; the second rotor transmission gear 60 connected with the other end of the coil spring 50; and the rotation of the transmission wheel Shaft 70.

The first rotor transmission gear 40 is formed in a disk shape having a larger diameter than the rotor pinion 32 , and is rotatably supported by a transmission wheel rotation shaft 70 . 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. In addition, although not shown in the figure, an optical detection unit for detecting the amount of rotation of the first rotor transmission gear 40 is provided, and through this non-contact detection unit, the first rotor transmission gear is driven by the piezoelectric driver 4 every time. 40 predetermined amount of rotation, the piezoelectric driver 4 is stopped, and the piezoelectric driver 4 is started after a predetermined time. The piezoelectric actuator 4 is driven periodically by repeating the start and stop in this way.

When the piezoelectric driver 4 stops, the abutting portion 212 of the piezoelectric driver 4 is pressed against the rotor ring 30 by the pressing spring 36 and frictionally engaged, so the rotor ring 30 is positioned at this position. Therefore, the rotor ring 30 does not move in the direction of rotation. Thus, the first rotor transmission gear 40 is also positioned in the rotational direction by the positioned rotor ring 30 . In addition, the position of the second rotor transmission gear 60 and the pointer wheel 3 in the direction of rotation is determined by the positioning hole 42 and the positioning pin 61 as the release restricting portion as described later, so the position of the pointer 2 is also positioned at a predetermined position.

The positioning hole 42 is a long hole formed along the outer circumference of the first rotor transmission gear 40 . The dimension of the opening of the positioning hole 42 in the direction along the outer circumference of the first rotor transmission gear 40 is set to such a length dimension (dimension of the play portion) that the second rotor transmission gear 60 is stopped in a state where the second rotor transmission gear 60 is stopped. A rotor transmission gear 40 can rotate in the normal direction (clockwise in FIG. 7 ) by the driving amount of one cycle of the piezoelectric driver.

The second rotor transmission gear 60 is fixed on the rotation shaft 70 of the transmission wheel. The second rotor transmission gear 60 has the same rotation axis as the first rotor transmission gear 40 and meshes with the pointer wheel 3 . On the second rotor transmission gear 60 , a cylindrical positioning pin 61 is fixed, and the positioning pin 61 protrudes toward the first rotor transmission gear 40 side and passes through the positioning hole 42 .

The coil spring 50 is formed by winding a spring wire having a circular cross section in a clockwise helical shape on the plane of FIG. 7 . The end portion on the outer peripheral side of the coil spring 50 is locked in the spring locking hole 41 , and the end portion on the central axis side of the coil spring 50 is fixed by being wound around the transmission wheel rotating shaft 70 .

When the first rotor transmission gear 40 rotates clockwise ahead of the second rotor transmission gear 60, the coil spring 50 is elastically deformed in the direction in which the number of turns increases, so that the driving force transmitted to the first rotor transmission gear 40 can be used as an elastic can accumulate.

Next, the condition in which the elastic deformation at the initial stage is maintained in the coil spring 50 will be described.

In the state where the above-mentioned coil spring 50 has an initial elastic deformation (about 3 turns), fix the end of the central side of the coil spring 50 on the transmission wheel rotating shaft 70, and lock the outer end of the coil spring 50 In the locking hole 41 for the above-mentioned spring.

When the first rotor transmission gear 40 and the second rotor transmission gear 60 are assembled as shown in FIG. 6 while maintaining the above-mentioned initial elastic deformation, the second rotor transmission gear 60 transmits the transmission to the first rotor through the elastic energy of the above-mentioned coil spring 50. The gear 40 applies a force to rotate in the normal rotation direction (clockwise in FIG. 7 ). However, since the positioning pin 61 is disposed in the positioning hole 42 , the second rotor transmission gear 60 is maintained at a position where the positioning pin 61 is in contact with the inner surface of the positioning hole 42 in the normal rotation direction with respect to the first rotor transmission gear 40 . , which is the state shown in FIG. 7 .

Furthermore, the first rotor transfer gear 40 meshes with the rotor pinion 32 . The rotor ring 30 integrated with the rotor pinion 32 is biased by the contact portion 212 of the piezoelectric actuator 4 as described above to be positioned. Therefore, in the stopped state of the piezoelectric driver 4, the rotor ring 30 is kept in the stopped state by the abutment of the contact portion 212 of the piezoelectric driver 4, and the first rotor transmission gear 40 meshing with the rotor pinion 32 is also kept in a state of being stopped. stop state. Furthermore, the second rotor transmission gear 60 is positioned relative to the first rotor transmission gear 40 at a position where the positioning pin 61 contacts the positioning hole 42 . In this way, the elastic deformation (initial elastic deformation) of the coil spring 50 is maintained.

Therefore, in this embodiment, the coil spring 50 constitutes the elastic device, the second rotor transmission gear 60 constitutes the rotated body, and the positioning pin 61 and the positioning hole 42 constitute the release restricting portion.

In addition, the above-mentioned positioning hole 42 and positioning pin 61 as the release restricting part maintain the elastic deformation (initial deflection) of the coil spring 50 in the initial stage as described above, but when the piezoelectric actuator 4 is further driven by one step (one cycle) ), it also has the function of keeping the second rotor transmission gear 60 and the pointer wheel 3 at predetermined positions.

That is, when the piezoelectric actuator 4 is driven by one step, the first rotor transmission gear 40 rotates clockwise by one cycle (one step) in FIG. 7 , and the coil spring 50 is also wound up. Then, with the help of the release force of the coil spring 50, the second rotor transmission gear 60 is also driven to rotate clockwise, but because the positioning pin 61 abuts and springs against the inner surface of the positioning hole 42 in the clockwise direction (Fig. In Fig. 7, on the inner surface contacted by the positioning pin 61), so the second rotor transmission gear 60 is positioned in the direction of rotation.

Furthermore, the vibrator 20 of the piezoelectric driver 4 is fixed on the base plate as the base frame of the timepiece 1 through the arm portion 211, and one end of the rotor rotating shaft 31, the transmission wheel rotating shaft 70, and the rotating shaft of the pointer wheel 3 is connected by the axis of the base plate. The support holes are pivotally supported, and their other ends are pivotally supported and held by a wheel train support portion arranged to face the bottom plate. Furthermore, the rotation shaft of the pointer wheel 3 and one end of each rotation shaft of the other pointer wheels are pivotally supported on the base plate, but the other ends may also be pivotally supported by a supporting member other than the wheel train.

(circuit structure of a clock)

Next, the circuit configuration of the timepiece 1 will be described with reference to FIG. 8 .

The drive circuit of the timepiece 1 includes an oscillation circuit 102 driven by a power source 101 composed of a primary battery or a secondary battery, a frequency dividing circuit 103 , and a control circuit 104 .

The oscillation circuit 102 outputs an oscillation signal to the frequency division circuit 103, which has a reference oscillation source such as a crystal oscillator.

The oscillating signal output from the oscillating circuit 102 is input to the frequency dividing circuit 103, and the frequency dividing circuit 103 outputs a timepiece reference signal (for example, a signal of 1 Hz) based on the oscillating signal.

The control circuit 104 counts time based on the reference signal output from the frequency dividing circuit 103 , and instructs the watch drive circuit 106 to output a watch drive signal conforming to the watch specification.

For example, when the timepiece 1 has hour, minute, and second hands and performs stepping operation every second, the control circuit 104 instructs the timepiece drive circuit 106 to output a timepiece drive signal every second.

On the other hand, when the timepiece 1 is a two-hand timepiece with an hour hand and a minute hand, and the minute hand is advanced by 2 degrees at intervals of 20 seconds, the control circuit 104 instructs the timepiece drive circuit 106 to output a timepiece every 20 seconds. drive signal.

In addition, the control circuit 104 is connected to a detection circuit (detection unit) 107 , and controls the operation of the watch drive 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 (the rotor ring 30 and the rotor pinion 32 ) reaches a predetermined amount, and outputs a detection signal to the control circuit 104 . Therefore, the detection circuit 107 can use various sensors capable of detecting the rotation amount (rotation angle) of the rotor, such as optical detection sensors using LEDs or the like, mechanical contacts using springs or the like, magnetic sensors, and the like.

Furthermore, the detection circuit 107 is not limited to a circuit that directly detects the movement amount of the rotor, and may indirectly detect the movement amount of the rotor ring 30 by detecting the movement amount (rotation angle) of the first rotor transmission gear 40 that directly operates relative to the rotor. circuit. That is, it is possible to detect the amount of movement of a member that is provided in front of the rotor to the coil spring 50 and that rotates together with the rotor.

In addition, in this embodiment, as mentioned above, the optical detection circuit (detection means) 107 which detects the rotation amount of the 1st rotor transmission gear 40 is provided.

Moreover, when the detection signal is output from the detection circuit 107, that is, when it is detected that the rotor has moved by a predetermined amount, the control circuit 104 controls the clock drive circuit 106 to stop outputting the drive signal, that is, stops the piezoelectric drive device 10. control.

For example, the control circuit 104 instructs the clock drive circuit 106 to output a drive signal every second when the second hand is moved in steps at intervals of one second. In this case, the detection circuit 107 is set to: detect the predetermined angle corresponding to the rotation of the rotor and the rotation of the second hand for 1 second, that is, 6 degrees. When the detection circuit 107 detects that the rotor has rotated the predetermined angle, the control circuit 104 The watch drive circuit 106 stops the output of the drive signal. Therefore, the piezoelectric drive device 10 is driven at intervals of one second to move the second hand by one second.

Also, when moving the minute hand forward by 2 degrees at 20-second intervals like a two-hand watch, the control circuit 104 instructs the watch drive circuit 106 to output a drive signal every 20 seconds. In this case, the detection circuit 107 is set to: detect the predetermined angle corresponding to the rotation of the rotor and the rotation of the minute hand for 20 seconds, that is, 2 degrees. When the detection circuit 107 detects that the rotor has rotated the predetermined angle, the control circuit 104 The output of the drive signal to the watch drive circuit 106 is stopped.

Furthermore, an operation detection unit 109 that detects operations of the time correction mechanism 108 such as a crown and buttons is connected to the control circuit 104 . When the operation detection unit 109 detects a predetermined operation of the time correction mechanism 108 , it detects the operation and sends a predetermined signal to the control circuit 104 . The control circuit 104 instructs the watch drive circuit 106 to output the drive signal, that is, to start driving the piezoelectric drive device 10 , or to stop the output of the drive signal, that is, to stop the drive of the piezoelectric drive device 10 . For example, if the pointer 2 is a second hand and rotates 6 degrees per second, and the reduction ratio of the movement mechanism 110 is 1/2, then the detection circuit 107 is set to: A detection signal is output when rotating 12 degrees.

(Operation at startup of piezoelectric actuator)

Next, the operation at the time of startup of the piezoelectric drive device 10 will be described.

First, when the drive voltage is applied to the vibrator 20 while the piezoelectric driver 4 is stopped, the rotation energy is transmitted from the rotor ring 30 to the first rotor transmission gear 40 through the rotor pinion 32, and these rotating bodies (rotor ring 30, rotor pinion The gear 32 and the first rotor transmission gear 40) start to rotate, and the coil spring 50 starts to elastically deform, and the transmitted rotational energy is accumulated as elastic energy of the coil spring 50 . Then, by virtue of the elastic energy of the coil spring 50, the second rotor transmission gear 60, the pointer wheel 3 and the pointer 2 start to rotate at the moment when the rotational energy applied to the second rotor transmission gear 60 reaches a predetermined magnitude. This so-called predetermined magnitude of rotational energy is rotational energy of the same magnitude as the total load of the moment of inertia of each rotating body (second rotor transmission gear 60, pointer wheel 3, and pointer 2) and the bearing loads of these respective rotating bodies.

Therefore, when the piezoelectric actuator 4 is driven for one cycle, as described above, the first rotor transmission gear 40 also rotates clockwise in FIG. 7 for one cycle, and at the same time, the coil spring 50 is also wound up. Thus, although the second rotor transmission gear 60 is driven to rotate clockwise by the release force of the coil spring 50, since the positioning pin 61 abuts and is pressed against the inner surface of the positioning hole 42 in the clockwise direction (FIG. 6, FIG. 7, the inner surface contacted by the positioning pin 61), so the second rotor transmission gear 60 and the pointer 2 are also positioned in the direction of rotation.

Thus, the piezoelectric drive device 10 is activated, and the pointer 2 rotates.

(Effects produced by this embodiment)

According to the present embodiment, the following effects can be obtained.

(1) With the coil spring 50, when the piezoelectric actuator 4 is started, after the driving force of the piezoelectric actuator 4 is accumulated as the elastic energy of the coil spring 50, the second rotor transmission gear 60 starts to rotate, so the piezoelectric actuator 4. When driving, the moments of inertia of the second rotor transmission gear 60, the pointer wheel 3 and the pointer 2 do not act on the piezoelectric driver 4, and the load applied to the piezoelectric driver 4 during startup is reduced, thereby reducing consumption. starting power.

Especially in an analog timepiece, the rod-shaped pointer 2 has a large moment of inertia, and the shape of the pointer varies depending on the design (model) of the timepiece. Therefore, the moment of inertia generated by the pointer 2 is different for each model of the timepiece, and the power consumption also varies in the conventional method. In the case of the clock driven by a battery, battery life varies by model.

On the other hand, in this embodiment, by providing the above-mentioned coil spring 50, the moment of inertia of the pointer 2 does not act on the piezoelectric actuator 4, so the influence of the variation of the moment of inertia of the pointer 2 can be eliminated, and the driving can be performed with low power. , and can prevent changes in battery life due to models.

From the above, it is also possible to use a disc-shaped pointer having a larger moment of inertia than the pointer 2, and it is possible to increase the degree of freedom in designing the timepiece.

(2) By having the coil spring 50, the load applied to the piezoelectric driver 4 at the time of starting is reduced, so that the driving speed of the piezoelectric driver 4 can be raised to a desired speed in a short time, and the starting time is shortened, so it is possible to Further reduce power consumption.

Here, the reason why the power consumption can be reduced by reducing the load applied to the piezoelectric driver 4 will be described with reference to FIGS. 9 and 10 .

Figures 9 and 10 show the results of driving a device with a predetermined amount of inertial load applied to the rotor (hereinafter referred to as 1 times the inertial load) and a device driving 10 times the inertial load (referred to as 10 times the inertial load). In this case, the relationship between the elapsed driving time and the rotational speed of the rotor, and the relationship between the elapsed driving time and the rotational angle of the rotor.

Here, the rotation speed gradually increases when a drive signal is supplied to the piezoelectric driver 4, and becomes a constant speed after a while. On the other hand, regarding the rotation angle, the rotation angle increases rapidly in the initial speed increase range, and when the rotation speed becomes constant, the rotation angle increases in proportion to time.

As shown in FIG. 9 and FIG. 10 , when the inertial load is low, the increase in the rotational speed is faster than when the inertial load is high, and the time for moving by a predetermined rotational angle can also be shortened. For example, in the examples of FIGS. 9 and 10 , assuming that the time until the rotation of 10 degrees is compared, when the inertial load shown in FIG. 9 is doubled, it takes about 0.0017 seconds. On the other hand, when the inertial load is 10 times as shown in FIG. 10 , it takes about 0.003 seconds, that is, about twice as long as when the inertial load is 1 time.

Therefore, when the rotor rotates by a fixed angle, the smaller the inertial load applied to the rotor, that is, the piezoelectric actuator, the driving time can be shortened, and the power consumption can be reduced accordingly.

(3) Due to the coil spring 50, when an impact from the outside acts on the pointer 2, such as when falling, the interference function of the coil spring 50 can quickly weaken the impact of the impact, and due to the impact force from the outside During the action, the driving force of the piezoelectric actuator 4 is accumulated in the coil spring 50, so that the rotation of the pointer 2 can be driven by the elastic energy of the coil spring 50 at the moment when the influence of the impact disappears. Therefore, the impact of the impact is not transmitted from the pointer 2 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 deformation) of the coil spring 50 is maintained, the force generated by the initial deflection always acts on the second rotor transmission gear 60, thereby suppressing Oscillation of pointer 2 caused by external shock.

(5) Even if the moment of inertia of the rotating system from the second rotor transmission gear 60 to the pointer 2 side is large, when the piezoelectric actuator 4 is driven intermittently, due to the play part of the positioning pin 61 and the positioning hole 42 The range of is set to the range corresponding to the driving amount of one cycle of the piezoelectric driver 4, so the load applied to the piezoelectric driver 4 due to the interference of the first rotor transmission gear 40 and the second rotor transmission gear 60 can be avoided. increase.

(6) Since the coil spring 50 is provided, even if the number of turns of the coil spring 50 is increased in order to secure a large amount of displacement, the coil spring 50 can be arranged with almost no expansion of the installation space compared with the case of using a U-shaped spring or a cantilever spring. .

Furthermore, since the coil spring 50 is provided, a large displacement amount can be ensured, and substantially constant elastic energy can be generated regardless of the displacement amount of the coil spring 50 . Therefore, since the second rotor transmission gear 60 receives substantially constant elastic energy from the coil spring 50 regardless of the magnitude of the external impact, the operation of the second rotor transmission gear 60 can be stabilized.

(7) Since the piezoelectric element 22 is formed in the shape of a rectangular plate, the thickness reduction of the piezoelectric drive device 10 can be promoted.

(8) Since the detection circuit 107 is provided to detect the movement amount of the first rotor transmission gear 40 , that is, the rotor, the movement amount of the pointer 2 can also be set accurately. That is, since the vibrator 20 and the rotor of the piezoelectric actuator 4 transmit torque through friction, it is difficult to accurately set the rotation amount of the rotor using the driving time of the piezoelectric actuator 4 . Therefore, in this embodiment, the detection circuit 107 actually detects the movement amount of the rotor or the first rotor transmission gear 40 directly driven with the rotor, and the detection circuit 107 stops the drive when the rotor moves a predetermined amount. The rotor, that is, the pointer 2, can be moved correctly.

(second embodiment)

Next, a piezoelectric drive device 10A in a timepiece according to a second embodiment of the present invention will be described with reference to FIGS. 11 to 14 .

FIG. 11 is a plan view showing a piezoelectric drive device 10A of a timepiece. 12 to 14 are vertical cross-sectional views showing the piezoelectric drive device 10A. Furthermore, FIG. 12 is a cross-sectional view of the transmission path connecting the rotor (rotor ring 30, rotor pinion 32, rotor gear 33), intermediate wheel 6, and rotor drive wheel 5A in FIG. 11. In addition, FIG. 13 is a cross-sectional view of the transmission path connecting the rotor, the pallet fork 8 , and the rotor drive wheel 5A in FIG. 11 . FIG. 14 is a cross-sectional view of the piezoelectric actuator 4A composed of the vibrator 20A and the rotor in FIG. 11 .

The piezoelectric drive device 10A differs from the piezoelectric drive device 10 of the above-mentioned first embodiment in the following points of structure: the piezoelectric drive device 10A has an escape wheel 60A corresponding to the second rotor transmission gear, and is driven by the piezoelectric driver 4A. The pallet fork 8 is used to limit the rotation of the escape wheel 60A at a predetermined rotation angle each time, and the other structures are substantially the same.

For example, the structure and operation of the piezoelectric actuator 4 in the first embodiment, the structure and operation of the pressing spring 36, the structure and operation of the coil spring 50, the basic structure and basic The operation, the circuit configuration and operation ( FIG. 8 ) of the timepiece are also the same in the second embodiment. In addition, regarding the rotation amount detection means and operation of the rotor transmission gear 40A in the second embodiment, the optical detection means for detecting the rotation amount of the first rotor transmission gear 40 in the first embodiment is used, and the same operation is performed.

The piezoelectric driving device 10A has: a piezoelectric driver 4A; an intermediate wheel 6 driven by the piezoelectric driver 4A; a rotor transmission wheel 5A that transmits the rotational drive of the intermediate wheel 6 to the pointer wheel 3 shown in FIG. 6 ; A cam gear 7 as a cam member driven by the driver 4A; and a pallet fork 8 oscillated by the cam gear 7 .

The piezoelectric actuator 4A is configured to include a vibrator 20A and a rotor ring 30 . On the rotor rotating shaft 31A of the rotor ring 30 , a rotor pinion 32 that transmits the rotational drive to the intermediate wheel 6 and a rotor gear 33 that transmits the rotational drive to the cam gear 7 are fixed. In addition, in this embodiment, the rotor is constituted by the rotor ring 30 , the rotor pinion 32 , and the rotor gear 33 . Therefore, although the piezoelectric actuator 4A differs from the piezoelectric actuator 4 of the first embodiment in that the rotor gear 33 is added, the structures, materials, and operations of the vibrator 20A, the rotor ring 30 , and the rotor pinion 32 are the same as those described above. The first embodiment is the same.

The rotor transmission wheel 5A is composed of: a rotor transmission gear 40A meshing with the intermediate wheel 6; a coil spring 50 whose one end is locked in the spring locking hole 41 of the rotor transmission gear 40A; the trailing wheel 60A; and the transmission wheel rotation shaft 70 . In this way, the second transmission path that transmits the driving force of the rotor ring 30 to the coil spring 50 is constituted.

In the rotor transmission gear 40A, a spring locking hole 41 and a positioning hole 42 penetrating in the rotation axis direction are formed similarly to the first embodiment described above.

The escape wheel 60A has fifteen escape teeth 62 , and the escape wheel 60A is supported at a position facing the pallet fork 8 . An escape pinion 67 ( FIG. 12 ) is fixed to the rotary wheel rotation shaft 70 together with the escape wheel 60A. The escape pinion 67 rotates integrally with the escape wheel 60A, and meshes with an unillustrated pointer wheel and the like. In addition, the rotor transmission gear 40A is rotatably supported on the transmission wheel rotation shaft 70 . Furthermore, since the other end of the coil spring 50 is fixed to the transmission wheel rotating shaft 70 , the escape wheel 60A is connected to the other end of the coil spring 50 .

In addition, a positioning pin 61 is fixed to the escape wheel 60A similarly to the second rotor transmission gear 60 of the first embodiment. The positioning pin 61 protrudes toward the rotor transmission gear 40A side and passes through the positioning hole 42 .

When assembling the rotor driving wheel 5A, and when assembling the rotor driving wheel 5A together with various components on the bottom plate or the like as shown in FIG. The initial deflection of the coil spring 50 is maintained.

The cam gear 7 includes a cam pinion 71 meshing with the rotor gear 33 , a circular cam 72 whose outer peripheral central axis is eccentric to the rotation axis, and a cam rotation shaft 73 fixing the cam pinion 71 and the cam 72 .

The pallet 8 includes a pallet main body 81 , two claws 82 and 83 , a notch 84 that engages with the cam 72 , and a pallet rotating shaft 85 .

The pallet fork main body 81 has a first arm 811 and a second arm 812 which are integrally formed on both sides with the pallet rotating shaft 85 interposed therebetween and supported so as to be able to The pallet fork rotating shaft 85 is a center swing. The first arm portion 811 extends from the pallet rotating shaft 85 to the side opposite to the rotor gear 33 side, and is fixed with a claw 82 protruding toward the escape wheel 60A side. The second arm portion 812 extends from the pallet rotating shaft 85 toward the rotor gear 33 , and is fixed with a claw 83 protruding toward the escape wheel 60A.

The width dimension of the second arm portion 812 expands as it approaches the rotor ring 30 from the pallet rotation shaft 85 . A notch portion 84 is formed in this expanded region, and the second arm portion 812 is formed in a substantially U-shape as a whole. The cam gear 7 is arranged such that the inner surface of the notch portion 84 abuts against the side surface of the cam 72 .

In such a structure, when the rotor gear 33 rotates, the cam gear 7 rotates, and the pallet fork 8 swings through the eccentric cam 72 . Here, when the cam gear 7 rotates once, the pallet fork 8 only swings back and forth once, and the two claws 82 and 83 of the pallet fork 8 abut against the escape wheel 60A alternately. In this way, a first transmission path for transmitting the driving force of the rotor ring 30 to the pallet fork 8 is formed.

In such a structure, when the escape wheel 60A rotates, the two pawls 82, 83 are alternately inserted between the escape teeth 62, thereby limiting the rotation angle of the escape wheel 60A at a constant angle. That is, when the pallet fork 8 swings in the first direction (counterclockwise in FIG. 11 ), a pawl 83 of the pallet fork 8 is inserted between the pallet teeth 62 and rotates with the pallet driven in the clockwise direction. When the escape tooth 62 of the escape wheel 60A contacts, the rotation of the escape wheel 60A is restricted.

Furthermore, when the pallet fork 8 swings to the second direction (clockwise in FIG. 11 ), a pawl 83 of the pallet fork 8 leaves between the escape teeth 62, and the restriction of the escape wheel 60A is released. . At the same time, the other claw 82 is inserted between the escape teeth 62, and the escape wheel 60A rotates at an angle equivalent to half the pitch of the escape teeth 62, and the other claw 82 of the pallet fork 8 and the escape wheel 60A The escapement tooth 62 abuts. In this way, the rotation of the escape wheel 60A is again restricted.

Therefore, in the present embodiment, the escape wheel 60A constitutes the body to be rotated, and the pallet fork 8 constitutes the rotation limiting device.

Furthermore, the vibrator 20 of the piezoelectric driver 4 is fixed on the bottom plate as the base frame of the timepiece 1 through the arm portion 211, and the rotor rotating shaft 31A, the rotating shaft of the intermediate wheel 6, the transmission wheel rotating shaft 70, and the cam of the cam gear 7 rotate. One end of the shaft 73, the pallet rotating shaft 85, and the rotating shaft of the pointer wheel 3 are pivotally supported by the shaft support hole of the bottom plate, and the other ends thereof are pivotally supported and held by the wheel train shaft support arranged opposite to the bottom plate. Furthermore, one end of the rotation shaft of the pointer wheel 3 and each rotation shaft of the other pointer wheels is pivotally supported on the base plate, but the other end may also be pivotally supported on a supporting member other than the wheel train.

In addition, the escape wheel 60A, the pallet fork 8 , and the respective gears rotated by the escape wheel 60A are preferably made of a non-magnetic material. However, these materials are not limited to non-magnetic materials.

In addition, this embodiment also has the same circuit configuration as that of the first embodiment ( FIG. 8 ), and also includes optical position detection means and a detection circuit 107 for detecting the rotational position of the rotor. When the rotor is driven to a predetermined position, the position detection unit outputs a predetermined position detection signal to the control circuit 104 . The control circuit 104 controls the watch drive circuit 106 to stop the output of the drive signal, that is, controls to stop the piezoelectric drive device 10 , when the detection signal is received.

Furthermore, the above-mentioned detection circuit 107 can directly detect the movement amount of the parts constituting the rotor such as the rotor ring 30 or the rotor gear 33, or it can detect the displacement of the intermediate wheel 6 or the rotor transmission gear 40A etc. on the torque transmission path compared to the coil spring. 50 is disposed closer to the rotor side and is driven synchronously with the rotor to indirectly detect the movement amount of the rotor.

Furthermore, by providing the pallet fork 8 and the escape wheel 60A, the movement of the escape wheel 60A, that is, the pointer 2 can be controlled with high precision. Therefore, the detection circuit for controlling the drive stop of the piezoelectric driver 4A is set to be able to drive the piezoelectric driver 4A so that one claw 82, 83 of the slave pallet 8 is engaged with the escape tooth 62 of the escape wheel 60A. The state is reliably changed to a state where the other claw 82 , 83 is engaged with the escape tooth 62 .

For example, in the present embodiment, it is set so that the engagement between the claws 82 and 83 of the pallet fork 8 and the escape tooth 62 is switched when the rotor ring 30 rotates 30 degrees. In this case, the detection circuit only needs to detect that the rotor ring 30 has indeed rotated by 30 degrees.

For example, considering the detection error of the detection circuit, the detection circuit may be configured to detect the rotation of the rotor ring 30 by 31 degrees, and may be set to detect the rotation of the rotor by at least 30 degrees or more. In this case, although the rotation angle of the cam gear 7 becomes slightly larger, as shown in FIG. , so the pallet fork 8 hardly moves, and the engaged state between the claws 82 and 83 of the pallet fork 8 and the escapement teeth 62 can be maintained. In addition, when the rotor slightly overruns, the rotor transmission gear 40A rotates with respect to the escape wheel 60A stopped by engaging with the claws 82 and 83 of the pallet fork 8 , but the amount of rotation is controlled by the coil spring 50 . It is absorbed by the winding, and the change of the elastic energy of the coil spring 50 caused by this is also very small, so the operation of the pointer 2 will not be affected.

Next, the operation of the piezoelectric drive device 10A will be described.

The rotor ring 30 , that is, the rotor, is rotated clockwise (in the direction of arrow A shown in FIG. 11 ) by the vibrator 20A. The rotation of the rotor ring 30 is transmitted to the intermediate wheel 6 and the cam gear 7, respectively. The rotation of the intermediate wheel 6 is transmitted to the rotor transmission gear 40A. The rotation of the rotor transmission gear 40A is transmitted to the escape wheel 60A by the elastic energy of the coil spring 50 .

Here, the gear train from the rotor ring 30 to the rotor transmission gear 40A is set so that when the rotor ring 30 rotates 30 degrees, the rotor transmission gear 40A rotates at a reduced speed of 12 degrees. In addition, the increased rotation of the rotor ring 30 is transmitted to the cam gear 7, and it is set such that the cam gear 7 rotates 180 degrees when the rotor ring 30 rotates 30 degrees.

While the escape wheel 60A is in a stopped state while the pallet fork 8 is restricting the rotation of the escape wheel 60A, the coil spring 50 elastically deforms to store the rotational energy of the rotor ring 30 as elastic energy. Then, the cam gear 7 rotates, and due to the eccentricity of the cam 72, the pallet fork 8 swings, and when one claw of the pallet fork 8 engaged with the escape wheel 60A disengages from the escape tooth 62 of the escape wheel 60A, the escapement The wheel 60A is rotated by the elastic energy of the coil spring 50 . At this time, the front end portion of the other claw of the pallet fork 8 is inserted between the escape teeth 62 . When the other claw of the pallet fork 8 is further inserted into the interior between the escape teeth 62 and the escape tooth 62 abuts against the claw, the rotation of the escape wheel 60A is restricted again. In addition, the escape wheel 60A rotates by 1 tooth pitch (24 degrees) by one reciprocating swing of the pallet fork 8 . That is, when the rotor ring 30 rotates 30 degrees, the cam gear 7 rotates 180 degrees, thereby the pallet fork 8 moves in one direction, and the escape wheel 60A rotates 12 degrees. At this time, the rotor transmission gear 40A rotates 12 degrees, so the coil spring 50 returns to the original state. Therefore, the escape wheel 60A is driven intermittently by the oscillation of the pallet fork 8 .

That is, in FIG. 11 , the state in which one pawl 83 of the pallet fork is engaged with the escapement tooth 62 of the escapement wheel 60A is defined as the start (the illustrated state in FIG. 11 ), and the following cycle is called escapement: One reciprocation of the vertical fork: the cam 72 starts to rotate, one claw 83 moves away from the escapement tooth 62, the other claw 82 of the pallet fork engages with the other escapement teeth 62, and the other claw 82 moves away from the other escapement teeth 62 , a pawl 83 again engages with the escape tooth 62 of the escape wheel 60A until the rotation of the cam 72 stops. Thus, one reciprocation of the pallet becomes one swinging reciprocation of the pallet.

The initial deflection of the coil spring 50 is maintained by contacting the positioning pin 61 and the positioning hole 42 in the initial assembled state of the rotor drive wheel 5A, so the gap between the positioning pin 61 and the positioning hole 42 is zero.

As shown in FIG. 11 , the positioning hole 42 and the positioning pin 61 are set so that a gap having a dimension L is formed in a state where the escapement tooth 62 is in contact with the claw 83 or 82 of the pallet fork. This gap is set to a value of the following degree: in the state where the escape tooth 62 is in contact with the claw 83 or 82 of the pallet fork, the size of the gap will not be larger even if there are fluctuations in related parts and assembly positions. 0. By providing the above-mentioned gap having a size L, the escape tooth 62 and the pallet forks 82 and 83 are reliably engaged.

Furthermore, by forming a clearance of size L, the pallet fork 8 is correctly positioned at a predetermined position by the escape wheel 60A. That is, when the escapement tooth 62 abuts against the claw 83 of the pallet fork 8 , the escapement tooth 62 presses the claw 83 of the pallet fork 8 by means of the spring force of the coil spring 50 , so that the pallet 8 is held in place. Rotate counterclockwise in Figure 11. Accordingly, the pallet 8 is positioned at the position where the pallet tooth 62 abuts against the claw 83 of the pallet 8 .

In addition, when the escapement tooth 62 abuts against the claw 82 of the pallet fork 8 , the escapement tooth 62 presses the claw 82 of the pallet fork 8 by means of the spring force of the coil spring 50 , thus causing the pallet 8 to be in the Rotate clockwise in Figure 11. Therefore, the pallet 8 is positioned at the position where the pallet tooth 62 abuts against the claw 82 of the pallet 8 .

Furthermore, the elasticity of the coil spring 50 exerts a force on the escape wheel 60A in the direction of clockwise rotation, so in the state where the pawls 82, 83 of the pallet fork 8 are in contact with the escapement teeth 62, the distance between them Friction increases.

In addition, even if the pallet 8 itself swings due to an external impact, since the pallet 8 and the cam gear 7 are connected by a cam mechanism, rotational energy is not transmitted from the pallet 8 to the cam gear 7 . Therefore, even if a force in a direction to swing the pallet fork 8 acts due to the impact, it will not be transmitted as a force for rotating the cam 72, so that the pallet fork 8 will not swing to release the restriction of the escape wheel 60A. situation, the position of the pointer, etc. can be maintained.

According to such this embodiment, in addition to the effect substantially the same as the effect of said (1)-(8), the following effect can be acquired.

(9) Rotational energy is applied to the escape wheel 60A by the drive of the piezoelectric driver 4A, and the rotation of the escape wheel 60A is limited by a constant angle by the pallet fork 8, so even with respect to the drive of the piezoelectric driver 4A The amount of rotation of the escape wheel 60A is not determined solely. Since the pallet fork 8 limits the rotation angle of the escape wheel 60A to a constant angle if the escape wheel 60A rotates at a constant angle, the rotation amount of the escape wheel 60A is also correctly constant. Therefore, the escape wheel 60A rotated by the piezoelectric actuator 4A can be prevented from overrunning, so it is not necessary to strictly control the rotation angle of the rotor ring 30, the precision of the rotation angle of the escape wheel 60A can be improved, and the escape wheel can be improved. Wheel 60A rotates the pointer 2 etc. to display the accuracy of the display unit.

(10) Furthermore, by providing the pallet fork 8 and the escape wheel 60A, the movement of the escape wheel 60A, that is, the pointer 2 can be controlled with high precision. Therefore, in the detection circuit, even if the detection error is considered and the rotor is set to rotate slightly larger than the predetermined target value for detection, the overrun amount can be determined by the cam gear 7, the pallet fork 8, and the pallet. The vertical tooth 62, the coil spring 50, etc. are absorbed, and the escape wheel 60A or the pointer 2 can be driven correctly.

(11) Furthermore, since the claws 82 and 83 of the pallet fork 8 mesh with the escape wheel 60A, it is possible to restrict the rotation of the wheel train during the time correction operation by a time correction mechanism such as a crown. Therefore, it is possible to realize the function of the regulating lever that regulates the rotation of the wheel train when the time is corrected in a general quartz timepiece, and the regulating lever can be eliminated in the present embodiment.

(12) Since the drive source of the escape wheel 60A and the drive source of the pallet fork 8 can be shared, the number of components can be reduced and the timepiece can be miniaturized.

(13) Since the reciprocating action of the pallet fork 8 is implemented by the cam 72, it is not necessary to configure the piezoelectric actuator 4A as the drive source of the pallet fork 8 to be rotatable in two directions, and it can be formed to be rotatable in one direction. structure. In particular, since the vibrator 20A in the shape of a rectangular plate is used, the contact position with the rotor ring 30 can be freely selected in the single-rotation type, so that the transmission efficiency of the driving force can be improved, and the reduction in power and the increase in torque can be promoted.

(third embodiment)

Next, a piezoelectric drive device 10B in a timepiece according to a third embodiment of the present invention will be described with reference to FIGS. 15 to 18 .

FIG. 15 is a plan view showing a piezoelectric drive device 10B in a timepiece. 16 and 17 are vertical cross-sectional views showing the piezoelectric drive device 10B. FIG. 18 is a plan view for explaining the driving of the piezoelectric driving device 10B.

The piezoelectric drive device 10B is different in structure from the piezoelectric drive device 10A of the above-mentioned second embodiment in that a driven wheel 60B is used as a to-be-rotated body instead of the escape wheel 60A, and a drive wheel is used as a rotation limiting device. 9 instead of pallet fork 8, other structures are roughly the same.

The piezoelectric drive device 10B is configured to include: an intermediate wheel 6A that rotates while meshing with the rotor ring 30A; a driving wheel 9 that is rotated by the intermediate wheel 6A; and a rotor transmission wheel 5B.

The rotor ring 30A is fixed to the rotor rotating shaft 31A together with the rotor gear 33 , and the rotor of the present invention is constituted by the rotor ring 30A and the rotor gear 33 .

The drive wheel 9 is configured to include: a drive pinion 91 meshing with the intermediate wheel 6A; a drive cam 92 ; and a drive rotation shaft 93 to which these drive pinion 91 and drive cam 92 are fixed.

The driving cam 92 has two cam pieces 921 formed in a substantially fan-shaped radial direction around the driving rotation shaft 93 . The two cam pieces 921 are formed at intervals of 180 degrees around the main rotation shaft 93 , and are point-symmetrical to each other with respect to the central axis of the main rotation shaft 93 . In addition, recessed portions 922 are formed at positions shifted by 90 degrees in both directions from the respective cam pieces 921 , and these two recessed portions 922 are opposed to each other centering on the main rotation axis 93 .

The rotor transmission wheel 5B is configured to have: a rotor transmission gear 40A, a coil spring 50, a driven wheel 60B, and a transmission wheel rotation shaft 70, as shown in FIG. The sequential arrangement of the coil spring 50 and the driven wheel 60B.

The rotor transmission gear 40A meshes with the rotor gear 33 , and the rotor transmission gear 40A is rotatably supported by the transmission wheel rotating shaft 70 . A positioning plate 43 is fixed to the rotor transmission gear 40A. The positioning plate 43 is a substantially circular plate-shaped member as a whole, and has a string-shaped side portion 431 on a part of its side surface. At the center of the string-shaped side portion 431, a positioning locking piece 432 protruding radially is formed. The locking piece 432 for positioning is bent toward the driven wheel 60B side at the middle portion, and its front end is extended toward the driven wheel 60B.

The driven wheel 60B is fixed on the transmission wheel rotating shaft 70 . In the driven wheel 60B, a positioning hole 63 penetrating in the rotation axis direction and a spring locking hole 64 are formed. The positioning hole 63 is a long hole formed along the outer periphery of the driven wheel 60B, and the front end of the positioning locking piece 432 is inserted into the positioning hole 63 . On the outer periphery of the driven wheel 60B, nine driven teeth 65 protruding in the radial direction are formed at intervals of 40 degrees, and the front ends of the driven teeth 65 are processed into a semicircular arc shape.

The end of the coil spring 50 on the outer peripheral side is locked in the spring locking hole 64 , and the end of the coil spring 50 on the central axis side is wound and fixed to the cylindrical portion 44 of the rotor transmission gear 40A.

The driving wheel 9 and the rotor driving wheel 5B are arranged at the positions where the driven teeth 65 and the cam pieces 921 mesh. Therefore, in the present embodiment, the release restricting portion is constituted by the positioning plate 43 and the positioning hole 63 . In this way, the rotor ring 30A transmits the rotation to the intermediate wheel 6A and the rotor transmission gear 40A. Therefore, the rotation limiting means is constituted by the driving pulley 9, and the Oldham wheel mechanism is constituted by the driving pulley 9 and the driven pulley 60B.

In addition, also in this embodiment, like the first and second embodiments, a detection circuit for detecting the rotation of the rotor is provided. In this embodiment, the detection circuit may directly detect the movement amount of components constituting the rotor such as the rotor ring 30A or the rotor gear 33, or may be arranged on the rotor side of the coil spring 50 by detecting the rotor transmission gear 40A and the like and synchronized with the rotor. The amount of movement of the driven parts is used to indirectly detect the amount of movement of the rotor.

Furthermore, since the Oldham wheel mechanism composed of the driving wheel 9 and the driven wheel 60B is provided, it is possible to control the driven wheel 60B with high precision, as in the second embodiment with the pallet fork 8 and the escape wheel 60A. Movement of pointer 2. Furthermore, the detection circuit is also set to reliably detect that the rotor ring 30A has moved by at least a predetermined angle in consideration of detection errors. At this time, even if the rotor runs overrun, the displacement of the overrun part can be absorbed by the engaging part of the driving wheel 9 and the driven wheel 60B or the coil spring 50 , and the movement of the pointer 2 will not be affected.

Next, the operation of the piezoelectric drive device 10B will be described.

The rotor ring 30A is rotated counterclockwise (direction of arrow A) by the vibrator 20A. The rotation of the rotor ring 30A is transmitted to the intermediate wheel 6A and the rotor transmission gear 40A via the rotor gear 33 . The rotor of the intermediate wheel 6A is transferred to the driving wheel 9 . The rotation of the rotor transmission gear 40A is transmitted to the driven wheel 60B by the elastic energy of the coil spring 50 .

Here, the gear train from the rotor ring 30A to the rotor transmission gear 40A is set such that when the rotor ring 30A rotates 20 degrees, the rotor transmission gear 40A rotates at a speed up to 40 degrees, that is, doubles. In addition, the increase in rotation of the rotor ring 30A is transmitted to the driving wheel 9, and it is set such that the driving wheel 9 rotates 180 degrees when the rotor ring 30A rotates 20 degrees. The driven wheel 60B is intermittently driven by the driving cam 92 of the driving wheel 9 . Therefore, while the driven cam 92 restricts the rotation of the driven wheel 60B, the coil spring 50 is elastically deformed while the driven wheel 60B is stopped, and the rotational energy of the rotor ring 30A is stored as elastic energy.

Then, the driving wheel 9 rotates, and the cam piece 921 that restricts the rotation of the driven wheel 60B is fed counterclockwise. When the concave portion 922 is fed to a position opposite to the driven wheel 60B, the restriction of the driven wheel 60B is released during this period, and the driven wheel 6OB starts to rotate by virtue of the elastic energy of coil spring 50 (FIG. 18). Next, the driving wheel 9 rotates, and when the cam piece 921 on the opposite side advances to a position opposite to the driven wheel 60B, the cam piece 921 on the opposite side meshes with the next driven tooth 65, limiting the rotation of the driven wheel 60B again. .

Furthermore, when the driving wheel 9 rotates 180 degrees, the driven wheel 60B rotates one tooth pitch (40 degrees). That is, when the rotor ring 30A rotates 20 degrees, the driving wheel 9 rotates 180 degrees, thereby the driven wheel 60B rotates 40 degrees, at this time, the rotor transmission gear 40A rotates 40 degrees through the rotor ring 30A, so the coil spring 50 returns to initial state.

According to such this embodiment, substantially the same effects as the effects of (1) to (13) above can be achieved.

(14) In particular, rotational energy is applied to the driven wheel 60B by the driving of the piezoelectric driver 4A, and the rotation of the driven wheel 60B is limited by the driving wheel 9 at a constant angle each time, so even with respect to the driving of the piezoelectric driver 4A The amount of rotation of the driven wheel 60B does not determine the rotation amount of the driven wheel 60B. Since the driving wheel 9 limits the rotation angle of the driven wheel 60B to a constant angle when the driven wheel 60B rotates at a constant angle, the rotation amount of the driven wheel 60B is accurately constant. Therefore, the overrunning of the driven wheel 60B rotated by the piezoelectric actuator 4A can be prevented, so it is not necessary to strictly control the rotation angle of the rotor ring 30A, the precision of the rotation angle of the driven wheel 60B can be improved, and the rotation angle of the driven wheel 60B can be improved. Rotating pointer 2 etc. display unit display accuracy.

(fourth embodiment)

Next, a piezoelectric drive device 10C in a timepiece according to a fourth embodiment of the present invention will be described with reference to FIGS. 19 to 21 .

FIG. 19 is a plan view showing a piezoelectric drive device 10C in a timepiece. 20 and 21 are vertical cross-sectional views showing the piezoelectric drive device 10C. In the piezoelectric drive device 10B of the third embodiment described above, the coil spring 50 is arranged between the rotor transmission gear 40A and the driven wheel 60B. On the other hand, the piezoelectric drive device 10C of the present embodiment has a structure in which the coil spring 50B differs in that it is disposed between the rotor gear 33A and the rotor transmission gear 34 , but the other configurations are substantially the same. In addition, in this embodiment, the structure of the detection circuit 107 is demonstrated concretely.

The rotor ring 30B is fixed to the rotor gear 33A, and the rotor ring 30B and the rotor gear 33A constitute the rotor of the present invention. The rotor gear 33A is made of synthetic resin, for example, and is fixed to the rotor rotating shaft 31B made of metal. These rotor ring 30B, rotor gear 33A, and rotor rotating shaft 31B rotate integrally.

The rotor gear 33A has a rotor gear main body portion 332 engaged with and fixed to the rotor ring 30B, and a rotor gear portion 333 extending in the radial direction from the end portion on the rotor transmission gear 34 side. A spring housing recess 334 for housing the coil spring 50B is formed on the rotor transmission gear 34 side of the rotor gear main body portion 332 .

As shown in FIG. 21 , the position detection hole 331 is formed in the rotor gear main body portion 332 and penetrates in the rotation axis direction. The position detection holes 331 are formed at intervals of 20 degrees along the outer circumference, and a part thereof is shown in FIG. 19 .

A positioning notch 335 and a spring locking notch 336 are formed at substantially opposing positions on the inner peripheral surface of the spring housing recess 334 . The end of the coil spring 50B on the outer peripheral side is engaged with the spring locking notch 336 , and the end of the coil spring 50B on the central axis side is wound and fixed to the cylindrical portion 341 of the rotor transmission gear 34 .

On the rotor transmission gear 34 , a positioning protrusion 342 protruding toward the rotor gear 33A side and inserted into the positioning notch 335 is formed. Therefore, in the present embodiment, the rotor transmission gear 34 constitutes the to-be-rotated body, and the positioning protrusion 342 and the positioning notch 335 constitute the release restriction portion.

The driving wheel 9 and the rotor driving wheel 5C are arranged at the positions where the driven teeth 65A mesh with the cam piece 921 .

A photo-interrupter 51 is arranged at a position sandwiching the position detection hole 331 . The photointerrupter 51 is a transmission type detector having a light emitter 511 and a light receiver 512 and detecting the position detection hole 331 . In addition, a reflective detector such as a photoreflector may be used instead of the photointerrupter 51, and the position of the rotor gear 33A may be detected by recognizing a detection pattern formed on the rotor gear 33A or the like.

According to such this embodiment, in addition to the effects substantially the same as the effects of (1) to (14) above, the following effects can be achieved.

(15) Since the rotation shaft of the rotor ring 30B and the rotation shaft of the rotor transmission gear 34 are formed on the same axis, the rotor rings are arranged between the rotor ring 30B and the coil spring 50B as in the above-mentioned first to third embodiments. The driving force of the ring spring 30B is transmitted to other rotating bodies of the coil spring 50B (the first rotor transmission gear 40, etc.) The load is reduced by an amount equivalent to the moment of inertia of other rotating bodies. Therefore, the piezoelectric actuator 4B can be driven at high speed with a reduced amount of moment of inertia, and the power input time when the piezoelectric actuator 4B is driven by a predetermined amount can be shortened, and power reduction can be promoted.

(fifth embodiment)

Next, a piezoelectric drive device 10D in a timepiece according to a fifth embodiment of the present invention will be described with reference to FIGS. 22 and 23 .

FIG. 22 is a plan view showing a piezoelectric drive device 10D in a timepiece. FIG. 23 is an exploded perspective view showing the structure of the rotor ring of the piezoelectric drive device 10D.

The piezoelectric driving device 10D is configured to swing the counter escapement pallet fork 8A by the driving force of the piezoelectric driver 4C, and the counter escapement pallet fork 8A and the counter escapement escapement wheel 60C to swing. The vertical tooth 62A abuts to rotate the reverse escapement escapement wheel 60C, and the piezoelectric drive device 10D is a drive device that is in a part of the transmission mechanism from the rotor ring 30C to the reverse escapement escapement wheel 60C , the transmission mechanism constituted by the coil spring 50 in the piezoelectric drive device 10 of the first embodiment described above is used.

As shown in FIG. 22 , the piezoelectric drive device 10D has a piezoelectric driver 4C, a reverse escapement pallet fork 8A as a swing unit, and a reverse escapement wheel 60C.

On both surfaces of the piezoelectric element 22A constituting the vibrator 20B of the piezoelectric actuator 4C, electrodes are formed by plating. In this embodiment, the cross-shaped drive electrodes 231 are formed by insulating the plating with grooves. The electrodes 232, 233 are driven. With these drive electrodes 231 to 233, the piezoelectric element has a structure divided into five parts. Then, when a voltage is applied to the drive electrodes 231 to 233 , by switching the applied drive electrodes 232 and 233 , the abutting portion 212A vibrates so as to draw an elliptical locus in the clockwise or counterclockwise direction.

The rotor ring 30C of the piezoelectric driver 4C is rotatably supported on the support arm 35A, and is biased by the contact portion 212A of the piezoelectric driver 4C. When the abutting portion 212A of the piezoelectric actuator 4C vibrates clockwise or counterclockwise to draw a substantially elliptical orbit, an appropriate frictional force is generated between the abutting portion 212A and the rotor ring 30C, and the driving of the piezoelectric actuator 4C The force is transmitted to the rotor gears 33B, 33C, and the rotor gears 33B, 33C rotate clockwise or counterclockwise.

The reverse escapement pallet 8A is configured to include a pallet main body 81A, two claws 82A, 83A, and a gear (pallet pinion) 86 .

The pallet main body portion 81A has a first arm portion 811A, a second arm portion 812A, and a pallet rotating shaft 85A, and they are integrally formed. The pallet main body 81A is supported on a base plate or the like so as to be able to swing about a pallet rotating shaft 85A.

The first arm 811A and the second arm 812A are extended on both sides with the pallet rotating shaft 85A in between. The first arm 811A has a claw 82A, and the second arm 812A has a claw 83A.

The pallet pinion 86 is fitted on the pallet rotating shaft 85A, and meshes with the rotor gears 33B, 33C. Thus, the driving force of the rotor gears 33B, 33C is transmitted to the reverse escapement pallet fork 8A.

Here, for example, by setting the number of teeth of the rotor gears 33B, 33C to 36 and the number of teeth of the pallet pinion 86 to 9, the rotational speed of the counter escapement pallet fork 8A is compared with that of the rotor gears 33B, 33C. The speed increase ratio is set to 4 times. That is, the pallet fork is configured to rotate 24 degrees when the rotor gears 33B and 33C rotate 6 degrees.

The two claws 82A and 83A are provided at two places across the pallet rotating shaft 85A of the pallet main body 81A. In addition, inclined surfaces 821 and 831 are formed at the front ends of the two claws 82A and 83A. The inclined surfaces 821, 831 are for making the reverse escapement move when the pallet fork 8A of the reverse escapement swings, and when the claws 82A, 83A abut against the escape teeth 62A of the escape wheel 60C of the reverse escapement described later. The escape wheel 60C is provided to generate a rotational driving force.

The reverse escapement escape wheel 60C is a gear having 30 escape teeth 62A, which is freely rotatably supported relative to the base plate. In addition, the reverse escapement escapement wheel 60C is provided at a position facing the two claws 82A, 83A of the reverse escapement pallet fork 8A, and the reverse escapement escapement wheel 60C is mounted with a The second hand shown.

The inclined surface 621 which contacts the inclined surfaces 821 and 831 of the two pawls 82A and 83A is formed at the tip of the escape tooth 62A. In addition, between each escape tooth 62A, there is formed a tooth groove 66 that locks the two claws 82A, 83A, so that when the reverse escapement escape wheel 60C rotates, the reverse escapement escape wheel The 60C is limited to a constant angle of rotation. In this embodiment, the rotation restricting part of this invention is comprised by two claws 82A and 83A. That is, the reverse escapement pallet fork 8A swings in the first direction (counterclockwise direction), and when the escapement of one claw 83A of the reverse escapement pallet fork 8A and the reverse escapement escapement wheel 60C When the teeth 62A abut against each other, the escape teeth 62A are pressed in the counterclockwise rotation direction, so the reverse escapement escapement wheel 60C rotates in a constant direction. Further, the tooth groove 66 of the reverse escapement escape wheel 60C is engaged with the claw 83A of the reverse escapement pallet fork 8A, thereby restricting the rotation of the reverse escapement escape wheel 60C at a constant angle.

When the reverse escapement pallet fork 8A swings in the second direction (clockwise direction), the claw 83A of the reverse escapement pallet fork 8A disengages from the tooth groove 66, and the reverse escapement escapement is released. Then, the other claw 82A of the pallet fork 8A of the reverse escapement abuts against the escapement tooth 62A, and the escapement tooth 62A is pressed in the counterclockwise direction of rotation, so the reverse escapement escapes The wheel 60C rotates in the same upward direction. Then, the tooth groove 66 of the reverse escapement escape wheel 60C is engaged with the claw 82A of the reverse escapement pallet fork 8A, thereby restricting the rotation of the reverse escapement escape wheel 60C at a constant angle. The respective claws 82A, 83A of the reverse escapement pallet fork 8A are arranged with respect to the respective escape teeth 62A of the reverse escapement escape wheel 60C so as to be able to operate as described above.

On the reverse escapement escape wheel 60C, a gear (escape pinion) 67A is mounted concentrically with the rotation axis of the reverse escapement escape wheel 60C, and the escape pinion 67a meshes with the third wheel 68 .

As shown in FIG. 23 , the rotor ring 30C is fixed to the rotor rotating shaft 31B, and rotates integrally with the rotor rotating shaft 31B. Two gears, a first rotor gear 33B and a second rotor gear 33C, are rotatably supported on the rotor rotating shaft 31B with the rotor ring 30C interposed therebetween. Spring locking holes 336B, 336C are formed in the first and second rotor gears 33B, 33C, respectively.

Between the rotor ring 30C and the first and second rotor gears 33B and 33C, a first coil spring 50C and a second coil spring 50D are disposed, respectively.

The first coil spring 50C is formed by winding a spring wire clockwise, its outer peripheral end is locked in the spring locking hole 336B, and its central axis side end is fixed to the rotor rotating shaft 31B by winding. superior. When the rotor ring 30C rotates in the counterclockwise direction prior to the first rotor gear 33B, the first coil spring 50C elastically deforms in the direction in which the number of turns increases, and the counterclockwise driving force transmitted to the rotor ring 30C can be used as elastic energy. accumulate.

The second coil spring 50D is formed by winding a spring wire counterclockwise, its outer peripheral end is locked in the spring locking hole 336C, and its central axis side end is fixed to the rotor rotating shaft 31B by winding. superior. When the rotor ring 30C rotates in the clockwise direction prior to the second rotor gear 33C, the second coil spring 50D elastically deforms in the direction in which the number of turns increases, so that the clockwise driving force transmitted to the rotor ring 30C can be used as elastic energy. accumulate.

Therefore, in this embodiment, the rotor is constituted by the rotor ring 30C, and the object to be rotated is constituted by the first rotor gear 33B and the second rotor gear 33 .

In addition, in this embodiment, similarly to the above-described embodiments, a detection circuit is provided for detecting the amount of rotation of the rotor to control the driving of the piezoelectric driver 4C.

Next, an operation method of the piezoelectric drive device 10D will be described.

When the reverse escapement pallet fork 8A swings in the first direction (counterclockwise), the reverse escapement escapement wheel 60C rotates by a rotation angle equivalent to half the tooth pitch of the gear. Furthermore, when the reverse escapement pallet fork 8A swings in the second direction (clockwise), the reverse escapement escapement wheel 60C further rotates by a rotation angle equivalent to half the tooth pitch of the gear. By repeating the above-mentioned operation, the reverse escapement escapement wheel 60C is intermittently rotated every half pitch of the teeth by the swing of the reverse escapement pallet fork 8A. Accordingly, a one-second-sized stepping operation of the second hand 91 mounted on the reverse escapement escapement wheel 60C is realized.

According to such this embodiment, in addition to the effects substantially the same as those of the above-described embodiments, the following effects can be achieved.

(16) By providing an elastic device composed of first and second coil springs 50C and 50D, the load on the piezoelectric actuator 4C can be reduced, the rotation speed of the rotor ring 30C can be increased, and the time for advancing at a desired pace can be shortened, Low power consumption can be achieved.

(Modification of the present invention)

In addition, the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope of achieving the object of the present invention are also included in the present invention.

For example, in the above-mentioned first embodiment, it was illustrated that the first rotor transmission gear 40 has the positioning hole 42, and the second rotor transmission gear 60 has the release restriction portion of the positioning pin 61, but for example, the first rotor transmission gear 40 may have The positioning pin, the second rotor transmission gear 60 has a positioning hole. In addition, as long as the release restricting portion maintains at least the initial deflection of the elastic device, methods other than the engagement of pins and holes may be used. Protrusion.

In the first embodiment described above, the coil spring 50 is used as the elastic means, the end in the outer peripheral direction is fixed to the first rotor transmission gear 40, the end in the central direction is fixed to the second rotor transmission gear 60, and the The coil spring 50 is installed in such a direction that the amount of deformation of the coil spring 50 increases when the first rotor transmission gear 40 is first rotated in the driving direction of the piezoelectric actuator, but the winding direction of the coil spring may also be used. The opposite coil spring, and the fixing method is reversed. That is, the end of the coil spring in the central direction is fixed to the first rotor transmission gear, the end in the outer peripheral direction is fixed to the second rotor transmission gear, and the coil spring is installed in such a direction (from the second rotor transmission gear Viewing the coil spring from the side, the direction in which a left-handed helix is formed): When only the first rotor transmission gear is rotated first, the deformation amount of the coil spring increases.

In each of the above-mentioned embodiments, a coil spring is used as the elastic means, but it is not limited thereto, and a U-shaped spring, a cantilever spring, a coil spring, etc. may also be used. In addition, although the coil spring 50 in which the cross section of the spring wire is circular is illustrated, it may be a coil spring having a cross-sectional shape such as a rectangle.

In the above-mentioned fourth embodiment, the detection means for detecting the movement amount of the rotor gear 33A was exemplified, but the detection means for detecting the movement amount of the rotor ring 30B may also be used. In addition, in each embodiment, the detection means may be of any type other than the optical type, for example, a magnetic type or a mechanical type (contact type, engaging or non-engaging means between parts, etc.). However, considering the influence of external magnetic force, an optical detection unit is preferable.

In the second embodiment, one piezoelectric driver is provided as the driving source for the first transmission path and the second transmission path, but it is also possible to separately provide the first piezoelectric driver and the first piezoelectric driver for driving the first transmission path. A second piezoelectric driver for driving the second transmission path.

For example, the vibrator of the first piezoelectric driver can be used to drive the intermediate wheel 6 or the rotor transmission gear 40A in FIG. 11, and the vibrator of the second piezoelectric driver can be used to drive the rotor ring 30 in FIG. The intermediate wheel 6 meshes) or an additional fixed rotor part on the cam gear 7.

Furthermore, in the second embodiment, the cam 72 of the cam gear 7 rotates in the cutout portion 84 of the pallet fork 8 to swing the pallet fork 8, but the swing structure of the pallet fork 8 is not limited to the above content, and may be arbitrary structure. For example, at the position where the above-mentioned notch portion 84 is arranged on the pallet 8, a shaft support hole member (formed with a hard material such as ruby) with a shaft support hole is inserted and fixed, instead of the notch portion, protruding from the cam gear 7. An eccentric pin that is eccentric with respect to the rotation center is provided, and the eccentric pin is inserted into the shaft support hole. In this case, compared with the structure of the second embodiment, the planar area becomes smaller, the friction between the shaft support hole and the eccentric pin becomes smaller, the contact radius becomes shorter, and the lubricating oil adhering to the contact portion is less likely to flow out due to surface tension. etc., thereby obtaining an efficient reciprocating swing mechanism with reduced mechanical loss.

In the above-mentioned fifth embodiment, the mechanism of the reverse escapement using the piezoelectric actuator that can be driven in two directions has been described, but it is also possible to use a piezoelectric actuator that can be driven in one direction, and the reverse escapement can be driven by a cam mechanism. The pallet fork of the jig machine swings.

In each of the above-mentioned embodiments, the pointer 2 has been described as the object to be driven by the piezoelectric drive device. However, the pointer 2 may be exemplified by a second hand, a minute hand, or an hour hand, or may be combined. In addition, the object to be driven is not limited to the hands 2, and may be a rotating object such as a calendar display panel of a watch.

In addition, in each of the above-mentioned embodiments, the to-be-rotated body is rotated using the elastic energy of the elastic device, but the driven body driven by the elastic device may be a non-rotation-driven driven body. The aforementioned non-rotational drive may be, for example, linear drive, linear reciprocating drive, arc reciprocating drive, and the like.

For example, it is only necessary that a pinion is integrally formed on the lower side of the rotor rotationally driven by the piezoelectric vibrator, and a rack formed with ratchet teeth meshing with the teeth of the pinion is linearly driven, elastically Elastic energy is accumulated in the device (coil spring, etc.), which is arranged on the front end side of the rack, and expands and contracts in the linear direction that drives the above rack, and releases the elastic energy of the elastic device at an appropriate timing, thereby linearly driving the arrangement The driven device on the front end side of the elastic device. When the above-mentioned driven device linearly drives to a predetermined position, it will return to the original position. At this time, it may be configured such that when the driven device returns to its original position, the elastic device is pressed, the rack is also pressed back, and the rack returns while moving away from the outer peripheral side of the pinion. At the same time, the teeth of the pinion mesh with the ratchet teeth of the rack, so that the rack is positioned.

In addition, when linearly driving the rack as described above, the piezoelectric vibrator may be linearly driven in direct contact with the rack without using the rotor.

In addition, the piezoelectric drive device of the present invention is not limited to a watch, but can also be used as a drive source for various electronic devices. That is, as electronic equipment having the piezoelectric driving device of the present invention, for example, various timepieces that drive display needles by the piezoelectric driving device, electronic equipment that drives a driven object such as a turntable, and the like. In particular, since the piezoelectric drive device of the present invention is superior in magnetic resistance compared with a stepping motor or the like, it can be widely used as a drive source requiring magnetic resistance.

In addition, although the best structure, method, etc. for carrying out this invention are disclosed in the said description, this invention is not limited to this. That is, although the present invention has been particularly illustrated and described with respect to specific embodiments, those skilled in the art can understand the above-described embodiments without departing from the scope of the technical idea and purpose of the present invention. The method performs various deformations in shape, material, quantity, and other detailed structures.

Therefore, descriptions that limit the shapes, materials, etc. disclosed above are descriptions that are illustrated to facilitate the understanding of the present invention, and do not limit the present invention, and are limited by a part or all of the restrictions that deviate from these shapes, materials, etc. Descriptions by names of components are also included in the present invention.

Claims (19)

1. a Piexoelectric actuator is characterized in that, said Piexoelectric actuator has:

Piezoelectric actuator, it has: have the oscillator of piezoelectric element and pass through this oscillator and rotor rotated;

Elastic device, it can be accumulated the energy of rotation of said rotor as elastic energy; And

Be rotated body, it rotates through the elastic energy of in this elastic device, being accumulated,

Said elastic device has initial deflection,

Said rotor and said being rotated on the body, be formed with the release restrictions of keeping said initial deflection.

2. a Piexoelectric actuator is characterized in that, said Piexoelectric actuator has:

Piezoelectric actuator, it has: have the oscillator of piezoelectric element and pass through this oscillator and rotor rotated;

Rotor drive, the rotation of said rotor are passed to this rotor drive;

Elastic device, it can be accumulated the energy of rotation of said rotor drive as elastic energy; And

Be rotated body, it rotates through the elastic energy of in this elastic device, being accumulated,

Said elastic device has initial deflection,

Said rotor drive and said being rotated on the body, be formed with the release restrictions of keeping said initial deflection.

3. Piexoelectric actuator according to claim 1 and 2 is characterized in that,

Said Piexoelectric actuator has the swiveling limitation mechanism that the said anglec of rotation that is rotated body is restricted to predetermined angular.

4. Piexoelectric actuator according to claim 3 is characterized in that,

Said Piexoelectric actuator has:

First bang path, its with the energy of rotation of said rotor without said elastic device be delivered to said swiveling limitation mechanism; With

Second bang path, its energy of rotation with said rotor is delivered to said elastic device.

5. Piexoelectric actuator according to claim 3 is characterized in that,

Said swiveling limitation mechanism engages with the said body that is rotated.

6. Piexoelectric actuator according to claim 3 is characterized in that,

The said body that is rotated is an escape wheel, and said swiveling limitation mechanism is an escapement lever.

7. Piexoelectric actuator according to claim 6 is characterized in that,

Said Piexoelectric actuator has cam part, and this cam part engages with said escapement lever, and is driven by said piezoelectric actuator,

This cam part constitutes under the situation that this cam part rotates a circle, and said escapement lever carries out the once reciprocating action.

8. Piexoelectric actuator according to claim 3 is characterized in that,

Constitute said body and the said swiveling limitation mechanism of being rotated with Maltese cross.

9. Piexoelectric actuator according to claim 1 and 2 is characterized in that,

Said elastic device is a disc spring.

10. Piexoelectric actuator according to claim 2 is characterized in that,

This rotor drive is configured on the identical rotating shaft with the said body that is rotated,

One end of said elastic device engages with said rotor drive, and the other end of said elastic device engages with the said body that is rotated.

11. Piexoelectric actuator according to claim 1 and 2 is characterized in that,

Said rotor is configured on the identical rotating shaft with the said body that is rotated,

One end of said elastic device engages with said rotor, and the other end of said elastic device engages with the said body that is rotated.

12. Piexoelectric actuator according to claim 1 is characterized in that,

Said release restrictions only has the play that can make said rotor rotation in the direction of the deflection that increases said elastic device,

The maximum deflection of said elastic device is set according to the play amount of said release restrictions.

13. Piexoelectric actuator according to claim 2 is characterized in that,

Said release restrictions only has the play that can make said rotor drive rotation in the direction of the deflection that increases said elastic device,

The maximum deflection of said elastic device is set according to the play amount of said release restrictions.

14. Piexoelectric actuator according to claim 12 is characterized in that,

Said piezoelectric actuator constitutes and carries out stepper drive,

The play of said release restrictions is a rotation amount corresponding with the driving of a step size of said piezoelectric actuator at least, said rotor.

15. Piexoelectric actuator according to claim 13 is characterized in that,

Said piezoelectric actuator constitutes and carries out stepper drive,

The play of said release restrictions is the rotation amount that goes on foot corresponding, the said rotor drive of driving of size at least with one of said piezoelectric actuator.

16. Piexoelectric actuator according to claim 1 and 2 is characterized in that,

Said Piexoelectric actuator has: swing unit, and it is rotated body and alternately swings to first and second directions through said; With second be rotated body, whenever said swing unit during to said first and second directions swing, this second is rotated body and rotates to constant direction through said swing unit,

Said swing unit have at every turn by constant angle limit said second be rotated the anglec of rotation of body the rotation restrictions.

17. Piexoelectric actuator according to claim 1 and 2 is characterized in that,

Said oscillator forms tabular, and constitutes and have the abutting part that contacts with the outer peripheral face of said rotor,

Said Piexoelectric actuator has the unit of pushing, this push the unit with the arbitrary side in said oscillator and the said rotor by the opposing party of pressing to said oscillator and said rotor.

18. an electronic equipment is characterized in that, said electronic equipment has:

The described Piexoelectric actuator of in the claim 1 to 17 each; With

By said Piexoelectric actuator drive by drive division.

19. electronic equipment according to claim 18 is characterized in that,

Said is the clocking information display part that shows the clocking information that arrives through timing portion instrumentation by drive division.

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