JPH0336945Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] This invention relates to a pointer type watch.

[Background of the idea]

Generally, in pointer-type electronic watches, etc., the analog movement is driven by a pulse motor consisting of a coil, stator, rotor, etc., but the parts used in the pulse motor are thin wire coils, highly magnetic materials, etc. Like the rotor of
It is a special and expensive product, and requires an anti-magnetic structure, which not only complicates the structure, but also has drawbacks such as the possibility of the coil breaking, which requires careful handling.

Therefore, it has been considered to use an electromechanical transducer using a piezoelectric element in place of the step motor, as described in Japanese Patent Application Laid-Open No. 54-34010.

However, a step motor can rotate one step with a single signal and can reliably rotate for one second.
Since the piezoelectric element only moves back and forth, JP-A-54-
As shown in Japanese Patent No. 34010, it is necessary to ensure that one step can be obtained with one vibration using a ratchet gear.

However, since the amount of vibration of the piezoelectric element is small, in order to create a gear in which one vibration of the piezoelectric element advances one tooth, many small teeth must be formed, making it extremely difficult to manufacture a ratchet gear.

Therefore, as shown in Japanese Patent Publication No. 33-9195, for example, it has been considered to apply a vibrating member to the outer circumferential surface of the car to convert linear motion into rotational motion using friction, but the vibrating member Since the vibrator contacts the convex arcuate outer circumferential surface of the vibrator, the vibrator may slide on the arcuate surface and vibrations may not be transmitted.

If the diameter of the wheel is small, it will be easy to slip, so it is possible to increase the diameter of the wheel to make it less slippery, but this has the disadvantage that the entire watch becomes larger because the vibrating device is located outside the car.

[Purpose of the invention] This invention was developed against the background of the above-mentioned circumstances, and it has a simple structure and can efficiently convert the reciprocating motion of a piezoelectric actuator into rotational motion to move the hands, and is also capable of moving the hands of a watch. The object of the present invention is to provide a pointer type timepiece that can be downsized.

[Main points of the invention] In order to achieve the above-mentioned purpose, this invention provides a friction ring rotatably inside the watch case, fixes an internal gear with approximately the same inner diameter to this friction ring, and connects the friction ring and internal gear. A piezoelectric actuator, a wheel train mechanism, and a pointer shaft, which have a vibrator reciprocated by a piezoelectric element and contact the inner circumferential surface of the friction ring from a direction inclined at a predetermined angle to rotate the friction ring by frictional force, are installed inside the This is what was placed.

[Embodiment] An embodiment of this invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is a sectional view of the analog movement, and FIG. 2 is a plan view thereof taken along the - line. This analog movement 1 has a circuit board 3 on the main plate 2.
A piezoelectric actuator 4 provided at It is designed to move the hands of the clock and indicate the time.

That is, as shown in FIG. 3, the piezoelectric actuator 4 has a piezoelectric element 7, which vibrates when a predetermined alternating current voltage is applied, sandwiched between diaphragms 8, 8, and is attached to a frame member 9. A controller 10 is provided in the center of a diaphragm 8, which is provided on a circuit board 3 equipped with an electronic component 3a such as an LSI, and each diaphragm 8 is connected to the circuit board via lead wires 12. Connected to 3. Therefore, in the piezoelectric actuator 4, when a predetermined AC voltage is applied from the circuit board 3 to each diaphragm 8, 8, the piezoelectric element 7 and each diaphragm 8, 8 vibrate with a constant amplitude, and this vibration The operator 10 accordingly moves in and out, thereby moving the friction ring 13 in the direction of arrow X, as shown in FIG. That is, the operator 10 is located inside the friction ring 13 (on the right side in FIG. The friction ring 13 is brought into contact with the friction surface (friction surface) from an oblique side, and the friction ring 13 is moved by mutual frictional force. In this case, in order to move the friction ring 13 smoothly, the operator 10 is designed to be slightly bent and deformed as shown by the dotted line when it comes into contact with the friction ring 13 and is further pushed out. Further, the friction ring 13 is fixed on the internal gear 14. This internal gear 14 is shown in FIGS.
As shown in the figure, it is rotatably arranged on the base plate 2 via four ball bearings 15a of bearings 15, and rotates as the friction ring 13 moves. Note that this internal gear 14 is controlled by a control lever (not shown) so that it does not operate uncontrollably due to external forces.

On the other hand, the wheel train mechanism 6 includes a transmission wheel 16, a fourth wheel & pinion 17, a third wheel & pinion 18, a second wheel & pinion 19, a pinion pinion 20, a hinohira wheel 21, an hour wheel 22, etc. rotated by an internal gear 14. A transmission wheel 16, a fourth wheel & pinion 17, and a third wheel & pinion 18 are arranged between the main plate 2 and the train wheel bridge 5 via bearings 16a, 17a, and 18a, respectively. A pinion wheel 20, a center wheel 19, and an hour wheel 22 are arranged concentrically, and a hinohira wheel 21 is also arranged. In this case, the transmission wheel 16 meshes with the internal gear 14 to rotate, and this rotation is transmitted to the third wheel & pinion 18 via the fourth wheel & pinion 17. The upper part of the third wheel & pinion 18 projects upward through the train wheel bridge 5, and the center wheel & pinion 19 meshes with this projecting portion, transmitting its rotation to the center wheel & pinion 19. This center wheel 19 is a cylinder pinion 2 placed on the train wheel bridge 5.
0 for frictional transmission. This cylinder pinion 20 is a minute hand shaft to which a minute hand (not shown) is attached at its upper end, and the rotation of the center wheel & pinion 19 is transmitted by friction, thereby causing it to rotate. It is transmitted to the hour wheel 22 via the rear wheel 21. The hour wheel 22 is an hour hand shaft to which an hour hand (not shown) is attached at its upper end, and is rotatably attached to the cylinder pinion 20.

The base plate 2 and the gear train bridge 5 are attached to each other with screws 23 at a predetermined distance.

Next, the operation of the analog movement 1 configured as described above will be briefly explained.

When a predetermined AC voltage is applied from the circuit board 3 to each diaphragm 8, 8 of the piezoelectric type actuator 4 shown in FIG. 3, the piezoelectric element 7 and each diaphragm 8, 8 vibrate, and along with this vibration, The operator 10 moves in and out. Then, as shown in FIG. 4, when the operator 10 is pushed out, it comes into contact with the inner surface (friction surface) of the friction ring 13 from the diagonal side, and the friction ring 13 moves in the direction of arrow X due to mutual frictional force. move it. As the friction ring 13 moves in this way, the internal gear 14 rotates in the same direction, and as shown in FIGS. Indicate the time by moving the hands.

However, according to the above-mentioned pointer type watch,
Since the piezoelectric actuator 4 is used as a drive source and the analog movement 1 is driven by the piezoelectric actuator 4, there is no need to use expensive parts such as a coil made of thin wire or a rotor made of highly magnetic material as in the past. Not only is there no need for it, but there is also no need for an anti-magnetic structure, so it can be manufactured at low cost. Moreover, since it is only necessary to attach the piezoelectric actuator 4 to the circuit board 3 and connect each diaphragm 8, 8 to the circuit board 3 with the lead wires 12... There is no need to use the parts, the parts are easy to handle, and the assembly work is easy.

As explained above, according to the pointer type timepiece of this invention, since the diameter of the friction ring can be increased, the reciprocating force of the vibrator can be efficiently converted into the rotational force of the friction ring, and the piezoelectric actuator can be made smaller.

Furthermore, since the piezoelectric actuator, wheel train mechanism, and pointer shaft are arranged inside the friction ring and internal gear, the watch can be made more compact.

[Brief explanation of drawings]

The first embodiment of this invention is shown in Figs. 1 to 4, and Fig. 1 is a cross-sectional view of an analog movement;
FIG. 2 is a plan view taken along the line 2, FIG. 3 is an external perspective view of the piezoelectric actuator, and FIG. 4 is an enlarged plan view of essential parts showing its operating state. 1...analog movement, 4...piezoelectric actuator, 6...wheel train mechanism.

Claims (1)

[Claims for Utility Model Registration] A friction ring that is rotatably installed inside a watch case, and a ring-shaped ring that has approximately the same inner diameter as the friction ring, is fixed to the friction ring, and rotates as the friction ring rotates. an internal gear, the friction ring, and a vibration that is reciprocated by a piezoelectric element disposed inside the internal gear and contacts the inner circumferential surface of the friction ring from a direction inclined at a predetermined angle to rotate the friction ring by a frictional force. a piezoelectric actuator having a ring; a gear train mechanism disposed inside the friction ring and the internal gear and meshing with the internal gear to transmit rotation of the internal gear; A pointer-type timepiece, comprising: a pointer shaft that moves a pointer attached to its tip by rotation transmitted by the arranged wheel train mechanism;