JP3115479B2 - Electronically controlled watch with mainspring generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts a mechanical energy when a mainspring is opened into electric energy by a generator, drives a control circuit by the electric energy, and controls a rotation cycle of the generator. The present invention relates to a watch that accurately drives a pointer fixed to a wheel train.

[0002]

2. Description of the Related Art As a watch equipped with a generator, an electronic timepiece with a power generating device described in Japanese Patent Application Laid-Open No. 52-84774 is known.

Further, a watch (hereinafter referred to as an electronic control) which accurately displays time by driving a circuit with electric energy of a generator driven from a mainspring via a train, and controlling a current value flowing through a coil of the generator. Japanese Patent Publication No. 3-37152, Japanese Unexamined Patent Publication No.
The ones described in JP-A-9-135388, JP-A-59-116078 and JP-A-61-95272 are known.

[0004]

However, in an electronic timepiece with a power generating device, a secondary battery that temporarily stores generated power has a limited life and has a problem of replacement and disposal. In addition, since a generator for converting the potential energy of the rotary weight into electric energy and a motor for driving the hands with the electric energy are required, the number of parts is increased, the cost is increased, and the electric energy and the motor for operating the circuit are increased. Must generate electrical energy to drive the watch, and must input large amounts of mechanical energy to operate the watch.

[0005] On the other hand, the electronic control mecha watch has a feature that the driving of the hands is performed by the mainspring as a power source, so that a motor is not required, the number of parts is small, and the cost is low.
In addition, only a small amount of electrical energy required to operate the electronic circuit needs to be generated, and the watch can be operated with low input energy.

[0006] However, the electronically controlled watch has the following problems. That is, the mechanical energy supplied from the mainspring is consumed as magnetic loss, electric loss, and power generated by hysteresis loss and eddy current loss, and the ratio of the hysteresis loss is extremely large.

Here, the efficiency is defined as the ratio of the generated power to the mechanical energy supplied from the mainspring. In general, it is known that the efficiency of a generator that rotates at a constant speed changes depending on the capacitor voltage charged, and the efficiency decreases with a certain capacitor voltage peaking at a higher or lower value.

In the case of a watch, power of at least 1 V and 0.1 μA is required to operate an electronic circuit. This corresponds to the generated power. Also, in order to increase the duration without increasing the speed increase ratio from the mainspring to the generator too much, it is desirable to reduce the rotation speed of the generator as much as possible. For this reason, the electromotive voltage of the generator is set slightly higher than the required capacitor voltage of 1 V, the capacitor voltage is higher than the maximum efficiency point, and the efficiency is considered to be poor. By the way, with a general generator that can be mounted on a watch, each loss when generating 0.1 μA at 1 V is as follows: hysteresis loss is 1 μW, eddy current loss is 0.1 μW, and electric loss is 0.2 μW. Was. Therefore, the efficiency of this generator is calculated to be 7%. Also, it can be seen that 70% of the whole is lost due to hysteresis loss.

If the amount of magnetic flux flowing through the magnetic circuit is reduced in order to reduce the hysteresis loss, the generator must be rotated at a higher speed in order to secure an electromotive voltage of 1V. Accordingly, the hysteresis loss in one rotation of the generator decreases, but the total number of hysteresis losses does not decrease so much because the rotation speed increases. Also the same 1
In order to generate an electromotive voltage of about V, the same eddy current loss torque is required, and the eddy current loss increases as the number of rotations increases. Therefore, the total magnetic loss hardly changes.

Accordingly, the present invention is to solve such a problem and reduces the hysteresis loss of the magnetic circuit of the generator and improves the conversion efficiency from mechanical energy to electric energy, thereby improving the operation duration. The purpose of the present invention is to provide a long electronically controlled watch.

[0011]

An electronically controlled watch with a mainspring generator according to the present invention comprises a generator for converting mechanical energy of a mainspring into electric energy via a train wheel, and a pointer is provided on the train wheel. The magnetic circuit of the generator is formed by at least a rotor having a permanent magnet, a stator facing the permanent magnet, and a coil block having a coil wound around a magnetic core. (Oe) The coercive force after magnetization is 0.05 (Oe) or less.

It is desirable that the material of the stator and the magnetic core be PC permalloy or supermalloy.

[0013]

According to the present invention, a mainspring-type generator that makes use of the features inherent in an electronically controlled mechanical watch is constructed.
This is to extend the operation duration of the electronically controlled mechanical watch.

As described above, the features of the electronically controlled mechanical watch are as follows. There is no need for a motor to drive the hands. Therefore, the only required power is to operate the electronic circuit (small power generation is required).-The mainspring torque must be constant because the hands are connected to the wheel train, but they must be maintained for a long time. Therefore, it is necessary to slowly release the power generation energy of the mainspring over time (small power generation, long-term operation).

On the other hand, an electronic timepiece with a power generator requires much more power than an electronically controlled mechanical watch.
For this reason, the generator of an electronic timepiece with a power generation device attaches importance to the amount of generated power rather than the efficiency of power generation, but in the case of an electronically controlled mechanical watch, the power generation efficiency is more important than the amount of generated power.

Therefore, the present invention aims to improve the power generation efficiency based on this. Therefore, the generator is configured to exhibit magnetic characteristics such that the area of the hysteresis loop of the stator and the magnetic core constituting the magnetic circuit of the generator is reduced. As a result, the hysteresis loss can be reduced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is a plan view showing a main part of an electronic control device according to the present invention, FIGS. 2 and 3 are sectional views thereof, and FIG. 4 is a block diagram showing the concept of power generation and control.

First, the configuration of the electronic control mecha watch will be described. Reference numeral 1 denotes a barrel car, a mainspring 1a, a barrel gear 1b,
It is composed of a barrel barrel 1c and a barrel lid 1d. Spring 1
As for a, the outer end is fixed to the barrel gear 1b and the inner end is fixed to the barrel barrel 1c. The barrel case 1c is supported by the main plate 2 and the train wheel bridge 3, and is fixed by a square hole screw 5 so as to rotate integrally with the square hole wheel 4.
Although the square wheel 4 rotates clockwise, it engages with the hammer 6 so as not to rotate counterclockwise. In addition, about the method of rotating the square wheel 4 clockwise and winding the mainspring,
It is the same as a self-winding or manual winding mechanism of a mecha watch, and the present invention does not limit the same, so that the description is omitted here.

The rotation of the barrel gear 1b is increased seven times and the second wheel 7 is sequentially increased by 6.4 times, the third wheel 8 is increased, 9.375 times is increased and the fourth wheel 9 is increased three times. The fifth wheel & pinion 10 is speeded up 10 times and the sixth wheel & pinion 11 is speeded up 10 times to the rotor 12 to increase the speed by a total of 126,000 times. The second car 7 has a pipe kana 7
a, a minute hand 13 is fixed to the cannon pinion 7a, and a second hand 14 is fixed to the fourth wheel 9. Therefore, in order to rotate the second wheel & pinion 7 at 1 rpm and the fourth wheel & pinion 9 at 1 rpm, the rotor 12 must rotate at 5 rpm.
What is necessary is just to control so that it may rotate at ps. At this time, the barrel gear 1b becomes 1/7 rph.

The generator includes a rotor 12, a stator 15, and a coil block 16. The rotor 12 includes a rotor magnet 12a, a rotor pinion 12b, a rotor inertial disk 12
c. The rotor inertia disk 12c is a barrel car 1
This is for reducing the variation in the number of revolutions of the rotor 12 with respect to the variation in the driving torque. The stator 15 is formed by winding a 40,000-turn stator coil 15b around a stator body 15a. The coil block 16 is formed by winding a coil 16b of 110,000 turns around a magnetic core 16a. Here, the stator body 15a and the magnetic core 16a are made of PC permalloy. Further, the stator coil 15b and the coil 16b are connected in series so that an output voltage obtained by adding the respective generated voltages is obtained.

Next, an example of the concept of charging and control will be described with reference to FIG. The part surrounded by the broken line is the IC 31. The AC output of the generator 20 is connected to diodes 21 and 22.
And the variable resistance means 2
Divide into four sides. When a voltage of 1 V is stored in the capacitor 23, the oscillation circuit 30 drives the crystal oscillator 29 and sends time information to the frequency dividing circuit 26. The arithmetic circuit 25 compares the signal of the frequency dividing circuit 26 with the period detecting means 27 for detecting the number of revolutions of the generator 20, and controls the variable resistance means 24 by the variable resistance control means 28. If the rotation cycle of the generator 20 is short, the normal cycle can be restored by reducing the resistance value of the variable resistance means 24 and increasing the electromagnetic brake amount. Here, the current consumption of the IC 31 is 0.1 μA.
Therefore, the power consumption is less than 0.1 μA at a power generation capacity of 1 V when the rotor 12 rotates at 5 rps, and the voltage of the capacitor 23 does not fall below 1 V.

Next, the principle of torque operation in the present embodiment will be described. FIG. 5 is a graph showing the relationship between the mainspring torque Tz and the winding angle n of the mainspring. T described in the figure
n45gcm is the torque required for power generation, which is mainly the sum Ts33gcm of the friction transmission loss torque lost by the wheel train bearings and gears and the magnetic loss torque by the generator,
Electric loss torque Te8gcm in the generator and charging circuit,
The torque Tg of 4 gcm necessary for power generation corresponding to the electric energy of 0.1 μW consumed in the circuit is required. Tb150
gcm is the maximum braking torque added to Tn generated when the brake is applied. Tn + Tb is the maximum torque when the generator is used to brake the mainspring, and no further braking torque can be generated. Here, each torque is a value converted around the mainspring by a speed increase ratio of 126000 by the speed increasing wheel train.

It is a necessary condition for this system that Tz is larger than Tn and smaller than Tn + Tb. Therefore, from n = 0, Tz is equal to Tn.
In the region up to 5, the mainspring can be solved at a constant speed, which corresponds to the operation duration of the watch. At this time, Tz is Tn
You only have to apply the larger part of the electromagnetic brake. Therefore,
The total energy of the mainspring contributing to power generation is 45 gcm ×
It becomes 0.18 J in 6.5 turns, and the part larger than 45 gcm does not contribute to power generation. n at which Tz becomes 0 from n = 6.5
In the region up to = 8, the energy required for the operation of the circuit cannot be supplied from the mainspring, the circuit stops, and the correct time cannot be indicated.

Next, the characteristics of PC permalloy and PB permalloy used as materials constituting a magnetic circuit will be described.

FIG. 6 is a graph showing the measurement results of the relationship between the rotational speed of the rotor 12 and the magnetic loss torque Ts according to the present embodiment. The solid line indicates that the material of the magnetic core 16a is PC of this embodiment.
Permalloy, and the broken line is a PB permalloy generally used in electronic timepieces with a power generator. Note that PC permalloy was used for both the stator body 15a.

The difference between PC Permalloy and PB Permalloy is that the hysteresis loss torque, which is expressed as a loss torque without speed dependency, is about 30% lower for PC Permalloy than for PC Permalloy and 40 gcm for PB Permalloy. is there. This is because PC permalloy has a smaller hysteresis loop area due to its smaller coercive force than PB permalloy. By the way,
The coercive force after magnetization of 10 (Oe) was 0.1% for PC Permalloy.
The difference is about 01 (Oe) and that of PB permalloy is about 0.1 (Oe), which is about 10 times different. The slopes are almost the same, indicating that there is no difference in eddy current loss between PC Permalloy and PB Permalloy. At this time, rotor 1
When 2 rotates at 5 rps, the eddy current loss torque is 4
gcm.

The saturation magnetic flux density of PB permalloy is P
It is about twice as large as C permalloy. In an ordinary quartz watch stepping motor, it is necessary to cause a large amount of magnetic flux to flow through a magnetic core by an output pulse from a drive circuit. Since an electronic timepiece with a power generating device needs to generate a large amount of electric power by one rotation of the generator, a relatively large magnetic flux has to flow through the magnetic core. Here, when the saturation magnetic flux density of the magnetic core material is small, the magnetic core sectional area must be increased, and the space efficiency is poor.

On the other hand, when viewed as a generator, a material having a small hysteresis loop has a smaller loss, but if the electromotive voltage can be set to be considerably higher than the capacitor voltage, the influence of the hysteresis loss on the power generation efficiency is so large. Absent. Therefore, PB permalloy is generally suitable for a quartz watch motor or a generator of an electronic timepiece with a power generating device.

On the other hand, in the electronic control mecha watch,
Since only a small amount of power is generated at all times, the effect of hysteresis loss on power generation efficiency is large. In addition, the amount of magnetic flux flowing through the magnetic core may be small as much power is not generated.
Incidentally, when the rotor 12 is rotated at 5 rps in the generator of this embodiment shown in FIG. 6, the hysteresis loss is 0.7 μm.
W, eddy current loss is 0.1 μW, another experiment shows that electric loss is 0.2 μW, generated power is 0.1 μW, and input energy is 1.1 μW. Therefore, the power generation efficiency is about 9%. Here, if the core material is PB permalloy, as shown in FIG. 6, the hysteresis loss is 1 μW, the input energy is 1.4 μW, and the power generation efficiency is about 7%. Therefore, the electronically controlled watch has P
It turns out that C permalloy is suitable.

FIG. 7 is a graph showing the relationship between the coercive force Hc of the magnetic core material and the operation duration t of the watch based on the results of FIGS. While the total energy of the mainspring contributing to power generation described in FIG. 5 is 0.18 J, the input energy is 1.1 μW in PC permalloy and 1.4 in PB permalloy.
μW. When the total energy is divided by the input energy, the operation duration is calculated to be 45 hours for PC Permalloy and 36 hours for PB Permalloy. Further, the hysteresis loss is determined by the area of the hysteresis loop, and is proportional to the square of the coercive force. Therefore, if a material having a coercive force intermediate between PC permalloy and PB permalloy is used,
It is calculated when a curve as shown in FIG. 7 is obtained.

Here, the operation duration of the watch will be briefly described. Considering that the average person removes his watch at 6 o'clock at night and puts it on his hand at 8 in the morning, a clock of 14 hours will keep running without stopping. However, 1
If there are days that do not date, a minimum duration of 38 hours is required. As a result, the duration of a long-standing general mecha watch is set to about 42 hours. Accordingly, the coercive force must be 0.05 (Oe) or less as shown in FIG.

Up to this point, PC permalloy has been described as a material for the members forming the magnetic circuit. However, it is needless to say that supermalloy has the same effect, and a material having a coercive force of 0.05 (Oe) or less. If there is, it is not necessary to be a permalloy material. In addition, the rotor, the stator, and the coil block have been described as the components that form the magnetic circuit. However, two coil blocks, a two-piece stator, or other components having a coercive force defined by the present invention or more are used. The same effect can be obtained even if is included in the magnetic circuit.

[0034]

As described above, the present invention has the following effects.

That is, the coercive force of the stator and the magnetic core forming the magnetic circuit of the generator of the electronic control mecha-watch is set to 0.
By setting the area to be equal to or less than 05 (Oe), the area of the hysteresis loop is small, the hysteresis loss can be reduced, and an electronically controlled watch with a long duration can be realized.

In particular, it is possible to achieve an operation duration in which the practicality of the watch is sufficiently considered.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an electronic control device, showing an embodiment of the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a sectional view of FIG. 1;

FIG. 4 is a block diagram showing an example of a charging and control concept used in FIG. 1;

FIG. 5 is a graph showing a mainspring torque and a winding angle of an electronically controlled electric power watch.

FIG. 6 is a graph showing the measurement results of the relationship between the rotational speed of the rotor and the magnetic loss torque Ts in FIG. 1;

FIG. 7 is a graph showing the relationship between the coercive force Hc and the operation duration time t of the watch.

[Explanation of symbols]

 1. Barrel car 1a. Mainspring 2. Main plate 3. Wheel train receiver 12. Rotor 12a. Rotor magnet 13. Minute hand 14. Second hand 15. Stator 15a. Stator body 15b. Stator coil 16. Coil block 16a. Magnetic core 16b. Coil 20. Generator

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-4-242226 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G04C 10/00-10/02

Claims (2)

(57) [Claims] 1. A watch comprising a generator for converting mechanical energy of a mainspring into electric energy via a train wheel, wherein a watch has a pointer coupled to the train wheel, wherein a magnetic circuit of the generator has at least a rotor having a permanent magnet. , A stator facing the permanent magnet, and a coil block formed by winding a coil wire around a magnetic core,
An electronically controlled mecha watch equipped with a mainspring type generator, wherein the coercive force of both the stator and the magnetic core after 10 (Oe) magnetization is 0.05 (Oe) or less. 2. An electronically controlled electronic watch with a mainspring type generator according to claim 1, wherein said stator and said magnetic core are made of PC permalloy or supermalloy.