JPH0738029B2 - Small generator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a small power generator which can be used as a power source for an electronic timepiece.

[Prior Art] Conventionally, batteries are almost all energy sources for portable electronic devices such as electronic timepieces. This battery has a battery life determined by the capacity of the battery and the current consumption of the watch body, and the trouble of battery replacement has always been a problem. Therefore, in order to solve this drawback, for example, an attempt has been made to provide a power generation mechanism inside the timepiece. The attempt was made in the conventional Japanese Patent Laid-Open No. 50-1786.
As in No. 6, the power generation efficiency is poor, the size is large, and there is a problem with durability, and it has not been put to practical use.

[Purpose] The present invention is intended to solve the above-mentioned drawbacks and to provide a power generator having extremely high power generation efficiency, high size flexibility, and excellent durability.

Example An example of the present invention will be described with reference to the drawings. A wristwatch was used as an example of a portable device in which the small power generator is incorporated.

FIG. 1 is a block diagram showing the concept of a quartz wristwatch system that effectively utilizes the present invention. Reference numeral 1 is a means for generating a rotational torque, which is an unbalanced vehicle in which the center of rotation and the center of gravity are eccentric. The rotational movement of the rotating means 1 is accelerated by the speed increasing train wheel 2 to rotate the rotor of the converter A3 as a power generation mechanism to generate an alternating current. This alternating current is rectified by the rectifier circuit 4 and stored in the storage means 5. In this embodiment, an electric double layer capacitor, which is a large-capacity capacitor, is used as the electricity storage means. Using the large-capacity capacitor as a power source, the control circuit 6 including a crystal serving as a time standard and the drive circuit 7 controlled by the control circuit 6 operate. Energy is supplied by the drive circuit 7 to operate the converter B8, and the movement of this converter B8 is reduced by the reduction gear train 9
Is transmitted to the pointer 10 and the time is displayed.

FIG. 2 is an explanatory diagram of the converter A3 as a power generation mechanism. Stator 21 so that rotor 20 including permanent magnet 20a
Are arranged. The coil 22 is wound around a magnetic core 22a, and the magnetic core 22a and the stator 21 are fixed to each other by screws 23. When the rotor 20 rotates, a starting force E and a current I represented by the following equation are generated in the coil.

N: Number of turns of coil φ: Number of magnetic flux passing through magnetic core 22a t: Time R: Resistance of coil W: Rotational speed of rotor 20 L: Inductance of coil This starting force is an AC having a sin curve. The rotor 20 and the hole of the stator 21 that encloses the rotor 20 are concentric circles and enclose the rotor magnet over almost the entire circumference. As a result, the force (pulling torque) that tends to stop at the rotor is minimized. The explanation that the stator having such a shape reduces the pulling torque will be described in more detail. The stator 21 has two pole piece parts 21a and 21b.
And a thin portion 21c connecting the respective pole piece portions is formed so as to surround the rotor magnet 20a. For example rotor magnet 20a
When the N magnetic pole is rotated from one stator pole piece 21a toward the other stator pole piece 21b and reaches the vicinity of the narrow portion 21c connecting between the stator pole pieces, a part of the magnetic flux is thin portion 2
It will leak and flow toward the other stator pole piece 21b via 1c. In other words, this means that the magnetic flux remaining in the stator pole piece 21a on the one side at the beginning is reduced, and as a result, the maximum pulling torque for returning the rotor to the magnetically stable point is reduced accordingly. become. For example, in the case of a stator (for example, the stator disclosed in FIG. 1 of Japanese Patent Laid-Open No. 52-80871) in which a gap is formed without the thin portion 21c, the magnetic resistance of the gap is significantly increased, and therefore the rotor magnetic pole is formed. The magnetic flux tries to remain in the stator pole piece on the first side until it exceeds the air gap, and as a result the pulling torque becomes significantly large. Since the magnetic flux leaks to 21b, the pulling torque will be significantly reduced. Therefore, even if the unbalanced vehicle is small, the rotor can be easily started.

When the rotor starts to rotate beyond the initial maximum pulling torque, the unbalanced vehicle continues to rotate due to inertia, but in the second half of the rotation, the unbalanced vehicle is unable to cross the pulling tokule due to low energy. Will stop.
Therefore, the smaller the pulling torque, the wider the rotation angle of the rotor. In the configuration of the present invention, since the pulling torque is small as described above, the unbalanced vehicle can be rotated further by that amount, and the rotation angle can be widened to secure a sufficient amount of power generation. In particular, since the unbalanced vehicle and the rotor are connected by the speed-up gear train, even a slight increase in the rotation angle of the unbalanced vehicle corresponds to several rotations with the rotor, which has no effect on the small power generator. It is quite large, and is a key point to improve power generation efficiency.

Since the leakage of the magnetic flux reduces the amount of change dφ of the magnetic flux, it is expected that the starting force E will also decrease. However, in reality, the pulling torque becomes smaller, so the rotation speed of the rotor becomes faster and the changing speed of the magnetic flux becomes faster. Since 1 / dt becomes large, the starting force E does not substantially decrease.

FIG. 3 is a sectional view for explaining the mechanism from the rotating means 1 to the converter A3 via the speed increasing train wheel 2. 31 is an unbalanced car in which the center of rotation and the center of gravity are eccentric, 32 is the main plate,
33 is the recipient. The rotational movement caused by the unbalance of the unbalanced vehicle 31 is increased by the gear trains 31a and 34 and the rotor pinion 2
Rotation of the rotor magnet 20a is caused by 0b. Reference numeral 22b denotes a coil lead substrate, which is used to end the coil, and the coil lead substrate 22b and the rotating substrate 35 come into contact with each other to transmit the electric power induced in the coil to the circuit.

As described above, if the pulling torque of the rotor is small, the unbalance amount of the unbalanced wheel 31 may be small. The minimum condition for starting is (rotor pulling torque) <(unbalanced torque of unbalanced vehicle).

Next, the configuration of the rectifier circuit for reducing the size and improving the power generation efficiency, which is the object of the present invention, will be described.

FIG. 4 is an explanatory diagram of the conventional rectifier circuit 4. Rectifier circuit
It is composed of four diodes 41, 42, 43, and 44.
Reference numeral 5 denotes a storage means, and in this embodiment, an electric double layer capacitor which is a large capacity capacitor is used. When the electric power indicated by the thin line 45 is induced in the coil 22, the current flows as indicated by the thin line and is stored in the capacitor 5. When it flows as shown by the broken line 46, it is also stored in the capacitor 5 in the same direction as when 45.

Generally, full-wave rectification is considered to be more efficient than half-wave rectification, but when this is used in a small power generator that rotates a rotor magnet in an unbalanced vehicle as the subject of the present invention, the situation is quite different. That is, when the rotor magnet is rotating, electric power is generated, and at the same time, an electromagnetic brake that tries to hinder the rotation of the rotor by the generated current (induced current) flowing in the coil is generated. Naturally, this electromagnetic brake apparently reduces the driving energy of the unbalanced car, and it makes the same state as if using an unbalanced car that is one size smaller. In full-wave rectification, this electromagnetic brake acts over the entire rotation of the rotor, so that the unbalanced vehicle cannot stop the pulling torque and stops at an earlier point of rotation. As a result, the rotation angle of the unbalanced vehicle is narrowed and the power generation efficiency is extremely deteriorated.

In the present invention, this problem has been solved by using half-wave rectification, which was conventionally considered to be inefficient. An example thereof is shown in FIG. FIG. 5 is an explanatory diagram of a charging circuit according to the present invention. The torque generated by the unbalanced vehicle 51 is transmitted to the rotor 53 by the speed increasing train wheel 52. A change in the magnetic field generated by the rotation of the rotor 53 is transmitted to the coil 55 via the stator 54, and an induced voltage is generated at both ends of the coil. Reference numeral 57 is a capacitor that is a power storage means, stores the electric power generated in the coil 55 through O ₁ and O ₂ , and supplies the electric power to the timepiece body 56. This condenser
The limiter 58 is an overcharge prevention circuit having a withstand voltage of 57 or higher.

59 is a diode that acts as a half-wave rectifier. Again 59
Also serves as a backflow prevention diode that prevents the power stored in the capacitor 57 from being lost through the coil 55 when no AC power is generated in the coil 55.

The difference in power generation between using the half-wave rectification circuit and using full-wave rectification will be described with reference to FIG.

FIG. 6 shows a current waveform flowing into the power storage means 57,
6 is a comparison of the conventional full-wave rectification circuit shown in FIG. 4 and the half-wave rectification by one diode 59 according to the present invention shown in FIG. 60 is the reference line. 61 is the generated current in the conventional rectifier circuit, 62 is the generated current in the present invention, 63 is the loss due to the voltage drop in the conventional full-wave rectifier circuit, and 64 is the voltage in the half-wave rectifier circuit according to the present invention. It is the loss due to the drop. Conventionally, the amount of electric charge stored in the storage means is the area covered by 61 and 63.
It is the area covered by 62 and 64. In this area comparison, there is almost no difference, and the storage performance is the same. The reason why there is no difference in the power storage performance when half-wave rectification is used compared to conventional full-wave rectification is described below. No current flows through the coil 22 during the period of being cut by half-wave rectification (indicated by 66 in FIG. 6), and therefore the electromagnetic brake torque applied to the rotor is small, so the unbalanced vehicle moves faster. That is, the energy for the period of 66 is stored as kinetic energy of the unbalanced vehicle and is released at the time of power generation. Therefore, the peak value of 62 is larger than that of 61. In addition, the rectification loss is also reduced by halving the number of diodes to two. As a result, the power generation and storage performance of the half-wave rectification is not worse than that of the full-wave rectification.

When half-wave rectification is used, since the kinetic energy of the unbalanced vehicle can be rotated in a higher state due to the smaller number of magnetic brakes as described above, the rotation angle of the unbalanced vehicle must be larger than that of full-wave rectification. It is possible to generate electricity by rotating the rotor extra. In this way, by increasing the rotation angle of the rotor to increase the rotation angle, it is possible to secure an amount of power generation that is comparable to full-wave rectification despite half-wave rectification, and to retain the drive energy of unbalanced vehicles. As a result, the rotation angle of the rotor is surely expanded and the power generation efficiency is improved. In particular, the speedup ratio between the unbalanced vehicle and the rotor is extremely large, so even a slight increase in the rotation angle of the unbalanced vehicle will lead to a large rotation of the rotor, which will have a considerable impact on the power generation efficiency for the small power generator. . According to the configuration of the present invention, even if the person carrying the wrist watch makes a slight movement such as desk work, the unbalanced vehicle immediately starts,
It connects the tilt of the unbalanced car to the effective rotation of the rotor, ensuring that enough power is stored to run the clock.

Of course, full-wave rectification uses four diodes, whereas half-wave rectification requires only one diode, which is of course advantageous in terms of space efficiency required for small portable devices. . Since the number of elements is small, it is easy to manage the reliability.

The control circuit 6, the drive circuit 7, the converter B8, the reduction wheel train 9, and the pointer 10 from the storage means 5 onward in FIG. 1 are the same as the conventional ones, and well-known mechanisms are used.

In the power generator of the present embodiment, the rotor magnet is a thick-walled cylindrical type and is extremely easy to process, and any magnet such as a rare earth magnet can be used. Further, since the magnetic flux of the magnet is formed by taking out the magnetic circuit by the high magnetic permeability material such as the stator and the magnetic core, the number of magnetic flux φ interlinking the coils is extremely large. Therefore, from this aspect as well, the power generation efficiency is significantly increased. Further, in this embodiment, the magnet and the coil are arranged so as not to be cut on the layout, and the magnet and the coil are magnetically coupled with each other by the plate-shaped stator, so that the magnet and the coil are easily assembled, and a thin power generator is provided. Further, since each element can be arranged in a distributed manner, it is possible to freely arrange other components, for example, a clearance such as a train wheel or a circuit, in consideration of the layout of the entire timepiece, and the space efficiency is extremely good.

Further, in this embodiment, a large-capacity capacitor is used as the electricity storage means. The capacitor is not a chemical reaction such as a battery but a physical phenomenon, and the life of the power storage means itself is extremely long.According to the system according to the present embodiment, the same life as that of the conventional mainspring system can be obtained. It is possible to realize a highly accurate timepiece such as a quartz timepiece without any trouble.

In addition, by disposing the diode on the power generator side of the limiter, the adverse effect at the time of current cut of half-wave rectification is absorbed to improve the charging efficiency.

Unbalanced part 31b of unbalanced vehicle as rotating means
Of course, not only this structure but also others are possible. For example, in FIG. 3, if it is arranged on the bridge 33, a large amount of unbalance can be easily obtained.

Although a large-capacity capacitor is used as the power storage means 5 in this embodiment, any power source that can be charged may be used. For example, rechargeable lithium batteries, solid electrolyte batteries, and the like are being put into practical use in recent years, and these are also power sources suitable for the present invention because of their large capacity and long-term reliability. Further, the silver battery can be used as a power storage means although it has some problems in long-term reliability.

Further, although the configuration from the control circuit after the storage means to the pointer which is the display means in FIG. 1 is shown as an example of the needle display, the display means may be a digital display such as LCD instead of the needle.

[Effects] As described above, according to the configuration of the present invention, the leakage of magnetic flux caused by connecting the stator pole pieces with each other by the thin portion as described above is skillfully used, and the half-wave rectifier circuit is used. It was possible to use a balance car and reduce the size of the entire power generator so that it could be incorporated into a small portable device such as a wristwatch. At the same time, even if a small unbalanced vehicle is used, even a slight movement of a small portable device will surely activate the unbalanced vehicle and thus the rotor, and will surely expand the rotation angle of the unbalanced vehicle to enhance the power generation effect. The present invention provides a small power generator that can be put to practical use. When the small power generator of the present invention is incorporated into a wristwatch, it is possible to generate and store electricity enough to drive the watch even with a slight movement such as desk work, and the small power generator can be used in daily life. The device is provided.

In the power generator of the present invention, the magnet and the coil are cut off in the layout, and the magnet and the coil are magnetically coupled with each other by the plate-shaped stator, so that the power generator is easy to install and is a thin power generator. Further, since each element can be arranged in a distributed manner, the layout of the mobile device can be taken into consideration, and the elements can be freely arranged in the gaps of other constituent parts, for example, circuit parts, and the space efficiency thereof is outstanding. Furthermore, by using half-wave rectification, the number of elements can be reduced and the space can be reduced.

[Brief description of drawings]

 FIG. 1 is a block diagram showing the concept of the system of the present invention. FIG. 2 is an explanatory view of the power generation mechanism. FIG. 3 is a sectional view of a train wheel portion. FIG. 4 is an explanatory diagram of a conventional rectifier circuit. FIG. 5 is an explanatory diagram of a charging circuit according to the present invention. FIG. 6 is a stored current waveform diagram. 1 ... Rotating means 2 ... Speed increasing means 3 ... Power generation mechanism 4 ... Rectifier circuit 5 ... Storage means 20, 53 ... Rotor 21, 54 ... Stator 22, 55 ... Coil

Claims (1)

[Claims] 1. A mechanical-electrical converter comprising an unbalanced vehicle having an eccentric center of gravity with respect to a center of rotation, a rotor provided with a coil, a plate-shaped stator, and a permanent magnet, and a mechanical-electrical converter generating electric power by rotational movement of the rotor. A speed increasing train wheel that speeds up the rotation of the balance wheel and transmits the speed to the rotor, a rectifying unit that rectifies an alternating current generated by the mechanical-electrical converter, and a power storage that stores the current rectified by the rectifying unit. And a stator made of a high-permeability material having a hole concentric with the rotor, the two pole piece portions being connected so as to reduce the pulling torque between the pole piece portions, and the entire circumference of the rotor. And a rectifying means formed of a half-wave rectifying circuit.