JPS5829365A - Converter for electronic timepiece - Google Patents

Abstract

PURPOSE:To improve efficiency while reducing power consumption by using a strong magnet and increasing the thickness of a rotor. CONSTITUTION:Stators 2, 3 are arranged so as to surround a rotor 1 magnetized at two poles. The stators 2, 3 are joined by stator thinnest sections g<1>, g<2>, which are unified and width thereof is extrememly narrowed. The stators 2, 3 are fixed to a yoke 5, on which a coil 4 is wound, by means of screws 6, 6', and a pair of the stators are formed. Notches 2a, 3a are shaped to the stators 2, 3 so that the rotor 1 can be turned in the fixed direction, and the positions of magnetic poles in case of the rest of the rotor 1 are displaced to one of the stators 2, 3. The radius Rr of the rotor 1, the radus Sr of the surfaces opposite to the rotor 1 of the stators 2, 3, the thickness Rt of the rotor 1 and the thickness St of the stators 2, 3 are set so as to satisfy the relationship of 0.6>Rr/ Sr>0.3 and 1.5>Rt/St>=0.8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a conversion iK for electronic watches, and is particularly applicable to step motors that are often used for crystal watches.

The object of the present invention is 2) to reduce the power consumption of such a converter.

The so-called quartz crystal analog hour hand uses a crystal oscillator as the time standard and mechanically displays seconds, minutes, 5 o'clock, etc. For tatami watches, the 1 hour standard is extremely accurate, and the reliability of the displayed time is high. On the other hand, the life span of the power supply battery is greatly affected by the fl& of the crystal oscillator, which is the time standard. In a crystal clock having an electromechanical conversion mechanism, the oscillation Lgl
The power consumption of the electromechanical conversion mechanism is much higher than the power consumption of the electronic circuit section including *, and higher efficiency and lower power consumption of the converter are expected to extend the life of the power source battery. So far, there have been 11 different ways to reduce the power consumption of converters, but there are still 11 ways to reduce power consumption! The fins are very large.

This invention has been developed by improving the most efficient motor among conventional step motors, resulting in a motor with even higher efficiency and lower power consumption.

Examples will be described in detail below.

Figures 1 and 2 show a motor according to the present invention.

1 is a nine rotor with two poles, and a stator 2.3 is arranged so as to surround this rotor 1.

The stator 2.3 is a single unit and is connected by a very narrow stator widest part gx 9 gm. This stator 2 and 3 are fixed to a yoke 5 wound with a coil 4t with screws 6 and 6', forming a set of stator wheels. The stator 2.3 has a notch 2as! so that the rotor 1 can rotate in a fixed direction. Sa is provided to shift the positions of the magnetic poles (N$P and 8) when the rotor 1 is at rest to 10,000 degrees from the stator 2 and 3. The dashed line indicates the rest position of the rotor poles. $
Figure S shows the driving voltage waveform applied to the coil 4. For example, a positive pulse and a negative pulse t are alternately applied every second (to form a so-called inverted pulse), so that the rotor 1° magnetic pole N
The pole ts#A is the applied voltage (the magnetic repulsion force and attraction force of the N-pole and the 8-pole generated in the system stator 2-5!47, l:l
-11t rotates 180°, and in the next pulse, the N pole I8 generated in the stator 2.3 also reverses, so the rotor 1 rotates 1000 times in l, and by repeating this sequentially, the rotation of the rotor 1 is stopped for one time. It is possible to continue with. This type of step motor has been used for a long time.

Among them, a motor that can obtain high efficiency is the best. Conventionally, when using this type of motor, the ratio of the rotor radius Rr and the rotor-to-rotor radius Sr of the stator is 16≦Rr /
It is said that S r ≦ 19 is optimal from the point of view of low power consumption, and in fact, in this plum step motor by Karichika, R r ≦ 19.
/ 8 r f @ (L 65 ~ l 7.

This transportation is based on the conventional step motor O-P.
Maximum energy product of magnet performance is 10~15M-G・0
・Using Ilf material In fact, in the past, practical magnetic materials were limited to rare earth copalt magnets of the order of 10 to 15 M-G-0 as mentioned above. It is from fc. Recently, however, many improvements have been made to such magnets, such as "m@(O
O* 7 e e○U.

With the development of new compositions such as Zr) and □ and an optimal aging treatment method for these, ultrahigh performance age-hardening quinary magnets of 50 M@G Oe have been put into practical use.

This one stone dramatically improves performance while other conditions,
For example, it is a magnet that is easy to put into practical use because it is superior to conventional 9mCOg magnets without being restricted by cost, processing conditions, etc.

The present invention applies such an ultra-high performance magnet to a step motor for an electronic wristwatch, thereby optimizing it and dramatically increasing the efficiency of the step motor.

As mentioned above, the present invention uses a strong magnet tf, f
7tj To increase the thickness of the rotor, F, Rr/8r(α
6, compared to the conventional step motor mentioned above, it achieves significant efficiency and reduction in power consumption. Conventionally, Rr
/ B r must be 16 or more and the next
Fig. B111) This was due to the fact that the required output torque (55 g - 6 m to 4 g am when the minute hand is turned) could not be obtained as shown in the conventional example. However, using a strong magnet (BHmaz=20~30M・G・0・),
If a thicker rotor is used, a good relationship as shown in Figure 4 can be obtained, and Rr / Sr ((Rr / 8 r≧α6゛) Of course, with the above, a large output torque can be obtained, but the current consumption becomes large, so it is not suitable for the purpose of low power consumption. Figure 5 shows an example of measuring the current consumption at one time for xr/BrtfjLfl. The magnet used is BHmax
x30, and Rt/Bt is constant at −1,0.

The size of each rotor (optimum size is determined by the size of the stator notch [ki product). Figure 5 O shows the current consumption To when the output torque is 45 g・1. In this way, R!
/ 8 The current consumption is smaller when r is (L6 or less)
%Rr/sr becomes the smallest when α45 to α6. Rr/Br t - If it is increased, the notch product of the stator must be reduced, and subtle differences in the stator in this area have a large impact on motor performance. This is because the area of the notch is only α5esm&t of the internal area of the stator with a radius of 8r, and even a slight difference in shape causes a large proportion of area change. This C
The curve shows that current consumption increases when Rr/Sr becomes too small. Since the starting current AD is reduced, the value of Rr/8r is effective up to α3, but reducing it below that value will conversely lead to an increase in current consumption.

The current consumption when the output torque is almost 0, that is, the minimum current required for the motor to start.This current value increases as Rr/8r increases, especially from 16 to ( It increases suddenly when it becomes larger than L7.This is proportional to the inertia of the rotor (proportional to the fourth power of the radius of inertia)
The main cause is an increase in This large starting current value is not desirable from the viewpoint of reliability.

In other words, the difference between the dynamic current and the current that produces an output torque of 55 g is small, so a slight difference in input energy will result in a large fluctuation in the output torque. For example, a slight drop in the pressure in electric a1 will cause the output torque to drop and cause the motor to stall.

Furthermore, it is not suitable for use as a motor that changes the output energy depending on the load, such as a pulse width control motor.

Figure 6g6, which explains the rotor thickness Rt and stator thickness St, shows that only the rotor thickness is changed without changing other conditions such as Rr s S r (that is, Rt/z
stt) and measure the current consumption. 6th
The figure y is the output torque of 55g and the current consumption of the country! D,@
Figure 6G shows the minimum power required for startup. Output torque l
The power consumption R1 during sg and -cyr increases as Rt/at becomes smaller, and shows a rapid increase when Rt/8t becomes 71, which is smaller than α8. - The starting electric current fiG increases as Rt/at increases, but the slope is gradual. Therefore, as a result, ηjima et al. decided that R
It can be said that it is advantageous to reduce the power consumption of the motor when t/day t is equal to or larger than αS. Regarding the upper limit of this Rt/at ratio, data up to 12 has been obtained here, but there is a possibility that it can be made even larger. Therefore, using common sense, it would be meaningless to increase this value (2ts or more).If you also take into account the implementation issues of making the watch thinner, the upper limit is approximately t2 to 1.25. Cheng Jia would be appropriate.

Thus obtained nine motors of the present invention and conventional motors (Rr/Sr≧α6*Rt/Bt-α
Comparing the best 7-IlB and 8-stone BHmaxxl 0-15), it is possible to reduce power consumption by 15-20%. The current consumption of an example of a conventional motor (at an output torque of 15g-m) is as shown in Fig. 5, 11iK1.In the conventional system, the limit is almost to a d-step motor's power consumption R of about 1μm. According to the present invention, there is a possibility that the size becomes smaller by αSμm or even smaller by 4h.

As described above, by applying the ultra-high performance magnet to the rotor of a step motor for electronic wristwatches, the present invention significantly increases efficiency and optimizes the structure of the motor. The major difference in the structure of the motor of the present invention is shown in FIG. That is, I! Reason 7 (a) is the configuration of a conventional motor, where the outer diameter of the rotor 12 is relatively close to the inner diameter of the stator, so the gap tO between the rotor 12 and stator 11 is small. On the other hand, Fig. 7 of the present invention (the structure of the phrase is the inner diameter of the stator!! 14 and the outer diameter of the rotor 15 O1l
However, the gap 16 between them is much larger than the conventional one.

Common sense suggests that the larger the gap between the rotor and the stator, the more difficult it is to reduce the conversion efficiency of the motor. Therefore.

I will briefly touch on the reasons why the configuration of the present invention improves efficiency.

One of the reasons is that the inner diameter of the stator is the same and the diameter of the rotor is smaller than the diameter of the rotor based on the structure of the present invention.
In other words, the rotor's inertia is heated by @destruction. If the inertia becomes smaller.

- 9 efficiencies with less inertia loss in the company are the same as above.

The l- in 1 and 2 depends on the magnetic flux distribution in relation to the rotor-stator. The output of the motor is as loud as the rotor's l.
I! The more magnetic flux there is, the larger it becomes. However, as the number of parts 11a increases, the magnetic attraction force between the rotor and the stator becomes greater.When driving, it is necessary to overcome this attraction force, and the current consumption increases accordingly. Furthermore, since this magnetic attraction force also affects the stability of the motor when it is stationary and cannot be reduced, the step motor is designed so that this magnetic attraction force is constant.

By the way, the configuration of the conventional step motor (Figure 7 (SL)
)) 1″ is the gap 1 between the rotor and stator 11
Almost all of the magnetic flux 13 of the narrowed rotor with a small 0 acts on the magnetic attraction force with the stator 11.

In contrast, in the configuration of the present invention (w, Figure 7(b)), the gap 16 is large, so the magnetic flux 1 that acts on the magnetic attraction force
7 and the magnetic flux 18 that closes on the rotor itself, and #I life has a relatively large number of these 6 fluxes 18.

Therefore, i! Assuming that (&) and (1+) have the same magnetic attraction force, the total magnetic flux of the rotor will be greater in Figure 7 (and there is more magnetic flux 18 that closes on itself).

Therefore, if the same driving force is applied, the step motor with the configuration of the present invention can obtain a larger output. Power consumption can be driven by electricity, increasing efficiency.

Although a detailed example of the present invention has been described above, the present invention is not limited to the detailed example described herein, and various modifications, changes, and applications are possible. For example, the rotor is not a perfect circle *m, but -i! as shown in Figure 8! yen l11rj
It is acceptable even if it has IJt.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a two-pole step motor for a quartz watch according to the present invention. Figure II2 is a sectional view of a portion of the rotor in Figure 111. Figure 3 shows the pulse waveform applied to the coil. Figure 4 shows output torque at the 1-minute hand, Rr/8r, and C) @ diagram. The ggs diagram is a diagram showing the relationship between the current consumption of the motor and Rr/sr. 6vjA is the motor current consumption and Rr/8r
FIG. FIG. 7 is a diagram showing the magnetic flux distribution in the rotor-stator relationship. FIG. 8 shows another example of the rotor shape. 1... Rotor 2-5... Stator 2a, 3a... Non-chip Rr... Radius of cylindrical rotor magnet Rt... Thickness of cylindrical rotor magnet 8r... Cylindrical rotor 6 of stator Radius St of the surface facing the stone...Thickness of the stator or more Applicant Suwa Keikosha Co., Ltd. Agent Patent Attorney Mogami Tsutomu No. 1! , 2'32 m-! j 3rd Snake Figure 8

Claims (1)

[Claims] fl+ A rotor made of Mizukude stone magnetized to at least two poles, an integral stator made of a plate-shaped high-ASI material that engages with the rotor six-dimensionally, and the stator and α6 > Rr / S r >
An electronic clock phase changer characterized by having a relationship α3 and a relationship t5>Rt/st≧α8 between the rotor thickness Rt and the stator thickness St. (2) The electronic timepiece converter according to claim 1, characterized in that the maximum energy fi (BHma:c) of the permanent foundation stones constituting the rotor is 20 M@G*Oe or more.