JPH0128353B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a small motor used in a watch.
More specifically, the present invention relates to a small motor having a function of notifying the user when the voltage of a battery power supply drops below a specified value.

In fields such as watches and calculators, there are devices that have a function that predicts the lifespan of batteries used as power sources, but conventionally, battery voltage drops are detected purely electrically, and when the voltage drops to a certain value, For example, by activating a buzzer or making the second hand advance by 2 seconds every 2 seconds, the user was warned that the battery was nearing its end of life and urged to replace the battery. . As a result, electrical circuits became complicated.

Therefore, the present invention is designed to make it possible to predict the battery life of an analog timepiece without making any changes to the electric circuit, and also to display an operation display at the same time.

In the first embodiment shown in FIG .
is composed of a plate 2 and a plate 3, the plate 3 is connected to both ends of the plate 2, and a bobbin 5 around which a coil 4 is wound is inserted through the plate 2. Two pairs of stator magnetic poles 6a, 6b and 7a, 7b are formed on the plate 3 at positions separated by a predetermined center distance d,
A first rotor 8 and a second rotor 9 are rotatably inserted between each set of stator magnetic poles 6a and 6b, 7a and 7b. stator magnetic poles 6a and 6b,
7a and 7b are a pair of notches 10 and 10, respectively.
and 11, 11 are formed facing each other, and due to the existence of these notches 10, 10 and 11, 11, the rotors 8, 9 are statically and stably stationary at an angle deviated from the dynamic magnetic center. However, the self-startability and rotational direction of the rotors 8 and 9 are thereby determined. That is, each time an inverted pulse signal is supplied to the coil 4, the rotors 8 and 9 move in the direction of the arrow.
Rotate in steps of 180°. Further, the stator magnetic poles 6a and 6b, 7a and 7b are respectively narrowed by the narrow portion 1.
Although they are mechanically connected as one body through the narrow portions 12 and 13, the narrow portions 12 and 13 have a large magnetic resistance, so they are effectively separated from each other magnetically. be equivalent to.

In such a step motor with a notch, the minimum starting voltage Vmin of the rotors 8 and 9 is determined by the gap e ₁ , e ₂ between the rotor and the stator magnetic poles, or by the notch 1.
This can be controlled by the radii R ₁ and R ₂ of 0 and 11, the magnetic flux density of the rotors 8 and 9, the inertia of the rotors 8 and 9, or a combination thereof. For example, as shown in FIG. 2, the gap e ₁ ,
As e ₂ increases, the minimum starting voltage Vmin decreases, and as the notch radii R ₁ and R ₂ increase, the minimum starting voltage Vmin increases. Further, as the magnetic flux density of the rotor increases, the minimum starting voltage Vmin increases, and as the inertia of the rotor increases, the minimum starting voltage Vmin increases.

Therefore, in the present invention, the gap e ₁ , e ₂ , the notch radius R ₁ , R ₂ , the magnetic flux density of the rotors 8, 9, and the inertia thereof are appropriately combined, and the rotors 8 and 9 are
The minimum starting voltage Vmin was set to be 1.1 volts and 1.2 volts, respectively. The rotor pinion 14 of the rotor 8 is meshed with a gear 15 of a clock train, and the rotor pinion 16 of the rotor 9 is meshed with a gear 17 with a battery life notice display. The top surface of this gear 17 with a battery life warning display is color-coded, for example, in two colors, red and white, at a predetermined center angle, and the top surface is a clock dial or case (both shown in the figure). It can be seen through a window hole 18 (not shown).

Use a battery with an initial normal voltage of 1.5 volts or more,
When an inverted pulse signal is supplied to the coil 4, the rotors 8 and 9 each rotate in steps of 180 degrees in the direction of the arrow. The pinion 14 of the rotor 8 drives a gear 15, which in turn drives the hour and minute hands via a well-known clock train. At this time, the pinion 16 of the rotor 9 is the gear 17
The color-coded portions on the upper surface of the gear 17 alternately appear in the window holes 18 to perform a second flash. That is, while the second flash is visible through the window hole 18, it means that the battery voltage is sufficient and the watch is operating normally. As time passes, the battery voltage drops, and when it drops below 1.2 volts, the rotor 8 is still operating and the clock is driven. However, since the rotor 9 stops operating, the second flash disappears from the window hole 18. This allows the user to know that the battery is nearing the end of its life and replace it with a new one.

The second embodiment shown in FIG. 3 is an example in which the design of the stator shape etc. has been changed. In this example, the stator 101 is formed into a U-shaped integral structure having parallel legs 102 and 103. has been done. coil 10
A bobbin 105 wound with 4 is inserted through the leg portion 102. The legs 102 and 103 have a pair of stator magnetic poles 106 separated by a predetermined center-to-center distance D.
Two sets, a, 106b and 107a, 107b, are formed facing each other, and a first rotor 108 and a second rotor 109 are respectively rotatably inserted between the stator magnetic poles of each set. Stator magnetic pole 106a
and 106b and 107a and 107b have notches 110, 110 and 111, 111, respectively.
are formed oppositely, and these notches 110, 111
Due to the existence of the rotors 108 and 109, the rotors 108 and 109 are statically and stably stationary at an angle deviated from the dynamic magnetic center, thereby determining the self-startability and rotational direction of the rotors 108 and 109. Similarly to the first embodiment, the minimum starting voltage Vmin of the rotor 109 is set higher than that of the rotor 108, and the rotor 108
A pinion 114 of the rotor 109 is meshed with a gear 115 of the clock train, and a pinion 116 of the rotor 109 is meshed with a gear 117 with a battery life notice display. The operation is the same as in the first embodiment.

It should be noted that the present invention can be modified in design without departing from its technical concept, and can be applied to, for example, a sweep type motor or a mechanical timer.

As described above, according to the present invention, it is possible to predict the battery life without providing a complicated circuit, and in addition, it is also possible to normally display an operation display such as a seconds flash. Moreover, it is easy to design and can be constructed at low cost.

[Brief explanation of drawings]

Fig. 1 is a partially sectional plan view of the first embodiment based on the present invention, and Fig. 2 is the minimum starting voltage Vmin at that time.
FIG. 3 is a partial cross-sectional front view of a second embodiment of the present invention. 1 , 101 ... Stator, 4, 104... Coil, 6a, 6b, 7a, 7b, 106a, 106
b, 107a, 107b...Stator magnetic pole, 8,
108...First rotor, 9,109...Second rotor, 15,115...Clock train gear, 17,1
17...Gear with battery life warning display.

Claims (1)

[Claims] 1. A small motor that includes a stator, a rotor, and a coil and uses a battery as a power source, the stator having two sets of paired stator magnetic poles, and a first rotor that drives a clock train. and a second rotor that drives the battery life notice display board is rotatably inserted between each set of stator magnetic poles, and the minimum starting voltage of the second rotor is higher than that of the first rotor. A small motor with a battery life warning function that is characterized by its large size.