JP2503748Y2 - Picture display quartz watch - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a quartz wristwatch that rotates a disk on which a picture or the like is printed.

[Conventional technology]

Conventionally, there was a quartz wristwatch equipped with a disk (hereinafter referred to as a picture board) printed with a picture of manga etc. on a thin sheet of transparent polyester instead of the second hand, but the output torque was limited and the small outer diameter Only things were practical.

[Problems to be solved by the device]

That is, when the outer diameter of the picture board is small, the picture to be printed is small, and since the printing is performed, the movement is small and the appearance is sober that the picture is not interesting. In some cases, the outer diameter of the picture board is set larger even at the expense of performance, but there is a problem that it caused a light shock during carrying and the clock stopped at low temperature in winter. there were.

An object of the present invention is to provide a quartz wrist watch that solves the above-mentioned conventional problems, realizes the original interest of the picture display, and does not worry about the quality of the watch. .

[Means for solving the problem]

In order to achieve the above object, the present invention has the following configuration. That is, in a quartz wristwatch in which a disk is driven by a step motor, the disk, which is a thin plate on which a picture or the like is printed, is fixed to a fourth wheel, and when the rotor of the step motor instantaneously makes a step rotation, this rotation is performed. The disk is also instantaneously step-rotated in conjunction with the rotation of the rotor, the rotor is rotating at a frequency of 2 Hz or higher, and the fourth wheel is rotated from the rotor to the rotor 4 times so as to rotate once per minute. It is configured such that the train wheel is decelerated and the disk is rotated once per minute at a frequency of 2 Hz or higher.

[Action]

With the above configuration, the picture board is rotated once per minute at a frequency of 2 Hz or higher. That is, as will be described in detail later, in the relationship between the rotor of the step motor and the torque of the picture board, the torque load applied to the rotor by the moment of inertia of the picture board is inversely proportional to the square of the reduction ratio between them, so the rotor frequency is increased. When the reduction ratio is increased by increasing the gear ratio, the moment of inertia of the picture board can be rapidly increased.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First
FIG. 1 is a sectional view of a train wheel portion of a quartz wrist watch according to the present invention. The step motor is composed of a stator 8, a rotor 7, and a coil (not shown). Rotation of the rotor 7 passes through a sixth wheel 6, a fifth wheel 5 and a fourth wheel 4 which are reduction gear trains.
Is transmitted to The rotor 7 having the two-pole magnet 7a is, for example, 4H
It rotates at z, the reduction ratio by the reduction gear train is set to 120 (the reduction ratio when rotating at 1 Hz is 30), and the fourth wheel & pinion 4 makes one rotation per minute. Next, decelerate via 3rd wheel 3 and 2nd wheel 2 and move to the minute hand
15 is moved. 12 is an hour wheel and 14 is an hour hand. 4th car 4
A picture board 16 in which a picture-printed polyester sheet 16c having a thickness of 0.05 mm is sandwiched between a shaft 16a and a seat 16b is fixed to the tip of the. 1 is a main plate, 9 is a center bridge which fixes a central pipe 10 which serves as a rotation guide for 4th wheel 4 and 2nd wheel 2, 11 is a 4th spring which prevents uneven rotation due to inertia of a picture board 16, and 13 is a deceleration A train wheel bridge that supports the upper hoso of the train wheel, and 17 is a dial. Picture board 16
In the same manner, the rotor 7 is instantaneously stepwise rotated in association with the motion of the rotor 7 being instantaneously stepwise rotated.

FIG. 2 is an external view of a general wristwatch of a picture board display type including, but not limited to, the present invention introduced in FIG. A manga is printed on the picture board 16, and the radius of the disk is A. The parting diameter (the diameter through which the dial can be seen) was B.

FIG. 3 is a meshing diagram of tooth profiles of the sixth wheel and the fifth wheel of FIG. The pinion 6a of the sixth wheel & pinion 6 meshes with the fifth wheel 5a, which has thin teeth and long elasticity. Picture board (Fig. 1-16)
Has a function of reducing the sudden rotation of the picture board as an aid in reducing the load torque of the rotor (FIG. 1) due to the moment of inertia.

Fig. 4 shows the moment of inertia of the disk when the disk is attached instead of the second hand in the current general quartz watch.
It is the correlation diagram which calculated | required the relationship of the output torque (The numerical value which a clock stops when the load of the value of this output torque is applied) in a minute hand was calculated | required.

The timepiece transmits power to the minute hand via the reduction gear train by the rotation of the motor. This force fluctuates in the short term and in the long term due to the influence of the transmission efficiency and friction of the gears of the train wheel, the change due to the temperature and deterioration of oil, the resistance due to dust, and the like. The battery also has temperature characteristics such that the internal resistance increases at low temperatures and the motor output decreases. Further, a watch is often subjected to a moderate shock (a shock generated in daily life) while being carried. Even in such an environment, it is necessary to guarantee that the time of the clock will not be out of sync. For this guarantee, the lower limit of the output torque at the minute hand must be set, but this lower limit value is empirically known. This lower limit differs depending on the type of watch, but as shown by the shaded area in Fig. 4, it is set to about 2g · cm for general watches. That is, when the output torque is 2 gcm, the range of moment of inertia of the disk is about 200 m.
It shows that it is g · mm ² .

Now, the load torque T of the rotor due to the moment of inertia of the picture board is calculated.

The moment of inertia of the picture board; J Reduction ratio; N The angular acceleration of the rotor; if we put it, the angular acceleration of the picture board; / N Torque of the picture board; J / N Therefore, the load torque T applied to the rotor is T = J / N ² …… (1) On the other hand, when the picture board is a disk with outer diameter D, thickness t, and specific gravity γ, the moment of inertia J is J = πγD ⁴ t / 32 Substituting this into equation (1) gives T = KD ⁴ / N ² (2) (where K is πγt / 32) When a disk is attached instead of the second hand in the current general quartz watch, the moment of inertia of the disk is as shown in Fig. 4. As is increased, the output torque decreases. According to the experiments, the upper limit was about 200 mg · mm ² to guarantee the operation of the watch when it was subjected to external disturbance while carrying it and when the temperature was low in winter. (The shaded area in Fig. 4) If a polyester sheet is used, the outer diameter will be 14 mm even if the minimum thickness of 0.05 mm is used to obtain flatness without bending due to its own weight.
It is a degree. Examining with reference to FIG. 2, if the usual watch has a parting diameter B of about 25 mm and the outer diameter A of the disk is 14 mm, the picture is small and the movement toward the center is small. The outside diameter A of the picture board is not preferable in terms of design unless it is at least 70% of the parting diameter B and ideally about 90%.

Here, let's examine how large the outer diameter of the disk can be when the rotational frequency of the rotor is changed from 1 Hz to 4 Hz with the same load torque applied to the rotor. 1Hz and 4Hz
If the permissible outer diameters of the disk in the case of are D ₁ and D ₂ and the reduction ratios are N ₁ and N ₂ , respectively, then from the formula (2), D ₁ ⁴ / N ₁ ² = D ₂ ⁴ / N ₂ ² Therefore, D ₂ ² = D ₁ ² N ₂ / N ₁ (3) N ₂ / N ₁ = 4, so D ₂ = 2D _{1 From} this, it is calculated that the outer diameter is 2 times the outer diameter 14 mm at 1 Hz. It is possible to use a 28 mm disc and the parting diameter B
On the other hand, if the size is ideal, for example, B = 25 mm, 90% of the outer diameter of 22 to 23 mm can be reliably used.

As a method of increasing the outer diameter of the disc by a method different from the above, there is also a possibility of increasing the output of the motor. Supplying four times as much power to the motor as consuming the same power as 4Hz means that the battery limits the voltage and injects four times as much current, but the number of coil turns must be reduced. However, the efficiency of the motor is significantly reduced, and there is also a problem of the maximum allowable current of the battery, which cannot be adopted. Moreover, even if the output of 4 times can be obtained, if the formula (2) is examined, the outer diameter D is only 1.4 times even if T is 4 times.

In this embodiment, the rotor is set to 4 Hz, but this is convenient because it can be easily pulled out from the middle of the 1 Hz output frequency dividing circuit of the 1 second hand movement currently in use, but the present invention is particularly limited to 4 Hz. is not. The present invention also includes a system in which the user looks as if the picture board is driven once per second, not as signals at equal intervals, but as signals at non-equidistant intervals in which four signals are continuous in a short time.

It should be noted that a larger picture board can be attached by increasing the rotor driving frequency. For example, consider the case where the rotor driving frequency is 2 Hz.

If the allowable outer diameter of the disk at 1 Hz is D ₁ reduction ratio N _1, and the allowable outer diameter of the disk at 2 Hz is D ₃ reduction ratio N ₃ , then D ₃ ² = D ₁ ² N ₃ / N ₁ , N ₃ / N ₁ = 2, so D ₃ = 1.4D ₁ Therefore, it is possible to use a disk with an outer diameter of 1.4 times, which is D _{If 1} = 14 mm, D ₃ = 20 mm, and about 80% of the above-mentioned parting diameter B = 25 mm can be used as a disc, and a design that is comparable to that in design can be obtained. . In addition, in the above-described method of increasing the output of the motor, even if the output is doubled in the same manner,
The outer diameter is only 1.2 times (17 mm).

By the way, as described above, the reduction ratio N ₄ / N ₁ is calculated when the outer diameter A is set to about 70% of the parting diameter B.

(3) When the equation similar to equation of _{N 4 / N 1 = D 4} 2 / D 1 2 assigns to the to ^{_{N 4 / N 1 = 17.5 2}} /14 2 = 1.6 A / B = 0.7 From this, The drive frequency of the rotor is 1.6H
It will be better if it is larger than z, but in reality the integer drive frequency of the rotor is good, so if the board is rotated once per minute at a frequency of 2 Hz or higher, it may not look good in terms of design. You can get no clock. The picture board is supposed to have a picture printed on it, but the invention also includes a picture board on which another picture is pasted or punched.

[Effect of device]

As is clear from the above description, according to the present invention, not only is it possible to reduce the load torque of the rotor by increasing the reduction ratio of the train wheel, but also by increasing the rotation frequency of the disc, By making the angular acceleration smaller and thereby making it possible to lower the load torque due to the moment of inertia. By acting synergistically, the 4th wheel has a sufficiently large disk of 70 to 90% of the parting diameter of the watch. It can be attached, and it can be rotated without any problems in terms of quality, and it has the effect of providing a watch with an interesting design.

[Brief description of drawings]

FIG. 1 is a sectional view of a train wheel portion of a quartz wrist watch according to the present invention, FIG. 2 is an external view of a general picture display type wrist watch including the present invention, and FIG. 3 is a description of the train wheel engagement of FIG. Figure, 4th
The figure is a correlation diagram between the moment of inertia of the disk and the output torque. 4 …… No. 4 wheel, 7 …… Rotor, 16 …… Picture board.

Claims (1)

(57) [Scope of utility model registration request] 1. In a quartz wristwatch in which a disc is driven by a step motor, the disc, which is a thin plate on which a picture or the like is printed, is fixed to a fourth wheel, and the rotor of the step motor instantaneously makes a step rotation. At the same time, the disc is instantaneously stepwise rotated in conjunction with this rotation, and the rotor is
It rotates at a frequency of 2Hz or more, and the 4th wheel is 1
A disk-driven quartz wristwatch, characterized in that the rotor to the fourth wheel are decelerated so as to rotate once per minute, and the disk is rotated once per minute at a frequency of 2 Hz or higher.