JPH0112232Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a support shaft for pivoting a second wheel, which is part of a wheel train mechanism, in a pointer display type electronic wristwatch.

[Conventional technology and problems]

The basic hand displays of current hand display type electronic wristwatches include two-hand models that display hours and minutes, and three-hand models that display seconds. The conventional two-hand movement structures can be broadly classified into the following two types of structures.

One of these is a two-hand movement that moves the minute hand in steps of several seconds. In other words, the rotation angle of the minute hand is different from the second hand in 1 second.
Since the movement is extremely small at 0.1 degrees, a 2-hand movement can be used as a 1-hand movement just like a 3-hand movement.
Even if the hands move in second steps, the practical value of the product is low, so we prioritized longer battery life, which general users desire for electronic wristwatches.

That is, there are many methods to extend the life of a battery, but within a given movement size, a method that reduces the current consumption of the battery is widely used. Of the total current consumption of an electronic timepiece movement, the current consumed by the step motor is much larger than other current consumption, and by reducing the current consumption, it is relatively easy to extend the life of the battery. In order to reduce the current consumption of the step motor, it is sufficient to simply lengthen the drive interval of the step motor. In particular, as mentioned above, the rotor rotation interval of the step motor is set so that the minute hand moves in steps of several seconds. However, it has been put into practical use by determining the reduction ratio of the number of engagement stages of the pointer display wheel train in accordance with the rotation interval of the rotor.

Next, the other two-hand movement structure is
This method uses a 3-hand movement, removes the second hand engagement part of the 4th wheel to which the second hand is attached, and drives the minute hand in 1-second steps in the same way as the 3-hand movement. It has been put into practical use since it can be easily improved, the manufacturing load is small, and there is a great advantage of common parts.

However, it has been difficult to satisfy the latent market needs for low-cost, long battery life, and thinner electronic watches using the methods described above, but in recent years, two-hand and three-hand watches have been difficult to meet. 2-hand and 3-hand movements that have the advantages of both hand movements.
It is well known that movements with shared hands have been put into practical use.

In particular, recent technological advances have led to the miniaturization of major elements, including electrical elements such as crystal oscillators and circuit chips, batteries that power electronic watches, and step motors as electromechanical converters. The size of the 2-hand pointer display wheel train and the 3-hand pointer display wheel train need to be rearranged and arranged as the proportion of the planar space occupied by these main elements in the watch movement has decreased. A minimum planar space can be secured, making it possible to realize the above-mentioned shared movement.

In addition, switching between several-second step movement of a two-hand movement and one-second step movement of a three-hand movement is achieved by a circuit block that outputs drive pulses for the step motor, especially the output gates for two-hand pulses and three-hand pulses. By arbitrarily selecting a wiring pattern placed on a circuit block equipped with a circuit chip that is equipped with a circuit chip so as to be electrically conductive with the circuit chip, and cutting out unnecessary patterns, it is possible to eliminate the need to replace the circuit block. It can be easily switched.

Furthermore, there are many movement structures that take into account the market need for thinning, but the conventional method is to use a central pipe to attach the second wheel to which the minute hand is attached. In other words, if you look at a three-hand movement, the center pipe for pivoting the second wheel is installed in the middle bridge, and the second hand is moved by the through hole in the center pipe and the bearing in the gear train bridge. This structure supports the attached fourth wheel, and also determines the vertical position of the fourth wheel using the center pipe and gear train bridge.

If this is to be converted into a two-hand movement, the pointer display wheel train will need to be rearranged, but in order to reduce costs, a deceleration wheel train that moves the minute hand in steps of a few seconds will suffice. The 4th wheel, which is driven in 1-second steps and used in the needle wheel train, is no longer necessary, and there is no space between the center pipe and the train wheel bridge, and the space is hollow.

For this reason, when attaching the hour and minute hands of a two-hand electronic wristwatch, there is nothing in the center of the pointer display wheel train to support the needle setting push force, so the center bridge is deformed and the center bridge is deformed. There were major problems lurking in the needles due to mismatched needle spacing and gear train engagement failure.

[Purpose of invention]

The object of the present invention is to eliminate such drawbacks and to provide a wheel train structure in the center of a two-hand watch that is suitable for receiving the reaction force when setting the hands.

[Example of idea]

Hereinafter, one embodiment of the present invention will be described based on the drawings. In the explanation, we will explain a wristwatch that uses both a two-hand watch movement and a three-hand watch movement. Fig. 1 is a sectional view showing the pointer display wheel train of a three-hand movement that is commonly used to explain the embodiment of the present invention, and Fig. 2 is a sectional view showing the pointer display wheel train of a three-hand movement that is commonly used to explain the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a pointer display gear train when the movement is made into a two-hand movement. In addition,
In FIG. 1 and FIG. 2, the same numbers indicate the same elements.

FIG. 1 shows a gear train mechanism that has been widely used in the past, with reference numeral 1 indicating a base plate which is the base plate of a watch, reference numeral 2 having a bearing portion 2a that pivotally supports the lower handle 5a of a fifth wheel 5, and 2
The inner bearing 3 in which the central pipe 10 for pivotally mounting the number wheel 8 is installed is an outer ring bearing having a bearing portion that pivotally supports the upper handle of each car of the pointer display wheel train, and the wheel train bearing 3 is In order to create a low-cost movement, the main plate 1 and the middle bridge 2 are made of relatively thin plate-like members. These are so-called pillar-type clock structures that are supported by several spacing columns (not shown) and vehicles are placed between them. 11 is a coil, and 12 is a stator that includes a rotor 4 therein, and constitutes a step motor that is an electromechanical converter. The rotor 4 has a permanent magnet piece 4a, and bearings 1a, 3 installed in the base plate 1 and the gear train bridge 3.
A fifth wheel 5 is pivotally supported at a and meshes with the rotor 4.
transmits rotation to.

The wheel train mechanism meshes with the fifth wheel 5 and includes a wheel train transmission path of a fourth wheel 6 to which a second hand is attached → a third wheel 7 → a second wheel 8 → a hinōri wheel (not shown) → an hour wheel 9 Take.
In addition, in order to reduce the thickness of the central part of the gear train mechanism, two
The number wheel 8 and the hour wheel 9 are pivotally attached to the center pipe 10 so as to be stacked.

Further, the fourth wheel 6 is supported by the through hole 10a of the center pipe 10 and the gear train bridge 3, and when setting the needle, the fourth wheel pinion 6a is further connected to the gear train bridge 3 through the center pipe 10. The structure allows the movement to withstand the pressing force due to the rigidity of the entire movement. Note that 17 is a dial.

By the way, when considering a wheel train mechanism for changing a three-hand wheel train to a two-hand wheel train, the problem often arises as to how many seconds should be used to move the hands. If there is a margin in the relationship between battery capacity and current consumption when considering battery longevity, it is better to have smaller hand movement step intervals in terms of watch performance. Assuming that this is the gear used, the distance between the true centers of each wheel increases, and the center of each wheel in the gear train group of a 2-hand or 3-hand movement moves further away, allowing for more leeway in the gear train plane arrangement. . FIG. 2 shows a cross section of a two-hand pointer display wheel train that takes these into account. The base plate 1, the middle bridge 2, and the gear train bridge 3 are provided with holes for the bearing portions of each gear train of the three-hand movement even in the two-hand movement.

Furthermore, the basic structure of the watch movement is the same as the three-hand movement. As shown in Fig. 2, the 2-hand pointer display wheel train can be greatly simplified compared to the 3-hand movement, and includes a fourth wheel 6 to which the second hand is attached, When transmitting the signal to the second wheel 8, the third wheel 7, which has the role of decelerating the rotation to 1/60th of a rotation, can also be omitted.

In particular, a second third wheel 13 corresponding to the fifth wheel 5 in a three-hand movement that meshes with the rotor 4 in a two-hand movement is interposed as a reduction wheel between the second second wheel 14 and the second wheel & pinion 14. The second wheel and center wheel 14 onwards are the same as the three-needle wheel train.

However, in order to solve the problem of needle attachment pushing force, which has been a concern in the past, the present invention has two
End portion 15a of the center pipe 15 to which the number wheel 14 is attached
Even if the inner bridge 2 is slightly bent due to the needle attachment force, the end 15a of the center pipe comes into contact with the train train bridge before it is further deformed, and the entire movement is It has a structure that can withstand the pressing force of needle attachment with its rigidity.

Figures 3a, b, and c show the central pipe 15 of the present invention.
FIG. 1 is a partial sectional view showing another embodiment of the invention;
The same numbers as in FIG. 2 indicate the same elements.

FIG. 3a shows that the center pipe 10 for a three-hand movement is used in common with the two-hand movement, and the center pipe 10
A separate member 21 is disposed between the and the train wheel bridge 3, and the position of the separate member 21 is determined by the protrusion 2 of the separate member 21 in the through hole 10a provided in the center pipe 10.
It has a structure in which it engages at 1a.

FIG. 3b shows a case in which the center pipe 10 for three needles is used in common, as in FIG. This structure has the same effect as that shown in FIG. 3a in preventing various troubles caused by needle setting pushing force in a two-hand movement, which is the object of the present invention.

Furthermore, in Fig. 3c, the center pipe 23 for two needles is installed in the middle bridge 2, and the end 23a of the center pipe is extended to the vicinity of the top surface of the gear train bridge 3. , Directly attach the center pipe end 23 to the needle cradle.
This is a structure in which the inner support 2 is prevented from being deformed by contacting the inner support 2.

[Effect of idea]

As described above, with the present invention, it is possible to realize a highly reliable and low-cost structure that can prevent various troubles caused by needle setting pushing force in a two-hand and three-hand movement. We can supply movements that are easy to handle. Moreover, it is possible to change a two-hand movement to a three-hand movement by simply changing parts, making it possible to share a considerable number of parts, and to obtain mass production effects.

By the way, the embodiment of the present invention uses one step motor, and by rearranging the wheel train mechanism,
Although a shared movement has been constructed and explained, the present invention also applies to a shared movement in which two or more step motors are used to separate the train mechanism into a seconds display train, an hour and minute train, etc. A similar effect can be obtained.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing the pointer display gear train for 3 hands in a movement that can be used for both 2 and 3 hands.
FIG. 1 is a cross-sectional view showing an embodiment of the present invention and showing a gear train of a two-hand movement. FIG. 3 is a partial sectional view showing another embodiment of the present invention. 1... Main plate, 2... Middle bridge, 3... Gear train bridge, 1
0, 15, 23...center pipe, 17...dial board.

Claims (1)

[Scope of utility model registration request] A central part of a wristwatch in which a cylindrical support shaft is installed in the middle bridge interposed between the main plate and the gear train bridge, a second wheel is attached to the support shaft, and an hour wheel is attached to the second wheel. In the wheel train structure, the support shaft and the A second wheel of an electronic wristwatch with pointer display, characterized in that a protrusion is formed so as to have a slight gap between it and the train wheel bridge, so that the reaction force when setting the hands is received by the train train bridge. Support axis.