JP6433332B2 - Mechanical watch movement - Google Patents

Description

  The present invention relates to a movement of a mechanical timepiece.

  The mechanical timepiece achieves an accurate rate by oscillating the movement balance at a constant cycle. The balance oscillates with the balance being provided as a rotation axis by the balance being provided rotatably on a catch stone provided on the base plate and a catch stone provided on the balance.

  In general, the amplitude of a mechanical watch tenwa in the driving state is the balance between the energy consumption due to the viscous frictional resistance between the tenwa and air and the solid frictional resistance between the tenshin and the stone, and the energy supply transmitted from the barrel. Varies depending on

  Here, if the torque supplied to the tenwa is constant, the amplitude of the tenwa increases as the viscous friction resistance and the solid friction resistance decrease. For this reason, if the values of viscous friction resistance and solid friction resistance are small, the amplitude can be increased with less torque, so the smaller the values of viscous friction resistance and solid friction resistance in the movement, the better the performance of the watch. desirable.

  The value of viscous frictional resistance represents the viscous frictional resistance between the tenwa and the surrounding structure, and it is known that the gap between the tenwa and the ground plate and the receiver existing above and below it affects the value of the viscous frictional resistance. (For example, Patent Document 1).

  Further, it is known that the value of the viscous frictional resistance received from the ground plane side of the tenwa is inversely proportional to the distance from the ground plane and proportional to the facing area.

Japanese Patent No. 3456476 (first page, FIG. 7)

  The technique in Patent Document 1 is that the mechanism for reducing the viscous frictional resistance of the tenwa is made by devising a structure other than the tenwa (for example, increasing the distance between the tenwa and the ground plane). The idea to do was not given. For example, when the base plate thickness is originally designed to be thin, and it is not possible to provide a thinning structure or a through hole due to a design viewpoint, the device of Patent Document 1 is difficult to apply.

  The present invention has been made in view of the above circumstances, and provides a movement of a mechanical timepiece in which the viscous frictional resistance of the tenwa is lowered and the energy efficiency is improved by providing the balance itself with a structure for reducing the viscous frictional resistance. The purpose is to do.

The movement of the mechanical timepiece of the present invention is composed of a tenwa and an amida, and is arranged on the opposite side of the base plate with respect to the balance, a balance plate that vibrates around the balance, a ground plate provided at a position facing the balance. In a movement of a mechanical timepiece having a balance, a counter area where the tenwa and the balance plate face each other is compared with a counter area where the balance and the balance plate face each other. It is characterized in that the distance from the tenwa is longer than the distance between the base plate or the balance holder with the smaller facing area and the tenwa.

  By setting it as the said structure, the distance of a temper with a large opposing area, and a base plate or a temp receiving spreads, and the viscous frictional resistance of a temp can be reduced.

  When the tenwa has a larger area facing the ground plane than the area facing the balance, it is preferable that at least a part of the ground plane side surface of the tenwa is closer to the balance receiving side than the ground plane side surface of the amida.

  When the tenwa has a larger area facing the balance plate than the area facing the ground plate, it is preferable that at least a part of the surface of the balance on the balance sheet side is closer to the ground plate side than the surface of the balance on the balance sheet.

  The tenwa can obtain the same effect as the above configuration by providing a recess on the ground plate side or the balance receiving side having a large facing area.

It is a perspective view which shows the movement of the mechanical timepiece in 1st Embodiment of this invention. It is a perspective view which shows the movement of the mechanical timepiece in 1st Embodiment of this invention. It is sectional drawing which shows the shape of the balance in 1st Embodiment of this invention. It is sectional drawing which shows the shape of the balance in 1st Embodiment of this invention. It is sectional drawing which shows the comparative example with the balance in 1st Embodiment of this invention. It is sectional drawing which shows the shape of the balance in 2nd Embodiment of this invention. It is sectional drawing which shows the shape of the balance in 2nd Embodiment of this invention. It is a graph which shows the result of having verified the effect of the balance in 1st Embodiment of this invention.

[First Embodiment]
Hereinafter, a first embodiment of a movement of a mechanical timepiece according to the invention will be described with reference to the drawings.

<Composition of movement>
FIG. 1 is a perspective view showing a movement 100 according to a first embodiment of the present invention housed in, for example, a portable mechanical timepiece (for example, a wristwatch; hereinafter simply referred to as a timepiece).

  The illustrated movement 100 includes a barrel wheel 11, a second wheel 12, a third wheel 13, a fourth wheel 14, an escape wheel 15 and an ankle 16, a balance 17, a base plate 90, and a receiving member. ing.

  The barrel wheel 11 has a mainspring inside, and generates torque when the wound mainspring is unwound, which serves as a power source for the timepiece. The second wheel 12, the third wheel 13 and the fourth wheel 14 sequentially transmit the rotation of the barrel wheel 11 which is rotated by the torque generated by the mainspring of the barrel wheel 11. The escape wheel 15 and the ankle 16 constitute an escapement device. The balance 17 that vibrates around the balance 18 constitutes a speed governor.

  The balance 17 includes a balance 22 having an annular portion supported by a balance stem 18 and a hairspring 20.

The main plate 90 and the receiving member support the barrel wheel 11, the second wheel 12, the third wheel 13, the fourth wheel 14, the escape wheel 15, and the balance 17 in a vertically rotatable manner. In FIG. 1, the description of the receiving member is omitted. The receiving members are a barrel holder that supports the barrel 11, a wheel train holder that supports the second wheel 12, third wheel 13, fourth wheel 14, and escape wheel 15, and a balance (not shown) that supports the balance 17. And a receiver 21.

  FIG. 2 is a perspective view when the balance receiver 21 is installed on the movement 100 shown in FIG. 1. In general, the balance receiver 21 is arranged so as to cover part of the balance stem 18 and balance 17.

  FIG. 3 is a cross-sectional view showing the distance relationship between the balance 17, balance 21 and base plate 90 in the first embodiment. The balance 17 is composed of a tenwa 22 arranged on the outer periphery, and an amidus 23 that connects the tenth stem 18 and the tenwa 22. In the normal balance 17, two to three amidas 23 are arranged at equal intervals. A characteristic of the structure of the balance 17 of the first embodiment is that the thickness of the balance 22 is constant, and the shape of the balance 22 is shifted to the side where the balance area with the balance 10 22 is small (the balance 10 receiving side). Is away from.

  The distance h1 between the amida 23 and the base plate 90 is 0.45 mm, the distance h2 between the tenwa 22 and the balance holder 21 is 0.75 mm, and Δh is 0.2 mm. In FIG. 3, members such as the hairspring 20 are omitted in order to explain the distance relationship between the tenwa 22, the base plate 90, and the balance holder 21. Further, the base plate 90 side of the tenwa 22 is a lower surface and the balance receiver 21 side is an upper surface.

<Reduction mechanism of viscous frictional resistance>
A mechanism for reducing the viscous frictional resistance will be described with reference to FIG. FIG. 3 is a cross-sectional view showing the distance relationship between the balance 17, balance 21 and base plate 90 in the first embodiment. The balance 17 in the first embodiment has a shape in which the distance between the bottom surface 22a of the tenwa and the ground plane 90 is more than the distance h1 between the bottom surface 23a of the amida and the ground plane 90 by Δh, as compared with the conventional balance structure. Yes.

  It is known that the value of the viscous frictional resistance that the upper and lower surfaces of the tenwa 22 receive from the ground plane 90 and the balance holder 21 is inversely proportional to the distance from the ground plane 90 and proportional to the facing area.

  As in the movement shown in FIG. 2, the balance holder 21 is generally arranged so as to cover a part of the tenwa 22, and the area facing the tenwa 22 is small. Since they are arranged so as to face each other, the facing area is large, and the viscous frictional resistance generated between the tenwer 22 and the ground plane 90 having the large facing area is increased.

  For this reason, the viscous friction resistance that decreases when the tenwa lower surface 22a is separated by Δh from the lower surface 23a of the amida is larger than the viscous friction resistance that increases when the upper surface of the tenwa 22 approaches the balance 21. Resistance can be reduced.

  In the above description, the case where the entire bottom surface of the tenwa 22 and the ground plate 90 are opposed to each other and the balance 10 is opposed to a part of the top surface of the balance 10 is explained. If the balance 21 is larger, the shape of the balance 22 may approach the base plate 90 as shown in FIG.

<Operation of the movement>
As shown in FIG. 1, the movement 100 of the mechanical timepiece 100 according to the first embodiment configured as described above receives torque generated by the unwinding of the mainspring wound inside the barrel complete 11 from the barrel complete 11. It is sequentially transmitted to the second wheel 12, the third wheel 13, and the fourth wheel 14.
Then, the rotation transmitted from the fourth wheel 14 to the escape wheel 15 is adjusted by the interaction of the escape wheel 15, the ankle 16, the balance 17 and the hairspring 20.

  A characteristic of the structure of the balance 17 of the first embodiment is that the thickness of the balance 22 is constant, and the balance is shifted by a distance of Δh as a shape in which the balance 22 is shifted to the side having the small area facing the balance 10 (the balance 10 receiving side). It is away from the 90 side.

  FIG. 5 is a comparative example for verifying the effect of the first embodiment, and has a general balance 17 shape. The tenwa lower surface 22a and the amidar lower surface 23a are formed to be on the same plane. The size of the tenwa 22 is the same as that of the tenwa 22 shown in FIG. 3, and the weight is also the same.

  In order to explain the distance relationship between the balance 17, the main plate 90 and the balance receiver 21, members such as the hairspring 20 are omitted.

  The viscous frictional resistance has a component that decreases when the tenwa 22 is separated from the main plate 90 by a distance of Δh, and a component that increases when the tenwa 22 approaches the balance 21.

  For the sake of explanation, the ratio of the opposing area U1 between the tenwa 22 and the ground plane 90 and the opposing area U2 between the tenwa 22 and the balance holder 21 is 3: 1. h1 is 0.45 mm, h2 is 0.75 mm, and Δh is 0.2 mm.

  In the case of the shape of the tenwa 22 shown in FIG. 5, the ratio of the facing area and distance between the tenwa 22 and the ground plane 90 is U1 / h1, and the ratio of the facing area and distance between the tenwa 22 and the balance 21 is U2 / h2.

  It is known that the value of the viscous friction resistance received by the upper and lower surfaces of the tenwa 22 from the base plate 90 and the balance holder 21 is inversely proportional to the distance to the base plate 90 and proportional to the opposing area. The value of U1 / h1 + U2 / h2 The product of V and the constant K is the viscous frictional resistance F.

  In the case of the shape of the tenwa 22 shown in FIG. 3, the ratio of the facing area and distance between the tenwa 22 and the ground plane 90 is U1 / (h1 + Δh), and the ratio of the facing area and distance between the tenwa 22 and the balance holder 21 is U2 / (h2). -Δh), the value of U1 / (h1 + Δh) + U2 / (h2−Δh) multiplied by a constant K is the viscous frictional resistance F ′.

  The constant K varies depending on the shapes of the main plate 90 and the balance holder 21, but was about 0.5 in the movement in which the verification of the first embodiment was performed.

When the viscous frictional resistance F in the shape of the tenwa 22 shown in FIG. 5 is calculated, (U1 / h1 + U2 / h2) × multiplier K = (3 / 0.45 + 1 / 0.75) × 0.5 = 4 is obtained. When the viscous frictional resistance F ′ for the shape of the tenwa 22 shown is calculated, (U1 / (h1 + Δh) + U2 / (h2−Δh)) × 0.5 = (3 / (0.45 + 0.2) + 1 / (0.75) −0.2)) × 0.5 = about 3.22. At this time, the ratio between the viscous frictional resistance F and the viscous frictional resistance F ′ is approximately F: F ′ = 1: 0.8. In the above calculation, the ratio of the opposing area U1 between the tenwa 22 and the ground plane 90 and the opposing area U2 between the tenwa 22 and the balance holder 21 is directly substituted into the equation for the sake of explanation.

  That is, in the case of the tenwa 22 shape as shown in FIG. 3, the viscous frictional resistance acting on the tenwa 22 is reduced by about 20% compared to the tenwa 22 shape shown in FIG.

Next, the result of calculating the change in viscous frictional resistance of the entire balance 17 shown in FIGS. 3 and 5 will be described. As described above, the balance 17 is composed of the balance 22 and the amidus 23. Here, the ratio of the viscous frictional resistance contributed by the portion of the balancer 22 to the viscous frictional resistance of the entire balance 17 is 1 /. The description will be made assuming that the number is 3.

  First, the viscous frictional resistance Fa of the balance 17 having the shape of the tenwa 22 shown in FIG. 5 is defined. The viscous friction resistance Fa of the entire balance 17 is a value obtained by adding the viscous friction resistance 1/3 Fa contributed by the tenwa 22 portion and the viscous friction resistance 2/3 Fa contributed by the portion other than the tenwa 22 portion, Fa = 2/3 Fa + 1/3 Fa = 1Fa.

  Next, the viscous friction resistance Fa ′ of the entire balance 17 having the shape of the tenwa 22 shown in FIG. 3 is a viscous friction resistance 1/3 Fa × 0.8 contributed by the tenwa 22 portion and a viscous friction resistance 2 / contributed by other than the tenwa 22 portion. A value obtained by adding 3Fa is Fa ′ = 2 / 3Fa + 0.8 × 1 / 3Fa≈0.93Fa.

  From the above calculation results, it was found that the viscous frictional resistance Fa ′ of the whole tenwa 22 shown in FIG. 3 is reduced by about 7% compared with the viscous frictional resistance Fa of the whole tenwa 22 shown in FIG. .

  A description will be given of changes in amplitude when the balance-shaped balance 17 shown in FIGS. 3 and 5 is actually operated as a movement of a mechanical timepiece. The energy transmitted from the barrel complete 11 to the balance 17 is mainly consumed by the viscous frictional resistance between the balance 17 and air and the solid frictional resistance between the balance 18 and the receiving stone provided on the balance holder 21. Therefore, the energy consumed per cycle of the balance 17 and the transmitted energy from the barrel 11 per cycle of the balance 17 can be expressed equally. If the amplitude A of the balance 17 is constant, Equation 1 is established. .

  In the above formula 1, F is the viscous frictional resistance of the balance 17, T is the vibration period of the balance 17, R is the solid frictional resistance of the balance 17, f is the frequency of the balance 17, S is the power torque of the barrel 11, η Is the energy efficiency transmitted from the barrel 11 to the balance, and N is the ratio of teeth obtained by adding the number of teeth of the escape wheel 15 to the ratio of teeth from the barrel 11 to the fourth wheel 14.

The part (2A ² Fπ ² / T ² + 4AR / T) / f on the left side of Equation 1 indicates the energy consumption per period of the amplitude of the balance 17, and the part (2πSη) / N on the right side is the balance. The transmission energy from the barrel complete 11 per 17 amplitude cycles is shown.

Of (2A ² Fπ ² / T ² + 4AR / T) / f on the left side of Equation 1, the portion of 2A ² Fπ ² / T ² indicates energy consumption due to viscous frictional resistance, and the portion of 4AR / T is solid. It shows the energy consumed by frictional resistance.

  When Formula 1 is transformed into a form for obtaining the amplitude A of the balance 17, Formula 2 is obtained.

  FIG. 8 is a table describing the characteristics of the movement used for verifying the effects of the first embodiment, and describes the numerical values of the parameters of Equation 1. When the amplitude A is calculated by Equation 2 obtained by modifying Equation 1 using the numerical values of the respective parameters shown in FIG. 8, in the comparative example of the shape of the tenter 22 shown in FIG. In the first embodiment of the tenwa 22 shape shown in FIG. 3, the amplitude A is 290.2 °.

  That is, when the balance 17 shown in FIG. 5 is operated with the same torque torque from the barrel 11 as in the case where the balance 17 is operated with the amplitude value of the balance 17 being 280 °, the balance 17 is operated. It can be seen that the amplitude will increase by approximately 10 °. The same effect can be confirmed from the result of actually measuring the movement of the movement 17 and measuring the amplitude of the balance 17, and obtaining a movement of a mechanical timepiece that operates at a high amplitude value even with less power torque from the barrel complete 11. I was able to.

[Second Embodiment]
Next, a second embodiment of the movement of the mechanical timepiece according to the invention will be described with reference to FIGS. 2 and 5 to 7.

<Composition of movement>
Since the basic configuration of the movement of the mechanical timepiece in the second embodiment is the same as that of the first embodiment, only differences from the first embodiment will be described.

  FIG. 6 is a cross-sectional view showing the distance relationship between the balance 17, balance 21 and main plate 90 in the second embodiment. A feature of the structure of the tenwa 22 of the second embodiment is that a concave portion 22b is provided on the lower surface 22a of the tenwa having a large area facing the tenwa 22, and this concave 22b reduces the viscous frictional resistance generated between the main plate 90 and the base plate 90. Is.

  The ratio of the opposing area U1 between the tenwa 22 and the ground plane 90 and the opposing area U2 between the tenwa 22 and the balance holder 21 is 3: 1, h1 is 0.45 mm, and h2 is 0.75 mm.

  The concave portion 22b is formed so that the average value of the concave and convex portions provided on the tenwa lower surface 22a is Δh and is 0.2 mm.

<Reduction mechanism of viscous frictional resistance>
A mechanism for reducing viscous frictional resistance according to the second embodiment will be described with reference to FIGS. 2 and 5 to 7. In the second embodiment, the balance 17 is provided with a recess b on the lower surface 22a of the tenwa which has a large area facing the tenwa 22, and the average distance between the unevenness of the tenwa 22 and the ground plane 90 is widened. Viscous frictional resistance generated between them is reduced.

  As in the movement shown in FIG. 2, the balance 21 is generally arranged so as to cover a portion of the balance 17, and the area facing the balance 22 is small. Since they are arranged so as to face each other, the facing area is large, and the viscous frictional resistance generated between the tenwa 22 and the ground plane 90 is increased.

  For this reason, the viscous friction resistance that is reduced by providing the recess 22b on the lower surface 22a of the tenwa is larger than the viscous friction resistance that increases when the upper surface of the tenwa 22 approaches the balance 21. It is possible to reduce.

  In the above description, the case where the entire bottom surface of the tenwa 22 and the ground plate 90 face each other and a part of the top surface of the tenwa 19 faces the balance receiver 21 has been described. If the balance 21 is larger, the recess 22 b may be formed on the upper surface side of the tenwa 22.

<Operation of the movement>
For the movement 100 of the mechanical timepiece according to the second embodiment configured as described above, the viscous frictional resistance of the comparative example shown in FIG. 5 was compared as in the first embodiment.

  By reducing the sexual frictional resistance due to the provision of the recess 22b in the tenwa 22 shown in FIG. 6, the same power torque from the barrel complete 11 as in the case where the tenwa 22 shown in FIG. When the tenwa 22 shown in FIG. 4 is operated, the amplitude increases by about 10 degrees, and thus it has been found that a movement of a mechanical timepiece that operates at a high amplitude value can be obtained even with a smaller power torque from the barrel complete 11.

  In the above description, the example in which one recess 22b is provided in the tenwa 22 has been described. Needless to say, the same effect can be obtained by providing a plurality of recesses 22b, and the shape of the recess 22b is also shown in FIG. Such a mortar shape may be used and is not particularly limited.

11 barrel wheel 12 second wheel 13 third wheel 14 fourth wheel 15 escape wheel 16 ankle 17 balance 18 balance 18 balance 20 spring balance 22 balance 22a balance bottom 22b recess 23 amid 23a bottom 95 ground plate 100 movement

Claims (4)

A machine comprising a balance and an amider and having a balance that vibrates around the balance, a ground plate provided at a position opposite to the balance, and a balance receiving plate disposed on the opposite side of the balance from the balance plate. In the movement of the type watch,
Comparing the facing area where the tenwa and the base plate face each other and the facing area where the tenwa and the balance holder face each other, the distance between the ground plate or the balance holder and the tenwa with the larger facing area, The movement of the mechanical timepiece, characterized in that it is longer than the distance between the base plate or the balance holder with the smaller facing area and the balance. In the case where the facing area of the tenwa is larger than the facing area of the balance holder, the surface of the tenwa on the ground plane side of the tenwa is more than the balance of the balance on the ground plane side of the balance. The movement of the mechanical timepiece according to claim 1, wherein the movement is on the side. When the balance area of the balance with the balance plate is larger than the balance area with the ground plate, at least a part of the balance-side surface of the balance is larger than the balance plate-side surface of the amider. The movement of the mechanical timepiece according to claim 1, wherein the movement is on the side.   The movement of the mechanical timepiece according to claim 1, wherein the tenwa is provided with a recess on the base plate side or the balance receiving side having a large facing area.

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