JP6862847B2 - How to manufacture watch balance springs, watch power units, watch movements, watches and watch balance springs - Google Patents

Description

The present invention relates to a watch watch, a watch power unit, a watch movement, a watch and a method for manufacturing a watch watch.

In a mechanical timepiece, a power device including a barrel and a royal fern housed in the barrel is generally used as a power source (see, for example, Patent Document 1).
In the free state, the inner end side of the barrel, which is truly fixed to the barrel, is spirally wound about 1.5 turns.

Japanese Unexamined Patent Publication No. 2009-300439

When the royal fern as in Patent Document 1 is housed in the barrel, the inner end is fixed to the barrel true, the royal fern is wound around the barrel true, and the outer end engages with the inner wall of the barrel. Then, when the watch is used, winding and rewinding are repeated. Here, the spiral portion on the inner end side has a larger displacement amount due to winding and rewinding than the other portions.
Further, in a conventional spring as in Patent Document 1, the spiral portion on the inner end side is generally formed in a shape that plastically deforms when the spring is wound. Therefore, after being housed in the barrel and being wound, the durability is lower than that before being wound.
From these facts, there is a problem that the spiral portion on the inner end side of the royal fern is easily fractured by fatigue.

An object of the present invention is to provide a watch watch, a power unit for a watch, a movement for a watch, and a method for manufacturing a watch and a watchwork spring that are not easily fatigued.

The watch royal fern of the present invention is a watch royal fern that is housed in a barrel, has an inner end fixed to the barrel provided by the barrel, and has an outer end that engages with the inner wall of the barrel, and is not loaded. In the free state, it is characterized by having a spiral portion wound in a Bernoulli curve from the inner end.

Here, the free state in which no load is applied is, for example, a state in which a watch spring is placed on the upper surface of a flat table so that the axial direction of the spiral portion is orthogonal to the upper surface.
Further, the spiral shape is not intended to be a three-dimensional curved shape, but is intended to be a two-dimensional curved shape that does not displace in the axial direction of the spiral portion.
The watch royal fern is formed into a shape including the spiral portion before being housed in the barrel. Then, the molded royal fern for the watch is housed in the barrel, the inner end is truly fixed to the barrel, and the outer end is engaged with the inner wall of the barrel.
According to the present invention, in the spiral portion, plastic deformation due to winding can be suppressed, so that durability can be improved. As a result, it is possible to prevent the watch spring from fatigue fracture.

The watch spiral of the present invention is housed in a barrel and is continuous with the inner end of the barrel, which is fixed to the barrel, the inner end of the barrel, and the winding portion of the barrel, which is wound around the barrel. A watch royal fern having a spiral portion and an outer end that engages with the inner wall of the barrel, and the spiral portion is wound in a Bernoulli curve in a free state without a load. It is characterized by.

The winding portion is a portion where the barrel is truly wound even when the watch spring is rewound, and does not displace as the watch spring is tightened and rewound.
Therefore, even if the winding portion is not curved by Bernoulli, it is unlikely that the watch spring will be fatigued and broken. For this reason, the winding portion has a curved shape according to the outer circumference of the barrel, for example, in a free state so as to wrap around the barrel.
Since the spiral portion is wound in a Bernoulli curve in a free state, durability can be improved. As a result, it is possible to prevent the watch spring from fatigue fracture.

In the watch royal fern of the present invention, the number of turns of the spiral portion is preferably 2.5 or more.
The greater the number of turns of the spiral portion, the higher the durability.
By setting the number of turns of the spiral portion to 2.5 or more, it is possible to satisfy a general durability level (for example, the number of windings: 700 times).

In the watch royal fern of the present invention, the material of the watch royal fern is preferably a nickel-cobalt alloy.
According to the present invention, for example, the durability, torque, and corrosion resistance of the watch royal fern can be improved as compared with the case where the material of the watch royal fern is stainless steel.

In the watch royal fern of the present invention, the material of the watch royal fern is preferably stainless steel.
According to the present invention, for example, the material cost can be reduced as compared with the case where the material of the watch royal fern is a nickel-cobalt alloy.

The watch power unit of the present invention is characterized by including the watch spring and the barrel for accommodating the watch spring.
Since the watch spring is more fragile than the barrel, the watch spring is less likely to break, and the life of the parts of the watch power unit can be extended.

The watch movement of the present invention is characterized by including the watch power unit and gears driven by the watch power unit.
According to the present invention, since it is possible to prevent the watch spring from fatigue fracture, it is possible to prolong the replacement period of the movement parts.

The timepiece of the present invention is characterized by including the above-mentioned timepiece movement.
According to the present invention, since the watch spring can be prevented from being fatigued and broken, the time for replacing parts of the watch can be extended.

The present invention is a method for manufacturing a royal fern for a watch, which is housed in a barrel, whose inner end is fixed to the barrel provided by the barrel, and whose outer end engages with the inner wall of the barrel. , The royal fern member is characterized by forming a spiral portion wound in a Bernoulli curve from one end.
According to the present invention, the durability of the spiral portion can be improved, and the fatigue failure of the watch spring can be suppressed.

In the method for manufacturing a watch royal fern of the present invention, by ejecting the royal fern member and hitting it against an inclined surface, the royal fern member is curved, the ejection speed of the royal fern member, and the ejection position and the inclination of the royal fern member. It is preferable to form the spiral portion by adjusting the distance from the surface.
According to the present invention, for example, the spiral portion can be easily formed in a short time as compared with the case where the spiral portion is formed by winding the royal fern member around a rod-shaped jig.

The present invention is housed in an incense box, the inner end of the incense box is fixed to the inner end of the incense box, the outer end is engaged with the inner wall of the incense box, and a Bernoulli curve is formed from the inner end in a free state where no load is applied. A method for manufacturing a watch Zenmai having a spiral portion wound in a shape, wherein the length of a straight line drawn from the origin to a point on the curve in polar coordinates is R, and the straight line and the start line are defined. When the angle formed by and is θ, the angle formed by the tangent of the straight line and the point on the curve is b, the value of R when θ is 0 degrees is a, and the number of napiers is e, R = It is a curve that satisfies the relationship of ae ^{b θ , and when e b} is a constant A, the lower limit value of the constant A is determined based on the effective number of turns of the watch Zenmai, and the upper limit value of the constant A is the clock. Determined based on the durability and torque of the razor, the constant A is set to a value equal to or greater than the lower limit and equal to or less than the upper limit, and the zenmai member is deformed to form the spiral portion on the zenmai member. It is characterized by doing.

The effective number of turns of the watch spring, which determines the number of rotations of the barrel from the time the barrel is wound to the time it is rewound in the barrel, decreases as the value of the constant A decreases, and may not meet the standard value of the effective number of turns. is there. Therefore, in the present invention, the lower limit of the constant A is determined based on the number of effective turns. Further, the durability of the watch royal fern decreases as the value of the constant A increases. Therefore, when the constant A exceeds a certain value, it becomes impossible to obtain a state in which both durability and torque satisfy the standard values. Therefore, in the present invention, the upper limit of the constant A is determined based on durability and torque. Then, the constant A is set to a value equal to or higher than the lower limit value and equal to or lower than the upper limit value to form the spiral portion.
According to this, it is possible to surely manufacture a watch spring having effective turns, durability and torque satisfying standard values.

INDUSTRIAL APPLICABILITY The present invention includes an inner end of the incense box that is housed in the incense box and is fixed to the incense box, a winding portion that is continuous with the inner end and is wound around the incense box, and a spiral portion that is continuous with the winding portion. And, in a free state where no load is applied, the spiral portion is a method of manufacturing a watch zenmai wound in a Bernoulli curve, which is provided with an outer end that engages with the inner wall of the incense box. In the Bernoulli curve, the length of a straight line drawn from the origin to a point on the curve in polar coordinates is R, the angle between the straight line and the start line is θ, and the tangent line between the straight line and the point on the curve is formed. When the angle is b, the value of R when θ is 0 degrees is a, and the number of ^napiers is e, the curve satisfies the relationship of ^{R = ae bθ. When e b} is a constant A, the constant The lower limit value of A is determined based on the effective number of turns of the watch zenmai, the upper limit value of the constant A is determined based on the durability and torque of the watch zenmai, and the constant A is determined based on the lower limit value. It is characterized in that the spiral portion is formed on the zenmai member by setting the value above and below the upper limit value and deforming the zenmai member.
According to the present invention, it is possible to reliably manufacture a watch spring having effective turns, durability and torque satisfying standard values.

FIG. 5 is a sectional view showing a clock according to an embodiment of the present invention. FIG. 5 is a plan view showing a power unit in a state in which the mainspring is wound according to the embodiment. FIG. 5 is a plan view showing a power unit in a state where the mainspring is rewound in the embodiment. The figure which shows the free-state spring in an embodiment. The figure explaining the Bernoulli curve. The figure which shows the shape processing process in an embodiment. The figure which shows the shape processing process in an embodiment. The graph which shows the durability and torque of the royal fern in embodiment. The graph which shows the relationship between the constant A of the Bernoulli curve and the effective number of turns of the royal fern in the embodiment. The figure which shows the free-state spring in another embodiment which concerns on this invention. The figure which shows the spring of the comparative example. The figure which shows the spring of Example 1. FIG. The figure which shows the spring of Example 2. The figure which shows the spring of Example 3. FIG. The graph which shows the evaluation result of the durability of each Example and a comparative example. The graph which shows the evaluation result of the torque of each Example and a comparative example. The graph which shows the evaluation result of the duration of each Example and a comparative example.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a clock 1.
The watch 1 is provided with a drive mechanism (clock movement) 1A on the back cover side of the dial 11. The drive mechanism 1A includes a power unit (clock power unit) 30 composed of a clockwork (clockwork) 31 and a barrel 32 for accommodating the clockwork 31.
The barrel 32 includes a barrel 33, a barrel gear 34 attached to the barrel 33, and a barrel lid 35.

In the royal fern 31, the inner end 311 (see FIG. 3) is fixed to the barrel 33 and wound around the barrel 33, and the outer end 312 (see FIG. 2) is attached to the inner wall 341 (see FIG. 2) of the barrel gear 34. Engaged.
The barrel 33 is supported by the main plate 2 and the train wheel receiving 3, and is fixed by the square hole screw 5 so as to rotate integrally with the square hole wheel 4 provided in the drive mechanism 1A. The square hole wheel 4 meshes with a kohaze (not shown) so as to rotate clockwise but not counterclockwise.
Since the method of rotating the square hole wheel 4 clockwise and winding the royal fern 31 is the same as the automatic winding or manual winding mechanism of a general mechanical timepiece, the description thereof will be omitted.

The rotation of the barrel gear 34 is transmitted to gears such as the second wheel 7, the third wheel 8, the fourth wheel 9, and the cylinder wheel 10 included in the drive mechanism 1A. A second hand (not shown) is attached to the fourth wheel 9, a minute hand (not shown) is attached to the cylinder 7A of the second wheel 7, and an hour hand (not shown) is attached to the cylinder 10. As a result, each pointer is driven by the rotation of the barrel gear 34.

[Power unit configuration]
2 and 3 are plan views of the power unit 30 as viewed from the thickness direction. In addition, in FIGS. 2 and 3, the barrel lid 35 is not shown.
FIG. 2 shows a state after the royal fern 31 is wound in the barrel 32, and FIG. 3 shows a state after the royal fern 31 is rewound in the barrel 32 (released state).
The inner end 311 of the royal fern 31 is fixed to the barrel 33. In the present embodiment, the outer diameter of the barrel 33 is 2.6 mm. Here, the royal fern 31 is fixed to the barrel 33 so that the width direction is along the axial direction of the barrel 33.
The outer end 312 of the royal fern 31 is hooked on the notch formed in the inner wall 341 of the barrel gear 34, or is hooked on the inner wall 341 via a slipping attachment (not shown) or the like to engage with the inner wall 341. There is. In the present embodiment, the inner diameter of the barrel gear 34 (the diameter of the accommodation space of the royal fern 31) is 10.6 mm.

As shown in FIG. 2, the royal fern 31 is wound around the barrel 33 by rotating the barrel 33 by an external force.
Then, when the restraint state of the barrel gear 34 is released, the barrel gear 34 rotates about the barrel true 33 and rewinds as shown in FIG.
In the open state shown in FIG. 3, a portion having a predetermined length from the inner end 311 extends spirally in the plan view, and constitutes the spiral portion 313. In the present embodiment, the number of turns of the spiral portion 313 is 2.5 or more and 3.0 or less.
The portion of the royal fern 31 on the outer end 312 side of the spiral portion 313 is wound substantially concentrically around the barrel 33 in the plan view.
In this spiral portion 313, the amount of displacement due to winding and rewinding is large as compared with other portions, and the stress change is large.

[Structure of royal fern]
FIG. 4 is a diagram showing an unloaded free state fern 31 before being housed in the barrel 32. That is, it is a figure which shows the free state royal fern 31 before winding. Here, the free state in which no load is applied is, for example, a state in which a watch spring is placed on the upper surface of a flat table so that the axial direction of the spiral portion is orthogonal to the upper surface.
The royal fern 31 is continuous from the spiral portion 313, the connecting portion 315 that is not continuously shaped from the spiral portion 313, and the connecting portion 315, and is 10 in the direction opposite to the winding direction of the spiral portion 313. It is provided with a main body portion 314 of a royal fern that has been wound about once. The spiral shape is not intended to be a three-dimensional curved shape, but is intended to be a two-dimensional curved shape that does not displace in the axial direction of the spiral portion.

Here, the spiral portion 313 is wound in a Bernoulli curve from the inner end 311. Here, the details will be described in Examples described later, but in the present embodiment, the number of turns of the spiral portion 313 is preferably 2.5 or more in order to secure the required durability. It is preferably 3.0 volumes or less in order to secure the desired duration (for example, 46.5 hours).
As shown in FIG. 5, the Bernoulli curve has the length (distance from the origin) of the straight line L drawn from the origin to the point on the curve as R in polar coordinates, and the angle (bias) formed by the straight line L and the start line X. When the angle) is θ, the angle formed by the straight line L and the tangent of the point on the curve is b, the value of R when θ is 0 degrees is a, and the number of napiers is e, the following equation (1) ) Is a curve (spiral).

R = ae ^bθ (1)

That is, when e ^b is a constant A, the Bernoulli curve is represented by the following equation (2).

R = aA ^θ (2)

In this embodiment, the royal fern 31 is made of a nickel-cobalt alloy. The royal fern 31 may be made of another metal such as stainless steel.
Further, the royal fern 31 is formed with a constant width and a constant thickness over the entire length, the width dimension (the dimension in the axial direction of the barrel 33) is about 1 mm, and the thickness dimension is about 0.1 mm. .. The length of the royal fern 31 is about 300 mm.

[Manufacturing method of royal fern]
Next, a method for manufacturing the royal fern 31 will be described. The royal fern 31 is produced by subjecting the plate-shaped royal fern member 31M to a shape processing step of forming the shape shown in FIG. 4 and then heat-treating the royal fern member 31M.

[Shape processing equipment]
In the shape processing step, the shape processing apparatus 40 shown in FIG. 6 is used.
The shape processing device 40 includes an extrusion unit 41 including extrusion rollers 411 and 412 for extruding the mainspring member 31M, a guide unit 42 that guides the extruded mainspring member 31M in a predetermined direction and emits the extruded mainspring member 31M, and the emitted mainspring member. It is provided with shaping portions 43 and 44 for shaping (habiting) the 31M by deforming it.

The extrusion unit 41 is configured so that the extrusion speed (emission speed) of the royal fern member 31M can be adjusted by adjusting the rotation speeds of the extrusion rollers 411 and 412.
The guide unit 42 emits the royal fern member 31M from the exit unit 421 in a predetermined direction.

The shaping portion 43 is configured to be movable in the Z direction orthogonal to the exit direction of the royal fern member 31M and in the direction opposite to the Z direction.
Further, the shaping portion 43 includes an inclined surface 431 on which the mainspring member 31M emitted from the emitting portion 421 hits. The inclined surface 431 is inclined in a direction away from the exit portion 421 in the Z direction.

The shaping portion 44 is configured to be movable in the Z direction and in a direction opposite to the Z direction.
The shaping portion 44 includes an inclined surface 441 on which the mainspring member 31M emitted from the emitting portion 421 hits. The inclined surface 441 is inclined in a direction away from the exit portion 421 in a direction opposite to the Z direction.

[Shape processing process]
In the shape processing step, first, as shown in FIG. 6, the shaping portion 43 is arranged at a position where the mainspring member 31M emitted from the emitting portion 421 hits the inclined surface 431. At this time, the shaping portion 44 is arranged at a position where the emitted spring member 31M does not hit the inclined surface 441.
In this state, the extrusion unit 41 extrudes the royal fern member 31M. As a result, the mainspring member 31M emitted from the light emitting portion 421 hits the inclined surface 431, whereby the mainspring member 31M is curved from one end side.
At this time, the extrusion unit 41 extrudes the royal fern member 31M while adjusting the extrusion speed according to a preset program. Further, the shaping unit 43 adjusts the distance between the exit unit 421 (emission position) and the inclined surface 431 in the emission direction by moving in the Z direction or a direction opposite to the Z direction according to a preset program. While bending the fern member 31M.
By adjusting the pushing speed of the royal fern member 31M and the distance between the exiting portion 421 and the inclined surface 431 in this way, the royal fern member 31M can be formed into a predetermined spiral shape. In this embodiment, the extrusion speed and the distance are adjusted to form Bernoulli's curved spiral portion 313.

After forming the spiral portion 313, as shown in FIG. 7, the shaping portion 43 moves in the direction opposite to the Z direction, and the position where the royal fern member 31M emitted from the exit portion 421 does not hit the inclined surface 431. Wait at.
Then, the shaping portion 44 moves in the direction opposite to the Z direction, and moves to a position where the mainspring member 31M emitted from the emitting portion 421 hits the inclined surface 441.
In this state, the extrusion unit 41 extrudes the royal fern member 31M. As a result, the mainspring member 31M emitted from the light emitting portion 421 hits the inclined surface 441, whereby the mainspring member 31M is curved in the direction opposite to the spiral portion 313.
At this time, the extrusion unit 41 extrudes the royal fern member 31M while adjusting the extrusion speed according to a preset program. Further, the shaping portion 44 moves in the Z direction or a direction opposite to the Z direction according to a preset program, so that the royal fern member 44 adjusts the distance between the exit portion 421 and the inclined surface 441 in the emission direction. Bend 31M.
In the present embodiment, the extrusion speed and the distance are adjusted to form the mainspring main body portion 314 wound in the direction opposite to the connecting portion 315 and the spiral portion 313.
After the royal fern body portion 314 is formed, the royal fern member 31M is cut and then heat-treated at about 350 degrees. As a result, the royal fern 31 is generated.

[How to set the constant A of the Bernoulli curve]
Next, a method of setting the constant A used in the formula of the Bernoulli curve, which determines the shape of the spiral portion 313, will be described.
FIG. 8 is a graph showing the durability and torque characteristics of the mainspring 31 according to the value of the constant A.
The horizontal axis of the graph shows durability. Durability is represented by the number of times of winding (durability) until the royal fern 31 breaks when the royal fern 31 is repeatedly wound and rewound. The vertical axis of the graph shows torque. The torque is the torque 24 hours after the royal fern 31 is wound.
Point D1 in the figure is a point where the constant A is set to 1.07 and shows the characteristics of the three types of royal fern 31 manufactured at the first, second, and third heat treatment temperatures. The line L1 is a linear function obtained by linearly approximating the point D1. Point D2 is a point where the constant A is set to 1.10 and shows the characteristics of the three types of royal fern 31 manufactured at the first to third heat treatment temperatures. The line L2 is a linear function obtained by linearly approximating the point D2. The point D3 is a point where the constant A is set to 1.13 and shows the characteristics of the three types of royal fern 31 manufactured at the first to third heat treatment temperatures. The line L3 is a linear function obtained by linearly approximating the point D3.
As shown in FIG. 8, the durability decreases as the value of the constant A increases. Therefore, when the constant A exceeds a certain value, it becomes impossible to obtain a state in which both durability and torque satisfy the standard values. Therefore, in the present embodiment, the upper limit value of the constant A is set based on the durability and the torque.
In the example of FIG. 8, when the constant A is smaller than 1.13, it is possible to obtain a state in which both durability and torque satisfy the standard values depending on the heat treatment temperature, but when the constant A is 1.13. , Durability and torque will not be able to meet the standard values. Therefore, the upper limit of the constant A is set to, for example, 1.12.

FIG. 9 is a graph showing the relationship between the constant A and the effective number of turns of the royal fern 31 that determines the number of rotations of the barrel 32 from the time the barrel 31 is wound to the time it is rewound in the barrel 32.
The horizontal axis of the graph shows the value of the constant A. The vertical axis of the graph shows the number of effective turns.
As shown in FIG. 9, the effective number of turns decreases as the value of the constant A decreases, and may not satisfy the standard value. Therefore, in the present embodiment, the lower limit of the constant A is determined based on the effective number of turns of the royal fern 31.
In the example of FIG. 9, the effective number of turns is lower than the standard value when the constant A is 1.07, and exceeds the standard value when the constant A is 1.08. Therefore, the lower limit value of the constant A is set to, for example, 1. Set to 08.

Then, the constant A is set to a value equal to or higher than the lower limit value and equal to or lower than the upper limit value to form the spiral portion 313. As a result, the royal fern 31 whose effective turns, durability, and torque satisfy the standard values can be reliably manufactured.

[Action and effect of the embodiment]
Since the royal fern 31 includes a spiral portion 313 wound in a Bernoulli curve from the inner end 311, plastic deformation due to winding can be suppressed and durability can be improved. That is, the stress generated during winding can be sufficiently smaller than the elastic limit. As a result, it is possible to prevent the royal fern 31 from fatigue fracture.
Further, since the material of the royal fern 31 is a nickel-cobalt alloy, for example, the durability, torque, and corrosion resistance of the royal fern 31 can be improved as compared with the case where the material of the royal fern 31 is stainless steel. When stainless steel is used as the material of the royal fern 31, the material cost can be reduced as compared with the case where the nickel-cobalt alloy is used.
Further, since the royal fern 31 is more fragile than the barrel 32, the royal fern 31 is less likely to be broken, so that the life of parts of the power unit 30 can be extended.
Further, since the spring 31 can be prevented from being fatigued and broken, the parts replacement period of the drive mechanism 1A and the clock 1 can be lengthened.

Further, according to this, for example, as compared with the case where the thickness dimension of the royal fern 31 is increased to ensure durability, the thickness dimension of the royal fern 31 can be reduced, so that the number of turns of the royal fern body portion 314 can be increased and the duration can be increased. Can be lengthened. As a result, the change between the initial torque generated by the royal fern 31 and the torque after 24 hours can be reduced, and isochronism can be improved.
Further, for example, the hardness of the royal fern 31 can be increased as compared with the case where the toughness of the royal fern 31 is increased to ensure the durability, so that the torque generated by the royal fern 31 can be improved. As a result, the swing angle of the balance (not shown) included in the watch 1 can be increased to, for example, about 300 degrees.

In the shape processing step, the spiral portion 313 can be formed by adjusting the feeding speed of the royal fern member 31M and the distance between the exiting portion 421 and the inclined surface 431. Therefore, for example, the spiral portion 313 can be easily formed in a short time as compared with the case where the spiral portion 313 is formed by winding the royal fern member 31M around a rod-shaped jig.

[Other Embodiments]
The present invention is not limited to the configuration of the above embodiment, and various modifications can be made within the scope of the gist of the present invention.

In the above embodiment, the number of turns of the spiral portion 313 is 2.5 or more, but the present invention is not limited to this.
As the number of turns of the spiral portion 313 increases, the durability of the royal fern 31 increases. Therefore, the number of turns of the spiral portion 313 may be at least the minimum number of turns that can secure the required durability, and may be less than 2.5 turns.

In the above embodiment, the number of turns of the spiral portion 313 is 3 or less, but the present invention is not limited to this.
As the number of turns of the spiral portion 313 increases, the number of turns of the royal fern body portion 314 decreases, and the duration becomes shorter. Further, the duration varies depending on the outer diameter of the barrel 33, the inner diameter of the barrel gear 34, the thickness dimension, the width dimension, and the length dimension of the royal fern 31.
Therefore, the number of turns of the spiral portion 313 is set to the number of turns that can secure the required duration according to the outer diameter of the barrel 33, the inner diameter of the barrel gear 34, the thickness dimension, the width dimension, and the length dimension of the royal fern 31. It suffices if it is set, and may be more than 3 volumes such as 3.5 volumes and 4 volumes.

In the above embodiment, the width dimension of the royal fern 31 is set to about 1 mm, the thickness dimension is set to about 0.1 mm, and the length dimension is set to about 300 mm, but the present invention is limited thereto. Not done. These dimensions may be appropriately set according to the thickness of the barrel 32, the duration, and the required torque.
However, the width dimension of the royal fern 31 is set in the range of 0.8 mm or more and 2.0 mm or less, and the thickness dimension is set in the range of 0.06 mm or more and 0.20 mm or less for durability and duration. It is preferable to improve the above.
In the above embodiment, the royal fern 31 is generated by being shaped by the shape processing device 40, but the present invention is not limited thereto.
For example, the royal fern 31 may be generated by winding the royal fern member 31M around a spiral jig formed in a curved shape of Bernoulli.

In the above embodiment, the royal fern 31 is wound in a Bernoulli curve from the inner end 311 but the present invention is not limited thereto.
For example, a portion having a predetermined length continuous from the inner end 311 of the royal fern is wound around the barrel 33, that is, the portion is wound around the barrel 33 by elastic force even when the royal fern is rewound. In the configuration, the portion (winding portion) does not displace with the winding and rewinding of the mainspring. Therefore, even if the winding portion is not curved by Bernoulli, it is unlikely that the mainspring will suffer fatigue failure.
Therefore, in this case, the winding portion is formed to have a curved shape according to the outer circumference of the barrel 33 in a free state where no load is applied so that the winding portion wraps around the barrel 33.
Then, the spiral portion continuous with the winding portion is formed into a shape wound in a Bernoulli curve. As a result, the durability of the spiral portion can be improved, and the fatigue fracture of the mainspring can be suppressed.
FIG. 10 shows a royal fern 31D when a portion of 1.0 roll (rotation angle: 360 degrees) from the inner end 311 is wound around the barrel 33.
As shown in FIG. 10, the royal fern 31D is continuous with the inner end 311 and curved according to the outer circumference of the barrel 33, and is continuous with the winding portion 316D in the free state, and has a curved shape of Bernoulli. It has a spiral portion 313D wound around it.
Although not shown, the barrel 33 to which the royal fern 31D is attached has a substantially circular shape in a plan view when viewed from the axial direction. Then, in a plan view, the distance from the axial center of the barrel 33 to the outer circumference is constant from the position where the inner end 311 of the royal fern 31D is fixed to the position rotated 270 degrees in the winding direction of the royal fern 31D. The distance from the center of the shaft to the outer circumference gradually increases from the position rotated by 270 degrees to the position rotated by 360 degrees from the position where the inner end 311 is fixed. Therefore, as shown in FIG. 10, the winding portion 316D of the royal fern 31D has a constant R value and a rotation angle θ of 270 degrees or more and 360 degrees in a portion where the rotation angle θ is 0 degrees or more and 270 degrees or less. In the following part, the curve is such that the value of R gradually increases. Here, the value of R is set to a value shorter than the distance from the axis center of the barrel 33 to the corresponding outer circumference. As a result, the winding portion 316D is wound around the barrel 33 by the elastic force. According to this, for example, a hole is provided in the inner end 311 of the royal fern 31D, and the protrusion provided in the barrel 33 is inserted into the hole, so that the inner end 311 is fixed to the barrel 33. In, the protruding portion is less likely to come out from the hole, and the inner end 311 can be securely fixed to the barrel 33.
The length of the winding portion 316D is not limited to 1.0 winding from the inner end 311. That is, it is appropriately set according to the length of the royal fern 31D wound around the barrel 33. Further, the spiral portion 313D is preferably 2.5 to 3.0 rolls or less, similarly to the spiral portion 313 of the royal fern 31 of the above embodiment. Further, the winding portion 316D and the spiral portion 313D are formed by the same shape processing process as the royal fern 31.

Hereinafter, the characteristics of the royal fern 31 will be described in detail with reference to Examples and Comparative Examples. Table 1 shows the shape of the royal fern in each example and comparative example.

[Comparison example]
FIG. 11 is a diagram showing a spiral portion of the royal fern 51 of the comparative example.
(1) Structure of royal fern Using nickel-cobalt alloy as a material, the width dimension is about 1 mm, the thickness dimension is about 0.1 mm, and the length dimension is about 300 mm.
(2) Number of turns of the spiral part: 2.0 turns (rotation angle θ: 720 degrees)
(3) Shape of spiral part: It is not a Bernoulli curve.

[Example 1]
FIG. 12 is a diagram showing a spiral portion 313A of the royal fern 31A of the first embodiment.
(1) Structure of royal fern The same as the comparative example.
(2) Number of turns of the spiral part: 2.5 turns (rotation angle θ: 900 degrees)
(3) Shape of spiral portion: Bernoulli curve.

[Example 2]
FIG. 13 is a diagram showing a spiral portion 313B of the royal fern 31B of the second embodiment.
(1) Structure of royal fern The same as the comparative example.
(2) Number of turns of the spiral part: 3.0 turns (rotation angle θ: 1080 degrees)
(3) Shape of spiral portion: Bernoulli curve.

[Example 3]
FIG. 14 is a diagram showing a spiral portion 313C of the royal fern 31C of the third embodiment.
(1) Structure of royal fern The same as the comparative example.
(2) Number of turns of the spiral part: 3.5 turns (rotation angle θ: 1260 degrees)
(3) Shape of spiral portion: Bernoulli curve.

[Evaluation method]
The durability, torque, and duration of the royal fern were evaluated according to the following criteria. The evaluation results are shown in Table 2.
<Durability>
A: It is above the standard.
B: Equivalent to the standard.
C: Below the standard.
<Torque>
A: It is above the standard.
B: Equivalent to the standard.
C: Below the standard.
<Duration>
A: It is above the standard.
B: Equivalent to the standard.
C: Below the standard.

[Durability evaluation result]
FIG. 15 is a graph showing the durability of the royal fern according to the heat treatment temperature.
Durability is expressed by the number of windings (durability).
In the vicinity of 300 ° C. to 400 ° C., the higher the heat treatment temperature, the higher the hardness of the royal fern, but on the contrary, the toughness decreases, so that the durability tends to decrease.
Generally, it is required that the durability at a heat treatment temperature of about 340 ° C. is about 700 times or more.
In the comparative example, the durability is about 500 times, which does not satisfy the above level.
In the first embodiment, the durability is about 700 times, which is equivalent to the minimum level.
In the second embodiment, the durability is about 1100 times, which is significantly higher than the above level.
In the third embodiment, the durability is about 1700 times, which is significantly higher than the above level.
From these results, it can be seen that if the number of turns of the spiral portion 313 formed in the Bernoulli curve is 2.5 or more, the durability level is satisfied.

[Torque evaluation result]
FIG. 16 is a graph showing the torque generated by the mainspring according to the heat treatment temperature.
The torque is the torque 24 hours after the mainspring is wound.
In the vicinity of 300 ° C. to 400 ° C., as described above, the higher the heat treatment temperature, the higher the hardness of the royal fern, and therefore the torque tends to increase.
Generally, the torque at a heat treatment temperature of about 340 ° C. is required to be at least about 0.51 N · cm or more, preferably about 0.54 N · cm or more.
In the comparative example, the torque is about 0.57 N · cm, which exceeds the above level.
In the first embodiment, the torque is about 0.57 N · cm, which exceeds the above level.
In the second embodiment, the torque is about 0.56 N · cm, which exceeds the above level.
In Example 3, the torque is about 0.55 N · cm, which exceeds the above level.
From these results, it can be seen that the torque tends to increase as the number of turns increases. If the number of turns of the spiral portion 313 formed in the Bernoulli curve is 2.5 turns or more as described above, the torque is increased. It turns out that it meets the standard.

[Evaluation of duration]
FIG. 17 is a graph showing the duration.
Generally, the duration is required to be 46.5 hours or more.
In the comparative example, the duration is about 48 hours, which exceeds the above level.
In Example 1, the duration is about 48 hours, which exceeds the above level.
In Example 2, the duration is about 47 hours, which exceeds the above level.
In Example 3, the duration is about 45 hours, which is lower than the above level.
From these results, it can be seen that the larger the number of turns, the shorter the duration tends to be. This is because when the number of turns is large, the length of the spiral portion becomes long, and the length of the main body portion of the royal fern becomes short and the number of turns decreases.
That is, it can be seen that if the number of turns of the spiral portion 313 formed in the Bernoulli curve is 3 or less, the duration level is satisfied.

1 ... Clock, 1A ... Drive mechanism (movement for clock), 30 ... Power unit (power unit for clock), 31, 31A, 31B, 31C, 31D ... Spring (spring for clock), 31M ... Spring member, 32 ... Incense box , 33 ... barrel true, 34 ... barrel gear, 35 ... barrel lid, 40 ... shape processing device, 41 ... extrusion part, 42 ... guide part, 43,44 ... shaping part, 311 ... inner end, 312 ... outer end, 313, 313A, 313B, 313C, 313D ... spiral part, 314 ... mainspring body part, 315 ... connecting part, 316D ... winding part, 341 ... inner wall, 411,412 ... extrusion roller, 421 ... exit part, 431,441 … Inclined surface.

Claims (10)

A watch spring that is housed in a barrel, has an inner end fixed to the barrel provided by the barrel, and has an outer end that engages with the inner wall of the barrel.
In the free state without load, the spiral part wound in a Bernoulli curve from the inner end and
A connecting portion continuous from the spiral portion and
It is provided with a mainspring main body portion that is continuous from the connecting portion and is wound in a direction opposite to the winding direction of the spiral portion.
A watch royal fern characterized in that the number of turns of the spiral portion is 2.5 or more and 3.0 or less. An inner end housed in the barrel and fixed to the barrel, a winding portion continuous with the inner end and wound around the barrel, a spiral portion continuous with the winding portion, and the above. A watch royal fern with an outer edge that engages the inner wall of the barrel.
Between the spiral portion and the outer end, a connecting portion continuous from the spiral portion and a connecting portion continuous from the connecting portion and wound in a direction opposite to the winding direction of the spiral portion. The main body of the spiral is provided,
In the unloaded free state, the spiral portion is wound in a Bernoulli curve .
A watch royal fern characterized in that the number of turns of the spiral portion is 2.5 or more and 3.0 or less. In the watch fern according to claim 1 or 2.
The material of the watch royal fern is a nickel-cobalt alloy. In the watch fern according to claim 1 or 2.
The material of the watch fern is stainless steel. The watch royal fern according to any one of claims 1 to 4.
A watch power unit including the barrel for accommodating the watch spring. The power unit for a clock according to claim 5 and
A watch movement comprising a gear driven by the watch power unit. A timepiece comprising the timepiece movement according to claim 6. A method for manufacturing a watch royal fern, which is housed in a barrel, whose inner end is fixed to the barrel provided by the barrel, and whose outer end engages with the inner wall of the barrel.
By ejecting the royal fern member and hitting it against an inclined surface, the royal fern member is curved.
By adjusting the emission speed of the royal fern member and the distance between the emission position of the royal fern member and the inclined surface, the royal fern member was deformed and wound around the royal fern member in a Bernoulli curve from one end. A method for manufacturing a royal fern for a watch, which is characterized by forming a spiral portion. It is housed in the barrel, the inner end of the barrel is fixed to the barrel, the outer end is engaged with the inner wall of the barrel, and in a free state where no load is applied, the barrel is wound in a Bernoulli curve from the inner end. It is a manufacturing method of a watch barrel equipped with a spiral part.
In the Bernoulli curve, in polar coordinates, the length of a straight line drawn from the origin to a point on the curve is R, the angle between the straight line and the start line is θ, and the tangent line between the straight line and the point on the curve is When the angle formed is b, the value of R when θ is 0 degrees is a, and the number of napiers is e.
R = ae ^bθ
It is a curve that satisfies the relationship of
When e ^b is a constant A,
The lower limit of the constant A is determined based on the effective number of turns of the watch royal fern.
The upper limit of the constant A is determined based on the durability and torque of the watch royal fern.
A method for manufacturing a watch royal fern, characterized in that the constant A is set to a value equal to or higher than the lower limit value and equal to or lower than the upper limit value, and the royal fern member is deformed to form the spiral portion on the royal fern member. An inner end housed in the barrel and fixed to the barrel, a winding portion continuous with the inner end and wound around the barrel, a spiral portion continuous with the winding portion, and the above. In a free state with an outer end engaging with the inner wall of the barrel and no load, the spiral portion is a method of manufacturing a watch zenmai wound in a Bernoulli curve.
In the Bernoulli curve, in polar coordinates, the length of a straight line drawn from the origin to a point on the curve is R, the angle between the straight line and the start line is θ, and the tangent line between the straight line and the point on the curve is When the angle formed is b, the value of R when θ is 0 degrees is a, and the number of napiers is e.
R = ae ^bθ
It is a curve that satisfies the relationship of
When e ^b is a constant A,
The lower limit of the constant A is determined based on the effective number of turns of the watch royal fern.
The upper limit of the constant A is determined based on the durability and torque of the watch royal fern.
A method for manufacturing a watch royal fern, characterized in that the constant A is set to a value equal to or higher than the lower limit value and equal to or lower than the upper limit value, and the royal fern member is deformed to form the spiral portion on the royal fern member.

Images