JP2017198650A - Mainspring for timepiece, power device for timepiece, movement for timepiece, timepiece, and manufacturing method for mainspring for timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mainspring for a timepiece which is hard to be subjected to fatigue destruction, and a power device for a timepiece, a movement for a timepiece, a timepiece and a manufacturing method for a mainspring for a timepiece.SOLUTION: A mainspring for a timepiece being accommodated in a barrel, having an inner end fixed to a barrel arbor which the barrel comprises, and having an outer end engaging with an inner wall of the barrel comprises a spiral portion wound in a Bernoulli curve from the inner end in a free state in which a load is not applied thereto.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a timepiece spring, a timepiece power device, a timepiece movement, a timepiece, and a method for manufacturing a timepiece spring.

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

JP 2009-300439 A

When the mainspring as in Patent Document 1 is housed in the barrel, the inner end is fixed to the barrel, wound around the barrel, 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 amount of displacement associated with the winding and unwinding of the spiral portion on the inner end side is larger than that of the other portions.
Moreover, in the conventional spring like patent document 1, generally the spiral part of the inner end side is formed in the shape which plastically deforms when the mainspring is wound up. For this reason, after being accommodated in the barrel and being tightened, the durability is lowered as compared to before being tightened.
For these reasons, there is a problem that the spiral portion on the inner end side of the mainspring is easily damaged by fatigue.

  An object of the present invention is to provide a timepiece spring, a timepiece power unit, a timepiece movement, a timepiece, and a method for manufacturing a timepiece spring that are less susceptible to fatigue failure.

  The timepiece spring of the present invention is a timepiece spring housed in a barrel, the barrel end of the barrel is fixed to the inner end of the barrel, and the outer end engages with the inner wall of the barrel, and is not loaded. In a free state, a spiral portion wound in a Bernoulli curve from the inner end is provided.

Here, the free state in which no load is applied is, for example, a state in which the timepiece 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 does not intend a three-dimensional curved shape, but a two-dimensional curved shape that does not displace in the axial direction of the spiral portion.
The timepiece spring is molded into a shape including the spiral portion before being housed in the barrel. The molded timepiece spring is accommodated in the barrel, the inner end is fixed to the barrel, and the outer end is engaged with the inner wall of the barrel.
According to the present invention, since the plastic deformation due to the winding can be suppressed in the spiral portion, the durability can be improved. Thereby, it can suppress that the timepiece mainspring carries out fatigue destruction.

  The timepiece spring of the present invention is housed in a barrel and is fixed to a barrel complete with the barrel, continuous to the inner end, wound around the barrel, and continuous to the winding portion. A spiral spring having an outer end engaged with the inner wall of the barrel, and in a free state where no load is applied, the spiral portion is wound in a Bernoulli curve. It is characterized by.

The winding portion is a portion that is truly wound around the barrel even when the timepiece spring is rewound, and does not displace when the timepiece spring is wound and unwound.
For this reason, even if the winding part is not Bernoulli curved, the timepiece spring is less likely to be fatigued. For this reason, a winding part is made into the shape curved according to the outer periphery of barrel true in a free state, for example so that it may wind in barrel true.
Since the spiral portion is wound in a Bernoulli curve shape in a free state, durability can be improved. Thereby, it can suppress that the timepiece mainspring carries out fatigue destruction.

In the timepiece spring of the present invention, it is preferable that the number of turns of the spiral portion is 2.5 or more.
The durability increases as the number of turns of the spiral portion increases.
By setting the number of turns of the spiral portion to 2.5 or more, it becomes possible to satisfy a general durability level (for example, the number of windings: 700 times).

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

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

A timepiece power device according to the present invention includes the timepiece spring and the barrel that houses the timepiece spring.
Since the timepiece spring is more fragile than the barrel, the timepiece spring is less likely to break, so that the component life of the timepiece power unit can be extended.

A timepiece movement of the present invention includes the timepiece power device and a gear driven by the timepiece power device.
According to the present invention, it is possible to prevent the timepiece spring from being damaged by fatigue, and therefore, it is possible to lengthen the time for replacing the parts of the movement.

A timepiece according to the present invention includes the timepiece movement described above.
According to the present invention, since the timepiece spring can be prevented from being damaged by fatigue, the time for replacing a timepiece part can be lengthened.

The present invention is a manufacturing method of a timepiece spring which is housed in a barrel, the inner end is fixed to the barrel of the barrel, and the outer end engages with the inner wall of the barrel, and the spring member is deformed. The spiral member is formed with a spiral portion wound in a Bernoulli curve from one end.
ADVANTAGE OF THE INVENTION According to this invention, durability of a helical part can be improved and it can suppress that the timepiece mainspring carries out a fatigue failure.

In the method for manufacturing a timepiece spring according to the present invention, the mainspring member is emitted and applied to an inclined surface so that the mainspring member is bent, the emission speed of the mainspring member, and the emission position and the inclination of the mainspring member It is preferable to form the spiral portion by adjusting the distance to the surface.
According to the present invention, for example, the spiral portion can be easily formed in a short time compared to the case where the spiral portion is formed by winding the mainspring member around a rod-shaped jig.

The present invention is housed in a barrel, the inner end is fixed to the barrel of the barrel, the outer end is engaged with the inner wall of the barrel, and the Bernoulli curve from the inner end in a free state where no load is applied. A watch spring having a spiral portion wound in a shape, wherein the Bernoulli curve has, in polar coordinates, the length of a straight line drawn from the origin to a point on the curve as R, and the straight line and the start line Where θ is the angle between the straight line and the tangent of the point on the curve, b is the value of R when θ is 0 degrees, and e is the Napier number. ae ^bθ satisfying the relationship, where 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 timepiece spring, and the upper limit value of the constant A is set to the timepiece Determined based on the durability and torque of the mainspring, and before The constants A, set to the lower limit value or more and the value of less than the upper limit, to deform the mainspring member, and forming the spiral portion to the mainspring member.

The effective number of turns of the watch spring that determines the number of rotations of the barrel after the watch spring is wound in the barrel is reduced as the value of the constant A is smaller, and may not satisfy the standard value of the effective number of turns. is there. For this reason, in the present invention, the lower limit value of the constant A is determined based on the effective number of turns. Further, the durability of the timepiece spring decreases as the value of the constant A increases. For this reason, when the constant A exceeds a certain value, it becomes impossible to obtain a state in which both durability and torque satisfy the standard value. For this reason, in this invention, the upper limit of the constant A is determined based on durability and torque. Then, the constant A is set to a value not less than the lower limit and not more than the upper limit to form a spiral portion.
According to this, it is possible to reliably manufacture a timepiece spring that satisfies the standard values of the effective number of turns, durability, and torque.

The present invention includes an inner end housed in a barrel and fixed to a barrel full provided in the barrel, a winding portion continuous to the inner end and wound around the barrel, and a spiral portion continuous to the winding portion. And a manufacturing method of a timepiece spring having an outer end engaged with the inner wall of the barrel, and in a free state where no load is applied, wherein the spiral portion is wound in a Bernoulli curve shape, In 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 straight line and the tangent of the point on the curve are formed. the angle and b, theta is the value of R when the 0 degree as a, if the Napier number was e, is a curve which satisfies the relationship of ^R = ae bθ, when the e ^b a constant a, the constant The lower limit value of A is based on the effective number of turns of the watch mainspring. And determining the upper limit value of the constant A based on the durability and torque of the timepiece spring, setting the constant A to a value not less than the lower limit value and not more than the upper limit value, and deforming the spring member Thus, the spiral portion is formed on the mainspring member.
ADVANTAGE OF THE INVENTION According to this invention, the mainspring for timepieces in which effective winding number, durability, and a torque satisfy | fill a standard value can be manufactured reliably.

Sectional drawing which shows the timepiece in embodiment which concerns on this invention. The top view showing the power unit in the state where the mainspring in the embodiment was wound up. The top view showing the power unit in the state where the mainspring in the embodiment was rewound. The figure which shows the mainspring of the free state in embodiment. The figure explaining Bernoulli curve. The figure which shows the shape processing process in embodiment. The figure which shows the shape processing process in embodiment. The graph which shows the durability and torque of the mainspring in the embodiment. The graph which shows the relationship between the constant A of the Bernoulli curve in embodiment, and the effective winding number of a mainspring. The figure which shows the mainspring of the free state in other embodiment which concerns on this invention. The figure which shows the mainspring of a comparative example. The figure which shows the mainspring of Example 1. FIG. The figure which shows the mainspring of Example 2. FIG. The figure which shows the mainspring of Example 3. FIG. The graph which shows the durability evaluation result 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 timepiece 1.
The timepiece 1 includes a drive mechanism (timepiece movement) 1 </ b> A on the back cover side of the dial 11. The drive mechanism 1 </ b> A includes a spring (timepiece spring) 31 and a power unit (timepiece power unit) 30 configured by a barrel 32 that houses the spring 31.
The barrel box 32 includes a barrel box 33, and a barrel box gear 34 and a barrel box cover 35 attached to the barrel box 33.

The main spring 31 has an inner end 311 (see FIG. 3) fixed to the barrel complete 33, winds around the barrel complete 33, and an outer end 312 (see FIG. 2) is on the inner wall 341 (see FIG. 2) of the barrel gear 34. Is engaged.
The barrel complete 33 is supported by the main plate 2 and the train wheel bridge 3, and is fixed by a square hole screw 5 so as to rotate integrally with the square wheel 4 provided in the drive mechanism 1A. The square wheel 4 is meshed with a cork (not shown) so as to rotate clockwise but not counterclockwise.
The method of rotating the square wheel 4 in the clockwise direction and winding the mainspring 31 is the same as that of a general mechanical timepiece automatic winding or manual winding mechanism, and thus description thereof is 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 hour wheel 10 provided in the drive mechanism 1 </ b> A. A second hand (not shown) is attached to the fourth wheel 9, a minute hand (not shown) is attached to the hour pinion 7 </ b> A of the second wheel 7, and an hour hand (not shown) is attached to the hour wheel 10. Thereby, each pointer is driven by rotation of the barrel gear 34.

[Configuration of power unit]
2 and 3 are plan views of the power unit 30 as viewed from the thickness direction. In FIG. 2 and FIG. 3, the barrel cover 35 is not shown.
2 shows a state after the mainspring 31 has been wound in the barrel 32, and FIG. 3 shows a state after the mainspring 31 has been wound back in the barrel 32 (released state).
The inner end 311 of the mainspring 31 is fixed to the barrel complete 33. In the present embodiment, the outer diameter of the barrel complete 33 is 2.6 mm. Here, the mainspring 31 is fixed to the barrel complete 33 so that the width direction is along the axial direction of the barrel complete 33.
The outer end 312 of the mainspring 31 is engaged with the inner wall 341 by being hooked on a notch formed on the inner wall 341 of the barrel gear 34 or by being hooked on the inner wall 341 via a slipping attachment (not shown). Yes. In the present embodiment, the inner diameter of the barrel gear 34 (the diameter of the accommodation space of the mainspring 31) is 10.6 mm.

As shown in FIG. 2, the mainspring 31 is wound around the barrel full 33 by rotating the barrel full 33 with 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 released state shown in FIG. 3, a portion having a predetermined length from the inner end 311 extends in a spiral shape in the plan view and constitutes a spiral portion 313. In this embodiment, the number of turns of the spiral portion 313 is 2.5 or more and 3.0 or less.
A portion of the mainspring 31 that is closer to the outer end 312 than the spiral portion 313 is wound in a substantially concentric shape centered on the barrel 33 in the plan view.
The helical portion 313 has a large displacement amount due to tightening and unwinding compared to other portions, and the stress change is large.

[Structure of the mainspring]
FIG. 4 is a view showing the spring 31 in a free state where no load is applied before being housed in the barrel 32. That is, it is a view showing the spring 31 in a free state before being tightened. Here, the free state in which no load is applied is, for example, a state in which the timepiece 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 mainspring 31 includes a spiral portion 313, a connection portion 315 that is not continuously shaped from the spiral portion 313, and a connection portion 315 that is continuous from the connection portion 315, and is 10 in the direction opposite to the winding direction of the spiral portion 313. And a mainspring main body portion 314 wound about times. The spiral is not intended to be a three-dimensional curve, but is intended to be a two-dimensional curve that is not displaced 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, as will be described in detail in the examples described later, in the present embodiment, the number of turns of the spiral portion 313 is preferably 2.5 or more in order to ensure the required durability. Is preferably 3.0 volumes or less in order to ensure a sufficient duration (for example, 46.5 hours).
As shown in FIG. 5, in the Bernoulli curve, in polar coordinates, the length (distance from the origin) of the straight line L drawn from the origin to a point on the curve is R, and the angle (deviation) between the straight line L and the start line X is R. The angle (θ) is θ, the angle between 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 Napier number is e, the following equation (1) ) Is a curved line (spiral).

R = ae ^bθ (1)

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

R = aA ^θ (2)

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

[Manufacturing method of mainspring]
Next, a method for manufacturing the spring 31 will be described. The spring 31 is generated by subjecting the plate-shaped spring member 31M to a shape processing step for giving the shape shown in FIG.

[Shape processing equipment]
In the shape processing step, a shape processing apparatus 40 shown in FIG. 6 is used.
The shape processing apparatus 40 includes an extruding portion 41 including extruding rollers 411 and 412 for extruding the mainspring member 31M, a guide portion 42 for guiding and ejecting the extruded mainspring member 31M in a predetermined direction, and the ejected mainspring member Shape forming portions 43 and 44 for deforming 31M and performing shape forming (brazing) are provided.

The extruding unit 41 is configured to be able to adjust the extruding speed (exiting speed) of the mainspring member 31M by adjusting the rotational speed of the extruding rollers 411 and 412.
The guide part 42 emits the spring member 31M from the emitting part 421 in a predetermined direction.

The shaping part 43 is configured to be movable in the Z direction orthogonal to the emission direction of the mainspring member 31M and in the direction opposite to the Z direction.
Moreover, the shaping part 43 is provided with the inclined surface 431 where the mainspring member 31M emitted from the emission part 421 contacts. The inclined surface 431 is inclined in a direction away from the emitting portion 421 as it goes in the Z direction.

The shaping portion 44 is configured to be movable in the Z direction and the direction opposite to the Z direction.
The shaping portion 44 includes an inclined surface 441 that the spring member 31M emitted from the emission portion 421 contacts. The inclined surface 441 is inclined in a direction away from the emitting portion 421 as it goes in the direction opposite to the Z direction.

[Shaping process]
In the shape processing step, first, as shown in FIG. 6, the shaping portion 43 is disposed at a position where the mainspring member 31 </ b> M emitted from the emission portion 421 contacts the inclined surface 431. At this time, the shaping portion 44 is disposed at a position where the emitted spring member 31M does not hit the inclined surface 441.
In this state, the push-out unit 41 pushes out the spring member 31M. Thereby, the mainspring member 31M emitted from the emission part 421 hits the inclined surface 431, and thereby the mainspring member 31M is bent from one end side.
At this time, the push-out unit 41 pushes out the spring member 31M while adjusting the push-out speed in accordance with a preset program. Further, the shaping unit 43 adjusts the distance in the emission direction between the emission unit 421 (emission position) and the inclined surface 431 by moving in the Z direction or the direction opposite to the Z direction according to a preset program. Then, the mainspring member 31M is bent.
Thus, the mainspring member 31M can be formed in a predetermined spiral shape by adjusting the extrusion speed of the mainspring member 31M and the distance between the emitting portion 421 and the inclined surface 431. In the present embodiment, the extrusion speed and the distance are adjusted to form the Bernoulli 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 spring member 31M emitted from the emission portion 421 does not hit the inclined surface 431. Wait at.
Then, the shaping portion 44 moves in a direction opposite to the Z direction, and moves to a position where the mainspring member 31M emitted from the emission portion 421 contacts the inclined surface 441.
In this state, the push-out unit 41 pushes out the spring member 31M. As a result, the mainspring member 31M emitted from the emission portion 421 hits the inclined surface 441, whereby the mainspring member 31M is bent in the direction opposite to the spiral portion 313.
At this time, the push-out unit 41 pushes out the spring member 31M while adjusting the push-out speed in accordance with a preset program. Further, the shaping part 44 moves in the Z direction or the direction opposite to the Z direction according to a preset program, thereby adjusting the distance between the emission part 421 and the inclined surface 441 in the emission direction. Bend 31M.
In the present embodiment, the main body portion 314 wound in the opposite direction to the connecting portion 315 and the spiral portion 313 is formed by adjusting the extrusion speed and the distance.
After the mainspring main body portion 314 is formed, the mainspring member 31M is cut and then heat-treated at about 350 degrees. Thereby, the mainspring 31 is generated.

[How to set the Bernoulli curve constant A]
Next, a method for setting the constant A used in the Bernoulli curve formula for determining the shape of the spiral portion 313 will be described.
FIG. 8 is a graph showing the durability and torque characteristics of the spring 31 according to the value of the constant A.
The horizontal axis of the graph indicates durability. The durability is represented by the number of times of winding (the number of times of durability) until the spring 31 is broken when the spring 31 is repeatedly wound and unwound. The vertical axis of the graph represents torque. The torque is the torque 24 hours after the mainspring 31 is tightened.
Point D1 in the figure is a point indicating the characteristics of the three types of spring 31 manufactured at the first, second, and third heat treatment temperatures with the constant A set to 1.07. The line L1 is a linear function obtained by linearly approximating the point D1. Point D2 is a point indicating the characteristics of the three types of spring 31 manufactured at the first to third heat treatment temperatures with the constant A set to 1.10. The line L2 is a linear function obtained by linearly approximating the point D2. Point D3 is a point indicating the characteristics of the three types of spring 31 manufactured at the first to third heat treatment temperatures with the constant A set to 1.13. 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. For this reason, when the constant A exceeds a certain value, it becomes impossible to obtain a state in which both durability and torque satisfy the standard value. For this reason, in this embodiment, the upper limit value of the constant A is set based on durability and torque.
In the example of FIG. 8, when the constant A is smaller than 1.13, depending on the heat treatment temperature, it is possible to obtain a state in which both durability and torque satisfy the standard values, but when the constant A is 1.13. In addition, it becomes impossible to obtain a state in which both durability and torque satisfy the standard values. For this reason, the upper limit value of the constant A is set to 1.12, for example.

FIG. 9 is a graph showing the relationship between the constant A and the effective number of windings of the spring 31 that determines the number of rotations of the barrel 32 from the time when the spring 31 is wound in the barrel 32 to the time of rewinding.
The horizontal axis of the graph shows the value of constant A. The vertical axis of the graph indicates the effective number of 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. For this reason, in this embodiment, the lower limit value of the constant A is determined based on the effective winding number of the mainspring 31.
In the example of FIG. 9, the effective number of turns is less than the standard value when the constant A is 1.07, and exceeds the standard value when the constant A is 1.08. Set to 08.

  Then, the constant A is set to a value that is greater than or equal to the lower limit value and less than or equal to the upper limit value, thereby forming the spiral portion 313. Thereby, the mainspring 31 whose effective winding number, durability, and torque satisfy the standard values can be reliably manufactured.

[Effects of Embodiment]
Since the mainspring 31 includes a spiral portion 313 wound in a Bernoulli curve shape from the inner end 311, plastic deformation due to winding can be suppressed, and durability can be improved. That is, the stress generated at the time of winding can be made sufficiently smaller than the elastic limit. Thereby, it can suppress that the mainspring 31 carries out a fatigue failure.
Moreover, since the material of the mainspring 31 is a nickel cobalt alloy, for example, the durability, torque, and corrosion resistance of the mainspring 31 can be improved as compared with the case where the material of the mainspring 31 is stainless steel. In addition, when stainless steel is used for the material of the spring 31, the material cost can be reduced as compared with the case where a nickel cobalt alloy is used.
Moreover, since the mainspring 31 is more fragile than the barrel 32, the spring 31 is less likely to be broken, so that the component life of the power unit 30 can be extended.
Further, since the spring 31 can be prevented from being damaged by fatigue, the parts replacement time of the drive mechanism 1A and the timepiece 1 can be lengthened.

Moreover, according to this, since the thickness dimension of the mainspring 31 can be reduced as compared with, for example, increasing the thickness dimension of the mainspring 31 to ensure durability, the number of turns of the mainspring body portion 314 can be increased, and the duration time can be increased. Can be long. Thereby, the change of the initial torque which the mainspring 31 generate | occur | produces and the torque after 24 hours can be reduced, and isochronism can be improved.
Further, for example, since the hardness of the mainspring 31 can be increased as compared with the case where the toughness of the mainspring 31 is increased to ensure durability, the torque generated by the mainspring 31 can be improved. Thereby, the swing angle of the balance (not shown) included in the timepiece 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 mainspring member 31M and the distance between the emitting portion 421 and the inclined surface 431. Therefore, for example, the spiral portion 313 can be easily formed in a short time compared to the case where the spiral portion 313 is formed by winding the mainspring member 31M around a rod-shaped jig.

[Other Embodiments]
In addition, this invention is not limited to the structure of the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention.

In the 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 mainspring 31 increases. For this reason, the number of turns of the spiral portion 313 is not less than the minimum number of turns that can ensure the required durability, and may be less than 2.5 turns.

In the 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 main body portion 314 decreases and the duration becomes shorter. The duration varies depending on the outer diameter of the barrel complete 33, the inner diameter of the barrel gear 34, the thickness dimension, the width dimension, and the length dimension of the mainspring 31.
For this reason, the number of turns of the spiral portion 313 is set to the number of turns that can ensure the required duration according to the outer diameter of the barrel complete 33, the inner diameter of the barrel gear 34, the thickness dimension, the width dimension, and the length dimension of the mainspring 31. It may be set, and may be more than 3, such as 3.5 or 4 volumes.

In the above embodiment, the width of the mainspring 31 is set to about 1 mm, the thickness is set to about 0.1 mm, and the length is set to about 300 mm, but the present invention is not limited to this. Not. These dimensions should just be set suitably according to the thickness, duration, and required torque of the barrel 32.
However, the width of the mainspring 31 is set in the range of 0.8 mm or more and 2.0 mm or less, and the thickness is set in the range of 0.06 mm or more and 0.20 mm or less. It is preferable for improving the ratio.
In the said embodiment, although the mainspring 31 is produced | generated by carrying out shape processing by the shape processing apparatus 40, this invention is not limited to this.
For example, the mainspring 31 may be generated by winding the mainspring member 31M around a spiral jig formed in a Bernoulli curve.

In the embodiment, the mainspring 31 is wound in a Bernoulli curve shape from the inner end 311, but the present invention is not limited to this.
For example, a portion of a predetermined length continuous from the inner end 311 of the mainspring is wound around the barrel complete 33, that is, the portion is wound around the barrel full 33 by elastic force even when the mainspring is rewound. In the configuration, the portion (winding portion) is not displaced with the winding and unwinding of the mainspring. For this reason, even if a winding part is not Bernoulli curve shape, possibility that a mainspring will carry out fatigue failure is low.
Therefore, in this case, the winding portion is curved according to the outer periphery of the barrel complete 33 in a free state where no load is applied so that the winding portion is wound around the barrel full 33.
And let the spiral part continuous to a winding part be the shape wound by Bernoulli curve shape. Thereby, durability of a helical part can be improved and it can suppress that a mainspring carries out fatigue destruction.
FIG. 10 shows the mainspring 31 </ b> D in the case where a portion of 1.0 turns (rotation angle: 360 degrees) from the inner end 311 is wound around the barrel complete 33.
As shown in FIG. 10, the mainspring 31D is continuous with the inner end 311 in the free state, and is wound around the winding portion 316D curved according to the outer periphery of the barrel 33, and is continuously wound around the winding portion 316D. And a spiral portion 313D wound around.
Although not shown, the barrel complete 33 to which the mainspring 31D is attached has a substantially circular shape in a plan view viewed from the axial direction. In plan view, the distance from the center of the barrel 33 to the outer periphery is constant from the position where the inner end 311 of the mainspring 31D is fixed to the position rotated 270 degrees in the winding direction of the mainspring 31D. From the position rotated 270 degrees to the position rotated 360 degrees from the position where the inner end 311 is fixed, the distance from the axis center to the outer periphery gradually increases. For this reason, as shown in FIG. 10, the winding portion 316D of the mainspring 31D has a constant R value at a portion where the rotation angle θ is not less than 0 degrees and not more than 270 degrees, and the rotation angle θ is not less than 270 degrees and 360 degrees. In the following part, it is a curve in which the value of R gradually increases. Here, the value of R is set to a value shorter than the distance from the axial center of the barrel complete 33 to the corresponding outer periphery. Thereby, winding part 316D winds around barrel 33 by elastic force. According to this, for example, a hole is provided in the inner end 311 of the mainspring 31D, and the inner end 311 is fixed to the barrel complete 33 by inserting a protruding portion provided in the barrel complete 33 into the hole. In this case, the projecting portion is difficult to be removed from the hole, and the inner end 311 can be securely fixed to the barrel complete 33.
The length of the winding portion 316D is not limited to 1.0 winding from the inner end 311. That is, the length is appropriately set according to the length of the mainspring 31D wound around the barrel 33. Moreover, it is preferable that the spiral portion 313D has 2.5 or more and 3.0 or less turns, similarly to the spiral portion 313 of the mainspring 31 of the embodiment. Further, the winding portion 316D and the spiral portion 313D are formed by the same shape processing step as that of the mainspring 31.

  Hereinafter, the characteristics of the mainspring 31 will be described in detail with reference to examples and comparative examples. Table 1 shows the shape of the mainspring in each example and comparative example.

[Comparative example]
FIG. 11 is a diagram illustrating a spiral portion of the spring 51 of the comparative example.
(1) Structure of mainspring A nickel cobalt alloy is used as a material, a width dimension is about 1 mm, a thickness dimension is about 0.1 mm, and a length dimension is about 300 mm.
(2) Number of turns of the spiral portion: 2.0 (rotation angle θ: 720 degrees)
(3) Shape of the spiral portion: not a Bernoulli curve.

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

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

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

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

[Durability evaluation results]
FIG. 15 is a graph showing the durability of the spring according to the heat treatment temperature.
The durability is expressed by the number of windings (the number of durability).
In the vicinity of 300 ° C. to 400 ° C., the higher the heat treatment temperature is, the higher the hardness of the mainspring is. On the other hand, the toughness is lowered, so the number of durability tends to be lowered.
Generally, it is required that the number of times of durability at a heat treatment temperature of about 340 ° C. is about 700 times or more.
In the comparative example, the number of times of durability is about 500 times, which does not satisfy the above level.
In Example 1, the number of times of endurance is about 700, which is equivalent to the minimum level.
In Example 2, the endurance number is about 1100 times, which is significantly higher than the above level.
In Example 3, the number of times of durability is about 1700 times, which is significantly higher than the above level.
From these results, it can be seen that the durability level is satisfied when the number of turns of the spiral portion 313 formed in a Bernoulli curve is 2.5 or more.

[Torque evaluation results]
FIG. 16 is a graph showing the torque generated by the spring according to the heat treatment temperature.
Torque is the torque 24 hours after the mainspring is tightened.
In the vicinity of 300 ° C. to 400 ° C., as described above, the higher the heat treatment temperature, the higher the hardness of the spring, and thus the torque tends to be improved.
Generally, the torque at a heat treatment temperature of about 340 ° C. is required to be at least about 0.51 N · cm, preferably about 0.54 N · cm.
In the comparative example, the torque is about 0.57 N · cm, which exceeds the above level.
In Example 1, the torque is about 0.57 N · cm, which exceeds the above level.
In Example 2, 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 as the number of turns increases, the torque tends to increase. If the number of turns of the spiral portion 313 formed in the Bernoulli curve shape is 2.5 turns or more as described above, It can be seen that the level is satisfied.

[Evaluation of duration]
FIG. 17 is a graph showing the duration.
In general, 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 below the above level.
From these results, it can be seen that the greater the number of turns, the shorter the duration. This is because when the number of turns is large, the length of the spiral portion becomes long, and accordingly, the length of the mainspring body portion becomes short and the number of turns becomes small.
That is, it can be seen that the level of the duration is satisfied if the number of turns of the spiral portion 313 formed in the Bernoulli curve is 3 or less.

  DESCRIPTION OF SYMBOLS 1 ... Timepiece, 1A ... Drive mechanism (timepiece movement), 30 ... Power unit (power unit for timepiece), 31, 31A, 31B, 31C, 31D ... Mainspring (timepiece mainspring), 31M ... Mainspring member, 32 ... Incense box 33 ... barrel box true, 34 ... barrel box gear, 35 ... barrel box cover, 40 ... shape processing device, 41 ... extrusion part, 42 ... guide part, 43, 44 ... shaping part, 311 ... inner end, 312 ... outer end, 313, 313A, 313B, 313C, 313 ... spiral part, 314 ... mainspring body part, 315 ... coupling part, 316D ... winding part, 341 ... inner wall, 411, 412 ... extrusion roller, 421 ... emitting part, 431, 441 ... Inclined surface.

Claims (12)

A timepiece spring housed in a barrel, with the inner end truly fixed to the barrel provided in the barrel, and having an outer end engaged with the inner wall of the barrel,
A timepiece spring comprising a spiral portion wound in a Bernoulli curve from the inner end in a free state where no load is applied. An inner end housed in a barrel and fixed to a barrel complete with the barrel, a winding portion continuous to the inner end and wound around the barrel, a spiral portion continuous to the winding portion, and A watch spring having an outer end engaged with the inner wall of the barrel,
A timepiece spring, wherein the spiral portion is wound in a Bernoulli curve in a free state where no load is applied. In the timepiece spring according to claim 1 or 2,
The timepiece mainspring is characterized in that the number of turns of the spiral portion is 2.5 or more. The timepiece spring according to any one of claims 1 to 3,
The timepiece spring is made of a nickel-cobalt alloy. The timepiece spring according to any one of claims 1 to 3,
The timepiece spring is made of stainless steel. The timepiece spring. A timepiece spring according to any one of claims 1 to 5,
The clock power device comprising: the barrel for housing the timepiece spring. A timepiece power unit according to claim 6,
A watch movement, comprising: a gear driven by the watch power device. A timepiece comprising the timepiece movement according to claim 7. A method for producing a timepiece spring which is housed in a barrel and has an inner end fixed to the barrel which is provided in the barrel, and an outer end engages with the inner wall of the barrel,
A method of manufacturing a timepiece spring, comprising deforming the mainspring member to form a spiral portion wound in a Bernoulli curve from one end on the mainspring member. In the manufacturing method of the timepiece spring of Claim 9,
By projecting the spring member and hitting the inclined surface, the spring member is curved,
The method of manufacturing a timepiece spring, wherein the spiral portion is formed by adjusting an emission speed of the mainspring member and a distance between an emission position of the mainspring member and the inclined surface. The inner end of the barrel is contained in the barrel, the inner end is fixed to the barrel, the outer end engages with the inner wall of the barrel, and is wound in a Bernoulli curve from the inner end in a free state where no load is applied. A method of manufacturing a watch spring having a spiral portion,
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 straight line and the tangent of the point on the curve are When the angle formed is b, the value of R when θ is 0 degree is a, and the number of Napiers is e,
R = ae ^bθ
Is a curve that satisfies the relationship
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 mainspring,
The upper limit value of the constant A is determined based on the durability and torque of the timepiece spring,
The constant spring A is set to a value not less than the lower limit value and not more than the upper limit value, and the mainspring member is deformed to form the spiral portion in the mainspring member. An inner end housed in a barrel and fixed to a barrel complete with the barrel, a winding portion continuous to the inner end and wound around the barrel, a spiral portion continuous to the winding portion, and An outer end that engages with the inner wall of the barrel, and in a free state in which no load is applied, the spiral portion is a method for manufacturing a watch spring 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 straight line and the tangent of the point on the curve are When the angle formed is b, the value of R when θ is 0 degree is a, and the number of Napiers is e,
R = ae ^bθ
Is a curve that satisfies the relationship
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 mainspring,
The upper limit value of the constant A is determined based on the durability and torque of the timepiece spring,
The constant spring A is set to a value not less than the lower limit value and not more than the upper limit value, and the mainspring member is deformed to form the spiral portion in the mainspring member.

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