JP2013234901A - Collet, balance and watch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collet capable of accurately arranging a balance spring and capable of preventing occurrence of a crack when being externally engaged with a shaft, and to provide a balance provided with the collet, and a watch.SOLUTION: A welding surface 57 to which an inner peripheral side end part 43 of a balance spring 40 is to be welded is formed on a diameter-direction outer side surface of a collet 50, and when the collet 50 is externally engaged with a shaft 30, a pair of abutting points P2, P3 abutted on the outer peripheral surface of the shaft 30 are formed on a straight line T connecting a peripheral-direction center part P1 of the collet 50 to a center axis O of the collet 50 when viewing an axis direction of the collet 50, and a narrow width part 54 whose width is narrower than a separated distance between the center part P1 of the welding surface 57 and the first abutting point P2 is formed at least on a part of an area other than the straight line T.

Description

  The present invention relates to a beard ball, a balance with a beard ball and a timepiece.

  It is known that a mechanical timepiece includes an escapement and speed control mechanism for controlling the rotation of a barrel wheel, second wheel, third wheel and fourth wheel constituting a front train wheel. A typical escapement and speed control mechanism includes an escape wheel and a balance. The balance of the balance is a balance wheel, a balance spring that is the center of rotation of the balance wheel, a spiral spring formed along the Archimedes curve, and a balance spring that rotates the balance wheel by expansion and contraction, and a hair ball that fixes the balance spring in a true manner. And is formed by.

The whiskers are generally ring-shaped members that can be fitted out in a truly true manner, and have a welding surface on the radially outer side surface where the inner peripheral side end of the hairspring is welded. The hairspring and the hairball are fixed to each other in a state where the hairspring and the hairball are fixedly welded to each other so that the hairdressing ball is truly fitted onto the hairspring.
In addition, it is known that the accuracy of the mechanical timepiece depends on the deviation between the central axis of the balance that is the center of rotation of the balance with the central axis of the balance spring (that is, the central axis of the Archimedes curve). Therefore, it is required to accurately position the balance spring so that the center axis of the balance spring coincides with the center axis of the balance spring when the balance ball is externally fitted.

  For example, the collet described in Patent Document 1 (corresponding to the “beardball” in the claims of the present application) is formed of a metal band, and the collet is arranged on the inner contour of the collet. Equivalent to “true”)). In addition, an action point (corresponding to the “welding surface” in the claims) between the collet and the balance spring (corresponding to the “spring balance” in the claims) is located on the outer contour. It is arranged at the end of the arm where the distance from is larger than the other points of the outer contour.

The balance spring is fixed to the collet by welding the end of the inner curve of the balance spring (corresponding to the “inner peripheral side end” in the claims of the present application) to the collet operating point. The collet to which the balance spring is fixed is attached to the balance staff by press-fitting the band opening into the balance staff. That is, the balance spring is attached to the balance staff via the collet.
Also, when the band opening is press-fitted into the balance staff, the radially inner side of the point of action (that is, the inner peripheral surface of the band) is separated from the balance staff, and between the collet and the balance staff. Gaps are formed in the.

JP-A-2005-300532

However, the prior art whiskers have the following problems.
It is considered that the prior art beard ball is elastically deformed in the radial inner portion of the weld surface by a gap between the radial inner portion of the weld surface and the balance stem, and is press-fitted in a true fit. Therefore, there is a possibility that the welding surface is displaced inward in the radial direction, and the balance spring cannot be accurately arranged. As a result, a deviation occurs between the central axis of the balance spring and the central axis of the hairspring (that is, the central axis of the Archimedes curve), which may reduce the accuracy of the mechanical timepiece.

  Further, when welding the inner peripheral side end of the hairspring to the welding surface of the whistle ball, heat at the time of welding is transferred from the welding surface to the whisker ball. At this time, the radially outer portion of the whisker ball close to the weld surface becomes particularly hot and is annealed to lower the hardness. On the other hand, the radial inner portion of the whistle ball far from the weld surface is not annealed, so the hardness does not change, but the hardness is relatively higher than the annealed radial outer portion. For this reason, the hair ball after welding the hairspring has a relatively high hardness portion (that is, a portion not annealed) thinner in the radial direction than the hairball before welding the hairspring. Therefore, when the radially inner portion of the welding surface is elastically deformed and the whisker ball opening is fitted with a true outer fit, stress concentrates on the thinner and harder portion of the whisker ball radially inward and cracks occur. May occur and manufacturing defects may occur.

  Furthermore, in recent years, in order to form specially shaped whispers at low cost, a method of manufacturing using electroforming has been adopted. Generally, when forming a whisker ball using electroforming, nickel and a nickel alloy are employed as the whisker ball material. Here, since the melting point of nickel and a nickel alloy is higher than that of a metal such as iron, the welding temperature when welding the hairspring to the whisker is high. Thereby, the radial direction outer side part of the whistle ball near a welding surface becomes easier to anneal. Therefore, the above-mentioned problem becomes particularly noticeable because the relatively hard part inside the whisker ball in the radial direction becomes extremely thin in the radial direction.

  Accordingly, it is an object of the present invention to provide a beard ball capable of accurately arranging a balance spring and preventing cracking when the balance spring is truly fitted, a balance with the beard ball, and a timepiece.

  In order to solve the above problems, the whisker of the present invention is a whisker that is fitted and fixed coaxially to the balance spring, and fixes the inner peripheral side end of the balance spring to the true spring, A welding surface to which the inner peripheral side end of the hairspring is welded is formed on a radially outer side surface of the hairball, and the shaft of the hairball when the hairball is externally fitted to the balance As seen from the direction, on the straight line connecting the central portion of the whisker ball in the circumferential direction and the central axis of the whisker ball on the welding surface, and having a contact part that contacts the outer peripheral surface of the balance, It is characterized by having a narrow part whose width is narrower than the separation distance between the central part of the welding surface and the contact part in at least a part of the region other than the straight line.

According to the present invention, the narrow portion is formed in at least a part of the region other than the straight line where the contact portion is formed. It is possible to suppress elastic deformation and deformation between the contact portion and the welding surface. Further, since the contact portion is arranged on a straight line connecting the center portion of the whisker ball in the circumferential direction and the center axis of the whisker ball as viewed from the axial direction of the whistle ball, the contact portion and the welding surface By suppressing the deformation in between, it is possible to prevent the welding surface from being displaced with respect to the central axis of the whiskerball. Accordingly, the hairspring of the present invention can suppress the deviation between the center axis of the hairspring fixed to the weld surface and the center axis of the hairspring when the hairball is externally fitted to the balanceball. Can be placed accurately.
In addition, since the heat from the welding surface is difficult to transfer from the welding surface and is hard to be annealed on the radially inner side of the welding surface of the whistle ball, the relatively hard part becomes thinner in the radial direction and cracks when stress is applied. Is prone to occur. On the other hand, according to the present invention, when the beard ball is truly fitted out, the narrow portion is elastically deformed, so that the relatively high hardness portion is thinned on the contact portion and its periphery. Stress can be suppressed and cracking of the whisker balls when the whisker balls are truly fitted externally can be prevented.
Therefore, the whisker ball of the present invention can accurately arrange the hairspring and can prevent cracking when it is fitted externally.

  Moreover, the whisker of the present invention is characterized in that the narrow portion is formed so as to be separated from the balance when the whisker is externally fitted to the balance.

  According to the present invention, since the narrow portion is formed so as to be separated from the balance stem, a gap is formed between the narrow portion and the balance stem. As a result, the narrow portion can be elastically deformed so that it moves radially inward when the beard ball is truly fitted, so that the relatively hard portion is thinned. And the stress which acts on the periphery can be suppressed reliably. Therefore, it is possible to reliably prevent the whisker from being cracked when it is externally fitted.

  Further, the support includes: a main body having an opening that can be coaxially fitted to the spring; and a support that is formed to protrude outward in the radial direction of the main body and to which the hairspring is welded. The welding surface is formed on the side surface of the outer side in the radial direction of the portion, and a recess is formed on at least one end surface of both end surfaces of the support portion in the axial direction.

According to the present invention, since the concave portion is formed in the support portion, the cross-sectional area of the heat transfer path through which heat is transferred during welding can be made smaller than when the concave portion is not formed. Thereby, the heat transfer rate of a support part can be made low from a welding surface to a main-body part. Moreover, the heat at the time of welding is transferred from the welding surface to the main body portion through the recess. Thereby, since the heat transfer path from the welding surface to the main body becomes longer than when no recess is formed, the heat transfer coefficient of the support portion can be lowered. Furthermore, since the support portion has a surface area larger than that in the case where the concave portion is not formed by forming the concave portion, the heat can be radiated well.
As described above, since heat during welding is hardly transmitted from the weld surface to the main body, the range to be annealed can be limited from the weld surface to the vicinity of the recess. That is, a relatively hard portion that is not annealed and is relatively thick can be secured in the radial direction in the contact portion and its periphery in the main body portion of the whistle ball. In addition, since the narrow portion is elastically deformed when the beard ball is truly fitted, the stress acting on the contact portion of the relatively hard beard ball and its periphery can be reliably suppressed. Therefore, it is possible to reliably prevent the whisker from being cracked when the whisker is truly fitted.

  A main body having an opening that can be coaxially fitted to the balance; a plurality of protrusions formed on the radially outer side of the main body; and the welding surface is formed on the radially outer side surface. And a plurality of support portions are formed at equal pitches in the circumferential direction, and the narrow portions are formed at equal pitches in the circumferential direction.

According to the present invention, by forming the plurality of support portions and the narrow portions at equal pitches in the circumferential direction, the center of gravity of the whisker can be arranged at the rotation center of the whistle. Thereby, when the whistle ball rotates, it can rotate stably without vibrating. Therefore, when a balance and a timepiece are formed using the whisker ball of the present invention as a component, it is possible to ensure good performance with little rotational cycle error.
In addition, since it has a plurality of support portions formed with weld surfaces, when welding the balance spring to the ball, any one of the weld surfaces of the plurality of support portions and the inner peripheral side of the balance spring The end portions may be aligned and welded. Thereby, positioning with the welding surface of a whistle ball and the inner peripheral side edge part of a hairspring can be performed quickly rather than the case where the welding surface of a support part is one place. Furthermore, since the plurality of support portions are each formed with a recess, even if the inner peripheral end of the balance spring is welded to the weld surface of any of the support portions, the portion close to the weld surface of the main body portion is annealed. Can be suppressed. Therefore, the hairspring can be arranged with high accuracy, and the work efficiency when welding the hairspring to the hairball can be improved while preventing the hairball from cracking when the hairball is truly fitted over the balance.

  The whisker ball of the present invention is characterized by being formed by electroforming.

When manufacturing a whisker ball using electroforming, nickel and a nickel alloy are adopted as a material. As a result, the welding temperature at the time of welding the hairspring to the beard ball becomes high, and the range in which the beard ball is annealed is widened. There is a risk that cracks are likely to occur when the ball is truly fitted.
However, according to the present invention, when the beard ball is truly externally fitted, the narrow portion is elastically deformed and the stress acting on the contact portion of the high-hardness beard ball and its periphery can be suppressed. Can prevent cracking of balls. Therefore, a specially shaped whisker can be formed at low cost, and cracking of the whisker can be prevented when the whisker is truly externally fitted. Thus, the present invention is particularly suitable for a whisker ball formed by electroforming.

The balance with hairspring of the present invention is characterized by comprising the above-described whiskers.
The timepiece of the present invention is characterized by including the balance with the balance.

  According to the present invention, the hairspring can be arranged with high accuracy, and the hairball can be prevented from cracking when the hairdressing ball is truly fitted externally, so that a balance and a watch with high accuracy and no manufacturing defects can be formed.

According to the present invention, the narrow portion is formed in at least a part of the region other than the straight line where the contact portion is formed. It is possible to suppress elastic deformation and deformation between the contact portion and the welding surface. Further, since the contact portion is arranged on a straight line connecting the center portion of the whisker ball in the circumferential direction and the center axis of the whisker ball as viewed from the axial direction of the whistle ball, the contact portion and the welding surface By suppressing the deformation in between, it is possible to prevent the welding surface from being displaced with respect to the central axis of the whiskerball. Accordingly, the hairspring of the present invention can suppress the deviation between the center axis of the hairspring fixed to the weld surface and the center axis of the hairspring when the hairball is externally fitted to the balanceball. Can be placed accurately.
In addition, since the heat from the welding surface is difficult to transfer from the welding surface and is hard to be annealed on the radially inner side of the welding surface of the whistle ball, the relatively hard part becomes thinner in the radial direction and cracks when stress is applied. Is prone to occur. On the other hand, according to the present invention, when the beard ball is truly fitted out, the narrow portion is elastically deformed, so that the relatively high hardness portion is thinned on the contact portion and its periphery. Stress can be suppressed and cracking of the whisker balls when the whisker balls are truly fitted externally can be prevented.
Therefore, the whisker ball of the present invention can accurately arrange the hairspring and can prevent cracking when it is fitted externally.

It is a top view of the complete front side. It is a top view of the movement front side. It is a top view when the balance with hairspring is viewed in the axial direction. It is sectional drawing along the AA line of FIG. It is explanatory drawing of a hairspring. It is a top view of the whistle ball of the first embodiment. It is sectional drawing along the BB line of FIG. It is explanatory drawing when welding a hairspring to a whisker ball. It is side surface sectional drawing containing the central axis of the beard ball which concerns on the 1st modification of 1st embodiment. It is side surface sectional drawing containing the central axis of the beard ball which concerns on the 2nd modification of 1st embodiment. It is a flowchart of the manufacturing process of a beard ball. It is a figure which shows the state which immersed the electroforming mold in the electroforming liquid. It is a figure which shows the state which electroformed and performed the metal body in the hole for external shape formation. It is a top view of the whisker ball of the second embodiment. It is sectional drawing along CC line of FIG. It is a top view of the whistle ball of 3rd embodiment. It is sectional drawing along the DD line | wire of FIG. It is a top view of the whistle ball of 4th embodiment.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Below, after explaining a timepiece and a balance with hairspring first, the manufacturing method of the beard ball and the beard ball of the first embodiment will be described.

(clock)
In general, a machine body including a driving part of a timepiece is referred to as a “movement”. A state in which a dial and hands are attached to the movement and put into a watch case to make a finished product is called “complete” of the watch. Of the two sides of the base plate constituting the watch substrate, the glass case side of the watch case, that is, the dial plate side is called the “back side” or “glass side” or “dial side” of the movement. . Of the two sides of the main plate, the side with the back cover of the watch case, that is, the side opposite to the dial is referred to as “front side” or “back side” of the movement.

FIG. 1 is a plan view of the complete front side.
As shown in FIG. 1, the complete 1a of the timepiece 1 includes a dial 2 having a scale 3 or the like indicating information relating to the hour, an hour hand 4a indicating the hour, a minute hand 4b indicating the minute, and a second hand 4c indicating the second. And.

FIG. 2 is a plan view of the movement front side. In FIG. 2, in order to make the drawing easier to see, some of the timepiece components constituting the movement 100 are not shown.
A movement 100 of a mechanical timepiece has a main plate 102 constituting a substrate. A winding stem 110 is rotatably incorporated in the winding stem guide hole 102 a of the main plate 102. The winding stem 110 is positioned in the axial direction by a switching device including a setting lever 190, a yoke 192, a yoke spring 194 and a back presser 196.
Then, when the winding stem 110 is rotated, the hour wheel 112 is rotated through the rotation of the clutch wheel (not shown). The round hole wheel 114 and the square hole wheel 116 are sequentially rotated by the rotation of the hour wheel 112, and the mainspring (not shown) accommodated in the barrel complete 120 is wound up.

The barrel complete 120 is rotatably supported between the main plate 102 and the barrel holder 160. The second wheel 124, the third wheel 126, the fourth wheel 128, and the escape wheel 130 are supported rotatably between the main plate 102 and the train wheel bridge 162.
When the barrel wheel 120 is rotated by the restoring force of the mainspring, the second wheel 124, the third wheel 126, the fourth wheel 128, and the escape wheel 130 are sequentially rotated by the rotation of the barrel wheel 120. The barrel wheel 120, the second wheel 124, the third wheel 126, and the fourth wheel 128 constitute a front wheel train.

  When the center wheel & pinion 124 is rotated, a cylindrical pinion (not shown) is simultaneously rotated based on the rotation, and a minute hand 4b (see FIG. 1) attached to the cylindrical pinion displays "minute". . Further, the hour wheel (not shown) is rotated through the rotation of the minute wheel (not shown) based on the rotation of the hour pinion, and the hour hand 4a (see FIG. 1) attached to the hour wheel is “hour”. Is displayed.

The escapement and speed control device for controlling the rotation of the front train wheel is composed of an escape wheel 130, ankle 142 and balance 10.
Teeth 130 a are formed on the outer periphery of the escape wheel & pinion 130. The ankle 142 is rotatably supported between the main plate 102 and the ankle receiver 164, and includes a pair of pallets 142a and 142b. The escape wheel 130 is temporarily stopped in a state where one pallet 142a of the ankle 142 is engaged with the teeth 130a of the escape wheel 130.
The balance with hairspring 10 is reciprocally rotated at a constant period to alternately engage and release one claw stone 142 a and the other claw stone 142 b of the ankle 142 with the teeth 130 a of the escape wheel 130. Thereby, the escape wheel & pinion 130 is escaped at a constant speed.
Below, the structure of the balance with hairspring 10 is demonstrated in detail.

(Tempo)
FIG. 3 is a plan view when the balance 10 is viewed in the axial direction from the front side of the movement 100 (see FIG. 2). In FIG. 3, the whisker 106 is illustrated by a two-dot chain line.
4 is a cross-sectional view taken along line AA in FIG. In FIG. 4, the upper side of the paper surface with the base plate 102 interposed therebetween is the front side of the movement 100 (see FIG. 2), and the lower side of the paper surface with the base plate 102 interposed therebetween is the back side of the movement 100. In addition, the main plate 102, the balance holder 104 and the whiskers 106 are illustrated by two-dot chain lines.
As shown in FIG. 3, the balance with hairspring 10 includes a main balance wheel 20, a balance stem 30, a hairspring 40, and a hairball 50.

(Wheel)
The balance wheel 20 is formed of a metal such as brass, for example, and includes a balance wheel main body portion 21 formed in a substantially annular shape. The central axis of the balance wheel main body 21 coincides with the central axis O which is the center of rotation of the balance 10.
Four arm portions 23 (23a to 23d) extend from the inner peripheral surface 21a of the balance wheel main body portion 21 along the radial direction toward the central axis O. The four arm portions 23 a to 23 d are formed at substantially equal intervals so as to have a 90 ° pitch in the circumferential direction of the balance wheel main body portion 21.
The four arm portions 23 a to 23 d are formed so that the width gradually increases from the inner peripheral surface 21 a of the balance wheel main body portion 21 toward the central axis O, and are connected in the vicinity of the central axis O.
As shown in FIG. 4, a fitting hole 25a coaxial with the central axis O is formed in the connecting portion 25 of the four arm portions 23a to 23d.

(Tenshin)
The balance with hairspring 10 is provided with a balance stem 30 coaxially with the central axis O. The balance stem 30 is a rod-shaped member made of metal such as brass.
The balance stem 30 includes tenons 31 (31a, 31b) that are tapered at both ends in the axial direction. The balance stem 30 has a central axis O when one tenon 31a is pivotally supported by the balance 104 via a bearing (not shown) and the other tenon 31b is pivotally supported by the main plate 102 via a bearing (not shown). It can be rotated around.
In the balance 30, a fitting hole 25 a of the balance wheel 20 is press-fitted in an approximate center in the axial direction. Thereby, the balance wheel 20 and the balance stem 30 are integrated.

  The balance stem 30 includes a swing seat 35 having a substantially cylindrical shape on the main plate 102 side (lower side in FIG. 4) with respect to the balance wheel 20 in the axial direction. The swing seat 35 is formed with a flange portion 36 projecting in the radial direction. On the radially outer side of the flange portion 36, a rock stone (not shown) is provided at a predetermined position. The granite rocks up one crucifix 142a (see FIG. 2) and the other pallet 142b (see FIG. 2) of the ankle 142 alternately in synchronism with the period of the reciprocating rotation of the balance 10. Thereby, one pallet 142a and the other pallet 142b of the ankle 142 are engaged with and released from the teeth 130a (see FIG. 2) of the escape wheel 130.

(Beard spring)
As shown in FIG. 4, the balance with hairspring 10 is provided with a hairspring 40 on the balance receiver 104 side (upper side in FIG. 4) with respect to the balance wheel 20.
FIG. 5 is an explanatory diagram of the hairspring 40. In FIG. 5, the hairspring 40 is illustrated on the polar coordinates with the central axis O as the origin. Further, the Archimedes curve X, the balance stem 30, and the whisker ball 50 described later are shown by two-dot chain lines.

As shown in FIG. 5, the hairspring 40 is a thin plate spring made of a metal such as iron or nickel, for example, and has a spiral hairspring main body 41 having a plurality of turns and an outer peripheral side of the hairspring main body 41. And an arc portion 42.
The hairspring main body 41 is formed along a so-called Archimedes curve X.
The Archimedean curve X is
r = aθ (a is a constant) (1)
It is a curve obtained by.
By forming the mainspring main body 41 along the Archimedes curve X, the mainspring main body 41 is arranged in a spiral shape and adjacent to each other at substantially equal intervals in the radial direction when viewed from the axial direction.

  As shown in FIG. 3, the outer peripheral side of the hairspring main body 41 is an arc portion 42 having a radius of curvature larger than that of the hairspring main body 41. An outer peripheral side end portion 42a of the arc portion 42 is fixed to a beard 106 that is erected from a balance holder 104 (see FIG. 4) via a not-shown beard retainer. Also, the inner peripheral side end 43 of the hairspring 40 is fixed to the hairball 50.

(Beard ball of the first embodiment)
FIG. 6 is a plan view of the whisker ball 50 of the first embodiment when viewed from the axial direction. In FIG. 6, the front side of the paper surface is the balance 104 (see FIG. 4) side, and the back side of the paper surface is the base plate 102 (see FIG. 4) side. Further, in FIG. 6, the balance stem 30 and the hairspring 40 are illustrated by a two-dot chain line. Moreover, in FIG. 6, the narrow part 54 mentioned later is illustrated by hatching.
FIG. 7 is a cross-sectional view taken along line BB in FIG. In FIG. 7, the left side of the paper surface is the balance 104 (see FIG. 4) side, and the right side of the paper surface is the base plate 102 (see FIG. 4) side. In FIGS. 6 and 7, a boundary between a main body 51 and a support 55 described later is illustrated by a one-dot chain line.

  As shown in FIG. 6, the ball 50 is an annular member formed of a metal such as nickel or a nickel alloy, for example, and a main body 51 that is externally fitted coaxially with the central axis O to the balance 30. , And a support portion 55 that protrudes outward in the radial direction of the main body portion 51. As shown in FIG. 7, the axial thickness of the main body 51 of the hair ball 50 is formed sufficiently thicker than the axial thickness of the hairspring 40 (that is, the width of the hairspring 40).

As shown in FIG. 6, the main body 51 has a substantially elliptical outer shape, has a long axis in a first direction F (the left-right direction in FIG. 6) along the radial direction, It has a minor axis in a second direction S (vertical direction in FIG. 6) perpendicular to it.
The main body 51 has a constant width in the radial direction over the entire circumference, and has an opening 53 in the center. The opening 53 is formed in a substantially elliptical shape having a major axis in the first direction F and a minor axis in the second direction S corresponding to the outer shape of the main body 51. The main body 51 is formed to be able to be externally fitted to the balance stem 30 through the opening 53.

  The whisker ball 50 includes a pair of support parts 55 and 55 that are formed to protrude outward in the radial direction of the main body part 51. The pair of support portions 55, 55 are formed on both sides in the radial direction in the second direction S across the central axis O, and are integrally formed with the main body portion 51. The support portion 55 is formed in a tapered shape in which the width in the direction along the first direction F gradually decreases from the radially inner side to the radially outer side. The pair of support portions 55, 55 are formed at an equal pitch (180 ° pitch in the present embodiment) in the circumferential direction of the main body portion 51.

A welding surface 57 is formed on each of the radially outer side surfaces of the pair of support portions 55 and 55. Of the hairspring main body 41 of the hairspring 40, the inner circumferential surface 43a of the inner circumferential side end 43 is welded to the welding surface 57 by, for example, laser welding. The weld nugget 71 formed when laser welding is performed is formed on the end surface in the axial direction of the support portion 55 and the hairspring 40 so as to straddle the weld surface 57.
For example, the welding surface 57 is formed in a curved surface having a curvature corresponding to the Archimedes curve X (see FIG. 5) along the inner peripheral surface 43 a of the inner peripheral side end 43 of the hairspring 40.

  A pair of welding surfaces 57 are formed on both sides in the radial direction with the central axis O interposed therebetween, corresponding to the pair of support portions 55, 55. Therefore, as will be described later, when welding the hairspring 40 to the hairball 50, the welding surface 57 of one of the support portions 55 and the inner peripheral side of the hairspring 40 among the welding surfaces 57 of the pair of support portions 55, 55. The end portion 43 may be aligned and welded. Therefore, the positioning of the welding surface 57 of the whistle ball 50 and the inner peripheral side end portion 43 of the hairspring 40 can be performed more quickly than in the case where the welding surface 57 of the support part 55 is provided at one place. Thereby, the work efficiency at the time of welding the hairspring 40 to the ball 50 can be improved.

By the way, the error in the rotation period of the balance with hairspring 10 depends on the accuracy of the position where the hairspring 40 is fixed. Specifically, as shown in FIG. 5, when viewed from the axial direction, the central axis of the Archimedes curve X corresponding to the balance spring main body 41 and the central axis O of the balance with hairspring 10 are designed to coincide with each other. Therefore, the smaller the positional deviation between the two (hereinafter referred to as “lateral runout”), the smaller the error of the balance of the balance 10.
Further, the balance with the balance between the center axis of the Archimedes curve X corresponding to the hairspring main body 41 and the center axis O of the balance 10 when viewed from the outside in the radial direction is smaller. The error of 10 rotation cycles is small.

  Here, since the welding surface 57 is formed into a curved surface having a curvature corresponding to the Archimedes curve X, when the inner peripheral side end 43 of the hairspring 40 is welded to the welding surface 57, the welding surface of the support portion 55. 57 and the inner peripheral surface 43a of the hairspring 40 can be brought into surface contact. Thereby, the position shift of the welding surface 57 and the hairspring 40 is suppressed, and the balance 10 can be stably welded in a state where the lateral vibration and the vertical vibration of the hairspring 40 are small. Therefore, the balance with less rotation period error can be formed.

(Contact point)
As shown in FIG. 6, on the straight line T connecting the central portion P1 in the circumferential direction of the welding surfaces 57 and 57 and the central axis O among the inner peripheral surface 51a of the main body 51, the outer peripheral surface of the balance 30 is It has a pair of contact points P2 and P3 (corresponding to “contact portion” in the claims).
The first contact point P <b> 2 is provided on one welding surface 57 side (upper side in FIG. 6) of the inner peripheral surface 51 a of the main body 51 to which the hairspring 40 is welded. Further, the second contact point P3 is provided on the other welding surface 57 side (lower side in FIG. 6) of the inner peripheral surface 51a of the main body 51, to which the hairspring 40 is not welded.
The central portion P1 of the welding surface 57 and the first contact point P2 have a predetermined separation distance L1.
The main body 51 sandwiches the balance stem 30 when the pair of contact points P2 and P3 are in line contact with the balance stem 30 from both sides in the second direction S. In the main body 51, the inner peripheral surfaces 51a on both sides in the circumferential direction of the contact points P2, P3 across the contact points P2, P3 and the straight line T are in surface contact with the balance 30 from both sides in the second direction S. Therefore, the balance stem 30 may be clamped.

  Here, the first contact point P <b> 2 is provided on the inner circumferential surface 51 a of the main body portion 51 on the radial inner side of the welding surface 57 of the whistle ball 50. When the hairspring 40 is welded to the hair ball 50, the radially outer portion of the main body 51 close to the welding surface 57, and the vicinity of the stepped portion 61 described later becomes particularly high in temperature and is annealed to reduce the hardness. On the other hand, the radial inner portion of the main body 51 far from the weld surface 57, that is, the first contact point P2 and its surroundings are not annealed, so the hardness does not change, but from the vicinity of the annealed step 61. The hardness becomes relatively high.

(Narrow part)
The main body 51 has a pair of narrow portions 54 and 54 in a region other than on the straight line T. The narrow portion 54 of the present embodiment is a region R (hatched region in FIG. 6) that is not connected to the support portion 55 among regions other than the straight line T in the main body 51.
The pair of narrow portions 54, 54 are formed to have a constant width L2 in the radial direction on both sides of the first direction F across the central axis O. In other words, the pair of narrow portions 54, 54 are formed at positions shifted by 90 ° in the circumferential direction from the support portion 55, and are equidistant in the circumferential direction of the main body 51 (180 ° pitch in the present embodiment). Is formed.
Further, the narrow portion 54 is formed so as to bulge outward in the radial direction, and is formed so as to be separated from the balance 30. As a result, a gap is formed between the inner peripheral surface 54 a of the narrow portion 54 and the outer peripheral surface of the balance 30.

Here, the separation distance L1 between the central portion P1 and the first contact point P2 and the width L2 of the narrow portion 54 are:
L1> L2 (2)
It is formed to satisfy. That is, the width L2 of the narrow portion 54 is formed to be narrower than the separation distance L1 between the central portion P1 and the first contact point P2. In addition, a gap is formed between the inner peripheral surface 54 a of the narrow portion 54 and the outer peripheral surface of the balance 30. Therefore, when the main body 51 of the whistle ball 50 is press-fitted into the balance 30, the narrow portion 54 is radially inward while the angle on the inner peripheral side of the narrow portion 54 separated from the balance 30 is opened. It can be easily elastically deformed so as to move. Thereby, since the stress acting on the first contact point P2 of the whisker ball 50 and its periphery can be surely suppressed, the whisker ball 50 can be prevented from cracking when it is externally fitted to the hand stem 30, and the balance stem 30 Therefore, it is possible to secure an appropriate holding force.

(Step part)
As shown in FIG. 7, of the both end surfaces 56 (56 a, 56 b) of the support portion 55 in the axial direction, a step is formed as a recess 60 on one end surface 56 a on the base plate 102 side (see FIG. 4, right side in FIG. 7). A portion 61 is formed. The step portion 61 is formed by denting the one end surface 56a of the support portion 55 from the main body portion 51 side to the welding surface 57 in the axial direction. As a result, the support portion 55 is formed with a side wall surface 62 facing radially outward.

The depth in the axial direction of the stepped portion 61 is formed to be about half of the axial thickness of the main body 51, for example. By forming the stepped portion 61, the stepped portion forming region 55 a radially outside the side wall surface 62 of the support portion 55 is more axially disposed than the stepped portion non-forming region 55 b radially inside the side wall surface 62. Formed thin.
In addition, the axial thickness of the stepped portion forming region 55a (that is, the axial width of the welding surface 57) is desirably thicker than the axial thickness of the hairspring 40 (that is, the width of the hairspring 40). Thereby, the inner peripheral surface 43a of the hairspring 40 can be welded in surface contact without protruding from the welding surface 57 in the axial direction. Therefore, it is possible to weld firmly while suppressing the displacement between the welding surface 57 and the hairspring 40. The axial width of the welding surface 57 is more preferably less than 1.2 times the width of the hairspring 40, for example.

Here, the stepped portion 61 has a shortest distance between the side wall surface 62 of the stepped portion 61 and the opening 53 as L3, and a shortest distance between the side wall surface 62 of the stepped portion 61 and the welding surface 57 is L4.
L3> L4 (3)
It is formed to satisfy.
That is, by forming the step portion 61 so as to satisfy the expression (3), the shortest distance L3 between the side wall surface 62 of the step portion 61 and the opening 53 is reduced to the shortest distance between the side wall surface 62 of the step portion 61 and the welding surface 57. It is secured larger than the distance L4. Thereby, when the inner peripheral side end 43 of the hairspring 40 is welded to the welding surface 57 of the hair ball 50, the range to be annealed by the heat at the time of welding is limited to a short distance from the welding surface 57 to the vicinity of the side wall surface 62. it can.
Further, since the heat transfer rate can be lowered by ensuring a long heat transfer path from the side wall surface 62 to the main body 51, the heat that could not be dissipated from the side wall surface 62 of the stepped portion 61 flows from the side wall surface 62 of the stepped portion 61. It becomes difficult to transmit to the main body 51. Therefore, the relatively hard part of the main body 51 of the whisker ball 50 that is not annealed can be secured thicker, and the relatively hard part can be further prevented from being thinned. It is possible to reliably prevent the main body 51 from cracking when 50 is externally fitted.

Further, the stepped portion 61 is formed in the same shape on a pair of support portions 55 and 55 formed at an equal pitch in the circumferential direction. Thereby, since the weight of a pair of support parts 55 and 55 becomes substantially the same, the gravity center of the beard ball 50 can be arrange | positioned in the rotation center (namely, central axis O) of the beard ball 50. FIG. Therefore, when the whistle ball 50 is rotated, it can be stably rotated without vibration. Therefore, the balance 10 (see FIG. 3) and the timepiece 1 (see FIG. 1) are made using the whistle ball 50 of this embodiment as a component. When formed, good performance is ensured with little rotational cycle error.
Further, since the pair of support portions 55, 55 are each formed with a stepped portion 61, the main body portion can be obtained even if the inner peripheral side end portion 43 of the hairspring 40 is welded to the welding surface 57 of any support portion 55. It can suppress that the part close | similar to the welding surface 57 of 51 is annealed. Therefore, the working efficiency when welding the hairspring 40 to the ball 50 can be improved, and the main body 51 can be prevented from cracking when the hairball 50 is externally fitted into the balance 30.

(Welding the beard ball and the hairspring)
FIG. 8 is a schematic explanatory diagram when the hairspring 40 is welded to the hairball 50.
As shown in FIG. 8, the inner peripheral side end 43 of the hairspring 40 is welded to the welding surface 57 of the hair ball 50 described above by, for example, laser welding. As a specific welding method, first, the other end surface 56b in the axial direction of the support portion 55 and the other end surface 41b in the axial direction of the hairspring main body 41 are brought into contact with the flat plate-shaped position regulating jig 86, thereby supporting the support portion. The other end face 56b of 55 and the other end face 41b of the hairspring main body 41 are aligned to a substantially flush position.
Subsequently, using a laser welding machine 85 having a predetermined laser output and irradiation range, a laser 88 having a predetermined output is provided near the welding surface 57 of the whistle ball 50 from the one end surface 56a side where the stepped portion 61 is formed. Irradiate and perform laser welding. As a result, as shown in FIG. 6, a weld nugget 71 is formed on one end surface 56 a of the support portion 55 and one end surface 41 a of the hairspring main body 41 so as to straddle the welding surface 57, and the hairspring 40 is formed on the hair ball 50. Welded.

  Here, by forming the step portion 61 in the support portion 55, the step portion forming region 55a of the support portion 55 is formed thinner in the axial direction than the step portion non-forming region 55b. For this reason, the cross-sectional area perpendicular to the second direction S, that is, the cross-sectional area of the heat transfer path through which heat is transferred during welding, is smaller than when the stepped portion 61 is not formed, and the heat transfer coefficient is low. It has become. As described above, since the step portion 61 suppresses transmission of heat during welding to the main body portion 51, the annealing range is limited from the weld surface 57 to the vicinity of the step portion 61. Therefore, it is possible to secure a relatively high hardness portion of the main body 51 of the whistle ball 50 without being annealed, and to suppress a relatively high hardness portion from being thinned.

(Each variation of the first embodiment)
Then, the beard ball 50 which concerns on each modification of 1st embodiment is demonstrated.
FIG. 9 is a side sectional view including the central axis O of the whisker ball 50 according to the first modification of the present embodiment.
FIG. 10 is a side cross-sectional view including the central axis O of the whisker ball 50 according to the second modification of the present embodiment.
In the beard ball 50 of the first embodiment, the stepped portion 61 is formed on the one end face 56a in the axial direction of the beard ball 50 (see FIG. 7). On the other hand, in the whisker ball 50 of the first modified example, as shown in FIG. 9, the first embodiment is different from the first embodiment in that a step 61 is formed on the other end surface 56 b in the axial direction of the whistle ball 50. Is different. Further, in the beard ball 50 of the second modified example, as shown in FIG. 10, stepped portions 61 a and 61 b are formed as concave portions 60 a and 60 b on both end surfaces 56 a and 56 b in the axial direction of the beard ball 50. This is different from the first embodiment. Detailed description of the same configuration as in the first embodiment will be omitted.

As shown in FIG. 9, in the first modification, the stepped portion 61 is formed by denting the other end surface 56 b of the support portion 55 in the axial direction from the main body portion 51 side to the welding surface 57.
As shown in FIG. 10, in the second modification, the first stepped portion 61 a is formed by denting one end surface 56 a of the support portion 55 from the main body portion 51 side to the welding surface 57 in the axial direction. The second stepped portion 61 b is formed by denting the other end surface 56 b of the support portion 55 from the main body portion 51 side to the welding surface 57 in the axial direction.

(effect)
According to this embodiment and each modification, since the narrow portion 54 is provided in a region other than the straight line T where the contact points P2, P3 are formed, the whisker ball 50 is externally fitted to the balance 30. Sometimes, the narrow portion 54 is elastically deformed, and deformation between the first contact point P2 and the welding surface 57 can be suppressed. Further, the contact points P2 and P3 are arranged on a straight line T connecting the central portion P1 of the whistle ball 50 in the circumferential direction and the central axis O of the whistle ball 50 when viewed from the axial direction of the whistle ball 50. By suppressing the deformation between the first contact point P <b> 2 and the welding surface 57, the displacement of the welding surface 57 with respect to the central axis O of the whisker ball 50 can be prevented. Accordingly, when the whistle ball 50 is externally fitted to the balance stem 30, the whisker ball 50 can suppress the deviation between the central axis of the hairspring 40 fixed to the welding surface 57 and the central axis O of the balance stem 30. The mainspring 40 can be accurately placed on the balance 30.
Further, the inner side in the radial direction of the welding surface 57 of the whistle ball 50 is difficult to transmit heat from the welding surface 57 and is hard to be annealed. Therefore, a relatively hard portion is thinned in the radial direction and stress is applied. Sometimes cracks are likely to occur. On the other hand, according to this embodiment and each modification, when the whistle ball 50 is externally fitted to the balance 30, the narrow portion 54 is elastically deformed. The stress acting on the periphery can be suppressed, and cracking of the whisker ball 50 when the whisker ball 50 is fitted on the balance 30 can be prevented.
Therefore, according to the beard ball 50 of the present embodiment and each modified example, the hairspring 40 can be arranged with high accuracy, and cracking of the beard ball 50 when it is externally fitted to the balance stem 30 can be prevented.

(Beard ball manufacturing process)
Then, the manufacturing process of the beard ball 50 (refer FIG. 6) of 1st embodiment mentioned above is demonstrated with reference to drawings.
FIG. 11 is a flowchart of the manufacturing process of the beard ball 50.
FIG. 12 is a view showing a state in which the electroforming mold 94 is immersed in the electroforming liquid W.
FIG. 13 is a diagram showing a state in which the metal body 99 is grown in the outer shape forming hole 95 by performing electroforming.
As shown in FIG. 11, the manufacturing process of the whisker ball 50 of this embodiment includes an electroforming process S10, a thickness adjusting process S20, and a removing process S30. Below, each process is demonstrated.

(Electroforming process S10)
First, an electroforming process S10 for forming the outer shape of the whisker ball 50 (see FIG. 6) is performed.
As shown in FIG. 12, in the electroforming step S <b> 10, the outer shape of the whisker ball 50 is formed using the electroforming mold 94 formed as follows.
The electroforming mold 94 is formed using a photolithography technique.
Specifically, first, after preparing the silicon substrate 90, a conductive film 91 mainly composed of gold, silver, copper, nickel, or the like is formed on the surface of the silicon substrate 90. Subsequently, a first photosensitive material 94 a is applied on the conductive film 91. The first photosensitive material 94a may be either a positive resist or a negative resist, but in this embodiment, a negative resist is used. Subsequently, the first photosensitive material 94a is exposed using a photoresist mask (not shown) that is patterned into the outer shape of the whisker ball 50 and that has other regions opened. Then, since the first photosensitive material 94a is a negative resist, the exposed portion is cured.
Subsequently, the first photosensitive material 94a is developed using a developer (not shown). Then, since the first photosensitive material 94a is a negative resist, the unexposed area is dissolved. Subsequently, in order to form the outer shape of the stepped portion 61 (see FIG. 6), the second photosensitive material 94b is applied so as to overlap the first photosensitive material 94a. Then, similarly to the above, the second photosensitive material 94b is exposed and developed.
Thereby, the outer shape forming hole 95 is formed in the first photosensitive material 94a and the second photosensitive material 94b following the outer shape of the whisker ball 50 having the stepped portion 61, and the conductive film 91 is exposed. Thus, the electroforming mold 94 capable of forming the whisker ball 50 is formed.

  In the electroforming step S <b> 10, first, the entire silicon substrate 90 is immersed in the electroforming liquid W stored in the treatment tank 96. In addition, when performing this electroforming process S10, the electroforming liquid W is selected according to the metal material which should be electroformed. For example, when nickel electroforming is performed, a sulfamic acid bath, a watt bath, a sulfuric acid bath, or the like is used.

  If nickel electroforming is performed using a sulfamic acid bath, a sulfamic acid bath mainly composed of nickel sulfamate hydrate is placed in the treatment tank 96. Further, an anode electrode 97 made of a metal material to be electroformed (in this embodiment, nickel) is immersed in a sulfamic acid bath. As the anode electrode 97, for example, a plurality of balls made of a metal material to be electroformed are prepared, and the metal balls are placed in a metal cage made of titanium or the like.

  Then, after immersing the silicon substrate 90 in the sulfamic acid bath, the conductive film 91 formed on the silicon substrate 90 is connected to the cathode of the power source 98 and the anode electrode 97 is connected to the anode of the power source 98 to perform electroforming. To start. Then, the metal constituting the anode electrode 97 is ionized and moves in the sulfamic acid bath, and is deposited as a metal on the conductive film 91 exposed in the outer shape forming hole 95, and this metal gradually grows. Then, as shown in FIG. 13, the metal is grown until at least the metal body 99 that completely closes the outer shape forming hole 95 is obtained. At this time, since the outer shape forming hole 95 follows the outer shape of the whisker ball 50 (see FIG. 6) having the stepped portion 61 as described above, the whisker ball having the stepped portion 61 also on the grown metal body 99. It is in a state of following 50 external shapes. When the outer shape of the whisker ball 50 is formed, the electroforming step S10 is completed.

(Thickness adjustment step S20)
Next, a thickness adjustment step S20 is performed in which the thickness of the metal body 99 is adjusted to be the thickness of the whistle ball 50 (see FIG. 6).
In the thickness adjusting step S20, the silicon substrate 90 is pulled up from the processing tank 96 and cleaned with pure water or the like. Thereafter, the metal body 99 overflowing from the outer shape forming hole 95 is removed, and the thickness of the remaining metal body 99 is adjusted so as to be the thickness of the whisker ball 50 (see FIG. 6). This method may be performed by polishing such as CMP (chemical mechanical polishing).

(Removal step S30)
Finally, a removal step S30 for removing the first photosensitive material 94a, the second photosensitive material 94b, the conductive film 91, and the silicon substrate 90 is performed.
In the removal step S30, the first photosensitive material 94a and the second photosensitive material 94b are removed by an ashing process, a peeling solution method, or the like, and the silicon substrate 90 and the conductive film 91 are removed by a CMP method or the like. Thereby, the whisker ball 50 can be produced by electroforming.
When the silicon substrate 90 and the conductive film 91 are removed, the removal step S30 is completed and all the manufacturing steps of the whistle ball 50 are completed.

(effect)
In order to form the specially shaped whistle ball 50 at a low cost, a method of manufacturing using electroforming is employed. Here, when forming the ball 50 by electroforming, nickel and a nickel alloy are often employed as the material. In general, since the melting point of nickel and nickel alloy is higher than that of metal such as iron, the welding temperature when welding the hairspring 40 to the ball 50 is high. As a result, the range to be annealed on the radially inner side of the weld surface 57 is widened, and the first contact point P <b> 2 and the relatively hard portion around the first contact point P <b> 2 are further thinned. There is a possibility that cracks are likely to occur when fitted externally.
However, according to the present embodiment, when the beard ball 50 is externally fitted to the balance 30, the narrow portion 54 is elastically deformed, and the first contact point P 2 of the relatively high-hardness beard ball 50 and Since the stress acting on the periphery can be suppressed, the whisker ball 50 can be prevented from cracking. Therefore, the specially shaped whisker ball 50 can be formed at low cost, and cracking when the whistle ball 50 is externally fitted to the balance stem 30 can be prevented. As described above, the present invention is particularly suitable for the whisker ball 50 formed by electroforming.

(Second embodiment)
Next, the whistle ball 50 of the second embodiment will be described.
FIG. 14 is an explanatory diagram of the whisker ball 50 of the second embodiment. FIG. 14 illustrates a state viewed from the one end face 56 a of the whistle ball 50.
FIG. 15 is a cross-sectional view taken along the line CC of FIG.
In the beard ball 50 of the first embodiment, the step portion 61 is formed as the recess 60 on the one end surface 56a of the beard ball 50 (see FIG. 7). On the other hand, in the whisker ball 50 of the second embodiment, as shown in FIG. 14, the first embodiment is different from the first embodiment in that a groove 64 is formed in the one end surface 56 a of the whistle ball 50 as a recess 60. Is different. Detailed description of the same configuration as in the first embodiment will be omitted.

  The groove 64 is formed on the one end surface 56 a of the whistle ball 50 so as to extend along the circumferential direction of the main body 51. The inner wall surface 64 a on the inner side in the circumferential direction of the groove 64 is formed along the main body 51 so as to be separated from the opening 53 of the main body 51 by a predetermined distance on the outer side in the radial direction from the main body 51. An outer wall surface 64b on the outer side in the circumferential direction of the groove 64 is formed to be separated from the welding surface 57 of the support portion 55 by a predetermined distance. The depth of the groove 64 in the axial direction is formed to be about half of the thickness of the main body 51 in the axial direction, for example. By forming the groove 64, the groove forming region 55a in which the groove 64 is formed in the support portion 55 is formed thinner in the axial direction than the groove non-forming region 55b on the radially outer side and radially inner side than the groove 64. Is done.

Here, in the first embodiment, as shown in FIG. 8, the stepped portion 61 is formed by notching the corner portion between the one end surface 56 a and the welding surface 57. For this reason, at the time of welding the hairspring 40 and the hairball 50, the flat other end face 56b is brought into contact with the position regulating jig 86 to align with the other end face 41b of the hairspring main body 41, and then the one end face It was necessary to weld from the 56a side.
On the other hand, in the second embodiment, as shown in FIG. 15, the groove 64 is formed by notching the radially inner side from the corner portion of the one end face 56 a and the welding surface 57. The one end face 56a on the radially inner side and the radially outer side is substantially flush. Accordingly, the position regulating jig 86 (see FIG. 8) can be brought into contact with the one end face 56a and the other end face 56b without distinction, so that alignment with the one end face 41a or the other end face 41b of the hairspring main body 41 can be performed. The welding process time can be shortened.

In the first embodiment, the welding surface 57 is formed in the step portion forming region 55a (see FIG. 7), whereas in the second embodiment, the welding surface 57 is formed in the groove non-forming region 55b. Therefore, it is desirable that the axial thickness of the groove non-formation region 55b (that is, the axial width of the welding surface 57) is larger than the axial thickness of the hairspring 40 (that is, the width of the hairspring 40).
Further, as shown in FIG. 15, when the shortest distance between the groove 64 and the opening 53 is L5 and the shortest distance between the groove 64 and the welding surface 57 is L6,
L5> L6 (4)
It is formed to satisfy. Thereby, the range annealed with the heat at the time of welding can be restrict | limited to the short distance from the welding surface 57 to the groove | channel 64 vicinity.

(Effect of the second embodiment)
According to the second embodiment, the range to be annealed by heat during welding can be limited to a short distance from the weld surface 57 to the vicinity of the outer wall surface 64b of the groove 64. Further, since the support portion 55 has a surface area larger than that in the case where the groove 64 is not formed by forming the groove 64, the heat can be radiated well. Therefore, the relatively hard part of the main body 51 of the whisker ball 50 that is not annealed can be secured thicker, and the relatively hard part can be further prevented from being thinned. It is possible to reliably prevent the main body 51 from cracking when 50 is externally fitted.
Further, by forming the recess 60 as the groove 64, the recess 60 can be easily formed by electroforming, machining, or the like.

(Third embodiment)
Then, the whisker ball 50 of 3rd embodiment is demonstrated.
FIG. 16 is an explanatory diagram of the whistle ball 50 of the third embodiment. FIG. 16 illustrates a state viewed from the one end face 56 a of the whistle ball 50.
17 is a cross-sectional view taken along the line DD of FIG.
In the whisker ball 50 of the first embodiment, the stepped part 61 is formed as the recess 60 on one end surface 56a of the axially opposite end faces 56a, 56b of the whistle ball 50 (see FIG. 7). On the other hand, in the whisker ball 50 of the third embodiment, as shown in FIG. 16, a through hole 66 is formed as the recess 60 that communicates the axial end faces 56 a and 56 b of the whistle ball 50. This is different from the first embodiment. Detailed description of the same configuration as in the first embodiment will be omitted.

  As shown in FIG. 17, the through hole 66 is formed by communicating one end surface 56 a and the other end surface 56 b of the whisker ball 50. The inner peripheral surface 66 a of the through hole 66 is formed so as to follow the outer shape of the support portion 55 and the main body portion 51 on the radially outer side of the main body portion 51. An inner peripheral surface 66 a of the through hole 66 is formed to be separated from the welding surface 57 of the support portion 55 and the opening 53 of the main body portion 51 by a predetermined distance. In the third embodiment as well, as in the second embodiment, the one end face 56a and the other end face 56b are brought into contact with the position restricting jig 86 (see FIG. 8) without distinction, so that the hairspring main body 41 Since alignment with the one end surface 41a or the other end surface 41b can be performed, the time of the welding process can be shortened.

In the first embodiment, the welding surface 57 is formed in the step portion forming region 55a (see FIG. 7), but in the present embodiment, the welding surface 57 is formed in the hole non-forming region 55b. Therefore, it is desirable that the axial thickness of the hole non-formation region 55b (that is, the axial width of the welding surface 57) is larger than the axial thickness of the hairspring 40 (that is, the width of the hairspring 40).
When the shortest distance between the through hole 66 and the opening 53 is L5 and the shortest distance between the through hole 66 and the welding surface 57 is L6, the through hole 66 is similar to the second embodiment,
L5> L6 (4)
It is formed to satisfy. Thereby, the range annealed with the heat at the time of welding can be restrict | limited to the short distance from the welding surface 57 to the through-hole 66 vicinity.

(Effect of the third embodiment)
According to the third embodiment, as in the first embodiment, a relatively high hardness portion that is not annealed in the main body 51 of the whistle ball 50 can be secured thicker, and a relatively high hardness portion is thin. Therefore, it is possible to reliably prevent the main body 51 from cracking when the whistle ball 50 is externally fitted to the balance 30. Further, by forming the recess 60 as the through hole 66, the recess 60 can be easily formed by electroforming, machining, or the like.

(Fourth embodiment)
Next, the whisker ball 50 of the fourth embodiment will be described.
FIG. 18 is an explanatory diagram of the whistle ball 50 of the third embodiment. FIG. 18 illustrates a state viewed from the other end face 56 b of the whistle ball 50.
In the whisker ball 50 of the first embodiment, the main body 51 is formed in a substantially elliptical ring shape having a major axis in the first direction F and a minor axis in the second direction S, and a pair of support parts 55, 55 were formed at a 180 ° pitch in the circumferential direction of the main body 51 (see FIG. 6). On the other hand, as shown in FIG. 18, in the whisker ball 50 of the fourth embodiment, the main body portion 51 is formed in a substantially heart shape, and only one support portion 55 is formed in the main body portion 51. This is different from the first embodiment. Detailed description of the same configuration as in the first embodiment will be omitted.

As shown in FIG. 6, the main body 51 of the whistle ball 50 of the fourth embodiment is formed in a substantially heart shape that is line-symmetric with respect to the axis in the second direction S. The main body 51 has a constant width in the radial direction over the entire circumference, and has an opening 53 in the center. The opening 53 is formed in a substantially heart shape corresponding to the outer shape of the main body 51.
The support portion 55 is formed to protrude outward in the radial direction of the main body portion 51 at a position corresponding to a substantially heart-shaped pointed portion in the second direction S. A welding surface 57 is formed on the radially outer side surface of the support portion 55. In addition, a stepped portion 61 is formed as the recessed portion 60 in the support portion 55 as in the first embodiment.

Of the inner peripheral surface 51 a of the main body 51, the straight line T has a pair of contact points P <b> 2 and P <b> 3 that contact the outer peripheral surface of the balance 30. The central portion P1 of the welding surface 57 and the first contact point P2 have a predetermined separation distance L1. The main body 51 sandwiches the balance stem 30 when the pair of contact points P2 and P3 are in line contact with the balance stem 30 from both sides in the second direction S.
A region R (hatching region in FIG. 18) other than the straight line T in the main body 51 and not connected to the support portion 55 is a narrow portion 54 having a constant width L2 in the radial direction. Yes.
The distance L1 between the central portion P1 and the first contact point P2 and the width L2 of the narrow portion 54 are as follows:
L1> L2 (2)
It is formed to satisfy.
The narrow portion 54 is curved and formed on both sides of the first direction F across the central axis O so as to correspond to the substantially heart shape of the main body 51. The narrow portion 54 is formed such that the narrow portion 54 is separated from the balance 30, and a gap is formed between the inner peripheral surface 54 a of the narrow portion 54 and the outer peripheral surface of the balance 30. .

(Effect of the fourth embodiment)
According to the fourth embodiment, the main body 51 is formed in a substantially heart shape, and the pair of contact points P2 and P3 are in line contact with the balance 30 from both sides in the second direction S. A larger gap can be secured between the inner peripheral surface 54a of the portion 54 and the outer peripheral surface of the balance 30 than in the first embodiment. Accordingly, the narrow portion 54 can be elastically deformed so as to move further inward in the radial direction when the whistle ball 50 is externally fitted to the balance 30, so that the relatively hard part is thinned. The stress acting on the first contact point P2 and its periphery can be reliably suppressed. Therefore, it is possible to reliably prevent the whisker ball 50 from cracking when the whistle ball 50 is externally fitted to the balance 30.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  The external shape of the whisker ball 50 is not limited to each embodiment. For example, the main body 51 of the whisker ball 50 of the first embodiment has a substantially elliptical outer shape. On the other hand, the main body 51 of the whistle ball 50 may have an outer shape that is substantially circular. However, by forming the main body 51 in an approximately elliptical ring shape, a gap is formed between the inner peripheral surface 54a of the narrow portion 54 and the outer peripheral surface of the balance stem 30, and the narrow portion 54 moves radially inward. It can be easily elastically deformed. As a result, the stress acting on the first contact point P2 of the whisker ball 50 and its periphery can be reliably suppressed, cracking of the whisker ball 50 can be prevented, and an appropriate holding force for the balance stem 30 can be secured. In this respect, the first embodiment has an advantage.

  In the first embodiment, laser welding has been described as an example of a method for welding the hairspring 40 to the ball 50, but the welding method is not limited to laser welding. For example, the hairspring 40 may be welded to the hair ball 50 by arc welding, resistance welding, friction stir welding, or the like. By providing the narrow portion 54, the effect of the present invention can be obtained in any welding method.

DESCRIPTION OF SYMBOLS 1 ... Clock 10 ... Balance 30 ... Balance 40 ... Beard spring 43 ... Inner peripheral side end 50 ... Beard ball 51 ... Main body 53 ... Opening 54 ..Narrow part 55 ... support part 57 ... welded surface 60 ... concave O ... center axis P1 ... center part T ... straight line P2 ... first contact point ( Contact part) P3 ... Second contact point (contact part)

Claims (7)

It is a whisker ball that is externally fitted and fixed coaxially to the balance, and for fixing the inner peripheral side end of the balance spring to the balance,
A welding surface to which the inner peripheral side end of the hairspring is welded is formed on a radially outer side surface of the hairball,
When the beard ball is externally fitted to the balance ball, when viewed from the axial direction of the whisker ball, on the straight line connecting the central part of the whisker ball in the circumferential direction on the welding surface and the central axis of the whistle ball And a contact portion that contacts the outer peripheral surface of the brass, and at least part of the region other than the straight line is narrower than the distance between the center portion of the weld surface and the contact portion. A whisker having a narrow part. The beard ball according to claim 1,
The whisker is characterized in that the narrow part is formed so as to be separated from the balance when the whistle is externally fitted to the balance. The beard ball according to claim 1 or 2,
A main body having an opening that can be coaxially fitted to the balance;
A support part which is formed to protrude outward in the radial direction of the main body part and to which the hairspring is welded;
With
The welding surface is formed on the radially outer side surface of the support portion,
A whisker is characterized in that a recess is formed in at least one of the end faces of the support part in the axial direction. The beard ball according to claim 1 or 2,
A main body having an opening that can be coaxially fitted to the balance;
A plurality of support portions which are formed to protrude outward in the radial direction of the main body portion, and the welding surface is formed on a side surface of the radial outer side;
With
The whisker is characterized in that the plurality of support portions are formed at an equal pitch in the circumferential direction, and the narrow portions are formed at an equal pitch in the circumferential direction.   5. The whistle ball according to claim 1, wherein the whistle ball is formed by electroforming.   A balance with the beard ball according to claim 1.   A timepiece comprising the balance according to claim 6.

Images