CN108375891B

CN108375891B - Temperature compensation type balance wheel, movement, and timepiece

Info

Publication number: CN108375891B
Application number: CN201810066749.4A
Authority: CN
Inventors: 中岛正洋; 川内谷卓磨; 幸田雅行; 藤枝久
Original assignee: Seiko Instruments Inc
Current assignee: Seiko Instruments Inc
Priority date: 2017-01-31
Filing date: 2018-01-24
Publication date: 2021-06-15
Anticipated expiration: 2038-01-24
Also published as: JP6789140B2; CH713409B1; JP2018124114A; CH713409A2; CN108375891A

Abstract

The invention provides a temperature compensation type balance wheel, a movement and a clock, which have excellent temperature compensation performance. The temperature compensation type balance wheel comprises: a balance wheel main body having a balance shaft (61) extending along a1 st axis (O1) and rotating around the 1 st axis (O1) by the power of a balance spring (63); and an adjusting part (100) which is extended along the 2 nd axis (O2) from a position rotationally symmetrical around the 1 st axis (O1) on the balance body, and is configured to be capable of adjusting the position around the 2 nd axis (O2), wherein the adjusting part comprises a bimetal (121) formed by laminating materials with different thermal expansion coefficients in a direction intersecting with the 2 nd axis (O2).

Description

Temperature compensation type balance wheel, movement, and timepiece

Technical Field

The present invention relates to a mechanical timepiece.

Background

A balance serving as a speed regulator of a mechanical timepiece includes: a pendulum shaft extending along an axis; a balance wheel fixed on the balance shaft; and a balance spring. The balance staff and the balance wheel periodically rotate (oscillate) in the forward and reverse directions around the axis line in accordance with the expansion and contraction of the balance spring.

In the balance described above, it is important to set the oscillation period within a predetermined value. If the oscillation period deviates from a predetermined value, the difference rate of the mechanical timepiece (the slowness of the timepiece) changes.

The oscillation period T of the balance is represented by the following equation (1). In formula (1), I represents the "moment of inertia" of the balance spring, and K represents the "spring constant" of the balance spring.

[ equation 1 ]

According to equation (1), when the inertia moment I of the balance spring or the spring constant K of the balance spring changes due to a temperature change or the like, the oscillation period T of the balance spring changes. Specifically, there are cases where: the balance described above is formed of a material having a positive thermal expansion coefficient (a material that expands due to a temperature rise). In this case, when the temperature rises, the balance expands in diameter and the inertia moment I increases. On the other hand, there are cases where: the balance spring is formed of a material (e.g. steel material) having a young's modulus with a negative temperature coefficient. In this case, the spring constant K decreases as the temperature increases.

Therefore, as the temperature rises, the inertia moment I increases, or the spring constant K decreases, whereby the vibration period T becomes longer. As a result, the oscillation cycle T of the balance becomes shorter at low temperatures and longer at high temperatures, and the temperature characteristics of the timepiece become faster at low temperatures and slower at high temperatures.

Therefore, as a countermeasure for improving the temperature dependence of the vibration period T, it is conceivable to use a constant-elasticity material (for example, cobalt-ellingwal constant-elasticity alloy or the like) for the material of the balance spring. It can be considered that: by using the constant-elasticity material, it is possible to suppress the variation of the spring constant K accompanying the temperature change, thereby suppressing the temperature dependence of the vibration cycle T. However, in order to suppress the variation of the temperature coefficient of young's modulus, strict manufacturing management is required, and there is a problem that it is difficult to manufacture the balance spring.

On the other hand, as a countermeasure for improving the temperature dependency of the vibration period T, the following configuration may be considered: at a rotationally symmetrical position on the balance, a bimetal is provided. The bimetal is formed by laminating plate materials with different thermal expansion coefficients.

According to this structure, the bimetal deforms, for example, radially inward due to the difference in thermal expansion coefficient between the plate materials when the temperature rises. This reduces the average diameter of the balance, thereby reducing the inertia moment I. As a result, the temperature characteristic of the inertia moment I can be corrected, and the temperature dependency of the vibration cycle T can be suppressed.

For example, patent document 1 below discloses a structure in which: by changing the effective length of each bimetal (the amount of protrusion from the balance), the temperature coefficient correction amount (the amount of change in the bimetal in the radial direction with respect to a temperature change) can be changed. According to this structure, it can be considered that: by adjusting the effective length of each bimetal in accordance with the temperature coefficient of the young's modulus, it is easy to eliminate the variation in the temperature coefficient of the young's modulus in accordance with the temperature characteristics of the moment of inertia I.

Patent document 1: british patent specification No. 256953

However, the structure of patent document 1 has a problem that it is difficult to make the effective lengths of the respective bimetal pieces uniform. If the effective lengths of the bimetal strips are different, the center of gravity of the balance is shifted from the rotational axis. As a result, the balance weight is biased (piece weight り), and the fluctuation of the oscillation period T due to the balance posture becomes large (so-called posture difference occurs).

In addition, when a constant-elasticity material is used as the material of the balance spring, the temperature coefficient of young's modulus may fluctuate to positive or negative depending on the processing conditions in the manufacturing process (for example, melting or heat treatment) of the balance spring.

However, in the balance including the conventional bimetal, the adjustment of the temperature coefficient (the tendency of the temperature characteristic) of the inertia moment I can be performed only in either the positive or negative direction.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a high-quality temperature compensation type balance with excellent temperature compensation performance, a movement, and a timepiece.

In order to solve the above problem, a temperature compensation type balance according to an aspect of the present invention includes: a balance wheel main body having a balance shaft extending along a1 st axis and rotating around the 1 st axis by the power of a balance spring; and an adjusting portion that extends along a2 nd axis line from a position on the balance wheel main body that is rotationally symmetrical about the 1 st axis line, and is configured to be able to adjust a position about the 2 nd axis line, the adjusting portion including a bimetal formed by laminating materials having different thermal expansion coefficients in a direction intersecting the 2 nd axis line.

According to this aspect, the bimetal deforms with a change in temperature, and thereby the average diameter of the balance-spring main body changes. This makes it possible to correct the temperature characteristic of the moment of inertia.

In particular, in this aspect, the adjusting portion is configured to be capable of position adjustment about the 2 nd axis, and therefore, the orientation of the bimetal can be changed in accordance with the temperature coefficient of the young's modulus of the balance spring. This makes it possible to change the temperature coefficient correction amount of the bimetal to both positive and negative, and to correct the temperature coefficient of the moment of inertia of the balance to both positive and negative. That is, it is easy to eliminate the variation in the temperature coefficient of the young's modulus according to the temperature characteristics of the moment of inertia of the balance. As a result, the oscillation cycle of the balance can be kept constant, and a balance with excellent temperature compensation characteristics can be provided.

In this aspect, even if the orientation of the bimetal is changed, the length of the adjusting portion in the 2 nd axial direction is maintained constant. Therefore, unlike the conventional case where the effective length of the bimetal is changed, it is possible to suppress the center of gravity of the balance from shifting at a predetermined temperature (normal temperature (for example, about 23 ℃). As a result, the occurrence of biased weight application can be suppressed, and the posture difference can be reduced.

In the above aspect, the balance main body may include: the pendulum shaft; and a balance attached to the balance staff and having a rim portion surrounding the balance staff from the outside in the 1 st radial direction perpendicular to the 1 st axis, wherein the adjusting portion is provided extending from the rim portion.

According to this aspect, since the adjusting portion is provided at the rim portion of the balance, the adjusting portion can be spaced apart from the 1 st axis in the 1 st radial direction. This makes it possible to increase the amount of radial deformation of the adjustment portion (the difference between the distance between the distal end portion of the adjustment portion and the 1 st axis at a predetermined temperature in the 1 st radial direction and the distance between the distal end portion of the adjustment portion and the 1 st axis at the time of temperature change), and to increase the amount of temperature coefficient correction by the bimetal.

In the above aspect, the adjusting portion may be disposed inside the rim portion in a plan view seen in the 1 st axial direction and may extend in a tangential direction of the rim portion.

According to this aspect, the amount of radial deformation associated with a temperature change can be ensured while suppressing an increase in size of the balance caused by the addition of the adjustment portion.

In the above aspect, the bimetal may be disposed at a position different from the rim portion in the 1 st axial direction.

According to this aspect, when the adjustment portion deforms in the 1 st radial direction with a change in temperature, interference between the rim portion and the adjustment portion can be suppressed, and the amount of radial deformation of the adjustment portion can be ensured.

In the above aspect, the adjusting unit may include a weight applying unit.

According to this aspect, since the weight of the adjustment portion can be increased, the temperature coefficient correction amount by the bimetal can be increased.

In the above aspect, the balance body may be formed with a through hole that penetrates the balance body in the 2 nd axial direction, the adjusting portion may include a fixing portion that is located on one side in the 2 nd axial direction with respect to the bimetal and is fitted into the through hole, and an engaging portion that is engaged with a tool may be formed on an end surface of the fixing portion that faces the one side in the 2 nd axial direction.

According to this aspect, the tool can be engaged with the engaging portion of the fixing portion through the through hole. Therefore, the position of the adjusting portion about the 2 nd axis can be easily adjusted. Further, by changing the rotation angle of the adjustment portion via the fixing portion, plastic deformation of the adjustment portion at the time of position adjustment of the adjustment portion can be suppressed as compared with a case where the rotation angle of the adjustment portion is changed via the tip portion (bimetal or weight portion). Therefore, the following can be suppressed: the difference rate deviation at a predetermined temperature is generated by the plastic deformation of the adjusting part.

In the above aspect, the adjusting portion may extend along the 2 nd axis in a cantilever manner.

According to this aspect, the amount of radial deformation associated with a temperature change can be secured, and the amount of temperature coefficient correction by the bimetal can be increased.

In the above aspect, the balance spring may be formed of a constant-elasticity material.

According to this aspect, the change in young's modulus associated with a temperature change can be reduced, thereby suppressing the temperature dependence of the vibration cycle. In this aspect, since the variation in the temperature coefficient of the young's modulus can be corrected by the rotation angle of the adjusting portion, the manufacturing management at the time of manufacturing the balance spring becomes easy. Therefore, not only can the manufacturing efficiency of the balance spring be improved, but also the cost can be reduced.

In the above aspect, the center of gravity of the adjusting portion may be located on the 2 nd axis.

According to this aspect, since the center of gravity of the adjusting portion is located on the 2 nd axis, when the position of the adjusting portion around the 2 nd axis is adjusted, it is possible to prevent the center of gravity of the adjusting portion from being displaced from the 2 nd axis in accordance with the rotation angle of the adjusting portion. As a result, the center of gravity of the balance can be prevented from shifting according to the rotation angle of the adjustment portion, and therefore the difference in posture can be reliably reduced.

A movement according to an aspect of the present invention may include the temperature compensation type balance wheel according to the above aspect.

A timepiece according to an aspect of the present invention may include the movement according to the above aspect.

According to this aspect, since the temperature compensation type balance of the present aspect is provided, it is possible to provide a high-quality movement and timepiece with a small variation in rate of difference.

According to the present invention, a high-quality temperature-compensated balance, a movement, and a timepiece having excellent temperature compensation performance can be provided.

Drawings

Fig. 1 is an external view of a timepiece according to embodiment 1.

Fig. 2 is a plan view of the movement of embodiment 1 as viewed from the front side.

Fig. 3 is a plan view of the balance wheel of embodiment 1 as viewed from the front side.

Fig. 4 is a side view of the balance of embodiment 1.

Fig. 5 is a sectional view corresponding to the line V-V of fig. 3.

Fig. 6 is a sectional view taken along line VI-VI of fig. 3.

Fig. 7 is a partial plan view of the balance for explaining the operation of the adjusting portion.

Fig. 8 is an enlarged cross-sectional view of the adjustment unit with the adjustment unit at the reference position.

Fig. 9 is an enlarged cross-sectional view of the adjusting part in a state where the rotation angle θ of the adjusting part is 45 (deg).

Fig. 10 is an enlarged cross-sectional view of the adjusting part in a state where the rotation angle θ of the adjusting part is 90 (deg).

Fig. 11 is an enlarged cross-sectional view of the adjusting part in a state where the rotation angle θ of the adjusting part is-45 (deg).

Fig. 12 is an enlarged cross-sectional view of the adjusting part in a state where the rotation angle θ of the adjusting part is-90 (deg).

Fig. 13 is a graph showing a relationship between the orientation of the bimetal and the amount of deformation of the bimetal when the rotation angle θ of the adjusting portion is changed from-90 (deg) to 90 (deg).

Fig. 14 is a graph showing the relationship between the rotation angle θ of the adjusting unit and the radius change amount Δ R.

Fig. 15 is a graph showing a relationship between temperature (° c) and a difference rate when temperature coefficients of young's moduli of the balance spring are different.

Fig. 16 is a perspective view of the balance of embodiment 2.

Fig. 17 is a plan view of a balance according to a modification example, as viewed from the front side.

Fig. 18 is a cross-sectional view corresponding to fig. 6 of a modification.

Fig. 19 is a partial plan view of a balance according to a modification.

Description of the reference symbols

1: a timepiece;

2: a movement;

54: a balance spring;

61: a pendulum shaft;

62: a balance wheel;

73: a rim portion;

100: an adjustment part;

115: mounting holes (through holes);

117: a working hole (through hole);

120: a fixed part;

121: a bimetal;

122: a weight applying part;

135: a card-holding section;

202: a support portion;

205: mounting holes (through holes).

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

(embodiment 1)

[ watch ]

Fig. 1 is an external view of the timepiece 1. In the drawings shown below, in order to make the drawings easy to see, the following may occur: the timepiece components are partially omitted from the drawings, and the respective timepiece components are simplified and shown in the drawings.

As shown in fig. 1, the timepiece 1 of the present embodiment is configured by incorporating a movement 2, a dial 3, various hands 4 to 6, and the like into a timepiece case 7.

The timepiece case 7 includes a case body 11, a case cover (not shown), and a cover glass 12. A crown 15 is provided at a3 o' clock position (right side in fig. 1) on the side of the housing main body 11. The crown 15 is used to operate the movement 2 from the outside of the case main body 11. The crown 15 is fixed to a stem 19, and the stem 19 is inserted through the housing body 11.

[ movement ]

Fig. 2 is a plan view of movement 2 viewed from the front side.

As shown in fig. 2, the movement 2 is configured such that a plurality of gear bodies and the like are rotatably supported on a bottom plate 21 that constitutes a base plate of the movement 2. In the following description, the cover glass 12 side (dial 3 side) of the timepiece case 7 is referred to as the "back side" of the movement 2 and the case lid side (opposite side to the dial 3 side) is referred to as the "front side" of the movement 2 with respect to the bottom plate 21. Each gear body described below is provided with the front-back direction of the movement 2 as the axial direction.

The stem 19 is assembled to the bottom plate 21. The stem 19 is used for date or time correction. The stem 19 is rotatable about its axis and movable in the axial direction. The stem 19 is positioned in the axial direction by a switching device having a pull-out piece 23, a clutch lever 24, a clutch lever spring 25, and a pull-out pressure spring 26.

When the stem 19 is rotated, the vertical wheel 31 is rotated by the rotation of a clutch wheel (not shown). By the rotation of the vertical wheel 31, the small steel wheel 32 and the large steel wheel 33 are sequentially rotated, and the power spring (not shown) housed in the barrel wheel 34 is wound up.

The barrel wheel 34 is rotatably supported between the bottom plate 21 and the barrel support 35. The second wheel 41, the third wheel 42, and the fourth wheel 43 are rotatably supported between the base plate 21 and the train wheel support 45.

When barrel wheel 34 rotates by the restoring force of the clockwork spring, second wheel 41, third wheel 42, and fourth wheel 43 rotate in sequence due to the rotation of barrel wheel 34. The barrel wheel 34, the second wheel 41, the third wheel 42 and the fourth wheel 43 constitute a front-side wheel train.

The minute hand 5 is attached to the second wheel 41 in the front side gear train described above (see fig. 1). The hour hand 4 is attached to an hour wheel (not shown) that rotates with the rotation of the second wheel 41. The second hand 6 (see fig. 1) is configured to rotate based on the rotation of the fourth wheel 43.

A speed regulating escapement 51 is mounted on the movement 2.

The speed regulating escapement 51 has an escape wheel 52, a pallet 53, and a balance (temperature compensation balance) 54.

The escape wheel 52 is rotatably supported between the base plate 21 and the train wheel support 45. The escape wheel 52 rotates with the rotation of the fourth wheel 43.

The pallet fork 53 is supported to be capable of reciprocating rotation between the bottom plate 21 and the pallet fork plate 55. The pallet 53 includes a pair of

pallet stones

56a and 56 b. The

pallet stones

56a and 56b alternately engage with the pallet gear 52a of the escape wheel 52 in accordance with the reciprocating rotation of the pallet 53. When one pallet of a pair of

pallets

56a, 56b engages with pallet gear 52a, escape wheel 52 temporarily stops rotating. In addition, when a pair of pallet-

stones

56a, 56b is disengaged from the pallet-gear 53a, the escape wheel 52 rotates. By continuously repeating these operations, the escape wheel 52 is intermittently rotated. The above-described train wheel (spur-side train wheel) is intermittently operated by the intermittent rotational motion of the escape wheel 52, thereby controlling the rotation of the spur-side train wheel.

< sprung balance >

Fig. 3 is a plan view of the balance 54 viewed from the front side. Fig. 4 is a side view of the balance 54.

As shown in fig. 3 and 4, the balance 54 regulates the escape wheel 52 (escapement wheel 52 is escaped at a constant speed). The balance 54 mainly has a balance staff 61, a balance 62, and a balance spring 63.

As shown in fig. 4, the swing shaft 61 is supported between the bottom plate 21 and the swing plate 65 so as to be rotatable about the 1 st axis O1. In the following description, there are cases where: the direction along the 1 st axis O1 is referred to as the 1 st axial direction, the direction perpendicular to the 1 st axis O1 is referred to as the 1 st radial direction, and the direction of rotation about the 1 st axis O1 is referred to as the 1 st circumferential direction. In this case, the 1 st axis direction coincides with the front-back direction.

The balance staff 61 rotates clockwise and counterclockwise with a fixed period of oscillation about the 1 st axis O1 by the power transmitted from the balance spring 63. The swing shaft 61 is supported at its front end in the 1 st axial direction by a swing plate 65 through a bearing (not shown). The rear end of the swing shaft 61 in the 1 st axis direction is supported by a bearing (not shown) formed on the base plate 21.

A double disk 67 is externally fitted to the rear end of the pendulum shaft 61 in the 1 st axial direction. The double disk 67 is formed in a cylindrical shape disposed coaxially with the 1 st axis O1. A disc pin 68 is provided on the double disc 67 at a1 st circumferential portion. The disc pin 68 repeatedly engages with and disengages from a pallet fork case (アンクルハコ) of the pallet fork 53 in synchronization with the reciprocating rotation of the balance 54. As a result, the

pallet stones

56a and 56b repeatedly engage with and disengage from the escape wheel 52 by reciprocating the pallet 53.

Fig. 5 is a sectional view corresponding to the line V-V of fig. 3.

As shown in fig. 3 and 5, the balance 62 is fixed to the front side in the 1 st axial direction with respect to the double roller 67 on the balance staff 61. The balance 62 mainly includes a hub portion 71, a spoke portion (あみだ portion) 72, and a rim portion 73. In the present embodiment, the hub portion 71, the spoke portions 72, and the rim portion 73 are integrally formed of a metal material (e.g., brass).

The boss portion 71 is fixed to the swing shaft 61 by press fitting or the like.

The spokes 72 are provided to protrude outward in the 1 st radial direction from the boss portion 71. In the present embodiment, the spoke portions 72 are provided so as to project from positions opposed to each other in the 1 st radial direction with the 1 st axis O1 in the hub portion 71 interposed therebetween. However, the protruding positions, the number of spokes 72, and the like can be appropriately changed.

The rim portion 73 is formed in an annular shape arranged coaxially with the 1 st axis O1. The rim portion 73 surrounds the boss portion 71 from the 1 st radial direction outer side. The 1 st radial outer end of the spoke portion 72 is connected to the inner peripheral surface of the rim portion 73.

The balance spring 63 is a spiral flat spring in a plan view seen from the 1 st axial direction. Balance spring 63 is wound in a manner along the archimedes curve. The inner end of balance spring 63 is connected to balance staff 61 via collet 75. The outer end of balance spring 63 is connected to a balance bridge 65 by an external peg (not shown). Balance spring 63 serves the function of: the power transmitted from the fourth wheel 43 to the escape wheel 52 is accumulated and transmitted to the swing shaft 61.

In the present embodiment, a constant-elasticity material (for example, cobalt-einlaval constant-elasticity alloy or the like) is suitably used for the balance spring 63. The young's modulus of balance spring 63 in the use temperature range is a positive temperature characteristic. In this case, the temperature coefficient of the young's modulus of balance spring 63 is adjusted to: the oscillation cycle of the balance 54 is made as constant as possible with respect to the temperature characteristic of the moment of inertia of the balance 62 according to the temperature change. However, balance spring 63 may be formed of a material other than a constant elastic material. In this case, as the balance spring 63, a general steel material having a negative temperature coefficient (a characteristic that a spring constant is decreased due to a temperature increase) of young's modulus can be used.

Here, the balance 54 of the present embodiment includes a pair of adjustment portions 100 at positions on the balance 62 that are rotationally symmetrical about the 1 st axis O1 (2-fold symmetry in the present embodiment).

The rotating object referred to herein is an example of an expression for characterizing a pattern, and a property that overlaps itself when n is an integer of 2 or more and is rotated by (360/n) ° around a certain center (in the case of a 2-dimensional pattern) or an axis (in the case of a 3-dimensional pattern), for example, is referred to as n-order symmetry, n-symmetry, or (360/n) -degree symmetry, or the like, which is a known concept. For example, when n is 2, the two are 2-fold symmetry overlapping with each other when rotated by 180 °. Each adjusting portion 100 is formed in a rod shape extending along the 2 nd axis O2 parallel to the tangent of the rim portion 73. Each of the adjustment portions 100 is supported by a pair of support portions 110 connected to the rim portion 73. Since the respective adjustment portions 100 and the support portions 110 have the same configuration, one adjustment portion 100 and one support portion 110 will be described as an example in the following description. In the following description, the following may be the case: the direction along the 2 nd axis O2 is referred to as the 2 nd axial direction, the direction perpendicular to the 2 nd axis O2 is referred to as the 2 nd radial direction, and the direction revolving around the 2 nd axis O2 is referred to as the 2 nd circumferential direction.

Fig. 6 is a sectional view taken along line VI-VI of fig. 3.

The support portion 110 bulges inward in the 1 st radial direction from the inner peripheral surface of the rim portion 73. The support portion 110 is formed with a mounting hole (through hole) 115 penetrating the support portion 110 in the 2 nd axial direction. The mounting hole 115 is formed in a circular shape (perfect circular shape) in a plan view seen from the 2 nd axial direction. The shape of the mounting hole 115 is not limited to a circular shape, and may be a rectangular shape, a triangular shape, or the like.

A groove 116 communicating with the inside of the mounting hole 115 is formed in a portion of the support portion 110 on the back side in the 1 st axial direction. The groove 116 is formed over the entirety of the support portion 110 in the 2 nd axial direction.

As shown in fig. 4, in the rim portion 73, a working hole (through hole) 117 penetrating the rim portion 73 in the 2 nd axial direction is formed in a portion overlapping the mounting hole 115 when viewed from the 2 nd axial direction. The working hole 117 is configured to allow insertion of a tool (e.g., a driver) not shown.

As shown in fig. 3, the adjusting portion 100 is cantilevered by the support portion 110 inside the rim portion 73. Specifically, the adjusting unit 100 is formed to: the fixing portion 120, the bimetal 121, and the weight portion 122 are connected in this order from the base end side (fixed end side) to the tip end side (free end side) in the 2 nd axial direction.

As shown in fig. 6, the fixing portion 120 is formed of, for example, a metal material. The fixing portion 120 is formed in a circular shape in a plan view seen from the 2 nd axial direction corresponding to the mounting hole 115. The fixing portion 120 is press-fitted (elastically held) into the mounting hole 115. The fixing portion 120 may be press-fitted so as to straddle the mounting hole 115 and the work hole 117.

In the present embodiment, the interference between the fixing portion 120 and the mounting hole 115 is set to such an extent as follows: when a predetermined torque is applied to the adjuster 100 about the 2 nd axis O2 (in the 2 nd circumferential direction), the adjuster 100 can rotate about the 2 nd axis O2. That is, the adjusting unit 100 of the present embodiment is configured to: the position of the adjusting portion about the 2 nd axis O2 can be adjusted by rotating the adjusting portion about the 2 nd axis O2 while sliding the outer peripheral surface of the fixing portion 120 on the inner peripheral surface of the mounting hole 115.

The cross-sectional shape of the fixing portion 120 is not limited to a circular shape, and may be a rectangular shape, a triangular shape, or the like. In the present embodiment, the cross-sectional shape of the fixing portion 120 is formed to correspond to the mounting hole 115, but the fixing portion 120 and the mounting hole 115 may have different shapes as long as the fixing portion 120 is configured to be rotatable about the 2 nd axis O2.

As shown in fig. 4, a locking portion 135 is formed on the proximal end surface of the fixing portion 120 in the 2 nd axial direction. The locking portion 135 is a groove linearly extending in the 2 nd radial direction. The tool is inserted into the engagement portion through the work hole 117. The locking portion 135 is not limited to a groove as long as it can be locked to a tool.

As shown in fig. 3, the bimetal 121 is joined (e.g., welded, bonded, or the like) to the distal end surface of the fixing portion 120 in the 2 nd axial direction. The bimetal 121 is formed in a plate shape extending linearly in the 2 nd axial direction on the inner side in the 1 st radial direction with respect to the rim 73. The bimetal 121 is formed by stacking 2 plate materials (the low expansion member 130 and the high expansion member 131) having different thermal expansion coefficients in the 2 nd radial direction. In the present embodiment, invar (Ni — Fe alloy), silicon, ceramic, or the like is suitably used for the low expansion member 130. For the high expansion member 131, copper or a copper alloy, aluminum, or the like is suitably used. The low-expansion member 130 and the high-expansion member 131 are formed in the same shape as each other (the cross-sectional shape perpendicular to the 2 nd axis O2 is a rectangular shape). In the illustrated example, the boundary portion of the low expansion member 130 and the high expansion member 131 is located on the 2 nd axis O2. Further, it is preferable that the center of gravity of each adjustment portion 100 is located on the 2 nd axis O2. Therefore, the low-expansion member 130 and the high-expansion member 131 may have different plate thicknesses from each other (the plate thicknesses may be appropriately changed). In the case where the plate thicknesses of the low expansion member 130 and the high expansion member 131 are different, the boundary portion of the low expansion member 130 and the high expansion member 131 extends in parallel with the 2 nd axis O2.

The bimetal 121 (the low expansion member 130 and the high expansion member 131) is configured to: the orientation of the bimetal in the 2 nd radial direction can be changed in accordance with the rotation of the adjusting portion 100 about the 2 nd axis O. The bimetal 121 is configured to be deformable in the 2 nd radial direction in accordance with a temperature change by a difference between thermal expansion rates of the low expansion member 130 and the high expansion member 131. The specific operation of the bimetal 121 will be described later.

As shown in fig. 3, the weight portion 122 is joined (e.g., welded, bonded, etc.) to the end surface of the bimetal 121 in the 2 nd axial direction. The weight 122 is formed of, for example, a metal material. The weight 122 has a circular cross-sectional shape perpendicular to the 2 nd axis O2. The outer shape of the weight 122 is larger than the bimetal 121 in a front view seen from the 2 nd axial direction. The weight 122 may be detachably attached to the bimetal 121.

[ temperature correction method ]

Next, a method of adjusting the temperature coefficient correction amount in the above-described balance 54 will be described. Fig. 7 is a partial plan view of the balance 54 for explaining the operation of the adjustment unit 100. In the state of fig. 7, with respect to the bimetal 121, in a state where the low expansion member 130 is located on the inner side of the 1 st radial direction, the low expansion member 130 and the high expansion member 131 are aligned in the 1 st radial direction.

As shown in fig. 7, in the balance 54 of the present embodiment, when a temperature change occurs, the bimetal 121 is bent and deformed by a difference in thermal expansion rate between the low expansion member 130 and the high expansion member 131. Specifically, when the temperature rises from a predetermined temperature T0 (normal temperature (e.g., about 23 ℃)), the high-expansion member 131 expands more than the low-expansion member 130. Thereby, the adjusting portion 100 is deformed to one side (the 1 st radial direction inner side in fig. 7) in the stacking direction of the low-expansion member 130 and the high-expansion member 131. When the temperature is lowered from the predetermined temperature T0, the high expansion member 131 contracts more than the low expansion member 130. Thereby, the adjusting portion 100 is deformed toward the other side (the 1 st radial direction outer side in fig. 7) in the stacking direction.

By deforming the adjustment portion 100, the distance in the 1 st radial direction between the distal end portion of the adjustment portion 100 and the 1 st axis O1 changes. Specifically, when the distance between the distal end portion of the adjustment portion 100 and the 1 st axis O1 in the 1 st radial direction is R0 at a predetermined temperature T0 and the distance between the distal end portion of the adjustment portion 100 and the 1 st axis O1 in the 1 st radial direction is R1 at a temperature change, the difference between the distance R0 and the distance R1 is the radial change amount Δ R in the 1 st radial direction. The average diameter of the balance 62 can be reduced or expanded in accordance with the change in radius Δ R, and the inertia moment of the balance 54 about the 1 st axis O1 can be changed. That is, when the temperature rises, the average diameter of the balance 62 can be reduced to reduce the moment of inertia. When the temperature is lowered, the average diameter of the balance 62 is expanded to increase the moment of inertia. This makes it possible to correct the temperature coefficient of the moment of inertia.

However, when a constant-elasticity material is used for the balance spring 63 as in the present embodiment, the temperature coefficient of young's modulus may fluctuate positively or negatively depending on the processing conditions in the manufacturing process (for example, melting or heat treatment) of the balance spring.

In contrast, in the present embodiment, the orientation of the bimetal 121 (the rotation angle θ about the 2 nd axis O2) can be changed in accordance with the temperature coefficient of the young's modulus of the balance spring 63. Specifically, the tool is inserted through the working hole 117 and is locked in the locking portion 135 of the adjusting portion 100 shown in fig. 4. Then, by rotating the tool about the 2 nd axis O2, the adjusting portion 100 is rotated about the 2 nd axis O2 while the outer peripheral surface of the fixing portion 120 slides on the inner peripheral surface of the mounting hole 115. Thereby, the rotation angle θ is changed.

Fig. 8 to 12 are enlarged cross-sectional views of the adjustment unit 100.

In the state shown in fig. 8, in a state where the low expansion member 130 and the high expansion member 131 are aligned in the 1 st axial direction, the low expansion member 130 is located on the front surface side in the 1 st axial direction. The rotation angle θ about the 2 nd axis O2 is adjusted using this state as the reference position (0(deg)) of the adjustment unit 100. For example, in fig. 9, the adjusting portion 100 is rotated 45(deg) in the clockwise direction (+ direction) about the 2 nd axis O2 from the reference position. In fig. 10, the adjuster 100 is rotated 90(deg) in the clockwise direction (+ direction) about the 2 nd axis O2 from the reference position.

In fig. 11, the adjusting part 100 is rotated 45(deg) in the counterclockwise direction (the minus direction) about the 2 nd axis O2 from the reference position. In fig. 12, the adjuster 100 is rotated by-90 (deg) in the clockwise direction (-direction) about the 2 nd axis O2 from the reference position.

Fig. 13 is a graph showing a relationship between the orientation of the bimetal 121 and the amount of deformation of the bimetal 121 when the rotation angle θ of the adjusting unit 100 is changed from-90 (deg) to 90(deg) at the same temperature (at high temperature). In fig. 13, the X-axis represents a component in the 1 st radial direction (hereinafter, referred to as an X-component) in the deformation vector of the bimetal 121. The Y axis represents a component in the 1 st axis direction (hereinafter, referred to as a Y component) of the deformation vector of the bimetal 121. In this case, in fig. 13, the-X direction coincides with the inner side in the 1 st radial direction, and the + X direction coincides with the outer side in the 1 st radial direction. In fig. 13, the bimetal 121 located at the origin point shows a state at a predetermined temperature T0 (before deformation).

As shown in fig. 13, when the adjustment portion 100 is at the reference position (0(deg)), the bimetal 121 is deformed only to the front side in the 1 st axial direction (a 1 in fig. 13). Therefore, at the reference position, the Y component of the deformation vector of the bimetal 121 becomes maximum, and the X component is 0. In this case, since the radius change amount Δ R is 0, the temperature coefficient of the moment of inertia does not change.

When the adjustment portion 100 is rotated in the + direction from the reference position, the bimetal 121 is also deformed outward in the 1 st radial direction, and a + X component (a 2, A3 in fig. 13) in the deformation vector of the bimetal 121 is generated. Then, by increasing the rotation angle θ in the + direction, the + X component gradually increases. That is, by shifting the rotation angle θ of the adjusting portion 100 from the reference position in the + direction, the amount of increase in the moment of inertia of the balance 54 at the time of temperature increase can be increased. When the rotation angle θ is 90(deg) (a 3 in fig. 13), the bimetal 121 is deformed only outward in the 1 st radial direction. Therefore, when the rotation angle θ is 90(deg), the + X component becomes maximum, and the Y component is 0. By rotating the adjustment unit 100 in the + direction from the reference position in this way, the temperature coefficient of the moment of inertia can be increased.

On the other hand, when the adjustment portion 100 is rotated in the minus direction from the reference position, the bimetal 121 is also deformed inward in the 1 st radial direction, and a minus X component (a 4, a5 in fig. 13) among the deformation vectors of the bimetal 121 is generated. Further, by increasing the rotation angle θ in the minus direction, the minus X component becomes large. That is, by shifting the rotation angle θ of the adjusting portion 100 from the reference position in the minus direction, it is possible to suppress an increase in the moment of inertia of the balance 54 when the temperature increases. When the rotation angle θ is 90(deg) (a 5 in fig. 13), the bimetal 121 is deformed only inward in the 1 st radial direction. Therefore, when the rotation angle θ is 90(deg), the-X component becomes maximum and the Y component is 0. By rotating the adjustment unit 100 in the negative direction from the reference position in this way, the temperature coefficient of the moment of inertia can be reduced.

Fig. 14 is a graph showing the relationship between the rotation angle θ and the radius change amount Δ R of the adjusting unit 100.

As shown in fig. 14, according to the result of fig. 13, when the adjustment unit 100 is rotated from the reference position in the + direction, the amount of change in radius Δ R of the adjustment unit 100 increases in the + direction (outward in the 1 st radial direction). On the other hand, when the adjustment unit 100 is rotated in the minus direction from the reference position, the radial variation Δ R of the adjustment unit 100 increases in the minus direction (inward in the 1 st radial direction).

Fig. 15 is a graph showing a relationship between temperature (° c) and a difference rate when the temperature coefficient of the young's modulus of balance spring 63 is different. In fig. 15, a broken line G1 indicates a case where the difference rate (oscillation cycle of the balance 54) has a negative temperature characteristic, and a chain line G2 indicates a case where the difference rate has a positive temperature characteristic.

As shown in G1 of fig. 15, when the difference rate has negative temperature characteristics according to the relationship between the young's modulus of the balance spring 63 and the moment of inertia of the balance 54, the difference rate tends to be slower as the temperature increases. In this case, the adjustment unit 100 is rotated in the minus direction from the reference position. Accordingly, the temperature coefficient of the moment of inertia can be reduced by securing the radial change amount Δ R toward the inner side in the 1 st radial direction in association with the temperature increase, and therefore, the increase in the moment of inertia of the balance 54 in association with the temperature increase can be suppressed. As a result, the temperature coefficient of the oscillation cycle of the balance 54 is adjusted in a direction approaching zero, and the difference rate is maintained constant regardless of the temperature change (see the solid line G3 in fig. 15).

On the other hand, as shown in G2 of fig. 15, when the difference rate has a positive temperature characteristic, the difference rate tends to become faster as the temperature rises, based on the relationship between the young's modulus of the balance spring 63 and the moment of inertia of the balance 54. In this case, the adjustment unit 100 is rotated in the + direction from the reference position. Accordingly, the temperature coefficient of the moment of inertia can be increased by securing the amount of change Δ R in the radius outward in the 1 st radial direction in association with the temperature increase, and therefore, the amount of increase in the moment of inertia of the balance 54 in association with the temperature increase can be increased. As a result, the temperature coefficient of the oscillation cycle of the balance 54 is adjusted in a direction approaching zero, and the difference rate is maintained constant regardless of the temperature change (see the solid line G3 in fig. 15).

By changing the rotation angle θ of the adjustment unit 100 in accordance with the temperature characteristic of the difference rate in this manner, the temperature coefficient of the moment of inertia of the balance 54 can be corrected to both positive and negative sides. This makes it easy to eliminate the variation in the temperature coefficient of the young's modulus according to the temperature characteristics of the moment of inertia of the balance 54.

As described above, according to the present embodiment, the bimetal 121 is provided at the rotationally symmetrical position on the balance 62.

According to this configuration, the bimetal 121 deforms with a change in temperature, and thereby the average diameter of the balance 62 changes. This makes it possible to correct the temperature characteristic of the moment of inertia.

In particular, in the present embodiment, the adjusting portion 100 is configured to be capable of adjusting the position around the 2 nd axis O2. Therefore, the orientation of bimetal 121 can be changed in accordance with the temperature coefficient of the young's modulus of balance spring 63. This can change the temperature coefficient correction amount of the bimetal 121 to both positive and negative, and can correct the temperature coefficient of the moment of inertia of the balance 54 to both positive and negative. That is, it is easy to eliminate the variation in the temperature coefficient of the young's modulus according to the temperature characteristics of the moment of inertia of the balance 54. As a result, the oscillation cycle of the balance 54 can be kept constant, and the balance 54 having excellent temperature compensation characteristics can be provided.

In the present embodiment, even if the orientation of the bimetal 121 is changed, the length of the adjustment portion 100 in the direction of the 2 nd axis O2 is maintained constant. Therefore, unlike the case where the effective length of the bimetal 121 is changed as in the related art, the center of gravity of the balance 54 can be prevented from shifting at the predetermined temperature T0. As a result, the occurrence of biased weight application can be suppressed, and the posture difference can be reduced.

In the present embodiment, since the adjustment portion 100 is provided to the rim portion 73 of the balance 62, the adjustment portion 100 can be spaced apart from the 1 st axis O1 in the 1 st radial direction. This can increase the amount of radial deformation Δ R, and can increase the temperature coefficient correction amount by the bimetal 121.

In the present embodiment, the adjustment unit 100 is configured to: is disposed radially inward of the rim portion 73 in the 1 st direction, and extends along a tangent to the rim portion 73.

According to this configuration, the radial deformation amount Δ R associated with the temperature change can be secured while suppressing an increase in size of the balance 54 due to the addition of the adjustment unit 100.

In the present embodiment, since the adjusting portion 100 has the weight applying portion 122 at the distal end portion, the weight of the distal end portion, which is the maximum deformation portion in the adjusting portion 100, can be increased. Therefore, the temperature coefficient correction amount by the bimetal 121 can be increased.

In the present embodiment, since the adjustment portion 100 extends in a cantilever manner, the amount of radial deformation Δ R associated with a temperature change can be secured, and the amount of temperature coefficient correction by the bimetal 121 can be increased.

In the present embodiment, since the working hole 117 is formed in the rim portion 73, a tool can be passed through the working hole 117 and locked to the locking portion of the fixing portion 120. Therefore, the position of the adjuster 100 can be easily adjusted about the 2 nd axis O2. Further, by changing the rotation angle θ of the adjustment portion 100 via the fixing portion 120, plastic deformation of the adjustment portion 100 at the time of position adjustment of the adjustment portion 100 can be suppressed, as compared with the case where the rotation angle θ of the adjustment portion 100 is changed via the tip portion (bimetal 121 or weighting portion 122). Therefore, the following can be suppressed: the plastic deformation of the adjustment portion 100 causes a difference rate deviation at a predetermined temperature T0.

In the present embodiment, the balance spring 63 is formed of a constant elastic material.

According to this configuration, the change in young's modulus associated with a temperature change can be reduced, thereby suppressing the temperature dependence of the vibration cycle. In addition, in the present embodiment, since the variation in the temperature coefficient of young's modulus can be corrected by the rotation angle θ of the adjustment portion 100, the manufacturing management at the time of manufacturing the balance spring 63 becomes easy. Therefore, not only can the manufacturing efficiency of hairspring 63 be improved, but also the cost can be reduced.

In the present embodiment, since the center of gravity of the adjusting portion 100 is located on the 2 nd axis O2, when the position of the adjusting portion 100 about the 2 nd axis O2 is adjusted, it is possible to prevent the center of gravity of the adjusting portion 100 from being displaced from the 2 nd axis O2 in accordance with the rotation angle θ of the adjusting portion 100. As a result, the center of gravity of the balance 54 can be prevented from shifting according to the rotation angle θ of the adjustment portion 100, and therefore the attitude difference can be reliably reduced.

Since the movement 2 and the timepiece 1 according to the present embodiment include the balance 54 described above, it is possible to provide a high-quality movement 2 and a timepiece 1 with small variations in the rate of difference.

(embodiment 2)

Next, embodiment 2 of the present invention will be explained. Fig. 16 is a perspective view of the balance 201 according to embodiment 2. The present embodiment is different from the above-described embodiments in the following points: the support portion 202 protrudes in the 1 st axis direction from the rim portion 73. In the following description, the same components as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

In the balance 201 shown in fig. 16, a support portion 202 is formed at a rotationally symmetrical position of the rim portion 73. The support portion 202 protrudes from the rim portion 73 to the rear side in the 1 st axial direction, and protrudes inward in the 1 st radial direction. A mounting hole 205 penetrating the support portion 202 in the 2 nd axial direction is formed in a portion of the support portion 202 projecting inward in the 1 st radial direction with respect to the rim portion 73. The fixing portion 120 of the adjuster 100 is press-fitted into each mounting hole 205.

As described above, in the present embodiment, the rim portion 73 and the adjusting portion 100 are disposed at different positions in the 1 st axial direction. Therefore, when the adjustment portion 100 deforms in the 1 st radial direction with a change in temperature, interference between the rim portion 73 and the adjustment portion 100 can be suppressed, and the radial deformation amount Δ R of the adjustment portion 100 can be ensured.

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be added within a scope not departing from the gist of the present invention.

For example, in the above embodiment, the configuration in which 2 adjustment portions 100 are provided at the rotationally symmetrical positions of the rim portion 73 has been described, but the present invention is not limited to this configuration. That is, if each adjustment unit 100 is provided at a rotationally symmetric position, a plurality of adjustment units 100 of 3 or more may be provided as shown in fig. 17, for example.

In the above-described embodiment, the structure in which the adjustment portion 100 is rotated about the 2 nd axis O2 while the outer peripheral surface of the fixing portion 120 is slid on the inner peripheral surface of the mounting hole 115 has been described, but the structure is not limited thereto. That is, the adjusting portion 100 may be configured to be capable of position adjustment about the 2 nd axis O2. In this case, for example, as shown in fig. 18, the following configuration may be adopted: the male spline 120a formed in the fixing portion 120 is engaged with the female spline 115a formed in the mounting hole 115. According to this configuration, the position of the adjustment portion 100 can be adjusted about the 2 nd axis O2 by fitting the fixing portion 120 into the mounting hole 115 after aligning the orientation of the bimetal 121.

Further, it may be: after the adjustment unit 100 is positionally adjusted, the adjustment unit 100 is fixed to the support unit 110 so as not to be rotatable. The adjusting portion 100 may be fixed by welding, bonding, or the like, or may be fixed by using another fastening member (for example, a fastening screw or the like).

In the above-described embodiment, the structure in which the fixing portion 120 is fitted into the mounting hole 115 has been described, but the present invention is not limited to this structure, and the mounting method of the adjustment portion 100 can be appropriately changed. For example, a convex portion formed in the rim portion 73 and a concave portion formed in the adjusting portion 100 may be fitted.

In the above-described embodiment, the configuration in which the 2 nd axis O2 of the adjustment portion 100 extends along the tangent of the rim portion 73 has been described, but the present invention is not limited to this configuration. That is, any structure may be used as long as: the X component is generated in the deformation vector of the adjusting unit 100 by the deformation of the bimetal 121 accompanying the temperature change. In this case, the 2 nd axis O2 may be set to a direction intersecting the 1 st axis direction, a direction parallel to the 1 st axis direction, or the like.

In the above-described embodiment, the structure in which the adjusting portion 100 is supported by the rim portion 73 via the supporting portion 110 has been described, but the invention is not limited to this structure. That is, the adjusting portion 100 may be provided in a portion (balance body) of the balance 54 that rotates by the power of the balance spring 63. In this case, the balance main body may be the balance staff 61, the balance 62 (the hub portion 71, the spoke portion 72, and the like), the double roller 67, and the like.

In the above-described embodiment, the case where the low-expansion member 130 and the high-expansion member 131 are formed of the plate material having the same shape has been described, but the present invention is not limited to this configuration. For example, as shown in fig. 19, the low-expansion member 130 and the high-expansion member 131 may be different in thickness from each other. The cross-sectional shapes of the low expansion member 130 and the high expansion member 131 perpendicular to the 2 nd axis O2 are not limited to rectangular shapes, and may be appropriately modified to triangular shapes, semicircular shapes, or the like.

In the above-described embodiment, the description has been made on the structure in which the low-expansion member 130 and the high-expansion member 131 are laminated in the 2 nd radial direction, but the structure is not limited to this, and in the case where the low-expansion member 130 and the high-expansion member 131 are laminated in the direction intersecting the 2 nd axial direction, for example, as shown in fig. 19, the low-expansion member 130 that gradually becomes thicker toward the distal end side and the high-expansion member 131 that gradually becomes thinner toward the distal end side may be laminated.

In the above-described embodiment, the structure in which the adjustment portion 100 linearly extends has been described, but the invention is not limited to this structure. The adjusting portion 100 may extend so as to intersect the 2 nd axial direction or may be formed in a corrugated shape as long as it is configured to be capable of position adjustment about the 2 nd axial line O2.

In the above-described embodiment, the structure in which the adjustment unit 100 extends in a cantilever manner has been described, but the present invention is not limited to this structure, and may be a structure in which both ends are supported.

In the above embodiment, the following description is made: in the adjusting portion 100, the bimetal 121 is formed over the entire area between the support portion 110 and the weight portion 122, but is not limited to this structure. At least a part of the adjusting part 100 may be formed of the bimetal 121.

In addition, the components in the above embodiments may be replaced with known components as appropriate within a range not departing from the gist of the present invention, and the above modifications may be combined as appropriate.

Claims

1. A temperature compensation type balance spring is characterized in that,

the temperature compensation type balance wheel comprises:

a balance wheel main body having a balance shaft extending along a1 st axis and rotating around the 1 st axis by the power of a balance spring; and

and an adjusting portion that extends along a2 nd axis line from a position on the balance main body that is rotationally symmetrical about the 1 st axis line, and is configured to be able to adjust a position about the 2 nd axis line, the adjusting portion including a bimetal formed by laminating materials having different thermal expansion coefficients in a direction intersecting the 2 nd axis line.

2. The temperature-compensated balance according to claim 1,

the balance wheel main body includes:

the pendulum shaft; and

a balance attached to the balance staff and having a rim portion surrounding the balance staff from the outside in the 1 st radial direction perpendicular to the 1 st axis,

the adjusting portion extends from the rim portion.

3. The temperature-compensated balance according to claim 2,

the adjusting portion is disposed inside the rim portion in a plan view seen in the 1 st axial direction, and extends in a tangential direction of the rim portion.

4. The temperature-compensated balance according to claim 2,

the bimetal is disposed at a position different from the rim portion in the 1 st axial direction.

5. The temperature-compensated balance according to claim 1,

the adjusting part is provided with a weight applying part.

6. The temperature-compensated balance according to claim 1,

a through hole is formed in the balance main body, the through hole penetrating the balance main body in a2 nd axial line direction,

the adjusting portion includes a fixing portion that is located on one side in the 2 nd axial direction with respect to the bimetal and is fitted in the through hole,

an engaging portion to which a tool is engaged is formed on an end surface of the fixing portion facing the one side in the 2 nd axial direction.

7. The temperature-compensated balance according to claim 1,

the adjustment portion extends in a cantilevered manner along the 2 nd axis.

8. The temperature-compensated balance according to claim 1,

the balance spring is formed of a constant elastic material.

9. The temperature-compensated balance according to claim 1,

the center of gravity of the adjusting part is located on the 2 nd axis.

10. A machine core is characterized in that a machine core is provided,

the movement is provided with a temperature-compensated balance according to any one of claims 1 to 9.

11. A timepiece, characterized in that it comprises, in a case,

the timepiece is provided with the movement of claim 10.