JP7159077B2 - Temperature compensated balance, movement and watch - Google Patents

Description

The present invention relates to a temperature compensated balance, movement and timepiece.

A balance that functions as a speed governor of a mechanical watch includes a balance extending along an axis, a balance wheel fixed to the balance, and a balance spring. The balance spring and the balance wheel periodically rotate (vibrate) forward and backward about the axis as the balance spring expands and contracts.

In the above-described balance, it is important that the oscillation period is set within a predetermined specified value. If the vibration period deviates from the specified value, the rate of the mechanical timepiece (degree of delay or advance of the clock) will change.

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

Based on the formula (1), when the moment of inertia I of the balance and the spring constant K of the balance spring change due to changes in temperature or the like, the vibration period T of the balance changes. Specifically, the above-described balance wheel may be made of a material with a positive coefficient of thermal expansion (a material that expands with temperature rise). In this case, when the temperature rises, the balance wheel expands and the moment of inertia I increases.
Therefore, as the temperature rises, the moment of inertia I increases, and the vibration cycle T lengthens. As a result, the oscillation cycle T of the balance becomes shorter at low temperatures and longer at high temperatures, so that the temperature characteristics of the timepiece progress at low temperatures and lag at high temperatures.

As a countermeasure for improving the temperature dependence of the vibration period T, it is conceivable to provide a bimetal at a rotationally symmetrical position on the balance wheel (for example, see Non-Patent Document 1 below). The bimetal is formed by laminating plate materials having different coefficients of thermal expansion.
According to this configuration, when the temperature rises, the bimetal deforms, for example, radially inward due to the difference in thermal expansion coefficient between the plate members. Accordingly, the moment of inertia I can be reduced by reducing the average diameter of the balance wheel. As a result, it is considered that the temperature characteristics of the moment of inertia I can be corrected, and the temperature dependence of the vibration period T can be suppressed.

Swiss University of Watchmaking, "The Theory of Horology", 2nd English Edition, April 2003, pp. 136-137

For example, if the bimetal is not formed in the desired shape due to manufacturing variations, etc., the temperature coefficient of the bimetal (the amount of deformation of the bimetal with respect to temperature changes) will become unstable, and the temperature characteristics of the bimetal may not be corrected accurately. was there. In such a case, it is conceivable to adjust the temperature characteristics of the moment of inertia I (the amount of change in the moment of inertia I with respect to temperature change) by attaching a screw to the bimetal.

However, in adjusting the temperature characteristics with a chiller screw, it was only possible to change the mounting position, change the mounting position, and adjust the weight of the chiller screw to be installed. .

The present invention provides a high-quality temperature-compensating balance, a movement, and a timepiece with excellent temperature-compensating performance, capable of easily and precisely adjusting the temperature characteristics of the moment of inertia while suppressing rate changes. .

In order to solve the above-described problems, a temperature-compensating balance according to one aspect of the present invention includes a main shaft extending along a first axis, and a balance spring rotatably attached to the main shaft about the first axis by the power of a hairspring. a balance body having a high expansion portion and a low expansion portion with different coefficients of thermal expansion; a deformable portion that can be deformed in a radial direction orthogonal to the first axis, and a weight portion having a center of gravity at a position eccentric to the second axis along the radial direction; and an adjusting portion attached to the deformation portion so as to be rotatable about the second axis while movement in directions along two axes is restricted.

According to this aspect, the amount of radial deformation (the distance from the first axis before and after deformation) of the deformable portion differs depending on the position in the circumferential direction. The accompanying radial deformation amount of the weight portion can be changed (adjusted).
In particular, in this aspect, the center of gravity of the weight can be changed continuously in the circumferential direction by changing the rotational position of the weight, so that the amount of radial deformation of the weight can be finely adjusted.
Moreover, in this aspect, since the weight rotates while movement in the second axis direction is restricted, it is possible to suppress radial movement of the weight along with the rotation of the weight. As a result, fluctuations in the average diameter (moment of inertia) of the balance body due to changes in the position of the center of gravity of the weight can be suppressed.
As a result, it is possible to easily adjust the temperature characteristic of the moment of inertia with high accuracy while suppressing rate changes, and to provide a high-quality temperature-compensating balance with excellent temperature-compensating performance.

In the above aspect, the deformation portion is a bimetal in which the high expansion portion and the low expansion portion are overlapped in the radial direction and extend along the circumferential direction around the first axis, and the balance body is and a connecting portion that connects between a first end portion of the deformation portion in the circumferential direction and the stem.
According to this aspect, the deformation of the deformation portion changes the average diameter of the balance body, and the temperature characteristic of the moment of inertia can be corrected.
Moreover, by providing the deformed portion as a bimetal only on the rim portion of the balance, the degree of freedom in designing the connecting portion can be improved as compared with the case where the deformed portion is formed by the entire balance body. In addition, since the deformable portion extends in a cantilevered manner starting from the first end, the amount of radial deformation of the deformable portion with respect to temperature changes gradually increases from the fixed end toward the free end. Therefore, by changing the center of gravity of the weight in the circumferential direction, it is possible to gradually decrease or increase the amount of radial deformation of the weight with respect to temperature changes. As a result, it is possible to more easily adjust the temperature characteristic of the moment of inertia.

In the above aspect, the adjusting portion includes a shaft portion that extends along the second axis and is supported by the deforming portion, and one of the shaft portions that is positioned radially outward of the deforming portion. and the weight portion.
According to this aspect, the weight can be operated from the outside of the balance body, which facilitates adjustment of the temperature characteristics.

In the above aspect, the shaft portion and the weight portion may be integrally formed.
According to this aspect, since the shaft portion and the weight portion are integrally formed, it is possible to reduce the number of parts and simplify the configuration.

In the above aspect, the shaft portion and the weight portion may be formed separately.
According to this aspect, suitable materials and the like can be selected for each of the shaft portion and the weight portion. Therefore, it is possible to improve the degree of freedom in design.

In the above aspect, the weight portion is formed with a chamfered portion along a tangential direction of an imaginary circle centered on the second axis in a side view viewed from the radial direction, and the first axis of the deformation portion is formed. The facing edge may be formed parallel to the chamfered portion in a state in which the chamfered portion faces the first axial direction.
According to this aspect, in a state in which the chamfered portion faces the first axial direction, it is possible to suppress the amount of protrusion of the weight portion in the first axial direction from the deformation portion. As a result, an increase in the size of the balance wheel in the direction of the first axis can be suppressed.
Further, when the weight is operated, the tool and the weight can be prevented from rotating by holding the weight using the chamfered portion. Therefore, since it is not necessary to separately provide a tool locking portion in the weight, the degree of freedom in designing the weight can be improved.

In the above aspect, attachment portions to which the adjustment portion is detachably attached may be arranged in the deformation portion at intervals in a circumferential direction around the first axis.
According to this aspect, since a plurality of attachment portions are formed in the deformation portion, it is possible to change the number of adjustment portions attached to the deformation portion and the attachment positions of the adjustment portions. As a result, the temperature characteristic of the moment of inertia can be adjusted with higher accuracy and in a wider range.

A movement according to an aspect of the present invention may include the temperature-compensated balance as described above.
A timepiece according to one aspect of the present invention may include the movement of the aspect described above.
According to this aspect, since the temperature-compensating balance of this aspect is provided, a high-quality movement and timepiece can be provided.

According to the present invention, it is possible to easily and precisely adjust the temperature characteristics of the moment of inertia while suppressing rate changes, and to provide a high-quality temperature-compensating balance, movement, and timepiece with excellent temperature-compensating performance. can provide.

1 is an external view of a timepiece according to a first embodiment; FIG. It is the top view which looked at the movement concerning 1st Embodiment from the front side. It is the perspective view which looked at the balance which concerns on 1st Embodiment from the front side. Fig. 2 is a side view of the balance according to the first embodiment; 4 is a partial plan view of the balance according to the first embodiment; FIG. 6 is a view in the direction of arrow VI in FIG. 5; FIG. FIG. 5 is a partial plan view of the balance for explaining the operation of the deformable portion; FIG. 10 is a side view of the balance for explaining the operation of the adjusting section; FIG. 10 is a side view of the balance for explaining the operation of the adjusting section; FIG. 5 is a partial plan view of the balance for explaining the operation of the adjusting section; FIG. 5 is a partial plan view of the balance for explaining the operation of the adjusting section; FIG. 6 is a partial cross-sectional view of the balance according to the second embodiment; 12. It is a XIII arrow directional view of FIG. FIG. 11 is a perspective view of a balance according to a third embodiment; FIG. 15 is a cross-sectional view along line XV-XV of FIG. 14;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In addition, in each embodiment described below, the same code|symbol may be attached|subjected to the corresponding structure and description may be abbreviate|omitted.
(First embodiment)
[clock]
FIG. 1 is an external view of a timepiece 1. FIG. It should be noted that, in each drawing shown below, in order to make the drawings easier to see, there are cases in which some of the timepiece parts are omitted and the respective timepiece parts are illustrated in a simplified manner.
As shown in FIG. 1, a timepiece 1 of this embodiment is constructed by incorporating a movement 2, a dial 3, various pointers 4 to 6, and the like into a timepiece case 7. As shown in FIG.

The watch case 7 includes a case body 11 , a case lid (not shown), and a cover glass 12 . A crown 15 is provided on the side surface of the case body 11 at the 3 o'clock position (on the right side in FIG. 1). The crown 15 is for operating the movement 2 from outside the case body 11 . The crown 15 is fixed to a winding stem 19 inserted through the case body 11 .

[movement]
FIG. 2 is a plan view of the movement 2 viewed from the front side.
As shown in FIG. 2, the movement 2 is constructed by rotatably supporting a plurality of rotating bodies (gears, etc.) on a main plate 21 that constitutes a substrate of the movement 2 . In the following description, the cover glass 12 side (dial plate 3 side) of the watch case 7 with respect to the main plate 21 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 "back side" of the movement 2. It is called the "front side" of the movement 2. Further, each rotating body described below is provided with the front and rear surfaces of the movement 2 as its axial direction.

The main plate 21 incorporates the winding stem 19 described above. The stem 19 is used to correct the date and time. The winding stem 19 is rotatable about its axis and axially movable. The winding stem 19 is axially positioned by a switching device including a lever 23 , a bar 24 , a bar spring 25 and a back retainer 26 .
When the winding stem 19 is rotated, the pick wheel 31 is rotated through rotation of a handwheel (not shown). As the ratchet wheel 31 rotates, the ratchet wheel 32 and the ratchet wheel 33 rotate in order, and the mainspring (not shown) accommodated in the barrel wheel 34 is wound.

The barrel wheel 34 is rotatably supported between the main plate 21 and the barrel bridge 35 . The center wheel & pinion 41 , third wheel & pinion 42 , and fourth wheel & pinion 43 are rotatably supported between the main plate 21 and the train wheel bridge 45 .
When the barrel wheel 34 rotates due to the restoring force of the mainspring, the rotation of the barrel wheel 34 causes the center wheel & pinion 41, the third wheel & pinion 42 and the fourth wheel & pinion 43 to rotate in order. The barrel wheel 34, the center wheel & pinion 41, the third wheel & pinion 42 and the fourth wheel & pinion 43 constitute a front train wheel.

A minute hand 5 (see FIG. 1) is attached to the center wheel & pinion 41 of the above-described front train wheel. The above-described hour hand 4 is attached to an hour wheel (not shown) that rotates as the center wheel & pinion 41 rotates. Second hand 6 (see FIG. 1) is configured to rotate based on rotation of fourth wheel & pinion 43 .

A speed controlling escapement 51 is mounted on the movement 2 .
The speed governing escapement 51 has an escape wheel 52 , an anchor 53 and a balance (temperature compensation type balance) 54 .

Escape wheel 52 is rotatably supported between main plate 21 and train wheel bridge 45 . The escape wheel 52 rotates as the fourth wheel & pinion 43 rotates.
The ankle 53 is supported between the base plate 21 and the ankle support 55 so as to be reciprocally rotatable. The ankle 53 has a pair of pawl stones 56a and 56b. The pawl stones 56a and 56b alternately engage with the escape gear 52a of the escape wheel 52 as the pallet 53 reciprocates. The escape wheel 52 temporarily stops rotating when one of the pair of pawl stones 56a and 56b is engaged with the escape gear 52a. Also, the escape wheel 52 rotates when the pair of pawl stones 56a and 56b are disengaged from the escape wheel 52a. By continuously repeating these operations, the escape wheel 52 rotates intermittently. The intermittent rotational motion of the escape wheel & pinion 52 intermittently operates the above-described train wheel (front train wheel), thereby controlling the rotation of the front train wheel.

<Balance>
FIG. 3 is a perspective view of the balance 54 viewed from the front side. 4 is a side view of the balance 54. FIG.
As shown in FIGS. 3 and 4, the balance wheel 54 regulates the speed of the escape wheel & pinion 52 (escapes the escape wheel & pinion 52 at a constant speed). The balance 54 has a balance 61 , a balance wheel 62 , a balance spring 63 and an adjustment section 64 . The balance wheel 62 and the adjustment portion 64 constitute the balance body of the present embodiment.

As shown in FIG. 4, the balance 61 is supported between the main plate 21 and the balance bridge 65 so as to be rotatable around the first axis O1. In the following description, the direction along the first axis O1 is referred to as the first axial direction, the direction perpendicular to the first axis O1 is referred to as the first radial direction, and the direction rotating around the first axis O1 is referred to as the first circumferential direction. There is a case. In this case, the direction of the first axis coincides with the direction of the front and back surfaces.

The balance spring 61 rotates in forward and reverse directions about the first axis O1 with a constant vibration cycle by the power transmitted from the balance spring 63 . A front end of the balance 61 in the direction of the first axis is supported by a balance bridge 65 . The rear end of the stem 61 in the direction of the first axis is supported by the main plate 21 .

A rear end portion of the stem 61 in the direction of the first axis is fitted into a swing seat 67 . The swing seat 67 is formed in a cylindrical shape coaxial with the first axis O1. A swing stone 68 is provided on a part of the swing seat 67 in the first circumferential direction. The swing stone 68 repeats engagement and disengagement with the ankle box of the ankle 53 in synchronization with the reciprocating rotation of the balance 54 . As a result, the pallets 56a and 56b repeat engagement and disengagement with the escape wheel 52 by reciprocating rotation of the pallet 53. As shown in FIG.

As shown in FIG. 3 , the balance wheel 62 is fixed to the front side of the swing seat 67 of the balance stem 61 in the direction of the first axis. The balance wheel 62 includes a connecting portion 70 and a rim portion 73 .

The connecting portion 70 connects between the stem 61 and the rim portion 73 . The connecting portion 70 includes a hub portion 71 and a braid portion 72 .
The hub portion 71 is fixed to the stem 61 by press fitting or the like.
The braid portion 72 protrudes outward in the first radial direction from the hub portion 71 . In this embodiment, three braid portions 72 are formed radially with respect to the first axis O1. The position of the braided portion 72 in the first circumferential direction, the number of the braided portion 72, and the like can be changed as appropriate.

The rim portion 73 has a plurality of deformation portions 80 . Each deformable portion 80 extends in a cantilever manner from each of the above-described braid portions 72 toward one side in the first circumferential direction. In the present embodiment, the deformation portion 80 is formed rotationally symmetrical (three-fold symmetrical in the present embodiment) about the first axis O1. A rotational object is an example of representation for characterizing a figure, and is a well-known concept. For example, let n be an integer of 2 or more, and rotate (360/n)° around a certain center (in the case of a two-dimensional figure) or an axis (in the case of a three-dimensional figure) to overlap with itself. It is called n-phase symmetry, (360/n) degree symmetry, and the like. For example, when n=3, when rotated by 120°, it becomes 3-fold symmetrical with itself.

The rim portion 73 is formed in an annular shape as a whole coaxially with the first axis O1 by arranging the deformation portions 80 on the same circumference at intervals in the first circumferential direction. . The rim portion 73 surrounds the connecting portion 70 from the outside in the first radial direction.

The deformation portion 80 is a so-called bimetal in which two plate materials having different coefficients of thermal expansion are superimposed in the first radial direction. The deformation portion 80 includes a low expansion portion 81 positioned inside in the first radial direction, and a high expansion portion 82 positioned outside the low expansion portion 81 in the first radial direction. Using the difference in thermal expansion coefficient between the low-expansion portion 81 and the high-expansion portion 82, the deformable portion 80 expands in the first radial direction from the fixed end (the boundary portion with the braid portion 72) as the temperature changes. It is configured to be deformable. In the present embodiment, the high expansion portion 82 is positioned on the outer side in the first radial direction, so when the temperature rises, the deformation portion 80 deforms inward in the first radial direction. In the illustrated example, the thickness of the low expansion portion 81 in the first radial direction is greater than that of the high expansion portion 82 . However, the plate thicknesses of the low expansion portion 81 and the high expansion portion 82 can be changed as appropriate.

In this embodiment, invar (Ni—Fe alloy), silicon, ceramics, or the like is preferably used for the low expansion portion 81 . Copper, a copper alloy, aluminum, or the like is preferably used for the high expansion portion 82 . However, the materials of the low expansion portion 81 and the high expansion portion 82 can be changed as appropriate.

A mounting hole (mounting portion) 85 is formed at the free end (tip in the first circumferential direction) of the deformation portion 80 . The attachment hole 85 penetrates the deformation portion 80 in the first radial direction. The positions of the mounting holes 85 can be changed as appropriate as long as they are formed in positions that are rotationally symmetrical to each other in the deformation portions 80 .

The hairspring 63 is a flat spiral in a plan view viewed from the direction of the first axis. The hairspring 63 is wound along an Archimedes curve. The inner end of the hairspring 63 is connected to the mainspring 61 via a hairball 87 . The outer end of the balance spring 63 is connected to the balance bridge 65 via a balance holder (not shown). The balance spring 63 plays a role of storing power transmitted from the fourth wheel & pinion 43 to the escape wheel & pinion 52 and transmitting it to the balance wheel 61 .

In this embodiment, a constant elastic material (for example, coelin bar or the like) is preferably used for the hairspring 63 . The balance spring 63 has a positive temperature characteristic of Young's modulus in the operating temperature range. In this case, the temperature coefficient of the Young's modulus of the balance spring 63 is adjusted so that the vibration period of the balance 54 becomes as constant as possible with respect to the temperature characteristics of the moment of inertia of the balance wheel 62 due to temperature changes. However, the hairspring 63 may be made of a material other than the constant elastic material. In this case, as the hairspring 63, it is possible to use a general steel material whose Young's modulus has a negative temperature coefficient (the characteristic that the spring constant decreases as the temperature rises).

<Adjuster>
FIG. 5 is a partial plan view of the balance 54. As shown in FIG.
As shown in FIGS. 3 and 5, the adjusting portion 64 is separately attached to each deformation portion 80 described above. In other words, each adjusting portion 64 is provided at a position to rotate about the first axis O1. The adjusting portion 64 includes an engaging portion 100 , a pin member 101 and a weight portion 102 . The adjusting portion 64 is shaped like a rod extending along the second axis O2. In this embodiment, the second axis O2 extends along the first radial direction. In the following description, a direction along the second axis O2 is called a second axial direction (first radial direction), a direction orthogonal to the second axis O2 is called a second radial direction, and the second radial direction rotates around the second axis O2. The direction may be referred to as the second circumferential direction.

The engaging portion 100 is formed in a stepped tubular shape extending in the second axial direction. Specifically, the engaging portion 100 includes a large-diameter portion 110 positioned inside in the second axial direction (inward in the first radial direction) and a small-diameter portion 110 positioned outside the large-diameter portion 110 in the second axial direction. It has a part 111 and.

The small-diameter portion 111 is press-fitted into the mounting hole 85 of the deformation portion 80 from the inside in the second axial direction. As a result, the engaging portion 100 is in a state in which the stepped surface 112 between the large diameter portion 110 and the small diameter portion 111 abuts or approaches the inner peripheral surface of the deformable portion 80 from the inside in the second axial direction. It is fixed (engaged) to 80 . Note that the engaging portion 100 may be fixed to the deformation portion 80 by adhesion or the like.

The pin member 101 is arranged coaxially with the second axis O2. The pin member 101 has a shaft portion 115 and a head portion 116 .
The inner end portion of the shaft portion 115 in the second axial direction is press-fitted into the engaging portion 100 from the outside in the second axial direction.
The head portion 116 protrudes from the outer edge of the shaft portion 115 in the second axial direction. In addition, in a side view from the direction of the second axis, the center of gravity of the engaging portion 100 and the pin member 101 is located on the second axis O2.

6 is a view in the direction of arrow VI in FIG. 5. FIG.
As shown in FIG. 6, the weight section 102 is attached to the shaft section 115 so as to be rotatable around the second axis O2. Specifically, the weight portion 102 is attached to the outer end portion of the shaft portion 115 in the second axial direction while being biased inward in the second radial direction. Weight portion 102 is formed in a C shape surrounding shaft portion 115 in a side view. Therefore, in a side view, the center of gravity G of the weight portion 102 is eccentric in the second radial direction with respect to the second axis O2.

The weight portion 102 is configured to be rotatable around the second axis O2 while sliding on the outer peripheral surface of the shaft portion 115 . Therefore, as the weight 102 rotates, the center of gravity G of the weight 102 moves (revolves) around the second axis O2. As a result, the center of gravity G of the weight portion 102 moves along the first circumferential direction (specifically, the tangential direction passing through the mounting hole 85 on the outer peripheral surface of the deformation portion 80). Note that the shape of the weight portion 102 when viewed from the side is not limited to a circular shape, and may be a polygonal shape or the like. Further, in the present embodiment, the biasing force of the weight portion 102 is used to position the shaft portion 115 in the second circumferential direction, but the present invention is not limited to this configuration. For example, the weight portion 102 and the shaft portion 115 may be positioned in the second circumferential direction by unevenness or the like that can ride over in the second circumferential direction.

Chamfered portions 120 are formed at both end portions in the second circumferential direction of the weight portion 102 of the present embodiment. The chamfered portion 120 is a flat surface extending along the tangential direction of an imaginary circle centered on the second axis O2. The chamfered portion 120 is arranged parallel to both edges of the deformation portion 80 facing the first axial direction while facing the first axial direction. In the illustrated example, the weight portion 102 has a uniform thickness in the second radial direction over the entire circumference. However, the weight portion 102 may change its thickness depending on the position in the second circumferential direction.

The position of the center of gravity of the weight portion 102 (the eccentricity of the center of gravity G) can be changed as appropriate. Methods for changing the position of the center of gravity of weight 102 include changing the shape of weight 102 and changing the specific gravity of weight 102 . For example, the weight portion 102 can be made of a material having a relatively large specific gravity (for example, compared to the engaging portion 100 and the pin member 101). In this case, gold (Au), platinum (Pt), tungsten (W), or the like is preferably used for the weight portion 102 .

The weight portion 102 is sandwiched between the outer peripheral surface of the deformation portion 80 and the head portion 116 in the second axial direction. As a result, the weight portion 102 is restricted from moving in the second axial direction by the deformation portion 80 and the pin member 101 . A slight gap may be formed between the weight portion 102 and the outer peripheral surface of the deformation portion 80 and between the weight portion 102 and the head portion 116 .

In the present embodiment, the configuration in which only the weight portion 102 is rotatable around the second axis O2 has been described, but the configuration is not limited to this configuration. That is, if at least the weight portion 102 is rotatable around the second axis O2, the adjustment portion 64 is configured such that the engagement portion 100 and the pin member 101 are rotatable together with the weight portion 102 in addition to the weight portion 102. There may be. That is, when the engaging portion 100 is inserted into the mounting hole 85, the pin member 101 is fixed to the engaging portion 100, and the weight portion 102 is fixed to the pin member 101, the adjustment portion 64 itself rotates. It may be a possible configuration. Further, the pin member 101 and the weight portion 102 may be configured to be rotatable by fixing the engaging portion 100 within the mounting hole 85 and inserting the pin member 101 into the engaging portion 100 .

[Temperature coefficient correction method]
Next, a method for correcting the temperature coefficient of the balance 54 described above will be described. FIG. 7 is a partial plan view of the balance 54 for explaining the operation of the deformation section 80. As shown in FIG.
As shown in FIG. 7 , in the balance 54 of the present embodiment, when the temperature changes, the deformable portion 80 bends and deforms due to the difference in thermal expansion coefficient between the low expansion portion 81 and the high expansion portion 82 . Specifically, when the temperature rises above a predetermined temperature T0 (ordinary temperature (for example, about 23° C.)), the high expansion portion 82 expands more than the low expansion portion 81 . As a result, the deformation portion 80 deforms inward in the first radial direction (symbol A in FIG. 7). When the temperature drops below the predetermined temperature T0, the high expansion portion 82 contracts more than the low expansion portion 81 does. As a result, the deformation portion 80 deforms outward in the first radial direction (symbol B in FIG. 7).

The deformation of the deformable portion 80 changes the distance in the first radial direction between the free end of the deformable portion 80 and the first axis O1. Specifically, the distance in the first radial direction between the free end of the deformable portion 80 and the first axis O1 at the predetermined temperature T0 is defined as R0, and the distance between the free end of the deformable portion 80 and the first axis O1 when the temperature rises is Assuming that the distance in the first radial direction is R1, the difference between the distance R0 and the distance R1 is the radial change amount ΔR1 in the first radial direction when the temperature rises. On the other hand, when the distance in the first radial direction between the free end of the deformable portion 80 and the first axis O1 when the temperature drops is R2, the difference between the distances R0 and R2 is the difference between the distances R0 and R2 in the first radial direction when the temperature drops. is the amount of change in radius ΔR2 at . Note that the radial deformation amounts ΔR1 and ΔR2 gradually increase from the fixed end toward the free end.

Then, the average diameter of the balance wheel 62 can be reduced or expanded according to the radius change amounts ΔR1 and ΔR2, and the moment of inertia of the balance wheel 62 about the first axis O1 can be changed. That is, when the temperature rises, the average diameter of the balance wheel 62 can be reduced to reduce the moment of inertia. When the temperature drops, the average diameter of the balance wheel 62 can be increased to increase the moment of inertia. Thereby, the temperature characteristic of the moment of inertia can be corrected.

By the way, if the deformed portion is not formed in a desired shape due to manufacturing variations or the like, the amount of deformation of the deformed portion 80 due to temperature changes will vary, and there is a possibility that the temperature characteristics of the deformed portion 80 will not be accurately corrected. be.

Therefore, in this embodiment, the position of the center of gravity of the weight portion 102 in the first circumferential direction can be changed according to the temperature coefficient of the deformation portion 80 . Specifically, as shown in FIG. 5, the reference position is the position where the center of gravity G of the weight portion 102 and the second axis O2 are aligned in the first axis direction.

8 and 9 are side views corresponding to FIG. 5 for explaining the operation of the adjusting section 64. FIG. 10 and 11 are partial plan views of the balance 54 for explaining the operation of the adjusting section 64. FIG.
As shown in FIGS. 8 and 10, when the temperature coefficient of the deformation portion 80 is higher than the desired value, the weight portion 102 is rotated around the second axis O2 so that the center of gravity G of the weight portion 102 moves to the deformation portion 80. to the fixed end of the As a result, compared to when the weight 102 is at the reference position, the amount of change in the radius of the weight 102 due to temperature changes can be reduced, and the moment of inertia of the balance wheel 62 can be reduced.

On the other hand, as shown in FIGS. 9 and 11, when the temperature coefficient of the deformation portion 80 is lower than the desired value, the weight portion 102 is rotated around the second axis O2 to deform the center of gravity G of the weight portion 102. It is moved toward the free end of the portion 80 . As a result, compared to when the weight 102 is at the reference position, the amount of radial deformation of the weight 102 with respect to temperature changes can be increased, and the moment of inertia of the balance wheel 62 can be increased.

As described above, according to the present embodiment, the weight portion 102 having the center of gravity G at a position eccentric to the second axis O2 is configured to be rotatable around the second axis O2.
According to this configuration, the amount of radial deformation of the deformable portion 80 varies depending on the position in the first circumferential direction. The amount of radial deformation of 102 can be changed (adjusted).
In particular, in this embodiment, the center of gravity G of the weight 102 can be changed continuously in the circumferential direction by changing the rotational position of the weight 102, so that the amount of radial deformation of the weight 102 can be finely adjusted.
Moreover, since the weight portion 102 rotates in a state where the movement in the first radial direction is restricted by the deformation portion 80 and the head portion 116, the weight portion 102 moves in the first radial direction as the weight portion 102 rotates. can be suppressed. As a result, fluctuations in the average diameter of the balance wheel 62 due to changes in the position of the center of gravity of the weight portion 102 can be suppressed.
As a result, it is possible to easily adjust the temperature coefficient with high precision while suppressing the rate change, and to provide a high-quality balance 54 with excellent temperature compensation performance.

In the present embodiment, the configuration is such that the deformation portion 80 is formed by overlapping the low expansion portion 81 and the high expansion portion 82 .
According to this configuration, the deformation of the deformation portion 80 changes the average diameter of the balance wheel 62 to correct the temperature characteristic of the moment of inertia.
Moreover, by providing the deformable portion 80 as a bimetal only on the rim portion 73 of the balance 54, the degree of freedom in designing the connecting portion 70 and the like can be improved compared to the case where the deformable portion is constituted by the entire balance body. In addition, since the deformable portion 80 extends in a cantilever manner, the amount of radial deformation of the deformable portion 80 with respect to temperature changes gradually increases from the fixed end toward the free end. Therefore, by changing the center of gravity G of the weight portion 102 in the circumferential direction, the amount of radial deformation of the weight portion 102 with respect to temperature changes can be gradually reduced or increased. As a result, it is possible to more easily adjust the temperature characteristic of the moment of inertia.

In the present embodiment, the weight portion 102 is arranged outside the deformation portion 80 in the first radial direction (second axial direction).
According to this configuration, the weight 102 can be operated from the outside of the balance 54, so that the temperature characteristics can be easily adjusted.

In this embodiment, the shaft portion 115 and the weight portion 102 are formed separately.
According to this configuration, it is possible to select suitable materials for each of the shaft portion 115 and the weight portion 102 . Therefore, it is possible to improve the degree of freedom in design.

In the present embodiment, the edge of the deformation portion 80 facing in the first axial direction is formed parallel to the chamfered portion 120 with the chamfered portion 120 facing in the first axial direction.
According to this configuration, it is possible to suppress the amount of protrusion of the weight portion 102 from the deformation portion 80 in the first axis direction in a state in which the chamfered portion 120 faces the first axis direction. As a result, it is possible to suppress an increase in the size of the balance wheel 62 in the direction of the first axis.
Further, when the weight portion 102 is operated, the tool and the weight portion 102 can be prevented from rotating by holding the weight portion 102 using the chamfered portion 120 . Therefore, since it is not necessary to separately provide a tool locking portion in the weight portion 102, the degree of freedom in designing the weight portion 102 can be improved.

Since the movement 2 and the timepiece 1 of the present embodiment are provided with the balance 54 described above, it is possible to provide a high-quality movement 2 and timepiece 1 with little rate variation.

(Second embodiment)
Next, a second embodiment according to the invention will be described. FIG. 12 is a partial cross-sectional view of the balance 54 according to the second embodiment. 13 is a view in the direction of arrow XIII of FIG. 12. FIG. This embodiment differs from the above-described first embodiment in that a shaft portion 201 and a weight portion 202 are integrally formed in an adjusting portion 200 .
The adjusting portion 200 shown in FIGS. 12 and 13 includes an engaging portion 100 and a pin member 210. As shown in FIG.
A small diameter portion 111 of the engaging portion 100 is inserted into the mounting hole 85 .

The pin member 210 has a shaft portion 201 and a weight portion 202 .
The shaft portion 201 is press-fitted into the engaging portion 100 through the mounting hole 85 . Thereby, the pin member 210 is configured to be rotatable around the second axis O2 together with the engaging portion 100 .

The weight portion 202 is formed at the outer end portion of the shaft portion 201 in the direction of the second axis. Weight portion 202 has a larger diameter than shaft portion 201 . The weight portion 202 sandwiches the deformable portion 80 between itself and the step surface 112 of the engaging portion 100 in the second axial direction. Thereby, the movement of the weight portion 202 in the second axial direction with respect to the deformation portion 80 is restricted.

As shown in FIG. 13, weight 202 is formed in a circular shape centered at a position eccentric from second axis O2 in side view. Accordingly, in a side view, the center of gravity G of the weight portion 202 is eccentric from the second axis O2. However, the shape of the weight portion 202 can be changed as appropriate.

A tool locking portion 211 is formed on the outer end surface of the weight portion 202 in the direction of the second axis. The tool locking portion 211 is a groove that passes through the center of gravity G and extends linearly along the second radial direction. The tool locking portion 211 is configured so that a tool can be locked. That is, the adjusting portion 200 is configured to be rotatable around the second axis O2 via the tool locked to the tool locking portion 211 . Note that the tool locking portion 211 is not limited to a groove as long as it can be locked to a tool.

According to this embodiment, by rotating the tool around the second axis O2 in a state where the tool is latched to the tool latching portion 211, the adjusting portion 200 rotates around the second axis O2. As a result, the center of gravity G of the weight portion 202 moves in the first circumferential direction. As a result, the same effects as those of the above-described first embodiment can be obtained.
Furthermore, in this embodiment, since the shaft portion 201 and the weight portion 102 are integrally formed, the number of parts can be reduced and the configuration can be simplified.

(Third embodiment)
Next, a third embodiment according to the present invention will be described. FIG. 14 is a perspective view of the balance 54 according to the third embodiment. This embodiment differs from the above-described embodiments in that the mounting position of the adjusting portion 301 can be changed.
In the balance 54 shown in FIG. 14, a plurality of mounting holes 310 are formed in each deformation portion 80 . In this embodiment, the mounting holes 310 are formed at intervals in the first circumferential direction.

15 is a cross-sectional view along line XV-XV of FIG. 14. FIG.
As shown in FIGS. 14 and 15 , the adjustment portion 301 is detachably attached to the deformation portion 80 through at least one of the attachment holes 310 .

A male threaded portion 311 is formed on the shaft portion 115 of the pin member 101 in the adjusting portion 301 . The male threaded portion 311 is formed on a portion of the shaft portion 115 that protrudes inward in at least the deformation portion 80 in the second axial direction.

A female screw portion 321 is formed on the inner peripheral surface of the engaging portion 320 . The engaging portion 320 is detachably attached to the shaft portion 115 by screwing the female thread portion 321 onto the male thread portion 311 .

In this embodiment, in addition to the same effects as those of the first embodiment described above, the following effects are achieved.
That is, since a plurality of mounting holes 310 are formed in the deformation portion 80, the number of adjustment portions 301 to be mounted on the deformation portion 80 and the mounting positions of the adjustment portions 301 can be changed. As a result, the temperature characteristic of the moment of inertia can be adjusted with higher accuracy and in a wider range.

(Other modifications)
The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in the above-described embodiment, the case where a bimetal is used as the deformable portion 80 has been described, but the configuration is not limited to this. The deformable portion may have a structure in which the average diameter of the balance wheel changes due to relative deformation of the high expansion portion and the low expansion portion due to temperature changes. In this case, for example, one of the high-expansion portion and the low-expansion portion of the balance wheel is used to form the lobe portion, and the other of the high-expansion portion and the low-expansion portion is used to form the rim portion. good too. In this case, the rim portion is not limited to being cantilevered, and may be double-supported. That is, in the temperature-compensating balance according to the present invention, it is sufficient that a part of the balance (balance body) other than the balance has a deformed portion.

In the embodiment described above, the configuration in which the weight portion is arranged outside the deformation portion 80 in the first radial direction has been described, but the configuration is not limited to this. The weight portion may be arranged inside the deformation portion 80 in the first radial direction or on both sides in the first axial direction.
Although the configuration in which the adjusting section is attached to the deformation section 80 through the attachment hole has been described in the above-described embodiment, the configuration is not limited to this configuration. The adjusting section may be configured to be rotatable about the second axis while at least the weight section is restricted from moving along the second axis.
In the above-described embodiment, the configuration in which the moment of inertia is adjusted by the adjuster has been described. In addition, a screw or the like may be separately provided to adjust the moment of inertia of the balance wheel.

In addition, it is possible to appropriately replace the constituent elements in the above-described embodiment with well-known constituent elements without departing from the scope of the present invention, and the modifications described above may be combined as appropriate.

1... Clock 2... Movement 54... Balance 62... Balance wheel (balance body)
63 Hair spring 64, 200, 300 Adjusting part (balance body)
80 Deformation portion 102, 202 Weight portion 310 Mounting hole (mounting portion)

Claims (9)

a stem extending along a first axis;
a balance main body provided on the main body so as to be rotatable about the first axis by the power of a balance spring and having a high expansion portion and a low expansion portion with different coefficients of thermal expansion;
The balance body is
a deformable portion that is deformable in a radial direction perpendicular to the first axis in response to temperature changes due to the difference in coefficient of thermal expansion between the high expansion portion and the low expansion portion;
It has a weight portion having a center of gravity at a position eccentric to the second axial line along the radial direction. and an adjustment part rotatably attached to the deformation part. The deformation portion is a bimetal in which the high expansion portion and the low expansion portion are overlapped in the radial direction and extend along the circumferential direction around the first axis,
2. The temperature-compensating balance according to claim 1, wherein the balance body has a connecting portion that connects the first end of the deformation portion in the circumferential direction and the balance. The adjustment unit
a shaft portion that extends along the second axis and is supported by the deformation portion;
3. The temperature-compensating balance according to claim 1, further comprising: the weight portion of the shaft portion positioned radially outwardly of the deformation portion. 4. The temperature compensating balance according to claim 3, wherein said shaft and said weight are integrally formed. 4. The temperature-compensating balance according to claim 3, wherein said shaft and said weight are formed separately. A chamfered portion is formed in the weight portion along a tangential direction of an imaginary circle centered on the second axis in a side view viewed from the radial direction,
6. The edge of the deformation portion facing the first axial direction is formed parallel to the chamfered portion in a state in which the chamfered portion faces the first axial direction. The temperature-compensated balance according to any one of the items. 7. The deformable portion according to any one of claims 1 to 6, wherein mounting portions to which the adjusting portion is detachably mounted are arranged at intervals in a circumferential direction around the first axis. The temperature-compensated balance described in . A movement comprising the temperature-compensated balance according to any one of claims 1 to 7. A timepiece comprising the movement according to claim 8 .

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