JP6025203B2 - Temperature-compensated balance, movement for watch, mechanical watch, and method for manufacturing temperature-compensated balance - Google Patents

Description

  The present invention relates to a temperature-compensated balance, a timepiece movement, a mechanical timepiece, and a method for producing a temperature-compensated balance.

A governor of a mechanical timepiece is generally composed of a balance with a balance and a hairspring. Of these, the balance with hair is a member that vibrates by rotating forward and backward periodically around the true rotation axis, and it is important that the vibration cycle is set within a predetermined value. This is because if the vibration period deviates from the specified value, the rate of the mechanical timepiece (timepiece delay, degree of advancement) changes. However, the vibration cycle is likely to change due to various causes, and for example, changes due to temperature changes.
Here, the vibration period T is expressed by the following equation (1).

In the above formula (1), I represents “the moment of inertia of the balance”, and K represents “the spring constant of the hairspring”. Therefore, when the moment of inertia of the balance or the spring constant of the hairspring changes, the vibration period also changes.
Here, the metal material used for the balance with hairspring is generally a material having a positive coefficient of linear expansion, and expands as the temperature rises. As a result, the balance wheel expands in diameter and increases the moment of inertia. Moreover, since the Young's modulus of the steel material generally used for the hairspring has a negative temperature coefficient, the spring constant is lowered by the temperature rise.

  As described above, when the temperature rises, the moment of inertia increases and the spring constant of the mainspring decreases. Therefore, as apparent from the above formula (1), the vibration period of the balance with hairspring becomes a characteristic that is short at a low temperature and long at a high temperature. For this reason, the time characteristic of the timepiece is such that it proceeds at a low temperature and is delayed at a high temperature.

Thus, for example, the following two methods are known as measures for improving the temperature characteristic of the vibration cycle of the balance with hairspring.
As a first method, instead of making the balance wheel into a circular shape that forms a complete closed loop, the balance wheel is divided into two arcuate portions in the circumferential direction, and each arcuate portion has a coefficient of thermal expansion. A method is known in which metal plates made of different materials are formed of bimetals joined in the radial direction, and one end portion in the circumferential direction of the arcuate portion is a fixed end and the other end portion in the circumferential direction is a free end (patent) Reference 1).

  Normally, as described above, the balance wheel expands due to thermal expansion as the temperature rises, so that the effective moment of inertia increases. However, according to the first method, when the temperature rises, the balance wheel is made of bimetal. The arcuate portion deforms inward so that the free end side moves inward in the radial direction due to the difference in thermal expansion coefficient. As a result, the average diameter of the balance wheel can be reduced, the effective moment of inertia can be reduced, and the temperature characteristic of the moment of inertia can have a negative slope. As a result, the moment of inertia can be changed to such an extent that the temperature dependency of the hairspring can be offset, and the temperature dependency of the vibration cycle of the balance with hairspring can be kept low.

As a second method, by adopting a constant elastic material such as coelin bar as a material for the hairspring, the temperature coefficient of Young's modulus near the operating temperature range of the watch (for example, 23 ° C. ± 15 ° C.) is positive. It is a method.
According to the second method, the change in the moment of inertia of the balance with respect to the temperature can be canceled by canceling the linear expansion coefficient of the balance wheel and the linear expansion coefficient of the balance spring within the above operating temperature range. The temperature dependency of the vibration cycle of the balance with hairspring can be kept low.

Japanese Patent Publication No. 43-26014

By the way, in the first method described above, the bimetallic arc-shaped portion is formed by joining the radially inner metal plate and the radially outer metal plate having different thermal expansion coefficients. Examples of the joining method include brazing and pressure bonding. However, with these methods,
Since the finish depends on the joining conditions and the like at that time, it is difficult to ensure a certain shape accuracy. In addition, since the arc-shaped portion is constituted by the two metal plates, there is a possibility that the two metal plates are plastically deformed when brazing, pressure bonding, or forming each arc-shaped portion by cutting.

  For these reasons, it is difficult to finish the arcuate portion that is a bimetal with high accuracy, and adjustment of the moment of inertia and setting of the temperature compensation amount are likely to be unstable. In addition, iron-based materials (low thermal expansion materials) such as invar are generally used as the material for the metal plate disposed on the radially inner side, but there is a problem that rust occurs unless a plating process or the like is performed. It was. Therefore, it takes time to manufacture and there is room for improvement.

  In the second method described above, when the balance spring is made of a constant elastic material such as a coelin bar, the temperature coefficient of Young's modulus may greatly change depending on various processing conditions such as the composition at the time of melting and heat treatment. Therefore, a strict manufacturing control process is required, and it is not easy to manufacture the hairspring. Therefore, it may be difficult to make the temperature coefficient of Young's modulus positive near the operating temperature range of the watch.

  The present invention has been made in view of such circumstances, and the purpose thereof is excellent in shape accuracy, can be stably performed as intended for temperature correction, and is not easily rusted. Temperature compensation type balance that can be efficiently produced while suppressing the addition of), a timepiece movement having the same, a mechanical timepiece, and a method for producing the temperature compensation type balance.

The present invention provides the following means in order to solve the above problems.
(1) A temperature-compensated balance according to the present invention is arranged in a circumferential direction around a rotation shaft of the balance stem rotating around the shaft and around the rotation shaft of the balance, and along the circumferential direction of the rotation shaft. A plurality of bimetal portions extending in an arc shape, and a balance wheel having a connecting member for connecting the plurality of bimetal portions and the balance in the radial direction, the bimetal portion including the first member, The second member disposed radially outward from the first member is a laminated body that overlaps in the radial direction, and one end in the circumferential direction is a fixed end connected to the connecting member, The other end is a free end, the first member is made of a ceramic material, and the second member is made of a metal material having a different coefficient of thermal expansion from the first member.

  According to the temperature-compensated balance according to the present invention, when a temperature change occurs, the bimetal portion is bent and deformed in the radial direction from the fixed end as a result of the difference in thermal expansion coefficient between the first member and the second member. The free end of the part can be moved radially inward or outward. Thereby, the position of the free end of a bimetal part can be changed to radial direction. Therefore, the average diameter of the balance wheel can be reduced or expanded, and the moment of inertia of the entire balance of the balance can be changed by changing the distance from the rotation axis of the balance. Thereby, the inclination of the temperature characteristic of the moment of inertia can be changed, and temperature correction can be performed.

  In particular, since the first member of the bimetal part is formed of a ceramic material, it is possible to suppress plastic deformation of the bimetal part, and even if the deformation of the free end is repeated due to temperature correction, the bimetal part has stable accuracy over time. Can be formed.

As mentioned above, since the bimetal part can be formed with excellent shape accuracy while preventing plastic deformation, temperature correction work can be performed stably as intended, and the rate is difficult to change due to temperature change, temperature compensation High quality balance with excellent performance can be obtained.
In addition, since the shape of the bimetal portion can be defined, the degree of freedom in shape of the bimetal portion can be increased, and for example, the temperature compensation amount can be easily controlled by increasing the displacement amount. Moreover, since the first member is a ceramic material, it is difficult to rust even if it is not plated. Therefore, a plating process or the like is unnecessary, and it becomes possible to manufacture efficiently.
In addition, since the inner first member is formed of a ceramic material in the bimetal portion formed by the first member and the second member that overlap each other in the radial direction, thermal deformation of the first member due to temperature change is suppressed. As a result, the desired moment of inertia adjustment amount can be obtained while suppressing the deformation of the bimetal portion according to the temperature change. In other words, since the inner member of the bimetal portion is not a metal or the like but a ceramic material, the amount of deformation of the free end portion of the bimetal can be designed without considering the amount of thermal deformation of the inner member too much. Become. Therefore, the temperature correction of the moment of inertia becomes easy and the correction accuracy can be improved.

(2) In the temperature compensated balance according to the present invention, the first member and the connecting member are integrally formed of a ceramic material, and the second member is a metal having a coefficient of thermal expansion different from that of the first member. An electroformed product made of a material is preferable.

In this case, since the first member constituting the connecting member and the bimetal portion of the balance wheel is integrally formed of a ceramic material, semiconductor manufacturing technology (technology including photolithography technology, etching processing technology, etc.) is used. For example, it can be integrally formed from a silicon substrate with excellent shape accuracy. In addition, since the semiconductor manufacturing technique is used, it can be formed in a desired fine shape without applying an extra external force to the connecting member and the first member.
On the other hand, since the 2nd member which comprises a bimetal part is an electroformed product, it can be joined with respect to a 1st member by the simple operation | work only to grow a metal material by electroforming. Therefore, unlike the conventional methods such as brazing and crimping, the second member can be joined without applying an extra external force to the first member. Therefore, it is possible to prevent plastic deformation of the bimetal part and to form the bimetal part with excellent shape accuracy.

(3) In the temperature-compensated balance according to the present invention, the second member includes a second engagement portion that engages with the first engagement portion formed on the first member, and maintains the engagement. It is preferable that the first member is bonded as it is.

  In this case, since the joint strength between the first member and the second member can be increased by the engagement between the first engagement portion and the second engagement portion, the operation reliability as the bimetal portion is improved. be able to. Further, since the second member is positioned in the circumferential direction with respect to the first member by the engagement of both the engaging portions, the second member can be joined to the region targeted by the first member. Also in this point, the operation reliability as a bimetal part can be improved.

(4) In the temperature compensated balance according to the present invention, it is preferable that the first member and the second member are joined via an alloy layer.

  In this case, since the 1st member and the 2nd member are joined via the alloy layer, the joint strength of both members can be raised and the operation reliability as a bimetal part can be improved.

(5) In the temperature compensated balance according to the present invention, it is preferable that a weight portion is provided at a free end of the bimetal portion.

  In this case, since the weight of the free end of the bimetal portion can be increased by the weight portion, the temperature of the moment of inertia can be more effectively corrected with respect to the amount of change in the radial direction at the free end. Therefore, it is easy to improve the temperature compensation performance.

(6) In the temperature-compensated balance according to the present invention, the first member and the connecting member are made of any material of Si, SiC, SiO ₂ , Al ₂ O ₃ , ZrO ₂ , or C. It is preferable that

In this case, Si, SiC, SiO ₂ , Al ₂ O ₃ , ZrO ₂ , or C is employed as the ceramic material, so that it is possible to suitably perform etching processing, particularly dry etching processing. Therefore, the connecting member and the first member can be formed more easily and efficiently, and the manufacturing efficiency can be further increased.

(7) In the temperature-compensated balance according to the present invention, the second member is preferably made of any material of Au, Cu, Ni, Ni alloy, Sn, or Sn alloy.

  In this case, since Au, Cu, Ni, Ni alloy, Sn, or Sn alloy is adopted as the metal material, the metal material can be grown smoothly by electroforming, and the second member is efficiently formed. It is possible. Therefore, it is easy to further improve the manufacturing efficiency.

(8) A timepiece movement according to the present invention includes a barrel wheel having a power source, a train wheel that transmits the rotational force of the barrel wheel, an escapement mechanism that controls rotation of the train wheel, and the escapement mechanism. And a temperature-compensated balance according to the present invention.

  According to the timepiece movement according to the present invention, the temperature-compensated balance with high temperature compensation performance as described above is provided, so that it is possible to obtain a high-quality timepiece movement with less error in rate.

(9) A mechanical timepiece according to the present invention includes the timepiece movement according to the present invention.

  According to the mechanical timepiece of the invention, since the timepiece movement described above is provided, a high-quality mechanical timepiece with less error in rate can be obtained.

(10) A method for producing a temperature-compensated balance according to the present invention is a method for producing the temperature-compensated balance according to the present invention, wherein a ceramic substrate is processed by a semiconductor manufacturing technique, and a plurality of the connection members are formed on the connecting member. The first member is integrally connected, and an electroforming guide wall that defines an open space for electroforming between the first member and the first member is integrally connected to the first member. A substrate processing step for forming a precursor, and the second member is formed by growing the metal material in the open space for electroforming in the precursor by electroforming, and the first member and the second member And a removing step of removing the electroforming guide wall from the first member. The electroforming step of forming the bimetal portion joined in a radial direction.

According to the method for producing a temperature-compensated balance according to the present invention, the same operational effects as those of the above-described temperature-compensated balance can be achieved. In other words, since the bimetal part can be formed with excellent shape accuracy while preventing plastic deformation, the temperature correction work can be performed stably as intended, and the high-quality temperature compensation performance that does not easily change the rate due to temperature changes It can be an excellent balance with a balance.
In particular, during the substrate processing step, in addition to the connecting member and the first member, a precursor in which electroforming guide walls are integrally connected is formed. Therefore, the electroforming open space defined between the electroforming guide wall and the first member can be formed with excellent shape accuracy. In the electroforming process, the second member is formed by growing a metal material in the open space for electroforming, so that the second member having excellent shape accuracy can be formed. It is possible to obtain a high-quality bimetal part having Thereby, the effect mentioned above can be achieved more remarkably.

(11) In the method for producing a temperature compensated balance according to the present invention, after the electroforming step, a heat treatment step of heat-treating the precursor on which the bimetal portion is formed in a predetermined temperature atmosphere for a predetermined time. Preferably it is done.

  In this case, the second member is joined to the first member by electroforming to form a bimetal portion, and then heat treatment is performed. Therefore, the metal material forming the second member that is an electroformed product is used as the first member. Can be diffused along the interface between the first member and the second member, and an alloy layer can be formed between the first member and the second member. Thereby, a 1st member and a 2nd member can be joined via an alloy layer, and the joint strength of both members can be raised. Therefore, the operation reliability as a bimetal part can be improved.

  According to the present invention, shape accuracy is excellent, temperature correction work can be performed stably as intended, and it is difficult to rust and can be efficiently manufactured while suppressing the application of extra external force (stress). A temperature compensated balance with improved temperature compensation performance can be obtained.

It is a figure which shows embodiment which concerns on this invention, Comprising: It is a block diagram of the movement of a mechanical timepiece. It is a perspective view of the balance (temperature compensation type balance) which comprises the movement shown in FIG. It is AA sectional drawing shown in FIG. It is a perspective view of the balance wheel which comprises the balance shown in FIG. It is BB sectional drawing shown in FIG. FIG. 5 is a process diagram when the balance wheel shown in FIG. 4 is manufactured, and is a cross-sectional view showing a state in which a silicon oxide film is formed on a silicon substrate. FIG. 7 is a cross-sectional view showing a state in which arc-shaped grooves are formed in the silicon oxide film from the state shown in FIG. 6. It is a perspective view of the state shown in FIG. FIG. 8 is a cross-sectional view showing a state in which a resist pattern is formed on a silicon oxide film from the state shown in FIG. 7. FIG. 10 is a perspective view of the state shown in FIG. 9. FIG. 10 is a top view of the state shown in FIG. 9. FIG. 10 is a cross-sectional view showing a state where the silicon oxide film is selectively removed from the state shown in FIG. 9 using the resist pattern as a mask. It is a perspective view of the state shown in FIG. It is sectional drawing which shows the state which removed the silicon substrate selectively from the state shown in FIG. 12 by using a resist pattern and a silicon oxide film as a mask. It is a perspective view of the state shown in FIG. It is sectional drawing which shows the state which removed the resist pattern from the state shown in FIG. 14, and formed the precursor. It is a perspective view of the state shown in FIG. FIG. 17 is a cross-sectional view illustrating a state in which the precursor illustrated in FIG. 16 is reversed and then bonded to the adhesive layer of the first support substrate. It is a perspective view of the state shown in FIG. FIG. 19 is a cross-sectional view showing a state in which the second member is formed by growing gold by electroforming in the precursor electroforming open space from the state shown in FIG. 18. It is a perspective view of the state shown in FIG. FIG. 21 is a cross-sectional view showing a state in which the precursor is removed from the first support substrate and reversed again from the state shown in FIG. 20 and then bonded to the adhesive layer of the second support substrate. It is sectional drawing which shows the state which removed the electrocasting guide wall from the state shown in FIG. It is a perspective view which shows the state which removed the 2nd support substrate from the state shown in FIG. FIG. 25 is a cross-sectional view showing a state where the silicon oxide film is removed from the state shown in FIG. 24. It is a perspective view of the state shown in FIG. It is a perspective view which shows the modification of the balance wheel which concerns on this invention. It is a perspective view which shows the modification of the balance with the present invention. It is an enlarged top view of the bimetal part in the balance shown in FIG. It is a perspective view which shows another modification of the balance with the present invention. It is an enlarged top view of the bimetal part in the balance shown in FIG. It is a figure which shows the optimal heat processing temperature in each combination while showing an example of the combination of the material of a 1st member and the material of a 2nd member which comprises the bimetal part which concerns on this invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.
[Configuration of mechanical watch, watch movement, temperature compensation balance]
As shown in FIG. 1, the mechanical timepiece 1 of the present embodiment is, for example, a wristwatch, and includes a movement (timepiece movement) 10 and a casing (not shown) that houses the movement 10.

(Composition of movement)
This movement 10 has a base plate 11 constituting a substrate. A dial (not shown) is arranged on the back side of the main plate 11. A train wheel incorporated on the front side of the movement 10 is referred to as a front train wheel 28, and a train wheel incorporated on the back side of the movement 10 is referred to as a back train wheel.
A winding stem guide hole 11a is formed in the base plate 11, and a winding stem 12 is rotatably incorporated therein. The winding stem 12 is positioned in the axial direction by a switching device having a setting lever 13, a yoke 14, a yoke spring 15 and a back presser 16. In addition, a chichi wheel 17 is rotatably provided on the guide shaft portion of the winding stem 12.

  Under such a configuration, the winding stem 12 is rotated in a state where the winding stem 12 is at the first winding stem position (0th stage) closest to the inside of the movement 10 along the rotation axis direction, for example. As a result, the chisel wheel 17 rotates through the rotation of the pinion wheel (not shown). And when this chi-wheel 17 rotates, the round hole wheel 20 which meshes with this rotates. And when this round hole wheel 20 rotates, the square wheel 21 which meshes with this rotates. Further, when the square hole wheel 21 rotates, the mainspring (power source) (not shown) housed in the barrel complete 22 is wound up.

  The front wheel train 28 of the movement 10 includes a second wheel 25, a third wheel 26 and a fourth wheel 27 in addition to the barrel wheel 22, and has a function of transmitting the rotational force of the barrel wheel 22. . Further, an escapement mechanism 30 and a speed control mechanism 31 for controlling the rotation of the front train wheel 28 are disposed on the front side of the movement 10.

The center wheel 25 is a gear that meshes with the barrel complete 22. The third wheel 26 is a gear that meshes with the second wheel 25. The fourth wheel 27 is a gear that meshes with the third wheel 26.
The escapement mechanism 30 is a mechanism that controls the rotation of the front wheel train 28 described above, and an escape wheel 35 that meshes with the fourth wheel 27 and an ankle that moves the escape wheel 35 and rotates it regularly. 36.
The speed regulating mechanism 31 is a mechanism for regulating the escapement mechanism 30, and includes a balance (temperature compensated balance) 40.

(Structure of balance)
As shown in FIGS. 2 and 3, the balance with hairspring 40 rotates around an axis (rotation axis) O (rotates about the axis) and a balance wheel 42 attached to the balance 41. And a balance spring (spring spring) 43, and is a member that is rotated forward and backward around the axis O with a constant vibration cycle by the power transmitted from the balance spring 43.
In the present embodiment, a direction orthogonal to the axis O is referred to as a radial direction, and a direction around the axis O is referred to as a circumferential direction.

  The balance stem 41 is a rotating shaft body that extends vertically along the axis O, and the upper end portion and the lower end portion thereof are pivotally supported by members (not shown) such as a base plate and a balance holder that constitute the above-described movement 10. A substantially intermediate portion in the vertical direction of the balance stem 41 is a large diameter portion 41a having the largest diameter. Further, in the balance stem 41, a cylindrical swing seat 45 is externally provided coaxially with the axis O at a portion located below the large diameter portion 41a. The swing seat 45 has an annular flange 45a projecting outward in the radial direction, and a swing stone 46 for swinging the ankle 36 is fixed to the flange 45a. .

The hairspring 43 is, for example, a flat whiskers wound spirally in one plane, and the inner end portion of the hairspring 43 is fixed to a portion located above the large-diameter portion 41 a of the balance stem 41 via a whisker ball 47. ing. The balance spring 43 plays a role of storing power transmitted from the fourth wheel 27 to the escape wheel 35 and transmitting the power to the balance wheel 42 as described above.
In addition, the hairspring 43 of the present embodiment is formed of a general steel material having a negative temperature coefficient of Young's modulus, and has a characteristic that the spring constant decreases as the temperature increases.

  As shown in FIGS. 4 and 5, the balance wheel 42 includes three bimetal portions 50 arranged in the circumferential direction around the axis O of the balance stem 41, and the three bimetal portions 50 and the balance stem 41. And a connecting member 51 that is connected in the radial direction.

The connecting member 51 is disposed coaxially with the axis O, and includes a connecting disc 55 having an axial hole 55a formed at the center thereof, and a connecting ring that surrounds the connecting disc 55 with a gap from the outside in the radial direction. 56, and three connection bridges 57 that connect the outer periphery of the connection disk 55 and the inner periphery of the connection ring 56.
The connecting member 51 is integrally attached to the balance stem 41 by being fixed to the large-diameter portion 41a of the balance stem 41 by, for example, press fitting through the shaft hole 55a.

  Three support protrusions 58 protrude from the outer peripheral portion of the connection ring 56 toward the outer side in the radial direction. These three support protrusions 58 are equally arranged with a certain interval in the circumferential direction. Each support protrusion 58 is formed with an inclined surface 58a that is inclined toward one side in the circumferential direction (in the direction of arrow T shown in FIG. 4) from the outer peripheral portion of the coupling ring 56 toward the outer side in the radial direction. ing.

  The connection bridge 57 is a member that connects the connection disk 55 and the connection ring 56 in the radial direction, and is evenly arranged at a certain interval in the circumferential direction. In the illustrated example, the three connection bridges 57 and the three support protrusions 58 are disposed in a state where the positions thereof are shifted from each other in the circumferential direction. However, the present invention is not limited to this case.

  The bimetal part 50 is a laminated body in which a first member 60 located on the inner side in the radial direction and a second member 61 located on the outer side in the radial direction of the first member 60 are joined to each other in the radial direction. Yes, it is formed in a strip shape extending in an arc shape along the circumferential direction. And this bimetal part 50 is arrange | positioned in the state which left the space | interval outer side of the connection ring 56 in the radial direction, and was located in a line with the circumferential direction, and fixed end 50A with which the one end part of the circumferential direction was connected with the connection member 51. It is said that.

  Specifically, the fixed end 50 </ b> A of the bimetal part 50 is connected to a surface opposite to the inclined surface 58 a in the support protrusion 58 protruding from the connection ring 56. The bimetal portion 50 extends from the support protrusion 58 in the arrow T direction along the circumferential direction. Thereby, the three bimetal parts 50 are equally arrange | positioned in the circumferential direction.

The other end in the circumferential direction of the bimetal portion 50 is a free end 50B that is movable in the radial direction by bending deformation accompanying a temperature change. The free end 50 </ b> B is mainly formed by the first member 60, and is formed wider in the radial direction than the other parts of the bimetal portion 50 by projecting inward in the radial direction.
Thereby, the weight of the free end 50 </ b> B is designed to be heavier than the other parts of the bimetal part 50. Moreover, a weight hole 62 is formed in the free end 50B of the present embodiment, and a weight portion 65 (see FIGS. 2 and 3) is attached to the weight hole 62 by, for example, press fitting. Therefore, the free end 50B is designed to be sufficiently heavier than the other parts of the bimetal portion 50, with the weight of the weight portion 65 added.

2 and 3, the weight portion 65 is formed like a rivet with a shaft portion 65a inserted into the weight hole 62 and a head portion 65b exposed on the upper surface of the free end 50B. Take the case as an example.
Further, as shown in FIG. 4, a portion of the free end 50 </ b> B facing inward in the radial direction is opposed to the inclined surface 58 a of the support protrusion 58, and is opposed to the inclined surface 66 inclined according to the inclination of the inclined surface 58 a. It is said that.

  Incidentally, as described above, the bimetal portion 50 is formed by laminating the first member 60 and the second member 61 in the radial direction as shown in FIGS. 4 and 5. It is made of materials with different coefficients of thermal expansion.

Specifically, the first member 60 located inside in the radial direction is formed of a ceramic material, which is a low thermal expansion material, in this embodiment, silicon (Si). On the other hand, the second member 61 located on the outer side in the radial direction is a high thermal expansion material having a larger coefficient of thermal expansion than the first member 60, and is an electroforming metal material, which is gold (Au) in this embodiment. Is formed.
Therefore, when the temperature rises, the second member 61 expands more thermally than the first member 60, so that the bimetal portion 50 has the free end 50B moving inward in the radial direction with the fixed end 50A as a base point. Bends and deforms.

  Further, the first member 60 of this embodiment is formed integrally with the connecting member 51. Accordingly, the connecting member 51 is also formed of silicon, as with the first member 60. That is, in the balance wheel 42 constituting the balance 40, the connecting member 51 and the first member 60 are made of silicon, and only the second member 61 is made of gold.

Moreover, the second member 61 is an electroformed product formed by electroforming, and is tightly bonded to the first member 60 during the gold growth process by electroforming. In addition, both end portions in the circumferential direction of the second member 61 are formed with wedge-shaped portions (second engaging portions) 67 having a V-shape in a plan view and gradually extending in the circumferential direction toward the inner side in the radial direction. The first member 60 is joined in a state of being engaged with a V-shaped concave portion (first engaging portion) 68 formed on the side of the first member 60.
Thereby, the second member 61 is joined to the first member 60 in a state where the second member 61 is positioned in the circumferential direction.

[Temperature correction method]
Next, a method for correcting the temperature of the moment of inertia using the balance 40 will be described.
According to the balance with hairspring 40 of the present embodiment, as shown in FIG. 2, when a temperature change occurs, the bimetal portion 50 has the fixed end 50 </ b> A as a base point due to a difference in thermal expansion coefficient between the first member 60 and the second member 61. Since it is bent and deformed in the radial direction, the free end 50B of the bimetal portion 50 can be moved toward the inside or the outside in the radial direction. That is, when the temperature rises, the bimetal part 50 bends and deforms inward in the radial direction, so that the free end 50B can be moved toward the inside in the radial direction. It can be moved outward in the radial direction.

  Therefore, the average diameter of the balance wheel 42 can be reduced or expanded, and the moment of inertia of the balance 40 can be changed by changing the distance from the axis O of the balance stem 41. That is, when the temperature rises, the average diameter of the balance wheel 42 can be reduced to reduce the moment of inertia, and when the temperature drops, the average diameter of the balance wheel 42 can be increased to increase the moment of inertia. Can be bigger. Thereby, the inclination of the temperature characteristic of the moment of inertia can be changed to a negative inclination, and temperature correction can be performed.

  That is, even if the hairspring 43 having a negative temperature coefficient of Young's modulus is provided, the moment of inertia can be reduced simultaneously with the decrease of the Young's modulus of the hairspring 43 when the temperature rises. The period can be kept constant and temperature correction can be performed. Further, when the temperature is lowered, the moment of inertia can be increased simultaneously with the increase of the Young's modulus of the hairspring 43, so that the vibration cycle of the balance 40 can be kept constant and the temperature can be corrected.

[Method for manufacturing balance]
Next, a method for manufacturing the balance with hairspring 40 will be described with reference to the drawings.
The method of manufacturing the balance with hairspring 40 includes a step of manufacturing the balance stem 41, a step of manufacturing the balance wheel 42, a step of manufacturing the hairspring 43, and a step of assembling them together. Here, the process of manufacturing the main wheel 42 will be described in detail.

First, as shown in FIG. 6, after preparing a silicon substrate (ceramic substrate) 70 that will later become the connecting member 51 and the first member 60, a silicon oxide film (SiO ₂ ) 71 is formed on the surface thereof. At this time, a silicon substrate 70 having a thickness larger than the thickness of the balance wheel 42 is used. The silicon oxide film 71 is formed by a method such as plasma enhanced chemical vapor deposition (PCVD) or thermal oxidation.

  Here, in order to simplify the description, a case where only one balance wheel 42 is manufactured from a silicon substrate 70 having a square shape in plan view will be described as an example. However, a wafer-like silicon substrate may be prepared and a plurality of balance wheels 42 may be manufactured simultaneously.

  Subsequently, as shown in FIGS. 7 and 8, a part of the silicon oxide film 71 is selectively removed by etching or the like so that three arc-shaped groove portions 72 are arranged at intervals in the circumferential direction. Form. The groove portion 72 is a groove for forming an electroforming guide wall 70 </ b> A to be formed later, and is formed so as to be positioned on the radially outer side than the second member 61.

  Subsequently, as shown in FIGS. 9 to 11, after forming a photoresist on the inner region surrounded by the three groove portions 72 on the silicon oxide film 71, a resist pattern 73 is formed by patterning the photoresist. . At this time, the resist pattern main body 73A patterned according to the shapes of the connecting member 51 and the first member 60, and the guide wall pattern in which the both end portions in the circumferential direction are connected to the resist pattern 73 while entering the three groove portions 72 described above. The resist pattern 73 is formed so as to be composed of 73B.

  Note that the photoresist may be formed by a general method such as spin coating or spray coating. The resist pattern 73 may be formed by patterning a photoresist by a general method such as a photolithography technique.

Subsequently, as shown in FIGS. 12 and 13, a region of the silicon oxide film 71 that is not masked by the resist pattern 73 is selectively removed. Specifically, the silicon oxide film 71 is removed by wet etching using a buffered hydrofluoric acid aqueous solution or etching processing by dry etching such as reactive ion etching (RIE).
Thereby, the silicon oxide film 71 can be left only under the resist pattern 73, and the silicon oxide film 71 can be patterned into a shape following the resist pattern 73.

Subsequently, as shown in FIGS. 14 and 15, regions of the silicon substrate 70 that are not masked by the resist pattern 73 and the silicon oxide film 71 are selectively removed. Specifically, the silicon substrate 70 is removed by etching using dry etching such as deep reactive ion etching (DRIE).
Thereby, the silicon substrate 70 can be left only under the resist pattern 73 and the silicon oxide film 71, and the silicon substrate 70 can be patterned into a shape following the resist pattern 73.

  In particular, the portion of the patterned silicon substrate 70 left under the guide wall pattern 73B functions as an electroforming guide wall 70A.

  Subsequently, as shown in FIGS. 16 and 17, the resist pattern 73 used as a mask is removed. Examples of this removal method include dry etching using fuming nitric acid and dry etching using oxygen plasma.

  Through the above steps, the silicon substrate 70 is processed by semiconductor technology, and the three first members 60 are integrally connected to the connecting member 51, and the open space S for electroforming is formed between each first member 60. The precursor 75 in which the guide wall 70A for electroforming to be defined is integrally connected to each first member 60 can be obtained. (Thus, each process described above is a substrate processing process in the present invention.)

  After the precursor 75 is formed, the second member 61 is formed by growing gold in the electroforming open space S by electroforming, and the first member 60 and the second member 61 are joined to each other. An electroforming process for forming 50 is performed. This electroforming process will be specifically described.

  First, as shown in FIGS. 18 and 19, after preparing the first support substrate 80 in which the adhesive layer 80C is bonded to the substrate body 80A via the electrode layer 80B, for example, the precursor 75 is turned upside down. Then, the patterned silicon oxide film 71 is bonded to the adhesive layer 80C. In the illustrated example, the precursor 75 and the first support substrate 80 are bonded to such an extent that the silicon oxide film 71 is embedded in the adhesive layer 80C.

  The adhesive layer 80C is not particularly limited, but for example, a photoresist is preferably used. In this case, bonding may be performed in a state where the photoresist is in a paste state, and then the photoresist may be cured to a state where the paste is removed.

And after performing the said bonding, as shown in FIG. 18, the part connected to the open space S for electroforming of the precursor 75 among the adhesive layers 80C is selectively removed. Thereby, the electrode layer 80B can be exposed in the open space S for electroforming.
At this time, for example, when the adhesive layer 80 </ b> C is a photoresist, it is possible to easily perform an operation of selectively removing by a photolithography technique.

Subsequently, as shown in FIGS. 20 and 21, electroforming is performed using the electrode layer 80 </ b> B, gold is gradually grown from the electrode layer 80 </ b> B in the electroforming open space S, and the electroforming open space S An electroformed product 81 is produced that fills the interior and further expands the open space S for electroforming. Then, the expanded electroformed product 81 is polished so as to be flush with the precursor 75. Thereby, this electroformed product 81 can be used as the second member 61, and the bimetal portion 50 in which the first member 60 and the second member 61 are joined can be formed.
In addition, when performing the said grinding | polishing, you may grind | polish the silicon substrate 70 of the precursor 75 simultaneously.

At this stage, the above-described electroforming process is completed. In FIGS. 20 and 21, illustration of general components (such as an electroforming tank) necessary for electroforming is omitted.
After the electroforming is completed, a removal step of removing the electroforming guide wall 70A from the first member 60 is performed. This removal step will be specifically described.

  First, as shown in FIG. 22, after preparing the second support substrate 85 in which the adhesive layer 85B is formed on the substrate body 85A, the precursor 75 removed from the first support substrate 80 is reversed again and again, The surface of the silicon substrate 70 opposite to the side on which the silicon oxide film 71 is formed is bonded to the adhesive layer 85B.

Subsequently, as shown in FIG. 23, only the electroforming guide wall 70A of the precursor 75 is selectively removed. Specifically, in the precursor 75, for example, a region other than the electroforming guide wall 70A is covered with a mask (not shown) from above, and is masked by an etching process using dry etching such as deep reactive ion etching (DRIE). The electroforming guide wall 70A which is not present is removed.
At this stage, the removal process is completed.

Subsequently, after the second support substrate 85 is removed as shown in FIG. 24, the remaining silicon oxide film 71 is removed by wet etching using, for example, BHF, as shown in FIGS.
The silicon oxide film 71 is not necessarily removed, but is preferably removed. In FIGS. 25 and 26, since the thickness of the silicon oxide film 71 is exaggerated, a step is generated between the first member 60 and the second member 61. It is slightly (for example, about 1 μm), and is substantially equivalent to no step between the first member 60 and the second member 61 as shown in FIG.

Finally, the balance wheel 42 shown in FIG. 2 can be manufactured by fixing the weight portion 65 to the weight hole 62 by press-fitting or the like.
Thereafter, as described above, the balance 40 and the balance spring 43 manufactured separately and the balance wheel 42 are assembled together to complete the production of the balance 40.

(Function and effect)
As described above, according to the balance with hairspring 40 of the present embodiment, since the first member 60 of the bimetal part 50 is formed of a ceramic material, plastic deformation of the bimetal part 50 can be suppressed, and deformation of the free end 50B can be performed by temperature correction. Even if this is repeated, it is possible to form the bimetal part 50 with stable accuracy over time.
In addition, since the inner first member 60 is formed of a ceramic material in the bimetal portion 50 that is configured by the first member 60 and the second member 61 that overlap each other in the radial direction, the first member 60 that accompanies a change in temperature. Thus, the desired moment of inertia adjustment amount can be obtained while suppressing the deformation of the bimetal portion 50 according to the temperature change. That is, since the inner member of the bimetal portion 50 is not a metal or the like but a ceramic material, the deformation amount of the free end 50B of the bimetal portion 50 can be designed without considering the amount of thermal deformation amount of the inner member. It becomes like this. Therefore, the temperature correction of the moment of inertia becomes easy and the correction accuracy can be improved.

In addition, since the amount of deformation of the free end 50B of the bimetal portion 50 can be reduced when a desired inertia moment adjustment width is secured, a gap around the free end 50B (a space sandwiched between the bimetal portion 50 and the connecting member 51). Thus, the balance 40 can be formed at a high density. Therefore, the desired rigidity can be secured even in the balance formed of the ceramic material.
Further, since the high-density bimetal portion 50 is formed only on the outermost periphery, a desired moment of inertia can be obtained while suppressing the overall weight. That is, by suppressing the weight of the balance with the silicon material (ceramic material), the impact applied to the balance stem 41 when the watch is dropped can be reduced. Therefore, the frequency of occurrence of true bending and true folding can be suppressed, and the reliability of the watch can be improved.

  In addition, since the connecting member 51 and the first member 60 of the balance wheel 42 are integrally formed of silicon, a silicon substrate is utilized by utilizing a semiconductor manufacturing technique (a technique including a photolithography technique, an etching technique, etc.). 70 can be integrally formed with excellent shape accuracy. In addition, since the semiconductor manufacturing technique is used, the connection member 51 and the first member 60 can be formed in a desired fine shape without applying an extra external force.

  On the other hand, since the second member 61 constituting the bimetal part 50 is an electroformed product, the second member 61 can be joined to the first member 60 by a simple operation of growing gold by electroforming. Therefore, unlike the conventional methods such as brazing and pressure bonding, the second member 61 can be joined without applying an extra external force to the first member 60. Therefore, plastic deformation of the bimetal part 50 can be prevented, and the bimetal part 50 can be formed with excellent shape accuracy. Moreover, ceramic materials such as silicon are difficult to plastically deform. Also in this point, the plastic deformation of the bimetal part 50 can be prevented.

As described above, since the bimetal portion 50 can be formed with excellent shape accuracy while preventing plastic deformation, the temperature correction operation can be performed stably as intended, and the rate is difficult to change due to temperature changes. A high-quality balance 40 with excellent compensation performance can be obtained.
Moreover, since the shape of the bimetal part 50 can be prescribed | regulated, the freedom degree of the shape of the bimetal part 50 can be raised, for example, it is easy to control the temperature compensation amount by enlarging the amount of displacement.

Further, when the balance wheel 42 is manufactured, in addition to the connecting member 51 and the first member 60, the precursor 75 in which the electroforming guide wall 70A is integrally formed is formed. Therefore, the electroforming open space S defined between the electroforming guide wall 70A and the first member 60 can be formed with excellent shape accuracy. And in the case of electroforming, since the 2nd member 61 is formed by growing gold in this open space S for electroforming, the 2nd member 61 of the outstanding shape precision can be formed, and, as a result, desired A high-quality bimetal part 50 having a shape can be obtained.
Thereby, the effect mentioned above can be achieved more remarkably.

  Further, since the connecting member 51 and the first member 60 are made of silicon, they are not easily rusted without being plated. In addition, since the second member 61 is gold, it is excellent in rust prevention. By these things, a plating process etc. are unnecessary and it becomes possible to manufacture efficiently.

  Further, since the first member 60 and the second member 61 constituting the bimetal part 50 are engaged with each other also by the engagement of the wedge part 67 and the recessed part 68, the joining strength can be increased, and the bimetal part The operation reliability as 50 can be improved. Further, since the second member 61 is positioned in the circumferential direction with respect to the first member 60 by the engagement, the second member 61 can be joined to a region targeted by the first member 60. Also in this point, the operation reliability as the bimetal part 50 can be improved.

Further, according to the movement 10 of the present embodiment, since the temperature compensation balance 40 having high temperature compensation performance is provided, it is possible to obtain a high-quality movement with less error in yield.
Furthermore, according to the mechanical timepiece 1 of this embodiment provided with the movement 10, a high-quality timepiece having a low rate error is similarly obtained.

(Modification)
In the above embodiment, the weight portion 65 is provided at the free end 50B of the bimetal portion 50. However, the weight portion 65 is not essential and may not be provided. However, since the weight of the free end 50B can be increased by providing the weight portion 65, the temperature of the moment of inertia can be more effectively corrected with respect to the amount of change in the radial direction at the free end 50B. It is easy to improve the temperature compensation performance.
The shape of the weight portion 65 may be determined from the weight of the weight portion 65 and the amount of inertia moment required for the weight portion 65.

Moreover, when providing the weight part 65, it is not restricted to the weight part 65 fixed to the weight hole 62 like the said embodiment by press injection etc., You may change freely.
For example, as shown in FIG. 27, an electroformed product obtained by growing gold in the weight hole 62 by electroforming may be used as the weight portion 90.
In this case, at the time of manufacturing, when part of the adhesive layer 85B is removed and the electrode layer 80B is exposed to the electroforming open space S, the adhesive layer 85B corresponding to the weight hole 62 is simultaneously removed. The electrode layer 80B is exposed. Then, when the second member 61 is formed by growing gold by electroforming, the weight portion 90 may be formed by simultaneously growing gold in the weight hole 62.

  By doing in this way, since the 2nd member 61 and the weight part 90 can be formed simultaneously by one electroforming process, manufacturing efficiency can further be improved. Moreover, since the weight part 90 can be formed, without applying external force to the free end 50B of the bimetal part 50, it is more preferable.

Moreover, in the said embodiment, the 1st member 60 and the 2nd member in the state which engaged the wedge part 67 provided in the both ends of the circumferential direction of the 2nd member 61 with the recessed part 68 by the side of the 1st member 60. Although the case where 61 and 61 are joined was demonstrated, the engagement by the wedge part 67 and the recessed part 68 is not essential and does not need to be provided. However, it is preferable to provide the bonding strength because it is possible to increase the bonding strength and regulate the peeling of the second member 61 from the first member 60 and the displacement in the radial direction and the circumferential direction with respect to the first member 60.
Further, instead of the wedge part 67 and the recessed part 68, another engaging member may be provided on the first member 60 and the second member 61. In addition to the wedge part 67 and the recessed part 68, another engagement member may be provided. Members may be added to the first member 60 and the second member 61.

For example, as shown in FIG. 28 and FIG. 29, two engagement recesses (first engagement portions) 91 that are opened outward in the radial direction are provided on the outer peripheral portion of the first member 60 at intervals in the circumferential direction. Two engaging convex portions (second engaging portions) 92 that protrude toward the inner side in the radial direction on the inner peripheral portion of the second member 61 and engage with the engaging concave portion 91 are provided at intervals in the circumferential direction. It doesn't matter.
Thus, by further adding the engagement recess 91 and the engagement protrusion 92, the bonding strength between the first member 60 and the second member 61 can be further increased, which is more preferable. Note that the number of the engagement concave portions 91 and the engagement convex portions 92 is not limited to two.

30 and 31, the first member 60 and the second member 61 may be joined via an alloy layer 95.
In the case of forming the alloy layer 95, after the second member 61 is formed by an electroforming process, the precursor 75 on which the bimetal portion 50 is formed is heat-treated for a predetermined time in a predetermined temperature atmosphere. Perform the process. By performing the heat treatment in this way, the gold of the second member 61, which is an electroformed product, can be diffused along the bonding interface with the first member 60, and the first member 60 and the first member can be diffused using this diffusion. An alloy layer 95 can be formed between the two members 61.
Even in this case, the bonding strength between the first member 60 and the second member 61 can be increased, and the operation reliability as the bimetal portion 50 can be increased.

  The timing for performing the heat treatment may be after the electroforming process, and may be before or after the electroforming guide wall 70A is removed. However, since the alloy layer 95 is also formed between the electroforming guide wall 70A and the second member 61 by the heat treatment, it is preferably performed after the electroforming guide wall 70A is removed.

  Moreover, in the case of the said embodiment, since the 1st member 60 is a silicon | silicone and the 2nd member 61 is gold | metal | money, it can be performed as about 1000 degreeC as heat processing temperature. The heat treatment can be performed in the air, but is preferably performed in a vacuum atmosphere or in an argon gas or nitrogen gas atmosphere in order to prevent oxidation.

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

  For example, in the above embodiment, the number of the bimetal portions 50 is three, but may be two or four or more. Even in these cases, the bimetal portions 50 may be evenly arranged in the circumferential direction, and similar effects can be obtained. Moreover, the shape of the connection member 51 is an example, and may be changed as appropriate.

  In the above embodiment, a constant elastic material such as Elinvar is used as the material of the hairspring 43, and the second member 61 in the bimetal portion 50 is made of a metal material having a lower thermal expansion coefficient than the first member 60 made of a ceramic material. It may be formed. Even in this case, the temperature characteristic of the moment of inertia can be finely adjusted so as to cancel the positive temperature coefficient of the hairspring 43.

Moreover, in the said embodiment, although the connection member 51 and the 1st member 60 which comprise the balance wheel 42 were made into silicon | silicone, it should just be formed with the ceramic material, and is not limited to silicon.
For example, silicon carbide (SiC), silicon dioxide (SiO ₂ ), sapphire, alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), glassy carbon (C), or the like may be employed as the ceramic material. . Even if any of these is adopted, it is possible to suitably perform the etching process, particularly the dry etching process, and the connecting member 51 and the first member 60 can be formed more simply and efficiently, further increasing the production efficiency. easy.

  In addition, as a ceramic material in this embodiment, it is preferable to have insulation with high electrical resistance. Further, a coating film such as an oxide film or a nitride film may be provided on the surfaces of the connecting member 51 and the first member 60.

The second member 61 constituting the balance wheel 42 is gold. However, the first member 60 may be any metal material that has a different coefficient of thermal expansion (preferably large) and can be electroformed, and is limited to gold. Is not to be done.
For example, Au, Ni, Ni alloy (Ni—Fe, etc.), Sn, Sn alloy (Sn—Cu, etc.) may be employed. Even if any of these is adopted, the metal material can be grown smoothly by electroforming, and the second member 61 can be formed efficiently.

In particular, even if any of the above metal materials is adopted, the alloy layer 95 can be formed by heat treatment. In this case, the combination of ceramic materials on the first member 60 side is particularly preferably silicon (Si) or silicon carbide (SiC).
Note that FIG. 32 shows a preferable heat treatment temperature in the heat treatment step when these combinations are performed. By performing heat treatment at the heat treatment temperature shown in FIG. 32, it is possible to form an alloy layer 95 sufficient to increase the bonding strength.

O ... Axis (rotating axis)
S ... Open space for electroforming 1 ... Mechanical watch 10 ... Movement (watch movement)
22 ... barrel wheel 28 ... front wheel train
30 ... Escapement mechanism 40 ... Balance (temperature compensation type balance)
41 ... balance 42 ... balance wheel 50 ... bimetal part 50A ... fixed end 50B ... free end 51 ... coupling member 60 ... first member 61 ... second member 65, 90 ... weight part 67 ... wedge part (second engagement part) )
68 .. recessed portion (first engaging portion)
70 ... Silicon substrate (ceramic substrate)
70A ... Electroforming guide wall 75 ... Precursor 91 ... Engagement recess (first engagement part)
92 ... engaging convex part (second engaging part)
95 ... Alloy layer

Claims (11)

With the balance rotating around the axis,
A plurality of bimetal portions arranged in a circumferential direction around the rotation axis of the balance shaft and extending in an arc shape along the circumferential direction of the rotation shaft, and each of the plurality of bimetal portions and the balance stem A balance wheel having a connecting member to be connected in the radial direction,
The bimetal portion is a laminated body in which a first member and a second member arranged radially outside the first member overlap in the radial direction, and one end portion in the circumferential direction is connected to the connecting member. The connected fixed end, the other end in the circumferential direction is the free end,
The first member is formed of a ceramic material,
The temperature-compensated balance balance is characterized in that the second member is made of a metal material having a coefficient of thermal expansion different from that of the first member. In the temperature compensated balance according to claim 1,
The first member and the connecting member are integrally formed of a ceramic material,
The temperature-compensated balance balance, wherein the second member is an electroformed product made of a metal material having a coefficient of thermal expansion different from that of the first member. In the temperature compensation type balance according to claim 1 or 2,
The second member includes a second engagement portion that engages with a first engagement portion formed on the first member, and is joined to the first member while maintaining the engagement. A temperature-compensated balance that features In the temperature compensation type balance according to claim 1 or 2,
The temperature compensation type balance with which the first member and the second member are joined via an alloy layer. The temperature-compensated balance according to any one of claims 1 to 4,
A temperature compensated balance with a weight portion provided at a free end of the bimetal portion. In the temperature compensation type balance according to any one of claims 1 to 5,
The temperature-compensated balance balance characterized in that the first member and the connecting member are made of any one material of Si, SiC, SiO ₂ , Al ₂ O ₃ , ZrO ₂ , or C. In the temperature compensation type balance according to any one of claims 1 to 6,
The temperature-compensated balance balance characterized in that the second member is made of any material of Au, Cu, Ni, Ni alloy, Sn, or Sn alloy. A barrel complete with a power source;
A train wheel for transmitting the rotational force of the barrel wheel,
An escapement mechanism for controlling rotation of the train wheel;
A timepiece movement comprising the temperature compensated balance according to claim 1, wherein the escapement mechanism is controlled.   A mechanical timepiece comprising the timepiece movement according to claim 8. A method for producing the temperature-compensated balance according to claim 1,
An electroforming process in which a ceramic substrate is processed by a semiconductor manufacturing technique, and a plurality of the first members are integrally connected to the connecting member, and an open space for electroforming is defined between each of the first members. A substrate processing step in which a guide wall for forming a precursor integrally connected to each of the first members;
The second member is formed by growing the metal material by electroforming in the open space for electroforming in the precursor, and the first member and the second member are joined in a radial direction. An electroforming process for forming the bimetal portion;
And a removing step of removing the electroforming guide wall from the first member. In the manufacturing method of the temperature compensation type balance according to claim 10,
A temperature-compensated balance balance manufacturing method characterized by performing a heat treatment step of heat-treating the precursor on which the bimetal portion is formed in a predetermined temperature atmosphere for a predetermined time after the electroforming step.

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