• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A high quality thermocompensation type sprung balance is provided, which enables the moment of inertia to be easily and precisely adjusted, while suppressing variations affecting the rate, and which exhibits excellent thermal compensation performance. A spring balance of the thermocompensation type according to the invention comprises a balance (62) which is provided with a balance shaft rotating around a first axis by the power of a hairspring and which comprises a high expansion part (82) and a low expansion part (81) having different thermal expansion coefficients. The rocker (62) thus comprises a deformation part (80) which is deformable in a radial direction as a function of a change in temperature, due to the difference between the thermal expansion coefficient of the high expansion part (82) and the coefficient of thermal expansion of the low expansion portion (81), as well as an adjusting portion (64) comprising a weight (102) having a center of gravity at a position eccentric with respect to a second axis (O2) in the radial direction, and attached to the deformation part (80) so as to be rotatable about the second axis (O2) in a state where at least the movement of the weight (102) in a direction along the second axis (O2 ) is blocked.
    公开号:CH715890A2
    申请号:CH00226/20
    申请日:2020-02-25
    公开日:2020-08-31
    发明作者:Nakajima Masahiro；Kawauchiya Takuma；Fujieda Hisashi
    申请人:Seiko Instr Inc；
    IPC主号:
    专利说明:

    BACKGROUND OF THE INVENTION
    1. Field of the invention
    The present invention relates to a spring balance of the thermocompensation type, a movement and a timepiece.
    2. Description of the related prior art
    A sprung balance which has the function of a regulating member of a mechanical timepiece comprises a balance shaft which extends along an axis, a balance fixed to the balance shaft, as well as a hairspring. The balance shaft and the balance rotate in a periodic movement (they oscillate) around the axis, depending on the expansion of the balance spring and its contraction.
    [0003] In the sprung balance described above, it is important that the sprung balance has an oscillation period set within a predefined specified value. When the oscillation period deviates from the specified value, the rate (delay of the timepiece, amount of advance) of the mechanical timepiece is changed.
    A period of oscillation T of the sprung balance is expressed by the following equation (1). In equation (1), I represents the “moment of inertia” of the balance spring, while K represents the “elastic torque” of the balance spring.
    [0005] Based on equation (1), when the moment of inertia I of the balance spring or the elastic torque K of the balance spring changes due to a change in temperature or the like, the period of oscillation T of the sprung balance is modified. Specifically, there is a case where the balance described above is made of a material having a positive coefficient of thermal expansion (it is a material which expands when the temperature increases). In this case, when the temperature increases, the diameter of the balance increases and the moment of inertia I increases.
    [0006] Consequently, when the moment of inertia I increases due to an increase in temperature, the period of oscillation T becomes longer. As a result, the period of oscillation T of the sprung balance is short at low temperatures and long at high temperatures, while the thermal characteristic of the timepiece is to advance at low temperatures and retard at high temperatures.
    As a measure to improve the temperature dependence of the period of oscillation T, a configuration in which bimaterials (bimetals) equip a balance in rotationally symmetrical positions has been considered (refer, for example, to 'Theory of Horology' Swiss University of the Watch Piece, Second edition of the English version, April 2003, pages 136-137 (non-patent document cited 1)). The bimaterial is produced by shaping into bimetallic (by shaping in the form of plywood) sheet materials having different coefficients of thermal expansion.
    [0008] According to this solution, when the temperature increases, the bimaterial is deformed inwardly in a radial direction, for example, due to the difference between the thermal expansion coefficients of the sheet materials. Consequently, the moment of inertia I can be reduced since the average diameter of the balance is reduced. As a result, it is considered that the thermal characteristic of the moment of inertia I can be corrected and the dependence of the oscillation period T on the temperature can be suppressed.
    [0009] For example, in the case where the bimaterial is not produced to the desired shape due to fluctuations in manufacturing or the like, it is possible that the thermal coefficient of the bimaterial (the amount of which the bimaterial is deformed as a function of 'a change in temperature) is not stable and the correction of the thermal characteristic by the bimaterial is not carried out precisely. In such a case, a method for adjusting the thermal characteristic of the moment of inertia I (amount by which the moment of inertia I changes for a change in temperature) by mounting a balancing screw on the bimaterial is considered.
    [0010] However, in adjusting the thermal characteristic by means of a balancing screw, it was only possible to change the presence or absence of the balancing screw, to modify the mounting position of the screw balancing or adjusting the weight of the balancing screw to be mounted and, thus, it was not possible to achieve fine adjustment or continuous adjustment of the thermal characteristic.
    SUMMARY OF THE INVENTION
    One aspect of the present application is to provide a high quality thermocompensation type sprung balance, which makes it possible to easily and precisely adjust the thermal characteristic of the moment of inertia while preventing variations in rate, and which has excellent performance in terms of thermal compensation, a movement, as well as a timepiece.
    According to the aspect of the present application, there is proposed a spring balance of the thermocompensation type, comprising: a balance shaft extending along a first axis; and a balance main body which is provided with the balance shaft rotating around the first axis by the power of a hairspring and which includes a high expansion part and a low expansion part having different thermal expansion coefficients, wherein the balance main body includes a deformation part which is deformable in a radial direction orthogonal to the first axis, depending on a change in temperature, due to the difference between the thermal expansion coefficient of the high expansion part and the thermal expansion coefficient of the low expansion part, and an adjusting part comprising a weight having a center of gravity located in an eccentric position with respect to a second axis extending in the radial direction, and attached to the deformation part so as to be rotatable about the second axis, in a state where at least the movement of the weight in a direction ection along the second axis is blocked.
    According to this aspect, as the deformation part is deformed radially by an amount (distance to the first axis before and after the deformation) which depends on the position in the circumferential direction, the center of gravity of the weight being changeable according to this first circumferential direction, it follows that the amount of radial displacement of the flyweight depending on the deformation of the deformation part can be changed (adjusted).
    In particular, with this aspect, since the center of gravity of the flyweight can be moved continuously in the circumferential direction depending on the angular position of the flyweight, fine adjustment of the amount of radial displacement of the flyweight is made. possible.
    In addition, with this aspect, since the weight rotates in a state where the movement in the second axial direction is stopped, a movement of the weight in the radial direction following a rotation of this weight can be prevented. Therefore, a change in the average diameter of the balance due to a change in the position of the center of gravity of the weight can be made impossible.
    As a result, it is possible to provide a high quality sprung balance, which makes it possible to easily and precisely adjust the thermal characteristics of the moment of inertia while eliminating a variation in the rate, and which gives excellent results in thermal compensation.
    [0017] In one aspect, the deformation part may be a bimaterial in which the high expansion part and the low expansion part overlap each other in the radial direction and which extends in a circumferential direction. around the first axis, while the main balance body may include a connecting portion which connects a first end, in the circumferential direction, of the deformation part and the balance shaft to one another.
    With this aspect, the thermal characteristics of the moment of inertia can be corrected by a change in the average diameter of the balance by a deformation of the deformation part.
    [0019] Further, by providing the deformation part as a bimaterial only at the rim of the sprung balance, it is obtained that the degree of freedom for designing the connecting portion and the like can be improved, compared to the case where the deformation part is formed by the whole balance main body. In addition, since the deformation part extends cantilever from the first end, the amount of which the deformation part is radially deformed by a change in temperature gradually increases as one moves. from the fixed end to the free end. Therefore, by moving the center of gravity of the weight in the circumferential direction, one can gradually reduce or increase the amount by which the weight is moved radially due to a temperature variation. As a result, the thermal characteristic of the moment of inertia can be adjusted more easily.
    [0020] According to one aspect, the adjustment part may comprise a portion forming a shaft extending along the second axis and carried by the deformation part, and the flyweight positioned on the outer side of the deformation part in the radial direction in the tree portion.
    With this aspect, as the weight can be maneuvered from the outer side of the sprung balance, the adjustment of the thermal characteristic is made easy.
    [0022] According to one aspect, the shaft portion and the flyweight can be integral with one another.
    [0023] With this aspect, since the shaft portion and the flyweight are integral with each other, the number of components can be reduced and the constitution can be simplified.
    [0024] In one aspect, the shaft portion and the flyweight may be elements formed separately.
    With this aspect, it is possible to choose an appropriate material or the like for each of the separate elements that are the shaft portion and the weight. Therefore, the margin of freedom for the design can be improved.
    [0026] According to one aspect, a chamfer in a direction tangential to a virtual circle around the second axis in a side view obtained by looking from the radial direction can be formed in the flyweight, while an edge which is turned towards the first axial direction and which is an edge of the deformation portion may be parallel with the chamfer when the chamfer is facing the first axial direction.
    With this aspect, it is possible to eliminate the weight protruding by a certain amount relative to the deformation part in the first axial direction when the chamfer is rotated in the first axial direction. Therefore, an enlargement of the balance in the first axial direction can be avoided.
    In addition, when the weight is maneuvered, one can avoid rotation of the tool and the weight relative to each other by holding this weight by using the chamfer. Therefore, the margin of freedom for the design of the flyweight can be improved since it is not necessary to separately provide a locking portion of a tool in the flyweight.
    [0029] According to one aspect, an attachment portion which comprises the deformation part and to which the adjustment part is mounted so as to be removable may be in several copies succeeding one another at intervals in the circumferential direction around the first axis.
    With this aspect, as several attachment portions are provided in the deformation part, it is possible to modify the number and the position (s) of the attachment portion (s) attached to the deformation part. Therefore, the thermal characteristic of the moment of inertia can be set over a wide range, with higher precision.
    [0031] A movement according to one aspect of the present application may comprise a spring balance of the thermocompensation type as defined above.
    [0032] A timepiece according to one aspect of the present application can include a movement as defined above.
    With this aspect, since the thermocompensation sprung balance is provided therein, it is possible to provide a movement and a timepiece which are of high quality.
    According to the present application, it is possible to provide a high quality sprung balance, which makes it possible to easily and precisely adjust the thermal characteristics of the moment of inertia while eliminating a variation in the rate, and which gives excellent results in thermal compensation, a movement and a timepiece.
    BRIEF DESCRIPTION OF THE DRAWINGS
    [0035] FIG. 1 is an external view of a timepiece according to a first embodiment. Fig. 2 is a plan view taken when a movement according to the first embodiment is viewed from the front. Fig. 3 is a perspective view taken when a sprung balance according to the first embodiment is viewed from the front. FIG. 4 is a side view of the sprung balance according to the first embodiment. FIG. 5 is a partial plan view of the sprung balance according to the first embodiment. Figure 6 is a view taken looking along arrow VI in Figure 5. Figure 7 is a partial plan view of the sprung balance and illustrates an operation of the deformation part. Figure 8 is a side view of the sprung balance and illustrates the operation of the adjustment part. Figure 9 is a side view of the sprung balance and illustrates the operation of the adjustment part. FIG. 10 is a partial plan view of the sprung balance and illustrates an operation of the adjustment part. FIG. 11 is a partial plan view of the sprung balance and illustrates an operation of the adjustment part. FIG. 12 is a view in partial section of a sprung balance according to a second embodiment. Figure 13 is a view taken looking along arrow XIII in Figure 12. Figure 14 is a perspective view of a sprung balance according to a third embodiment. Figure 15 is a sectional view along the line XV-XV of Figure 14.
    DESCRIPTION OF EMBODIMENTS
    [0036] In the following, embodiments of the present invention will be described with reference to the drawings. In each embodiment described below, corresponding components sometimes receive the same reference numbers and their descriptions are omitted.
    First embodiment
    Timepiece
    [0037] Figure 1 is an external view of a timepiece 1. In addition, in each of the following drawings, it happens that, in order to make the drawing easier to understand, certain components of the timepiece timepiece are omitted and components of the timepiece are shown in a simplified manner.
    As shown in Figure 1, the timepiece 1 of this embodiment is arranged with a movement 2, a dial 3, several hands 4 to 6 or the like, which are placed in a watch case 7.
    The watch case 7 comprises a main box body 11, a case back (not shown) and a protective glass 12. A crown 15 is provided at the 3 o'clock position (on the right side in Figure 1) on the side surface of the box main body 11. The crown 15 is provided to operate the movement 2 from outside the box main body 11. The crown 15 is fixed to a winding rod 19 inserted in the box main body 11.
    Movement
    Figure 2 is a plan view of the movement 2 as seen from the front.
    As shown in Figure 2, the movement 2 is arranged so that several rotating bodies (such as gears) are carried, so as to be rotating, by a plate 21 which forms a frame of the movement 2. In the description which follows, the side (the dial side 3) of the plate 21 where there is the protective glass 12 of the watch case 7 is called the rear side of the movement 2, while the side where there is the back ( the side opposite to the dial side 3) is called the front side of movement 2. Each rotating body described below has the anteroposterior direction of movement 2 as the axial direction.
    The winding stem 19 mentioned above is mounted in the plate 21. The winding stem 19 is used to correct the date and time. The winding stem 19 is rotatable about its axis and it is movable in the axial direction. The position of the winding stem 19 in the axial direction is determined by a switching device comprising a pull tab 23, a lever 24, a lever spring 25 and a pull tab 26.
    When rotating the winding stem 19, a winding pinion 31 rotates due to the rotation of a sliding pinion (not shown). A crown wheel 32 and a ratchet 33 in turn rotate due to the rotation of the winding pinion 31 and a mainspring (not shown) housed in a movement barrel 34 is armed.
    The movement barrel 34 is rotatably mounted between the plate 21 and a barrel bridge 35. A center mobile 41, a third mobile 42 and a second mobile 43 are rotatably mounted between the plate 21 and a bridge cog 45.
    When the movement barrel 34 is rotated by the return force of the mainspring, the center mobile 41, the third mobile 42 and the second mobile 43 turn as a result of the rotation of the barrel. movement 34. The movement barrel 34, the center mobile 41, the third mobile 42 and the seconds mobile 43 form a going gear.
    A 5 minute hand (refer to Figure 1) is attached to the center gear 41 in the going gear described above. The aforementioned hour hand 4 is attached to an hour wheel (not shown) which rotates by the rotation of the center mobile 41. In addition, the seconds hand (refer to figure 1) is arranged to rotate. based on the rotation of the second mobile 43.
    A regulating exhaust 51 is mounted on the movement 2.
    The regulating escapement 51 comprises an escapement mobile 52, an anchor 53 and a sprung balance 54 (corresponding to what is called the "spring balance of the thermocompensation type" in the appended claims).
    The exhaust mobile 52 is rotatably mounted between the plate 21 and the gear bridge 45. The exhaust mobile 52 rotates by the rotation of the second mobile 43 which rotates.
    The anchor 53 is mounted between the plate 21 and an anchor bridge 55, so as to be able to pivot back and forth. The anchor 53 includes a pair of paddles 56a and 56b. The vanes 56a and 56b are alternately engaged with an escape wheel 52a of the escape wheel set 52, by the back and forth pivoting of the anchor 53. The escape wheel body 52 temporarily stops. turn when one of the two vanes 56a and 56b is in engagement with the escape wheel 52a. In addition, the escape wheel 52 rotates when the two vanes 56a and 56b are away from the escape wheel 52a. By repeating these operations continuously, the exhaust mobile 52 rotates intermittently. In addition, the rotation of the going gear is controlled by the intermittent operation of the gear wheel described above (going gear) by the operation of intermittent rotation of the exhaust mobile 52.
    Spiral balance
    [0051] Figure 3 is a perspective view when the sprung balance 54 is seen from the front. Figure 4 is a side view of the sprung balance 54.
    As shown in Figures 3 and 4, the sprung balance 54 regulates the exhaust mobile 52 (releases the escape mobile at a constant speed). The sprung balance 54 includes a balance shaft 61, a balance 62, a hairspring 63 and an adjusting part 64. Further, the balance 62 and the adjusting part 64 form a balance main body of the present embodiment.
    As shown in Figure 4, the balance shaft 61 is carried between the plate 21 and a balance bridge 65 so as to be rotatable about a first axis O1. In the following description, a direction along the first axis O1 is called a first axial direction, while a direction orthogonal to the first axis O1 is called a first radial direction and a direction around the first axis O1 is called a first circumferential direction. In the present case, the first axial direction coincides with the anteroposterior direction.
    The balance shaft 61 pivots back and forth with a period of constant oscillation, around the first axis O1, by the power transmitted from the hairspring 63. The front end of the balance shaft 61 in the first axial direction is carried by the balance shaft 61. The rear end of the balance shaft 61 in the first axial direction is carried by the plate 21.
    A rear end segment of the balance shaft 61 in the first axial direction receives a double plate 67. The double plate 67 has a tubular shape positioned coaxially with the first axis O1. An impulse pin 68 is provided on a part of the double plate 67 in the first circumferential direction. Repeatedly, the impulse pin 68 cooperates with and separates from the fork of the anchor 53, in synchronization with the reciprocating pivoting of the sprung balance 54. Therefore, like the anchor 53 pivots back and forth, the vanes 56a and 56b are repeatedly engaged with and released from the exhaust mobile 52.
    As shown in Figure 3, the balance 62 is fixed on the balance shaft 61, on the front side of the double plate 67, in the first axial direction. The balance 62 comprises a connecting portion 70 and a rim 73.
    The connecting portion 70 connects the balance shaft 61 and the rim 73 to each other. The connecting portion comprises a hub 71 and a ridge portion 72 (spoke portion).
    The hub 71 is fixed to the balance shaft 61 by driving or the like.
    The ridge portion 72 projects from the hub 71, outwards in the first radial direction. In the present embodiment, three crest portions 72 (three radii 72) are formed radially with respect to the first axis O1. Further, the position of the ridge portions 72 in the first circumferential direction, their number, etc., can be appropriately changed.
    The rim 73 comprises several deformation parts 80. Each deformation part 80 extends cantilevered from one of the ridge portions 72 described above, towards one side in the first circumferential direction . In the present embodiment, the deformation parts 80 are arranged in rotational symmetry (in the present embodiment, rotational symmetry of order 3) about the first axis O1 (they form a rotational invariant figure) . The rotation target is an example of an expression intended to characterize a figure, and it is a known concept. For example, when n is an integer greater than or equal to 2, and the rotation target is rotated by an angle equal to (360 / n) ° around a certain center (in the case of a two-person figure dimensions) or of an axis (in the case of a three-dimensional figure), the fact that the properties coincide is called a rotational symmetry of order n, a folding symmetry of order n, a symmetry of (360 / n) ° or the like. For example, in the case where n = 3, when the rotation target is rotated 120 °, the properties are called 3rd order rotational symmetry by coinciding with each other.
    Taken as a whole, the rim 73 has an annular shape coaxial with the first axis O1, obtained by positioning the deformation parts 80 following in the first circumferential direction, on the same circumference. The rim 73 surrounds the periphery of the connecting portion 70 from the outside in the first radial direction.
    The deformation portion 80 is commonly referred to as a bimaterial (bimetallic strip) in which two sheet materials having different thermal expansion coefficients mutually overlap in the first radial direction. The deformation part 80 comprises a low expansion part 81 placed on the inner side in the first radial direction, as well as a high expansion part 82 positioned on the outer side in the first radial direction, relative to the low expansion part 81 The deformation part 80 is formed so as to be deformable in the first radial direction, from a fixed end (part at the junction with the ridge portion 72), as a function of changes in temperature, by means of the difference between the thermal expansion coefficient of the low expansion part 81 and the thermal expansion coefficient of the high expansion part 82. In the present embodiment, since the high expansion part 82 is placed on the outer side according to the first radial direction, the deformation portion 80 deforms inwardly in the first radial direction in the case where the temperature increases. Further, in the example shown, 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 blade thicknesses of the low expansion portion 81 and the high expansion portion 82 can be suitably changed.
    [0063] In the present embodiment, invar (Ni-Fe alloy), silicon, ceramics or the like is preferably used for the low expansion part 81. Copper, a copper alloy, Aluminum or the like is preferably employed for the high expansion portion 82. However, the materials used for the low expansion portion 81 and for the high expansion portion 82 can be suitably changed.
    An attachment hole 85 (corresponding to what is called the "attachment portion" in the appended claims) is formed at the free end (end located at the end in the first circumferential direction) of the deformation part 80. The attachment hole 85 enters the deformation part 80 in the first radial direction. Further, the position where the attachment hole 85 is formed can be suitably changed as long as the deformation portions 80 are placed in positions which are targets of rotation of each other (which are rotational invariant between they).
    [0065] The hairspring 63 is a flattened hairspring, spiral in a plan view taken looking in the first axial direction. The spiral 63 is wound according to an Archimedean curve. The inner end of the hairspring 63 is connected to the balance shaft 61, via a ferrule 87. The outer end of the hairspring 63 is connected to the balance bridge 65, via a stud (not shown). The hairspring 63 plays a role of storing the energy transmitted from the second mobile 43 to the exhaust mobile 52 and of transmission, to the balance shaft 61, of the stored energy.
    In the present embodiment, a material having a coefficient of expansion with a negative Young's modulus (characteristic according to which the elastic torque decreases with an increase in temperature) is used for the hairspring 63. However, the hairspring 63 can be made of a constant elastic material (eg coelinvar) having a thermal coefficient with a positive Young's modulus in the operating temperature range.
    Adjustment part
    [0067] FIG. 5 is a partial plan view of the sprung balance 54.
    As shown in Figures 3 and 5, an adjustment part 64 is attached to each of the deformation parts 80 described above. In other words, each adjustment part 64 is provided in one of several positions which are invariant with respect to each other by rotation about the first axis O1. The adjustment portion 64 includes an engaging portion 100, a rod 101 and a weight 102. The adjustment portion 64 is in the form of a bar extending along the second axis O2. In the present embodiment, the second axis O2 extends in the first radial direction. In the following description, a direction along the second axis O2 is called a second axial direction (corresponding to what is called the radial direction in the appended claims), while a direction orthogonal to the second axial direction O2 is called a second radial direction and that a direction around the second axis O2 is called a second circumferential direction.
    The engaging part 100 has a tubular shape extending in the second axial direction, with a shoulder. More specifically, the engaging portion 100 comprises a large diameter portion 110 positioned on the inner side in the second axial direction (corresponding to what is referred to as the "inner side in the radial direction" in the appended claims), as well as 'a portion of small diameter 111 positioned on the inner side in the second axial direction, relative to the portion of large diameter 110.
    The small diameter portion 111 is driven into the attachment hole 85 of the deformation part 80, from the inside in the second axial direction. Therefore, the engaging portion 100 is fixed to (in engagement with) the deformation portion 80, in a state where a shoulder 112 between the large diameter portion 110 and the small diameter portion 111 abuts ( or near the inner side in the second axial direction) the inner circumferential surface of the deformation part 80. Further, the engaging part 100 can be fixed to the deformation part by adhesion or the like.
    The rod 101 is arranged coaxially with the second axis O2. The rod 101 includes a shaft portion 115 and a head 116.
    The inner end of the shaft portion 115 in the second axial direction is driven into the engagement portion 100 from the outside, in the second axial direction.
    The head 116 projects from the outer end, in the second axial direction, of the shaft portion 115. In addition, the center of gravity of the engaging part 100 and of the rod 101 is positioned on the second axis O2 in a side view taken looking in the second axial direction.
    FIG. 6 is a view taken looking along the arrow VI of FIG. 5.
    As shown in Figure 6, the weight 102 is attached to the shaft portion 115, so as to be rotatable about the second axis O2.
    More specifically, the flyweight 102 is attached to the outer end, in the second axial direction, of the shaft portion 115, in a state where it is urged inwardly in the second radial direction. The flyweight 102 has a C-shape surrounding the periphery of the shaft portion 115 in a side view. Consequently, in a side view, the center of gravity G of the weight 102 is eccentric with respect to the second axis O2, in the second radial direction.
    The weight 102 is arranged so as to be able to rotate around the second axis O2 by sliding on the outer circumferential surface of the shaft portion 115. Consequently, the center of gravity G of the weight 102 moves (rotates) around of the second axis O2 as a function of the rotation of the flyweight 102. Consequently, the center of gravity G of the flyweight 102 moves along the first circumferential direction (more precisely, a tangential direction passing through the attachment hole 85 on the outer circumferential surface of the deformation portion 80). Further, the outer shape of the flyweight 102 in a side view is not limited to a circular shape, and it may be a polygonal shape or the like. Further, although in the embodiment an arrangement is employed in which the positioning of the shaft portion 115 in the second circumferential direction is effected by a biasing force of the flyweight 102, the present invention is not limited to this arrangement. For example, the flyweight 102 and the shaft portion 115 may be positioned in the second circumferential direction by an unevenness or the like which protrudes along the second circumferential direction.
    In the flyweight 102 of the present embodiment, a chamfer 120 is formed at each of the two ends in the second circumferential direction. The chamfer 120 is a flat surface extending in a tangential direction of a virtual circle around the second axis O2. The chamfer 120 is arranged so that, when facing the first axial direction, it is parallel with the two edges of the deformation portion 80 which face the first axial direction. In addition, in the example shown, the thickness of the weight 102 in the second radial direction is uniform over the entire circumference. However, the thickness of the weight 102 may vary depending on the position in the second circumferential direction.
    [0079] In addition, the position of the center of gravity (amount of which the center of gravity G is eccentric) of the flyweight 102 can be changed appropriately. Examples of methods for moving the center of gravity of the flyweight 102 include a method for changing the shape of the flyweight 102 and a method for changing the density of the flyweight 102. For example, a material having a relatively high density (for example compared to engaging portion 100 or rod 101) may be selected for flyweight 102.
    [0080] In this case, the flyweight 102 is preferably made of gold (Au), platinum (Pt), tungsten (W) or the like.
    The weight 102 is sandwiched between the outer circumferential surface of the deformation part 80 and the head 116, in the second axial direction. Consequently, the movement of the flyweight 102 in the second axial direction is blocked by the deformation part 80 or by the rod 101. Further, a small clearance can be provided between the flyweight 102 and the outer circumferential surface of the stem part. deformation 80 or else between the weight 102 and the head 116.
    In the present embodiment, the constitution is that described above, in which the weight 102 is rotatable about the second axis O2. However, one is not limited to this constitution. In other words, when the adjustment part 64 has a constitution in which at least the weight 102 is rotatable about the second axis O2, a constitution in which, in addition to the weight 102, the engaging part 100 or the rod 101 is rotatable with this weight 102 can be used. In other words, since the engagement portion 100 is inserted into the attachment hole 85, the rod 101 is attached to the engagement portion 100, and the weight 102 is attached to the rod 101, the adjustment part 64 may itself be provided to be rotatable. Further, since the engaging portion 100 is fixed in the attachment hole 85 and the rod 101 is inserted into the engaging portion 100, the rod 101 and the weight 102 can be rotatably provided.
    Thermal coefficient correction method
    A method of correcting the thermal coefficient for the sprung balance 54 described above will now be explained. Figure 7 is a partial plan view of the sprung balance 54 and is intended to describe an operation of the deformation portion 80.
    As shown in Figure 7, in the sprung balance 50 of the present embodiment, when a temperature change occurs, the deformation portion 80 bends (more) and deforms due to the difference between the coefficient of thermal expansion of the low expansion portion 81 and the thermal expansion coefficient of the high expansion portion 82. Specifically, in the case where the temperature increases from a predetermined temperature T0 (normal temperature (e.g. 'order of 23 ° C)), the high expansion part 82 expands more than the low expansion part 81. Therefore, the deformation part 80 deforms inwardly in the first radial direction (see symbol A in figure 7). In the case where the temperature decreases from the predetermined temperature T0, the high expansion part 82 contracts more than the low expansion part 81. Therefore, the deformation part 80 deforms outward in the first direction. radial (see symbol B in figure 7).
    As the deformation part 80 is deformed, the distance between the free end of the deformation part and the first axis O1, in the first radial direction, is modified. Specifically, in the case where the distance in the first radial direction between the free end of the deformation part 80 and the first axis O1 is R0 at the predetermined temperature T0, while the distance in the first radial direction between the end free of the deformation part 80 and the first axis O1 is R1 when the temperature has increased, the difference between the distance R0 and the distance R1 is an amount of variation in radius ΔR1 in the first radial direction when the temperature has increased. On the other hand, in the case where the distance in the first radial direction between the free end of the deformation part 80 and the first axis O1 is R2 when the temperature has decreased, the difference between the distance R0 and the distance R2 is an amount of variation in radius ΔR2 in the first radial direction when the temperature has decreased. In addition, the amounts of radial deformation ΔR1 and ΔR2 gradually increase from the fixed end to the free end.
    In addition, the average diameter of the balance 62 can be reduced or increased depending on the quantities of variation in radius ΔR1 and ΔP2, while the moment of inertia of the balance 62 about the first axis O1 can be modified. In other words, in the event that the temperature has increased, the average diameter of the balance 62 can be decreased in order to reduce the moment of inertia. In the event that the temperature has increased, the average diameter of the balance 62 can be increased and the moment of inertia can be increased. Therefore, the thermal characteristic of the moment of inertia can be corrected.
    Incidentally, in the case where the deformation part does not have the desired shape due to manufacturing fluctuations or the like, it is possible that the amount of which the deformation part 80 deforms due to a change in temperature, and that the correction of the thermal characteristic by the deformation portion 80 is not performed accurately.
    Here, in the present embodiment, the position of the center of gravity of the flyweight 102 in the first circumferential direction can be changed depending on the thermal coefficient of the deformation portion 80. Specifically, as shown in Figure 5 , the position in which the center of gravity G of the weight 102 and the second axis O2 are aligned in the first axial direction is chosen as the reference position.
    Figures 8 and 9 are side views which correspond to Figure 5 and are provided to illustrate how the adjusting part 64 acts. Figures 10 and 11 are partial views, in plan, of the sprung balance 54 and are provided to illustrate how the adjusting part 64 works.
    As shown in Figures 8 and 10, in the case where the thermal coefficient of the deformation part 80 is higher than the desired value, the weight 102 is rotated around the second axis O2 and the center of gravity G of this flyweight 102 is moved by being brought closer to the fixed end of the deformation portion 80. Therefore, compared to the case where the flyweight 102 is in the reference position, the amount of change in radius of the flyweight 102 due to A change in temperature can be made small and the amount by which the moment of inertia of the balance wheel 62 is changed can be made small.
    On the other hand, as shown in Figures 9 and 11, in the case where the thermal coefficient of the deformation part 80 is less than the desired value, the weight 102 is rotated around the second axis O2 and the center of gravity G of the flyweight 102 is moved so as to be brought closer to the free end of the deformation part 80. Therefore, compared with the case where the deformation part is in the reference position, the amount of radial deformation of the flyweight 102 due to a change in temperature can be made larger and the amount by which the moment of inertia of the balance 62 is changed can be made larger.
    Above, according to the present embodiment, the weight 102 having its center of gravity G in an eccentric position relative to the second axis O is provided to rotate about the second axis O2.
    According to this constitution, since the deformation part 80 has an amount of radial deformation that changes as a function of the position in the first circumferential direction, while the center of gravity G of the weight 102 is movable in the first circumferential direction, the amount of radial displacement of the flyweight 102 as a function of the deformation of the deformation portion 80 can therefore be changed (adjusted).
    In particular, in the present embodiment, since the center of gravity G of the flyweight 102 can be moved continuously in the circumferential direction depending on the angular position of the flyweight 102, fine adjustment of the amount of radial displacement of the weight 102 is made possible.
    In addition, since the weight 102 rotates under conditions where the movement in the first radial direction is limited by the deformation part 80 and by the head 116, a movement of the weight 102 in the first radial direction consecutively to a rotation of this weight 102 can be prevented. Therefore, a change in the average diameter of the balance 62 due to a change in the position of the center of gravity of the weight 102 can be made impossible.
    It follows that it is possible to provide the sprung balance 54, that is to say a high quality sprung balance, which makes it possible to easily and precisely adjust the thermal coefficient while eliminating a variation of walking, and which gives excellent results in thermal compensation.
    In the present embodiment, the low expansion part 81 and the high expansion part 82 are arranged so that there is mutual overlap in the deformation parts 80.
    According to this arrangement, the thermal characteristics of the moment of inertia can be corrected by a change in the average diameter of the balance 62 by a deformation of the deformation parts 80.
    Further, by providing the deformation portion 80 as a bimaterial only at the level of the rim 73 of the sprung balance 54, it is obtained that the degree of freedom to design the connecting portion 70 and the like can be improved, compared with the case where the deformation part is formed by the whole balance main body. In addition, since the deformation portion 80 extends cantilever, the amount by which the deformation portion 80 is radially deformed by a change in temperature gradually increases as one moves from the end. fixed to the free end. Therefore, by changing the center of gravity of the flyweight 102 in the circumferential direction, one can gradually reduce or increase the amount by which the flyweight 102 is moved radially due to a change in temperature. As a result, the thermal characteristic of the moment of inertia can be adjusted more easily.
    [0100] In the present embodiment, the weight 102 is provided to be disposed outside the deformation part 80 in the first radial direction (the second axial direction).
    [0101] According to this arrangement, as the weight 102 can be operated from the outer side of the sprung balance 54, the adjustment of the thermal characteristic is made easy.
    [0102] In the present embodiment, the shaft portion 115 and the flyweight 102 are designed as being separate elements.
    [0103] According to this constitution, it is possible to choose a suitable material or the like for the shaft portion 115 and a suitable material or the like for the flyweight 102. Therefore, the design freedom margin can be improved.
    [0104] In the present embodiment, the edge of the deformation portion 80 facing the first axial direction is provided to be parallel to the chamfer 120 when the chamfer 120 is facing the first axial direction.
    According to this constitution, it is possible to eliminate the weight protruding by a certain amount relative to the deformation portion 80 in the first axial direction when the chamfer 120 is rotated in the first axial direction. Therefore, an enlargement of the balance 62 in the first axial direction can be avoided.
    [0106] In addition, when the flyweight 102 is operated, one can avoid rotation of the tool and the flyweight 102 relative to each other by holding this flyweight 102 by using the chamfer 120. Consequently, the margin of freedom for the design of the flyweight 102 can be improved since it is not necessary to provide separately a locking portion of a tool in the flyweight 102.
    [0107] With the movement 2 and the timepiece 1, it is possible to provide a movement and a timepiece which are of high quality and the rate of which varies little, since this movement 2 and this timepiece 1 of this embodiment are equipped with the sprung balance 54 described above.
    Second embodiment
    [0108] A second embodiment of the present invention will now be described. FIG. 12 is a partial sectional view of a sprung balance 54 according to the second embodiment. Figure 13 is a view taken looking along the arrow XIII shown in Figure 12. The present embodiment differs from the first embodiment described above, in that a shaft portion 201 and a weight 202 are of integral with each other, within an adjustment part 200.
    [0109] The adjusting portion 200 shown in Figures 12 and 13 includes the engaging portion 100 and a rod 210.
    [0110] The small diameter portion 111 of the engaging portion 100 is inserted into the attachment hole 85.
    [0111] The rod 210 comprises the portion forming the shaft 201 and the weight 202.
    [0112] The shaft portion 201 is embedded in the engagement portion 100, through the attachment hole 85. Therefore, the rod 210 is arranged to be rotatable with the engagement portion 100, around the second axis O2.
    [0113] The weight 202 is formed at the level of the outer end of the portion forming a shaft 201 in the second axial direction. The flyweight 202 is wider in the direction of the diameter, relative to the shaft portion 201. The flyweight 202 and the shoulder 112 of the engaging portion 100 sandwich the deformation portion 80 together, depending on the pattern. second axial direction. Therefore, the movement of the weight 202 in the second axial direction, relative to the deformation portion 80, is stopped.
    [0114] As shown in FIG. 13, the weight 202 has a circular shape around a position eccentric with respect to the second axis O2 in a side view. Therefore, in a side view, the center of gravity G of the flyweight 202 is eccentric with respect to the second axis O2. However, the shape of the flyweight 202 can be appropriately changed.
    [0115] A tool locking portion 201 is formed in the outer end surface of the weight 202 in the second axial direction. The tool locking portion 211 is a groove extending linearly along the second radial direction passing through the center of gravity G. The tool locking portion 211 is shaped such that a tool can be mated to it. In other words, the adjustment part 200 is arranged so that it can be rotated about the second axis O2, by means of a tool locked to the tool locking portion 211. Further, the locking portion d The tool 211 is not limited to a groove since it makes it possible to couple a tool.
    According to the present embodiment, the adjustment part 200 is rotated around the second axis O2 by rotating a tool around this second axis O2 in a state where this tool is coupled to the tool locking portion 211. Consequently, the center of gravity G of the flyweight 202 is moved in the first circumferential direction. As a result, the same effects are obtained as those obtained with the first embodiment described above.
    [0117] In addition, in the present embodiment, since the shaft portion 201 and the flyweight 202 are integrally with each other, the number of components can be reduced and the constitution can be simplified. .
    Third embodiment
    A third embodiment of the present invention will now be described. FIG. 14 is a perspective view of a sprung balance 54 according to the third embodiment. The present embodiment is different from each of the embodiments described above, in that the position where the adjustment part 301 is attached can be changed. In the sprung balance 54 shown in FIG. 14, several holes d 'fastener 310 succeed each other at intervals in the first circumferential direction.
    FIG. 15 is a section view along the line XV-XV shown in FIG. 14.
    [0120] As shown in Figures 14 and 15, the adjustment part 301 is attached, so as to be removable, to the deformation part 80, by means of at least one attachment hole 310 among the holes of clip 310.
    [0121] In the adjustment part 301, a male thread 311 is formed in the shaft portion 115 of the rod 101. This male thread 311 is formed on a part of the shaft portion 115, namely on a part which protrudes. inwards in the second axial direction, relative to the deformation part 80.
    [0122] A female thread 321 is formed on the inner circumferential surface of the engagement portion 320. The engagement portion 320 is removably mounted on the shaft portion 115 by means of a screwing the female thread 321 onto the male thread 311.
    In the present embodiment, the same functions and the same effects are obtained as those of the first embodiment described above and, in addition, the functions and effects which follow.
    [0124] In other words, since several attachment holes 310 are formed in the deformation part 80, the number and position (s) of the adjustment parts 301 attached to the deformation part 80 can be changed. , the thermal characteristics of the moment of inertia can be adjusted over a wide range with increased precision.
    Other examples of modifications
    [0125] The technical scope of the present invention is not limited to the embodiments described above and various modifications can be made without departing from the scope of the present invention.
    For example, a case has been described which is that of the embodiments described above and in which a bimaterial is used to form the deformation part 80. However, it is not limited to this case. The deformation part can be designed so that the average diameter of the pendulum is changed by means of a relative deformation of the high expansion part and the low expansion part as a result of a temperature change. In this case, for example, the ridge portion may be formed, in the balance, by a portion, any of the high expansion part and the low expansion part, while the ridge may be formed by the the other portion among the high expansion part and the low expansion part. In this case, the serge is not limited to the case of a cantilever mounting, but it can be mounted with a support at both ends. In other words, in the sprung balance according to the present invention, the deformation part can be provided at any part (balance main body), except the balance shaft, among the sprung balance.
    We have described the constitution which is that of the embodiments described above and in which the weight is placed on the outside in the first radial direction, relative to the deformation part 80. However, we are not limited to this constitution. The weight can be positioned on the internal side of the deformation part 80, in the first radial direction, or else on both sides of the deformation part 80 in the first axial direction.
    The constitution has been described which is that of the embodiments described above and in which the adjustment part is attached to the deformation part by means of an attachment hole. However, one is not limited to this constitution. The adjustment part may be arranged to be rotatable about the second axis, in a situation where at least the movement of the weight is stopped in the direction along the second axis.
    We have described the constitution which is that of the embodiments described above and in which the moment of inertia is adjusted by means of the adjustment part. However, in addition to this, the moment of inertia of the balance can be adjusted by means of a balance screw or the like provided separately.
    [0130] In addition, it is possible to replace, in an appropriate manner, the constituent elements of the embodiments described above, by known constituent elements, without departing from the scope of the present invention, and the examples of modifications described above. can be combined with each other.
    权利要求:
    Claims (9)
    [1]
    1. Spring-balance of the thermocompensation type, comprising:a balance shaft extending along a first axis; anda balance main body which is provided with the balance shaft rotating around the first axis by the power of a hairspring and which comprises a high expansion part and a low expansion part having different thermal expansion coefficients,in which the main balance body comprisesa deformation part which is deformable in a radial direction orthogonal to the first axis, depending on a change in temperature, due to the difference between the coefficient of thermal expansion of the high expansion part and the coefficient of thermal expansion of the low expansion part, andan adjustment part comprising a weight having a center of gravity located in an eccentric position with respect to a second axis extending in the radial direction, and attached to the deformation part so as to be rotatable about the second axis, in a state where at least the movement of the weight in a direction along the second axis is blocked.
    [2]
    2. Spring balance of the thermocompensation type according to claim 1,wherein the deformation part is a bimaterial in which the high expansion part and the low expansion part overlap each other in the radial direction and extend in a circumferential direction around the first axis, andwherein the balance main body comprises a connecting portion which connects a first end, in the circumferential direction, of the deformation part and the balance shaft to each other.
    [3]
    3. Spring balance of the thermocompensation type according to claim 1 or 2,wherein the adjusting part comprisesa shaft portion extending along the second axis and carried by the deformation part, andthe weight positioned on the outer side of the deformation part in the radial direction in the shaft portion.
    [4]
    4. Spring balance of the thermocompensation type according to claim 3,wherein the shaft portion and the flyweight are integral with each other.
    [5]
    5. Spring balance of the thermocompensation type according to claim 3,wherein the shaft portion and the flyweight are separately formed elements.
    [6]
    6. Spring balance of the thermocompensation type according to one of claims 3 to 5,wherein a chamfer in a direction tangential to a virtual circle around the second axis is formed in the flyweight in a side view obtained by looking from the radial direction, andwherein an edge which faces the first axial direction and which is an edge of the deformation portion is parallel with the chamfer when the chamfer is turned towards the first axial direction.
    [7]
    7. Spring balance of the thermocompensation type according to one of claims 1 to 6,in which an attachment portion which comprises the deformation part and to which the adjustment part is mounted so as to be removable is in several copies successive at intervals in the circumferential direction around the first axis.
    [8]
    8. Movement comprising:a spring balance of the thermocompensation type according to one of claims 1 to 7.
    [9]
    9. Timepiece comprising:a movement according to claim 8.
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    同族专利:
    公开号 | 公开日
    CN111610707A|2020-09-01|
    JP2020134428A|2020-08-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    JP2019031407A|JP2020134428A|2019-02-25|2019-02-25|Temperature compensation type balance, movement, and watch|
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