JP2010230384A - Speed governor of mechanical timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a speed governor of a mechanical timepiece is affected by the gravity center displacement and radial load of a hairspring and causes fluctuations in a vibration period. <P>SOLUTION: A plurality of hairsprings 5, 5', which have nearly the same shape, are placed at rotationally symmetric positions with a balance staff as the axis, and are wound in the same direction, are attached to the balance staff on the same plane. The plurality of hairsprings 5, 5', which are on the same plane and are placed at rotationally symmetric positions, can cancel out torque generated by the gravity center displacement of the hairsprings 5, 5' and the radial load generated by the hairsprings 5, 5', thereby minimizing their influence on the accuracy of the timepiece. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a speed control device for a mechanically driven timepiece.

  A speed control device for a mechanically driven timepiece has a structure having a ten wheel and a hairspring. The hairspring is a so-called spiral spring, and the inner end is fixed to the true spring and the outer end is fixed to the beard.

  In general, a hairspring is a shape in which a plate-shaped material having a rectangular cross section is wound into an Archimedes curve expressed by Equation 1, and when a rotating body mainly composed of a ten-wheel is rotated from an equilibrium position of the system, Torque is generated so as to return to the equilibrium position, and the rotating body receives this torque and performs rotational vibration. In Equation 1, r is the distance from the starting point of the curve, θ is the winding angle, and a is a constant that determines the pitch of the Archimedes curve.

  The hairspring is usually wound about 10 to 16 times, and the generated torque is given by an expression approximately proportional to the rotation angle from the equilibrium position. When the rotating body receives only this torque and vibrates, the period T of the rotating vibration does not depend on the amplitude of the rotating vibration or the posture of the watch, and the inertia moment of the rotating body is I, which is proportional to the torque generated by the hairspring. If the constant is k, it is expressed by Equation 2.

  Here, in addition to the torque described above, the rotating body receives torque generated by the single weight of the rotating body, friction between the stem and the receiving stone, fluid resistance of the air, and a single weight of the hairspring that will be described later. Variations in the period occur depending on the amplitude and the posture of the watch.

  Of these fluctuation factors, the single spindle of the hairspring will be described. The barycentric point of the Archimedes curve does not exist at the start point, and therefore the barycentric spring center point which is an Archimedes curve having the rotation center as the start point does not exist at the rotation center. For this reason, unless the installation surface of the hairspring is perpendicular to the gravity, torque is generated by the gravity. In this paper, the phenomenon that the center of gravity of the hairspring exists at a position different from the center of rotation is described as a single spindle of the hairspring.

  Since the magnitude and direction of the torque generated by the one balance of the hairspring is determined by the direction in which gravity acts on the hairspring, the torque acting on the rotating body varies greatly depending on the posture of the watch. This change in torque contributes to a change in the vibration cycle due to the watch's posture, that is, a so-called posture difference, and has a great influence on the performance.

  In order to avoid the influence of the single spring of the hairspring, there has been proposed a structure in which two hairsprings are attached in a rotationally symmetrical manner (Patent Document 1).

  The structure described in Patent Document 1 will be described with reference to FIG.

  The speed governor shown in FIG. 7 has a structure in which, in the configuration of the speed governor described above, a single hairspring is not used, but the two hairsprings are attached in a stepwise manner and in a positional relationship that is rotationally symmetric about the balance. It has become.

The center of gravity of each hairspring does not exist at the center of rotation, but by attaching the two hairsprings in a rotationally symmetric positional relationship, it becomes possible to cancel the torque associated with each weight of each hairspring. . However, this method has a problem that the installation space increases because the hairspring is attached in two stages.

  The balance spring also generates a radial load that depends on the rotation angle from the equilibrium position of the rotating body, and the frictional force applied to the core due to this radial load changes the vibration cycle due to the posture difference and amplitude. It has a great influence on.

  FIG. 8 is a diagram showing the relationship of the radial load when each of the hairsprings 15 and 15 'generates a radial load in the speed governor of FIG. In the structure shown in FIG. 7, since the mounting positions of the hairsprings 15 and 15 ′ are different, the axes of the radial loads f12 and f12 ′ generated by the hairsprings 15 and 15 ′ are different as shown in FIG. The load cannot be canceled out, and torque in the clockwise direction in FIG. As a result, both ends of the tenth are pressed against the portion supporting the tenth, and a frictional force is generated, resulting in disturbance.

  Further, there is a problem that the adjustment of the hairspring after the attachment becomes difficult by attaching it in two stages.

  Normally, the hairspring is made with an error of about 10 microns with respect to the outer diameter of several millimeters of winding, while the winding pitch is about 100 microns, so when two hairsprings are arranged in the same plane, There is a possibility that the distance between the hairsprings near the outer diameter becomes almost zero. In this state, when deformation due to rotation is further applied, contact between the hairsprings can occur relatively easily.

Therefore, it is necessary to avoid contact between the hairsprings by increasing the winding pitch of the hairspring more than usual or by arranging two hairsprings in a different manner as shown in the conventional example.
Here, increasing the winding pitch of the hairspring is generally in the direction of reducing the performance of the hairspring as a spring, and is not a good option.

Japanese Patent Laid-Open No. 55-101848

  The object of the present invention is to cancel the fluctuation of the vibration cycle due to the change in amplitude and posture by canceling the radial load caused by the balance spring and the balance spring, and it is an excellent machine that does not require adjustment of the balance spring It is providing the speed control apparatus of a type | formula timepiece.

  In order to solve the above-described problems, the speed control device for a mechanical timepiece according to the invention has the following configuration.

  A speed control device for a mechanically driven timepiece, which has a plurality of hairsprings, all of which have substantially the same shape and have a rotationally symmetrical positional relationship with respect to the same axis. These are wound in the same direction, both are arranged in the same plane, and are integrated with a portion used for attachment to the tenth.

  The hairspring is preferably processed by any one of photolithography and electroforming techniques.

  The balance springs arranged on the same plane and rotationally symmetric cancel out the torque generated by each single spindle, and cancel out the radial load generated by the balance spring, thereby reducing the tensile force caused by the variation in radial load. It is possible to suppress the fluctuation of the frictional force acting on the. As a result, the fluctuation of the vibration period of the speed governor accompanying the change in posture and amplitude is reduced and stabilized, so that the accuracy of the timepiece can be improved.

  In addition, by integrating the hairspring and the mustache ball, the process of attaching the hairspring to the mustache ball is omitted, and the shape of the inner and outer ends of the hairspring that has been adjusted by the operator in the past is wound. It becomes possible to process the part simultaneously and accurately. For this reason, adjustment by the operator is unnecessary, individual differences can be suppressed, and the performance of the watch can be improved.

  Furthermore, by using a technique such as photolithography, it becomes possible to process the hairspring with smaller errors, improving the torque canceling effect by the single spindle, obtaining the radial load canceling effect, and reducing individual differences. Can do.

1 is a schematic view of a speed governing device according to the present invention. Schematic of the conventional beard holding. Schematic of the whiskers in the embodiment of the speed governor according to the present invention. The shape figure of the hairspring which was integrated with the whistle ball of the speed governor by this invention. FIG. 3 is a schematic diagram of a structure for canceling torque by a single spindle of a hairspring of the governor according to the present invention. The radial load cancellation structure schematic diagram of the hairspring of the speed governor according to the present invention. The figure which shows the example of the speed control apparatus of a prior art. Schematic of the radial load in the speed governor of a prior art.

  Hereinafter, embodiments of a speed governing device according to the present invention will be described based on the drawings.

FIG. 1 is a schematic view of a speed control device for a mechanical timepiece according to the present invention. As shown in FIG. 1, a speed control device 1 for a mechanical timepiece according to the present invention rotates integrally with a tenth true stem 2, a ten wheel 3 attached to the tenth true stem 2, a beard ball 4, and a beard ball 4. It is configured with two hairsprings 5 and 5 'attached to the balance 2 in a symmetrical positional relationship, and beards 6 and 6' that support the outer ends of the hairsprings 5 and 5 '. Details of the hairsprings 5 and 5 ′ will be described later. Both ends of the ten true are supported by the receiving stone 7 in such a manner that they can freely rotate. In this example, the number of springs is described as two, but may be three or more.

  The ten wheel 3 and the tenth true 2 receive a torque from the balance springs 5 and 5 'that receives a torque approximately proportional to the rotation angle from the equilibrium position of the system, and perform rotational vibration. The mechanical timepiece mechanically extracts this vibration cycle. Displays the time. The whiskers 6 and 6 'and the slow and quick needles 8 and 8' are used for adjusting the equilibrium position of the system and adjusting the vibration period.

  The whiskers are generally attached so as to be able to rotate on the same rotational axis as the tenth shaft. However, in the present invention, the whiskers 6 and 6 ' It is also desirable to configure so that the rotationally symmetrical positional relationship is maintained.

  FIG. 2 is a schematic diagram of a conventional whisker, and FIG. 3 is a schematic diagram of a whisker used in a governor for a mechanical timepiece according to the present invention. As shown in FIG. 2, the whiskers usually have a shape in which a rod 11 extends from the ring 10, and a beard holder 12 is provided near the tip of the rod 11 to fix the beard. Although it is possible to configure the apparatus by providing a plurality of whiskers having the same shape, as shown in FIG. 3, rods 11 and 11 ′ are formed symmetrically with respect to one ring 10, and the positional relationship between them is determined. It is desirable to keep it rotating.

  The speed governor 1 is provided with slow and fast needles 8 and 8 'for adjusting the period of rotational vibration. It is desirable that the slow and steep needles 8 and 8 'be formed so as to be able to rotate while maintaining a rotationally symmetrical positional relationship similarly to the whiskers 6 and 6'. The slow and steep needles 8 and 8 'can be omitted.

  Usually, the hairspring is fixed to a bearded ball attached by press fitting or the like by means such as welding, whiskers, or caulking, and then a predetermined shape is obtained through adjustment by an operator. In this method, especially adjustment, the variation of the mainspring shape is increased due to human hands.

  FIG. 4 is a drawing showing the shape of the hairspring used in the speed governor of the present invention. The hairball 4 and the hairsprings 5 and 5 'are integrated, and the inner ends of the hairsprings 5 and 5' are also processed into a predetermined shape. In this embodiment, the shape of the inner end of the hairspring is made to follow one of the common inner end shapes, but this shape is not necessarily required.

  Further, in the speed governor of the present invention, since a plurality of hairsprings are installed, the space between the hairsprings becomes narrow, and the hairsprings show different deformation behaviors depending on their shape errors. Contact is likely to occur. Here, improvement of machining accuracy was selected as a main means for avoiding the contact of the hairspring. Specifically, the hairspring is processed using a photolithography or electroforming technique capable of processing with submicron accuracy. In addition, it can be said that improving machining accuracy is a good choice because it generally works in the direction of improving performance.

FIG. 5 shows an outline of the torque canceling effect of the balance spring half weight in this embodiment.
When the rotating body is in the equilibrium position, the gravity center points g1 and g1 ′ of the hairsprings 5 and 5 ′ are located at positions where the distance from the center is a / p in a direction approximately 90 degrees back from the winding end position. . In FIG. 5, the position of the winding end of the mainspring is not illustrated, but the drawing is performed assuming that the position is in the direction of the end point of the range illustrated.

It is assumed that gravity acts downward along the paper surface. Since the loads f1 and f1 'due to gravity applied to the hairsprings 5 and 5' are equal in size and the length of the arm with respect to the center of rotation is also equal, the torque due to the single spindle of each hairspring is equal in magnitude to each other. , Will be reversed and will cancel each other. Note that when the rotating body rotates, the center-of-gravity points g1 and g1 ′ move with the rotation, but this movement occurs symmetrically, so the cancellation structure does not change.

  FIG. 6 shows an outline of the effect of canceling the radial load of the hairspring in this embodiment. Since the hairsprings 5 and 5 'are similarly deformed according to the rotation angle of the rotating body, symmetrical radial loads f2 and f2' are generated as shown in FIG. Accordingly, the radial loads f2 and f2 'generated by the respective hairsprings 5 and 5' cancel each other. Although the radial load generated by the hairspring changes with the rotation of the rotating body, the symmetry of the radial load is maintained, so the canceling structure does not change.

  Here, the shapes of the hairsprings 5 and 5 ′ need to be substantially the same for avoiding contact and for canceling the torque and radial load due to the single spindle, but if the performance of the watch is finally improved, For the purpose of, for example, averaging the difference between the impulse caused by the entering nail and the impulse caused by the exiting nail, a slight difference in shape may be provided, for example, the thickness of a part may be different or the shapes of the inner end and the outer end may be different.

  As described above, in the speed control device for a mechanical timepiece according to the present invention, the two hairsprings 5 and 5 ′ are installed at rotationally symmetrical positions with respect to the tenth true stem 2, so that the hairsprings 5 and 5. The torque associated with the loads f1 and f1 'due to the single spindle and the radial loads f2 and f2' due to the balance springs 5 and 5 'are generated in a direction that cancels each other, thus reducing fluctuations in the vibration period due to fluctuations in posture and amplitude It becomes possible to make it.

  In addition, the balance position of the rotational vibration can be adjusted without losing the balance between the hairsprings 5 and 5 ′ by using the symmetrically produced whiskers 6 and 6 ′.

  Further, by integrating the beard ball 4 and the hairsprings 5 and 5 ′, the process of attaching the hairsprings 5 and 5 ′ to the beard ball 4 is omitted, and further adjustment by the operator is unnecessary, so that the shape error can be suppressed. It is possible to reduce disturbances and individual differences due to shape errors and improve the performance of the watch.

  Furthermore, by using the technique of photolithography or electroforming for the processing of the hairspring, it becomes possible to process the hairspring with higher accuracy, improving the effect of canceling the single spindle of the hairspring, the effect of canceling the radial load, A reduction in individual differences can be obtained.

DESCRIPTION OF SYMBOLS 1 Speed control device 2 for mechanical watches Ten true 3 Ten wheel 4 Whistle ball 5, 5 ', 15, 15' Spiral spring 6, 6 'Whisker 7 Receiving stone 8, 8' Slow and quick hand 9 Ten receiving g1, g1 ' Center-of-gravity positions f1 and f1 'of the hairsprings 5 and 5' Loads f2 and f2 'caused by the single spindle of the hairsprings 5 and 5' Radial loads f12 and f12 'generated by the hairsprings 5 and 5' are generated. Radial load

Claims (2)

  A speed control device for a mechanically driven timepiece having a plurality of hairsprings, all of which have substantially the same shape and have a rotationally symmetrical positional relationship with the same axis as the balance A speed control device for a mechanical timepiece which is wound in the same direction and is arranged in the same plane and integrated with a portion used for attachment to the tenth true.   The speed control device for a mechanical timepiece according to claim 1, wherein the hairspring is processed by any one of photolithography and electroforming techniques.

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