JP7706984B2 - Mechanical Watches - Google Patents

Description

The present invention relates to a mechanical watch.

Patent Document 1 discloses a mechanical timepiece that generates electricity based on the movement of a magnet attached to the axle (balance wheel) and adjusts the rate by observing the period of rotation of the balance (see, for example, paragraphs 0072, 0073, and Figure 27 of Patent Document 1). In addition, structures such as those disclosed in Patent Documents 2 and 3 are known as bearing structures for rotating shafts used in timepieces.

JP 2020-38206 A Special Publication No. 36-11942 JP 2014-77788 A

Here, in the mechanical watch disclosed in Patent Document 1, if the magnet is subjected to magnetic influence from other components, the accuracy of the watch's rate will decrease.

The present invention was made in consideration of the above problems, and its purpose is to provide a mechanical watch that prevents a decrease in rate accuracy.

(1) A mechanical watch comprising: a power source; a rotating shaft; a speed control mechanism including a balance wheel that rotates around the rotating shaft by the power from the power source; and a hairspring that elastically deforms to rotate the balance wheel in forward and reverse directions; a coil; and a permanent magnet that rotates in forward and reverse directions on the same axis as the balance wheel in accordance with the forward and reverse rotational motion of the balance wheel. The speed control means adjusts the speed based on a detection voltage generated in the coil by the forward and reverse rotational motion of the permanent magnet and a reference frequency of a reference signal source. The bearing structure supports the end of the rotating shaft that is closer to the permanent magnet. The bearing structure includes an elastically deforming part that elastically deforms in accordance with the displacement of the rotating shaft and is made of a non-magnetic material.

(2) In the mechanical watch of (1), the elastic deformation portion is shaped so as to be elastically deformable in at least one of the radial and axial directions of the rotating shaft in response to the displacement of the rotating shaft.

(3) A mechanical watch according to (1) or (2), wherein the bearing structure includes a stone hole in which an axle hole is formed and through which the end of the rotating shaft is inserted, and a holding part that holds the stone hole, is connected to the elastic deformation part, and is made of a non-magnetic material.

(4) A mechanical watch according to any one of (1) to (3), which has a housing member that houses the bearing structure, the housing member including a first peripheral surface that surrounds the end of the rotating shaft, a second peripheral surface that is provided closer to the balance wheel than the first peripheral surface and has a smaller diameter than the first peripheral surface, and a step portion that connects the first peripheral surface and the second peripheral surface, and the outer edge of the elastic deformation portion is fixed to the step portion.

(5) In (4), the diameter of the permanent magnet is smaller than the diameter of the second circumferential surface,
A mechanical timepiece, wherein at least a portion of the permanent magnet and the second circumferential surface are provided at the same position in the axial direction of the rotating shaft.

(6) In any one of (1) to (5), the rate adjustment means includes a control circuit that is driven by the back electromotive force generated in the coil by the forward and reverse rotational motion of the permanent magnet.

According to aspects (1) to (6) of the present invention, it is possible to prevent the rate accuracy from decreasing.

FIG. 2 is a perspective view showing the base plate and each member assembled thereto according to the present embodiment. FIG. 2 is a perspective view showing a mechanism for transmitting power and its surroundings in the embodiment. 2 is an exploded perspective view showing the speed regulating mechanism and its peripheral members disassembled from the main plate in the embodiment. FIG. 2 is a diagram showing a cross section of a support member and a soft magnetic core of the present embodiment, and their surroundings. FIG. 2A and 2B are a plan view showing a soft magnetic core and its periphery according to the embodiment, and an enlarged plan view showing a part of the soft magnetic core and its periphery in an enlarged manner. FIG. 2 is a plan view showing the speed regulating mechanism and its periphery according to the embodiment. 5 is a graph illustrating the holding torque of a permanent magnet in the present embodiment. 1 is a block diagram showing the overall configuration of a mechanical timepiece according to an embodiment of the present invention. FIG. 2 is an exploded perspective view showing an air resistance member disassembled from a base plate. FIG. 4 is a perspective view showing the operation of the balance wheel of the present embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an air resistance member in a modified example of the embodiment. FIG. 11 is a perspective view showing a balance wheel and an elastic member in a modified example of the embodiment. FIG. 11 is a perspective view showing another example of a balance wheel as viewed from the side where the hairspring is provided. FIG. 11C is a perspective view showing the balance wheel shown in FIG. 11K as viewed from the side opposite to the side where the hairspring is provided. FIG. 4 is a plan view showing a state in which the hairspring is in a neutral position of its elastic deformation. 1 is a plan view showing a state in which the hairspring is elastically deformed in an expanding direction from a neutral position. FIG. 1 is a plan view showing a state in which the hairspring is elastically deformed in a contracting direction from a neutral position. FIG. 5A and 5B are diagrams illustrating the relationship between the operation of the balance wheel and the back electromotive voltage generated in the coil in the embodiment. FIG. 4 is a diagram showing a back electromotive force detected by a coil in the arrangement of permanent magnets in the first embodiment. FIG. 11 is a diagram showing a back electromotive force detected by a coil in the arrangement of permanent magnets in the second embodiment. FIG. 11 is a diagram showing a back electromotive force detected by a coil in the arrangement of permanent magnets according to the third embodiment. FIG. 2 is a circuit diagram showing an example of a circuit according to the present embodiment. FIG. 4 is a circuit diagram showing another example of the circuit according to the embodiment. 4A to 4C are diagrams illustrating control of the movement of a permanent magnet by a speed control pulse in this embodiment. 4A to 4C are diagrams illustrating control of the movement of a permanent magnet by a speed control pulse in this embodiment. 5 is a flowchart showing an example of a rate adjustment control according to the present embodiment. 10 is a timing chart showing an example in which a detection signal is detected within an output period of a reference signal. 10 is a timing chart showing an example in which the detection timing of a detection signal is earlier than the output period of a reference signal. 11 is a timing chart showing an example in which the timing at which a detection signal is detected is later than the output period of a reference signal. 13 is a flowchart showing a first modified example of the rate adjustment control. 6 is a timing chart showing a detection signal and a reference signal in a first modified example of rate adjustment control. 13 is a flowchart showing a second modified example of the rate adjustment control. 10 is a timing chart showing a detection signal and a reference signal in a second modified example of the rate adjustment control. FIG. 4 is a diagram showing an example of a speed control pulse. 4 is a timing chart showing an example of a rate adjustment control when a power supply circuit starts to start up from a stopped state. 5 is a timing chart showing an example of rate adjustment control taking into account the influence of disturbances. 5 is a flowchart showing an example of a rate adjustment control taking into consideration the influence of disturbance. 21 is a flowchart showing rate adjustment control in which the influence of disturbance is taken into consideration in the first modified example of the rate adjustment control shown in FIG. 20. 10 is a timing chart showing an example of rate adjustment control when failure to detect a detection signal occurs successively. 10 is a timing chart showing an example of rate adjustment control when failure to detect a detection signal occurs successively. 10 is a flowchart showing an example of rate adjustment control assuming that detection failures of a detection signal occur consecutively. 4 is a timing chart showing an example of output timing of a reference signal. 2 is a cross-sectional view showing the bearing structure and its periphery according to the embodiment. FIG. FIG.

The following describes in detail an embodiment of the present invention (hereinafter, referred to as the present embodiment) with reference to the drawings.

[Overall configuration overview]
First, an overview of the overall configuration of a mechanical timepiece 1 according to this embodiment will be described with reference to Figs. 1 to 8. Fig. 1 is a perspective view showing the main plate of this embodiment and the various components incorporated therein. Fig. 2 is a perspective view showing the mechanism for transmitting power and its periphery in this embodiment. Fig. 3 is an exploded perspective view showing the speed regulating mechanism and its peripheral components in this embodiment disassembled from the main plate. Figs. 1 to 3 show the mechanical timepiece 1 as viewed from the back side. The back side is the side in the thickness direction of the mechanical timepiece 1 where the back cover of the exterior case is disposed.

Figure 4 shows a cross section of the support member and soft magnetic core of this embodiment, and their surroundings. Figure 5 shows a plan view of the soft magnetic core of this embodiment and its surroundings, and an enlarged plan view of a portion of it. Figure 6 shows a plan view of the speed regulating mechanism of this embodiment and its surroundings. Figure 7 is a graph explaining the holding torque of the permanent magnet in this embodiment. Figure 8 is a block diagram showing the overall configuration of the mechanical watch according to this embodiment. Note that Figure 5 shows the mechanical watch 1 as seen from the back side, and Figure 6 shows the mechanical watch 1 as seen from the front side. Note that the front side is the side of the mechanical watch 1 in the thickness direction from which the user can view the hands and dial.

In this embodiment, the counterclockwise direction of the balance wheel 31 and the permanent magnet 41 in each figure except for FIG. 6 is defined as the positive direction, and the clockwise direction is defined as the negative direction.

The mechanical watch 1 is a watch that uses a power spring 11 as its power source, and uses an escapement mechanism 20 and a speed regulator mechanism 30 to control the movement of the power spring 11 and drive the hands. The mechanical watch 1 is constructed by housing a main plate 10, into which the mechanisms that drive the hands are assembled, in an exterior case. Note that in this embodiment, the exterior case is not shown. Also, the crown that is located on the side of the exterior case is not shown. The crown is attached to the end of the winding stem 2 shown in FIG. 1.

[Overview of overall configuration: Configuration of drive mechanism]
An overview of the drive mechanism of the mechanical timepiece 1 will be described. In this embodiment, the mechanism including the power spring 11, which is the power source, the wheel train 12, and the hand shaft 13 is referred to as the "drive mechanism." Note that, among the hands, only the second hand 131 is shown in Fig. 2. The drive mechanism shown in Fig. 2 is one example, and is not limited to this, and may include gears other than those shown in the figure.

The power spring 11 is made of a metal band-shaped body and is housed in a barrel 110 with multiple teeth formed on its outer circumference. The barrel 110 is disk-shaped and has a cavity formed therein to house the power spring 11. The inner end of the power spring 11 is fixed to a barrel stem (not shown), which is a rotating shaft provided at the center of the barrel 110, and its outer end is fixed to the inner surface of the barrel 110. When the crown is rotated by the user's operation, the winding stem 2 rotates. The power spring 11 is wound up as the winding stem 2 rotates. The wound power spring 11 is unwound by its elastic force. The operation of the power spring 11 at this time causes the barrel 110 to rotate.

The wheel train 12 includes at least a center wheel 122, a third wheel 123, and a fourth wheel 124. The center wheel 122 includes a pinion that meshes with multiple teeth formed on the barrel 110, which functions as the first wheel, a rotating shaft, and multiple teeth, and transmits the rotation of the barrel 110 to the third wheel 123. The rotating shaft of the center wheel 122 is the pointer axis of the minute hand (not shown). The third wheel 123 includes a pinion that meshes with multiple teeth of the center wheel 122, a rotating shaft, and multiple teeth, and transmits the rotation of the center wheel 122 to the fourth wheel 124. The fourth wheel 124 includes a pinion that meshes with multiple teeth of the third wheel 123, a rotating shaft, and multiple teeth, and transmits the rotation of the third wheel 123 to the escapement mechanism 20. As shown in FIG. 2, the rotating shaft of the fourth wheel 124 is the pointer axis 13 of the second hand 131.

[Overview of Overall Configuration: Overview of Configurations of Escapement Mechanism 20 and Speed Regulating Mechanism 30 and Their Operations]
Next, the escapement mechanism 20 and the regulating mechanism 30 will be described. Power from the power spring 11 is transmitted to the escapement mechanism 20 and the regulating mechanism 30 through the wheel train 12. The escapement mechanism 20 is configured to include an escape wheel 21 and an anchor 22. The regulating mechanism 30 is configured to include a balance wheel 31 and a hairspring 32. The regulating mechanism 30 is sometimes called a balance.

The escape wheel 21 is a part that receives the rhythm of the speed regulating mechanism 30 from the pallet fork 22 by meshing with the pallet fork 22 and converts it into regular reciprocating motion. The escape wheel 21 includes a pinion that meshes with multiple teeth of the second wheel 124, a rotating shaft, and multiple teeth. As shown in FIG. 2, the multiple teeth of the escape wheel 21 are formed with wider circumferential spacing than the teeth of each gear of the train wheel 12.

The pallet fork 22 rotates forward and backward around the pallet fork arbor 221 shown in FIG. 5 as the rotation axis. The pallet fork 22 extends from the pallet fork arbor 221 toward the center of the balance wheel 31 (balance arbor 311), and has a rod portion 222 that strikes the impulse jewel 315 (see FIG. 6) that rotates together with the balance arbor 311. The impulse jewel 315 is fixed to a disk-shaped portion of the balance arbor 311 that has a predetermined width in the radial direction. FIG. 6 shows the balance wheel 31 rotated θ from a rotation angle of 0°, and the position of the impulse jewel 315 in that state.

The pallet fork 22 has a first arm 223 to which a recessed prong 223a is attached, which strikes against multiple teeth of the escape wheel 21, and a second arm 224 to which an outward prong 224a is attached, which extends in the opposite direction to the first arm 223 and strikes against multiple teeth of the escape wheel 21. The recessed prong 223a and the outward prong 224a may be made of a stone such as sapphire.

The balance wheel 31 rotates forward and backward around the balance stem 311 by the power transmitted by the wheel train 12. In the following description, the forward motion of the forward and reverse rotational motion is sometimes called "forward rotation" and the reverse motion is sometimes called "reverse rotation". The details of the structure of the balance wheel 31 will be described later. The balance stem 311 is supported by a bearing structure 330 (see FIGS. 3 and 33; not shown in FIG. 4) which is fixed to the support member 33 via a frame member 35 shown in FIGS. 3 and 4.

The hairspring 32 expands and contracts (elastically deforms) so as to rotate the balance wheel 31 forward and backward. The hairspring 32 is spiral-shaped, with its inner end fixed to the balance arbour 311 and its outer end fixed to the balance holder 34. The balance holder 34 is fixed to the main plate 10 together with the support member 33. As shown in FIG. 3, the balance holder 34 is sandwiched between the support member 33 and the frame member 35.

The escape wheel 21 rotates with the rotation of the fourth wheel 124. When the escape wheel 21 rotates, it collides with the pallet 223a of the pallet fork 22, and the pallet fork 22 rotates around the pallet fork arbor 221. The rod part 222 of the rotating pallet fork 22 collides with the impulse jewel 315 fixed to the balance arbor 311, causing the balance wheel 31 to rotate. When the balance wheel 31 rotates, the pallet 224a of the pallet fork 22 collides with the escape wheel 21, stopping the escape wheel 21. When the balance wheel 31 rotates in the opposite direction due to the restoring force of the hairspring 32, the pallet 223a of the pallet fork 22 is released, and the escape wheel 21 rotates again. As described later, the balance wheel 31 is designed to perform one cycle of operation in two seconds, so the escape wheel 21 performs one step of operation per second.

As explained above, the speed regulating mechanism 30 repeatedly rotates the balance wheel 31 in forward and reverse directions (reciprocating motion) at a constant cycle by the expansion and contraction motion of the hairspring 32. The escapement mechanism 20 continuously applies a force to the balance wheel 31 to cause it to reciprocate. This configuration and operation drives the hands such as the second hand 131.

[Overall Configuration: Configuration of Rate Adjustment Means 40]
Next, a description will be given of the configuration of the rate adjustment means 40. The mechanical timepiece 1 according to this embodiment includes the rate adjustment means 40 in addition to the drive mechanism, the escapement mechanism 20, and the speed regulation mechanism 30.

The rate adjustment means 40 is composed of a permanent magnet 41, a soft magnetic core 42 (sometimes called a stator), a coil 43, and various circuits (see FIG. 8). The rate adjustment means 40 adjusts the rate based on a detection signal detected based on the forward and reverse rotational motion of the permanent magnet 41 and the reference frequency of a quartz oscillator 70 (see FIG. 8), which is a reference signal source. Note that in this embodiment, the quartz oscillator 70 is used as a reference signal source to achieve high frequency accuracy, but this is not limiting, and for example, a CR oscillator composed of a capacitor and a resistor may be used.

Although not shown in the drawings, the coil 43 may be arranged so as to overlap an inner frame provided inside the outer case in a plan view. Alternatively, a notch may be formed in a portion of the inner frame in the circumferential direction, and the coil 43 may be arranged within the notch.

The permanent magnet 41 is a bipolar magnetized disk-shaped rotating body, and is magnetized with a north pole and a south pole in the radial direction. In other words, the permanent magnet 41 is a magnet that includes an north pole portion 411 and an south pole portion 412.

The permanent magnet 41 is attached to the balance stem 311, which is the rotation axis of the balance wheel 31 (see FIG. 10 described later), and is arranged to rotate forward and backward in accordance with the forward and reverse rotation of the balance wheel 31 (balance stem 311). In other words, the permanent magnet 41 rotates forward and backward together with the balance wheel 31 so that its rotation angle is the same as the rotation angle of the balance wheel 31. The permanent magnet 41 may be fixed to the balance stem 311 by press-fitting, gluing, or the like.

The permanent magnet 41 is preferably an isotropic magnet with its axis of easy magnetization pointing in a random direction. The permanent magnet 41 is preferably magnetized by applying a magnetic field to it using a Helmholtz coil or the like while attached to the balance shaft 311. By employing such a magnetization method, the magnetization direction of the permanent magnet 41 can be accurately aligned.

The soft magnetic core 42 is made of a soft magnetic material, and as shown in FIG. 5, has a first magnetic part 421 including a first end 421a that is provided along the outer periphery of the permanent magnet 41, and a second magnetic part 422 including a second end 422a that is provided along the outer periphery of the permanent magnet 41, and forms a magnetic circuit together with the coil 43. The first end 421a and the second end 422a both have a semicircular inner circumferential surface, and are arranged opposite each other via the permanent magnet 41.

In this embodiment, when the hairspring 32 is in the neutral position of elastic deformation, the permanent magnet 41 has the N-pole portion 411 disposed on the second magnetic portion 422 side and the S-pole portion 412 disposed on the first magnetic portion 421 side (see the enlarged view in FIG. 5). Note that the arrangement of the N-pole portion 411 and the S-pole portion 412 may be reversed, but in that case, the winding direction of the coil 43 must be reversed to that of this embodiment.

As shown in Figures 3 and 4, the soft magnetic core 42 is fixed to the support member 33 by the fixing members, pipe 33a and screw 33b. With this configuration, the soft magnetic core 42 is attached to the base plate 10 together with the support member 33. The support member 33 and the soft magnetic core 42 are positioned by the positioning pin 10a provided on the base plate 10 and the frame member 35.

As shown in FIG. 4, the frame member 35 has an annular convex portion 35a. The convex portion 35a is fitted to the inner peripheral surface of the first end portion 421a and the second end portion 422a of the soft magnetic core 42. The soft magnetic core 42 is positioned at two points, the frame member 35 and the positioning pin 10a. With this configuration, the soft magnetic core 42 can be assembled to the base plate 10 with good positional accuracy. As a result, the positional accuracy of the soft magnetic core 42 relative to the permanent magnet 41 can be improved. Here, the soft magnetic core 42 is made of a magnetic material, and the magnetic properties may deteriorate if a strong stress is applied. For example, if the soft magnetic core 42 is directly fastened to the base plate 10 by a screw or the like, the magnetic properties may deteriorate. Therefore, in this embodiment, the fitting of the positioning pin 10a and the frame member 35 is a clearance fit, and the soft magnetic core 42 is fixed to the support member 33 by the pipe 33a and the screw 33b, thereby achieving both positioning and fixing of the soft magnetic core 42. By adopting such a configuration, it is possible to improve the positioning accuracy of the soft magnetic core 42 without deteriorating the magnetic properties of the soft magnetic core 42. In addition, in this embodiment, the soft magnetic core 42 is fixed to the support member 33, but it is also possible to arrange the permanent magnet 41 corresponding to the soft magnetic core 42 between the balance wheel 31 and the main plate 10, and directly fasten the soft magnetic core 42 to the main plate 10 by a screw or the like.

Of the components assembled to the base plate 10, the components such as the support member 33, balance holder 34, frame member 35, balance spring 32, and balance wheel 31, which are located close to the permanent magnet 41 except for the soft magnetic core 42, are desirably made of non-magnetic materials so as not to affect the forward and reverse rotational motion of the speed-regulating mechanism 30 or the back electromotive force generated by the coil 43 described later.

As shown in FIG. 5, the soft magnetic core 42 includes a first welded portion 423, which is a first separation portion that separates the magnetic coupling between the first end 421a and the second end 422a, and a second welded portion 424, which is a second separation portion that separates the magnetic coupling between the first end 421a and the second end 422a and is disposed opposite the first welded portion 423 via the permanent magnet 41. The first welded portion 423 and the second welded portion 424 are preferably formed in a gap that physically separates the first end 421a and the second end 422a.

The permanent magnet 41 is in a magnetically balanced position when the magnetization direction is perpendicular to the opposing direction of the first welded portion 423 and the second welded portion 424. In this embodiment, the magnetically balanced position of the permanent magnet 41 is a rotation angle of 0°. In this position, the holding torque of the permanent magnet 41 is approximately 0. The opposing direction of the first welded portion 423 and the second welded portion 424 is the direction in which a straight line connecting the first welded portion 423 and the second welded portion 424 extends, as shown in FIG. 5.

When the rotation angle of the permanent magnet 41 is shifted 90° in the positive direction from 0°, the magnetization direction is the same as the opposing direction of the first welded portion 423 and the second welded portion 424. At this position, the holding torque of the permanent magnet 41 is approximately 0. The dashed thick line graph in Figure 7 shows the holding torque of the permanent magnet 41 due to the formation of the first welded portion 423 and the second welded portion 424.

As shown in FIG. 5, in this embodiment, notches are formed on the inner circumferential surfaces of the first end 421a and the second end 422a of the soft magnetic core 42. Specifically, notch n11 and notch n12 are formed on the first end 421a. Also, notch n21 is formed on the second end 422a facing notch n11 via the permanent magnet 41, and notch n22 is formed on the second end 422a facing notch n12 via the permanent magnet 41. By forming the notches in this manner, the magnetic influence that the permanent magnet 41 receives from the soft magnetic core 42 is reduced. Therefore, the holding torque of the permanent magnet 41 can be reduced.

One dashed line graph in FIG. 7 shows the holding torque of the permanent magnet 41 due to the formation of notches n11 and n21 arranged opposite each other, and the other dashed line graph shows the holding torque of the permanent magnet 41 due to the formation of notches n12 and n22 arranged opposite each other.

The solid line graph in FIG. 7 shows the composite holding torque obtained by combining the above-mentioned three broken line graphs. That is, the solid line graph in FIG. 7 shows the holding torque of the permanent magnet 41 due to the first welded portion 423, the second welded portion 424, and the notches n11, n12, n21, and n22 formed on the soft magnetic core 42. As shown in FIG. 7, in the configuration of this embodiment, the holding torques shown in the broken line graphs cancel each other out at each rotation angle, and the composite holding torque of the permanent magnet 41 is close to 0 at any rotation angle. Therefore, even if a hairspring 32 made of a material with a low Young's modulus is used as described later, the permanent magnet 41 can be rotated smoothly. Note that the number, arrangement, and shape of the notches shown in FIG. 5 are merely examples and are not limited thereto. It is preferable that at least one pair of mutually opposing notches that reduce the holding torque of the permanent magnet 41 are formed on the first end 421a and the second end 422a.

[Overall configuration: Overview of rate adjustment]
As shown in Fig. 8, the mechanical timepiece 1 includes a rectifier circuit 50, a power supply circuit 60, and a quartz crystal oscillator 70 in addition to the power spring 11, the wheel train 12, the escapement mechanism 20, the speed control mechanism 30, and the rate adjustment means 40 described above. Also, as shown in Fig. 8, the rate adjustment means 40 includes a control circuit 44, a rotation detection circuit 45, a speed control pulse output circuit 46, a frequency division circuit 47, and an oscillation circuit 48 in addition to the permanent magnet 41, the soft magnetic core 42, and the coil 43 described above. Note that the configuration of the rate adjustment means 40 shown in Fig. 8 is one example. The rate adjustment means 40 does not need to have each circuit shown in Fig. 8 independently, and it is sufficient if it can realize each function described below.

The control circuit 44 is a circuit that controls the operation of each circuit included in the rate adjustment means 40.

The oscillator circuit 48 outputs a predetermined oscillation signal based on the frequency of the crystal oscillator 70. The frequency of the crystal oscillator 70 is 32768 [Hz]. The frequency divider circuit 47 divides the oscillation signal output from the oscillator circuit 48. The frequency divider circuit 47 generates a reference signal OS that is output approximately every 1000 [ms] by dividing the oscillation signal based on the crystal oscillator 70. However, this is not limited, and the reference signal OS may be output every 2000 [ms] or every 3000 [ms]. In other words, the reference signal OS may be output every second. Also, this is not limited, and the reference signal OS may be output corresponding to the period of the speed regulator mechanism 30.

The rotation detection circuit 45 detects a detection signal based on the voltage waveform generated in the coil 43 by the movement of the permanent magnet 41. The speed control pulse output circuit 46 outputs a speed control pulse based on the reference signal generated by the frequency divider circuit 47 and the detection signal detected by the rotation detection circuit 45. Specifically, the detection timing of the detection signal detected by the rotation detection circuit 45 is compared with the output timing of the reference signal of about 1000 [Hz], and if there is a discrepancy between these timings, the speed control pulse output circuit 46 outputs a speed control pulse so that the period at which the detection signal is detected approaches 1000 [ms] (= 1 second).

The speed control pulse is output by energizing the coil 43. Therefore, when the period in which the detection signal is detected is faster than the reference signal, the speed control pulse output circuit 46 energizes the coil 43 so that a torque acts in a direction that slows the movement of the permanent magnet 41, and when the period in which the detection signal is detected is slower than the reference signal, the speed control pulse output circuit 46 energizes the coil 43 so that a torque acts in a direction that speeds up the movement of the permanent magnet 41. Details of the rate adjustment control, including the output timing of the speed control pulse, will be described later.

[Overview of Overall Configuration: Speed Regulating Mechanism 30 as a Generator]
The mechanical timepiece 1 also has a power generation function that uses the principle of electromagnetic induction. In this embodiment, the speed-regulating mechanism 30 functions as part of the generator. Specifically, the permanent magnet 41 rotates forward and backward in accordance with the forward and reverse rotation of the balance wheel 31, and power is generated by the current generated in the coil 43 based on the change in the magnetic field caused by the movement of the permanent magnet 41. The power extracted by this operating principle is used to start the power supply circuit 60. The start of the power supply circuit 60 makes it possible to drive the control circuit 44 included in the rate adjustment means 40. Because this configuration is adopted, in this embodiment, the control circuit 44 can be driven without providing a separate power source such as a battery.

The rectifier circuit 50 rectifies the current generated in the coil 43 by the motion of the permanent magnet 41 associated with the forward and reverse rotational motion of the balance wheel of the speed regulating mechanism 30. The power supply circuit 60 is, for example, a circuit including a capacitor, and stores power for driving the control circuit 44 based on the current rectified by the rectifier circuit 50.

[Overall configuration: Tenshin bearing structure]
Here, a bearing structure 330 of the balance shaft 311 in this embodiment will be described with reference to Fig. 33 and Fig. 34. Fig. 33 is a cross-sectional view showing the bearing structure and its periphery in this embodiment. Fig. 34 is a plan view showing an elastically deformable member.

The bearing structure 330 supports the end of the balance shaft (rotating shaft) 311 that is closer to the permanent magnet 41. As shown in FIG. 33, the balance shaft 311 has a tenon portion 311a at its tip. The tenon portion 311a is a portion of the balance shaft 311 that has a smaller diameter than the other portions. The bearing structure 330 supports the tenon portion 311a of the balance shaft 311 as shown in FIG. 33.

The bearing structure 330 is a structure including at least a hole stone 331, an elastic deformation member 332, a receiving stone 333, a holding member 334 that holds the receiving stone 333, and a receiving stone spring 335. The bearing structure 330 is housed in a frame member 35, which is a housing member. As shown in FIG. 33, the holding member 334 is fixed to the above-mentioned frame member 35. In other words, the bearing structure 330 is fixed to the support member 33 via the frame member 35.

The stone spring 335 holds the retaining member 334 at its inner edge, and is arranged so that a portion of its outer edge is hooked onto the frame member 35. The outer edge of the stone spring 335 is in elastic contact with the frame member 35. The stone spring 335 is one of the members that contributes to absorbing shock in the axial direction of the balance shaft 311. The retaining member 334 and the stone spring 335 are preferably made of a non-magnetic material. For example, the retaining member 334 is preferably made of brass, which is an alloy of copper and zinc.

The hole stone 331 is fitted into an opening 3323h (described later) formed in the elastic deformation member 332 and is fixed to the elastic deformation member 332. In addition, an axial hole 331h is formed in the center of the hole stone 331, through which the tenon portion 311a of the balance shaft 311 is inserted. The tenon portion 311a is inserted into the axial hole 331h, and is positioned radially by the hole stone 331.

The stone 333 abuts against the tip of the tenon 311a. The stone 333 determines the vertical position of the tenon 311a.

The hole stone 331 and the end stone 333 are preferably precious stones that have good sliding properties with the tenon portion 311a and are advantageous in terms of rotational movement and wear. Specifically, the hole stone 331 and the end stone 333 are preferably ruby, sapphire, or the like. However, they are not limited to this, and the hole stone 331 and the end stone 333 may be made of any non-magnetic material.

Here, if an external shock or the like occurs to the mechanical watch 1, there is a risk that the balance stem 311 will shift in position in the vertical or radial direction. Here, the vertical direction refers to the direction in which the axis ax of the balance stem 311 shown in FIG. 33 extends (hereinafter also referred to as the axial direction), and the radial direction refers to the direction perpendicular to the direction in which the axis ax extends. If the balance stem 311 shifts in position, the rotation of the balance wheel 31 and the permanent magnet 41 will be disrupted, and there is a risk that the accuracy of the rate will decrease or the power generation efficiency will decrease. Therefore, in this embodiment, a configuration is adopted in which the bearing structure 330 has an elastic deformation member 332.

As shown in FIG. 34, the elastically deforming member 332 has a spiral shape including an annular outer edge portion 3321 that constitutes its outer shape, an elastically deforming portion 3322, and an annular holding portion 3323 that holds the hole stone 331.

34, the elastic deformation portion 3322 includes a first connection portion 3322a extending radially inward from a portion of the outer edge portion 3321 in the circumferential direction, a semicircular arc portion 3322b connected to the outer edge portion 3321 via the first connection portion 3322a and extending along the outer edge portion 3321, and a second connection portion 3322c extending radially inward at the end of the semicircular arc portion 3322b opposite the first connection portion 3322a and connecting the semicircular arc portion 3322b to the holding portion 3323. The outer edge portion 3321 is fixed to the frame member 35 by being sandwiched between the frame member 35 and the holding member 334.

As shown in FIG. 33, the frame member 35 includes a first peripheral surface 351 that surrounds the end of the balance shaft 311, a second peripheral surface 352 that is located closer to the balance wheel 31 than the first peripheral surface 351 and has a smaller diameter than the first peripheral surface 351, and a step portion 353 that connects the first peripheral surface 351 and the second peripheral surface 352. Note that the first peripheral surface 351 is a peripheral surface with a diameter R1 shown in FIG. 33, and the second peripheral surface 352 is a peripheral surface with a diameter R2 (<R1) shown in FIG. 33. The outer edge portion 3321 of the elastic deformation member 332 is fixed by being sandwiched between the step portion 353 of the frame member 35 and the holding member 334.

When the balance shaft 311 is displaced in the radial direction due to an external impact or the like, the semicircular arc portion 3322b elastically deforms in the radial direction with the first connection portion 3322a as a fulcrum, and the holding portion 3323 elastically deforms in the radial direction with the second connection portion 3322c as a fulcrum. Here, "displacement" refers to the balance shaft 311 moving to a position deviated from the normal position.

In addition, when an external impact is applied and the balance shaft 311 is displaced in the axial direction, the semicircular arc portion 3322b elastically deforms in the axial direction with the first connection portion 3322a as a fulcrum, and the holding portion 3323 elastically deforms in the axial direction with the second connection portion 3322c as a fulcrum.

In this way, by adopting a configuration in which the bearing structure 330 includes the elastic deformation portion 3322, the balance shaft 311 maintains the correct position due to the elastic force of the elastic deformation portion 3322 even if a positional deviation occurs in the radial or axial direction. As a result, deterioration in rate accuracy and power generation efficiency are suppressed.

Furthermore, the elastic deformation portion 3322 may be made of a non-magnetic material. A non-magnetic material is a material other than a ferromagnetic material that is not affected by a magnetic field or is less affected by a magnetic field than a ferromagnetic material. Specifically, the elastic deformation portion 3322 may be made of a metal material such as NiP (nickel phosphorus), TiCu (titanium copper), or a copper-nickel alloy. The elastic deformation portion 3322 may be formed through an aging treatment (heat treatment). This makes it possible to obtain a thin elastic deformation portion 3322 that can ensure elasticity. The outer edge portion 3321 and the holding portion 3323 may also be made of a non-magnetic material, similar to the elastic deformation portion 3322. In other words, the entire elastic deformation member 332 may be made of a non-magnetic material.

In this way, since the elastic deformation member 332 (elastic deformation portion 3322), which is one of the members arranged near the permanent magnet 41, is made of a non-magnetic material, it is possible to prevent the permanent magnet 41 from being affected by magnetic forces. This stabilizes the operation of the permanent magnet 41. As a result, it is possible to prevent a decrease in rate accuracy and a decrease in power generation efficiency.

In addition, because the elastic deformation member 332 and the holding member 334 are made of a non-magnetic material, it is possible to place the bearing structure 330 of the balance shaft 311 closer to the permanent magnet 41. As a result, the mechanical timepiece 1 can be made smaller in the thickness direction. Furthermore, because the elastic deformation member 332 is made of a non-magnetic material, the permanent magnet 41 can be made larger. As a result, the power obtained by the operation of the permanent magnet 41 can be increased, and power generation performance can be improved.

In this embodiment, as shown in FIG. 33, the diameter of the permanent magnet 41 is smaller than the smallest diameter (diameter R2) of the opening diameters of the frame member 35. That is, the frame member 35 has an opening that can secure a space large enough to place the permanent magnet 41 in a position close to the bearing structure 330. The permanent magnet 41 is provided at a position that passes through a virtual plane P that is perpendicular to the axial direction ax of the balance shaft 311 and passes through the frame member 35. In other words, the permanent magnet 41 and the frame member 35 are provided at least partially at the same position in the axial direction ax. FIG. 33 shows an example in which the permanent magnet 41 and the second peripheral surface 352 of the frame member 35 are provided at least partially at the same position in the axial direction ax. Note that a frame member having an opening slightly larger than the diameter of the balance shaft has been used in the past, but in such a configuration, the balance shaft may interfere with the frame member due to an impact, and the end of the balance shaft may be damaged. In this embodiment, the frame member 35 has an opening with a diameter much larger than the diameter of the balance shaft 311, so the balance shaft 311 will not interfere with the frame member 35 even if an external impact is applied.

The shape of the elastic deformation member 332 shown in Figures 33 and 34 is an example and is not limited to this. The elastic deformation member 332 (elastic deformation portion 3322) may have a shape that is elastically deformable in at least one of the radial and axial directions of the tension shaft 311 in response to the displacement of the tension shaft 311.

Although not shown in the figure, the end of the balance shaft 311 farther from the permanent magnet 41 may also be supported by a structure equivalent to the bearing structure 330. This allows the same member to be used to support one end and the other end of the balance shaft 311, thereby reducing manufacturing costs.

The permanent magnet 41 may be attached directly to the balance shaft 311 as shown in FIG. 10, or may be attached to the balance shaft 311 via a housing member 410 that houses the permanent magnet 41 as shown in FIG. 33.

[Slowing down the balance wheel 31]
Here, in the mechanical timepiece 1, the faster the movement of the balance wheel 31, i.e., the faster the operation cycle of the balance wheel 31, the more easily the mechanisms that transmit power (e.g., the escape wheel 21 and the anchor 22) wear out and the durability decreases. On the other hand, since the amount of current generated in the coil 43 is proportional to the angular velocity of the permanent magnet 41, if the movement of the balance wheel 31 is slow, the amount of power generation required to drive the control circuit 44 cannot be obtained.

Therefore, in this embodiment, a configuration is adopted that slows down the movement of the balance wheel 31 while ensuring sufficient power generation.

10 is a perspective view showing the operation of the balance wheel of this embodiment. In FIG. 10, the balance wheel 31, the anchor 22, the permanent magnet 41, and the air resistance member 15 described later are shown. In FIG. 10, the reference numerals are omitted except for the figure showing the state of the rotation angle of 0°. FIG. 12 is a diagram explaining the relationship between the operation of the balance wheel in this embodiment and the back electromotive force generated in the coil. In the graph in the upper part of FIG. 12, the vertical axis is the angular velocity [rad/s] of the balance wheel 31, and the horizontal axis is the measurement time [s]. In the graph in the middle part of FIG. 12, the vertical axis is the rotation angle [deg] of the balance wheel 31, and the horizontal axis is the measurement time [s]. In the graph in the lower part of FIG. 12, the vertical axis is the back electromotive force [V] generated in the coil 43, and the horizontal axis is the measurement time [s]. In addition, each graph shown in FIG. 12 shows an example in which the movement of the balance wheel 31 (permanent magnet 41) was measured for 4 seconds.

In this embodiment, the balance wheel 31 is designed to perform one reciprocating motion every two seconds. To achieve this, a resin material with a low Young's modulus is used as the material for the hairspring 32. This allows the balance wheel 31 to oscillate at a slower speed than when it is made of a metal material. If one were to try to achieve a slower oscillation speed with a metal hairspring, it would be necessary to either reduce the cross-sectional area of the hairspring 32 to a level that makes it difficult to process, or to increase the length of the hairspring to a level that makes it difficult to handle.

In this embodiment, a resin having a Young's modulus of about 5 [GPa] was used as the material for the hairspring 32. Specifically, polyester was used as the material for the hairspring 32. The hairspring 32 made of a resin material may be manufactured, for example, by laser processing. The Young's modulus of a typical metal hairspring is about 200 [GPa]. The Young's modulus shown here is an example, and the Young's modulus of the hairspring 32 may be 20 [GPa] or less. That is, the Young's modulus of the hairspring 32 may be 1/10 or less of the Young's modulus of the metal hairspring. More preferably, the Young's modulus of the hairspring 32 may be 10 [GPa] or less. That is, the Young's modulus of the hairspring 32 may be 1/20 or less of the Young's modulus of the metal hairspring. In addition, the Young's modulus may be 20 [GPa] or less, and the hairspring 3 may be made of a material such as paper or wood. Details of the shape of the hairspring 32 will be described later with reference to Figures 11M to 11O.

In addition, in this embodiment, the rotation angle [deg] of the balance wheel 31 and the permanent magnet 41 when the hairspring 32 is in the neutral position of elastic deformation is set to 0°. The neutral position of elastic deformation of the hairspring 32 is, in other words, the position where the hairspring 32 is at its natural length. Power is supplied from the power spring 11 to the balance wheel 31 when the hairspring 32 is in the neutral position of elastic deformation. In other words, the balance wheel 31 and the permanent magnet 41 are in a power supply position where power is supplied from the power spring 11 when the rotation angle is 0°. As described above, in this embodiment, the permanent magnet 41 is in a magnetically balanced position when the rotation angle is 0°.

In addition, in this embodiment, the balance wheel 31 is designed to drive within a rotation angle range of 340° to -340°. Therefore, the permanent magnet 41 also drives within a rotation angle range of 340° to -340°. However, this is just one example, and it is preferable that the movement range of the balance wheel 31 is equal to or greater than the range of rotation angles of 270° to -270°. Increasing the movement range of the balance wheel 31 to a certain extent in this way makes it possible to achieve slow vibration of the balance wheel 31.

In addition, in FIG. 10, the balance wheel 31 is shown rotating in the positive direction from a rotation angle of 0° in increments of 45° or 90°. Note that FIG. 10 only shows the balance wheel 31 at positive angles (0° to 340°), and does not show the balance wheel 31 at negative angles.

[Slowing down the balance wheel 31: air resistance member 15]
Furthermore, in this embodiment, the air resistance member 15, which is the deceleration means, is attached to the main plate 10, and a configuration is adopted in which an acted portion 313 that receives air resistance from the air resistance member 15 is formed on a part of the circumferential direction of the balance wheel 31. Figure 9 is an exploded perspective view showing the air resistance member disassembled from the main plate.

The balance wheel 31 includes a circular part 312 that rotates forward and backward around the balance stem 311, and an acted part 313 that protrudes radially from a part of the circumference of the circular part 312. In this embodiment, the acted part 313 is the part of the balance wheel 31 that has the longest radial length. In this embodiment, the acted part 313 has a fan-like shape, as shown in FIG. 10.

The air resistance member 15 has a resistance wall that forms an air resistance area AR that generates air resistance. Specifically, the air resistance member 15 includes a first wall portion 151 that faces one surface of the acted part 313 of the balance wheel 31, a second wall portion 152 that faces the other surface of the acted part 313 of the balance wheel 31, and a third wall portion 153 that connects the first wall portion 151 and the second wall portion 152, and these walls form the air resistance area AR. In addition, the air resistance member 15 has a base portion 154 that is integral with the first wall portion 151, the second wall portion 152, and the third wall portion 153 and is fixed to the base plate 10.

The air resistance member 15 is fixed to the base plate 10. In this embodiment, as shown in FIG. 9, an opening 10b is formed in a part of the base plate 10, the air resistance member 15 is fitted into the opening 10b, and the base 154 is fixed to the base plate 10 by a fastener such as a bolt. The air resistance member 15 may be fitted into the opening 10b from the side of the base plate 10 opposite to the side where the drive mechanism, escapement mechanism 20, speed control mechanism 30, etc. are assembled. In other words, the base 154 may be fixed to the side of the base plate 10 opposite to the side where the drive mechanism, escapement mechanism 20, speed control mechanism 30, etc. are assembled. Note that FIG. 9 shows an example in which the opening 10b is formed in a part of the base plate 10, but this is not limited thereto, and any other hole that penetrates from one side of the base plate 10 to the other side may be used. For example, the base plate 10 may have a notch into which the air resistance member 15 is fitted instead of the opening 10b.

In this embodiment, the air resistance member 15 is provided in a predetermined direction relative to the balance stem 311, and is arranged so that the acted upon portion 313 is located within the air resistance area AR when the rotation angle of the balance wheel 31 is between 135° and 225° (intermediate periods in the forward and reverse motions). That is, the acted upon portion 313 of the balance wheel 31 experiences air resistance when the rotation angle of the balance wheel 31 is between 135° and 225°, causing the angular velocity to decrease. Similarly, although not shown, the acted upon portion 313 of the balance wheel 31 experiences air resistance when the rotation angle of the balance wheel 31 is between -135° and -225° (intermediate periods in the forward and reverse motions), causing the angular velocity to decrease.

The rotational speed of the balance wheel 31 passing through the air resistance area AR decreases because the escape route for the air is blocked by the first wall portion 151, the second wall portion 152, and the third wall portion 153, causing the air to stagnate in the air resistance area AR, and the stagnant air impedes the movement of the balance wheel 31.

As shown in the upper and middle graphs of FIG. 12 at the timing before the measurement time reaches 2.0 seconds, the angular velocity of the balance wheel 31 rises rapidly from the position where the balance wheel 31 has a rotation angle of 0°, and reaches a peak at the measurement time of 2.0 seconds. This is because the balance wheel 31 receives power from the power spring 11 when the balance wheel 31 has a rotation angle of 0°.

The balance wheel 31 rotates in the forward direction from a rotation angle of 0°, and its angular velocity gradually decreases until it reaches 0 at a rotation angle of 340°, which is the halfway point between the forward and reverse rotational motion. After that, the balance wheel 31 rotates in the reverse direction from the rotation angle of 340° due to the elastic deformation of the hairspring 32.

As described above, the balance wheel 31 experiences air resistance from the air resistance member 15 when the rotation angle is between 135° and 225°, and so the angular velocity during this period decreases. Therefore, as shown in the middle graph of FIG. 12, the change in the rotation angle of the balance wheel 31 becomes gentle as it rotates in the reverse direction from a rotation angle of 340° to a rotation angle of 0°.

Then, the balance wheel 31 returns to the position of 0° rotation angle, and receiving power from the power spring 11, the angular velocity in the reverse direction increases rapidly and reaches a peak. The angular velocity of the balance wheel 31 in the reverse rotation gradually decreases, and at a rotation angle of -340° (measurement time 3.0 seconds), the angular velocity becomes 0. The balance wheel 31 then rotates in the forward direction from the rotation angle position of -340° due to the elastic deformation of the hairspring 32.

Here, since the balance wheel 31 includes the acted part 313 that protrudes in the radial direction, the center of gravity of the balance wheel 31 is closer to the acted part 313 than the balance stem 311 (center of rotation). In a configuration in which the center of gravity is shifted from the balance stem 311 at the center of the balance wheel 31, the rotational motion of the balance wheel 31 becomes unstable. Therefore, in this embodiment, an opening 312h is formed in a part of the circular part 312 so that the center of gravity of the balance wheel 31 coincides with or approaches the balance stem 311 (center position). As shown in FIG. 10, the opening 312h is formed so as to be adjacent to the acted part 313 in the circumferential direction. By adopting such a configuration, the rotational motion of the balance wheel 31 is less likely to become unstable. In particular, even if the attitude of the mechanical watch 1 is displaced, it is possible to stably rotate the balance wheel 31.

In this embodiment, the air resistance member 15 is arranged so that the acted upon portion 313 is located within the air resistance area AR when the rotation angle of the balance wheel 31 is between 135° and 225°. The air resistance area AR is also arranged so that its center position 15C in the circumferential direction (see FIG. 6) overlaps with the 180° and -180° positions of the balance wheel 31 in the rotation direction of the balance wheel 31. This makes the air resistance experienced by the acted upon portion 313 symmetrical when the balance wheel 31 rotates in the forward direction and when it rotates in the reverse direction. Therefore, as shown in the graph in the middle of FIG. 12 described below, the angular velocity of the balance wheel 31 is symmetrical when it rotates in the forward direction and when it rotates in the reverse direction.

[Modification of the structure for reducing the angular velocity of the balance wheel 31]
Here, with reference to Figures 11A to 11J, modified examples of the structure for reducing the angular velocity of the balance wheel 31 will be described. Figures 11A to 11I are perspective views showing the balance wheel and air resistance member in a modified example of this embodiment. Figure 11J is a perspective view showing the balance wheel and elastic member in a modified example of this embodiment.

The balance wheel 31 shown in FIG. 11A is the balance wheel 31 shown in FIG. 10, with three notches 313A provided in the acted part 313 so that resistance walls intersecting in the circumferential direction are formed. The notches 313A are formed so that they pass through the air resistance area AR as the balance wheel 31 rotates.

The balance wheel 31 shown in FIG. 11B is the balance wheel 31 shown in FIG. 10, with three grooves 313B extending radially so as to form resistance walls that intersect in the circumferential direction on the acted part 313. The grooves 313B are formed so as to pass through the air resistance area AR as the balance wheel 31 rotates.

The balance wheel 31 shown in FIG. 11C is the balance wheel 31 shown in FIG. 10, with three through holes 313C provided in the acted part 313 so that resistance walls intersecting in the circumferential direction are formed. The through holes 313C are formed so that they pass through the air resistance area AR as the balance wheel 31 rotates.

By adopting the acted part 313 shown in Figures 11A to 11C, when the acted part 313 passes through the air resistance area AR, the air flow within the air resistance area AR is disturbed, and the air resistance experienced by the acted part 313 increases. This makes it possible to slow down the speed of the acted part 313 passing through the air resistance area AR.

The configuration of the balance wheel 31 shown in Figures 11A to 11C is one example, and is not limited to these, as long as the shape has a recess in which a resistance wall that increases air resistance is formed. In other words, the positions and number of notches, etc., are not limited to those shown in the figures.

Figure 11D shows an example in which the third wall portion 153 of the air resistance member 15 shown in Figure 10 is removed, and the first wall portion 151 and the second wall portion 152 are provided radially inward from the orbit of the acted portion 313. In other words, the air resistance member 15 forms the air resistance area AR only with the first wall portion 151 and the second wall portion 152 that face each other. Note that the first wall portion 151 and the second wall portion 152 may be assembled to the base plate 10 etc. independently of each other.

In addition, in FIG. 11D, the acted upon portion 313 protrudes radially inward. Therefore, the acted upon portion 313 passes through the air resistance area AR as the balance wheel 31 rotates. The configuration shown in FIG. 11D makes it possible to prevent the balance wheel 31 and the air resistance member 15 from becoming large in the radial direction.

Figure 11E shows an example in which the acted upon portion 313 is provided at a position different from the circular portion 312 in the axial direction of the balance shaft 311. In addition, the air resistance member 15 is provided at a position in the axial direction of the balance shaft 311 where the acted upon portion 313 can pass through the air resistance area AR.

In FIG. 11F, as in the modified example shown in FIG. 11E, the acted upon portion 313 is provided at a different position from the circular portion 312 in the axial direction of the balance stem 311. The air resistance member 15 is provided at a position in the axial direction of the balance stem 311 where the acted upon portion 313 can pass through the air resistance area AR. Furthermore, the circular portion 312 of the balance wheel 31 is semicircular. This reduces the weight of the balance wheel 31.

In the example shown in Figures 11E and 11F, the acted-on portion 313 is located at a different axial position from the circular portion 312, so that the center of gravity of the balance wheel 31 can be adjusted.

Figure 11G shows an example in which the diameter of the circular portion 312 is smaller than that of the balance wheel 31 shown in Figure 10, and the thickness of the portion facing the acted portion 313 via the balance stem 311 is thicker. In other words, the weight of the circular portion 312 is greater at the portion facing the acted portion 313 via the balance stem 311. With this configuration, the center of gravity of the balance wheel 31 can be aligned with the balance stem 311 (the center position of the balance wheel 31). In addition, the configuration of Figure 11G in which the diameter of the balance wheel 31 is smaller has the advantage of improving the degree of freedom in the layout of the balance spring 34 that fixes the outer end of the hairspring 32.

Figure 11H shows an example in which the air resistance member 15 does not have the first wall portion 151 and the second wall portion 152, but only includes a configuration corresponding to the third wall portion 153. That is, the air resistance member 15 in Figure 11H is composed of a base portion 154 and a third wall portion 153 that stands up from the base portion 154 and has a shape that follows the rotation trajectory of the balance wheel 31.

Figure 11I shows an example in which grooves 153I, which are recesses that form resistance walls that intersect with the circumferential direction of the balance wheel 31, are formed in the air resistance member 15 shown in Figure 11H. A plurality of grooves 153I are formed along the axial direction of the balance arbour 311. With this configuration, it is possible to increase the air resistance acting on the acted part 313 passing through the air resistance area AR, compared to Figure 11H.

Figure 11J shows an example of a configuration that uses contact resistance (friction resistance) rather than air resistance to slow down the speed of the balance wheel 31. Specifically, the balance wheel 31 has a protrusion 316 formed on the circular part 312 as the acted part. In addition, an elastic member is used as the friction resistance part.

Specifically, a first elastic member 151J is provided with which the protrusion 316 comes into contact when the balance wheel 31 is positioned at a rotation angle of 135°, and a second elastic member 152J is provided with which the protrusion 316 comes into contact when the balance wheel 31 is positioned at a rotation angle of 225°. The ends of the first elastic member 151J and the second elastic member 152J are preferably fixed to the base plate 10.

When the protrusion 316 of the balance wheel 31 comes into contact with the first elastic member 151J and the second elastic member 152J, the first elastic member 151J and the second elastic member 152J elastically deform while generating frictional resistance between the protrusion 316 and the protrusion 316. While the balance wheel 31 is in contact with the protrusion 316, the speed of the balance wheel 31 is reduced by the frictional resistance. In the example shown in FIG. 11J, the region through which the protrusion 316 passes while in contact with the first elastic member 151J and the second elastic member 151J is the resistance region R1.

The configurations shown in Figures 10 and 11A to 11J are merely examples, and any configuration that acts on the balance wheel 31 to decelerate it during the intermediate periods of both the forward and reverse motions is sufficient, and is not limited to the examples shown.

Furthermore, with reference to Figures 11K and 11L, another example of the balance wheel 31 will be described. Figure 11K is a perspective view showing another example of the balance wheel as seen from the side where the hairspring is provided. Figure 11L is a perspective view showing the balance wheel shown in Figure 11K as seen from the side opposite the side where the hairspring is provided.

The balance wheel 31 shown in Figures 11K and 11L has a circular part 312 and an acted part 313, similar to the one shown in Figure 10 etc. In addition, an opening 312h is formed in the circular part 312 at a position overlapping with the acted part 313 in the circumferential direction.

Furthermore, in the balance wheel 31 shown in Figures 11K and 11L, the edge 312a of the circular portion 312 protrudes in the axial direction of the balance arbour 311. That is, the edge 312a is thicker than the part of the circular portion 312 on the inside of the edge 312a. Also, the acted upon portion 313 is formed flush with the edge 312a. That is, the thickness of the acted upon portion 313 is the same as that of the edge 312a, and is thicker than the part of the circular portion 312 on the inside of the edge 312a.

In the balance wheel 31 shown in Figures 11K and 11L, the thickness of the acted part 313 is relatively thick, so that the surface of the acted part 313 that receives air resistance is relatively wide. This makes it possible to increase the amount of air pushed aside by the acted part 313 within the air resistance area AR shown in Figure 10, making it easier to hinder the movement of the balance wheel 31 and make it easier to slow down. In addition, by arranging the hairspring 32 on the relatively thin parts of the balance wheel 31 other than the edge part 312a and the acted part 313, it is possible to reduce the total thickness of the hairspring 32 and the balance wheel 31 in the axial direction of the balance arbour 311.

Furthermore, as shown in FIG. 11L, the thickness of the surface of the circular portion 312 of the balance wheel 31 opposite the side where the hairspring 32 is provided has been partially increased. If the thickness of the acted upon portion 313 is increased, the weight of the acted upon portion 313 will increase, and the center of gravity of the balance wheel 31 will move closer to the acted upon portion 313. However, by partially increasing the thickness of the circular portion 312, the position of the center of gravity of the balance wheel 31 can be aligned with the balance arbour 311 (the center position of the balance wheel 31).

Furthermore, the balance spring 32 will be described in detail with reference to Figures 11M to 11O. Figure 11M is a plan view showing the balance spring in its neutral position of elastic deformation. Figure 11N is a plan view showing the balance spring in its elastically deformed state in the expansion direction from the neutral position. Figure 11O is a plan view showing the balance spring in its elastically deformed state in the contraction direction from the neutral position.

The hairspring 32 has an outer end 321 connected to the hairspring holder 34 and an inner end 322 connected to the balance arbor 311. The inner end 322 is annular and follows the circumferential surface of the balance arbor 311. The outer end 321 and the inner end 322 are thicker than the other parts of the hairspring 32 (the parts that undergo elastic deformation). This maintains the strength of the connection to the hairspring holder 34 and the balance arbor 311.

By increasing the overall length of the hairspring 32, the spring force of the hairspring 32 can be reduced, thereby achieving low vibration. Increasing the overall length of the hairspring 32 results in a larger diameter of the hairspring 32. In order to increase the overall length of the hairspring 32 while making it smaller, it is advisable to shorten the distance between the inner and outer parts of the hairspring 32. In other words, it is advisable to narrow the pitch of the hairspring 32.

A logarithmic spiral shape is used for the hairspring 32. As described above, a logarithmic spiral hairspring can be easily manufactured by performing laser processing. By adopting a logarithmic spiral shape, the distance between the pitches of the hairspring 32 on the inner end 322 side can be made smaller than the uniform-pitch Archimedes' spiral that is commonly used as a hairspring shape, making it possible to increase the overall length of the hairspring and reduce its diameter. As a result, the spring force can be reduced while the diameter of the hairspring 32 is reduced, and low vibration can also be achieved. However, when the hairspring 32 is manufactured by laser processing as described above, it is difficult to narrow the pitch. This is because the shape of the hairspring 32 may be deformed by the heat of the laser light.

In order to maintain the dimensional accuracy of the hairspring 32 while narrowing the pitch, the inner end 322 is configured to include a fixed portion 322a and a pitch expansion portion 322b, as shown in Figs. 11M to 11O. The fixed portion 322a is a portion that is fixed to the balance arbour 311. The pitch expansion portion 322b is a portion narrower than the fixed portion 322a, and expands the pitch between the inner end 322 and a portion 323 of the hairspring 32 that is adjacent to the inner end 322 in the radial direction. The portion 323 of the hairspring 32 that is adjacent to the inner end 322 in the radial direction is a portion other than the inner end 322, and is the portion that is located on the innermost side. W shown in Figs. 11M to 11O indicates the distance between the inner end 322 and the portion 323 that is adjacent to the inner end 322 in the radial direction.

Note that, although an example in which the inner end 322 is annular, that is, an example in which the fixed portion 322a and the pitch enlargement portion 322b are connected, is shown in Figs. 11M to 11O, this is not limiting. For example, the inner end 322 may be partially separated in the circumferential direction, and the separated portion may function as the pitch enlargement portion 322b. However, it is easier to ensure the strength of the fixation to the balance shaft 311 when the inner end 322 is annular. Note that, although an example in Figs. 11M to 11O shows the hairspring 32 in a shape using a logarithmic spiral, this is not limiting, and the configuration in which the pitch enlargement portion 322b is formed is particularly effective for hairsprings in which the pitch is narrower on the inside of the diameter than on the outside of the diameter.

In the present embodiment and the modified example, an example in which the balance wheel 31 is slowed down has been described, but the present invention is not limited to this. By increasing the speed of the balance wheel 31, the number of reciprocating movements of the balance wheel 31 per second is increased, and the error per second, i.e., the effect on the rate accuracy, is reduced. In this manner, a configuration in which the balance wheel 31 is relatively fast may be adopted in which the above-mentioned elastic deformation portion 332 is provided.

[Regarding power generation timing]
The amount of current generated in the coil 43 by the movement of the permanent magnet 41 increases in proportion to the angular velocity of the permanent magnet 41. Therefore, in order to generate power efficiently, it is preferable to use the current generated in the coil 43 when the angular velocity of the permanent magnet 41 is high.

In this embodiment, therefore, power is generated based on a current corresponding to the back electromotive force (detected voltage) detected by the coil 43 due to the movement of the permanent magnet 41 when the permanent magnet 41 (balance wheel 31) is at the 0° position or immediately thereafter. In other words, as shown in the lower graph of FIG. 12, power is generated when the back electromotive force detected by the coil 43 reaches its peak.

The timing for generating electricity is not limited to when the balance wheel 31 is at a rotation angle of 0° or immediately thereafter, but may be any time before the acted upon part 313 (balance wheel 31) reaches the position of the air resistance member 15 in either the forward or reverse rotational motion of the balance wheel 31. In other words, electricity may be generated based on the current corresponding to the back electromotive force detected by the coil 43 during the period before the angular velocity of the balance wheel 31 decreases due to the acted upon part 313 receiving air resistance from the air resistance member 15.

As shown in the lower graph of FIG. 12, in this embodiment, the voltage waveforms detected when the balance wheel 31 moves in the forward direction and the reverse direction are the same. Therefore, in the mechanical watch 1, in order to time the power generation, it is not necessary to know whether the balance wheel 31 is moving in the forward direction or the reverse direction.

[Relationship between magnetization direction of permanent magnet 41 and power generation efficiency]
Here, the relationship between the magnetization direction of the permanent magnet 41 and power generation efficiency will be described with reference to FIGS. 5, 12, and 13A to 13C.

In the mechanical watch 1 according to this embodiment, power is generated based on the power obtained by rectifying the current corresponding to the back electromotive force generated in the coil 43 using the rectifier circuit 50. Here, as the rectification by the rectifier circuit 50, full-wave rectification using a bridge circuit including multiple diodes, or half-wave rectification using a circuit including one diode can be considered. When multiple diodes are used, a voltage drop occurs according to the number of diodes, resulting in a loss of power obtained. Therefore, in this embodiment, a configuration is adopted in which half-wave rectification is performed by the rectifier circuit 50. In addition, in half-wave rectification, a difference is made between the shape of the positive back electromotive force and the negative back electromotive force, and power is generated based on the back electromotive force with the larger absolute value, thereby enabling efficient power generation. Therefore, in this embodiment, the permanent magnet 41 is arranged so that a back electromotive force suitable for half-wave rectification is detected.

Figure 13A shows the back electromotive force detected by the coil 43 in the arrangement of the permanent magnet 41 in Example 1. Figure 13B shows the back electromotive force detected by the coil 43 in the arrangement of the permanent magnet 41 in Example 2. Figure 13C shows the back electromotive force detected by the coil 43 in the arrangement of the permanent magnet 41 in Example 3.

[Relationship between magnetization direction of permanent magnet 41 and power generation efficiency: Example 1]
In the first embodiment, the permanent magnet 41 is arranged so that the magnetization direction is perpendicular to the opposing direction of the first welded portion 423 and the second welded portion 424 when the hair spring 32 is in its neutral position of elastic deformation.

Here, we will explain the back electromotive force detected by coil 43 as permanent magnet 41 rotates in the forward direction from the rotation angle position of 0°, rotates in the reverse direction due to the elastic force of hairspring 32, and then rotates again in the forward direction due to the elastic force of hairspring 32.

The counter electromotive voltage generated in the coil 43 due to the change in the magnetic field when the N-pole portion 411 of the permanent magnet 41 moves in a direction toward the first end 421a of the soft magnetic core 42 is defined as a "positive" counter electromotive voltage. On the other hand, the counter electromotive voltage generated in the coil 43 due to the change in the magnetic field when the N-pole portion 411 moves in a direction away from the first end 421a of the soft magnetic core 42 is defined as a "negative" counter electromotive voltage.

In Example 1, the permanent magnet 41 is in a position of magnetic balance at a rotation angle of 0°. Therefore, at a rotation angle of 0°, the back electromotive voltage generated in the coil 43 is zero. At a rotation angle of 0°, the permanent magnet 41 is supplied with power from the power spring 11. That is, the angular velocity of the permanent magnet 41 is maximum immediately after the rotation angle of 0°. Also, while the permanent magnet 41 rotates in the forward direction from a rotation angle of 0° to 180°, the N pole portion 411 moves in a direction approaching the first end 421a. Thus, in Example 1, the permanent magnet 41 is arranged so that the back electromotive voltages detected in the coil 43 during the period from the power supply position to the rotation of 180° in the forward direction are of the same polarity.

Therefore, while the permanent magnet 41 rotates from a rotation angle of 0° to 180°, the angular velocity of the permanent magnet 41 reaches a maximum, and the positive back electromotive voltage generated in the coil 43 reaches a peak.

At a rotation angle of 180°, where the permanent magnet 41 is in a magnetically balanced position, the back electromotive force generated in the coil 43 becomes zero.

When the permanent magnet 41 rotates in the positive direction from a rotation angle of 180°, the N pole portion 411 moves in a direction away from the first end 421a. Therefore, a negative back electromotive force is generated in the coil 43 while the permanent magnet 41 rotates from a rotation angle of 180° to 340°. The angular velocity of the permanent magnet 41 at this time is smaller than the angular velocity when it moves from a rotation angle of 0° to 180°. Therefore, the absolute value of the peak of the negative back electromotive force is smaller than the absolute value of the peak of the positive back electromotive force.

The angular velocity of the permanent magnet 41 becomes zero at a rotation angle of 340°, which is the turning point of the reciprocating motion. Therefore, at a rotation angle of 340°, the back electromotive voltage generated in the coil 43 becomes zero.

When the permanent magnet 41 reaches a rotation angle of 340°, it starts to rotate in the reverse direction due to the elastic force of the hairspring 32. When the permanent magnet 41 rotates from a rotation angle of 340° to 180°, the N-pole portion 411 moves in a direction approaching the first end 421a. Therefore, a positive back electromotive force is generated in the coil 43 while the permanent magnet 41 rotates from a rotation angle of 340° to 180°.

In addition, at a rotation angle of 180°, where the permanent magnet 41 is in a magnetically balanced position, the back electromotive force generated in the coil 43 becomes zero.

Furthermore, the permanent magnet 41 rotates from a rotation angle of 180° to 0°. When the permanent magnet 41 rotates from a rotation angle of 180° to 0°, the N pole portion 411 moves in a direction away from the first end 421a. Therefore, when the permanent magnet 41 rotates from a rotation angle of 180° to 0°, a negative back electromotive voltage is generated in the coil 43.

In addition, at a rotation angle of 0°, where the permanent magnet 41 is in a magnetically balanced position, the back electromotive force generated in the coil 43 is zero.

When the permanent magnet 41 reaches a rotation angle of 0°, power is supplied from the power spring 11. That is, the angular velocity of the permanent magnet 41 reaches a maximum immediately after the rotation angle reaches 0°. Also, while the permanent magnet 41 rotates from a rotation angle of 0° to -180°, the N pole portion 411 moves in a direction approaching the first end 421a. Thus, in Example 1, the permanent magnet 41 is positioned so that the back electromotive voltage detected in the coil 43 during the time it rotates in the reverse direction from the power supply position to -180° has the same polarity.

Therefore, while the permanent magnet 41 rotates from a rotation angle of 0° to -180°, the angular velocity of the permanent magnet 41 reaches a maximum, and the positive back electromotive force generated in the coil 43 reaches a peak.

At a rotation angle of -180°, where the permanent magnet 41 is in a magnetically balanced position, the back electromotive force generated in the coil 43 becomes zero.

When the permanent magnet 41 rotates in the reverse direction from a rotation angle of -180°, the N pole portion 411 moves in a direction away from the first end 421a. Therefore, a negative back electromotive force is generated in the coil 43 while the permanent magnet 41 rotates from a rotation angle of -180° to -340°. The angular velocity of the permanent magnet 41 at this time is lower than the angular velocity when it moves from a rotation angle of 0° to -180°. Therefore, the absolute value of the peak of the negative back electromotive force is smaller than the absolute value of the peak of the positive back electromotive force.

The angular velocity of the permanent magnet is zero at a rotation angle of -340°, which is the turning point of the reciprocating motion. Therefore, the back electromotive force generated in the coil 43 is zero at a rotation angle of -340°.

When the permanent magnet 41 reaches a rotation angle of -340°, it starts to rotate in the forward direction due to the elastic force of the hairspring 32. When the permanent magnet 41 rotates from a rotation angle of -340° to -180°, the N pole portion 411 moves in a direction approaching the first end 421a. Therefore, a positive back electromotive force is generated in the coil 43 while the permanent magnet 41 rotates from a rotation angle of -340° to -180°.

Furthermore, at a rotation angle of -180°, where the permanent magnet 41 is in a magnetically balanced position, the back electromotive force generated in the coil 43 becomes zero.

Furthermore, the permanent magnet 41 rotates from a rotation angle of -180° to 0°. When the permanent magnet 41 rotates from a rotation angle of -180° to 0°, the N pole portion 411 moves in a direction away from the first end 421a. Therefore, when the permanent magnet 41 rotates from a rotation angle of -180° to 0°, a negative back electromotive voltage is generated in the coil 43.

By repeating the above operations, in the arrangement of the permanent magnet 41 of Example 1, a back electromotive voltage with the waveform shown in FIG. 13A is generated in the coil 43. As shown in FIG. 13A, the peaks of the back electromotive voltage are different for positive back electromotive voltage and negative back electromotive voltage. In other words, the maximum absolute value of the positive back electromotive voltage is greater than the maximum absolute value of the negative back electromotive voltage. Furthermore, the waveform of the detected back electromotive voltage is the same when the permanent magnet 41 moves in the positive direction and when it moves in the reverse direction.

[Relationship between magnetization direction of permanent magnet 41 and power generation efficiency: Example 2]
Next, a second embodiment will be described with reference to Fig. 13B. In the second embodiment, the permanent magnet 41 is disposed such that the magnetization direction is inclined by 45° toward the opposing direction of the first welded portion 423 and the second welded portion 424 when the hairspring 32 is in the neutral position of its elastic deformation. That is, in the second embodiment, the position of the rotation angle of 0° is inclined by -45° from that in the second embodiment.

In Example 2, when the permanent magnet 41 rotates in the positive direction from a rotation angle of 0°, first, the N-pole portion 411 moves in a direction away from the first end 421a. Then, when the permanent magnet 41 passes a rotation angle of 45°, the N-pole portion 411 moves in a direction approaching the first end 421a. Therefore, while the permanent magnet 41 rotates in the positive direction from a rotation angle of 0° to 225°, a negative back electromotive force is generated in the coil 43 immediately after the rotation, and then, after passing the rotation angle of 45°, a positive back electromotive force is generated in the coil 43.

In Example 2, the permanent magnet 41 rotates in the forward direction from a rotation angle of 0° to 340°, rotates in the reverse direction due to the elastic force of the hairspring 32, and returns to a rotation angle of 0°. When the permanent magnet 41 rotates in the reverse direction from a rotation angle of 0°, the N-pole portion 411 moves in a direction approaching the first end 421a. In other words, when the permanent magnet 41 rotates in the reverse direction from a rotation angle of 0°, a positive back electromotive voltage is generated in the coil 43.

In this way, in Example 2, the waveforms of the positive back electromotive voltage and the negative back electromotive voltage are different at least around a rotation angle of 0° in the forward and reverse directions of rotation. Therefore, the magnitude of the peak of the back electromotive voltage is different in the forward and reverse directions of rotation. In addition, since the peak position of the back electromotive voltage is different in the forward and reverse directions of rotation, it may be determined that the period of the forward and reverse rotational motion of the balance wheel 31 is disturbed, and the rate may be erroneously adjusted. Therefore, in the configuration of Example 2, it becomes necessary for the rate adjustment means 40 to have a means for determining in advance whether the balance wheel 31 is moving in the forward direction or the reverse direction.

[Relationship between magnetization direction of permanent magnet 41 and power generation efficiency: Example 3]
Next, Example 3 will be described with reference to Fig. 13C. In Example 3, the permanent magnet 41 is arranged so that the magnetization direction is the same as the opposing direction of the first welded portion 423 and the second welded portion 424 when the hairspring 32 is in the neutral position of its elastic deformation. That is, in Example 3, the position of the rotation angle of 0° is arranged at a tilt of -90° from the present embodiment.

In Example 3, when the permanent magnet 41 rotates in the positive direction from a rotation angle of 0°, first, the N-pole portion 411 moves in a direction away from the first end 421a. Then, when the permanent magnet 41 passes a rotation angle of 90°, the N-pole portion 411 moves in a direction approaching the first end 421a. Therefore, while the permanent magnet 41 rotates in the positive direction from a rotation angle of 0° to 180°, a negative back electromotive voltage is generated in the coil 43 immediately after the rotation, and then, after passing a rotation angle of 90°, a positive back electromotive voltage is generated in the coil 43.

In Example 3, the permanent magnet 41 rotates in the forward direction from a rotation angle of 0° to 340°, rotates in the reverse direction due to the elastic force of the hairspring 32, and returns to a rotation angle of 0°. When the permanent magnet 41 rotates in the reverse direction from a rotation angle of 0°, the N-pole portion 411 moves in a direction approaching the first end 421a. In other words, when the permanent magnet 41 rotates in the reverse direction from a rotation angle of 0°, a positive back electromotive voltage is generated in the coil 43.

In this way, in the third embodiment, the waveforms of the positive back electromotive voltage and the negative back electromotive voltage are different at least at around 0° of rotation angle in the forward and reverse directions. Therefore, the magnitude of the peak of the back electromotive voltage is different in the forward and reverse directions. In the configuration of the third embodiment, the peak of the back electromotive voltage is smaller in the forward and reverse directions compared to the first embodiment, and it cannot be said that the back electromotive voltage is suitable for half-wave rectification. In addition, since the peak of the back electromotive voltage is different in the forward and reverse directions, it may be necessary to make the threshold value Vth different in some cases. As a result, as in the second embodiment, it becomes necessary for the rate adjustment means 40 to have a means for determining in advance whether the balance wheel 31 is moving in the forward or reverse direction.

[Summary of the relationship between the magnetization direction of the permanent magnet 41 and power generation efficiency]
As described above, in the first embodiment, regardless of whether the rotation direction of the permanent magnet 41 is forward or reverse, a back electromotive voltage having the same waveform is detected. Therefore, in the first embodiment, the peaks of the positive back electromotive voltage are detected with the same magnitude and at a constant period. Furthermore, in the first embodiment, the shapes of the positive back electromotive voltage and the negative back electromotive voltage are asymmetric. Specifically, the peaks of the positive back electromotive voltage are larger than the peaks of the negative back electromotive voltage. Therefore, in the arrangement of the permanent magnet 41 in the first embodiment, it can be said that the back electromotive voltage has a waveform suitable for rate adjustment and half-wave rectification, compared to the second and third embodiments.

The arrangement of the permanent magnet 41 shown in FIG. 5 is an example, and the permanent magnet 41 is preferably arranged so that its magnetization direction is the same as the opposing direction of the first end 421a and the second end 422a when the hairspring 32 is in the neutral position of its elastic deformation. The opposing direction of the first end 421a and the second end 422a is a direction perpendicular to the opposing direction of the first welded portion 423 and the second welded portion 424 shown in FIG. 5. However, this is not limited to this, and the magnetization direction of the permanent magnet 41 should be directed toward the first end 421a or the second end 422a at least when the hairspring 32 is in the neutral position of its elastic deformation.

Furthermore, the permanent magnet 41 is preferably arranged so that, when the hairspring 32 is in the neutral position of its elastic deformation, the boundary B between the north pole portion 411 and the south pole portion 412 overlaps with a virtual strip-shaped area (S shown in FIG. 5) that connects the first welded portion 423 and the second welded portion 424. Note that the strip-shaped area S is a virtual area defined for the sake of convenience to indicate the arrangement of the permanent magnet 41, and does not physically exist as part of the configuration of the mechanical timepiece 1.

[Circuit diagram]
Here, an overview of the rectifier circuit in this embodiment will be described with reference to Fig. 14A, which is a circuit diagram showing an example of the circuit in this embodiment.

In this embodiment, a rectifier circuit 50 including one diode D is used to half-wave rectify the current corresponding to the back electromotive force generated in the coil 43 by the motion of the permanent magnet 41. The rectifier circuit 50 is a circuit that eliminates the negative voltage portion of the back electromotive force generated in the coil 43 and converts it to direct current.

The transistors TP1 and TP2 are respectively connected to the first terminal O1 and the second terminal O2 of the coil 43. The back electromotive voltage generated in the coil 43 is input to the transistors TP1 and TP2, and the rotation detection circuit 45 detects a detection signal based on the back electromotive voltage. That is, by turning on the transistor TP2 at a predetermined timing, the induced voltage generated at the first terminal O1 and the second terminal O2 corresponding to the transistors can be extracted as a detection signal, which is a voltage signal.

The transistors P11 and P12 are connected to the first terminal O1 of the coil 43, and the transistors P21 and P22 are connected to the second terminal O2 of the coil 43. The transistors P11, P12, P21, and P22 are controlled to be turned on and off by the speed control pulse from the speed control pulse output circuit 46. When generating electricity, the gate terminals of the transistors P11, P12, P21, and P22 are turned off. In this state, the rectifier circuit 50 is formed by the transistors TP1 and TP2 and the diode D. When the permanent magnet 41 rotates forward and backward, a current flows through the coil 43 and the capacitor C is charged. When a certain amount of charge is stored in the capacitor C, the power supply circuit 60 is started. Then, when the power supply circuit 60 is started, the control circuit 44 is started, and the control circuit 44 controls each circuit included in the rate adjustment means 40.

In this embodiment, as shown in FIG. 14A, a configuration is adopted in which half-wave rectification is performed using a rectifier circuit 50 including one diode D, so that the circuit configuration can be simplified and voltage drops can be made less likely to occur. Note that the circuit shown in FIG. 14A is just one example, and as shown in FIG. 14B, a voltage doubler rectifier circuit that can also rectify the back electromotive force in the reverse direction may be used as the rectifier circuit 50. FIG. 14B shows an example of a voltage doubler rectifier circuit including two diodes D1, D2 and two capacitors C1, C2. In a voltage doubler rectifier circuit, the number of diodes can be reduced compared to a full-wave rectifier circuit. In other words, voltage drops can be made less likely to occur.

[Details about the speed adjustment control]
Details of the rate adjustment control in this embodiment will be described below with reference to Fig. 12 and Fig. 15A to Fig. 19. Fig. 15A and Fig. 15B are diagrams for explaining the control of the movement of the permanent magnet by the speed control pulse in this embodiment.

In this embodiment, the speed control pulse output circuit 46 outputs a speed control pulse to control the movement of the permanent magnet 41, thereby controlling the movement of the balance wheel 31 and adjusting the rate.

In this embodiment, as shown in FIG. 15A, when a speed control pulse is output to the first terminal O1 of the coil 43, the first end 421a is defined as having an S pole and the second end 422a is defined as having an N pole. On the other hand, as shown in FIG. 15B, when a speed control pulse is output to the terminal O2 of the coil 43, the first end 421a is defined as having an N pole and the second end 422a is defined as having an S pole. Note that when the winding direction of the coil 43 is reversed, the polarities of the first end 421a and the second end 422a are reversed.

[Details of speed adjustment control: Output timing of speed adjustment pulse]
Here, when the angular velocity of the permanent magnet 41 is high, it is difficult to adjust the rate at the desired timing. This is because when the angular velocity of the permanent magnet 41 is high, there is a high possibility that the output timing of the speed control pulse will be shifted.

Therefore, in this embodiment, in the forward and reverse rotational motion of the permanent magnet 41, a speed control pulse is output while the permanent magnet 41 rotates in the reverse direction from a rotation angle of 180° to 0°, and while the permanent magnet 41 rotates in the forward direction from a rotation angle of -180° to 0°. In other words, a speed control pulse is output during the period before the balance wheel 31 is supplied with power from the power spring 11. This makes it possible to output a speed control pulse when the angular velocity of the permanent magnet 41 is relatively slow. In addition, in this embodiment, the balance wheel 31 receives air resistance from the air resistance member 15 between rotation angles of 225° and 135°, so the angular velocity of the permanent magnet 41 is particularly slow between rotation angles of 180° and 0°. The same is true for rotation angles between -225° and -135°. In this way, in the forward and reverse motion of the forward and reverse rotational motion of the balance wheel 31, it is preferable to perform the rate adjustment during the period after the acted part 313 reaches the position of the air resistance member 15.

By adopting such a configuration, it is possible to prevent deviations in the output timing of the speed control pulse. As a result, it is possible to maintain the rate accuracy. In FIG. 12, the timing for rate adjustment is indicated by a band-shaped area. As shown in the upper graph of FIG. 12, rate adjustment is performed during the period when the angular velocity of the permanent magnet 41 is slow.

[Details about the rate adjustment control: Coil terminal where the speed adjustment pulse is output]
Figure 15A shows an example in which a speed control pulse is output to coil 43 at a timing when permanent magnet 41 rotating in the forward direction is at a rotation angle of -90°, and at a timing when permanent magnet 41 rotating in the reverse direction is at a rotation angle of 90°.

As shown in FIG. 15A, when a speed control pulse is output to the first terminal O1 of the coil 43 as the permanent magnet 41 rotates in the forward direction from a rotation angle of -90°, the permanent magnet 41 receives a repulsive force from the soft magnetic core 42. In other words, the forward rotation of the permanent magnet 41 is braked. On the other hand, when a speed control pulse is output to the first terminal O1 of the coil 43 as the permanent magnet 41 rotates in the reverse direction from a rotation angle of 90°, the permanent magnet 41 receives a repulsive force from the soft magnetic core 42. In other words, the reverse rotation of the permanent magnet 41 is braked.

Also, as shown in FIG. 15B, when a speed control pulse is output to the second terminal O2 of the coil 43 as the permanent magnet 41 rotates in the forward direction from a rotation angle of -90°, the permanent magnet 41 receives an attractive force from the soft magnetic core 42. In other words, the forward rotation of the permanent magnet 41 is accelerated. On the other hand, when a speed control pulse is output to the second terminal O2 of the coil 43 as the permanent magnet 41 rotates in the reverse direction from a rotation angle of 90°, the permanent magnet 41 receives an attractive force from the soft magnetic core 42. In other words, the reverse rotation of the permanent magnet 41 is accelerated.

In this manner, in this embodiment, regardless of whether the permanent magnet 41 is rotating in the forward or reverse direction during its forward or reverse rotational motion, the rotation of the permanent magnet 41 can be weakened by outputting a speed control pulse to the first terminal O1, while the rotation of the permanent magnet 41 can be strengthened by outputting a speed control pulse to the second terminal O2.

In other words, regardless of whether the permanent magnet 41 is rotating in the forward or reverse direction, if the rate is to be adjusted to a delayed rate, it is sufficient to energize the first terminal O1, and if the rate is to be adjusted to a fast rate, it is sufficient to energize the second terminal O2.

[Details of the rate adjustment control: Operation flow of the rate adjustment control]
16 is a flow chart showing an example of the rate adjustment control of this embodiment. In the following description, a signal detected by the rotation detection circuit 45 when a back electromotive force equal to or greater than a predetermined threshold value Vth is generated is defined as a detection signal DE. The control circuit 44 controls the speed control pulse output circuit 46 based on the detection signal DE detected by the rotation detection circuit 45 and the reference signal OS generated by the frequency divider circuit 47.

The detection signal DE is detected when a large back electromotive force is generated in the coil 43. In other words, when the angular velocity of the permanent magnet 41 is fast. Therefore, in the forward and reverse rotational movements of the balance wheel 31, the control circuit 44 may perform rate adjustment based on the detection voltage generated in the coil 43 by the movement of the permanent magnet 41 and the reference signal OS before the acted part 313 reaches the position of the air resistance member 15.

In this embodiment, the power supply circuit 60 is started by generating electricity through the movement of the permanent magnet 41 (Y in ST1), and then the rate adjustment means 40 performs rate adjustment control.

When the detection signal DE is detected within the output period of the reference signal OS (Y in ST2), i.e., when no rate deviation occurs, the rate adjustment control is terminated. Note that FIG. 17 is a timing chart showing an example of when the detection signal is detected within the output period of the reference signal. As shown in FIG. 17, in this embodiment, the output period of the reference signal OS is set to an output period ts having a predetermined width.

If the detection signal DE is not detected within the output period of the reference signal OS (N in ST2), i.e., if a rate deviation has occurred, the control circuit 44 determines whether the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (ST3).

If the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Y in ST3), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to terminal O1 (ST4).

Figure 18 is a timing chart showing an example in which the detection timing of the detection signal is earlier than the output period of the reference signal. Figure 18 shows an example in which the speed control pulse p1 is output to the first terminal O1 of the coil 43 at a timing when a time tp1 has elapsed from the detection timing of the detection signal DE. As shown in Figure 18, the period in which the detection signal DE is detected is different before and after the output of the speed control pulse p1. In other words, the period in which the detection signal DE is detected after the speed control pulse p1 is output is longer than the period in which the detection signal DE is detected before the speed control pulse p1 is output. As a result, after the speed control pulse p1 is output, the detection signal DE is detected within the output period ts of the reference signal OS.

If the detection timing of the detection signal DE is slower than the reference signal OS (N in ST3), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to terminal O2 (ST5).

Figure 19 is a timing chart showing an example in which the timing at which the detection signal is detected is later than the output period of the reference signal. Figure 19 shows an example in which the speed control pulse p2 is output to the second terminal O2 of the coil 43 at a timing when a time tp2 has elapsed since the detection timing of the detection signal DE. As shown in Figure 19, the period in which the detection signal DE is detected is different before and after the output of the speed control pulse p2. In other words, the period in which the detection signal DE is detected after the speed control pulse p2 is output is shorter than the period in which the detection signal DE is detected before the speed control pulse p2 is output. As a result, after the speed control pulse p2 is output, the detection signal DE is detected within the output period ts of the reference signal OS.

The speed control pulse p1 output to the first terminal O1 and the speed control pulse p2 output to the second terminal O2 may have different output timings or output periods. This is because the amount of correction caused by the output of the speed control pulse may differ between the direction in which the permanent magnet 41 advances and the direction in which it delays.

[Details of the rate adjustment control: Operation flow of the first modified example of the rate adjustment control]
Next, a first modified example of the rate adjustment control will be described with reference to Figures 20 and 21. Figure 20 is a flow chart showing the first modified example of the rate adjustment control.

In this example, the rate adjustment means 40 may have a first counter that counts the number of times the detection signal DE is detected, and a second counter that is an accumulation unit that accumulates the period difference between the detection signal DE and the reference signal OS (the amount of deviation in the detection timing of the detection signal DE from the output timing of the reference signal OS).

In the first variation of the rate adjustment control, the power supply circuit 60 is started by generating electricity through the movement of the permanent magnet 41 (Y in ST1), and then the rate adjustment means 40 performs the rate adjustment control.

The control circuit 44 determines whether the balance wheel 31 (permanent magnet 41) has rotated forward and backward eight times. Specifically, the control circuit 44 determines whether the count of the first counter is eight (ST21).

If the count of the first counter is not 8 (N in ST21), calculate the period difference between the detection signal DE and the reference signal OS, and accumulate the period difference (ST22). After that, increment the count of the first counter by 1 (ST23).

On the other hand, if the count of the first counter is 8 (Y in ST21), reset the first counter to 0 (ST24).

Then, the control circuit 44 determines whether the accumulated amount of the period difference between the detection signal DE and the reference signal OS is 0 or within a predetermined range (ST25). If the accumulated amount of the period difference between the detection signal DE and the reference signal OS is 0 or within a predetermined range, the count number of the first counter is incremented by 1 without performing rate adjustment (ST23).

If the accumulated amount of the period difference between the detection signal DE and the reference signal OS is positive (N in ST25, Y in ST26), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to the first terminal O1 (ST4).

On the other hand, if the accumulated amount of the period difference between the detection signal DE and the reference signal OS is negative (N in ST25, N in ST26), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to the second terminal O2 (ST5).

The upper part of FIG. 21 shows an example in which when the first counter is 2, the detection timing of the detection signal DE is t earlier than the output period of the reference signal OS, when the first counter is 3, the detection timing of the detection signal DE is 2t earlier than the output period of the reference signal OS, and when the first counter is 6, the detection timing of the detection signal DE is t later than the output period of the reference signal OS. In this example, the accumulated amount of the period difference becomes +2t by the time the first counter becomes 8. In other words, the timing at which the detection signal DE is detected is 2t earlier than the reference signal OS in total. Therefore, the control circuit 44 outputs a speed control pulse to the first terminal O1 to delay the rate.

The lower part of Figure 21 shows an example in which, when the first counter is 2, the detection timing of the detection signal DE is 3t earlier than the output period of the reference signal OS, when the first counter is 3, the detection timing of the detection signal DE is 2t earlier than the output period of the reference signal OS, and when the first counter is 6, the detection timing of the detection signal DE is t later than the output period of the reference signal OS. In this example, the accumulated amount of the period difference becomes +4t by the time the first counter reaches 8. In other words, the timing at which the detection signal DE is detected is 4t earlier than the reference signal OS in total. Therefore, a speed control pulse is output to the first terminal O1 to delay the rate.

In addition, in the example in the lower part of FIG. 21, the accumulated amount of period difference is greater than in the example in the upper part of FIG. 21, so the output period of the speed control pulse is made longer. Specifically, the output period p112 of the speed control pulse shown in the lower part of FIG. 22 is made longer than the output period p111 of the speed control pulse shown in the upper part of FIG. 22. Note that in both the examples in the upper and lower parts of FIG. 22, the speed control pulse is output at a timing when tp111 has elapsed since the reference signal OS, which is output when the first counter is at 8, is output. In other words, the output timing of the speed control pulse is the same regardless of the output period of the speed control pulse.

In the first variant of the rate adjustment control described above, the rate adjustment is not performed every second, so the number of times that the speed adjustment pulse is output can be reduced. As a result, power consumption can be reduced.

[Details of the rate adjustment control: Operation flow of the second modified example of the rate adjustment control]
Next, a second modified example of the rate adjustment control will be described with reference to Fig. 22 and Fig. 23. Fig. 22 is a flow chart showing the second modified example of the rate adjustment control.

In this example, the rate adjustment means 40 may have a first counter that counts the number of times the detection signal DE is detected, and a second counter that is an accumulation unit that accumulates the period difference between the detection signal DE and the reference signal OS (the amount of deviation in the detection timing of the detection signal DE from the output timing of the reference signal OS). In the second modified example of the rate adjustment control, the second counter is reset to a count of 7.

In the second variation of the rate adjustment control, the power supply circuit 60 is started by generating electricity through the movement of the permanent magnet 41 (Y in ST1), and then the rate adjustment control is performed by the rate adjustment means 40.

The control circuit 44 determines whether the balance wheel 31 (permanent magnet 41) has rotated forward and backward eight times. Specifically, the control circuit 44 determines whether the count of the first counter is eight (ST21).

If the count of the first counter is not 8 (N in ST21), the control circuit 44 calculates the period difference between the detection signal DE and the reference signal OS (ST31).

Then, if the detection timing of the detection signal DE is within the output period of the reference signal OS (Y in ST32), the control circuit 44 adds 1 to the count number of the first counter without performing rate adjustment (ST23).

If the detection timing of the detection signal DE is not within the output period of the reference signal OS (N in ST32), the control circuit 44 determines whether the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (ST33).

If the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Y in ST33), the second count is subtracted according to the period difference (ST34). If the detection timing of the detection signal DE is later than the output period of the reference signal OS (N in ST33), the second count is added according to the period difference (ST35). After that, the count number of the first counter is incremented by 1 (ST23).

If the count of the first counter is 8 (Y in ST21), reset the first counter to 0 (ST24).

Then, the control circuit 44 determines whether the count of the second counter is 7 (ST36). If the count of the second counter is 7 (Y in ST36), the control circuit 44 adds 1 to the count of the first counter without performing rate adjustment (ST23).

If the count of the second counter is not 7 (N in ST36), the control circuit 44 determines whether the count of the second counter is less than 7 (ST37). If the count of the second counter is less than 7 (Y in ST37), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to the first terminal O1 (ST4). If the count of the second counter is greater than 7 (N in ST37), the control circuit 44 controls the speed control pulse output circuit 46 to output a speed control pulse to the second terminal O2 (ST5). After that, the count of the second counter is reset to 7 (ST38).

In the second variant of the rate adjustment control described above, the rate adjustment is not performed every second, so the number of times that the rate adjustment pulse is output can be reduced. As a result, power consumption can be reduced.

In FIG. 23, when the first counter is 2, the detection timing of the detection signal DE is t earlier than the output period of the reference signal OS, when the first counter is 3, the detection timing of the detection signal DE is 2t earlier than the output period of the reference signal OS, and when the first counter is 6, the detection timing of the detection signal DE is t later than the output period of the reference signal OS. In this example, by the time the first counter reaches 8, the second counter is 5. That is, the timing at which the detection signal DE is detected is 2t earlier than the reference signal OS in total. Therefore, the control circuit 44 outputs a speed control pulse to the first terminal O1 to delay the rate.

The speed control pulse is not limited to a single pulse, and may be a pulse group including multiple single pulses as shown in FIG. 24. By making the speed control pulse a pulse group, it is possible to absorb manufacturing variations and driving variations of the speed control mechanism 30. In this case, instead of changing the output period of the speed control pulse as shown in FIG. 21, the attractive or repulsive force acting on the permanent magnet 41 may be controlled by changing the duty ratio of the speed control pulse. Note that the duty ratio indicates the proportion of pulses output within a specified period. FIG. 24 shows an example of a speed control pulse with a duty ratio of 3/5.

[Details of the rate adjustment control: Rate adjustment control when the power supply circuit starts up from a stopped state]
FIG. 25 is a timing chart showing an example of the rate adjustment control when the power supply circuit starts to start up from a stopped state.

As described above, the power supply circuit 60 is started by generating electricity through the motion of the permanent magnet 41, and then the rate adjustment means 40 performs rate adjustment control. Therefore, it is preferable that the output of the reference signal OS used for the rate adjustment control is started after the power supply circuit 60 is started. For example, as shown in FIG. 25, it is preferable that the output of the reference signal OS is started starting from the timing when the detection signal DE is first detected. In FIG. 25, the peak of the back electromotive force gradually increases, and the output of the reference signal OS is started starting from the timing when the threshold value Vth is first exceeded. In other words, the output of the reference signal OS is started from the next timing (1 second after) when the threshold value Vth is first exceeded. However, this is not limited to this, and the output of the reference signal OS may be started starting from the point when the detection signal DE is detected multiple times (predetermined number of times) in consideration of the unstable rotation state immediately after the start of the power supply circuit 60.

[Details of the rate adjustment control: Rate adjustment control considering the influence of disturbances]
Fig. 26 is a timing chart showing an example of rate adjustment control considering the influence of disturbance. Fig. 27 is a flow chart showing an example of rate adjustment control considering the influence of disturbance. Fig. 28 is a flow chart showing rate adjustment control considering the influence of disturbance in the first modified example of the rate adjustment control shown in Fig. 20.

When an external magnet approaches the mechanical watch 1 or an impact is applied to it, the back electromotive force may be disturbed momentarily due to the external disturbance, and the detection signal DE may not be detected. In this case, the control circuit 44 may erroneously determine that the watch has significantly lost its rate.

Therefore, as shown in FIG. 26, if the detection signal DE is not detected in a predetermined period including before and after the output period of the reference signal OS, the rate adjustment may not be performed. The upper part of FIG. 26 shows a state in which the detection signal DE is not detected near the measurement time of 2.0 [s] due to the action of external disturbance. Specifically, it shows a state in which the detection signal is not detected in the output period ts of the reference signal OS, the period dt1 immediately before the output period ts, and the period dt2 immediately after the output period ts. Note that FIG. 26 shows an example in which the periods dt1 and dt2 are the same length, but they may be different lengths. In addition, it is preferable that the speed control pulse is output while avoiding the periods dt1 and dt2. This is because outputting the speed control pulse may disrupt the coil waveform (waveform of the back electromotive force), which may reduce the detection accuracy of the detection signal DE.

The flowchart in FIG. 27 shows an example in which rate adjustment is performed if the detection signal DE is output (detected) during a predetermined detection period (dt1 to ts to dt2) (Y in step ST11) after the power supply circuit 60 is started by generating electricity through the movement of the permanent magnet 41 (Y in ST1). On the other hand, if the detection signal DE is not output (detected) during the predetermined detection period (dt1 to ts to dt2) (N in step ST11), rate adjustment is not performed. Note that each step shown in FIG. 27 is the same as that shown in FIG. 16 except for ST11, so detailed explanations will be omitted.

The flowchart in FIG. 28 shows an example in which, after the power supply circuit 60 is started by generating electricity through the movement of the permanent magnet 41 (Y in ST1), if the detection signal DE is output (detected) during a predetermined detection period (dt1 to ts to dt2) (Y in step ST11), rate adjustment is performed. On the other hand, if the detection signal DE is not output (detected) during the predetermined detection period (dt1 to ts to dt2) (N in step ST11), rate adjustment is not performed and the first counter is reset (ST12). In this way, when there is an influence of a disturbance or the like, the first counter is reset and the count of the number of times the detection signal DE is detected is restarted.

Note that each step shown in FIG. 28 is the same as that shown in FIG. 20 except for ST11 and ST12, and the function of the first counter is also the same, so detailed explanations are omitted.

By adopting the configurations shown in Figures 26 to 28, highly accurate rate adjustment is possible even when disturbances are present. In addition, unnecessary output of speed control pulses can be prevented, reducing power consumption.

[Details of the rate adjustment control: Rate adjustment control when detection of the detection signal is continuously failed]
29 and 30 are timing charts showing an example of rate adjustment control when detection of a detection signal fails continuously, and Fig. 31 is a flowchart showing an example of rate adjustment control assuming that detection of a detection signal fails continuously.

When the power spring 11 is unwound, the rotational force of the rotor 41 weakens, and the back electromotive force may not exceed the threshold value Vth. In this case, the amount of power generated decreases, and the amount of charge stored in the capacitor C also decreases. In other words, the mechanical timepiece 1 is in a state where it is likely to stop, and the power supply circuit 60 is also in a state where it is likely to stop. In such a case, in order to save power, it is preferable not to output a speed control pulse. In other words, it is preferable not to adjust the rate.

Therefore, in the examples shown in Figures 29 and 30, a configuration is adopted in which a third counter that counts the number of consecutive failures to detect the detection signal DE and a fourth counter that counts the number of consecutive successes to detect the detection signal DE are used to switch between a "speed control pulse output setting" that outputs a speed control pulse and a "speed control pulse stop setting" that stops the output of the speed control pulse.

Specifically, when the third counter reaches 10, i.e., when the detection signal DE fails to be detected 10 times in succession, the setting is switched to stop the speed control pulse. Also, when the fourth counter reaches 20, i.e., when the detection signal DE is successfully detected 20 times in succession, the setting is switched to output the speed control pulse. Note that the count number that triggers the setting switch is just an example, and is not limited to the one shown here.

Figure 29 shows an example in which the peak of the back electromotive force is small and the detection signal DE fails to be detected 10 times in succession, causing the setting to switch to stop the speed control pulse.

In FIG. 30, an example is shown in which the speed control pulse stop setting is switched to when the detection signal DE fails to be detected 10 times in succession, and then the speed control pulse output setting is switched to when the detection signal DE is successfully detected 20 times in succession, thereby outputting the speed control pulse p1. Whether or not the detection signal DE is successfully detected is determined by whether or not the detection signal DE is output (detected) during a predetermined detection period (dt1 to ts to dt2), as in the examples shown in FIGS. 26 to 28.

In the flowchart shown in FIG. 31, after the power supply circuit 60 is started by generating electricity through the motion of the permanent magnet 41 (Y in ST1), it is determined whether or not the speed control pulse stop setting is in progress (ST41). Note that whether or not the speed control pulse stop setting is in progress may be determined, for example, based on whether or not the speed control pulse stop flag is set.

If the speed control pulse stop setting is not in progress (N in ST41), the control circuit 44 determines whether the third counter is 10 or not (ST42). That is, the control circuit 44 determines whether the detection of the detection signal DE has failed 10 times in succession. If the third counter is not 10 (N in ST42), the control circuit 44 determines whether the first counter is 8 or not (ST21). That is, the control circuit 44 determines whether the number of times the detection signal DE has been detected is 8 or not.

If the first counter is 8 (Y in ST21), the process from ST24 onwards shown in Fig. 20 is carried out. On the other hand, if the first counter is not 8 (N in ST21), the control circuit 44 judges whether or not the detection signal DE is output (detected) during the predetermined detection period (dt1 to ts to dt2) (ST43). If the detection signal DE is not output (detected) during the predetermined detection period (dt1 to ts to dt2) (N in ST43), the third counter count is incremented by 1 (ST44) and the first counter count is incremented by 1 (ST23). On the other hand, if the detection signal DE is output (detected) during the predetermined detection period (dt1 to ts to dt2) (Y in ST43), the third counter is reset (ST45), and the period difference between the detection signal DE and the reference signal OS is calculated and accumulated (ST22).

Also, when the speed control pulse stop setting is being performed in ST41 (Y in ST41), the control circuit 44 judges whether the count number of the fourth counter is 20 or not (ST51). That is, the control circuit 44 judges whether the detection signal DE has been successfully detected 20 times in succession. When the fourth counter is not 20 (N in ST51), the control circuit 44 judges whether the detection signal DE has been output (detected) during a predetermined detection period (dt1 to ts to dt2) (ST52). When the detection signal DE has not been output (detected) during the predetermined detection period (dt1 to ts to dt2) (N in ST52), the control circuit 44 resets the fourth counter (ST53). When the detection signal DE has been output (detected) during the predetermined detection period (dt1 to ts to dt2) (Y in ST52), the control circuit 44 adds 1 to the count number of the fourth counter (ST54).

If the count of the fourth counter is 20 in ST51 (Y in ST51), the fourth counter is reset (ST55) and switched to the speed control pulse output setting (ST56).

In addition, if the count of the third counter is 10 in ST42 (Y in ST42), the third counter is reset (ST61) and the speed control pulse output setting is switched to (ST62). Note that when the power supply circuit 60 stops and then starts operating, the amount of charge stored in the capacitor C is small, so the power supply circuit 60 is likely to stop again. Therefore, when the power supply circuit 60 stops and then starts operating, it is advisable to increase the number of consecutive successful detection signals DE required before rate adjustment can be started. For example, in ST51 of FIG. 31, when the count of the fourth counter is 60, that is, when the detection signal DE is successfully detected 60 times in a row, the speed control pulse output setting is switched to.

In the examples of Figures 29 to 31 described above, restricting rate adjustment can reduce power consumption, and it is also easier to immediately switch to rate adjustment when the power spring 11 is wound up.

In the examples of Figures 29 to 31, if a back electromotive force exceeding the threshold value Vth is not detected for a predetermined number of consecutive seconds, a function may be provided to notify the user that the mechanical timepiece 1 is in a state where it is likely to stop. As a means of notification, for example, the position indicated by the hands may be used. This makes it possible to prompt the user to perform an operation to wind up the power spring 11.

In the examples of Figures 29 to 31, if a back electromotive force exceeding the threshold Vth is not detected for a predetermined number of consecutive seconds, the threshold voltage may be lowered. Specifically, for example, when the threshold Vth is 0.5V, if the detection signal DE fails to be detected 10 times in succession, the threshold voltage may be set to 0.25V. This makes it easier for the power supply circuit 60 to stop, but allows the accuracy of the rate to be maintained. Then, after lowering the threshold Vth, if a back electromotive force exceeding the lowered threshold is detected for a predetermined number of consecutive seconds, the original threshold Vth may be restored. Also, if a back electromotive force exceeding the threshold Vth is not detected for a predetermined number of consecutive seconds, the threshold may be lowered in stages.

[Details of the rate adjustment control: Rate adjustment control taking into account the rotation direction of the balance wheel]
32 is a timing chart showing an example of the output timing of the reference signal. The rotation angle of the balance wheel 31 may differ between the forward and reverse directions due to manufacturing variations during assembly of the mechanical timepiece 1, or due to position adjustment of the balance wheel 31 by the support member 33 during shipping inspection. If the rotation angle differs, the timing at which the detection signal DE is detected will differ between the forward and reverse directions. This may result in unnecessary output of a speed control pulse even though there is no rate deviation overall.

Therefore, in the example shown in FIG. 32, a configuration is adopted in which the reference signal OS is set on a two-step (2-second) basis. The upper part of FIG. 32 shows an example of a back electromotive voltage waveform when the detection signal DE detected in the forward direction and the reverse direction is different. The lower part of FIG. 32 shows an example of a timing chart in which the reference signal OS is set on a two-step (2-second) basis. As shown in the lower part of FIG. 32, the output interval of the odd-numbered reference signal OS from the left is set to tr1, and the output interval of the even-numbered reference signal OS from the left is set to tr2 (= tr1). This example may be realized by the control circuit 44 performing two-system control in two-step units (2-second units). Then, if a rate abnormality is detected in any of the control systems, a rate adjustment may be performed. Note that, in order to simplify the circuit configuration, only one control system with an output interval of either tr1 or tr2 may be used.

In the example shown in Figure 32, the reference signal OS is set to a two-step standard (tr1 and tr2), and the rate is adjusted according to each step. This makes it possible to adjust the rate with high precision, without the circuit stopping due to disturbances, even if there is a difference between the forward and reverse rotation angles of the balance wheel 31.

The middle part of Figure 32 shows a timing chart for the case where the reference signal OS is set on a one-step (one second) basis, i.e., the example shown in Figure 17 and other figures above. In the example shown in the middle part of Figure 32, the peak positions of the back electromotive force are different in the forward and reverse directions, so even though there is no rate deviation overall, the output timing of the even-numbered detection signals DE from the left is always shifted. In such a case, a speed control pulse will be output unnecessarily.

[summary]
In this embodiment, a configuration is adopted in which the angular velocity of the balance wheel 31 is slowed down, so that the wear of each mechanism that transmits power (for example, the escape wheel 21 and the anchor 22) can be suppressed. As a result, the durability of the mechanical timepiece 1 is improved. In addition, a configuration is adopted in which the angular velocity of the balance wheel 31 is slowed down during the intermediate period of the forward and reverse movements of the balance wheel 31 by using the air resistance member 15. This allows a sufficient amount of power to be generated by generating power during the period in which the balance wheel 31 is not subjected to air resistance by the air resistance member 15 while slowing down the rotation period of the balance wheel 31. In addition, the accuracy of the rate adjustment can be maintained by performing the rate adjustment during the period in which the balance wheel 31 is subjected to air resistance by the air resistance member 15 or after it has been subjected to the air resistance. In addition, a configuration is adopted in which the permanent magnet 41 is arranged so as to obtain a back electromotive voltage suitable for half-wave rectification, so that power can be efficiently extracted using half-wave rectification.

[others]
The rate adjustment means 40 obtains a detection signal based on the operation of the two-pole magnetized permanent magnet 41, and the detection accuracy may be reduced if there are members that have a magnetic effect around the permanent magnet 41. For this reason, it is advisable to use materials that have little magnetic effect as the materials for the members around the permanent magnet 41.

For example, a resin material may be used as the material for the support member 33 and the hairpin holder 34. Phosphor bronze may be used as the material for the fastener 33a for fixing the support member 33 to the base plate 10. A resin material or aluminum may be used as the material for the balance wheel 31. An acrylic resin may be used as the air resistance member 15. Note that the materials listed here are merely examples and are not limited to these.

As described above, the hairspring 32 is made of resin to reduce the Young's modulus, which reduces the magnetic effect on the permanent magnet 41 compared to when it is made of metal. If the hairspring 32 is made of a magnetic metal, it may be magnetically affected by the permanent magnet 41 and may cause the shape and posture of the hairspring 32 to change. In this embodiment, the hairspring 32 is made of resin, which stabilizes the shape and posture of the hairspring 32 itself. A separate magnetic shield made of a magnetic material may also be provided on the mechanical watch 1. This prevents the forward and reverse rotational motion of the permanent magnet 41 (balance wheel 31) from being disturbed even when an external magnet approaches the mechanical watch 1, allowing for stable rate adjustment.

In the present embodiment, as shown in FIG. 5, an example is shown in which the first end 421a and the second end 422a of the soft magnetic core 42 are integrated via the first welded portion 423 and the second welded portion 424, but this is not limited to the above. For example, the first welded portion 423 and the second welded portion 424 may not be present, and the first end 421a and the second end 422a may be magnetically separated via a gap. In addition, the present embodiment is not limited to a case in which the magnetic coupling is completely separated. For example, the first end 421a and the second end 422a may be physically connected via a narrowed portion that is a separating portion.

Although not shown in the figures, the mechanical watch 1 may have an opening or transparent portion on the dial or back cover that allows the balance wheel 31 to be viewed from the outside.

Furthermore, the arrangement angle of the permanent magnets 41 described in this embodiment is merely an example and is not limited to that described in this embodiment.

In addition, in this embodiment, an example in which an air resistance member 15 is provided has been described, but this is not limited thereto, and the air resistance member 15 may not be provided. Furthermore, if there is no air resistance member 15, the balance wheel 31 may not have an acted upon portion 313.

When using a configuration in which air resistance is applied to the balance wheel 31 using an air resistance member 15 as in this embodiment, the duration of the power spring 11 is shortened by the amount of energy consumed by the air resistance. On the other hand, in this embodiment, a resin material with a low Young's modulus is used as the material for the hairspring 32, slowing down the movement of the balance wheel 31, resulting in a longer duration compared to conventional mechanical watches with 6 to 8 vibrations. In other words, slowing down the movement of the balance wheel 31 can compensate for the reduction in duration due to air resistance. As a result, a sufficient duration can be achieved as a mechanical watch.

1 Mechanical watch, 2 Winding stem, 10 Main plate, 10a Positioning pin, 10b Opening, 11 Power spring, 12 Wheel train, 122 Center wheel, 123 Third wheel, 124 Fourth wheel, 13 Pointer shaft, 131 Second hand, 15 Air resistance member, 151 First wall portion, 152 Second wall portion, 153 Third wall portion, 154 Base portion, 20 Escape mechanism, 21 Escape wheel, 22 Ankle, 221 Ankle stem, 222 Pole portion, 223 First arm portion, 224 Second arm portion, 30 Speed regulating mechanism, 31 Balance wheel, 311 Balance stem, 311a Tenon portion, 312 Circular portion, 313 Acting portion, 315 Impulse jewel, 32 Hairspring, 321 Outer end portion, 322 Inner end portion, 322a Fixed portion, 322b Pitch enlargement portion, 33 Support member, 33a Pipe, 33b Screw, 34 Hairpin holder, 35 Frame member, 35a Convex portion, 40 Speed adjustment means, 41 Permanent magnet, 410 Housing member, 42 Soft magnetic core, 421 First magnetic portion, 421a First end portion, 422 Second magnetic portion, 422a Second end portion, 43 Coil, 44 Control circuit, 45 Rotation detection circuit, 46 Speed control pulse output circuit, 47 Frequency divider circuit, 48 Oscillation circuit, 50 Rectification circuit, 60 Power supply circuit, 70 Quartz crystal oscillator, 331 Hole, 331h Shaft hole, 332 Elastic deformation member, 3321 Outer edge portion, 3322 Elastic deformation portion, 3322a First connection portion, 3322b Semicircular arc portion, 3322c Second connection portion, 3323 Retaining portion, 3323h opening, 333 stone, 334 retaining member, n11, n12, n21, n22 notches.

Claims (5)

A power source;
a speed-regulating mechanism including: a rotating shaft; a balance wheel that rotates about the rotating shaft by power from the power source; and a hairspring that elastically deforms so as to rotate the balance wheel in forward and reverse directions;
a rate adjusting means including a coil and a permanent magnet which rotates in a forward and reverse direction on the same axis as the balance wheel in accordance with the forward and reverse rotation of the balance wheel, and which adjusts the rate based on a detection voltage generated in the coil by the forward and reverse rotation of the permanent magnet and a reference frequency of a reference signal source;
a bearing structure for supporting an end of the rotating shaft close to the permanent magnet;
having
The bearing structure includes:
a hole formed in the hole, through which the end of the rotating shaft is inserted;
A holding portion that holds the hole stone and is made of a non-magnetic material;
an elastic deformation portion that is integral with the holding portion, elastically deforms in response to displacement of the rotating shaft, and is made of a non-magnetic material ;
Including,
Mechanical watch. The elastic deformation portion has a shape that can elastically deform in at least one direction, a radial direction or an axial direction, of the rotating shaft in response to a displacement of the rotating shaft.
2. The mechanical watch according to claim 1. A power source;
a speed-regulating mechanism including: a rotating shaft; a balance wheel that rotates about the rotating shaft by power from the power source; and a hairspring that elastically deforms so as to rotate the balance wheel in forward and reverse directions;
a rate adjusting means including a coil and a permanent magnet which rotates in a forward and reverse direction on the same axis as the balance wheel in accordance with the forward and reverse rotation of the balance wheel, and which adjusts the rate based on a detection voltage generated in the coil by the forward and reverse rotation of the permanent magnet and a reference frequency of a reference signal source;
a bearing structure for supporting an end of the rotating shaft close to the permanent magnet;
a housing member that houses the bearing structure;
having
the bearing structure includes an elastically deformable portion that is elastically deformed in response to a displacement of the rotating shaft and is made of a non-magnetic material;
the housing member includes a first circumferential surface surrounding an end of the rotary shaft, a second circumferential surface provided closer to the balance wheel than the first circumferential surface and having a smaller diameter than the first circumferential surface, and a step portion connecting the first circumferential surface and the second circumferential surface,
An outer edge of the elastic deformation portion is fixed to the step portion.
Mechanical watch. The diameter of the permanent magnet is smaller than the diameter of the second circumferential surface,
The permanent magnet and the second circumferential surface are at least partially disposed at the same position in the axial direction of the rotating shaft.
4. The mechanical watch according to claim 3 . The rate adjustment means includes a control circuit that is driven by the back electromotive force generated in the coil by the forward and reverse rotational motion of the permanent magnet.
The mechanical timepiece according to any one of claims 1 to 4 .

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