Patent Application
20240126212
The present invention relates to a mechanical timepiece.
In Patent Literature 1, there is disclosed a mechanical timepiece having functions of performing power generation based on a motion of a magnet mounted to a shaft (balance staff), and also performing rate adjustment by observing a cycle of rotation of a balance (for example, paragraphs 0072 and 0073, FIG. 27, and the like of Patent Literature 1). Further, in Patent Literature 2, there is disclosed a configuration in which power generation is performed by means of electric power obtained by performing full wave rectification through use of a rectifier including four diodes (for example, FIG. 13 of Patent Literature 2).
In this case, the electric power to be caused by the motion of the magnet accompanying the motion of the balance staff is very small, and hence it is required to devise a way to efficiently extract the electric power. However, when full wave rectification is performed by means of a rectifier including a plurality of diodes as in Patent Literature 2, a voltage drop corresponding to the number of diodes occurs, resulting in occurrence of power loss.
The present invention has been made in view of the above-mentioned problems, and has an object to efficiently extract electric power in a mechanical timepiece in which rate adjustment is performed through use of electromagnetic means.
According to the aspects of Items (1) to (25) of the present invention described above, the electric power can be efficiently extracted in the mechanical timepiece in which the rate adjustment is performed through use of the electromagnetic means.
Description is made below in detail of an embodiment (hereinafter referred to as this embodiment) of the present invention based on the drawings.
First, with reference to
In this embodiment, in each view excluding
The mechanical timepiece 1 is a timepiece which uses a power spring 11 as a power source, and uses an escapement mechanism 20 and a speed governing mechanism 30 to control a motion of the power spring 11 and also drive hands. The mechanical timepiece 1 is formed by accommodating, into an exterior case, a main plate 10 to which each mechanism for driving the hands is incorporated. In this embodiment, illustration of the exterior case is omitted. Further, illustration of a crown to be arranged on a side surface of the exterior case is also omitted. The crown is mounted to an end portion of a winding stem 2 illustrated in
An outline of a drive mechanism included in the mechanical timepiece 1 is described. In this embodiment, a mechanism including the power spring 11 serving as the power source, a wheel train 12, and a hand shaft 13 is referred to as “drive mechanism.” In
The power spring 11 is formed of a band-like member made of a metal, and is accommodated into a barrel 110 having a plurality of teeth formed on an outer periphery thereof. The barrel 110 has a disc shape, and has a cavity formed therein for accommodating the power spring 11. The power spring 11 has its inner end fixed to a barrel arbor (not shown) serving as a rotary shaft provided at the center of the barrel 110, and has its outer end fixed to an inner side surface of the barrel 110. When the crown is rotated through the operation of the user, the winding stem 2 is rotated. Along with the rotation of the winding stem 2, the power spring 11 is wound up. The wound power spring 11 is unwound due to its elastic force. The barrel 110 is rotated along with the operation of the power spring 11 at this time.
The wheel train 12 at least includes a center wheel and pinion 122, a third wheel and pinion 123, and a fourth wheel and pinion 124. The center wheel and pinion 122 includes a pinion for meshing with the plurality of teeth formed on the barrel 110 functioning as a mainwheel, a rotary shaft, and a plurality of teeth. The center wheel and pinion 122 transmits the rotation of the barrel 110 to the third wheel and pinion 123. The rotary shaft of the center wheel and pinion 122 is a hand shaft of a minute hand (not shown). The third wheel and pinion 123 includes a pinion for meshing with the plurality of teeth of the center wheel and pinion 122, a rotary shaft, and a plurality of teeth. The third wheel and pinion 123 transmits the rotation of the center wheel and pinion 122 to the fourth wheel and pinion 124. The fourth wheel and pinion 124 includes a pinion meshing with the plurality of teeth of the third wheel and pinion 123, a rotary shaft, and a plurality of teeth. The fourth wheel and pinion 124 transmits the rotation of the third wheel and pinion 123 to the escapement mechanism 20. As illustrated in
Next, the escapement mechanism 20 and the speed governing mechanism 30 are described. The motive power from the power spring 11 is transmitted via the wheel train 12 to the escapement mechanism 20 and the speed governing mechanism 30. The escapement mechanism 20 includes an escape wheel and pinion 21 and a pallet fork 22. The speed governing mechanism 30 includes a balance wheel 31 and a hairspring 32. The speed governing mechanism 30 is sometimes referred to as “balance with hairspring.”
The escape wheel and pinion 21 is a component for meshing with the pallet fork 22 so as to receive, from the pallet fork 22, rhythm kept by the speed governing mechanism 30, thereby converting the rhythm into a regular reciprocating motion. The escape wheel and pinion 21 includes a pinion for meshing with the plurality of teeth of the fourth wheel and pinion 124, a rotary shaft, and a plurality of teeth. As illustrated in
The pallet fork 22 uses a pallet fork staff 221 illustrated in
Further, the pallet fork 22 includes a first arm portion 223, and a second arm portion 224 extending in a direction opposite to the first arm portion 223. An entry pallet 223a for colliding with the plurality of teeth of the escape wheel and pinion 21 is mounted to the first arm portion 223, and an exit pallet 224a for colliding with the plurality of teeth of the escape wheel and pinion 21 is mounted to the second arm portion 224. It is preferred that each of the entry pallet 223a and the exit pallet 224a be, for example, a stone such as a sapphire.
The balance wheel 31 performs a forward/reverse rotational motion about the balance staff 311 serving as a rotation center, through use of the motive power transmitted by the wheel train 12. In the following description, in some cases, in the forward/reverse rotational motion, a forward direction motion is referred to as “rotation in the forward direction,” and a reverse direction motion is referred to as “rotation in the reverse direction.” Details of the configuration of the balance wheel 31 are described later. The balance staff 311 is supported by a bearing structure 330 (see
The hairspring 32 performs an expansion/contraction motion (elastic deformation) so as to cause the balance wheel 31 to perform the forward/reverse rotational motion. The hairspring 32 has a spiral shape, and has an inner end fixed with respect to the balance staff 311 and an outer end fixed with respect to a stud support 34. The stud support 34 is fixed with respect to the main plate 10 together with the support member 33. Further, as illustrated in
The escape wheel and pinion 21 is rotated along with the rotation of the fourth wheel and pinion 124. When the escape wheel and pinion 21 is rotated, the escape wheel and pinion 21 collides with the entry pallet 223a of the pallet fork 22 so that the pallet fork 22 is rotated about the pallet fork staff 221 serving as a center. The lever portion 222 of the rotated pallet fork 22 collides with the impulse jewel 315 fixed to the balance staff 311, thereby causing the balance wheel 31 to rotate. When the balance wheel 31 is rotated, the exit pallet 224a of the pallet fork 22 collides with the escape wheel and pinion 21 so that the escape wheel and pinion 21 is stopped. When the balance wheel 31 is rotated in the reverse direction due to a restoring force of the hairspring 32, the entry pallet 223a of the pallet fork 22 is released so that the escape wheel and pinion 21 is rotated again. As described later, the balance wheel 31 is designed so as to perform an operation of one cycle in two seconds, and hence the escape wheel and pinion 21 performs an operation of one step in one second.
As described above, the speed governing mechanism 30 causes the balance wheel 31 to repeatedly perform the forward/reverse rotational motion (reciprocating motion) in a certain cycle, through use of the expansion/contraction motion of the hairspring 32. The escapement mechanism 20 continuously applies, to the balance wheel 31, a force for performing the reciprocating motion. With such a configuration and operation, hands such as the second hand 131 are driven.
Next, a configuration of rate adjustment means 40 is described. 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 governing mechanism 30.
The rate adjustment means 40 includes a permanent magnet 41, a soft magnetic core 42 (sometimes referred to as “stator”), a coil 43, and various circuits (see
Although not shown, it is preferred that the coil 43 be arranged so as to overlap, in plan view, a casing frame provided on the inner side of the exterior case. As another example, it is preferred that a cutout be formed in a part of the casing frame in the circumferential direction, and the coil 43 be arranged inside of this cutout.
The permanent magnet 41 is a disc-shaped rotary member magnetized into two poles, and is magnetized into an N pole and an S pole in the radial direction. That is, the permanent magnet 41 is a magnet including an N-pole portion 411 and an S-pole portion 412.
The permanent magnet 41 is mounted to the balance staff 311 serving as the rotary shaft of the balance wheel 31 (see
It is preferred that the permanent magnet 41 be an isotropic magnet having an axis of easy magnetization directed in a random direction. It is preferred that the permanent magnet 41 be magnetized by being applied with a magnetic field by a Helmholtz coil or the like under a state in which the permanent magnet 41 is mounted to the balance staff 311. When such a magnetization method is adopted, a direction of magnetization of the permanent magnet 41 can be accurately adjusted.
The soft magnetic core 42 is made of a soft magnetic material. As illustrated in
In this embodiment, in the permanent magnet 41, under a state in which the hairspring 32 is brought to a neutral position of elastic deformation, the N-pole portion 411 is arranged on the second magnetic portion 422 side, and the S-pole portion 412 is arranged on the first magnetic portion 421 side (see the enlarged view of
Further, as illustrated in
Further, as illustrated in
It is desired that, among the components to be mounted to the main plate 10, components present at positions close to the permanent magnet 41 excluding the soft magnetic core 42, such as the support member 33, the stud support 34, the frame member 35, the hairspring 32, and the balance wheel 31, be made of a non-magnetic material so as not to affect the forward/reverse rotational motion of the speed governing mechanism 30 or a counter-electromotive voltage to be caused by the coil 43 to be described later.
Further, as illustrated in
The permanent magnet 41 is brought to a magnetically balanced position when the permanent magnet 41 is brought into a state of being positioned so that the direction of magnetization is orthogonal to an opposing direction of the first welding portion 423 and the second welding portion 424. In this embodiment, the magnetically balanced position of the permanent magnet 41 is defined as a rotation angle of 0°. At this position, the holding torque of the permanent magnet 41 is almost 0. As illustrated in
When the permanent magnet 41 is brought to a position at which its rotation angle is shifted by 90° from 0° in the forward direction, the direction of magnetization becomes the same as the opposing direction of the first welding portion 423 and the second welding portion 424. At this position, the holding torque of the permanent magnet 41 is almost 0. The thick broken-line graph of
As illustrated in
One broken-line graph of
Further, the solid-line graph of
As illustrated in
The control circuit 44 is a circuit for controlling operations of the respective circuits included in the rate adjustment means 40.
The oscillation circuit 48 outputs a predetermined oscillation signal based on the frequency of the quartz crystal oscillator 70. The frequency of the quartz crystal oscillator 70 is 32,768 [Hz]. The frequency dividing circuit 47 divides the frequency of the oscillation signal output from the oscillation circuit 48. The frequency dividing circuit 47 divides the frequency of the oscillation signal which is based on the quartz crystal oscillator 70 so as to generate a reference signal OS output roughly at every 1,000 [ms]. However, the present invention is not limited thereto, and the reference signal OS may be output at every 2,000 [ms] or every 3,000 [ms]. That is, the reference signal OS is only required to be output at every right seconds. Moreover, the present invention is not limited thereto, and the reference signal OS is only required to correspond to the cycle of the speed governing mechanism 30.
The rotation detecting circuit 45 detects a detection signal based on a voltage waveform caused in the coil 43 due to the motion of the permanent magnet 41. The speed governing pulse output circuit 46 outputs a speed governing pulse based on the reference signal generated by the frequency dividing circuit 47 and on the detection signal detected by the rotation detecting circuit 45. Specifically, a detection timing of the detection signal detected by the rotation detecting circuit 45 and an output timing of the reference signal of about 1,000 [Hz] are compared with each other, and when there is a time lag between those timings, the speed governing pulse output circuit 46 outputs the speed governing pulse so that the cycle in which the detection signal is detected comes close to 1,000 [ms] (=one second).
The output of the speed governing pulse is performed through energization of the coil 43. Accordingly, it is preferred that, when the cycle in which the detection signal is detected is faster than the reference signal, the speed governing pulse output circuit 46 energize the coil 43 so that a torque acts in a direction of slowing down the movement of the permanent magnet 41, and, when the cycle in which the detection signal is detected is slower than the reference signal, the speed governing pulse output circuit 46 energize the coil 43 so that a torque acts in a direction of accelerating the movement of the permanent magnet 41. Details of rate adjustment control including the output timing of the speed governing pulse are described later.
Further, the mechanical timepiece 1 has a power generating function using a principle of electromagnetic induction. In this embodiment, the speed governing mechanism 30 functions as a part of the power generator. Specifically, the permanent magnet 41 performs the forward/reverse rotational motion along with the forward/reverse rotational motion of the balance wheel 31, and electric power is generated by a current caused in the coil 43 based on a change in a magnetic field caused by the motion of the permanent magnet 41. The power supply circuit 60 is activated through use of the electric power extracted by such an operating principle. When the power supply circuit 60 is activated, the control circuit 44 included in the rate adjustment means 40 can be driven. Because such a configuration is adopted, in this embodiment, the control circuit 44 can be driven without separately providing a power supply such as a battery.
The rectifying circuit 50 rectifies the current caused in the coil 43 due to the motion of the permanent magnet 41 accompanying the forward direction motion and the reverse direction motion in the forward/reverse rotational motion of the balance wheel of the speed governing mechanism 30. The power supply circuit 60 is, for example, a circuit including a capacitor, and stores the electric power for driving the control circuit 44 based on the current rectified by the rectifying circuit 50.
Now, with reference to
The bearing structure 330 supports an end portion of the balance staff (rotary shaft) 311 on a side closer to the permanent magnet 41. As illustrated in
The bearing structure 330 is a structure at least including a hole stone 331, an elastic deformation member 332, a cap jewel 333, a holding member 334 for holding the cap jewel 333, and a cap jewel spring 335. The bearing structure 330 is accommodated in the frame member 35 serving as an accommodating member. As illustrated in
The cap jewel spring 335 is provided so that its inner edge holds the holding member 334, and a part of its outer edge is caught by the frame member 35. Further, the outer edge of the cap jewel spring 335 is elastically in contact with the frame member 35. The cap jewel spring 335 is one of members contributing to impact absorption in an axial direction of the balance staff 311. It is preferred that the holding member 334 and the cap jewel spring 335 be made of a non-magnetic material. For example, it is preferred that the holding member 334 be made of brass which is an alloy of copper and zinc.
The hole stone 331 is fitted into an opening 3323h to be described later, which is formed in the elastic deformation member 332, so as to be fixed with respect to the elastic deformation member 332. Further, at a center portion of the hole stone 331, a shaft hole 331h into which the pivot portion 311a of the balance staff 311 is to be inserted is formed. When the pivot portion 311a is inserted into the shaft hole 331h, the pivot portion 311a is positioned in the radial direction by the hole stone 331.
The cap jewel 333 is brought into abutment against a distal end of the pivot portion 311a. The pivot portion 311a is positioned in the up-down direction by the cap jewel 333.
It is preferred that the hole stone 331 and the cap jewel 333 be jewels having good slidability with respect to the pivot portion 311a and having advantage in rotational operation and wearing. Specifically, it is preferred that each of the hole stone 331 and the cap jewel 333 be a ruby, a sapphire, or the like. However, the present invention is not limited thereto, and each of the hole stone 331 and the cap jewel 333 is only required to be made of a non-magnetic material.
In this case, when an external impact or the like is applied to the mechanical timepiece 1, there is a fear in that the balance staff 311 is misaligned in the up-down direction or the radial direction. In this case, the up-down direction refers to a direction in which an axis “ax” of the balance staff 311 illustrated in
As illustrated in
As illustrated in
In this case, as illustrated in
When the balance staff 311 is displaced in the radial direction due to occurrence of an external impact or the like, the half arc portion 3322b is elastically deformed in the radial direction through use of the first connection portion 3322a as a fulcrum, and the holding portion 3323 is elastically deformed in the radial direction through use of the second connection portion 3322c as a fulcrum. In this case, “deformation” refers to movement of the balance staff 311 to a position deviated from a regular position.
Further, when the balance staff 311 is displaced in the axial direction due to application of an impact from the outside, the half arc portion 3322b is elastically deformed in the axial direction through use of the first connection portion 3322a as a fulcrum, and the holding portion 3323 is elastically deformed in the axial direction through use of the second connection portion 3322c as a fulcrum.
As described above, when a configuration in which the bearing structure 330 includes the elastic deformation portion 3322 is adopted, even in a case in which misalignment occurs in the radial direction or the axial direction, the balance staff 311 is maintained to a regular position due to the elastic force in the elastic deformation portion 3322. As a result, reduction of the rate accuracy and reduction of the power generation efficiency are suppressed.
Further, it is preferred that the elastic deformation portion 3322 be made of a non-magnetic material. The non-magnetic material is a material other than a ferromagnetic material, and is a material that is not affected by a magnetic field or is less affected by a magnetic field than in the case of the ferromagnetic material. Specifically, it is preferred that the elastic deformation portion 3322 be made of a metal material such as nickel phosphorus (NiP), titanium copper (TiCu), or a copper nickel alloy. It is preferred that the elastic deformation portion 3322 be formed through aging treatment (heat treatment). In this manner, the elastic force can be ensured, and a thin elastic deformation portion 3322 can be obtained. It is preferred that the outer edge portion 3321 and the holding portion 3323 also be made of a non-magnetic material similarly to the elastic deformation portion 3322. That is, it is preferred that the entire elastic deformation member 332 be made of a non-magnetic material.
As described above, when the elastic deformation member 332 (elastic deformation portion 3322), which is one of members arranged in the vicinity of the permanent magnet 41, is made of a non-magnetic material, the permanent magnet 41 can be prevented from receiving the magnetic influence. In this manner, the operation of the permanent magnet 41 is stabilized. As a result, reduction of the rate accuracy and reduction of the power generation efficiency are suppressed.
Further, when the elastic deformation member 332 and the holding member 334 are made of a non-magnetic material, the bearing structure 330 of the balance staff 311 can be arranged close to the permanent magnet 41. As a result, the mechanical timepiece 1 can be downsized in the thickness direction. Moreover, when the elastic deformation member 332 is made of a non-magnetic material, the size of the permanent magnet 41 can be increased. As a result, electric power to be obtained by the operation of the permanent magnet 41 can be increased, and the power generation performance can be improved.
Further, in this embodiment, as illustrated in
The shape of the elastic deformation member 332 illustrated in
Although not shown, an end portion of the balance staff 311 on a side farther from the permanent magnet 41 may also be supported by a structure equivalent to the bearing structure 330. In this manner, members for supporting one end and another end of the balance staff 311 can be common members, and the manufacturing cost can be reduced.
The permanent magnet 41 may be directly mounted to the balance staff 311 as illustrated in
The bearing structure 330 of the balance staff 311 described with reference to
[Reducing Speed of Balance Wheel 31]
In this case, in the mechanical timepiece 1, as the speed of the movement of the balance wheel 31 is higher, that is, as the operation cycle of the balance wheel 31 is faster, each mechanism for transmitting the motive power (for example, the escape wheel and pinion 21 or the pallet fork 22) is liable to be worn, and the durability is reduced. Meanwhile, an amount of current to be caused in the coil 43 is proportional to an angular velocity of the permanent magnet 41, and hence, when the speed of the movement of the balance wheel 31 is low, a power generation amount required for driving the control circuit 44 cannot be obtained.
In view of the above, in this embodiment, a configuration capable of reducing the speed of the movement of the balance wheel 31 and also capable of ensuring the power generation amount is adopted.
In this embodiment, the balance wheel 31 is designed so as to perform one back-and-forth operation in two seconds. Thus, a resin material having a low Young's modulus is adopted as the material of the hairspring 32. In this manner, as compared to a case in which the hairspring 32 is made of a metal material, low speed oscillation of the balance wheel 31 can be achieved. When the low speed oscillation is to be achieved by a metal hairspring, it is required to reduce the cross-sectional area of the hairspring 32 to a level that is difficult to process, or to increase the hairspring length to a level that is difficult to handle.
In this embodiment, as the material of the hairspring 32, a resin having the Young's modulus of about 5 [GPa] is used. Specifically, as the material of the hairspring 32, polyester is used. It is preferred that the hairspring 32 made of a resin material be manufactured by, for example, laser processing. A general hairspring made of a metal has a Young's modulus of about 200 [GPa]. The Young's modulus given here is merely an example, and it is preferred that the Young's modulus of the hairspring 32 be 20 [GPa] or less. That is, it is preferred that the Young's modulus of the hairspring 32 be 1/10 or less of the Young's modulus of the hairspring made of a metal. It is more preferred that the Young's modulus of the hairspring 32 be 10 [GPa] or less. That is, it is preferred that the Young's modulus of the hairspring 32 be 1/20 or less of the Young's modulus of the hairspring made of a metal. Further, the Young's modulus is only required to be 20 [GPa] or less, and thus the hairspring 32 may be made of a material such as paper or wood. Details of the shape of the hairspring 32 are described later with reference to
Further, in this embodiment, the rotation angle [deg] of each of the balance wheel 31 and the permanent magnet 41 under a state in which the hairspring 32 is brought to a neutral position of elastic deformation is defined as 0°. The neutral position of elastic deformation of the hairspring 32 refers to, in other words, a position at which the hairspring 32 has an equilibrium length. Further, it is assumed that the balance wheel 31 in a state in which the hairspring 32 is brought to the neutral position of elastic deformation is supplied with the motive power from the power spring 11. That is, the balance wheel 31 and the permanent magnet 41 are each at a motive power supply position at which the motive power is supplied from the power spring 11, at the position of the rotation angle of 0°. Further, as described above, in this embodiment, the permanent magnet 41 is brought to a magnetically balanced position at the position of the rotation angle of 0°.
Further, in this embodiment, the balance wheel 31 is designed so as to be driven in a range of from a rotation angle of 340° to a rotation angle of −340°. Thus, the permanent magnet 41 is also driven in a range of from the rotation angle of 340° to the rotation angle of −340°. However, this range is merely an example, and it is preferred that the moving range of the balance wheel 31 be equal to or larger than the range of from a rotation angle of 270° to a rotation angle of −270°. When the moving range of the balance wheel 31 is increased to some extent as described above, the low speed oscillation of the balance wheel 31 can be achieved.
In
[Reducing Speed of Balance Wheel 31: Air Resistance Member 15]
Further, in this embodiment, there is adopted a configuration in which the air resistance member 15 serving as speed reduction means is mounted to the main plate 10, and an affected portion 313 for receiving air resistance from the air resistance member 15 is formed in a part of the balance wheel 31 in the circumferential direction.
The balance wheel 31 includes a circular portion 312 and the affected portion 313. The circular portion 312 performs the forward/reverse rotational motion about the balance staff 311 serving as a center. The affected portion 313 projects in the radial direction in a part of the circular portion 312 in the circumferential direction. In this embodiment, the affected portion 313 is a part of the balance wheel 31 having the largest length in the radial direction. Further, in this embodiment, as illustrated in
The air resistance member 15 includes a resistance wall for forming an air resistance region AR for causing air resistance. Specifically, the air resistance member 15 includes a first wall portion 151, a second wall portion 152, and a third wall portion 153. The first wall portion 151 is opposed to one surface of the affected portion 313 of the balance wheel 31. The second wall portion 152 is opposed to another surface of the affected portion 313 of the balance wheel 31. The third wall portion 153 connects the first wall portion 151 and the second wall portion 152 to each other. Those wall portions form the air resistance region AR. Further, the air resistance member 15 includes a base portion 154 which is integrated with the first wall portion 151, the second wall portion 152, and the third wall portion 153, and is to be fixed with respect to the main plate 10.
The air resistance member 15 is fixed with respect to the main plate 10. In this embodiment, as illustrated in
In this embodiment, the air resistance member 15 is arranged so that the air resistance member 15 is provided in a predetermined direction with respect to the balance staff 311 and that the affected portion 313 is positioned inside of the air resistance region AR when the rotation angle of the balance wheel 31 falls within 1350 to 225° (halfway period in the forward direction motion and the reverse direction motion). That is, the affected portion 313 of the balance wheel 31 receives air resistance when the rotation angle of the balance wheel 31 falls within 135° to 225°, resulting in reducing the angular velocity. Further, although not shown, similarly, the affected portion 313 of the balance wheel 31 receives air resistance when the rotation angle of the balance wheel 31 falls within −135° to −225° (halfway period in the forward direction motion and the reverse direction motion), resulting in reducing the angular velocity.
The rotation speed of the balance wheel 31 passing through the air resistance region AR is reduced because an air escape passage is blocked by the first wall portion 151, the second wall portion 152, and the third wall portion 153, and thus the air stagnates in the air resistance region AR so that the stagnant air prevents the balance wheel 31 from moving.
As indicated by the graphs at the upper stage and the middle stage of
The balance wheel 31 is rotated in the forward direction from the rotation angle of 0°, and its angular velocity is gradually reduced so that the angular velocity becomes 0 at the position of the rotation angle of 340° corresponding to a turnaround point of the forward/reverse rotational motion. After that, the balance wheel 31 is rotated in the reverse direction along with the elastic deformation of the hairspring 32 from the position of the rotation angle of 340°.
The balance wheel 31 receives the air resistance caused by the air resistance member 15 when the balance wheel 31 is brought to the rotation angle of from 1350 to 225° as described above, and hence the angular velocity is reduced during this period. Accordingly, as shown in the graph at the middle stage of
Then, the balance wheel 31 comes back to the position of the rotation angle of 0° again so as to receive the motive power from the power spring 11, and thus the angular velocity in the reverse direction sharply rises to reach the peak. The angular velocity in the rotation in the reverse direction of the balance wheel 31 is gradually reduced so that the angular velocity becomes 0 at the position of the rotation angle of −340° (measurement time period of 3.0 seconds). After that, the balance wheel 31 is rotated in the forward direction along with the elastic deformation of the hairspring 32 from the position of the rotation angle of −340°.
In this case, the balance wheel 31 includes the affected portion 313 projecting in the radial direction, and hence a center-of-gravity position of the balance wheel 31 is shifted to the affected portion 313 side with respect to the balance staff 311 (rotation center). In a configuration in which the center-of-gravity position is deviated from the balance staff 311 present at the center position of the balance wheel 31, the rotational motion of the balance wheel 31 becomes unstable. In view of the above, in this embodiment, an opening 312h is formed in a part of the circular portion 312 so that the center-of-gravity position of the balance wheel 31 matches or comes close to the balance staff 311 (center position). As illustrated in
In this embodiment, the air resistance member 15 is arranged so that, when the rotation angle of the balance wheel 31 falls within 1350 to 225°, the affected portion 313 is positioned inside the air resistance region AR. Further, the air resistance region AR is arranged so that its center position 15C (see
[Modification Examples of Structure For Reducing Angular Velocity of Balance Wheel 31]
Now, with reference to
The balance wheel 31 illustrated in
The balance wheel 31 illustrated in
The balance wheel 31 illustrated in
Through adoption of the affected portions 313 illustrated in
The configurations of the balance wheel 31 illustrated in
Further, in
Also in
In the examples illustrated in
Specifically, a first elastic member 151J and a second elastic member 152J are provided. The projection 316 is brought into contact with the first elastic member 151J when the balance wheel 31 is positioned at the rotation angle of 135°. The projection 316 is brought into contact with the second elastic member 152J when the balance wheel 31 is positioned at the rotation angle of 225°. It is preferred that the first elastic member 151J and the second elastic member 152J have their ends fixed to the main plate 10.
When the projection 316 of the balance wheel 31 is brought 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 are elastically deformed while causing a frictional resistance with respect to the projection 316. The balance wheel 31 is reduced in speed by the frictional resistance while the first elastic member 151J and the second elastic member 152J are in contact with the projection 316. In the example illustrated in
The configurations illustrated in
Further, with reference to
The balance wheel 31 illustrated in
Further, in the balance wheel 31 illustrated in
In the balance wheel 31 illustrated in
Further, as illustrated in
Further, with reference to
The hairspring 32 includes an outer end portion 321 to be connected to the stud support 34, and an inner end portion 322 to be connected to the balance staff 311. The inner end portion 322 has an annular shape for following the peripheral surface of the balance staff 311. The outer end portion 321 and the inner end portion 322 each have a thickness larger than that of another part (part to be elastically deformed) of the hairspring 32. Accordingly, a connection strength to the stud support 34 and the balance staff 311 is maintained.
When the entire length of the hairspring 32 is increased, a spring force of the hairspring 32 is reduced, thereby being capable of achieving low oscillation. When the entire length of the hairspring 32 is increased, the diameter of the hairspring 32 is increased. In order to increase the entire length while downsizing the hairspring 32, it is preferred that a distance between an inner part and an outer part of the hairspring 32 be decreased. That is, it is preferred that a pitch of the hairspring 32 be narrowed.
The hairspring 32 adopts a shape using a logarithmic spiral. As described above, when laser processing is performed, a logarithmic-spiral hairspring can be easily manufactured. When the shape using the logarithmic spiral is adopted, as compared to an Archimedean spiral having an equal pitch, which is generally used as the shape of the hairspring, a distance between pitches of the hairspring 32 on the inner end portion 322 side can be decreased. Thus, the entire length of the hairspring can be increased, and the diameter can be decreased. As a result, the spring force can be reduced while the diameter of the hairspring 32 is reduced, thereby also being capable of achieving low oscillation. However, when the hairspring 32 is manufactured by laser processing as described above, it is difficult to narrow the pitch. Narrowing the pitch is difficult because there is a possibility that, due to the heat of laser light, the shape of the hairspring 32 may be deformed.
In view of the above, in order to maintain a dimension accuracy of the hairspring 32 while narrowing the pitch, as illustrated in
In this embodiment, an example in which the configuration for reducing the speed of the balance wheel 31 is adopted has been described, but the present invention is not limited thereto. When the number of times the balance wheel 31 performs the reciprocating motion per second is increased by increasing the speed of the balance wheel 31, an error per second, that is, the influence of the rate accuracy is decreased. The configuration including the elastic deformation portion 3322 described above may be adopted in the configuration in which the balance wheel 31 is relatively increased in speed as described above.
[Timing of Power Generation]
An amount of current to be caused in the coil 43 due to the motion of the permanent magnet 41 is increased in proportional to the angular velocity of the permanent magnet 41. Accordingly, in order to efficiently perform power generation, it is preferred that a current to be caused in the coil 43 be used at the time when the angular velocity of the permanent magnet 41 is fast.
In view of the above, in this embodiment, at a timing at which the permanent magnet 41 (balance wheel 31) is at the position of 0° or at a timing immediately after this timing, power generation is performed based on a current corresponding to a counter-electromotive voltage (detection voltage) to be detected in the coil 43 due to the motion of the permanent magnet 41. That is, as shown in the graph at the lower stage of
The timing to perform the power generation is not limited to the timing at which the balance wheel 31 is at the position of the rotation angle of 0° or the timing immediately after this timing, and the timing is only required to be a timing before the affected portion 313 (balance wheel 31) reaches the position of the air resistance member 15 in any of the forward direction motion or the reverse direction motion in the forward/reverse rotational motion of the balance wheel 31. That is, the power generation may be performed based on the current corresponding to the counter-electromotive voltage detected in the coil 43, during a period before the angular velocity of the balance wheel 31 is reduced when the affected portion 313 receives the air resistance by the air resistance member 15.
As shown in the graph at the lower stage of
[Relationship Between Direction of Magnetization of Permanent Magnet 41 and Power Generation Efficiency]
Now, with reference to
In the mechanical timepiece 1 according to this embodiment, the power generation is performed based on electric power obtained by rectifying, by the rectifying circuit 50, a current corresponding to the counter-electromotive voltage caused in the coil 43. In this case, as the rectification to be performed by the rectifying circuit 50, it is conceivable to perform full wave rectification using a bridge circuit including a plurality of diodes or to perform half-wave rectification using a circuit including one diode. When a plurality of diodes are used, a voltage drop occurs in accordance with the number of diodes, and thus loss is caused in the electric power to be obtained. Accordingly, in this embodiment, a configuration in which the half-wave rectification is performed by the rectifying circuit 50 is adopted. Further, in the half-wave rectification, when a difference in shape is provided between the positive counter-electromotive voltage and the negative counter-electromotive voltage, and the power generation is performed based on the counter-electromotive voltage having a larger absolute value, efficient power generation can be performed. In view of the above, in this embodiment, the permanent magnet 41 is arranged so that the counter-electromotive voltage suitable for the half-wave rectification is detected.
[Relationship Between Direction of Magnetization of Permanent Magnet 41 and Power Generation Efficiency: This Embodiment]
In this embodiment, the permanent magnet 41 is arranged so that, under a state in which the hairspring 32 is brought to its neutral position of elastic deformation, the direction of magnetization is orthogonal to the opposing direction of the first welding portion 423 and the second welding portion 424.
Now, description is given of the counter-electromotive voltage to be detected in the coil 43 during a period in which the rotational motion is performed in the forward direction from when the permanent magnet 41 is positioned at the rotation angle of 0°, then the rotational motion is performed in the reverse direction due to the elastic force of the hairspring 32, and further the rotational motion is performed in the forward direction due to the elastic force of the hairspring 32.
Further, a counter-electromotive voltage to be caused in the coil 43 due to a change in a magnetic field at the time when the N-pole portion 411 of the permanent magnet 41 moves in a direction of coming close to the first end portion 421a of the soft magnetic core 42 is referred to as “positive” counter-electromotive voltage. Meanwhile, a counter-electromotive voltage to be caused in the coil 43 due to a change in a magnetic field at the time when the N-pole portion 411 moves in a direction of separating away from the first end portion 421a of the soft magnetic core 42 is referred to as “negative” counter-electromotive voltage.
In this embodiment, the permanent magnet 41 is brought to a magnetically balanced position at the rotation angle of 0°. Accordingly, at the rotation angle of 0°, the counter-electromotive voltage to be caused in the coil 43 becomes 0. The permanent magnet 41 is supplied with motive power from the power spring 11 at the rotation angle of 0°. That is, the angular velocity of the permanent magnet 41 becomes maximum at the timing immediately after the rotation angle of 0°. Further, while the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0° to 180°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. As described above, in this embodiment, the permanent magnet 41 is arranged so that the counter-electromotive voltage to be detected in the coil 43 has the same polarity while the permanent magnet 41 is rotated by 180° in the forward direction from the motive power supply position.
Accordingly, while the permanent magnet 41 is rotated from the rotation angle of 0° to 180°, the angular velocity of the permanent magnet 41 becomes maximum, and the positive counter-electromotive voltage to be caused in the coil 43 reaches a peak.
At the rotation angle of 180° at which the permanent magnet 41 is brought to the magnetically balanced position, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
When the permanent magnet 41 is rotated in the forward direction from the rotation angle of 180°, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated from the rotation angle of 180° to 340°, a negative counter-electromotive voltage is caused in the coil 43. The angular velocity of the permanent magnet 41 at this time is smaller than the angular velocity obtained while the permanent magnet 41 is moved from the rotation angle of 0° to 180°. Accordingly, the absolute value of the peak of the negative counter-electromotive voltage comes out to be smaller than the absolute value of the peak of the positive counter-electromotive voltage.
Further, the angular velocity of the permanent magnet 41 becomes 0 at the rotation angle of 340° corresponding to the turnaround position of the reciprocating motion. Accordingly, at the rotation angle of 340°, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
The permanent magnet 41 which has reached the rotation angle of 340° starts to rotate in the reverse direction due to the elastic force of the hairspring 32. When the permanent magnet 41 is rotated from the rotation angle of 340° to 180°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated from the rotation angle of 340° to 180°, a positive counter-electromotive voltage is caused in the coil 43.
Further, at the rotation angle of 180° at which the permanent magnet 41 is brought to the magnetically balanced position, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
Further, the permanent magnet 41 is rotated from the rotation angle of 180° to 0°. When the permanent magnet 41 is rotated from the rotation angle of 180° to 0°, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated from the rotation angle of 180° to 0°, a negative counter-electromotive voltage is caused in the coil 43.
Further, at the rotation angle of 0° at which the permanent magnet 41 is brought to the magnetically balanced position, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
The permanent magnet 41 which has reached the rotation angle of 0° is supplied with the motive power from the power spring 11. That is, the angular velocity of the permanent magnet 41 becomes maximum immediately after reaching the rotation angle of 0°. Further, while the permanent magnet 41 is rotated from the rotation angle of 0° to −180°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. As described above, in this embodiment, the permanent magnet 41 is arranged so that the counter-electromotive voltage to be detected in the coil 43 has the same polarity while the permanent magnet 41 is rotated by −180° in the reverse direction from the motive power supply position.
Accordingly, while the permanent magnet 41 is rotated from the rotation angle of 0° to −180°, the angular velocity of the permanent magnet 41 becomes maximum, and the positive counter-electromotive voltage to be caused in the coil 43 reaches a peak.
At the rotation angle of −180° at which the permanent magnet 41 is brought to the magnetically balanced position, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
When the permanent magnet 41 is rotated in the reverse direction from the rotation angle of −180°, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated from the rotation angle of −180° to −340°, a negative counter-electromotive voltage is caused in the coil 43. The angular velocity of the permanent magnet 41 at this time is smaller than the angular velocity obtained while the permanent magnet 41 is moved from the rotation angle of 0° to −180°. Accordingly, the absolute value of the peak of the negative counter-electromotive voltage comes out to be smaller than the absolute value of the peak of the positive counter-electromotive voltage.
Further, the angular velocity of the permanent magnet becomes 0 at the rotation angle of −340° corresponding to the turnaround position of the reciprocating motion. Accordingly, at the rotation angle of −340°, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
The permanent magnet 41 which has reached the rotation angle of −340° starts to rotate in the forward direction due to the elastic force of the hairspring 32. When the permanent magnet 41 is rotated from the rotation angle of −340° to −180°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated from the rotation angle of −340° to −180°, a positive counter-electromotive voltage is caused in the coil 43.
Further, at the rotation angle of −180° at which the permanent magnet 41 is brought to the magnetically balanced position, the counter-electromotive voltage to be caused in the coil 43 becomes 0.
Further, the permanent magnet 41 is rotated from the rotation angle of −180° to 0°. When the permanent magnet 41 is rotated from the rotation angle of −180° to 0°, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Accordingly, when the permanent magnet 41 is rotated from the rotation angle of −180° to 0°, a negative counter-electromotive voltage is caused in the coil 43.
The above-mentioned operation is repeated so that, in the arrangement of the permanent magnet 41 in this embodiment, a counter-electromotive voltage having a waveform shown in
[Relationship Between Direction of Magnetization of Permanent Magnet 41 and Power Generation Efficiency: Comparative Example 1]
Next, with reference to
In Comparative Example 1, when the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0°, first, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Then, when the permanent magnet 41 passes the rotation angle of 45°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0° to 225°, a negative counter-electromotive voltage is caused in the coil 43 immediately after the rotation, and then, after passing the rotation angle of 45°, a positive counter-electromotive voltage is caused in the coil 43.
In Comparative Example 1, when the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0° to 340°, then is rotated in the reverse direction by the elastic force of the hairspring 32, and further comes back to the rotation angle of 0° again so as to be rotated in the reverse direction from the rotation angle of 0°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. That is, when the permanent magnet 41 is rotated in the reverse direction from the rotation angle of 0°, a positive counter-electromotive voltage is caused in the coil 43.
As described above, in Comparative Example 1, the rotation in the forward direction and the rotation in the reverse direction have different waveforms of the positive counter-electromotive voltage and the negative counter-electromotive voltage at least before and after the rotation angle of 0°. Accordingly, the rotation in the forward direction and the rotation in the reverse direction have different magnitudes of the peak of the counter-electromotive voltage. Further, the peak position of the counter-electromotive voltage varies between the rotation in the forward direction and the rotation in the reverse direction, and hence there is a possibility that it is determined that the cycle of the forward/reverse rotational motion of the balance wheel 31 is disturbed so that rate adjustment is unexpectedly performed. Accordingly, in the configuration of Comparative Example 1, the rate adjustment means 40 is required to include means for grasping in advance in which direction of the forward direction motion or the reverse direction motion the balance wheel 31 is preforming the motion.
[Relationship Between Direction of Magnetization of Permanent Magnet 41 and Power Generation Efficiency: Comparative Example 2]
Next, with reference to
In Comparative Example 2, when the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0°, first, the N-pole portion 411 moves in the direction of separating away from the first end portion 421a. Then, when the permanent magnet 41 passes the rotation angle of 90°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. Accordingly, while the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0° to 180°, a negative counter-electromotive voltage is caused in the coil 43 immediately after the rotation, and then, after passing the rotation angle of 90°, a positive counter-electromotive voltage is caused in the coil 43.
In Comparative Example 2, when the permanent magnet 41 is rotated in the forward direction from the rotation angle of 0° to 340°, then is rotated in the reverse direction by the elastic force of the hairspring 32, and further comes back to the rotation angle of 0° again so as to be rotated in the reverse direction from the rotation angle of 0°, the N-pole portion 411 moves in the direction of coming close to the first end portion 421a. That is, when the permanent magnet 41 is rotated in the reverse direction from the rotation angle of 0°, a positive counter-electromotive voltage is caused in the coil 43.
As described above, in Comparative Example 2, the rotation in the forward direction and the rotation in the reverse direction have different waveforms of the positive counter-electromotive voltage and the negative counter-electromotive voltage at least before and after the rotation angle of 0°. Accordingly, the rotation in the forward direction and the rotation in the reverse direction have different magnitudes of the peak of the counter-electromotive voltage. In the configuration of Comparative Example 2, the peak of the counter-electromotive voltage is smaller in the rotation in the forward direction or the rotation in the reverse direction as compared to that in Comparative Example 1, and hence it cannot be said that this counter-electromotive voltage is suitable for the half-wave rectification. Further, the rotation in the forward direction and the rotation in the reverse direction have different peaks of the counter-electromotive voltage, and hence, in some cases, a threshold value Vth is also required to be changed. As a result, similarly to Comparative Example 1, the rate adjustment means 40 is required to include means for grasping in advance in which direction of the forward direction motion or the reverse direction motion the balance wheel 31 is performing the motion.
[Relationship Between Direction of Magnetization of Permanent Magnet 41 and Power Generation Efficiency: Summary]
As described above, in this embodiment, regardless of whether the rotating direction of the permanent magnet 41 is the forward direction or the reverse direction, a counter-electromotive voltage having a waveform of the same shape is detected. Accordingly, in this embodiment, the peak of the positive counter-electromotive voltage is detected at the same magnitude and a constant cycle. Further, in this embodiment, the positive counter-electromotive voltage and the negative counter-electromotive voltage have an asymmetric shape. Specifically, the peak of the positive counter-electromotive voltage comes out to be larger than the peak of the negative counter-electromotive voltage. Accordingly, it can be said that, in the arrangement of the permanent magnet 41 in this embodiment, as compared to Comparative Examples 1 and 2, the counter-electromotive voltage has a waveform suitable for rate adjustment and half-wave rectification.
The arrangement of the permanent magnet 41 illustrated in
Further, it is preferred that the permanent magnet 41 be arranged so that, under a state in which the hairspring 32 is brought to its neutral position of elastic deformation, a boundary B between the N-pole portion 411 and the S-pole portion 412 overlaps an imaginary band-shaped region (S indicated in
[Circuit Diagram]
Now, with reference to
In this embodiment, there is adopted a configuration in which, through use of the rectifying circuit 50 including one diode D, a current corresponding to the counter-electromotive voltage caused in the coil 43 due to the motion of the permanent magnet 41 is subjected to half-wave rectification. The rectifying circuit 50 is a circuit for eliminating a negative voltage part of the counter-electromotive voltage caused in the coil 43 so as to achieve conversion into a direct current.
A transistor TP1 and a transistor TP2 are connected to a first terminal O1 and a second terminal O2 of the coil 43, respectively. The counter-electromotive voltage caused in the coil 43 is input to the transistors TP1 and TP2, and the rotation detecting circuit 45 detects the detection signal based on this input. That is, when the transistor TP2 is turned on at a predetermined timing, an induced voltage generated at the first terminal O1 and the second terminal O2 corresponding to those transistors can be extracted as the detection signal being a voltage signal.
Further, transistors P11 and P12 are connected to the first terminal O1 of the coil 43, and 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 or off by the speed governing pulse from the speed governing pulse output circuit 46. At the time of power generation, gate terminals of the transistors P11, P12, P21, and P22 are turned off. Under this state, the rectifying circuit 50 is formed of the transistors TP1 and TP2 and the diode D. When the permanent magnet 41 performs the forward/reverse rotational motion, a current flows through the coil 43 so that a capacitor C is charged. When the capacitor C is charged to some extent, the power supply circuit 60 is activated. Then, through activation of the power supply circuit 60, the control circuit 44 is activated so that the control of each circuit included in the rate adjustment means 40 is performed by the control circuit 44.
In this embodiment, as illustrated in
[Details of Rate Adjustment Control]
Now, with reference to
In this embodiment, the speed governing pulse output circuit 46 outputs the speed governing pulse so as to control the movement of the permanent magnet 41, thereby controlling the movement of the balance wheel 31 so as to perform the rate adjustment.
In this embodiment, it is defined that, as illustrated in
[Details of Rate Adjustment Control: Output Timing of Speed Governing Pulse]
In this case, under a state in which the angular velocity of the permanent magnet 41 is fast, it is difficult to perform the rate adjustment at a desired timing. The reason therefor is because, under a state in which the angular velocity of the permanent magnet 41 is fast, it is highly possible that the output timing of the speed governing pulse is deviated.
In view of the above, in this embodiment, the speed governing pulse is output while the permanent magnet 41 is rotated in the reverse direction from the rotation angle of 180° to 0°, and while the permanent magnet 41 is rotated in the forward direction from the rotation angle of −180° to 0° in the forward direction motion and the reverse direction motion in the forward/reverse rotational motion of the permanent magnet 41. That is, the speed governing pulse is output during a period before the balance wheel 31 is supplied with the motive power from the power spring 11. In this manner, the speed governing pulse can be output under a state in which the angular velocity of the permanent magnet 41 is relatively low. Further, in this embodiment, the balance wheel 31 receives the air resistance caused by the air resistance member 15 during a period from the rotation angle of 225° to 135°, and hence the angular velocity of the permanent magnet 41 is particularly low during the period from the rotation angle of 180° to 0°. The same holds true also during a period from the rotation angle of −225° to −135°. As described above, it is preferred that the rate adjustment be performed during a period after the affected portion 313 has reached the position of the air resistance member 15 in the forward direction motion and the reverse direction motion in the forward/reverse rotational motion of the balance wheel 31.
When such a configuration is adopted, deviation of the output timing of the speed governing pulse can be suppressed. As a result, the rate accuracy can be maintained. In
[Details of Rate Adjustment Control: Coil Terminal To Which Speed Governing Pulse Is Output]
As illustrated in
Further, as illustrated in
As described above, in this embodiment, regardless of whether the rotation is in the forward direction or in the reverse direction in the forward/reverse rotational motion of the permanent magnet 41, when the speed governing pulse is output to the first terminal O1, the rotation of the permanent magnet 41 can be weakened. Meanwhile, when the speed governing pulse is output to the second terminal O2, the rotation of the permanent magnet 41 can be strengthened.
That is, regardless of whether the rotation is in the forward direction or in the reverse direction in the forward/reverse rotational motion of the permanent magnet 41, when the rate is to be adjusted in a delaying direction, the first terminal O1 may be energized, and when the rate is to be adjusted in an advancing direction, the second terminal O2 may be energized.
[Details of Rate Adjustment Control: Operation Flow of Rate Adjustment Control]
The timing at which the detection signal DE is detected is when a large counter-electromotive voltage is caused in the coil 43, that is, when the angular velocity of the permanent magnet 41 is high. Accordingly, it is preferred that the control circuit 44 perform the rate adjustment based on the reference signal OS and the detection voltage caused in the coil 43 due to the motion of the permanent magnet 41 before the affected portion 313 reaches the position of the air resistance member 15 in the forward direction motion and the reverse direction motion in the forward/reverse rotational motion of the balance wheel 31.
In this embodiment, after the power supply circuit 60 is activated through the power generation caused by the motion of the permanent magnet 41 (Y in Step ST1), the rate adjustment control is performed by the rate adjustment means 40.
When the detection signal DE is detected within the output period of the reference signal OS (Y in Step ST2), that is, when no rate deviation occurs, the rate adjustment control is ended.
When the detection signal DE is not detected within the output period of the reference signal OS (N in Step ST2), that is, when a rate deviation occurs, the control circuit 44 determines whether or not the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Step ST3).
When the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Y in Step ST3), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the terminal O1 (Step ST4).
When the detection timing of the detection signal DE is later than the reference signal OS (N in Step ST3), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the terminal O2 (Step ST5).
The speed governing pulse p1 to be output to the first terminal O1 and the speed governing pulse p2 to be output to the second terminal O2 may have different output timings or different output periods. The reason therefor is because, in some cases, the direction of advancing the permanent magnet 41 and the direction of delaying the permanent magnet 41 have different correction amounts due to the output of the speed governing pulse.
[Details of Rate Adjustment Control: Operation Flow of First Modification Example of Rate Adjustment Control]
Next, with reference to
In this example, it is preferred that the rate adjustment means 40 include a first counter and a second counter. The first counter counts the number of times of detection of the detection signal DE. The second counter is an accumulating unit for accumulating a period difference between the detection signal DE and the reference signal OS (deviation amount of the detection timing of the detection signal DE with respect to the output timing of the reference signal OS).
In the first modification example of the rate adjustment control, after the power supply circuit 60 is activated through the power generation caused by the motion of the permanent magnet 41 (Y in Step ST1), the rate adjustment control is performed by the rate adjustment means 40.
The control circuit 44 determines whether or not the forward/reverse rotational motion of the balance wheel 31 (permanent magnet 41) is the eighth forward/reverse rotational motion. Specifically, the control circuit 44 determines whether or not the count number of the first counter is 8 (Step ST21).
When the count number of the first counter is not 8 (N in Step ST21), a period difference between the detection signal DE and the reference signal OS is calculated, and the period difference is accumulated (Step ST22). After that, the count number of the first counter is incremented by 1 (Step ST23).
Meanwhile, when the count number of the first counter is 8 (Y in Step ST21), the first counter is reset, and the count number is set to 0 (Step ST24).
Then, the control circuit 44 determines whether or not the accumulation amount of the period difference between the detection signal DE and the reference signal OS is 0 or falls within a predetermined range (Step ST25). When the accumulation amount of the period difference between the detection signal DE and the reference signal OS is 0 or falls within a predetermined range, the control circuit 44 increments the count number of the first counter by 1 without performing the rate adjustment (Step ST23).
When the accumulation amount of the period difference between the detection signal DE and the reference signal OS is positive (N in Step ST25 and Y in Step ST26), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the first terminal O1 (Step ST4).
Meanwhile, when the accumulation amount of the period difference between the detection signal DE and the reference signal OS is negative (N in Step ST25 and N in Step ST26), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the second terminal O2 (Step ST5).
The upper stage of
The lower stage of
Further, in the example of the lower stage of
In the first modification example of the rate adjustment control described above, the rate adjustment is not performed every seconds, and hence the number of times the speed governing pulse is output can be decreased. As a result, the power consumption can be reduced.
[Details of Rate Adjustment Control: Operation Flow of Second Modification Example of Rate Adjustment Control]
Next, with reference to
In this example, it is preferred that the rate adjustment means 40 include a first counter and a second counter. The first counter counts the number of times of detection of the detection signal DE. The second counter is an accumulating unit for accumulating a period difference between the detection signal DE and the reference signal OS (deviation amount of the detection timing of the detection signal DE with respect to the output timing of the reference signal OS). In the second modification example of the rate adjustment control, the count number becomes 7 when the second counter is reset.
In the second modification example of the rate adjustment control, after the power supply circuit 60 is activated through the power generation caused by the motion of the permanent magnet 41 (Y in Step ST1), the rate adjustment control is performed by the rate adjustment means 40.
The control circuit 44 determines whether or not the forward/reverse rotational motion of the balance wheel 31 (permanent magnet 41) is the eighth forward/reverse rotational motion. Specifically, the control circuit 44 determines whether or not the count number of the first counter is 8 (Step ST21). When the count number of the first counter is not 8 (N in Step ST21), the control circuit 44 calculates a period difference between the detection signal DE and the reference signal OS (Step ST31).
Then, when the detection timing of the detection signal DE is within the output period of the reference signal OS (Y in Step ST32), the control circuit 44 increments the count number of the first counter by 1 without performing the rate adjustment (Step ST23).
When the detection timing of the detection signal DE is outside of the output period of the reference signal OS (N in Step ST32), the control circuit 44 determines whether or not the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Step ST33).
When the detection timing of the detection signal DE is earlier than the output period of the reference signal OS (Y in Step ST33), the second count is reduced in accordance with this period difference (Step ST34). When the detection timing of the detection signal DE is later than the output period of the reference signal OS (N in Step ST33), the second count is increased in accordance with this period difference (Step ST35). After that, the count number of the first counter is incremented by 1 (Step ST23).
When the count number of the first counter is 8 (Y in Step ST21), the first counter is reset, and the count number is set to 0 (Step ST24).
Then, the control circuit 44 determines whether or not the count number of the second counter is 7 (Step ST36). When the count number of the second counter is 7 (Y in Step ST36), the control circuit 44 increments the count number of the first counter by 1 without performing the rate adjustment (Step ST23).
When the count number of the second counter is not 7 (N in Step ST36), the control circuit 44 determines whether or not the count number of the second counter is smaller than 7 (Step ST37). When the count number of the second counter is smaller than 7 (Y in Step ST37), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the first terminal O1 (Step ST4). When the count number of the second counter is larger than 7 (N in Step ST37), the control circuit 44 controls the speed governing pulse output circuit 46 so as to output the speed governing pulse to the second terminal O2 (Step ST5). After that, the count number of the second counter is reset so that the count number becomes 7 (Step ST38).
In the second modification example of the rate adjustment control described above, the rate adjustment is not performed every seconds, and hence the number of times the speed governing pulse is output can be decreased. As a result, the power consumption can be reduced.
The speed governing pulse is not limited to a single pulse, and may be formed of a pulse group including a plurality of single pulses as illustrated in
[Details of Rate Adjustment Control: Rate Adjustment Control At Time When Power Supply Circuit Starts To Activate From Stop State]
As described above, after the power supply circuit 60 is activated through the power generation caused by the motion of the permanent magnet 41, the rate adjustment control is performed by the rate adjustment means 40. Accordingly, it is preferred that the output of the reference signal OS to be used in the rate adjustment control be started after the power supply circuit 60 is activated. For example, as illustrated in
[Details of Rate Adjustment Control: Rate Adjustment Control Considering Influence of Disturbance]
When an external magnet comes close to the mechanical timepiece 1 or an impact is applied to the mechanical timepiece 1, a disturbance momentarily acts so that the counter-electromotive voltage is disturbed. Thus, in some cases, the detection signal DE cannot be detected. In those cases, the control circuit 44 erroneously determines that the rate is greatly delayed.
Accordingly, as illustrated in
The flow chart of
The flow chart of
Each step illustrated in
When the configurations illustrated in
[Details of Rate Adjustment Control: Rate Adjustment Control in Case in Which Failure of Detection of Detection Signal Occurs Successively]
As the power spring 11 is unwound, a rotational force of the rotor 41 is weakened, and, in some cases, the counter-electromotive voltage does not exceed the threshold value Vth. In those cases, the power generation amount is reduced, and the charged amount of the capacitor C is also reduced. That is, the mechanical timepiece 1 is brought into a state of being liable to be stopped, and the power supply circuit 60 is brought into a state of being liable to be stopped. In such cases, it is preferred that no speed governing pulse be output for power saving. That is, it is preferred that no rate adjustment be performed.
In view of the above, in the example illustrated in
Specifically, there is adopted a configuration in which, when the third counter reaches 10, that is, when the detection of the detection signal DE has successively failed 10 times, the setting is switched to the speed governing pulse stop setting. Further, there is adopted a configuration in which, when the fourth counter reaches 20, that is, when the detection of the detection signal DE has successively succeeded 20 times, the setting is switched to the speed governing pulse output setting. The count number serving as a trigger for switching the setting is merely an example, and the present invention is not limited to the represented count number.
In the flow chart of
When the present setting is not the speed governing pulse stop setting (N in Step ST41), the control circuit 44 determines whether or not the third counter is 10 (Step ST42). That is, the control circuit 44 determines whether or not the detection of the detection signal DE has successively failed 10 times. When the third counter is not 10 (N in Step ST42), the control circuit 44 determines whether or not the first counter is 8 (Step ST21). That is, the control circuit 44 determines whether or not the number of times of detection of the detection signal DE is 8.
When the first counter is 8 (Y in Step ST21), Step ST24 and subsequent process steps illustrated in
Further, in Step ST41, when the present setting is the speed governing pulse stop setting (Y in Step ST41), the control circuit 44 determines whether or not the count number of the fourth counter is 20 (Step ST51). That is, the control circuit 44 determines whether or not the detection of the detection signal DE has successively succeeded 20 times. When the fourth counter is not 20 (N in Step ST51), the control circuit 44 determines whether or not the detection signal DE is output (detected) during the predetermined detection period (dt1 to “ts” to dt2) (Step ST52). When no detection signal DE is output (detected) during the predetermined detection period (dt1 to “ts” to dt2) (N in Step ST52), the fourth counter is reset (Step ST53). When the detection signal DE is output (detected) during the predetermined detection period (dt1 to “ts” to dt2) (Y in Step ST52), the count number of the fourth counter is incremented by 1 (Step ST54).
When the count number of the fourth counter is 20 in Step ST51 (Y in Step ST51), the fourth counter is reset (Step ST55), and the setting is switched to the speed governing pulse output setting (Step ST56).
Further, when the count number of the third counter is 10 in Step ST42 (Y in Step ST42), the third counter is reset (Step ST61), and the setting is switched to the speed governing pulse stop setting (Step ST62). When the operation of the power supply circuit 60 is started after the power supply circuit 60 is stopped, the charged amount of the capacitor C is small, and hence it can be said that the power supply circuit 60 is in a state of being liable to be stopped again. Accordingly, it is preferred that, when the operation of the power supply circuit 60 is started after the power supply circuit 60 is stopped, the number of times of successive success of the detection signal DE required until the rate adjustment is started be increased. For example, it is preferred that, in Step ST51 of
In the example of
In the example of
Further, in the example of
[Details of Rate Adjustment Control: Rate Adjustment Control Considering Rotating Direction of Balance Wheel]
In view of the above, in the example illustrated in
With reference to the example illustrated in
The middle stage of
In this embodiment, there is adopted a configuration in which the angular velocity of the balance wheel 31 is reduced, and hence wearing of each mechanism for transmitting the motive power (for example, the escape wheel and pinion 21 or the pallet fork 22) can be suppressed. As a result, the durability of the mechanical timepiece 1 is improved. Further, there is adopted a configuration in which, through use of the air resistance member 15, the angular velocity of the balance wheel 31 is reduced during the halfway period in each of the forward direction motion and the reverse direction motion of the balance wheel 31. In this manner, while the cycle of the rotation of the balance wheel 31 is delayed, electric power is generated during a period in which the balance wheel 31 receives no air resistance by the air resistance member 15, thereby being capable of ensuring a sufficient power generation amount. Further, the rate adjustment is performed during a period in which the balance wheel 31 receives the air resistance by the air resistance member 15 or a period after the balance wheel 31 receives the air resistance by the air resistance member 15, thereby being capable of maintaining the accuracy of the rate adjustment. Further, there is adopted a configuration in which the permanent magnet 41 is arranged so that a counter-electromotive voltage suitable for half-wave rectification can be obtained, and hence electric power can be efficiently extracted through use of the half-wave rectification.
[Others]
The rate adjustment means 40 obtains the detection signal based on the operation of the permanent magnet 41 magnetized into two poles. When a member causing a magnetic effect is present around the permanent magnet 41, there is a possibility that the detection accuracy is reduced. Accordingly, it is preferred that, as a material of a member present around the permanent magnet 41, a material causing less magnetic effect be adopted.
For example, it is preferred that a resin material be used as materials of the support member 33 and the stud support 34. Further, it is preferred that phosphor bronze be used as a material of the fixing tool 33a for fixing the support member 33 with respect to the main plate 10. Further, it is preferred that a resin material or aluminum be used as the material of the balance wheel 31. Further, it is preferred that an acrylic resin be used as the air resistance member 15. The materials given here are merely examples, and the present invention is not limited to those materials.
Further, as described above, the hairspring 32 is made of a resin so that the Young's modulus is reduced. Thus, as compared to the case in which the hairspring 32 is made of a metal, the magnetic effect to be applied to the permanent magnet 41 can be reduced. Further, when the hairspring 32 is made of a metal having magnetism, there is a possibility that the hairspring 32 receives a magnetic effect from the permanent magnet 41 so that the shape or the posture of the hairspring 32 is changed. In this embodiment, the hairspring 32 is made of a resin so that the shape and the posture of the hairspring 32 itself can be stabilized. Further, an antimagnetic plate made of a magnetic material may be separately provided to the mechanical timepiece 1. In this manner, even when an external magnet comes close to the mechanical timepiece 1, a disturbance of the forward/reverse rotational motion of the permanent magnet 41 (balance wheel 31) can be suppressed, and stable rate adjustment can be performed.
Further, in this embodiment, as illustrated in
Further, although not shown, it is preferred that the mechanical timepiece 1 include, on a dial or a back cover, an opening or a transparent portion for allowing the balance wheel 31 to be visually recognized from the outside.
Further, in this embodiment, an example in which the air resistance member 15 is provided has been described. However, the present invention is not limited thereto, and the mechanical timepiece 1 is not required to include the air resistance member 15. Further, when the air resistance member 15 is absent, the balance wheel 31 is not required to include the affected portion 313.
When a configuration in which the air resistance member 15 is used to cause air resistance to act on the balance wheel 31 is adopted as in this embodiment, energy is consumed by the air resistance, and thus the duration of the power spring 11 is reduced. Meanwhile, in this embodiment, a resin material having a low Young's modulus is adopted as the material of the hairspring 32 so that the speed of the operation of the balance wheel 31 is reduced, and thus the duration is increased as compared to that in a mechanical timepiece having six to eight oscillations in the related art. That is, the reduction in speed of the operation of the balance wheel 31 can compensate for the reduction of the duration caused by the air resistance. Accordingly, sufficient duration as the mechanical timepiece can be achieved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-023509 | Feb 2021 | JP | national |
| 2021-131592 | Aug 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/000922 | 1/13/2022 | WO |
