JP2021067672A - Watch movement and watch - Google Patents

Abstract

To provide watch movement and a watch which are capable of highly accurately detecting the reference position of a pointer.SOLUTION: A watch 1 comprises a first motor 20A having a rotor 22 that rotates an hour hand, and a first wheel train group 30 having gears that rotate on the basis of rotation of the rotor 22. The first wheel train group 30 comprises: a third hour intermediate pinion 34b; a first hour intermediate pinion 32b; a 24-hour gear 42a that is arranged so as to engage with the third hour intermediate pinion 34b, that has a first reference load part 60A for changing a load received by the rotor 22 at engagement with the third hour intermediate pinion 34b, and that rotates at a first reduction ratio with respect to the rotor 22; and a second hour intermediate gear 33a that is arranged so as to engage with the first hour intermediate pinion 32b, that has a second reference load part 60B for changing a load received by the rotor 22 at engagement with the first hour intermediate pinion 32b, and that rotates at a second reduction ratio, smaller than the first reduction ratio, with respect to the rotor 22.SELECTED DRAWING: Figure 5

Description

The present invention relates to watch movements and watches.

In a timepiece, as a method of detecting the position of the pointer, a train wheel is formed so that the load fluctuates in the rotor of the stepping motor when the pointer is located at the reference position, and the rotational state of the rotor is detected by the induced voltage to detect the pointer. There is a technique to judge the reference position of. As an example of a mechanism that causes a motor to generate a load fluctuation corresponding to a reference position of a pointer, a method has been developed in which one tooth of a predetermined gear that rotates in conjunction with the pointer is formed into a shape different from that of the other teeth. .. As a result, the load fluctuates in the rotor when the one tooth meshes with the other gear (see, for example, Patent Document 1).

JP-A-2019-124681

However, for example, if the gear that causes the load fluctuation is a gear having a relatively large reduction ratio with respect to the rotor, a plurality of hand movement steps may be required from the start to the end of the load fluctuation. In this case, the magnitude of the load detected by the induced voltage of the motor varies depending on the drive voltage of the motor, the magnitude of the drive pulse, and the like, and it may be difficult to detect the reference position of the pointer.

Therefore, the present invention provides a watch movement and a watch that can accurately detect the reference position of the pointer.

The watch movement of the present invention includes a stepping motor having a rotor for rotating a pointer and a train wheel group having gears that rotate based on the rotation of the rotor, and the train wheel group includes a first gear and a first gear. It has a second gear and a first reference load portion which is arranged so as to mesh with the first gear and changes the load received by the rotor when meshing with the first gear, and has a first reference load portion with respect to the rotor. The rotor has a third gear that rotates at a reduction ratio and a second reference load portion that is arranged so as to mesh with the second gear and changes the load received by the rotor when meshing with the second gear. On the other hand, it is characterized by including a fourth gear that rotates at a second reduction ratio smaller than the first reduction ratio.

According to the present invention, the fourth gear having the second reference load portion rotates more than the third gear having the first reference load portion every time the rotor rotates one step. Therefore, the frequency with which the second reference load unit and the second gear mesh with each other is higher than the frequency with which the first reference load unit and the first gear mesh with each other. As a result, the second reference load unit generates load fluctuations that the rotor receives more frequently than the first reference load unit.
Here, because the first reduction ratio is relatively large, the first reference load unit may mesh with the first gear over a plurality of steps of rotation of the rotor. In this case, since the load fluctuation received by the rotor by the first reference load unit occurs over the rotation of a plurality of steps of the rotor, the guideline that rotates in synchronization with the third gear only by the load fluctuation by the first reference load unit is used. It may be difficult to determine the reference position of.
Therefore, by combining the low-frequency load fluctuation caused by the first reference load unit with the high-frequency load fluctuation caused by the second reference load unit, it is possible to accurately determine the reference position of the pointer.
Therefore, the reference position of the pointer can be detected with high accuracy.

In the watch movement, the train wheel group has a vehicle to which the pointer is attached and rotates at a third reduction ratio with respect to the rotor, and the first reduction ratio is the third reduction ratio. It may be a multiple of the ratio.

According to the present invention, the pointer can be rotated once every time the third gear is rotated by an integral number of revolutions. Therefore, the pointer can be configured to be positioned at the same position each time at any timing when the first reference load unit meshes with the first gear. Therefore, it is possible to accurately determine the reference position of the pointer.

In the watch movement, the first reduction ratio may be a multiple of the second reduction ratio.

According to the present invention, the third gear can be rotated once for every rotation of the fourth gear by an integral number of revolutions. Therefore, the timing at which the load fluctuation is generated by the second reference load unit can be fixedly set with respect to the timing at which the load fluctuation is generated by the first reference load unit. Therefore, the reference position of the pointer can be easily determined by the combination of the load fluctuation caused by the first reference load unit and the load fluctuation caused by the second reference load portion.

In the above-mentioned watch movement, the second reference load portion is provided on one tooth of the fourth gear, and the number of steps of the stepping motor required to rotate the fourth gear once is the fourth gear. It may be equal to the number of teeth of.

According to the present invention, the period in which the second reference load unit meshes with the second gear to change the load received by the rotor is a period equivalent to approximately one step of the stepping motor. As a result, the second reference load unit generates load fluctuations for a period of approximately one step of the stepping motor while the fourth gear makes one rotation. Therefore, the reference position of the pointer can be determined more accurately. In addition, the degree of freedom in the train wheel configuration can be improved.

In the watch movement, the train wheel group has a train wheel train that transmits the rotation of the rotor to at least one of the pointer and the display vehicle that displays information, and the train wheel train is the third wheel train. The gear and the fourth gear may be included.

According to the present invention, gears that transmit the rotation of the rotor to at least one of the pointer and the display wheel can be used as the third gear and the fourth gear. Therefore, it is possible to form a watch movement that exerts the above-mentioned effects without increasing the number of gears.

In the watch movement, the train wheel group has a train wheel that transmits the rotation of the rotor to at least one of the pointer and the display wheel for displaying information, the third gear and the fourth gear. At least one of the gears may be provided separately from the gears included in the train wheel.

According to the present invention, at least one of the third gear and the fourth gear is provided separately from the gear that transmits the rotation of the rotor to at least one of the pointer and the display wheel. Without modification, it is possible to form a watch movement that exerts the above-mentioned effects.

In the above-mentioned watch movement, the first reference load portion may be elastically deformed in contact with the first gear, and the second reference load portion may be elastically deformed in contact with the second gear.

According to the present invention, when the first reference load portion comes into contact with the first gear and is elastically deformed, energy loss due to the elastic deformation occurs in the train wheel group. Further, when the second reference load portion comes into contact with the second gear and elastically deforms, energy loss due to the elastic deformation occurs in the train wheel group. The energy loss in the train wheel increases the load on the rotor. Therefore, it is possible to form the first reference load section and the second reference load section that change the load received by the rotor.

The timepiece of the present invention is characterized by including the above-mentioned timepiece movement.

According to the present invention, it is possible to provide a clock capable of accurately grasping the position of a pointer.

According to the present invention, it is possible to provide a timepiece movement and a timepiece that can accurately detect a reference position of a pointer.

It is an external view of the timepiece which shows 1st Embodiment. It is a top view of the movement front side of 1st Embodiment. It is sectional drawing of the movement of 1st Embodiment. It is a top view of the back side of the movement of 1st Embodiment. It is a top view which shows a part of the movement of 1st Embodiment, and is the figure which looked at the 1st wheel train group from the front side. It is a perspective view of the 2nd time intermediate vehicle which concerns on 1st Embodiment. It is a top view which shows a part of the movement of 2nd Embodiment, and is the figure which looked at the 1st wheel train group from the front side. It is a top view which shows a part of the movement of 3rd Embodiment, and is the figure which looked at the 1st wheel train group from the front side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals are given to configurations having the same or similar functions. Then, the duplicate description of those configurations may be omitted.

[First Embodiment]
Generally, a mechanical body including a driving part of a watch is referred to as a "movement". The state in which the dial and hands are attached to this movement and placed in the watch case to make a finished product is called "complete" of the watch. Of both sides of the main plate constituting the watch substrate, the side with the glass of the watch case (that is, the side with the dial) is referred to as the "back side" of the movement. Further, of both sides of the main plate, the side of the watch case with the case back cover (that is, the side opposite to the dial) is referred to as the "front side" of the movement.

FIG. 1 is an external view of a timepiece showing the first embodiment.
As shown in FIG. 1, the complete watch 1 of the present embodiment includes a movement 4 (clock movement), a dial 5 having a scale, and a dial 5 having a movement 4 (clock movement) and a scale in a watch case 2 composed of a case back cover and a glass 3 (not shown). It includes an hour hand 6 (pointer), a minute hand 7, a second hand 8 (pointer), and a 24-hour hand 9. The dial 5 is opened with a sun window 5a for clearly indicating the day letter 46a displayed on the day wheel 46 (display car) described later. As a result, the clock 1 can confirm the date in addition to the time.

FIG. 2 is a plan view of the front side of the movement of the first embodiment. FIG. 3 is a cross-sectional view of the movement of the first embodiment.
As shown in FIGS. 2 and 3, the movement 4 includes a main plate 11, a train wheel receiving 12, a date wheel holder 13, a second receiving 14, a first motor 20A, a second motor 20B, and a first. It mainly includes a train wheel group 30 and a second wheel train group 50.

As shown in FIG. 3, the main plate 11 constitutes the substrate of the movement 4. The train wheel receiver 12 is arranged on the front side of the main plate 11. The sun wheel holder 13 is arranged on the back side of the main plate 11. The second receiver 14 is arranged between the main plate 11 and the train wheel receiver 12.

As shown in FIG. 2, the first motor 20A and the second motor 20B are stepping motors having a stator 21 and a rotor 22, respectively. The number of magnetic poles of the rotor 22 is 2. Each of the first motor 20A and the second motor 20B rotates the rotor 22 by 180 ° in one step. The first motor 20A generates power to rotate the hour hand 6, the 24-hour hand 9, and the date wheel 46 (all of which see FIG. 1). The first motor 20A rotates the rotor 22 one step every minute. The second motor 20B generates power to rotate the minute hand 7 and the second hand 8 (both see FIG. 1). The second motor 20B rotates the rotor 22 in two steps every second. A kana is formed on each rotor 22 of the first motor 20A and the second motor 20B.

FIG. 4 is a plan view of the back side of the movement of the first embodiment. FIG. 5 is a plan view showing a part of the movement of the first embodiment, and is a view of the first wheel train group as viewed from the front side.
As shown in FIGS. 4 and 5, the first train wheel group 30 has gears that rotate based on the rotation of the rotor 22 of the first motor 20A. The first wheel train group 30 includes an hour wheel train 31 that transmits the rotation of the rotor 22 of the first motor 20A to the hour hand 6, and a calendar that transmits the rotation of the rotor 22 of the first motor 20A to the 24 hour hand 9 and the date wheel 46. It includes a train wheel 41.

As shown in FIGS. 3 and 5, the hour wheel train 31 includes a first hour intermediate vehicle 32, a second hour intermediate vehicle 33, a third hour intermediate vehicle 34, and a cylinder wheel 35.
The first time intermediate vehicle 32 is rotatably supported by the main plate 11 and the train wheel receiving 12. The first hour intermediate wheel 32 has a first hour intermediate gear 32a and a first hour intermediate kana 32b. The first hour intermediate gear 32a meshes with the kana of the rotor 22 of the first motor 20A between the main plate 11 and the train wheel receiving 12. The first intermediate vehicle 32 rotates at a reduction ratio of 6 with respect to the rotor 22. That is, the first intermediate wheel 32 makes one rotation every six rotations of the rotor 22 of the first motor 20A.

The second intermediate vehicle 33 is rotatably supported by the main plate 11 and the train wheel receiving 12. The second hour intermediate wheel 33 has a second hour intermediate gear 33a and a second hour intermediate kana 33b. The second hour intermediate gear 33a meshes with the first hour intermediate kana 32b of the first hour intermediate vehicle 32 between the main plate 11 and the train wheel receiving 12. The second hour intermediate vehicle 33 is a driven gear with respect to the first hour intermediate vehicle 32. The second hour intermediate vehicle 33 rotates at a reduction ratio of 7.5 with respect to the first hour intermediate vehicle 32. That is, the second intermediate vehicle 33 rotates at a reduction ratio of 45 with respect to the rotor 22 of the first motor 20A.

The third hour intermediate vehicle 34 is rotatably supported by the main plate 11 between the main plate 11 and the sun wheel holder 13. The third hour intermediate wheel 34 has a third hour intermediate gear 34a and a third hour intermediate kana 34b. The third hour intermediate gear 34a meshes with the second hour intermediate kana 33b of the second hour intermediate vehicle 33 on the back side of the main plate 11. The third hour intermediate vehicle 34 is a driven gear with respect to the second hour intermediate vehicle 33. The third hour intermediate vehicle 34 rotates at a reduction ratio of 8 with respect to the second hour intermediate vehicle 33. That is, the third hour intermediate vehicle 34 rotates at a reduction ratio of 360 with respect to the rotor 22 of the first motor 20A.

The cylinder wheel 35 is rotatably extrapolated to the central pipe 15 on the back side of the main plate 11. The central pipe 15 is held by the main plate 11. The central pipe 15 projects from the main plate 11 to the back side. The cylinder wheel 35 is pressed by the date wheel retainer 13 from the back side via a needle seat. The end portion on the back side of the cylinder wheel 35 projects to the back side from the date wheel holder 13. An hour hand 6 (see FIG. 1) is attached to the rear end of the cylinder wheel 35. The cylinder wheel 35 has a cylinder gear 35a. The tubular gear 35a meshes with the third hour intermediate gear 34a of the third hour intermediate wheel 34. The cylinder wheel 35 is a driven gear with respect to the third hour intermediate vehicle 34. The cylinder wheel 35 rotates at a reduction ratio of 1 with respect to the third hour intermediate vehicle 34. That is, the cylinder wheel 35 rotates at a reduction ratio of 360 with respect to the rotor 22 of the first motor 20A.

As shown in FIG. 5, the calendar wheel train 41 includes the above-mentioned first hour intermediate car 32, second hour intermediate car 33, third hour intermediate car 34, 24 o'clock car 42, and day-turning intermediate car 43. To be equipped with.
The 24:00 car 42 is rotatably supported by the main plate 11 between the main plate 11 and the sun wheel holder 13. The shaft portion of the 24:00 car 42 projects to the back side from the sun wheel holder 13. A 24-hour hand 9 (see FIG. 1) is attached to the end on the back side of the shaft. The 24-hour wheel 42 has a 24-hour gear 42a. The 24 hour gear 42a meshes with the 3rd hour intermediate kana 34b of the 3rd hour intermediate vehicle 34 on the back side of the main plate 11. The 24:00 car 42 is a driven gear with respect to the 3rd hour intermediate car 34. The 24 o'clock car 42 rotates at a reduction ratio of 2 with respect to the 3rd hour intermediate car 34. That is, the 24-hour car 42 rotates at a reduction ratio of 720 with respect to the rotor 22 of the first motor 20A.

The day turning intermediate car 43 is rotatably supported by the main plate 11 between the main plate 11 and the day wheel holder 13. The center of rotation of the day-turning intermediate vehicle 43 is provided around the center of rotation of the 24-hour vehicle 42 at an angle of less than 180 ° from the center of rotation of the third-hour intermediate vehicle 34. That is, the rotation center of the day-turning intermediate vehicle 43 is provided at a position deviated from the straight line passing through the rotation center of the 24 o'clock vehicle 42 and the rotation center of the third hour intermediate vehicle 34 in a plan view. The day-turning intermediate wheel 43 has a day-turning intermediate gear 43a and a disk wheel 43b. The daily intermediate gear 43a meshes with the 24-hour gear 42a on the back side of the main plate 11. The day-turning intermediate car 43 is a driven car with respect to the 24:00 car 42. The day-turning intermediate vehicle 43 rotates at a reduction ratio of 1 with respect to the 24:00 vehicle 42. That is, the day-turning intermediate vehicle 43 rotates at a reduction ratio of 720 with respect to the rotor 22 of the first motor 20A. The disc wheel 43b overlaps the daily rotation intermediate gear 43a. The disc wheel 43b includes feed dogs 43c. The feed dog 43c projects radially outward from the outer peripheral surface of the disc wheel 43b.

The day wheel 44 is rotatably supported by the main plate 11 between the main plate 11 and the day wheel holder 13. The day wheel 44 has a day wheel 44a. The day-turning gear 44a is formed so as to be meshable with the feed dog 43c of the day-turning intermediate wheel 43. The day wheel 44 rotates when the feed dog 43c of the day turn intermediate car 43 enters and engages with the rotation locus of the day turn gear 44a. Therefore, the day-turning wheel 44 rotates intermittently due to the rotation of the day-turning intermediate car 43. The day wheel 44 rotates the day wheel 46.

The date wheel 46 is a ring-shaped member rotatably attached to the main plate 11. The date wheel 46 is pressed from the back side by the date wheel holder 13 (see FIG. 4). On the back surface of the date wheel 46, the date information 46a (see FIG. 1), which is date information, is displayed along the circumferential direction. The date wheel 46 displays date information by exposing the day letter 46a through the day window 5a of the dial 5. A plurality of internal teeth 46b are formed on the inner peripheral edge of the date wheel 46 over the entire circumference. The internal teeth 46b mesh with the day gear 44a. The day wheel 46 rotates in conjunction with the rotation of the day wheel 44. Therefore, the day wheel 46 is intermittently rotated by the rotation of the day turn intermediate car 43. The position of the date wheel 46 in the rotation direction is regulated by the jumper 47. The jumper 47 regulates the rotation of the date wheel 46 by engaging the claw at the tip with the internal teeth 46b of the date wheel 46.

As shown in FIGS. 2 and 3, the second train wheel group 50 has gears that rotate based on the rotation of the rotor 22 of the second motor 20B. The second wheel train group 50 includes a front wheel train 51 that transmits the rotation of the rotor 22 of the second motor 20B to the second hand 8 and the minute hand 7 (both see FIG. 1). The front wheel train 51 includes a fourth intermediate car 52, a fourth car 53, a third car 54, and a second car 55.

The fourth intermediate wheel 52 is rotatably supported by the main plate 11. The fourth intermediate wheel 52 has a fourth intermediate gear 52a and a fourth intermediate kana 52b. The fourth intermediate gear 52a meshes with the kana of the rotor 22 of the second motor 20B between the main plate 11 and the train wheel receiving 12. The fourth intermediate wheel 52 rotates at a reduction ratio of 6 with respect to the rotor 22 of the second motor 20B.

The fourth wheel 53 is rotatably supported by the train wheel receiving 12. The fourth wheel 53 has a fourth true 53a, a fourth gear 53b assembled to the fourth true 53a, and a fourth kana 53c formed on the fourth true 53a. The fourth true 53a is inserted inside the second true 55a, which will be described later. The fourth true 53a protrudes to the back side of the second true 55a. A second hand 8 (see FIG. 1) is attached to the rear end of the fourth true 53a. The fourth gear 53b meshes with the fourth intermediate kana 52b. The fourth wheel 53 is a driven gear with respect to the fourth intermediate wheel 52. The fourth wheel 53 rotates at a reduction ratio of 10 with respect to the fourth intermediate wheel 52. That is, the fourth wheel 53 rotates at a reduction ratio of 60 with respect to the rotor 22 of the second motor 20B.

The third wheel 54 is rotatably supported by the main plate 11 and the train wheel receiving 12. The third wheel 54 includes a third gear 54a and a third kana (not shown). The third gear 54a meshes with the fourth kana 53c. The third wheel 54 is a driven gear with respect to the fourth wheel 53. The third wheel 54 rotates at a reduction ratio of 20 with respect to the fourth wheel 53. That is, the third wheel 54 rotates at a reduction ratio of 400 with respect to the rotor 22 of the second motor 20B.

The second wheel 55 is rotatably supported by the second receiver 14 and the central pipe 15. The second wheel 55 has a second true 55a and a second gear 55b assembled to the second true 55a. The second true 55a is formed in a cylindrical shape and is inserted inside the central pipe 15. The second true 55a protrudes to the back side of the cylinder wheel 35. A minute hand 7 (see FIG. 1) is attached to the rear end of the second true 55a. The second gear 55b meshes with the third gear. The second wheel 55 is a driven gear with respect to the third wheel 54. The second wheel 55 rotates at a reduction ratio of 9 with respect to the third wheel 54. That is, the second wheel 55 rotates at a reduction ratio of 3600 with respect to the rotor 22 of the second motor 20B.

As shown in FIG. 5, a reference load unit 60 is provided on two of the plurality of gears included in the first wheel train group 30. The 24-hour gear 42a has a first reference load unit 60A. The second hour intermediate gear 33a has a second reference load portion 60B. Since the first reference load section 60A and the second reference load section 60B are formed in the same manner, the second reference load section 60B will be described below, and the configuration of the first reference load section 60A will be described in detail. Is omitted.

FIG. 6 is a perspective view of the second time intermediate vehicle according to the first embodiment.
As shown in FIG. 6, the second hour intermediate gear 33a has a plurality of teeth 61 and an elastic portion 65. The plurality of teeth 61 include a standard tooth 62 and an elastic tooth 63 as a second reference load portion 60B. The standard tooth 62 is all the teeth 61 among the plurality of teeth 61 except the elastic tooth 63. The standard tooth 62 is a general gear tooth, and is a tooth formed in an arc tooth profile, an involute tooth profile, a cycloid tooth profile, or the like. The elastic tooth 63 is one of a plurality of teeth 61 included in the second intermediate gear 33a. The elastic tooth 63 is formed so as to be elastically displaceable.

The elastic portion 65 is a cantilever beam having elastic teeth 63 at its tip and formed so as to be flexible and deformable. The elastic portion 65 is a portion between the first slit 67 and the second slit 68 formed in the second intermediate gear 33a. The first slit 67 extends radially inward from one tooth groove adjacent to the elastic tooth 63 and then extends toward one side in the circumferential direction. The second slit 68 extends along the first slit 67 from the other tooth groove adjacent to the elastic tooth 63. As a result, the elastic portion 65 extends with a substantially constant width and is formed so as to be elastically deformable so as to displace the elastic tooth 63 at the tip in the radial direction.

The operation of the reference load unit 60 will be described.
As shown in FIGS. 5 and 6, of the plurality of teeth 61 of the second intermediate gear 33a, when the tooth engaging with the first intermediate kana 32b changes from the standard tooth 62 to the elastic tooth 63, the elastic tooth The tooth of 32b, which is the middle of the first hour, comes into contact with 63. After that, when the first middle kana 32b further rotates, the elastic tooth 63 is displaced inward in the radial direction with elastic deformation of the elastic portion 65. As a result, energy loss due to elastic deformation of the elastic portion 65 occurs in the first wheel train group 30. Therefore, the elastic tooth 63 increases the load received by the rotor 22 of the first motor 20A when the standard tooth 62 meshes with the first intermediate kana 32b as compared with the case where the standard tooth 62 meshes with the first intermediate kana 32b. That is, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A once for each rotation of the second intermediate vehicle 33.

Since the first reference load unit 60A is provided on the 24-hour gear 42a, the load received by the rotor 22 of the first motor 20A when the teeth of the third reference load unit 60A come into contact with the teeth of the third hour intermediate kana 34b. To increase. That is, the first reference load unit 60A changes the load received by the rotor 22 of the first motor 20A once for each rotation of the 24 hour vehicle 42. Further, since the 24-hour wheel 42 makes one rotation every two rotations of the cylinder wheel 35, the first reference load unit 60A receives the load received by the rotor 22 of the first motor 20A once every two rotations of the hour hand 6. Fluctuate.

The second intermediate vehicle 33 rotates with respect to the rotor 22 of the first motor 20A at a reduction ratio smaller than the reduction ratio of the 24 hour vehicle 42. Therefore, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A more frequently than the first reference load unit 60A. In particular, the reduction ratio of the 24:00 vehicle 42 is an integral multiple of the reduction ratio of the second intermediate vehicle 33. Therefore, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A at a frequency that is an integral multiple of the first reference load unit 60A.

The 24-hour gear 42a meshes with the day-turning intermediate gear 43a in addition to the third hour intermediate kana 34b. The 24-hour gear 42a is a driven gear for the third hour intermediate kana 34b, whereas it is a driving gear for the daily rotating intermediate gear 43a. Therefore, the load fluctuation when the teeth of the daily rotation intermediate gear 43a come into contact with the first reference load portion 60A is larger than the load fluctuation when the teeth of the third intermediate kana 34b come into contact with the first reference load portion 60A. Small enough. Therefore, the load fluctuation due to the engagement with the third intermediate gear 34b can be discriminated separately from the load fluctuation due to the engagement with the daily rotation intermediate gear 43a.

Moreover, the rotation center of the day-turning intermediate vehicle 43 is provided at a position deviated from the straight line passing through the rotation center of the 24 o'clock vehicle 42 and the rotation center of the third hour intermediate vehicle 34 in a plan view. Therefore, based on the relationship between the timing at which the load fluctuates due to the engagement with the third intermediate kana 34b and the timing at which the load fluctuates due to the engagement with the daily intermediate gear 43a, the third hour intermediate kana 34b The load fluctuation due to meshing can be discriminated separately from the load fluctuation due to meshing with the daily rotation intermediate gear 43a.

As shown in FIG. 2, also in the second wheel train group 50, the reference load unit 60 is provided on the two gears (in FIG. 2, only one reference load unit 60 is shown). In the present embodiment, the reference load unit 60 is provided on each of the second gear 55b and the fourth gear 53b. The fourth wheel 53 rotates with respect to the rotor 22 of the second motor 20B at a reduction ratio smaller than the reduction ratio of the second wheel 55. Therefore, the reference load unit 60 provided on the fourth wheel 53 changes the load received by the rotor 22 of the second motor 20B more frequently than the reference load section 60 provided on the second wheel 55.

As described above, in the present embodiment, the first wheel train group 30 of the movement 4 is arranged so as to mesh with the third hour middle kana 34b, and when meshing with the third hour middle kana 34b, the first motor 20A It has a first reference load unit 60A that fluctuates the load received by the rotor 22 of the first motor 20A, and meshes with a 24-hour gear 42a that rotates at a reduction ratio of 720 with respect to the rotor 22 of the first motor 20A and a kana 32b in the middle of the first hour. It has a second reference load unit 60B that changes the load received by the rotor 22 of the first motor 20A when it meshes with the rotor 32b of the first motor 20A, and decelerates with respect to the rotor 22 of the first motor 20A. A second hour intermediate gear 33a that rotates at a ratio of 45 is provided.

According to this configuration, the second hour intermediate gear 33a having the second reference load portion 60B rotates one step each time the rotor 22 of the first motor 20A rotates more than the 24 hour gear 42a having the first reference load portion 60A. It makes a big turn. Therefore, the frequency of engagement between the second reference load unit 60B and the first time intermediate kana 32b is higher than the frequency of engagement of the first reference load unit 60A and the third time intermediate kana 34b. As a result, the second reference load unit 60B generates load fluctuations received by the rotor 22 of the first motor 20A more frequently than the first reference load unit 60A. Here, because the reduction ratio of the 24-hour gear 42a is relatively large, the first reference load unit 60A may mesh with the third hour intermediate kana 34b over the rotation of the rotor 22 of the first motor 20A in a plurality of steps. In this case, the load fluctuation received by the rotor 22 of the first motor 20A by the first reference load unit 60A occurs over the rotation of the rotor 22 in a plurality of steps. Therefore, the load fluctuation by the first reference load unit 60A alone is not enough. It may be difficult to determine the reference position of the hour hand 6 that rotates in synchronization with the 3 o'clock middle kana 34b. Therefore, by combining the low-frequency load fluctuation caused by the first reference load unit 60A with the high-frequency load fluctuation caused by the second reference load unit 60B, the reference position of the hour hand 6 can be accurately determined. Therefore, the reference position of the hour hand 6 can be detected with high accuracy.

Further, the first wheel train group 30 includes a cylinder wheel 35 to which an hour hand 6 is attached and which rotates at a reduction ratio of 360 with respect to the rotor 22 of the first motor 20A. The reduction ratio of the 24-hour gear 42a is a multiple of the reduction ratio of the cylinder wheel 35. According to this configuration, the hour hand 6 can be rotated once every time the 24-hour gear 42a is rotated by an integer number of revolutions. Therefore, the hour hand 6 can be configured to be positioned at the same position each time at any timing when the first reference load unit 60A meshes with the third time intermediate kana 34b. Therefore, it is possible to accurately determine the reference position of the hour hand 6.

The reduction ratio of the 24-hour gear 42a is a multiple of the reduction ratio of the second intermediate gear 33a. According to this configuration, the 24-hour gear 42a can be rotated once every time the second hour intermediate gear 33a is rotated by an integer number of revolutions. Therefore, the timing at which the load fluctuation is generated by the second reference load unit 60B can be fixedly set with respect to the timing at which the load fluctuation is generated by the first reference load unit 60A. Therefore, the reference position of the hour hand 6 can be easily determined by the combination of the load fluctuation caused by the first reference load unit 60A and the load fluctuation caused by the second reference load unit 60B.

Further, the first wheel train group 30 transmits the rotation of the rotor 22 of the first motor 20A to the hour hand 6 and the rotation of the rotor 22 of the first motor 20A to the 24 hour hand 9 and the date wheel 46. The calendar wheel train 41 and the like. The hour train 31 and the calendar train 41 include a 24-hour gear 42a and a second hour intermediate gear 33a. According to this configuration, a gear that transmits the rotation of the rotor 22 of the first motor 20A to at least one of the hour hand 6, the 24 hour hand 9, and the date wheel 46 is provided to the first reference load unit 60A and the second reference load unit. It can be used as a gear having 60B. Therefore, it is possible to form the movement 4 that exerts the above-mentioned action and effect without increasing the number of gears.

Further, the first reference load portion 60A is elastically deformed in contact with the third intermediate kana 34b. The second reference load portion 60B is elastically deformed in contact with the first intermediate kana 32b. According to this configuration, when the first reference load portion 60A comes into contact with the third intermediate kana 34b and elastically deforms, energy loss due to the elastic deformation occurs in the first wheel train group 30. Further, when the second reference load portion 60B comes into contact with the first intermediate kana 32b and elastically deforms, energy loss due to the elastic deformation occurs in the first wheel train group 30. The energy loss in the first wheel train group 30 increases the load received by the rotor 22 of the first motor 20A. Therefore, the first reference load section 60A and the second reference load section 60B that give fluctuations to the load received by the rotor 22 of the first motor 20A can be formed.

Since the clock 1 of the present embodiment includes the movement 4 described above, the clock can be a clock whose position of the hour hand 6 is accurately grasped.

In the above description, the effects of the first reference load section 60A and the second reference load section 60B in the first wheel train group 30 have been described, but the pair of reference load sections 60 in the second wheel train group 50 have also been described. It has the same effect. That is, since the fourth gear 53b and the second gear 55b each have a reference load portion 60, the reference positions of the minute hand 7 and the second hand 8 are accurately determined based on the fluctuation of the load received by the rotor 22 of the second motor 20B. It becomes possible.

[Second Embodiment]
FIG. 7 is a plan view showing a part of the movement of the second embodiment, and is a view of the first wheel train group viewed from the front side.
In the first embodiment shown in FIG. 5, both the first reference load section 60A and the second reference load section 60B are provided on at least one of the gears of the hour wheel train 31 and the calendar wheel train 41. On the other hand, the second embodiment shown in FIG. 7 is different from the first embodiment in that the second reference load unit 60B is provided on a gear different from the hour wheel train 31 and the calendar wheel train 41. The configuration other than that described below is the same as that of the first embodiment.

As shown in FIG. 7, in the first wheel train group 30A of the present embodiment, the dedicated gear 36 is added to the first wheel train group 30 of the first embodiment, and the second reference load unit 60B is second. It has a configuration provided in the dedicated gear 36 instead of the hour-intermediate gear 33a. The dedicated gear 36 meshes only with the first hour intermediate kana 32b of the first hour intermediate vehicle 32. The dedicated gear 36 is a driven gear for the first intermediate vehicle 32. The dedicated gear 36 is arranged on a torque transmission path of the rotor 22 of the first motor 20A in the first wheel train group 30A, which does not transmit torque to any of the hour hand 6, the hour hand 9, and the date wheel 46. There is. The dedicated gear 36 rotates at a reduction ratio of 7.5 with respect to the first intermediate vehicle 32. That is, the dedicated gear 36 rotates at a reduction ratio of 45 with respect to the rotor 22 of the first motor 20A.

As described above, the dedicated gear 36 has a second reference load portion 60B. Therefore, similarly to the second intermediate gear 33a of the first embodiment, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A once for each rotation of the dedicated gear 36. Let me. Then, the dedicated gear 36 rotates with respect to the rotor 22 of the first motor 20A at a reduction ratio smaller than the reduction ratio of the 24 hour vehicle 42. Therefore, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A more frequently than the first reference load unit 60A. In particular, the reduction ratio of the 24-hour vehicle 42 is an integral multiple of the reduction ratio of the dedicated gear 36. Therefore, the second reference load unit 60B changes the load received by the rotor 22 of the first motor 20A at a frequency that is an integral multiple of the first reference load unit 60A.

As described above, in the present embodiment, the first wheel train group 30A of the movement 4 includes a 24-hour gear 42a having a first reference load unit 60A, a dedicated gear 36 having a second reference load unit 60B, and the like. Therefore, it is possible to obtain the same action and effect as in the first embodiment.

Further, the dedicated gear 36 is provided separately from the gears included in the hour wheel train 31 and the calendar wheel train 41. According to this configuration, at least one of the hour hand 6, the 24 hour hand 9, and the date wheel 46 is provided with a dedicated gear 36 in addition to the gear that transmits the rotation of the rotor 22 of the first motor 20A. The movement 4 that exerts the above-mentioned action and effect can be formed without changing the configuration of the above.

[Third Embodiment]
FIG. 8 is a plan view showing a part of the movement of the third embodiment, and is a view of the first wheel train group viewed from the front side.
The third embodiment shown in FIG. 8 is different from the first embodiment in that the second intermediate vehicle 33 rotates at a reduction ratio of 36 with respect to the rotor 22 of the first motor 20A. The configuration other than that described below is the same as that of the first embodiment.

As shown in FIG. 8, the first wheel train group 30B of the present embodiment has a reduction ratio of the first wheel train group 30 of the first embodiment to the rotor 22 of the first motor 20A of the second intermediate vehicle 33. Is changing. The number of teeth of the second hour intermediate gear 33a of the second hour intermediate wheel 33 is 72. The second hour intermediate vehicle 33 rotates at a reduction ratio of 6 with respect to the first hour intermediate vehicle 32. That is, the second intermediate vehicle 33 rotates at a reduction ratio of 36 with respect to the rotor 22 of the first motor 20A. The third hour intermediate vehicle 34 rotates at a reduction ratio of 10 with respect to the second hour intermediate vehicle 33. That is, the third hour intermediate vehicle 34 rotates at a reduction ratio of 360 with respect to the rotor 22 of the first motor 20A.

In the present embodiment, the number of magnetic poles of the rotor 22 of the first motor 20A is 2. Therefore, the number of steps of the first motor 20A required to rotate the second intermediate gear 33a provided with the second reference load unit 60B once is 72, which is equal to the number of teeth of the second intermediate gear 33a.

According to the present embodiment, the period in which the second reference load unit 60B meshes with the first intermediate kana 32b to change the load received by the rotor 22 is a period equivalent to approximately one step of the first motor 20A. As a result, the second reference load unit 60B generates load fluctuations for a period of approximately one step of the first motor 20A while the second intermediate gear 33a makes one rotation. Therefore, it is possible to more accurately determine the reference position of the hour hand 6 as compared with the configuration in which the reference load unit generates load fluctuations over a period of a plurality of steps of the first motor 20A. In addition, the degree of freedom in the train wheel configuration can be improved.

The present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within the technical scope thereof.
For example, in the above embodiment, in the first wheel train group 30, the reference load portion 60 is provided on the second hour intermediate gear 33a and the 24 hour gear 42a, but even if the reference load portion is provided on other gears. Good. However, it is desirable that the reference load portion is provided on the driven gear of the pair of gears that mesh with each other. As a result, the load received by the rotor 22 can be increased as compared with the configuration in which the reference load portion is provided on the gear on the drive side.

Further, in the above embodiment, the first reference load unit 60A is provided on the gear included in the calendar wheel train 41, but the first reference load unit 60A is a gear not included in the hour wheel train 31 and the calendar wheel train 41. It may be provided in.

Further, in the above embodiment, the reference load portion 60 is formed by making one tooth of the gear elastically displaceable, but the present invention is not limited to this. For example, the reference load portion may be formed by making one tooth of the gear different from the other teeth.

Further, in the above embodiment, the date wheel 46 has been described as an example of the display vehicle for displaying information, but the present invention is not limited to the date wheel 46. For example, a day car that displays the day of the week as information may be applied as a display car.

In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate without departing from the spirit of the present invention, and the above-described embodiments may be combined as appropriate.

1 ... Clock 4 ... Movement (movement for clock) 6 ... Hour hand (pointer) 8 ... Second hand (pointer) 20A ... 1st motor (stepping motor) 20B ... 2nd motor (stepping motor) 22 ... Rotor 30, 30A, 30B ... 1st wheel train group (wheel train group) 31 ... hour wheel train (wheel train) 32b ... 1st hour intermediate kana (1st gear) 33a ... 2nd hour intermediate gear (4th gear) 34b ... 3rd hour intermediate kana (2nd gear) 35 ... Cylinder wheel (car) 41 ... Calendar wheel train 42a ... 24 hour gear (3rd gear) 46 ... Sun wheel (display car) 50 ... 2nd wheel train group (wheel train group) 60A ... No. 1 reference load section 60B ... 2nd reference load section

Claims (8)

A stepping motor with a rotor that rotates the pointer,
A train wheel group having gears that rotate based on the rotation of the rotor, and
With
The train wheel group
With the first gear
With the second gear
It is arranged so as to mesh with the first gear, has a first reference load portion that changes the load received by the rotor when meshing with the first gear, and rotates at a first reduction ratio with respect to the rotor. With the third gear
It is arranged so as to mesh with the second gear, has a second reference load portion that changes the load received by the rotor when meshing with the second gear, and has a reduction ratio higher than that of the first reduction ratio with respect to the rotor. A fourth gear that rotates at a small second reduction ratio,
To prepare
A watch movement that features this. The train wheel group has a vehicle to which the pointer is attached and rotates at a third reduction ratio with respect to the rotor.
The first reduction ratio is a multiple of the third reduction ratio.
The watch movement according to claim 1. The first reduction ratio is a multiple of the second reduction ratio.
The watch movement according to claim 1 or 2. The second reference load portion is provided on one tooth of the fourth gear.
The number of steps of the stepping motor required to rotate the fourth gear once is equal to the number of teeth of the fourth gear.
The watch movement according to any one of claims 1 to 3, wherein the movement is characterized in that. The train wheel group has a train wheel that transmits the rotation of the rotor to at least one of the pointer and the display vehicle that displays information.
The train wheel includes the third gear and the fourth gear.
The watch movement according to any one of claims 1 to 4. The train wheel group has a train wheel that transmits the rotation of the rotor to at least one of the pointer and the display vehicle that displays information.
At least one of the third gear and the fourth gear is provided separately from the gear included in the train wheel.
The watch movement according to any one of claims 1 to 4. The first reference load portion comes into contact with the first gear and is elastically deformed.
The second reference load portion comes into contact with the second gear and elastically deforms.
The watch movement according to any one of claims 1 to 6, wherein the movement is characterized in that. A timepiece comprising the watch movement according to any one of claims 1 to 7.

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