JP2011169799A - Timepiece including mainspring torque compensation mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a timepiece including a mainspring torque compensation mechanism which can correct the torque for a mainspring to drive a timepiece gear train so that the torque is stabled wholly for a long period of time and with which the duration of generating a practical torque value can be extended than the previous cases, with no special friction loss. <P>SOLUTION: The timepiece includes: a barrel containing the mainspring; a detection means which detects the winding-up amount of the mainspring and outputs it as a rotation angle of an output shaft; a plurality of transmission gear mechanisms for transmitting rotation of the barrel to the timepiece gear train with different acceleration rates; and a switching mechanism which selects one of the plurality of transmission gear mechanisms in response to the rotation angle of the output shaft of the detection means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mechanical timepiece having a mainspring torque correction mechanism. More specifically, the present invention relates to a mechanical timepiece having a built-in mechanism for changing the speed increasing ratio from the barrel to the timepiece wheel train in accordance with the winding state of the mainspring, particularly to a wristwatch.

  The torque generated by the timepiece spring is preferably stable at a level as high as possible while the timepiece is operating. This is because the time error is reduced by always giving a sufficiently large and stable swing angle to the balance.

  FIG. 5 shows an output torque curve 80 of the mainspring in a conventional ordinary timepiece. This output torque is transmitted to the timepiece wheel train at a predetermined speed increase ratio from the gear of the barrel having the mainspring and drives the timepiece mechanism including the escapement. In general, the output torque is maximum when the mainspring is close to the tightened state, the torque gradually decreases when the mainspring is loosened with the progress of the timepiece operation, and rapidly decreases when the end of the winding amount is reached. Therefore, in the conventional ordinary timepiece, the curve 80 has a predetermined practical torque minimum value 81 or more and uses a relatively flat portion, and the period (duration) T0 is, for example, 2 days (48 hours) or more. I am doing so.

  There was also an attempt to flatten the mainspring output torque. For example, a so-called umbrella-carrying transmission system is well known in which a truncated cone-shaped output wheel that is tapered by a mainspring is driven, a chain of tension wound around the output wheel is kept constant, and a clock train is driven by the chain. ing.

  There is also a technique disclosed in Patent Document 1 below. This technology is considered for watches. The watch is provided with a cam and a spring on the output shaft of the mainspring hoisting amount display device (having a differential gear mechanism for detecting the difference between the rotational speed of the mainspring upper wheel train and the barrel rewinding speed), and the mainspring is wound. In the process, a spring is charged by a cam, and a mechanism is provided for causing the spring to act on the cam so that the force from the spring assists the output torque of the mainspring as the mainspring is wound back.

JP2008-268177

The above-described conventional umbrella-conducting system requires a large space and cannot be used for a wristwatch.
In addition, the technique disclosed in Patent Document 1 seems to be able to considerably improve the flatness of the output torque combining the mainspring and the auxiliary spring, but the energy of the mainspring during the winding process charges a powerful auxiliary spring. In this case, there is a drawback in that it is diminished due to sliding friction loss between the cam and the spring, and is not used effectively.

  The purpose of the present invention is to correct the mainspring driving torque wheel train so as to stabilize it over a long period of time, and to extend the duration of generating a practical torque value than before. Furthermore, it is an object to provide a timepiece with a mainspring torque correction mechanism that does not involve any particular friction loss.

  The timepiece with the mainspring torque correcting mechanism of the present invention employs the following configuration in order to achieve the above object.

A barrel with a built-in spring,
Detection means for detecting the amount of winding of the mainspring and outputting the rotation angle of the output shaft;
A plurality of transmission gear mechanisms for transmitting the rotation of the barrel to the clock train wheel at different speed increasing ratios;
A switching mechanism for selecting one of a plurality of transmission gear mechanisms corresponding to the rotation angle of the output shaft of the detecting means is provided.

  With such a configuration, it is possible to selectively use one of the transmission gear mechanisms having different speed increasing ratios according to the winding amount of the mainspring, and to stabilize the driving torque of the timepiece wheel train over a long period of time. it can.

  The switching mechanism selects a transmission gear mechanism having a relatively large speed increase ratio when the mainspring is relatively wound up, and selects a transmission gear mechanism having a relatively small speed increase ratio when the mainspring is relatively unwound. You may do it.

  With such a configuration, when the mainspring is relatively wound up, the output torque from the mainspring to the timepiece wheel train is suppressed, and when the mainspring is relatively unwound, the output torque is controlled to increase. The driving torque can be stabilized over a wide range of the winding amount of the mainspring.

  The output shaft of the detecting means rotates with the switching gear meshing with the output shaft of the differential gear mechanism that detects the difference between the rotation of the barrel complete with the inner end of the mainspring and the rotation of the barrel, and the switching mechanism A switching cam to be operated may be provided.

  With such a configuration, a specific mechanism for operating the switching mechanism by detecting the amount of winding of the mainspring can be realized.

  The differential gear mechanism may be a part of the remaining amount display mechanism of the mainspring hoisting amount.

  With such a configuration, it is possible to achieve simplification and downsizing of the timepiece mechanism by using the same mechanism for both the indication of the remaining amount of winding of the mainspring and the stabilization of the driving torque of the timepiece wheel train. .

The plurality of transmission gear mechanisms are engaged with the first barrel gear and the second barrel gear provided in the barrel, the first barrel gear and the first barrel gear at a first speed increase ratio, and transmit the barrel output torque to the clock train. 1 transmission gear, a second barrel gear and a second transmission gear which meshes with the second speed increasing ratio and transmits the output torque of the barrel to the clock wheel train,
The switching mechanism moves up and down together with a first transmission gear and a second transmission gear that are coaxially opposed to each other and a switching lever that moves between the two transmission gears and moves up and down according to the unevenness of the switching cam. A selection wheel that engages with one of the gear and the second transmission gear may be included.

  With such a configuration, a specific structure for switching the driving torque of the timepiece wheel train can be realized.

  The selection wheel is characterized in that it can be engaged with both the first transmission gear and the second transmission gear at an intermediate position of the vertical movement.

With such a configuration, it is possible to prevent a phenomenon in which the selected wheel does not engage with any of the transmission gears and the mainspring is unloaded and rapidly rewinds in an intermediate process of switching between the two transmission gears.

  According to the present invention, the mainspring corrects the torque for driving the watch wheel train to be stabilized over a long period of time, and extends the period in which the duration for generating a practical torque value can be extended. In addition, it is possible to provide a timepiece with a mainspring torque correction mechanism that does not involve any particular friction loss.

It is a plane arrangement view of the principal part of the example of the present invention. It is principal part sectional drawing of the Example of this invention. It is a block diagram of the Example of this invention. It is a graph explaining the effect of the Example of this invention. It is a graph which shows the relationship between the amount of windings of a mainspring, and output torque in a prior art example.

[Basic explanation]
First, the basic operation and effect of the embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram illustrating an embodiment of the present invention.
FIG. 4 shows the effect of the present invention.

  In FIG. 3, a hoisting wheel train 61 by manual winding or automatic winding drives a barrel 62 which is directly connected to the square hole wheel which is the final stage, and a spring 63 having a spiral inner end engaged with it. Roll up. The outer end of the spring 63 is engaged with the inner peripheral surface of the barrel 64 and outputs the torque wound up by the barrel gear of the barrel 64. The barrel gear is finally connected to a clock wheel train 69 (including an escapement and a gear having a time indicator), and rewinds the mainspring 63 as time passes.

  On the other hand, the difference between the rotational speed of the barrel 62 and the rotational speed of the barrel 64 indicates the remaining amount of winding (reserved amount) of the mainspring, which is detected by the differential detection mechanism 65 such as a planetary gear mechanism. The output proportional to the winding amount rotates the reserve display train 66, and the winding amount is displayed on the reserve display means 67 using a dedicated pointer or the like. The output shaft of the gear that forms part of the reserve display train wheel 66 operates the train wheel torque switching mechanism 68 at the predetermined angular position to increase the drive torque acting on the watch train wheel 69 output from the barrel 64. A change (increase or decrease) is made by selectively using one of a plurality of intermediate gears having different speed ratios.

  As a result of the above operation, the torque at which the output of the barrel moves the train wheel changes as shown in FIG. That is, when the mainspring is sufficiently wound up and the winding amount is relatively large, the train wheel driving torque decreases from the maximum value with the passage of time as shown by the curve of the initial torque 50. However, when the hoisting reduction amount reaches the hoisting amount P point, the train wheel torque switching mechanism is activated, and the speed increasing ratio from the barrel to the watch train wheel is slightly reduced, so that the train wheel drive torque becomes late. It increases like a torque 52 curve. Further, in the process in which the hoisting recovers from the state in which the hoisting amount is reduced, a reverse change occurs, and the speed increasing ratio starts from decreasing to increasing.

A curved line 51 indicated by a broken line indicates a conventional late torque in the case where there is no train wheel torque switching mechanism.
A straight line 53 indicates the minimum value of a predetermined practical torque that is allowed to maintain the accuracy of the timepiece. By switching the speed increasing ratio halfway as in the present invention, the time until the mainspring is completely unwinded is shorter than in the prior art, but it is a region in which a driving torque exceeding the predetermined practical torque minimum value 53 is output. The duration T1 of the present invention is longer than the conventional duration T0 and represents the effect of the present invention.

A specific embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan layout view of main components in a mechanical wristwatch that is Embodiment 1 of the present invention. Each gear is depicted in a perspective view by a contour circle. The contour circle of each gear is not an outer diameter but a pitch circle. This is due to the advantage that the pitch circle is almost close to the outer diameter of the gear and that it is easy to visually recognize that the gears in contact with the pitch circle are engaged with each other.
2 is a cross-sectional view of a main part of the first embodiment of the present invention. FIG. 2 (a) is mainly a cross section of the differential detection mechanism, and FIG. Show.

  Reference numeral 1 denotes a ground plate on which a timepiece mechanism is mounted, and one bearing of each gear is provided, a part of which is illustrated. Reference numeral 2 denotes a train wheel bridge, which is on the upper side of the main plate 1 and has a bearing on the upper side of the timepiece wheel train (the pointer is the lower side of the sectional view), and is shown only in FIG. Reference numeral 3 denotes a reserve receiver, which is located below the main plate 1 and includes a lower bearing of the reserve wheel train, which is shown only in FIG. Reference numeral 4 denotes a spring, and 5 a barrel. The inner surface of the barrel 5 is engaged with the outer end of the spring 4 accommodated therein. A barrel 6 is engaged with the inner end of the mainspring 4. Reference numeral 7 denotes a square hole wheel, which is fixed to the barrel 6 at the final stage of a wheel train (not shown in its entirety) that winds the mainspring 4. The above is shown in FIG.

  Hereinafter, the mechanism will be described with reference to FIGS. On the outer periphery of the barrel 5, two barrel gears, a barrel first gear 11 and a barrel second gear 12, are provided, and the former has a slightly larger diameter (or a slightly larger number of teeth). A small-diameter barrel rotation detection gear 13 is fixed to the center of the barrel 5. Further, the barrel complete rotation detection gear 14 is fixed to the barrel complete 6.

  The differential gear mechanism which the some gear group 16, 17, 20a, 20b, 21, 22, 23 comprises is demonstrated. The rotation of the barrel rotation detection gear 13 is reversed by the idler gear 15 (having the rotation shaft 15a on the main plate 1 as shown in FIG. 2A) meshing with the barrel rotation detection gear 13, and loosely engages with the differential gear shaft 23a. The barrel moving gear 16 is driven. The barrel complete rotation detection gear 14 directly drives the barrel complete interlocking gear 17. A planetary shaft 20c is implanted in the barrel interlocking gear 16, and a planetary gear A20a and a planetary gear B20b fixed and integrated with each other are engaged with the shaft so as to be rotatable. Each of the planetary gears A and B meshes with a sun gear A21 fixed to the differential gear shaft 23a and a sun gear B22 fixed to the barrel complete gear 17 and loosely engaged with the differential gear shaft 23a. With the above configuration, the difference between the rotation speed of the barrel 5 and the rotation speed of the barrel 6 is output as the rotation angle of the differential output gear 23 fixed to the differential gear shaft 23a. The gear ratio of each gear is appropriately selected so that the purpose of the differential gear mechanism is achieved.

  The differential output gear 23 includes a switching gear 25 which is a subsequent reserve gear train, a reserve transmission gear 26a shown only in FIG. 1 below, a reserve transmission pin 26b coaxial therewith, a reserve display gear 27, and a reserve attached to the shaft thereof. The display hands 28 are sequentially driven. The reserve display needle 28 informs the user of the amount of winding of the mainspring by the position within the reserve display range 29 that forms a sector.

Next, the train wheel torque switching mechanism will be described. The differential output gear 23 rotates a switching gear 25 meshing with the differential output gear 23 and a switching cam 25a fixed thereto. The upper surface of the switching cam 25a is half high and half low, and is provided with a high and low surface having an inclined surface in the middle. The switching lever 30 has a spring property on this surface and the root is fixed to the base plate 1 with a screw. The sliding pin 30a is pressed and is in contact. The rotational ratio and phase of the differential gear mechanism and the switching gear are set so that the height of the upper surface of the switching cam 25a is high when the winding amount of the mainspring 4 is large and low when the winding amount is small. .

  A forked portion 30b at the tip of the switching lever 30 is engaged with a constricted portion 42a of a selection wheel 42 having a drum shape, and when the sliding pin 30a moves up and down, the selection wheel 42 is moved in the axial direction of the selection axle 42b. Slide up and down. The selection wheel 42 has a square hole, and the sliding surface of the selection wheel shaft 42b has a square bar shape that engages with the square hole, and torque is transmitted between the two regardless of the sliding position of the selection wheel 42. On the upper and lower surfaces of the selection wheel 42, sawtooth teeth are formed in a coronal shape (that is, in the axial direction).

  A first crown gear 40a having serrated teeth that can be engaged with upper serrated teeth when the selected wheel 42 moves upward is loosely coupled to the upper end side of the selected axle 42b. The barrel 1st transmission gear 40 which meshes with 11 is fixed. A second crown gear 41a having serrated teeth that can be engaged with lower serrated teeth when the selected wheel 42 moves downward is loosely coupled to the lower end side of the selected axle 42b. The barrel transmission gear 41 that meshes with the two gears 12 is fixed. The selection wheel 42 engages with either the first or second crown gear, and transmits torque received from the engaged counterpart to the selection axle 42b. The selected axle output wheel 43 is fixed to the lowermost end of the selected axle 42b, and the output torque of the barrel 5 is taken out from the selected axle output gear 43.

  Since the force required to slide the selected wheel 42 is small because the direction generated by the transmission torque is orthogonal to the direction, the friction loss in the operation of the selection switching mechanism is small, and the energy for winding the mainspring 4 is substantially reduced. There is no loss.

  The selected axle output gear 43 meshes with the third pinion 44a of the third wheel which forms part of the watch wheel train, and the third pinion 44a meshes with the second wheel 46. A minute hand (not shown) is attached to the lower end of the second axle 46a. The third gear 44b meshes with the fourth pinion 45a, and a second hand (not shown) is attached to the lower end of the fourth wheel shaft 45c. The fourth gear 45b drives the fifth wheel, escape wheel, and escapement (ankle and balance) in this order in the same manner as a normal mechanical timepiece, but these are not shown.

  The diameter (or the number of teeth) of the barrel transmission gear 40 is smaller than the diameter (or the number of teeth) of the barrel transmission gear 41 (the diameter or the number of teeth of the barrel first gear 11 and the barrel second gear 12). Because it corresponds to the relationship). Accordingly, the speed increasing ratio from the barrel 5 to the selected axle output wheel 43 becomes large when the selected wheel 42 is in the upper position and engaged with the first crown gear 40a, and the selected wheel 42 is in the lower position and the first speed ratio is increased. It becomes smaller when engaged with the two crown gear 41a, and in the latter case, the output torque increases. Since the height of the upper surface of the switching cam 25a corresponds to the winding amount of the mainspring 4 as described above, the watch wheel train corrected according to the winding amount as shown by the curves 50 and 52 in FIG. A driving torque can be obtained.

  Supplementary explanation of the train wheel torque switching mechanism. The selection wheel 42 engages with only one of the first crown gear 40a and the second crown gear 41a at the upper and lower ends of the sliding position. The positional relationship between the three is set so as to interfere with the sawtooth teeth of the crown gear. If the selected wheel 42 does not engage with any crown gear at the intermediate position of the sliding, the load on the barrel 5 is lost at the intermediate position, and the mainspring 4 may be rapidly wound back. This is to prevent this phenomenon.

This will be specifically described with reference to FIG. FIG. 2B shows a state in which the selection wheel 42 is completely meshed with the second crown gear 41a and is not meshed with the first crown gear 40a. A clearance a between the tooth tip of the upper serrated tooth of the selection wheel 42 and the tooth tip of the lower tooth of the first crown gear 40a (maximum value), and the saw tooth shape of the lower side of the selection wheel 42 The relationship of a <b is given between the tooth and the amount of biting b (maximum value) between the tooth and the upper toothed tooth of the second crown gear 41a. Of course, although not shown, even when the selection wheel 42 is completely meshed with the first crown gear 40a and is not meshed with the second crown gear 41a, sawtooth-like teeth generated at a position that is reversed upside down from FIG. The same magnitude relationship is established for the maximum gap amount a between the sawtooth teeth and the maximum bite amount b between the serrated teeth.

  Hereinafter, some modifications of the first embodiment will be described without using the drawings.

[Modification 1 of Example]
The elastic energy that can be stored in the spring is substantially proportional to the volume of the space that houses the spring.
In FIG. 2 of Example 1, the barrel first gear 11 and the barrel second gear 12 are provided on the outer periphery of the barrel 5. In this case, the maximum diameter of the barrel inner space that houses the spring 4 is limited by the diameter of the barrel second gear 12 having a small diameter. It is the eye of this modification that the maximum diameter of the space in the barrel is expanded to near the tooth bottom of the barrel first gear 11 without this restriction. Therefore, the barrel second gear is provided in close contact with the lower surface (or upper surface) of the barrel. However, in this modification, the total thickness of the barrel, and thus the thickness of the watch, may be slightly increased due to the addition of the barrel second gear.

[Modification 2 of Example]
In this example, the barrel first gear and the barrel second gear are shared by a single barrel gear provided on the outer periphery of the barrel or a plurality of gears having the same diameter (tooth profile). In order to obtain different speed increasing ratios from barrel gears of the same tooth profile, a plurality of intermediate wheels meshing with each other and having different numbers of teeth are provided, and each intermediate wheel drives the barrel first transmission wheel and barrel second transmission wheel. That's fine. Although the number of gears is increased by this example, the outer diameter of the spring housing space of the barrel can be increased to the full inside of the single barrel gear. A plurality of intermediate wheels are limited in diameter, and are arranged in a plane in a gap between other parts.

[Modification 3 of the embodiment]
In the first embodiment, the barrel transmission gear 1, the barrel transmission gear 2, and the selection wheel are arranged to overlap in the thickness direction of the timepiece. However, in the present modification, these three components are all planar gears. To place. The switching cam has a cam shape on the side surface, and meshes with one of the barrel transmission gear 1 and the barrel transmission gear 2 by swinging the selected wheel in the plane direction. With this configuration, the train wheel torque switching mechanism can be thinned. In this example as well, at the intermediate position of the selection vehicle that moves, it may interfere with both transmission vehicles.

[Modification 4 of the embodiment]
In Example 1, the operation of the switching lever (and hence the operation of the selected vehicle) was slow due to sliding with the switching cam. For example, in some power switches, even if the lever is operated slowly, the internal contact spring instantaneously jumps to a different position. Such a mechanism is applied to change the position of the selected vehicle instantaneously. As a result, it is possible to eliminate an operation state including a little instability, such as causing the selected vehicle to interfere with the two transmission gears at an intermediate position.

  As mentioned above, although the Example of this invention and its modification were described, it cannot be overemphasized that the embodiment of this invention is not restricted to the above-mentioned example, and can add another change. For example, there is a possibility of realizing a mechanism for switching and selecting three or more speed increasing ratios.

DESCRIPTION OF SYMBOLS 1 Ground plate 2 Wheelset holder 3 Reserve holder 4 Spring mainspring 5 Incense box 6 Incense box true 7 Square hole wheel 11 Incense box first gear 12 Incense box second gear 13 Incense box rotation detection gear 14 Incense box true rotation detection gear 15 Idler gear 16 Incense box interlocking gear 17 Incense box True interlocking gear 20a Planetary gear A
20b Planetary gear B
21 Sun Gear A
22 Sun Gear B
23 differential output gear 23a differential gear shaft 25 switching gear 25a switching cam 26a reserve transmission gear 26b reserve transmission kana 27 reserve display gear 28 reserve display needle 29 reserve display range 30 switching lever 30a sliding pin 30b fork portion 40 barrel box first 1 transmission gear 40a first crown gear 41 barrel second transmission gear 41a second crown gear 42 selected wheel 42a constricted portion 42b selected axle 43 selected axle output gear 44a third pinion 44b third pinion 45a fourth pinion 45b fourth gear 45c No. 4 axle 46 No. 2 gear 46a No. 2 shaft 50 Initial torque 51 Conventional late torque 52 Late torque of the present invention 53 Predetermined practical torque minimum 61 Hoisting wheel train 62 Winding barrel true 63 Winding spring 64 Winding barrel 65 Differential detection mechanism 66 Reserve display train wheel 67 Reserve display means 68 Train wheel torque switching mechanism 69 Clock train wheel 80 Conventional mainspring output torque 81 Predetermined practical torque minimum value a Maximum amount of gap between serrated teeth b Maximum amount of bite between serrated teeth P Lifting amount at which torque is switched T0 Conventional duration T1 Duration of the present invention

Claims (6)

A barrel with a built-in spring,
Detecting means for detecting the amount of winding of the mainspring and outputting it as a rotation angle of the output shaft;
A plurality of transmission gear mechanisms for transmitting rotation of the barrel to the timepiece wheel train at different speed increasing ratios;
A timepiece with a mainspring torque correction mechanism, comprising: a switching mechanism that selects one of the plurality of transmission gear mechanisms in accordance with a rotation angle of an output shaft of the detection means.   The switching mechanism selects a transmission gear mechanism having a relatively large speed increasing ratio when the mainspring is relatively wound up, and has a relatively small speed increasing ratio when the mainspring is relatively unwound. The timepiece with a spring torque correction mechanism according to claim 1, wherein the timepiece is selected.   The output shaft of the detecting means rotates together with the switching gear that meshes with the output shaft of the differential gear mechanism that detects the difference between the rotation of the barrel complete with the inner end of the mainspring and the rotation of the barrel. 3. A timepiece with a spring torque correcting mechanism according to claim 1, further comprising a switching cam for operating the switching mechanism.   4. The timepiece with a mainspring torque correcting mechanism according to claim 3, wherein the differential gear mechanism forms a part of a remaining amount display mechanism for a mainspring hoisting amount. The plurality of transmission gear mechanisms mesh with the first barrel gear and the second barrel gear provided in the barrel, the first barrel gear with the first barrel gear at a first speed increase ratio, and the output of the barrel to the clock wheel train. A first transmission gear that transmits torque, and a second transmission gear that meshes with the second barrel gear at a second speed increase ratio and transmits the output torque of the barrel to the clock train,
The switching mechanism moves up and down together with the first transmission gear and the second transmission gear that are coaxially opposed to each other, and a switching lever that moves between the two transmission gears and moves up and down according to the unevenness of the switching cam. 5. A timepiece with a mainspring torque correction mechanism according to claim 3, further comprising a selection wheel that engages with one of the first transmission gear and the second transmission gear.   6. The timepiece with a mainspring torque correction mechanism according to claim 5, wherein the selected wheel can be engaged with both the first transmission gear and the second transmission gear at an intermediate position of the vertical movement thereof. .

Images