JP2013238627A - Timepiece wheel train and timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a timepiece wheel train capable of effectively reducing resistance during sliding at a shaft part and a bearing part, and a timepiece.SOLUTION: A timepiece includes a timepiece wheel train having respective wheels each having a shaft part 17 and pinions, and a bearing part 16 holding shaft parts 17 of the respective wheels rotatably. A DLC film is formed on each of the shaft parts 17 of those wheels, and lubricating oil having DLC fine powder dispersed is provided between the shaft parts 17 and bearing part 16.

Description

  The present invention relates to a timepiece wheel train for driving hands of a timepiece, and a timepiece having the timepiece wheel train.

  Conventionally, in a watch train wheel that drives a watch pointer, since a large lateral pressure is applied to the shaft portion of each gear, wear occurs between the shaft portion and the bearing portion, which is caused by deterioration of wear powder and lubricating oil caused by these wears. There have been problems such as an increase in driving resistance, a decrease in watch life, and a deterioration in the accuracy of hand movement of the watch. On the other hand, the structure which reduces the abrasion in a sliding contact part is known (for example, refer patent document 1).

  In the analog timepiece described in Patent Document 1, in a configuration in which a metal rotating shaft of a rotor is supported by a rotating shaft support member, a hard carbon film (DLC film: Diamond Like Carbon film) is formed on the rotating shaft support member. The structure which reduces by the oil supply and wear between a rotating shaft and a rotating shaft support member is taken.

JP-A-11-133162

  By the way, in the above-mentioned patent document 1, there is a configuration in which there is no lubricating oil and sliding with only a DLC film with low resistance. However, since a large lateral pressure is applied to a watch wheel train of a mechanical timepiece, resistance is efficiently reduced. There is a problem that the resistance increases due to wear powder of the shaft member.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a timepiece train wheel and a timepiece capable of effectively reducing resistance during sliding in a shaft portion and a bearing portion.

  A timepiece wheel train of the present invention is a timepiece wheel train provided with a rotating body having a shaft portion and a bearing portion that rotatably holds the shaft portion of the rotating body, and the shaft portion and the bearing portion There is lubricating oil in which fine powder of the hard carbon film is diffused, and the hard carbon film is formed on one of the shaft part and the bearing part, and the hard carbon of the shaft part and the bearing part is formed. The other of which the film is not formed is formed of a hard material whose hardness is lower than that of the hard carbon film.

In the present invention, the timepiece wheel train includes a shaft portion of a rotating body such as a gear, and a bearing portion that rotatably supports the shaft portion, and a hard carbon film is provided between the shaft portion and the bearing portion. There is a lubricating oil in which fine powder (DLC film: Diamond Like Carbon film) is diffused. The fine powder is generated when the shaft portion on which the DLC film is formed is rotationally worn or diffused in advance in the lubricating oil.
The fine powder of these DLC films has a small friction coefficient and acts as a lubricant. Further, since the fine powder of the DLC film is diffused in the lubricating oil, it is possible to uniformly reduce the sliding friction resistance in the sliding contact range of the shaft portion and the bearing portion. In addition, the presence of the lubricating oil does not accumulate the generated wear powder in part, and the effect of reducing sliding resistance can be maintained.
Moreover, in this invention, the other side in which a DLC film is not formed is formed below the hardness equivalent to a DLC film. For example, when a DLC film (hardness 20 GPa) is formed on the shaft portion, the bearing portion is formed of a hard material having a hardness equal to or lower than that of the DLC film, such as ruby (hardness 15 GPa). By using such a hard material, even when it is in sliding contact with the DLC film, the DLC film has a sufficiently high hardness and the sliding friction resistance of the DLC film is small, so that wear of the hard material can be suppressed, and low friction is achieved. The effect can be sustained. In addition, since the hardness is smaller than that of the DLC film, the DLC film is not excessively worn by the hard material, and it slides in a well-balanced manner by the low friction effect by the DLC film and the low friction effect by the fine powder of the DLC film in the lubricating oil. Dynamic frictional resistance can be reduced.

  In the timepiece train of the present invention, the fine powder of the hard carbon film diffused in the lubricating oil is generated when the hard carbon film formed on one of the shaft portion and the bearing portion is rotated when the shaft portion rotates. It is preferably a hard carbon film abrasion powder generated when worn.

  In this invention, when the shaft portion is rotated and the DLC film is worn by sliding contact, the fine powder of the DLC film diffuses into the lubricating oil and acts as a lubricant, thereby reducing the frictional resistance of the shaft portion and the bearing portion. Can be reduced. In this case, as an initial state, the DLC wear powder may not be diffused in the lubricating oil. Even in such a case, in this initial state, the sliding frictional resistance is reduced by the lubricating oil and the DLC film, and when the DLC film is worn by the rotation of the shaft portion with the elapsed time, The abrasive powder acts as a lubricant by being dispersed in the lubricating oil.

  In a timepiece train wheel as a related art of the present invention, a hard carbon film is formed on at least one of the shaft portion and the bearing portion.

In this related technology, a DLC film is formed on at least one of the shaft part and the bearing part, and the lubricating oil or the lubricating oil in which fine powder of the DLC film is diffused is present between the shaft part and the bearing part. .
Here, the DLC film itself can uniformly reduce the sliding friction resistance in the sliding contact range of the shaft portion and the bearing portion by the effect of low friction and wear resistance, and further the shaft portion rotates. Even when the DLC film is worn by sliding contact, the fine powder of these DLC films has a small friction coefficient and acts as a lubricant as described above. At this time, since there is lubricating oil between the shaft portion and the bearing portion, the fine powder of the DLC film is diffused in this lubricating oil, so that the sliding friction resistance in the sliding contact range of the shaft portion and the bearing portion is uniform. It is possible to reduce it.

  In the timepiece train wheel of the present invention, the hard carbon film is preferably formed by physical vapor deposition.

  In the present invention, the DLC film is formed by a physical vapor deposition method (PVD method: Physical Vapor Deposition). Here, in the so-called CVD method (Chemical Vapor Deposition method) in which a film is deposited by a chemical reaction on the surface of the shaft portion or the bearing portion, the formed DLC film is not in the shaft portion in a fine shape such as a watch part. When the hardness is 20 GPa or less, sufficient hardness cannot be obtained, and adhesion to the shaft portion and the bearing portion becomes insufficient. On the other hand, in the PVD method such as ion plating method in which ionized DLC film molecules are accelerated and collided with the shaft portion and the bearing portion, the adhesion to the shaft portion and the bearing portion in a fine shape such as a watch part is also good. In addition, it is possible to stably mold a DLC film having a hardness of 20 GPa to 40 GPa. In this way, by forming a DLC film with high strength and good adhesion on either the shaft part or the bearing part, it is possible to prevent the DLC film from peeling off during the rotation of the shaft part, and wear powder generated by wear. The particle size of the resin becomes small, and can function as a good quality lubricant. Therefore, it is possible to further reduce the sliding friction between the shaft portion and the bearing portion in the watch wheel train that receives a strong lateral pressure.

In the timepiece train wheel of the present invention, it is preferable that the hard carbon film is formed by the physical vapor deposition in an atmosphere containing no hydrogen.
In the present invention, a hydrogen-free DLC film is formed by a PVD method in an atmosphere not containing hydrogen, that is, a hydrogen-free PVD method. When hydrogen is mixed in forming a DLC film by the PVD method, in addition to the sp3 bond that is a diamond structure in the crystal structure of the DLC film, the proportion of the sp2 structure that is a graphite structure increases, and high adhesion and A DLC film that achieves both high hardness is not sufficiently formed. On the other hand, in the present invention, by forming a hydrogen-free DLC film by the hydrogen-free PVD method, in the crystal structure of the DLC film, the proportion of sp3 bonds is increased, and a DLC film having higher hardness and higher adhesion is formed. It becomes possible to do.

  In the timepiece train wheel of the present invention, a metal intermediate layer is formed on one surface of the shaft portion and the bearing portion where the hard carbon film is formed, and the hard carbon film is formed on the metal intermediate layer. Preferably it is formed.

  A metal intermediate layer is formed on the base material of the shaft or bearing, and a hard carbon film is formed through this metal intermediate layer, so that the metal intermediate layer absorbs the stress difference between the base material and the hard carbon film. The adhesion of the DLC film can be increased. In this way, by forming a DLC film with high adhesion and having a sliding contact with a mating member (a member in which the DLC film is not provided in the shaft part or the bearing part) having a hardness lower than that of the DLC film, The particle size of the wear powder of the DLC film generated by friction becomes 100 μm or less. The wear powder of the DLC film having a thickness of 100 μm or less does not partially harden the wear powder of the DLC film, is well dispersed in the lubricating oil, and is uniform in friction resistance with respect to the shaft portion and the bearing portion. Can be reduced.

  In the timepiece train wheel as the related art of the present invention, oil / hard carbon that suppresses the diffusion of the lubricating oil and holds fine powder of the hard carbon film on at least one of the shaft portion and the bearing portion. A membrane fine powder holding layer is formed.

  In the related technology, since the oil and hard carbon film fine powder holding layer is formed on the shaft and the bearing, the lubricating oil does not disperse from the shaft and the bearing, and the shaft and the bearing can be satisfactorily used for a long time. Hold for a long time between the parts. Therefore, the fine powder of the DLC film interposed between the shaft portion and the bearing portion is also diffused to the lubricating oil held between the shaft portion and the bearing portion, and the fine powder is scattered on other members or partially solidified. Inconveniences such as this can be avoided, and the frictional resistance of the shaft portion and the bearing portion can be further reduced by being held in the lubricating oil for a long time.

  In the related art, the oil / hard carbon film fine powder holding layer is preferably formed by coating a fluororesin.

According to this related technology, the oil / hard carbon film fine powder holding layer is formed by fluorine resin coating.
With such a fluororesin coating, an oil / hard carbon film fine powder retaining layer can be easily formed by coating, etc., and the oil / hard carbon film fine powder retaining effect during shaft rotation can be continued well. Can do. Even when the DLC film is peeled off, the fluororesin of the oil / hard carbon film fine powder holding layer is renewed to the peeled surface, so that the oil / hard carbon film fine powder holding effect can be maintained for a long time.
Moreover, this fluorine resin coating can also be expected to have an effect of further reducing the frictional resistance of the shaft as a solid lubricant due to the low friction effect of fluorine.

In the timepiece train wheel of the present invention, the fine particle diameter of the hard carbon film is preferably 100 nm or less.
Here, the fine powder of the hard carbon film is generated by friction between the shaft portion and the bearing portion, and the fine powder of the hard carbon film dispersed in the lubricating oil and the hard carbon film dispersed in the lubricating oil in advance. Contains both fines.
In the present invention, the particle size of the fine powder of the hard carbon film is 100 nm or less, which is a sufficiently small size. For this reason, the fine powder of these hard carbon films can be disperse | distributed favorably in lubricating oil, for example, the trouble that the fine powder of a hard carbon film hardens in one place can be avoided. In addition, the fine powder of the hard carbon film having such a small particle size is dispersed in the lubricating oil, so that the frictional resistance can be uniformly reduced with respect to the shaft portion and the bearing portion. An effect can be obtained.

  The timepiece of the present invention is a timepiece in which a pointer is driven by a timepiece wheel train having a rotating body having a shaft portion and a bearing portion that rotatably holds the shaft portion of the rotating body, and the shaft portion And there is lubricating oil in which fine powder of a hard carbon film is diffused between the bearing portions, and the hard carbon film is formed on one of the shaft portion and the bearing portion, and the shaft portion and the bearing portion Of these, the other on which the hard carbon film is not formed is formed of a hard material having a lower hardness than the hard carbon film.

  In the present invention, as described above, the sliding frictional resistance of the shaft portion and the bearing portion can be reduced over a long period of time, so that the watch life can be extended.

It is a top view which shows the principal part of the electronically controlled mechanical timepiece (timepiece) provided with the timepiece wheel train which concerns on this embodiment. It is sectional drawing which shows the principal part of the electronically controlled mechanical timepiece of the said embodiment. It is another sectional view showing the important section of the electronically controlled mechanical timepiece of the embodiment. It is a block diagram which shows the structure of the electronically controlled mechanical timepiece of the said embodiment. It is a figure which shows the side pressure which concerns on each number wheel which comprises the timepiece wheel train of the said embodiment. It is sectional drawing which shows the principal part of 2nd wheel, 3rd wheel, and 4th wheel. In FIG. 6, it is the enlarged view to which the 3rd wheel vicinity was expanded. It is a photograph which shows the lubricating oil of the DLC film vicinity observed by TEM when the timepiece durability test was done to the timepiece which formed the DLC film. It is a figure which shows the relationship between content of the fine powder of the DLC film contained in lubricating oil, and torque increase amount. (A) is a figure which shows the analysis result by FTIR (Fourier Transform Infrared Spectroscopy: Fourier transform infrared spectroscopy) of the lubricating oil of a durability test degree, (B) is after the test completion | finish when a DLC film is formed. It is a figure which shows the value which deducted the light absorbency obtained by FTIR with respect to the lubricating oil after completion | finish of the test in case the DLC film is not formed from the light absorbency obtained by FTIR with respect to lubricating oil. DLC film is not formed, bearing structure with lubricating oil containing DLC fine powder, DLC film is formed and bearing structure with lubricating oil containing DLC fine powder, and DLC film is not formed, lubricating oil It is a figure which shows the result of the timepiece durability test in each of the bearing structures in which DLC fine powder is not contained. It is the observation photograph after the endurance test progress of the 3rd wheel with the DLC film thickness formed to 0.35 μm and the 3rd wheel with the DLC film thickness formed to 0.8 μm. It is a figure which shows the result of the timepiece endurance test of the third wheel when a DLC film having a thickness of 1 μm is formed and a large number of coarse particles are generated. It is a figure which shows the result of the indentation test in the DLC film formed by the hydrogen free PVD method, and the DLC film formed by the plasma CVD method. It is a figure which compares the hardness of the DLC film formed by the hydrogen free PVD method, and the DLC film formed by the plasma CVD method. It is a figure which shows the adhesive force of the DLC film formed by the hydrogen free PVD method, and the DLC film formed by the plasma CVD method.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing a main part of an electronically controlled mechanical timepiece (timepiece) provided with a timepiece train wheel according to the present embodiment, and FIGS. 2 and 3 are sectional views thereof.

An electronically controlled mechanical timepiece 100 (hereinafter referred to as a timepiece 100) includes a barrel 1 composed of a mainspring 1a, a barrel gear 1b, a barrel complete 1c, and a barrel lid 1d, which are mechanical energy sources. The mainspring 1a has an outer end fixed to the barrel gear 1b and an inner end fixed to the barrel complete 1c. The barrel complete 1c is supported by the base plate 10 and the train wheel bridge 11, and is fixed by a square hole screw 13 so as to rotate integrally with the square hole wheel 12.
The square wheel 12 is meshed with the helix 14 (see FIG. 1) so as to rotate clockwise but not counterclockwise. In addition, since the method of rotating the square wheel 12 clockwise and winding the mainspring 1a is the same as the automatic winding or the manual winding mechanism of a mechanical wristwatch, description is abbreviate | omitted.
In this embodiment, the mainspring 1a is used as the mechanical energy source. However, the present invention is not limited to this. For example, a stepping motor driven by power supplied from a battery may be used as the mechanical energy source. The mechanical energy source may be used.

  In the present embodiment, the rotation of the barrel wheel 1b is caused by the timepiece wheel train 100A including the second wheel 2, the third wheel 3, the fourth wheel 4, the fifth wheel 5, and the sixth wheel 6 which are rotating bodies according to the present invention. And is transmitted to the rotor 7 through the motor. Specifically, the rotation of the barrel wheel 1b is increased by 7 times and transmitted to the second wheel 2 and increased from the second wheel 2 to the third wheel 3 by 6.4 times. No. 4 is increased by 9.375 times, No. 4 from No. 4 to No. 5 is increased by 3 times, No. 5 from No. 5 to No. 6 is increased by 10 times, and No. 6 No. 6 generates power. The speed of the rotor 7 constituting the machine is increased 10 times, and the speed is increased 126,000 times in total and transmitted to the rotor 7.

  The second wheel 2 of the timepiece wheel train 100A has a cylindrical pinion 2c, the minute hand 200 at the hour pinion 2c, and the hour hand 210 at the hour wheel 21 that is rotated from the hour pinion 2c through the minute wheel 20. The second hand 400 is fixed to the fourth wheel 4 respectively. Therefore, in order to rotate the second wheel 2 at 1 rph and the fourth wheel 4 at 1 rpm, the rotor may be controlled to rotate at 8 rps. At this time, the barrel wheel rotates at 1/7 rph.

The generator 8 of the timepiece 100 also serves as a speed governor, and includes a rotor 7, a stator 81, and a coil block 82.
The rotor 7 includes a rotor magnet 70, a rotor pinion 7a, and a rotor inertia disc 71. The rotor inertia disc 71 is for reducing the rotational speed fluctuation of the rotor 7 with respect to the driving torque fluctuation from the barrel complete 1.

  The stator 81 is obtained by winding a stator coil 81b of, for example, 40,000 turns around a stator body 81a. The coil block 82 is obtained by winding a coil 82b of 110,000 turns around a magnetic core 82a. The coil 82b is configured to detect the rotation of the rotor 7 by detecting a change in the output voltage. Further, the coil 82b and the stator coil 81b are connected in series so that an output voltage obtained by adding the respective power generation voltages is output. The stator body 81a and the magnetic core 82a are made of PC permalloy or the like.

FIG. 4 is a block diagram showing a configuration of the timepiece 100 of the present embodiment.
As described above, the timepiece 100 includes the mainspring 1a, the timepiece wheel train 100A that accelerates the rotation of the mainspring 1a and transmits it to the generator 8, and hands 200, 210, which are coupled to the timepiece wheel train 100A and display the time. 400.

  The generator 8 is driven by the mainspring 1a through the clock train 100A, generates an induced electric power, and supplies electric energy. The AC output from the generator 8 is stepped up and rectified through a rectifier circuit 83 and charged and supplied to a capacitor 84.

  The rotation control device 85 configured by a one-chip IC is driven by the electric power supplied from the capacitor 84. The rotation control device 85 includes an oscillation circuit 86, a rotation detection circuit 87 for the rotor 7, and a brake control circuit 88.

  The oscillation circuit 86 outputs an oscillation signal (32768 Hz) using a crystal resonator 89 as a time standard source, divides the oscillation signal by a predetermined frequency dividing circuit, and outputs it as a reference signal fs to the control circuit 88. ing.

The rotation detection circuit 87 detects the rotation speed of the rotor 7 from the power generation waveform output from the generator 8 and outputs the rotation detection signal FG to the control circuit 88.
The control circuit 88 adjusts the speed by inputting a brake signal to the generator 8 (speed governor) based on the phase difference of the rotation detection signal FG with respect to the reference signal fs. Here, the rotation of the barrel wheel 1 containing the mainspring 1a from the rotation control device 85, the generator 8, and the clock train 100A is controlled to release the mechanical energy stored in the mainspring 1a. The speed control mechanism includes a rotation control device 85, a generator 8, a timepiece wheel train 100A, and a barrel complete 1.

  Here, in the present embodiment, as shown in FIG. 3, a bearing portion 16 that is made of ruby and also serves as a decoration is press-fitted into the main plate 10, the train wheel bridge 11, and the second ring 15. The tenon 173A and 173B of each of the number wheels 2 to 6 and the tenon 173A and 173B of the rotor 7 are supported by the bearing portion 16. That is, each of the number wheels 2 to 6 and the rotor 7 are supported by a sliding bearing device 160 having a shaft portion 17 and a bearing portion 16. The bearing portion 16 is a member formed of a highly hard material having a hardness of 10 GPa to 30 GPa. In this embodiment, for example, a ruby having a hardness of 10 GPa is used for a DLC film having a hardness of 20 GPa. The bearing portion 16 is not limited to ruby, and other precious stones may be used as long as they have the above hardness range and wear resistance. Moreover, although the earthquake-resistant structure is applied to the sliding bearing device 160 of the fifth wheel 5, the sixth wheel 6, and the rotor 7, since the structure is a known structure, the description is omitted.

  As described above, in the timepiece 100 as described above, it is understood that the lower tenon 173B of the third wheel 3 is subjected to an extremely high lateral pressure as compared with the surface pressure applied to the tenons 173A and 173B of the other wheel 2-6. ing. FIG. 5 is a diagram showing the side pressures relating to the respective number wheels 2 to 6. As shown in FIG. 5, in particular, the lower tenon 173B of the third wheel 3 is subjected to a larger side pressure than the tenon 173A, 173B of the other number wheel 2, 4-6. For this reason, the third wheel 3 is very easily worn, and when the wear progresses, there is a possibility that the accuracy of the hand movement may be lowered, and a periodic overhaul is necessary. In addition, a large force is applied because the torque is transmitted by meshing with the gear of the center wheel & pinion 2, and there is a possibility that the accuracy of the hand movement may be lowered by long-term use.

FIG. 6 is a cross-sectional view showing the main parts of the second wheel 2, the third wheel 3, and the fourth wheel 4. FIG. 7 is an enlarged view of the vicinity of the third wheel 3 in FIG.
Here, in the present embodiment, a hard carbon film (DLC film: Diamond Like Carbon) is formed on the lower tenon 173B of the third wheel & pinion 3 where the lateral pressure is the largest, thereby improving wear resistance and generating friction. We are trying to reduce it.

The shaft 17 of the third wheel 3 has an upper tenon 173A from the upper end side (upper side in FIGS. 6 and 7), an upper setting portion 172, a gear 170, a kana 171, a lower setting portion 172, and a lower tenon. 173B is provided. A gap is provided between the awning determining portion 172 and the bearing portion 16, and when the third wheel 3 receives an impact in the axial direction, the third wheel 3 moves in the axial direction by the gap, thereby receiving an impact. It can be absorbed.
Here, the third wheel & pinion 3 is formed in a fine shape, and in the specific dimension example, as shown in FIG. 7, the diameter (diameter) of the upper tenon 173A is 0.14 (mm). The diameter dimension of the upper flaming determination part 172 is 0.28 (mm), the diameter dimension of the central part of the shaft is 0.65 (mm), the diameter dimension of the kana 171 is 0.74 (mm), and the lower flaming determination part 172 Is formed with a diameter of 0.30 (mm) and the diameter of the lower tenon 173B is 0.18 (mm), and the total length is 3.10 (mm) with respect to the axial direction of the shaft portion 17 of the third wheel & pinion 3. ), The total dimension of the shaft center part and the kana 171 is 2.07 (mm), the dimension of the kana 171 is 0.42 (mm), the dimension of the lower flaring determining part is 0.12 (mm), and the lower tenon 173B A dimension of 0.20 (mm) is formed. The DLC film is formed on the lower tenon 173B (diameter 0.18 mm, length 0.20 mm).
In the present embodiment, the lower tenon 173B of the third wheel & pinion 3 is exemplified as a range in which the DLC film is formed. However, the present invention is not limited thereto. It may be formed, or may be only a sliding contact portion with another part such as a gear.

In addition, the configuration of the number wheels 5 to 6 in the present embodiment is substantially the same as that of the third wheel 3 and the description thereof is omitted.
An abacus ball 174 is provided on the lower end side (lower side in FIG. 6) of the shaft portion 17 of the fourth wheel 4, and a second hand 400 is attached to the lower end. The abacus ball 174 is a bearing part that comes into contact with the inner peripheral surface of the cylindrical main body 22 of the center wheel 2, and the center wheel 2 and the fourth wheel 4 are eccentrically rotated by the weight of the hands 200, 400 and the like. To prevent that. An upper end portion of the shaft portion 17 is provided with an awning determination portion 172 having the same configuration as that of the third wheel & pinion 3.
The second wheel & pinion 2 is configured by attaching a cylindrical pinion 2c having a minute hand 200 to a cylindrical main body 22 having a gear 170 and a pinion 171 and having the shaft portion 17 of the fourth wheel & pinion 4 inserted therein. The upper end side (upper side in FIG. 6) of the main body is an upper tenon 173 </ b> A that is formed thin and inserted into the bearing portion 16. The upper end of the upper tenon 173A is a sliding portion 23 that comes into contact with the fourth wheel 4.

[Bearing structure of third wheel]
Next, the bearing configuration of the third wheel & pinion 3 will be described. The DLC film formed on the third wheel 3 has a hardness of 20 GPa to 40 GPa and has a hardness equal to or higher than a ruby (for example, a hardness of 15 GPa in this embodiment) which is a highly rigid material forming the bearing portion 16. doing. Therefore, although wear of the DLC film due to sliding contact with the bearing portion 16 occurs, the wear can be sufficiently suppressed as compared with, for example, a hard film having a hardness of the bearing portion 16 or less. The DLC film is held in the portion 17. Furthermore, since the DLC film has low frictional resistance and low aggressiveness against the counterpart (bearing part 16), wear due to sliding contact of the bearing part 16 with the DLC film is also suppressed. Therefore, it is possible to suppress both wear due to the sliding contact between the shaft portion 17 and the bearing portion 16, and it is possible to maintain the accuracy of the hand movement of the timepiece 100 for a long period of time.
More specifically, for the shaft portion 17 of the third wheel & pinion 3, for example, carbon steel (hardness: 3 to 8 GPa) is used as a base material, and Ni plating is performed as a surface treatment of the carbon steel, for example. Then, a Ti layer is formed by sputtering on the Ni plating surface as a base for the DLC film. The DLC film is formed on this Ti layer. Thus, by forming the DLC film with the Ti layer as a base, the stress difference between the carbon steel and the DLC film can be absorbed, and the adhesion of the DLC film can be ensured. In this embodiment, an example in which a Ti layer is formed as the metal intermediate layer of the present invention is shown. However, for example, another metal layer such as a Cr layer may be formed as the metal intermediate layer.

In the present embodiment, there is lubricating oil in which fine powder of the DLC film (hereinafter referred to as DLC fine powder) is diffused between the shaft portion 17 and the bearing portion 16.
Here, in the present invention, the sliding friction resistance of the shaft portion 17 and the bearing portion 16 is reduced by diffusing the DLC fine powder in the lubricating oil. However, in the timepiece 100 of the present embodiment, the DLC fine powder into the lubricating oil is reduced. In the following, an example in which the wear powder of the DLC film is diffused as fine powder in the lubricating oil by the watch endurance test assuming long-time use of the watch 100 will be described. This watch endurance test is an accelerated endurance test in which the wheel train is driven at a speed higher than usual. The wear of the DLC film formed on the shaft portion 17 generates wear powder of the DLC film. The abrasion powder diffuses in the lubricating oil as DLC fine powder. In the timepiece 100 of the present embodiment, a Ti layer as a base is formed on a base material of a lower tenon 173B (shaft portion 17) obtained by applying Ni plating to carbon steel, and a DLC film is formed on the Ti layer. . In such a configuration, when the hardness of the DLC film is larger than that of the bearing portion 16, the wear powder of the DLC film generated by the sliding contact between the DLC film of the shaft portion 17 and the bearing portion 16 has a particle size of Is at most 100 nm.
The method of diffusing the DLC fine powder into the lubricating oil is not limited to this. For example, the DLC fine powder is generated in advance and diffused in the lubricating oil, and the lubricating oil is poured between the shaft portion 17 and the bearing portion 16. May be.

FIG. 8 shows a DLC film observed by a transmission electron microscope (TEM) when a timepiece durability test was performed on a watch in which a DLC film having a thickness of 1.5 μm was formed on the lower tenon 173B of the third wheel 3. It is a photograph which shows the lubricating oil of the vicinity.
As shown in FIG. 8, in the timepiece 100 of the present embodiment, only DLC fine powder having a maximum of 100 nm or less was observed in the lubricating oil. In the watch endurance test, it can be confirmed that abrasion powder is generated by the wear of the DLC film and the bearing portion 16 and is diffused into the lubricating oil. The particle size of the abrasion powder is a minute size that cannot be observed. To a fine powder of up to about 100 nm. As described above, when the DLC fine powder is sufficiently fine and diffused in the lubricating oil, the wear powder acts as a high-quality lubricant due to the low friction property of DLC. For this reason, the sliding frictional resistance between the shaft portion 17 and the bearing portion 16 is further reduced by the synergistic effect of the DLC film, the lubricating oil, and the DLC fine powder formed on the tenon 173A and 173B.

  Here, FIG. 9 shows a comparison between the torque of the third wheel using the lubricating oil in which the DLC fine powder is diffused and the torque of the third wheel using the lubricating oil in which the DLC fine powder is not diffused. FIG. 9 shows the third wheel with the DLC fine powder content of 0.8 mass%, the third wheel with the DLC fine powder content of 4.0 mass%, and the DLC fine powder content of 7. It is a figure which shows the change state of the torque at the time of a timepiece durability test of the 3rd wheel with a 0.0 mass% lubricant and the 3rd wheel with a lubricant not containing DLC wear powder.

  In FIG. 9, a DLC film having a thickness of 0.1 μm is formed on the shaft portion 17, and the DLC film is abraded in a specified amount of lubricating oil, whereby a lubricating oil having a DLC fine powder content of 0.8 mass% is obtained. Can be obtained. Further, by forming a DLC film of 0.5 μm on the shaft portion 17 and wearing this DLC film, lubricating oil having a DLC fine powder content of 4.0 mass% can be obtained. By forming a DLC film having a thickness of 0.8 μm and wearing this DLC film, a lubricating oil having a DLC fine powder content of 7.0 mass% can be obtained.

And as shown in FIG. 9, even when the content of the DLC fine powder in the lubricating oil is increased, no torque increase is observed, and in all cases, the torque increase is less than half that of the sample not containing the DLC fine powder. It can be confirmed. The optimum film thickness of the DLC film of this embodiment is 1 μm (details will be described later), and lubricating oil is poured between the shaft part 17 and the bearing part 16 on which such a DLC film is formed, and one year has elapsed. When a watch endurance test (accelerated endurance test) corresponding to the lapse of 10 years is performed, the content of DLC fine powder in the lubricating oil is approximately in the range of 0.8 to 7.0 mass%.
From FIG. 9, when the DLC fine powder is diffused in the lubricating oil between the shaft portion 17 and the bearing portion 16 and the DLC fine powder is not contained, the DLC fine powder is diffused in the lubricating oil. In this case, it can be confirmed that the torque at the time of rotation of the shaft portion 17 is reduced as compared with the case where the DLC fine powder is not included.

On the other hand, although illustration is omitted, the lubricating effect of the DLC fine powder can be confirmed even when the content of the wear powder in the lubricating oil is 0.8 mass% or less. However, in this case, depending on the state of progress of wear of the lubricating oil and the DLC film, there is a possibility that the DLC wear powder does not disperse in the necessary place, and the frictional resistance is reduced by the lubricating oil and the DLC film dispersed in the lubricating oil. In some cases, synergistic effects cannot be obtained effectively.
As mentioned above, it is preferable that the quantity of the DLC fine powder contained in lubricating oil is 0.8 mass%-7.0 mass%.

Next, the deterioration state of the lubricating oil will be described.
FIG. 10 (A) is a diagram showing the results of analysis by FTIR (Fourier Transform Infrared Spectroscopy) of a lubricating oil having a durability test degree, and (B) is a test when a DLC film is formed. It is a figure which shows the value which deducted the light absorbency obtained by FTIR with respect to the lubricating oil after completion | finish of a test in case the DLC film is not formed from the light absorbency obtained by FTIR with respect to the lubricating oil after completion | finish.

As shown in FIG. 10, the deterioration state of the lubricant after the watch durability test when the DLC film is not formed, the deterioration state of the lubricant after the watch durability test when the DLC film is formed, and the watch durability Comparing the deterioration state of the lubricating oil before the test reveals the following points. That is, as shown in FIG. 10B, the lubricating oil when the DLC film is not formed is particularly 2924 (cm ⁻¹ ) or 2854 compared to the lubricating oil when the DLC film is formed. There is a large difference in absorbance in the region of (cm ⁻¹ ), 1850 (cm ⁻¹ ) to 1550 (cm ⁻¹ ).
Here, the difference in the region from 1850 (cm ⁻¹ ) to 1550 (cm ⁻¹ ) is because a structure having a carboxylate or a condensed ring as a main structure is generated when the DLC film is not formed. . In addition, in the lubricating oil when the DLC film is not formed, the aromatic ring and components including the aromatic ring contained in the lubricating oil are often decomposed, and the lubricating oil and the DLC film are formed when the DLC film is formed. In the case where the lubricant is not used, a difference occurs in the proportion of C—H bonds. Therefore, also in 2924 ^{(cm -1)} and 2853 ^{(cm -1),} a large difference in absorbance occurs. As described above, when the DLC film is not formed, the lubricating oil deteriorates due to the wear powder of the lower tenon 173B and the bearing portion 16 dispersed in the lubricating oil, the lubricating performance is deteriorated, and the life of the lubricating oil is decreased. Is also shortened.

Therefore, in order to obtain stable lubrication performance without deteriorating the lubricating oil for a long time, it is important to suppress wear of the base material of the shaft portion 17 and the bearing portion 16. In the present embodiment, wear of the base material of the shaft portion 17 is prevented by forming the DLC film on the shaft portion 17 (lower tenon 173B).
Here, FIG. 11 shows a bearing structure having a lubricating oil containing no DLC film and containing DLC fine powder, a bearing structure having a DLC film and containing lubricating oil containing DLC fine powder, and a DLC film. The results of a watch durability test in each of the bearing structures that are not formed and that do not contain DLC fine powder in the lubricating oil are shown. In the test endurance test shown in FIG. 11, the elapsed time shown on the horizontal axis is a period longer than the elapsed time of the test endurance test in FIG. 9.

In FIG. 11, in the samples A, B, and C in which the DLC film is not formed on the shaft portion 17 and the DLC fine powder is contained in the lubricating oil, the base material (carbon steel, Ni plating) of the shaft portion 17 is 0. It was confirmed that 5 μm was worn. In the case where the DLC fine powder is contained in the lubricating oil, as described with reference to FIG. 9, the increase in torque can be suppressed by the DLC fine powder in the lubricating oil, but the base material of the shaft portion 17 (carbon steel) When the Ni plating is worn, the wear powder is diffused in the lubricating oil, and the lubricating oil is deteriorated as shown in FIG.
On the other hand, in Samples D and E in which the DLC film is formed on the shaft portion 17, the wear of the 0.2 μm DLC film was confirmed, and the wear of the base material of the shaft portion 17 was not confirmed. In such samples D and E, since the wear powder of the base material of the shaft portion 17 does not diffuse into the lubricating oil, the deterioration of the lubricating oil is suppressed as shown in FIG. Moreover, since DLC fine powder diffuses as fine powder in the lubricating oil, an increase in torque can be effectively suppressed. In addition, although the DLC fine powder content of the lubricating oil after the DLC film of the shaft portion 17 was worn was 8.22 mass%, no torque increase was observed due to this, and the DLC fine powder diffused in the lubricating oil. It can be seen that acts as a lubricant.
From the above, it can be confirmed that an effective lubricating effect can be obtained by the DLC film formed on the shaft portion 17 and the lubricating oil in which the DLC fine powder is diffused, and the DLC film prevents the wear of the base material. Thus, deterioration of the lubricating oil can be prevented, and the bearing structure can have a long life and a torque reduction effect can be obtained over a long period of time.
Further, as described above, the presence of the lubricating oil between the shaft portion 17 and the bearing portion 16 has an advantage that the DLC fine powder generated by the friction between the shaft portion 17 and the bearing portion 16 is not scattered. That is, in the absence of lubricating oil, the DLC fine powder may be scattered on the other part of the timepiece train wheel 100A, the electronic circuit part, etc., which may affect the operation of the timepiece 100 or may accumulate on a part thereof. Therefore, there is a disadvantage that it becomes resistance of the movement of the train wheel and deteriorates the clock operation accuracy. On the other hand, as in the present embodiment, the presence of the lubricating oil between the shaft portion 17 and the bearing portion 16 prevents DLC fine powder from scattering and adversely affects the driving and circuits of other gears in the timepiece 100. There is no effect.

The DLC film as described above is formed on the surface of the third wheel 3 with a film thickness of about 0.8 μm to 2.0 μm, and more preferably with a film thickness of about 1 μm.
An ion plating method is used in the formation of the DLC film as described above. In film formation by the ion plating method, as the film formation time becomes longer, the amount of deposits having a large particle diameter such as coarse particles increases during the film formation process. Accordingly, when the thickness of the DLC film is 2.0 μm or more, the time for forming the DLC film becomes longer, and thus the generation amount of coarse particles or the like may increase. When such coarse particles adhere to the surface of a part, the detachment of deposits occurs due to the rotation of the shaft, and these deposits are dispersed in the lubricating oil, effectively reducing the sliding frictional resistance. It becomes difficult.
Here, FIG. 12 shows the observation after the endurance test of the third wheel 3 having a DLC film thickness of 0.35 μm and the third wheel 3 having a DLC film thickness of 0.8 μm. Show photos. FIG. 13 shows the results of a watch durability test of the third wheel 3 when a DLC film having a thickness of 1 μm is formed and a large number of coarse particles are generated. FIG. 13 is a diagram showing test results for a sample in which the DLC film is formed sufficiently long as compared with the case where the DLC film is normally formed to 1 μm, and the DLC film is easily peeled off.
As shown in FIG. 13, when the film formation time of the DLC film becomes long, coarse particles are likely to be generated even if the film thickness is about 1 μm. When such particles are generated, the torque for rotating the third wheel & pinion 3 temporarily increases as shown in FIG. When the film thickness of the DLC film is 2 μm or more, the film formation time of the DLC film becomes longer according to the film thickness, and therefore the probability that the above deposits are generated becomes higher. For this reason, in the present invention, the film thickness of the DLC film is preferably less than 2.0 μm, which does not require a long film formation time and can reduce the probability of deposits.
Even when the above deposits are generated, as shown in FIG. 13, the torque is confirmed to decrease with the passage of time, and thereafter the DLC film and the film formation time are short and peeling is unlikely to occur. It can be confirmed that the torque change state is almost equivalent. This is because even when the above-mentioned deposits are generated, these deposits are subdivided by wear or the like with the passage of time and become a size of 100 nm or less, and these deposits are the same quality as the DLC film. This is because it is a substance and acts as a lubricant by being subdivided as described above.

On the other hand, when the film thickness is 0.5 μm or less, peeling of the DLC film due to sliding contact with the bearing portion 16 may frequently occur. In such peeling of the DLC film, since it is diffused into the lubricating oil as a lump larger than the DLC fine powder, there is a risk of increasing the sliding frictional resistance. Further, even when the DLC film is not peeled off, as shown in FIG. 12, the DLC film may be worn out and the base of the lower tenon 173B may be exposed. Even in this case, since the DLC fine powder is dispersed in the lubricating oil, there is a lubricating effect as compared with the case where the DLC film is not formed, but the lower tenon 173B is exposed. In this case, when the lower tenon 173B is worn, there is a possibility that the lubricating oil is deteriorated by the wear powder.
For the above reasons, the DLC film is preferably formed to a thickness of about 0.8 μm to 2.0 μm. In this way, by forming the DLC film to a thickness of about 0.8 μm to 2.0 μm, it is possible to prevent the DLC film from being worn and to prevent the occurrence of peeling pieces, so that the lubrication effect can be sustained well. be able to. Moreover, the particle size of the DLC wear powder when the wear powder is generated by sliding contact with the bearing portion 16 becomes 100 nm or less, and is diffused into the lubricating oil as a good lubricant. In this case, since the abrasion powder does not become a peeling piece, the sliding frictional resistance of the shaft portion 17 and the bearing portion 16 can be effectively reduced.

  Here, the method for forming the DLC film as described above will be described in more detail. In the formation of the DLC film, for example, a hydrogen-free raw material such as graphite is used, and a hydrogen-free atmosphere (hydrogen-free atmosphere) is formed by a hydrogen-free PVD (Physical Vapor Deposition) method such as an ion plating method. . In such a hydrogen-free PVD method, a DLC film having high adhesion and high hardness can be formed on a fine part such as each shaft portion 17 in the watch train wheel 100A of the present embodiment. It is possible to prevent peeling of the DLC film and excessive wear of the DLC film when the part 17 and the bearing part 16 are in sliding contact. Usually, in a minute shaft portion of a fine component such as a watch component, the film quality on the test piece and the shaft portion are different under the same conditions, and the original hardness and adhesion cannot be secured. That is, in such a DLC film formed by the hydrogen-free PVD method, peeling and wear that expose the surface of the shaft portion 17 are prevented, and an appropriate amount of DLC fine powder is generated so that the shaft portion 17 is not exposed. Is possible. In addition, as described above, the DLC fine powder generated in this manner is diffused in the lubricating oil, so that the sliding friction resistance of the shaft portion 17 and the bearing portion 16 is further reduced, and the DLC film is further peeled off and worn. It will be suppressed.

  Further, the third wheel 3 is entirely coated with a fluorine resin, and an oil / hard carbon film fine powder holding layer is formed on the DLC film. Here, lubricating oil is injected between the tenon 173A and 173B of the third wheel 3 and the bearing portion 16, but the oil / hard carbon film fine powder holding layer prevents diffusion of the lubricating oil. It has a function of being held between the mortises 173A and 173B and the bearing portion 16. In addition, on the lower tenon 173B, the oil / hard carbon film fine powder holding layer formed of the fluorine-based resin has fluorine on the peeling surface even when the DLC film peels off due to the sliding contact between the shaft part 17 and the bearing part 16. System resin is renewed. Accordingly, there is no scattering of the lubricating oil accompanying the peeling of the DLC film, and the lubricating oil can be held for a long time. Such an oil / hard carbon film fine powder holding layer has a high-performance fluorine homopolymer processing stock solution synthesized in a fully fluorinated inert liquid and an appropriate solubility in the fluorine inert liquid, In addition, the third wheel 3 is immersed in a mixed solution obtained by mixing a diluent that does not dissolve moisture, and dried.

  Next, differences in characteristics due to the manufacturing method of the DLC film formed on the lower tenon 173B of the third wheel 3 of the watch wheel train 100A as described above, in particular, adhesion and hardness will be described with reference to the drawings. That is, in this embodiment, as described above, the DLC film is formed by the hydrogen-free PVD method. However, the DLC film formed by the hydrogen-free PVD method and the DLC film formed by the plasma CVD method are used. The characteristics will be described.

  FIG. 14 is a diagram showing the pressure required for the indentation depth in the DLC film formed by the hydrogen-free PVD method and the DLC film formed by the plasma CVD method on the axis of the timepiece component of this embodiment. It is. FIG. 15 is a diagram comparing the hardness of the DLC film formed by the hydrogen-free PVD method of this embodiment and the DLC film formed by the plasma CVD method. FIG. 16 is a diagram showing the adhesion between the DLC film formed by the hydrogen-free PVD method of this embodiment and the DLC film formed by the plasma CVD method.

As shown in FIG. 14, as a result of the indentation test, the DLC film formed by the hydrogen-free PVD method has a lower indentation depth than the plasma CVD method exhibits lower hardness than the test piece. It was confirmed that it showed high hardness equivalent to the test piece.
Further, as shown in FIG. 15, it can be confirmed by experiments that the DLC film formed by the hydrogen-free PVD method has a hardness as high as 20 GPa in terms of hardness per unit area. It can be seen that higher hardness can be realized as compared with the formed DLC film.
Further, as shown in FIG. 16, in the DLC film formed by the plasma CVD method, wear starts when a vertical load in a scratch test of 10 mN is applied, and peeling starts when a vertical load of 81 mN is applied. On the other hand, in the DLC film formed by the hydrogen-free PVD method, the vertical load at which wear starts is 54 mN, and the vertical load at which peeling occurs is 103 mN. That is, it can be confirmed that the DLC film formed by the hydrogen-free PVD method has good adhesion to the shaft portion 17. Also, when the thickness of the DLC film is 0.3 μm, it can be confirmed that the vertical load at which peeling occurs is smaller than when the film thickness is 1.0 μm. You can see that it occurs. Here, as described above, even when the DLC film is formed to have a thickness of 0.5 μm or less, the sliding frictional resistance of the lower tenon 173B and the bearing portion 16 is reduced, and the torque increase associated with the elapsed years is prevented. However, in order to prevent deterioration of the lubricating oil, it is not preferable to expose the lower tenon 173B. Therefore, in order to prevent exposure of the lower tenon 173B by abrasion or peeling of the DLC film, it is preferable to form the DLC film with a thickness of 0.8 μm or more.

[Effects of this embodiment]
As described above, in the timepiece 100 of this embodiment, in the lower tenon 173B of the third wheel & pinion 3 constituting the timepiece train wheel 100A, there is lubricating oil in which DLC fine powder is diffused between the shaft portion 17 and the bearing portion 16. Here, when the DLC has a small resistance value and is diffused and present in the lubricating oil as fine particles, these wear powders act as a lubricant, so that the sliding friction resistance of the shaft portion 17 and the bearing portion 16 is further increased. Can be reduced. Accordingly, these DLC fine powders are uniformly distributed in the sliding range of the shaft portion 17 and the bearing portion 16, and the sliding frictional resistance can be reduced. As a result, the timepiece wheel train 100A can accurately transmit the driving force to the hands over a long period of time, and the hand movement accuracy in the timepiece 100 can be maintained with high precision over a long period of time, thereby extending the life of the timepiece. Can do. In addition, since the torque for rotating the third wheel & pinion 3 having the largest side pressure can be kept low, the load on the motor, which reduces energy generation, can be reduced, and energy saving can be promoted.

A DLC film is formed on the lower tenon 173B of the third wheel & pinion 3.
For this reason, the sliding resistance of the shaft portion 17 and the bearing portion 16 can be further reduced by the DLC film. Further, even when DLC fine powder is generated by the rotation of the shaft portion 17, the wear powder is diffused in the lubricating oil, and as described above, the wear powder can act as a lubricant. Therefore, the sliding friction resistance can be reduced by the synergistic effect of the DLC film and the lubricating oil at the start of use of the watch, and after a predetermined number of years, the synergistic effect of the DLC film, the lubricating oil, and the DLC fine powder diffused in the lubricating oil. Thus, sliding frictional resistance can be reduced. Therefore, the shaft portion 17 can be protected by the DLC film over a long period of time, and the sliding friction can be kept low. As a result, the timepiece wheel train 100A can accurately transmit the driving force to the hands over a long period of time, and the hand movement accuracy in the timepiece 100 can be maintained with high precision over a long period of time, thereby extending the life of the timepiece. Can do.
Further, since the DLC film is formed on the shaft portion 17, it is possible to prevent the base material of the shaft portion 17 from being worn when the shaft portion 17 is driven to rotate. Therefore, the wear powder of the base material of the shaft portion 17 is not diffused into the lubricating oil, and the deterioration of the lubricating oil can be prevented. Thereby, the fall of the lubricating efficiency of lubricating oil can be prevented and the lifetime of lubricating oil can be extended.

The DLC film formed on the third wheel & pinion 3 is formed by a hydrogen-free PVD method.
For this reason, a DLC film having a high adhesiveness and a high hardness is applied to a lower tenon 173B, which is a minute part having a diameter of about 0.18 mm, such as a gear of a wristwatch, with a film thickness of about 0.8 μm to 2.0 μm The film can be stably formed with a thickness.
In addition, by forming a hydrogen-free DLC film by the hydrogen-free PVD method, in the crystal structure of the DLC film, it is possible to increase the proportion of sp3 bonds rather than sp2 bonds, and it is possible to form a DLC film with higher hardness It becomes. In addition, the hydrogen-free DLC film can further reduce the sliding frictional resistance, and the compatibility with the lubricating oil becomes good. Even when the DLC fine powder is generated, it can be efficiently diffused in the lubricating oil.

Further, the DLC film is formed so that the film thickness is about 0.8 μm to 2.0 μm. In this case, exposure of the lower tenon 173B due to abrasion or peeling of the DLC film can be prevented, and deterioration of the lubricating oil can be prevented. In addition, the DLC film can be easily formed with a uniform film thickness by the hydrogen-free PVD method, and the film thickness accuracy of the DLC film is improved.
That is, even when the thickness of the DLC film is 0.5 μm or less, the sliding friction resistance can be reduced and the torque can be reduced. However, as described above, the lower tenon 173B may be exposed due to abrasion or peeling of the DLC film. In this case, the lubricating oil may be damaged by abrasion. Even when the DLC film thickness is 2.0 μm or more, by maintaining the hardness and adhesion of the DLC film appropriately, the sliding frictional resistance of the lower tenon 173B and the bearing portion 16 can be reduced, and the torque can be reduced. Play. However, in the film formation by the hydrogen-free PVD method, the risk of occurrence of surface deposits such as coarse particles increases, and the film formation process and the film formation time become longer, and the accuracy for making the film thickness uniform ( There is also a problem that the film thickness accuracy is also deteriorated.
On the other hand, as described above, when the film thickness of the DLC film is about 0.8 μm to 2.0 μm, the hydrogen-free PVD method minimizes the risk of occurrence of surface deposits such as coarse particles. A DLC film having a uniform thickness and appropriate hardness and adhesion can be easily formed. Further, as shown in FIG. 12, the DLC film can be prevented from being worn out, and the lower tenon 173B is not exposed, so that deterioration of the lubricating oil due to wear of the lower tenon 173B can also be prevented.
At this time, the particle size of the DLC fine powder is 100 nm or less. For this reason, DLC fine powder does not become resistance during rotation but can act as a lubricant, and the sliding friction resistance can be more effectively reduced by the synergistic effect of the DLC film, lubricating oil, and DLC fine powder. It becomes.

And with respect to the shaft portion 17 on which the DLC film is formed, the bearing portion 16 is formed of ruby which is a highly rigid member having a hardness equal to or lower than that of the DLC film. For example, in the present embodiment, the DLC film is 20 GPa or more, and the bearing portion 16 is formed of ruby which is a high hardness material having a hardness of 15 GPa.
For this reason, damage to the DLC film due to the shaft portion 17 formed of ruby can be suppressed, and excessive wear of the DLC film can be prevented. In addition, since the DLC film has low resistance, even when the DLC film is harder than the bearing part 16, the aggressiveness to the bearing part 16 is small, and damage to the bearing part 16 can be suppressed. As described above, damage due to sliding friction of both the shaft portion 17 and the bearing portion 16 can be suppressed, the moving accuracy of the timepiece 100 can be maintained satisfactorily, and the timepiece life can be extended.
Further, a Ti layer is formed on a lower tenon 173B (shaft portion 17) using a carbon steel plated with Ni as a base material, and a DLC film is formed on the Ti layer. Thus, by forming the DLC film through the Ti layer, the Ti layer can absorb the stress difference between the DLC film and the base material, and the adhesion of the DLC film can be increased. Therefore, even when friction occurs between the DLC film and the bearing portion 16, the particle size of the DLC wear powder can be made 100 μm or less. Therefore, when DLC wear powder is generated by friction between the DLC film and the bearing portion 16, the wear powder can be diffused in the lubricating oil, and a good lubricating effect can be obtained.

Further, the shaft portion 17 and the bearing portion 16 are provided with a fluorine coating that is an oil / hard carbon film fine powder holding layer.
For this reason, the lubricating oil is held between the shaft portion 17 and the bearing portion 16 by the fluorine coating. That is, the oil / hard carbon film fine powder holding layer has no problem such as scattering of the lubricating oil, and can be held between the shaft portion 17 and the bearing portion 16 over a long period of time. The sliding frictional resistance between the parts 16 can be effectively reduced. Thereby, maintenance of the hand movement accuracy of the timepiece 100 over a long period of time and an extension of the life of the timepiece 100 can be achieved.
In addition, since the oil / hard carbon film fine powder holding layer is a fluorine resin coating, even if the DLC film of the shaft portion 17 is peeled off by sliding contact, the fluorine resin extends and peels off on the upper surface of the peeled surface. It becomes possible to renew and form the fluororesin on the surface.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, and includes other configurations and the like that can achieve the object of the present invention, and includes the following modifications and the like.

  For example, as described above, the portion where the DLC film is formed is the lower tenon 173 </ b> B of the third wheel 3 on which the largest side pressure acts, but is not limited thereto, and there is at least the entire number 2 to 6. It is good also as a structure formed only in tenon 173A, 173B of each number wheel 2-6. When such a configuration is adopted, not only between the tenon 173A, 173B and the bearing portion 16, but also the frictional resistance generated in the kana 171 and the gear 170 can be reduced, so that the minimum torque reduction necessary for moving the needle is reduced. It is possible to improve the accuracy of hand movement of the timepiece 100 and extend the life of the timepiece.

  Furthermore, although the DLC film is formed on the shaft portion 17, the DLC film may be formed on the bearing portion 16. Furthermore, a DLC film may be formed on both the bearing portion 16 and the shaft portion 17.

  As the timepiece 100 of the present invention, the power generation function timepiece that automatically winds the mainspring is illustrated, but the present invention is not limited thereto, and may be applied to other mechanical timepieces. More specifically, a machine comprised of a mainspring that is a mechanical energy source, a second wheel that meshes with a barrel wheel that incorporates the mainspring, an escape wheel, ankle, a balance, and the like, and is stored in the mainspring. In a mechanical timepiece having a speed control mechanism that periodically releases an energy source and a pointer coupled to the train wheel, from the second wheel and second wheel to which at least the minute hand is attached among the number wheels constituting the train wheel The watch wheel train of the present invention is constituted by the third wheel to which the rotation of the second wheel is transmitted and the fourth wheel that is arranged on the shaft of the second wheel and transmits the rotation from the third wheel and to which the second hand is attached. It may be a watch. Further, the timepiece is not limited to the timepiece that moves the hands with the mainspring, but may be a timepiece driven by another driving force such as a stepping motor. Even in these cases, by forming a DLC film on the tenon of each wheel, it is possible to extend the life of the timepiece and improve the accuracy of hand movement of the timepiece.

  In addition, the specific structure and procedure for carrying out the present invention can be appropriately changed to other structures and the like within a range in which the object of the present invention can be achieved.

  2, 3, 4, 5, 6 ... number wheel as a rotating body, 16 ... bearing portion, 17 ... shaft portion, 100 ... watch, 100A ... watch wheel train.

Claims (7)

A timepiece wheel train comprising a rotating body having a shaft portion and a bearing portion for rotatably holding the shaft portion of the rotating body,
Between the shaft portion and the bearing portion, there is a lubricating oil in which fine powder of a hard carbon film is diffused,
The hard carbon film is formed on one of the shaft portion and the bearing portion,
The other of the shaft portion and the bearing portion on which the hard carbon film is not formed is formed of a hard material having a hardness lower than that of the hard carbon film. The timepiece wheel train according to claim 1,
The fine powder of the hard carbon film diffused in the lubricating oil is hard carbon generated when the hard carbon film formed on one of the shaft portion and the bearing portion is worn during rotation of the shaft portion. A watch train wheel characterized by the abrasion powder of the film. In the timepiece wheel train according to claim 1 or 2,
The hard carbon film is formed by a physical vapor deposition method. The timepiece train wheel according to claim 3,
The hard carbon film is formed by the physical vapor deposition in an atmosphere containing no hydrogen. In the timepiece wheel train according to any one of claims 1 to 4,
A metal intermediate layer is formed on one surface of the shaft portion and the bearing portion where the hard carbon film is formed,
The hard carbon film is formed on the metal intermediate layer. In the timepiece wheel train according to any one of claims 1 to 5,
The clock wheel train, wherein a particle diameter of the fine powder of the hard carbon film is 100 nm or less. A timepiece in which a pointer is driven by a timepiece wheel train including a rotating body having a shaft portion, and a bearing portion that rotatably holds the shaft portion of the rotating body,
Between the shaft portion and the bearing portion, there is a lubricating oil in which fine powder of a hard carbon film is diffused,
The hard carbon film is formed on one of the shaft portion and the bearing portion,
The other of the shaft portion and the bearing portion, on which the hard carbon film is not formed, is formed of a hard material having a hardness lower than that of the hard carbon film.