JP2002323114A - Gear for timepiece, gear device for the timepiece and the timepiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear for a timepiece, a gear device for the timepiece and the timepiece capable of dispensing with preventive treatment, without using lead as material. SOLUTION: A base material of a third shaft member 231 having a third pinion 231A is made of stainless steel and hardening treatment is performed for the third pinion 231A, after performing gear milling. Because stainless steel is used as the base material of the third shaft member 231, the need for using a material containing lead is eliminated and lead can be minimized in the third shaft member 231. Because the stainless steel is an alloy steel having excellent corrosion resistance, the rust preventive treatment such as a plating process can be unnecessitated. The hardening treatment is performed after the gear milling, and thereby, even if burr is generated in the third pinion 231A, when performing the gear milling, a burr is hardened and is made fragile by the hardening treatment and the burr can be easily removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece gear, a timepiece gear device provided with the timepiece gear, and a timepiece provided with the timepiece gear or the timepiece gear device.

[0002]

2. Description of the Related Art Conventionally, as a power transmission device for a timepiece, a wheel train using a large number of gears is frequently used. Since these gears are generally formed by cutting, which is a cutting process, as a base material of the gear, high-carbon steel containing a trace amount of lead, which is considered to have good machinability, is usually used. . Then, after the gear is subjected to the tooth splitting processing, a rust prevention treatment such as a plating treatment is performed.

[0003]

However, since such a gear is made of carbon steel, rust prevention treatment such as plating is indispensable, and there is a problem that the treatment takes time and effort. . In particular, when plating treatment is performed as rust prevention treatment, so-called pinholes such as small blisters and holes are generated during the treatment, and the surface roughness becomes rough. In addition, when the adhesion strength between the plating and the base material is low, there is a problem that the plating is peeled off and the wear resistance is impaired. In addition, in consideration of environmental issues in recent years, what is called lead-free without using lead as a material has been demanded, and it has been demanded to form a gear from a material containing no lead.

An object of the present invention is to provide a timepiece gear, a timepiece gear device, and a timepiece that do not use lead as a material and can eliminate the need for rustproofing.

[0005]

The timepiece gear according to the present invention comprises:
A stainless steel is used as a base material, and a hardening process is performed after a tooth splitting process is performed. According to the present invention, since stainless steel is used as the base material of the timepiece gear, it is not necessary to use a material containing lead, and the timepiece gear can be made lead-free. Further, since stainless steel is an alloy steel having excellent corrosion resistance, rust prevention treatment such as plating treatment can be unnecessary, and labor and time can be greatly reduced. In addition, the force applied per unit area is higher than gears used in other fields,
In watch gears with severe operating conditions, the base material is made of stainless steel and hardened, so high hardness is obtained, and when used in watches, the watch's wear resistance and long-term reliability are improved. be able to. In addition, when the timepiece is subjected to a tooth cutting process, burrs may be generated at the ends of the timepiece gear, and when the size of the timepiece gear is small, the size of the gear itself and the burrow is small. Removal of burrs becomes difficult. In the present invention, by performing a hardening process after the tooth splitting process, even when the clock gear has a burr during the tooth splitting process, the burr is hardened by the hardening process and becomes brittle. It can be easily removed.

In the timepiece gear of the present invention, the hardening treatment is desirably any one of a nitriding treatment, a carburizing treatment, and a quenching. As a hardening process, by heating steel in ammonia, penetrate nitrogen into the steel surface, and harden the steel surface, so-called nitriding treatment, nitrogen is dissolved in stainless steel, contained in stainless steel The surface of the timepiece gear is hardened by Cr or the like. If a so-called carburizing treatment, in which the surface of steel is made high carbon by carburizing and then hardened by quenching, is employed as the hardening treatment, the carburized layer on the surface is hardened and the surface of the timepiece gear is hardened. As a hardening treatment, if so-called quenching, in which steel is heated to an appropriate temperature to make it a uniform austenite state and then quenched in an appropriate coolant, so-called martensitic transformation occurs in stainless steel, The gear is hardened. The quenching may be surface quenching in which only the surface of the stainless steel is hardened, and in such a case, the surface of the timepiece gear is hardened. Since the surface of the timepiece gear can be hardened by any of these hardening treatments, a timepiece gear excellent in wear resistance can be manufactured. In particular, when a nitriding treatment is adopted as the hardening treatment, the heating temperature of the stainless steel may be low, and quenching may not be performed after the nitriding, so that the heat hardly causes distortion in the timepiece gear. For this reason, a timepiece gear can be manufactured with high precision.

When a nitriding treatment is employed as the hardening treatment, the stainless steel is preferably a martensitic stainless steel. If you do this,
Since it can be cured while maintaining the rust resistance of stainless steel, it is not necessary to perform rust prevention treatment after curing treatment,
Production efficiency can be improved.

[0008] On the other hand, a timepiece gear device of the present invention comprises any one of the above-mentioned timepiece gears and another gear meshed with the timepiece gear, and the other gear is made of a copper alloy. Characterized by being formed from
With this configuration, a timepiece gear device having the same operation and effect as any of the above-described timepiece gears can be obtained. In addition, since the other gear that is made of stainless steel and meshes with the hardened watch gear is made of a copper alloy, when the other gear meshes with the watch gear, The generated wear amount can be reduced, and the wear resistance of the timepiece gear device can be improved.

On the other hand, a timepiece of the present invention is characterized by being manufactured using any of the above-mentioned timepiece gears or the above timepiece gear device. By doing so, a timepiece having the same operation and effect as any of the above-described timepiece gears or the same operation and effect as the timepiece gear device can be obtained, and the durability and reliability of the timepiece can be obtained. And other performances can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a main part of an electronically controlled mechanical timepiece according to one embodiment of the present invention,
2 and 3 show cross-sectional views thereof, respectively. The electronically controlled mechanical timepiece is a barrel car comprising a mainspring 1A for storing mechanical energy, a barrel gear 1B rotatably driven by the mainspring 1A, a barrel barrel 1C for winding up the spring 1A, and a barrel lid 1D. 1 is provided. The mainspring 1A has an outer end fixed to the barrel gear 1B and an inner end fixed to the barrel barrel 1C. The barrel case 1 </ b> C is rotatably supported between the main plate 2 and the train wheel bridge 3 that are arranged to face each other. A square wheel 4 is fixed to the barrel true 1C with a square screw 5 so that the barrel true 1C and the square wheel 4 rotate integrally. By rotating the hour wheel 4 clockwise with a crown (not shown), the mainspring 1A can be wound up by the barrel barrel 1C. In addition, the square wheel 4 meshes with a hammer 6 (FIG. 1) so as to rotate clockwise but not counterclockwise.

The rotation of the barrel gear 1B, which is rotationally driven by the mainspring 1A, is transmitted to a second wheel & pinion 22, then increased in speed to a third wheel & pinion 23, and further sequentially increased in speed to a fourth wheel & pinion 24,
It is transmitted to the fifth wheel & pinion 25, the sixth wheel & pinion 26, and the rotor 112 (described later). Here, the second wheel 22 has a cylinder pinion 107A.
, The second hand 9 is fixed to the fourth wheel & pinion 24. These wheels 107 to 111 constitute a wheel train 117 as a clock gear device for transmitting the mechanical energy of the mainspring 1A to the rotor 112. The minute hand 8 and the second hand 9 are driven by driving the wheel train 117. Are driven.

The electromagnetically controlled mechanical timepiece is provided with a generator 120 for generating electric power by the mechanical energy of the mainspring 1A transmitted via the wheel train 117.
Is configured to include the rotor 112, the stator 113, the first coil block 114, and the second coil block 115 described above. The rotor 112 has a rotor magnet 112A, a rotor pinion 112B,
And a rotor inertial disk 112C. Among them, the rotor inertia disk 112C is provided to reduce the rotation speed fluctuation of the rotor 112 with respect to the driving torque fluctuation from the barrel car 1.

The stator 113 forms a magnetic circuit of the generator 120 together with the rotor magnet 112A of the rotor 112. The stator 113 has first and second
Magnetic cores 114A and 115A around which the coil blocks 114 and 115 are respectively wound are provided. These magnetic cores 114A and 115A are made of a soft magnetic material having high magnetic permeability such as PC permalloy and are connected to each other by screws 121. Accordingly, when the rotor magnet 112A rotates, an induced electromotive voltage corresponding to the rotation of the rotor magnet 112A is generated at both ends of the first and second coil blocks 114 and 115, and electric energy is obtained from the generator 120. It has become. The generator 120 having such a configuration not only converts mechanical energy from the mainspring 1A into electric energy but also functions as a governor for adjusting the rotation speed of the rotor 112. 120 using the electrical energy generated at 120
The rotation speed is adjusted.

Next, the center wheel & pinion 22, which constitutes the train wheel 117,
Third wheel 23, fourth wheel 24, fifth wheel 25, and sixth wheel 2
6 will be described in detail. 2nd wheel 22, 3rd wheel 2
The third, fourth and fourth wheels 24, fifth wheel 25, and sixth wheel 26 have substantially the same configuration, each serving as a rotating shaft, a second pinion (tube pin) 221A, and a third pinion 231.
A, fourth kana 241A, fifth kana 251A, sixth kana 2
The second shaft member 22 in which 61A is integrally formed.
1, a third shaft member 231, a fourth shaft member 241, a fifth shaft member 251, a sixth shaft member 261, and respective shaft members 221 to 261
The second gear 222, the third gear 232, the fourth gear 242, the fifth gear 252, and the sixth gear 262, which are penetrated and fixed to the second gear 221 and have larger dimensions than the respective pins 221 </ b> A to 261 </ b> A. The third kana 231A and the fourth kana 2
41A, 5th pinion 251A, and 6th pinion 261A are the timepiece gears of the present invention, respectively, and the 2nd gear 222, the 3rd gear 232, the 4th gear 242, and the 5th gear 252 are each other of the present invention. Gears. Here, these cars 22
4 to 26 will be described in more detail.
As shown by a third wheel 23 as a representative, the third shaft member 23
1 has a tenon 231B integrally formed at both ends thereof.

The third gear 232 has a fixing hole 232B at its center of rotation for penetrating and fixing the third shaft member 231.
Are formed, and a plurality of teeth 232A meshing with the pinion of the fourth wheel & pinion 24 are formed on the outer periphery thereof. The third gear 232 is made of brass, and is manufactured by cutting or punch press or the like. The third pinion 231A has a plurality of teeth 1 meshing with the second wheel 222 of the second wheel 22 on its outer periphery.
0 is formed. The base material of the third shaft member 231 formed with such a third pinion 231A is stainless steel.

The procedure for manufacturing the third shaft member 231 will be described below with reference to FIG. First,
A rod-shaped member 3 whose base material is stainless steel as shown in FIG.
1 was cut by a lathe or the like, and as shown in FIG.
The first part 32A to be the third kana 231A and the tenon 2
The first processing member 32 is formed by cutting out the second portion 32B to be 31B. In this cutting step, the third kana 2
No teeth are formed on the outer periphery of the first portion 32A that is to be 31A.

Thereafter, by means of a tooth splitting process, as shown in FIG.
As shown in FIG. 7, the teeth 10 are cut out on the outer periphery of the first portion 32A to form the third kana 231A, and the second processed member 33 is formed. It should be noted that the tooth splitting process may be a cutting tool having a contour of a groove between the teeth 10, and may be a process by a full-shape cutting method in which each tooth is cut out one by one. The processing may be performed by a generating gear cutting method in which the teeth 10 are shaved using a tool such as a gear-type cutter, a rack-type cutter, or a hob cutter. Here, at the time of the tooth splitting processing, depending on the cutting conditions and the like, burrs may be formed on the ends of the teeth 10 of the third pinion 231A and the ends of the grooves between the teeth 10.

After the tooth splitting is completed, the second processing member 3
3 are cut off one by one, and these second processing members 3
3 is subjected to a curing treatment. Here, in the present embodiment, a nitriding treatment is employed as the curing treatment. When the second processing member 33 is cut off one by one, the second portion 32B
A tenon 231B is formed (see FIG. 5D). In the nitriding treatment, as shown in FIG. 5 (D), by heating the second processing member 33 in ammonia, nitrogen generated from ammonia is dissolved in the second processing member 33, and the stainless steel as a base material is formed. A hardened layer is formed on the surface of the second processed member 33 by Cr and the like contained in the second processing member 33. In such a nitriding process, the thickness and the surface of the hardened layer (nitrided layer) formed on the surface of the second processing member 33 are set by arbitrarily setting various processing conditions such as an atmospheric gas, a temperature, and a processing time. The hardness can be arbitrarily selected. For example, about Hv
550 ℃ of stainless steel (SUS301) of about 200
When the gas nitrocarburizing treatment is performed for 2 hours in a state where the stainless steel is heated, the stainless steel can be hardened to about Hv1200. As the nitriding treatment, a method such as gas nitriding, liquid nitriding, or nitrocarburizing may be employed.

Here, in the hardening process, the burrs generated by the tooth splitting process are also hardened. Since the burrs are originally small and thin, they become brittle and are easily broken from the second processed member 33. After performing this nitriding treatment, the second processing member 33 is polished by a barrel polishing machine. Specifically, as shown in FIG. 5 (E), abrasive grains, a compound, water, and a second processing member 33 are charged into a barrel 40 of a barrel polishing machine, and the barrel 40 is rotated or vibrated to form a tooth. The third shaft member 231 is completed by removing the burrs generated during the splitting process and polishing the second processing member 33 (FIG. 5F). It should be noted that after this, the third kana 231
Polishing of the teeth 10 of A and polishing of the tenon 231B may be performed.

The third shaft member 231 thus completed
Constitutes a part of the third wheel & pinion 23 and engages with the gear 222 of the adjacent second wheel & pinion 22 as described above. Here, the gear 222 of the second wheel & pinion 22 is made of a stainless steel which has been subjected to a nitriding treatment in consideration of the wear resistance when the third wheel & pinion 23 of the stainless steel subjected to the nitriding treatment is engaged with the third pinion 231A. It is formed of a material that is compatible with, for example, brass or the like.

The good compatibility between brass and the nitrided stainless steel will be specifically described based on the results of a friction and wear test. In this friction and wear test, the diameter 3 /
A 16-inch (0.47625 cm) ball was pressed against the plate with a load of 0.5 N, and the plate was linearly reciprocated in this state, and the frictional force acting between the ball and the plate was measured. Nitrided stainless steel (SUS
301) plate with balls made of brass (C27)
Table 1 shows the results of the friction and wear tests for the case where the ball was formed of the high-carbon chromium bearing steel (SUJ2).

[0022]

[Table 1]

It can be seen from Table 1 that after the plate has reciprocated 1350 times, the width of the wear mark formed on the plate by the ball is smaller for the brass ball. From this result, it can be seen that the wear amount of the brass ball is smaller than that of the SUJ2 ball for the stainless steel plate. That is, the gear 2 of the second wheel & pinion 22 meshed with the third pinion 231A of the third wheel & pinion 23 formed of stainless steel (SUS301).
22 is made of brass (C2700) rather than SUJ2.
W) has less wear between the third pinion 231A of the third wheel & pinion 231 and the gear 222 of the second wheel & pinion 22, and the third pinion 231A of the third wheel & pinion 23 and the gear 22 of the second wheel & pinion 22
The wear resistance between the two becomes good.

In the above description, the third wheel 2 of the third wheel 23 is used.
31A is made of stainless steel, and the gear 222 of the second wheel & pinion 22 is made of brass, so that the wear resistance between the third wheel & pinion 23 and the second wheel & pinion 22 is improved.
4, 5th wheel 25, 6th wheel 26 each 241A, 251
A and 261A are made of stainless steel similarly to the third wheel kana 231A of the third wheel 23, and the third wheel 23 and the fourth wheel 2
The gears 232, 242 and 252 of the fourth and fifth wheel & pinion 25 may be made of brass similarly to the gear 222 of the second wheel & pinion 22. In such a case, the wear resistance between the respective vehicles 22 to 26 is improved, and the wear resistance of the wheel train 117 is improved. Here, the fourth wheel 24, the fifth wheel 25, the sixth wheel 26
When each of the kana 241A, 251A, 261A is made of stainless steel, like the third wheel & pinion 23, each shaft member 24
What is necessary is just to manufacture 1,251,261 by the manufacturing process similar to the 3rd axis | shaft member 231 mentioned above. The second pinion 221A and the rotor pinion 112B may be made of stainless steel, and the barrel gear 1B and the sixth gear 262 may be made of brass.

According to the above-described embodiment, the following effects can be obtained. In the present embodiment, the third shaft member 231,
Since stainless steel is used as a base material of the fourth shaft member 241, the fifth shaft member 251 and the sixth shaft member 261, it is not necessary to use a material containing lead in each of the shaft members 231 to 261. , Lead-free can be achieved. Further, since stainless steel is an alloy steel having excellent corrosion resistance, rust prevention treatment such as plating treatment can be unnecessary, and labor and time can be greatly reduced. In addition, each torque 231A, 241A,
In 251A and 261A, since the base material was made of stainless steel and hardened, a high hardness was obtained.
When used in the electronically controlled mechanical timepiece of the present embodiment, the durability and reliability of the timepiece can be improved. In addition, since the hardening process is performed after the tooth splitting process, each pinion 231A, 241A, 251A, 2
Even if burrs are formed on the 61A, the burrs are hardened and made brittle by the curing treatment, so that the burrs can be easily removed.

Each of the kana 231A, 24
Since the surfaces of 1A, 251A, and 261A are hardened, each kana 231A, 241 excellent in wear resistance and durability is provided.
A, 251A and 261A can be manufactured. Further, since the nitriding treatment is employed as the hardening treatment, the heating temperature of the stainless steel can be low, and quenching after nitriding can be omitted. Therefore, by the heat applied during the curing process,
Almost no distortion occurs in the portions of the kana 231A, 241A, 251A, 261A, and the kana 231A, 241
A, 251A and 261A can be manufactured with high accuracy.

Each of the kana 231A, 241A, 251A,
Since the second gear 222, the third gear 232, the fourth gear 242, and the fifth gear 252 meshing with the respective gears 261A and 261A are formed of brass having good compatibility, each pinion 231A, 2
41A, 251A, 261A and gears 222, 23
2,242,252 can reduce the amount of friction
The abrasion resistance of the train wheel 117 can be improved, and the performance such as durability and reliability of the electronically controlled mechanical timepiece can be improved.

It should be noted that the present invention is not limited to the above embodiment, and modifications and improvements as long as the object of the present invention can be achieved are included in the present invention. For example,
The stainless steel is not limited to austenitic stainless steel, but may be stainless steel such as martensitic stainless steel or ferritic stainless steel. In particular, if a nitriding treatment is selected as the hardening treatment, and martensitic stainless steel is used as a base material of the timepiece gear, the hardening can be performed while maintaining the rustproofness of the stainless steel. It is not necessary to perform a rust prevention treatment after the treatment, and the production efficiency can be improved.

The curing treatment is not limited to the nitriding treatment, but may be a carburizing treatment or a curing treatment such as quenching. Here, as a hardening treatment, after the surface of steel is made high carbon by carburizing, and then hardened by quenching, so-called carburizing treatment is adopted, the carburized layer on the surface is hardened,
The surface of the watch gear is hardened. As the carburizing treatment, any method such as solid carburizing, liquid carburizing, and gas carburizing may be employed. On the other hand, when the steel is heated to an appropriate temperature to form a uniform austenite state and then rapidly cooled in an appropriate coolant, so-called quenching, martensitic transformation occurs in the stainless steel. hand,
The clock gear is hardened. The quenching may be surface quenching in which only the surface of stainless steel is hardened, and in such a case, the surface of the timepiece gear is hardened. As the quenching, any method such as induction quenching, flame quenching, electrolytic quenching, ordinary quenching, time quenching, and high-temperature quenching may be employed. As described above, even when the above-described hardening treatment is employed, the surface of the timepiece gear can be hardened, so that a timepiece gear excellent in wear resistance and corrosion resistance can be manufactured.

The timepiece gear is not limited to the pinion, but may be a gear meshing with the pinion. Further, various types of gears having a twist angle such as a spur gear, a helical gear, and a helical gear may be used. It can be widely applied to gears. Also,
The usage of the timepiece gear of the present invention is not limited to the wheel train of an electronically controlled mechanical timepiece, but may be applied to a wheel train of a mechanical timepiece or a quartz timepiece, and the same effects as in the above embodiment can be obtained.

[0031]

According to the present invention, there is an effect that lead is not used as a material and rust prevention treatment can be eliminated.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an electronically controlled mechanical timepiece according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the electronically controlled mechanical timepiece according to the embodiment.

FIG. 3 is a sectional view showing a main part of the electronically controlled mechanical timepiece according to the embodiment.

FIG. 4 is a sectional view showing a third wheel in the embodiment.

FIG. 5 is a schematic diagram for explaining a manufacturing process of a third shaft member of a third wheel and wheel in the embodiment.

[Explanation of symbols]

 117 Wheel train as a timepiece gear device 222 Second gear (other gear) 231A Third pinion (watch gear) 232 Third gear (other gear) 241A Fourth pinion (watch gear) 242 Fourth gear ( Other gears) 251A 5th gear (watch gear) 252 5th gear (other gear) 261A 6th gear (watch gear)

Claims (7)

[Claims] 1. A timepiece gear comprising a stainless steel as a base material and a hardening process after a tooth splitting process. 2. The timepiece gear according to claim 1, wherein the hardening process is a nitriding process. 3. The timepiece gear according to claim 2, wherein the stainless steel is a martensitic stainless steel. 4. The timepiece gear according to claim 1, wherein the hardening process is a carburizing process. 5. The timepiece gear according to claim 1, wherein the hardening treatment is quenching. 6. The timepiece gear according to claim 1, further comprising another gear meshed with the timepiece gear, wherein the other gear is made of a copper alloy. A timepiece gear device characterized by being formed. 7. A timepiece manufactured by using the timepiece gear according to any one of claims 1 to 5, or the timepiece gear device according to claim 6.