JPH1054886A - Clock train guide structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a timepiece with reduced cost by reducing man-hours in part processing and to provide a timepiece made of plastic, such as a base plate, a receiver, a wheel train, and the like. A timepiece wheel train guide structure in which a reduction gear train composed of a plastic rotor having a magnet insert-molded therein and a gear made of a plastic material is supported between a base plate and a bearing member of a train wheel bridge. The train wheel bridge is formed of a plastic material, one of the bearing members is formed with a concave groove bearing portion, and the other bearing member is formed with a through hole bearing portion, and the plastic rotor is a shaft of the plastic rotor. The position is determined by the end of the shaft and the bearing, and the end of the shaft is supported in the bearing without protruding from both bearing members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a train guide structure for a low-cost analog timepiece.

[Purpose] An object of the present invention is to provide an analog timepiece whose thickness is reduced and cost is reduced by a high-quality wheel train guide structure in a timepiece structure formed of a plastic member.

[0003]

2. Description of the Related Art Conventionally, in an analog type timepiece, a wheel train constituting member, which is a base plate, a receiver, and a very small part, is generally made of a metal material, and is partially used for insulating circuit parts, electronic circuits, and the like. Only plastic materials were used. However, providing a timepiece with reduced cost by reducing man-hours in parts processing is a great demand of the market, and the provision of a timepiece made of plastic, a base plate, a receiver, a wheel train, etc.
Cost reduction of about 1/2 compared with the conventional metal material configuration was achieved, and its practical use was urgently needed.

FIG. 2 shows an example of such a conventional configuration.

Referring to FIG. 2, 1 is a base plate formed of a plastic material, and 2 is a plastic rotor having a magnet 3 formed by insert. Reference numeral 4 denotes a fifth wheel made of a plastic material, which comprises a gear 4-a and a pinion 4-b. Reference numeral 5 denotes a fourth gear that meshes with a fifth pinion, and 6 denotes a second gear that meshes with a third pinion (not shown). Reference numeral 7 denotes a stator, and 9 denotes an hour wheel. Since each of them performs a known function, a detailed description is omitted. Reference numeral 8 denotes a train wheel bridge formed of a plastic material. As is clear from the figure, the lower handle 2-a, 4-c of the rotor and the fifth wheel are respectively connected to the upper handle 2 in the main plate holes 1-a, 1-b.
-B and 4-d are loosely fitted in the train wheel receiving holes 8-a and 8-b and are guided and positioned. The train wheel bridge has slope portions 8-c and 8-d corresponding to a vehicle position shift, a falling car number, and the like when the vehicle guide is incorporated, thereby improving incorporation.

However, this conventional example has the following serious disadvantages in terms of plastic processing characteristics. That is, each wheel is guided by a handle hole provided on the main plate and the train wheel bridge, and there is an extremely high risk of plastic burrs and burrs at the end of the hole.

FIG. 3 shows the structure of a molding die in the plastic molding of the hole. Generally, the pattern hole is formed by clamping with the A-type and the B-type shown in FIG. 3, but the pattern-hole is abutted against the B-type having the required pattern diameter d on the A-type surface. , Formed without any gaps. But B
The pin tip B-1 part provided in the mold always needs flatness,
A gap is formed due to sagging and mold abrasion, a gap between the A-type and B-type clamping parts and a pin tip dimension, and the plastic is partially filled to generate flat burrs 8-g. The burrs and the like eliminated rattling of the wheel train, and there was a high risk of causing serious defects such as stoppage of the timepiece. As shown in FIG. 2, the wheel train agaki is determined by the 1-c plane on the main plate side and the 8-e, 8-f plane on the wheel train receiving side. Therefore, there is a problem in terms of quality as a wheel train structure having a small holding torque like a wristwatch, because torque loss due to friction and the like is large because the wheel train is located on the outer peripheral side.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the conventional structure and to provide a wheel train guide structure in which burrs of a plastic receiving member are reduced and frictional torque is reduced.

[0009]

According to the present invention, there is provided a wheel train guiding structure for a timepiece, wherein a reduction gear train composed of a plastic rotor in which a magnet is insert-molded and a gear made of a plastic material is used as a base plate and a bearing member for a train wheel bearing. In the train wheel guide structure of the timepiece supported therebetween, the base plate and the train wheel bridge are formed of a plastic material, one of the bearing members is a bearing portion having a concave groove, and the other bearing member is a bearing having a through hole. Part is formed, the plastic rotor is positioned by the tip of the shaft of the plastic rotor and the bearing, and the tip of the shaft is supported in the bearing without projecting from both bearing members. It is characterized by becoming.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.

Referring to FIG. 1, 11 is a ground plate formed of a plastic material, and 12 is a plastic rotor having a magnet 13 formed by insert. Reference numeral 14 denotes a fifth wheel made of a plastic material, which comprises a gear 14-a and a pinion 14-b. Reference numeral 15 denotes a fourth gear that meshes with the fifth pinion, and 16 denotes a second gear that meshes with the third pinion (not shown). Reference numeral 17 denotes a stator, and 19 denotes an hour wheel. Since each of them performs a known function, a detailed description is omitted. Reference numeral 18 denotes a train wheel bridge made of a plastic material. As is clear from the figure, the lower handles 12-a, 14-c of the rotor and the fifth wheel are respectively provided in the main plate holes 11-a, 11-b, and the upper handles 12-b, 14-d are provided in the wheel train receiving holes 18 respectively. -A, 18-b and guide positioning. The train wheel bridge has the slope portions 18-c and 18-d corresponding to the vehicle position deviation, the falling of the guard wheel, etc. when the vehicle guide is incorporated,
Improve incorporation. The train wheel receiving hole 18-a of the train wheel bearing 18
18-b is formed by a concave groove, and the thickness T of the handle tip for determining the wheel train agaki needs to be about 0.2 to 0.25 mm due to the necessity of plastic filling.

According to this structure, no burr is generated around the receiving hole of the train wheel bridge, and the rotor and the gear are axially positioned at the tip of the handle to reduce the friction area. However, the friction torque loss can be significantly reduced. The lower handle of the rotor is pivotally supported by a receiving hole 11-a formed as a through hole in the main plate.
This is because a burr 12-c is usually provided at one end of the rotor shaft to prevent this portion from contacting the main plate. 11-c
Is a support part when the rotor moves largely in the axial direction due to impact or the like.

[0013]

As described above, according to the present invention, since the bearing portion of one bearing member is formed as a through hole, even if burrs are generated at the tip of the shaft portion of the plastic rotor in which the magnet is insert-molded, the burrs are formed. Does not touch the ground plane,
Incorrect rotation of the plastic rotor due to burrs can be avoided.

[0014] Further, since the tip of the shaft of the plastic rotor is supported in the bearing without protruding from the bearing member of the main plate and the train wheel bridge, for example, a metal needle is attached to the tip of the shaft during lubrication. Since the collision deforms the shaft portion or generates new burrs, there is an effect that a problem that rotation failure of the plastic rotor occurs can be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a train wheel guide structure according to the present invention.

FIG. 2 is a sectional view of a main part showing a train wheel guide structure according to a conventional example.

FIG. 4 is a diagram showing a molding die structure in a conventional gear train guide structure.

[Explanation of symbols]

 11… Main plate 12… Rotor 14… Fifth wheel 18… Wheel train

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 17, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

[0009]

According to the present invention, there is provided a timepiece train guide structure for a timepiece, wherein a reduction gear train composed of a plastic rotor having a magnet insert-molded therein and a gear made of a plastic material is used as a base plate and a bearing member for a train wheel bearing. In the train wheel guide structure supported between the timepieces, the base plate and the train wheel bridge are formed of a plastic material, and one of the bearing members has a bearing portion having a concave groove, and the other bearing member has a bearing portion having a through hole. Formed and said
The base plate is provided with a step around the through hole, the plastic rotor is positioned by the shaft tip of the plastic rotor and the bearing member, and the shaft tip does not protrude from both bearing members. It is characterized by being supported in a bearing portion. ────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] August 25, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a train wheel guide structure according to the present invention.

FIG. 2 is a sectional view of a main part showing a train wheel guide structure according to a conventional example.

FIG. 3 is a view showing a molding die structure in a conventional gear train guide structure.

[Explanation of Signs] 11 ... Main plate 12 ... Rotor 14 ... Fifth wheel 18 ... Wheel train receiver

Claims (1)

[Claims] 1. A timepiece wheel train guide structure in which a reduction gear train composed of a plastic rotor in which a magnet is insert-molded and a gear made of a plastic material is supported between a base plate and a bearing member of a train wheel receiver. And the train wheel bridge is formed of a plastic material, one of the bearing members is formed with a concave groove bearing portion, and the other bearing member is formed with a through hole bearing portion, and the plastic rotor is formed of the plastic rotor. A wheel train guide structure for a timepiece, wherein a position is determined by a tip of a shaft and the bearing, and the tip of the shaft is supported in the bearing without protruding from both bearing members.