JP3065014B2 - Method of manufacturing tubular parts for watches - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an hourglass hourpiece and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, in the case of manufacturing an hourglass for a timepiece, a cylindrical portion and a gear portion have been formed by cutting.

[0003]

However, in the above-mentioned conventional manufacturing method, it is necessary to form the shape and the tooth shape of the hour wheel by cutting using a material for cutting, and these cutting steps are time-consuming. However, there is a problem that the manufacturing cost is increased.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a manufacturing method capable of manufacturing a timepiece hour wheel quickly and at low cost.

[0005]

According to a method of manufacturing a cylindrical part for a timepiece of the present invention, a drawing is repeatedly performed on a plate to form a covered cylindrical projection and an inner portion near the tip of the projection is formed. A drawing step of forming a concave portion on the wall surface, and forming a press-fitting surface for press-fitting a timepiece hand on the outer peripheral surface of the protruding portion, and removing the flesh of the protruding portion which is unnecessary at the time of forming the press-fitting surface by using the covered cylinder. The method is characterized by comprising a pressure forming step of flattening the concave portion by shifting the thickness to the lid of the protruding portion, and a lid punching process of removing the lid to form a cylindrical portion.

[0006]

[0007]

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a timepiece hourpiece and a method of manufacturing the same according to the present invention will be described with reference to the drawings. FIG. 1 is a process cross-sectional view showing the entire process of manufacturing the timepiece hour wheel in the present embodiment. The outline of the present embodiment is as follows.
The drawing process is repeatedly performed by press working as shown in (b) and (c) to form a covered cylindrical projection 2 as shown in (d). Next, the protruding portion 2 is press-formed,
As shown in (e), the watch is formed into a shape that matches the shape of the tubular portion of the hour wheel. Further, the lid portion 2a of this protruding portion is punched out by a press, and as shown in FIG.
Is formed to complete the cylindrical portion 3.

Next, the disk-shaped gear portion 4 having the tooth shape 4a as shown in (g) is formed by pressing the plate-shaped body 1 around the cylindrical portion 3 into a tooth shape by pressing. Form. Finally, as shown in (h), the tubular hour wheel is completed by removing the tubular portion 3 and the gear portion 4 from the surrounding plate-like body 1.

The above processing step is performed on the band-shaped (ribbon-shaped) plate-like body 1 shown in FIG. In this plate-like body 1,
A plurality of pilot holes 11 drilled at equal intervals in two rows along both edges in the width direction, and punching holes 12, 13, 14, 14 formed at equal intervals between rows of the pilot holes 11. Fifteen
Are formed by press working. By these punched holes 12, 13, 14, 15, the support bridges 16, 19 and the support arms 17, 19,
Disc-shaped islands 2 supported by 18, 20, 21
2 are configured.

FIGS. 3A and 3B are enlarged views of the vicinity of the island portion 22 during the above manufacturing process. FIG. 3 (a) shows, as shown in FIGS. 1 (a) to 1 (d),
A state in which a depression 30 corresponding to the protruding portion 2 is formed in the center of the island-shaped portion 22 by drawing by pressing is shown. This depression 30 is gradually covered (or bottomed) by drawing.
Corresponding to the protruding portion 2 which is formed into a cylindrical shape, it is deformed into a glass (cup) shape. In this embodiment, 1
By drawing 0 times, it is processed to the shape shown in FIG. This drawing is shown in detail in FIG. Here, 2-1, 2-4 and 2-6 are shapes after the first, fourth and sixth drawing, respectively. Initially, it is recessed in a large bowl shape, and the rising part is gradually finished up into a vertical wall.

FIG. 3B shows that the gear surface 4 of the gear portion 4 is formed in a disk shape centering on the depression 30 in the island-like portion 22 by “pulling” by press working shown in FIG. It shows the state that was done. This “pulling” is performed by a die having a tooth-shaped opening for forming the tooth shape 4a of the gear portion 4 and a punch having a cross-sectional shape corresponding to the opening shape of the die. It is applied by pinching from above and below. Here, when the punch is completely inserted into the opening of the die, the gear portion 4 is “pulled out” from the island portion 22, but without removing the gear portion 4 from the island portion 22, the portion of the tooth shape 4 a is removed. The gear portion 4 is "pulled out" by allowing the gear portion 4 to be held in the plane of the island portion 22 only by being separated from the surrounding island portion 22 by the break.

As shown in FIG. 3 (b), the cylindrical portion 3 and the gear portion 4 which are "pulled out" have a die having an opening having a diameter corresponding to the outer diameter of the gear portion 4, and a die corresponding to the die. The "punch-out" is performed by the punch and the watch hour wheel is completed.
As described above, once the gear portion is "pulled out" and then "pulled out", the durability of the mold is improved and a highly accurate gear portion can be formed.

FIG. 5 shows a step of forming the projection 2 shown in FIG. 1D and forming the outer shape of the cylindrical portion 3 of the hourglass as shown in FIG. 1E. is there. The protruding portion 2 is press-formed by a punch A and a die B shown by a dashed line in the drawing. In the drawing, C indicates the contact surface of the stripper.
Here, the solid line is the cross-sectional shape of the protrusion 2 before molding, and the broken line X is the cross-sectional shape of the protrusion 2 after molding. On the outer surface side of the protrusion 2, a press-fit surface 2b of the hour hand, a tapered surface 2c, and an end surface 2d are formed according to the shape of the die B. Here, die B
In the lid portion 2a which is removed at the time of forming the opening 3a shown in FIG. 1 (f), a relief portion Ba to which excess molded meat is brought is formed, and the relief portion Ba is formed by molding. Part becomes thicker. Since this thick portion is removed by forming the opening 3a later, it does not affect the shape of the cylindrical portion 3 regardless of the shape.

A concave portion 2e peculiar to drawing is formed in the upper part of the wall surface of the projecting portion 2, but this concave portion 2e is completely eliminated in the above-mentioned forming step. In this molding step, the recess 2
In addition to the formation failure of the previous process such as e, the accuracy of the shape required for the hour wheel is ensured. For example, the press-fit surface 2b of the hour hand positions the hour hand. Further, since the inner peripheral surface of the protruding portion 2 determines the center of rotation when the pointer is driven to rotate, it also needs to be formed with high precision.

As described above, in this embodiment, a protruding portion is formed by drawing, and after forming this protruding portion,
Since the cylindrical part was formed by piercing,
A timepiece hour wheel can be manufactured in a short time and at low cost without performing a cutting process as in the related art.

Also, in the forming step, a relief portion is formed in the mold so that excess meat during molding escapes in the lid portion 2a of the projecting portion 2, so that the molding can be performed with high precision without affecting the preceding and following steps. It can be performed.

Further, in forming the gear portion, by performing "pulling out" and "pulling out", the durability of the mold can be improved as compared with the case where "pulling out" is performed at one time, Accuracy can be improved.

In this embodiment, a plurality of islands arranged on the plate 1 are sequentially fed by moving the band-like plate 1 sequentially by the transport means. Therefore, the productivity can be greatly improved as compared with the conventional manufacturing process by cutting, and a very remarkable effect such as a reduction in labor can be achieved.

[0020]

As described above, according to the present invention, the following effects can be obtained.

That is, since excess meat can be released at the time of molding, molding can be performed with high precision, and since this relief-shaped portion is removed in the lid removing step, it affects the preceding and following steps. It is possible to efficiently manufacture a cylindrical part.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram (a) to (h) showing an embodiment of a watch hour wheel and a method for manufacturing the same according to the present invention.

FIG. 2 is a partial plan view of the plate-like body in the embodiment.

FIGS. 3A and 3B are partial plan views showing a planar shape of a plate during a manufacturing process in the embodiment. FIGS.

FIG. 4 is a sectional view showing a shape at the time of drawing in the embodiment.

FIG. 5 is an enlarged sectional view showing a shape before and after a molding step in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate-shaped body 2 Projecting part 3 Cylindrical part 3a Opening 4 Gear part 4a Tooth shape 22 Island part

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G04B 13/02 G04B 19/06 G04B 19/247 G04B 29/02 G04D 3/00 B21D 28/00 B21D 53/00

Claims (1)

(57) [Claims] 1. A drawing process for forming a covered cylindrical protrusion by repeating drawing on a plate-like body and forming a concave portion on an inner wall surface near the tip of the protrusion, and an outer peripheral surface of the protrusion. In addition, a press-fitting surface for press-fitting the hands of a timepiece is formed, and the flesh of the projecting portion, which is unnecessary at the time of forming the press-fitting surface, is moved toward the lid of the covered cylindrical projecting portion to flatten the concave portion. A method for producing a cylindrical part for a timepiece, comprising: a pressure forming step; and a lid removing process of forming a cylindrical part by removing the lid part.