JPH0138276B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing timepiece hands such as minute hands and timepieces used in wall clocks and the like.

Figure 1 shows that conventional clock hands are manufactured by pressing a metal plate material such as an aluminum plate. A pipe-shaped rotating shaft 3 made of a molded product such as POM was fitted and fixed to the cylindrical portion 1, which protruded from the back side. However, such a conventional example has a problem in that the press-fit fixation may not be reliable due to the surface finish of the burred surface and the taper condition of the press-fit portion 3a of the rotary shaft 3.

The present invention has been made in view of the above-mentioned drawbacks.
The purpose of this is to create a watch manufacturing method that can form protrusions that serve as a stopper during the burring process, and that also allows the shape of the pattern of the protrusions to be easily changed and that functions such as rotation prevention and positioning can be added. is to provide.

The present invention will be explained below with reference to Examples. FIG. 2 shows a cross-sectional view of one embodiment, in which the needle body 2 is manufactured by pressing an aluminum plate material, and the rotating shaft 3
A plurality of protrusions 4 protrude in the circumferential direction on the inner periphery of the cylindrical part 1 into which the cylindrical part 1 is press-fitted. It is formed so as to be biased toward the opposite side of the press-fitting direction. Therefore, the needle body 2 and the rotating shaft 3 are fixed by press-fitting the cylindrical part 1 of the needle body 2 from above (in the direction of the arrow) so that it fits into the press-fitting part 3a of the rotating shaft 3 of the pipe-shaped molded product. At this time, as shown in FIG.
It bites into the hole and can be firmly fixed.

4 and 5 are drawings showing the manufacturing process of the needle body 2, and the needle body 2 is manufactured as follows.

That is, first, as shown in FIGS. 4a and 5a, a concentric convex pattern A is formed on the surface of a metal plate 5 such as an aluminum plate by pressing. These convex patterns A are formed in the circumferential direction, and some of them are missing here and there. The convex pattern A may have a spiral shape as shown in FIG. 6a, a mesh shape as shown in FIG. 6b, or a wavy line shape in the circumferential direction as shown in FIG. 6c. Next, a hole B is formed in the center of the convex pattern A by drilling as shown in FIGS. 4b and 5b.
Then, in the next burring process, the cylindrical portion 1 is made to protrude downward as shown in FIGS. 4c and 5c. At this time, a convex portion 4 is formed on the circumference of the cylindrical portion 1 by a convex pattern A. At this time, the top part 4a of the convex part 4 is oriented in the horizontal direction, so as shown in FIG.
In the process shown in FIG.
It points upward. After completing the burring process in this way, the needle body 2 is punched into the desired outer shape as shown in FIGS. 4e and 5e.

Note that, depending on the shape of the convex pattern A, the convex portion 4 has a function of preventing rotation of the rotating shaft 3 and a positioning function of press-fitting.
can be formed.

The present invention relates to a method for manufacturing clock hands in which the hands are pressed by a drilling process, a burring process, and an outline cutting process. A hole is drilled so as to leave a hole around the periphery, and the periphery of this hole is made to protrude backwards through a burring process to form a cylindrical part, and the convex pattern on the inner periphery of this cylindrical part generates an elastic adhesive force to the rotating shaft. Since the protrusions are formed and then the outer shape of the needle body is punched out, the shape of the protrusion pattern allows it to perform functions for various rotational axes, and the process of forming the protrusions can also be done in the burring process. This has the effect of reducing the number of steps.

[Brief explanation of drawings]

Fig. 1 is a partially omitted sectional view of a conventional example, Fig. 2 is a partially omitted sectional view of an embodiment of the clock hands of the present invention, Fig. 3 is an assembly explanatory diagram of the same, and Fig. 4 a. ~
e, Figures 5a to 5e are the same manufacturing process explanatory diagrams, and Figure 6
Figures a to c are top views of other examples of convex patterns;
is a cylindrical part, 2 is a needle body, 3 is a rotating shaft, 4 is a convex part, 4
a is the top, and A is the convex pattern.

Claims (1)

[Scope of Claims] 1. A method for manufacturing watch hands in which the hands are pressed by a drilling process, a burring process, and an outline cutting process, in which a convex pattern is engraved on a metal plate material before the drilling process. A hole is drilled so as to leave this convex pattern on the periphery, and the periphery of this hole is made to protrude backward through a burring process to form a cylindrical part, and the convex pattern on the inner periphery of the cylindrical part provides elasticity against the rotating shaft. A method for manufacturing watch hands, which comprises forming a convex portion that generates adhesive force, and then cutting out the outer shape of the needle body. 2. The method for manufacturing timepiece hands according to claim 1, further comprising a step of forming a convex portion on the inner periphery of the cylindrical portion between the burring step and the outline cutting step.