JP3201160B2 - Watch shoe and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timepiece foot and a method of manufacturing the timepiece, and more particularly, to a timepiece which is screwed to a fixing screw for fixing various parts of the timepiece to a base frame of a timepiece movement. Related to the received watch.

[0002]

2. Description of the Related Art Conventionally, a movement of a watch has a base frame,
It has a stepping motor, a gear, a crystal oscillator, a battery, and various components such as a holding plate for fixing these components, which are arranged on the base frame.
They are fixed by hooks, screws and the like.
Among these fixing methods, screwing is the most convenient because it can be freely removed and reattached.

In this case, in a state where various components are interposed on the base frame, a fixing screw (male screw) is screwed into a screw hole formed directly on the base frame or a female screw attached to the base frame. The component is clamped and fixed between the screw and the base frame. However, in this fixing method, the screw size may be small, and the mounting pitch and screw floating may occur due to the difference in screw pitch between the male screw and the female screw, the mismatch of the screw diameter, the uneven pitch and the screw thread, etc. The problem is that the yield is low. Therefore, there is a case where a pin-shaped portion having a center hole is integrally provided in a resin base frame, and the above-mentioned various components are simultaneously fixed to the pin-shaped portion while tapping with a self-tapping screw. According to this method, the above-described problem due to the screw failure does not occur.

[0004]

However, the resin pin-shaped portion of the above-mentioned conventional fixing method cannot provide a sufficient fixing strength of the self-tapping screw, so that the screwing length is inevitably increased. This is contrary to the miniaturization and thinning of the timepiece. Therefore, a method of forming a metal foot separate from the base frame instead of the pin-shaped part and attaching the foot to the base frame can be considered. According to this method, since the self-tapping screw is applied to the metal foot, it can be securely fixed without increasing the screw-in length. In this case, when the foot is manufactured by cutting, there is a problem that formation time and manufacturing cost are required due to small dimensions.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a metal foot that can be manufactured quickly and at low cost.

[0006]

Means taken by the present invention to achieve the above-mentioned object is to fix a part on the base frame by screwing it to a fixing screw while being attached to the base frame. In the timepiece foot that has been performed, a flange portion that engages with the base frame,
A timepiece foot formed by forming a center hole formed so as to be tapped by the fixing screw by a forging process and then performing an annealing process.

In this case, it is preferable that a knurl to be engaged with the base frame is formed on an outer edge of the flange.

It is preferable that a side of the center hole opposite to a side where the fixing screw is screwed is closed.

Next, as a method of manufacturing a watch receiving leg according to the present invention, a flange portion engaging with the base frame and a center hole formed so as to be tapped by the fixing screw are forged. And a step of annealing this molded product.

[0010]

According to the first or fourth aspect, the shape of the watch receiving leg is formed by forging and then subjected to an annealing process, so that it can be manufactured quickly and at low cost by forging. Hardness suitable for self-tapping can be adjusted by annealing.

According to the second aspect, since the knurl is provided on the collar portion of the watch receiving leg, it can be securely and firmly fixed to the base frame.

According to the third aspect, by closing the center hole of the watch receiving foot, shavings generated at the time of tapping by the self-tapping screw can be confined in the hole, and the shavings are not released to the outside. It is possible to prevent a failure or malfunction of the timepiece.

[0013]

Next, an embodiment according to the present invention will be described with reference to the drawings. FIG. 1 shows a state in which the foot of this embodiment is used for fixing a base frame of a timepiece and components. A mounting hole 11 is formed in the base frame 1, and a foot 2 having a center hole 21 is press-fitted into the mounting hole 11. This foot 2 is attached to the mounting hole 11.
2 corresponding to the counterbore 11a formed at the lower end of the
2 and a knurl 22 a is formed on the outer edge of the flange 22. When the foot 2 is pressed into the mounting hole 11 of the base frame 1, the knurls 22 a bite into the base frame 1 and fix the foot 2 to the base frame 1.

A holding plate 4 having a through hole 41 located above the mounting hole 11 is placed on the base frame 1, and a self-tapping screw 3 is screwed into the holding plate 4 from above. The self-tapping screw 3 has a head portion 31 and a screw forming portion 32. The screw forming part 32 of the self-tapping screw 3 is inserted into the center hole 21 of the receiving foot 2 while rotating, is screwed into the inner surface of the center hole 21 while cutting the screw, and the holding member 4 is placed on the base frame 1. It is tightened to be fixed.

FIG. 2 shows a foot 5 different from the foot 2 shown in FIG. The foot 5 has a flange 52 similar to the foot 2.
And a knurl 52a, but is provided with a round hole 51 closed on the bottom side instead of the center hole 21. According to this round hole 51, even if shavings occur when the screw is carved on the inner surface by the self-tapping screw 3 shown in FIG.
Since the dust is trapped in the round hole, there is an advantage that the dust is not released to the outside. Therefore, it is possible to prevent a defect or the like from being mixed due to dust or the like at the time of assembling the timepiece and causing a malfunction.

FIG. 3 shows how the receiving feet 5 are formed by forging. First, as shown in (a), a wire material having a circular cross section for forging is cut to form a shaft member 100, and this is forged with a punch a1 and a die b1 as shown in (b), and the peripheral surface is formed. A primary workpiece 101 having a tapered surface 101a and a round hole 101b drilled upward from the lower end surface is formed. Furthermore, primary processed goods 1
01 is the punch a2, a3 and the die b2 in the same posture.
As shown in (c), a secondary processed product 102 having a knurl 102a at the outer edge of the flange and a round hole 102b opened at the lower end is formed.

In the forging process, (a) and (b) of FIG.
The foot 5 is formed by the steps shown in FIGS.
In practice, one or more preliminary forging steps are provided before and after each step, thereby producing, for example, six steps, thereby facilitating processing and homogenizing and stabilizing material properties.

In this way, the shape of the receiving foot 5 is formed by the forging process, and the hardness of the metal material is greatly increased by the forging. For example, when a forging material having a Vickers hardness of about HV = 140 is used, the hardness increases to about HV = about 230 after the forging step. However, since this hardness has a problem in fastening the self-tapping screw, an annealing process is performed to reduce the hardness. This annealing treatment is performed at about 350 degrees. FIG. 4 shows annealing characteristics when a JIS standard C2600W- ／ H material is forged and annealed as a metal material. With this material, the hardness can be reduced to about HV = about 100 by performing an annealing process at 350 degrees, and the foot 5 softened by this annealing process has a hardness suitable for screw fixing by a self-tapping screw. Become.

In this embodiment, the production time can be greatly reduced as compared with the case of forming by cutting, and the production can be performed by using almost 100% of the raw material, so that the waste of the material is almost eliminated. Absent. Incidentally, when manufacturing the foot 5 having the above shape, the usage rate of the raw material is about 15%. Therefore, the manufacturing cost can be reduced as compared with the related art. Further, as shown in FIG. 4, by performing the annealing treatment at the end, the foot can be adjusted to a desired hardness suitable for tapping, so that the self-tapping screw can be securely and easily attached and fixed. it can.

[0020]

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

According to the first or fourth aspect, the shape of the watch receiving leg is formed by forging and then subjected to an annealing process, so that it can be manufactured quickly and at low cost by forging. Hardness suitable for self-tapping can be adjusted by annealing.

According to the second aspect, since the knurl is provided on the collar portion of the watch receiving leg, it can be securely and firmly fixed to the base frame.

According to the third aspect, by closing the center hole of the watch receiving foot, shavings generated during tapping by the self-tapping screw can be confined in the hole, and the scraps are not released to the outside. It is possible to prevent a failure or malfunction of the timepiece.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state where a base frame and a holding plate are fixed using an embodiment of a timepiece support according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the timepiece support according to the present invention.

FIG. 3 is a process diagram showing a forging process of the watch foot according to the present invention.

FIG. 4 is a graph showing the annealing characteristics of the timepiece support according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base frame 2, 5 Foot 3 Self-tapping screw 4 Holding plate 21 Center hole 51 Round hole

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G04B 29/04

Claims (4)

(57) [Claims] 1. A watch receiving foot formed to be screwed to a fixing screw in a state of being attached to a base frame and to fix a component on the base frame, a collar portion engaging with the base frame, A timepiece receiving foot, characterized in that a center hole formed so as to be threaded by the fixing screw is formed by a forging process and then subjected to an annealing treatment. 2. The timepiece bearing according to claim 1, wherein a knurl engaging with the base frame is formed on an outer edge of the flange. 3. The timepiece foot according to claim 1, wherein the center hole is closed on a side opposite to a side where the fixing screw is screwed. 4. A method of manufacturing a watch receiving foot formed so as to be screwed to a fixing screw while being attached to a base frame and to fix a part on the base frame, wherein the flange engaging with the base frame is provided. Part, and a step of forming a center hole formed so as to be tapped by the fixing screw by forging, and a step of annealing the formed product, and Production method.