JPH076552Y2 - Thin dial made of synthetic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a thin dial made of synthetic resin used as a dial for a wristwatch, for example.

[Prior Art and its Problems] Generally, a metal dial plate is used for a wristwatch. It has been considered that this metal dial plate is particularly suitable for a thin watch because it has excellent flatness and has a small gap between the watch dial and the hands of the watch so as not to hinder the rotational movement of the hands.

However, since the metal dial plate has a large number of characters to be embedded or printed characters on the surface of the metal plate, there is a drawback in that automation thereof is not easy and the cost is high.

Therefore, it is considered to mold the dial plate with synthetic resin instead of metal, but in this case, in normal injection molding, it is not possible to obtain a high precision product with a flatness of about 0.04 mm required as a countermeasure. In order to ensure accuracy, for example, by using molds 1 and 2 as shown in FIG. 4, the molds 1 and 2 are filled with the molten resin 3 at a special high speed and high pressure. Alternatively, it is necessary to remove the internal strain by molding by the injection-compression method.

However, since the pressure in the molds 1 and 2 is very high in the above-mentioned ones, when the mold 2 is opened and the molded product 3 is taken out to the outside, it is strongly stuck in the mold 1 and the mold release is not easy. .

Therefore, the molded product 3 is normally ejected by the ejecting device 4 as shown in FIG. 4, and the molded product 3 is taken out, but this has a drawback that the surface of the molded product 3 is scratched.

[Purpose of device]

The present invention has been made in view of the above circumstances, and the purpose thereof is that it can be easily molded by ordinary injection molding, and can be easily removed from the mold at the time of molding (removal at the time of molding). In addition, it is possible to solve the problem of scratches on the surface and provide a low cost synthetic resin thin dial plate in which the component synthetic resin and the sheet material are completely integrated and do not easily peel off. Is what you are trying to do.

[Outline of device]

In order to achieve the above-mentioned object, the present invention injects a molten synthetic resin on the back surface of a sheet material made of a porous material having characters or the like printed in advance, and the molten synthetic resin is injected inside the sheet material by this ejection force. When the molten synthetic resin is infiltrated and fixed, it is integrated with the sheet material.

[Example of device]

The present invention will be described below with reference to an embodiment shown in FIGS. This embodiment shows an application example as a dial of a timepiece.This dial 11 has a sheet material 13 on which a time display 14, a company name letter 18 and the like are printed in advance, and the back surface of the sheet material 13 is injection molded. The sheet material 13 is a porous member (paper, foamed synthetic resin sheet, non-woven fabric, etc.) into which molten resin permeates inside due to the radiation output during base molding. )
Is formed by.

Next, a method of manufacturing the dial 11 will be described. First, as shown in FIG. 3, the sheet material 13 on which the characters 18 and the like are printed is inserted into the mold 15 in advance, and then the molds 15 and 16 are closed to inject the molten synthetic resin. Then, the base 12 is molded. At this time, part of the molten synthetic resin penetrates into the sheet material 13 and the sheet material 13 and the synthetic resin (base material).
12) and are firmly integrated. In this way, after the molding is completed, the molds 15 and 16 are opened, and the dial 17 which is a molded product is sucked out by the robot 17 with the suction device into the open molds to finish the manufacturing.

As described above, since the synthetic resin base 12 is formed by injection molding on the back surface of the sheet material 13 on which the characters 18 and the like are printed, it is extremely easy to manufacture as compared with a metal dial plate, and the cost is low. A dial 11 can be provided.

Further, as shown in FIG. 3, when the dial plate surface is in contact with the moving side mold surface, the sheet material 13 on which characters and the like are printed in advance is inserted into the mold 15 to perform injection molding. The synthetic resin injected onto the inner surface of the mold 15 does not stick firmly, and it is easy to take out. Therefore,
It is possible to take out the molded product by suction and suction, and there is no fear of damaging the surface of the molded product.

Further, since the characters 18 and the like are printed on the surface of the sheet material 13 in advance, a high-quality dial plate can be manufactured at low cost by performing high-quality printing.

Although the case of the timepiece dial has been described in the above embodiment, the present invention is not limited to this and can be applied as a dial of a thin handheld calculator or the like.

[Effect of device]

Since the thin synthetic resin dial plate of the present invention has been described above, it can be easily molded by ordinary injection molding, and the mold can be easily removed during molding (removal at molding), and the surface can be easily removed. The effect of being able to solve the problem of being scratched, the synthetic resin which is a constituent element, and the sheet material being completely integrated and not easily peeled off, and the cost can be reduced.

[Brief description of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a plan view showing a dial, FIG. 2 is a side sectional view thereof, and FIG. 3 shows a molding state of the dial. Explanatory drawing, FIG. 4 is explanatory drawing which shows the shaping | molding state of the conventional dial. 12 …… Synthetic resin base, 13 …… Sheet material.

Claims (2)

[Scope of utility model registration request] 1. A molten synthetic resin is injected onto a back surface of a sheet material made of a porous material having characters printed in advance on its front surface, and the molten synthetic resin is permeated into the inside of the sheet material by this ejection force to melt the molten material. A thin dial made of synthetic resin, which is integrated with the sheet material when the synthetic resin is solidified. 2. The synthetic resin thin dial plate according to claim 1, wherein the porous material is paper, foamed resin, or non-woven fabric.