JPS6345292B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a method for molding a composite article in which a plastic molded article body and an elastic sealing material are integrally molded, and particularly relates to a method for molding a composite article in which a plastic molded article body and an elastic sealing material are integrally molded, and in particular, the adhesiveness between the plastic body and the elastic sealing material is improved. The present invention relates to a method for molding a composite article that has advantages such as improved performance and a simple molding process.

[Prior art and its problems]

The composite article according to the present invention refers to a composite body of a plastic molded body and an elastic sealing material, and specifically includes various automobile parts, such as oil pans, head covers, instrument covers, tail lamps, etc., or lids of various containers, Examples include stoppers.

Conventionally, this type of composite article is made by first molding a plastic molded product body, then separately molding an elastic sealing material, and punching this elastic sealing material into a desired shape, for example, a ring shape. , a method of pasting the ring-shaped elastic sealing material onto the sealing surface of the plastic molded body using an adhesive or the like, or a method of applying a liquid gasket onto the sealing surface after molding the plastic molded body. However, in the former method, the elastic sealing material is punched out, which results in material loss in the central punched area, which is not economical, but also requires a long pasting process. Moreover, the adhesion between the sealing surface of the plastic molded body and the elastic sealing material is insufficient, and especially if the sealing surface is not flat, the adhesion will be significantly reduced, and the latter will also cause liquid gasket damage. Not only is the application process difficult, but the coated surface lacks surface smoothness and leakage is likely to occur.

[Purpose of the invention]

The object of the present invention is to enable the sealing surface and the elastic sealing material to be integrally and tightly adhered to each other even if the sealing surface of the plastic body is not flat, to simplify the molding process, and to make the surface of the elastic sealing material smooth. It is an object of the present invention to provide a method for molding a composite article, which has excellent sealability and perfect sealing properties, and does not waste material, and which improves the drawbacks of the above-mentioned known techniques.

[Key points of the invention]

In order to achieve the aforementioned object, according to the present invention:
Using a molding machine equipped with a pair of mutually replaceable molds, one of the molds is used to mold a plastic molded product body having a sealing surface, and then this plastic molded product body is attached to one side of the mold. The present invention is characterized in that this one side and the other side of the mold are replaced with each other while being held in the mold, and an elastic sealing material is molded on the sealing surface of the plastic molded body at the replaced position.

[Specific examples of the invention]

Hereinafter, the present invention will be specifically explained using the accompanying drawings.

Fig. 1 shows an example of a molding machine used in the method of the present invention, Fig. 2 shows a perspective view of an oil pan molded using the molding machine of Fig. 1, and Figs. 4 and 5 are cross sections of an instrument cover and a container lid, respectively, molded by the method of the present invention; FIG. Show the diagram.

First, to explain the molding machine shown in FIG. 1, this molding machine is equipped with two injection devices 1a and 1b, and a pair of molds 2a and 2b, each of which has a rotary plate. They are arranged at opposing positions on the rotating plate 3, and can be replaced with each other by rotating the rotary plate 3. First, 150% of plastic material such as polyamide (6.6 nylon), polyacetal, polycarbonate, ABS resin, etc. is injected into the mold 2a of an oil pan from the injection device 1a.
The oil pan-shaped plastic molded body 4 is molded by injection at a temperature of .degree. C. to 200.degree. 5 is the sealing surface of the plastic molded body.

Next, the upper side 2a'' of the mold 2a is removed to open the mold, and the rotary plate 3 is quickly rotated 180 degrees to hold the plastic molded product 4 inside the lower side 2a'. The lower side 2b' of the other mold 2b is replaced with each other, that is, the lower side 2b' is placed at the position of the lower side 2a' in FIG. 1, and the lower side 2a' is placed at the position of the lower side 2b'. (This state is not shown.) In this replaced position, the elastic sealing material is attached to the upper side 2a' of the lower side 2a'.
b'' and clamp the mold again, and inject a synthetic resin sealing material such as silicone resin or polyurethane resin onto the sealing surface 5 from the injection device 1b to mold an elastic sealing material 6 on the sealing surface 5. A plastic molded body 4 and an elastic sealing material 6 as shown in the figure
Obtain a composite article consisting of: At this time, the lower side 2b' of the mold 2b has moved toward the injection device 1a, and here the lower side 2b' and the upper side 2a'' are brought together and clamped, and the same molding operation as described above is repeated.

In the present invention, since the elastic sealing material 6 is quickly attached to the sealing surface 5 by a molding operation, the sealing surface 5 does not necessarily have to be flat, and can be integrally formed in any shape. In addition, it is possible to mold an elastic sealing material that is tightly adhered and has any shape, and of course, it is easy to maintain the surface smoothness of the elastic sealing material, and there is no waste of material.

Furthermore, in the present invention, molding can be performed quickly with simple operations using a single molding machine, so the molding process is simple.

FIG. 3 shows various forms of the sealing surface 5 of the plastic molded body 4 and the elastic sealing material 6. Figure 3a
shows an example in which the elastic sealing material 6 is molded on a flat sealing surface. FIG. 3b shows an example in which the elastic sealing material 6 is molded on a sealing surface that partially has a through hole. In this case, the elastic sealing material 6 is completely held on the sealing surface, and there is no fear that it will shift during use. do not have.

FIG. 3c shows an example in which the elastic sealing material 6 is molded on a sealing surface having fine irregularities, and in this case, the adhesiveness of the elastic sealing material 6 to the sealing surface is perfect.

FIG. 3d shows an example in which the elastic sealing material 6 is molded into a groove on the sealing surface. In this case, the elastic sealing material 6 is completely held within the groove, there is no fear that it will shift during use, and the sealing performance is perfect.

FIG. 3e shows an example in which the elastic sealing material 6 is molded in two rows on the sealing surface, and the sealing performance is improved.

According to the present invention, the elastic sealing material can be easily molded even if the sealing surface is not necessarily flat as shown in FIGS. 3a to 3e.

4 and 5 show other examples of composite articles obtained by the method of the invention. FIG. 4 shows an example of an instrument cover. 7 is a frame of the instrument, 4 is an acrylic plastic cover (plastic molded body), and 6 is an elastic sealing material made of silicone rubber.

FIG. 5 shows an example of a container lid. 8 is a container, 4 is a lid body made of acrylic plastic, and 6 is an elastic sealing material made of silicone rubber.

〔Effect of the invention〕

In the present invention, the elastic sealing material 6 is quickly attached to the sealing surface 5 by a molding operation, so the sealing surface 5 does not necessarily have to be flat, and can be integrally formed in any shape. Therefore, it is possible to mold an elastic sealing material that is tightly adhered and has any shape, and of course, it is easy to maintain the surface smoothness of the elastic sealing material, and there is no waste of material. Furthermore, in the present invention, molding can be performed quickly with simple operations using one molding machine, so the molding process is simple.

[Brief explanation of the drawing]

Fig. 1 shows an example of a molding machine used in the present invention, Fig. 2 shows a perspective view of an oil pan molded by the method of the present invention, and Figs. 4 and 5 show other examples of composite articles molded by the method of the present invention. 1a, 1b... Injection device, 2a, 2b... Mold, 2a', 2b'... Lower side, 2a'', 2b''... Upper side, 3... Rotating plate, 4... Plastic molded product body, 5... Seal surface, 6... Elastic sealing material, 7...
... Instrument frame, 8... Container.

Claims (1)

[Claims] 1 Using a molding machine equipped with a pair of mutually replaceable molds, mold a plastic molded product body having a sealing surface using one of the molds, and then mold this plastic molded product body into the mold. A plastic molded product body, characterized in that one side and one side of the other mold are replaced with each other while being held in one side, and an elastic sealant is molded on the sealing surface of the plastic molded product body at the replaced position. A method of molding a composite article in which a material and an elastic sealing material are integrally molded.