JPH0438567B2 - - 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.

The composite article according to the present invention refers to a composite body consisting of a plastic molded body that partially forms a sealing surface between it and a mating article, and an elastic sealing material molded on the sealing surface. Various auto parts,
For example, oil pans that are fixed to the bottom of the engine's cylinder block, cylinder head cam covers that are attached to the top of the engine's cylinder head, instrument covers that cover and are fixed to the various instrument surfaces on the meter panel, tail lamps, etc. Examples include lenses that cover the light bulbs of lamps installed outside the body, and lids and stoppers of various containers.
In each case, a sealing surface between the mating article and the mating article is provided on the surface of the attachment part or the abutting part to the mating article, which is a part of the plastic molded body, and the sealing surface has a liquid-tightness or sealing surface between the mating article and the mating article. It is equipped with an elastic seal to maintain airtightness.

[Prior art and its problems]

Conventionally, this type of composite article has been produced by pre-molding a plastic molded body, then separately molding an elastic sealing material, and punching this elastic sealing material into a desired shape, for example, a ring shape. Thereafter, the ring-shaped elastic sealing material is pasted onto the sealing surface of the plastic molded body using an adhesive or the like, or a liquid gasket is applied onto the sealing surface after the plastic molded body is molded. However, in the former method, the elastic sealing material is punched out, which results in material loss in the central punched area, which is uneconomical, and also requires a lot of effort during the pasting process. Moreover, the adhesion between the sealing surface of the plastic molded body and the elastic sealing material is insufficient. Especially when the sealing surface is not flat, the adhesion is significantly reduced, and the latter is also prone to liquid Not only is the gasket application process difficult, but the applied surface lacks surface smoothness and leaks are likely to occur.

[Problem to be solved by the invention]

An object of the present invention is to provide a seal to which an elastic sealing material is attached to form a seal between the mating article and the mating article, for example, since the attachment part or abutting part of the plastic molded body of the mating article is determined by the relationship with the mating article. Even if the surface does not exist on a single flat plane, such a non-flat sealing surface and the elastic sealing material can be tightly and tightly adhered as one body, and the molding process is simple. Another object of the present invention is to provide a method for molding a composite article in which the surface smoothness of the elastic sealing material is high and the sealing performance is perfect, and the material is not wasted.

[Structure of the invention]

In order to achieve the aforementioned object, according to the present invention:
Using a molding machine equipped with a pair of molds that can be replaced with each other, one of the molds is used to partially form a sealing surface between the other product and a part of the sealing surface. A plastic molded body is formed with an irregular surface portion having a surface shape that does not match the remaining surface shape of the sealing surface in which holes, irregularities, grooves, etc. are formed, and then this plastic molded body is placed inside one side of the mold. This one side and the other side of the mold are replaced with each other while being held in place, and at this replaced position, the mold surface that comes into contact with the sealing surface of the plastic molded body is made to correspond to the irregular surface portion within the mold surface. The present invention is characterized in that an elastic sealing material is molded onto the irregular surface portion of the sealing surface using one side of the mold provided with a carved sealing molding groove.

[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. FIG. 2 is a partially enlarged cross-sectional view of part A in the figure, showing various forms of elastic sealing materials.

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, both of which are formed by rotating plates. 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.
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.

Seal surface 5 in the upper mold 2a″ of the mold 2a
A part of the mold surface for molding is formed with irregular surface molding parts such as columnar protrusions, fine irregularities, or ridges along the shape of a predetermined elastic sealing material, and the plastic is molded into the mold 2a. When the plastic molded body 4 is molded by material injection, a part of the sealing surface 5 of the plastic molded body 4 has a surface shape that does not match with the remaining surface of the sealing surface, such as a through hole, fine irregularities, or grooves. The irregular surface portion is integrally formed along the shape of the predetermined elastic sealing material.

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 body 4 inside the lower side 2a'. and the lower side 2b' of the other mold 2b are 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' At this replaced position, on the lower side 2a', there is a mold surface that comes into contact with the sealing surface 5 of the plastic molded body 4, and a mold surface that is carved in the mold surface and the sealing surface 5.
The upper side 2b'', which has a seal molding groove for molding an elastic sealing material having a shape corresponding to the irregular surface part of the mold, is brought together and clamped again, and a synthetic resin such as silicone resin, polyurethane resin, etc. is injected from the injection device 1b onto the sealing surface 5. A sealing material is injected and an elastic sealing material 6 is molded on the irregular surface portion of the sealing surface 5, and a plastic molded body 4 and an elastic sealing material 6 are formed, for example, as shown in FIG.
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, when the plastic molded product main body 4 is molded by the mold 2a, the plastic molded product main body 4 is molded by the upper side 2'' of the mold 2.
A part of the sealing surface 5 of the mold 2b is formed with an irregular surface portion such as a through hole, fine irregularities or grooves along the shape of a predetermined elastic sealing material, and is further formed on the upper side 2 of the mold 2b.
b'' is formed with a mold surface that comes into contact with the sealing surface 5 of the plastic molded product main body 4 held within the lower side 2a' of the mold 2a, and the irregular surface of the sealing surface 5 is formed within the mold surface. A seal molding groove having a shape corresponding to that is carved, and is formed on the upper side 2b'' when the lower side 2a' of the mold 2a and the upper side 2b'' of the mold 2b are clamped. The mold surface with a molding groove carved thereon is in pressure contact with the sealing surface 5, and in this state, the synthetic resin sealing material is injected into the sealing molding groove, so that a part of the sealing surface 5 is injected into the molding groove. An elastic sealing material 6 is molded onto the irregular surface portion that has been molded.

As described above, the injection molding of the elastic sealing material 6 is carried out by bringing the mold surface formed on the upper side 2b'' of the mold 2b into contact with the sealing surface 5 of the plastic molded body 4 that has already been molded. Since the molding cavity of the elastic sealing material 6 is formed by the irregular surface portion molded on the sealing surface 5 and the seal molding groove carved on the mold surface, the upper side 2 of the mold 2b
The contact portion of the mold surface that contacts the surface 5 of b'' with the sealing surface 5 is formed in the same shape as the mold surface for molding the sealing surface 5 on the upper side 2a'' of the mold 2a. This can be achieved by carving a seal molding groove corresponding to the irregular surface, so even if the seal surface 5 of the plastic molded body 4 has a three-dimensional shape that does not lie on the same flat surface, the seal molding groove The mold surface engraved with is in close contact with the sealing surface 5 of the plastic molded body 4, and the elastic sealing material 6 can be molded without generating burrs. The elastic seal material 6 is integrally and firmly fixed along the irregular surface portion, and the shape of the elastic seal material 6 on the seal surface 5 can be made into any shape by selecting the shapes of the seal molding groove and the irregular surface portion. Further, by selecting the cross-sectional shape of the seal molding groove, it is possible to maintain an arbitrary cross-sectional shape and surface smoothness of the elastic sealing material 6, and no material is wasted.

FIG. 3 shows various aspects of the irregular surface portions formed on the sealing surface 5 of the plastic molded body 4 and the elastic sealing material 6 molded onto these irregular surface portions.

FIG. 3a shows an example in which an elastic sealing material 6 is molded on a sealing surface 5 in which a through hole is partially formed as an irregular surface portion along the shape of a predetermined elastic sealing material 6.
In this case, the elastic sealing material 6 is anchored by the portion injected into the through hole and is completely held on the sealing surface 5, so there is no fear that it will shift during use.

FIG. 3b shows an example in which the elastic sealing material 6 is molded on the sealing surface 5 on which fine irregularities are formed along the predetermined shape of the elastic sealing material 6 as the irregular surface. Due to the large surface area of the unevenness, it adheres to the sealing surface 5, and the adhesion to the sealing surface 5 is perfect.

FIG. 3c shows an example in which the elastic sealing material 6 is molded into a groove as an irregular surface portion on the sealing surface 5. In this case, the elastic sealing material 6 is anchored in the groove and is completely held, so there is no fear that it will shift during use, and the sealing performance is perfect.

〔Effect of the invention〕

According to the present invention, when molding an elastic sealant onto a plastic molded product body, the sealing surface of the plastic molded product body is attached to one side of the mold that is fitted to one side of the mold while holding the plastic molded product body. Since the mold surface is in contact with the mold surface, and the seal molding groove is carved in the mold surface, the seal surface formed on a part of the surface of the plastic molded product body is flat in relation to the other product. Even if it does not exist on one plane and has a three-dimensional shape, the mold surface on which the seal molding groove is carved is the mold surface for molding the seal surface on one side of the mold when molding the plastic molded body. Since they have similar shapes, at least the grooved edge of the molded grooved portion of the mold surface is in close contact with the sealing surface of the plastic molded body, and is between the irregular surface portion that forms a part of the sealing surface. A space in the shape of a seal molding groove is formed, and an elastic sealing material is molded in the space, and the elastic sealing material is integrally and tightly adhered to the sealing surface, molded, and precisely positioned at a desired position on the sealing surface. is positioned.

The main body of the plastic molded product is molded from a plastic material and has some elasticity, so as the mold surface with the seal molding groove is pressed against the seal surface, the mold surface comes into close contact with the seal surface. Since the elasticity is good, the elastic sealant can be molded without creating burrs on the sealing surface, and the plastic molding body is replaced while being held in one side of the mold, and the elastic sealant is molded as described above. Therefore, due to the temperature remaining in the mold or the plastic molding body itself, the degree of integral adhesion of the elastic sealing material to the sealing surface is high.

In addition, the shape of the elastic sealing material on the sealing surface of the plastic molded body is such that when there is a bolt hole on the sealing surface used for fastening to a mating object, an annular elastic sealing material is integrated around the bolt hole. The shape on the seal surface can be formed by accurately positioning it at the desired position by making the shape of the seal molding groove carved on the mold surface into an arbitrary shape. The cross-sectional shape and surface smoothness of the material are also maintained by the cross-sectional shape of the seal molding groove.

In the present invention, in particular, when molding the plastic molded product main body, holes, irregularities, grooves, etc. are partially formed in a part of the sealing surface of the plastic molded product main body where the elastic sealing material is planned to be molded. A plastic molded product body is formed with an irregular surface portion that does not match the surface shape of the surface of the plastic molded product body, and then, when molding an elastic sealing material, a mold surface that contacts the sealing surface of the plastic molded product body is molded. Since the elastic sealing material is molded on the irregular surface portion of the sealing surface by one side of the mold having a seal molding groove carved corresponding to the irregular surface portion, the molded elastic sealing material is anchored to the irregular surface portion, Alternatively, due to the large surface area, it is tightly adhered to the plastic molded product body, and its retention to the main body of the plastic molded product is improved.

Furthermore, the composite article in which the plastic molded product body and the elastic sealing material are integrally molded according to the present invention is one in which a sealing surface between the plastic molded product body and the other product is formed on a part of the surface of the plastic molded product body. When fastened or attached to a mating object, the elastic sealing material molded on the sealing surface of the plastic molded body is accurately positioned at a desired position on the sealing surface, and the The planar shape and cross-sectional shape are always constant, so it can be molded to adhere well to the object, or maintain good liquid-tightness or air-tightness, and it can maintain adhesion for a long time, making it possible to mold the plastic molded object to the object. In addition to being able to be used for its specified purpose in relation to the article and maintaining good liquid-tightness or air-tightness between the two, the elastic sealing material can be molded onto the irregular surface molded on the sealing surface of the plastic molded product body. Since it is a plastic molded product, it has good adhesion to the main body of the plastic molded product, and can be held without slipping or peeling during use.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view of the main parts of a molding machine used in carrying out the present invention, FIG. 2 is a perspective view of an oil pan of an engine which is an example of a composite article molded according to the present invention, and FIGS. c shows a modification of the elastic sealing material integrally molded on the sealing surface. 1a, 1b...injection device, 2a, 2b...mold, 2
a', 2b'...lower side, 2a'', 2b''...upper side, 3...rotating plate, 4...plastic molded body, 5...sealing surface, 6...elastic sealing material.

Claims (1)

[Claims] 1 Using a molding machine equipped with a pair of molds that can be replaced with each other, one of the molds is used to form a sealing surface between a part of the surface and the other product, and a part of the sealing surface. A plastic molded body is formed with holes, irregularities, grooves, etc., and an irregular surface portion that does not match the surface shape of the remaining sealing surface, and then this plastic molded body is placed in the mold. This one side and the other side of the mold are replaced with each other while being held in one side of the mold, and at this replaced position, the mold surface that contacts the sealing surface of the plastic molded body and the irregular surface portion within the mold surface The elastic sealing material is integrally molded with the main body of the plastic molded article, characterized in that the elastic sealing material is molded on the irregular surface portion of the sealing surface by one side of the mold having a sealing molding groove carved in accordance with the above. Molding method for composite articles.