JPS6365487B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber/plastic molding method, for example, when a cone-shaped rubber/plastic mold is provided on an electric wire or cable.

An example of a conventional rubber/plastic molding method of this kind, such as a rubber vulcanization molding method for electric wires and cables, will be explained with reference to the drawings.

Figure 1 is a front sectional view showing a state in which a rubber mold is provided by the vulcanization molding method on an electric wire used for the outlet of equipment, and Figure 2 is a front sectional view of a conventional rubber vulcanization mold. So, Figure 3 shows the X-
It is an X sectional view.

Conventionally, a rubber mold placed in a cone shape on an electric wire/cable is, for example, as shown in Fig. 1.
It is provided on the outer periphery of an electric wire/cable 1 having a rubber insulator or a rubber sheath, is joined to a bushing 3 at adhesive surfaces 2a and 2b, and is used as an exit part of a device.

The rubber vulcanization molding method for this mold 2 uses vulcanization molds 4 and 5 as shown in FIGS. This was a method of passing through a guide hole 7 and filling the molds 4 and 5 through a plurality of injection holes 8 to perform vulcanization molding.

In this way, multiple (usually about 4) injection holes 8
The purpose of using this is to improve the balance of injection when filling unvulcanized rubber into the molds 4 and 5.

However, in this case, the string-shaped unvulcanized rubber extruded from the injection hole 8 is filled while intertwining with each other.
The flow of rubber near the injection hole 8 at the end of the filling operation becomes radial. When adhering the vulcanized rubber mold 2 to another article in this state or when stacking another rubber mold on top of it, the adhesion surfaces 2a and 2b are polished to improve adhesion. Fluff appears on the surface.

If this fuzz is present, the adhesive or unvulcanized rubber will not be completely filled, trapping air and creating so-called voids.

This generation of voids poses a problem in that it causes a decrease in adhesive strength or deterioration of electrical characteristics.

An object of the present invention is to provide a molding method that solves the above-mentioned problems, suppresses fuzz that occurs on the polished surface of a rubber mold, and can obtain a rubber mold that has good bonding properties with other articles. .

The present invention is a molding method in which a molding die is provided around the outer periphery of an arbitrary object and rubber plastic is injected into the molding die from all directions around the outer periphery of the object.
It is characterized by injection of plastic.

Embodiments of the present invention will be described below based on the drawings. FIG. 4 is a front sectional view of a rubber vulcanization mold used in an embodiment of the present invention, and FIG. 5 is a YY sectional view of FIG. 4. In these figures, the same parts as in the conventional figures are given the same reference numerals, and the differences between the rubber vulcanization molds 4 and 5 used in this embodiment from the conventional ones are from the gate hole 6. A gap 9 is formed so that the unvulcanized rubber is injected from all directions around the outer circumference of the electric wire/cable 1 inside the circular guide hole 7 into which the unvulcanized rubber fed under pressure flows.
The point is that this is provided.

The dimensions of this gap 9 are adjusted so that the unvulcanized rubber is injected into the molds 4 and 5 in a well-balanced manner.

When rubber vulcanization molding is performed using the molds 4 and 5 configured in this way, unvulcanized rubber is injected into the molds 4 and 5 in a uniform flow from the gap 9, A rubber mold 2 is formed.

Since the internal structure of this rubber mold 2 is configured to have a flow in a certain direction, the adhesive surface 2a,
When polishing 2b, polishing can be easily performed without going against the direction of flow of the tissue, and fuzziness on the polished surface can be suppressed.

Therefore, when the polished surface is bonded to other articles using an adhesive, or when rubber molds are stacked using unvulcanized rubber, it is possible to eliminate the occurrence of voids at the joint and reduce the adhesive strength. This can prevent deterioration of electrical characteristics.

As explained above, according to the molding method of the present invention, the fuzz that occurs on the polished surface of the rubber/plastic mold can be suppressed, and a rubber/plastic mold that has good bondability with other articles can be obtained. can be played.

[Brief explanation of drawings]

Fig. 1 is a front cross-sectional view showing a state in which a rubber mold is provided by the rubber vulcanization molding method on an electric wire used for the outlet of a device, and Fig. 2 is a front cross-sectional view of a conventional rubber vulcanization mold. 3 is a sectional view taken along line XX in FIG. 2, FIG. 4 is a front sectional view of a rubber vulcanization mold used in an embodiment of the present invention, and FIG. 5 is a sectional view taken along Y--
It is a Y cross-sectional view. 1: Electric wire/cable, 2: Rubber mold, 2
a, 2b: adhesive surface, 3: bush, 4, 5: mold, 6: gate hole, 7: guide hole, 8: injection hole.

Claims (1)

[Claims] 1 In a rubber/plastic molding method in which a molding die is provided around the outer periphery of an arbitrary object and rubber/plastic is injected, the rubber/plastic is injected through a gate hole 6 provided at a predetermined position of the molding die. It is once flowed into the annular guide hole 7 provided inside the mold, and from there, it is injected from all directions around the outer circumference of the object through the gap 9 provided inside the guide hole 7. A rubber/plastic molding method that is characterized by