JPS6018115B2 - Resin molding method for rubber/plastic cable connections - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin molding method for rubber/plastic cable connections.

For trunk cables with branch cables, branch connections are made within the factory.

For this branch connection, as shown in Fig. 1, the conductor 21' of the rubber/plastic branch cable 2' is connected to the conductor 11' of the rubber/plastic main cable 1' using a conductor connection fitting 3', and this connection is It is advantageous in terms of manufacturing efficiency to enclose the resin in a mold 4' and inject resin into the mold using an injection molding machine. In this case, since both the conductor of the main cable and the conductor of the branch cable are stranded conductors, during injection, the air in the mold is absorbed into the gap between the stranded conductors (of course, the stranded conductor is compressed and the compressed stranded conductor is compressed. However, it is impossible to completely seal the conductor strands, and there are usually small gaps between the conductor strands through which air can pass. Also, molds without voids are possible. However, this method has the problem that the cable, especially the cable sheath, is easily damaged by the injection pressure of the resin (the injection pressure here refers to the filling pressure in the mold, not the injection pressure, and is usually around 25k9/min). There is.

The resin molding method of the rubber/plastic cable connection part according to the present invention is a method that can eliminate the above-mentioned disadvantages, and the rubber/plastic branch cable is conductor-connected to the rubber/plastic main cable using a conductor connection fitting, and this conductor connection part is In this method, a resin is injected into the mold by surrounding it with a mold. An air chamber is provided in the mold interior space through a hole, and a part of the injected resin is released into the air chamber. This method is characterized in that the resin injection force is alleviated by compressed indoor air. The present invention will be explained below with reference to the drawings. In Fig. 2, 1 is a rubber/plastic trunk cable in which the conductor 11 is made of a stranded conductor such as copper or aluminum or a longitudinally stranded conductor, and 2 is a rubber/plastic trunk cable in which the conductor 21 is a stranded conductor such as copper or aluminum or compressed stranded. Rubber made of wire conductor
It is a plastic branch cable, and both cables 1.2 are connected by a conductor connection fitting 3.

In this case, the branch cables 2 are connected to the exposed conductor portions of the main cable 1 from which the insulation has been removed, and usually a large number of branch cables 2 are connected at predetermined intervals in the longitudinal direction of the main cable 1. 4 is a mold set on the conductor connection part, and has an air chamber 41, and this air chamber 41 and the space inside the mold are connected to the pongee hole 4.
It is passed through by 2.

The pores 42 are designed so that when the resin is injected into the mold, which will be described later, the resin flows into the air chamber 41 after being sufficiently removed from the mold. It is.
43 is a resin injection hole provided in the mold.

To carry out the present invention, resin G is added into the mold from an injection molding machine.
For example, injecting vinyl chloride compound.

This injected resin fills the inside of the mold with resin, and a portion of the resin flows into the air chamber. Therefore, the air in the air chamber is compressed and a compressed air layer is formed. In this case, the volume of the air chamber is determined by the ZO. of the resin injection space in the mold. If it is increased by 3 to 1.0 times, the compressed pressure of the air can be kept at about 12.5 to 19X9/c flow, and the resin pressure in the mold can be relaxed to the same extent as this compressed air pressure. Therefore, damage to the cable sheath due to resin pressure can be prevented. As described above, according to the present invention, it is possible to apply mold insulation to the conductor connection portion of a trunk cable with a branch cable by injection molding without causing damage to the cable.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a conventional resin molding method for a rubber/plastic cable connection portion, and FIG. 2 is an explanatory diagram showing a resin molding method according to the present invention. In the figure, 11 is a rubber/plastic trunk cable,
2 is a rubber/plastic branch cable, 3 is a conductor connection fitting, 4 is a mold, 41 is an air chamber, 42 is a pore, 43 is a resin injection hole, and G is a resin. Tsutomu'zu 2 illustrations

Claims (1)

[Claims] 1 A method in which a rubber/plastic branch cable is conductor-connected to a rubber/plastic trunk cable using a conductor connection fitting, this conductor connection part is surrounded by a mold, and resin is injected into the mold. A rubber/plastic cable connection part characterized in that an air chamber is provided which communicates through the air chamber, a part of the injected resin is released into the air chamber, and the resin injection pressure is alleviated by the air in the air chamber which is compressed by the released resin. Resin mold method.