JPS6112622B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for branching and connecting three-phase coaxial power cables.

A three-phase coaxial power cable is a cable in which conductors 1, 2, and 3 constituting a three-phase line are arranged coaxially through insulators 4, 5, and 6, as shown in Figure 1. , has been attracting attention in recent years as an efficient cable with low voltage drop.

By the way, when taking out the intermediate branch of this type of three-phase coaxial cable, as shown in Figure 2, first cut the cable, bundle each conductor 1, 2, and 3 together, and then remove the terminal part of each conductor. to terminal 7
are attached by crimping, and the same phase to be connected and the terminal 7 attached to the terminal part of the branch line 8 are also added, and connected with bolts 9 and nuts 10 as shown in Fig. 3. After that, insulation treatment is performed for each phase. 11 methods were used.

However, with this method, the branch connection becomes very large compared to the outer diameter of the cable main body, and for example, if this branch connection is prefabricated, it is extremely difficult to wrap it around a drum. When extending a prefabricated cable that has already been made a branch connection in order to be cut, tension is applied to the connection terminal, causing performance problems.

In view of the above points, the present invention solves the drawbacks of the prior art described above, provides a compact branch connection, and has sufficient strength against pull-in tension, that is, a connection that can be prefabricated. This cable was developed with the aim of providing a three-phase coaxial power cable, and its gist is that the conductors constituting the three-phase line are arranged coaxially through each insulator. At the intermediate branch connection part of a phase-coaxial power cable, a process of cutting the intermediate layer and the outer layer conductor without cutting the inner layer conductor, and stripping off the insulation to expose the inner layer conductor, and a process of connecting the branch line to the exposed inner layer conductor. , a process of applying insulation treatment to the outer periphery, a process of connecting the once cut intermediate layer conductor to the outer periphery and connecting a branch line and applying insulation treatment, a process of connecting the once cut outer layer conductor to the outer periphery and branching. A method for branching and connecting three-phase coaxial power cables, comprising the steps of connecting wires and applying insulation treatment.

An embodiment of the branch connection method of the present invention will be further described with reference to the accompanying drawings.

First, as shown in FIG. 4, after the outer layer conductor 3 and the intermediate layer conductor 2 are cut, the insulators 4, 5, and 6 are stripped in stages, and the inner layer conductor 1 is exposed without being cut.

Each of the conductor wires of the intermediate layer conductor 2 and the outer layer conductor 3 is divided into two or more groups.

Next, as shown in FIG. 5, a branch line 8 is connected to the inner layer conductor 1 using a C-shaped connector 12 as shown in FIG. 9, and an insulation treatment 13 is performed.

Next, as shown in FIG.
The branch line 8 is connected using a branch connector 14 as shown in the figure.

The branch wire 8 is divided into two parts corresponding to the divided wires of the intermediate layer conductor 2 and connected by a connector 14, but the branch wire 8 is connected to one group of wires and connected to the other wire group. It is also possible to provide a crossover wire to eliminate the bias in the in-phase current.

The structure of the connector 14 is such that only one hole is enlarged so that the intermediate layer conductor 2 and the branch line 8 can be inserted into one hole, and the intermediate layer conductor 2 can be inserted into the other hole.

After the branch connection between the intermediate layer conductor 2 and the branch line 8 is completed, this connection portion is placed in close contact with the insulation treatment portion 13 of the inner layer conductor connection portion, and insulation treatment 15 is performed.

Furthermore, as shown in FIG. 7, the branch connection of the outer layer conductor 3 is performed in the same manner as the branch connection of the intermediate layer conductor 2, and after the branch connection, the insulation treatment 16 is performed to complete the branch connection.

In terms of space, it is preferable that the connecting portions of the outer layer conductor 3 are shifted in the circumferential direction so that they do not overlap with the connecting portions of the intermediate layer conductor 2.

The connection section of this embodiment constructed in this way has a very compact finish because the conductor connection sections are arranged on top of each other in a roughly coaxial manner through each insulator, and are in close contact with each other. Become.

In addition, since the wires of the intermediate layer conductor and the outer layer conductor are divided into multiple groups and connected, the connector can be made smaller, and the tools for crimping it can be small and easy to handle. This has the advantage of improving workability and making the finished size more compact.

As a result, even if the intermediate branch of a three-phase coaxial cable is prefabricated, it can be easily drum-wound, and even when a prefabricated branched cable is extended, the tension can be divided by the inner layer conductor. The present invention has great industrial value because it allows safe installation without applying excessive tension to the connector connection portion.

[Brief explanation of the drawing]

Fig. 1 is an explanatory cross-sectional diagram showing an example of a three-phase coaxial cable, Fig. 2 is an explanatory diagram showing an example of a conventional branch connection part, Fig. 3 is an explanatory diagram showing an example of the conductor connection part, 4 to 7 are explanatory diagrams sequentially showing one embodiment of the connection method according to the present invention, and FIGS.
The figure is an explanatory diagram showing an example of a connector used therein. 1: Inner layer conductor, 2: Intermediate layer conductor, 3: Outer layer conductor, 4, 5, 6: Insulator, 7: Terminal, 8:
Branch wire, 9: Bolt, 10: Nut, 11: Insulation processing section, 12: C type connector, 13: Insulation processing section, 14: Connection branch connector, 15, 16: Insulation processing section.

Claims (1)

[Claims] 1. At the intermediate branch connection of a three-phase coaxial power cable in which the conductors constituting the three-phase line are arranged coaxially through each insulator, the intermediate and outer layer conductors are connected without cutting the inner layer conductor. A process of cutting and stripping off the insulator to expose the inner layer conductor, a process of connecting a branch line to the exposed inner layer conductor, a process of applying insulation treatment to the outer periphery, and then a process of connecting the intermediate layer conductor that has been cut once at the outer periphery. A three-phase coaxial power cable characterized by comprising a process of connecting branch lines and applying insulation treatment, and a process of connecting an outer layer conductor once cut at the outer periphery, connecting the branch lines and applying insulation treatment. Branch connection method.