JP3280502B2 - Cable terminal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable terminal, and more particularly to an improvement in a terminal of a bypass cable used for uninterruptible power works or as a transport or emergency cable.

[0002]

2. Description of the Related Art Conventionally, in order to avoid a power outage due to construction of a transmission and distribution line, or to provide an emergency power transmission in the event of an emergency, power can be supplied from outside the area using a bypass cable. Is being done.

[0003] As a terminal portion of such a bypass cable, for example, the following structure is known. That is, in this terminal portion, as shown in FIG. 4, a conductor 2 of a rubber or plastic cable 1 such as a stripped PN cable [ethylene propylene rubber (EP rubber) insulated chloroprene sheath cable] is attached to the terminal 2 by a conventional method. The conductor connection terminal 3 is connected, and a conical internal semiconductive portion 5 made of semiconductive EP rubber is provided from above the conductor connection terminal 3 to above the cable insulator 4. In addition, an insulation reinforcing tube having a terminal insertion port which tapers outwardly toward the end of the cable insulator 4 toward the outside thereof, and a cylindrical connection fitting 6 is integrally formed on the outer periphery of the distal end. 7
Are formed by an EP rubber mold, and three tin-plated soft copper braided wires 8 are vertically attached at regular intervals in the circumferential direction as lead wires on the insulating reinforcing cylinder 7. One end (tip) of each of the braided wires 8 is connected to the connection metal fitting 6, and the other end of the braided wire 8 is superimposed on a cable shielding braid 9 which is divided into approximately three equal parts and pulled out. It is connected by attachment. Further, on such a soldering portion, the cable sheath 1 is connected from the end of the connection fitting 6.
0, a protective and anticorrosive layer 11 is provided by a chloroprene rubber mold.

[0004]

By the way, in such a cable terminal, the connection fitting 6 and the cable shielding braid 9 are used.
If the connection with the terminal is incomplete, a voltage is induced in the connection fitting 6 in the case of one-end grounding, and there is a risk of electric shock when touched by a person. Therefore, the cable shielding braid 9 must be securely connected to the connection fitting 6 of the terminal via the lead wire.

However, the end portion of the bypass cable having the above structure is frequently bent at the time of use.
Since a tensile force is applied to the connection between the cable shielding braid 9 and the braided wire 8 (lead wire), there is a problem that the cable shielding braid 9 is easily cut at the soldered end. Then, when a break occurs in the cable shielding braid 9, in the case of one-end grounding, a voltage is induced in the connection fitting 6 as described above, and an electric shock accident may occur.

Conventionally, as shown in FIG. 4 , by measuring the electrical resistance between the connection metal fittings 6 at both ends of the cable 1, the cable shielding braid 9 described above is measured.
Is checked to confirm that the wire is securely connected to the connection fitting 6.

However, even when an abnormality is detected in the measured value, it is difficult to determine which side of the broken portion is the end portion, or whether it is the soldered end of the cable shielding braid 9 or the cable body. , It was difficult to determine clearly. Also, a connection fitting 6 is provided on one end.
However, when the shielding layer was not exposed on the surface, the above-mentioned resistance could not be measured.

[0008] The present invention has been made in view of such a point, and is a cable terminal that has good workability of confirming the continuity of a cable shielding layer and can easily and reliably detect an abnormality such as a disconnection. The purpose is to provide a part.

[0009]

According to the present invention, there is provided a cable terminal portion having a conductor connection terminal fixed to a conductor of a rubber or plastic cable which has been stripped, and an end of a cable insulator provided outside the conductor connection terminal. Straddling, providing a cylindrical insulating mold body in which a cylindrical connecting fitting is formed concentrically and integrally on the outer periphery of the distal end portion, and connecting the connecting fitting and the shielding layer of the cable via a lead wire. In the cable terminal portion which is connected and further provided with a protective anticorrosive layer from the end of the connection fitting over the sheath of the cable, the cable shield is provided on the outer surface of the cable sheath side end of the protective anticorrosive layer. It is characterized in that a conductor for conduction check electrically connected to the layer is embedded.

[0010]

In the cable terminal portion of the present invention, the conductor is embedded in the outer surface of the protective anticorrosion layer, and, since the conductor is connected to the cable shielding layer electrically, the exposed conductive material By measuring the electric resistance between the outer peripheral surface and the connection fitting fixed to the tip of the insulating mold body, it is possible to know whether or not there is a break in the soldered end of the cable shielding layer. Further, in this manner, the presence or absence of disconnection of the soldered end of the cable shielding layer can be determined for each side, and it is possible to determine which side of the terminal portion has an abnormality such as disconnection. Further, by measuring the resistance between the conductors at the terminal portions on both sides, the conduction of the shielding layer of the cable body can be confirmed.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a bypass cable terminal according to an embodiment of the present invention. In FIG. 1, parts common to FIG. 4 are denoted by the same reference numerals.

In FIG. 1, a conductor connection terminal 3 is connected to a conductor 2 of a rubber or plastic cable 1 such as a stripped PN cable by a conventional method.
A conical internal semiconductive portion 5 made of semiconductive EP rubber is provided from above to the cable insulator 4. In addition, there is provided a terminal insertion port which tapers outward toward the end of the cable insulator 4 toward the end of the cable insulator 4, and a cylindrical connection fitting 6 is integrally formed on the outer periphery of the tip. The reinforcing cylinder 7 is formed by an EP rubber mold,
Three tin-plated soft copper braided wires 8 are longitudinally attached on the insulating reinforcing cylinder 7 at equal intervals in the circumferential direction as lead wires. One end of each of the tin-plated soft copper braided wires 8 is connected to the connection fitting 6, and the other end thereof is overlapped with the end of the cable shielding braid 9 and soldered.

In this embodiment, as shown in FIG. 1, a metal ring 1 made of brass or the like and having a flange 12a on the inside is formed on the outer surface of the end of the protective and anticorrosive layer 11.
2 is buried, and a cable shielding braid 9 is directly or other conductively mounted on a flange 12a inside the metal ring 12.
They are connected by soldering or the like via wires .

Such a cable terminal is formed, for example, as follows. First, the conductor connection terminal 3 is connected to the conductor 2 of the rubber or plastic cable 1 such as a PN cable, which has been stripped off, in a conventional manner, and then the conductor connection terminal 3 and the cable insulator 4 are integrally formed by EP rubber molding in advance. It has a conical inner semiconductive portion 5 made of a semiconductive EP rubber mold on the inner periphery, a cylindrical connecting metal fitting 6 on the outer periphery of the tip, and is tapered toward the terminal. An insulating reinforcing cylinder 7 provided with a terminal insertion port 6a having a diameter increased in a shape is fitted. Next, three tin-plated annealed copper braided wires 8 are vertically attached at equal intervals in the circumferential direction as lead wires, and both ends of these braided wires 8 are connected to the connection metal fitting 6 and the cable shielding braid 9. Each end is connected by soldering or the like. Next, on the braided wire 8 and the like, the protective anticorrosion layer 1 in which a metal ring 12 is embedded on the outer surface of the end portion by integral molding of chloroprene rubber from the end of the connection fitting 6 to the cable sheath 10.
Form one. At this time, the end of the cable shielding braid 9 or the end of the conductor connected thereto is connected to the metal ring 12.
Is connected to the flange 12a by soldering or the like.

In the present invention, the metal ring 1 is used.
2 may have a split structure, and silver paint may be used in place of such a metal ring 12. Further, such a conductor may be partially provided on the outer surface.

Next, a method for confirming the presence or absence of a break in the cable shielding braid 9 in the bypass cable using such a terminal will be described.

First, the disconnection between the connection portions of the connection fitting 6 and the braided wire 8 of the cable shielding braid 9 at the terminal is caused by connecting the electrode terminals to the connection fitting 6 and the metal ring 12 as shown in FIG. Are brought into contact with each other, and the electric resistance between them is measured. When conduction is obtained, it is determined that there is no disconnection, and when conduction is not obtained, it is determined that there is disconnection.

Next, the disconnection of the cable shielding braid 9 in the cable body is determined in the same manner as described above by measuring the electric resistance between the metal rings 12 at both ends.

The terminal portion of the present invention can be widely applied to any terminal portion of a rubber or plastic cable whose shielding layer needs to be grounded, in addition to the bypass cable. In addition, outside the end of the protective and anticorrosion layer 11,
Normally, a protective cover made of EP rubber or the like is detachably fitted, and the metal ring 12 is covered with the protective cover except at the time of contact of the measurement electrode terminal for checking conduction.

[0021]

As described above, in the cable terminal portion of the present invention, by measuring the electric resistance between the conductors at both ends of the cable or between the conductor and the connection fitting at each terminal, Abnormalities such as disconnection between the cable shielding braid in the cable main body or the connection portion between the connection metal fitting 6 and the braided wire 8 of the cable shielding braid 9 at the cable terminal can be easily and reliably detected, and the disconnection location can be detected. Discrimination is also easy.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a bypass cable terminal according to an embodiment of the present invention.

FIG. 2 is a view for explaining a method of confirming the presence or absence of a break in the cable shielding braid in the embodiment.

FIG. 3 is a longitudinal sectional view showing a conventional bypass cable terminal portion.

FIG. 4 is a view for explaining a method of confirming whether or not a cable shielding braid is disconnected in a conventional bypass cable terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rubber and plastic cable 2 ... Cable conductor 3 ... Conductor connection terminal 4 ... Cable insulator 5 ... Internal semiconductive part 6 ... Connection metal fitting 7 ... Insulation reinforced cylinder 8: Tin-plated soft copper braided wire 9: Cable shielding braid 10: Cable sheath 11: Protective anticorrosion layer 12: Metal ring

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 3-124735 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02G 15/02

Claims (1)

(57) [Claims] 1. A conductor connecting terminal is fixed to a conductor of a rubber or plastic cable which has been peeled off stepwise, and a tubular member is formed on the outer periphery of the distal end portion over the end of a cable insulator outside the conductor connecting terminal. A connecting metal fitting is provided concentrically and integrally formed with a cylindrical insulating molded body, the connecting metal fitting and the shielding layer of the cable are connected via a lead wire, and further from the end of the connecting metal fitting. In a cable terminal portion provided with a protective anticorrosion layer over the cable sheath, on the outer surface of the cable sheath side end of the protective anticorrosion layer, a continuity check electrically connected to the cable shielding layer A cable terminal portion having a conductor embedded therein.