JPH04127818A - Device for annexing cable - Google Patents

Abstract

PURPOSE:To protect the line path near the supporting point of an insulated cable from thunder stroke or inductive lightning stroke and also prevent the tracking of the cable by taking out a branch line from near the supporting point of the insulated covered cable, and connecting that branch cable to a cable clamp or the insulator metal fitting on the side of the cable, and making the cable conductor, the cable clamp, and the insulator metal fitting on the cable side electrically conductive. CONSTITUTION:A cable 1 is supported by an anchor clamp 2. Next, a branch cable 4, which has branched from the branch connector 3 attached to the vicinity of the anchor clamp 2, is connected to the insulator metal fitting 5a on the side of the cable. And if lightning stroke or inductive lightning stroke occurs in the line path, the short-circuit current by thunder surge passes the branch line 4, and runs between the insulator metal fittings 5a and 5b, and escapes from there to the earth side.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention improves lightning resistance and anti-tracking performance. This invention relates to an accessory device for edge-covered electric wires.

(Prior art) In recent years, insulated wires with an insulation coating layer have been used instead of the conventional bare wires for overhead power lines to prevent danger. It's becoming more common. This means that if a thunderbolt occurs,
This is because in bare wires, the follow-on arc point moves due to electromagnetic force, etc., whereas insulated wires have a coating, so the arc point is fixed, making it easy for the insulation coating to break down and the wire conductor to melt.

Furthermore, if the surface of the organic insulator used in insulated wires is wet or contaminated, dielectric breakdown may occur. That is, when moisture or electrolytic solution is present on the surface of such an insulator, a relatively large leakage current causes a temperature rise, resulting in local irregularities in surface resistance, and discharge occurs here. As a result, a portion of the surface dries, and the material is partially carbonized or eroded by the heat of the scintillation (local minute luminescent discharge) that occurs, and this progresses gradually, eventually leading to dielectric breakdown. This is called destruction by tracking.

Furthermore, if rainwater or other intrusion of insulated wires occurs through peeled-off insulation coatings such as wire connections or tie-down points, stress corrosion cracking may occur, which may lead to abnormal disconnection of the wire conductor. Sufficient watertight performance is required for electrical wire connections and tie-down points.

(Problem to be solved by the invention) As mentioned above, in the line near the support point of the insulated wire, 1
There are three important issues: ) lightning, 2) tracking, and 3) stress corrosion cracking. Here, we will introduce a wire attachment device that protects the line near the supporting point of the insulated wire from lightning strikes and induced lightning, prevents tracking of the wire, and also prevents stress corrosion cracking.It is particularly structurally simple and economical. The purpose is to provide it as a

(Means for solving the problem) Take out a branch wire from near the support point of the insulated wire, connect the branch wire to a wire clamp or wire side insulator metal fitting, and connect the wire conductor, wire clamp, and wire side insulator metal fitting to each other. It was made conductive.

Further, the clamp body grips the electric wire, and the conductor of the electric wire and the clamp member are electrically connected to each other by a conductor that penetrates the insulating coating of the electric wire.

(Example) This will be explained based on the diagram. In Fig. 1, 1 is an electric wire.

The electric wire 1 is supported by a retaining clamp 2. 3 is a branch connector attached near the retaining clamp 2. A branch line 4 branched from a branch connector 3 is connected to an insulator metal fitting on the wire side of an insulator 5. In FIGS. 2 and 3, 6 is an arc horn attached to the insulator 5.

The retaining clamp 2 here has a watertight structure in which the tooth-like protrusions of the wedge break the insulation coating of the electric wire and can always stably grip the core wire.

For example, the branch connector No. 3 (Fig. 5)
337 can be used. This connector is #! It has a cut-through that reaches the core of the torn electric wire with edge sheathing, allowing electrical continuity, and there is no need for post-treatment such as insulation or watertightness.If you use this connector, It is very easy to work with, as there is no need for peeling or compression.

The insulator 5 is attached to the end of the retaining clamp 2, and is sandwiched between an electric wire side insulator fitting 5a and a ground side insulator fitting 5b.

The insulator 5 is a tension-resistant insulator type in the case of FIG. 1, a suspended insulator type in the case of FIG. 2, and an LP insulator type in the case of FIG.

Figure 4 shows the branch connector 3 as in the embodiments of Figures 1N to 3.
In this embodiment, the Ik@edge covering conductor III is stripped, and the branch line 4 is connected by the C-shaped sleeve 7 at this part. After connection, it is necessary to perform insulation watertight treatment 8. 9
is a connection part on the insulator side of the branch line 4, and is connected with a terminal or a screw.

(Other Examples) Figures 6 and 7v! J is an example using a suspended electric wire clamp. 10 is the clamp body, 11 is the clamp body 1
0 and the electric wire 12 is clamped by both members. Numeral 13 is a bolt that fastens the clamp body 1° and the restraining member 11.

14 is a wire covering (insulator), and 15 is a covering protection collar made of rubber. The cover protection collar 15 is divided into two parts as shown in FIGS. 8 and 9, and is molded from ABS resin or the like. The electric wire 12 is connected to the clamp body 1o and the restraining member 1 from above the sheath 14 through the sheath protection collar 15.
It is held with 1.

16 (FIG. 12) has a hole 16a into which a conductive needle 18 is inserted as a conductor for bringing the clamp body and the wire conductor to the same potential with a fixing bolt, and a threaded portion 16b into which a tightening bolt 17 is screwed. ing. A hole 17a into which the conductive needle 18 is inserted is provided at the tip of the tightening bolt 17. The tip of the conductive needle 18 passes through the protective collar 15 and also through the wire sheath 14 to contact the conductor of the wire 12.

The electric wire 12 and the holding member 11 which is the electric wire gripping part are connected to the conductive needle 18
The electric wire and the grip are always at the same potential. Note that the restraining member 11 may be omitted; in this case, the electric wire 12 may be suspended and supported by the clamp body 10, and the electric wire 12 may be secured with a bolt 13 to prevent the electric wire from moving upward. Further, the covering protective collar 15 is not necessarily required.

FIG. 8 is an example of a tension clamp. This is the special public service from 1986-
This utilizes the retaining clamp disclosed in No. 56047.

As shown in FIG. 13, this includes a restraining part 21 that clamps the electric wire 2o in cooperation with a clamp body 19 that can be directly connected to the retaining insulator.
and a metal wedge 23 that is provided inside the clamp body 19 and the restraining part 21 and has a tooth-shaped protrusion 22 that can break the coating of the electric wire 20 and engage with the conductor core wire, and the clamp body 19 and the wedge 23 or the restraining part. The retaining clamp includes an insulating collar 23a interposed between the portion 21 and the wedge 23, and a tightening bolt 24 that presses the restraining portion 21 against the main body 19. A stopper 25 is provided.

In the above configuration, if the intervening insulating collar 23a is eliminated or made conductive, the tooth-like protrusion 22 of the metal wedge 23 can be used to prevent the clamp body 19 or the restraining part 2
1 and the wire conductor are electrically connected and have the same potential.

(Effect) Since the conductor of the insulated wire is electrically connected to the wire clamp or the insulator metal fitting on the wire side, in the event of a lightning strike or induced lightning on the line, the short-circuit current due to the lightning surge will pass through the branch line, and the insulator metal fitting will The wires run through the ground and escape from there to the ground side, which prevents damage to the wires and clamps and protects the lines.

Furthermore, if an arc horn is attached as shown in FIGS. 2 and 3, flashovers and discharges due to lightning surges between the insulator fittings will be more effectively carried out, and damage to the insulators and melting of the wires can be prevented.

In addition, even if the wire does not break during a flash fault, small holes in the insulation (
Pinholes (pinholes) often occur, but since these are eliminated, the watertightness of the wire is maintained, and stress corrosion can also be prevented.

Furthermore, the tracking phenomenon, which is a particular problem in salt-damaged areas, is effectively prevented because the electric wire and the anchoring part are at the same potential, eliminating the problem of potential difference on the surface of the insulator, and no leakage current occurs.

With a device in which the wire is gripped by the clamp body and the conductor of the wire and the clamp member are held in the same position by a conductor that penetrates the insulation coating of the wire, special devices such as connectors and connecting members are not required. It can be implemented immediately by improving some of the existing clamps, and is compact and inexpensive. The effect is also equivalent to the type that uses branch lines.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the present invention. FIG. 2 also shows the second embodiment. FIG. 3 also shows the third embodiment. Figure 4 shows an example in which no connector is used. FIG. 5 is a perspective view of a branch connector for branching the branch line. FIG. 6 shows a suspension clamp embodying the present invention. FIG. 7 is a right side view of FIG. 6. FIG. 8 is a plan view of the protective collar. Figure 9 is also a front view. Figure 10 shows the tightening bolt. Figure 11 shows the fixing bolt. Figure 12 shows the conduction needle. FIG. 13 shows a tension clamp according to the present invention. 1 Electric wire 2 Detention clamp 3 Branch connector 4 Branch wire 5 Insulator 6 Arc horn 5a (Wire side) Insulator metal fitting sb (Ground side) Insulator metal fitting 7 C Type sleeve 8 Insulating watertight treatment 9 (branch line) connection part 10 Clamp body 11 Holding member 12 Electric wire 13 Bolt 14 Electric wire coating
15 Cover protection collar 16 Fixing bolt 1
6a Hole 16b Threaded portion 17 Tightening bolt 17a Hole 18 Conductive needle clamp body 20 Wire holding portion 22 Toothed protrusion wedge 23a Collar tightening bolt 25 Stopper and above Applicant: Railway Technology Research Institute (one other person) representative Isamu Ohashi, Patent Attorney Figure 3 Figure 4 Figure 5 Figure 12 Figure 8

Claims (4)

[Claims] (1) A branch wire is taken out from near the support point of the insulated wire, and the branch wire is connected to a wire clamp or an insulator fitting on the wire side, and electrical continuity is established between the wire conductor, the wire clamp, and the insulator fitting on the wire side. An electric wire accessory device featuring: (2) The wire attachment device according to claim 1, wherein a branch connector is used to take out the branch wire. (3) An electric wire attachment device characterized in that a clamp body grips an electric wire, and the conductor of the electric wire and the clamp member are electrically connected to each other by a conductor that penetrates the insulating coating of the electric wire. (4) The electric wire accessory device according to claim 1 or 3, wherein an arc horn is provided on the electric wire side insulator fitting and the ground side insulator fitting.