JPS59153414A - Sheath displacement preventive structure of power cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a structure for preventing sheath displacement of a power cable in a power cable end fixing structure that uses a bracket to fix the end of the power cable.

Description of Prior Art FIG. 1 is a partial sectional view showing a conventional power cable end fixing structure. For example, an electric cable 1 such as a crosslinked polyethylene insulated polyethylene sheath cable (hereinafter abbreviated as GE cable) has a cable insulation 2 exposed over a predetermined length at its end. A conductor 3 is further exposed and extends from the tip of the cable insulation 2, and is connected to a compression type terminal 4. Conductor 3 and terminal 4
An insulating tape 5 is wound around the connecting portion, and a vinyl protective tape 6 is further wound around the insulating tape 5. A head 7 is fixed below the connection portion between the conductor 3 and the compression type terminal 4 to prevent rainwater from entering. Furthermore, as is clear from Fig. 1, the cable insulation 2
A protective tape 6 is wrapped around the entire circumference.

On the other hand, at the end of the GE cable 1 where the cable insulation 2 is exposed, a thin copper tape 8 and a conductor M'A 9 are applied.
J3 and cable insulation 2 are exposed in this order. Although not particularly shown, a grounding wire is wound around and connected to the copper tape 8 around the shell 1b. A bind wire 10 is connected to the conductive layer 9, and is wound around the cable insulation 2 and extended outside the insulation tape 11.

Note that a protection 7-b 6 is also wound around the outside of the binding wire 10 over the entire circumference. Further, at the end of the GE cable 1, a protective cable 16 is wound around each exposed shielding copper cable 18 and S electric cable Fi9.

By the way, the end of the conventional GE cable 1 is fixed to the bracket 12 via jute m. However, as is clear from FIG. 2, which shows an enlarged view of this fixed part, the cable sheath 14 is held by the cable sheath 14 through the cushion layer 13 made of burlap or the like.
There is nothing that prevents the cable sheath 14 from shifting in the cable axial direction. However, there was a problem in that it was not possible to prevent the cable sheath 14 from shifting.However, since the protective tape 6 was wound around the outer circumference of the cable sheath 14, the winding of this tape Due to blood pressure, a horn is generated that prevents the cable sheath 14 from slipping slightly.However, this preventing force is necessarily extremely weak, and therefore the force required to effectively prevent the cable sheath 14 from slipping is small. It couldn't be.

As described above, the conventional end fixing structure of the GE cable 1 does not effectively prevent displacement of the cable sheath 14. As a result, water often enters due to exposure of the internal structure, or the internal shielding copper tape is cut, which is an extremely large cause of destruction of the CE cable 1. Therefore, the conventional end fixing structure of the GE cable 1 has various drawbacks such as requiring complicated collection work and shortening the cable life.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a structure for preventing sheath displacement of an electric cable, which eliminates the above-mentioned drawbacks and effectively prevents displacement of the cable sheath.

In summary, this invention includes a metal vibrator having a wavy portion on the inner surface and being inserted into and fixed to a cable sheath, and a retaining cotton connecting this metal vibrator and a bracket (-). This structure prevents the sheath fraying of the power cable, which is fixed to the cable sheath to prevent the softened cable sheath from dissolving and assimilating into the wavy portion of the inner surface of the cable sheath.

Preferably, the metal vibrator is provided with a slit RQIJ extending in the axial direction of the cable, which gives flexibility to the metal vibrator and prevents J to the internal components of the power cable.
It can prevent shadows.

Other objects and features of the invention will become more apparent from the following description of the embodiments, which is given in conjunction with the drawings.

DESCRIPTION OF THE EMBODIMENTS FIG. 3 is a partially sectional front view of an alternative structure for fixing the end of a power cable to which the present invention is applied, and is a view corresponding to FIG. 1 shown in the prior art.

FIG. 4 is a front view C showing a metal vibrator used in an embodiment of the present invention, and FIG. 5 is an enlarged view of a part of FIG. 3, showing an embodiment of the present invention. FIG.

The features of this embodiment are the metal vibrator 21 and the bracket 1.
2 and this metal vibrator 21 is provided with a pull line 22 made of a metal wire.

The other structure is the same as the end fixing structure of the conventional power cable shown in FIG. 1, and therefore the description thereof will be omitted by assigning corresponding reference numbers to corresponding parts. Note that 16 does not indicate a grounding wire.

By the way, as described later, the metal vibrator 21 is fixed to the cable sheath 14. Therefore, even if an external force is applied that causes the cable sheath 14 to shift in the seven directions shown in FIG. can be effectively prevented.

Next, the metal vibrator 21, which is a characteristic configuration of the present invention, will be explained. As can be clearly seen from FIG. 4, the metal pipe 21 has a wavy uneven portion 21a on its inner surface, and sleeves I to 21b are provided in the cable axis direction GJ. The slit 2111 is provided to impart flexibility to the metal pipe 2. Due to this flexibility, the metal pipe 21 can smoothly follow the expansion and contraction of the cable sheath that is inserted inside it, and is able to respond to heat cycles when the cable is energized or temperature changes in the outside air. Effectively prevents adverse effects on the cable's internal components.

Next, the process of implementing this embodiment will be explained with reference to FIG. First, process the electric cable terminal as specified,
Determine the mounting position of the bracket 12. Next, a metal pipe 21 is installed on the side of the electric cable where the bracket 12 is attached, that is, on the opposite side and adjacent to the terminal of the electric cable.

Metal pipe 21 attached to the outside of the couple sheath 14
The synthetic resin constituting the cable sheath 14 is softened by heating (by heating, for example, with a dryer). A portion of the softened cable sheath 14 is eluted into the wavy uneven portion 21a on the inner surface of the metal pipe 21. After that, it is left as it is. Alternatively, if forced cooling is performed, the eluted synthetic resin will harden and the metal pipe 21 will be fixed to the couple sheath 14.Next,
The other ends of the pair of retaining wires 22 connected to the metal pipe 21 are connected to ports i to 12a of the bracket 12. Finally, the metal pipe 21 is sealed by wrapping an insulating tape and a protective tape 6 around the metal pipe 21.

- [As mentioned above, since the metal pipe 21 is connected to the bracket 12 by the retaining wire 22, even if the couple sheath 14 tries to move in the 7 directions in FIG. It does not exceed the length of the tie line 22. Therefore, displacement of the cable sheath 14 is effectively prevented.

Above) In the book's actual example, the pull line 22 was made of a metal wire, but the pull line 22 is not limited to this.

For example, it may be an elongated metal plate or a band made of a rigid material other than metal. In short, the material a5 and its shape do not matter as long as the metal pipe 21 can be maintained at a constant distance from the bracket 1 to the metal pipe 12. It should also be pointed out that the slit 211 formed in the metal pipe 21 is not an essential feature of the present invention. However, the slit 21b is provided in the metal pipe 21 because it gives flexibility to the metal pipe 21 and prevents the adverse effects on the internal components of the couple due to machining.
It is preferable to set up

Effects of the Invention As described above, the present invention includes a metal pipe that has a wavy portion on the inner surface and is inserted through and fixed to the gooble sheath, and a pull wire that connects this metal pipe to the bracket 1. Since the metal pipe is fixed to the cable sheath by eluating and assimilating the cable sheath softened by heating into the wavy part of its inner surface, it is possible to prevent the sheath f of the electric cable from 1 to 1 in the electric cable end fixing structure. It can be extremely effectively and effectively prevented. Therefore, it is possible to prevent damage to the power cable due to exposure of internal components or cutting of the shielding copper tape due to misalignment of the cable sheath, and also eliminates the need for repair work that was previously required. It is possible.

This invention is not limited to the power cable of the above-mentioned embodiment,
It should be pointed out that it is applicable to all power cables having a synthetic resin sheath.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view showing a conventional power cable end fixing structure. FIG. 2 is a partially sectional view showing an enlarged main part of FIG. 1. FIG. 3 is a partial sectional view showing one embodiment of the present invention, and corresponds to FIG. 1. Fourth
The figure is a side view showing a metal pipe used in one embodiment of the present invention. FIG. 5 is a partially sectional side view showing an enlarged main part of FIG. 3. FIG. 1... Electric cable, 12... Bracket, 14.
... Cable sheath, 21... Metal pipe, 21a.
...Wavied portion, 21b...Slit, 22...Handling line. Ino 1 diagram

Claims (1)

[Claims] ('1) An electric cable end fixing structure that uses a bracket to fix an electric cable end (a structure for preventing sheath slippage of an electric cable, which has a wavy portion on the inner surface). ,
A metal pipe is inserted through and fixed to the cable sheath, and a retaining line connects the metal vibrator and the bra goods 1 to 1. This structure prevents the sheath of the power cable from slipping, which is fixed to the cable sheath. (2) The sheath slippage prevention structure for a power cable according to claim 1, wherein the pipe is provided with a slit extending in the axial direction of the cable.