JPS63211390A - Insulated rope for transmission line - 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 [Industrial Field of Application] The present invention relates to an insulating rope for power transmission lines, and particularly to an insulating rope for power transmission lines suitable for use in work such as relining overhead ground wires in a live line state.

[Prior Art] When replacing overhead ground wires during power transmission line work, it has become common to perform the work while keeping co-extended power lines in a live state.

Conventionally, the insulating rope used for this type of re-stretching work (the rope used to hold the overhead ground wire for re-stretching at a certain height) is made of aromatic polyamide organic fibers that are lightweight, have high tensile strength, and have high electrical insulation properties. Ropes are widely used.

Fig. 3 is an explanatory diagram of the implementation status of the overhead ground wire relining work, in which 6 is an insulating rope made of aromatic polyamide organic fiber, 7 is the existing overhead ground wire, and 8 is, for example, an optical fiber composite overhead ground wire. (OPGW), etc., 9 is a live power line, 10 is a steel tower, 11 is a single metal wheel, 12 is a circle metal wheel, and 13 is a delivery drum. The insulating rope 6 is fixed and grounded to the steel tower 10, and the circle metal wheel 1
2 are fixed and suspended from the rope 6 at intervals of 30 to 50 m, and the existing overhead ground wire 7 and the newly installed overhead ground wire 8 connected thereto are connected to the single metal wheel 11 and the circle metal wheel 12. The exchange will take place through .

When the power line 9 is in a live state, an induced voltage is generated in the overhead ground wire 7.8 and the insulating rope 6 due to electrostatic induction and electromagnetic induction, but since the overhead ground wires 7 and 8 are good conductors,
The induced voltage is released by grounding the drum 13 or the like. On the other hand, the induced voltage induced in the insulating rope 6 is
Since the insulation resistance of the rope 6 is extremely high, almost no current flows even if it is fixed to the steel tower 10 and grounded.

However, when a portion of the rope 6 is submerged in water, the insulation of this portion is extremely reduced and a current flows, causing local heat generation in the rope 6 and reducing its strength. For example, in the case of a rope made of aromatic polyamide organic fiber, when the exothermic temperature reaches about 200° C., the tensile strength decreases to less than half, and in the worst case, there is a risk of wire breakage.

Under these circumstances, in order to prevent water from entering the fiber rope, a waterproof coating layer made of synthetic resin such as polyurethane, vinyl, polyethylene, polyester, or rubber or the like is usually provided around the outer periphery of the fiber rope.

[Problems to be Solved by the Invention] An insulating rope subjected to this kind of water immersion prevention treatment was proposed, for example, in Japanese Patent Laid-Open No. 58-207806, but the outermost waterproof coating layer was damaged. If a nail or the like pierces the fiber rope, a hole will be formed at that location, and water will enter the fiber rope through this hole due to capillary action. Additionally, there is a problem in that moisture can enter due to the breathing effect caused by the expansion and contraction of the fiber rope due to changes in temperature.

In the event that water intrudes into the fiber rope, if the location of the inundation can be known in advance, accidents such as breakage of the insulating rope can be prevented in advance.

The present invention has been made in view of the above points, and an object of the present invention is to provide an insulating rope for power transmission lines in which the presence or absence of moisture intrusion can be confirmed in advance.

[Means for Solving the Problems] That is, the gist of the present invention is to provide an insulating rope for power transmission lines, which has a core made of a fiber rope made of a plurality of twisted fibers, and a waterproof coating layer provided on the outer periphery of the fiber rope. A feature is that an intermediate layer made of a moisture-sensitive material is provided inside the waterproof coating layer. For the middle layer, a moisture-sensing material is applied all over or intermittently around the fiber rope, or a tape-like material (paper tape, string, etc.) is used.
It is formed by enclosing it in a container and winding it or vertically attaching it.

[Function] A middle layer made of a moisture-sensing material is provided inside the waterproof coating layer, so if a hole occurs in the waterproof coating layer due to trauma and moisture enters, the middle layer will change in color or shape. By checking this with the naked eye or touch, the location of flooding can be determined.

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

FIG. 1 is a cross section showing one embodiment.

In Fig. 1, 1 is a fiber rope 1 formed by twisting together a large number of aromatic polyamide fibers 1a.2 is a fiber rope 1 formed by applying a material that changes color by absorbing moisture, such as silica gel, on the circumference of the fiber rope 1. The middle layer 2.3 is a waterproof coating layer 3 made of transparent polyurethane. Silica gel is a material that is known to be a highly adsorbent substance, has the property of absorbing moisture, and normally exhibits a blue color, but when it absorbs moisture, it changes color to red.

In the case of an insulating rope having such a structure, if a hole is generated in the waterproof coating layer 3 due to trauma and moisture enters through the hole, the color of the middle layer 2 changes from blue to red only in the water-inundated area. By visually checking through the semi-transparent waterproof coating layer, it is possible to easily identify the location of water intrusion, and it is now possible to easily identify water intrusion through minute holes, which were previously difficult to detect.

FIG. 2 is a sectional view showing another embodiment of the present invention, and the difference from the previous embodiment is that a plurality of strands 5 each having a waterproof coating layer 4 provided on the outer periphery of the fibers 1a are twisted together. rope 1
The second point is that the middle layer 2 is formed by winding a paper tape 2a coated with silica gel and wrapped around a fiber rope 7. Similar effects can be obtained in this embodiment as well.

In addition, when applying silica gel on one circumference of the fiber rope, it may be applied intermittently rather than on the entire surface, or when the paper tape 2a coated with silica gel is wound around the circumference of the fiber rope l, the intervals may be adjusted as appropriate. If necessary, it can be easily wound with gaps in between, and paper string or the like may be used instead of paper tape to hold it vertically.

In this way, the identified flooded area can be reused as a complete insulating rope without any flooded areas by cutting and removing this length and reconnecting it.

Although an example in which a material that changes color when absorbing moisture is used as a moisture-sensing material has been described above, the present invention is not limited to this. For example, materials that absorb moisture and expand, such as water-absorbing polymers or cement It may also be a material that absorbs moisture and hardens, such as Ceracola. In this case, the intrusion of moisture is manifested by the phenomenon of expansion or hardening of the material, so this can be easily confirmed and determined by the naked eye or touch.

[Effects of the Invention] As explained above, according to the insulating rope for power transmission lines of the present invention, it is possible to easily confirm and determine in advance the location of water intrusion from holes etc. that have occurred in the waterproof coating layer, and the rope can be cut. It is possible to prevent such accidents in advance.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing one embodiment of the insulating rope for power transmission lines of the present invention, and FIG. 3 is an explanatory diagram of the implementation status of overhead ground wire re-covering work in a live line state. 1: Fiber rope, 2: Middle layer made of moisture-sensing material, 3.4: Waterproof coating layer, 5: Cable line, 6: Insulated rope, 7: Overhead ground wire (existing), 8: Overhead ground wire (new), 9: Power line, 10: Steel tower, 11 Ni single metal wheel, 12: Circle metal wheel, 13: Delivery drum. Taste 1 No. 2 Diagram i line 5

Claims (4)

[Claims] (1) The core is a fiber rope made by twisting multiple fibers,
What is claimed is: 1. An insulating rope for a power transmission line, comprising a waterproof coating layer provided on the outer periphery of the insulating rope, characterized in that an intermediate layer made of a moisture-sensing material is provided inside the waterproof coating layer. (2) The insulating rope for a power transmission line according to claim 1, wherein the middle layer is formed by applying a moisture sensing material all over the circumference of the fiber rope or intermittently. (3) The insulating rope for power transmission lines according to claim 1, wherein the middle layer is formed by winding or longitudinally attaching a tape-like body containing a moisture-sensing material. . (4) The moisture sensing material is a material that changes color when it absorbs moisture, and the waterproof coating layer is made of a transparent or translucent material. The insulating rope for power transmission lines according to item 2.