JPH0547447A - Method for making cable branch connection watertight - Google Patents

Abstract

PURPOSE:To easily make a wiring branched connection watertight by providing a waterproof admixture piece to give a larger compressed deformation amount than a waterproof admixture, and compressing the admixture layers for close adhesion via the coherence of a cover. CONSTITUTION:A piece 4 of a viscous and elastic admixture to give a larger compressed deformation amount than a waterproof admixture layer 21 is provided in a gap between main and branch lines in such a way as superposed on the layer 21. In this state, a cover 1 is bent along a center folding line and cohered on the branch connection of a wire. Also, a lug section is bonded to the cover l and the layer 21 is compressed. In this case, the layer 21 is compressed, according to the coherence of the cover 1. Compression stress acting on both the layer 21 and the piece 4 can be made virtually equivalent, due to the viscous and elastic characteristics thereof and, therefore, the compressed deformation amount of the layer 21 can be made small. The reduction of the compressed deformation amount restrains an increase in the gap for loading the piece 4, due to the deformation thereof. As a result, the gap can be completely filled and made watertight, in conjunction with the large deformation amount of the piece 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for making a branch connection portion of an overhead distribution line watertight.

[0002]

2. Description of the Related Art In overhead distribution lines, in order to prevent stress corrosion of a copper conductor, it is necessary to use a covered wire for the wire and to make the wire connection portion watertight. However, the branch connection portion of the electric wire is more complicated in shape than the straight connection portion, and it is difficult to perform the watertightening treatment by the normal tape winding method.

Therefore, the applicant of the present invention compresses the waterproof admixture layers at both inner ends of the cover by tying the covers having the waterproof admixture layers on the inner surfaces of both ends on the branch connecting portions of the electric wires. However, it has already been proposed to seal both ends of the cover with this compression waterproof mixture layer (Japanese Patent Publication No. 55-2436).

This watertightening treatment method is easier to work than the tape winding treatment method, and is superior to the tape winding treatment because of the pressure deformability based on the viscoelasticity of the waterproof admixture layer. Can be expected.

[0005]

However, if the gap between the main line and the branch line at the location of the waterproof mixture seal is 10 mm or less, it is difficult to completely fill the gap with the waterproof mixture layer. .. An object of the present invention is to provide a method capable of treating a branch connection part of an electric wire with excellent watertightness by the cover method.

[0006]

According to the method for watertightening an electric wire branch connection portion according to the present invention, a cover having a waterproof admixture layer provided on the inner surface of each end portion is tied to the electric wire branch connection portion, and both ends in the conjugate are connected. In the method of making watertight with the waterproof admixture layer, a pace of the waterproof admixture having a larger amount of compressive deformation than the waterproof admixture is interposed between the main line and the branch line, and by conjugating the cover. The waterproof admixture layer is compressed and the waterproof admixture piece is compressed to bring them into close contact with each other.

[0007]

Since the waterproof admixture piece between the main line and the branch line is deformed by a large amount of compressive deformation, excellent watertightness can be guaranteed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A shows the cover used in the present invention.
FIG. 1 (B) is a developed plan view showing an example of FIG.
FIG. 6 is a sectional view taken along line ‘ In FIGS. 1A and 1B, 1 is a cover body (eg, polyethylene resin, polypropylene resin, polystyrene resin, AB).
(Made of S resin), and the folding line 11 is provided at the center.
Side walls 12 and 12 each having a bulge shape are provided on both sides of the side wall, and ears 13 and 13 are provided on the side walls 12 and 12, respectively. Reference numerals 21 and 22 denote waterproof mixture layers having viscoelasticity provided on the inner side surfaces of both ends of the cover body, for example, those containing rubbers such as butyl rubber and ethylene-propylene-terpolymer as a main component. Can be used.

FIG. 2 shows a branch connection portion of an overhead distribution line treated according to the present invention, and the ear portions 13 and 13 of the cover-1 described above.
Is bonded on the branch connection portion of the electric wire by adhesion with the adhesive, and the branch wire (insulation covered wire) 31 is attached from one end side of the cover-1.
Is pulled out, and the branch line 31 and the main line (insulated line) 30
The waterproof admixture piece 4 is interposed between and in contact with the waterproof admixture layer 21 on one end side of the cover.
The cloth 4 and the waterproof admixture layer 21 are closely integrated.

To water-tighten the branch connection part of the electric wire according to the present invention, first, the cover-1 is placed in the electric wire branch connection part in the expanded state, and then the cover on the branch line drawing side. At the position of the waterproof admixture layer 21 at one end, at least the piece of the viscoelastic admixture having a larger amount of compressive deformation than the waterproof admixture layer 21 is provided in the gap between the main line and the branch line. A part of the cloth is interposed so as to cover the waterproof admixture layer 21, and in this state, the cover is bound on the branch connection part of the electric wire by bending the central folding line to bond the ear part and to waterproof. Compress the admixture layer. In this case, the cover
As they are bound together, the waterproof admixture layer is compressed.

FIG. 3 shows a state during compression, wherein 1 is a cover, 30 is a main line, 31 is a branch line, 21 is a waterproof admixture layer, 4 is a waterproof admixture piece, 5, … Indicates each gap.

In FIG. 3, since the electric wires 30 and 31 are close to a rigid body to the waterproof mixture, the waterproof mixture piece 4 is compressed in the direction a, and the compression is caused by the deformation based on the Poisson's ratio. A lateral (b) direction expansion of the admixture piece 4 occurs, and this expansion causes the waterproof admixture layer 21 to be pressed and compressed in the o direction. In this case, since the waterproof admixture layer 21 and the waterproof admixture piece 4 both have viscoelasticity,
The compressive stress (pressure) acting on the waterproof admixture layer 21 and the waterproof admixture piece 4 is substantially equal.

Therefore, the waterproof admixture layer 21 under the same pressure
Is smaller than that of the waterproof admixture piece 4, and the compressive stress acting on the waterproof admixture layer 21 and the admixture piece 4 is due to their viscoelasticity. For example, the waterproof admixture piece 4 can be made substantially the same.
In comparison with the case where the same amount of compressive deformation as the waterproof admixture layer 21 is used, the amount of compressive deformation of the waterproof admixture layer 21 in the direction B can be reduced. This reduction in the compression deformation amount of the waterproof admixture piece suppresses an increase in the gap to be filled due to the deformation of the waterproof admixture piece 4, so that the deformation amount of the waterproof admixture piece is large. Combined with that, the above gap 5, ...
Can be completely filled.

Actually, a load of 1 k is applied to the waterproof mixture layer of the cover.
g Use a viscoelastic body with a compression deformation amount of 20% per minute, and use a viscoelastic piece with a 20% compression deformation amount between the main line and the branch line (gap of 10 mm). As a result, 30% of the voids remained, but the viscoelastic piece had 25
When the one with a% compressive deformation amount was used, the remaining voids could be reduced to zero. Further, a viscoelastic body having a compressive deformation amount of 40% per minute under a load of 1 kg is used for the waterproof mixture layer of the cover, and is interposed between the main line and the branch line (gap of 10 mm). −
When a 60% compressive deformation amount was used for the cloth, residual voids could be reduced to zero.

In the present invention, the ratio of the compression deformation amount of the waterproof admixture layer of the cover to the compression deformation amount of the waterproof admixture piece is 1
The effect of improving the watertightness described above becomes smaller as the temperature becomes closer to. Therefore, it is effective to set the ratio to 1.2 or more.

In the water-tight branched connection portion of the electric wire according to the present invention, the waterproof admixture layer having a small amount of compressive deformation bears the weight of the cover, and the waterproof admixture piece having a large amount of compressive deformation does not exist. Since it is not necessary to apply the weight of the cover, the watertightness can be stably maintained for a long period of time.

[0017]

As described above, according to the watertightening method of the electric wire branch connecting portion of the present invention, the cover having the waterproof admixture layer provided on the inner side surfaces of both ends is joined to the electric wire branch connecting portion. In the case of water-tightening the branch connection portion by simply inserting a waterproof admixture piece having a larger amount of compressive deformation than the waterproof admixture layer between the main line and the branch line, the main line and the branch line can be separated from each other. It is possible to easily water-tighten a branch connection portion, which is difficult to be water-tightened by the conventional method, such as a gap of 10 mm or less.

[Brief description of drawings]

FIG. 1A is a cover used in the present invention.
2 is an explanatory plan view showing a developed state of FIG. 1, and FIG. 1B is a sectional view taken along line A-B of FIG.

FIG. 2 is an explanatory view showing a branch connection portion of a water-tight electric wire according to the present invention.

FIG. 3 is an explanatory view showing a watertight state by the waterproof admixture according to the present invention.

[Explanation of symbols]

 1 cover 21 waterproof admixture layer 30 main line 31 branch line 4 waterproof admixture piece.

Claims (2)

[Claims] 1. A cover provided with a waterproof admixture layer on the inner surface of both ends.
In a method of tying a wire to a branch connection part of the electric wire and water-tightening both ends in the conjugate with the above-mentioned waterproof admixture layer, a waterproof with a larger amount of compressive deformation than the waterproof admixture between the main line and the branch line. The waterproof admixture layer is compressed by the conjugation of the cover with the admixture piece interposed, and the waterproof admixture piece is formed.
A method for watertightening a wire branch connection part, characterized by compressing the wire and bringing them into close contact with each other. 2. The method for watertightening a wire branch connecting portion according to claim 1, wherein the compression deformation amount of the waterproof admixture piece is 1.2 times or more the compression deformation amount of the waterproof admixture layer. ..