JPH04324263A - Water tighteness processing method for electric wire branch connecting part - Google Patents

Abstract

PURPOSE:To easily fill up a part between electric wires with a viscous seal material even with a low pressure by surely providing a space between the parallelly provided electric wires in a branch connecting part thereof, and covering over the branch connecting part with a viscous seal material-provided waterproof sheet. CONSTITUTION:A branch connecting part of electric wires is mounted onto a seal material 2 of a waterprof sheet A, in which the seal material 2 is provided on one surface of a protecting sheet 1, to arrange a parallelly provided electric wire group of a main and a branch wire in a transverse one-way condition. The sheet A is bent by placing the seal material 2 inside, and the sheet A, after its both end parts are put together while forcedly changing the parallelly provided electric wire group into circular arc-shaped arrangement in accordance with a curvature of curing the group, is pressurized. Here in the case of forcing the parallelly provided electric sire group to form the circular arc-shaped arrangement, the seal material 2 is extended, and when the electric wire group is returned to the transverse one-row condition at press pressurizing time because of plastic elongation at elongation time base on an imperfect elastic property, a space between the electric wires is spread because of this plastic elongation. Accordingly, even when press pressurizing force is low, the seal material 2 can be easily press-filled between the electric wires.

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 branch connections of electric wires watertight.

0002

[Prior art] Watertight treatment of electric wire connections guarantees insulation,
Indispensable for preventing corrosion of electric wire conductors and conductor connection fittings. The traditional method for making electrical wire connections watertight is to spirally wrap multiple layers of self-adhesive insulating tape over the electrical wire connections, and then wrap a protective tape around the outside of the self-adhesive insulating tape. However, with this method, it is necessary to wrap the narrow tape many times, which takes a long time. Especially when the wire connection part is a branch connection part, the shape of the wire connection part is complicated and the wire connection part is complicated. - It becomes even more difficult to wind the rope, and there are also problems with watertightness.

[0003] In order to eliminate such disadvantages, recently, waterproof sheets with a viscous sealing material (for example, a viscous material whose main component is uncrosslinked butyl rubber) provided on one side of the protective sheet have been replaced with viscous sealants. - Cover the wire connection part with the sealing material facing inward, and apply pressure to the viscous sealant from above the protective sheet using a press. A method has been proposed for making electric wire connections watertight by passing the wire around the wire.

0004

[Problem to be Solved by the Invention] At branch connections of electric wires, the main line and branch lines are often arranged in a horizontal line in close contact with each other. In order to apply this method, it is necessary to separate the main wire and the branch wire to some extent in advance and then apply the method in order to reliably fill the viscous sealant between the wires.

However, the distance between the wires is due to forced bending deformation of the wires, and due to the elapse of time until the above-mentioned waterproof sheet is placed over the wire joints, the wires may return to their original state. Wires often come into contact with each other.

[0006] However, when the electric wires are in contact with each other, the waterproof
If the wire is covered with a viscous sealant, it is necessary to increase the pressure of the viscous sealant and spread the space between the wires to fill the space between the wires, which inevitably increases the pressurizing force. be done. However, when the press pressure is increased, the viscous sealing material tends to protrude from the ends of the waterproof sheet, and there is also a risk that the conductor connection portion of the electric wire may be damaged.

An object of the present invention is to provide a waterproof seal with a viscous sealant by reliably creating a gap between the parallel wires at the branch connection part of the wire.
To provide a watertight treatment method for a branch connection part of an electric wire, in which a viscous sealing material can be easily filled between the electric wires even at a low press pressure.

[0008]

[Means for Solving the Problems] The method of making a wire branch connection part watertight according to the present invention includes applying a viscous sealing material to one side of a protective sheet on the waterproof sheet. Place the branch connection part of the electric wire, arrange the parallel electric wire group of the main line and the branch line in a horizontal line, and bend the waterproof sheet with the viscous sealing material inside to form the parallel electric wire group. Align both ends of the waterproof sheet while forcibly changing it into an arcuate arrangement according to the curvature of the bend,
After that, a structure characterized by pressurizing the waterproof sheet, or a waterproof sheet with a viscous sealing material provided on one side of the protective sheet, with the viscous sealing material side facing inside. The branch connection part of the electric wire is placed on the arc-shaped sealing surface, and the parallel electric wire group of the main line and the branch line is arranged along the bend of the waterproof sheet. This structure is characterized in that both ends of the waterproof sheet are brought together and then the waterproof sheet is pressurized. It is.

[0009]

[Function] When the group of parallel electric wires on the surface of the viscous sealing material is forced into an arcuate arrangement according to the bending curvature by bending the waterproof sheet, each electric wire and the viscous sealing material The distance between each bonding point increases, and the viscous sealing material stretches between the bonding points, and press is applied due to plastic elongation at the time of elongation based on the imperfect elastic property of the viscous sealing material. Sometimes, when the wires are returned to a horizontally aligned state, the spacing between the wires is expanded due to their plastic elongation. Therefore, even if the pressing force is low, the viscous sealant can be easily press-fitted between the wires. Also, in advance,
Even when a group of parallel electric wires is placed on the viscous seal material surface of a waterproof sheet bent into an arc, the viscous seal may be damaged due to bending deformation of the waterproof sheet when the parallel electric wire group is placed along the side. The material is in an elongated state, and when the wire group is returned to a horizontally aligned state during pressurization, the spacing between the wires is similarly expanded.

0010

[Embodiments] Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Figure 1 (a) shows waterproof sheet A used in the present invention.
FIG. 1B is a cross-sectional view of FIG. It shows the material. protection sheet
Dry edges are provided on all sides of the tray 1 as a picking allowance. This dry edge may be provided on one, two or three sides.

The protective sheet 1 is made of vinyl chloride, polyethylene, thermoplastic elastomer, or thermosetting elastomer.
Alternatively, engineering plastics such as polyethylene terephthalate and polybutylene terephthalate can be used.

For the viscous sealing material 2, a viscous material that does not soften or flow under heat at the operating temperature and has excellent corrosion resistance is used, such as a composition containing uncrosslinked butyl rubber or silicone rubber as a main component. can. The thickness of this viscous sealing material is usually 1/3 to 3 times the diameter of the wire.

FIGS. 2A to 2F are explanatory diagrams showing the working procedure of the method of making a wire branch connection portion watertight according to the present invention.

To carry out the present invention, first, as shown in FIGS. 2(a) and 2(b) [the cross-sectional view of FIG. Place the branch connection part B of the electric wire on the waterproof sheet A facing toward Place it in Next, as shown in FIG.
... is forcibly changed into an arcuate arrangement according to the curvature of the bend, and both ends a of the waterproof sheet A are brought together.

In this case, as shown in FIG. 3, if the bending radius of the upper surface 20 of the viscous sealing material is R, and the radius of the wire is r, then when the waterproof sheet A is bent, the wire and the viscous sealing material The distance L between the bonding points e and e is L=2r+rθ, where θ is the angle between the wires with the bending center O as the center point.
(1), and θ=2r/(R-r) (2)
becomes.

If the wires of the wire groups C1, C2, C3, etc. are in contact with each other at the stage shown in FIG. e', e'
The mutual spacing L' of is 2r. Therefore, in the process of moving from the stage (b) in FIG. 2 to the stage (c) in FIG. 2, the portion of the viscous sealing material between the bonding points is subjected to a tensile strain ε expressed by the following equation. ε=(L-L')/L'=θ/2
=r/(R-r) (3)

The bending radius R of the surface of the viscous sealing material is about 4 to 5 times the wire radius r, and the above strain ε is 1/3 to 1/4 (33 to 25%).
) The viscous seal between the above bonding points will result in a large strain rate.
The seal material portion plastically deforms due to the imperfect elasticity of the viscous seal material.

After the step of enclosing the electric wire branch connection part with the waterproof sheet A shown in FIG. -G1
The viscous sealing material 2 is pressurized from the outer surface of the waterproof sheet A by a press. During this process, as shown in FIG. As shown in (e), the waterproof sheet envelope undergoes a process in which it is flattened.

In the flattening process shown in FIG. 2(E), the electric wire groups C1, C2, C3, etc., which have been forcibly arranged in an arc shape, are restored to a horizontal line. Since the part of the viscous sealant between the bonding point of the wire and the viscous sealant undergoes plastic elongation, the distance between the wires is expanded by the amount of plastic elongation, and the viscous sealant is applied between the wires. can be easily press-fitted. Therefore, the press pressure can be lowered, and protrusion of the viscous sealant from the edge of the waterproof sheet can be effectively avoided.

In the above explanation, it is assumed that the wires of the wire groups C1, C2, C3, etc. are in contact with each other at the stage shown in (b) of FIG. 2, but even if there is no contact, Compared to the distance L between the bonding points e and e between the wires and the viscous sealing material under the forced arc-shaped arrangement of the wire group shown in FIG. 3, the bonding at the stage shown in (b) of FIG. If the distance between the points is narrow, the above-mentioned plastic elongation of the viscous sealing material occurs. Therefore, the above interval L is

L=Rθ=2Rr/(R−r)
(4), and at the stage (b) in Fig. 2, the bonding points e', e
'If the distance between the wires is L, the gap size G between the wires is (L-2r),

G=2Rr/(R−r)−2r=
2r2/(R-r) (5), and since R is usually (4~5)r, G is (2/3~1/2
), and if the gap between the wires in the wire group at the wire branch connection is less than 65% to 50% of the wire radius, plastic elongation of the viscous sealing material will occur due to the forced arc-shaped arrangement of the wire group. The distance between the electric wires can be expanded according to their plastic elongation, and the viscous sealing material can be easily press-fitted between the electric wires of the group of parallel electric wires.

Although illustration is omitted, for example, in advance,
In this state, the waterproof sheet is bent into an arc shape, and the parallel electric wire groups C1, C2, C3, etc. are placed on the viscous sealing material surface 20 of the waterproof sheet bent and deformed in this way. Place it along the bend of the sheet. Next, even if the branch connection is made watertight by going through the same processes as (c) to (f) in FIG. The gap between the wires is enlarged, so that the viscous sealant can be easily press-fitted between the wires.

In the waterproof sheet used in the present invention, as shown in FIG. Preferably, two recesses 20, 20 are provided.

[0025]

[Effects of the Invention] The watertight treatment method for electric wire branch connections of the present invention has the above-mentioned configuration, and when covering the electric wire branch connections with a waterproof sheet, the viscous sealing material is used to cover the parallel electric wires. Since plastic deformation is caused in the direction of increasing the distance between the wires in the group, the gap between the wires can be expanded immediately before pressing, and the viscous seal between the wires can be created by pressing. Materials can be easily press-fitted and press pressure can be low.

[Brief explanation of drawings]

FIG. 1: FIG. 1A is a plan view of a waterproof sheet used in the present invention, and FIG. 1B is a cross-sectional view of FIG.

FIG. 2 is an explanatory diagram showing the working procedure of the present invention.

FIG. 3 is an explanatory diagram showing a forced arcuate arrangement of a group of parallel electric wires in the present invention.

FIG. 4 is a plan view showing another example of the waterproof sheet used in the present invention.

[Explanation of symbols]

A Waterproof sheet 1 Protective sheet 2 Viscous sealing material B Wire branch connection C1 Electric wire C2 Electric wire C3 Electric wire C4 Electric wire

Claims (2)

[Claims] Claim 1: A waterproof sheet with a viscous sealing material on one side of the protective sheet, and placing the branch connection part of the electric wire on the sealing material to connect the main line and the branch line side by side. Arrange the wires in a row horizontally,
bending the waterproof sheet with the viscous sealing material inside, forcing the group of parallel electric wires into an arcuate arrangement according to the curvature of the bend, and aligning both ends of the waterproof sheet; A method for making a wire branch connection section watertight, which comprises subsequently applying pressure to a waterproof sheet. Claim 2: A waterproof sheet with a viscous sealing material provided on one side of the protective sheet is bent into an arc shape with the viscous sealing material side inward, and the waterproof sheet is placed on the arcuate sealing surface. Place the branch connection part of the electric wire, arrange the parallel electric wire group of the main line and branch line along the bend of the waterproof sheet, then align both ends of the waterproof sheet, and then, A method for making a wire branch connection section watertight, characterized by applying pressure to a waterproof sheet.