JPH05146026A - Repairing method for gas leakage from protecting case of cableconnection part - Google Patents

Abstract

PURPOSE:To repair leak of gas within a short period of time by holding a cable with a pair of semi-circular frames having internal cavity, applying these frames at the end face of the cable, supplying a foaming resin from a supply port of the upper frame until it overflows and then removing the frames after the resin is hardened. CONSTITUTION:A cable 1 is held with a pair of semi-circular frames 14 having internal cavity and the frames 14 are attached at the end face of cable. Thereafter, a foaming resin 16 of foaming urethane is supplied from the supply port 15 formed at the upper frame until it overflows. The supply port 15 is closed with a hand until the resin is hardened. Thereafter, the frames 14 are removed. Thereby, leak of gas between the cable 1 and the end face 5 can be repaired within a short period of time without decomposing a protection cable of the cable connecting portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a dry air inside an outer casing,
Maintained by pressurizing and enclosing a gas such as nitrogen, and has a semi-circular notch with which the outer peripheral surface of the cable for communication abuts in order to remove the jacket and maintain the airtightness of the part to which the core wire is connected. The present invention relates to a method for repairing gas leakage from a gap between an end face plate and a cable of a cylindrical cable connection part protection case in which one or more end face plates are arranged to abut against each other at each end of the portion.

[0002]

2. Description of the Related Art It is required for a communication line to guarantee a high communication quality for a long time. If water enters the communication cable, many copper wires housed in the communication cable will be electrically short-circuited and communication will be lost, or corrosion will occur and long-term reliability will be reduced. Occurs.
Therefore, especially in the underground where there is a danger of flooding, a maintenance method is taken to prevent flooding by continuously enclosing gas in the communication cable. This underground cable is usually connected in a manhole, but it is also required to seal the gas at the connection. For this reason, a gas-sealed cable connection part protection case called a standard closure is currently used. This is for accommodating a communication copper wire (hereinafter, referred to as a core wire connecting portion) connected by soldering or using a connector, and connecting the communication cables with each other in an airtight manner.

FIG. 3 is an external view of a standard closure currently in use, and FIG. 4 is an exploded view showing its internal structure.
FIG. 5 is an enlarged view showing the structure of the end plate 5.

The communication cable 1 is held by a holding metal piece 3. The sleeve 4 is for protecting the core wire connecting portion 2 of the communication cable 1. Semi-circular end plate 5
Are attached to both ends of the sleeve 4, and the communication cable 1
This is for maintaining airtightness between the sleeve 4 and the sleeve 4 and ensuring mechanical strength. Between the end plates 5, the end plates 5
A seam seal 6 for maintaining the airtightness of the seam is inserted. The communication cable 1 includes a communication cable 1 and an end plate 5.
An airtight tape 7 that keeps airtightness is wrapped around. The sleeve 4 is formed with a hole 9 into which the pin 8 is inserted to prevent the displacement of the airtight tape 7 due to gas pressure. The stainless steel band 10 is for strongly holding the mating surface of the sleeve 4. The pressure measuring valve 1 is provided on the outer peripheral surface of the sleeve 4.
1 is provided. On the outer peripheral surface of the end face plate 5, an end face plate gasket 1 for keeping airtightness at the joint between the end face plate 5 and the sleeve 4.
2 is provided, and a sleeve gasket 13 that maintains airtightness between the sleeves 4 is provided on the end face in the longitudinal direction of the sleeve 4.

FIG. 6 is a diagram showing the structure of the end face plate of the one-branch connection standard closure, and FIG. 7 is a diagram showing the structure of the end face plate of the two-branch connection standard closure.

Although the structure of the end plates 5A and 5B of each standard closure is different from that of the end plate 5 of the standard closure for linear connection shown in FIGS. 3 to 5, the basic structure is for the linear connection shown in FIGS. Same as standard closure.

[0007]

In the cable connection portion of the standard closure, a gap may be generated due to the internal pressure of the enclosed gas, the bending of the communication cable 1, etc. to cause gas leakage. Since gas leakage has a high risk of causing communication failure, it must be repaired immediately. Conventionally, the standard closure has been disassembled and the sealing material and the like at the gas leakage portion have been replaced. It is necessary for this work not to affect the communication cable and the connection part other than the gas leak point, and the disassembly is performed while supplying gas from the connection points before and after the gas leak point.
Since the gas maintenance cable monitors the gas pressure by telemetry, the standard closure causing the gas leak can be identified, but it cannot be determined from which part of the standard closure the leak occurs. For this reason, all the above-mentioned parts are removed, and the standard closure is assembled again. This work takes much longer than the time of assembling a new standard closure, and there is a drawback that a great deal of work is required together with the gas supply from the connection points on both sides of the gas leak point described above.

An object of the present invention is to provide a gas leakage repair method for a cable connection protection case, which enables repair of gas leakage in a short time without disassembling the cable connection protection case.

[0009]

In order to achieve the above object, a method for repairing a gas leakage of a cable connecting portion protective case of the present invention is to secure a closed space on the outer peripheral surface of the communication cable outside the end plate. As described above, the mold is attached, and the foam resin in the space is injected from the injection hole provided in the mold to cure it.

[0010]

[Function] The following conditions are required for repairing a gas leak. It should be possible to re-disassemble it to change the connection. Since it is installed in a narrow space, the volume increase should be minimized.

As a result of a detailed study on these conditions, the inventors have reached the following conclusions. That is, using an end plate with an overwhelmingly high gas leakage ratio and a plastic that can be easily removed without disassembling the surrounding area,
It is to repair the communication cable by covering it about several cm from the outside of the end plate.

Based on these conclusions, the materials and methods were examined in more detail, and a method satisfying all the requirements was established. The point is to form a protective layer of foamed resin on the site around the end plate and the communication cable.

Therefore, it is possible to repair the gas leakage of the cable connecting portion protecting cable without disassembling the cable connecting portion protecting case and in a short time.

[0014]

Embodiments of the present invention will now be described with reference to the drawings.

FIGS. 1A and 1B are views showing a first embodiment of the present invention.

First, two semi-circular molds 14 having a hollow inside are sandwiched by the cable 1 and pressed against the end face plate 5, and then from the injection port 15 formed in the upper mold 14. When the resin 16 of urethane foam is filled and the resin 16 overflows from the injection port 15, the injection is stopped and the injection port 15 is manually pressed until foaming and curing (FIG. 1 (1)). Resin 1
6 is filled in the end face plate 5 and the uneven portions around the end face plate 5 while foaming in the mold 14, and is cured in a state of being in close contact with the cable 1 and the end face plate 5. After that, the mold 16 is removed (FIG. 1 (2)). As a result, gas leakage from the gap between the cable 1 and the end plate 5 is repaired.

2 (1) and 2 (2) are views showing a second embodiment of the present invention.

In this embodiment, the mold 17 has a diameter smaller than that of the mold 14 and is long. Reference numeral 18 is an inlet for the foamed resin 16.

As the foamed resin, in addition to the above-mentioned polyurethane, any resin can be used as long as it can be foam-molded without tightly adhering to the cable connecting portion protective case. Regarding foamed polyurethane,
For example, Three Spar made by Tokyo Aerosol Co., Ltd. can be used. Further, it goes without saying that the present invention can be applied to the standard closure having the end face plate structure shown in FIGS. 6 and 7.

[0020]

As described above, the present invention repairs gas leakage without disassembling the cable connecting portion protection cable by forming the protective layer of foamed resin around the end plate and the communication cable. Therefore, the work can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is an external view of a standard closure currently in use.

FIG. 4 is an exploded view showing the internal structure of the standard closure of FIG.

FIG. 5 is a view showing a structure of an end plate for connecting a straight cable.

FIG. 6 is a diagram showing the structure of an end plate for connecting a one-branch cable.

FIG. 7 is a view showing a structure of an end plate for connecting a two-branch cable.

[Explanation of symbols]

 1 Communication Cable 2 Core Wire Connection Part 3 Grip Hardware 4 Sleeve 5 End Face Plate 6 Seam Seal 7 Airtight Tape 8 Pin 9 Hole 10 Stainless Steel Band 11 Pressure Measuring Valve 12 End Face Plate Gasket 13 Sleeve Gasket 14, 17 Form Frame 15, 18 Inlet 16 Foam resin

Claims (1)

[Claims] 1. An outer peripheral surface of a communication cable, which is maintained by pressurizing and enclosing a gas such as dry air or nitrogen inside the outer jacket, and which keeps the airtightness of the portion where the outer wire is removed and the core wire is connected. In a cylindrical cable connection part protection case in which two or more end face plates having semi-circular cutouts that abut against each other are arranged so as to abut against each other at each end of the portion, the communication case is provided outside the end face plates. Attaching a mold so as to secure a closed space with the outer peripheral surface of the cable, injecting foamed resin into the space from the injection hole provided in the mold and hardening it, protecting the cable connection part Case gas leak repair method.