JP2020061865A - Cable removing method and closure - Google Patents

Abstract

To further easily remove a cable held by a closure to which a tap cable is connected.SOLUTION: When a cable C1 on a gas supplying side connected to a closure 5A among closures 5A and 5B mutually connected with a tap cable C5 connecting a core wire but blocking gas is removed, a cable removing method has the steps of: demolishing the closure 5A; removing the cable C1 from the closure 5A; replacing an end face plate 53 holding the cable C1 with a new end face plate 13, replacing a sleeve body of the closure 5A with a sleeve body 12 with two bulbs 14A and 14B, and assembling the closure 1; and connecting one bulb 14A of the two bulbs 14A and 14B and a bulb 54 of the closure 5B with a gas pipe 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for removing an unnecessary metal cable.

  For maintenance of metal cables installed in underground facilities, gas (dry air) is supplied from the facility building (station building) into the metal cables, and pressure transmitters (closures) installed in the closures attached to the metal cables are used. Check the gas pressure inside) to monitor the gas pressure. An example is given regarding the installation of the pressure transmitter. The metal cable is 4km underground from the facility building, and is pulled up to the ground and wired to each home via a telephone pole. The nearest is a closure with a pressure transmitter installed about 500m from the facility building. After that, assume that pressure transmitters are installed in the closure at intervals of 1 km. Since manholes are installed every 250 m at the maximum, there are some closures at three locations on the way without pressure transmitters.

  When a gas leak is detected, the user goes to a place where the gas may leak, and a pressure measuring device is attached to the closure to measure the pressure of the gas in the closure to identify the leak point. Also, when the closure is assembled, a pressure measuring device is attached to the closure to make sure that there is no gas leakage due to improper assembly. This pressure measuring device is a portable type that is portable and uses, for example, a digital nanometer. In order to ensure such a function, the closure has one valve for mounting the pressure measuring device.

  On the other hand, with closures installed close to each other, the core wire may be diverged from another closure due to a shortage of the core wire due to an increase in demand downstream of a closure. In this case, gas is separately supplied to each closure from the upstream cable, so that no gas is mixed. Specifically, a tap cable that connects the core wires but shuts off gas is used to connect the closures arranged close to each other.

  FIG. 1 shows a state of an underground closure in which core wires are connected to each other by using a tap cable that shuts off gas. The left side of the figure is the upstream (equipment building side and gas supply side), and the right side is the downstream (user home side).

  In the upper closure 5A in FIG. 1, the core wire of the cable C1 and the core wire of the cable C2 are connected. Further, the core wire of the tap cable C5 branched from the lower closure 5B and the core wire of the cable C2 are also connected. Gas is supplied to the closure 5A through the cable C1. The gas supplied to the closure 5A is also supplied to the subsequent closure through the cable C2.

  In the closure 5B, the core wire of the cable C3 and the core wire of the cable C4 are connected, and a part of the core wire of the cable C3 is branched to the tap cable C5. Gas is supplied to the closure 5B through a cable C3. The gas supplied to the closure 5B is also supplied to the subsequent closure through the cable C4.

  A gas dam 7 is attached to the tap cable C5 that connects the closures 5A and 5B to shut off the gas. As a result, a part of the core wire of the cable C3 could be connected to the core wire of the cable C2 by the closure 5A without mixing the gas supplied by the cable C1 and the gas supplied by the cable C3.

  Each of the closures 5A and 5B is equipped with a valve 54, and a pressure measuring device can be attached to the valve 54 to measure the pressure of the gas in each of the closures 5A and 5B.

JP-A-9-229812

  In recent years, the spread of optical communication has reduced the demand for metal cables. Therefore, with regard to the metal cables on the same route, the cables are being removed after being replaced. For example, in FIG. 1, when the demand for the cable C2 downstream of the closure 5A decreases, the demand for the cable C1 is replaced with the cable C3, and then the cable C1 is removed.

  However, if the upstream cable C1 is removed, gas will not be supplied to the closure 5A, so a gas supply route must be secured. Conventionally, the tap cable C5 that shuts off gas is removed, and instead, a tap cable that does not shut off gas is newly installed, and gas is also supplied to the closure 5A through the newly installed tap cable. Hereinafter, a conventional procedure for removing the cable C1 will be briefly described.

  First, the closures 5A and 5B are disassembled.

  A tap cable is newly provided instead of the tap cable C5, and the core of the tap cable is connected to the core of the cable C3 and the core of the cable C2.

  Then, the core wire of the tap cable C5 is cut and the tap cable C5 is removed.

  The core wire of the cable C1 to be removed is cut, and the cable C1 is removed.

  Finally, the closures 5A and 5B are assembled.

  Through the above steps, after the cable C1 is removed, the gas supplied from the cable C3 to the closure 5B is supplied to the closure 5A through the newly installed tap cable.

  Thus, in the conventional method of newly installing the tap cable instead of the tap cable C5, the closures 5A and 5B are disassembled, the cores of the tap cables are connected to the closures 5A and 5B, respectively, and the closures 5A and 5B are assembled. I need to fix it. Therefore, there have been problems of high construction cost, temporary disconnection due to switching connection, and extension of construction period.

  The present invention has been made in view of the above, and an object thereof is to more easily remove a cable held by a closure to which a tap cable is connected.

  A cable removal method according to the present invention is a cable on a gas supply side connected to a first closure of a first closure and a second closure that are mutually connected by a tap cable that connects a core wire but blocks a gas. A method of removing the first closure, removing the cable from the first closure, replacing the end plate holding the cable with a new end plate, and Replacing the sleeve body of one closure with a sleeve body having two gas valves, and assembling the first closure, and connecting one gas valve of the two gas valves and the gas valve of the second closure with a gas pipe. And a step of performing.

  A closure according to the present invention is a closure to which a tap cable for connecting a core wire but for shutting off gas is connected, a sleeve body having two gas valves, and end face plates attached to both ends of the sleeve body, And a gas valve of one of the two gas valves and a gas valve of another closure connected to each other by the tap cable are connected by a gas pipe.

  According to the present invention, the cable held by the closure to which the tap cable is connected can be removed more easily.

It is a figure which shows the mode of the closure mutually connected using the tap cable which interrupts | blocks gas. It is a figure which shows a mode that the cable was connected using the closure of this embodiment. It is a flow chart explaining the procedure which attaches the closure of this embodiment. It is a figure which shows another mode which connected the cable using the closure of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram showing a state in which cables are connected using the closure of this embodiment. Specifically, the cable C1 of FIG. 1 is removed and the closure 5A is replaced with the closure 1 of the present embodiment. That is, FIG. 1 is a diagram showing a state before the cable C1 is removed, and FIG. 2 is also a diagram showing a state after the cable C1 is removed.

  The upper closure 1 in FIG. 2 is the closure 1 of this embodiment, and the lower closure 5B is the closure 5B in FIG. The left side of the figure is the upstream, and the right side is the downstream.

  In the closure 5B, the core wire of the cable C3 and the core wire of the cable C4 are connected, and a part of the core wire of the cable C3 is branched to the tap cable C5. Gas is supplied to the closure 5B through a cable C3. The gas supplied to the closure 5B is also supplied to the subsequent closure through the cable C4. Since the gas dam 7 is attached to the tap cable C5, the gas is shut off.

  In the closure 1, the core wire of the tap cable C5 branched from the closure 5B and the core wire of the cable C2 are connected. The closure 1 and the closure 5B are connected by a gas pipe 3. The gas supplied from the cable C3 to the closure 5B is supplied to the closure 1 via the gas pipe 3. The gas supplied to the closure 1 is also supplied to the subsequent closure through the cable C2.

  The gas pipe 3 is attached to a valve 54 arranged in the sleeve body 52 of the closure 5B and a valve 14A arranged in the sleeve body 12 of the closure 1. The valve 54 of the closure 5B utilizes a valve for mounting a pressure measuring device. The closure 1 comprises a sleeve body 12 with two valves 14A, 14B. The gas pipe 3 is attached to one valve 14A of the two valves 14A and 14B, and the pressure measuring device can be attached to the other valve 14B. The gas pipe 3 may be attached to the valve 14B, and the valve 14A may be attached to the pressure measuring device.

  Subsequently, the configuration of the closure 1 will be described.

  The closure 1 has a cylindrical shape that accommodates the connection portion of the cable C2 and the tap cable C5 therein, and has semi-cylindrical sleeve bodies 11 and 12, end face plates 13 provided at both axial ends of the closure 1, and a closure. A plurality of stainless steel bands 15 for pressing and fixing 1 from the side surface direction are provided.

  The side surfaces of the closure 1 are formed by combining the semi-cylindrical sleeve bodies 11 and 12. A sleeve gasket (not shown) is arranged at the joint between the sleeve bodies 11 and 12.

  The upper sleeve body 12 shown in FIG. 2 includes two valves 14A and 14B. The valves 14 </ b> A and 14 </ b> B are vents that communicate with the space inside the closure 1. The gas pipe 3 is connected to one valve 14A. A pressure measuring device can be attached to the other valve 14B at the time of inspection. Normally, the valve 14B is closed. The vicinity of the side surface to which the valves 14A and 14B are attached is flat. By flattening the vicinity of the valves 14A and 14B, when the valves 14A and 14B are screwed, the bolts can be tightened flat without being attached to the curved portion of the cylindrical side surface. From the viewpoint of work, each of the valves 14A and 14B may be arranged near both ends of the sleeve body 12 (near the end face plate 13). Further, each of the valves 14A and 14B may be arranged at equal distances from both ends of the sleeve body 12.

  The size of the valves 14A and 14B may be No. 6 or No. 5. The valves 14A and 14B are preferably compatible with the joint of the gas pipe 3. When the sizes of the valves 14A and 14B and the size of the joint of the gas pipe 3 are different from each other, an attachment for changing the size of the joint may be attached to the gas pipe 3. However, it is not preferable to attach the attachment because the height of the joint of the gas pipe 3 is increased by the amount of the attachment. The cost for attachments also increases.

  Each of the end plates 13 at both ends of the closure 1 has a through hole through which the cable C2 and the tap cable C5 pass. When the cable C2 and the tap cable C5 are passed through the end plate 13, an airtight tape that closes the gap between the cable C2 and the tap cable C5 is wound around the cable C2 and the tap cable C5. The end face plate 13 is formed by joining a semicircular member that divides the through hole with a bolt or the like. An end face gasket (not shown) is arranged at the joint between the end face plate 13 and the sleeve bodies 11 and 12, that is, at the outer peripheral portion of the end face plate 13. Since the end face plate 13 is a component different from the sleeve bodies 11 and 12, it is possible to arbitrarily select and use the end face plate 13 depending on the number and size of the cables to be passed.

  The stainless band 15 is wrapped around the outer circumferences of the sleeve bodies 11 and 12, and is tightened with a screw (not shown). The stainless band 15 presses and fixes the outer peripheries of the sleeve bodies 11 and 12.

  Similar to the closure 1 of the present embodiment, the conventional closure 5B also includes sleeve bodies 51 and 52, an end face plate 53, and a stainless band 55. It differs from the closure 1 in that the sleeve body 52 comprises only one valve 54.

  When the gas pipe 3 is connected to the valve 54, a pressure measuring device for measuring the gas pressure in the closure 5B cannot be attached, but since the closures 1 and 5B are connected by the gas pipe 3, the closures 1 and 5B The gas pressure is almost the same. By attaching a pressure measuring device to the valve 14B of the closure 1, the gas pressure in the closures 1 and 5B can be measured.

  Next, a procedure for removing the cable C1 of FIG. 1 and attaching the closure 1 of the present embodiment will be described.

  FIG. 3 is a flowchart illustrating a procedure for attaching the closure 1 of this embodiment.

  First, the closure 5A of FIG. 1 that holds the cable C1 to be removed is disassembled and the cable C1 is removed (step S1).

  When disassembling the closure 5A, the end face plate 53 through which the cable C2 passes can be used as it is, and therefore the cable C2 does not have to be removed from the downstream end face plate 53. The lower sleeve body 51 of the closure 5A may be used as it is. Therefore, when disassembling the closure 5A, the stainless band 55 may be removed, the upper sleeve main body 52 may be removed, and the upstream end face plate 53 through which the cable C1 is passed may be disassembled.

  After the closure 5A is disassembled, the cores of the cables C1 and C2 are disconnected and the cable C1 is removed. The cores of the tap cable C5 and the cable C2 remain connected.

  The closure 1 is assembled using the sleeve body 12 including the two valves 14A and 14B (step S2). The assembly of the closure 1 will be described below.

  An airtight tape is wound around the place where the end plate 13 of the tap cable C5 is attached. The end face plate 13 is attached to the tap cable C5 by joining the semicircular members of the end face plate 13 so that the tap cable C5 passes through the through hole. An end face plate gasket is attached to the outer circumference of the end face plate 13.

  Apply the lower sleeve body 11 (the sleeve body 51 of the closure 5A may be used as it is) to the end face plate 13, attach a sleeve gasket to the joint between the sleeve bodies 11 and 12, and cover the sleeve body 12 with the sleeve body 12. .

  The stainless band 15 is wrapped around the outer circumferences of the sleeve bodies 11 and 12, and the screw of the stainless band 15 is tightened.

  The closure 1 can be assembled through the above steps. After assembling the closure 1, after the closure 1 is filled with gas, a soap solution is used to check if there is any leakage spot. A leak test gas may be filled from either of the valves 14A and 14B.

  After assembling the closure 1, the closure 1 and the closure 5B are connected by the gas pipe 3 (step S3).

  After connecting the gas pipe 3, the gas supplied through the cable C3 is also supplied to the closure 1 through the gas pipe 3 and also to the subsequent stage closure of the closure 1 through the cable C2. After a certain period, the gas pressure becomes stable.

  Thus, when the cable C1 is removed, by using the closure 1 of the present embodiment, it is only necessary to disassemble and assemble the closure 5A that holds the cable C1, and it is not necessary to disassemble and assemble the other closure 5B. A part of the disassembled closure 5A can be used. Further, since the tap cable C5 is used as it is and the tap cable is not newly installed, the connection of the core wire is unnecessary.

  Next, another state in which a cable is connected using the closure 1 of this embodiment will be described.

  FIG. 4 is a diagram showing an example in which the tap cable C5 is passed through the same end face plate 53 as the remaining cable C2.

  In FIG. 1, the tap cable C5 passes through the same end face plate 53 as the cable C1 to be removed, but the tap cable C5 may pass through the same end face plate 53 as the downstream cable C2. In this case, when attaching the closure 1 of the present embodiment, neither the cable C2 nor the tap cable C5 is removed, so the end face plate 53 through which the cable C2 and the tap cable C5 are passed is used as it is. Since the cable is not passed through from the side where the cable C1 is removed, the end face plate 13 having no through hole for passing the cable is attached. Only the end plate 13 to be attached is different from that shown in FIG.

  In the construction method of this embodiment, since the tap cable C5 connecting the closures 5A and 5B is used as it is, it can be applied regardless of the place where the tap cable C5 is passed.

  As described above, according to the present embodiment, the gas supply side connected to the closure 5A of the closures 5A and 5B that are connected to each other by the tap cable C5 that connects the core wire but blocks the gas. When removing the cable C1, the closure 5A is disassembled, the cable C1 is removed from the closure 5A, the end face plate 53 holding the cable C1 is replaced with a new end face plate 13, and the sleeve body of the closure 5A is By replacing the sleeve body 12 with the valves 14A and 14B, assembling the closure 1, and connecting one valve 14A of the two valves 14A and 14B and the valve 54 of the closure 5B with the gas pipe 3, The tap cable C5 that shuts off can be used as it is. Therefore, the disassembling and assembling of the closure 5B and the work of connecting the core wires are not necessary, which saves labor, shortens the construction period, and improves the construction efficiency. Since the remaining closure 5B is not disassembled, the user downstream of the closure 5B is not disconnected.

  Further, since the end face plate 13 of the closure 5A that holds the removed cable C1 and the sleeve body 12 including the two valves 14A and 14B may be replaced and the gas pipe 3 may be connected, a cost reduction effect can be expected. .

DESCRIPTION OF SYMBOLS 1 ... Closure 11, 12 ... Sleeve main body 13 ... End face plate 14 ... Valve 14A, 14B ... Valve 15 ... Stainless steel band 3 ... Gas pipe 5A, 5B ... Closure 51, 52 ... Sleeve main body 53 ... End face plate 54 ... Valve 55 ... Stainless steel band 7 ... Gas Dam

Claims (3)

A method for removing a cable on a gas supply side, which is connected to a first closure of a first closure and a second closure that are connected to each other by a tap cable that connects a core wire but shuts off gas,
Disassembling the first closure;
Removing the cable from the first closure;
Replacing the end plate holding the cable with a new end plate, replacing the sleeve body of the first closure with a sleeve body provided with two gas valves, and assembling the first closure;
Connecting one gas valve of the two gas valves and the gas valve of the second closure with a gas pipe;
A method for removing a cable, characterized in that A closure to which a tap cable that connects the core wire but shuts off gas is connected,
A sleeve body with two gas valves,
End face plates attached to both ends of the sleeve body,
A closure, wherein one of the two gas valves and a gas valve of another closure connected to each other by the tap cable are connected by a gas pipe.   The closure of claim 2, wherein each of the two gas valves is compatible with the fitting of the gas pipe and is located equally spaced from both ends of the sleeve body.

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