JP6572359B1 - Cable removal method and closure - Google Patents

Abstract

An object of the present invention is to more easily remove a cable held by a closure to which a tap cable is connected. When removing a cable C1 on the gas supply side connected to the closure 5A of the closures 5A and 5B connected to each other by a tap cable C5 that connects the core wires but cuts off the gas, the closure 5A is removed. The step of disassembling, the step of removing the cable C1 from the closure 5A, the end plate 53 holding the cable C1 is replaced with a new end plate 13, and the sleeve body of the closure 5A includes two valves 14A and 14B. And replacing the sleeve body 12 to assemble the closure 1 and connecting one of the two valves 14A and 14B to the valve 54 of the closure 5B with the gas pipe 3. [Selection] Figure 2

Description

  The present invention relates to a technique for removing a metal cable that is no longer needed.

  In the maintenance of metal cables installed in underground facilities, gas (dry air) is supplied from the equipment building (station building) into the metal cables, and the pressure transmitter (closure) installed in the closure attached to the metal cables The gas pressure is monitored). An example is given regarding the installation of a pressure transmitter. The metal cable is 4 km from the equipment building on the underground route, and is pulled up to the ground and wired to each home via a utility pole. In the nearest place, there is a closure with a pressure transmitter attached about 500m from the equipment building. After that, it is assumed 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 three closures that are not attached with pressure transmitters.

  When a gas leak is detected, it goes to a place where there is a possibility of gas leak, and a pressure measuring device is attached to the closure to identify the leak point by measuring the gas pressure in the closure. In addition, when the closure is assembled, a pressure measuring device is attached to the closure in order to confirm that there is no gas leakage due to poor assembly. This pressure measuring device is a portable type that can be carried, and for example, a digital nanometer is used. In order to ensure such a function, the closure is provided with one valve for attaching a pressure measuring device.

  On the other hand, in a closure installed in close proximity, there is a case where a core wire is branched from another closure and used in response to a shortage of the core wire accompanying an increase in demand downstream of a certain closure. In this case, gas is supplied to each closure separately from the upstream cable, so that gas is not mixed. Specifically, the closures arranged close to each other are connected to each other using a tap cable that connects the core wires but cuts off the gas.

  FIG. 1 shows the state of underground closures connected to each other using tap cables that connect core wires and block gas. The left side of the figure is the upstream (facility 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 of the cable C3 and the core of the cable C4 are connected, and a part of the core of the cable C3 branches to the tap cable C5. Gas is supplied to the closure 5B through the 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 between the closures 5A and 5B to shut off the gas. Thus, a part of the cable C3 can be connected to the cable C2 by the closure 5A without mixing the gas supplied by the cable C1 and the gas supplied by the cable C3.

  The closures 5A and 5B are provided 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 demand for metal cables has decreased due to the spread of optical communications. Therefore, the removal of the cable is being promoted after the accommodation of the metal cable on the same route is changed. 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, no gas is supplied to the closure 5A, so a gas supply route must be secured. Conventionally, the tap cable C5 that shuts off the gas is removed, and instead, a tap cable that does not shut off the gas is newly installed, and the 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 in place of the tap cable C5, and the core wire of the tap cable is connected to the core wire of the cable C3 and also connected to the core wire 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.

  In the conventional method of newly installing the tap cable instead of the tap cable C5 in this way, the closures 5A and 5B are disassembled, the cores of the tap cables are connected to the closures 5A and 5B, and the closures 5A and 5B are assembled. I need to fix it. For this reason, the construction cost has been increased, the temporary disconnection associated with the switching connection, and the construction period being prolonged.

  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.

  The cable removal method according to the present invention is a gas supply-side cable connected to a first closure of a first closure and a second closure connected to each other by a tap cable that connects the core wires but cuts off the gas. A step of disassembling the first closure, a step of removing the cable from the first closure, replacing the end face plate holding the cable with a new end face plate, Replacing the sleeve body of one closure with a sleeve body having two gas valves to assemble the first closure and connecting one 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 that connects a core wire but cuts off a gas is connected, a sleeve body provided with two gas valves, end face plates attached to both ends of the sleeve body, The gas valve of one of the two gas valves and the 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 connected mutually 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 flowchart 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 illustrating a state in which a cable is connected using the closure of the present 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 illustrating a state before the cable C1 is removed, and FIG. 2 is a diagram illustrating a state after the cable C1 is removed.

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

  In the closure 5B, the core of the cable C3 and the core of the cable C4 are connected, and a part of the core of the cable C3 branches to the tap cable C5. Gas is supplied to the closure 5B through the 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 disposed on the sleeve body 52 of the closure 5B and a valve 14A disposed on the sleeve body 12 of the closure 1. The valve 54 of the closure 5B uses a valve for attaching a pressure measuring device. The closure 1 includes two valves 14 </ b> A and 14 </ b> B on the sleeve body 12. The gas pipe 3 is attached to one valve 14A of the two valves 14A and 14B, and a pressure measuring instrument can be attached to the other valve 14B. The gas pipe 3 may be attached to the valve 14B, and the pressure measuring device may be attached to the valve 14A.

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

  The closure 1 has a cylindrical shape that accommodates a connection portion between the cable C2 and the tap cable C5 therein, semi-cylindrical sleeve bodies 11 and 12, end face plates 13 provided at both ends in the axial direction 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 disposed at the joint between the sleeve bodies 11 and 12.

  The upper sleeve body 12 in FIG. 2 includes two valves 14A and 14B. The valves 14 </ b> A and 14 </ b> B are vent holes that communicate with the space in 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 in a closed state. 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 disposed near both ends of the sleeve body 12 (near the end face plate 13). Further, each of the valves 14 </ b> A and 14 </ b> B may be disposed at an equal distance 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 size of the valves 14A and 14B and the size of the joint of the gas pipe 3 are different, an attachment for converting the size of the joint may be attached to the gas pipe 3. However, it is not preferable to attach an attachment because the height of the joint of the gas pipe 3 is increased by the amount of attachment. The cost for attachments also increases.

  Each of the end face plates 13 at both ends of the closure 1 includes a through hole through which the cable C2 and the tap cable C5 are passed. When the cable C2 and the tap cable C5 are passed through the end face plate 13, an airtight tape that closes the gap between the through hole and the cable C2 and the tap cable C5 is wound. The end face plate 13 is formed by joining semi-circular members that divide the through holes with bolts or the like. An end face gasket (not shown) is disposed at the joint between the end face plate 13 and the sleeve main bodies 11, 12, that is, at the outer periphery of the end face plate 13. Since the end face plate 13 is a component different from the sleeve main bodies 11 and 12, it is possible to arbitrarily select and use one according to the number and size of cables to be passed.

  The stainless steel band 15 is wound around the outer circumferences of the sleeve bodies 11 and 12 and tightened with screws (not shown). The stainless steel band 15 presses and fixes the outer periphery of the sleeve main bodies 11 and 12.

  Similarly to the closure 1 of the present embodiment, the conventional closure 5B includes sleeve bodies 51 and 52, an end face plate 53, and a stainless steel band 55. It differs from the closure 1 in that the sleeve body 52 includes 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. However, since the closures 1 and 5B are connected by the gas pipe 3, 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 the present embodiment.

  First, the closure 5A shown in 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 is passed can be used as it is, so that the cable C2 does not have to be removed from the end face plate 53 on the downstream side. The sleeve body 51 on the lower side of the closure 5A may be used as it is. Therefore, when disassembling the closure 5A, the stainless steel band 55 is removed, the upper sleeve body 52 is removed, and the upstream end face plate 53 through the cable C1 is disassembled.

  After the closure 5A is disassembled, the cable C1 and the cable C2 are disconnected from each other, and the cable C1 is removed. The core wires 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). Hereinafter, the assembly of the closure 1 will be described.

  An air tight tape is wound around a place where the end face plate 13 of the tap cable C5 is attached. The semicircular member of the end face plate 13 is joined so that the tap cable C5 passes through the through hole, and the end face plate 13 is attached to the tap cable C5. An end face plate gasket is attached to the outer periphery of the end face plate 13.

  The lower sleeve main body 11 (the sleeve main body 51 of the closure 5A may be used as it is) is attached to the end plate 13, a sleeve gasket is attached to the joint between the sleeve main bodies 11 and 12, and the sleeve main body 12 is put on the sleeve main body 11. .

  The stainless steel band 15 is wound around the outer circumferences of the sleeve bodies 11 and 12, and the screws of the stainless steel band 15 are tightened.

  The closure 1 can be assembled by the above process. After the closure 1 is assembled, gas is sealed in the closure 1 and then a soap solution is used to check for leaks. A leak test gas may be sealed 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 the gas pipe 3 is connected, the gas supplied through the cable C3 is also supplied to the closure 1 through the gas pipe 3, and is also supplied to the closure at the rear stage of the closure 1 through the cable C2. After a certain period, the gas pressure stabilizes.

  As described above, when the cable C1 is removed, by using the closure 1 of the present embodiment, only the disassembly and assembly of the closure 5A that holds the cable C1, and the disassembly and assembly of the other closure 5B become unnecessary. A part of the disassembled closure 5A can also be used. Moreover, since the tap cable C5 is used as it is and a tap cable is not newly provided, connection of a core wire is unnecessary.

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

  FIG. 4 is a diagram illustrating an example in which the tap cable C5 is passed through the same end plate 53 as the cable C2 to be left.

  In FIG. 1, the tap cable C5 passes through the same end plate 53 as the cable C1 to be removed, but the tap cable C5 may pass through the same end 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 that the end face plate 53 through the cable C2 and the tap cable C5 is used as it is. Since the cable is not passed from the side where the cable C1 is removed, the end plate 13 having no through-hole through which the cable is passed is attached. Only the end face plate 13 to be attached is different from FIG.

  In the construction method of the present embodiment, the tap cable C5 connecting the closures 5A and 5B is used as it is, so that it can be applied regardless of the place through which the tap cable C5 is passed.

  As described above, according to the present embodiment, the gas supply side connected to the closure 5A among the closures 5A and 5B connected to each other by the tap cable C5 that connects the core wires but cuts off 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 replaced with two sleeve bodies. By replacing the sleeve main body 12 with the valves 14A and 14B, the closure 1 is assembled, and one of the two valves 14A and 14B and the valve 54 of the closure 5B are connected by the gas pipe 3, whereby the gas The tap cable C5 can be used as it is. Therefore, the disassembly and assembly of the closure 5B and the connecting work of the core wire are not required, the labor is eliminated, the construction period is shortened, and the construction efficiency can be expected to be improved. Since the remaining closure 5B is not dismantled, the user downstream of the closure 5B has no communication interruption.

  Moreover, since the end face plate 13 of the closure 5A holding the removed cable C1 and the sleeve main body 12 provided with the two valves 14A and 14B need only be replaced and the gas pipe 3 is 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 of removing a cable on a gas supply side connected to a first closure of a first closure and a second closure connected to each other with a tap cable that connects a core wire but cuts off gas,
Disassembling the first closure;
Removing the cable from the first closure;
Replacing the end face plate holding the cable with a new end face plate, replacing the sleeve body of the first closure with a sleeve body having 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 by comprising: A closure to which a tap cable that connects the core wire but cuts off the gas is connected,
A sleeve body with two gas valves;
An end face plate attached to both ends of the sleeve body,
A closure characterized in that one gas valve of the two gas valves and a gas valve provided in another closure connected to each other by the tap cable are connected by a gas pipe.   The closure according to claim 2, wherein each of the two gas valves is compatible with a joint of the gas pipe and is disposed at a position equally spaced from both ends of the sleeve body.

Images