JP2020159415A - Gas pipe closing device - Google Patents

Abstract

To provide a gas pipe closing device in which a pair of gas bags is easily extracted from the inside of a gas pipe.SOLUTION: A gas pipe closing device comprises: an outer cylinder 4 having a cylindrical shape and arranged so as to extend toward an opening part H formed in a gas pipe P; a pair of gas bags 6a and 6b that expands at both sides of the opening part H in the gas pipe P, and closes the gas pipe P; and a pair of operation units 5a and 5b that is arranged so as to extend inside the outer cylinder 4 and to which the pair of gas bags 6a and 6b is respectively connected in the vicinity of the tip part. The pair of operation units 5a and 5b is arranged so as to be able to move forward and backward individually in the outer cylinder 4, and one operation unit 5a is retracted and then the other operation unit 5b is retracted, so that the pair of contracted gas bags 6a and 6b is sequentially housed in the outer cylinder 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to a gas pipe closing device, and more particularly to a gas pipe closing device that inflates a pair of gas bags to close the gas pipe.

Conventionally, a gas pipe closing device for closing a gas pipe by forming an opening in the gas pipe, inserting the gas bag, and expanding the gas bag has been put into practical use. For example, when the gas pipe is damaged, the damage to the gas pipe can be safely repaired by closing the upstream side of the damaged portion with the gas pipe closing device. However, simply expanding one gas bag in the gas pipe may cause gas to flow out to the downstream side of the gas bag.

Therefore, as a technique for suppressing the outflow of gas to the downstream side of the gas bag, for example, Patent Document 1 proposes a gas bag insertion jig for inserting a pair of gas bags into a gas pipe by a no-blow method. This gas bag insertion jig is attached to the lower part of an air pressure feed pipe so that a pair of gas bags that have a drum shape when inflated face each other in opposite directions, and the pair of gas bags are inflated in a gas pipe. It is possible to suppress the outflow of gas to the downstream side of the gas bag.

Japanese Unexamined Patent Publication No. 10-82496

Here, the gas bag insertion jig of Patent Document 1 accommodates a pair of contracted gas bags in the gas bag insertion pipe when the pair of gas bags is taken out from the gas pipe, and is inside the gas pipe together with the gas bag insertion pipe. It is formed to pull out from. However, since the gas bag once inflated is folded larger than the gas bag before expansion, it is difficult to put the pair of gas bags together in the gas bag insertion pipe.

The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a gas pipe closing device for easily taking out a pair of gas bags from the inside of a gas pipe.

The gas pipe closing device according to the present invention has a tubular shape and expands on both sides of an outer cylinder formed in the gas pipe so as to extend toward the opening and on both sides of the gas pipe sandwiching the opening. It is provided with a pair of gas bags that close the gas pipe and a pair of operating units that are arranged so as to extend inside the outer cylinder and each of which is connected to a pair of gas bags near the tip, and the pair of operating units is outside. The inside of the cylinder is individually arranged so as to be able to advance and retreat, and by retracting one operating portion and then retracting the other operating portion, a pair of contracted gas bags are sequentially housed in the outer cylinder.

Here, the other operating unit is connected to one operating unit that has been retracted by a predetermined distance so that the pair of contracted gas bags are sequentially housed in the outer cylinder as the one operating unit retracts. It is preferable to further have a retreating connecting portion for causing.

Further, a forward connection for connecting the other operating unit to the advancing one operating unit so that the pair of gas bags before expansion are both moved from the outer cylinder into the gas pipe as the one operating unit advances. It is preferable to have more portions.

Further, the outer cylinder may have a sealing portion that seals between the pair of operating portions so that the pair of operating portions can move forward and backward.

Further, it is preferable to further have a connection valve connected to the gas pipe, the insertion path into which the outer cylinder is inserted extends toward the opening, and the insertion path is formed so as to be openable and closable.
Further, it is possible to further have a drilling machine which is fixed to the gas pipe and connected to the connection valve to form an opening for inserting the outer cylinder into the gas pipe.

Further, the outer cylinder may have an exhaust valve for exhausting the gas inside.

According to the present invention, a pair of operating portions are individually arranged so as to be able to advance and retreat in the outer cylinder, and a pair of gas bags contracted by retracting one operating portion and then retracting the other operating portion. Since the gas bags are sequentially housed in the outer cylinder, it is possible to provide a gas pipe closing device in which a pair of gas bags can be easily taken out from the gas pipe.

It is sectional drawing which shows the structure of the gas pipe closing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows an example of the attachment place of the gas pipe closing device. It is a figure which shows the state in which a drilling machine and a connection valve are attached to a gas pipe. It is sectional drawing which shows the appearance that the outer cylinder was attached to the connection valve via an adapter. It is sectional drawing which shows a mode that a pair of gas bags before expansion are moved from an outer cylinder into a gas pipe. It is sectional drawing which shows the state that a pair of contracted gas bags are sequentially housed in an outer cylinder. It is sectional drawing which shows the structure of the gas pipe closing apparatus which concerns on Embodiment 2. FIG. It is sectional drawing which shows the mode that the pair of gas bags contracted in Embodiment 2 are sequentially housed in the outer cylinder. It is sectional drawing which shows the structure of the gas pipe closing apparatus which concerns on Embodiment 3. It is a figure which shows the state in which the gas pipe closing device which concerns on other embodiment is attached to the gas pipe.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Embodiment 1
FIG. 1 shows the configuration of the gas pipe closing device according to the first embodiment of the present invention. This gas pipe closing device has a drilling machine 1 attached to the gas pipe P, and a connection valve 2, an adapter 3, an outer cylinder 4 and a pair of operating portions 5a and 5b are sequentially attached to the drilling machine 1. .. Further, a pair of gas bags 6a and 6b are arranged in the gas pipe P, and a pair of air supply / discharge portions 7a and 7b are connected to the gas bags 6a and 6b.

The drilling machine 1 is a so-called magic joint in which an opening H fixed to the gas pipe P and for inserting the outer cylinder 4 is formed in the gas pipe P, and a part of the gas pipe P is moved by an explosive. The opening H is formed by scraping off. Further, the drilling machine 1 has a connecting portion for connecting the connection valve 2, and an insertion path for inserting the outer cylinder 4 extends from the connecting portion toward the opening H in a direction orthogonal to the gas pipe P. It is formed like this.
The connection valve 2 has a pipe shape extending in a direction orthogonal to the gas pipe P, and one end thereof is connected to the connection portion of the drilling machine 1 and the other end portion is connected to the adapter 3. Inside the connection valve 2, an insertion path for inserting the outer cylinder 4 is formed so as to extend from the other end toward one end. Further, an opening / closing portion 2a for opening / closing the insertion path is arranged on the side portion of the connection valve 2.

The adapter 3 is for connecting the outer cylinder 4 to the connection valve 2, and is formed so as to be connectable to the other end of the connection valve 2. Further, an insertion path for inserting the outer cylinder 4 is formed inside the adapter 3. Therefore, an insertion path is formed so as to extend from the adapter 3 to the opening H of the gas pipe P via the connection valve 2 and the drilling machine 1. Further, on the inner surface of the adapter 3, a seal portion 3a is arranged to seal the outer cylinder 4 from the outer cylinder 4 so that the outer cylinder 4 can move forward and backward. The seal portion 3a is a so-called O-ring formed so as to surround the outer cylinder 4.

The outer cylinder 4 has a tubular shape and is formed so as to extend from the outside of the adapter 3 to the inside of the gas pipe P via an insertion path. That is, the outer cylinder 4 is formed so as to extend toward the opening H, and the tip portion thereof is arranged in the opening H. Further, in the outer cylinder 4, a moving path T for moving the operation portions 5a and 5b along the outer cylinder 4 is formed so as to extend from the base end portion to the tip end portion. Further, on the inner surface near the base end portion of the outer cylinder 4, a seal portion 4a that seals between the operation portions 5a and 5b so that the operation portions 5a and 5b can move forward and backward is arranged. The seal portion 4a is a so-called O-ring formed so as to surround the operation portions 5a and 5b, respectively.
Further, in the vicinity of the base end portion of the outer cylinder 4, an exhaust valve 8 for communicating with the moving path T and discharging the gas in the moving path T is arranged.

The operation units 5a and 5b are formed so as to extend from the base end side of the outer cylinder 4 to the inside of the gas pipe P via the moving path T, and are individually arranged so as to be able to advance and retreat inside the outer cylinder 4.
The air supply / exhaust portions 7a and 7b have a tube shape extending from the base end portion of the operation portions 5a and 5b to the tip end portion, and the gas bags 6a and 6b are connected to the tip end portion thereof. As a result, the gas bags 6a and 6b are connected to the vicinity of the tip portions of the operating portions 5a and 5b via the air supply / exhaust portions 7a and 7b, respectively. Further, at the base end portions of the air supply / exhaust portions 7a and 7b, a manual pump portion for supplying and discharging air into the gas bags 6a and 6b is arranged.

The gas bags 6a and 6b close the gas pipe P so as to expand in a disk shape according to the shape of the gas pipe P by supplying air from the air supply / exhaust portions 7a and 7b to the inside. It is formed. Further, the gas bags 6a and 6b are arranged in the gas pipe P so as to expand on both sides of the opening H. That is, the gas bags 6a and 6b are arranged so as to be separated from the tip portions of the operating portions 5a and 5b to the outside.

Next, a method of closing the gas pipe P will be described in detail.
For example, as shown in FIG. 2, when a gas leak occurs from the damaged part F of the gas pipe P, the gas pipe closing device is attached to the upstream side of the damaged part F with respect to the gas flow direction, for example, the attachment point S. Be done. Here, FIG. 2 shows that the gas pipe P for drawing gas into a building such as an apartment is branched into four gas pipes P, and one of the gas pipes P has a damaged part F. To do.

First, as shown in FIG. 3, the drilling machine 1 is fixed to the mounting portion S of the gas pipe P by an operator, and then one end of the connection valve 2 is attached to the connecting portion of the punching machine 1. Then, the opening / closing portion 2a of the connection valve 2 is closed, and the insides of the drilling machine 1 and the connection valve 2 are sealed. When the insides of the drilling machine 1 and the connection valve 2 are sealed in this way, the punching machine 1 forms an opening H in the gas pipe P. Subsequently, as shown in FIG. 4, the outer cylinder 4 is attached to the other end of the connection valve 2 via the adapter 3.
At this time, the operation portions 5a and 5b are attached to the outer cylinder 4 in advance together with the air supply / exhaust portions 7a and 7b. Further, the gas bags 6a and 6b are held in a folded state at the tips of the operating portions 5a and 5b.

In this way, the gas pipe closing device can be easily attached to the gas pipe P. Here, since the outer cylinder 4 is connected to the gas pipe P via the connection valve 2, gas leakage from the opening H of the gas pipe P can be suppressed only by closing the opening / closing portion 2a of the connection valve 2. Therefore, the outer cylinder 4 can be easily connected to the gas pipe P without covering the periphery of the gas pipe P with a no-blow bag or the like. Further, by arranging the drilling machine 1 between the gas pipe P and the connection valve 2, the opening H can be easily formed in the gas pipe P without opening and closing the opening / closing portion 2a.

Subsequently, as shown in FIG. 5A, when the operator opens the opening / closing portion 2a and pushes down the base end portion of the outer cylinder 4 toward the adapter 3, the tip end portion of the outer cylinder 4 connects to the adapter 3. The insertion path formed in the valve 2 and the drilling machine 1 is inserted toward the opening H of the gas pipe P. At this time, since the seal portion 3a that seals the outer cylinder 4 from the outer cylinder 4 so as to be able to move forward and backward is arranged on the inner surface of the adapter 3, the outer cylinder 4 can be moved while suppressing gas leakage from the insertion path. Can be inserted.
In this way, the tip of the outer cylinder 4 is inserted until it is located in the opening H of the gas pipe P. Here, the base end portion of the outer cylinder 4 is formed wide so as to come into contact with the upper edge portion of the adapter 3 when the tip end portion is pushed down until it is positioned in the opening H. As a result, the operator can easily grasp the insertion position of the outer cylinder 4, and can surely position the tip end portion of the outer cylinder 4 in the opening H.

When the outer cylinder 4 is inserted to the opening H, as shown in FIG. 5B, the operator pushes down the base ends of the operation portions 5a and 5b toward the outer cylinder 4, thereby causing the operation portion 5a and The tip portion of 5b advances the movement path T of the outer cylinder 4 toward the inside of the gas pipe P. At this time, since the sealing portion 4a that seals between the operating portions 5a and 5b so that the operating portions 5a and 5b can move forward and backward is arranged on the inner surface of the outer cylinder 4, gas leakage from the moving path T is suppressed. While doing so, the operating units 5a and 5b can be advanced. Further, since the outer cylinder 4 is inserted into the opening H, it is possible to prevent the gas bags 6a and 6b held at the tips of the operating portions 5a and 5b from coming into contact with the edges of the opening H and being damaged. can do.

In this way, the operating units 5a and 5b are advanced until the gas bags 6a and 6b move from the moving path T of the outer cylinder 4 into the gas pipe P. Here, the base end portions of the operating portions 5a and 5b are formed wide so as to come into contact with the outer cylinder 4 when the gas bags 6a and 6b are pushed down until they move into the gas pipe P. Therefore, the operator can easily grasp the insertion positions of the operation units 5a and 5b, and can reliably position the gas bags 6a and 6b in the gas pipe P.

Here, the gas leak is strengthened through a series of operations from the attachment of the gas pipe closing device to the gas pipe P to the arrangement of the gas bags 6a and 6b into the gas pipe P by the connection valve 2, the seal portion 3a, the seal portion 4a, and the like. Is suppressed. The work of arranging the gas bag in the gas pipe P while opening and closing the opening H of the gas pipe P as in the conventional case may cause a large amount of gas leakage from the opening H, and therefore, when performing the work In some cases, the gas flowing through the gas pipe was stopped in a wide range for safety.
For example, as shown in FIG. 2, when the gas pipe P branched into a plurality of systems is closed by a gas bag, the gas is stopped before the gas pipe P branches, for example, a former valve provided outside the building. In some cases, the V was closed to stop all gas drawn into the building. In the present invention, since gas leakage is strongly suppressed through a series of operations, it is only necessary to close the system valve V1 provided in the gas pipe P of one system, and the range of stopping the gas is minimized. Can be done.

When the gas bags 6a and 6b are moved into the gas pipe P in this way, air is supplied into the gas bags 6a and 6b from the air supply / discharge portions 7a and 7b. As a result, as shown in FIG. 1, the gas bags 6a and 6b expand on both sides of the gas pipe P with the opening H in between, and the gas pipe P is closed.
Since the gas pipe P is closed by the pair of gas bags 6a and 6b in this way, the outflow of gas to the downstream side of the gas bags 6a and 6b can be reliably suppressed.

When the gas pipe P is closed by the inflated gas bags 6a and 6b, the damaged portion F of the gas pipe P is repaired. At this time, when the gas moves beyond the gas bag 6a located on the upstream side of the gas bags 6a and 6b to the gas bag 6b side, the discharge valve 8 can be opened to discharge the gas to the outside. As a result, it is possible to more reliably suppress the outflow of gas to the downstream side of the gas bag 6b, and the damaged portion F can be safely repaired.

When the damaged portion F of the gas pipe P is repaired, the air in the gas bag 6a is discharged by the air supply / exhaust portion 7a to contract the gas bag 6a. Then, as shown in FIG. 6A, the contracted gas bag 6a is housed in the outer cylinder 4 by retracting the operation unit 5a. Subsequently, the air in the gas bag 6b is discharged by the air supply / discharge unit 7b to contract the gas bag 6b. Then, as shown in FIG. 6B, the contracted gas bag 6b is housed in the outer cylinder 4 by retracting the operation unit 5b.

As described above, since the operation units 5a and 5b are formed so as to be able to move forward and backward individually in the outer cylinder 4, the gas bags 6a and 6b can be sequentially housed in the outer cylinder 4. In general, it is difficult to fold the gas bags 6a and 6b once expanded to the size before expansion even if they are contracted. When the pair of operating portions 5a and 5b are retracted at the same time, for example, the tip of the outer cylinder 4 There is a possibility that the gas bags 6a and 6b cannot be accommodated in the outer cylinder 4 because the pair of gas bags 6a and 6b are clogged in the portion. On the other hand, if the diameter of the outer cylinder 4 is increased so that the gas bags 6a and 6b do not clog the tip of the outer cylinder 4, the opening H is unnecessarily large formed in the gas pipe P.
In the present invention, the pair of gas bags 6a and 6b can be easily taken out from the gas pipe P by forming the operating portions 5a and 5b so that they can move forward and backward individually. Further, if the gas bags 6a and 6b before expansion have an opening H having a size movable in the gas pipe P, the contracted gas bags 6a and 6b can be taken out from the gas pipe P, so that the opening H can be formed with a minimum size.

When the gas bags 6a and 6b are housed in the outer cylinder 4 in this way, the outer cylinder 4 is retracted together with the gas bags 6a and 6b to the vicinity of the other end of the connection valve 2, and the opening / closing portion of the connection valve 2 is opened and closed. 2a is closed. As a result, the insides of the drilling machine 1 and the connection valve 2 are sealed, and the outer cylinder 4 can be removed from the connection valve 2 together with the operation portions 5a and 5b.

According to the present embodiment, since the operation units 5a and 5b are individually arranged so as to be able to advance and retreat in the outer cylinder 4, the gas bags 6a and 6b connected to the vicinity of the tip portions of the operation units 5a and 5b are connected to the gas pipe. It can be easily taken out from inside P.

Embodiment 2
In the first embodiment described above, the operation units 5a and 5b are both operated so that the gas bags 6a and 6b are sequentially housed in the outer cylinder 4, but the inside of the outer cylinder 4 can be moved back and forth individually. It does not have to be limited to this as long as it is arranged.
For example, as shown in FIG. 7, the retracting connecting portions 21a and 21b can be newly arranged in the first embodiment.

The retracting connecting portions 21a and 21b are provided with respect to the operating portion 5a retracted by a predetermined distance so that the contracted gas bags 6a and 6b are sequentially housed in the outer cylinder 4 as the operating portion 5a retracts. The operation unit 5b is connected.
The retracting connecting portion 21a is fixed to an intermediate portion in the longitudinal direction in the operating portion 5a, and is formed in a rectangular parallelepiped shape protruding in the radial direction from the outer surface of the operating portion 5a.
The retreating connecting portion 21b is fixed to the operating portion 5b behind the retreating connecting portion 21a, that is, at a position separated from the base end portion side of the operating portion 5b by a predetermined distance, and protrudes radially from the outer surface of the operating portion 5b. It is formed to do. Here, the rear portion of the retracting connecting portion 21b is formed so as to project larger in the radial direction than the front portion. Specifically, the rear portion of the retracting connecting portion 21b is formed so as to project in the longitudinal direction of the operating portions 5a and 5b to a position overlapping the retracting connecting portion 21a. A hole is formed in the retracting connecting portion 21b at a position overlapping the operating portion 5a, and the operating portion 5a is inserted into the hole so as to be able to advance and retreat. Here, the predetermined distance between the retracting connecting portion 21a and the retracting connecting portion 21b retracts only the operating portion 5a and retracts when the contracted gas bag 6a is housed in the outer cylinder 4. The connecting portion 21a is set to abut the retracting connecting portion 21b.

With such a configuration, as shown in FIG. 8A, when the gas bag 6a is contracted and then only the operation unit 5a is retracted, when the contracted gas bag 6a is housed in the outer cylinder 4. The retracting connecting portion 21a comes into contact with the retracting connecting portion 21b, and the operating portion 5b is connected to the operating portion 5a. Subsequently, as shown in FIG. 8B, the gas bag 6b is contracted to further retract the operating portion 5a, whereby the operating portion connected to the operating portion 5a via the retracting connecting portions 21a and 21b. 5b retracts and the gas bag 6b is housed in the outer cylinder 4.

According to the present embodiment, the retracting connecting portions 21a and 21b are retracted by a predetermined distance so that the contracted gas bags 6a and 6b are sequentially housed in the outer cylinder 4 as the operating portion 5a retracts. Since the operation unit 5b is connected to the operation unit 5a, only the operation unit 5a can be operated to sequentially accommodate the gas bags 6a and 6b in the outer cylinder 4.
The retracting connecting portions 21a and 21b came into contact with each other after the gas bag 6a was housed in the outer cylinder 4, but it is sufficient if the gas bags 6a and 6b can be sequentially housed in the outer cylinder 4. It is not limited.

Embodiment 3
In the above-described first and second embodiments, the operation units 5a and 5b are both operated so that the gas bags 6a and 6b before expansion are both moved from the outer cylinder 4 into the gas pipe P, but outside. It suffices if the inside of the cylinder 4 is individually arranged so as to be able to advance and retreat, and the present invention is not limited to this.
For example, as shown in FIG. 9A, the forward connecting portions 31a and 31b can be newly arranged in the first embodiment.

The advancing connecting portions 31a and 31b operate with respect to the advancing operating portion 5a so that the gas bags 6a and 6b before expansion are both moved from the outer cylinder 4 into the gas pipe P as the operating unit 5a advances. The part 5b is connected.
The advancing connecting portion 31a is fixed to the base end portion of the operating portion 5a and is formed in a rectangular parallelepiped shape protruding in the radial direction from the outer surface of the operating portion 5a.
The advancing connecting portion 31b is fixed to the base end portion of the operating portion 5b and is formed so as to project radially from the outer surface of the operating portion 5b. Here, the front portion of the forward connecting portion 31b is formed so as to project larger in the radial direction than the rear portion. Specifically, the front portion of the forward connecting portion 31b is formed so as to project in the longitudinal direction of the operating portions 5a and 5b to a position overlapping the forward connecting portion 31a. A hole is formed in the advancing connecting portion 31b at a position overlapping the operating portion 5a, and the operating portion 5a is inserted into the hole so as to be able to advance and retreat.

With such a configuration, as shown in FIG. 9B, when the gas bags 6a and 6b before expansion are moved into the gas pipe P, only the operation portion 5a is advanced to advance the advancing connecting portion 31a. Is in contact with the advancing connecting portion 31b, and the operating portion 5b is connected to the operating portion 5a. Then, by further advancing the operating portion 5a, the operating portion 5b connected via the advancing connecting portions 31a and 31b advances, and both the gas bags 6a and 6b are moved from the outer cylinder 4 into the gas pipe P. To.

According to the present embodiment, the advancing connecting portions 31a and 31b advance so that the gas bags 6a and 6b before expansion are both moved from the outer cylinder 4 into the gas pipe P as the operating portion 5a advances. Since the operation unit 5b is connected to the operation unit 5a, only the operation unit 5a can be operated to move the gas bags 6a and 6b together into the gas pipe P.

Embodiment 4
In the above-described first to third embodiments, one gas pipe closing device is attached to the gas pipe P, but a plurality of gas pipe closing devices can also be attached.
For example, as shown in FIG. 10, the gas pipe closing device 41 and the gas pipe closing device 42 can be arranged so as to sandwich the damaged portion F of the gas pipe P.

In the gas pipe P, the gas pipe closing device 41 is arranged on the upstream side of the damaged portion F, and the gas pipe closing device 42 is arranged on the downstream side of the damaged portion F. In this way, the gas pipe closing devices 41 and 42 close the gas pipe P from both sides of the damaged part F, so that the valve on the downstream side is provided at a place far from the damaged part F, for example. The damaged part F can be safely repaired.
Further, after the damaged portion F is repaired, the closure by the gas pipe closing device 41 is opened, and the discharge valve 8 of the gas pipe closing device 42 arranged on the downstream side of the gas pipe closing device 41 is opened to perform the repair. The gas pipe P can be easily purged with gas.

According to the present embodiment, since the pair of gas pipe closing devices 41 and 42 are arranged so as to sandwich the damaged portion F of the gas pipe P, the damaged portion F can be repaired more safely.

In the above-described first to fourth embodiments, the operating units 5a and 5b were operated so that the gas bags 6a and 6b before expansion were both moved from the outer cylinder 4 into the gas pipe P, but the gas bag 6a was operated. And 6b can also be operated to move sequentially into the gas tube P.
For example, after the operation unit 5a is advanced to move the gas bag 6a into the gas pipe P, the operation unit 5b can be advanced to move the gas bag 6b into the gas pipe P. At this time, the forward connecting portion 31b of the third embodiment is arranged at a position away from the forward connecting portion 31a in the operating portion 5b.

Further, in the above-described first to fourth embodiments, the operation units 5a and 5b are operated so that the gas bag 6b is housed in the outer cylinder 4 following the contracted gas bag 6a, but the gas bag 6b Subsequently, the gas bag 6a can be operated so as to be housed in the outer cylinder 4.
That is, after the operation unit 5b is retracted to accommodate the gas bag 6b in the outer cylinder 4, the operation unit 5a can be retracted to accommodate the gas bag 6a in the outer cylinder 4. At this time, in the third embodiment, the retracting connecting portion 21a is arranged in the operating portion 5b, and the retracting connecting portion 21b is arranged in the operating portion 5a.

1 Drilling machine 2 Connection valve 2a Opening and closing part 3 Adapter 3a Seal part 4 Outer cylinder 4a Seal part 5a, 5b Operation part 6a, 6b Gas bag 7a, 7b Air supply / exhaust part 8 Discharge valve 21a, 21b Retracting connection part 31a, 31b Forward connection 41,42 Gas pipe closing device P Gas pipe H Opening T Movement path F Damaged part S Mounting point V Original valve V1 system valve

Claims (7)

An outer cylinder that has a tubular shape and is arranged so as to extend toward an opening formed in the gas pipe.
A pair of gas bags that expand on both sides of the gas pipe and close the gas pipe, respectively.
A pair of operating units are provided so as to extend inside the outer cylinder and to which the pair of gas bags are connected to each other in the vicinity of the tip portion.
The pair of operating units are individually arranged so as to be able to move forward and backward in the outer cylinder, and by retracting one operating unit and then retracting the other operating unit, the contracted pair of gas bags is removed from the outer cylinder. A gas pipe closing device that is sequentially housed in a cylinder. The other operating unit with respect to the one operating unit retracted by a predetermined distance so that the pair of contracted gas bags are sequentially housed in the outer cylinder as the one operating unit retracts. The gas pipe closing device according to claim 1, further comprising a retracting connecting portion for connecting the two. A forward movement in which the other operating unit is connected to one operating unit that advances so that the pair of gas bags before expansion are both moved from the outer cylinder into the gas pipe as the one operating unit advances. The gas pipe closing device according to claim 1 or 2, further comprising a connecting portion. The gas pipe closing device according to any one of claims 1 to 3, wherein the outer cylinder has a sealing portion that seals the pair of operating portions from each other so that the pair of operating portions can move forward and backward. Any one of claims 1 to 4, wherein the insertion path connected to the gas pipe and into which the outer cylinder is inserted extends toward the opening and further has a connection valve formed so that the insertion path can be opened and closed. The gas pipe closing device described in. The gas pipe closing device according to claim 5, further comprising a perforator fixed to the gas pipe and connected to the connection valve to form an opening for inserting the outer cylinder into the gas pipe. The gas pipe closing device according to any one of claims 1 to 6, wherein the outer cylinder has a discharge valve for discharging gas inside.