JPH11125387A - Mobile type conduit shutoff device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a device in small size, lightweight, and enable the device to pass through even in a joint of different type, in the mobile type conduit shutoff device freely movable in a conduit to air-tightly close it. SOLUTION: An elastic film body of a first/second stopper 11, 12 is formed roughly so as to have a cylindrical swell part 27 and a mounting part 28 in both sides extended inward in a radial direction. Through a passage 23, 24 provided in a main body 14, when air is fed in an internal peripheral side of the swell part 27, it is swollen, a peripheral surface thereof is made in close adhesion to an internal peripheral surface of a conduit, it can be airtightly closed. Since an amount of air and a pressure required for swelling can be decreased, a stopper 10 can be formed in small size, its weight can be lightened. Between each of a guide 30 and the first/second stoppers 11, 12 are connected by a universal joint 18, so as to facilitate even passing in a curved pipe. Since the guide 30 has a cone shape, a guide can be smoothed even in the curved pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable conduit blocking device for moving a conduit for transporting gas such as city gas and blocking the conduit at an arbitrary position.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Publication No. 1-2817
In the method of exchanging a gas transport conduit disclosed in Patent Document 1 and the like, a movable conduit shutoff device is used which is movable in an axial direction in the conduit, and can be stopped at an arbitrary position to hermetically close the pipe. ing. 2. Description of the Related Art The prior art relating to a mobile conduit blocking device is disclosed, for example, in Japanese Patent Publication No. 62-58435. In this prior art, an elastic membrane is attached around a main body that is substantially cylindrical and the outer diameter of a central portion is smaller than both ends in the axial direction, and a fluid is provided on the inner peripheral side of the elastic membrane. Is supplied and inflated, the outer peripheral side of the elastic membrane body is in close contact with the inner peripheral side of the conduit, and can be hermetically closed.

[0003]

A city gas transport conduit is buried in the ground 2 below the ground surface 1, for example, as shown in FIG. The city gas conduit 3 is buried in a shape that is as straight as possible at a basically constant depth from the ground surface 1, but may have a bent shape. For example, the city gas conduit 3 may be mainly composed of the horizontal pipes 4 and 5, and the overhang 6 may be provided to avoid the other buried objects 7. Although the shape of the city gas conduit 3 is bent in the depth direction in the overhanging part 6 shown in FIG. 8, in order to avoid other column-shaped buried objects buried in the vertical direction, the city gas conduit 3 must be in a horizontal plane. In some cases, the shape may be bent. The overhang portion 6 shown in FIG. 8 is formed by combining a plurality of 90 ° elbow joints 8 and a plurality of straight pipe portions 9 respectively.

In the prior art mobile conduit shut-off device disclosed in Japanese Patent Publication No. 62-58435, its main purpose is to move in a straight cast iron pipe, and it includes a plurality of 90 ° elbow joints 8 as shown in FIG. When moving in the city gas conduit 3, it is difficult to pass through the corner. In particular, when a plurality of 90 ° elbow joints 8 are continuously provided with a short straight pipe portion 9 interposed therebetween as shown in FIG. 8, movement in the pipe is almost impossible.

FIG. 9 shows the inside of the 90 ° elbow joint 8 shown in FIG. 8 in consideration of the difference in material. FIG. 9 (a) shows the inside of a 90 ° elbow joint 8a made of cast iron, and FIG. 9 (b) shows the inside made of a synthetic resin such as polyethylene.
The internal structure of the 0 ° elbow joint 8b is shown. Since the 90 ° elbow joint 8a of the cast iron pipe shown in FIG. 9A is connected to the cast iron pipe with a screw, the wall thickness is almost constant, and the corner portion is smoothly bent. On the other hand, the 90 ° elbow joint 8b for PE pipe shown in FIG. 9B is bent in such a shape that a clear edge is formed at approximately 90 ° inside the bent portion. It is particularly difficult for the prior art mobile conduit cutoff device to pass through such a 90 ° elbow joint 8b for PE pipe or the like, and as shown in FIG. It is almost impossible to pass through the constructed lie-over 6.

Further, in the movable conduit blocking device disclosed in Japanese Patent Publication No. 62-58435, the elastic membrane has a drum-shaped shape in which the central portion in the axial direction is concave inward in the radial direction. It is necessary to feed relatively high pressure water of about 6 kgf / cm ² at a relatively large flow rate in order to expand radially outward. Further, the outer diameter of the device is large, and not only 90 ° elbow joints 8a and 8b as shown in FIG.
A 5 ° joint is also difficult to pass.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a movable conduit shut-off device which can pass through a modified joint such as a 90 ° elbow joint and can reduce the pressure required for hermetically closing the inside of a conduit. It is.

[0008]

DISCLOSURE OF THE INVENTION The present invention is a movable conduit shutoff which is operable to move axially in a gas transport conduit, expands and hermetically closes the conduit, and shuts off gas flow. An elastic film body having a substantially cylindrical shape, an outer diameter smaller than the inner diameter of the conduit, and a mounting portion having a shape extending radially inward on both axial sides; and And a body in which a passage for guiding inflation gas is formed on the inner periphery side of the elastic film body in close contact with the inner peripheral side thereof, and a substantially disk-shaped body, on both sides in the axial direction of the main body. A holding plate attached to the elastic membrane body so as to sandwich the mounting portion between the end face of the main body and a holding plate having an outer diameter smaller than the inner diameter of the conduit and larger than the outer diameter of the elastic membrane body. Characteristic mobile conduit blocking device.

In accordance with the present invention, the elastic membrane is generally cylindrical, has an outer diameter smaller than the inner diameter of the conduit, and includes mounting portions extending radially inward on both axial sides. The main body is in close contact with the inner peripheral side of the elastic membrane. In the main body, a passage for guiding the gas for inflation is formed on the inner peripheral side of the elastic film body.
On both sides in the axial direction of the main body, holding plates are provided which sandwich the mounting portion of the elastic membrane between the end faces of the main body. The outer diameter of the holding plate is smaller than the inner diameter of the conduit and larger than the outer diameter of the elastic membrane. Therefore, when the elastic film is in close contact with the main body, it is movable in the conduit, and when the gas is supplied to expand the elastic film, the outer peripheral portion of the elastic film adheres to the inner peripheral surface of the conduit. The inside of the conduit can be hermetically closed.
Since the elastic membrane expands from a cylindrical state to perform airtight closure, the amount of gas required for expansion may be smaller than in the case of expanding from a drum-shaped shape. It can be airtight. Since the airtight closure by the elastic membrane can be achieved with a small gas pressure, the mechanical strength required for the main body and the holding plate is also reduced, so that the overall size and weight can be reduced and the passage of the curved portion can be facilitated. .

In the present invention, a plurality of combinations of the elastic membrane body, the main body and the holding plate are provided at intervals in the axial direction of the conduit, and the main body of each combination is arranged along the axis. It is connected by a provided universal joint, and the main bodies are also connected by a coil spring surrounding the universal joint.

According to the present invention, a plurality of sets of elastic membranes, a main body and a holding plate are arranged at intervals in the axial direction of the conduit, so that the inside of the conduit is airtightly closed at a plurality of places, and Sealing can be performed reliably. The connection of the main pipe uses a universal joint, and furthermore, a coil spring is provided around the universal joint, so that the direction can be easily changed and passed even in a bent conduit. Further, since the coil spring is provided on the outer peripheral side of the universal joint, the direction of the universal joint can be changed to the axial direction when passing through the linear portion.

In the present invention, the elastic membrane, the main body and the holding plate are provided at intervals in the axial direction of the conduit from the combination of the elastic membrane, the main body and the presser plate, and have a substantially conical shape, and are provided for traction in the conduit. A guide positioned at the top, wherein the guide has a conical bottom surface facing the combination side, and a plurality of radial grooves passing through a central portion are formed on a conical top portion, and Is connected to the center of the groove.

According to the present invention, a substantially conical guide is provided at an interval in front of the direction in which the combination of the elastic film body, the main body and the holding plate is moved. On the top side of the guide are formed a plurality of radial grooves passing through the center,
A towing wire is connected to the center and towed forward.
Since the guide has a conical shape, it can pass smoothly even when passing through the inside of a bent irregular joint or the like.
Since the groove is formed on the top side of the conical shape of the guide, even if the direction of the wire to be towed is inclined, it can be accommodated in the groove and can be smoothly pulled.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a stopper 10, which is a movable conduit blocking device according to an embodiment of the present invention.
The stopper 10 has a first stopper 11 and a second stopper 12 at intervals in the direction of the axis 10a. The first stopper 11 is on the front side in the moving direction. First stopper 11
The second stopper 12 is substantially the same, and has a substantially cylindrical elastic film body 13, a main body 14 disposed on the inner peripheral side of the elastic film body 13, and both sides in the direction of the axis 10 a of the main body 14. It has a front holding plate 15 and a rear holding plate 16 to be operated. The front holding plate 15 and the rear holding plate 16
To the main body 14. The universal joint 18 connects between the first stopper 11 and the second stopper 12 before and after in the direction of the axis 10a. The universal joint 18 connects the main bodies 14 of the first stopper 11 and the second stopper 12, and a coil spring 19 is also provided on the outer peripheral side thereof to connect the front and rear main bodies 14.

The main body 14 includes a cylindrical body 20 that is in close contact with the inner peripheral side of the elastic film body 13 and a core 2 that is disposed on the inner peripheral side of the cylindrical body 20.
1 A flange 22 is formed on the front side of the core body 21 in the direction of the axis 10a. Further, gas passages 23 and 24 for expanding the elastic film body 13 are formed from the core body 21 to the cylindrical body 20. The axis 10 of the core 21
On the front side in the a direction, a joint 25 is attached to the opening of the passage 23, and a gas supply / discharge tube 26 is connected.

The elastic film body 13 is substantially a drum type,
A right cylindrical expansion portion 27 and a mounting portion 28 extending radially inward at both ends of the expansion portion 27 in the direction of the axis 10a.
And The mounting portion 28 is sandwiched and fixed between the main body 14 and the front holding plate 15 and the rear holding plate 16. A plurality of ridges 29 are formed on the outer peripheral surface of the expansion portion 27,
When the elastic film body 13 expands, hermetic closing can be performed reliably.

A guide 30 is provided at an interval in front of the first stopper 11 in the direction of the axis 10a. Guide 30
Has a substantially conical shape, and the bottom surface 31 is the first stopper 1.
It faces one side. A radial groove 32 is provided on the conical top side of the guide 30, and a pulling wire 33 is attached to the center of the groove 32. The pulling wire 33 is housed in one hose 34 together with the plurality of tubes 26, and extends forward in the direction of the axis 10a. The groove 32 has a width that can be accommodated when the hose 34 is inclined.

The guide 3 of the stopper 10 as shown in FIG.
The length L behind 0 is, for example, 300 mm,
The outer diameter D is 100 mm. The stopper 10 having such a shape can pass through a curved portion having an inner diameter of 100 mm and a length of 250 mm.

FIG. 2 shows a state in which the elastic membrane 13 of FIG. 1 is expanded to hermetically close the inner peripheral surface of the conduit 40.
When air is sent into the inner peripheral surface of the expansion portion 27 of the elastic film body 13 through the hose 34, the tube 26, and the passages 23 and 24,
The expansion portion 27 expands radially outward, and becomes larger than the outer diameter of the front holding plate 15 and the rear holding plate 16, so that the conduit 40 can be hermetically closed. The material of the stopper rubber that is the elastic film body 13 is NBR (nitrile rubber) having excellent oil resistance, and can be expanded at a pressure of about 3.5 kgf / cm ² to hermetically close the inside of the conduit 40. Conduit 4
Numeral 0 is made of polyethylene (hereinafter sometimes abbreviated as “PE”), and the inner peripheral surface is smooth.
3 can be made thinner than in the prior art, and the pressure required for expansion can be reduced. The conduit 40 is a PE tube,
When the outer diameter A is 150 mm, L and D in FIG. When A = 200 mm, L = 375 mm, D =
It becomes 125.5 mm.

FIG. 3 shows an axial line 10 which is larger than the guide 30 of FIG.
The configuration related to the hose 34 on the front side in the a direction is shown. A coupler 41 is provided at the distal end of the hose 34, and a check valve is provided inside, so that the distal end of each tube 26 is hermetically sealed in a state where nothing is connected. The coupler 41 has the same outer diameter as that of the hose 34 and can be connected to an extension operation hose. A pulling wire 33 is inserted through the hose 34 and the operation hose. Hose 3
4 or by connecting and extending an operation hose for extension, it is possible to move freely in the conduit 40 of FIG.

FIG. 4 shows the overall structure of the stopper 10 of FIG. The elastic films 13 of the first stopper 11 and the second stopper 12 are individually connected to the tube 26 from the distal end of the hose 34.
A gas, such as air, can be supplied via a and 26b and can be separately expanded. In the hose 34, the second
The pressure of the gas on the rear side of the stopper 12 and the first stopper 1
Tubes 26c and 26d for measuring the pressure of gas in the space between the first and second stoppers 12 can also be housed. By monitoring the pressures of these gases, it is possible to confirm whether or not the hermetic blockage has been reliably performed in the conduit 40. The guide 30 and the first stopper 1
1 is also connected by the universal joint 18, but the coil spring 19 is not used.

FIG. 5 shows the structure of the guide 30 of the embodiment shown in FIG. FIG. 5A shows a state viewed from the front side, and FIG.
FIG. 5B shows a cross section taken along the line VV of FIG. 5A. A plurality of grooves 32 are provided radially, and a screw hole 43 for mounting a pulling wire is provided at the center. Around the screw hole 43, a through hole 44 for inserting a tube is provided. On the bottom surface 31 side behind the screw hole 43, a screw hole 45 for wearing a universal joint is also provided.

FIGS. 6A and 6B show a state in which the passage through a 90 ° elbow joint or the like is smoothly performed by using the guide 30 as shown in FIG. An interval is provided between the bottom surface 31 of the guide 30 and the first stopper 11,
Since they are connected by the universal joint 18, FIG.
It can smoothly pass through the inside of the 90 ° elbow joint 48 similar to the above.

FIGS. 7 (a) and 7 (b) show a state in which the stopper 10 of the present embodiment is used to replace the conduit 40 with an underground pipe. The underground pipe 50 is, for example, a cast iron pipe, and the conduit 40 is a PE pipe. When the replacement part of the underground pipe 50 is cut and removed and replaced with the conduit 40, if the replacement range is long, it is necessary to perform the work on a plurality of days. As shown in FIG. 7A, the end of the conduit 40 a for which the construction on the previous day has been completed is sealed with the stopper 10 of the present embodiment, and sealed with the terminal cup 51. As shown in FIG. 7B, the next day, a new conduit 4
0b is connected using an electro-fusion joint 51 or the like, and then an operation hose 53 connected to the coupler 41 of the hose 34 is pulled from the conduit 40a to the conduit 40b, and the stopper 10 is connected in the conduit.
, And sealing the end of the conduit 40b replaced the next day is repeated.

[0025]

As described above, according to the present invention, the elastic membrane can be expanded with a relatively small pressure to hermetically close the inside of the conduit. Since the main body and the holding plate can be reduced in size and weight, it is possible to easily move the curved section.

Further, according to the present invention, since the hermetic closure can be performed at a plurality of locations at intervals in the axial direction of the conduit, leakage of the base can be reliably prevented. Since the plurality of main bodies are connected by the universal joint and the coil spring on the outside thereof, the main bodies can be easily deformed even when moving along a curved section and can move smoothly.

Further, according to the present invention, since the traction is performed through the guide having a substantially conical shape, it is possible to easily and smoothly pass the elbow, the cheese or the like through the odd-shaped joint.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a side sectional view showing a state in which an elastic film body 13 is expanded in the embodiment of FIG.

FIG. 3 shows the embodiment of FIG.
It is a side view which shows the structure of the front side of a direction with a part cut away.

FIG. 4 is a side sectional view showing the overall configuration of the stopper 10 of FIG.

FIG. 5 is a front view and a cross-sectional view of the guide 30 of the embodiment of FIG.

FIG. 6 is a simplified side view showing a state where the stopper 10 of FIG. 1 passes through a 90 ° elbow joint.

FIG. 7 is a simplified side cross-sectional view showing a state in which underground pipe replacement work is performed using the stopper 10 of the embodiment of FIG. 1;

FIG. 8 is a simplified cross-sectional view showing a buried state of a city gas conduit 30 including an overhanging portion 6 that is difficult to pass with a conventional mobile conduit blocking device.

FIG. 9 is a cross-sectional view showing a structure of a 90 ° elbow joint used for the overlaid portion 6 in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Stopper 10a Axis 11 First stopper 12 Second stopper 13 Elastic film body 14 Main body 15 Front holding plate 16 Rear holding plate 18 Universal joint 19 Coil spring 20 Cylindrical body 21 Core body 22 Flange 23, 24 Passage 27 Expansion section 28 Mounting section DESCRIPTION OF SYMBOLS 30 Guide 31 Bottom surface 32 Groove 33 Traction wire 34 Hose 40 Conduit 48 90 ° elbow joint 50 Underground pipe

Claims (3)

[Claims] 1. A movable conduit shutoff device which is operable to move in an axial direction within a gas transport conduit, expands and closes the conduit airtightly, and shuts off gas flow. An elastic film body having an outer diameter smaller than the inner diameter of the conduit, and having mounting portions in a shape extending inward in the radial direction on both sides in the axial direction; and adhering the elastic film body to the inner peripheral side thereof. A main body in which a passage for guiding inflation gas is formed on the inner peripheral side of the elastic membrane body; and a substantially disc-shaped, mounting portion for the elastic membrane body on both axial sides of the main body. A holding plate attached to an end surface of the main body so as to be sandwiched between the holding member and a holding plate having an outer diameter smaller than the inner diameter of the conduit and larger than the outer diameter of the elastic film body. 2. A plurality of combinations of the elastic film body, the main body, and the holding plate are provided at intervals in an axial direction of the conduit, and a main body of each combination is provided along an axis. 2. The movable conduit blocking device according to claim 1, wherein the movable body is connected by a universal joint, and the main bodies are also connected by a coil spring surrounding the universal joint. 3. 3. A combination of the elastic membrane, the main body and the presser plate, which is provided at intervals in the axial direction of the conduit, has a substantially conical shape, and is used for pulling in the conduit. A guide positioned at the head, wherein the guide has a conical bottom side facing the combination side, and a plurality of radial grooves passing through a central portion formed on a top side of the conical shape; 3. The mobile conduit blocking device according to claim 1 or 2, wherein is connected to the center of the groove.