JPS6316180B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is designed to ensure sealing from the inner surface of the pipe while the pipe joint of an existing pipe, such as a gas pipe, is buried underground. This relates to a linking mechanism for a pig that is introduced into a pipe during repair.

[Conventional technology]

In existing pipes such as gas pipes that are connected underground (under roads) by connecting long cast iron pipes with water-type pipe joints, the joints at the pipe joints are susceptible to the load of vehicles passing over the pipes, earthquakes, or aging. In recent years, existing pipes have been replaced for the purpose of leak repair or preventive maintenance due to changes in the joint condition resulting in gaps in the joint, or deterioration of the constituent materials of the joint, which may cause leaks. It has been considered to repair the joint from the inside of the pipe while it is still in its installed state.

As a type of this repair method, the existing underground pipe is divided into repair units of a predetermined length, and a leading pig is moved from one separation opening into the existing pipe in the repair section while being inscribed on the inner surface of the pipe. and a replacement pig with resin placed between both pigs, and in the process of moving the resin along the inside of the pipe toward the other separation opening by pulling the pig, the resin is transferred to the rear replacement pig. A repair method for pipe joints has been proposed in which the pipe joints of existing pipes are sequentially filled with water through the pipes.

[Problem that the invention seeks to solve]

In the case of this repair work, it is necessary to leave a considerable distance between the leading pig and the replacement pig on the rear side, so that a sufficient amount of resin can be introduced to the front side of the replacement pig. In order to tow the pig, it is necessary to arrange a winch near the separation opening at the end of the existing pipe so that the pig can be pulled and taken out by winding the towing cable.

The problem here is that when the leading pig is taken out from the end separation opening of the existing pipe after the repair of a predetermined section of existing pipe is completed, the replacement pig on the rear side must be reeled in for a considerable length. Since the resin cannot be removed, the residual resin must be discharged at the same time as this removal, but the pig removal operation must be carried out quickly in consideration of the hardening of the residual resin.

In other words, if the rear replacement pig is stopped for a long time in the existing pipe, the lead pig is pulled out by unwinding the towing line, and the tow line is wrapped around the winch again and the rear replacement pig is pulled out, the remaining Curing of the resin may make it impossible to withdraw the displacement pig. In order to avoid such an inability to pull out the leading pig and then continue to pull out the replacement pig on the rear side by winding the tow line, the winch must be moved over a considerable distance to the separation opening of the existing pipe. The winch must be installed away from the edge, which poses a problem in terms of space for installing the winch.

[Means for solving problems]

The present invention was proposed to solve the above problem, and after hoisting the tow rope with a winch and pulling out the leading pig from the existing pipe, the connection between the leading pig and the towing rope is released by a simple procedure. This pig was used when repairing a pipe joint in an existing pipe in which the leading pig was left in place and the tow rope was subsequently hoisted to discharge the residual resin and take out the replacement pig at the rear. It attempts to provide a linkage mechanism.

For this purpose, the present invention introduces a lead pig into the existing pipe and a replacement pig at a predetermined distance behind it, and moves both pigs within the pipe by pulling a tow cable to remove the pipe joint. In a repair method in which the gap is filled with resin, the leading pig passes through the center of the towing cable so as to be able to slide forward and backward, and connects the leading pig through a collar with a clamp. By making it possible to connect the tow rope in both a fixed state and a free state, when taking out the pig from inside the pipe at the end of the repair of an existing pipe, the leading pig is in the free state and the rear replacement pig is moved by winding the tow rope. It is characterized by being able to be pulled out.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram schematically showing the entire repair construction apparatus to which the present invention is applied, and reference numeral 1 indicates an existing pipe to be repaired that is installed underground. This is a long piping system in which cast iron pipes of a predetermined size are connected by a pipe joint part 13 called a water pipe joint using a conventional piping system.

When repairing the pipe joint 13 of the existing pipe 1, the existing pipe 1 was first divided into repair sections L of appropriate length (for example, 100 mm) suitable for repair, and one separated end 11 of the sections was opened above ground. The other separated end 12 is exposed to the hard hole A and the hard hole B which is also opened on the ground, and a pig insertion conduit 5 and a pig extraction conduit 6, which will be described later, are connected to these separated ends 11 and 12.

Then, from one pig insertion conduit 5, a tow rope 4
is passed through the existing pipe 1 and pulled out from the other pig lead-out conduit 6, and its tip is wound up with the winch 9, thereby connecting the lead pig 2 attached to the towing line 4 and a predetermined position on the rear side. Replacement pigs 3 are installed at a distance, with low viscosity resin C placed in front of the leading pig 2, and joint sealing resin D placed in front of the rear replacement pig 3. It is introduced into the existing pipe 1 and is pulled and moved inside the pipe from the inlet side to the outlet side.

As shown in an enlarged sectional view in FIG. 5, the leading pig 2 includes a plurality of body pieces 21 made of a soft elastic material (for example, a hard neoprene sponge with a hardness of about 50 degrees) and a hard elastic material. (For example, hardness
A plurality of fin pieces 22 made of neoprene rubber (about 60 degrees) are joined alternately, and a truncated conical head piece 23 made of the same material as the hard elastic material is placed on the front side in the direction of movement. and metal support disks 24 and 25 are arranged in front and behind it,
It has a structure in which a stud bolt 26 is passed through between these front and rear support discs 24 and 25, and when the stud bolt 26 is tightened, the body piece 21, fin piece 22, and head piece 23 are integrated in tandem. The structure is such that the pieces are connected together so that they do not stretch in the longitudinal direction.

The leading pig has a hole 27 drilled in its center through which the towing line 4 is passed, and the leading pig 2 and the towing rope 4 are connected by collars with clamps 28 and 29 installed at the front and rear of the leading pig 2. The structure is such that they are connected together. The collars 28 and 29 with clamps have bolts 28a and 29a, respectively, and receiving seats 28b and 29b provided on the collars 28 and 29 in opposition to the bolts 28a and 29a, respectively.
It has a structure in which it is fixed to the tow rope 4 by tightening between. Note that the collars 28 and 29 with clamps are preferably provided at both ends of the flexible pipe inserted into the hole 27. In this way, the pipe functions not only to pass the tow rope 4, but also to function as an air passageway used to supply pressurized air from the front to the rear. Note that this pressure air supply passage may be provided separately.

In addition, as shown enlarged in FIGS. 6, 7, and 8, the rear replacement pig 3 has a truncated cone made of a hard elastic material (for example, neoprene rubber with a hardness of about 60 degrees) on the tip side in the direction of movement. A head piece 31 in the form of a shape, immediately followed by a truncated cone-shaped body tip piece 32 made of a soft elastic material (for example, a hard neoprene sponge with a hardness of about 50 degrees), and a cylindrical body tip piece 32 that continues immediately after the head piece 31. The body piece 33 is connected to the body piece 33, and a rear body piece 34 made of the same material as the soft elastic material and a fin piece 35 made of the same material as the hard elastic material are alternately connected in tandem to the rear part thereof. The entire body is held between support disks 36 and 37 provided at the front and rear ends. The support disks 36 and 37 are tightened with nuts 38c and 39d to bolt portions 38a and 28b provided at both ends of the wire 38, so that the respective pieces are crimped and supported together. In this case, an embedded disk 39 fixed to the tow rope 4 is provided on the forward end side of the cylindrical body piece 33 in the traveling direction, and this embedded disk 39 is screwed onto the bolt portion 38a with a nut 39a. The distance between the front support disk 36 and the embedded disk 39 is regulated via the bolt portion 38a, thereby preventing the head piece 31 and body end piece 32 from being compressed and deformed more than necessary. In addition, since the replacement pig 3 is stretched by a wire 38 in the middle, the elongation of the cylindrical body piece 33 that forms the main body is restricted while moving inside the pipe, and the overall length is relative to the diameter. Even though the tube is long, the flexibility of the body is ensured and the resistance to passage at the curved tube portion is reduced.

In addition, the rear replacement pig 3 is inserted between the pipe joint parts 13 when filling the pipe joint parts 13 with resin, which will be described later.
Because it is necessary to provide a function to replace the air stagnant inside with the resin, resin introduction grooves 17 are formed on the left and right positions of the circumferential surface of the outer body, which open toward the front end of the pig on the front side in the direction of travel. In addition, replacement grooves 18 are formed in the upper and lower positions of the circumferential surface of the body piece 33 so as to be parallel to this. These resin introduction grooves 17 and replacement grooves 18 are formed with phases shifted in left and right positions and up and down positions in the circumferential direction, but both grooves are formed in the axial direction (longitudinal direction). The ends of the grooves 17 and 18 are formed so as to overlap each other, and both the grooves 17 and 18 are formed so that they overlap each other.
Each rear end wall in the traveling direction is formed into a tapered end wall 17a, 18a that slopes obliquely toward the rear in the traveling direction, and the replacement groove 18 is formed on the replacement pig 3.
It communicates with a passage 19, such as a polyethylene tube, buried in the pig so as to open at the rear end of the pig.

Leading pig 2 and replacement pig 3 with such a configuration
As mentioned above, in the process of inserting into the existing pipe 1 in the repair section L and moving the low-viscosity resin C and the joint sealing resin D along the inside of the pipe, a plurality of pipe joints 13 interposed in that section are removed. As shown in FIGS. 4 and 9, the pipe joint part 13 is, for example, a large diameter part 13a provided at one end of one pipe, and a large diameter part 13b provided at the other end 13b of the pipe. A sealing material 14, commonly called "hemp skin", is filled in the butt-fitting portion, and the opening is sealed with a lead material 15.

In the existing pipe 1 to be repaired, the pig insertion conduit 5 is connected to one separated end 11 and the pig lead-out conduit 6 is connected to the other separated end 12, as described above. The conduits 5 and 6 are the second,
It is shown enlarged in Figure 3.

First, the pig insertion conduit 5 is removably connected to the opening of one separated end 11 of the existing pipe 1 with a clamp 51, as shown in FIG. , a resin filling opening 5a provided with an opening/closing socket 52, and an exhaust opening 5b provided with an opening/closing socket 53 at a slightly higher level position. Further, the resin filling tank 7 is communicated with the resin filling opening 5a through the opening/closing pot 52 through the hose 7a.
The filling pressure is applied from a small compressor 7c by driving a generator 7b.

The pig outlet conduit 6 also has a discharge port 6 for discharging residual resin, as shown in FIG.
A is provided, and an opening/closing pot 61 is provided there. Further, above the discharge port 61, the conduit 6 is provided with an air pressure supply port pipe 6b communicating with the compressor 10 and the pressure operation unit 10a. The lid 8 is also equipped with a guide reel 81 for leading out the tow rope 4 passing through the conduit 6.
is removably attached to the open end of the conduit 6 by a clamp 82. The lid 8 is split in half at the part where the tow rope 4 is led out.

The tip end of the tow rope 4 is wound around the drum 9a of the winch 9, and by winding the tow rope 4, the leading pig 2 and the replacement pig 3 on the rear side are inserted into the existing pipe through the insertion conduit 5. During this insertion, first the leading pig 2 is inserted, and the resin C is introduced into the front side thereof. Next, the rear replacement pig 3 is inserted into the insertion conduit 5, and the resin D is poured from the tank 7 in a state where the opposing space between the leading pig 2 and the replacement pig 3 corresponds to the resin filling opening 5a. It is filled with the pressure of the compressor 7c. At this time, the opening/closing pot 53 is opened to discharge the air in the opposing space, and the air is led out through the discharge port 5b. A cross pin 54 is detachably attached to the outer end of the insertion conduit 5 in order to prevent the rear displacement pig 3 from slipping out from the inlet end of the insertion conduit 5 during resin filling. The tow rope 4 is pulled by the winch 9 in a state where the opposed space between the pigs 2 and 3 is sufficiently filled with the resin D. Furthermore, upon completion of resin filling, the pot 52 is closed.

When the tow rope 4 is pulled, both the leading pig 2 and the replacement pig 3 on the rear side are pulled inside the pipe, but the resin C in front of the leading pig 2 is trapped between the dust in the existing pipe 1 and the pipe joint 13. 〓It works to remove the dust that is inside by adhering to it with its own adhesiveness.

Also, when the pigs 2 and 3 are pulled inside the pipe by this tow rope 4, the replacement pig 3 on the rear side is
The connection point between the tow rope 4 and the tow rope 4 is at the embedded disk 39, and therefore, the inner wall of the existing pipe 1 is compressed between the embedded disk 39 and the front support disk 36. The closeness to is improved. On the other hand, due to traction, an elongation action occurs in the trunk between the embedded disk 39 and the rear support disk 37;
Due to the action of the wire 38 and the bolt/nut, virtually no elongation occurs, so that contact with the inner wall of the existing pipe 1 is maintained virtually unhindered.

When the replacement pig 3 on the rear side reaches the position of the pipe joint part 13 interposed in the pipe line by pulling the pigs 2 and 3 and passes there (see Fig. 9), the resin on the front side of the replacement pig 3 While D is being towed and moved, sufficient filling pressure is generated at the rear end of the resin due to viscous resistance between it and the inner wall of the existing pipe 1, so this filling pressure causes the resin D to flow through the resin introduction groove 17. Pipe joint part 13
It flows into the space between 〓 and 〓. On the other hand, in response to the filling pressure caused by the inflow of the resin, the air remaining between the pipe joints 13 is naturally pushed out rearward via the displacement grooves 18. At this time, a negative pressure may be applied to the rear space of the replacement pig 3 so that the air discharged by the replacement groove 18 may be sucked and discharged.

When all the pipe joints 13 intervening in the existing pipeline in the repair section have been repaired in the manner described above and the leading pig 2 has reached the pig lead-out conduit 6, the clamp 8
2, remove the lid 8, divide it into two parts, open the pot 61, and first remove the top pig 2.
The remaining resin C is discharged before.

After that, the fixing bolts 28a, 2 of the leading pig 2 are
When loosening 8b and releasing the tightening of collar 28,
Since the connection between the leading pig 2 and the towing line 4 is released and the leading pig 2 becomes free, when the towing rope 4 is further pulled with the winch 9, the leading pig 2 does not move and only the replacement pig 3 on the rear side is moved. rises up inside the conduit 6. As a result, the residue of the resin D remaining in front of the rear replacement pig 3 is discharged from the resin discharge port 6a and collected in the container 41 below, and by the movement of the rear replacement pig 3, The pig 2 is pushed, and both the leading pig 2 and the rear replacement pig 3 are taken out from the pipe end outlet of the pig lead-out conduit 6. In this case, the lid 8
is divided into two parts as shown in the figure, so even if the tow line 4 is wound around the winch, it will not interfere with taking out the pigs 2 and 3.

In this embodiment, the lead pig 2 uses a collar 28 with a clamp that is integrally connected to the flexible pipe, but it is separate from the flexible pipe and is attached to the tow rope 4 at least on the rear side of the lead pig 2. By removably fixing the collar with a clamp with bolts,
Of course, the leading pig 2 may be prevented from shifting rearward during a towing operation, and may be configured to be able to interlock with the tow rope.

In addition, as shown in Fig. 10, a cylindrical brush 90 with a diameter slightly larger than the inner circumference of the existing pipe 1 is attached to the towing line 4 in front of the leading pig 2 using the same collar with a clamp, and this It may be made to pass through the inside of the tube 1. In this case, if a wire is used as the tow rope 4, the cylindrical brush 90 will rotate when the wire is twisted and turned by the traction force. For this reason, when passing through the pipe joint part 13, the dust stuck in the cavity of the pipe joint part 13 is swept and removed, so that at least the part from which the dust has been removed is cleaned during subsequent resin filling.
A durable resin filled layer is formed and sealing performance can be ensured.

〔Effect of the invention〕

As described in detail above, the present invention introduces into the existing pipe 1 a leading pig 2 attached to a towing line 4 and a replacement pig 3 attached to the rear side at a predetermined distance from this. In a device for repairing a pipe joint interposed in a pipe line, the leading pig 2 is passed through the tow rope 4 so as to be movable back and forth, and the leading pig 2 is inserted through the collars 28 and 29 with clamps.
can be connected to the tow rope 4 in a fixed state and in a free state, so that when removing the pig from the repair end of an existing pipe, the leading pig 2 is set in the free state and the tow rope is wound up so that the rear side Since the configuration allows the replacement pig 3 to be pulled out, the pigs 2 and 3 and the residual resin can be quickly taken out, and the leading pig 2 can be pulled out from the tow rope or the end of the tow rope can be pulled out again. There is no need to wind it around the winch 9 and perform the winding operation again, and the excellent effect of making the final work at the time of repairing the pipe joint part easier can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic diagram showing one embodiment of an existing pipe repair construction device to which the present invention is applied, Fig. 2 is a schematic side view showing an enlarged portion of a conduit for inserting a pig, and Fig. 3 is a schematic side view showing an enlarged portion of a pipe for inserting a pig. A schematic side view showing an enlarged portion of the lead-out conduit, FIG. 4 is a vertical cross-sectional side view showing the pig in a towed state, FIG. 5 is a half-sectional side view of the leading pig to which the present invention is applied, and FIG. 6 is a replacement A perspective view of the pig, Fig. 7 is a half-sectional side view of the same, Fig. 8 is a front view of the same, Fig. 9 is an enlarged sectional view showing the state of resin filling, and Fig. 10 is a usage state of the separately added cylindrical brush. FIG. 1... Existing pipe, 11, 12... Separation end, 13...
... Pipe joint part, 13a ... Large diameter part, 13b ... Pipe end, 14 ... Seal material, 15 ... Lead material, 17 ...
Groove for resin introduction, 18... Groove for replacement, 17a,
18a... Taper end wall, 19... Passage, 2... Top pig, 21... Body piece, 22... Fin piece, 23
...Head piece, 24, 25...Support disc, 26...
Stud bolt, 27...hole, 28, 29...collar with clamp, 28a, 29a...bolt, 2
8b, 29b... Receptacle, 3... Replacement pig, 31
...Head piece, 32... Body tip piece, 33... Body piece, 34... Rear body piece, 35... Fin piece, 3
6, 37...Support disk, 38...Wire, 38
a, 38b... Bolt, 38c, 38d... Nut, 39... Embedded disk, 39a... Nut,
4... Traction rope, 41... Container, 5... Pig insertion conduit, 5a... Resin filling port, 5b... Exhaust port, 51... Clamp, 52, 53... Kotuku,
54...Cross pin, 6...Pig lead-out conduit, 6
a...Discharge port, 6b...Air pressure supply part, 61
...Opening/closing handle, 7...Resin filling tank, 7a...
...Hose, 7b... Generator, 7c... Compressor, 8... Lid, 81... Guide reel, 82...
Clamp, 9...Winch, 9a...Drum, 1
0... Compressor, 10a... Pressure operation unit, 90... Cylindrical brush, A, B... Vertical hole, C,
D...Resin.

Claims (1)

[Scope of Claims] 1. A leading pig 2 attached to a tow rope 4 and a replacement pig 3 attached to the rear side at a predetermined distance from this are introduced into the existing pipe 1, and the tow rope 4 is In the repair method, the leading pig 2 and the replacement pig 3 are moved inscribed in the inner surface of the pipe by being pulled by the pipe, and the resin introduced into the pipe is filled between the pipe joints 13, The leading pig 2 on the front side of the towing cable 4 passes through the center of the towing cable 4 so as to be able to slide forward and backward, and the leading pig 2 is fixed to the towing cable 4 via collars 28 and 29 with clamps. When the pig is taken out from inside the pipe at the repair end of the existing pipe, the leading pig 2 is put in the free state and the replacement pig 3 on the rear side is pulled out by winding the tow rope 4. A pig connection mechanism for repairing pipe joints in existing pipes.