JP2001235060A - Sheath pipe propulsive method and propulsive device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aseismatic sheath pipe propulsive method that is for fluid transportation piping for water, gas, sewage and the like, and a pushing device that is suitable for use in the method. SOLUTION: For new arrangement of a pipeline of main pipes in a sheath pipe via an insertion and join of a spigot of each pipe in and to a socket of the preceding pipe at the rear end, with a rest mounted on a proper peripheral place on each main pipe to support it in the sheath pipe and with a cord having hooks capable of engagement with the back edge of the socket of each main pipe inserted in the main pipes, where the hooks are held engaged with the back edges of the sockets, a draw on the cord in a pushing direction pushes forward the main pipes supported on the rests. After the pushing, the main pipes supported on the rests are left in the sheath pipe, and the cord is drawn out of the sheath pipe and recovered after the hooks are disengaged from the back edges of the sockets. The pushing device has engaging devices, which include the hooks capable of engagement with the back edges of the sockets forming the pipe joints, and driving means for moving the hooks in a radial direction of the pipes, and which are secured at given intervals to the cord inserted in the pipes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe-in-pipe method, a sheath-type propulsion method, and a main-pipe propulsion apparatus used for laying a pipe for fluid transportation used for water supply, gas, sewerage and the like without cutting. It is.

[0002]

2. Description of the Related Art Conventionally, as a method of burying a pipe for fluid transportation such as a ductile cast iron pipe, a digging method of digging and laying the ground has been generally used, but recently, not only on a main road but also on a general road. As the traffic volume is increasing, it is difficult to cut off the traffic due to the excavation method. Therefore, only the starting shaft and the reaching shaft are cut open, and a fume pipe or steel pipe is protruded and buried as a sheath, and then a ductile cast iron pipe is inserted. The propulsion method, such as the pipe-in-pipe method, in which the main pipe is inserted to renew the pipeline, has become common, and the propulsion method of laying the pipeline by sequentially propelling the subsequent pipe while excavating the ground from the starting shaft is also used. Widely adopted.

In this type of fluid transport piping, in recent years,
Even when an unsteady external force directly hits the pipeline due to an earthquake or the like, seismic resistance capable of expanding and contracting within the joint and absorbing and relaxing the external force has been strongly required. To meet these needs, one of the joints conventionally used in the pipe-in-pipe method and the like is an earthquake-resistant pipe joint as shown in FIG. 17, for example. The joint 100 is called a PII type joint, and includes an insertion port 101, a receiving port 102, a lock ring 103, a set bolt 104, a rubber ring 105
Etc.

FIG. 18 shows an outline of a conventional pipe-in-pipe method. In this method, an existing pipe (sheath pipe) P ′ buried between a starting shaft S and a reaching shaft R is used. In this method, a main pipe P having a smaller diameter is inserted.
A hydraulic jack J is installed in the starting shaft, and the rear part of the hydraulic jack abuts against the reaction force receiver H, and the front part presses the main pipe P via the pushing angle B. Main P
By inserting the insertion port 101 at the distal end into the receptacle 102 at the rear end of the preceding main pipe, they are sequentially joined and pushed into the existing pipe P '. In addition, a leading sled K for reducing insertion resistance is attached to the tip of the leading main pipe.

The joining of the main pipes P,... Is performed as follows. First, the lock ring 103 and the rubber ring 105
To the inside of the socket. Thereafter, the hydraulic jack J is operated, the insertion port 101 is inserted into the receiving port 102, and the set bolt is tightened. Thereby, the following main pipe is joined to the rear part of the preceding main pipe whose rear end faces the starting shaft.
When the subsequent main pipes are joined, the main pipes are pressed by the hydraulic jack J to advance the joined series of pipe rows toward the reaching shaft. The driving force of the hydraulic jack is
3 is transmitted by contact of the side surface 107 of the lock ring groove 106 with the side surface 107 of the lock ring groove 106. In these figures, the pipeline is updated by inserting the main pipe into the existing pipe.First, the sheath is propelled underground, and the main pipe is inserted into the sheath by the pipe-in-pipe method. The sheath pipe propulsion method is being carried out similarly.

The P used in the pipe-in-pipe method is
In addition to the type II fittings, pipe fittings that take into account the seismic resistance used in the pipe-in-pipe method, in which the sheath is first propelled for the construction of a new pipeline and the pipeline is laid inside the sheath,
There are an S-shaped joint shown in FIG. 19, a US-shaped joint shown in FIG. 20, and the like.

[0007]

By the way, in the construction of the PII type joint for the pipe-in-pipe method, after the propulsion work is finished, the lock ring 103 is provided on the side face and the insertion opening 101 as shown in FIG. Since the side end faces 107 of the lock ring groove 106 are in contact with each other, that is, the joint is pushed in, only the pull-out allowance is secured, but the insertion port moves in the direction of fitting into the receptacle. Can not.
Further, in the S-shaped joint shown in FIG. 19, when the propulsion is completed, the distal end portion 201a of the insertion port is in contact with the rear end face 202a of the receiving port as shown by a dashed line.
In the US-type joint shown in FIG. 5, in the state where the propulsion is completed, the flange 111 provided on the rear side of the insertion port is in contact with the side end surface 114 of the receiving port opening.
As with the PII type joint, the insertion port cannot move in the direction of fitting into the receiving port. For this reason, there is a problem in that the joint only partially fulfills the performance as an earthquake-resistant pipe joint that requires expansion and contraction in both directions. This point is NS type, S type, SII
The same applies to joints of shapes and the like.

As a conventional technique for solving this problem, a technique described in Japanese Patent Publication No. 5-20636 is known.
In this technique, a sled body supporting a new insertion pipe is arranged at a joint between adjacent pipes, and the sled bodies are connected to each other by a connecting rod over the entire length of the insertion pipe and drawn into an existing pipe. According to this method, the main pipe can be propelled without applying a pushing force to the joint part of the pipe, so that the contraction allowance can be left at the joint part of the pipe after the propulsion.

However, according to this method, since the sled body and the connecting rod are left inside the sheath tube together with the insertion tube after the insertion tube is inserted, there is a problem that waste is increased and the cost is high. It is said that the problem that the sled body comes off from the tube bottom due to the rolling of the insertion tube can be easily solved by appropriately configuring the sled body. Is not disclosed,
In the invention described in the above publication, the problem of rolling can be said to be unsolved.

Therefore, the present invention solves the above-mentioned problems, and can be used for a wide range of pipe diameters from a small diameter to a large diameter, and secures a sufficient amount of expansion and contraction which is the maximum requirement for earthquake resistance. It is an object of the present invention to provide an economical pipe propulsion method in which a pipe and a joint can be inserted in a state where the pipe and the joint are inserted.

[0011]

In order to solve the above problems, the present invention employs the following configuration. In other words, the propulsion method according to the present invention is a propulsion method in which a pipe insertion port is inserted into a receptacle provided at the rear end of the preceding pipe and joined to form a new main pipe in the sheath. In addition, a gantry is attached to an appropriate position on the outer peripheral portion of the main pipe to support the inside of the sheath, and a cord body having a hook engaged with a rear end edge of the socket is inserted into the main pipe, and the hook is inserted. The main body supported by the gantry is propelled by pulling the cord body in the propulsion direction by engaging the hook with the rear end edge of the socket, and after the propulsion is completed, the hook is detached from the rear edge of the socket. The cord body is pulled out of the sheath and the main tube supported by the gantry is left in the sheath.

The main propulsion device according to the present invention includes:
The present invention is characterized in that an engaging device having a hook that can be engaged with a rear end edge portion of a receiving end of a pipe joint and a driving unit that moves the hook in a radial direction of the pipe is attached to a cord body at a predetermined interval. As a specific example of this propulsion device, for example, a hook that engages with the rear end edge of the socket of the pipe is supported on a base frame of the engagement device so as to be movable in the radial direction of the pipe by an expansion / contraction link. A movable shaft connected to the cord body is provided on the base frame so as to be movable back and forth by a predetermined distance with respect to the base frame, and the movable shaft and the expansion / contraction link expand / contract the expansion / contraction link in accordance with the moving direction of the movable shaft. Some devices are connected by actuation links.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments of the present invention shown in the drawings.

FIG. 1 is a side sectional view of a pipe joint in a preferred embodiment of the present invention. This pipe joint is an NS type joint usually used as a seismic joint for water supply, and includes an insertion port 1 and a receiving port 2. The insertion port 1 has a ring-shaped insertion port projection 3 integrally provided on the outer peripheral surface of the distal end portion of the ductile cast iron pipe.

A rubber ring 4 for sealing is provided on the inner peripheral surface of the receiving port 2.
Is provided with a rubber ring groove 4a and a lock ring groove 5a. A lock ring 5 formed as a single annular body is inserted into the lock ring groove 5a via a lock ring centering rubber 6, and when an excessive pulling force due to an earthquake or the like is applied, This lock ring 5
And the insertion projection 3 engages with the insertion opening 1.
Deviation is prevented.

A clearance L ₁ is secured between the distal end 1 b of the insertion port 1 and the rear end face 2 b of the receptacle 2, and a clearance L ₁ is provided between the insertion projection 3 and the lock ring 5. withdrawal allowance L ₂ is ensured. In this propulsion method,
The pipe is inserted while maintaining these expansion allowances.If an excessive force such as an earthquake acts after the completion of propulsion,
The pipe joint expands and contracts by the amount of expansion and contraction to absorb and reduce the excessive force.

The lower surface of the insertion tube (main tube) is mounted and supported on a gantry 10 as shown in FIG. This stand 1
0 is made of steel, plastic, etc.
As shown in FIG. 3, a comparatively thin plate material is bent to form a receiving portion 10a curved in an arc shape in a front view and leg portions 10b, 10b provided on both left and right sides of the receiving portion. I have. A sled-shaped sliding portion 1 is provided at a lower portion of the leg portion 10b.
0c is provided, and a belt hole 10d for inserting a belt 15 for winding around the main pipe and fixing the gantry to the main pipe is provided above the leg 10b. In addition, the gantry 1
The shape of 0 is not limited to the illustrated example, but may be another shape such as a block shape. It is preferable to use a mount having a shape in close contact with the outer peripheral portion of the main pipe, since the free movement of the pipe relative to the mount during the propulsion is restricted.

The gantry 10 supporting each main pipe is connected in series by a wire rope (hereinafter abbreviated as a wire) 20 which is a lace for the gantry. As shown in FIGS. 4 and 5, hooks 30, which are formed by bending a metal rod into a key shape, are fixed to the gantry wire 20 at predetermined intervals by mounting brackets 32. Each frame is attached to the wire 20 by engaging with the left and right legs 10b. In the illustrated example, a pair of left and right gantry wires 20, 20 each having a rearward-facing hook 30 attached thereto are provided, and these hooks 30, 30 are engaged with left and right legs of the gantry 10, respectively. The hook 30 may have another structure as long as it can be disengaged from the gantry 10.

On the other hand, a propulsion device M is disposed inside the main pipe P as shown in FIGS. The propulsion device M is connected to a string (rod row) formed by connecting a plurality of rods 40,... Via a universal joint 41,. Device ”), 50,
… Is attached. In the illustrated example, the rod 40 has a length close to the effective length of the main pipe, and is flexibly connected by universal joints 41 attached to the front and rear sides of the engagement device 50. As the flexible cord, a wire rope may be used instead of the rod 40 connected by such a universal joint.

The engagement device 50 includes a cylindrical base frame 51, and front and rear support members 5 provided at appropriate intervals on an outer peripheral portion of the base frame.
Front and rear expansion and contraction links 55 and 56 are attached to shafts 57 and 57, respectively.
It is attached rotatably. Front and back expansion link 5
Hooks 60 are rotatably mounted on the free ends of the shafts 61 and 61 at the free ends of the front and rear expansion links 55 and 56, respectively.
A parallel link is configured by 56, the base frame 51, and the hook 60. When the front and rear expansion links 55 and 56 rotate,
The hook 60 moves in the radial direction of the main pipe while maintaining the state parallel to the base frame 51.

The outer surface of the distal end of the hook 60 is formed as a wedge-shaped inclined surface 60a inclined in the front-rear direction, and an engaging step 60b is provided at the rear of the inclined surface. In the illustrated example, the combination of the expansion / contraction links 55 and 56 and the hook 60 is provided on the base frame at intervals of 120 degrees along the inner circumference of the main pipe. May be.

The engaging device 50 is provided with the following mechanism as driving means for driving the expansion / contraction link. That is,
A movable shaft 65 is inserted through a through-hole 51 a provided in a core portion of the base frame 51 so as to be movable in the front-rear direction, and both front and rear ends of the movable shaft 65 are connected to the rod 40 through the universal joints 41, 41.
It is connected to 40. Near the one end of the movable shaft 65, a support 67 similar to the support for the expansion / contraction link,
Are provided, and the bases of the operation links 70,... Are rotatably mounted on the shafts 71,. The distal end of the operating link 70 is pivotally connected by a shaft 72 near the distal end of the expansion / contraction link 56. Therefore, when the movable shaft 65 moves back and forth, the operating link 70 swings the expansion / contraction link 56 and moves the hook 60 in the radial direction of the tube. In addition,
The forward and backward movement distance of the movable shaft 65 is regulated by stoppers 68, 68, and at the most advanced position shown in FIG.
The expansion and contraction links 55, 0 are engaged until the
In the position shown in FIG. 7 in which the 56 is enlarged and retracted most, the expansion and contraction links 55 and 56 are contracted to disengage the hook 60 from the receiving port, and the hook is located on the inner side (axial side) of the inner surface of the tube. It is to be drawn. In addition, hook 6
The drive means for moving 0,... In and out to engage and disengage from the receptacle may be provided with a hydraulic actuator, an electric actuator, or another mechanism.

A moving device 80 is mounted on the base frame 51 of the engaging device 50.
Is provided. The moving device 80 includes three front and rear plate-shaped frames 81 fixed to the base frame 51, and a pair of left and right support frames 8 provided at the lower end of the plate-shaped frame.
2 and 82, and each support frame has a front and rear
A pair of bearings 85, 85 (four in total) are pivotally supported. Each bearing 85 has a ball 86 projecting downward.
Are rotatably provided, and these balls roll on the inner surface of the main pipe, thereby facilitating the movement of the propulsion device, and preventing the propulsion device from overturning during recovery.

Next, a method of propelling the main pipe P into the sheath P 'using the propulsion device will be described. First, a propulsion device is inserted into the main pipe from the arrival shaft side, and a new main pipe is connected to the preceding main pipe on the start shaft side. This connection is performed by inserting the insertion port 1 of the following main pipe into the receptacle 2 of the preceding main pipe. A gantry 10 is attached to the main pipe by a fixing means (a metal belt in the illustrated example) 15 such as a metal belt or an adhesive so as to be supported in the sheath. As shown in FIG. 2, it is important for the support of the main pipe by the gantry 10 to support the pipe so that a force in the pushing direction does not act on the insertion opening 1.

The hooks 30, 30 of the left and right wires 20, 20 are engaged with the left and right legs 10b, 10b of the gantry 10 fixed to the main pipe P, respectively. In the illustrated example, the hooks 30, 30 are both engaged with the front side of the leg 10b, and the gantry is pulled by the wires 20, 20 on both sides in the direction opposite to the propulsion direction. The main pipe is pulled in the direction of propulsion by the propulsion device.
0 is advanced by the wires 20, 20 while being urged backward by a force smaller than the traction force in the propulsion direction. In addition, according to the method of the illustrated example, since the wires 20, 20 that are tensioned on the left and right sides of the tube are present, lateral movement and rolling of the tube are prevented.

On the other hand, the propulsion device M inserted inside the main pipe
With regard to, the engaging device 50 is connected to the end of the rod 40 constituting the cord body through the universal joint 41, and the engaging device 50
The universal joint 41 and a new rod 40 are further connected to the rear end of the rod. In this state, the engagement devices 50,.
When a string body formed by connecting 0,... In series is pulled from the reaching shaft side in the propulsion direction by a winch or jack, the movable shaft 65 first moves by a predetermined amount in the pulling direction, and the operating link 70 moves the expansion / contraction link 56. Since the push-opening is performed, each hook 60 moves in the pulling direction as shown in FIG. 8, and engages with the receiving port rear end edge 2b. In this case, since the base frame 51 is supported on the axis of the main pipe by the moving device 80, the three hooks 60,. When the cord body 40 is further towed in the propulsion direction, the movable shaft 65 does not move any more, and the traction force is transmitted to the receiving end edge 2b via the hook, and the tube row is propelled. In this case, since the hook 60 is engaged with the rear end edge portion 2b of each tube, a force in the pushing direction does not act on the insertion port 1, and a predetermined amount of expansion and contraction can be maintained. Since the gantry 10, which supports the pipe, is moved while being pulled by the wire 20 in the direction opposite to the propulsion direction, runaway due to inertia or inclination is prevented, and steady progress is ensured. You.

After propulsion by a predetermined distance, a new main pipe is connected, and a new engagement device 50 is connected to the end of the last rod 40 via a universal joint 41. In the same manner as above, the main pipe will be sequentially added and propelled.

When the propulsion is completed, the pulling of the gantry wire 20 in the direction opposite to the propulsion direction is stopped, and the cord 40 of the propulsion device M is pulled in the direction (rearward) opposite to the propulsion direction. Then, since the movable shaft 65 is retracted by a predetermined amount with respect to the base frame 51, the operation link 70 pulls the contraction link 56 to contract. For this reason, as shown in FIG. 9, the hook 60 is retracted inward from the inner edge 2b of the receptacle and does not interfere with the inner surface of the tube. When the cord is further pulled in the direction opposite to the propulsion direction, the cord and the engaging devices 50,... Retreat through the main row as shown in FIG. Drawn out. In this case, since the propulsion device is provided with the moving device 80 that rolls on the inner surface of the main pipe, the engaging device 50 is supported at the center of the main pipe, and does not interfere with the inner surface of the pipe joint. The cord can be pulled out of the main pipe.

On the other hand, when the string 20 for the gantry is pulled in the direction opposite to the pulling direction, the hooks 30, 30 come off the gantry 10, so that the hooks can be easily collected together with the hooks. In this case, since the wire is twisted by the weight of the hook 30 and the hook 30 hangs downward as shown in FIG. 11, there is little possibility that the hook 30 will interfere with another stand and will not come off. The main pipe P inserted into the sheath tube is left in the sheath tube while being supported by the gantry 10.

According to this propulsion method, the insertion pipe is mounted on the gantry 10 and supported, and the propulsion is transmitted by the hook 60 engaged with the rear end edge of the receiving port while the propulsion is slid in the sheath or the pipe. The pushing force does not act on the vehicle, and the propulsion can be performed while maintaining the desired pushing allowance. Since the mount has a small area in contact with the sheath, the frictional force is small and the propulsive force is relatively small. In addition, if a cord (rod or wire) is inserted into both sides of the insertion tube as shown in the above-described example, the rolling is restricted by these members, so that a good main pipe can be laid. In addition, since a rod or a wire connected by a universal joint is used as the cord body, it can flexibly cope with a left-right curve or a vertical inclination, and smooth propulsion can be performed.

The gantry and the propulsion device can be made of inexpensive materials, for example, steel or resin blocks, and are economical because the cords such as wires, rods and engaging devices are collected. It is preferable to use a reused product as the resin block, because the cost can be reduced and environmental problems can be reduced. In addition, if the pedestal 10 is provided with a sled that slides in the sheath or a caster that rolls in the sheath, the propulsion can be performed more smoothly.

FIGS. 12 to 14 show an example slightly different from the moving device 80 in the above embodiment. In this embodiment, a moving device 80 'is replaced by the front and rear instead of the bearings 85,. Left and right four wheels 85 'are provided. Other structures are the same as those of the above-described embodiment, and the same portions are denoted by the same symbols. However, according to the results of the experiment, smooth movement was obtained with a bearing having a free rolling direction than with a wheel.

FIG. 15 shows a slightly different embodiment of the engagement device 50.
Instead of providing the operation link 70 in the above-described embodiment, the base end of the expansion / contraction link 55 is inserted into the base frame 51 from the longitudinal hole 51c provided in the base frame 51 and fixed to the base frame 51. A spring 101 constantly biased in the pulling direction is provided between the spring 101 and the support piece 51d. Further, the movable shaft 65 in the above embodiment is
It is fixed to the base frame 51 by 8, 68 and does not move in the axial direction. The point that the base of the expansion / contraction link 55 is pivotally connected to the base frame 51 by a shaft 57 is the same as in the above embodiment. In this embodiment, since the expansion / contraction link 56 is pulled by the spring 101 and always receives a force in the expansion direction, the hook 60 is held at a position farthest from the axis. For this reason, the hook 60 is securely engaged with the receiving port rear end edge portion 2b to transmit the propulsive force (in the direction of the arrow in the figure) to the main pipe.

When the cord body 40 is pulled in the direction opposite to the propulsion direction, the inclined surface 60a of the tip of the hook 60 is pressed in the contracting direction (inward) by the inner surface of the main pipe, and remains in a semi-contracted state. Slides on the inner surface of the main pipe. When the hook 60 reaches the subsequent joint portion, the hook 60 attempts to expand in the gap between the socket and the insertion port. Can be moved into the subsequent tube. This embodiment is particularly effective when the pipe diameter is small or the propulsion distance is short. It is preferable to provide an abrasion-resistant coating (for example, Teflon coating) having a small friction coefficient on the inclined surface 60a of the hook 60, since resistance during movement is small and abrasion hardly occurs.

FIG. 16 shows a further different embodiment, in which an engaging device 150 in this embodiment is different from that shown in FIG.
In this embodiment, the spring 101 is not provided, and the base end of the expansion / contraction link 55 inserted into the base frame 51 through the elongated hole 51c is supported by the shaft 152 on the receiving member 152 of the movable shaft 65. Further, the point that the portion of the base of the expansion / contraction link 55 outside the base frame 51 is pivotally connected with a shaft 57 is the same as in each of the above embodiments. In this embodiment, the movable shaft 65
Moves, the expansion / contraction link 55 rotates accordingly, so that the hook 60 moves inward and outward according to the pulling direction. For this reason, engagement and disengagement with respect to the back end edge part can be performed reliably. Also in this embodiment,
This is particularly effective when the pipe diameter is small or the propulsion distance is short. In any of the above embodiments, it is preferable to provide a wear-resistant coating (for example, Teflon coating) having a small coefficient of friction on the inclined surface 60a of the hook 60, because the resistance during movement is small and abrasion hardly occurs. . Although the moving device has been described as a wheel type, it goes without saying that the moving device can be implemented as a bearing.

[0036]

As is apparent from the above description, according to the present invention, a wide range of main pipes from a small diameter to a large diameter and a wide variety of joints can be provided with sufficient expansion and contraction allowance of the pipe joints.
Steel pipes, resin pipes, and the like other than ductile cast iron pipes can be easily inserted into the sheath, and a pipe with excellent earthquake resistance can be economically formed in the sheath.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of a pipe joint in a propulsion method according to the present invention.

FIGS. 2A and 2B are a partial cross-sectional side view showing the inside of a sheath tube, and FIG.

FIG. 3 is a front view (a) and a cross-sectional view (b) of a gantry.

FIG. 4 is a side view (a) and a plan view (b) showing a gantry wire to which a hook is attached.

FIG. 5 is a perspective view showing a state where a hook attached to a wire is engaged with a gantry.

FIG. 6 is an external view of the propulsion device with the hook extended.

FIG. 7 is an external view of a propulsion device with a hook in a contracted state.

FIGS. 8A and 8B are a partial cross-sectional side view showing the inside of the sheath tube during propulsion, and FIGS.

FIGS. 9A and 9B are a partial cross-sectional side view showing the inside of the sheath tube when the propulsion device is pulled out, and FIGS.

FIGS. 10A and 10B are a partial cross-sectional side view showing the inside of the sheath tube when the propulsion device is pulled out, and FIGS.

FIG. 11 is a perspective view of a gantry wire and a hook.

FIG. 12 is a longitudinal sectional view of a sheath tube in an embodiment different from the above.

FIGS. 13A and 13B are a partial sectional side view (a) and an FF arrow view (b) showing the inside of a sheath tube during propulsion in different embodiments.

FIG. 14 is a side view of an engagement device according to still another embodiment.

FIG. 15 is an external view of an engagement device according to a further different embodiment from FIG.

16 is an external view of the propulsion device in FIG.

FIG. 17 is a sectional view of a conventional PII type joint.

FIG. 18 is an explanatory view of a conventional sheath pipe propulsion method.

FIG. 19 is a sectional view of a conventional S-shaped joint.

FIG. 20 is a cross-sectional view of a conventional US joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion opening 2 Reception opening 3 Insertion projection 5 Lock ring 10 Mount 20 Wire 30 Hook (For mount) 40 Rod 41 Universal joint 50 Connecting device (engagement device) 51 Base frame 55, 56 Expansion / contraction link 60 Hook 65 Movable shaft 70 Actuating link 80,80 'Moving device 100,150 Engaging device

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshinori Yoshida 1-12-19 Kitahorie, Nishi-ku, Osaka-shi, Osaka F-term in Kurimoto Iron Works Co., Ltd. 2D054 AC18 AD28 AD37 FA11

Claims (5)

[Claims] 1. A propulsion method in which a pipe insertion opening is inserted into a receptacle provided at a rear end of a preceding pipe to join and form a new main pipe in a sheath. A gantry is attached at an appropriate position on the outer peripheral portion to support the inside of the sheath tube, and a cord body having a hook engaged with a rear end edge of the socket is inserted into the main pipe, and the hook is inserted into the socket rear end. The main body supported by the gantry is propelled by engaging the rim and pulling the cord body in the propulsion direction, and after completion of the propulsion, the hook is disengaged from the inner edge of the back end of the receiving port to sheathe the cord body. Pull out of the tube,
A sheath pipe propulsion method, wherein the main pipe supported by the gantry is left in the sheath. 2. The propulsion system according to claim 1, wherein the gantry is connected to a gantry string disposed outside the main pipe, and tension is applied to the lace to restrain free movement of the main pipe. Nosaya pipe propulsion method. 3. A string inserted into the inside of a pipe, comprising: an engaging device having a hook engageable with a rear end edge of a receiving end of the pipe joint and driving means for moving the hook in a radial direction of the pipe. A main propulsion device which is attached to a body at a predetermined interval. 4. The driving means according to claim 3, further comprising: an expansion / contraction link having a base portion pivotally supported by the base frame and a hook attached to a distal end thereof; and an expansion / contraction link operating means for enlarging / reducing the expansion / contraction link. Main propulsion device. 5. A movable shaft supported by a base frame so as to be able to move back and forth by a predetermined distance by pulling a cord body as the expansion / contraction link operating means, and moving the movable shaft by connecting the movable shaft and the expansion / contraction link. The main propulsion device according to claim 4, further comprising an operation link that expands and contracts the expansion link according to the direction.