JP2001311480A - Pull up jig for plastic pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pull up jig capable of continuously pulling up a plastic pipe properly without causing the tearing or breaking of the pipe, and slipping of the jig from the pipe even when pulling up force is too strong, and allowing the efficient insertion of the pipe into the existent one. SOLUTION: The jig G comprises a press mechanism 13 which pushes a press member 12 consisting of four sector members 17 fitted into the pipe end part 1a of a PE pipe 1 toward the outer-diameter direction of the pipe end part 1a, a reaction force receiver(r) which receives the expanding force of the diameter of the pipe end part 1a by the action of the press member 12 with a ring member 21 fitted onto the pipe end part 1a, and further, the jig comprises a projecting part 14 formed on the section member 17 capable of nipping in the tube end part 1a, and a pull up part 10b with a freely detachably coupled pull up wire 2 for pulling the PE pipe 1 at the top end of a bolt member 20 which, together with wedge members 18, constitutes the press member 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin pipe drawing jig for pulling synthetic resin pipes into existing pipes in order to regenerate existing pipes such as gas pipes and drain pipes.
More specifically, the present invention relates to a technique for preventing a jig from coming off from an end of a resin tube even when a strong traction force is applied, thereby enabling a reliable operation of drawing a resin tube.

[0002]

2. Description of the Related Art Piping such as gas conduits buried underground often causes corrosion and rust due to aging, bending stress acting due to a change in earth pressure, etc., which develop and eventually crack. At least after a certain period of time, a flexible pipe along the inner surface of the existing pipe is lined to rehabilitate the pipe, or a new pipe is inserted in the existing pipe to prevent cracks from occurring. In many cases, renewal work is performed, such as renewing the piping by inserting a pipe. A synthetic resin pipe such as a polyethylene pipe (hereinafter abbreviated as a PE pipe) or the like is used as a pipe inserted into the existing pipe for regeneration of such a pipe, and the resin pipe is inserted into the existing pipe. As a jig for transmitting a traction force caused by a traction line such as a wire rope to a resin pipe, the following means have been taken.

[0003] That is, means for folding the end of the resin tube and passing it through a shackle for a winch or the like, and tying the folded end and the resin tube with a wire or the like;
As shown in FIG. 5 of Japanese Patent No. 27047, means for folding and flattening an end portion of a resin pipe, opening a hole and passing through a shackle, and as shown in Japanese Patent Application Laid-Open No. 7-208645, Four fan-shaped members arranged around the bolt member to be pulled are fitted inside the end of the resin pipe, and the fan-shaped member is moved by expanding the diameter by rotating the bolt member and pressed against the inner peripheral surface of the pipe. It is a means to attach by frictional force.

[0004]

In the above means, when a large traction load is applied, the wires that tie the resin tubes together may come off, or the resin tubes may extend and come off. In the above means, the load is concentrated on the hole through the shackle, and the resin pipe is easily torn, or a large-diameter resin pipe is difficult to fold and has poor workability, and the pipe rigidity is not sufficiently reduced and it is difficult to bend. Therefore, the traction load is further increased to pass through the bent portion of the existing pipe. or,
Although it was attempted to strengthen the flat crushed part by sandwiching it with a plate in the above method, depending on the existing pipe length, such as a long pipe or a lot of bends, there is no breakage at the shackle insertion part. Could not be done.

[0005] The above-mentioned means is good in that a traction force is applied to a wide surface over substantially the entire circumference of the inner surface of the resin pipe. However, in the case of a relatively soft pipe such as a resin pipe, (a) the pipe itself is stretched and deformed and becomes loose (B) The fan-shaped member and the resin pipe are gouged as they pass through the bent part of the existing pipe, and the resin pipe is stretched and deformed by repeating this a plurality of times, and the frictional force is reduced to come off. (C) If a groove or a claw that bites into the inner surface of the resin pipe is provided on the fan-shaped member as a retaining means, the resin pipe is too soft to bite, resulting in a hole and eventually breaking. In other words, there is room for improvement in any of the means.

[0006] An object of the present invention is that even if a large traction force is applied, the resin pipe is not torn or cut, and the traction means can be continuously pulled well without coming off the resin pipe. An object of the present invention is to provide a towing jig capable of efficiently performing a work of inserting a resin pipe into an existing pipe.

[0007]

Means for Solving the Problems The structure of claim 1 is, as illustrated in FIGS. 4 and 7, fitted to a tube end 1a of a synthetic resin tube 1 in a resin tube towing jig G. Pressing part 1
A pressing mechanism 13 for pressing the tube end 1a in the radial direction of the tube end 1a, and a pressing mechanism 13 for pressing the tube end 1a in the radial direction to receive the radial pressing force acting on the tube end 1a by the pressing mechanism 13. The pipe end 1a on the side opposite to the side where the part 12 exists
And a reaction force receiving portion r fitted into the tube. The projection portion 14 can bite into the tube end 1a and the synthetic resin tube 1 is pulled into one of the pressing portion 12 and the reaction force receiving portion r. Is provided with a freely connectable traction portion 20b.

As shown in FIGS. 3 and 9, in the structure of claim 2, in the structure of claim 1, the projecting portion 14 is formed by a front inclined surface 14 a on the lower side and a rear inclined surface on the upper side in the pulling direction of the resin pipe. Surface 14b, and is constituted by a ridge extending in the circumferential direction of the tube end 1a, and the inclination angle of the rear inclined surface 14b is set to be smaller than the inclination angle of the front inclined surface 14a. Things.

A third aspect of the present invention is the same as that of the first or second aspect, as illustrated in FIGS.
a, a plurality of substantially fan-shaped members 17 to be fitted into the tube end 1a are provided in a state in which a circular arc portion 17a is provided along the inner peripheral surface of the pressing portion 1.
And a rod-shaped body 1 that can be contacted over the pipe center side of a plurality of substantially fan-shaped members 17 arranged in the circumferential direction of the pipe end 1a.
5 is provided with a taper angle θ at which the substantially sector-shaped member 17 can be moved in the radially expanding direction along with the movement of the rod 15 in the resin pipe pulling direction. A pressing mechanism 13 is provided by providing a forcible moving mechanism 16 for forcibly moving the resin tube in the resin tube pulling direction, the protrusion 14 is formed on the arcuate portion 17a, the pulling portion 20b is formed on the rod 15 and the tube end 1a. The reaction force receiving portion r is constituted by an annular body 21B fitted to the outside.

The structure of claim 4 is as shown in FIG.
In the configuration of claim 3, the support body 21A, which is capable of restricting the forcibly moving mechanism 16 by fitting the rod-shaped body 15 therein and receiving the downward movement of the pressing portion 12 in the resin tube pulling direction.
And a moving means i for forcibly moving the rod 15 toward the lower side in the resin pipe pulling direction with respect to the support 21A, and is provided with the support 21A and the ring 21B integrally. It is characterized in that the component main body 21 is constituted.

The structure of claim 5 is, as exemplified in FIGS. 4, 7, and 8, in the structure of claim 4, in which the pressing portion 12 and the ring 21B whose diameter has been moved by the operation of the pressing mechanism 13 are connected to the pipe end. In the traction state in which the portion 1a is pressed and held, the pipe end 1
The jig main body 21 is configured such that a is closed, and a supply hole 23 for supplying heated steam to the inside of the synthetic resin pipe 1 and the jig main body 21 are formed inside the synthetic resin pipe 1. A drain hole 24 for removing the drain is provided so as to be able to be closed together.

[0014] As shown in FIG. 14, in accordance with the structure of claim 6, as the rod 15 moves in the direction of pulling the resin pipe, the substantially fan-shaped members 17 are spaced at substantially equal intervals in the pipe circumferential direction. It is characterized in that a guide portion H for guiding to move in the diameter increasing direction is provided.

As described above, the reference numerals are used for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Operation] The present invention corresponds to an improved technique of the above-mentioned means. According to the first aspect of the present invention, the pressing portion moves the resin tube from the inner diameter side to the expanding direction or the outer diameter side. Since the pressing force in the diameter-reducing direction is received by the reaction force receiving portion that is externally or internally fitted, the pressing portion and the reaction force receiving portion can firmly hold the pipe end. This is advantageous in that the elongation of the resin tube can be regulated as compared with the above-described means in which the resin tube is pressed in the radially expanding direction without the reaction force receiving portion.

[0015] Since either the pressing portion or the reaction force receiving portion is provided with a protruding portion that can bite into the end of the tube, the protruding portion bites into the resin tube with the pressing and holding. As compared with the case of pressing in a mere surface contact state, the critical release load can be increased, and the pressing part or the reaction force receiving part whose critical release load is strengthened is pulled,
The limit of the tractive force can be increased more than before. Therefore, the synergistic effect of these actions makes it possible to pull the resin pipe without any inconvenience such as being pulled out or being torn even if a strong pulling force for pulling and inserting the existing pipe is applied.

According to the second aspect of the present invention, when a traction force is applied to the traction jig, a force in which the protruding portion bites into the resin tube relatively acts, and from this point, the limit traction force is reduced. It is possible to increase. That is, as shown in FIG. 9, the center line x of the apex angle of the ridge 14 which is the included angle between the front inclined surface 14a and the rear inclined surface 14b is in the traction direction with respect to the radial direction of the resin pipe 1a (FIG. 9). To the right), which causes the ridge 1 to be pulled when the towing jig is pulled.
4 acts to bite into the resin tube more.

According to the third aspect of the present invention, the lower side of the drawing direction of the resin pipe is arranged so as to be in contact with the circumference of the tapered angled rod having a smaller diameter and is fitted inside the pipe end. Therefore, when the rod-shaped body is forcibly moved in the resin tube pulling direction by the forcible moving mechanism, the plurality of substantially sector-shaped members move in the diameter-enlarging direction and press and hold the tube end with the ring. Then, since the pulling state of the resin tube is obtained by pulling the rod-shaped body in the pulling direction, a pulling force causes a component force to move the fan-shaped member in the radially expanding direction. The pinching force acts in a direction to increase, and it becomes even more difficult for the resin tube to fall out of the towing jig during the towing operation.

Also, since a relatively bulky mechanism for pressing and holding the pipe end is disposed on the inner diameter side of the pipe and the ring is disposed on the outer diameter side of the pipe, a towing jig is used. The tool can be made relatively compact with a radial dimension slightly larger than the outer diameter of the resin tube.

According to the fourth aspect of the present invention, an annular body for holding the pipe end between the substantially fan-shaped member and the supporting body for relatively moving the rod-shaped member is integrally provided. Therefore, as compared with the case where these are separate bodies, the support body and the ring body reinforce each other to increase the strength, and the operation of attaching the ring body to the pipe end can be omitted. . In addition, it becomes difficult to lose either the ring or the support.

According to the configuration of claim 5, the following operation is provided. In other words, existing piping is rarely a simple straight line shape, and it is common for there to be some bent parts. It is necessary to keep the tube soft. Also, in order to rehabilitate the existing pipe described above, when performing lining for bringing the drawn-in resin pipe into close contact with the inner surface of the existing pipe, expanding the thermoplastic resin pipe such as the PE pipe drawn into the existing pipe. Is required.

Therefore, when the resin pipe is pulled in by pulling, a high-pressure, high-temperature heating steam is supplied into the resin pipe to perform a softening treatment for softening the resin pipe. Therefore, the towing jig is basically attached to the end of the pipe so that the opening of the pipe can be closed, and if a hole for supplying heated steam is provided, the towing jig is mounted. As it is, it becomes possible to supply steam to the resin tube for softening treatment. This is different from conventional means that removes the towing jig and replaces it with a rubber cap for pressurization and sends steam.
This is preferable because the rubber cap and the replacement operation thereof are not required.

In addition, since the steam supplied to the resin pipe cools and condenses when drained, a drain is formed. Therefore, a drain hole is provided in the towing jig so that the drain can be taken out of the resin pipe from the drain hole. By doing so, the inconvenience of drain remaining in the resin pipe after lining can be solved by using a towing jig.

According to the configuration of claim 6, when the rod-shaped body is forcibly moved in the resin pipe pulling direction, the plurality of substantially sector-shaped members move in the radially expanding direction at substantially equal intervals in the pipe circumferential direction. Since the tube end is pressed and held between the ring and the ring, the pressing force for pressing and holding the tube end can be applied substantially uniformly along the circumferential direction of the tube.

[Effect] In the resin pipe traction jig according to any one of the first to fifth aspects, the pressing portion and the reaction force receiving portion hold the pipe end inside and outside in the radial direction and press them. By providing a protruding part and a traction part that bites into the pipe end in either the part or the reaction force receiving part, the critical load with the jig can be increased without damaging the pipe end, and the resin pipe can be inserted into the existing pipe. It was possible to obtain the connection strength enough to withstand the traction force for pulling in smoothly without difficulty.

In the resin pipe drawing jig according to the second aspect,
When the protrusion that cuts into the resin pipe is formed as a ridge that extends in the circumferential direction, and the front inclination angle is steeper than the rear inclination angle, when the traction force acts, the protrusion tries to bite into the resin pipe more. The force is generated in a relatively large area, and it is possible to continue to apply a strong traction force to the resin tube during the traction operation without damage due to the biting of the protrusion.

In the resin pipe drawing jig according to any one of the third to fifth aspects, the action of the pulling force is converted into a force for pressing and holding the pipe end more, and the mechanism for this is settled in the resin pipe. Therefore, it is possible to continue to apply a strong traction force to the resin pipe during the traction work, while having a small size substantially equal to the outer diameter of the resin pipe.

In the resin pipe drawing jig according to the fourth and fifth aspects, the support body supporting the pressing portion and the annular body are integrated.
There is an advantage that the strength of each other can be improved and the handleability can be improved, and the risk of loss can be eliminated.

In the resin pipe drawing jig according to the fifth aspect,
The pipe end can be closed with the heating steam supply hole and the drain hole through which the heating steam is cooled, so that no special closing means is required, which makes it economical and excellent in work efficiency. Moreover, the softening of the resin pipe can be performed while contributing to the smooth pipe lining processing.
Another advantage is that by pressing the inside of the resin tube using the supply hole in a state where the tension is applied by traction, it is possible to perform the operation while preventing dents in the bent tube portion.

In the resin pipe drawing jig according to the sixth aspect,
Even when the pressing portion fitted to the tube end of the resin tube passes through the bent tube portion, there is little possibility that the pressing portion comes off from the tube end and comes off. In other words, when the pressing portion fitted to the tube end of the resin tube passes through the bent tube portion, the portion of the pressing portion located on the outer peripheral side of the bend easily comes off from the tube end, and therefore, the pressing If the pinching force acts on a specific portion in the circumferential direction of the pipe and the portion of the pressing portion where the pressing pinching force is small is located on the outer peripheral side of the bend, it is easier to come out, but the pressing pinching force is increased. Can be distributed substantially uniformly along the circumferential direction of the pipe, so that the part of the pressing part located on the outer peripheral side of the bend is difficult to come out of the pipe end, and the pressing part comes out of the pipe end. There is little risk of falling off.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 shows a situation in which a PE pipe, which is an example of a thermoplastic synthetic resin, is drawn into a gas pipe (an example of an existing pipe) buried underground and is internally installed. That P
The procedure of the interior construction of the E pipe 1 will be described briefly. First, working holes 10A and 10B are excavated at both ends of an existing pipe 4A in a section to be repaired in a gas pipe.
The existing pipe 4A is cut in A and 10B [see FIG.

Then, with respect to the pipe 4 having both ends cut, one working hole 10B is directed toward the other working hole 10B.
A towing line (an example of a towing member) 2 and a steam hose 3 are inserted from the side of A, and the other working hole 10B has an outer diameter smaller than the inner diameter of the pipe 4 and is formed to a predetermined length. The prepared PE pipe 1 is prepared, and a preparation step of attaching the towing jig G to one pipe end 1a of the PE pipe 1 and the plug 5 to the other pipe end 1b is performed. [See FIG. 1 (b)].

The tow line 2 and the steam hose 3 passed through the pipe 4 are pulled out from the other working hole 10B, and the tow line 2 is connected to the tow portion 20b of the tow jig G via the guide body 6. Further, the steam hoses 3 are respectively connected to the supply holes 23 of the towing jig G, and the steam heated by the steam generator 26 is supplied to the steam hose 3.
Is filled into the PE tube 1 through the above, and the PE tube 1 is heated and softened.

When the PE pipe 1 is sufficiently softened, the tow line 9 is pulled by the winch 9 or the like while the steam hose 3 is being pulled back, so that the other working hole 10 is pulled.
From the side B, the PE pipe 1 is connected to the pipe 4 including the bent pipe portion 4r.
Then, an insertion step of pulling out one end 1a on which the towing jig G is mounted is performed on the side of the one working hole 10A [see FIG. 1 (c)].

Then, the water extraction hose 11 is connected to the hole 24 of the towing jig G, the supply of the heating steam is stopped, and the PE pipe 1 inserted into the pipe 4 is cooled. The drain generated in the PE pipe 1 is discharged from the water extraction hose 11 to the outside of the pipe by the suction device 27 and removed. Next, a towing jig G for pulling the PE pipe 1 will be described.

As shown in FIGS. 2 to 4, the towing jig G
Is a male screw member 20 to which the towing line 2 is connected, a conical wedge member 18 that is screwed to the male screw member 20 to form the rod 15, and a relative rotation and relative sliding of the male screw member 20. It is composed of a jig body 21 which is freely fitted to the outside, and four substantially fan-shaped members 17 which are externally provided on the wedge member 18. The general operation of the towing jig G is as follows. In a state where the pipe end 1a of the PE pipe 1 is inserted between the ring portion 21B of the jig body 21 and the four substantially fan-shaped members 17, the male screw member is used. By rotating the 20 and pulling the wedge member 18 toward the jig body 21, the diameter of the substantially fan-shaped member 17 is increased, and the tube end 1a is pressed and held for connection.

As shown in FIG. 2 to FIG.
Are four arc grooves 17b, three arc parts 17a (projections 14), and front and rear spacer parts 17c, 1
7d, and a tapered concave peripheral surface 17e which is in contact with the outer peripheral tapered surface (wedge surface) 18a of the wedge member 18 on the inner peripheral side.
Are formed. The tapered concave peripheral surface 17e has a taper angle θ in which the diameter on the lower side in the traction direction (right side in FIG. 2) is small and the diameter on the upper side in the traction direction (left side in FIG. 2) is large.
Is attached.

The arc groove 17b is for mounting the rubber ring 19, and the four rubber rings 19 are wound around each of the arc grooves 17b over the four substantially fan-shaped members 17 so that the four substantially fan-shaped members are formed. 17 are pressed and urged toward the reduced diameter side so as not to be separated from each other, and the wedge member 18 is packaged in a circular state. In addition, 17f
Is a through hole for inserting steam and a hose, and is also a weight reducing hole. If a circular arc groove is formed in the front surface of the substantially fan-shaped member 17 so as to open in the through hole 17f and extend along the circumferential direction, the communication between the supply hole 23 of the towing jig G and the through hole 17f can be further improved. It is convenient.

Three arc portions 1 of the substantially fan-shaped member 17
7a is formed not on a plane along the pulling direction, but on the projection 14 whose entire surface is inclined. That is, as shown in FIG. 9, the front inclined surface 14 on the lower side in the pulling direction of the PE pipe 1 is used.
a and a protruding ridge extending in the circumferential direction of the end of the tube, having a rear inclined surface 14b on the upper side. Then, each inclination angle with respect to the towing direction is defined as an angle α of the front inclined surface.
The angle β of the rear inclined surface is set to be smaller than that. As a result, the bisector x of the sharp angle (γ + γ) of the projection 14 falls in the towing direction, so that the substantially sector-shaped member 1
When the pulling member 7 is pulled in the pulling direction, a component force is generated in a direction in which the protrusion 14 bites into the PE pipe 1.

As shown in FIGS.
Is a tapered outer peripheral taper surface 18a having a smaller diameter on the lower side in the traction direction (right side in FIG. 2) and a larger diameter on the upper side in the traction direction (left side in FIG. 2), and a female formed at the center. It is a substantially conical member having a screw hole 18b and a stop ring 18c for preventing the substantially fan-shaped member 17 from coming off. At the small diameter side of the outer peripheral tapered surface 18a, four mounting grooves 18d for mounting four partition plates 22 that partition the four substantially fan-shaped members 17 in the circumferential direction are formed at intervals of 90 degrees.

As shown in FIGS. 4, 7, and 8, the male screw member 2
0 is a bolt portion 20a that is loosely fitted into the jig body 21;
It is composed of a pulling portion 20 b which is a ring portion for hooking the pulling rope 2 via the guide body 6, and a washer portion 20 c which comes into contact with the jig main body 21. The bolt portion 20a is screwed to the wedge member 18 through the bolt insertion hole 21a of the jig main body 21.

As shown in FIGS. 2 and 7, the jig main body 21
Bolt insertion hole 21a for fitting male screw member 20 inside.
And a ring portion (an example of an annular body and a reaction force receiving portion r) 21 fitted to the tube end 1a.
B and a substantially cylindrical member integrally provided. The tapered shape of the support 21A is to advance the bent pipe 4r of the pipe 4 with less resistance.

The tube end 1a side of the support 21A is formed as a flat vertical wall. When the tube end 1a is sandwiched between the substantially fan-shaped member 17 and the ring portion 21B, the tube end 1a is closed. Thus, the inside and outside of the PE pipe 1 are shut off (that is, in the traction state in which the pipe end 1a is pressed and sandwiched between the pressing portion 17 whose diameter has been moved by the operation of the pressing mechanism 13 and the ring 21B). The jig main body 21 is configured so that the tube end 1a is closed.) In the support 21A, a supply hole 23 for supplying the heating steam into the PE pipe 1 and a drain hole 24 for extracting the drain generated in the PE pipe 1 are formed so as to be able to be closed, respectively. .

For example, each of the holes 23, 24 is threaded with female threads 23a, 24a at the lower end in the pulling direction, and a closing bolt 25 is provided when not used. In the case of entry, the blocking bolt 25 is removed, and the steam hose 3 is screwed into the female screw portion 23a of the supply hole 23, or the water extraction hose 1 is used.
1 may be screwed into the female screw portion 24a of the hole 24. Here, 21b is a weight reducing hole extending in the towing direction.

As shown in FIG. 6, the guide 6 has a shaft 6A having holes 6a for hooking at both ends.
And a curved guide plate 6B having eight arc-shaped outer peripheral surfaces 6b arranged at equal angles around the shaft body 6A.

A procedure for connecting and fixing the PE pipe 1 to the towing jig G will be described. First, the male screw member 20 is sufficiently rotated to the loose side to move the four substantially fan-shaped members 17 to the reduced diameter side, and a sufficient radial gap with the ring portion 21B of the jig main body 21 is kept. In this state, the tube end 1a is inserted between the substantially fan-shaped member 17 and the ring portion 21B until it comes into contact. Then, the male screw member 20 is rotated to the tightening side, and the wedge member 18 is pulled toward the lower side in the pulling direction and moved to forcibly expand and move the four substantially fan-shaped members 17 to the ring portion 21B. Is completed by pressing and holding the pipe end 1a.

At the time of actual use, as shown in FIG. 8, by using two shackles 28, the pulling portion 20b of the male screw member 20 and one end of the shaft 6A of the guide body 6 are connected.
With the other end of the shaft 6A and the tip 2a of the towing line 2 being connected to each other, the PE tube 1 is pulled in. Towing unit 2
By devising the guide body 6 between the tubing 0b and the traction cable 2, an increase in traction force when passing through the bent portion 4r of the existing pipe 4 can be reduced, and PE can be more efficiently used.
The pipe 1 can be retracted.

In this embodiment, four substantially fan-shaped members 1
7, the pressing portion 12 is formed, and the female screw hole 18 of the wedge member 18 is formed.
b and the bolt 20a of the male screw member 20, the support 2
A moving means i for forcibly moving the rod 15 toward the lower side in the towing direction with respect to 1A is provided. Also, male screw member 20
And a support means 21A for receiving and regulating the movement of the substantially sector-shaped member 17 toward the lower side in the towing direction, and a moving means i, and a wedge member 18 and a male screw member 20. And the pressing mechanism 13
Is configured.

[Second Embodiment] As shown in FIG. 10, the circular arc portion 17a of the substantially fan-shaped member 17 is formed in a shape in which the projecting portion 14 is arranged between flat circular arc portions 29, 29 parallel to the pulling direction. Arc part 1 that contacts resin pipe 1 in a large area
7a is desirable. The front inclination angle α and the rear inclination angle β of the projection 14
Is the aforementioned bisector x whose outer diameter side is oriented toward the upper side in the towing direction.
In order to obtain the relationship, α may be set to satisfy the relationship α> β, and α may be set to 90 degrees as in the first embodiment. The number of the arc portions 17a formed in one substantially fan-shaped member 17 may be two or another number. Further, the support body 21A and the ring body 21B which is the reaction force receiving portion r may be formed separately.

[Third Embodiment] As shown in FIG. 11, a jig main body 30 having an inner peripheral surface 30a having a tapered angle whose diameter becomes smaller toward the upper side in the pulling direction, and a protrusion projecting in the small diameter direction A substantially sector-shaped member 3 which is formed on an inner circumferential arc 31a having an outer peripheral surface 31b having a tapered angle and having a smaller diameter toward the upper side in the traction direction.
1, a support portion 32 having a stop portion 32 a for receiving the lower end of the substantially sector-shaped member 31 in the pulling direction, and an annular reaction force receiving portion r fitted inside the resin pipe 1. 32
It is also possible to configure the towing jig G by screwing a pressing bolt 33 capable of pressing the jig main body 30 and the jig main body 30 in the direction of relative separation with the jig main body 30.

In this case, a plurality of tow portions 20b for connecting the tow lines 2 are provided in the jig main body 30, and the plurality of substantially fan-shaped members 17 are urged in the radially expanding direction.
A mold snap ring 34 is preferably provided. That is, when the pressing bolt 33 is tightened, the jig body 30 moves to the lower side in the pulling direction with respect to the substantially sector-shaped member 31 whose position is regulated by the stop portion 32a, and the substantially sector-shaped member 31 is forcibly moved in the diameter reducing direction. Thus, the resin tube 1 can be pressed and held between the resin tube 1 and the reaction force receiving portion r.

[Fourth Embodiment] FIGS. 12 and 13 show that six substantially fan-shaped members 17 in the circumferential direction are moved in the circumferential direction of the resin pipe along with the movement of the rod 15 toward the lower side in the resin pipe pulling direction. 6 shows a resin pipe towing jig G provided with a guide portion H for guiding it to move in the radially increasing direction at substantially equal intervals.

The rod 15 is a wedge member 1 having a substantially hexagonal pyramid shape.
8, a male screw member 20 is screwed concentrically,
The male screw member 20 passed through the thrust bearing 35 is inserted into the bolt insertion hole 21 a of the jig main body 21 so that the wedge member 18
And a seal ring 36 for sealing a gap between the male screw member 20 and the bolt insertion hole 21a.
It is attached to the inner peripheral surface.

As shown in FIGS. 14 and 15, each of the substantially sector-shaped members 17 has a flat tapered surface 17e which is in surface contact with the wedge surface 18a of the wedge member 18, and each tapered surface 17e has:
Along the center in the width direction, a guide groove 37 having a T-shaped cross section is formed, and each wedge surface 18 of the wedge member 18 is formed.
A guide portion H is formed by fixing a guide ridge 38 having a T-shaped cross section which is slidably fitted into the guide groove 37 along the center in the width direction of the guide a. Other configurations are the same as in the first embodiment.

[Fifth Embodiment] FIG. 16 shows a modification of the resin pipe traction jig G shown in the fourth embodiment. Instead of the rubber ring 19, a coil spring 39 inserted into an arc groove 17b is used. The six substantially fan-shaped members 17 adjacent to each other are elastically connected to each other in the circumferential direction of the resin pipe so as to be relatively displaceable, and each tapered surface 17e of the substantially fan-shaped member 17 has a cross-sectional shape along the center in the width direction thereof. Forms a rectangular guide groove 37, and is slidably fitted into the guide groove 37 along the center in the width direction of each wedge surface 18a of the wedge member 18, and has a rectangular cross-sectional shape. Fixing the ridge 38, the guide portion H
Is configured. Other configurations are the same as in the fourth embodiment.

[Other Embodiments] A resin pipe tow jig according to the present invention is formed by, for example, forming a plurality of holding portions (such as a robot hand) that can be freely held and released by a pressing mechanism 13 such as a hydraulic cylinder in a circular shape. The towing jig G having the pressing portion 12 arranged side by side may be used, and the structure and shape of the forcible moving mechanism 16 and the jig body 21 can be variously changed.

[Brief description of the drawings]

FIG. 1 shows an interior construction work for an existing pipe of a PE pipe.
Is the excavation process, (b) is the preparation process, and (c) is the insertion process.

FIG. 2 is a cross-sectional view showing a connection structure between a towing jig and a PE tube.

FIG. 3 is an enlarged sectional view showing the structure of a substantially fan-shaped member;

FIG. 4 is an exploded perspective view showing the structure of the towing jig.

FIG. 5 is a perspective view showing the structure of a conical member.

FIG. 6 is a side view and a sectional view showing a structure of a guide body.

FIG. 7 is a sectional view showing a state in which the towing jig is loosely fitted in the PE tube 1.

FIG. 8 is a side view showing a towed state of the PE pipe.

FIG. 9 is a side view showing a state in which the protruding portion bites into the PE tube.

FIG. 10 is a sectional view showing a towing jig according to a second embodiment.

FIG. 11 is a view showing the principle of a towing jig according to a third embodiment.

FIG. 12 is a sectional view showing a towing jig according to a fourth embodiment.

FIG. 13 is an exploded perspective view showing a towing jig according to a fourth embodiment.

FIG. 14 is a side view showing a state in which the PE pipe is pulled by the towing jig of the fourth embodiment.

FIG. 15 is a sectional view taken along line XV-XV in FIG. 14;

FIG. 16 is an essential part cross-sectional view showing a towing jig according to a fifth embodiment.

[Explanation of symbols]

 Reference Signs List 1 resin pipe 1a pipe end 2 traction member 6 guide body 12 pressing portion 13 pressing mechanism 14 protrusion 14a front inclined surface 14b rear inclined surface 15 rod-shaped body 16 forcible moving mechanism 17 substantially fan-shaped member 17a arc portion 20b traction portion 21 jig Main body 21A support 21B ring 23 Supply hole 24 Drilling hole G Towing jig r Reaction force receiving part i Moving means θ Bar-shaped taper angle H Guide part

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Mae 4-1-2, Hirano-cho, Chuo-ku, Osaka-shi, Osaka Inside Osaka Gas Co., Ltd. (72) Inventor Noboru Fujiwara 2 Tamade-higashi, Nishinari-ku, Osaka-shi, Osaka -9-41 Kinki Piping Co., Ltd. F term (reference) 3H025 EA01 EB23 EC06 ED02 4F211 AA04 AD03 AD12 AG03 AG08 AH43 AJ08 SC03 SD04 SJ11 SJ13 SJ15 SJ22

Claims (6)

[Claims] 1. A pressing mechanism for pressing a pressing portion fitted to a pipe end of a synthetic resin pipe in a radial direction of the pipe end, and a radial pressing force acting on the pipe end by the pressing mechanism. A reaction force receiving portion fitted to the tube end on the side opposite to the pressing portion existing side with respect to the inside and outside in the radial direction of the tube end, wherein the pressing portion and the reaction force receiving portion A jig which can bite into the pipe end, and a pulling portion to which a pulling member for pulling the synthetic resin pipe can be connected. 2. The method according to claim 1, wherein the projecting portion is formed of a ridge extending in a circumferential direction of the end of the tube having a front inclined surface on a lower side and a rear inclined surface on a better side in a resin pipe pulling direction. The jig according to claim 1, wherein the inclination angle of the rear inclined surface is set to be smaller than the inclination angle of the inclined surface. 3. The pressing portion is provided by providing a plurality of substantially fan-shaped members to be fitted into the tube end in a state where the tube end is provided with an arc portion along the inner peripheral surface of the tube end. The plurality of substantially fan-shaped members arranged in the circumferential direction are spread on the outer peripheral surface of the rod-like body which can be contacted over the center of the pipe as the rod-like body moves in the resin pipe pulling direction. The pressing mechanism is provided by providing a taper angle that is freely movable in a radial direction, and a forcible moving mechanism that forcibly moves the rod-shaped body with respect to the pressing section in the resin pipe pulling direction. 3. The reaction force receiving part is formed by an annular body which is formed on the pipe, the traction part is formed on the rod-shaped body, and an annular body is fitted around the pipe end.
The jig for towing a resin pipe described in 1. 4. A support body for supporting said rod-shaped body in said forcible movement mechanism and capable of receiving and regulating the downward movement of said pressing portion in the direction of pulling said resin pipe, and A moving means for forcibly moving the rod-shaped body toward the lower side in the direction of pulling the resin pipe, and a jig body is integrally provided with the support and the ring. 3. The jig for drawing a resin pipe according to item 3. 5. In a traction state in which the tube end is pressed and clamped by the pressing portion and the ring body whose diameter has been moved by the operation of the pressing mechanism, the tube end is closed so as to be closed. A jig body is formed, and a supply hole for supplying heated steam to the inside of the synthetic resin tube, and a drain hole for removing drain generated inside the synthetic resin tube are provided on the jig body. The resin pipe towing jig according to claim 4, wherein both are provided so as to be able to be closed. 6. A guide portion is provided for guiding the substantially fan-shaped members to move in the radially expanding direction at substantially equal intervals in the circumferential direction of the pipe as the rod-shaped body moves in the resin pipe pulling direction. The resin pipe traction jig according to any one of claims 3 to 5, wherein