JPH07103780B2 - Curved propulsion method and propulsion support - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a curving propulsion method and a propulsion support, and more specifically, when burying an underground burial pipe such as a sewer pipe, without excavating the ground. Of the so-called propulsion method, in which the buried pipe is buried in the buried hole formed while directly forming the buried hole in the ground, especially the method of constructing a curved portion, that is, the curved propulsion method and this curved propulsion method It concerns propulsion supports.

[Prior Art] Since the propulsion method does not require wide excavation of the ground along the buried route, research and development is being promoted as a preferable method for construction sites where there is a lot of traffic and it is difficult to restrict traffic.

In the conventional general propulsion method, first, a vertical shaft is excavated and formed in the ground, and a horizontal burying hole is formed on the side surface of the vertical shaft by a device called a front conductor. The method of forming the buried hole includes a method of forming a buried hole by excavating the ground by an excavating means such as an earth auger provided in the front conductor, and a method of consolidating the ground with the conical tip of the front conductor Is a method of forming a slab, and either method is selected depending on the soil quality and construction conditions. Buried pipes are successively added behind the front conductor. At the rear end of this buried pipe, a propulsion force is applied by an original push jack installed in the shaft to propel the buried pipe row and the lead conductor, while forming the buried hole by the lead conductor and laying the buried pipe. Is.

When burying a sewer pipe or the like, in order to change the direction of the sewer pipe or avoid obstacles, the buried pipe may be buried in a curved shape. When applying the propulsion method to the curved part,
First, in order to form a curved buried hole, a plurality of direction control jacks are provided in the circumferential direction of the leading conductor, and the leading control conductor is deflected by expanding and contracting the direction controlling jack. Turn the curve direction of. In this state, if a propulsive force is applied to the tail end of the buried pipe row in the same manner as described above, the leading conductor is propelled in the curved direction to form a curved buried hole, and the buried pipe also has this curved shape. It is sent along the buried hole.

Since the buried pipe itself has the same linear cylindrical shape as the normal straight part, the end faces of the buried pipes propelled along the curved part have a V-shaped gap inside and outside the curvature. It will be. The V-shaped gap is filled and sealed from the inner surface side after the buried pipe is laid.

[Problems to be Solved by the Invention]

However, the above-described conventional curve propulsion method has a problem that a buried pipe is broken or an accident in which propulsion is impossible frequently occurs.

This is because when the embedded pipe is propelled to the curved portion, the propulsive force from the rear is transmitted in the state where there is a V-shaped gap between the embedded pipes as described above. That is, on the end surface of the buried pipe, the propulsive force is applied only to a part inside the curve, and a large concentrated stress is generated in this part. Thus, the stress concentration in a part of the buried pipe causes the buried pipe to be deformed or damaged, and in the worst case, the buried pipe cannot be propelled.

Therefore, a cushion material made of styrofoam or the like is sandwiched between the end surfaces of the embedded pipes, and the cushion material is partially deformed as the gap between the end surfaces of the embedded pipes changes in the curved portion. There has been proposed a method for preventing local stress concentration by keeping the cushion material in constant contact with.

However, although the cushioning material has a function of closing the gap between the buried pipes, the effect of preventing concentration of stress applied to the end face of the buried pipe cannot be expected so much. That is, the cushioning material does not deform at the outside of the curved part where the gap between the buried pipes is large, and the cushioning material is only compressed and deformed at the inside of the curved part where the gap between the buried pipes is small. Although there is an effect of slightly increasing the stress transmission surface at, the stress transmitted through the end faces of the buried pipes hardly increases at the outer portion of the curved portion, and the stress cannot be dispersed over the entire end face of the buried pipe. Therefore,
After all, most of the propulsive force is transmitted inside the curved portion, so stress is likely to be concentrated and deformed or damaged at the end surface of the buried pipe in this portion.

Further, in the prior art disclosed in Japanese Examined Patent Publication No. 1-56240, a plurality of opening adjusting members are sandwiched between the end faces of the buried pipe, and the length of the opening adjusting member is set when propelling a curved portion. By adjusting the inner diameter and the outer diameter of the curved portion, the embedded pipe is propelled in an accurate curved shape in a state where the end surfaces of the embedded pipe are connected by the opening adjusting member. In this method, the transmission of the propulsive force is transmitted between the buried pipes through the opening adjusting member on both the inner and outer peripheral sides of the curved portion, so that a large stress concentration is caused only at one point inside the curved portion. It never happens.

However, even in the above method, since the force for linearly propelling the rear buried pipe along its axial direction is transmitted to the front buried pipe whose axial direction is deviated by a certain angle, the inner peripheral side of the curved portion The difference between the transmitted force, that is, the stress generated at the end face of the buried pipe occurs between the outer peripheral side and the outer peripheral side, and inevitably a larger stress is generated on the inner peripheral side of the curved portion than on the outer peripheral side. Therefore, even with this method, there remains a problem that the inner peripheral side of the curved portion is easily deformed or damaged at the end surface of the buried pipe.

Therefore, the object of the present invention is to solve the problems of the prior art in the propulsion method for the curved portion as described above,
It is an object of the present invention to provide a method capable of reliably preventing deformation and damage of an embedded pipe without causing local stress concentration on the end surface of the embedded pipe. Another object is to provide a propulsion support which is an apparatus used in the above method.

[Means for Solving the Problems]

The curved propulsion method according to claim 1 of the present invention, which solves the above-mentioned problems, is a curved propulsion method in which a buried pipe is formed along a curved buried hole while a curved buried hole is formed by a conductor. The propulsion support body is sequentially connected to the rear of the body through a deflection connecting means capable of adjusting the deflection angle, and a holding member having a radially inflatable expansion mechanism provided on the outer periphery of the propulsion support body is held. The embedded pipe is held and fixed to the propulsion support body by the fixing means via the expansion mechanism, and the axial direction of the propulsion support bodies is deflected at a predetermined angle by the deflection connecting means, and the propulsion force is applied to the propulsion support body. Is added to promote the lead conductor and the buried pipe in a curved shape.

Further, the propulsion support according to claim 2 is used in the above method, and has a shaft-like shape into which an embedded pipe can be inserted and fitted on the outer circumference, and has an expansion mechanism that can expand in the radial direction. A holding and fixing means for holding and fixing the buried pipe is provided on the outer periphery, and the propulsion supports can be connected to each other at the axial end portion,
A turning connection means is provided which can turn the axial directions of the propulsion supports at a predetermined angle.

As the lead conductor, the same one as used in the ordinary propulsion method is used. The outer diameter of the leading conductor is set according to the outer diameter of the buried pipe to be laid. As described above, the leading conductors include those equipped with an excavating means such as an earth auger and those equipped with a tip portion for consolidation, and any structure can be used. Moreover, the thing which circulates and supplies the muddy water from the conductor to the ground surface, and discharges the excavated earth and sand with the muddy water is also used. The front conductor is provided with a turning means such as a direction control jack for changing the direction of the tip. The specific structure of the diverting means may be the same as that of the lead conductor in the usual propulsion method. The leading conductor itself may not be provided with a turning means, but the leading conductor may be connected to the driving support immediately after it by a turning connecting means for the driving support described later.

The propulsion support body is a shaft body made of a cylinder having a diameter slightly smaller than the inner diameter of the buried pipe to be laid, and the length of the propulsion support body is
It is formed to the same length as the buried pipe. The propulsion support is connected to the rear of the leading conductor and is sequentially added.

Inside the propulsion support, an auger screw that drives the earth auger of the lead conductor to send the excavated earth and sand backward, and hydraulic and pneumatic piping that operates the deflection means of the lead conductor,
A power cable and the like are accommodated. Also,
If the propulsion support is applied to a large-diameter buried pipe, a worker may be allowed to enter the inside of the propulsion support.

The end face of the propulsion support is provided with deflection connecting means for connecting the lead conductor and the propulsion support or the propulsion supports. The deflection connecting means connects the propulsion supports in the axial direction and can integrally move or transmit the propulsion force, and can freely move the axial directions of the connected front and rear propulsion supports at a predetermined angle. It can be changed. Usually, a connecting means for connecting the propulsion supports to each other in a state where the axial angle is free and an angle adjusting means for adjusting and fixing the axial angle to a desired angle are provided, but the connecting means and the angle adjusting means are provided. May be performed by the same mechanism.

Specifically, as the connecting means, for example, if a hinge mechanism that can be connected and detached is provided at symmetrical positions on the outer circumferences of both ends of the propulsion support, and the front and rear propulsion supports are connected by this hinge mechanism, Since the propulsion supports are integrally connected and the front and rear propulsion supports can pivot about the hinge mechanism, the axial direction of the propulsion support can be freely changed.

However, the hinge mechanism alone does not determine the angle in the axial direction. Therefore, as an angle adjusting means for adjusting and fixing the axial angle between the propulsion supports, a screw jack, a hydraulic / pneumatic cylinder, or other expansion / contraction mechanism is provided between the end faces of the propulsion support.
Detachable at multiple locations on the outer circumference. By adjusting the expansion and contraction amounts of the expansion and contraction mechanisms at these plural positions, the distance between the end faces of the propulsion support body changes depending on the place, and as a result, the axial direction of the front and rear propulsion support bodies can be adjusted and fixed at an arbitrary angle.
Since the expansion / contraction mechanism such as a screw jack can bear a certain amount of load, the angle adjusting means can also function as a connecting means for connecting the propulsion supports. In addition, the hinge mechanism and the expansion and contraction mechanism described above,
This is one example of the deflection connecting means in the present invention, and if the mechanism as described above can be performed, it is possible to use the connecting structure and the angle adjusting structure in various ordinary mechanical devices in combination.

The operation of the angle adjusting means may be performed by manually adjusting the screw jack or the like at the connecting portion of each propulsion support, but, for example, the screw jack is driven by a motor, and all the connecting portions of each propulsion support are operated. If the drive motors of (1) and (2) are electrically controlled together, it is possible to accurately adjust the drive motor to an appropriate angle according to the angle of the curved portion where the lead conductor and the propulsion support body are propelled. This method can be applied to a mechanism other than the screw jack as long as the angle adjusting means can be electrically controlled. In addition, if the angle adjusting means at the connecting portion of each propulsion support is mechanically connected to the shaft by a universal joint or a wire, a cam, a gear, etc., the angle adjusting means at a plurality of positions can be mechanically operated. Can be done at the same time. If an angle detecting means such as a sensor for detecting the turning angle of the front and rear propulsion supports is provided, the operation of the angle adjusting means is controlled based on the detected turning angle, and the turning angle is more accurately determined. It becomes possible to adjust.

Next, the propulsion support is provided with holding and fixing means for holding and fixing the buried pipe. The holding and fixing means holds the embedded pipe on the outer periphery of the propulsion support body and holds it from the inner surface of the embedded pipe to propel the embedded pipe against the frictional resistance force applied from the ground to the embedded pipe during propulsion. It may be fixed on the support.
Specifically, for example, an expansion body made of a rubber bag or the like that expands when a pressure medium such as air is supplied is provided on the outer periphery of the propulsion support, and the expansion body is expanded to contact the inner surface of the buried pipe. If pressed, the friction support force between the expander and the buried pipe
The embedded pipe can be held and fixed to the expander.

The buried pipe used in the propulsion method can be a sewer pipe, a conduit pipe, or the like having any material and dimensions according to the purpose, and specifically, a fume pipe, a reinforced resin pipe, a vinyl chloride pipe, a steel pipe, and the like. The pipe material to which the usual propulsion method can be applied can be freely used. The diameter and length of the buried pipe are appropriately sized according to the purpose, as in the ordinary propulsion method.

It is preferable to fit a short tubular collar at the joint between the buried pipes so that dirt and the like will not enter the buried pipe through the joint. The specific structure of the collar may be the same as that used in a normal propulsion method. As the material of the collar, the same material as that of the above-mentioned buried pipe is used. When the buried pipe is propelled through the curved portion of the buried hole, the gap at the joint portion of the buried pipe partially expands. Therefore, the collar has a structure that can cope with such variation in the gap at the joint portion. Those are preferable. It is preferable that the collar, when mounted on the buried pipe, not project beyond the outer diameter of the buried pipe. Therefore, it is preferable that the outer diameter of the collar is set to be equal to or slightly smaller than the outer diameter of the embedded pipe, and a step portion for inserting the collar is formed at the outer peripheral end of the embedded pipe. Also, if a flange portion that protrudes inward is provided on the inner peripheral surface of the cylindrical collar,
The collar does not come off from the joint portion of the buried pipe, and moreover, the flange portion abuts on the end surface of the buried pipe for protection.

A curve propulsion method using each device member having the above structure will be described.

It is normal to form a buried hole by excavating a vertical shaft at an appropriate distance in the ground where the buried pipe is to be laid and propelling the front conductor into the ground from the side of the vertical shaft. It is the same as the construction method. However, in the conventional propulsion method, the buried pipe is directly connected to the rear of the front conductor, and propulsive force is applied to the tail end of this buried pipe by the original push jack installed in the shaft. The propulsive force applied to the buried pipe from the above was sequentially transmitted to the buried pipe in the front, and finally the leading conductor at the front was to be propelled. However, in the method of the present invention, the propulsion support body in which the embedded pipe is inserted and retained and fixed is connected to the rear side of the front conductor, and the propulsion support body is sequentially added. In this state, a propulsion force is applied to the propulsion support by using a pushing jack or the like. The propulsive force applied to the propulsion support body is sequentially transmitted to the front propulsion support body and is also transmitted to the embedded pipe through the holding and fixing means. The propulsive force is also transmitted to the leading conductor to propel the leading conductor.

Next, when the propulsion method is applied to the curved portion, the turning means of the lead conductor is operated to change the traveling direction of the lead conductor. This is the same as the conventional propulsion method.

When the lead conductor turns, the propulsion support and the buried pipe that follow must also be propelled in turn. Therefore, the deflection connecting means connecting the propulsion supports is deflected by a predetermined angle according to the deflection angle of the leading conductor, that is, the curvature of the buried hole. Then,
The propulsion support body is propelled while smoothly changing its direction according to the curvature of the buried hole. Since the embedded pipe is held and fixed to the propulsion support, it is naturally deflected at the same angle as the propulsion support, and is propelled while smoothly changing its direction along the curved portion of the embedding hole. If the curvature of the curved portion of the buried hole changes, the turning angle of the turning connecting means of the propulsion support also changes.

When the lead conductor is propelled to the intended shaft, the lead conductor and the propulsion support are removed from the burial hole, leaving only the burial pipe in the burial hole. The deflection connecting means connecting the propulsion supports to each other sequentially releases the connection. Also, the propulsion support is removed while releasing the holding and fixing of the buried pipe by the holding and fixing means of the propulsion support. After the removal of the lead conductor and the propulsion support, the inner surface of the buried pipe is subjected to a finishing treatment such as a water sealing treatment, and the subsequent steps are carried out in exactly the same manner as the usual propulsion method.

In the above method, if the burial hole formed between the starting shaft and the target shaft, that is, the laying route of the burial pipe is only a curved portion having the same curvature, the turning angle of the turning connecting means for connecting the propulsion supports to each other. Should be fixed at a fixed angle from the beginning. However, when the curvature of the curved portion changes depending on the location, or when the curved portion and the straight portion are mixed, the deflection angle of the deflection connecting means is changed stepwise depending on the propulsion positions of the buried pipe and the propulsion support. Or it needs to be changed continuously. In this way, when it is necessary to change the turning angle, as described above, the angle adjusting means of the turning connecting means is collectively adjusted electrically or mechanically in a vertical shaft outside the buried hole. It would be very convenient if it could work.
As can be seen from the above description, the curve propulsion method according to the present invention can be applied not only to the construction of the curved portion but also to the construction place where the curved portion and the straight portion are mixed.

[Action]

If the embedded pipe is held and fixed to the propulsion support, the propulsion support is connected to the rear of the front conductor to apply a propulsive force to the propulsion support. Since the propulsion force is transmitted from the propulsion support body, it is not necessary to transmit the propulsion force between the end faces of the buried pipe.

The propulsion supports can be freely adjusted in their axial angles with each other by the deflection connecting means, and thus can be propelled along an arbitrary curve.

As a result, even if the embedded pipe is propelled through the curved embedded hole, no external force acts between the end faces of the embedded pipes. In addition, since the turning angle of the propulsion support can be adjusted according to the curvature of the curved portion, and the propulsion support can be propelled accurately and smoothly along the curved portion, the embedded pipe held and fixed to the propulsion support is capable. Even without being caught in the buried hole or plunged into the ground, it is propelled while changing its direction accurately and smoothly along the curved part. As a result, the resistance force of the ground applied to the buried pipe in the curved portion becomes extremely small.

Therefore, the problem that local stress concentration occurs due to the imbalance of the transmission force applied to the end surface of the buried pipe as in the conventional construction method is solved, and the buried pipe is damaged or promoted even when propelling the curved part. Is never impossible.

Since the propulsion support can be made much stronger and more durable than the buried pipe, it can be said that there is an imbalance in transmission force between the end faces of the propulsion support. However, there is no problem.

Furthermore, since the buried pipe is held and fixed to the propulsion support through the expansion mechanism, when the propulsion support deflection angle is changed, the buried pipe is smoothly deflected without excessive force being applied to it. The angle changes. This is because the buffering action of the elastically deformable expansion mechanism allows the force applied from the propulsion support to the embedded pipe to be dispersed and transmitted to the entire embedded pipe. If the propulsion support and the buried pipe are rigidly connected, excessive stress concentration may occur at a specific portion of the buried pipe during the turning operation. When the buried pipe is propelled in a straight line, variations in the hardness and pressure of the ground may not have much effect, but let's change the direction of the buried pipe to a direction different from the direction of the buried hole. In this case, the difference in the local resistance force has a great influence, so that the cushioning action by the expansion mechanism is extremely effective.

〔Example〕

Next, the present invention will be described in detail below with reference to the drawings illustrating an embodiment.

FIG. 1 shows the construction state of the curved propulsion method for the horizontal section of the ground.

First, the leading conductor 10 is arranged at the head. The front conductor 10 has a cylindrical outer diameter, and a tip 11 is conically pointed and inclined inward, and the tip 11 is pushed toward the ground. The earth and sand taken inside the tip 11 is
And is finally discharged from a shaft (not shown).

A propulsion support 20 is connected behind the front conductor 10.
The propulsion support 20 has a shaft-like shape made of a fixed-length steel pipe or the like,
The tip is connected to the back of the front conductor 10 by a hinge mechanism 30 which can be swung. The propulsion support body 20 and the leading conductor 10 are also connected by a telescopic mechanism 40 which is provided at a plurality of locations on the outer circumference and is capable of telescoping. The propulsion support 20 is sequentially connected to the rear via the hinge mechanism 30 and the expansion / contraction mechanism 40, and the rearmost end of the propulsion support 20 is
It reaches the starting shaft and is connected to a propulsion force adding means such as a push jack.

2 and 3, a hinge mechanism 30 and a telescopic mechanism are shown.
The detailed structure of 40 is shown.

As shown in FIG. 3, the hinge mechanisms 30 are provided at diametrically symmetrical positions on the outer circumference of the end face of the propulsion support member 20, and the hinge plate 34 is formed to project from one end face of the propulsion support member 20. With the tip of a forked hinge plate 36 projecting from the other end surface of the propulsion support 20, the hinge pins 36 are fitted and inserted, and the hinge plates 34, 36 on both sides are pivotally connected. ing. As a result, the front and rear propulsion supports 20 can freely rotate about a diametrical direction connecting the hinge pins 36, that is, the hinge mechanism 30, as a rotation axis. The hinge pin 36 is detachably attached so that the propulsion support 20 can be connected and disassembled.

The expansion / contraction mechanisms 40 are provided on the outer periphery of the end surface of the propulsion support 20 at symmetrical positions in the diametrical direction orthogonal to the hinge mechanism 30, and are provided with a so-called screw jack mechanism. That is, the threaded shaft 42 is formed such that the threading directions from the center to the left and right are reversed, and for example, if the right side is a right thread, the left side is a left thread. Cylindrical nuts 44, 44 are respectively screwed into both ends of the screw shaft 42.
The nuts 44, 44 are rotatably supported while being sandwiched between a pair of bearing plates 46, 46 fixed to the outer surface of the propulsion support 20 by welding or the like. A drive motor 48 is attached to one end of the screw shaft 42 so that the screw shaft 42 can be rotated. When the turning angle of the propulsion support 20 is changed, the position of the drive motor 48 moves. Therefore, the drive motor 48 is movable with respect to the propulsion support 20 and the reaction force at the time of rotational drive is applied. Attach it in a condition that it can be supported.

When the drive motor 48 is driven to rotate, the screw shaft 42
The nuts 44,44 and the screw shaft 42 try to move in the axial direction relative to each other by rotating inside the 4,44. Since the screw shaft 42 has the left-right screw direction reversed, the direction of relative movement between the nut 44 on the right side and the screw shaft 42 and the direction of relative movement between the nut 44 on the left side and the screw shaft 42 are also opposite. Since the screw shaft 42 itself cannot be expanded and contracted, the left and right nuts 44, 44 tend to move toward or away from each other. That is, the expansion / contraction mechanism 40 that expands or contracts the distance between the left and right nuts 44, 44 is configured.

Since the nuts 44,44 are rotatably supported by the bearing plates 46,46 fixed to the propulsion support 20, the nuts 44,44 move forward and backward through the bearing plates 46,46 as the nuts 44,44 move. The supports 20, 20 move in a direction of approaching or moving away from each other. In FIG. 2, screw shafts 42, 42 located on both sides of the hinge mechanism 30
Are rotated in opposite directions so that one end faces of the propulsion supports 20 and 20 come close to each other and the other end faces move away from each other, the propulsion supports 20 and 20 perform a pivoting motion around the hinge mechanism 30. It will be. That is, the front and rear propulsion supports 20, 20 are turned at a predetermined angle. Screw shaft 42,
By controlling the rotation angle or speed of 42, the propulsion support
The turning angle of 20,20, that is, the turning angle can be freely adjusted.

In the above-described expansion / contraction mechanism, the screw shafts 42, 42 are rotated by the drive motor 48, and if the operation of the drive motor 48 is electrically controlled, a large number of the propulsion support members 20 used in a connected state can be obtained. Each turning angle, on the shaft or on the ground,
It is possible to perform adjustment operations collectively. However, screw shaft
Instead of the drive motor 48, a crank-shaped operating arm etc. is attached to 42, 42, and this operating arm is manually operated to
May be rotationally actuated to deflect the propulsion support 20.

The embodiment shown in FIG. 4 is one in which the operation of the screw shaft 42 can be mechanically collectively controlled in the above-described expansion and contraction mechanism. The basic structure of the hinge mechanism 30 and the expansion / contraction mechanism 40 provided at the connecting portion of the propulsion supports 20, 20 is the same as that of the above-described embodiment. At both ends of the screw shaft 42, the drive motor 48
Instead of the or manual operation arm, a connecting shaft 49 is attached via a universal joint 47. Therefore, the screw shafts 42 of the many propulsion supports 20 connected to the front and rear are all connected and integrated by the universal joint 47 and the connecting shaft 49. In this state, if the drive motor 48 as described above is attached to the screw shaft 42 or the connecting shaft 49 of the rearmost propulsion support body 20, one drive motor 48 can drive all the propulsion support bodies 20. By rotating the screw shafts 42 all at once, the turning angles of the respective propulsion supports 20 can be adjusted at the same time. When the propulsion support 20 is deflected, the axial directions of the screw shafts 42 do not line up in a straight line, but since the screw shafts 42 are connected by the universal joint 47 and the connecting shaft 49, they are not in a straight line. The series of screw shafts 42 can be rotated.

Next, on the outer periphery of the propulsion support 20, annular expansion mechanisms 50 are provided as holding and fixing means near both ends in the axial direction. 2 and 3 show the detailed structure of the expansion mechanism 50.

A tubular expander 52 made of an elastic material such as rubber is installed so as to surround the outer periphery of the propulsion support 20. The inflatable body 52 is attached and fixed to the support frame 54 attached to the propulsion support 20 on the inner peripheral side. In addition, the expander 52,
A supply / discharge unit (not shown) for supplying and discharging a pressure medium such as compressed air is provided. A valve or the like for normal pressure piping is attached to the supply / discharge unit. The expansion bodies 52 before and after the propulsion support 20 may be connected by pressure pipes. In addition, the expansion body 52 of the propulsion support 20 connected to the front and rear
They can also be connected to each other by a flexible pipe or the like.

When the pressure medium is introduced into the expansion body 52 with the embedded pipe 60 fitted in the outer periphery of the propulsion support 20, the expansion body 52 expands toward the outer periphery, and the outer surface of the expansion body 52 becomes the inner surface of the embedded pipe 60. It abuts and presses. If a constant pressure is applied from the expander 52 to the buried pipe 60, a frictional supporting force is generated between the expander 52 and the buried pipe 60, so that the buried pipe 60 does not shift in the axial direction and the propulsion support 20 It will be securely held in place.
By changing the amount or pressure of the compressed air introduced into the expander 52, the pressing force, that is, the holding and fixing force with respect to the buried pipe 60 can be adjusted. Once the pressurized air introduced into the expander 52 is released, the holding and fixing to the embedded pipe 60 is released, and the propulsion support 20 can be extracted from the embedded pipe 60.

As shown in the figure, the structure of the inflatable body 52 is not limited to a tubular shape surrounding the outer periphery of the propulsion support body 20, but also a flat bag-shaped inflatable body extending along the axial direction of the propulsion support body 20 for propulsion support. A plurality of bodies are installed in the circumferential direction of the body 20, and each inflatable body expands in the radial direction and abuts on the inner surface of the buried pipe 60. If possible, a structure other than the one shown in the figure can also be adopted.

The expansion mechanism as described above is used as a means for holding and fixing the buried pipe 60.
If 50 is used, the inflatable body 52 elastically abuts the inner surface of the buried pipe 60, so that the inner surface of the buried pipe 60 can be securely held and fixed without being damaged or deformed, and there is variation or error in the inner diameter of the buried pipe 60. Even if there is, it can be absorbed by the elastic deformation of the expander 52, there is no possibility of failure because there is no complicated actuation mechanism, and it is easy and reliable to hold and release the buried pipe 60 simply by controlling the supply of pressure medium. It is possible to exert excellent action and effect.

A curved propulsion method using the propulsion support 20 described above will be described.

Propulsion of the front conductor 10 from the side surface of the shaft into the ground to form a buried hole is performed in exactly the same manner as in a normal propulsion method.
The propulsion support 20 is connected to the rear of the front conductor 10 via a hinge mechanism 30 and an expansion / contraction mechanism 40. At this time, the propulsion support
After embedding a buried pipe 60 made of a fume pipe or the like on the outer periphery of 20, the pressure medium is introduced into the expansion body 52 of the propulsion support body 20 to expand it, and the embedded pipe 60 is held and fixed to the propulsion support body 20. Keep it.

At the end of the propulsion support 20 connected to the rear of the front conductor 10,
If a propulsion force is applied from the source jack in the vertical shaft,
10 and the propulsion support 20 are propelled into the ground and
A buried hole is formed by. The buried pipe 60 held and fixed to the propulsion support 20 is propulsively buried in the embedding hole together with the propulsion support 20.

If the single propulsion support 20 and the buried pipe 60 are propulsively embedded in the embedding hole, a new propulsion support 20 is again attached to the rear end of the propulsion support 20 via the hinge mechanism 30 and the expansion / contraction mechanism 40. Link. The embedded pipe 60 is also held and fixed to the propulsion support 20. A collar 70 is attached to the joint portion of the front and rear buried pipes 60, as shown in detail in FIG. The collar 70 is made of synthetic resin or the like, has a tubular shape as a whole, and has a T-shaped cross section in which a flange portion 72 protruding inward at a constant width in an annular shape is provided in the center of the inner surface. Also,
The end portions of the embedded pipes 60, 60 are formed with a shallow step portion 62 having a constant width on the outer periphery. The collar 70 is fitted into the step portion 62, and the collar 70 flange portion 72 is the end surface of the embedded pipes 60, 60. It is attached in the state of facing. With such a collar 70, the buried pipe 6
By covering the 0, 60 joint, it is possible to prevent the intrusion of earth and sand from the joint. Flange 72 is buried pipe 6
By interposing in the gap between the end faces of 0, 60, the collar 70
Can be prevented from moving in the axial direction, and the end faces of the buried pipes 60, 60 can be prevented from colliding with each other.

Next, as shown in FIG. 1, a curved buried hole is formed by the front conductor 10, and the buried pipe 60 is propulsively buried in the formed curved buried hole. First, the propulsion direction of the front conductor 10 is changed by the changing means or the like provided in the front conductor 10. In the illustrated embodiment, the length of the expansion / contraction mechanism 40 that connects the lead conductor 10 and the propulsion support 20 is changed to turn the lead conductor 10. When the buried conductor has a curved shape after the advance direction of the front conductor 10 has ended, the subsequent propulsion support
The propulsion direction of 20 and the buried pipe 60 must also be changed. Therefore, as shown in FIG. 2, the front and rear propulsion supports 2
Of the pair of expansion and contraction mechanisms 40 connecting 0 and 20, one is extended and the other is contracted, so that the front and rear propulsion supports 20, 20 are connected.
Change the axis direction of. At this time, the front and rear buried pipes 60,60
, The gap widens on one end face and narrows on the other end face. The collar 70 can sufficiently cover the gap between the buried pipes 60, 60 even if the gap is widened, and the buried pipe 6
In the place where the gap of 0,60 is narrow, the buried pipes 60,60 are
The flange portions 72 of the collar 70 are abutted against each other, and it is possible to reliably prevent the end surfaces of the embedded pipes 60, 60 from contacting and rubbing or scratching.

The turning angle of the propulsion support 20 is set according to the curvature of the buried hole. When the buried hole moves from a straight line to a curved line or when the curvature of the curved line gradually changes, as the propulsion position of the propulsion support 20 moves, the operation amount of each expansion / contraction mechanism 40 is adjusted to always provide an appropriate deflection. It is preferable to maintain the angle.

In the curved propulsion method according to the present invention, since the deflection angle of the propulsion support 20 can be arbitrarily changed to cope with the change in the curvature of the buried hole, the route of the buried hole can be freely designed. For example, when changing the direction of the buried hole by a certain angle, instead of the conventional direction in which the straight line portion is immediately connected to the straight line portion in the target direction through the arcuate curved portion having a constant curvature, the straight line portion is gradually changed. After moving to the curved part while increasing the curvature,
This time, it becomes possible to design a very complicated buried hole path such that the curvature is gradually reduced and the straight line is connected in a desired direction.

〔The invention's effect〕

According to the curved propulsion method and the propulsion support body of the present invention described above, the propulsion force is transmitted by the propulsion support body, and the embedded pipe is only held and fixed to the propulsion support body. Therefore, no external force acts on the end faces of the buried pipes. Moreover, since the propulsion support for holding and fixing the buried pipe is connected through the deflection connecting means capable of adjusting the deflection angle, the front and rear propulsion supports can be arbitrarily changed according to the curvature of the curved portion. The angle can be adjusted. Therefore, the buried pipe can be propelled extremely accurately and smoothly in accordance with the curvature of the buried hole without fear of local stress concentration on the end surface.

As a result, the problem that the buried pipe is damaged or cannot be propelled during the curve propulsion method is completely solved, and it is possible to perform a reliable, prompt, and stable construction work of the buried pipe.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a working state showing an embodiment of the present invention, FIG. 2 is an enlarged detailed sectional view of an essential part, FIG. 3 is a sectional view in a direction orthogonal to FIG. 2, and FIG. It is sectional drawing which shows the Example of. 10 …… Lead conductor, 20 …… Propulsion support, 30 …… Hinge mechanism,
40 …… Expansion mechanism, 50 …… Expansion mechanism, 60 …… Buried pipe, 70…
…Color

Claims (2)

[Claims] 1. In a curving propulsion method in which a buried pipe is buried along a curved buried hole while forming a curved buried hole in the conductor, a changeable angle can be adjusted behind the front conductor. The propulsion supports are sequentially connected via the directional connecting means, and the embedded pipe is propulsively supported via the expansion mechanism by the holding and fixing means provided on the outer circumference of the propulsion support and having the expansion mechanism capable of expanding in the radial direction It is held and fixed to the body, and the deflection connecting means deflects the axial directions of the propulsion supports at a predetermined angle, and applies a propulsive force to the propulsion supports to form the lead conductor and the buried pipe in a curved shape. Curved propulsion method, which is characterized in that 2. A propulsion support for use in the curved propulsion method according to claim 1, which has a shaft-like shape into which an embedded pipe can be fitted and which has an expansion mechanism capable of expanding in the radial direction. A holding and fixing means for holding and fixing the buried pipe through a mechanism is provided on the outer periphery, and the axial end portions can connect the propulsion supports to each other and can change the axial directions of the propulsion supports at a predetermined angle. A propulsion support characterized in that it comprises a connecting means.