JPH03267496A - Curved driving method and drive bearing body - Google Patents

Abstract

PURPOSE:To drive forward smoothly by connecting successively drive bearing bodies at the rear of a guider through an alteration coupling means and, at the same time, fitting and loading buried pipes to the peripheral surfaces of the drive bearing bodies, and alternating the axial directions of the drive bearing bodies by the alteration coupling means. CONSTITUTION:Drive bearing bodies 20 are connected at the rear of a guider 10 through hinge machineries 30 and expansion machineries 40 and, at the same time, buried pipes 60 are fitted and loaded to the peripheral surfaces of the bearing bodies 20. After that, driving force is added to the last end of the bearing bodies 20 from a breech pushed jack in a vertical shaft, and buried holes are excavated by the guider 10. Then, a new bearing body is connected to the last end of the existing bearing body 20 through the machineries 30 and 40 and, at the same time, collars 70 are loaded to joint parts of the pipes 60 and 60. One of the machineries 40 is extended, the other of them is shrunk to alternate the axial directions of the bearing bodies 20 and 20 and, at the same time, the ends of the pipes 60 are covered with the collars 70. Accordingly, stress concentration to the ends of the pipes 60 is avoided, and smooth driving can be made.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a curved propulsion construction method and a propulsion support, and more specifically, the present invention relates to a curve propulsion construction method and a propulsion support. Among the so-called propulsion construction methods, in which a buried pipe is buried directly in the formed burial hole while forming a burial hole directly in the ground, there is a method that specifically constructs curved sections, that is, a curved propulsion method, and the method used for this curve propulsion method. It concerns a propulsion support.

[Conventional technology]

Since the propulsion method does not require extensive excavation of the ground along the buried route, research and development is progressing as a preferred method for construction sites where traffic volume is high and it is difficult to restrict access.

The conventional propulsion method is to first excavate a shaft in the ground, and then use a device called a guide to form a horizontal burial hole on the side of the shaft. There are two methods for forming a burial hole: one is to excavate the ground with a digging means such as an earth auger equipped on the guide body, and the other is to compact the ground with the conical tip of the guide body. There are several methods of forming a Buried pipes are successively added to the rear of the leading body.

Propulsive force is applied to the rear end of this buried pipe by a pusher jack installed in the shaft to propel the buried pipe row and leading body, while forming a buried hole with the leading body and laying the buried pipe. It is.

In the construction of underground sewer pipes, etc., the buried pipes are sometimes buried in a curved shape in order to change the direction of the sewer pipe or avoid obstacles. When applying the propulsion method to curved sections,
First, in order to form a curved buried hole, a plurality of direction control jacks are provided in the circumferential direction of the guide body, and by expanding and contracting the direction control jacks, the direction of the guide body is changed to a predetermined position. Orient the curve direction. In this state, if a driving force is applied to the last end of the buried pipe row in the same manner as above, the guide body will be propelled in the curved direction, a curved buried hole will be formed, and the buried pipe will also follow this curved hole. It is sent along the buried hole.

In addition, since the buried pipes themselves are straight cylindrical like normal straight sections, there is a figure 7-shaped gap between the inner and outer peripheries of the curvature on the end surfaces of the buried pipes that are propelled along the curved sections. It will be dark. After the buried pipe is laid, this 7-shaped gap is filled and sealed from the inner side.

[Problem to be solved by the invention]

However, the conventional curved propulsion construction method as described above has the problem of frequently causing damage to buried pipes and accidents that make propulsion impossible.

This is because, as described above, when the buried pipes are propelled along the curved portion, a V-shaped gap is left between the ends of the buried pipes, and the propulsion force from behind is transmitted. In other words, the propulsive force is applied only to a portion of the end face of the buried pipe that is inside the curve, and a large concentrated stress is generated in this portion. This concentration of stress in a portion of the buried pipe causes deformation and damage of the buried pipe, and in severe cases, it becomes impossible to move the buried pipe.

Therefore, a cushioning material made of deformable polystyrene foam or the like is sandwiched between the end faces of the buried pipes, and as the gap between the end faces of the buried pipes changes at the curved part, the cushioning material partially deforms, causing the end faces of the buried pipes to A method has been proposed in which the cushioning material is constantly in contact with the cushioning material to prevent local stress concentration.

However, although the cushioning material has the effect of closing the gaps between the buried pipes, it cannot be expected to be very effective in preventing the concentration of stress applied to the end faces of the buried pipes. In other words, the cushioning material is not deformed at the outside of the curved section where there is a large gap between the buried pipes, and the cushioning material is only compressed and deformed at the inside of the curved section where the gap between the buried pipes is small. Even if there is an effect of slightly increasing the stress transmission surface at , the stress transmitted through the end faces of the buried pipes will hardly increase at the outside of the curved part, and the stress cannot be dispersed over the entire end face of the buried pipes. therefore,
After all, most of the propulsion force is transmitted inside the curved portion, so there is a high possibility that stress will be concentrated on the end face of the buried pipe in this portion, causing deformation or damage.

Furthermore, in the prior art disclosed in Japanese Patent Publication No. 1-56240, a plurality of opening adjustment members are sandwiched between the end faces of a buried pipe, and when moving a curved portion, the length of the opening adjustment members is adjusted. By making the adjustment, the end faces of the buried pipe are connected to each other by the opening adjusting member on both the inner and outer peripheries of the curved portion, and are propelled in an accurate curved shape. In this method, both the inner and outer circumferential sides of the curved part,
Since the propulsion force is transmitted between the buried pipes via the opening adjustment member, a large stress concentration does not occur only at one point inside the curved portion.

However, even in the above method, the force that attempts to linearly propel the rear buried pipe along its axial direction is transmitted to the front buried pipe whose axial direction is shifted by a certain angle, so the inner peripheral side of the curved part There is a difference in the force transmitted, that is, the stress generated on the end face of the buried pipe, between the curved portion and the outer circumferential side, and inevitably a larger stress is generated on the inner circumferential side of the curved portion than on the outer circumferential side. Therefore, even with this method, there remains the problem that the inner peripheral side of the curved portion of the end face of the buried pipe is easily deformed or damaged.

Therefore, the object of this invention is to solve the problems of the prior art in the propulsion method for curved sections as described above,
It is an object of the present invention to provide a method that does not cause local stress concentration on the end face of a buried pipe and can reliably prevent deformation and breakage of the buried pipe. Another object of the present invention is to provide a propulsion support, which is a device used in the above method.

[Means to solve the problem]

A curved propulsion method according to claim 1 of the present invention that solves the above problems is a curved propulsion method in which a curved buried hole is formed with a guide body and a buried pipe is buried along the curved buried hole. The propulsion supports are sequentially connected to the rear of the body through a direction change connecting means that can adjust the direction change angle, and a holding and fixing device is provided on the propulsion supports by inserting a buried pipe into the outer periphery of the propulsion supports. The buried pipe is held and fixed to the propulsion support by the means, and the axial direction of the propulsion supports is changed at a predetermined angle by the direction change connecting means, and the leading force is applied to the propulsion support. The body and buried pipe are propelled in a curved manner.

Further, the propulsion support according to claim 2 is used in the above method, and has a shaft shape into which a buried pipe can be inserted into the outer periphery, and has a holding and fixing structure that holds and fixes the buried pipe inserted into the outer periphery. The axial end portion is provided with a direction change connecting means that can connect the propulsion supports to each other and change the axial direction of the propulsion supports at a predetermined angle.

The guide body used is the same as that used in normal propulsion methods. The outer diameter of the guide body is set according to the outer diameter of the buried pipe to be laid. As described above, there are some guide bodies equipped with excavating means such as an earth auger, and others equipped with a tip for consolidation, and either structure can be used. Also used is one that circulates and supplies muddy water from a guide body to the ground surface and discharges excavated earth and sand together with the muddy water. The guide body is provided with direction changing means such as a direction control jack for changing the direction of the tip. The specific structure of the deflection means may be similar to that of the guide body in the normal propulsion method. Note that the leading body itself may not be provided with the direction change means, and the leading body and the propulsion support immediately after it may be connected by a direction change connection means of the propulsion support described later.

The propulsion support is shaped like a cylindrical shaft that is slightly thinner than the inner diameter of the buried pipe to be laid, and the length of the propulsion support is as follows:
It is formed to approximately the same length as the buried pipe. The propulsion support body is connected to the rear of the guide body and is successively added.

Inside the propulsion support body, there is an auger screw that drives the earth auger of the guide body and sends excavated earth backward, and hydraulic and pneumatic piping that operates the direction change means of the guide body.
It accommodates power cables, etc. Also,
If the propulsion support is applied to a large-diameter buried pipe, the operator may be able to enter inside the propulsion support.

A direction changing connection means for connecting the leading body and the propulsion support or the propulsion supports to each other is provided on the end face of the propulsion support. The direction change connecting means connects the propulsion supports in the axial direction so that they can move together and transmit propulsion force, and also allows the axial direction of the connected front and rear propulsion supports to be freely moved at a predetermined angle. It is something that can be changed. Normally, the propulsion supports are provided with a connecting means that connects the propulsion supports to each other in a free axial angle, and an angle adjusting means that adjusts and fixes the axial angle to a desired angle, but the connecting means and the angle adjusting means may be performed by the same mechanism.

Specifically, as a connecting means, for example, a hinge mechanism that can be connected and detached is provided at symmetrical positions on the outer periphery of both ends of the propulsion support, and if the front and rear propulsion supports are connected by this hinge mechanism, the front and rear propulsion supports can be connected. The two propulsion supports are integrally connected, and the front and rear propulsion supports can pivot around the hinge mechanism, making it possible to freely change the axial direction of the propulsion support. However, the hinge mechanism alone is not enough. , the axial angle cannot be determined. Therefore, as an angle adjustment means for adjusting and fixing the axial angle between the propulsion supports, screw jacks, hydraulic and pneumatic cylinders, and other telescoping mechanisms can be attached and detached at multiple locations on the outer periphery between the end faces of the propulsion supports. establish. By adjusting the amount of expansion and contraction of the expansion and contraction mechanisms at these multiple locations, the distance between the end faces of the propulsion support body changes depending on the location, and as a result, the axial direction of the front and rear propulsion support bodies can be adjusted and fixed at any angle. Since a telescopic 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. The hinge mechanism and expansion/contraction mechanism described above are examples of the direction changing connection means of the present invention, and as long as they can perform the functions described above, they can be used in combination with connection structures and angle adjustment structures in various ordinary mechanical devices. It is possible to do so.

The operation of the angle adjustment means may be adjusted manually by using the above-mentioned screw jack at the connecting portion of each propulsion support, but for example, by driving the screw jack with a motor, If the drive motors for the parts are electrically controlled all at once, the leading body and propulsion support body can be accurately adjusted to the appropriate angle according to the angle of the curved part being propelled. . This method can be applied to mechanisms other than screw jacks as long as the angle adjustment means is electrically controllable. In addition, if the angle adjustment means at the connecting parts of each propulsion support are mechanically connected and interlocked with the shaft using a universal joint, wire, cam, gear, etc., the angle adjustment means at multiple locations can be adjusted mechanically. can be done at the same time. If an angle detection means such as a sensor that detects the deflection angle of the front and rear propulsion supports is provided, the operation of the angle adjustment means can be controlled based on the detected deflection angle, and the deflection angle can be adjusted more accurately. It becomes possible to adjust.

Next, the propulsion support is equipped with a holding and fixing means for holding and fixing the buried pipe. The holding and fixing means holds the buried pipe from the inner surface with the buried pipe fitted around the outer periphery of the propulsion support, and propels the buried pipe against frictional resistance, etc. applied to the buried pipe from the ground during propulsion. It may be fixed to a support.

Specifically, for example, an inflatable body made of a rubber bag or the like that is inflated by supply of a pressure medium such as air is provided on the outer periphery of the propulsion support, and this inflatable body is expanded so as to come into contact with the inner surface of the buried pipe. If it is pressed, the frictional support force between the expanding body and the buried pipe will cause
The buried pipe can be held and fixed to the expansion body. In addition, a friction retaining plate that mechanically moves from the outer periphery of the propulsion support toward the buried pipe to press the inner surface of the buried pipe may be provided, or an appropriate locking recess or protrusion may be formed on the inner surface of the buried pipe. In addition, an engaging member that engages and operates with this locking uneven portion can be installed on the propulsion support, or a holding structure or a fixing structure in various other mechanical devices can be used.

The buried pipes used in the propulsion method can be of any material and size depending on the purpose, such as sewage pipes and electrical conduit pipes.Specifically, underground pipes such as water pipes, reinforced resin pipes, PVC pipes, steel pipes, etc. Pipe materials to which normal propulsion methods can be applied are freely available. The diameter and length of the buried pipe are determined to be appropriate depending on the purpose, as in normal propulsion construction methods.

It is preferable to fit a short cylindrical collar at the joint between the buried pipes to prevent earth and sand from entering the pipe through the joint. The specific structure of the collar may be similar to that used in normal propulsion methods. The material used for the collar is the same as the material for the buried pipe described above. Note that when the buried pipe is pushed through the curved part of the buried hole, the gap at the joint part of the buried pipe partially widens, so the collar is designed to have a structure that can accommodate such fluctuations in the gap at the joint part. Preferably. Preferably, the collar does not protrude beyond the outer diameter of the buried pipe when attached to the buried pipe. Therefore, it is preferable to set the outer diameter of the collar to be the same as or slightly smaller than the outer diameter of the buried pipe, and to form a stepped portion at the outer peripheral end of the buried pipe for inserting the collar. Furthermore, if a flange part that protrudes inward is provided on the inner peripheral surface of the cylindrical collar, the collar will not come off from the joint of the buried pipe, and the flange part will come into contact with the end face of the buried pipe. can be protected.

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

The normal propulsion method is to excavate a shaft at an appropriate distance in the ground along the route where the buried pipe is to be laid, and then propel a guide body into the ground from the side of the shaft to form a buried hole. It is the same as the construction method. However, in the conventional propulsion method, a buried pipe is directly connected to the rear of the leading body, and propulsion force is applied to the tail end of this buried pipe with a main push jack installed in the shaft. The propulsion force applied to the buried pipe was to be sequentially transmitted to the buried pipes in front, and ultimately propel the leading body. However, in the method of the present invention, a propulsion support body in which a buried pipe is inserted and held and fixed is connected to the rear of the guide body, and the support bodies are successively added.

In this state, a propulsion force is applied to the propulsion support using a push jack or the like. The propulsive force applied to the propulsion support is sequentially transmitted to the forward propulsion support and is also transmitted to the buried pipe via the holding and fixing means. The propulsion force is also transmitted to the leading-edge leading body to propel it.

Next, when carrying out the propulsion method on a curved section, the direction changing means for the guide body is activated to change the direction in which the guide body moves. This is the same as the conventional propulsion method.

When the leading body changes direction, the propulsion support and the buried pipe following it must also be propelled while changing direction in turn. Therefore, the direction change connecting means connecting the propulsion supports to each other is changed by a predetermined angle in accordance with the direction change angle of the guide body, 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 buried 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 direction along the curved portion of the buried hole. If the curvature of the curved portion of the buried hole changes, the deflection angle of the deflection connecting means of the propulsion support body also changes.

Once the guide body is propelled to the target shaft, the guide body and the propulsion support are removed from the buried hole, leaving only the buried pipe in the buried hole. The direction change connecting means connecting the propulsion supports are sequentially disconnected. Further, 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 guide body and the propulsion support are removed, the subsequent steps, such as performing finishing treatments such as water sealing on the inner surface of the buried pipe, are carried out in exactly the same way as in the normal propulsion method.

In the above method, if the buried hole formed between the starting shaft and the destination shaft, that is, the laying route of the buried pipe, is only a curved portion of the same curvature, the direction change angle of the direction change connection means that connects the propulsion supports to each other. should be fixed at a certain angle from the beginning. However, if the curvature of a curved part changes depending on the location, or if curved parts and straight parts coexist, the direction change angle of the direction change connection means can be changed in stages depending on the propulsion position of the buried pipe and propulsion support. Or it needs to be changed continuously. In this way, if it is necessary to change the deflection angle, the angle adjustment means of the deflection coupling means can be adjusted electrically or mechanically in a vertical shaft, etc. outside the buried hole, as described above. It would be very convenient if it worked. As can be seen from the above description, the curve propulsion construction method according to the present invention can be applied not only to construction on curved sections, but also to construction sites where curved sections and straight sections coexist.

[For production]

With the buried pipe held and fixed to the propulsion support, this propulsion support is connected to the rear of the leading body, and if a propulsive force is applied to the propulsion support, the buried pipe will be held and fixed. Since the propulsion force is transmitted from the propulsion support body, there is no need to transmit the propulsion force between the end faces of the buried pipe.

Since the propulsion supports can freely adjust their mutual axial angles using the direction change connecting means, they can be propelled along any curve.

As a result, even when the buried pipes are pushed into the curved buried hole, no external force acts between the end faces of the buried pipes. In addition, the angle of change of direction of the propulsion support can be adjusted according to the curvature of the curved part, and the propulsion support can be accurately and smoothly propelled along the curved part. The robot is also propelled while accurately and smoothly changing direction along curved sections without getting caught in buried holes or plunging into the ground. As a result, the resistance force of the ground that is applied to the buried pipe in the curved portion becomes extremely small.

Therefore, the problem of local stress concentration occurring due to the unbalance of the transmission force applied to the end face of the buried pipe, which is the problem with conventional construction methods, is resolved, and even if the curved section is pushed forward, the buried pipe may not be damaged or pushed forward. will no longer be impossible.

In addition, the propulsion support can be made much stronger and more durable than buried pipes, so even if there is an imbalance in the transmission force between the end surfaces of the propulsion support, is not a problem either.

〔Example〕

Next, the present invention will be explained in detail below with reference to the drawings showing examples.

Figure 1 shows the construction status of the curved propulsion method on a horizontal cross section of the ground.

First, the guide body 10 is placed at the beginning. The guide body 10 has a cylindrical outer diameter and a tip 11 that is pointed in a conical shape and slopes inward, and the tip 11 is pushed into the ground. The earth and sand taken inside the tip portion 11 is sent to the rear of the guide body 10 and finally discharged from a shaft (not shown).

A propulsion support 20 is connected to the rear of the guide body 10. The propulsion support body 20 has the shape of a shaft made of a fixed-length steel pipe or the like, and has a pivotable hinge mechanism 30 at the tip of the leading body 10.
is connected behind. The propulsion support body 20 and the guide body 10 are
They are also connected by telescopic mechanisms 40 provided at multiple locations on the outer periphery. The propulsion support body 20 includes a hinge mechanism 30
The propulsion support body 20 is sequentially connected to the rear via a telescopic mechanism 40, and the rear end of the propulsion support body 20 reaches the starting shaft, and is connected to propulsive force adding means such as a head jack.

2 and 3 show detailed structures of the hinge mechanism 30 and the telescopic mechanism 40.

As shown in FIG. 3, the hinge mechanism 30
A hinge plate 34 is provided at diametrically symmetrical positions on the outer periphery of the end surface of the propelling support 20, and a hinge plate 34 protrudes from one end surface of the propulsion support 20, and a hinge plate 34 protrudes from the other end surface of the propulsion support 20. With the ends of the fork-shaped hinge plates 36 overlapped, insert the hinge bins 36 into the hinge plates 34 on both sides.
．． 36 are rotatably connected. As a result, the front and rear propulsion supports 20 are connected to the hinge bin 36, that is, the hinge mechanism 3
It is designed to be able to rotate freely using the diametrical direction connecting 0 as the rotation axis. Note that the hinge bin 36 is attached so as to be removable and removable, allowing the propulsion support 20 to be connected and disassembled.

The expansion and contraction mechanisms 40 are provided at symmetrical positions in the diametrical direction orthogonal to the hinge mechanism 30 on the outer periphery of the end surface of the propulsion support body 20, and have a so-called screw jack mechanism. That is, the threaded shaft 42 is formed with the left and right threading directions reversed from the center, for example, if the right side is right-handed, the left side is left-handed. Screw shaft 42
A cylindrical oak (44, 44) is screwed into each end near each end. The nuts 44.44 are connected to a pair of bearing plates 46.44, which are respectively fixed to the outer surface of the propulsion support 20 by welding or the like.
46, and is rotatably supported. A drive motor 48 is attached to one end of the screw shaft 42 so that the screw shaft 42 can be rotated. Note that when the direction angle of the propulsion support body 20 is changed, the position of the drive motor 48 is moved, so that the drive motor 48 is movable with respect to the propulsion support body 20, and at the same time, the reaction force during rotational driving is suppressed. Install it in such a way that it can be supported.

When the drive motor 48 is driven to rotate, the threaded shaft 42 rotates inside the nut 44.44, and the threaded shaft 42 and the threaded shaft 44 tend to move relative to each other in the axial direction. Since the screw direction of the screw shaft 42 is reversed left and right, the direction of relative movement between the right-hand Nand 44 and the screw shaft 42 and the direction of relative movement between the left-hand slot 44 and the screw shaft 42 are also opposite. Screw shaft 42
Since they themselves cannot expand or contract, the left and right Naso) 44. 44 try to move toward or away from each other. In other words, it constitutes a telescopic mechanism 40 in which the distance between the left and right nuts 44 and 44 is extended or contracted.

Since the navel) 44.44 is rotatably supported by a bearing plate 46.46 fixed to the propulsion support 20, the naso 1-
As 44.44 moves, the front and rear propulsion supports 20.20 move toward or away from each other via bearing plates 46.46. In FIG. 2, the hinge mechanism 3
By rotating the screw shafts 42.42 located on both sides of the propulsion support 20.20 in opposite directions, one end surface of the propulsion support 20.20 approaches each other and the other end surface moves away from each other.
The propulsion support 20.20 will perform a pivoting movement about the hinge mechanism 30. That is, the front and rear propulsion supports 20
．． 20 will change direction at a predetermined angle. Screw shaft 42
．． By controlling the rotation angle or number of rotations of the propulsion support 20.20, the rotation angle, that is, the turning angle of the propulsion support 20.20 can be freely adjusted.

In the above-mentioned telescopic 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, the propulsion supports 20 used in a plurality of connected It becomes possible to adjust the deflection angles of each of the two at once, either in the shaft or on the ground. However, a crank-shaped operating arm or the like is attached to the screw shaft 42 instead of the drive motor 48, and this operating arm is manually operated to rotate the screw shaft 42 and change the direction of the propulsion support 20. You can also do this.

The embodiment shown in FIG. 4 is one in which the operations of the screw shafts 42 can be mechanically operated all at once in the above-mentioned telescopic mechanism. The basic structures of the hinge mechanism 30 and the telescoping mechanism 40 provided at the connecting portion of the propulsion supports 20 and 20 are the same as those of the embodiments described above. At both ends of the screw shaft 420,
A universal joint 47 replaces the drive motor 48 and manual operation arm.
A connecting shaft 49 is attached via. Therefore, the screw shafts 42 of a large number of propulsion supports 2° connected back and forth are all connected and integrated by the universal joint 47 and the connecting shaft 49.

In this state, the screw shaft 4 of the rearmost propulsion support 2o
If a drive motor 48 as described above is attached to the connecting shaft 49 or the connecting shaft 49, the screw shafts 42 of all the propulsion supports 2o can be rotated at the same time by one drive motor 48, and the screw shafts 42 of all the propulsion supports 2o can be rotated simultaneously. It becomes possible to adjust the turning angle of both at the same time. Note that when the propulsion support body 20 changes direction, the axial directions of the screw shafts 42 are no longer aligned in a straight line, but since the screw shafts 42 are connected by a universal joint 47 and a connecting shaft 49, they are not linear. 1 series screw shaft 4
Next, on the outer periphery of the propulsion support body 20, annular expansion mechanisms 50 are provided near both ends in the axial direction as holding and fixing means. The detailed structure of the expansion mechanism 50 is shown in FIGS. 2 and 3.

A tubular expansion body 52 made of an elastic material such as rubber is installed so as to surround the outer periphery of the propulsion support body 20 . The expansion body 52 is fixed to a support frame 54 attached to the propulsion support 20 on the inner peripheral side. Note that the expansion body 52 is provided with a supply/discharge section (not shown) for supplying and discharging a pressure medium such as pressurized air. The supply/discharge section is equipped with valves and the like for normal pressure piping. The expansion bodies 52 before and after the propulsion support body 20 may be connected by pressure piping. Further, the expansion bodies 52 of the propulsion support bodies 20 connected back and forth can also be connected with flexible piping or the like.

With the buried pipe 60 inserted into the outer periphery of the propulsion support 20,
When a pressure medium is introduced into the expansion body 52, the expansion body 52 expands toward the outer periphery, and the outer surface of the expansion body 52 comes into contact with and presses the inner surface of the buried pipe 60. If a constant pressure is applied from the expansion body 52 to the buried pipe 60, a frictional support force will be generated between the expansion body 52 and the buried pipe 60, so that the buried pipe 60 will not shift in the axial direction and will be able to support the propulsion support 20. It will be securely held and fixed. By changing the amount or pressure of pressurized air introduced into the expansion body 52, the pressing force against the buried pipe 60, that is, the holding and fixing force can be adjusted. Once the pressurized air introduced into the expansion body 52 is released, the holding and fixing to the buried pipe 60 is released, and the propulsion support body 20 can be extracted from the buried pipe 60.

The structure of the expansion body 52 is similar to that of the propulsion support 20 as shown in the figure.
In addition to the tube-shaped inflatable bodies surrounding the outer periphery of the propulsion support body 20, a plurality of flat bag-shaped inflatable bodies extending with a constant width along the axial direction of the propulsion support body 20 are installed in the circumferential direction of the propulsion support body 20,
Structures other than those shown may also be used as long as they can be held and fixed by contacting the inner surface of the buried pipe 60, such as a structure in which each expander expands in the radial direction and comes into contact with the inner surface of the buried pipe 60.

If the above-described expansion mechanism 50 is used as a means for holding and fixing the buried pipe 60, the expansion body 52 will elastically abut against the inner surface of the buried pipe 60, so that the inner surface of the buried pipe 60 will not be damaged or deformed, and the expansion mechanism 50 can be used reliably. Even if there is variation or error in the inner diameter of the buried pipe 60, it can be absorbed by the elastic deformation of the expansion body 52. Since there is no complicated operating mechanism, there is less possibility of failure, and the supply of pressure medium is controlled. By simply doing this, the buried pipe 60 can be held, fixed and released easily and reliably, and excellent effects can be achieved.

A curve propulsion construction method using the propulsion support body 20 explained above will be explained.

Forming a buried hole by propelling the guide body 10 into the ground from the side of a shaft is performed in exactly the same way as a normal propulsion method. A propulsion support body 20 is connected to the rear of the leading body 10 via a hinge mechanism 30 and a telescoping mechanism 40 . At this time,
A buried pipe 60 made of a hume pipe or the like is inserted into the outer periphery of the propulsion support 20 , and then a pressure medium is introduced into the expansion body 52 of the propulsion support 20 to inflate it.
Keep it fixed at 0.

When a propulsion force is applied from a main push jack in the shaft to the rear end of the propulsion support 20 connected to the rear of the guide body 10, the guide body 10 and the propulsion support 20 are propelled into the ground,
A buried hole is formed by the guide body 10 . Propulsion support 2
The buried pipe 60 held and fixed at 0 is the propulsion support 20
At the same time, it is propelled and buried in the burial hole.

Once one propulsion support 20 and buried pipe 60 have been propulsion-buried inside the burial hole, a new propulsion support 20 is inserted again into the rear end of the propulsion support 20 via the hinge mechanism 30 and the telescoping mechanism 40. Link. This propulsion support 20 also has a buried pipe 6.
Keep it fixed at 0. In addition, the front and rear buried pipes 60.6
As shown in detail in FIG. 3, a collar 70 is attached to the joint portion of 0. The collar 70 is made of synthetic resin or the like, and has a cylindrical shape as a whole, and has a T-shaped cross section with a flange portion 72 that annularly protrudes inward with a constant width at the center of the inner surface. Further, at the end of the buried pipe 60.60, a shallow stepped portion 62 of a constant width is formed on the outer periphery, a collar 70 is fitted into this stepped portion 62, and the flange portion 72 of the collar 70 is attached to the buried pipe 60. It is attached facing the end face of 60. With such a collar 70, the buried pipe 60,
By covering the seam part 60, it is possible to prevent earth and sand from entering through the joint part. By interposing the flange portion 72 in the gap between the end faces of the buried pipes 60.60, it is possible to prevent the collar 70 from moving in the axial direction and also to prevent the end faces of the buried pipes 60.60 from colliding with each other. can.

Next, as shown in FIG.
We will continue to promote and bury it. First, the direction of propulsion of the guide body 10 is changed using a direction changing means or the like provided in the guide body 10 . In the illustrated embodiment, the length of the telescoping mechanism 40 connecting the guide body 10 and the propulsion support 20 is changed to change the direction of the guide body 10. When the advancing direction of the leading body 10 changes and the buried hole becomes curved, the propulsion direction of the following propulsion support 20 and buried pipe 60 must also be changed. Therefore, as shown in FIG. 2, one of the pair of telescoping mechanisms 40 connecting the front and rear propulsion supports 20.20 is extended and the other is contracted, so that the axis of the front and rear propulsion supports 20.20 is change direction. At this time, the gap between the front and rear buried pipes 60, 60 widens on one end surface, and narrows on the other end surface. The collar 70 can sufficiently cover the gap between the buried pipes 60 and 60 even when the gap has widened, and also
In places where the gap is narrowed, the buried pipes 60 and 60
They come into contact with the flange portion 72 of the collar 70 sandwiched between them, and it is possible to reliably prevent the end surfaces of the buried pipes 60 and 60 from coming into contact with each other and being rubbed or damaged.

The deflection angle of the propulsion support body 20 is set according to the curvature of the buried hole. When the buried hole changes from a straight line to a curved line or when the curvature of the curve gradually changes, the propulsion support 2
As the zero propulsion position moves, it is preferable to adjust the amount of operation of each telescoping mechanism 40 to maintain an appropriate deflection angle at all times.

In the curved propulsion construction method according to the present invention, the direction angle of the propulsion support 20 can be arbitrarily changed to accommodate changes in the curvature of the buried hole, so the route of the buried hole can be designed freely. For example, when changing the direction of a buried hole by a certain angle, instead of the conventional method of immediately connecting a straight part to an arc-shaped curved part with a certain curvature and then connecting to a straight part in the desired direction, It is possible to design an extremely complex buried hole route, such as increasing the curvature and transitioning to a curved section, and then gradually decreasing the curvature while connecting to a straight section in the desired direction.

〔Effect of the invention〕

According to the curve propulsion construction method and propulsion support according to the present invention described above, the propulsion force is transmitted by the propulsion support, and the buried pipe is simply held and fixed to the propulsion support. (This means that no external force acts on the end faces of the buried pipes. Moreover, the propulsion support that holds and fixes the buried pipes has a direction change connecting means that can adjust the direction change angle. Because they are connected through the pipe, the front and rear propulsion supports can be adjusted to any deflection angle according to the curvature of the curved section.Therefore, local stress concentration occurs on the end face of the buried pipe. There is no need to worry, and it will be propelled very accurately and smoothly according to the curvature of the buried hole.

As a result, problems such as the buried pipe being damaged or being unable to be propelled during the curved propulsion method are completely eliminated, and it becomes possible to perform the buried pipe construction work reliably, quickly, and stably.

[Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view of the construction state showing an embodiment of the present invention, Fig. 2 is an enlarged detailed sectional view of the main part, Fig. 3 is a cross-sectional view in the direction perpendicular to Fig. 2, and Fig. 4 is a separate view. FIG. 10... Guide body 20... Propulsion support body 30...
Hinge mechanism 40... Telescopic mechanism 50... Expansion mechanism 60... Buried pipe 70... Collar

Claims (1)

[Claims] 1. In a curved propulsion method in which a buried pipe is buried along a curved buried hole while forming a curved buried hole with a leading body, the turning angle can be adjusted behind the leading body. At the same time, the propulsion supports are sequentially connected through the direction changing connection means, and the buried pipe is inserted into the outer periphery of the propulsion support, and the buried pipe is held and fixed to the propulsion support by the holding and fixing means provided on the propulsion support. Then, the axial direction of the propulsion supports is changed at a predetermined angle by the direction change connecting means, and a propulsive force is applied to the propulsion supports to propel the leading body and the buried pipe in a curved shape. A curved propulsion construction method characterized by the ability to move forward. 2. A propulsion support for use in the curved propulsion construction method according to claim 1, which has a shaft shape into which a buried pipe can be inserted into the outer periphery, and includes holding and fixing means for holding and fixing the buried pipe inserted into the outer periphery. A propulsion support, characterized in that the axial end portion thereof is provided with a direction changing connection means that can connect the propulsion supports to each other and change the axial direction of the propulsion supports at a predetermined angle.