JP2014221998A - Reconstruction propulsion unit for existing underground pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To install a propulsion unit with a sufficient propulsion stroke by using an existing manhole and further install a drive unit with high output by using a manhole on the arrival side to enable efficient propulsion and earth removal.SOLUTION: The reconstruction propulsion unit includes: a propulsion unit that is arranged in a starting side manhole and has a propulsion cylinder for generating propulsion force for propelling a renewal pipe and a guiding pipe; a rotation drive unit that is arranged in an arrival side manhole and outputs torque for rotating an excavation head and a screw; and a division type transmission rod that interconnects the rotation drive unit and the excavation head through the inside of an underground pipe to transmit the torque output by the rotation drive unit to the excavation head. The propulsion unit includes a propulsion stroke doubling mechanism that enables continuous propulsion strokes of a first stage and a second stage by a full stroke of the propulsion cylinder.

Description

  The present invention relates to an apparatus for carrying out a method for promoting the reconstruction of an existing buried pipe, in which an old buried pipe such as an sewage pipe is replaced with a new pipe without excavation.

  Buried pipes such as sewage pipes may deteriorate due to secular changes, or may deteriorate due to the effects of earthquakes or the ground, which may hinder continuous use. Such an aged or deteriorated buried pipe needs to be updated to a new pipe in a timely manner.

  Conventionally, when renewing an existing buried pipe, the ground pipe was excavated and the buried pipe was excavated, and then the renewed pipe was reburied, but recently, the existing buried pipe is buried in the ground without excavation. A reconstruction promotion method that promotes an updated pipe at the same time as the pipe is crushed has become widespread (for example, see Patent Document 1).

Therefore, a conventional reconstruction promotion method will be described with reference to FIG.
In FIG. 7, reference numeral 100 indicates a sewer pipe. In order to update the aged sewer pipe 100, first, the start shaft 200 is excavated, and the propulsion unit 16 for propelling the update pipe 120 is installed in the start shaft 200.
In this propulsion device 16, a cutter head 20 for crushing the sewer pipe 100 is attached to the tip of the screw 22, and the sewer pipe 100 is crushed with a cutter of the cutter head 20, and fragments and soil are removed by the screw 22. Transferred to start-up response 200.

  Simultaneously with the crushing of the sewer pipe 100, the propulsion device 16 applies a driving force to the renewal pipe 120 and pushes the renewal pipe 120 by the length of the crushed sewer pipe 100. By promoting the renewal pipe 120 while adding it, the existing sewer pipe 100 can be replaced with the renewal pipe 120.

  In the conventional reconstruction propulsion method, main mechanical equipment including the propulsion unit 16 is concentrated on the start shaft 200. Normally, existing manholes are not large enough to install propulsion units, so it is necessary to remove manholes and build starter shafts there, or to construct new starter shafts along the pipeline. There wasn't. In addition, since the mechanical equipment to be installed on the start shaft is complicated and large in size, the place where a large start shaft can be constructed is limited, and the construction is expensive.

  Therefore, the present applicant has installed a guide pipe extending from the start side manhole to the arrival side manhole from the beginning on the plan line of the propulsion path in the existing pipe, and installed a screw on the guide pipe and an excavation head. There has been proposed a remodeling propulsion device in which a driving device to be driven is installed in a leading conduit, and a propulsion device is further installed in a starting side manhole (see Patent Document 2).

  In the remodeling propulsion device disclosed in Patent Document 2, the driving device for driving the excavation head and the screw is installed in the front conduit. Therefore, the propulsion device such as a cylinder is used using an existing manhole and a sewer pipe. It will be possible to install.

JP 2008-038485 A JP 2013-23830 A

  However, depending on the renovation site, the manhole used as a start-up shaft does not always have a sewer pipe that extends rearward conveniently, and the remodeling propulsion device described in Patent Document 2 cannot often be installed.

  In addition, when a driving device for driving an excavation head (cutter head) or a screw is installed in the front conduit, there is a problem that a driving device having a large output cannot be incorporated.

  Furthermore, an existing manhole will be used on the arrival side, but such a facility has not been installed in the manhole space and has not been effectively utilized.

  Therefore, the object of the present invention is to solve the problems of the prior art, and to install a propulsion device with sufficient propulsion stroke using an existing manhole even in a situation where there is no sewage pipe behind the manhole. In addition, another object of the present invention is to provide a renovation propulsion device for an existing buried pipe that uses a manhole on the arrival side to install a high-power drive device and enables efficient propulsion and soil removal.

  In order to achieve the above-mentioned object, the present invention breaks an existing buried pipe with an excavation head provided in a leading conduit preceding the renewal pipe, and simultaneously discharges the soil with a screw provided in the leading conduit and the renewing pipe. In the reforming propulsion device for an existing buried pipe for propelling the renewal pipe, the propulsion device is disposed in the start side manhole and has a propulsion cylinder that generates thrust for propelling the renewal pipe and the leading pipe, and is disposed in the arrival side manhole, A rotary drive device that outputs torque for rotationally driving the excavation head and the screw, and the rotary drive device and the excavation head are connected through the buried pipe, and the torque output by the rotary drive device is transmitted to the excavation head. A split transmission rod, and the propulsion device is a continuous first stage and second stage by a full stroke of the propulsion cylinder. It is characterized in that it has a propulsion stroke doubling mechanism allowing the advance stroke.

It is a longitudinal cross-sectional view which shows one Embodiment of the reconstruction promotion apparatus of the existing underground pipe | tube by this invention. It is a top view of the reconstruction promotion apparatus of the existing underground pipe. It is a top view which shows operation | movement of the 1st step stroke of a propulsion apparatus, and a 2nd step stroke in the reconstruction propulsion apparatus of the existing underground pipe | tube by one Embodiment of this invention. FIG. 6 is a plan view showing a propulsion operation using a spacer after the second stage stroke of the propulsion device in the existing propulsion pipe reforming propulsion device according to the embodiment of the present invention. It is sectional drawing explaining the installation method of a transmission rod when an existing underground pipe is straight before starting the propulsion by the reconstruction propulsion apparatus of the existing underground pipe of this invention. It is sectional drawing explaining the installation method of a transmission rod in case the existing embedment pipe is bent, before starting the promotion by the reforming propulsion device of the existing embedment pipe of the present invention. It is a longitudinal cross-sectional view which shows the reconstruction promotion apparatus of the conventional existing buried pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a reforming propulsion device for an existing buried pipe according to the present invention will be described with reference to the attached drawings.
FIG. 1 and FIG. 2 are diagrams showing a reforming propulsion device for an existing buried pipe according to the present embodiment. 1 and 2, reference numeral 100 indicates an aging sewer pipe that is an existing buried pipe to be remodeled. Reference numeral 120 indicates an update pipe that is promoted in place of the buried pipe 100. Reference numeral 10 is an existing manhole on the start side which is the starting point of the reconstruction promotion construction method. Reference numeral 12 indicates an existing manhole on the arrival side which is the end point. In this reconstruction promotion method, existing manholes are used for the start and reach shafts without digging the start and reach shafts. In addition, the start side manhole 10 is a manhole having a structure in which a sewer pipe does not extend to the rear in the direction opposite to the propulsion direction.

  In the reconstruction propulsion apparatus according to the present embodiment, first, the leading conduit 14 is connected to the tip of the renewal pipe 120 so as to precede the renewal pipe 120. The propulsion device 16 that generates the propulsive force of the tip conduit 14 is installed in the manhole 10 on the start side. The end of the update pipe 120 is connected to the propulsion device 16. The configuration of the propulsion device 16 will be described later.

  Inside the leading pipe 14 and the renewal pipe 120, the casings 18 are added one by one and extend in the axial direction. The casing 18 is inserted coaxially with the front conduit 14. A cutter head (excavation head) 20 is disposed at the tip of the leading conduit 14. The cutter head 20 is connected to the tip of a screw 22 inserted in the casing 18. A plurality of bit cutters 23 are attached to the face plate of the cutter head 20. The earth and sand excavated by the cutter head 20 and the fragments of the buried pipe 100 are transferred to the starting manhole 10 by the screw 22.

  Next, in FIG. 1 and FIG. 2, reference numeral 24 is a rotary drive device that rotates the cutter head 20 and the screw 22. The rotational drive device 24 according to this embodiment is installed in the manhole 12 on the arrival side. The rotational drive device 24 includes a reduction gear in addition to the drive motor 25, and the rotational torque of the drive motor 25 is transmitted to the rotating disk 26.

  As shown in FIG. 5, the transmission rod 30 is installed in the existing buried pipe 100 so as to reach the starting side manhole 12 from the starting side manhole 10 prior to the propulsion step. The end of the transmission rod 30 is connected to the center of the cutter head 20 in order to transmit rotational torque from the rotational drive device 24 in the manhole 12 on the reaching side. The transmission rod 30 also functions as a guide for propelling the front conduit 14.

  The transmission rod 30 is a split-type rod in which a single unit rod is connected to the joint 32 via a pin. In the case of this embodiment, the turntable 26 of the rotary drive device 24 is provided with a slide fitting portion 28 having a square hole, and the square hole of the slide fitting portion 28 is provided with a deformed hollow rod. A square hollow rod 32 having a quadrangular cross section is slidably fitted. The leading portion of the transmission rod 30 protruding into the reaching side manhole 12 is inserted into the rectangular hollow rod 32. At the tip of the square hollow rod 32, the tip of the transmission rod 30 is fixed by an adapter 34 via a pin.

  In this way, the rotational torque of the rotational drive device 24 is transmitted to the transmission rod 30 via the rectangular hollow rod 32 that is slidably fitted to the slide fitting portion 28, so that the transmission rod that moves forward together with the leading conduit 14. The rotation can be transmitted to 30, and the cutter head 30 and the screw 22 can be rotationally driven. In addition, about the square hollow rod 32, you may make it use the hollow rod in which the spline was formed in the outer periphery.

Next, the configuration of the propulsion device 16 will be described.
1 and 2, the propulsion device 16 includes two sets of propulsion cylinders 36, and the propulsion force is applied to the leading conduit 14 and the update pipe 120 by the propulsion cylinders 36.

  By the way, one unit of the renewal pipe 120 needs to be a pipe having a length that can be put into the starting manhole 10. If the tube is longer than the diameter of the starting side manhole 10, it cannot be inserted. On the other hand, if the pipe is too short, the propulsion efficiency is greatly reduced since the work of adding one pipe is frequently performed after one pipe is propelled. Therefore, it is desirable to increase the propulsion efficiency by using as long a pipe as possible as the unit pipe of the renewal pipe 120 and using a hydraulic cylinder having a long stroke as the propulsion cylinder 36.

  However, a large hydraulic cylinder with a long stroke cannot be used for the propulsion cylinder 36 in a manhole in which the sewage pipe does not extend rearward like the starting side manhole 10 in this embodiment. That is, in the circular space of the manhole 10, the length of the cylinder tube of the propulsion cylinder 36 and the extension length of the piston rod must be ensured, so the stroke of the propulsion cylinder 36 must be shortened.

  Therefore, the propulsion device 16 mainly composed of the propulsion cylinder 36 allows the first stage propulsion stroke and the second stage propulsion stroke to be continuously performed, so that the propulsion device 36 is substantially twice the original full stroke. The propulsion stroke can be earned.

  1 and 2, a receiving plate 37 is attached to the peripheral wall of the starting side manhole 10 on the rear side of the propulsion device 16, and this receiving plate 37 is used to connect a piston rod of the propulsion cylinder 36. The connecting seat 38 is fixed.

  A set of guide rails 40 are installed at the bottom of the start-side manhole 10 in parallel with the propulsion direction. On this guide rail 40, the thrust plate support base 44 which supports the thrust plate 42 is each slidably mounted. The thrust plate 42 is in contact with the end of the renewal tube 120.

  The cylinder tube which is the main body of the propulsion cylinder 36 is supported in a horizontal posture by a cylindrical cylinder bracket 43 connected to the thrust plate support base 44. The propulsion cylinder 36 is slidably fitted to the cylinder bracket 43. In the case of this embodiment, the following structure is adopted as a propulsion stroke doubling means that enables a two-stage continuous propulsion stroke.

  In the propulsion cylinder 36, a first-stage stroke reaction force transmission member 46 is attached to the rod side of the cylinder tube (rear side in the propulsion direction), and the first-stage stroke reaction force transmission member 46 is connected to the cylinder tube. It is designed to move back and forth as a unit. It is assumed that the piston rod of the propulsion cylinder 36 extends and pushes the inner wall of the starting side manhole 10 in a state where the first stage stroke reaction force transmission member 46 is in contact with the rear end of the cylinder bracket 43. The reaction force at this time is transmitted from the cylinder bracket 43 to the thrust plate 42 via the first stage stroke reaction force transmission member 46 and propels the renewal pipe 120 and the leading conduit 14 until the piston rod of the propulsion cylinder 36 is fully extended. The thrust to be generated is generated. The above process is the first stage stroke.

  Further, in this embodiment, as shown in FIG. 2, a first pin hole 50 for inserting a pin is formed at the front end of the cylinder bracket 43 in the propulsion direction in order to enable the second step stroke. ing. A second pin hole 51 is formed on the end side of the propulsion cylinder 36 (front side in the propulsion direction).

  Here, the positional relationship between the cylinder bracket 43 and the propulsion cylinder 36 when the first stage stroke is completed is as shown in FIG. In the process of the first step stroke, the propulsion cylinder 36 and the cylinder bracket 43 move together, so that the pin hole 50 and the pin hole 51 are in a separated positional relationship.

  Thereafter, when the piston rod of the propulsion cylinder 36 is retracted, the cylinder tube of the propulsion cylinder 36 moves backward in the propulsion direction while sliding the cylinder bracket 43. On the other hand, the cylinder bracket 43 integrated with the thrust plate 42 does not move and remains in position. In this case, the stroke is set so that the first pin hole 50 and the second pin hole 51 overlap each other when the propulsion cylinder 36 is fully retracted (see FIG. 3C).

  Therefore, the pin 48 is inserted when the first pin hole 50 and the second pin hole 51 overlap. The reaction force when the piston rod of the propulsion cylinder 36 extends and pushes the inner wall of the starting side manhole 10 is transmitted from the cylinder bracket 43 to the thrust plate 42 via the pin 48 until the piston rod of the propulsion cylinder 36 is fully extended. Then, the renewal pipe 120 and the leading conduit 14 can be driven (see FIG. 3D). The above process is the second stage stroke.

The reforming propulsion device for an existing buried pipe according to the present embodiment is configured as described above. Next, its operation and effect will be described in relation to the reforming propulsion method.
First, as shown in FIG. 5, the buried pipe 100 extends straight without being bent, and when the accuracy of the center line straightness of the buried pipe 100 is good, a plurality of center guide type spacers 110 are provided in some places. The transmission rod 30 is installed on the center line in the buried pipe 100 so as to penetrate from the start side manhole 10 to the arrival side manhole 12 using this spacer 110.

  When the bending of the buried pipe 100 is large, as shown in FIG. 6, the tensioning device 130 is installed in the start-side manhole 10 and the transmission rod 30 is placed in a tensioned state on the center line of the buried pipe 100. The filler pipe 112 may be inserted from the reaching side manhole 12 to be solidified by injection of the filler 114.

  Next, the equipment constituting the propulsion device 16 is carried into the starting manhole 10 to assemble the propulsion device 16. The leading conduit 14 and the leading portion of the casing 18 and the screw 22 are also brought into the starting manhole 10 and incorporated into the leading conduit 14. In addition, a rotation drive device 24 is carried and installed in the arrival side manhole 12. The tip of the transmission rod 30 extending from the leading conduit 14 toward the reaching side manhole 12 is inserted into the rectangular hollow rod 32.

  In the propulsion process, the propulsion operation is performed while propelling the leading conduit 14 and then adding the renewal pipe 120 to the leading conduit 14 one by one.

  When the transmission rod 30 is rotated by the rotation driving device 24, the cutter head 20 and the screw 22 are rotated. At the same time, the propulsion cylinder 36 propels the formation of the leading conduit 14 and the renewal tube 120 as follows.

  Thus, the operation of the propulsion device 16 in the propulsion process will be described with reference to FIGS. 3 and 4. The same applies to the case where only the leading conduit 14 is propelled at the beginning of the process and the case where the formation of the leading conduit 14 and the renewal pipe 120 is propelled.

  FIG. 3A shows the positional relationship between the propulsion cylinder 36, the thrust plate 42, and the cylinder bracket 43 at the initial position for starting propulsion. As described above, the propulsion cylinder 36 can perform propulsion by the two-stage continuous stroke method as follows.

  As shown in FIG. 3B, when the piston rod of the propulsion cylinder 36 is extended, the thrust plate 42 moves forward by the reaction force when the propulsion cylinder 36 pushes the peripheral wall of the starting side manhole 10, so that the leading conduit 14 The update pipe 120 can be propelled by the first stage stroke S1. During this time, the relative positional relationship between the cylinder bracket 43 integral with the thrust plate 42 and the cylinder tube of the propulsion cylinder 36 does not change.

Next, in FIG. 3C, when the piston rod of the propulsion cylinder 36 is retracted, the cylinder tube moves backward. Since the position of the thrust plate 42 remains the same, the first pin hole 50 and the second pin hole 51 are overlapped. Therefore, after inserting the pin 48 into the overlapped pin holes 50 and 51, the piston rod of the propulsion cylinder 36 is moved. When extended, as shown in FIG. 3D, the thrust plate 42 moves forward, and the formation of the leading conduit 14 and the renewal tube 120 can be propelled by the second stage stroke S2.

  Thus, when the two-stage continuous propulsion of the first stage stroke S1 and the second stage stroke S2 is finished, the pin 48 is pulled out and the piston rod of the propulsion cylinder 36 is retracted. Further, when the propulsion plate 42 is manually returned to the initial position, the state becomes the same as the propulsion start position in FIG. At this time, a space corresponding to the two-stage stroke propulsion S1 + S2 up to that time is vacated between the end of the update pipe 120 and the propulsion plate 42.

  Therefore, as shown in FIG. 4A, using the space formed between the end of the renewal pipe 120 and the propulsion plate 42, it has a length corresponding to two-stage stroke propulsion and has the same diameter as the renewal pipe. This tubular spacer 60 is incorporated between the end of the renewal tube 122 and the propulsion plate 42.

  In the propulsion using the spacer 60, the two-stage continuous propulsion of the first stage stroke S1 and the second stage stroke S2 in FIGS. 3 (a) to 3 (d) is repeated in exactly the same manner. As a result, as shown in FIGS. 4B and 4C, the formation of the leading conduit 14 and the update pipe 120 can be promoted by earning a stroke twice that of the two-stage stroke promotion.

  In this way, even with the start-side manhole 10 having no duct on the rear side, by installing the propulsion cylinder 36 having a relatively short stroke that is easy to install and combining with the continuous stroke doubling mechanism, Two strokes can be realized, and further, by using the spacer 60 having the length corresponding to the two-stage stroke propulsion, the two-stage continuous stroke is propelled, so that the propulsion cylinder 36 is substantially four times as long. It is possible to earn strokes. When the propulsion using the spacer 60 is completed, the one renewal pipe 120 can be propelled. Further, a large thrust can be secured by adopting a hydraulic cylinder having a large diameter as the propulsion cylinder 36.

  The above is the description of the operation of the propulsion device in the process of propelling the formation of the leading conduit 14 and the update pipe 120. Next, the operation of the rotary drive device 24 in the propulsion process will be described.

  In FIG. 1, when the rectangular hollow rod 32 fitted to the slide fitting portion 28 is rotated by the rotation driving device 24, the rotation is transmitted from the transmission rod 30 to the cutter head 20 and the screw 22. Therefore, in the tip conduit 14 propelled by the propulsion device 16 described above, the bit cutter 23 crushes the existing sewer pipe 100 and excavates the ground by the rotation of the cutter head 20. These crushed pieces and earth and sand are taken into the tip conduit 14 and transferred to the starting manhole 10 by the screw 22.

  When one of the renewal pipes 120 is pushed forward and the addition work is performed, the adapter 34 is removed, and then the rectangular hollow rod 32 is pushed back to the original position and the projecting rod for one unit protruding is removed. Done.

  Since such a rotary drive device 24 is installed in the arrival-side manhole 12 separately from the propulsion device 16, a large-sized device having a drive motor with a large output can be installed, so that the cutter head 20 can be driven with a large torque. And the screw 22 can be driven. Thereby, it is possible to increase excavation efficiency and prevent the screw 22 from being clogged with discharged soil.

  Furthermore, in this embodiment, since the transmission rod 30 is arranged on the propulsion plan line, the transmission rod 30 not only transmits rotation to the cutter head 20 and the screw 22 but also functions as a guide for the leading conduit 14. Therefore, even the existing pipe 100 having a low accuracy with a bend can be propelled along the planned line without requiring a direction correction during the propulsion.

DESCRIPTION OF SYMBOLS 10 ... Start side manhole, 12 ... Arrival side manhole, 14 ... Lead pipe, 16 ... Propulsion device, 18 ... Casing, 20 ... Cutter head, 22 ... Screw, 23 ... Bit cutter, 24 ... Rotation drive device, 28 ... Slide fitting portion, 30 ... transmission rod, 32 ... square hollow rod, 36 ... propulsion cylinder, 37 ... receiving plate, 38 ... connecting seat, 40 ... guide rail, 42 ... thrust plate, 43 ... cylinder bracket, 46 ... first Step stroke reaction force transmitting member, 48 ... pin, 50 ... first pin hole, 51 ... second pin hole, 100 ... buried pipe, 120 ... update pipe

Claims (8)

In a renovation propulsion device for an existing buried pipe, the existing buried pipe is crushed by a drilling head provided in a previous pipe preceding the renewed pipe, and the renewed pipe is simultaneously propelled while being soiled by a screw provided in the previous pipe and the renewed pipe. ,
A propulsion device having a propulsion cylinder disposed in the starting side manhole and generating thrust for propelling the renewal pipe and the leading conduit;
A rotational drive device that is disposed in the reaching-side manhole and outputs torque for rotationally driving the excavation head and the screw;
A split-type transmission rod that connects the rotary drive device and the excavation head through the buried pipe and transmits torque output from the rotary drive device to the excavation head;
The propulsion device has a propulsion stroke doubling mechanism that enables continuous propulsion strokes of the first stage and the second stage by the full stroke of the propulsion cylinder. The propulsion device is
A connecting seat fixed to the peripheral wall of the starting side manhole and connected to the tip of the piston rod of the propulsion cylinder;
A guide rail laid in parallel to the propulsion direction at the bottom of the starting manhole;
A thrust plate that abuts the end of the leading conduit or the renewal pipe and transmits the thrust generated by the propulsion cylinder;
A thrust plate support that supports the thrust plate and is movably mounted on the guide rail;
2. A reforming propulsion device for an existing buried pipe according to claim 1, further comprising: a cylinder bracket that is attached to the thrust plate support base in a horizontal posture and in which a main body of the propulsion cylinder is slidably fitted. . The propulsion stroke doubling mechanism is
The propulsion cylinder is attached to the rod side of the main body of the propulsion cylinder, abuts against the cylinder bracket when the cylinder main body moves forward in the first stroke, and transmits a reaction force to the thrust plate via the cylinder bracket. Having a 1-stage reaction force transmission plate,
Forming a first pin hole at a front end portion of the cylinder bracket and forming a second pin hole at an end side of the main body of the propulsion cylinder;
After the first step stroke is completed, the first pin hole and the second pin hole are overlapped when the propulsion cylinder body is retracted by a full stroke, and the second step hole is overlapped with the first pin hole and the second pin hole. By inserting a stroke reaction force transmission pin, the cylinder body and the cylinder bracket are connected, and when the cylinder body moves forward in the stroke of the second stage stroke, the reaction force is transmitted through the cylinder bracket before the thrust. The apparatus for propagating an improvement of an existing buried pipe according to claim 2, wherein the device is transmitted to a plate.   After the stroke of the second stage stroke is completed, a tubular spacer which can be attached between the end of the leading conduit or the renewal pipe and the reaction force plate when the thrust plate is returned to the initial position is provided. The reforming propulsion device for an existing buried pipe according to claim 3. The rotational drive device is
A deformed hollow rod into which the leading rod of the transmission rod is inserted and fixed;
The repositioning and propulsion device for an existing buried pipe according to claim 1, further comprising: a turntable having a slide fitting portion in which the hollow rod is slidably fitted so that rotation can be transmitted.   6. The propulsion of an existing buried pipe according to claim 5, wherein the transmission rod is preliminarily installed on a planned line serving as a reference for a propulsion path and serves also as a propulsion guide for correcting the direction of the leading conduit. apparatus.   The reforming propulsion device for an existing buried pipe according to claim 6, wherein the transmission rod is installed in the buried pipe via a center guide when the accuracy of the buried pipe is good.   7. The existing buried pipe according to claim 6, wherein when the accuracy of the buried pipe is poor, the transmission rod is consolidated by a filler in a tensioned state on the center line of the buried pipe. Home improvement promotion device.