JPH069408B2 - Tube straightening method for underground pipes - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to a pipe straightening method for an underground pipe that is laid underground, for example, to draw in a telecommunications cable. Then, the present invention relates to a pipe straightening method for an underground pipe to repair the cable so that it can be pulled in.

[Prior art]

As shown in FIG. 3, this type of underground pipeline A usually has a diameter of 7 mm below the road, such as between manholes B and C.
It is made by laying a plurality of pipes of about 15 cm in a gathered and aligned form. At the time of the first laying construction, in the future,
An extra empty pipeline, which is expected to be expanded, is laid at the same time, and a cable to be added thereafter has a form in which an arbitrary pipeline which is the empty pipeline is selected and drawn. By the way, such underground pipes may break, break away, flatten, bend sharply, or have holes in the pipe body due to fluctuations in the ground or the load of vehicles passing on the road during the years after installation. However, there are cases where a defective phenomenon such as intrusion of foreign matter or corrosion occurs, which causes a problem that the cable is newly disturbed. When repairing such a defective pipe, for example, when repairing a defective portion such as breakage, separation, flatness, etc., the repair method using the cylinder device D as shown in FIGS. 3 and 4 is the applicant. Have been proposed by. This cylinder device D
Is configured as follows. That is, a cone-shaped expanding head 1 is provided at the tip, and a pulling wire 2 is connected to the front end of the expanding head 1. A hammer rod 3 is connected to the rear end of the expanding head 1 and the hammer rod 3 is inserted into the cylinder 4. A hammer head 5 is provided at the rear end of the hammer rod 3, and the hammer head 5 and the cylinder are
A compression coil spring 6 is interposed between the front end wall 4 and the front end wall 4. A piston 7 is slidably fitted into the cylinder 4, and compressed air is supplied from the rear end of the cylinder 4 into the cylinder 4 through a pressure-resistant hose 8 from a compressor 9. There is. A rubber collar 10 for holding the cylinder 4 in the central position in the underground conduit A is attached to the outer periphery of the rear portion of the cylinder 4. Then, in order to insert the cylinder device D configured as described above into the underground pipeline A to be repaired, between the manholes B and C which are one section of the underground pipeline A, the above-mentioned pulling from one manhole B is performed. Insert the wire 2 into the other manhole C. Then, when the wire 2 is taken out from the manhole C on the opposite side, wound up by a winch 11 or the like and pulled, the cylinder device D is introduced into the underground conduit A from the manhole B. When the cylinder device D reaches a defective portion X shown in FIG. 3 (in the drawing, an internal bulging portion is shown, the same applies to breakage, detachment, misalignment, flatness, etc.).
Impinges on the defective portion X and prevents the progress. At this time, compressed air is supplied from the compressor 9 into the cylinder 4 via the pressure-resistant hose 8, and the piston 7 strikes the hammer head 5. The impact force of this tapping is added to the expanding head 1,
Push the defective point X outward to expand it. By repeating this tapping, the cylinder device D corrects the defective portion X and corrects the underground conduit A.
The new cable can be pulled in after passing through.

[Problems to be Solved by the Invention]

However, the above-described conventionally well-known cylinder device D requires a predetermined linear length in order to perform the tapping action by the piston,
Therefore, the cylinder device D can be used when it can pass through the pipeline while correcting the defective portion of the underground pipeline A, but there is a curved pipe portion near the manhole, and the defective portion is generated there. In such a pipeline, even if the cylinder device D is used to correct it, it cannot be used because the cylinder device D is blocked by the curved pipe portion and is prevented from advancing and cannot pass through the pipeline. There was a problem.

[Object of the Invention]

The present invention has been made in view of the above-mentioned problems, and provides a pipe straightening method for an underground pipe that enables correction of a defective portion occurring in a curved pipe portion near a manhole in the underground pipe. The purpose is to do.

[Constitution of the invention]

To achieve this object, the pipe straightening method of the present invention, the pipe body of the underground pipeline laid under the road through the manhole, the inside of the manhole, the inside of the pipe When forcibly inserting the expanding head for straightening to a predetermined inner diameter at the head, a pressing rod of a predetermined length is interposed between the pressing device installed in the manhole and the expanding head. It is characterized in that the diameter expanding head is inserted to a predetermined position by selecting the number, and the tubular body is corrected.

【Example】

An embodiment of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 1, the expanding head 20 used here is separated from the pressing device 21 and inserted into the underground conduit A, and the pressing device 21 is placed in the manhole B to be repaired underground. It is installed so as to face the pipe line A, and its pressing rod 22 is projected toward the pipe body. The pressing device 21 may be an air drive system similar to the hitting device of the conventional example, or may be a pressing device using a hydraulic cylinder. The diameter-expanding head 20 has a cone-shaped tip and a cone-shaped recess 20a at the center of its rear portion.
When a pressing force from the rear is applied to the inside of a, the diameter is slightly increased in the circumferential direction via the slit 20b. Immediately after the diameter-expanding head 20, a pressing body 23 having a tip fitted into the recess 20a is provided. The pressing body 23 penetrates the diameter-expanding head 20 and the central portion of the pressing body 23 and extends rearward, and A return wire 24 extending to the outside is provided. A pulling wire may be connected to the tip of the diameter expanding head 20. Between the pressing body 23 and the pressing rod 22 of the pressing device 21,
The push rod 25 is interposed. The push rod 25 has a columnar shape whose outer diameter is slightly smaller than the inner diameter of the underground conduit A. As shown in FIG. 1 (B), a wire insertion groove 25a is formed from the side surface to the shaft center. And
It can be inserted into and removed from the return wire 24. When using the straightening device having such a configuration to correct the underground conduit A having a defective portion, first, from the manhole B, the expanding head 20 and the pressing body 23 are inserted into the underground conduit A, and the pressing device 21 is pressed. Is operated to extend the pressing rod 22 and press the pressing body 23, thereby advancing in the underground conduit A. Next, the push rod 22 is retracted, the push rod 25 is fitted into the return wire 24 by the wire insertion groove 25a, and the push device 21 is again pushed.
Is operated to push the push rod 25 to advance the diameter expansion head 20. Then, in the same way, multiple push rods 25
While gradually increasing the diameter expansion head 20 in the underground pipeline A even if there is a curved pipe portion, the diameter expansion head 20 reaches the deformation point X of the underground pipeline A (in this case, the internal bulging portion). When the expansion head 20 is resisted and the progress is hindered, the pressing device
21 Push rod 22 pushes multiple push rods 25
Press the pressing body 23 strongly through the
The inner bulging portion X, which is the deformed portion, is expanded outward while slightly expanding the diameter through 20b to correct it. After completion of the straightening work, the pressing rod 22 is retracted, and the return wire 24 is pulled by using a small winch or the like, and the plurality of pressing rods 25, the diameter expansion head 20, and the pressing body 23 are connected to the underground conduit A
Get out. At this time, since the pressing force on the pressing body 23 is released, the diameter-expanding head 20 has a reduced diameter and can be pulled backward easily. In this correction work, the case of internal bulging was described as the deformation of the underground pipe A, but the deformation of the curved pipe portion is also corrected to a perfect circle, and various defective points such as sharp bends and bends are also made. It is also applicable to the correction of. Further, by selecting the number of the push rods 25, the insertion depth of the diameter expanding head 20 can be arbitrarily adjusted.

【The invention's effect】

As described in detail above, the pipe straightening method of the underground pipeline according to the present invention is performed by pressing between the expanding head inserted from the manhole into the underground pipeline to be repaired and the pressing device installed in the manhole. Since the rods are interposed and the number of the rods is selected, it is possible to insert the diameter-expanding head to a desired depth position of the underground conduit and correct it. Also, since the push rod can be arbitrarily increased or decreased, even if a curved pipe part is formed in the underground pipe line, it can pass through this and correct the defective part, and the pipe line that could not be repaired by the conventional cylinder device Can be repaired.

[Brief description of drawings]

1 (A) is a longitudinal side view showing an embodiment of the present invention, FIG.
(B) is a sectional view taken along the line bb of FIG. 1 (A), FIG. 1 (C) is a perspective view of a diameter-expanding head, FIG. 2 is a vertical side view of a conventional example, and FIG. It is a figure. 20 ... Expanding head, 20a ... Recessed portion, 20b ... Slit, 21 ...
Pressing device, 22 ... pressing rod, 23 ... pressing body, 24 ... return wire, 25 ... pressing rod, 25a ... wire insertion groove, A ... underground conduit, B ... manhole, X ... deformation point.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takayuki Kamo 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Fumio Yabuhara 1-1-6 Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inventor Motoyuki Koga 1-9-18 Nakamachi, Meguro-ku, Tokyo (72) Inventor Akira Shimada Four-share company, Hatsuko Development Technology Research Co., Ltd., 3-18 Daikan City, Kanagawa Prefecture In-house

Claims (1)

[Claims] 1. For a pipe of an underground pipe laid underground through a manhole under a road or the like, a diameter-expanding head that corrects the inside of the pipe to a predetermined inner diameter is provided at the inside of the pipe from the manhole. When forcibly inserting the diametrically expanding head, the diametrical expansion head is specified by inserting a pressing rod of a predetermined length between the diametrical expansion head and the pressing device installed in the manhole, and selecting the number of the pressing rods. A pipe straightening method for underground pipes, which is characterized in that the pipe is straightened up to the position.