JPH11141736A - Renovating device for pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rationalize the work of renovating a cast iron pipe buried in the underground to a flexible pipe or a steel pipe under a non-excavated state. SOLUTION: This renovating device A comprises a cutting part 10 having a plurality of cutters arranged at prescribed angle in the circumferential direction, a dividing part 11 having dividing rollers 20a to 20c for vertically applying force to a cast iron pipe 1 to break it, a diameter enlarging part 12 having diameter enlarging rollers 23a to 23e, a connecting part 13, a flexible joint 14 by which the cutting part 10 is connected to the dividing part 11 and a flexible joint 15 by which the dividing part 11 is connected to the diameter enlarging part 12. The updating device is moved to the inner part of the cast iron pipe 1 to form a cutting groove on an inner peripheral surface. The cutting groove is broken as a starting point to form a plurality of circular arc piece. These pieces are bent and inserted into natural ground under pressure to form a tunnel surrounded by the ground crests and a PE pipe 6 is pulled inside. The periphery of the PE pipe 6 is covered with a plurality of circular arc pipeces.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe updating apparatus for updating a cast iron pipe buried underground with a new pipe.

[0002]

2. Description of the Related Art Many pipelines are laid underground, such as a gas pipeline for flowing fuel gas and a water pipeline for flowing clean water. The gas pipeline is configured by connecting or welding a steel pipe having a certain length by a pipe joint such as a socket, or by connecting a cast iron pipe by a pipe joint.

[0003] In a gas pipeline made of the above-mentioned steel pipe or cast iron pipe, when a large force is applied during an earthquake, a part of the pipe joint or other parts may be broken and gas leakage may occur, which may cause a great disaster. Are known. For this reason, in a gas pipeline, a flexible synthetic resin pipe such as polyethylene or a steel pipe is replaced regardless of the diameter of the pipeline.

[0004] When replacing a pipe buried underground with a new pipe, a method of digging a road along the existing pipe may be adopted. However, this method may adversely affect the traffic situation in the surrounding area. Recently, a tunnel has been formed by cutting the existing pipe in the vertical direction and expanding its diameter. A technique of drawing in and replacing a new pipe has been proposed.

[0005] For example, a technique (first known technique) disclosed in Japanese Patent Application Laid-Open No. 2-266185 relates to an "existing pipe laying replacement device", and includes a clamp device for pressing an inner wall of an existing pipe,
A notch cutter that provides a notch in the axial direction of the pipe inner wall, and a moving cylinder that is arranged to expand and contract in the pipe axis direction,
An expansion device that splits a notch and expands the notch is connected in a row, and a new pipe is connected to the rear of the expansion device. In this technology, by driving the moving cylinder by pressing the inner wall of the tube by the clamp device, the functional unit connected to the rear of the clamp device is moved to form a notch in the inner wall of the tube and draw in the new tube, The tube expansion device is driven to split the notch and expand the tube. In other words, the notch cutter and the pipe expanding device intermittently move inside the existing pipe like a measuring insect to replace a new pipe. With this technology,
Existing pipes can be replaced with new pipes in one process, and can be applied to existing pipes including cast iron pipes.

The technique disclosed in Japanese Patent Application Laid-Open No. 6-238509 (second known technique) relates to a "cutting / expanding tool" in which a guide roller and a cutter are mounted along a longitudinal axis of a support. It was done. In this technique, a main pipe is cut along an axis. When an expander is connected to the support body, the main pipe cut by the expander is expanded to form a tunnel in which the expanded main pipe functions as a roof.

[0007]

In the first known technique, a plurality of hydraulic devices are used in a clamping device, a moving cylinder, or a pipe expanding device. For this reason, the equipment is inevitably increased in size and cannot be applied to existing pipes of small diameter.Although existing pipes can be replaced with new pipes in one process, the progress of equipment and new pipes Has a problem that it takes a long time to take a construction time per unit length.

[0008] In particular, when replacing an existing pipe in use represented by a gas pipe, it is essential that the replacement be carried out in a short time so as not to have a great effect on each household. It is important to be able to replace existing pipes.

In the second known technique, an expander is connected to a support body, and these are arranged in the main pipe and continuously moved to cut and expand the main pipe.
However, in practice, good results are obtained when applied to steel pipes, but when applied to cast iron pipes with a small elastic modulus compared to steel pipes, axial tearing is possible,
There is a problem that the cast iron pipe, which becomes the main pipe at the time of expansion, is crushed in an unmanaged state.

In the second known technique, since the new pipe is limited to a pipe having an outer diameter that can be inserted into the main pipe expanded along the axis, the pipe is replaced with a pipe having a larger diameter than the existing pipe. There is a problem that you can not do.

Further, the present inventor has conducted an experiment,
It was found that a groove cannot be formed in an existing pipe simply by arranging a rotary cutter when forming a groove in the existing pipe. That is, the rotary cutter must be positively driven, and there is a problem that the rotary cutter cannot be applied when the diameter of the existing pipe is small in order to constitute this drive system.

Therefore, the applicant of the present application has developed a "pipe renewal method and apparatus thereof" which has solved the above-mentioned problem, and has already filed a patent application (Japanese Patent Application No. 9-98889). In this technique, an existing pipe made of a cast iron pipe can be torn, and the torn existing pipe can be expanded and pressed into the ground to be used as armor of a new pipe.

However, repeated tracking experiments have revealed that this technique has some problems to be improved.

For example, when branching a branch pipe from an existing pipe,
A connecting sleeve composed of a pair of semi-cylindrical parts is fixed to the outer periphery of the existing pipe, and the branch pipe branches off from the connecting sleeve. For this reason, it is necessary to tear the connecting sleeve together with the existing pipe at the branch portion. In the above invention, if the connecting sleeve is made of ordinary cast iron, it can be torn without any problem, but if a high-strength material such as ductile cast iron is used, a large force is required. There is a problem.

Also, existing pipes that have been buried in the ground for a long period of time do not maintain the straightness at the time of laying, and are often bent. For this reason, a force in the direction of tangling acts on the cutting blade constituting the cutting means, the friction generated between the side surface of the cutting blade and the existing pipe increases, and a high thrust is required. There is a problem in that the cutting force breaks the individual cutting blades.

It is an object of the present invention to further develop the invention according to the above-mentioned application and to replace an existing pipe made of cast iron pipe buried underground with a pipe having the same diameter or a larger diameter as the pipe. It is an object of the present invention to provide a pipe updating apparatus which can use the existing pipe divided in the longitudinal direction as a component of a new pipe.

[0017]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an apparatus for updating a pipe according to the present invention moves inside an existing pipe to be updated, tears the existing pipe in an axial direction, and cuts the pipe in a longitudinal direction. And forming a space surrounded by the plurality of arc-shaped pieces and the ground portion by press-fitting the arc-shaped pieces into the ground and forming a new pipe in the space. An updating device for a pipe to be retracted, comprising: a cutting means disposed on a front side in a moving direction; a dividing means continuous on a rear side of the cutting means; a diameter expanding means continuous on a rear side of the dividing means; and a rear side of the diameter expanding means. The cutting means comprises: a cutting means main body; and a distance from the front end of each cutting blade attached to the cutting means main body to the center axis of the cutting means, which is axially frontward to rearward. A plurality of cutting blades arranged linearly in order so as to increase in order toward The cutter body is composed of four cutters, each of which has its plate surface inclined at an angle smaller than 90 degrees with respect to a horizontal line passing through the center axis of the cutting means body in the cross section of the cutting means body. The dividing means is provided with at least a pair of split rollers arranged at positions opposed to each other in a vertical direction in a cross section of the dividing means main body, and the diameter expanding means has a tapered shape. A diameter dividing roller group disposed at a plurality of positions in the axial direction between cutter bodies in the cutting means at positions obtained by dividing the outer periphery of the main body at a predetermined angle,
The expanding roller arranged on the front side in the expanding roller group cuts the existing pipe to form a plurality of arc-shaped pieces that are continuous in the longitudinal direction, and converts the formed arc-shaped piece from an arc. The connecting means is arranged so as to bend within the elastic limit around a position spaced apart in the outer peripheral direction, and the connecting means has a chuck for connecting the new pipe.

In the pipe updating device, the plurality of cutting blades are provided at positions where the circumference is divided at a predetermined angle, and the plurality of cutting blades are linearly arranged so that the distance from the center to the tip increases in order from the front side to the rear side. A cutting means having a cutter body arranged in a shape is arranged inside the existing pipe, and the cutting means is advanced in the pipe axis direction to cut the inner peripheral surface of the existing pipe to form a cutting groove and perform the cutting. Grooves can be grown. Then, the existing pipe is divided in the vertical direction with the cutting groove as a starting point by the dividing means following the cutting means, torn, and further, a plurality of arc-shaped pieces torn by the diameter expanding means following the dividing means. Can be formed.

The arc-shaped piece functions as a cantilever having a joint point with the existing pipe (a breaking start point at which the existing pipe changes into an arc-shaped piece) as a fulcrum. For this reason, by applying a force in the direction of increasing the radius in accordance with the radial position of the expanding roller in the expanding means, it is possible to cause deflection within the elastic limit. As a result, the arc-shaped pieces are pressed into the ground against the earth pressure, and at the same time, the soil and sand in gaps formed between the adjacent arc-shaped pieces are pushed up to consolidate the ground. Then, a space (tunnel) in which the peripheral wall is protected by the armor consisting of the compacted ground and a plurality of arc-shaped pieces can be formed. Therefore, the pipe can be updated by drawing a new pipe into the tunnel.

In the above-mentioned pipe updating apparatus, since the existing pipe is divided into a plurality of pieces in the circumferential direction and is torn, the broken arc-shaped piece is treated as a cantilever, and the bending within the elastic limit in the longitudinal direction is performed. The generation can increase the diameter to a desired diameter.

Also, four cutting grooves can be formed in the inclined direction with respect to the horizontal line and the vertical line in the cross section of the existing pipe, and force is applied to the existing pipe in the vertical direction (vertical direction) by the dividing roller. , The existing pipe can be torn. In particular, when a connecting sleeve is attached to an existing pipe, a pulling force is applied to the bolts holding the pair of connecting sleeves by applying a force in the vertical direction of the existing pipe by a split roller to pull the connecting sleeve. You can shred it. For this reason, even if the connecting sleeve is made of a high-strength material such as ductile cast iron, the existing pipe is stably cut by cutting the bolt regardless of this material. You can do it. And the arc-shaped piece located at the top protects the top area of the new pipe, especially when excavation work by backhoe etc. is performed along the new pipe buried after pipe replacement, the backhoe claw from above The new pipe can be reliably protected from the influence of.

Preferably, the cutting means and the dividing means are connected via a flexible joint. By providing the flexible joint between the cutting means and the dividing means in this way, even if the existing pipe is bent, an excessive force does not act following the bent.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the updating apparatus will be described below with reference to the drawings. 1 is a plan view illustrating the configuration of the updating device, FIG. 2 is a side view illustrating the configuration of the updating device, FIG. 3 is a partial cross-sectional view illustrating the configuration of the cutting unit, and FIG. FIGS. 5 and 5 are partial cross-sectional views illustrating the configuration of the dividing means, FIG. 6 is a partial cross-sectional view illustrating the configuration of the diameter expanding means, and FIG. 7 is a direction in which an arc-shaped piece obtained by breaking an existing pipe is bent. FIG. 8 is a sectional view showing the connecting sleeve attached to the existing pipe and the expanded state of the torn existing pipe and the buried state of the new pipe, and FIG. 9 is a diagram showing a method of updating the existing pipe. FIG.

The pipe renewing apparatus according to the present embodiment is a gas pipe for supplying city gas, which is a pipe having a small diameter of about 75 A to 200 A and having a diameter equal to or higher than the rank. This makes it possible to perform the work of updating the pipe in a single step, and it is possible to realize a large retraction speed without requiring a large power.

In this embodiment, a case in which a cast iron pipe as a gas pipe is replaced with a synthetic resin pipe having flexibility will be described. However, the present invention is not limited to the above-described example. It may be a cast iron pipe for water supply with a predetermined lining, or a new pipe, for example, a steel pipe.

First, a method of updating an existing pipe to a new pipe will be schematically described with reference to FIG. In the figure, a cast iron tube 1
The starting shaft 2 and the retracting shaft 3 are provided at predetermined positions (positions having a distance corresponding to the renewal length that can be constructed in a time zone that does not adversely affect the life) of the gas pipeline composed of. A drawing device 4 is installed in the drawing shaft 3, and a pull rod 5 driven by the drawing device 4 is inserted into the cast iron pipe 1. An updating device A is connected to the tip of the pull rod 5, and a new tube, for example, a polyethylene (PE) tube 6 is connected to the updating device A.

Then, the pulling device 4 is driven to drive the pull rod 5
Is drawn into the shaft 3 to apply a pulling force to the updating device A to move the inside of the cast iron pipe 1, and with this movement, a plurality of arc-shaped pieces (FIG. 8, and by bending the arc piece 1a in a direction in which the radius increases, the ground piece has an inner diameter sufficiently larger than the cast iron pipe 1 and a plurality of arc pieces 1a and The PE pipe 6 is inserted into the tunnel 7 while forming a tunnel 7 having a peripheral wall made of earth and sand compacted with the press-fitting of the piece 1a.
The PE pipe 6 can be armored with a plurality of arc pieces 1a arranged around the pipe 6 to form a new pipe line.

The starting shaft 2 and the retracting shaft 3 are cut off from the ground, the cast iron tube 1 is cut with its end protruding from the peripheral wall, and when the renewal device A is pulled into the cast iron tube 1 on the starting shaft 2 side. Guide 1b is attached. Also, shaft 3
A drawing device 4 is attached to the cast iron tube 1 on the side.

The structure of the pull-in device 4 is not particularly limited. The retraction device 4 according to the present embodiment connects a frame 4a, which is disposed in parallel with each other and has a conductive member such as a ball screw (not shown) provided therein, to one end of the frame 4a, and connects the end of the cast iron tube 1 to the center. Platen 4b, which is attached to a part and is fixed to each other and has a pipe fixing bracket 8 through which a pull rod 5 passes, and a rear platen 4c, which connects the other end of the frame 4a and passes the pull rod 5 in the center.
And a motor 4d attached to the frame 4a and a transmission system (not shown) for transmitting the rotation of the motor 4d to the ball screw, and being interposed between the frame 4a and screwed to the ball screw and engaged with the pull rod 5 (coupler 5a). And a rod fixing bracket 4e for fixing.

The retracting device 4 is installed in the retractable shaft 3 with its level adjusted so that the movement path of the rod fixing member 4e can substantially coincide with the axis of the cast iron tube 1. Therefore, both platens 4
Jacks 9 for level adjustment are attached to b and 4c, and a pair of outriggers for receiving a reaction force when pulling the pull rod 5 is provided to the front platen 4b.

The pull rod 5 has a length corresponding to or slightly shorter than the stroke of the rod fixing bracket 4e in the retracting device 4, and has a strength capable of transmitting the power generated by the motor 4d to the updating device. ing. This pull rod 5
Are connected inside the cast iron tube 1 by a required number in the longitudinal direction by a coupler 5a, and the front end is connected to the updating device A and the rear end is fixed to the rod fixing bracket 4e of the retracting device 4.

Next, the configuration of the updating apparatus A will be described with reference to FIGS. The updating device A includes a cutting unit 10 serving as cutting means for forming a plurality of cutting grooves 1c on the inner peripheral surface of the cast iron pipe 1.
And a unidirectional force is applied to the cast iron tube 1 disposed after the cutting portion 10 to break the cast iron tube 1 starting from the cutting groove 1c to form an arc piece 1a, and to cover the cast iron tube 1 A dividing portion 11 serving as a dividing means for breaking a bolt 19 for fixing the connected connecting sleeve 18, and a diameter increasing portion serving as a diameter expanding means for bending the arc piece 1a to press-fit the ground at the same time as consolidating the ground. 12 and a connecting portion 13 serving as connecting means for connecting the PE pipe 6 as a new pipe. Further, the cutting portion 10 and the split portion 11 are connected via a flexible joint 14, and the split portion 11 and the enlarged diameter portion 12 are also connected via a flexible joint 15.

In FIG. 1, a region X corresponds to the divided portion 10 and is a region for surely realizing the tearing of the cast iron pipe 1. A region Y is a region where the arc piece 1a is bent in a direction in which the diameter of the cast iron pipe 1 is expanded to be pressed into the ground, and a region Z is a region where the bending of the arc piece 1a is returned to be parallel.

A cutter body 16 is provided on the main body 10a of the cutting section 10. The cutter body 16 is formed by fixing cutters 16a to 16d having a plurality of saw blades 17a to the main body 10a. Each cutter 16a-16d
Are formed with a plurality of cutting blades 17a at a predetermined pitch, and a valley 17b deeper than a general saw blade is formed on the rake face side of the cutting blade 17a.
Are formed.

The cutters 16a to 16d are arranged so that the cutting blade 17a can gradually protrude from the front side (the left side in FIG. 1, the side where the pull rod 5 is mounted) to the rear side (the right side in FIG. 1, the enlarged diameter portion 12 side). It is fixed to 10a. That is, the cutting part 10
The main body 10a is formed with a guide portion 10b having a preset inclination angle, and is attached to the guide portion 10b by fastening the fixing member 10c along the cutters 10a to 16d with bolts 10d. ing.

The cutters 16a to 16d are arranged in directions perpendicular to each other and in directions that do not coincide with a horizontal line and a vertical line (vertical direction) in the cross section of the cast iron pipe 1 (for example, a direction approximately 45 degrees with respect to the horizontal line). Have been. Cutters 16a-16d
By arranging in this manner, the arc piece 1a formed when the existing pipe 1 is torn is set so as to be positioned in the horizontal direction, and by applying a force in the vertical direction by the dividing portion 11, It is possible to break the bolt 19 of the connecting sleeve 18 provided on the existing pipe 1 by applying a tensile force to the bolt 19.

In the cutters 16a to 16d, the distance from the center of the main body 10a to the tip of the cutting blade 17a increases in order from the front side to the rear side, and a circle connecting the tips of the cutting blades 17a located at the most front side. Has a diameter substantially equal to the inner diameter of the cast iron tube 1. In the following, the diameter of the circle connecting the tips of the cutting blades 17a is preset and increases at a rate,
Thereby, the wall of the cast iron pipe 1 is cut and the cut groove 1c is cut.
Grow.

The dividing portion 11 is formed by the cutting groove 1c in the cutting portion 10.
Has a function of applying a force in the vertical direction to the cast iron tube 1 on which is formed to break the cast iron tube 1 to form an arc piece 1a. In particular, at the same time as the cast iron pipe 1 is torn, a pair of connecting sleeves 18 are used to branch the branch pipe into the cast iron pipe 1.
When a socket or other joints (not shown) for connecting the cast iron pipe 1 are mounted, the joint sleeve 18 or the socket or other joints are provided with a force that separates them from each other. Then, a tensile force is applied to the bolt 19 to cause the bolt 19 to break.
Alternatively, the cast iron pipe 1 is surely torn regardless of the shape or material of a socket or other joints not shown.

For this reason, the dividing portion 11 is provided with a plurality of divided rollers 20a to 20d each having a predetermined pitch, each of which is composed of a pair of rollers arranged so that the outer periphery thereof is directed upward and downward. Each of the split rollers 20a to 20d has a pair of rollers 21 each having a crown formed so as to be in contact with the inner peripheral surface of the cast iron pipe 1. A shaft having these rollers 21 attached to the main body 11a of the split portion 11 is provided. It is configured to be rotatably mounted on 22. The roller 21 has a different diameter corresponding to each of the divided rollers 20a to 20d to be applied, and is configured to apply a vertical force to the cast iron pipe 1 in accordance with the change in the diameter. . In addition, the rollers 21 abut each other on opposing surfaces,
Thereby, it is constituted so that the reaction force at the time of breaking the cast iron pipe 1 can be supported.

In the present embodiment, the difference between the maximum dimension in the vertical direction of the dividing roller 20a disposed on the front side of the dividing section 11 and the maximum dimension in the vertical direction of the dividing roller 20d disposed on the rear side is as follows. By propelling the divided portion 11 into the inside of the cast iron tube 1 in which the cutting groove 1c is formed,
And the connecting sleeve 18 or the socket (not shown) and other joints (not shown) provided on the cast iron pipe 1 can be broken.

The cutting portion 10 constructed as described above is used for the cast iron pipe 1
When moved inside the cutting blade, the cutting blade located at the front
17a functions as a guide so that the axis of the main body 10a can coincide with the axis of the cast iron tube 1. A cutting groove 1c is formed in a direction inclined with respect to a horizontal line and a vertical line of the inner peripheral surface of the cast iron pipe 1 by the subsequent cutting blade 17a, and grows. Then, following the cutting section 10, the dividing section 11 moves into the interior of the cast iron pipe 1, and the dividing rollers 20a to 20d abut against the vertical direction of the cast iron pipe to apply a force for dividing the cast iron pipe 1 in the vertical direction. As a result, the cast iron pipe 1 is surely torn and the connecting sleeve 18 having a larger diameter than the cast iron pipe 1 or a bolt 19 for fastening a socket or other joints not shown.
Or a socket or the like can be broken.

The enlarged diameter portion 12 is a plurality of enlarged diameter rollers 23a to 23e rotatably arranged at predetermined intervals in the axial direction between the cutters 16a to 16d on the outer periphery of the tapered main body 12a. It is configured. The diameter of the expanding rollers 23a to 23e increases in order from the front side to the rear side in accordance with the taper of the main body 12a, so that the arc piece 1a can be bent into a predetermined shape.

The expanding rollers 23a to 23e arranged from the front side to the rear side are constituted by four rollers 24 which are narrower than the rollers 21 arranged in the dividing section 11, respectively. The diameters of the expanding rollers 23d and 23e have the same diameter as the inner diameter of the target tunnel 7.

The four rollers 24 constituting each of the expanding rollers 23a to 23e are rotatably supported by a shaft 25 attached to the main body 12a. Each roller 24 has a curved center corresponding to the inner peripheral surface of the cast iron pipe 1 at the center in the thickness direction on the outer peripheral surface, and both ends are tapered. The four rollers 24 are configured such that the tapered portions on the outer peripheral surface thereof are in contact with each other and rotate, and the curved surface portions can be in contact with the inner peripheral surface of the cast iron pipe 1. When expanding the arc-shaped piece 1a, each roller 24
Can cancel each other out.

The cast iron tube 1 is torn near the rear end of the cutting portion 10. Therefore, on the rear side of the cutting portion 10, the cast iron pipe 1 becomes a cantilever-shaped arc piece 1a having the rear end position of the cutting portion 10 as a fulcrum. The upstream enlarged rollers 23a and 23b in the enlarged diameter portion 12 are arranged on an arc having a center Oa on the outer peripheral side of the cast iron pipe 1, and the enlarged diameter rollers 23c and 23d are disposed on the inner peripheral side of the existing pipe 1. They are arranged on an arc having the center Ob.

The expanding rollers 23a and 23b have a function of causing the arc pieces 1a to bend in the direction in which the radius increases in order to increase the diameter, and to reduce the earth pressure of the ground due to the movement of the updating device A. It is possible to apply a concentrated load that can be opposed.

The deflection δ of the arc segment 1a is δ = (Wl 3
) / (3EI), where the radius of curvature R is R =
(EIL) / M. Here, W is the load applied by the expanding rollers 23a and 23b,
Is the distance between the rear end of the cutting portion 10 and the diameter-enlarging roller 23a and the distance between the diameter-enlarging rollers 23a and 23b, E is the longitudinal elastic modulus, I is the secondary moment of area, and M is the bending moment acting on the arc piece 1a. .

It is necessary that the deflection δ generated in the arc piece 1a is within the elastic limit of the cast iron as the material. In the cast iron pipe 1, when the amount of bending becomes large, the possibility of breakage increases. When the arc segment 1a breaks, it becomes difficult to properly protect the tunnel formed underground.

The expanding rollers 23b to 23d have the function of setting the arc piece 1a to the target diameter of the tunnel 7, and press-fitting each arc piece 1a into the ground to consolidate the periphery. That is,
Earth pressure acting on the arc piece 1a that has been bent in the direction in which the radius increases causes the arc piece 1a to bend so as to be parallel to the original cast iron pipe 1. At this time, an evenly distributed load w acts on the arc piece 1a due to the earth pressure. Therefore, the deflection δw of the arc piece 1a is derived by δw = (wl 4) / (8EI).

Expanding rollers 23a to 23e in the expanding section 12
The gradient angle of the line connecting the ends of the circles is not uniquely set, but is set so that the deflection of the arc-shaped piece 1a falls within the elastic limit. That is, it is appropriately set according to the material of the existing pipe to be replaced.

A connecting portion 13 is formed on the main body 12a of the enlarged diameter portion 12. The connecting portion 13 is constituted by a chuck for gripping the distal end of the PE pipe 6.

The guide 26 is provided on the main body 12a of the enlarged diameter portion 12 behind the cutters 16a to 16d provided on the cutting portion 10. The guide 26 is provided with the adjacent arc pieces 1 corresponding to the diameter expansion of the torn arc pieces 1a by the diameter expanding rollers 23a to 23e.
It is formed in a wedge shape that can respond to a change in the separation distance a.

A flexible joint 14 for connecting the cutting part 10 and the dividing part 11
The flexible joint 15 connecting the divided portion 11 and the enlarged diameter portion 12 realizes relatively free displacement without connecting and fixing each portion linearly. The connection of each of the parts 10 to 12 via a flexible joint has been found by the present inventors in the course of repeating the experiment.

That is, the cast iron tube 1 has linearity, and it was not considered that the cast iron tube 1 itself is bent. However, the cast iron pipe 1 buried in the ground for a long time is slightly bent by the action of earth pressure and other forces. And the cutting blade 17a is damaged. For this reason, the cutting device 10, the dividing portion 11, and the enlarged diameter portion 12 are connected by the flexible joints 14 and 15, so that the updating device A
Can be bent, thereby solving the above-mentioned problems.

The flexible joint 14 has two balls 27, which are fastened to the main body 10a of the cutting portion 10 by screws 28 and fastened to the main body 11a of the divided portion 11 by screws 28. The ball 27 is rotatably accommodated in casing members 29a to 29c divided into three so as to be bendable.

That is, the ball 27 has a spherical portion of at least a hemisphere with a plane formed at a position deviated from the center of the sphere, and a screw 28 is formed on the opposite side of this plane. In the casing members 29a and 29b, a hole is formed at the center for passing the screw 28, and a hemispherical seat for receiving a half of the ball 27 on the screw 28 side is formed. Screw with a sufficiently large diameter
30 (female screw) is formed. Also, the casing member 29
c, a screw 30 is formed at both ends of the outer peripheral portion to be screwed into a screw 30 formed on the casing members 29a and 29b, and a ball is provided inside.
A seat is formed to receive the side forming the 27 planes.

The procedure for constructing the flexible joint 14 will be described. First, the balls 27 are fastened to the screws 28 with the casing members 29a, 29b attached to the screws 28 formed on the main bodies 10a, 11a of the cutting portion 10 and the split portion 11, respectively, to prevent a predetermined loosening. In this state, the cutting part 10 and the division part 11 are not connected. Thereafter, the balls 27 are opposed to each other, and the casing member 29c is screwed into the screws 30 of the casing members 29a and 29b.
By tightening the screws 30 of each
The balls 27 are rotatably accommodated in the casing members 29a to 29c, respectively, and the cutting portion 10 and the divided portion 11 have a degree of freedom of bending with respect to each other.

In the flexible joint 14 configured as described above, any of the thrusts acting in the front-rear direction can be transmitted by contact between the surface of the ball 27 and the seats formed on the inner surfaces of the casing members 29a to 29c. It is.

The flexible joint 15 is substantially the same as the above-described flexible joint 14, and although the ball 27 is fastened to the main body 12a of the enlarged diameter portion 12, the casing member 29c is attached to the main body 11a of the divided portion 11.
Are directly connected. In the flexible joint 15 configured as described above, the range of the bending angle is narrower than that of the above-described flexible joint 14, but the function is not different at all.

A case in which the gas pipeline made of the cast iron pipe 1 is replaced with the PE pipe 6 using the updating apparatus A configured as described above will be described. The pull rod 5 previously inserted into the interior of the cast iron pipe 1 is connected to the main body 10a of the cutting unit 10 of the updating device A, and the PE pipe 6 is connected to the connection unit 13.

Next, when the pull-in device 4 is driven to pull the pull rod 5 into the pull-in shaft 3, the updating device A moves inside the cast iron pipe 1 with this pull-in.
The inner peripheral surface of the cast iron pipe 1 is cut by the cutting blades 17a of the cutters 16a to 16d to form the cutting grooves 1c. Then, the divided part 11 following the cutting part 10 moves inside the cast iron pipe 1, and the cast iron pipe 1 is torn starting from the cutting groove 1b to form a plurality of arc pieces 1a. Further, the connecting sleeve 18 or the socket (not shown) or other joints provided on the cast iron tube 1 is also broken or torn, so that the cast iron tube 1 becomes a bendable elongated arc-shaped piece 1a.

As the renewal device A continues to move, the cast iron pipe 1 is reliably torn by the guide 26,
23a to 23e cause the arc piece 1a to bend within the elastic limit and in the direction of increasing the radius, and as a result, the arc piece 1a
Are each pressed into the ground and compact the surrounding ground. That is,
The ground facing the arc piece 1a is firmly consolidated by the arc piece 1a, and the earth and sand between the arc pieces 1a is guided by the top surface of the guide 26, and is surrounded by the ground and the arc piece 1a. A tunnel 7 is formed. At the same time as the formation of the tunnel 7, the PE pipe 6 connected to the connection portion 13 is drawn into the tunnel 7.

When the cast iron pipe 1 is replaced with the PE pipe 6 as described above, if the cast iron pipe 1 is bent, the flexible joints 14 and 15 are displaced in accordance with the bending, and are displaced with respect to the cutting portion 10. The dividing part 11 is tilted by
Is tilted, so that an unnecessary twisting force does not act on the entire updating device A. Therefore, the thrust is not increased, and there is no possibility that the cutting blade 17a is damaged.

Immediately after the PE pipe 6 is buried, a gap exists between the inner circumference of the torn connecting sleeve 18 and the arcuate piece 1a and the outer circumference of the PE pipe 6 which have been torn and expanded. Under the earth pressure, the arc piece 1a is brought into close contact with the PE pipe 6,
An arc piece 1a arranged around the PE pipe 6 is integrated to form a conduit protecting the PE pipe 6 like an armor.

As described above, the periphery of the PE pipe 6 is armored with the plurality of arc pieces 1a made of cast iron, so that the strength against the earth pressure is improved. In particular, since the armor of the plurality of arc pieces 1a is configured along the laying path of the PE pipe 6, when excavation work is performed around the periphery by, for example, a backhoe or the like, P
It is possible to protect the E tube 6 from the backhoe claw.

Thereafter, when the pull rod 5 having a unit length is retracted by the retracting device 4, the rod 5 is connected to the coupler 5.
Removed from a. Then, the rod fixing bracket 4e moves forward, fixes the subsequent coupler 5a, and continuously pulls the updating device A into the pulling shaft 3 side. Updating device A is the incoming shaft 3
Is reached, the cast iron pipe 1 between the starting shaft 2 and the drawing shaft 3 is updated to the PE tube 6.

In the above-described embodiment, the cutter body 16 including the cutters 16a to 16d having the saw blade-like cutting blades 17a is used as the main body.
Although the cutting unit 10 is configured by being attached to 10a, the cutting tool is not limited to the cutter, and a broach (not shown) can be used.

[0068]

As described in detail above, in the pipe renewing apparatus according to the present invention, the new pipe is pulled in while the existing pipe is torn into a plurality of arc pieces at a predetermined angle, and the armature is wound around the new pipe. It is possible to constitute a conduit in which the mounted arc-shaped pieces are integrated. For this reason, the renewal work can be performed in one process regardless of the diameter of the existing pipe, and the construction period can be shortened.

In particular, the arc-shaped piece can be bent by the diameter-expanding roller disposed in the diameter-expanding means, and the arc piece can be pressed into the ground and compacted according to the deflection. Therefore, it is possible to form a tunnel-like space surrounded by the arc pieces pressed into the ground and the compacted ground part, and further, the new pipe is drawn in at the same time as the formation of the tunnel-like space, and the new pipe and its surroundings are formed. It is possible to construct a protective armor for a new tube composed of arc-shaped pieces.

Further, since the cutting means has a cutter body in which cutting blades whose distance from the center to the tip increases in order from the front to the back are arranged in a straight line, the inner peripheral surface of the existing pipe is cut with the advancement of the cutting means. As a result, a cutting groove can be formed, and reliable tearing can be realized.

Further, by providing a split roller for applying a diametrical force to the existing pipe at a split section provided behind the cutting means, the bolt fixing the connecting sleeve for the branch pipe, which is provided on the existing pipe, is broken and Sockets and the like can be torn in good condition. For this reason, no matter what parts are mounted on the buried existing pipe, these parts can be torn similarly to the existing pipe.

Further, when the cutting means and the dividing means are connected by a flexible joint, even if the existing pipe is bent, it is possible to bend the two means mutually and follow the existing pipe. And without increasing the thrust,
In addition, the cutting blade is not damaged.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a configuration of an updating device.

FIG. 2 is a side view illustrating a configuration of an update device.

FIG. 3 is a partial sectional view illustrating a configuration of a cutting unit.

FIG. 4 is a diagram illustrating a configuration of a joint portion.

FIG. 5 is a partial cross-sectional view illustrating a configuration of a dividing unit.

FIG. 6 is a partial cross-sectional view illustrating a configuration of a diameter expanding unit.

FIG. 7 is a view for explaining the direction and principle when bending an arc-shaped piece obtained by breaking an existing pipe.

FIG. 8 is a cross-sectional view showing a connection sleeve attached to an existing pipe, a diameter-expanded state of the torn existing pipe, and an embedded state of a new pipe.

FIG. 9 is a diagram illustrating a method of updating an existing pipe.

[Explanation of symbols]

 A Renewal device 1 Cast iron tube 1a Arc piece 1c Cutting groove 2 Starting shaft 3 Retraction shaft 4 Retraction device 5 Pull rod 6 PE tube 7 Tunnel 9 Jack 10 Cutting unit 10a Main unit 10b Guide unit 10c Fixing member 10d Bolt 11 Split unit 11a Main unit 12 Expansion Diameter part 12a Body 13 Connection part 14, 15 Flex joint 16 Cutter body 16a-16d Cutter 17a Cutting blade 17b Valley 18 Connection sleeve 19 Bolt 20a-20d Split roller 21 Roller 22 Axis 23a-23e Expanding roller 24 Roller 25 Axis 26 Guide 27 Ball 28, 30 Screw

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Hirai 19-18 Sakuradacho, Atsuta-ku, Nagoya-shi, Aichi, Japan

Claims (3)

[Claims] 1. An existing pipe to be renewed is moved inside, and the existing pipe is torn in an axial direction to form a plurality of arc-shaped pieces that are continuous in a longitudinal direction. A pipe renewing device for forming a space surrounded by a plurality of arc-shaped pieces and a ground portion by press-fitting the pipe and drawing a new pipe into the space. The cutting means includes a cutting means main body, the cutting means, a cutting means body, a cutting means body, a cutting means body, and a cutting means. A plurality of cutting blades arranged linearly in order so that the distance from the tip of each cutting blade attached to the means main body to the central axis of the cutting means increases in the axial direction from the front side to the rear side in order. It consists of a cutter body composed of four cutters each provided, and each cutter The plate surface is attached to the cutting means main body in a direction inclined at an angle smaller than 90 degrees with respect to a horizontal line passing through the center axis of the cutting means main body in the cross section of the cutting means main body, and the dividing means is divided means. At least one pair of split rollers are provided at positions opposed to each other in the vertical direction in the cross section of the main body, and the expanding means is a position obtained by dividing the outer periphery of the tapered main body at a predetermined angle, and is provided at the cutting means. And a plurality of expanding rollers arranged at a plurality of positions in the axial direction between the cutter bodies, wherein the expanding rollers arranged on the front side of the expanding rollers break the existing pipe. A plurality of arc-shaped pieces that are continuous in the longitudinal direction are formed, and the formed arc-shaped pieces are arranged so as to be bent within an elastic limit around a position that is separated from the arc in the outer peripheral direction, and the connection means is provided. Connect the new pipe Updating apparatus of the tube and having a chuck. 2. The pipe updating apparatus according to claim 1, wherein the cutting means and the dividing means are connected via a flexible joint. 3. The flexible joint has a first sphere fastened to a main body of the cutting means via a screw and a second sphere fastened to a main body of the dividing means via a screw, and the first sphere. The pipe updating apparatus according to claim 2, wherein the casing and the second sphere are accommodated in a casing so as to face each other.