JP2014141809A - Pipe renewal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a renewal device for renewing an existing pipe to a new pipe by breaking the existing pipe in which a connection part between pipes has an external diameter larger than that of the pipe or the existing pipe in which an elastic seal member such as a rubber ring is arranged.SOLUTION: A renewal device A includes: a body member 10 having a shaft shape part 11 having a smaller diameter than the internal diameter of an existing pipe B and a diameter-expanded part 12 configured integrally with the shaft shape part and having a rear end side formed to be larger than the external diameter of the existing pipe; a connection member 15 which is arranged at a tip of the shaft shape part 11, and to which pulling means is connected; a roller 18 arranged in the shaft shape part, brought into contact with the inner surface and rotating, and approximately aligning a shaft center 13 of the body member with the center of the existing pipe; a plurality of rotary cutters 20, 21 arranged at prescribed position following after the roller, rotatably attached to shafts 20a, 21a provided at positions eccentric from the shaft center of the body member, and arranged so that cutting edges 20b, 21b can project farther than the maximum external diameter at a joint part of the existing pipe; and a chuck 25 arranged at the rear end of the diameter-expanded part 12 and connecting a new pipe 4 to be drawn in.

Description

  TECHNICAL FIELD The present invention relates to a pipe updating device for updating an existing pipe buried in the ground to a new pipe, and in particular, an existing pipe having an outer diameter larger than the outer diameter of the pipe. Alternatively, this is advantageous when an existing pipe in which a sealing member having elasticity such as a rubber ring is arranged at the connection portion is updated.

  Many pipes are laid in the ground, such as a gas pipe for circulating fuel gas and a water pipe for circulating clean water. Among such pipes, for example, there are existing pipes for water supply constructed by connecting hard vinyl chloride pipes of unit length in the axial direction. In this existing pipe, it is common to realize a seal of the connecting portion by arranging a sealing member having elasticity such as a rubber ring and formed in a ring shape at the connecting portion between the pipes. . In addition, existing pipes for gas connected with steel pipes and cast iron pipes of unit length are also laid.

  In the case of existing pipes as described above, when a large force is applied due to an earthquake or ground subsidence, etc., there is a risk that the pipe connection will break and the fluid flowing inside will leak, especially in gas pipelines, Replacing an aged pipe line with a flexible synthetic resin pipe including a polyethylene pipe has been performed. In addition, with increasing demand for water and gas, there is a demand to replace existing pipes with thicker pipes.

  When replacing an existing pipe laid in the ground with a new pipe, a tunnel is formed by cutting the existing pipe in the axial direction and expanding the diameter, and a new pipe having flexibility in this tunnel. A technique for pulling in and replacing is proposed.

  For example, the inventions described in Patent Documents 1 and 2 relate to an updating device that can form a tunnel by tearing an existing pipe made of a cast iron pipe and press-fitting it into a natural ground. This updating device includes a cutting means, a dividing means, a diameter expanding means, and a connecting means. For example, in the process of drawing in by a drawing device described in Patent Document 3, a cast iron pipe is provided by a plurality of cutting blades provided in the cutting means. A plurality of cutting grooves are formed on the inner surface of the steel plate, the cast iron pipe is divided into a plurality of pieces by a plurality of dividing rollers provided in the dividing means, and a tunnel is formed by press-fitting the plurality of pieces into the ground by a diameter expanding means. The new pipe connected to the connecting means can be renewed by being pulled into the tunnel.

  The invention described in Patent Document 4 connects a longitudinal cutting cutter having a cutter part and an expander part to the tip of a wire rope, and connects a polyethylene pipe (PE pipe) behind the expander part to pull back the wire rope. Thus, the cutter part cuts the buried pipe, and the expander part draws in and updates the polyethylene pipe (PE pipe) while expanding the diameter of the buried pipe. In this device, the cutter is arranged only on one surface (lower surface) of the expander part, and after cutting the existing pipe with this cutter, the diameter can be expanded starting from the side opposite to the cut portion of the cut existing pipe. It is configured.

Japanese Patent No. 3389080 (Japanese Patent Laid-Open No. 11-141736) Japanese Patent No. 3304051 (Japanese Patent Laid-Open No. 10-292881) Japanese Patent No. 3154687 (Japanese Patent Laid-Open No. 11-264296) Japanese Patent No. 3261400 (Japanese Patent Laid-Open No. 2000-130082)

  In the invention described in Patent Literature 1 to Patent Literature 3, the existing pipe to be renewed is a steel pipe or cast iron pipe, and it is effective for tearing the existing pipe having rigidity. . However, when a unit-length rigid polyvinyl chloride pipe is applied to an existing pipe connected through an elastic seal member such as a rubber ring, the following problems occur.

  That is, the present inventors used an apparatus described in Patent Documents 1 to 3 to connect an existing pipe in which a unit-length hard vinyl chloride pipe is connected via an elastic seal member such as a rubber ring to polyethylene. An experiment was conducted to renew the pipe (PE pipe), but there was no particular problem immediately after the retraction of the renewal device. However, as the retraction length increased, the hard vinyl chloride cutting waste was sawtooth-shaped. There is a problem that it is not smoothly removed by being sandwiched between the cutting blades, and a problem that the cutting edge of the saw blade bites into the inner surface of the existing pipe, resulting in an increase in load when the renewal device is pulled.

  Further, when the cutting blade reaches the connecting portion of the pipe and the sealing member disposed at the connecting portion is cut, the sealing member is caught by the blade tip and stretched, and there is a problem that the cutting member is not cut. In particular, since the seal member is not fixed to the existing pipe, the seal member may move while being caught by the cutting blade. In this case, there is a problem that the existing pipe is also adversely affected.

  In the invention described in Patent Document 4, an existing pipe is cut in a line in the axial direction by a cutter, and then the diameter is expanded by an expander portion. For this reason, the diameter of the existing pipe is expanded starting from the wall on the side opposite to the cutting site, and the existing pipe that has been expanded tends to return to its original shape, which increases the load when the new pipe is drawn. There is a fear.

  An object of the present invention is to dispose an existing pipe having an outer diameter larger than the outer diameter of the pipe, or an elastic seal member such as a rubber ring at the pipe-to-tube connection. Another object of the present invention is to provide a pipe updating apparatus that can divide an existing pipe in the axial direction and update it to a new pipe.

  In order to solve the above-mentioned problems, the pipe renewal device according to the present invention moves the inside of an existing pipe where the pipe and the pipe are connected by a connecting portion having an outer diameter larger than the outer diameter of the pipe. Is a tube renewal device for drawing a new pipe while pressing the broken piece into the ground, and having a diameter smaller than the inner diameter of the existing pipe to be renewed A main body member having a diameter-increased portion integrally formed with the shaft-shaped portion and having a distal end side smaller than the inner diameter of the existing tube and a rear end side larger than the outer diameter of the existing tube; A connecting member disposed at the tip of the shaft-like portion of the main body member and connected to the traction means; and disposed on the shaft-like portion of the main body member following the connecting member and in contact with the inner surface of the existing pipe. A roller that rotates so that the center of the body member substantially coincides with the center of the existing pipe; The cutter is arranged on the outer peripheral side of the main body member opposite to the roller after the roller, and the other rotary cutter is the same as the roller in the main body member after the one rotary cutter. Are disposed on the outer peripheral side of the main body member, are rotatably mounted on shafts provided at positions eccentric from the center of the main body member, and the cutting edge can protrude beyond the maximum outer diameter at the connecting portion of the existing pipe. It has at least two rotary cutters arranged, and a chuck that connects a new pipe that is arranged at the rear end of the enlarged diameter portion of the main body member and is to be pulled in.

  In the tube updating apparatus, it is preferable that the one rotary cutter is disposed on the shaft-like portion of the main body member, and the other rotary cutter is disposed on the enlarged diameter portion of the main body member.

  In the pipe updating apparatus according to the present invention, the roller disposed on the shaft-like portion of the main body member comes into contact with the inner surface of the existing pipe, so that the center of the main body member can be made substantially coincident with the center of the existing pipe. In addition, at least two rotary cutters arranged following the roller are arranged on the opposite side of the roller and on the same side as the roller, and the cutting edge of each rotary cutter is connected to the existing pipe It protrudes beyond the maximum outer diameter at. For this reason, the existing pipe can be cut into two pieces by two rotary cutters, and the cut piece can be press-fitted into the natural ground, increasing the load required for cutting the existing pipe and press-fitting into the natural ground. There is nothing.

  In particular, when a sealing member having elasticity, such as a rubber ring, is arranged at the connection portion of the existing pipe, the rotary cutter attaches this sealing member to the inner surface of the pipe on the outer peripheral side or the inner surface of the pipe joint arranged at the connection portion. It can be cut by pressing. That is, the sealing member does not get caught and stretched, and the rotary cutter rotates from the inner surface side to the outer surface side of the existing tube, so that the inner surface of the pipe existing on the outer peripheral side of the sealing member, the inner surface of the pipe joint Therefore, good cutting can be realized.

It is a top view explaining the structure of an update apparatus. It is a side view explaining the structure of an update apparatus. It is a figure explaining the structure of a roller and a rotary cutter, and is sectional drawing of FIG. It is a figure explaining the cutting state of the existing pipe. It is a figure which shows the diameter expansion state of an existing pipe, and the embedment state of a new pipe. It is a figure explaining the example of a structure and pipe joint of a hard vinyl chloride pipe. It is a side view explaining the other structural example of an update apparatus.

  Hereinafter, the configuration of the updating apparatus according to the present invention will be described with reference to the drawings. The update device A according to the present invention includes two existing pipes in which a sealing member having elasticity such as a rubber ring is arranged at a connection portion between the pipes, or an existing pipe constituted by bonding a pipe and a socket (pipe joint). The tunnel is cut into pieces, the cut pieces are press-fitted into a natural ground, a tunnel is formed, and a new pipe can be drawn into the tunnel for renewal.

  First, prior to the description of the updating apparatus A, an example of the pipe 1 and the pipe joint 2 constituting the existing pipe B will be described with reference to FIG. FIG. 6A is a view for explaining a pipe 1 made of vinyl chloride, and FIG. 6B is a view for explaining a pipe joint 2 made of vinyl chloride.

  The pipe 1 constituting the existing pipe B is formed with a straight tubular straight pipe portion 1a over substantially the entire length, and one end side of the straight pipe portion 1a (the left side in the figure, hereinafter also referred to as "tip side"). ), And the joint portion 1c is formed on the other end side (right side in the drawing, hereinafter also referred to as “rear end side”). A fitting portion 1d is formed with a fitting portion 1d that expands the diameter of the straight pipe portion 1a and receives an insertion portion of another adjacent pipe, and a part of the fitting portion 1d is molded to form the seal member 3. A receiving portion 1e for receiving is formed.

  The length and thickness of the pipe 1 have optimum values according to conditions such as the nature of the fluid flowing through the installed pipe line and the flow rate. For example, in this embodiment, a pipe 1 made of a hard polyvinyl chloride pipe having a nominal diameter of 100 is used. In this pipe 1, the length of the straight pipe portion 1a is set to about 5000 mm, the inner diameter is set to about 100 mm, and the outer diameter is set to about 114 mm. Further, the inner diameter of the fitting portion 1d of the joint portion 1c is set to about 115 mm, and the maximum outer diameter is set to about 150 mm. In addition, pipes that are relatively frequently used as water supply pipes have a nominal diameter 75 (maximum outer diameter of the joint portion 1c of 120 mm), a nominal diameter 150 (maximum outer diameter of the joint portion 1c of 208 mm), and the like.

  The pipe joint 2 connects a straight pipe made of vinyl chloride or the insertion part 1b side of the pipe 1, and is formed into a shape in which the above-described joint part 1c is opposed and integrated. For this reason, the part which has the same function as the joint part 1c of the pipe | tube 1 attaches | subjects the same code | symbol, and abbreviate | omits description.

  An elastic seal member 3 such as a rubber ring is attached to the receiving portion 1 e of the pipe 1 and the pipe joint 2. The seal member 3 is manufactured by being molded into a ring shape. The material is styrene butadiene rubber, EDPM, CR, or the like, and any material that can seal the connecting portion of the tube can be used. The cross-sectional shape, inner diameter, outer diameter, and other dimensions of the seal member 3 are such that when the tube 1 having a preset outer diameter is inserted, the seal member 3 can be brought into contact with the outer peripheral surface of the tube 1 to achieve a reliable seal. Respectively.

  And the existing pipe | tube B is laid by arranging the some pipe | tube 1 which mounted | wore with the sealing member 3 to the receiving part 1e of the coupling part 1c in the longitudinal direction, and inserting and connecting the insertion part 1b to the coupling part 1c. . When the pipe 1 is connected, the seal member 3 is not necessarily required. The joint portion 1c is a straight tube having an inner diameter slightly larger than the outer diameter of the pipe 1, and is inserted into the joint portion 1c. Connection and sealing may be performed by inserting and bonding the portion 1b. In this case, a socket formed in a straight tubular shape can be used as the pipe joint.

  Next, the configuration of the update device A according to the first embodiment will be described. The renewal device A according to the present embodiment moves by pulling the inside of the existing pipe B in which the seal member 3 is arranged at the joint portion of the pipe 1 and the pipe 1 and moves the pipe 1 constituting the existing pipe B in this moving process. A new pipe 4 made of, for example, a flexible polyethylene pipe (PE pipe) is cut while a plurality of pieces are cut in the axial direction, the seal member 3 is cut, and the cut pieces 5 are pressed into the ground. It is configured to retract. The new pipe 4 is not limited to a polyethylene pipe, and a general synthetic resin pipe having flexibility can be adopted.

  The update device A includes a main body member 10 having a shaft-shaped portion 11 and a diameter-expanded portion 12 integrally formed with the shaft-shaped portion 11, a connecting portion 15 disposed at the tip of the shaft-shaped portion 11, a shaft The roller 18 arranged rotatably in the shape part 11, the two rotary cutters 20, 21 arranged at predetermined positions of the main body member 10, and the rear end of the enlarged diameter part 12 constituting the main body member 10. And a chuck 25.

  In the main body member 10, a shaft-like portion 11 having a diameter smaller than the inner diameter of the pipe 1 constituting the existing pipe B is disposed on the front end side (left end portion in FIG. 1), and the rear end side (in FIG. 1). On the right side), a diameter-expanded portion 12 having a tip side smaller than the inner diameter of the tube 1 and a rear end side larger than the outer diameter of the tube 1 is disposed, and the shaft-shaped portion 11 and the diameter-expanded portion 12 are integrated. Has been configured. The gradient of the enlarged diameter portion 12 is not particularly limited. Since the target pipe 1 is made of vinyl chloride, no particularly large load is generated even if the gradient is relatively strong.

  In the main body member 10 configured as described above, when the main body member 10 is moved inside the tube 1 with the shaft-shaped portion 11 at the top, the shaft-shaped portion 11 exerts any expansion force on the inner surface of the tube 1. Never give. However, the enlarged diameter portion 12 can contact the inner peripheral surface of the tube 1 and apply an expansion force to the tube 1.

  A connecting portion 15 is disposed at the tip of the shaft-like portion 11 constituting the main body member 10. The connecting portion 15 is a portion to which a traction force by a retracting device (not shown) is transmitted, and is configured as a screw-like member. And it is comprised so that the update apparatus A can be pulled by connecting the tension | pulling member 16 used as the traction means connected to the drawing-in apparatus by the turnbuckle-like coupling 17, and operating this drawing-in apparatus.

  When the connecting portion 15 is formed at the tip of the shaft-like portion 11, a screw-like member can be erected as in the present embodiment, but the present invention is not necessarily limited to this configuration. For example, a screw-like member May be configured through a bendable joint such as a ball joint. In this way, by connecting the tension member 16 to the connecting portion 15 via a bendable joint, the main body member 10 and the tension member 16 of the updating device A can be flexibly connected, and the existing pipe B can be connected to the existing pipe B. It is possible to cope even if the land is uneven.

  In addition, the connection part 15 does not necessarily need to be a screw-shaped member, and it is necessary to set it as the optimal structure according to the structure of the pulling means of a drawing-in apparatus. For example, when the member that transmits the pulling force of the retracting device is a wire rope, the connecting portion 15 may be configured by an eyebolt and a wire clip so as to ensure the wire rope.

  A roller 18 is disposed on the shaft-like portion 11 constituting the main body member. The roller 18 is rotatably mounted on a shaft 18a provided at a position eccentric from the shaft center 13 which is the center of the main body member 10, and a roller top 18b protruding from the shaft-shaped portion 11 is included in the tube 1 constituting the existing tube B. It is comprised so that it may contact with a surrounding surface. The distance from the roller top 18 b protruding from the shaft-shaped portion 11 to the shaft center 13 is set to a dimension substantially equal to the radius of the tube 1. Therefore, when the roller top 18 b of the roller 18 comes into contact with the inner peripheral surface of the tube 1, the axis 13 of the main body member 10 substantially coincides with the axis of the tube 1.

  The roller 18 may be in contact with any position on the inner peripheral surface of the tube 1. However, when the renewal device A is first inserted into the existing pipe B, it is preferable that the roller 18 is disposed on the lower side to support the weight. Then, by pulling the update device A in this state, the roller 18 rotates in contact with the bottom surface of the tube 1.

  The rotary cutters 20 and 21 are arranged at predetermined positions of the main body member 10. These rotary cutters 20 and 21 have a function of cutting the pipe 1 or the pipe joint 2 and the seal member 3 as the renewal device A moves inside the existing pipe B, and this function is efficient. It is configured to be able to demonstrate well.

  The rotary cutters 20 and 21 are formed in a disk shape with sharp edges 20b and 21b so that when the pipe 1 or the pipe joint 2 and the seal member 3 are cut, they can be cut by applying a shearing force. ing. When the tube 1 is cut by the rotary cutters 20 and 21 configured as described above, the tube 1 is pressed against and supported by the ground, so that the shearing force by the rotary cutters 20 and 21 is applied to the tube 1. And can be cut reliably. Further, when the sealing member 3 having elasticity is cut, the sealing member 3 can be reliably cut by being pressed against the joint portion 1c of the pipe 1 and the joint portion 1c of the pipe joint 2.

  The rotary cutters 20, 21 are arranged on the common diameter of the main body member 10, and are arranged on the front and rear and top and bottom, and the roller 18 is also arranged on the common diameter with the rotary cutters 20, 21. That is, the roller 18 is provided at a position that is eccentric downward from the axis 13 of the main body member 10 in the shaft-like portion 11 (below in FIG. 2, for the sake of convenience, the upper and lower sides are expressed below). It is attached to the shaft 18a. Further, the rotary cutter 20 is rotatably mounted on a shaft 20a which is the shaft portion 11 and is disposed behind the roller 18 and above the shaft center 13, and rotates with the center line in the width direction of the roller 18. The center line in the width direction of the cutter 20 is disposed on the common diameter of the main body member 10.

  Accordingly, the roller 18 and the rotary cutter 20 act on the opposite side with respect to the tube 1, and the reaction force when the rotary cutter 20 cuts the tube 1, the pipe joint 2 or the seal member 3 can be supported by the roller 18. It becomes possible. In addition, since the roller 18 is in contact with the inner surface of the tube 1, the shaft center 13 substantially coincides with the center of the tube 1, the distance between the shaft 20 a of the rotary cutter 20 and the shaft center 13 is substantially constant. That is, the position of the rotary cutter 20 in the height direction does not fluctuate.

  The rotary cutter 21 is rotatably attached to a shaft 21 a provided behind the rotary cutter 20 and below the shaft center 13 in the enlarged diameter portion 12 of the main body member 10. And the center line in the width direction of the rotary cutter 20 are arranged on a common diameter of the main body member 10. That is, the rotary cutter 21 acts on the side opposite to the rotary cutter 20 with respect to the tube 1.

  The rotary cutters 20 and 21 are configured such that the respective blade edges 20b and 21b can protrude from the joint 1c of the pipe 1 and the pipe joint 2 which are the parts having the maximum outer diameter in the connection part of the existing pipe B. Yes. That is, the rotary cutters 20 and 21 set the eccentric dimensions of the shafts 20a and 21a from the shaft center 13 according to the respective diameters and the radii of the joint portion 1c, so that the blade edges 20b and 21b have the outer diameter of the joint portion 1c. It is comprised so that it can protrude rather than. However, the dimension in which the blade edges 20b and 21b protrude from the outer diameter of the joint portion 1c is not limited, and is preferably set appropriately in consideration of the conditions including the shapes of the blade edges 20b and 21b. For example, in the present embodiment, the blade edges 20a and 21a of the rotary cutters 20 and 21 are configured to protrude 10 mm further than the maximum outer diameter portion of the joint portion 1c.

  In particular, since the rotary cutter 21 is disposed in the enlarged diameter portion 12 of the main body member 10, when the tube 1 is cut by the rotary cutter 21, the inner diameter of the tube 1 is increased by the action of the enlarged diameter portion 12. Yes. For this reason, it is preferable that the eccentric dimension from the axis 13 of the shaft 21a of the rotary cutter 21 is set in consideration of the expansion of the inner diameter of the tube 1.

  The chuck 25 is disposed at the rear end of the enlarged diameter portion 12 disposed on the rear end side of the main body member 10 and has a function of reliably grasping the front end portion of the new pipe 4 to be retracted. The chuck 25 is not particularly limited as long as it has this function. However, the chuck 25 is preferably configured to be able to grip the new tube 4 so as to be rotatable and bendable concentrically with the axis 13 of the main body member 10.

  For this reason, the chuck 25 intersects with the axis 13 with respect to the rotating member 25a disposed concentrically with the axis 13 with respect to the rear end of the enlarged diameter portion 12 constituting the main body member 10. The shaft 25b is provided in the direction to be rotated, and the grip portion 25c is attached to the shaft 25b so as to be rotatable. Accordingly, when the new tube 4 is gripped by the gripping portion 25c, the new tube 4 rotates in the direction intersecting the rotation of the rotation member 25a around the axis 13 and the axis 13 around the axis 25b. It is possible to bend freely in the direction in which the rotation is combined.

  Next, a method of drawing the new pipe 4 while cutting the existing pipe 1 with the updating device A configured as described above will be described.

  First, the updating device A is arranged in a shaft (not shown) at the upstream end of the existing pipe B to be updated, and the rear end of the enlarged diameter portion 12 constituting the main body member 10 of the updating device A is arranged. The end of the long new tube 4 is connected to the arranged chuck 25. Further, a retracting device (not shown) described in Patent Document 3, for example, is installed in a shaft (not shown) at the downstream end of the existing pipe B. Then, the tensile member 16 is inserted from the downstream shaft of the existing pipe B toward the upstream shaft, and is connected to the connecting portion 15 arranged at the tip of the main body member 10.

  Next, the drawing device is driven to draw the updating device A into the existing pipe B. At this time, as shown in FIG. 3 (a), the posture of the main body member 10 is adjusted so that the roller 18 comes into contact with the bottom surface of the pipe 1, so that the axis 13 of the main body member 10 is the axis of the existing pipe B. Approximate with the heart.

  When the renewal device A is moved from the upstream side to the downstream side of the existing pipe B as described above, the rotary cutter 20 rotates clockwise in FIG. 2 and starts cutting the pipe 1. Since the rotary cutter 20 is disposed on the shaft-like portion 11 of the main body member 10 as described above, the shaft-like portion 11 may contact the inner peripheral surface of the tube 1 as shown in FIG. In other words, the pipe 1 holds the laid state. That is, the outer peripheral surface of the tube 1 is kept in contact with the natural ground.

  And when the cutting | disconnection from the upstream edge part is started with respect to the upper part of the pipe | tube 1 with the rotary cutter 20, the shear force by the rotary cutter 20 acts so that the pipe | tube 1 may be pressed against a natural ground. At this time, the part to be cut of the tube 1 is supported by the natural ground, and the reaction force generated along with the cutting is supported by the roller 18 disposed on the lower side of the shaft 11, so that the cutting operation is performed in a stable state. Can be done.

  Even when the joint 1c of the pipe 1 or the joint 1c of the pipe joint 2 is cut by the rotary cutter 20, the cutting edge 20b of the rotary cutter 20 is in a position protruding from the joint 1c, so that reliable cutting is possible. Can be realized.

  The case where the sealing member 3 attached to the receiving part 1e constituting the joint part 1c of the pipe 1 is cut will be described. The seal member 3 attached to the receiving portion 1e has an outer peripheral surface in contact with the inner surface of the receiving portion 1e, and an inner peripheral surface in contact with the outer surface of the insertion portion 1b of the adjacent pipe 1 connected via the joint portion 1c. And is held. For this reason, the seal member 3 is sandwiched between the two pipes 1 and attached to the receiving portion 1e in a stable state.

  As described above, when the sealing member 3 attached to the receiving portion 1e of the joint portion 1c is cut by the rotary cutter 20, the rotary cutter 20 rotates in the clockwise direction, so that the shearing force of the pipe 1 inserted inward is obtained. The insertion portion 1b, the seal member 3, and the joint portion 1c of the outer pipe 1 are transmitted in this order. For this reason, a force that shifts in the axial direction of the tube 1 does not act on the seal member 3, and the seal member 3 is smoothly cut while being held in the receiving portion 1 e (see FIG. 4A). .

  As the renewal device A moves further downstream in the existing pipe B, the pipe 1 is cut by the rotary cutter 21 while the cutting of the rotary cutter 20 to the pipe 1 is continued. The cutting operation of the tube 1 by the rotary cutter 21 is substantially the same as the cutting of the tube 1 by the rotary cutter 20 described above. However, since the rotary cutter 21 is disposed in the diameter-expanded portion 12 of the main body member 10, the tube 1 maintains a diameter-expanded state corresponding to the position where the rotary cutter 21 is disposed.

  As shown in FIG. 3 (c), when the rotary cutter 21 reaches the pipe 1 and starts cutting, the enlarged diameter portion 12 of the main body member 10 comes into contact with the inner surface of the pipe 1, and the upper part is rotated by the rotary cutter 20. Is expanding the diameter of the cut tube 1. Accordingly, the outer peripheral surface of the tube 1 is pressed by the enlarged diameter portion 12 and is in pressure contact with the natural ground. Further, as the renewal device A moves downstream, the rotary cutter 21 rotates counterclockwise in FIG. 2, and the tube 1 is further pressed against the ground by this rotation. For this reason, the tube 1 is cut on the side opposite to the cutting portion by the rotary cutter 20 and divided into two pieces 5 as shown in FIG.

  Further, as the renewal device A moves downstream in the existing pipe B, the piece 5 divided into two is expanded in diameter by the expanded diameter portion 12 of the main body member 10, and FIG. As shown in Fig. At this time, since the curvature of the piece 5 and the curvature of the enlarged diameter portion 12 are different, the both ends of the piece 5 in the vertical direction and the substantially central portion are in contact with the outer periphery of the enlarged diameter portion 12, and the portion therebetween is the tube 1. It press-fits in a state where it is bent in a three-letter shape with the curvature substantially maintained. As the two pieces 5 are press-fitted into the ground, a tunnel whose diameter is enlarged by the enlarged diameter portion 12 is formed between the pieces 5.

  Then, when the new pipe 4 is drawn into the tunnel formed by the natural rock expanded by the two pieces 5 and the enlarged diameter portion 12 and the renewal device A reaches the downstream shaft, the new pipe 4 is formed by the chuck 25. The existing pipe B between the upstream shaft and the downstream shaft is updated to the new tube 4 by releasing the grip.

  The tunnel in which the new pipe 4 is laid as described above contracts, and as shown in FIG. 5B, the two pieces 5 sandwich the new pipe 4 like a sheath, and at the same time, the space above and below the new pipe 4 By burying earth and sand, it is possible to maintain a stable laying state.

  Next, the configuration of the updating apparatus A according to the second embodiment will be described with reference to FIG. In the first embodiment described above, since the rotary cutter 21 is disposed in the enlarged diameter portion 12, when the tube 1 is cut, a force in the enlarged diameter direction acts on the tube 1 so that the tube wall is broken. May be cut off. For this reason, the renewal device A according to the present embodiment prevents the force in the diameter expanding direction from acting on the tube 1 when the tube 1 is cut. In the updating apparatus according to the present embodiment, the same parts as those of the updating apparatus A according to the first embodiment and the parts having the same functions are denoted by the same reference numerals.

  In the updating apparatus A according to the present embodiment, the length of the shaft-like portion 11 of the main body member 10 is increased, and the roller 18 and the rotary cutters 20 and 21 are arranged on the shaft-like portion 11. The arrangement of these is the same as in the first embodiment described above, the roller 18 is arranged at the head, the rotary cutter 20 is arranged on the side opposite to the roller 18 following the roller 18, and the subsequent The rotating cutter 21 is arranged on the same side as the roller 18.

  By disposing the roller 18 and the rotary cutters 20 and 21 in this way, when the tube 1 is cut by the rotary cutter 21, no force in the diameter expansion direction by the diameter expansion portion 12 acts on the tube 1. For this reason, only the shearing force by the rotary cutters 20 and 21 acts on the pipe 1 without acting in the diameter expansion direction, and smooth cutting can be realized.

  In the first and second embodiments described above, the two rotary cutters 20 and 21 are provided, but it is not always necessary to have two rotary cutters. Three or more rotary cutters are arranged. May be. However, even when three or more rotary cutters are arranged, the arrangement positions of the roller 18 and the rotary cutters 20 and 21 are not changed, and three or more rotary cutters are arranged in a row behind the rotary cutters 20 and 21, respectively. It is necessary to arrange so that.

  For example, when four rotary cutters are to be arranged at 90 ° intervals in the circumferential direction, it is difficult to arrange them on the same cross section in the shaft-like part 11 or the enlarged diameter part 12 of the main body member 10. For this reason, although it will arrange | position in the front-back direction along an axial center, after cut | disconnecting the pipe | tube 1 into at least 2 piece, when the rotary cutter of the back row arrange | positioned at 90 degree intervals of these cut pieces contacts Each cut piece is not cut even if it is pressed to the natural ground side.

  However, when the third and subsequent rotary cutters are arranged following the rotary cutters 20 and 21, even if uncut portions are generated when the tube 1 is cut by the rotary cutters 20 and 21, this uncut portion Can be separated.

  The renewal device A according to the present invention is a pipe represented by a pipe made of vinyl chloride, and is connected by an existing pipe B in which a pipe having a unit length is connected via a sealing member having elasticity such as a rubber ring, or by bonding. This is advantageous when the existing pipe B is used to update to a long pipe.

A renewal device B existing pipe 1 pipe 1a straight pipe part 1b insertion part 1c joint part 1d fitting part 1e receiving part 2 pipe joint 3 seal member 4 new pipe 5 piece 10 body member 11 shaft-like part 12 enlarged diameter part 13 shaft center DESCRIPTION OF SYMBOLS 15 Connection part 16 Tensile member 17 Joint 18 Roller 18a Shaft 18b Roller top 20, 21 Rotating cutter 20a, 21a Shaft 20b, 21b Cutting edge 25 Chuck 25a Rotating member 25b Shaft 25c Gripping part

Claims (2)

The pipe is moved inside the existing pipe connected by the connecting portion having an outer diameter larger than the outer diameter of the pipe to tear the existing pipe in the axial direction, and the broken piece is ground A pipe renewal device that pulls in a new pipe while being press-fitted into the pipe,
A shaft-shaped portion having a diameter smaller than the inner diameter of the existing pipe to be renewed, a front end side smaller than the inner diameter of the existing pipe that is integrally formed with the shaft-shaped section, and a rear end side that is the outer diameter of the existing pipe A body member having an enlarged diameter portion formed larger than
A connecting member that is disposed at the tip of the shaft-like portion of the main body member and to which the traction means is connected;
A roller disposed on the shaft-like portion of the main body member subsequent to the coupling member, rotating in contact with the inner surface of the existing pipe, and a roller that substantially matches the center of the main body member with the center of the existing pipe;
One rotary cutter is disposed on the outer peripheral side of the main body member on the opposite side of the roller following the roller, and the other rotary cutter is subsequent to the one rotary cutter on the main body member. It is arranged on the outer peripheral side on the same side as the roller, and is rotatably mounted on a shaft provided at a position eccentric from the center of the main body member, and the cutting edge protrudes from the maximum outer diameter at the connection portion of the existing pipe. At least two rotating cutters arranged to obtain;
A chuck for connecting a new pipe to be retracted, which is disposed at the rear end of the enlarged diameter portion of the main body member;
An apparatus for updating a tube, comprising:   2. The tube updating apparatus according to claim 1, wherein the one rotary cutter is disposed in a shaft-like portion of the main body member, and the other rotary cutter is disposed in a diameter-expanded portion of the main body member.