JP2021085502A - Piping renewal method - Google Patents

Abstract

To provide a piping renewal method which extremely dispenses with the dismantling of a construction at the renewal of piping, and also dispenses with a special consideration to construction at the new installation of the piping.SOLUTION: A piping renewal method at the renewal of existing piping Po covered with a tubular protection material G to new piping Pn includes: an existing piping division step for dividing the existing piping Po into a plurality of cut pieces Ps by cutting the existing piping Po in a radial direction and a pipe axial direction; a withdrawal step for withdrawing the plurality of cut pieces Ps from the protection material; and a new piping insertion step for inserting the new piping Pn into the protection material G while making the new piping Pn going along an internal peripheral face of the protection material G in a state in which the protection material G is not removed from an installation object of the existing piping Po.SELECTED DRAWING: Figure 5

Description

The present invention relates to a pipe renewal method for renewing an existing pipe covered with a protective material such as a heat insulating material to a new pipe.

Piping covered with a protective material such as a heat insulating material is widely used. Such a pipe connects a water heater and a hot water supply target portion as a hot water supply pipe provided in a building, for example. Alternatively, connect the water meter and the water supply target location as a water supply pipe. These pipes are provided under the floor in a building or the like.

The pipe may be renewed depending on the degree to which this pipe has deteriorated due to aging or the like. Conventionally, in such a case, all the protective materials and piping have been replaced.

On the other hand, Patent Document 1 describes a method for renewing a pipe covered with a protective material (“protective pipe” according to the description of Patent Document 1). According to this method, the existing pipe is pulled out from the protective material, and then the pipe is renewed by passing the new pipe through the existing protective material.

Japanese Unexamined Patent Publication No. 2004-150145

However, with the conventional construction method, it is possible to work without temporarily dismantling a part of the building (for example, the floor material when the pipe is installed under the floor) to expose the protective material and the pipe. There wasn't. For this reason, the renewal work has become large-scale, and the construction cost has been increased accordingly.

Further, in the construction method described in Patent Document 1, protective materials and pipes are laid in advance in a building or the like when a pipe is newly installed, in consideration of facilitating the work of pulling out the pipe. For this reason, it takes time and effort to construct a new pipe because the shape of the pipe is taken into consideration. In addition, some pipes, such as metal reinforced resin pipes, cannot be constructed in this way.

Therefore, it is an object of the present invention to provide a pipe renewal method that eliminates the need for dismantling a building as much as possible when renewing a pipe and does not require much consideration for construction at the time of new pipe construction.

The present invention is a pipe renewal method for renewing an existing pipe covered with a tubular protective material to a new pipe, and by cutting the existing pipe in the radial direction and the pipe axial direction, a plurality of cuts are made. The existing pipe dividing step of dividing into pieces, the pulling step of pulling out the plurality of cut pieces from the protective material, and the new pipe with the protective material in a state where the protective material is not removed from the installation target of the existing pipe. It is a pipe renewal method characterized by including a new pipe insertion step of passing through the inside of the protective material along the inner peripheral surface of the pipe.

According to the above configuration, the protective material covering the existing pipe can be left fixed to the installation object such as a building, and this protective material can be used as a guide when laying the new pipe. Moreover, the existing pipe dividing step and the pulling step make it easy to pull out the pipe without being affected by the laying shape of the pipe.

Further, the existing pipe division step and the new pipe insertion step may be performed at the end where the existing pipe and the protective material are exposed to the outside of the building.

According to the above configuration, since the existing piping and the protective material can work at the end exposed to the outside of the building, there is no need to dismantle the building, which can contribute to the cost reduction of the construction.

Further, the existing pipe dividing step includes a grooving step of forming a groove along the pipe axis direction on the inner peripheral surface of the existing pipe, and the existing pipe dividing step includes the groove formed in the grooving step. Can be used as a guide to cut the existing pipe.

According to the above configuration, by cutting the existing pipe using the groove formed in the grooving step as a guide, the cutting does not fail in the existing pipe dividing step, and reliable cutting is possible.

Further, in the existing pipe dividing step, the cutting can be performed without performing prior processing on the inner peripheral surface of the existing pipe.

According to the above configuration, a series of steps can be shortened by performing the existing pipe dividing step without performing prior processing.

Further, two winches capable of winding the cord-like body are used, and one winch, which is one of the two winches, is arranged at one end of the existing pipe and the protective material, and the two winches are arranged. The other one, the other winch, is arranged at the other end of the existing pipe and the protective material, and the end of the cord-like body of the one-side winch and the end of the cord-like body of the other winch. By connecting a piping processing jig to the existing pipe so as to pass through the inside of the existing pipe and alternately operating the one-side winch and the other-side winch, the pipe processing is performed on the existing pipe. The jig can be reciprocated, and the grooving step and the existing pipe splitting step can be performed along with the reciprocating movement.

According to the above configuration, the grooving step and the existing pipe splitting step are performed by using two winches and reciprocating the pipe processing jig connected to the cord-like body. Therefore, preparations for inserting a new pipe can be efficiently performed.

According to the present invention, the protective material can be used as a guide when laying a new pipe. Moreover, the work of pulling out the pipe can be easily performed without being affected by the laying shape of the pipe. For this reason, when renewing the piping, it is not necessary to dismantle the building, and it is not necessary to give special consideration to the construction when the piping is newly installed.

It is the schematic which shows the arrangement example in a building of the pipe which is the object of the pipe renewal method which concerns on one Embodiment of this invention. It is the schematic which shows the combination of the winch used for the pipe renewal method and a pipe cutting jig. (A) is a half cross-sectional view of the pipe cutting jig. (B) is a plan view of the first blade attached to the pipe cutting jig. (C) is a plan view of the second blade attached to the pipe cutting jig. (D) is a plan view of the third blade attached to the pipe cutting jig. (A) is an axial sectional view showing a preparatory stage of a grooving process in the pipe renewal method. (B) is an axial sectional view showing a grooving process (first step). (C) is a radial cross-sectional view of the existing pipe after the grooving step (first step). (D) is an axial sectional view showing a grooving process (second stage). (E) is a radial cross-sectional view of the existing pipe after the grooving step (second stage). (A) is an axial sectional view showing a grooving process (third stage) in the pipe renewal method. (B) is a radial cross-sectional view of the existing pipe after the grooving step (third stage). (C) is an axial sectional view showing a grooving process (fourth step). (D) is a radial cross-sectional view of the existing pipe after the grooving step (fourth step). (E) is an axial sectional view showing an existing pipe division process. (F) is a radial cross-sectional view of the existing pipe after the existing pipe dividing step. (A) is an axial sectional view showing a drawing process in the pipe renewal method. (B) is an axial sectional view showing a preparatory stage of a new pipe insertion process. (C) is an axial sectional view showing a new pipe insertion process. (D) is an axial sectional view showing a state after laying a new pipe. (E) is a radial cross-sectional view showing a state after laying a new pipe.

First, the present invention will be described by taking up one embodiment. FIG. 1 shows an example of arranging the existing pipe Po, which is the target of the pipe renewal method of the present embodiment, on a building. The existing pipe Po is, for example, a pipe for hot water supply, and the outer circumference is covered with a tubular protective material G. The existing pipe Po and the new pipe Pn are resin pipes, for example, a polyethylene pipe (PE pipe), a cross-linked polyethylene pipe (PE-X pipe), and a polybutene pipe (PB pipe). The resin pipe may be a multi-layer pipe having a metal layer such as an aluminum alloy sandwiched between them, such as a metal reinforced resin pipe. The protective material G has an inner diameter dimension equal to or larger than the outer diameter dimension of the existing pipe Po and the new pipe Pn, and is formed of a flexible material such as foamed resin, for example, foamed polyethylene, and has heat insulation and heat retention in the radial direction. It has a function. Regarding the above-mentioned "flexible", in the present embodiment, when the protective material G receives an external force from each of the existing pipes Po and the new pipe Pn when the existing pipe Po and the new pipe Pn are inserted and removed, the axis is deformed or the diameter is displaced. It suffices to have enough flexibility to perform compression deformation in the direction. Incidentally, in the conventional method (see, for example, Japanese Patent Application Laid-Open No. 2004-150145 (Patent Document 1)), when the existing pipe is pulled out from the protective material and when the new pipe is passed through the existing protective material, a foamed resin or the like is used. If a protective material made of a flexible material is used, the pipe breaks through the protective material at the corners and band fixing portions and is damaged. That is, the conventional construction method could not be applied to the protective material formed of a flexible material.

FIG. 1 shows an example of arranging the existing pipe Po in a building (for example, a house) C. The new pipe Pn after the pipe update is also arranged in the building C in the same form as the existing pipe Po. In the existing pipe Po, at least an intermediate portion in the pipe axial direction is covered with the floor material F. The "pipe axis direction" means a direction along the axis center of the existing pipe Po. Further, in the existing pipe Po, the inlet end and the outlet end in the pipe axis direction are exposed upward from the floor material F or laterally from the outer wall, and the inlet end of the existing pipe Po is, for example, a water heater (not shown). It is connected and the outlet end is connected to, for example, a bathroom faucet V. The existing pipe Po is fixed to the foundation B located below the floor material F at predetermined intervals in the pipe axial direction by a band or the like so as not to run wild due to water pressure during water flow. At the time of fixing, as shown in FIG. 1, the protective material G receives an external force in the in-diameter direction by a band or the like and the foundation B, and the outer diameter of the protective material G formed of a flexible material such as foamed resin is an external force. It is compressed and reduced in diameter.

Next, the apparatus and the jig used in the pipe renewal method of the present embodiment will be described. In this embodiment, a winch (winding machine) 1, a pipe cutting jig 2 as a pipe processing jig, and a pipe inserting jig 3 are mainly used.

Two winches 1 are used as a set. One winch 1 is arranged at both ends of the pipe to be constructed. The winch 1 is configured so that the wire 11 which is a cord-like body can be wound up. One winch 1 is arranged on one end side of the existing pipe Po and another winch 1 is arranged on the other end side. In a state where the wires 11 are connected by two winches 1, one winch 1 in one set generates a tensile force when the wire 11 is wound up, and the other winch 1 receives the tensile force. The wire 11 is pulled out. The drive system of the winch 1 may be manual or may use the power of a prime mover such as electric power.

A jig connecting portion 12 is provided at the tip of the wire 11. In the jig connection portion 12, the wire side connection portion connected to the wire 11, the jig side connection portion connected to the pipe cutting jig 2, and the jig side connection portion rotate with respect to the wire side connection portion. A rotary connecting portion for connecting both connecting portions is provided so as to be possible. As the rotary connecting portion, a bearing 121 is built in the jig connecting portion 12. This bearing allows the jig connection portion 12 to rotate in the circumferential direction with respect to the wire 11. As a result, the pipe cutting jig 2 connected to the wire 11 (more specifically, the blade 4 attached to the pipe cutting jig 2) can be shifted in the circumferential direction. Therefore, in the grooving step and the existing pipe dividing step described later, for example, even if the wire 11 is twisted, the pipe cutting jig 2 is not affected by the twist and is in the circumferential direction with respect to the existing pipe Po. The pipe cutting jig 2 can be moved in the pipe axial direction while maintaining a constant position. Further, even if the pipe cutting jig 2 receives resistance from the existing pipe Po when moving in the existing pipe Po, it rotates with respect to the wire 11 so as to alleviate the resistance, so that the processing resistance can be suppressed.

The jig connecting portion 12 of the present embodiment is provided on one end side in the axial direction and the other end side in the axial direction of the pipe cutting jig 2, and one jig connecting portion 12 connects the one wire 11 to the pipe cutting jig. It is connected to one end side of 2, and the other jig connecting portion 12 connects the other wire 11 to the other end side of the pipe cutting jig 2. The connected wire 11 extends coaxially with respect to the pipe cutting jig 2.

The pipe cutting jig 2 has a substantially cylindrical shape with both ends reduced in the longitudinal direction. The pipe cutting jig 2 functions as a pipe processing tool in combination with the jig connecting portion 12. The half-cross-sectional shape of the pipe cutting jig 2 in a side view is shown in FIG. 3 (a). The outer diameter dimension of the large diameter portion on the central side in the longitudinal direction of the pipe cutting jig 2 is smaller than the inner diameter of the existing pipe Po to be constructed. The pipe cutting jig 2 includes wire mounting portions 21 at both ends in the longitudinal direction and in the center in the radial direction. A jig connecting portion 12 provided at the tip of the wire 11 is connected to the wire mounting portion 21. In this embodiment, the two are connected by screwing. Further, the pipe cutting jig 2 includes a blade mounting portion 22.

Here, the blade 4 which is an example of the processing means mounted on the blade mounting portion 22 will be described. The blade 4 is flat and has blades 41 for cutting the existing pipe Po at both ends in the radial direction while attached to the pipe cutting jig 2. Further, as shown in FIGS. 3A to 3C, a mounting hole 42 is formed in the central portion of the cutting tool 4. That is, the blade 4 as the processing means is provided with a mounting hole 42 as a mounting portion for the blade mounting portion 22 as a processing means mounting portion and blades 41 at both ends in the central portion. The blades 41 at both ends are provided so that the cutting edges are in the same direction, specifically, one side in the width direction of the blade 4. In the present embodiment, the first blade 4A (FIG. 3 (b)) and the second blade 4B (FIG. 3 (b)) have different radial lengths when mounted on the blade mounting portion 22, depending on the depth of cut into the existing pipe Po. 3 types of 3 (c)) and 3rd blade 4C (FIG. 3 (d)) are used. That is, the blade 4 as the processing means has a plurality of types of processing members (in the present embodiment, the first blade 4A, the second blade 4B, and the third blade 4C) so that different processing can be performed on the existing pipe Po. Including. In each of the blades 4A to 4C, the blade 41 is mounted on the blade mounting portion 22 so that the high side of the blade 41 is located at the moving source of the blade mounting portion 22 and the low side is located at the moving destination of the blade mounting portion 22. The proper use of each blade 4A to 4C will be described later.

The blade mounting portion 22 has two blade through holes 221 extending in the radial direction. The two through holes 221 for blades are provided so as to be offset by 90 degrees in the circumferential direction and offset so as not to overlap in the longitudinal direction. In the pipe cutting jig 2, a screw hole 222 is provided so as to be orthogonal to the through hole 221 for the blade, and a fixing screw (not shown) is attached to the screw hole 222, and a fixing screw is attached to the mounting hole 42 of the blade 4. By fitting the tip, the blade 4 inserted into the through hole 221 for the blade can be fixed by pressing the blade 4 with the tip of the fixing screw.

As shown in FIG. 6C, the pipe insertion jig 3 is used by being fixed to the end of the new pipe Pn. The fixing to the new pipe Pn may be performed by forming the portion to be inserted into the new pipe Pn into a so-called "bamboo shoot" shape in which a step is formed in the axial direction, or the pipe penetrates the side surface of the new pipe Pn. It may be fixed by using a screw leading to the insertion jig 3, and the specific means is not particularly limited. The pipe insertion jig 3 includes a wire mounting portion 31 at a portion exposed from the new pipe Pn when fixed to the end of the new pipe Pn. A jig connecting portion 12 provided at the tip of the wire 11 is connected to the wire mounting portion 31. In the present embodiment, like the pipe cutting jig 2, the two are connected by screwing.

Next, the pipe renewal method will be described. The pipe renewal method of the present embodiment includes a grooving process, an existing pipe division process, a drawing process, and a new pipe insertion process. In the following, one set of winches 1 will be referred to as a right winch 1R and a left winch 1L according to the arrangement shown in FIGS. 4 to 6. The terms "left and right" in the following are used for convenience of explanation, and the directions are not limited to those described below.

In the grooving process, a groove S along the pipe axis direction is formed on the inner peripheral surface of the existing pipe Po. Prior to the grooving process, as shown in FIG. 4A, the wire 11 is passed through the existing pipe Po from the right winch 1R (not shown). At this time, the wire 11 is pushed from the right side to the left side in the drawing by the operator, and is pulled out from the left end in the drawing in the existing pipe Po.

FIG. 4B shows the first stage of the grooving process. In the state shown in FIG. 4A, the tip of the wire 11 of the right winch 1R and the tip of the wire 11 of the left winch 1L are connected by the pipe cutting jig 2 via the jig connecting portion 12. At this time, one first blade 4A is attached to the pipe cutting jig 2. In this way, the blade 4 as a processing means is removable from the pipe cutting jig 2, and when attached to the pipe cutting jig, the blades 41 at both ends are attached to the pipe cutting jig 2. It protrudes in the out-of-diameter direction. In this state, the right winch 1R is operated to move the pipe cutting jig 2 from the left end shown in the existing pipe Po to the right end shown in the drawing so that the blade 41 of the first blade 4A is in contact with the inner surface of the existing pipe Po. Here, as shown in FIG. 3A, since both ends of the pipe cutting jig 2 in the longitudinal direction have reduced diameters, the pipe cutting jig 2 can be easily inserted into the existing pipe Po. Further, as described above, since the external dimension of the large diameter portion of the pipe cutting jig 2 on the central side in the longitudinal direction is smaller than the inner diameter of the existing pipe Po, the pipe cutting jig 2 is less likely to receive resistance from the existing pipe Po, and the existing pipe is not easily affected. The Po can be easily moved from the left end shown in the figure to the right end shown in the figure. As a result, as shown in FIG. 4C, two grooves S facing each other in the radial direction are formed in the inner peripheral portion of the existing pipe Po.

FIG. 4D shows the second stage of the grooving process. Two first blades 4A are attached to the pipe cutting jig 2 so as to be orthogonal to each other in the axial direction. The orientation of the first blade 4A is reversed from that of the first stage. That is, the cutting tool 4 as the processing means is configured so that the processing direction of the pipe cutting jig 2 can be changed between the one end side in the axial direction and the other end side in the axial direction. To change the orientation of the blade 4, the orientation of the pipe cutting jig 2 to which the blade 4 is attached may be changed, or the orientation of the blade 4 attached to the blade mounting portion 22 may be changed. With the two first blades 4A attached to the pipe cutting jig 2, the left winch 1L is operated to move the pipe cutting jig 2 from the right end shown in the existing pipe Po to the left end shown in the figure. At this time, one of the first blades 4A is aligned with the groove S formed in the first stage. That is, one of the first blades 4A does not actively cut the existing pipe Po in the second stage, and the pipe cutting jig 2 (particularly, the other attached first blade 4A). Functions as a "guide" to prevent the existing pipe Po from shifting in the circumferential direction. Then, the blade 41 of the other one of the first blades 4A is moved so as to be in contact with the inner surface of the existing pipe Po at a position deviated by 90 degrees in the circumferential direction with respect to the groove S formed in the first stage. Let me. As a result, as shown in FIG. 4 (e), four grooves S are formed in the inner peripheral portion of the existing pipe Po at intervals of 90 degrees in the circumferential direction. As described above, by making one of the first blades 4A function as a "guide", the four grooves S can be reliably formed.

FIG. 5A shows the third stage of the grooving process. One second blade 4B is attached to the pipe cutting jig 2. The second blade 4B has a larger amount of protrusion of the blade 41 in the radial direction than the first blade 4A. In this state, the right winch 1R is operated, and while the blade 41 of the second blade 4B is aligned with the groove S formed in the first stage or the second stage, the pipe cutting jig 2 is placed from the left end shown in the existing pipe Po to the right end shown in the drawing. Move to. As a result, as shown in FIG. 5B, the two grooves S facing each other in the radial direction become deeper.

FIG. 5C shows the fourth stage of the grooving process. Here, too, one second blade 4B is attached to the pipe cutting jig 2. The orientation of the second blade 4B is reversed from that of the third stage. In this state, operate the left winch 1L, and while aligning the blade of the second blade 4B along a groove S different from the groove S along which it was aligned in the third stage, install the pipe cutting jig 2 from the right end of the existing pipe Po in the drawing. Move to the left end in the figure. As a result, as shown in FIG. 5D, the two grooves S, which are the other grooves S and face each other in the radial direction, become deeper. This completes the grooving process. In the grooving step, a part of the grooves S is formed first among the plurality of grooves S, and the remaining grooves S are formed by using the grooves S as a guide to reduce the distance between the plurality of grooves S. It can be made constant in the axial direction. Further, by dividing the formation of the groove S into a plurality of stages and gradually deepening the groove S, the machining resistance can be reduced and a straight groove can be formed in the axial direction. By cutting the existing pipe Po in the following existing pipe dividing step in the state where the groove S is formed in the existing pipe Po by the above grooved process, the cutting fails in the existing pipe dividing step (for example, the cut piece Ps). The width of the pipe is not narrowed in the middle of the longitudinal direction and cuts), and reliable cutting in the pipe axis direction is possible. Further, in the existing pipe dividing step described below, the resistance in cutting can be reduced by cutting along the groove S.

In the existing pipe division step, the existing pipe Po is cut in the radial direction and the pipe axial direction, so that the existing pipe Po is cut in the pipe axial direction at a plurality of locations at intervals in the radial direction to form a plurality of cut pieces Ps. To divide. In the present embodiment, radial cutting is performed at a plurality of locations (4 locations) at a constant distance (every 90 degrees at an angle) in the circumferential direction, and this cutting is continuously performed in the pipe axis direction.

FIG. 5 (e) shows an existing pipe splitting process. Two third blades 4C are attached to the pipe cutting jig 2. The third blade 4C has a larger amount of protrusion of the blade 41 in the radial direction than the second blade 4B. In this state, operate the right winch 1R, and while aligning the blade of the third blade 4C along the groove S deepened through the third and fourth stages of the grooving process, the pipe cutting jig 2 is attached to the existing pipe Po. Move from the left end in the figure to the right end in the figure. As a result, as shown in FIG. 5 (f), the existing pipe Po is divided into a plurality of parts in the circumferential direction (in FIG. 5 (f), it is divided into four). Further, in the existing pipe dividing step, the resistance at the time of cutting can be reduced by aligning the blade 41 so as to correspond to the plurality of grooves S formed in the grooved step. Further, in the present embodiment, the shape of each cut piece Ps can be made substantially the same by dividing the existing pipe Po into a plurality of pieces at regular intervals in the circumferential direction.

In the drawing step, as shown in FIG. 6A, for example, on the right side of the drawing, a plurality of cut pieces Ps are pulled out from the protective material G. As a result, the existing pipe Po is removed from the inside of the protective material G. The pulling out is performed by the operator grasping each cut piece Ps with a tool such as a hand or pliers. Basically, it is pulled out one by one, but in some cases, it is possible to pull out multiple pieces at once. Each cut piece Ps has a band shape curved in the width direction, and four pieces are arranged along the circumferential direction. The cross-sectional shape of each cut piece Ps is smaller than the cross-sectional shape of the internal space of the protective material G, and the flexibility of each cut piece Ps is increased in the internal space, so that the degree of freedom of movement in the radial direction and the circumferential direction is increased. Therefore, it is possible to pull out with a much smaller tensile force than pulling out from the protective material G in the state of the pipe without cutting the existing pipe Po. Further, since the possibility that the protective material G is damaged by pulling out is small, the existing protective material G can be continuously used. As described above, the drawing step of the present embodiment is effective for the protective material G formed of a flexible material (material that is easily damaged) such as foamed resin. It is effective when the protective material G receives an external force in the in-diameter direction by the band or the like and the foundation B, and is compressed to reduce the diameter.

In the new pipe insertion step, the new pipe Pn is passed through the inside of the protective material G along the inner peripheral surface of the protective material G. Prior to the new pipe insertion step, as shown in FIG. 6B, the wire 11 is passed from the right winch 1R into the inside of the protective material G. At this time, the wire 11 is pushed from the right side to the left side in the drawing by the operator, and is taken out from the left end in the drawing of the protective material G. Next, a new pipe Pn is prepared on the left side of the figure of the protective material G. The pipe insertion jig 3 is fixed to the right end of the new pipe Pn, and the tip of the wire 11 is connected to the pipe insertion jig 3 via the jig connection portion 12. At this stage, the left winch 1L and its wire 11 are not used. Then, as shown in FIG. 6C, by operating the right winch 1R and pulling the new pipe Pn, the new pipe Pn is passed through the inside of the protective material G. By passing the new pipe Pn inside the protective material G by pulling, the new pipe Pn is passed while suppressing the possibility of being caught even at the bent part of the protective material G, as compared with passing the new pipe Pn by pushing. Can be passed through. Further, if the protective material G is formed of a flexible material such as a foamed resin, the axis of the protective material G is displaced when the new pipe Pn is passed through, for example, a portion where the protective material G is curved. Since the curvature changes temporarily due to the deformation of the new pipe, it is difficult to give resistance to the new pipe Pn that moves in the new pipe insertion process. Further, since the protective material G is compressed in the radial direction at the portion where the protective material G is fixed to the building C by a band or the like, it is difficult to give resistance to the new pipe Pn that moves in the new pipe insertion process. As described above, the new pipe insertion step of the present embodiment is effective for the protective material G formed of a flexible material (material that is easily damaged) such as foamed resin. It is effective when the protective material G receives an external force in the in-diameter direction by the band or the like and the foundation B, and is compressed to reduce the diameter. The state in which the pipe insertion jig 3 is removed from the new pipe Pn is shown in FIGS. 6 (d) and 6 (e). This completes the renewal of the piping, and then connects both ends to the water heater and faucet to complete the construction.

As described above, in the construction method of the present embodiment, the existing pipe Po and the protective material G can work at the end exposed to the outside of the building C. Therefore, the work of replacing the existing pipe Po with the new pipe Pn can be performed without removing the protective material G from the installation target of the existing pipe Po (in this embodiment, the foundation B and the floor material F of the building C). it can. In addition, the operation of each winch 1, the pulling out of the existing pipe Po from the protective material G, and the insertion of the new pipe Pn into the protective material G are all outside the building C (specifically, the floor material F and the foundation B in the building C). It can be done outside the closed space between and. Therefore, since it is not necessary to dismantle the building C, it is possible to contribute to the cost reduction of the construction work.

As described above, according to the pipe renewal method of the present embodiment, the protective material G covering the existing pipe Po is left fixed to the building C, and this protective material G is used as a guide when laying the new pipe Pn. it can. Moreover, the existing pipe dividing step and the pulling step make it easy to pull out the pipe without being affected by the laying shape of the pipe.

In addition, the dismantling of the building C is not required as much as possible when the piping is renewed, and no special consideration is required for the construction when the piping is newly installed. This "remarkable consideration" means consideration that goes beyond the minimum consideration of not forming a sharp bend that causes breakage of the pipe. By adopting the pipe renewal method of the present embodiment in this way, the pipe route at the time of new pipe construction may be roughly set, and whether or not the pipe can be inserted into and removed from the protective material G at the site at the time of new pipe construction. Since it is not necessary to carry out such a test, the man-hours required for new piping installation will not increase as compared with the conventional method.

Further, in a piping processing tool including a main body portion having a pipe cutting jig 2 and a cutting tool 4 as a processing means, and a jig connecting portion 12 for connecting the main body portion to a wire 11, the pipe cutting jig 2 and the cutting tool 4 However, different processing can be performed depending on whether the existing pipe Po is processed by entering the existing pipe Po from one end side in the axial direction or the existing pipe Po is processed by entering the existing pipe Po from the other end side in the axial direction. Specifically, it is changed by changing the direction of the blade 41 as in each stage of the grooving process or the existing pipe dividing process, or by changing the type of each blade 4A to 4C to the pipe cutting jig 2. By doing so, one end side of the pipe cutting jig 2 enters from the inlet to the outlet of the existing pipe Po at the head, and the other end side of the pipe cutting jig 2 enters the inlet from the outlet of the existing pipe Po at the head. Since it is possible to perform processing different from that in the case of recovery, it is possible to efficiently process the existing pipe Po.

Although the embodiments of the present invention have been described above with reference to an example, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, even if the protective material G has the functions of heat insulation and heat retention, it does not have the functions of heat insulation and heat retention and merely covers the pipe (existing pipe Po or new pipe Pn). You may. Further, the protective material G does not have to cover the entire pipe axial direction, and may partially cover the pipe axial direction. Further, the protective material G may have a cut in the circumferential direction, such as a radial cross section “C” shape.

Further, although the winch 1 is used in the above embodiment, various devices capable of pulling a cord-like material such as a wire or a chain in the longitudinal direction may be used even if the device does not correspond to a winch (winding machine). Can be done.

Further, in the present embodiment, the pipe cutting jig 2 is provided between the end of the wire 11 of the one-side winch (right winch 1R) and the end of the wire 11 of the other winch (left winch 1L). The case where the grooved process and the existing pipe splitting process are performed by connecting them has been described, but the present invention is not limited to this. For example, the pipe cutting jig 2 may be connected to the wire 11 of the right winch 1R and the wire 11 of the left winch 1L. As a result, it is not necessary to use the jig connecting portion 12 attached to the tip of the wire 11, and preparation can be performed efficiently. Further, a winch on one side is provided on one end side of one wire, a winch on the other side is provided on the other end side, and a pipe cutting jig 2 is connected to an intermediate portion of the wire, that is, at both ends of one wire. A winch may be provided for each, and the wire may be inserted through the pipe cutting jig 2. In either case, the pipe cutting jig 2 is connected to the wire having the winch on one side and the wire having the winch on the other side so as to pass through the inside of the existing pipe Po. Therefore, the pipe cutting jig 2 is reciprocated by using two winches, and the grooving process and the existing pipe dividing process are performed.

Further, although the pipe cutting jig 2 has a substantially columnar shape in the above embodiment, it does not hinder the movement in the pipe axis direction in the existing pipe Po, and can support a cutting tool for cutting the existing pipe Po. If so, it may have another shape. Further, the blade mounted on the pipe cutting jig 2 may be either a fixed blade or a rotary blade. Further, the shape of the blade 41 is not particularly limited. In the above embodiment, the blade 41 can cut in one direction in the pipe axis direction, but the blade 41 can cut in both directions in the pipe axis direction. As a result, the grooving step or the existing pipe splitting step can be performed without changing the orientation of the cutting tool 4 described above, so that the pipe renewal method of the present embodiment can be efficiently performed.

Further, the number of steps and the processing content regarding the steps in the grooving process are not limited to those shown in the above-described embodiment (first step to fourth step), and can be changed in various ways. Further, the grooving step can be omitted. That is, in the existing pipe dividing step, it is possible to cut the inner peripheral surface of the existing pipe Po without performing prior processing. In this case, there is an advantage that a series of steps can be shortened by performing the existing pipe dividing step without performing prior processing.

Further, in the present embodiment, the case where the existing pipe Po is cut along the groove S formed in the grooved step in the existing pipe dividing step has been described, but the present invention is not limited to this, and the groove S is provided with the first blade. The blade 41 of the 4A or the second blade 4B may be fitted and used as a guide to cut a portion other than the groove S with the blade 41. In any case, by cutting the existing pipe Po using the groove S as a guide, the pipe can be reliably divided without failing to cut.

Further, the number of divisions of the existing pipe Po that has undergone the grooving step and the existing pipe division step is not limited to the four divisions of the above embodiment, and may be three divisions or less, or five divisions or more. In particular, the number of divisions may be appropriately determined in consideration of the ease of pulling out the cut pieces Ps from the protective material G in the pulling step according to the diameter and length of the existing pipe Po. Further, the spiral cutting piece Ps may be formed by inclining the cutting locus with respect to the pipe axis direction.

1 winch 11 cord, wire 12 jig connection 2 piping processing jig, piping cutting jig 3 piping insertion jig 4 blade C building Po existing piping Pn new piping Ps cutting piece S groove G protective material

Claims (5)

This is a pipe renewal method when renewing an existing pipe covered with a tubular protective material to a new pipe.
An existing pipe dividing step of dividing the existing pipe into a plurality of cutting pieces by cutting the existing pipe in the radial direction and the pipe axial direction.
A drawing step of pulling out the plurality of cut pieces from the protective material, and
A new pipe insertion step in which the new pipe is passed through the inside of the protective material along the inner peripheral surface of the protective material without removing the protective material from the installation target of the existing pipe.
Piping renewal method characterized by including. The pipe renewal method according to claim 1, wherein the existing pipe dividing step and the new pipe inserting step are performed at an end where the existing pipe and the protective material are exposed to the outside of the building. Including a grooving step of forming a groove along the pipe axis direction on the inner peripheral surface of the existing pipe prior to the existing pipe splitting step.
The pipe renewal method according to claim 1 or 2, wherein in the existing pipe dividing step, the existing pipe is cut by using the groove formed in the grooved step as a guide. The pipe renewal method according to claim 1 or 2, wherein in the existing pipe splitting step, the cutting is performed without performing prior processing on the inner peripheral surface of the existing pipe. Two winches capable of winding the cord-like body are used, one winch, which is one of the two winches, is arranged at one end of the existing pipe and the protective material, and the other of the two winches. One other winch is placed at the other end of the existing pipe and the protective material.
A piping processing jig is connected between the end of the cord-like body of the one-side winch and the end of the cord-like body of the other winch so as to pass through the inside of the existing pipe.
By alternately operating the one-side winch and the other-side winch, the piping processing jig is reciprocated with respect to the existing pipe, and along with this reciprocating movement, the grooving process and the existing pipe division are performed. The pipe renewal method according to claim 3, wherein the process is performed.

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