JP7429418B2 - Piping renewal method - Google Patents

Description

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

Piping covered with a protective material such as a heat insulator is widely used. Such piping is, for example, a hot water supply piping installed in a building that connects a water heater and a location to which hot water is to be supplied. Alternatively, connect the water meter and the target water supply area as a water supply pipe. These pipes are installed under the floor of a building.

Depending on the extent to which this piping has deteriorated over time, the piping may be updated. Conventionally, in such cases, the protective material and piping were all replaced.

On the other hand, Patent Document 1 describes a method for updating piping covered with a protective material (according to the description in Patent Document 1, a "protective tube"). According to this construction method, the existing piping is pulled out from the protective material, and then the new piping is passed through the existing protective material to renew the piping.

Japanese Patent Application Publication No. 2004-150145

However, with conventional construction methods, work cannot be done without temporarily dismantling a part of the building (for example, the flooring if the piping is installed under the floor) and exposing the protective material and piping. There wasn't. For this reason, the renewal work became large-scale, and the construction cost was correspondingly large.

Furthermore, in the construction method described in Patent Document 1, protective materials and pipes are laid in buildings etc. in advance when newly installing pipes, taking into consideration the ease of pulling out the pipes. For this reason, it took a lot of time and effort to install new pipes as the shape of the pipes had to be taken into account. Additionally, there were some pipes, such as metal-reinforced resin pipes, that could not be constructed in this way.

Therefore, an object of the present invention is to provide a piping renewal method that eliminates the need for demolition of buildings as much as possible when renewing piping, and does not require special consideration when installing new piping.

The present invention is a piping renewal method for replacing existing piping covered with a tubular protective material with new piping, in which multiple cuts are made by cutting the existing piping in the radial direction and the pipe axial direction. an existing pipe dividing step of dividing the existing pipe into pieces; and a step of separating the new pipe into pieces while aligning the new pipe with the inner circumferential surface of the existing pipe without removing the protective material and the existing pipe from the object to which the existing pipe is installed. and a step of inserting a new pipe into the existing pipe.

According to the above configuration, the protective material and the existing piping can be left fixed to the object to be installed such as a building, and the protective material and the divided existing piping can be used as a guide when laying the new piping. Moreover, by using the guide as the guide, it becomes easy to install new pipes, and the renewal of the pipes can be made less affected by the shape of the pipes.

The method further includes a grooving step of forming grooves along the pipe axis direction on the inner peripheral surface of the existing pipe prior to the existing pipe dividing step, and in the existing pipe dividing step, the groove formed in the grooving step is The existing piping can be cut using the guide.

According to the above configuration, by cutting the existing pipe using the groove formed in the grooving process as a guide, there is no failure in cutting in the existing pipe dividing process, and reliable division is possible.

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

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

Further, the existing pipe dividing step and the new pipe insertion step may be performed at an end portion of the existing pipe and the protective material exposed to the outside of the building.

According to the above configuration, work can be performed at the ends of the existing piping and protective material exposed to the outside of the building, so there is no need to demolish the building, which can contribute to lower construction costs.

Further, two winches capable of winding up the cable-like body are used, one of the two winches is placed at one end of the existing piping and the protection material, and one of the two winches is placed at one end of the existing pipe and the protection material. Another winch on the other side is arranged at the other end of the existing piping and the protective material, and a pipe cutting jig is attached to the cord-like body of the winch on the one side and the cord-like body of the winch on the other side. is connected so that it can pass through the inside of the existing piping, and by alternately operating the winch on one side and the winch on the other side, the piping cutting jig can be moved back and forth with respect to the existing piping, and this reciprocation The grooving process and the existing pipe dividing process may be performed along with the movement.

According to the above configuration, the grooving process and the existing pipe dividing process are performed by using two winches and reciprocating the pipe cutting jig connected to the cable-shaped body. Therefore, preparations for inserting new piping can be made efficiently.

According to the present invention, the protective material and existing piping can be used as a guide when installing new piping. Moreover, the piping can be easily updated without being affected by the installed shape of the piping. Therefore, when updating the piping, it is not necessary to demolish the building, and there is no need to take special consideration when installing new piping.

FIG. 1 is a schematic diagram showing an example of the arrangement of piping, which is a target of a piping renewal method according to an embodiment of the present invention, in a building. FIG. 2 is a schematic diagram showing a combination of a winch and a pipe cutting jig used in the pipe renewal method. (a) is a half 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 a second cutter attached to the pipe cutting jig. (d) is a plan view of a third blade attached to the pipe cutting jig. (a) is an axial cross-sectional view showing a preparatory stage of a grooving process in the pipe renewal method. (b) is an axial cross-sectional view showing the grooving process (first stage). (c) is a radial cross-sectional view of the existing pipe after the grooving process (first stage). (d) is an axial cross-sectional view showing the grooving process (second stage). (e) is a radial cross-sectional view of the existing pipe after the grooving process (second stage). (a) is an axial sectional view showing a grooving step (third stage) in the pipe renewal method. (b) is a radial cross-sectional view of the existing pipe after the grooving process (third stage). (c) is an axial cross-sectional view showing the grooving process (fourth stage). (d) is a radial cross-sectional view of the existing pipe after the grooving process (fourth stage). (e) is an axial cross-sectional view showing an existing pipe dividing 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 new pipe insertion process in the pipe renewal method. (b) is an axial cross-sectional view showing the state after new piping is installed. (c) is a radial cross-sectional view showing the state after new piping is installed.

First, the present invention will be explained by taking up one embodiment. FIG. 1 shows an example of the arrangement of existing piping Po, which is the target of the piping renewal method of this embodiment, in a building (for example, a house) C. The existing pipe Po is, for example, a pipe for supplying hot water, and its outer periphery is covered with a tubular protective material G. The existing pipe Po and the new pipe Pn are resin pipes, such as polyethylene pipes (PE pipes), crosslinked polyethylene pipes (PE-X pipes), and polybutene pipes (PB pipes). The resin tube can also be a multilayer tube with metal layers such as aluminum alloy sandwiched therebetween. The protective material G has an inner diameter larger than the outer diameter of the existing pipe Po and the new pipe Pn, is made of a flexible material such as foamed resin, for example foamed polyethylene, and has heat insulation and heat retention properties in the radial direction. It has a function. Regarding the above-mentioned "flexible", in this embodiment, when the protective material G receives an external force in the radial direction from each pipe Po and Pn when the existing pipe Po and the new pipe Pn are inserted or removed, the axis of the inner diameter is shifted. It is sufficient that the inner diameter portion is flexible enough to be deformed as shown in FIG. By the way, in conventional construction methods (for example, see Japanese Unexamined Patent Publication No. 2004-150145 (Patent Document 1)), when pulling out existing piping from the protective material, or when passing new piping through the existing protective material, foamed resin, etc. If a protective material made of a flexible material is used, the piping will break through the protective material at the corner or band fixing portion and be damaged. In other words, conventional construction methods cannot be applied to protective materials made of flexible materials.

The new pipe Pn after the pipe renewal is also arranged in the same form as the existing pipe Po in the building C. The existing pipe Po is covered with the floor material F at least in the middle in the pipe axis direction. Note that "pipe axis direction" means a direction along the axial center of the existing pipe Po. In addition, the inlet end and outlet end of the existing pipe Po in the pipe axis direction are exposed upward from the flooring F or laterally from the outer wall, and the inlet end of the existing pipe Po is connected to, for example, a water heater (not shown). The outlet end is connected, for example, to a bathroom faucet V. The existing pipes Po are fixed to the foundation B located below the flooring F at predetermined intervals in the pipe axis direction using bands I or the like so that they do not become violent due to the water pressure during water flow. When fixing, as shown in FIG. 1, the protective material G receives an external force in the radial inward direction by the band I etc. and the base B, and the outer diameter of the protective material G made of a flexible material such as foamed resin is It is compressed and reduced in diameter by external force.

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

Two winches 1 are used as a set. One winch 1 is placed at each end of the pipe to be constructed. The winch 1 is configured to be able to wind up a wire 11 that is a cable-like body. One winch 1 is disposed at one end of the existing pipe Po, and the other winch 1 is disposed at the other end. When the wire 11 is connected between the two winches 1, one of the winches 1 in the set generates a tensile force as the wire 11 is wound up, and the other winch 1 receives the tensile force. Wire 11 is pulled out. The winch 1 may be driven manually, or may be driven by a motor such as an electric motor.

A jig connection portion 12 is provided at the tip of the wire 11. The jig connection part 12 includes a wire side connection part that is connected to the wire 11, a jig side connection part that is connected to the pipe cutting jig 2, and a jig side connection part that rotates with respect to the wire side connection part. and a rotary connection part that connects both the connection parts so that the connection parts can be connected together. A bearing 121 is built in as this rotational connection part. This bearing 121 allows the jig connection portion 12 to rotate in the circumferential direction with respect to the wire 11. Thereby, the pipe cutting jig 2 (more specifically, the blade 4 attached to the pipe cutting jig 2) connected to the wire 11 can be shifted in the circumferential direction. Therefore, in the grooving process and the existing pipe dividing process, which will be described later, even if the wire 11 is twisted, the pipe cutting jig 2 will not be affected by the twist and will maintain a constant position in the circumferential direction. It is possible to move within the existing pipe Po in the pipe axis direction. Further, even if the pipe cutting jig 2 receives resistance from the existing pipe Po when moving within the existing pipe Po, it rotates relative to the wire 11 to alleviate the resistance, so that machining resistance can be suppressed.

The jig connection parts 12 of this embodiment are provided at one end in the axial direction and the other end in the axial direction of the pipe cutting jig 2, and one jig connection part 12 connects one wire 11 to the pipe cutting jig. 2, and the other jig connecting portion 12 connects the other wire 11 to the other end 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 a reduced diameter at both ends in the longitudinal direction. This pipe cutting jig 2 functions as a pipe processing tool in combination with the jig connection part 12. A half-sectional shape of the pipe cutting jig 2 in a side view is shown in FIG. 3(a). The outer diameter of the large diameter portion on the longitudinal center side 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 a wire mounting portion 21 at both ends in the longitudinal direction and in the center in the radial direction. A jig connection portion 12 provided at the tip of the wire 11 is connected to this wire attachment portion 21 . In this embodiment, both 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 a processing means mounted on the blade mounting part 22, will be explained. This blade 4 has a planar shape and has blades 41 at both ends in the radial direction when attached to the pipe cutting jig 2 for cutting the existing pipe Po. Further, as shown in FIGS. 3(a) to 3(c), a mounting hole 42 is formed in the center portion of the blade 4. That is, the cutter 4 as a processing means includes a mounting hole 42 in the center as a mounting part for the cutter mounting part 22 as a processing means mounting part, and blades 41 at both ends. The blades 41 at both ends are provided with their cutting edges facing in the same direction, specifically, toward one side in the width direction of the blade 4. In this embodiment, the cutter 4 includes a blade 41 as a processing blade for cutting from the inner diameter side of the existing pipe Po, specifically, a blade 41 provided at both ends. A first knife 4A (FIG. 3(b)), a second knife 4B (FIG. 3(c)), which have different radial lengths when attached to the knife mounting portion 22, depending on the depth of the cut into the pipe Po. Three types of third cutlery 4C (FIG. 3(d)) are used. That is, the cutter 4 as a processing means has a plurality of types of processing members (in this embodiment, a first cutter 4A, a second cutter 4B, and a third cutter 4C) so that different processing can be performed on the existing pipe Po. include. Each of the blades 4A to 4C is mounted on the blade mounting section 22 such that the higher side of the blade 41 is located at the movement source of the blade mounting section 22, and the lower side is located at the movement destination of the blade mounting section 22. The proper use of each of the blades 4A to 4C will be described later.

The blade mounting portion 22 has two blade through holes 221 that extend in the radial direction. The two cutter through holes 221 are provided so as to be offset by 90 degrees in the circumferential direction and 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 cutter, and a fixing screw (not shown) is attached to the screw hole 222, and the fixing screw is inserted into the attachment hole 42 of the cutter 4. By fitting the tip, the cutter 4 inserted into the cutter through hole 221 can be fixed by holding the cutter 4 with the tip of the fixing screw.

The pipe insertion jig 3 is used by being fixed to the end of the new pipe Pn, as shown in FIG. 6(a). Fixing to the new pipe Pn may be done by making the part to be inserted into the new pipe Pn into a so-called "bamboo shoot" shape with a step formed in the axial direction, or by penetrating the side of the new pipe Pn. It may be fixed 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 attachment part 31 at a portion exposed from the new pipe Pn when fixed to the end of the new pipe Pn. A jig connection portion 12 provided at the tip of the wire 11 is connected to this wire attachment portion 31 . In this embodiment, similar to the pipe cutting jig 2, the two are connected by screwing.

Next, we will explain the piping renewal method. The piping renewal method of this embodiment includes a grooving process, an existing piping division process, and a new piping insertion process. Hereinafter, one set of winches 1 will be described as a right winch 1R and a left winch 1L according to the arrangement shown in FIGS. 4 to 6. Note that "left and right" in the following is 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 circumferential surface of the existing pipe Po. Prior to the grooving process, as shown in FIG. 4(a), the wire 11 and the jig connection part 12 attached to its tip are passed through the existing pipe Po from the right winch 1R (not shown). At this time, the wire 11 and the jig connection part 12 are pushed from the right side in the figure to the left side by the operator's hands, and are taken out from the left end in the figure of the existing piping Po.

FIG. 4(b) 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 connection part 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 it is attached to the pipe cutting jig 2, the blades 41 at both ends are detachable from the pipe cutting jig 2. and protrudes radially outward. In this state, the right winch 1R is operated to move the pipe cutting jig 2 from the left end of the existing pipe Po to the right end of the existing pipe Po so that the blade 41 of the first cutter 4A comes into contact with the inner surface of the existing pipe Po. Here, as shown in FIG. 3(a), since both ends in the longitudinal direction of the pipe cutting jig 2 have a reduced diameter, the pipe cutting jig 2 can be easily inserted into the existing pipe Po. In addition, as described above, since the external dimensions of the large diameter part on the longitudinal center side of the pipe cutting jig 2 are smaller than the inner diameter of the existing pipe Po, the pipe cutting jig 2 is less susceptible to resistance from the existing pipe Po, and the existing pipe Po can be easily moved from the left end in the figure to the right end in the figure. As a result, as shown in FIG. 4(c), two radially opposing grooves S are formed in the inner peripheral portion of the existing pipe Po.

FIG. 4(d) shows the second stage of the grooving process. Two first blades 4A are attached to the pipe cutting jig 2 so as to be perpendicular to each other when viewed in the axial direction. The direction of the first cutter 4A is reversed from the first stage. Note that the orientation of the blade 4 may be changed by changing the orientation of the pipe cutting jig 2 to which the blade 4 is attached, or by changing the orientation of the blade 4 attached to the blade attachment portion 22. 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 in the figure of the existing pipe Po to the left end in the figure. At this time, one of the first blades 4A is placed along the groove S formed in the first step. In other words, one of the first blades 4A does not actively cut the existing pipe Po in this second stage, and the pipe cutting jig 2 (in particular, the other first blade 4A installed) It functions as a "guide" to prevent the pipe from shifting in the circumferential direction with respect to the existing pipe Po. 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 shifted by 90 degrees in the circumferential direction with respect to the groove S formed in the first step. let As a result, as shown in FIG. 4(e), four grooves S are formed at intervals of 90 degrees in the circumferential direction on the inner circumference of the existing pipe Po. As described above, by causing one of the first blades 4A to function as a "guide", the four grooves S can be reliably formed.

FIG. 5(a) shows the third stage of the grooving process. One second blade 4B is attached to the pipe cutting jig 2. The amount of protrusion of the blade 41 in the radial direction of the second blade 4B is larger than that of the first blade 4A. In this state, operate the right winch 1R, align the blade 41 of the second cutter 4B along the groove S formed in the first or second step, and move the pipe cutting jig 2 from the left end of the existing pipe Po to the right end of the diagram. move it to. As a result, as shown in FIG. 5(b), the two grooves S facing each other in the radial direction become deeper.

FIG. 5(c) shows the fourth stage of the grooving process. Also here, one second blade 4B is attached to the pipe cutting jig 2. The direction of the second cutter 4B is reversed from the third stage. In this state, operate the left winch 1L and move the pipe cutting jig 2 from the right end of the existing pipe Po while aligning the blade of the second cutter 4B along a groove S different from the groove S along which it was aligned in the third stage. Move it to the left end in the illustration. As a result, as shown in FIG. 5(d), the two radially opposing grooves S, which are the other grooves S, become deeper. The grooving process is now complete. In the above-mentioned grooving process, some of the grooves S are formed first, and the remaining grooves S are formed using the grooves S as a guide, so that the intervals between the plurality of grooves are adjusted as a guide. It can be made constant in the direction. Further, by dividing the formation of the groove S into multiple stages and gradually deepening the groove S, it is possible to reduce machining resistance and form a straight groove in the axial direction. With the groove S formed in the existing pipe Po by the above grooving process, by using the groove S as a guide and cutting the existing pipe Po in the existing pipe dividing process described below, cutting fails in the existing pipe dividing process. (For example, the width of the cut piece Ps becomes narrow in the middle of the longitudinal direction and is cut), and reliable cutting in the tube axis direction is possible. Furthermore, in the existing pipe dividing process described below, cutting along the groove S can reduce the resistance during cutting.

In the existing pipe dividing step, the existing pipe Po is divided into a plurality of cut pieces Ps by cutting in the radial direction and the pipe axis direction. In this embodiment, cuts in the radial direction and the tube axis direction are made at multiple locations (four locations) at a constant distance (every 90 degrees) in the circumferential direction, and these cuts are made continuously in the tube axis direction. It will be done.

FIG. 5(e) shows the existing pipe division process. Two third blades 4C are attached to the pipe cutting jig 2. The amount of protrusion of the blade 41 in the radial direction of the third blade 4C is larger than that of the second blade 4B. In this state, operate the right winch 1R and move the pipe cutting jig 2 to the existing pipe Po while aligning the blade 41 of the third cutter 4C along the groove S that has become deeper through the third and fourth stages of the grooving process. from the left end of the figure to the right end of 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 (divided into four in FIG. 5(f)). Furthermore, in the existing pipe dividing step, the cutting resistance can be reduced by placing the blade 41 along the plurality of grooves S formed in the grooving step. Furthermore, in this embodiment, by dividing the existing pipe into a plurality of pieces at regular intervals in the circumferential direction, the shapes of the cut pieces Ps can be made substantially the same. Therefore, the insertion resistance when inserting the new pipe can be made uniform in the circumferential direction, making it easier to insert the new pipe Pn straight.

In the new pipe insertion process, the new pipe Pn is passed through the protective material G and the inside of the existing pipe Po while being aligned with the inner peripheral surface of the existing pipe Po. Prior to the new pipe insertion process, in the existing pipe division process, a jig connection part 12 and a pipe cutting jig 2 were installed at the tip of the wire 11 passed from the left winch 1L into the protective material G and the existing pipe Po. Disconnect from. Next, a new pipe Pn is prepared on the right side of the protective material G and the existing pipe Po in the figure. The pipe insertion jig 3 is fixed to the left end of the new pipe Pn, and as shown in FIG. Connect via. Thereby, preparations for inserting the new pipe Pn can be made efficiently. Then, by operating the left winch 1L and pulling the new pipe Pn, the new pipe Pn is passed through the inside of the protective material G and the existing pipe Po. By passing the new piping Pn through the protective material G and existing piping Po by pulling, it is more likely to get caught even in bent parts of the protective material G and existing piping Po, compared to passing the new piping Pn by pushing. It is possible to pass the new pipe Pn while suppressing the damage. FIGS. 6(b) and 6(c) show the state in which the pipe insertion jig 3 is removed from the new pipe Pn. This completes the piping update, and then connects both ends to the water heater and faucet to complete the work.

In this embodiment, the outer diameter of the new pipe Pn is the same as or slightly larger than the inner diameter of the existing pipe Po. Therefore, in the new pipe insertion process, the new pipe Pn is inserted into the existing pipe Po while pushing the plurality of cut pieces Ps outward in the radial direction. Here, as mentioned above, since the protective material G is made of a flexible material (for example, foamed resin, etc.), when the protective material G is pushed out, the inner diameter of the protective material G is radially outwardly moved by the cut piece Ps. Being pushed out. That is, a new pipe Pn whose outer diameter is the same as or slightly larger than the inner diameter of the existing pipe Po is inserted into the existing pipe Po with the protective material G made of a flexible material and the existing pipe Po divided into a plurality of cut pieces Ps. Then, while holding the divided existing pipe Po in a tubular shape with the protective material G, the inner diameter of the flexible protective material G deforms and absorbs the pushing and spreading due to the insertion of the new pipe Pn. The pipe Pn can be inserted smoothly while being firmly guided by the protective material G and the existing pipe Po. Furthermore, if the protective material G is flexible, even when the new pipe Pn passes through the part fixed to the foundation B by the band I (the part compressed and reduced in diameter by tightening the band I), By deforming the inner diameter of the protective material G, insertion resistance can be alleviated.

In the construction method of this embodiment, work can be carried out at the ends of the existing piping Po and the protective material G exposed to the outside of the building C. For this reason, the work of updating the existing piping Po to the new piping Pn is performed without removing the existing piping Po and the protective material G from the installation target of the existing piping Po (in this embodiment, the foundation B of the building C and the flooring F). It can be done in the state. In addition, the operation of each winch 1 and the insertion of the new pipe Pn into the existing pipe Po and the protective material G are performed outside the building C (more specifically, outside the closed space between the flooring F and the foundation B in the building C). ). Therefore, there is no need to demolish building C, which can contribute to lower construction costs.

As described above, according to the piping renewal method of this embodiment, the existing piping Po and the protective material G remain fixed to the building C, and the existing piping Po and the protective material G are used as a guide when laying the new piping Pn. Available. Furthermore, the existing piping division process and the new piping insertion process eliminate the need to pull out the existing piping Po, making it easy to update the piping without being affected by the installed shape of the piping.

Further, when updating the piping, it is unnecessary to dismantle the building C as much as possible, and there is no need to take special consideration when installing new piping. This "extraordinary consideration" means consideration beyond the minimum consideration of not forming sharp bends that could cause pipe breakage. In this way, by adopting the piping renewal method of this embodiment, the piping route can be set roughly when installing new piping, and when new piping is installed, the new piping can be connected to the existing piping Po and protective material G at the site. Since it is not necessary to test whether the pipe can be inserted or removed, the number of man-hours required when installing new piping does not increase compared to the conventional method.

Further, in a pipe processing tool that includes a main body having a pipe cutting jig 2 and a cutter 4 as a processing means, and a jig connection part 12 that connects this main body to the wire 11, the pipe cutting jig 2 and the cutter 4 are provided. However, different machining can be performed depending on the case where the existing pipe Po is entered from one end in the axial direction and processed, and the case where the existing pipe Po is entered and processed from the other end in the axial direction. Specifically, changes can be made by changing the direction of the blade 41 at each stage of the grooving process or in the process of cutting existing pipes, or by changing the type of each blade 4A to 4C to the pipe cutting jig 2. By doing this, there are two cases: one end of the pipe cutting jig 2 enters first from the inlet to the outlet of the existing pipe Po, and the other end of the pipe cutting jig 2 enters first from the exit of the existing pipe Po to the inlet. Since different processing can be performed depending on the case of double movement, the existing piping Po can be processed efficiently.

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

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

Further, although the winch 1 is used in the above embodiment, various devices capable of pulling cable-like materials such as wires and chains in the longitudinal direction may be used even if the device does not correspond to a winch (winding machine). I can do it.

Furthermore, in this embodiment, a pipe cutting jig 2 is provided between the end of the wire 11 of one winch (right winch 1R) and the end of the wire 11 of the other winch (left winch 1L). Although a case has been described in which the groove forming process and the existing pipe dividing process are performed by connecting the pipes, the present invention is not limited thereto. 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. This eliminates the need to use the jig connection part 12 attached to the tip of the wire 11, allowing efficient preparation. Also, one side winch is provided on one end side of one wire, the other side winch is provided on the other end side, and the pipe cutting jig 2 is connected to the middle part of the wire. A winch may be provided for each, and the wire may be passed 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 be able to pass through the inside of the existing pipe Po. Therefore, the pipe cutting jig 2 is moved back and forth 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 cylindrical shape in the above embodiment, it can move in the pipe axis direction within the existing pipe Po without any hindrance, and can support the blade 4 for cutting the existing pipe Po. Other shapes may be used if possible. Further, the blade 4 attached to the pipe cutting jig 2 may be either a fixed blade or a rotating blade. Further, the shape of the blade 41 is not particularly limited either. In the embodiment, the blade 41 can cut in one direction along the tube axis, but the blade 41 can cut in both directions along the tube axis. Thereby, the grooving process or the existing pipe dividing process can be performed without changing the orientation of the cutter 4 described above, so that the pipe renewal method of this embodiment can be performed efficiently.

Further, the number of stages and processing contents regarding the stages in the grooving process are not limited to those shown in the above embodiment (1st stage to 4th stage), but can be changed in various ways. Furthermore, the grooving process can also be omitted. That is, in the existing pipe dividing process, it is also possible to cut the existing pipe Po without performing any prior processing on the inner circumferential surface of the existing pipe Po. In this case, there is an advantage that a series of steps can be shortened by performing the existing pipe dividing step without performing any prior processing.

Furthermore, in the present embodiment, in the existing pipe dividing process, a case has been described in which the existing pipe is cut along the groove S formed in the grooving process, but the present invention is not limited to this. Alternatively, the blade 41 of the second blade 4B may be fitted and used as a guide to cut the 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, it is possible to reliably divide the existing pipe Po without failure in cutting.

Furthermore, some of the cut pieces Ps among the plurality of cut pieces Ps within the protective material G may be pulled out from the protective material G prior to the new pipe insertion step. In this case, by pulling out some of the cut pieces Ps from the protective material G, the inside of the protective material G can be enlarged, so that a new pipe Pn can be inserted using that size.

Further, the number of divisions of the existing pipe Po through the grooving process and the existing pipe dividing process is not limited to four divisions as in the above embodiment, but may be three or less divisions, or five divisions or more. In particular, the number of divisions may be determined as appropriate depending on the diameter and length of the existing pipe Po. Moreover, a spiral cut piece Ps may be formed by inclining the cutting locus with respect to the tube axis direction.

1...Winch, 1R...Right winch, 1L...Left winch, 11...Cable body, wire, 12...Jig connection part, 121...Bearing, 2...Piping cutting jig, 21...Wire attachment part, 22...Blade attachment Part, 221...Threaded hole for cutter, 222...Threaded hole, 3...Piping insertion jig, 31...Wire attachment part, 4...Cuttle, 4A...First cutter, 4B...Second cutter, 4C...Third cutter, 41 ...Blade, 42...Mounting hole, C...Building, Po...Existing pipe, Pn...New pipe, Ps...Cut piece, S...Groove, G...Protective material, V...Bathroom faucet, F...Floor material, B ...Basic, I...Band

Claims (6)

A piping renewal method when replacing existing piping covered with a tubular protective material with new piping,
a grooving step of forming a groove along the pipe axis direction on the inner circumferential surface of the existing pipe;
an existing pipe dividing step of dividing the existing pipe into a plurality of cut pieces by cutting the existing pipe in the radial direction and the pipe axis direction;
New piping in which the new piping is passed through the protective material and the existing piping while being aligned along the inner peripheral surface of the existing piping without removing the protective material and the existing piping from the object to which the existing piping is installed. an insertion process;
It is a construction method that includes
Two winches capable of winding up the cord are used, and one of the two winches is placed at one end of the existing piping and the protection material, and the other one of the two winches is placed at one end of the existing piping and the protection material. one other side winch is arranged at the other side end of the existing piping and the protective material,
A pipe cutting jig is connected to the cable-like body of the one side winch and the cable-like body of the other side winch so as to be able to pass through the inside of the existing pipe,
By alternately operating the winch on one side and the winch on the other side, the pipe cutting jig can be reciprocated with respect to the existing pipe, and with this reciprocating movement, the grooving process and the dividing of the existing pipe are performed. A piping renewal method characterized by the following steps : A piping renewal method when replacing existing piping covered with a tubular protective material with new piping,
an existing pipe dividing step of dividing the existing pipe into a plurality of cut pieces by cutting the existing pipe in the radial direction and the pipe axis direction without cutting the protective material covering the existing pipe;
The new pipe is passed through the protective material and the inside of the existing pipe while following the inner peripheral surface of the existing pipe without removing the uncut protective material from the object to be installed of the existing pipe. Piping insertion process,
A piping renewal method characterized by including. prior to the existing pipe dividing step, including a grooving step of forming a groove along the pipe axis direction on the inner circumferential surface of the existing pipe,
3. The piping renewal method according to claim 2 , wherein in the existing piping dividing step, the existing piping is cut using the grooves formed in the grooving step as a guide. 3. The piping renewal method according to claim 2 , wherein in the existing piping dividing step, the cutting is performed without performing any prior processing on the inner circumferential surface of the existing piping. The piping renewal according to any one of claims 2 to 4 , wherein the existing piping dividing step and the new piping insertion step are performed at an end where the existing piping and the protective material are exposed to the outside of the building. Construction method. Two winches capable of winding up the cord are used, and one of the two winches is placed at one end of the existing piping and the protection material, and the other one of the two winches is placed at one end of the existing piping and the protection material. one other side winch is arranged at the other side end of the existing piping and the protective material,
A pipe cutting jig is connected to the cable-like body of the one side winch and the cable-like body of the other side winch so as to be able to pass through the inside of the existing pipe,
By alternately operating the winch on one side and the winch on the other side, the pipe cutting jig can be reciprocated with respect to the existing pipe, and with this reciprocating movement, the grooving process and the dividing of the existing pipe are performed. The piping renewal construction method according to claim 3 , wherein the step is performed.