Pipe connection structure and pipe connection method

Abstract

The object of the present invention is to solve the problems of the prior art, namely, to provide a pipe connection structure and a pipe connection method that can connect two pipes more easily and in a shorter time compared to the prior art. [Solution] The pipe connection structure of the present invention is a structure for connecting two pipes that are butted together, and comprises two or more divided fitting bodies. Multiple circumferential grooves are formed on the outer circumferential surface of the end of each pipe, aligned in the direction of the pipe axis, and multiple protrusions are formed on the inner circumferential surface of the divided fitting body. The two pipes are butted together, and then the two or more divided fitting bodies are placed over them so that the protrusions fit into the circumferential groove of one pipe and the circumferential groove of the other pipe, thereby connecting the two pipes.

Description

Technical Field

[0001] The present invention relates to a joint for a pipeline that houses, for example, a power cable. More specifically, it relates to a pipe connection structure that can easily connect two pipes compared to the prior art, and a method for connecting pipes using the same.

Background Art

[0002] Electricity of several thousand to several tens of thousands of volts is generated at power plants. However, in order to avoid losses due to electrical resistance, it is transmitted at an ultra-high voltage of about several hundred thousand volts. Then, the voltage is gradually reduced at each substation such as an ultra-high voltage substation, a primary substation, a secondary substation, and a distribution substation, and then supplied to factories and the like. Further, the voltage is reduced by a pole-mounted transformer or the like and supplied to households. In any case, the electricity generated at the power plant is supplied to users via transmission lines and distribution lines (hereinafter, these are collectively referred to as "power cables"), and naturally, a huge amount of power cables are wired throughout the country.

[0003] Conventionally, it has been the mainstream to string power cables on power poles. However, in recent years, the undergrounding of power cables has been promoted. For example, according to "Tokyo Electric Power (Tokyo Electric Power Holdings Co., Ltd.) as seen in numbers", 48.0% has been undergrounded within the Tokyo metropolitan area, and among them, up to 88.7% has been undergrounded in some parts of Chuo-ku, Chiyoda-ku, and Minato-ku. However, when looking at the country as a whole, the undergrounded section is still only 6.0% (both as of 2022), and currently, the power cables strung on power poles still account for the majority.

[0004] Burying power cables underground not only improves the urban landscape, but also allows for wider sidewalks due to the removal of power poles, making it safer for strollers and wheelchairs. Furthermore, it prevents power poles from falling or power cables from sagging and blocking roads during disasters such as typhoons and earthquakes, allowing emergency vehicles to pass more smoothly. In addition, the risk of power cables being severed during disasters is reduced, thus suppressing power outages and ensuring a stable supply of electricity. For these reasons, it is expected that the undergrounding of power cables will be further promoted in the future.

[0005] Typically, when burying power cables underground, conduits to house the cables are buried. To bury these conduits, the open-cut method is sometimes employed, which involves excavating from the surface while using retaining walls, laying the conduits in the resulting space, and then backfilling the site. Alternatively, a trenchless method may be used, where drilling machines are used to bore holes into the ground, and the conduits are inserted into these holes. While this trenchless method requires the procurement of drilling equipment, it is superior to the open-cut method in terms of environmental protection because it requires less excavation (and therefore less soil removal), and it is also a superior method in terms of safety because it avoids accidents such as falls and retaining wall collapses.

[0006] The horizontal directional drilling method (HDD method) is widely used as a trenchless method for burying pipelines. The HDD method will be briefly explained below with reference to Figure 8. First, as shown in Figure 8(a), a drilling machine (drill machine BM) is installed on the launching side, and this drill machine BM is used to form a pilot hole. Specifically, while spraying slurry (bentonite) to protect the hole wall, the ground is drilled with a bit attached to the tip of the drill rod RD. At this time, a worker on the ground detects the position of the bit with a locator LC, which allows the pipeline to be advanced according to the plan while avoiding existing buried objects.

[0007] Once the pilot hole is formed, as shown in Figure 8(b), an enlargement jig (reamer RM) is attached to the tip of the drill rod RD, and the pilot hole is enlarged using this reamer RM. Then, using the enlarged underground hole, the pipe material PE placed on the receiving side is pulled towards the launching side, as shown in Figure 8(c). The pipe material PE is made of a material that is easily deformable to accommodate the curves of the underground hole, such as polyethylene. When laying a three-wire power cable, the three pipe materials PE are bundled together with binding wire or similar before being pulled into the underground hole.

[0008] By the way, the stroke length per pass when the drill machine BM pulls in polyethylene pipe (PE) is limited. Therefore, it is usually pulled in while connecting PE pipes of a length that matches this stroke length (for example, about 6m). Traditionally, "BF (butt fusion) joining" was used to connect polyethylene pipes (PE). Although this BF joining method ensures that the PE pipes are reliably connected on-site, it requires numerous steps such as cleaning the connection surface of the PE pipes, installing a heating device, heating with the heating device, removing the heating device, crimping and cooling the PE pipes, and bead treatment inside and outside the PE pipes, so the work time per pass was about 30 minutes. On the other hand, it only takes a few minutes for the drill machine BM to prepare for the next pulling operation (so-called setup change) after pulling in just one stroke. Therefore, there is a so-called "play" on the drill machine BM side, making the overall process inefficient.

[0009] Therefore, efforts have been made to shorten the time required to connect PE pipes. For example, Patent Document 1 proposes a technique for connecting resin pipes with flanges at their ends using a connecting device such as a clamp. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2024-61833 [Overview of the project] [Problems that the invention aims to solve]

[0011] The following describes the procedure for connecting resin pipes using the technology disclosed in Patent Document 1. First, with the flat flanges 1a and 2a of both resin pipes 1 and 2 butted together, the engaging projection 25 of the upper split body 10 is inserted into the engaging hole 16 of the lower split body 20. Next, the upper split body 10 is rotated relative to the lower split body 20 to achieve the correct position. Then, the upper split body 10 is fixed to the lower split body 20 by screwing a bolt 31 onto a nut 32 housed in an anti-rotation projection 29. Thus, according to the technology of Patent Document 1, an extremely complicated and delicate procedure is required, and it is conceivable that it may take a considerable amount of time depending on the worker.

[0012] However, using conventional techniques for BF fusion of resin pipes on-site would require a considerable amount of time, as mentioned above. Moreover, since the quality of the joints formed by BF fusion varies depending on the skill level of the workers, there are problems such as the difficulty in securing specific workers and the occurrence of defective products.

[0013] The object of the present invention is to solve the problems of the prior art, namely, to provide a pipe connection structure and a pipe connection method that can connect two pipes more easily and in a shorter time compared to the prior art. [Means for solving the problem]

[0014] The present invention focuses on the fact that two butted pipes are connected by fitting together a circumferential groove provided on the outer surface of the pipe material with a projection provided on the inner surface of the split fitting, without using BF fusion bonding, and is based on an unprecedented idea.

[0015] The pipe connection structure of the present invention is a structure for connecting two butted pipes, and comprises two or more segmented fitting bodies. Multiple circumferential grooves are formed on the outer circumferential surface of the end of each pipe, aligned in the direction of the pipe axis, and multiple projections are formed on the inner circumferential surface of the segmented fitting body. The two pipes are then butted together, and the two or more segmented fitting bodies are placed over them so that the projections fit into the circumferential grooves of one pipe and the other pipe, respectively, thereby connecting the two pipes.

[0016] The pipe connection structure of the present invention may further include a sleeve. This sleeve is cylindrical and is fitted onto two or more segmented fitting bodies, which are arranged so that projections fit into circumferential grooves.

[0017] The pipe connection structure of the present invention may further include a guide tube positioned inside the pipe. In this case, the two pipes can be butted together by inserting the guide tube attached to one pipe into the other pipe.

[0018] The pipe connection method of the present invention is a method for connecting two pipes using the pipe connection structure of the present invention, and comprises a pipe arrangement step and a divided fitting installation step. In the pipe arrangement step, the two pipes are placed butt against each other. In the divided fitting installation step, two or more divided fittings are placed over the circumferential grooves of one pipe and the circumferential grooves of the other pipe, respectively, so that their projections fit into each other. The two pipes are then connected by the installation of the divided fittings.

[0019] The pipe connection method of the present invention may further include a sleeve temporary placement step and a sleeve installation step. In the sleeve temporary placement step, a cylindrical sleeve is fitted onto one of the pipes. In the sleeve installation step, after the divided fitting installation step, the sleeve is moved along the pipe to fit onto two or more divided fittings. [Effects of the Invention]

[0020] The pipe connection structure and pipe connection method of the present invention have the following effects. (1) Compared with the prior art, the pipes can be connected easily and in a short time. (2) Since the pipes can be connected in approximately the same time as the setup change on the drill machine side, the "slack" on the drill machine side is eliminated, that is, the overall process becomes extremely efficient. (3) Since it does not depend on the proficiency or skills of the operator, there is no need to secure a specific operator, and moreover, it can be surely connected while ensuring good quality.

Brief Description of the Drawings

[0021] [Figure 1] Side view schematically showing the pipe targeted by the pipe connection structure of the present invention. [Figure 2] (a) is a partial perspective view showing the end of the main body pipe, and (b) is a longitudinal sectional view schematically showing the guide cylinder at the pipe connection part. [Figure 3] (a) is a perspective view showing two split fitting bodies, and (b) is a perspective view showing a split fitting body arranged to cover the circumferential groove part. [Figure 4] Longitudinal sectional view schematically showing the situation where the split fitting body is installed at the joint of two pipes. [Figure 5] Longitudinal sectional view schematically showing the sleeve constituting the pipe connection structure of the present invention. [Figure 6] Flow chart showing the main process flow of laying the pipe in the ground while connecting the pipe using the pipe connection structure of the present invention. [Figure 7] Step diagram showing each step of connecting the pipe using the pipe connection structure of the present invention. [Figure 8] Step diagram showing the procedure for laying the pipe by the HDD method.

Modes for Carrying Out the Invention

[0022] An example of an embodiment of the pipe connection structure and pipe connection method of the present invention will be described with reference to the figures. Although the present invention can be used when connecting various tubular members (hereinafter simply referred to as "pipes"), for convenience, the example of a pipe buried underground to house power cables will be described here.

[0023] 1.Pipe connection structure First, the pipe connection structure of the present invention will be explained in detail with reference to the diagrams. The pipe connection method of the present invention is a method of connecting pipes using the pipe connection structure of the present invention. Therefore, the pipe connection structure of the present invention will be explained first, followed by a detailed explanation of the pipe connection method of the present invention.

[0024] Figure 1 is a schematic side view showing the pipe 100 targeted by the pipe connection structure of the present invention. As shown in this figure, the pipe 100 targeted by the pipe connection structure of the present invention is composed of a main pipe 110 and a circumferential groove 120 provided on the outer surface of its end, and can be, for example, a hollow tubular shape with a circular cross-section. In this embodiment, since the pipe 100 is buried underground to house power cables, it is preferable to use one made of easily deformable polyethylene so as to be compatible with the HDD construction method described above. Of course, the pipe 100 is not limited to polyethylene, but can also be made of various materials such as other resins or steel.

[0025] The pipe connection structure of the present invention connects two pipes 100 by butting them together. To distinguish between the two pipes 100, one pipe 100 will be referred to as "left pipe 100L" and the other as "right pipe 100R". Similarly, the main pipe 110 and circumferential groove 120 of the left pipe 100L will be referred to as "left main pipe 110L" and "left circumferential groove 120L", respectively, and the main pipe 110 and circumferential groove 120 of the right pipe 100R will be referred to as "right main pipe 110R" and "right circumferential groove 120R", respectively. Furthermore, as shown in Figure 1, the longitudinal direction passing through the center of the cross-section of the pipe 100 will be referred to as the "pipe axis direction". The main elements constituting the pipe connection structure of the present invention will be described below.

[0026] (Circumferential groove and guide tube) Figure 2(a) is a partial perspective view showing the end of the pipe material 100. As shown in this figure, multiple circumferential grooves 120 are formed on the outer circumferential surface of the end of the main pipe 110. These circumferential grooves 120 are recessed grooves from the surface of the main pipe 110, and when viewed from the front (viewed in the direction of the pipe axis), they have a shape (for example, circular) that follows the outer circumference of the main pipe 110. The multiple circumferential grooves 120 are formed to be aligned along the direction of the pipe axis and arranged approximately parallel (including parallel).

[0027] The circumferential groove 120 can be formed by directly cutting the outer surface of the main pipe 110, or by fixing a short pipe (hereinafter referred to as "grooved short pipe") with the circumferential groove 120 on its outer surface to the end of the main pipe 110. BF jointing can be used to fix the separately manufactured grooved short pipe to the end of the main pipe 110. In this case, the work can be carried out in advance at the factory rather than on-site, ensuring quality and not affecting on-site work time. Of course, the short pipe can be fixed to the main pipe 110 using various conventional methods, not limited to BF jointing, such as socket jointing, flange jointing, adhesive jointing, and screw jointing.

[0028] A guide tube 130 can also be attached to the end of the main pipe 110. This guide tube 130 is a short, cylindrical member with the same cross-sectional shape (for example, circular) as the main pipe 110. The guide tube 130 is installed such that approximately half of its total length in the axial direction of the pipe is housed within the main pipe 110, and the remaining half protrudes from the main pipe 110. For example, if a guide tube 130 is attached to the end of the left pipe member 100L, the left pipe member 100L and the right pipe member 100R can be properly butted together simply by inserting the protruding part of the guide tube 130 into the right pipe member 100R. Therefore, focusing on the connection between the two pipe members 100, if a guide tube 130 is provided on one pipe member 100 (for example, the left pipe member 100L), then a guide tube 130 is not provided on the other pipe member 100 (for example, the right pipe member 100R).

[0029] By the way, when a power cable is housed inside the pipe 100 as in this embodiment, it is preferable that the internal cross-section be wide, and it is desirable that the inner circumferential surface be a uniform continuous surface without any steps or other unevenness. Figure 2(b) is a schematic diagram showing the guide tube 130 at the connection part of the pipe 100, and is a longitudinal cross-sectional view taken from a plane in the direction of the pipe axis. As shown in this figure, the tip of the left main pipe 110L (right end in the figure) has a portion where the pipe wall is notched in the thickness direction (hereinafter referred to as "notch portion 140"), and the guide tube 130 is housed in the notch portion 140 before being installed. This notch portion 140 is a recess formed in a band shape along the inner circumference of the pipe 100. In this way, even when the guide tube 130 is installed, the effect of housing the guide tube 130 in the notch portion 140 ensures that the original internal cross-section of the main pipe 110 is secured, and the inner circumferential surfaces of the main pipe 110 and the guide tube 130 are flush. The guide tube 130 can be attached simply by fitting it into the notched portion of the main tube 110, or it can be further secured using adhesive, screws, or the like.

[0030] As shown in Figure 2(b), a notch 140 is also formed at the tip of the right main tube 110R (the left end in the figure). When the protruding part of the guide tube 130 is inserted into the right main tube 110R, the guide tube 130 is accommodated in the notch 140 of the right main tube 110R. As a result, even when the guide tube 130 is inserted, the original internal cross-section of the main tube 110 is maintained, and the inner surfaces of the main tube 110 and the guide tube 130 are flush.

[0031] (Divided interlocking body) Figure 3 shows a divided fitting body 200 that constitutes the pipe connection structure of the present invention, where (a) is a perspective view showing two divided fitting bodies 200 and (b) is a perspective view showing a divided fitting body 200 that is positioned to cover the circumferential groove 120 portion of the pipe material 100. As previously described, the pipe connection structure of the present invention is composed of two or more divided fitting bodies 200, and the two or more divided fitting bodies 200 can cover all (or part) of the outer circumferential surface of the main pipe 110. In other words, each divided fitting body 200 is formed by dividing a cylindrical member, which has the same cross-sectional shape as the main pipe 110, into two or more parts in the cross-sectional direction. For example, the two divided fitting bodies 200 shown in Figure 3(a) are semicircular in shape when viewed from the front (viewed in the direction of the pipe axis), meaning that the two divided fitting bodies 200 are configured to cover the entire circumference of the main pipe 110, which has a circular cross-section. Of course, the pipe connection structure of the present invention can be composed of two divided fittings 200 as shown in Figure 3(a), or it can be composed of three or more divided fittings 200.

[0032] Furthermore, the divided fitting body 200 has multiple protrusions 210 formed on its inner circumferential surface. These protrusions 210 protrude convexly from the inner circumferential surface of the divided fitting body 200 and are fitted into the circumferential groove 120 of the main pipe 110. Therefore, the multiple protrusions 210 are formed to be aligned along the pipe axis, similar to the circumferential groove 120, and to be arranged substantially parallel (including parallel).

[0033] Figure 4 is a schematic longitudinal cross-sectional view showing how the split fitting body 200 is installed at the joint of two butted pipes 100. As shown in this figure, the split fitting body 200 is installed so as to straddle the left pipe 100L and the right pipe 100R when the left pipe 100L and the right pipe 100R are butted together, that is, when the left circumferential groove 120L and the right circumferential groove 120R are continuous. Therefore, the projections 210 of the split fitting body 200 are formed in an arrangement and number (number of left circumferential grooves 120L + number of right circumferential grooves 120R) that corresponds to the left circumferential groove 120L and the right circumferential groove 120R. Furthermore, it is preferable that the dimensions of the split fitting body 200 in the axial direction of the pipe are longer than or approximately equal to the length of the continuous left circumferential groove 120L and the right circumferential groove 120R.

[0034] As shown in Figure 4, when the divided fitting body 200 is placed over the pipe member 100 so that the continuous left circumferential groove 120L and right circumferential groove 120R engage with the projection 210, that is, so that it straddles the left pipe member 100L and the right pipe member 100R, the left pipe member 100L and the right pipe member 100R are connected. At this time, the divided fitting body 200 can be installed from various directions. For example, when installing a two-part divided fitting body 200, it can be installed by covering it from above and below, or by covering it from the side.

[0035] Due to the fitting effect between the circumferential groove 120 and the projection 210, the divided fitting body 200 will not detach from the pipe material 100 even if it is simply placed over the pipe material 100, that is, the connection between the left pipe material 100L and the right pipe material 100R is maintained. To install the divided fitting body 200 more securely, two or more divided fitting bodies 200 installed on the pipe material 100 can be fastened together using binding wire, connected using tape, or fixed using screws, for example. Alternatively, the circumferential groove 120 can be made of metal and a magnet can be attached to a part of the divided fitting body 200 (or vice versa), allowing two or more divided fitting bodies 200 to be installed on the pipe material 100 by magnetic force.

[0036] (sleeve) To securely install the segmented fittings 200, or in other words, to prevent the installed two or more segmented fittings 200 from detaching from the pipe material 100, in addition to the methods described above, the sleeve 300 shown in Figure 5 can be used. This sleeve 300 is a short, cylindrical member with the same cross-sectional shape (for example, circular) as the main pipe 110, and is fitted onto the two or more segmented fittings 200 installed on the pipe material 100. Therefore, the inner diameter of the sleeve 300 is set to a size that can accommodate the two or more segmented fittings 200. By having the fitted sleeve 300 accommodate the two or more segmented fittings 200, it is possible to prevent the installed two or more segmented fittings 200 from detaching from the pipe material 100. Furthermore, it is also possible to use flat screws or bolts to screw and join the fitted sleeve 300 and the two or more segmented fittings 200.

[0037] When externalizing the sleeve 300 onto the split fitting 200, it is best to slide the sleeve 300 along the pipe 100 (i.e., in the direction of the pipe axis). In other words, after butting the left pipe 100L and the right pipe 100R together, the two-part split fitting 200 is placed over them in the circumferential groove 120, which moves the sleeve 300 from the right pipe 100R (or left pipe 100L) to the position of the split fitting 200. Therefore, it is best to insert the sleeve 300 through the right pipe 100R (or left pipe 100L) beforehand, and then butt the left pipe 100L and the right pipe 100R together.

[0038] For example, when a pipe 100 is pulled into a borehole using the HDD method, the sleeve 300 connecting the pipe 100 will also move within the borehole. Since the sleeve 300 is slightly larger in diameter than the pipe 100, it is possible that the sleeve 300 may hinder the smooth movement within the borehole. Therefore, it is advisable to provide tapered sections TP at both ends of the sleeve 300, as shown in Figure 5. These tapered sections TP are shaped to be inclined so as to decrease in diameter towards the end in the direction of the pipe axis, thereby allowing the sleeve 300 to move smoothly within the borehole.

[0039] (modified version) Up to this point, the pipe connection structure of the present invention has been described in an example that includes two or more divided fitting bodies 200, but the pipe connection structure of the present invention can also include a short, cylindrical "fitting body". In this case, a helical screw groove (so-called female screw) is formed on the outer circumferential surface of the end of the main pipe 110, and a helical screw thread (so-called male screw) is formed on the inner circumferential surface of the fitting body. When the left pipe 100L and the right pipe 100R are butted together, that is, when the female screw of the left pipe 100L and the female screw of the right pipe 100R are continuous, the left pipe 100L and the right pipe 100R are connected by screwing the fitting body into these female screws. For this reason, it is preferable to insert the fitting body into the right pipe 100R (or left pipe 100L) in advance before butting the left pipe 100L and the right pipe 100R together.

[0040] 2.Pipe connection method Next, the pipe connection method will be explained in detail with reference to Figures 6 and 7. The pipe connection method of the present invention is a method of connecting pipes using the pipe connection structure described so far. Therefore, explanations that overlap with those described in the section on pipe connection structure will be avoided, and the explanation will mainly focus on aspects specific to the pipe connection method of the present invention. In other words, anything not described here is the same as what was explained in "1. Pipe Connection Structure".

[0041] Figure 6 is a flowchart showing the main steps involved in laying pipes 100 underground while connecting them using the pipe connection structure of the present invention. Figure 7 is a step diagram showing each step involved in connecting the pipes 100 using the pipe connection structure of the present invention. For convenience, the explanation here will use an example of laying pipes 100 using the HDD method.

[0042] As shown in Figure 6, first a pilot hole is formed using the drill machine BM (Step 10 in Figure 6), and then the pilot hole is enlarged using the reamer RM (Step 20 in Figure 6). Once the enlarged underground hole is formed, the pipe material 100 is drawn in one stroke at a time by the drill machine BM (Step 30 in Figure 6).

[0043] When one stroke's worth of pipe material 100 is drawn in, the drill machine BM is changed on the starting side, and the pipe material 100 is connected using the pipe material connection structure of the present invention on the receiving side (Step 50 in Figure 6). In connecting the pipe material 100, first, as shown in Figure 7(a), the sleeve 300 is fitted onto the right pipe material 100R in advance (Step 51 in Figure 6: Sleeve temporary placement process), and then the guide cylinder 130 attached to the left pipe material 100L is inserted into the right pipe material 100R (Step 52 in Figure 6), thereby bringing the left pipe material 100L and the right pipe material 100R together (Step 53 in Figure 6: Pipe material placement process).

[0044] As shown in Figure 7(b), when the left pipe 100L and the right pipe 100R are butted together, as shown in Figure 7(c), the split fitting body 200 is placed over the pipe 100 so that the continuous left circumferential groove 120L and right circumferential groove 120R engage with the projection 210 (Step 54 in Figure 6: Split fitting body installation process). Then, as shown in Figure 7(d), the sleeve 300 is moved along the pipe 100 to the position of the split fitting body 200, and the sleeve 300 is fitted onto two or more split fitting bodies 200 installed on the pipe 100 (Step 55 in Figure 6: Sleeve installation process). Once the sleeve 300 is fitted onto the split fitting body 200, the sleeve 300 and the split fitting body 200 are screwed together using a flat screw or the like (Step 56 in Figure 6).

[0045] Furthermore, when laying three power cables, that is, when laying three pipes 100 simultaneously, the series of procedures from Step 51 to Step 56 will be repeated three times. However, when the inventors actually tested this, the time required for these three repetitions was approximately the same as the time it takes to change the setup of the drill machine BM. In other words, it was confirmed that the "play" in the drill machine BM that occurred in the conventional technology is eliminated, and the overall process becomes extremely efficient.

[0046] Once the pipe 100 is connected, the drill machine BM pulls in another stroke of the pipe 100 (Step 30). When the pipe 100 is laid throughout the entire section (Yes in Step 40 of Figure 6), the work is completed; otherwise (No in Step 40 of Figure 6), the pipe 100 is connected again (Step 50). [Industrial applicability]

[0047] The pipe connection structure and pipe connection method of the present invention can be used when connecting various pipes, including pipes that house power cables. According to the present invention, power transmission lines and the like can be buried underground efficiently and safely, resulting in an improved urban landscape, safer use of strollers and wheelchairs, and stable electricity supply even during disasters. Considering these factors, the invention is not only industrially applicable but also has the potential to make a significant contribution to society. [Explanation of Symbols]

[0048] 100 (Pipe material covered by the present invention) 100L left pipe material 100R right pipe material 110 Main pipe 110L left main body tube 110R Right main body tube 120 Circumferential groove 120L left circumferential groove 120R Right circumferential groove 130 Guide Tube 140 Notch 200-part interlocking body 210 Protruding strip 300 sleeves BM Drill Machine LC Locator PE (conventional) pipe material RD Drill Rod RM Reamer TP tapered section

Claims

1. A structure that connects two butted pipes, Multiple circumferential grooves are formed on the outer surface of the end of the pipe material, aligned in the direction of the pipe axis. It comprises two or more segmented fitting bodies, each having multiple protrusions formed on its inner surface, Two pipes are connected by covering them with two or more of the segmented fitting bodies such that the projections fit into the circumferential grooves of one of the butted pipes and the circumferential grooves of the other pipe. A pipe connection structure characterized by the following features.

2. The two or more segmented fitting bodies, each having a projection that fits into the circumferential groove, are further provided with a cylindrical sleeve that is fitted onto the outside. The pipe connection structure according to claim 1.

3. The pipe further comprises a guide tube positioned inside the aforementioned pipe, When the guide tube attached to one of the aforementioned pipes is inserted into the other pipe, the two pipes are brought together. The pipe connection structure according to claim 1.

4. A method of connecting two pipes using a pipe connection structure, The pipe connection structure has two or more segmented fitting bodies, each having multiple protrusions formed on its inner surface. Multiple circumferential grooves are formed on the outer surface of the end of the pipe material, aligned in the direction of the pipe axis. A pipe arrangement step in which two of the aforementioned pipes are placed together, The process includes a step of installing a divided fitting body, in which two or more divided fitting bodies are placed over the circumferential groove of one of the butted pipe materials and the circumferential groove of the other pipe material, respectively, so that the protrusions fit into each other. The two pipe members are connected when the aforementioned split fitting is installed. A method for connecting pipes, characterized by the following features.

5. One of the steps involves a temporary sleeve placement step in which a cylindrical sleeve is fitted onto the aforementioned pipe material, The invention further comprises a sleeve installation step, in which, after the division fitting installation step, the sleeve is moved along the pipe material to externally fit the sleeve onto two or more division fittings, The pipe connection method according to feature 4.

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