Method for disassembling pipe joint and jig for disassembling pipe joint

Abstract

To provide a method for disassembling a pipe joint and a jig for disassembling a pipe joint which can smoothly perform work for disassembling a pipe joint even at a narrow part where it is hard to secure a sufficient work space.SOLUTION: In a method for disassembling a pipe joint, a pipe body insertion hole 7 is formed on a pipe outer surface of an inserting-side pipe body P2, then a jig 1 for disassembling a pipe joint is inserted into the pipe body insertion hole 7 and the jig 1 for disassembling a pipe joint is installed on the insertion-side piper body P2, an extending / contracting member 4 is intervened between the jig 1 for disassembling a pipe joint and a receiving-side pipe body P1, and the extending / contracting member 4 is extended along a pipe axis direction and then the inserting-side pipe body P2 is pulled out from the receiving-side pipe body P1 to dismantle a pipe joint. The jig 1 for disassembling the pipe joint is configured to comprise a base part 2 that acts as a reaction force receiver for the extending / contracting member 4 that applies pull-out force to the pipe joint, and an inserting member 3, provided to protrude from the base part 2, which is inserted into the pipe body insertion hole 7 formed on the pipe outer surfaces of the pipe bodies P1 and P2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pipe joint dismantling method and a pipe joint dismantling jig. [Background technology]

[0002] Cast iron pipes are mainly used for firefighting piping and water and sewerage pipes laid inside tunnels, and the pipelines are formed using a joint system in which the spigot of the spigot is inserted into the spigot of the receiving pipe. Recently, there has been an increase in the number of replacement works for cast iron pipes laid during the period of high economic growth. For this replacement work, the cast iron pipes must first be removed, and prior to removal, the pipe joints are dismantled at the installation site.

[0003] For example, in the configuration described in Patent Document 1 below, a pair of ring bodies are provided that fit around the entire circumference of the pipe at the socket and spigot, and claw bodies provided on the inner circumference of the ring bodies are pressed against the outer surface of the pipe with a set screw, and a jack is provided between the pair of ring bodies and extended to dismantle the pipe joint.In addition, in the configuration described in Patent Document 2 below, ring-shaped members are fixed to the socket and spigot with fixing bolts, a hydraulic cylinder is provided between the two ring-shaped members, and the pipe joint is dismantled by operating the hydraulic cylinder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-127036 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-17833 Summary of the Invention [Problem to be solved by the invention]

[0005] When a pipeline is laid in a narrow section, it is difficult to secure working space on the side or bottom of the pipe, which poses a problem of the extremely difficult task of dismantling the pipe joints by extending a ring (ring-shaped member) or a jack (hydraulic cylinder) that is provided around the entire circumference of the pipe, as shown in Patent Documents 1 and 2. In this case, cutting the pipe body is one possible method, but because sparks are generated during cutting, cutting work is limited in places where open flames are strictly prohibited, such as inside tunnels. Another possible method is to wrap a sling around the pipe and pull it out, but there is a risk that pipe joints other than the one to be dismantled may be accidentally removed, hindering subsequent transportation work.

[0006] Therefore, an object of the present invention is to provide a pipe joint dismantling method and a pipe joint dismantling jig that enable pipe joint dismantling work to be carried out smoothly even in narrow areas where it is difficult to secure sufficient working space. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: A pipe fitting disassembly method for disassembling a pipe fitting joined by inserting an insertion port of an insertion-side pipe body into a receiving port of a receiving-side pipe body, A pipe fitting dismantling method has been constructed, which is characterized by forming a pipe body insertion hole on the outer surface of the insertion side pipe body, inserting a pipe fitting dismantling jig into the pipe body insertion hole to install the pipe fitting dismantling jig on the insertion side pipe body, interposing an expandable member between the pipe fitting dismantling jig and the receiving side pipe body, and extending the expandable member along the pipe axis direction to pull out the insertion side pipe body from the receiving side pipe body and dismantle it.

[0008] In this way, the pipe joint dismantling jig can obtain a reaction force by inserting it into a pipe insertion hole formed in a part of the insertion side pipe (for example, the top of the pipe), so there is no need to provide a ring-shaped member around the entire circumference of the pipe.This means that pipe joint dismantling work can be carried out smoothly even in narrow spaces where it is difficult to secure sufficient working space.

[0009] In the pipe fitting dismantling method having the above configuration, the pipe insertion hole is a through hole that penetrates from the outer surface of the insertion side pipe body to the inner surface of the pipe, and a key portion is formed at the tip of the insertion side of the pipe fitting dismantling jig into the pipe insertion hole, extending along the pipe axis direction of the insertion side pipe body to the opposite side to the joining side with the receiving side pipe body, and after the key portion is inserted into the pipe insertion hole, the pipe fitting dismantling jig is preferably configured to engage the key portion with the inner surface of the pipe and install the pipe fitting dismantling jig on the insertion side pipe body.

[0010] In this way, the engagement between the key portion and the inner surface of the insertion side pipe body allows the pipe joint dismantling jig to be securely installed on the insertion side pipe body, and the pipe joint dismantling jig can reliably receive the reaction force acting on it when the telescopic member is extended.

[0011] Alternatively, the pipe insertion hole may be a through hole that penetrates from the outer surface of the insertion side pipe body to the inner surface of the pipe, and a key portion extending along the pipe axis direction of the insertion side pipe body is formed at the tip of the pipe fitting dismantling jig on the insertion side into the pipe insertion hole, when the pipe fitting dismantling jig is installed on the insertion side pipe body, and after the key portion is inserted into the pipe insertion hole, the pipe fitting dismantling jig can be rotated a predetermined angle around an axis perpendicular to the pipe axis direction to engage the key portion with the pipe inner surface and install the pipe fitting dismantling jig on the insertion side pipe body.

[0012] In this way, similar to the configuration in which the pipe joint dismantling jig is slid in the pipe axial direction, the pipe joint dismantling jig can be securely installed on the insertion side pipe body by engaging the key portion with the inner pipe surface of the insertion side pipe body, and the pipe joint dismantling jig can securely receive the reaction force acting on it when the telescopic member is extended.

[0013] In all of the above-mentioned pipe fitting dismantling methods, a pipe insertion hole may be formed on the outer surface of the receiving side pipe body, and a pipe fitting dismantling jig other than the pipe fitting dismantling jig installed on the insertion side pipe body may be inserted into the pipe insertion hole to install the other pipe fitting dismantling jig on the receiving side pipe body, and the expandable member may be interposed between the pipe fitting dismantling jigs installed on the receiving side pipe body and the insertion side pipe body, respectively.

[0014] In this way, even if there is not enough surface area to abut the expansion member against the receiving port of the receiving side pipe body, such as in the case of a K-type ductile cast iron pipe in which the water-stopping member is pushed in by a pressure ring, the pipe joint can be smoothly dismantled using the expansion member installed between the pipe joint dismantling jigs installed on both the receiving side pipe body and the inserting side pipe body.

[0015] In order to solve the above problems, the present invention provides: A pipe joint dismantling jig used to dismantle a pipe joint that joins pipe bodies, a base portion that acts as a reaction force receiver for the expansion and contraction member that applies a pull-out force to the pipe joint; an insertion member provided to protrude from the base portion and inserted into a tube insertion hole formed on an outer surface of the tube; A pipe joint dismantling jig was constructed, which is characterized by having the above features.

[0016] In this way, the pipe joint dismantling jig can obtain a reaction force by inserting it into a pipe insertion hole formed in a part of the pipe (for example, the top of the pipe), so there is no need to provide a ring-shaped member around the entire circumference of the pipe. Therefore, by using this pipe joint dismantling jig, pipe joint dismantling work can be carried out smoothly even in narrow spaces where it is difficult to secure sufficient working space.

[0017] In the pipe fitting dismantling jig having the above configuration, it is preferable that a key portion extending in a direction perpendicular to the insertion direction is formed at the tip of the insertion member on the insertion side into the pipe insertion hole.

[0018] In this way, the engagement between the key portion and the inner surface of the pipe body allows the pipe joint dismantling jig to be securely installed on the pipe body, and the pipe joint dismantling jig can reliably receive the reaction force acting on it when the telescopic member is extended.

[0019] In all of the above-described configurations of the pipe fitting dismantling jig, it is preferable that a female thread is formed on the base and a male thread is formed on the insertion member, and that the amount of protrusion of the insertion member from the base can be adjusted by changing the amount of threading of the insertion member into the base.

[0020] In this way, work efficiency can be improved by using a common pipe joint dismantling jig regardless of the nominal diameter or thickness of the pipe body, and further, the pipe joint dismantling jig can be fixed to the pipe body by tightening the screws. [Effects of the Invention]

[0021] In this invention, a pipe fitting dismantling method involves forming a pipe body insertion hole in the outer surface of an insertion-side pipe body, inserting a pipe fitting dismantling jig into this pipe body insertion hole to install the pipe fitting dismantling jig on the insertion-side pipe body, interposing an expandable member between the pipe fitting dismantling jig and the receiving-side pipe body, and extending this expandable member along the pipe axial direction to pull the insertion-side pipe out of the receiving-side pipe body and dismantle it.The pipe fitting dismantling jig is configured to have a base that acts as a reaction force receiver for the expandable member that applies a pull-out force to the pipe fitting, and an insertion member that protrudes from this base and is inserted into the pipe body insertion hole formed in the outer surface of the pipe body.This eliminates the need to provide a ring-shaped member that extends around the entire circumference of the pipe, and allows the pipe fitting to be dismantled smoothly even in narrow areas where it is difficult to secure sufficient working space. [Brief explanation of the drawings]

[0022] [Figure 1] 1A and 1B are cross-sectional views showing a pipe joint disassembly method using a pipe joint disassembly jig according to a first embodiment of the present invention, in which (a) shows a state in which the pipe joint disassembly jig is installed on an insertion-side pipe body, and (b) shows a state in which an expandable member is interposed between the pipe joint disassembly jig and a receiving-side pipe body. [Figure 2] 1(a) is a cross-sectional view taken along line II-II in FIG. 1(b), and FIG. 1(b) is a cross-sectional view showing another example of the fixed state of the pipe joint dismantling jig shown in FIG. 1(a). [Figure 3] A cross-sectional view showing another example of the pipe joint dismantling jig shown in FIG. 1(a). [Figure 4] 10A is a cross-sectional view showing a pipe joint disassembly method using a pipe joint disassembly jig according to a second embodiment of the present invention, in which (a) shows a state in which a key portion formed on the pipe joint disassembly jig is inserted into a pipe body insertion hole formed on the insertion side pipe body, and (b) shows a state in which the pipe joint disassembly jig is slid in the pipe axial direction to fix the pipe joint disassembly jig to the insertion side pipe body, and an expandable member is interposed between the pipe joint disassembly jig and the receiving side pipe body. [Figure 5] Cross-sectional view along line VV in Figure 4(b) [Figure 6] 10A is a cross-sectional view showing a pipe joint disassembly method according to a third embodiment of the present invention, in which (a) shows a state in which a key portion formed on a pipe joint disassembly jig is inserted into a pipe body insertion hole formed on an insertion-side pipe body, and (b) shows a state in which the pipe joint disassembly jig is rotated 90 degrees around an axis perpendicular to the pipe axial direction, the pipe joint disassembly jig is fixed to the insertion-side pipe body, and an expandable member is interposed between the pipe joint disassembly jig and the receiving-side pipe body. [Figure 7] FIG. 10 is a plan view of a pipe insertion hole formed in an insertion-side pipe in a pipe joint disassembling method according to a third embodiment; [Figure 8] FIG. 10 is a cross-sectional view of a state in which pipe joint disassembly jigs are fixed to an insertion-side pipe body and a receiving-side pipe body, respectively, and an expandable member is interposed between the two pipe joint disassembly jigs, in a pipe joint disassembly method using a pipe joint disassembly jig according to a second embodiment of the present invention. [Figure 9] In a pipe joint disassembly method using a pipe joint disassembly jig of a different configuration from each of the above embodiments, a pipe joint disassembly jig is fixed to an insertion side pipe body, and an expandable member is interposed between the pipe joint disassembly jig and the receiving side pipe body. [Figure 10] Cross-sectional view along line XX in Figure 9 DETAILED DESCRIPTION OF THE INVENTION

[0023] The following describes, with reference to the drawings, a pipe fitting disassembly jig 1 according to a first embodiment of the present invention, and a pipe fitting disassembly method using this pipe fitting disassembly jig 1. In this embodiment, a push-on type pipe fitting is used, in which a waterproofing member is provided on the inner surface of the socket of the receiving pipe P1, and the pipes are joined together by inserting the insertion port of the insertion pipe P2 into the socket of the receiving pipe P1.

[0024] The pipe fitting dismantling jig 1 is a jig used when dismantling a pipe fitting in which pipe bodies (a receiving side pipe body P1 and an inserting side pipe body P2) are joined together, and as shown in Figures 1(a)(b) and 2(a), it has a base 2 and an insertion member 3.

[0025] The base 2 is a member that acts as a reaction force receiver for the expandable member 4 that applies a pull-out force to the pipe joint. A base insertion hole 5 is formed in the base 2, penetrating in a direction perpendicular to the pipe axis direction. One end of the base 2 in the pipe axis direction (the end opposite the side that abuts the expandable member 4) is formed with an inclined portion 6 that has an inclined surface in side view. By forming the inclined portion 6, the weight of the base 2 is reduced. The insertion member 3 is a round bar-shaped member inserted into the base insertion hole 5. An end of the insertion member 3 protrudes from the base 2, and this protruding end is inserted into a pipe insertion hole 7 formed on the outer surface of the pipe (in this embodiment, the insertion side pipe P2).

[0026] The pipe fitting disassembly method is a method for disassembling a pipe fitting that has been joined by inserting the insertion port of an insertion-side pipe P2 into the reception port of a receiving-side pipe P1. In this pipe fitting disassembly method, first, a pipe insertion hole 7 is formed in the outer surface of the pipe near the insertion port of the insertion-side pipe P2. In this embodiment, the pipe insertion hole 7 is a through-hole that penetrates from the outer surface of the insertion-side pipe P2 to the inner surface of the pipe, and has an inner diameter slightly larger than the outer diameter of the insertion member 3 so that the insertion member 3 can be inserted smoothly. The position where the pipe insertion hole 7 is formed is not particularly limited, but in this embodiment, it is formed at the top of the pipe, where working space can be secured around it.

[0027] Next, as shown in FIG. 1(a), the insertion member 3 of the pipe joint disassembly jig 1 is inserted into this pipe insertion hole 7. Then, the bottom surface of the base 2 is brought into contact with the outer surface of the inserting-side pipe P2, and the tip (lower end) of the insertion member 3 is brought into contact with the inner bottom surface of the inserting-side pipe P2. Furthermore, as shown in FIG. 1(b), an expandable member 4 is interposed between the pipe joint disassembly jig 1 and the receiving end surface of the receiving-side pipe P1. Then, the expandable member 4 is extended along the pipe axis direction, and the inserting-side pipe P2 is pulled out of the receiving-side pipe P1 by the reaction force. In this embodiment, a hydraulic jack is used as the expandable member 4.

[0028] In this pipe fitting dismantling method, the pipe fitting dismantling jig 1 receives a reaction force by being inserted into the pipe body insertion hole 7 formed in a part (the pipe top) of the insertion-side pipe P2, so there is no need to provide a ring-shaped member around the entire circumference of the pipe. This allows the pipe fitting dismantling work to be carried out smoothly even in narrow spaces where it is difficult to secure sufficient working space.

[0029] In this embodiment, the tip (lower end) of the insertion member 3 is simply abutted against the bottom of the inner surface of the insertion side pipe body P2, but by forming a sharp protrusion at the tip of the insertion member 3 and abutting this protrusion against the bottom of the inner surface of the pipe, it may be possible to prevent the insertion member 3 from tilting within the insertion side pipe body P2 when the reaction force of the expansion and contraction member 4 acts on the pipe joint dismantling jig 1.

[0030] In the above example, one pipe joint dismantling jig 1 is provided on the insertion side pipe P2, but as long as there is sufficient working space, two pipe joint dismantling jigs 1 installed at different positions in the pipe axis direction can be provided so that they cross each other, as shown in Figure 2(b). In this way, each pipe joint dismantling jig 1 can be provided with an expandable member 4, allowing a large pull-out force to be applied to the pipe joint.

[0031] In this first embodiment, as shown in Figure 3, a female thread 8 can be formed on the inner surface of the base insertion hole 5 and a male thread 9 can be formed on the outer periphery of the insertion member 3, and the base 2 and the insertion member 3 can be integrated by screwing the male thread 9 into the female thread 8. By adjusting the amount of screwing before integration, the pipe joint dismantling jig 1 can be stably fixed to the insertion-side pipe P2. Furthermore, by changing the amount of screwing of the insertion member 3 into the base 2, the amount of protrusion of the insertion member 3 from the base 2 can be adjusted, so a common pipe joint dismantling jig 1 can be used regardless of the nominal diameter or wall thickness of the pipe, improving workability.

[0032] A pipe joint disassembly jig 1 according to a second embodiment of the present invention, and a pipe joint disassembly method using this pipe joint disassembly jig 1, are shown in Figures 4(a) and 4(b) and 5. This pipe joint disassembly jig 1 is similar to the pipe joint disassembly jig 1 according to the first embodiment in that it includes a base 2 and an insertion member 3, but differs in that a female thread 8 is formed on the inner surface of the base insertion hole 5 and a male thread 9 is formed on the outer periphery of the insertion member 3, and the base 2 and the insertion member 3 are integrated by threading this male thread 9 into the female thread 8, and in that a key portion 10 that is L-shaped in front view is formed on the tip of the insertion member 3 on the side that is inserted into the pipe insertion hole 7, extending in a direction perpendicular to the insertion direction (the pipe axial direction of the insertion-side pipe P2) to the opposite side from the side that is joined to the receiving-side pipe P1.

[0033] In the pipe joint disassembly method using the pipe joint disassembly jig 1 having the key portion 10 formed on the insertion member 3, as in the pipe joint disassembly method according to the first embodiment, first, a pipe body insertion hole 7, which is a through hole, is formed in the top of the insertion-side pipe P2 near the insertion port. The length of this pipe body insertion hole 7 in the pipe axis direction is long enough to allow the L-shaped key portion 10 to be smoothly inserted when viewed from the front.

[0034] Next, as shown in FIG. 4( a), the insertion member 3 (key portion 10) of the pipe joint disassembly jig 1 is inserted into the pipe insertion hole 7. Furthermore, as shown in FIG. 4( b), the pipe joint disassembly jig 1 is slid toward the side opposite to the joining side with the receiving-side pipe P1, so that the insertion-side pipe P2 is inserted between the base 2 and the key portion 10. The pipe joint disassembly jig 1 can then be fixed to the insertion-side pipe P2 by adjusting the amount of threading of the insertion member 3 into the base 2 to engage the key portion 10 with the inner surface of the pipe. Then, the telescopic member 4 is interposed between the pipe joint disassembly jig 1 and the receiving end face of the receiving-side pipe P1. This allows the pipe joint disassembly jig 1 to be stably installed on the insertion-side pipe P2, and ensures that the pipe joint disassembly jig 1 can withstand the reaction force acting on it when the telescopic member 4 is extended.

[0035] Instead of threading the base 2 and the insertion member 3 together, the base 2 and the insertion member 3 can be fixed together in advance by welding or other means, and the key portion 10 can be engaged with the inner surface of the pipe, thereby fixing the pipe joint dismantling jig 1 to the insertion-side pipe body P2. If a gap occurs between the key portion 10 or the base 2 and the insertion-side pipe body P2 during this fixing, the gap can be filled by inserting a cushioning material such as rubber.

[0036] A pipe fitting dismantling method according to a third embodiment of the present invention is shown in Figures 6(a) and 6(b) and 7. The pipe fitting dismantling jig 1 used in this pipe fitting dismantling method is the same as the pipe fitting dismantling jig 1 according to the second embodiment, but the method of use is different.

[0037] In this pipe joint disassembly method, first, as shown in Figure 7, a pipe insertion hole 7, which is a through hole, is formed in the top of the insertion-side pipe P2 near the insertion port. This pipe insertion hole 7 is formed so that the length perpendicular to the pipe axial direction is longer than the length in the pipe axial direction. This perpendicular length is long enough to allow smooth insertion of the L-shaped key portion 10 when viewed from the front.

[0038] Next, as shown in FIG. 6(a), the insertion member 3 (key portion 10) of the pipe joint disassembly jig 1 is inserted into this pipe insertion hole 7. Furthermore, as shown in FIG. 6(b), the pipe joint disassembly jig 1 is rotated a predetermined angle (90 degrees in this embodiment) around an axis perpendicular to the pipe axial direction, so that the insertion-side pipe P2 is inserted between the base portion 2 and the key portion 10. The pipe joint disassembly jig 1 can then be fixed to the insertion-side pipe P2 by adjusting the amount of threading of the insertion member 3 into the base portion 2 to engage the key portion 10 with the inner surface of the pipe. Thereafter, the expandable member 4 is interposed between the pipe joint disassembly jig 1 and the receiving end face of the receiving-side pipe P1. By doing this, as with the pipe fitting dismantling method of the second embodiment, the pipe fitting dismantling jig 1 can be stably installed on the insertion side pipe body P2 by engaging the key portion 10 with the inner pipe surface of the insertion side pipe body P2, and the pipe fitting dismantling jig 1 can reliably receive the reaction force acting on it when the telescopic member 4 is extended.

[0039] As in the second embodiment, instead of threading the base 2 and the insertion member 3 together, the base 2 and the insertion member 3 may be fixed together in advance by welding or other means, and the key portion 10 may be engaged with the inner surface of the pipe, thereby fixing the pipe joint dismantling jig 1 to the insertion-side pipe body P2. If a gap occurs between the key portion 10 or the base 2 and the insertion-side pipe body P2 during this fixing, the gap may be filled by inserting a cushioning material such as rubber.

[0040] In the case of the push-on type pipe joint described above, the end of the expandable member 4 can be abutted against the receiving end face of the receiving side pipe P1 to obtain a reaction force during extension. However, in the case of a pipe joint of the type in which a water-stopping member is pushed between the receiving end of the receiving side pipe P1 and the insertion end of the insertion side pipe P2 with a push ring, as shown in Figure 8 (for example, a pipe joint connecting K-type ductile cast iron pipes), it may be difficult to abut the end of the expandable member 4 against the receiving end face of the receiving side pipe P1.

[0041] In this case, it is preferable to form a pipe insertion hole 7 on the outer surface of the receiving-side pipe P1, insert a pipe joint dismantling jig 1 other than the pipe joint dismantling jig 1 fixed to the insertion-side pipe P2 into the pipe insertion hole 7 to fix the other pipe joint dismantling jig 1 to the receiving-side pipe P1, and interpose an expandable member 4 between the pipe joint dismantling jigs 1 fixed to the receiving-side pipe P1 and the insertion-side pipe P2. In this way, even if a sufficient surface cannot be secured for the expandable member 4 to abut against the socket of the receiving-side pipe P1, the pipe joint can be smoothly dismantled by the expandable member 4 provided between the pipe joint dismantling jigs 1 fixed to both the receiving-side pipe P1 and the insertion-side pipe P2.

[0042] 9 and 10 show a pipe joint disassembly method using a pipe joint disassembly jig 1 in a form different from the above-described embodiments. This pipe joint disassembly jig 1 does not have an insertion member 3 and is composed only of a base 2. A magnet 11, such as a neodymium magnet, is embedded in the base 2. In this pipe joint disassembly method using this pipe joint disassembly jig 1, a pipe insertion hole 7 is not formed in the insertion-side pipe P2, and the pipe joint disassembly jig 1 is directly fixed to the outer surface of the pipe near the insertion port of the insertion-side pipe P2 by the magnetic force of the magnet 11 provided in the base 2, and an expandable member 4 is interposed between the pipe joint disassembly jig 1 and the receiving-side pipe end face.

[0043] In this way, it is not necessary to form the tube insertion hole 7 in the insertion-side tube P2 as in the above-described embodiments, and therefore the disassembled insertion-side tube P2 can be reused.

[0044] The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. Therefore, the scope of the present invention is defined by the claims, not by the above description, and is intended to include the meaning equivalent to the claims and all modifications thereof. [Explanation of symbols]

[0045] 1. Pipe joint dismantling jig 2 base 3 Inserts 4. Elastic members 5 Base insertion hole 6 Slope 7. Tube insertion hole 8 Female thread 9 Male thread 10 Keys 11 Magnet P1 Receiving pipe (pipe) P2 Insertion side body (body)

Claims

1. A pipe joint disassembly method for disassembling a pipe joint joined by inserting an insertion port of an insertion-side pipe body (P2) into a receiving port of a receiving-side pipe body (P1), A pipe fitting dismantling method characterized by forming a pipe insertion hole (7) on the outer surface of the insertion-side pipe (P2), inserting a pipe fitting dismantling jig (1) into the pipe insertion hole (7) to install the pipe fitting dismantling jig (1) on the insertion-side pipe (P2), interposing an expandable member (4) between the pipe fitting dismantling jig (1) and the receiving-side pipe (P1), and extending the expandable member (4) along the pipe axis direction to pull out the insertion-side pipe (P2) from the receiving-side pipe (P1) and dismantle it.

2. 2. The pipe fitting dismantling method according to claim 1, wherein the pipe insertion hole (7) is a through hole that penetrates from the outer surface of the insertion-side pipe (P2) to the inner surface of the pipe, and a key portion (10) is formed at the tip of the pipe joint dismantling jig (1) on the insertion side into the pipe insertion hole (7) along the pipe axis direction of the insertion-side pipe (P2) to the opposite side to the joining side with the receiving-side pipe (P1), and after the key portion (10) is inserted into the pipe insertion hole (7), the pipe fitting dismantling jig (1) is slid to the opposite side to engage the key portion (10) with the pipe inner surface, thereby installing the pipe fitting dismantling jig (1) on the insertion-side pipe (P2).

3. 2. The pipe fitting dismantling method according to claim 1, wherein the pipe insertion hole (7) is a through hole that penetrates from the outer surface of the insertion-side pipe (P2) to the inner surface of the pipe, and a key portion (10) is formed at the tip of the pipe joint dismantling jig (1) on the insertion side into the pipe insertion hole (7), the key portion (10) extending along the pipe axis direction of the insertion-side pipe (P2) when the pipe joint dismantling jig (1) is installed on the insertion-side pipe (P2), and after the key portion (10) is inserted into the pipe insertion hole (7), the pipe joint dismantling jig (1) is rotated by a predetermined angle around an axis perpendicular to the pipe axis direction to engage the key portion (10) with the pipe inner surface, thereby installing the pipe fitting dismantling jig (1) on the insertion-side pipe (P2).

4. 4. A pipe fitting dismantling method according to any one of claims 1 to 3, wherein a pipe insertion hole (7) is formed in the outer surface of the receiving-side pipe (P1), and a pipe fitting dismantling jig (1) different from the pipe fitting dismantling jig (1) installed on the insertion-side pipe (P2) is inserted into the pipe insertion hole (7) to install the different pipe fitting dismantling jig (1) on the receiving-side pipe (P1), and the expandable member (4) is interposed between the pipe fitting dismantling jigs (1) installed on the receiving-side pipe (P1) and the insertion-side pipe (P2), respectively.

5. A pipe joint dismantling jig used to dismantle a pipe joint formed by joining pipe bodies (P1, P2), a base (2) that acts as a reaction force receiver for the expansion and contraction member (4) that applies a pull-out force to the pipe joint; an insertion member (3) provided to protrude from the base portion (2) and inserted into a pipe insertion hole (7) formed on the outer surface of the pipe (P1, P2); A pipe joint dismantling jig comprising:

6. 6. A pipe joint disassembly jig as set forth in claim 5, wherein a key portion (10) extending in a direction perpendicular to the insertion direction is formed at the tip of the insertion member (3) on the side that is inserted into the pipe insertion hole (7).

7. 7. A pipe joint dismantling jig as described in claim 5 or 6, wherein a female thread (8) is formed on the base (2) and a male thread (9) is formed on the insert member (3), and the amount of protrusion of the insert member (3) from the base (2) can be adjusted by changing the amount of threading of the insert member (3) into the base (2).

Images