JP3730509B2 - Pipe joint structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint structure that normally maintains a predetermined insertion position of an insertion port in a withdrawal direction in a withdrawal direction and further resists the force against a large withdrawal force such as an earthquake. Is.
[0002]
[Prior art]
A pipe line is a facility that consists of a pipe joint in which the insertion hole of another pipe is inserted into the receiving hole of one pipe in order in the pipe line direction. Generally, the pipe joint is expanded and contracted (inserted into the receiving hole). It is a flexible structure that adapts to earthquakes and land subsidence to some extent by inserting and removing the mouth and bending. In this flexible structure pipe, a chain structure in which a larger expansion allowance and a detachment prevention function (prevention function) are added to the pipe joint is used as a further flexible structure. This chain-structure pipe line follows a large ground change, just like a chain buried in the ground, while the joint expands / contracts and bends, and after extending to the limit, the pipe is separated by a separation prevention structure. Maintain the road.
[0003]
Examples of the joint having the separation prevention and expansion / contraction function include an NS joint shown in FIG. 10, an SII joint and an S joint shown in FIG. As shown in the figure, the NS type joint is provided with a lock ring 2 that can be split open on the inner surface of a receiving port 1a of one tube 1 via a centering rubber 2a, and an insertion port for another tube 3 A projection 4 is provided on the outer surface of 3a, and the insertion port 3a is inserted into the receiving port 1 by centering the projection 4 and expanding the diameter of the lock ring 2 while contracting the rubber 2a so as to get over the lock ring 2. It is a configuration. In this configuration, when the insertion port 3a further enters the receiving port 1a, the contraction between the two tubes 1 and 3 is absorbed, and the protrusion 4 is engaged with the lock ring 2 so that both the tubes 1 and 3 are extended. That is, it prevents the exit. In the figure, reference numeral 5 denotes a rubber ring for sealing. When the water pressure rises above a certain level and the water pressure rises, the water pressure presses against the inner surface of the receiving port and the outer surface of the insertion port, and the surface pressure increases. Demonstrate self-sealing function.
[0004]
As shown in FIG. 11, the SII type joint is provided with a protrusion 14 on the outer surface of the insertion port 13a of the other tube 13, inserted into the receiving port 11a of one tube 11, and divided into the inner surface of the receiving port 11a. After providing the self-opening lock ring 12, a sealing rubber ring 15 is interposed between the receiving port 11 a and the insertion port 13 a, and the rubber ring 15 is pushed in with the push ring 16. In this configuration, T-bolts and nuts 17 inserted between the flanges of the receiving port 11a are tightened. Also in this configuration, when the insertion opening 13a further enters the receiving opening 11, the contraction between both the pipes 11 and 13 is absorbed, and the protrusion 14 engages with the lock ring 12 so that the both pipes 11 and 13 come out. Is blocked. In the figure, 18 is a backup ring.
[0005]
The joints, including these NS joints and SII joints, in which the insertion port is inserted into and removed from the receiving port (expandable), ensure a pipe line corresponding to small ground fluctuations due to its elasticity. In particular, NS type joints and SII type joints are suitable for ground fluctuations such as when an earthquake occurs or during subsidence, and the expansion and contraction mechanisms and bending mechanisms prevent the pipes and joints from generating large stresses. Adapt to fluctuations and prevent slipping out.
[0006]
Japanese Patent Laid-Open No. 10-122466 discloses a technique in which a pipe joint that has only the expansion and contraction function of both pipes and does not have a pull-out prevention function is added to the pipe outer surface. In this technique, a cylindrical member extending between the receiving port and the insertion port is fitted to the outer periphery of the pipe joint, and the protruding pieces at both ends of the cylindrical member are engaged with the receiving port and the insertion port to prevent the both from coming off.
[0007]
Furthermore, in Japanese Patent Laid-Open No. 2000-17987, a foamed resin is interposed between the receiving port and the insertion port, and when this foamed resin is less than a predetermined pushing force (insertion force) of the insertion port, the receiving port and the insertion port. A technique is disclosed in which the insertion position is maintained constant and the foaming resin is crushed (contracted) with respect to the pushing force exceeding the pressure, and the insertion port and the receiving port are allowed to expand and contract.
[0008]
[Problems to be solved by the invention]
In the pipe joint structure having the expansion and contraction function as described above, the water pressure test to confirm the leakage of the joint at the time of pipe construction is performed by refilling the facility pipe and using the earth pressure (passive earth pressure). It is done in a state where the movement of is blocked. If water pressure is applied without performing backfilling, the water pressure causes the insertion port to move in the direction of withdrawal and the pipe meanders, and in the worst case, the insertion port comes out of the receiving port. .
[0009]
However, if water leakage occurs at the joint due to water leakage during the water pressure test, it is in the soil, so it is not easy to find the location of the water leakage, and the backfilled soil is removed to check for water leakage and repair. It is necessary and has a serious impact on the construction process.
[0010]
Further, as shown in FIG. 14, various deformed pipes 20 are employed in the curved part (the same figure (a)) and the branch part (the same (b)) of the pipe line. As shown by an arrow P in the figure, a non-average force is exerted by water pressure, and a force in the withdrawal direction or bending direction is applied to the receiving port and the insertion port forming the pipe joint. At this time, a pipe joint (with a rigid structure) that makes the insertion port immovable with respect to the receiving port is employed so as to resist the above-mentioned non-average force P.
[0011]
For example, as shown in FIG. 12, in the pipe joint in which the insertion port 23 of the deformed tube 20 is inserted into the straight tube receiving port 1a, the liner 7 is provided on the inner surface of the receiving port 1a via the centering rubber 6. The liner 7 prevents the insertion opening 23a from being inserted, and the movement width of the protrusion 24 with respect to the lock ring 2 is reduced to form a rigid structure pipe joint. In the figure, 8 is a bending prevention protrusion. Further, as shown in FIG. 13, in the pipe joint in which the straight pipe insertion port 3a is inserted into the deformed pipe receiving port 21a, similarly, the movement width of the projection 4 with respect to the lock ring 2 is reduced, and the bending prevention ring 9 is provided. A rigid structure pipe joint is formed by pressure contact with the outer surface of the insertion port 3a by a set bolt 9a.
[0012]
However, there is no problem if these rigid structure pipe joints are a small part of the pipe line, but in the congested pipe line, bent pipes and the like continue, so the rigid structure part of the adjacent deformed pipes continues. As a result, the entire pipeline becomes a rigid structure, making the above-described chain structure very difficult. Rigid pipes have low seismic resistance and are easily damaged by earthquakes. If damaged, lifelines are lost and become a problem.
[0013]
The present invention enables a water pressure test to be performed without backfilling even if the pipe joint structure can be expanded and contracted, and enables the construction of a pipe joint having an expansion and contraction function even if it is a deformed pipe. This is the issue.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention focuses on the technology against the predetermined pushing force described in the above-mentioned Japanese Patent Application Laid-Open No. 2000-17987, and in the direction in which the insertion opening comes out between the receiving opening and the insertion opening. A member for preventing movement is provided, and this member is not contracted by a pull-out force less than a predetermined value, and is contracted by a pull-out force greater than a predetermined value.
[0015]
In the present invention, if the predetermined pull-out force is set higher than the force generated by the water pressure in the water pressure test, the insertion port does not move with respect to the receiving port even if the water pressure test is performed without backfilling. The fact that this backfilling is not performed means that the pipeline is exposed, and it is easy to find the leaking part and to repair it.
[0016]
Further, in the joint portion of the deformed pipe, if the predetermined pull-out force is set higher than the non-average force, pipe deformation due to the non-average force can be prevented.
[0017]
In any case, if an exit force greater than the predetermined exit force is applied due to an earthquake or the like, the blocking member is compressed to secure the amount of expansion and contraction in the contraction direction of the joint portion.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
As an embodiment of the present invention, referring to the technique described in the above-mentioned Japanese Patent Application Laid-Open No. 10-122466, in a pipe joint structure in which an insertion port of another tube is inserted into a receiving port of one tube so as to expand and contract, A member is provided on one outer surface of the tube so as to move integrally with the one tube, and the member has a projecting piece that reaches the outer surface of the other tube and faces the outer surface. Protruding pieces are provided on the outer surface of the pipe, and a member is provided between the protruding pieces to prevent the insertion port from moving in the pulling-out direction. Employs a contracting configuration.
[0019]
In this configuration, the protrusions are locked by the maximum contraction due to the breakage of the interposition member between the protrusions, and the engagement of the insertion port is prevented by this locking.
[0020]
In this configuration, it is preferable that the protruding piece on the other pipe outer surface is provided on the insertion opening side. This is because, in general, the outer peripheral edge of the opening of the receiving port is a flange-like protrusion, and a member that moves integrally with one pipe can be moved integrally with the protrusion (see the embodiment of FIG. 1).
[0021]
In addition, these structures provide a so-called earthquake-resistant joint in which a lock ring is provided on the inner surface of the receiving port, and a protrusion is provided on the outer surface of the insertion port, and the both pipes are prevented from coming off by locking the lock ring and the protrusion. Can be adopted.
[0022]
In this configuration, both the above-described contact of the two projecting pieces and the locking of the lock ring and the projections prevent the insertion port from coming off, and either of the contact or locking may occur earlier. The setting is performed by adjusting the distance between the projecting pieces in the normal state and between the lock ring and the projection. Note that if the locking ring and the protrusion are locked when the interposition member between the two protruding pieces is contracted to the maximum, the contact between the protruding pieces and the locking ring and the protrusion are locked to prevent the insertion hole from being removed. It is performed at the same time, and the effect is high compared to the case where it is performed separately.
[0023]
As the member interposed between the two projecting pieces, any member can be used as long as it can perform the above-described action.For example, a honeycomb-shaped porous member such as a spring, metal, or resin can be employed. For example, foamed polystyrene, foamed polypropylene, or the like can be employed, and a metal or resin hollow body, self-crushing concrete, or the like can also be employed.
[0024]
Each of the above embodiments can be employed not only for straight pipes but also for various pipe joint structures of straight pipes and deformed pipes, and deformed pipes. For this reason, even deformed pipes can have a chain structure.
[0025]
【Example】
FIGS. 1 to 3 show an embodiment. In this embodiment, in the NS type pipe joint structure made of ductile cast iron shown in FIG. 10, a ring 30 is covered over the insertion port 3a and the receiving port 1a. As shown in FIG. 1B, the ring 30 is divided into two parts, and is integrated by fastening the flange 31 of the divided part with bolts and nuts 32. Both side edges of the ring 30 have flanges 33 and 34, respectively, and one flange 33 is engaged with a protrusion (flange) 1c at the opening edge of the receiving port 1a. The material of the ring 30 may be any material as long as it matches the action, and for example, metal, engineer plastic, or the like is adopted.
[0026]
On the other hand, a flange 35 is fixed to the outer peripheral surface of the insertion port 3a inside the other flange 34 of the ring 30 by welding, and an annular member 36 made of expanded polystyrene is taped between the flange 35 and the flange 34 of the ring 30. It is interposed by winding or bonding. The annular member 36 is divided in the circumferential direction, such as in two, three, etc., and is set before the ring 30 is attached. Further, the annular member 36 has such a strength that it does not break without contracting the elastic deformation of the pipes 1 and 3 depending on the hydraulic pressure or non-average force of the hydraulic test.
[0027]
Note that the flanges 34 and 35 correspond to the protruding pieces referred to in the claims, and therefore, the flanges 34 and 35 are not continuous on the entire circumference, but are continuous ones of the intermittent protruding pieces or the protruding pieces. What is necessary is just to hold | maintain the member 36.
[0028]
In this embodiment, as shown in FIGS. 2 (a) to 2 (b), as in the prior art, the insertion port 3a is inserted into the receiving port 1a and the annular member 36 is fitted. 30 is attached ((c) of the figure).
[0029]
In the normal state, as shown in FIG. 3A, the tip (projection 4) of the insertion port 3a is substantially between the lock ring 2 and the receiving inner surface step 1b, as in the state shown in FIG. It is located in the middle and allows the movement of the insertion port 3a in the gap to cope with small ground deformations. Moreover, in the water pressure test at the time of piping construction, the annular member 36 resists the water pressure and prevents the pipe from coming out.
[0030]
In this state, if there is a large ground change due to an earthquake or the like, as shown in FIG. 3B, the annular member 36 is crushed (plastically deformed), and both flanges 34 and 35 come into contact with each other. The protrusion 4 is engaged with the lock ring 2 to prevent the lock ring 2 from coming off. On the other hand, for the shrinkage, as shown in FIG. 5C, the insertion port 3a enters into the receiving inner surface step portion 1b and absorbs it. In this way, the seismic function is exhibited.
[0031]
4 to 9 show other embodiments. In the embodiment shown in FIG. 4, set bolts 37 are provided at equal intervals in the circumferential direction instead of the flange 33 of the ring 30, and the set bolt 37 and the receiving port 1a are provided. The protrusions 1c are locked so that the ring 30 moves in the pull-out direction and moves integrally with the receiving port 1a. In the embodiment of FIG. 5, the insertion port 3a side flange 35 is formed by a split ring 38, the number of divisions is arbitrary, and the divided portions are fastened with bolts and nuts. The split ring 38 is fitted in the groove 39 of the insertion port 3a and stopped. The embodiment shown in FIG. 6 employs the present invention in the SII type pipe joint structure of FIG. 11, and can adopt the form of the set bolt 37 of FIG. 4 and the split ring 38 of FIG.
[0032]
In the embodiment shown in FIGS. 7 to 9, the annular member 36 is provided on the receiving port 1a side. At this time, an appropriate flange 40 is provided as a support member for the member 36 on the receiving port 1a side by welding or the like. be able to. The ring 30 may be welded to the insertion port 3a side as shown in FIG.
[0033]
Although each said Example is a case of the pipe joint structure of the straight pipes in the past, also in the pipe joint structure of a deformed pipe shown in FIG. It may have an earthquake resistance function. The present invention can also be applied to a pipe joint that does not have a retaining function by locking the lock ring 2 and the protrusion 4.
[0034]
【The invention's effect】
As described above, the present invention is designed to resist the pulling force up to a predetermined force with the retaining member as described above, so that a water pressure test can be performed without backfilling. Therefore, it is easy to construct a chain channel using a deformed tube.
[Brief description of the drawings]
FIG. 1A is a front view of an upper cut portion of an embodiment, FIG. 1B is a left side view of the ring, FIG. 2 is an assembly operation diagram of the embodiment, and FIG. 4 is a cut end view of the main part of another embodiment. FIG. 5A is a cut end view of the main part of another embodiment, FIG. 4B is a right side view of the flange, and FIG. FIG. 6 is a cut end view of a main part of another embodiment. FIG. 7 is a cut end view of a main part of another embodiment. FIG. 8 is a cut end view of a main part of another embodiment. Cutaway end view of the main part of the example. FIG. 10 Cut end view of the main part of the conventional example. FIG. 11 Cut end view of the main part of the conventional example. FIG. Cutaway end view of main part [Fig. 14] Illustration of piping [Explanation of symbols]
1, 11, 3, 13 Tubes 1a, 11a, 21a Receiving port 2, 12 Lock ring 3a, 13a, 23a Insertion port 4, 14 Retaining projection 5 Seal rubber ring 20 Deformed tube 30 Ring 34, 35 Flange (projection piece )
36 annular member (movement blocking member, interposition member)

Claims (6)

A pipe joint structure in which the insertion ports 3a, 13a, and 23a of the other tubes 3, 13, and 23 are inserted into the receiving ports 1a, 11a, and 21a of the one tube 1, 11, and 20 so as to be extendable and retractable so that they can be inserted and removed. In
A member 30 is provided on one outer surface of each of the two tubes so that the one tube and the one tube move together with each other at the time of extraction , and this member 30 straddles the receiving end surface and reaches the outer surface of the other tube. It has a protruding piece 34, 33 toward the projecting pieces 35, 40 provided, the member 36 interposed between the both projecting pieces to the other tube outer surface between the projecting pieces 34, 33 and the socket end face The pipe joint structure is characterized in that the interposition member 36 does not contract with a pull-out force less than a predetermined value and contracts with a pull-out force greater than a predetermined value. 2. The pipe joint structure according to claim 1 , wherein the projecting piece 35 on the other pipe outer surface is provided on the insertion port side.   One outer surface of the two tubes is the outer surface of the insertion port 13a, and the projecting pieces 35 and 40 provided on the other tube outer surface between the projecting pieces 34 and 33 and the receiving end surface are used as flanges of the receiving end portion. The pipe joint structure according to claim 1. The pipe joint structure according to any one of claims 1 to 3, wherein the interposition member 36 between the two projecting pieces is made of foamed resin. The lock rings 2 and 12 are provided on the inner surface of the receiving port, and the projections 4 and 14 are provided on the outer surface of the insertion port. The locking rings 2 and 12 and the projections 4 and 14 are locked to prevent the pipes from coming off. and the lock ring 2, 12 and the projection 4, 14 locking is according to any one of claims 1 to 4, characterized in that is performed when the maximum contraction of the intervening member 36 between the both projecting pieces Pipe joint structure.   The pipe joint structure according to claim 1, wherein at least one of the two pipes is a deformed pipe 20.

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