JP2011052783A - Expandable flexible pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expandable flexible pipe joint which copes with both displacement absorption and axial thrust. <P>SOLUTION: This expandable flexible pipe joint includes a pair of reaction receiving rods constituted of the reaction receiving rod 40 (40A) for connecting a reaction pipe 20R positioned on one side with respect to a sleeve pipe 10, to a spigot tube 30L positioned on the other side, and the reaction receiving rod 40 (40A) for connecting a reaction pipe 20L positioned on the other side with respect to the sleeve pipe 10, to a spigot tube 30R positioned on the other side, has reaction receiving parts 21, 21 in a pipe end inner sides of the reaction pipes 20R, 20L, and has a plurality of the paired reaction receiving rods, and at least the one paired reaction receiving rods are connected to a rotary member 12 in the central portions of the respective reaction receiving rods. The problem is solved by the expandable flexible pipe joint. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an expansion / contraction flexible pipe joint that can absorb displacement caused by various forces applied to the inside and outside of a pipe line.

Water pipes, etc. that are buried in the ground, etc. are configured by connecting multiple pipes, but such pipes are subject to the expansion and contraction of pipes due to changes in ambient temperature, the influence of the surrounding environment such as land subsidence, axial thrust, etc. Displacement.
As a pipe connection structure, it is well known that the flange portions of the pipe ends are connected using fastening means such as bolts and nuts. However, with this connection structure alone, The road may not be able to absorb the displacement and may be damaged.
Therefore, in order to prevent the breakage of the pipe and the accompanying fluid leakage in the pipe, an elastic flexible pipe joint is arranged at an appropriate position between the pipes constituting the pipe to absorb the generated displacement of the pipe. Like to do.

However, a general expansion / contraction flexible pipe joint cannot sufficiently cope with the axial thrust generated by the internal fluid pressure generated in the bent pipe portion or the closed end portion of the pipe line simply by causing elongation. Therefore, in a place where a high axial thrust is generated in the pipe line such as the vicinity of the curved pipe part of the pipe line or the closed part at the pipe end, in order to absorb the displacement due to the axial thrust, in particular, FIG. 4206 of JIS B 0151. A pressure balance type joint as disclosed in US Pat.
As shown in FIG. 8, the pressure balance type joint X100 includes a central large-diameter pipe part 110 in which the left and right small-diameter pipe parts 120 are continuously and integrally connected with a step 115 so that the pipe parts 110 and 120 are connected to each other. The bellows mechanism is formed in a bellows shape, and further, one end of the large-diameter pipe portion 110 and the other end of the small joint pipe portion 120 are connected by a tie rod 140. Further, the internal cross-sectional area of the small-diameter pipe part 120 is configured to be equal to the area obtained by subtracting the internal cross-sectional area of the small-diameter pipe part 120 from the internal cross-sectional area of the large-diameter pipe part 110. With this structure, the axial thrust from one small-diameter pipe part side acts on the step 115 between the other small-diameter pipe part and the large-diameter pipe part, and the thrust is generated by expansion and contraction of each pipe by a bellows mechanism and a coupling mechanism by a tie rod. The balance is maintained.

However, this conventional bellows mechanism type pressure balance type joint X100 cannot absorb the displacement in the twisting direction of the tube shaft as shown in FIG. There is a drawback that the displacement in the direction cannot be sufficiently absorbed as in a flexible flexible pipe joint using a general sealing.
In particular, in a pipeline in which the pipeline 100 as shown in FIG. 10 extends from the outside of the structure to the inside of the structure, the inside of the structure is caused by various forces such as shaking of the structure 101 and ground subsidence. A pipe in which various displacements are likely to occur between the pipe line and the external pipe line of the structure (X portion in the figure), and the closed part or the bent pipe part is located immediately after the pipe line enters the structure. In the path 100, the pipe line is also affected by the axial thrust F.
However, as described above, the conventional general expansion / contraction flexible pipe joints and pressure balance type joints do not have a sufficient displacement absorbing function and cannot cope with such pipe line positions.

JP2008-180323 JP2008-151292

  Therefore, the present invention improves the above-described drawbacks of the conventional flexible flexible pipe joint and the pressure balance type joint, and the displacement in the pipe axis twist direction, the displacement in the pipe axis deviation direction, the expansion and contraction due to external force, An object of the present invention is to provide a pressure balance type expansion / contraction flexible pipe joint that can absorb a wide variety of displacements such as expansion and contraction due to axial thrust, and also has improved problems such as one-side wear of sealing.

The present invention and effects obtained by solving the above problems are as follows.
<Invention of Claim 1>
A sleeve tube, a reaction force pipe partially inserted into each end of the sleeve tube, and a spigot pipe partially inserted into each reaction force pipe,
A first sealing that holds liquid tight between the sleeve tube and the reaction pipe; a second sealing that holds liquid tight between the reaction pipe and the spigot pipe;
A mounting pin provided in the longitudinal center of the sleeve tube, and a rotating member rotatably attached to the mounting pin;
A reaction force receiving rod that connects a reaction pipe located on one side with respect to the sleeve tube and a spigot pipe located on the other side, and a reaction force pipe located on the other side and located on the other side with respect to the sleeve tube. A pair of reaction force receiving rods composed of a reaction force receiving rod that connects the spigot pipe,
The reaction force pipe has a reaction force receiving portion inside the tube end, and a plurality of pairs of the reaction force receiving rods, and at least a pair of the reaction force receiving rods are located at the central portion of each reaction force receiving rod. An expansion / contraction flexible pipe joint characterized by being connected to a rotating member.

<Invention of Claim 2>
The expansion / contraction flexible pipe joint according to claim 1, wherein the area of the reaction force receiving portion and the inner cross-sectional area of the spigot pipe are in an equal relationship.

<Invention of Claim 3>
The expansion / contraction flexible pipe joint according to claim 2, wherein the reaction force receiving rod is connected to each pipe via a ball joint.

<Invention of Claim 4>
The retractable housing according to any one of claims 1 to 3, further comprising a detachable housing at the tube ends of the sleeve tube and the reaction force pipe, wherein the first sealing and the second sealing are accommodated in the housing. Flexible pipe joint.

<Invention of Claim 5>
The expansion / contraction flexible pipe joint according to any one of claims 1 to 4, wherein at least one of the first sealing and the second sealing is an automatic seal.

<Invention of Claim 6>
The expansion / contraction flexible pipe joint according to claim 1, further comprising an embedded cover that covers the other part in a state where the ends of the spigot pipes at both ends are exposed.

The present invention as described above can absorb the expansion / contraction displacement generated in the pipe line by the double insertion / extraction movement of the reaction force pipe and each spigot pipe, and has a very high expansion / contraction displacement absorption capacity, and also the structure of the reaction force receiving rod. With this, the position of the sleeve tube is always at an appropriate position with respect to the spigot pipe, in particular, at the center of both ends of each spigot pipe, thereby preventing the breakage of the pipe connecting portion due to the expansion and contraction displacement generated in the pipe line. The wear does not concentrate on the sealing slidingly contacting one of the pipes, the service life of the sealing can be improved, and the displacement due to the axial thrust can be absorbed by the reaction force pipe and the reaction force receiving rod.
If the end portion of the reaction force receiving rod is a ball joint, the displacement in the direction of twisting of the tube axis can be absorbed while further supporting the displacement due to the axial thrust.
Further, even when axial thrust is generated in the pipe line due to the presence of the reaction force receiving rod, the spigot pipe does not come out of the sleeve pipe.

  Therefore, according to the present invention as described above, the disadvantages of the conventional expansion / contraction flexible pipe joints and pressure balance type joints are improved, the displacement in the direction of twisting of the pipe axis occurring in the pipe line, the displacement in the direction of deviation of the pipe axis, and the extension by external force, A pressure balance type expansion / contraction flexible pipe joint that can absorb various displacements such as contraction, extension and contraction due to axial thrust, and also improves problems such as one-side wear of sealing is provided.

It is a partial cross section side view of the expansion-contraction flexible pipe joint of this form. It is a partial cross section enlarged view of the expansion-contraction flexible pipe joint of this form. It is a 1st form figure for demonstrating operation | movement and an effect of the expansion-contraction flexible pipe joint of this form. It is a 2nd form figure for demonstrating operation | movement and an effect of the expansion-contraction flexible pipe joint of this form. It is a 3rd form figure for demonstrating the operation | movement of the expansion / contraction flexible pipe joint of this form, an effect | action, and an effect. It is a 4th form figure for demonstrating operation | movement and an effect of the expansion-contraction flexible pipe joint of this form. It is a 5th form figure for demonstrating operation | movement and an effect of the expansion-contraction flexible pipe joint of this form. It is a figure for demonstrating a pressure balance type coupling. It is a figure for demonstrating the twist of a pipe axis. It is a figure for showing a pipe line example.

  Next, embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a partial cross-sectional side view of the stretchable flexible pipe joint of the present embodiment. FIG. 2 is an enlarged cross-sectional view of the vicinity of the housing. 3-7 is a figure for demonstrating the effect | action of the expansion-contraction flexible pipe joint of this form.

“Structure of expansion / contraction flexible pipe joint”
As shown in FIG. 1, the expansion / contraction flexible pipe joint 1 of the present embodiment includes a sleeve tube 10, reaction force pipes 20 </ b> R and 20 </ b> L partially inserted at both ends of the sleeve tube 10, and each reaction force pipe. Spigot pipes 30R, 30L partially inserted into 20R, 20L.

  That is, in the main pipe joint 1, reaction force pipes 20R and 20L and spigot pipes 30R and 30L are inserted into both ends of the sleeve pipe 10 in a so-called telescopic manner.

  Further, in the main pipe joint 1, as can be understood from FIG. 2, flanges 31, 31 for connecting to other pipes constituting other pipe lines at the end portions of the spigot pipes 30 </ b> R, 30 </ b> L. Is provided and can be connected to other pipes constituting the pipe line via the flange 31. However, it is good also as a structure connected with a housing type coupling instead of the connection by a flange. The connection method between the spigot pipes 30R and 30L and the other pipes constituting the pipe line and the configuration therefor are not limited in the present invention.

  On the other hand, between the sleeve tube 10 and the reaction force pipes 20R and 20L, and between the reaction force pipes 20R and 20L and the spigot pipes 30R and 30L, liquid tightness is maintained by the first and second sealings 22 and 32. (In the present invention and the specification, the first sealing 22 is used to maintain a liquid-tight seal between the sleeve tube and the reaction pipe, and the sealing is used to hold a liquid-tight seal between the reaction pipe and the spigot pipe. Second sealing 32).

  In the illustrated embodiment, between the tube end of the sleeve tube 10 and the outer peripheral surface of the reaction force pipes 20R and 20L, and between the tube end of the reaction force pipes 20R and 20L and the spigot pipes 30R and 30L, Removable housings 23 and 33 are provided, and the sealings 22 and 32 are housed in the housings.

  The specific configurations of the housings 23 and 33 and the ceilings 22 and 32 are not particularly limited, and a known configuration can be adopted. For example, the housings 22 and 33 can be divided into two semicircular shapes or more. Those that are detachable from the tube end are suitable. By making the housings 22 and 33 detachable in this way, the sealings 22 and 32 can be easily replaced.

  Here, the seals 22 and 32 can be appropriately selected and used from a rubber packing or the like in which an elastic material such as rubber is formed in an annular shape, and in particular, from inside the pipe to outside the pipe through between the pipes. It is preferable to have a so-called automatic seal mechanism in which a sealing function is exhibited when a fluid pressure is generated. In the illustrated embodiment, an annular packing with a lip is formed by an elastic body such as rubber disposed annularly along the outer periphery of the reaction force pipes 20R and 20L and the spigot pipes 30R and 30L in the housing (the lip in the figure). The portion is indicated by reference numerals 22L and 32L).

  On the other hand, the reaction force pipes 20R and 20L have a predetermined diameter larger than the diameter of the spigot pipes 30R and 30L, and a flange-like portion is formed at the tube end exposed from the sleeve tube 10. The tube inner surface side of the flange-shaped portion is formed as reaction force receiving portions 21R and 21L that receive axial thrust.

  Here, the inner diameters of the reaction force pipes 20R and 20L are √2 times the inner diameters of the spigot pipes 30R and 30L. Therefore, the respective areas of the substantial reaction force receiving portions 21R and 21L and the spigot pipes 30R and 30L, Each inner diameter cross-sectional area of 30L is equal. For this reason, for example, when fluid pressure is applied to the easily closed portion or the like in the spigot pipe on one side and thereby axial thrust is generated, the axial thrust acts on the reaction force receiving portion 21 of the other reaction pipe.

  On the other hand, the main pipe joint 1 includes a rotating member 12 that is rotatably attached to a central portion in the longitudinal direction of the sleeve pipe 10 via an attachment pin 11.

  In the illustrated main pipe joint 1, as a preferred example, a pair of mounting pins 11 are provided symmetrically with respect to the core of the sleeve pipe 10, and a rotating member 12 is mounted on each mounting pin 11. .

  The rotating member 12 is a plate-like member having a height (width) slightly larger than the diameter of the sleeve tube 10. In the illustrated embodiment, the rotating member 12 is arranged along the outer peripheral surface of the sleeve tube 10 in order to improve compactness. It is configured as an arc-shaped plate having a cross-sectional arc shape having a larger radius of curvature than the radius of the sleeve tube 10. In particular, the rotating member 12 in the main pipe joint 1 has tapered tip portions 12t and 12t in a direction perpendicular to the mounting core from the mounting pin, and the mounting pin 11 is axially centered while being arcuate. The rotation amount of the rotating member 12 is configured to be ensured to be large.

  Further, in the main pipe joint 1, characteristically, a reaction force receiving rod 40 (40 </ b> A) that connects a reaction force pipe 20 </ b> R located on one side to the sleeve pipe 10 and a spigot pipe 30 </ b> L located on the other side, And a pair of reaction force receiving rods 40 (40A) which connect a reaction force pipe 20L located on the other side to the sleeve tube 10 and a spigot pipe 30R located on the other side. A plurality of pairs of rods 40 (40A) are provided. The pair of reaction force receiving rods are arranged symmetrically with respect to the axis of the sleeve tube 10.

  In the form shown in the figure, three pairs of reaction force receiving rods 40 in total are provided. Of the pair of reaction force receiving rods 40A and 40A, the center of the reaction force receiving rods 40A and 40A is rotatable with respect to the tapered tip ends 12t and 12t of the rotating member 12 via an axis. It is connected to.

  Here, the reaction force receiving rod acts on the other side as a reaction force using the force generated in one of the connecting portions, and is constituted by a member that does not have stretchability like a so-called tie rod.

  On the other hand, the reaction force receiving rod 40 (40A) and each pipe 20R, 20L, 30R, 30L are connected by forming a flange-like convex part 25 at the pipe end of each pipe 20R, 20L, 30R, 30L. In contrast, the reaction force receiving rod 40 (40A) is connected. Thus, the reaction force receiving rod 40 (40A) is positioned so as to extend in the tube center direction of the sleeve tube 10 at a position spaced from the outer peripheral surface of each pipe 20R, 20L, 30R, 30L by an appropriate distance. .

  Particularly, in the illustrated embodiment, as a preferred example, the rod end 40e of the reaction force receiving rod 40 (40A) is a ball-type rod end, and each pipe 20R, 20L, 30R is connected via a ball joint mechanism. , 30L. The reaction force receiving rod 40 (40A) can move freely with respect to each pipe while the connecting portion is compact by such a ball joint. By adopting such a configuration, the reaction force receiving rod 40 (40A) can move smoothly corresponding to the movement of each pipe accompanying the expansion and contraction and displacement of the pipeline. The specific configuration of the ball joint is not limited, and a known configuration can be adopted. That is, the two objects to be connected can freely move left and right and up and down around the ball.

  On the other hand, in the expansion / contraction flexible pipe joint 1 of the present invention, the embedment cover 50 is provided so that the expansion / contraction mechanism can be sufficiently exhibited even during embedment. In this embodiment, the buried cover 50 is a cylindrical cover formed by bolting and joining semi-cylindrical members. A concave groove is formed on the inner peripheral surface of the pipe end, and the pipe end of the spigot pipe is formed. The provided flange-like portion to which the reaction force receiving rod is connected is configured to fit into the concave groove. With this configuration, the embedded cover 50 itself can follow the movement of the spigot pipe or the like by the action of the reaction force receiving rod 40 (40A).

“Operation of expansion and contraction flexible pipe joints”
Next, the operation and effect of the telescopic flexible pipe joint 1 of the present invention described above will be described in detail. In addition, in the figure for demonstrating operation | movement, the form except the embedding cover 50 is referred.

  As shown in FIG. 3, the expansion / contraction flexible pipe joint 1 is arranged such that the axial directions of the pipes 20R, 20L, 30R, 30L extend substantially in the same direction, as shown in FIG. . Assuming that the total length of the expandable flexible pipe joint 1 in this initial state is L. The term “substantially” means that a slight error or the like during embedding is allowed.

  At this time, the axial direction of the reaction force receiving rods 40A and 40A connected to the rotary member 12 positioned at the center position in the longitudinal direction of the sleeve tube 10 and the axial direction of each pipe 20R, 20L, 30R and 30L are the same. It has become. Further, the exposed lengths of the reaction force pipes 20R and 20L protruding from both ends from the center of the sleeve tube 10 and the exposed lengths of the spigot pipes 30R and 30L protruding from the reaction force pipes 20R and 20L are made equal. Yes. In other words, the insertion lengths for the pipes 20R, 20L, 30R, and 30L are equal at both ends of the sleeve tube 10.

  In such a state, the line connecting the twelve tip portions 12t, 12t of the rotating member 12 connected to the reaction force receiving rods 40A, 40A is perpendicular to the axial direction of each pipe 20R, 20L, 30R, 30L. Therefore, the rotatable amount of the rotating member 10 is uniform.

(Operation for duct displacement)
Next, a description will be given of the case where an axial displacement occurs in the axial direction with respect to a pipeline (not shown) from the embedded state. When an extension displacement occurs in such a pipe, the expansion / contraction flexible pipe joint 1 contracts by a length L corresponding to the extension of the pipe as shown in FIG. 4 in order to absorb the extension of the pipe. However, the total length becomes LE.

  In the present expansion pipe joint, when the total length is contracted to LE, for example, the case where the extension of the pipe located on one side of the expansion / contraction flexible pipe joint is absorbed (in the description, for the sake of convenience, the right side of the figure). First, the extension force is transmitted to the spigot pipe 30R located on one side (the right side in the drawing) of the sleeve tube 10, and the spigot pipe 30R is inserted into the right reaction pipe 20R. It is. At this time, since the right reaction pipe 20R is connected to the left spigot pipe via the reaction force receiving rod 40 (40A), the right reaction pipe 20R is not moved.

  Then, the axial thrust of the pipe is inserted into the reaction force pipe 20R of the right spigot pipe 30R and transmitted to the reaction force pipe 20L located on the other side (left side) via the reaction force receiving rod 40 (40A), The transmitted left reaction force pipe 20L moves in the direction in which the exposed length from the sleeve pipe becomes longer. At this time, the left spigot pipe 20L is not moved either.

  At this time, in the main joint 1, the reaction force receiving rods 40 </ b> A and 40 </ b> A are connected to the rotating member 12, so that the rotating member 12 moves along with the movement of the pair of connected reaction force receiving rods 40 </ b> A and 40. The mounting pin 11 to the sleeve tube 10 is rotated about the axis. In the main pipe joint 1, the sleeve tube 10 moves in the direction in which the right reaction force receiving rod 40 is moved as the rotation member 12 rotates from the position of the reaction force receiving rod 40 with respect to the rotating member 12. Is done. In the rotating member 12, the position of the mounting pin 10 is in the center of the sleeve tube, and the exposed lengths of the reaction force pipes 20R and 20L and the spigot pipes 30R and 30L are set at both ends of the sleeve tube 10 at the time of installation and embedding. Therefore, the sleeve tube 10 acts as a centering mechanism for the sleeve tube 10, and the sleeve tube 10 is positioned at the center of the joint when the total length after expansion and contraction becomes LE.

  Thus, the expansion / contraction flexible pipe joint 1 of the present invention can sufficiently cope with the extension of the pipe line. At the same time, the movement of one of the spigot pipes 30R, 30L is linked to the other reaction force pipe 20R, 20L via the reaction force receiving rod 40 (40A), so the spigot pipes 30R, 30L and the reaction force pipes 20R, 20L The sliding distance of the second sealing 32, 32 between the two is uniform on the left and right, and the ends of the pipes are evenly frictioned, so that only one of them is not worn. Further, since the sleeve tube 10 is always moved to the center of the pipe joint 1 by the centering mechanism by the rotating member 12 and the reaction force receiving rod 40 (40A), the sleeve tube 10 and the reaction force pipe 20R, The sliding distance between the seals (first seals) 22 and 22 between 20L is also equal on the left and right, and friction is evenly applied to each pipe end, so that only one of them is not worn.

(Operation for contraction displacement of pipe)
Next, a description will be given of a case where the pipe line contracts in the axial direction when the expansion / contraction flexible pipe joint 1 of the present invention is embedded and installed (for the sake of explanation, the expansion / contraction flexible pipe joint is the same as the case where the joint contracts). This will be described based on an example in which the right side pipe line is expanded and contracted). In addition, description is abbreviate | omitted about the point which overlaps with the said expansion-contraction effect | action.

  When contraction displacement in the axial direction occurs in the pipe line from the embedded installation state, the expansion / contraction flexible pipe joint 1 absorbs the shrinkage of the pipe line as shown in FIG. The length corresponding to the length expands and the total length becomes L + E.

  In particular, in the present expansion pipe joint 1, when the contraction of the pipe line located on one side of the expansion / contraction flexible pipe joint 1 is absorbed when the total length is extended to L + E, first, one side of the sleeve pipe 10 (the right side of the drawing) The contraction force is transmitted to the spigot pipe 30R located at (1), and the spigot pipe 30R moves in the direction of being pulled out from the right reaction pipe 20R.

  At this time, until the predetermined contraction force value is exceeded, the force for contraction is not transmitted to the right reaction force pipe 20R, and the right reaction force pipe 20R is not moved. The contraction force of the conduit is transmitted to the reaction force pipe 20L located on the other side (left side) via the reaction force receiving rod 40 (40A) together with the pulling movement of the right spigot pipe 30R from the reaction force pipe 20L. Then, the transmitted reaction force pipe 20L on the left side is moved so as to be inserted into the sleeve tube 10. At this time, the left spigot pipe 30L is not moved below the predetermined contraction force.

  Then, by the same operation as the centering mechanism described above, the rotating member 12 rotates around the mounting pin 11 to the sleeve tube 10 as the reaction force receiving rod 40A moves, and as a result, the sleeve tube 10 rotates. The expansion / contraction flexible pipe joint 1 is always moved to the center position, and the relative position to each pipe is adjusted.

  Thus, the expansion / contraction flexible pipe joint 1 of the present invention can sufficiently cope with the expansion and contraction of the pipeline. At the same time, the movement of one of the spigot pipes 30R, 30L is linked to the other reaction force pipe 20R, 20L via the reaction force receiving rod 40 (40A), so the spigot pipes 30R, 30L and the reaction force pipes 20R, 20L The sliding distance of the second sealing 32, 32 between the two is uniform on the left and right, and the ends of the pipes are evenly frictioned, so that only one of them is not worn. Further, since the sleeve tube 10 is moved so as to be always located at the center of the pipe joint 1 by the centering mechanism by the rotating member 12 and the reaction force receiving rod 40 (40A), the sleeve tube 10 and the reaction force pipe 20R, The sliding distance between the seals (first seals) 22 and 22 between 20L is also equal on the left and right, and friction is evenly applied to each pipe end, so that only one of them is not worn.

(Operation against eccentricity of pipe line [direction of pipe axis deviation])
Next, the operation when the telescopic flexible pipe joint 1 of the present invention shrinks in the axial direction in the pipe line in the embedded installation state and is eccentric is described. Note that the description overlapping with the expansion and contraction operations and the like is omitted.

  As shown in FIG. 6, the expansion / contraction flexible pipe joint 1 absorbs the extension of the pipe line when the extension eccentricity in the axial direction occurs in the pipe line from the embedded installation state. The length corresponding to the length of expansion and contraction and the length associated with the eccentricity are contracted so that the total length becomes LE, and the angle θ corresponding to the eccentricity between the tube core of the sleeve tube and the core of each pipe is absorbed to absorb the eccentricity. To make an angle of minutes.

  Also for the eccentricity of the pipe line, basically, the reaction force pipe and spigot pipe insertion and extraction operations based on the above-described extension and extension operations are performed.

  Here, as understood from FIG. 5, when absorbing the eccentricity, the sleeve tube 10 is inclined eccentrically with respect to the axial centers of the reaction force pipes 20R and 20L and the spigot pipes 30R and 30L. Even in this case, the reaction force receiving rod 40 (40A) of this embodiment is connected to the pipes 20R, 20L, 30R, and 30L by ball joints, so that each pipe can be inserted and removed without unnecessary resistance. Such force can be transmitted without problems. Further, in the main pipe joint 1, the rotating member 12 is located at the center of the sleeve pipe 10, and the exposed lengths of the reaction pipes 20R and 20L and the spigot pipes 30R and 30L from both ends of the sleeve pipe 10 are made equal. Therefore, even when the eccentricity of the pipe line is absorbed, the centering mechanism works effectively, and the sleeve pipe 10 is always positioned at the center of the expansion joint.

In addition, about eccentricity of a pipe line, the form of the shift | offset | difference which is eccentric, although the axial direction of each pipe line extended from the both ends of the expansion-contraction flexible pipe joint 1 is the same direction, and one or both pipe lines However, the main pipe joint 1 is useful in any case. Also, it is useful when the expansion and contraction and extension occur in the pipeline together with these eccentricities. The operation principle of these combined modes such as eccentricity and expansion is basically the same as that when expansion and contraction occur in the upper tract. In the case of eccentricity, the sleeve tube 10 and the axes of the pipes 20R, 20L, 30R, and 30L are eccentric, and this is a simple double-pipe structure tube comprising a sleeve tube 10 and a spigot pipe. Similar to the principle in the joint, this can be dealt with by having a predetermined play between the sleeve tube and the sugopit pipe or the like via a seal. Needless to say, even if there is such play, the liquid tightness is maintained by the sealing provided in place.
Thus, the expansion / contraction flexible pipe joint of the present invention can sufficiently cope with the eccentricity of the pipe line (the direction of pipe axis deviation).

(Operation for twisting direction of pipe axis)
Next, the operation when the shaft is twisted without changing the axial direction on the left and right of the telescopic flexible pipe joint when the telescopic flexible pipe joint 1 of the present invention is installed in an embedded state will be described. Note that the description overlapping with the expansion and contraction operations and the like is omitted.

  In the case where a displacement in which the shaft twists in a pipe line extending in the left-right direction of the expansion / contraction flexible pipe joint occurs from the embedded installation state, the expansion / contraction flexible pipe joint 1 has a reaction force pipe 20R against the sleeve pipe 10. 20L, the spigot pipes 30R, 30L are free via the ceilings 22, 32, and the spigot pipes 30R, 30L and the reaction force pipes 20R, 20L rotate in the twist direction.

  Note that in this telescopic flexible pipe joint, one spigot pipe 30R, 30L and the other reaction force pipe 20R, 20L are connected by a reaction force receiving rod 40 (40A). Even when the reaction force receiving rod 40 (40A) is connected to each pipe via the ball joint 40e, the spigot pipe rotates without any problem in the twisting direction.

  That is, when the shaft twist indicated by the arrow in FIG. 8 occurs. First, one spigot pipe (for explanation, this one spigot pipe is described as the right spigot pipe) is rotated in the twist direction.

  At this time, in this telescopic flexible pipe joint, the right spigot pipe 20R and the left reaction force pipe 30L are connected by the reaction force receiving rod 40 (40A) via the ball joint 40e. The reaction pipe 20L is rotated in the direction opposite to the right spigot pipe 30R. The left reaction force pipe 30L is relatively moved in the direction of the sleeve tube 10.

As the reaction pipe 30L on the left side moves, the centering mechanism by the rotating member 12 acts to move the sleeve tube 10, so that only one of the left and right sealings 22 and 32 is also operated in this twisting direction. There is no wear.
Thus, the expansion / contraction flexible pipe joint of the present invention can sufficiently cope with the twist of the pipe shaft.

(Operation for axial thrust)
Next, with reference to FIG. 7, an explanation will be given of the operation in the case where the axial thrust force due to the fluid is generated in the pipe line when the expansion / contraction flexible pipe joint 1 of the present invention is embedded and installed. The description overlapping with the expansion and contraction operation etc. will be omitted.

  The present flexible flexible pipe joint 1 has a very characteristic advantage that it can cope with this axial thrust while being able to absorb the above-mentioned various displacements. For the sake of explanation, the case where the right-side conduit of the telescopic flexible pipe joint 1 is closed will be described for convenience.

  First, in the vicinity of the closed part of the pipe line or the bent pipe part, the fluid pressure in the pipe line acts in a direction toward the closed part of the pipe line, and an axial thrust in the opposite direction is generated. This axial thrust acts on the inner surface of the tube when there is no escape space, causing damage to the tube. Further, the conventional flexible flexible pipe joint composed of a sleeve pipe and a spigot pipe cannot be accommodated because it continues to extend from the sleeve pipe of the spigot pipe so that the exposure becomes longer.

  In the expansion / contraction flexible pipe joint 1 of the present invention, when installed at a location where such axial thrust is generated, the axial thrust F ′ having the same pressure as the fluid pressure F toward the closing portion (right side in the figure) is blocked. It acts on the reaction force receiving portion 21L from the gap between the reaction force pipe 20L and the sleeve tube 10 opposite to the portion side.

  At this time, as described above, in the telescopic flexible pipe joint, the reaction force pipe (left reaction force pipe) 20L having the reaction force receiving portion 21L that receives the axial thrust force and the side (right side) on which the fluid is to flow. Since the spigot pipe 30R is connected by the reaction force receiving rod 40 (40A), the joint itself does not extend.

  Furthermore, the inner diameters of the reaction force pipes 20R and 20L are √2 times the inner diameters of the spigot pipes 30R and 30L, and the areas of the reaction force receiving portions 21R and 21L and the inner diameter cross-sectional areas of the spigot pipes 30R and 30L are Since they are equal, the balance between the fluid pressure F and the axial thrust F ′ generated thereby is maintained.

  That is, in the present telescopic flexible pipe joint 1, even if axial thrust is generated, the right spigot pipe 30 </ b> R and the left reaction force pipe 20 </ b> L try to extend in the opposite directions with the same force, Since it is connected by the rod 40 (40A), it does not stretch, and the force (= fluid pressure F) for moving the right spigot pipe 30R and the reaction force receiving portion 21L of the left reaction force pipe 20L Since the force applied to the shaft (shaft thrust F ′) becomes equal, the right spigot pipe 30R and the left reaction pipe 20L do not shift or move with respect to the sleeve tube 10, and the shaft thrust is stably generated. The axial pressure balance in the axial direction is maintained.

  In addition, in the above operation | movement, although the form at the time of embedding was made into the state shown in the said FIG. 3, it does not necessarily need to be this form at the time of embedding. It can be embedded in an appropriate state as long as it does not interfere with the effects and operations of the present invention.

  As described above in detail, the expansion / contraction flexible pipe joint 1 according to the present invention includes a rotating member 12, a reaction force pipe, a sugopit pipe, and a reaction force receiving rod connected to the sleeve member 10 having a predetermined structure. In this structure, displacement due to various causes that occur in the pipeline, including displacement due to axial thrust, can be effectively absorbed, and the sleeve tube is positioned at the center of the pipe joint at that time. It is.

  And by sharing the amount of insertion and removal of the reaction force pipe and the sgot pit pipe with respect to each tubular body located on both end sides of the sleeve pipe, the amount of expansion and contraction displacement absorption can be set more than the conventional apparatus, Since the amount of wear of the sealing is also shared, the lifetime of the sealing is extended and the durability of the product is improved.

  Furthermore, as another effect, the bellows mechanism is the same as the double pipe structure, because the operation is based on the relative insertion / extraction and eccentricity of the pipe, although it is a triple pipe structure of reaction force pipe, sugopit pipe and sleeve pipe. Compared with a pressure balance type pipe joint or the like having a large degree of freedom, the movable degree of freedom and load are small, and high pipe support strength is not required.

  Moreover, since the sealing can be changed by attaching and detaching the housing, the maintenance is excellent.

  Furthermore, if the above-mentioned buried cover is provided, the effect can be more fully exhibited without losing stretchability even in the soil.

  DESCRIPTION OF SYMBOLS 1 ... Telescopic flexible pipe joint, 10 ... Sleeve pipe, 11 ... Mounting pin, 12 ... Rotating member, 12t ... Tip part of rotating member, 20R, 20L ... Reaction force pipe, 21 ... Reaction force receiving part, 22 ... First DESCRIPTION OF SYMBOLS 1 sealing, 23 ... Housing, 30R, 30L ... Spigot pipe, 31 ... Flange, 32 ... 2nd sealing, 33 ... Housing, 40, 40A ... Reaction force receiving rod, 50 ... Buried cover, L ... Pipe fitting at the time of embedding full length.

Claims (6)

A sleeve tube, a reaction force pipe partially inserted into each end of the sleeve tube, and a spigot pipe partially inserted into each reaction force pipe,
A first sealing that holds liquid tight between the sleeve tube and the reaction pipe; a second sealing that holds liquid tight between the reaction pipe and the spigot pipe;
A mounting pin provided in the longitudinal center of the sleeve tube, and a rotating member rotatably attached to the mounting pin;
A reaction force receiving rod that connects a reaction pipe located on one side with respect to the sleeve tube and a spigot pipe located on the other side, and a reaction force pipe located on the other side and located on the other side with respect to the sleeve tube. A pair of reaction force receiving rods composed of a reaction force receiving rod that connects the spigot pipe,
The reaction force pipe has a reaction force receiving portion inside the tube end, and a plurality of pairs of the reaction force receiving rods, and at least a pair of the reaction force receiving rods are located at the central portion of each reaction force receiving rod. An expansion / contraction flexible pipe joint characterized by being connected to a rotating member.   The expansion / contraction flexible pipe joint according to claim 1, wherein the area of the reaction force receiving portion and the inner cross-sectional area of the spigot pipe are in an equal relationship.   The expansion / contraction flexible pipe joint according to claim 2, wherein the reaction force receiving rod is connected to each pipe via a ball joint.   The retractable housing according to any one of claims 1 to 3, further comprising a detachable housing at the tube ends of the sleeve tube and the reaction force pipe, wherein the first sealing and the second sealing are accommodated in the housing. Flexible pipe joint.   The expansion / contraction flexible pipe joint according to any one of claims 1 to 4, wherein at least one of the first sealing and the second sealing is an automatic seal.   The expansion / contraction flexible pipe joint according to claim 1, further comprising an embedded cover that covers the other part in a state where the ends of the spigot pipes at both ends are exposed.

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