JP5377095B2 - Fitting structure and connecting pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint structure reducing an inserting force to be required for inserting a cut pipe spigot into a connection pipe socket. <P>SOLUTION: In the pipe joint structure, a cut pipe is connected to another pipe via a connection pipe. The connection pipe has the connection pipe socket and a connection pipe spigot, the cut pipe has the cut pipe spigot inserted into the connection pipe socket, a space between the cut pipe spigot and the connection pipe socket is sealed by a seal material 12, and the seal material 12 has a first valve 30 and a second valve 31. On the outer periphery of the first valve 30, a first seal portion 37 is formed to be pressed against the inner peripheral face of the connection pipe socket. On the inner periphery of the second valve 31, a second seal portion 38 is formed to be pressed against the outer peripheral face of the cut pipe spigot. A constricted portion 33 is formed on a joint area between the first valve 30 and the second valve 31. The second valve 31 has an inner diameter set smaller than the outer diameter of the cut pipe spigot, and it is expandable in the radial direction of the pipe with the deformation of the constricted portion 33. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a pipe joint in which a cut pipe having a cut end manufactured by cutting to a predetermined size at a construction site and a receiving port formed at the end of another pipe are connected via a connecting pipe. The present invention relates to the structure and the connecting pipe.

  Conventionally, in a construction site, there is a case where a straight pipe having a specified dimension (specified length) is cut based on an actually measured pipe dimension to adjust the pipe length, and the cut cut pipe is connected to another pipe. is there. FIG. 11 shows a pipe joint structure 83 that connects the above-described cut pipe 81 and another pipe 82, and the cut pipe 81 and the other pipe 82 are connected via a connection pipe 84. The cut pipe 81 is obtained by cutting a straight pipe standard pipe (for example, a cast iron pipe manufactured by centrifugal casting specified in JIS) into a predetermined pipe size (length) actually used at a construction site. It is fabricated and has a straight tubular cut end 85.

  The other pipe 82 is a straight tubular standard pipe (cast iron pipe) having an insertion port (not shown) at one end and a receiving port 86 at the other end. A fitting groove 87 and a lock ring receiving groove 88 located on the back side of the fitting opening with respect to the fitting groove 87 are formed on the inner peripheral surface of the receiving opening 86 over the entire circumference. A lock ring 89 and a holding ring 90 are housed in the lock ring housing groove 88. An annular sealing material 91 made of an elastic material such as rubber is fitted in the fitting groove 87.

  The connecting pipe 84 is a cast iron pipe, and has a connecting pipe insertion opening 93 at one end and a connecting pipe receiving port 94 at the other end. The connecting pipe insertion opening 93 is inserted into the receiving opening 86, and a retaining protrusion 95 that can be engaged with the lock ring 89 from the back of the receiving opening is formed on the outer periphery of the distal end portion of the connecting pipe insertion opening 93. .

  The sealing material 91 is sandwiched between the inner peripheral surface of the receiving port 86 and the outer peripheral surface of the connecting pipe insertion port 93 and compressed in the pipe radial direction, whereby the inner peripheral surface of the receiving port 86 and the connecting pipe are inserted. A space between the outer peripheral surface of the opening 93 is sealed with a sealing material 91.

  The cut end portion 85 of the cut tube 81 is inserted into the connection tube receiving port 94 of the connection tube 84 as the cut tube insertion port 85. Further, the connection tube receiving port 94 is provided with a detachment preventing means 96 for preventing the cut tube insertion port 85 and the connection tube receiving port 94 from being separated. The detachment preventing means 96 tries to move the retaining member 97 that can bite into the outer peripheral surface of the cut tube insertion port 85 from the radial direction, and the cut tube insertion port 85 and the connection tube receiving port 94 relatively move in the separation direction. In this case, there is a biting means 98 for biting and moving the retaining member 97 inwardly in the pipe radial direction. The biting means 98 includes a pressing bolt 99 that is provided in the connection pipe receiving port 94 and presses the retaining member 97 inward in the pipe radial direction.

  As shown in FIGS. 11 to 13, an annular sealing material 100 made of rubber that seals between the connection tube receiving port 94 and the cut tube insertion port 85 over the entire circumference is provided on the inner periphery of the connection tube receiving port 94. Has been placed. The sealing material 100 includes a heel portion 101 and a valve portion 102. The valve portion 102 is formed so as to have a smaller inner diameter toward the back side of the connection pipe receiving port 94, and its cross-sectional shape is formed in a substantially oval shape protruding in a tongue shape in an oblique direction toward the center of the pipe.

  Further, a sealing material arrangement recess 103 is formed on the entire inner periphery of the connection pipe receiving port 94, and a locking groove 104 is formed on the entire bottom surface of the sealing material arrangement recess 103. The heel portion 101 of the sealing material 100 is fitted into and engaged with the locking groove 104, and the valve portion 102 is sandwiched between the outer peripheral surface of the cut tube insertion opening 85 and the bottom surface of the sealing material disposing recess 103 and is in the tube diameter direction. Is compressed.

Hereinafter, the operation of the above configuration will be described.
First, the heel portion 101 of the sealing material 100 is fitted into the locking groove 104 of the connection pipe receiving port 94, and the retaining member 97 and the pressing bolt 99 are assembled to the connection pipe receiving port 94 to connect the cut tube insertion port 85. The tube is inserted into the tube receiving port 94 from the axial direction of the tube.

  When the cut tube insertion opening 85 passes through the inner periphery of the sealing material 100, as shown in FIG. 12, the inner peripheral portion of the valve portion 102 bends outward in the tube radial direction as indicated by a solid line. The valve portion 102 is sandwiched between the outer peripheral surface of the cut tube insertion opening 85 and the bottom surface of the sealing material disposing concave portion 103 and compressed in the tube diameter direction. Is sealed over the entire circumference.

Thereafter, the pressing bolt 99 is tightened, and the retaining member 97 is bitten and moved with respect to the outer peripheral surface of the cut tube insertion opening 85.
Further, as shown in FIG. 11, the lock ring 89 and the holding ring 90 are accommodated in the lock ring accommodating groove 88 of the receiving port 86 of the other pipe 82, and the sealing material 91 is fitted in the fitting groove 87, so that the connecting pipe is inserted. 93 is inserted into the receiving port 86 from the axial direction of the tube. As a result, the retaining projection 95 of the connection pipe insertion port 93 passes through the inner periphery of the lock ring 89 from the opening side (front side) of the receiving port 86 to the back side, and the sealing material 91 is the inner peripheral surface of the receiving port 86. And the outer peripheral surface of the connection pipe insertion opening 93 and compressed in the pipe radial direction, whereby the space between the connection pipe insertion opening 93 and the receiving opening 86 is sealed over the entire circumference.

  When the detachment force (extraction force) acts on the pipe joint structure 83 due to ground fluctuation such as an earthquake and the like, and the cut tube 81 and the connection tube 84 try to move away relatively, the retaining member 97 is inwardly in the tube radial direction. The cutting tube insertion port 85 and the connection tube receiving port 94 are strongly maintained.

  Further, when the detachment force acts and the connection pipe 84 and the other pipe 82 try to detach relatively, the retaining projection 95 is engaged with the lock ring 89 from the back of the receiving port, The relative detachment movement of the connection pipe insertion opening 93 and the receiving opening 86 is strongly prevented.

  In addition, the pipe joint structure 83 that connects the cut pipe 81 and the other pipe 82 via the connection pipe 84 as described above is described in, for example, Patent Document 1 below.

Patent No. 4204337

  However, in the above-described conventional format, as shown in FIG. 12, when the cut tube insertion port 85 is inserted into the connection tube receiving port 94, the inner peripheral portion of the valve portion 102 of the sealing material 100 is shown as a phantom line from a solid line. As shown, it has been difficult to reduce the force required for deformation so as to bend outward in the pipe radial direction. For this reason, there has been a problem that a large insertion force (joining force) needs to be applied when the cut tube insertion port 85 is inserted into the connection tube receiving port 94.

  An object of this invention is to provide the pipe joint structure and connection pipe which can reduce the insertion force required when inserting a cut pipe insertion opening in a connection pipe receptacle.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a cut tube having a cut end portion manufactured by cutting to a predetermined size at a construction site, and a receptacle formed at an end portion of another tube. A pipe joint structure connected via a connecting pipe,
The connecting pipe has a connecting pipe receptacle at one end and a connecting pipe insertion opening at the other end,
The cut end of the cut tube is inserted into the connection tube receiving port of the connection tube as a cut tube insertion port,
The connecting pipe insertion port of the connecting pipe is inserted into the receiving port of another pipe,
The connection pipe insertion opening is provided with a locking protrusion that can be engaged from the receiving port back side to a locking member provided on the inner periphery of the receiving port of the other tube.
A detachment preventing means for preventing detachment between the cut tube insertion port and the connection tube receiving port is provided,
Between the cut tube insertion port and the connection tube receiving port is sealed over the entire circumference by an annular sealing material made of an elastic material,
The sealing material includes a heel portion that is fitted into a fitting groove formed on the inner peripheral surface of the connection pipe receiving port, and a valve portion that is sandwiched between the inner peripheral surface of the connection pipe receiving port and the outer peripheral surface of the cut tube insertion port. Have
The valve portion includes a first valve and a second valve joined to each other,
A first seal portion that is in pressure contact with the inner peripheral surface of the connection pipe receiving port is formed on the outer peripheral portion of the first valve,
A second seal portion that is in pressure contact with the outer peripheral surface of the cut tube insertion opening is formed on the inner peripheral portion of the second valve,
The first valve is joined to the heel,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is located on the back side of the connection pipe receiving port with respect to the first valve, and is inclined from the first valve toward the pipe center,
The heel portion is located on the opening side opposite to the back side of the connection pipe receiving port with respect to the first valve,
The second valve, the inner diameter is smaller than the outer diameter of the cut pipe spigot, and, Ri scaled freely der in pipe diameter direction by the deformation of the constricted portion,
On the inner peripheral surface of the connection pipe receptacle, a recess located on the back side of the fitting groove is formed,
The thickness of the first valve in the radial direction is thinner than the thickness of the second valve in the radial direction,
A gap is formed between the outer periphery of the second valve and the bottom surface of the recess of the connection pipe receiving port .

  According to this, when connecting a cut pipe and another pipe | tube via a connection pipe, the connection pipe insertion port of a connection pipe is inserted in the receptacle of another pipe | tube. Furthermore, the heel portion of the sealing material is fitted into the fitting groove in the connecting pipe receiving port of the connecting pipe, and the sealing material is mounted in the connecting pipe receiving port.

  Thereafter, the cut tube and the other tube are connected via the connection tube by inserting the cut tube insertion port of the cut tube into the connection tube receiving port. At this time, the second valve is enlarged (expanded) in the tube diameter direction by the cut tube insertion, the cut tube insertion is inserted into the inner periphery of the sealing material, and the first seal portion of the valve portion is connected to the connection tube receiving port. The second seal portion is pressed against the outer peripheral surface of the cut tube insertion while being pressed against the inner peripheral surface. Thereby, a high water-tightness can be maintained between the connection tube receiving port and the cut tube insertion port, and the gap between the cut tube insertion port and the connection tube receiving port is reliably sealed by the sealing material.

When the cutting tube insertion port is inserted into the connection tube receiving port as described above, the second valve expands in the tube radial direction due to the deformation of the constricted portion , so that the second valve is expanded in the tube radial direction. The required force is reduced, whereby the insertion force (joining force) required when inserting the cut tube insertion port into the connection tube receiving port can be reduced.

Further, when the cut tube insertion port moves along the inner circumference of the first valve in the tube axis direction, the thickness of the first valve is thinner than the thickness of the second valve. , The cutting tube insertion smoothly moves along the inner circumference of the first valve in the direction of the tube axis, and the insertion force (joining force) required to insert the cutting tube insertion into the connection tube receiving port is further reduced. can do.
Further, when the cut tube insertion moves in the tube axis direction along the inner periphery of the second valve, the gap becomes a clearance, and the second valve faces outward in the radial direction with respect to the cut tube insertion. It can be displaced to escape. Thereby, the insertion force (joining force) required when inserting the cut tube insertion port into the connection tube receiving port can be further reduced.
In addition, when water pressure acts on the pipes joined to each other, the water pressure also acts on the gap between the outer periphery of the second valve and the bottom surface of the recess, so that a pressing force toward the center of the pipe acts on the second valve. Thus, the second seal portion of the second valve is strongly pressed against the outer peripheral surface of the cut tube insertion port, and the watertightness between the cut tube insertion port and the connection tube receiving port is further improved.
Also, when the separation force (extraction force) acts on the pipe joint structure due to ground fluctuation such as an earthquake, and the connection pipe and other pipes attempt to move away relatively, the retaining protrusion is received by the locking member. By engaging from the back side of the mouth, the relative disengagement between the connecting pipe insertion opening and the receiving opening is strongly prevented.

Furthermore, when the above detachment force acts and the cut tube and the connection tube try to move relatively apart, the connection between the cut tube insertion port and the connection tube receiving port is strongly maintained by the separation preventing means. .
In the second aspect of the present invention, a convex portion located between the fitting groove and the concave portion is formed on the inner peripheral surface of the connection pipe receptacle.
The first seal portion is in pressure contact with the inner peripheral surface of the convex portion,
The position of the first seal part and the position of the second seal part are shifted in the tube axis direction.

  According to this, the diameter of the first valve can be reduced, and the inner diameter of the convex portion of the connection pipe receptacle can be reduced, thereby reducing the gap between the convex portion of the connection pipe receptacle and the cut tube insertion opening. Therefore, the absolute value of the water pressure acting on the sealing material at the time of water pressure load becomes small. Therefore, it is difficult for the sealing material to be detached from the gap between the connection pipe receiving port and the cut tube insertion port even under a high water pressure load.

In the third aspect of the invention, the seal material side recesses are respectively formed on the inner peripheral surface and the outer peripheral surface of the constricted portion.
According to this, when the first valve is compressed in the pipe radial direction by the cut tube insertion when the cut tube insertion is inserted and joined to the connection tube receiving port, the seal material side concave portion becomes the clearance allowance. The compression amount of one valve decreases. As a result, the cutting tube insertion port smoothly moves in the direction of the tube axis along the inner periphery of the first valve, thereby reducing the insertion force (joining force) required when the cutting tube insertion port is inserted into the connection tube receiving port. be able to.

According to the fourth aspect of the present invention, a concave portion is formed at a joint portion between the first valve and the heel portion.
According to this, when the first valve is compressed in the pipe radial direction by the cut tube insertion when the cut tube insertion is inserted and joined to the connection tube receiving port, the seal material side concave portion becomes the clearance allowance. The compression amount of one valve decreases. As a result, the cutting tube insertion port smoothly moves in the direction of the tube axis along the inner periphery of the first valve, thereby reducing the insertion force (joining force) required when the cutting tube insertion port is inserted into the connection tube receiving port. be able to.

In the fifth aspect of the present invention, the constricted portion is thinner than the first and second valves .

According to the sixth aspect of the present invention, the detachment preventing means is provided at the connection pipe receiving port.
According to the seventh aspect of the present invention, the detachment preventing means is provided on a detachment prevention ring that is externally fitted to the cut tube insertion port and the connection tube receiving port and is fixed to the connection tube receiving port.

  According to the eighth aspect of the present invention, the separation preventing means is configured such that the retaining member that can bite and move from the pipe radial direction to the outer peripheral surface of the cut tube insertion port, and the cut tube insertion port and the connection tube receiving port relatively move in the separation direction. And a biting means for biting and moving the retaining member inwardly in the pipe radial direction.

  According to this, when the detachment force acts on the pipe joint structure due to ground fluctuation such as an earthquake, and the cutting pipe and the connecting pipe try to detach and move relative to each other, the retaining member is further moved radially inward by the biting means. Since the bite moves to the side, the connection between the cut tube insertion port and the connection tube receiving port is strongly maintained.

The ninth invention is a connecting pipe for connecting a cut tube having a cut end portion manufactured by cutting into a predetermined dimension at a construction site and a receiving port formed at an end portion of another tube,
A connection pipe receiving port into which the cut end of the cut tube is inserted as a cut tube insertion port is provided at one end,
A connecting tube insertion port to be inserted into the receiving port of another tube is provided at the other end,
The connection pipe insertion opening is provided with a locking protrusion that can be engaged from the receiving port back side to a locking member provided on the inner periphery of the receiving port of the other tube.
Detachment between the cutting tube insertion port and the connection tube receiving port is prevented by the separation preventing means,
An annular sealing material made of an elastic material that seals between the cut tube insertion port and the connection tube receiving port over the entire circumference is disposed in the connection tube receiving port,
The sealing material includes a heel portion that is fitted in a fitting groove formed on the inner peripheral surface of the connection tube receiving port, and a valve portion that is sandwiched between the inner peripheral surface of the connection tube receiving port and the outer peripheral surface of the cut tube insertion port. And
The valve portion includes a first valve and a second valve joined to each other,
A first seal portion that is in pressure contact with the inner peripheral surface of the connection pipe receiving port is formed on the outer peripheral portion of the first valve,
A second seal portion that is in pressure contact with the outer peripheral surface of the cut tube insertion opening is formed on the inner peripheral portion of the second valve,
The first valve is joined to the heel,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is located on the back side of the connection pipe receiving port with respect to the first valve, and is inclined from the first valve toward the pipe center,
The heel portion is located on the opening side opposite to the back side of the connection pipe receiving port with respect to the first valve,
The second valve, the inner diameter is smaller than the outer diameter of the cut pipe spigot, and, Ri scaled freely der in pipe diameter direction by the deformation of the constricted portion,
On the inner peripheral surface of the connection pipe receptacle, a recess located on the back side of the fitting groove is formed,
The thickness of the first valve in the radial direction is thinner than the thickness of the second valve in the radial direction,
A gap is formed between the outer periphery of the second valve and the bottom surface of the recess of the connection pipe receiving port .

  As described above, according to the present invention, it is possible to reduce the insertion force required when inserting the cut tube insertion port into the connection tube receiving port.

It is sectional drawing of the pipe joint structure which connects the cut pipe and other pipe | tube in the 1st Embodiment of this invention. It is an expanded sectional view of the connection part of the cut pipe of a pipe joint structure, and a connection pipe same as the above. It is sectional drawing which looked at the detachment | leave prevention means of the pipe joint structure from the pipe axial center direction. It is a cross-sectional view in the natural state (non-compressed state in which the seal material is removed from the pipe joint) of the seal material of the pipe joint structure. FIG. 3 is a cross-sectional view showing the dimensions of each part in the natural state of the sealing material of the pipe joint structure (an uncompressed state in which the sealing material is removed from the pipe joint). It is sectional drawing which shows the procedure which connects the cut pipe of a pipe joint structure to a connection pipe. It is sectional drawing which shows the procedure which connects the cut pipe of a pipe joint structure to a connection pipe. It is sectional drawing which shows the procedure which connects the cut pipe of a pipe joint structure to a connection pipe. It is sectional drawing which shows the procedure which connects the cut pipe of a pipe joint structure to a connection pipe. It is sectional drawing of the removal prevention means of the pipe joint structure in the 2nd Embodiment of this invention. It is sectional drawing of the pipe joint structure which connects the conventional cut pipe and another pipe. It is an expanded sectional view of the connection part of the cut pipe of a pipe joint structure, and a connection pipe same as the above. It is a cross-sectional view in the natural state (non-compressed state in which the seal material is removed from the pipe joint) of the seal material of the pipe joint structure.

A first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, reference numeral 1 denotes a pipe joint structure in which a cut pipe 2 and another pipe 3 are connected via a connecting pipe 4. The cut tube 2 is manufactured by cutting into a predetermined dimension (predetermined length) at a construction site, and the cut end portion serves as a cut tube insertion opening 6. The other pipe 3 is a straight tubular standard pipe (cast iron pipe or the like) having an insertion opening (not shown) at one end and a receiving opening 7 at the other end.

  The connecting pipe 4 is a cast iron pipe, and has a connecting pipe receiving port 8 at one end and a connecting pipe insertion port 9 at the other end. The cut tube insertion port 6 is inserted into the connection tube receiving port 8, and the connection tube insertion port 9 is inserted into the receiving port 7. An annular anticorrosion member 10 (for example, anticorrosion rubber) having water tightness is attached to the cut end of the cut tube insertion opening 6.

  The connection tube receiving port 8 is provided with a separation preventing means 11 for preventing the cut tube insertion port 6 and the connection tube receiving port 8 from separating, and a first seal material 12. In addition, a second sealing material 13, a lock ring 14 (an example of a locking member), and a centering body 15 are provided at the receiving port 7 of the other pipe 3.

  As shown in FIGS. 2 and 3, the detachment preventing means 11 includes a plurality of retaining members 17 that can bite and move from the pipe radial direction to the outer peripheral surface of the cut tube insertion port 6, the cut tube insertion port 6, and the connection tube receiving port. 8 is provided with a biting means 18 for biting and moving the retaining member 17 toward the inner side 53 in the pipe radial direction when moving toward the disengagement direction.

  A plurality of retaining recesses 19 that open toward the inner side 53 in the radial direction of the pipe are formed at a plurality of locations at equal intervals in the circumferential direction of the inner peripheral surface of the connection pipe receiving port 8. The retaining member 17 is fitted into the retaining recess 19 so as to be able to bite and move inward in the tube radial direction 53. A biting protrusion 20 is formed on the inner surface of each retaining member 17.

  The biting means 18 includes a receiving surface 21 formed on the outer surface of the retaining member 17, and a plurality of pressing bolts 22 (an example of pressing means) that press the retaining member 17 toward the radially inner side 53 through the receiving surface 21. ). The receiving surface 21 is inclined outward in the pipe radial direction toward the back side of the connection pipe receiving port 8. The pressing bolt 22 is screwed into a screw hole 23 that penetrates both the inside and outside of the connection pipe receiving port 8, is inclined so as to be orthogonal to the receiving surface 21, and the tip portion is a receiving surface. 21 abuts.

  In addition, on the inner peripheral surface of the connection pipe receiving port 8, a fitting groove 25 located on the back side of the retaining recess 19 and a concave part 26 located on the back side of the fitting groove 25 are formed over the entire circumference. ing. Between the fitting groove 25 and the recessed part 26, the convex part 27 which protrudes toward the pipe radial direction inner side 53 is formed over the perimeter.

  As shown in FIGS. 2, 4, and 5, the first sealing member 12 seals between the cut tube insertion port 6 and the connection tube receiving port 8 over the entire circumference. One example) The valve portion 29 that is made of an annular shape and is sandwiched between the heel portion 28 fitted in the fitting groove 25, and the inner peripheral surface of the connection tube receiving port 8 and the outer peripheral surface of the cut tube insertion port 6. And have. The heel portion 28 is an annular member having a square cross-sectional shape (cross-sectional shape perpendicular to the circumferential direction).

  The valve part 29 is an annular member and includes a first valve 30 and a second valve 31 that are joined to each other. As shown in FIGS. 4 and 5, in the non-compressed state (non-use state) in which the first seal member 12 is removed from the connection pipe receiving port 8, the cross-sectional shape of the first valve 30 is long in the tube axis direction. The second valve 31 has a circular shape with a radius r2 and has a circular shape with a semicircular portion with a radius r1 at both ends. The radius r1 is smaller than the radius r2, and the thickness T1 of the first valve 30 is thinner than the thickness T2 of the second valve 31. Further, the diameter (= 2 × r2) of the cross section of the second valve 31 is formed larger than the interval S in the tube diameter direction between the inner peripheral surface of the convex portion 27 and the outer peripheral surface of the cut tube insertion opening 6.

  The first valve 30 is joined to the heel portion 28, and a sealing material side recess 32 is formed on the outer peripheral portion of the joint portion between the first valve 30 and the heel portion 28. The inner diameter of the first valve 30 is slightly smaller than the outer diameter of the cut tube insertion opening 6, and the outer diameter of the first valve 30 is slightly larger than the inner diameter of the convex portion 27.

  The heel portion 28 is located on the opening side (front side) opposite to the back side of the connection tube receiving port 8 with respect to the first valve 30. Further, a constricted portion 33 that is thinner than the first and second valves 30 and 31 is formed at a joint portion between the first valve 30 and the second valve 31. Arc-shaped sealing material side concave portions 34 and 35 are formed on the inner peripheral surface and the outer peripheral surface of the constricted portion 33, respectively.

  The second valve 31 is located on the back side of the connection pipe receiving port 8 with respect to the first valve 30 and faces the pipe center from the first valve 30 in an uncompressed state in which the first seal member 12 is removed. Is inclined. As shown in FIG. 5, the surface including the center P1 of the semicircular portion of the end portion of the first valve 30 near the second valve 31 and the center P2 of the second valve 31 is L1, and includes the center P1. If the radial surface of the first sealing material 12 is L2, the inclination angle M of the surface L1 with respect to the surface L2 is set to 15 to 35 °. Furthermore, the inner diameter d of the second valve 31 is set to be smaller than the outer diameter D (see FIG. 2) of the cut tube insertion opening 6, and the second valve 31 can be expanded and contracted in the tube diameter direction by elastic deformation of the constricted portion 33. Further, the inner diameter J of the heel portion 28 is set larger than the inner diameter K of the first valve 30.

  A first seal portion 37 that is in pressure contact with the inner peripheral surface of the convex portion 27 (the inner peripheral surface of the connection pipe receiving port 8) is formed on the outer peripheral portion of the first valve 30 over the entire periphery. Further, a second seal portion 38 that is in pressure contact with the outer peripheral surface of the cut tube insertion opening 6 is formed on the inner peripheral portion of the second valve 31 over the entire periphery. The position of the first seal portion 37 and the position of the second seal portion 38 are shifted in the tube axis direction. The length of the convex portion 27 in the tube axis direction is set to a length that does not compress the second valve 31. The heel portion 28 is made of a harder rubber than the valve portion 47.

  As shown in FIG. 1, a retaining protrusion 45 is formed on the outer periphery of the distal end portion of the connection pipe insertion opening 9 over the entire periphery. It should be noted that the removal protrusion 45 is formed at a position retracted in the extraction direction by a predetermined distance from the distal end surface of the connection tube insertion opening 9.

  Further, on the inner peripheral surface of the receiving port 7 of the other pipe 3, there are a fitting groove 46, a concave portion 47 positioned on the deeper side of the receiving port than the fitting groove 46, and a lock positioned on the deeper side of the receiving port than the concave portion 47. A ring receiving groove 48 is formed over the entire circumference. A convex portion 49 is formed between the fitting groove 46 and the concave portion 47.

  The lock ring 14 and the centering body 15 are housed in the lock ring housing groove 48. The lock ring 14 is a metal ring that is divided by one piece in the circumferential direction, and is configured to elastically hold onto the outer peripheral surface of the connection pipe insertion opening 9 by having an elastic diameter reducing force. The centering body 15 is made of an elastic material such as rubber, and is arranged between the outer peripheral surface of the lock ring 14 and the bottom surface of the lock ring receiving groove 48, and the connecting pipe insertion port 9 is inserted into the receiving port 7. When not, the lock ring 14 can be held in a centered state with respect to the receiving port 7. Note that the retaining protrusion 45 of the connection pipe insertion opening 9 can be engaged with the lock ring 14 from the back of the receiving opening.

  The second sealing material 13 seals between the receiving port 7 and the connecting pipe insertion port 9 over the entire circumference, and is connected to the heel portion 50 fitted in the fitting groove 46 and the inner peripheral surface of the receiving port 7. And a valve portion 51 sandwiched between the outer peripheral surface of the tube insertion opening 9. The second sealing material 13 has the same configuration as the first sealing material 13.

Hereinafter, the operation of the above configuration will be described.
When the cut tube 2 and the other tube 3 are connected via the connection tube 4, the heel of the first sealing material 12 is inserted into the fitting groove 25 in the connection tube receiving port 8 of the connection tube 4 as shown in FIG. The first sealing material 12 is mounted in the connection pipe receiving port 8 by fitting the portion 28.

  Thereafter, the cut tube insertion opening 6 of the cut tube 2 is inserted into the connection tube receiving port 8. At this time, as shown in FIG. 7, the tip of the cut tube insertion opening 6 is inserted into the inner periphery of the first valve 30, contacts the second valve 31, and pushes the second valve 31 in the insertion direction. As a result, as shown in FIG. 8, the second valve 31 is expanded (expanded) in the tube diameter direction, and a gap 52 is formed between the expanded outer periphery of the second valve 31 and the bottom surface of the recess 26. Formed over. Thereafter, as shown in FIG. 9, the cut tube 2 and the connection tube 4 are connected by further inserting the cut tube insertion port 6 into the connection tube receiving port 8.

  At this time, since the second valve 31 is in an expanded (expanded) state in the tube diameter direction, the second valve 31 sticks to the outer peripheral surface of the cut tube insertion opening 6 and is attached to the expanded diameter of the second valve 31. The valve 30 is pushed outward in the pipe radial direction. As a result, the first seal portion 37 of the first valve 30 is pressed against the inner peripheral surface of the convex portion 27 (the inner peripheral surface of the connection pipe receiving port 8), and the second seal portion 38 of the second valve 31 is cut off. Since it press-contacts with the outer peripheral surface of the insertion port 6, high watertightness can be maintained between the connection pipe receiving port 8 and the cut tube insertion port 6, and between the cut tube insertion port 6 and the connection tube reception port 8 Is reliably sealed by the first sealing material 12.

  When the cut tube insertion port 6 is inserted into the connection tube receiving port 8 as described above, the constricted portion 33 thinner than the first and second valves 30 and 31 is deformed as shown by the phantom line in FIG. Since the second valve 31 expands in the tube diameter direction, the force required to expand the second valve 31 in the tube diameter direction is reduced, and thereby the cut tube insertion port 6 is inserted into the connection tube receiving port 8. The insertion force (bonding force) required at the time can be reduced.

  Further, as shown in FIG. 5, since the inner diameter J of the heel portion 28 is larger than the inner diameter K of the first valve 30, the first valve 30 is connected to the outer peripheral surface of the cut tube insertion opening 6 and the inner peripheral surface of the convex portion 27. A portion of the first valve 30 can escape between the heel portion 28 and the cut tube insertion opening 6 when being compressed in the tube radial direction. Also by this, the insertion force (bonding force) can be reduced.

  Furthermore, as shown in FIG. 8, when the first valve 30 is compressed in the pipe radial direction between the outer peripheral surface of the cut tube insertion opening 6 and the inner peripheral surface of the convex portion 27, each sealing material side concave portion 32, 34 and 35 (refer FIG. 5) become clearance, and the compression amount of the 1st valve | bulb 30 reduces. Thereby, since the cut tube insertion opening 6 smoothly moves in the tube axis direction along the inner periphery of the first valve 30, the insertion force (joining force) can be reduced.

  Further, as shown in FIG. 5, since the thickness T1 of the first valve 30 is thinner than the thickness T2 of the second valve 31, the cut tube insertion opening 6 extends the inner periphery of the first valve 30 in the direction of the tube axis. When moving, the amount of compression in the tube diameter direction of the first valve 30 decreases, and the cut tube insertion port 6 moves smoothly in the tube axis direction along the inner periphery of the first valve 30, and the above insertion force (joining force) Can be reduced.

  Furthermore, as shown in FIG. 9, when the cut tube insertion opening 6 moves on the inner periphery of the second valve 31, the gap 52 becomes a clearance, and the second valve 31 moves relative to the cut tube insertion opening 6. It is possible to escape by displacing outward in the tube diameter direction. Thereby, the insertion force (bonding force) can be further reduced.

  Further, when water pressure acts inside the cut pipe 2 and the connecting pipe 4 joined to each other, as shown in FIG. 2, the water pressure causes the valve portion 29 to be opened from the back side of the connecting pipe receiving port 8 to the opening side (front side). The pushing force F1 to be pushed out acts on the tube axis direction. On the other hand, since the position of the first seal portion 37 and the position of the second seal portion 38 are displaced in the tube axis direction, the valve portion 29 is opened from the back side of the connection tube receiving port 8 by the pushing force F1. It can prevent being pushed out to the side. In particular, the greater the displacement amount A in the tube axis direction between the position of the first seal portion 37 and the position of the second seal portion 38 is, the more the valve portion 29 is pushed out with respect to a large pushing force F1. Can be prevented. Thereby, the watertightness between the cut tube insertion port 6 and the connection tube receiving port 8 is improved.

  Further, since the first seal portion 37 of the first valve 30 is in pressure contact with the inner peripheral surface of the convex portion 27 in the connection pipe receiving port 8, the outer diameter of the first valve 30 is reduced and the inner diameter of the convex portion 27 is increased. Accordingly, the gap between the convex portion 27 and the cut tube insertion opening 6 is reduced, and the absolute value of the water pressure acting on the first sealing material 12 during a hydraulic load is reduced. Therefore, the first sealing member 12 is not easily detached from the gap between the cut tube insertion opening 6 and the connection pipe receiving port 8 even under high water pressure load.

  Further, the diameter (= 2 × r2) of the cross section of the second valve 31 shown in FIG. 5 is larger than the interval S in the radial direction between the inner peripheral surface of the convex portion 27 and the outer peripheral surface of the cut tube insertion opening 6. Therefore, even if the valve portion 29 is pushed by the pushing force F1, the second valve 31 does not easily pass through the interval S, and the valve portion 29 is also opened from the back side of the connection pipe receiving port 8 by this. It can prevent being pushed out to the side.

  Further, since water pressure also acts on the gap 52 between the outer periphery of the second valve 31 and the bottom surface of the concave portion 26, a pressing force F2 directed toward the center of the tube acts on the second valve 31, thereby the second valve 31. The second seal portion 38 is strongly pressed against the outer peripheral surface of the cut tube insertion opening 6, and the watertightness between the cut tube insertion opening 6 and the connection tube receiving opening 8 is further improved.

  After that, as shown in FIG. 2, each pressing bolt 22 is tightened and each retaining member 17 is pressed toward the inner side 53 in the radial direction of the tube, so that the biting protrusion 20 of the retaining member 17 is Cut into the outer peripheral surface.

  Further, as shown in FIG. 1, the lock ring 14 and the centering body 15 are fitted into the lock ring receiving groove 48 of the receiving port 7 of the other pipe 3, and the second seal is inserted into the fitting groove 46 of the receiving port 7. The heel portion 50 of the material 13 is fitted, and the second sealing material 13 is mounted in the receiving port 7. Thereafter, the connecting pipe insertion opening 9 is inserted into the receiving opening 7, and the retaining protrusion 45 of the connecting pipe insertion opening 9 is passed from the receiving opening side of the lock ring 14 to the receiving opening back side.

  At this time, the retaining projection 45 of the connection pipe insertion opening 9 passes through the inner periphery of the second sealing material 13, but the connection pipe insertion opening 9 is inserted into the receiving opening 7 in the same manner as the first sealing material 12. The insertion force (bonding force) required at the time can be reduced. Similarly to the first sealing material 12, the second sealing material 13 improves the watertightness between the receiving port 7 and the connecting pipe insertion port 9.

  In addition, when the disconnection force (extraction force) acts on the pipe joint structure 1 due to ground fluctuation such as an earthquake and the like, and the connection pipe 4 and the other pipe 3 try to move away relatively, the retaining protrusion 45 is locked. By engaging the ring 14 from the back side of the receiving port, the relative disengagement between the connecting tube insertion port 9 and the receiving port 7 is strongly prevented.

  Furthermore, when the above detachment force acts and the cutting tube 2 and the connecting tube 4 try to move relatively away, each retaining member 17 bites and moves toward the radially inner side 53 by the biting means 18. Since the biting protrusion 20 bites into the outer peripheral surface of the cut tube insertion opening 6, the connection between the cut tube insertion opening 6 and the connection pipe receiving opening 8 is strongly maintained.

Moreover, as shown in FIG. 1, although the cut end surface of the cut tube insertion opening 6 is not painted, since the anticorrosion member 10 is attached, corrosion can be prevented.
Next, a second embodiment of the present invention will be described with reference to FIG.

  The detachment preventing means 60 is provided in an annular detachment preventing ring 61 that is externally fitted to the cut tube insertion opening 6 and the connection tube receiving opening 8. Similar to the first embodiment, the separation preventing means 60 includes a plurality of retaining members 17 and a biting means 18. The plurality of retaining recesses 19 are formed on the inner peripheral surface of one end of the separation preventing ring 61 in the tube axis direction, and the retaining member 17 is fitted in the retaining recess 19. The biting means 18 has a receiving surface 21 and a pressing bolt 22.

  Fixing means 62 for fixing the separation preventing ring 61 to the outer periphery of the connection tube receiving port 8 is provided at the other end of the separation preventing ring 61 in the tube axis direction. The fixing means 62 includes a fixing groove 63 formed on the entire inner periphery of the separation preventing ring 61, a fixing ring 64 fitted in the fixing groove 63, and pressing the fixing ring 64 toward the radially inner side 53. And a plurality of fixing bolts 65.

  The fixing ring 64 is a metal ring having a circumferentially divided structure, and is externally fitted to the connection pipe receiving port 8. Further, the fixing bolts 65 are provided at a plurality of locations at equal intervals in the circumferential direction of the separation preventing ring 61.

Hereinafter, the operation of the above configuration will be described.
With the fixing ring 64 fitted in the fixing groove 63, the separation preventing ring 61 is fitted on the connection pipe receiving port 8, and the fixing bolt 65 is tightened to press the fixing ring 64 toward the inner side 53 in the radial direction. To do. As a result, the fixing ring 64 is pressed against the outer peripheral surface of the connection pipe receiving port 8, so that the separation preventing ring 61 is fixed to the outer periphery of the connection pipe receiving port 8.

  Next, in a state where the retaining member 17 is fitted in the retaining recess 19, the cut tube insertion port 6 is inserted into the connection tube receiving port 8, and then the pressing bolt 22 is tightened to bring the retaining member 17 into the radial direction. By pressing toward the direction 53, the biting protrusion 20 is bitten into the outer peripheral surface of the cut tube insertion opening 6.

  When the detachment force acts on the pipe joint structure 1 due to ground fluctuation such as an earthquake, and the cutting pipe 2 and the connecting pipe 4 attempt to detach and move relative to each other, each retaining member 17 is brought into the pipe radial direction by the biting means 18. Since the biting protrusion 20 bites into the outer peripheral surface of the cut tube insertion opening 6, the connection between the cut tube insertion opening 6 and the connection tube receiving opening 8 is strongly maintained.

DESCRIPTION OF SYMBOLS 1 Pipe joint structure 2 Cut pipe 3 Other pipe 4 Connection pipe 6 Cut pipe insertion slot 7 Receptacle 8 Connection pipe receptacle 9 Connection pipe insertion slot 11,60 Detachment prevention means 12 1st sealing material 14 Lock ring (locking Element)
17 Detachment member 18 Biting means 25 Fitting groove 26 Recessed portion 27 Protruded portion 28 Heel portion 29 Valve portion 30 First valve 31 Second valve 32, 34, 35 Sealing material side recessed portion 33 Constricted portion 37 First seal portion 38 Second seal portion 45 Prevention protrusion 52 Gap 61 Detachment prevention ring T1 Thickness in the radial direction of the first valve T2 Thickness in the radial direction of the second valve

Claims (9)

A pipe joint structure in which a cut tube having a cut end portion manufactured by cutting to a predetermined size at a construction site and a receiving port formed at the end portion of another pipe are connected via a connecting pipe. ,
The connecting pipe has a connecting pipe receptacle at one end and a connecting pipe insertion opening at the other end,
The cut end of the cut tube is inserted into the connection tube receiving port of the connection tube as a cut tube insertion port,
The connecting pipe insertion port of the connecting pipe is inserted into the receiving port of another pipe,
The connection pipe insertion opening is provided with a locking protrusion that can be engaged from the receiving port back side to a locking member provided on the inner periphery of the receiving port of the other tube.
A detachment preventing means for preventing detachment between the cut tube insertion port and the connection tube receiving port is provided,
Between the cut tube insertion port and the connection tube receiving port is sealed over the entire circumference by an annular sealing material made of an elastic material,
The sealing material includes a heel portion that is fitted into a fitting groove formed on the inner peripheral surface of the connection pipe receiving port, and a valve portion that is sandwiched between the inner peripheral surface of the connection pipe receiving port and the outer peripheral surface of the cut tube insertion port. Have
The valve portion includes a first valve and a second valve joined to each other,
A first seal portion that is in pressure contact with the inner peripheral surface of the connection pipe receiving port is formed on the outer peripheral portion of the first valve,
A second seal portion that is in pressure contact with the outer peripheral surface of the cut tube insertion opening is formed on the inner peripheral portion of the second valve,
The first valve is joined to the heel,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is located on the back side of the connection pipe receiving port with respect to the first valve, and is inclined from the first valve toward the pipe center,
The heel portion is located on the opening side opposite to the back side of the connection pipe receiving port with respect to the first valve,
The second valve, the inner diameter is smaller than the outer diameter of the cut pipe spigot, and, Ri scaled freely der in pipe diameter direction by the deformation of the constricted portion,
On the inner peripheral surface of the connection pipe receptacle, a recess located on the back side of the fitting groove is formed,
The thickness of the first valve in the radial direction is thinner than the thickness of the second valve in the radial direction,
A pipe joint structure characterized in that a gap is formed between the outer periphery of the second valve and the bottom surface of the recess of the connection pipe receiving port . On the inner peripheral surface of the connection pipe receptacle, a convex portion is formed between the fitting groove and the concave portion,
The first seal portion is in pressure contact with the inner peripheral surface of the convex portion,
The pipe joint structure according to claim 1, wherein the position of the first seal part and the position of the second seal part are shifted in the axial direction of the pipe. The pipe joint structure according to claim 1 or 2, wherein a concave portion on the sealing material side is formed on each of an inner peripheral surface and an outer peripheral surface of the constricted portion. The pipe joint structure according to any one of claims 1 to 3, wherein a concave portion on the sealing material side is formed at a joint portion between the first valve and the heel portion. The pipe joint structure according to any one of claims 1 to 4, wherein the constricted portion is thinner than the first and second valves . The pipe joint structure according to any one of claims 1 to 5, wherein the detachment preventing means is provided in the connection pipe receiving port. 6. The disengagement prevention means is provided on a disengagement prevention ring that is externally fitted to the cut tube insertion port and the connection tube receiving port and is fixed to the connection tube receiving port. The pipe joint structure according to claim 1. The separation preventing means includes a retaining member that can bite and move from the pipe radial direction to the outer peripheral surface of the cut tube insertion opening, and a retaining member when the cut tube insertion opening and the connection tube receiving port are relatively moved in the separation direction. The pipe joint structure according to any one of claims 1 to 7, further comprising: a biting unit that bites and moves the pipe toward an inner side in the pipe radial direction. A connecting pipe that connects a cut tube having a cut end manufactured by cutting into a predetermined dimension at a construction site and a receiving port formed at the end of another pipe,
A connection pipe receiving port into which the cut end of the cut tube is inserted as a cut tube insertion port is provided at one end,
A connecting tube insertion port to be inserted into the receiving port of another tube is provided at the other end,
The connection pipe insertion opening is provided with a locking protrusion that can be engaged from the receiving port back side to a locking member provided on the inner periphery of the receiving port of the other tube.
Detachment between the cutting tube insertion port and the connection tube receiving port is prevented by the separation preventing means,
An annular sealing material made of an elastic material that seals between the cut tube insertion port and the connection tube receiving port over the entire circumference is disposed in the connection tube receiving port,
The sealing material includes a heel portion that is fitted in a fitting groove formed on the inner peripheral surface of the connection tube receiving port, and a valve portion that is sandwiched between the inner peripheral surface of the connection tube receiving port and the outer peripheral surface of the cut tube insertion port. And
The valve portion includes a first valve and a second valve joined to each other,
A first seal portion that is in pressure contact with the inner peripheral surface of the connection pipe receiving port is formed on the outer peripheral portion of the first valve,
A second seal portion that is in pressure contact with the outer peripheral surface of the cut tube insertion opening is formed on the inner peripheral portion of the second valve,
The first valve is joined to the heel,
A constriction is formed at the joint between the first valve and the second valve,
The second valve is located on the back side of the connection pipe receiving port with respect to the first valve, and is inclined from the first valve toward the pipe center,
The heel portion is located on the opening side opposite to the back side of the connection pipe receiving port with respect to the first valve,
The second valve has its inner diameter is smaller than the outer diameter of the cut pipe spigot, and, Ri scaled freely der in pipe diameter direction by the deformation of the constricted portion,
On the inner peripheral surface of the connection pipe receptacle, a recess located on the back side of the fitting groove is formed,
The thickness of the first valve in the radial direction is thinner than the thickness of the second valve in the radial direction,
A connection pipe characterized in that a gap is formed between the outer periphery of the second valve and the bottom surface of the recess of the connection pipe receiving port.

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