JP6525636B2 - How to connect backup ring, fittings and pipes - Google Patents

Description

  The present invention relates to a joint for connecting pipes such as cast iron pipes, a backup ring used for the joint, and a method of connecting pipes using the joint.

  Conventionally, as a joint of this type, for example, as shown in FIG. 21, an annular rubber ring 103 in which an insert 102 is inserted into a socket 101 and seals a gap between the socket 101 and the socket 102; A seal member accommodating portion 104 for accommodating the inner ring 103 between the inner peripheral surface of the socket 101 and the outer peripheral surface of the slot 102, and a push ring 105 for pressing the rubber ring 103 backward from the opening end of the socket 101 are provided. ing.

  A constricted portion 106 is formed on the inner side of the receiving port 101 than the sealing member accommodating portion 104. The distance 107 between the inner peripheral surface of the socket 101 and the outer peripheral surface of the inlet 102 in the narrowed portion 106 is narrower than the distance 108 between the inner peripheral surface of the socket 101 and the outer peripheral surface of the inlet 102 in the seal member housing 104 It is formed. The joint 109 provided with such a rubber ring 103 and a push ring 105 is described, for example, in Patent Document 1 below.

  According to this, when pressing the rubber ring 103 with the pressing ring 105, if an excessive pressing force acts on the rubber ring 103, the inner end of the rubber ring 103 enters the narrowed portion 106 from the seal member accommodation portion 104. There is a possibility that the surface pressure of the rubber ring 103 may be reduced to reduce the water tightness (sealing performance).

  In addition, as another joint, as shown in FIG. 22, there is a type in which a backup ring 112 is provided to prevent the back end portion of the sealing material 113 from entering the lock ring 114 side. The joint 115 provided with such a backup ring 112 is described, for example, in Patent Document 2 below.

Japanese Utility Model Hei 6-40570 Japanese Patent Application Publication No. 2008-89095

  When the backup ring 112 of another joint 115 shown in FIG. 22 is provided in the joint 109 shown in FIG. 21, the back end of the rubber ring 103 is a backup ring even if an excessive pressing force acts on the rubber ring 103. By coming into contact with 112, it is difficult for the back end of the rubber ring 103 to enter the narrowed portion 106.

  However, since the interval 107 of the constricted portion 106 fluctuates due to manufacturing tolerances of the inlet 101 and the inlet 102, the rear end of the rubber ring 103 is constricted from the seal member accommodating portion 104 together with the backup ring 112 when the interval 107 becomes large. There is a risk of getting into the unit 106.

  An object of the present invention is to provide a backup ring, a joint, and a method of connecting pipes, which can reliably prevent the seal member from entering the narrowed portion from the seal member accommodating portion.

In order to achieve the above object, according to the first aspect of the present invention, an insertion port is inserted into a socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A backup used in a joint in which a narrow portion where the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing is deeper than the seal housing. A ring,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is annularly formed, has a plurality of cut portions in the circumferential direction, is provided in the ring main body portion, is radially deformable, and has an inner peripheral surface of the socket and a slot It abuts on any other surface of the outer peripheral surface.

  According to this, the ring body portion of the backup ring is fitted between the back end portion of the seal member and the constriction portion, and either the inner circumferential surface of the socket or the outer circumferential surface of the inlet is inserted by the body pressing portion. In this state, the seal member is locked to the constriction portion from the pressing direction of the seal member. Therefore, even when the gap (spacing) of the constriction is increased due to manufacturing tolerances of the socket and the insert, it is possible to prevent the ring main body of the backup ring from entering the gap of the constriction from the seal member housing. .

Then, the ring body portion of the backup ring is pressed against one of the inner peripheral surface of the socket and the outer peripheral surface of the insertion opening, and the main body pressing portion of the backup ring abuts the other surface. Even when the gap between the two members is large, it is possible to reliably prevent the seal member from entering the narrowed portion from the seal member accommodation portion.
Further, since the main body pressing portion can be easily curved in an annular shape, the backup ring can be easily attached to the joint.

In the backup ring in the second aspect of the present invention, the main body pressing portion is provided at a plurality of locations of the ring main body portion in the axial direction of the tube.
According to this, since the ring main body portion is provided with a plurality of main body pressing portions, the ring main body portion is strongly pressed against one of the inner peripheral surface of the socket and the outer peripheral surface of the insertion port. Can be prevented from separating from the one end face and between the deep end portion of the seal member and the narrowed portion.

In the backup ring according to the third aspect of the present invention , a socket is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A backup used in a joint in which a narrow portion where the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing is deeper than the seal housing. A ring,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is provided on the ring main body portion, is radially deformable, and abuts on the other of the inner peripheral surface of the socket and the outer peripheral surface of the insertion port,
At least two body pressing parts are provided opposite to each other in the axial direction of the tube and provided on the ring body;
In the natural state where the joint is not attached, both body pressing parts are inclined such that the distance between the free ends is larger in the tube axial direction than the distance between the base ends attached to the ring body. It is
According to this, the ring main body portion can be attached in a stable posture by the free end portions of both the main body pressing portions coming into contact with either the inner peripheral surface of the socket or the other outer peripheral surface of the inlet. . Furthermore, when the gap in the narrowed portion becomes smaller, the backup ring is easily compressed in the radial direction, and at the same time, the main body pressing portion in contact with the back end of the seal member is deformed in the direction of resisting the pressing direction of the seal member. The sealing member can be reliably prevented from entering the gap of the narrowed portion.

In the backup ring according to the fourth aspect of the present invention, in the natural state where the joint is not attached, the distance between the free ends of the two main body pressing portions in the axial direction is longer than the length of the ring main portion in the axial direction. is there.
According to this, even when both the main body pressing portions are deformed in the radial direction, the free end portions of both main body pressing portions surely ensure the respective surfaces of the inner peripheral surface of the receptacle and the outer peripheral surface of the insertion opening. The ring body can be attached in a stable posture.

In the backup ring according to the fifth aspect of the present invention, the main body pressing portion is formed in an annular shape, and has a plurality of cut portions in the circumferential direction .
According to this, since the main body pressing portion can be easily curved in an annular shape, the backup ring can be easily attached to the joint.
In the backup ring according to the sixth aspect of the present invention, the length of the main body pressing portion in the radial direction is larger than the thickness of the ring main body portion in the radial direction in a natural state where the backup ring is not attached to the joint.
According to this, since the main body pressing portion is deformed in the radial direction, it is possible to widely follow the change in the size of the gap of the narrowed portion, and the ring main body portion is stabilized regardless of the manufacturing tolerance of the socket and the insertion port. It can be attached in the same posture.

In the backup ring according to the seventh aspect of the present invention, in the natural state in which the joint is not mounted, the cross-sectional shape of the backup ring intersecting the plane including the tube axis is symmetrical with respect to the straight line passing the backup ring from the tube axis It is.
According to this, when attaching the backup ring to the joint, it is possible to prevent the attachment direction of the backup ring from being mistaken.

An eighth invention is a joint provided with the backup ring according to any one of the first to seventh inventions,
Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A narrowed portion in which the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is smaller than that of the seal member housing portion is formed deeper in the socket than the seal member housing portion .
In the joint according to the ninth aspect of the present invention , a projection projecting radially inward is formed on the inner peripheral surface of the socket,
The constriction is formed between the projection and the mouthpiece,
The ring body portion of the backup ring is fitted between the back end of the seal member and the projection, and is engaged with the projection from the pressing direction of the seal member,
The main body pressing portion is in contact with the outer peripheral surface of the insertion opening, and presses the ring main body portion against the inner peripheral surface of the socket.
According to this, even when the gap of the constriction part is enlarged due to the manufacturing tolerance of the socket and the insertion port, it is possible to prevent the ring body of the backup ring from entering the gap of the constriction part from the seal member accommodating part. In addition, the sealing member can be reliably prevented from entering the narrowed portion from the sealing member accommodation portion.

Joint in the tenth invention, the outer peripheral surface of the inserting, projections projecting radially outward are formed,
The constriction is formed between the projection and the socket,
The ring body portion of the backup ring is fitted between the back end of the seal member and the projection, and is engaged with the projection from the pressing direction of the seal member,
The main body pressing portion is in contact with the inner peripheral surface of the socket, and presses the ring main body portion against the outer peripheral surface of the insertion opening.
According to this, even when the gap of the constriction part is enlarged due to the manufacturing tolerance of the socket and the insertion port, it is possible to prevent the ring body of the backup ring from entering the gap of the constriction part from the seal member accommodating part. In addition, the sealing member can be reliably prevented from entering the narrowed portion from the sealing member accommodation portion.

In the joint according to the eleventh aspect of the present invention, the projection has a locking surface orthogonal to the tube axis on the near side in the tube axis direction,
The ring main body portion of the backup ring is engaged with the locking surface of the projection in the pressing direction of the seal member.
According to this, the ring main body portion of the backup ring is fitted between the back end portion of the seal member and the projection, and is locked to the locking surface of the projection in the pressing direction of the seal member. As a result, even when the gap in the constriction part is increased due to manufacturing tolerances of the socket and the insertion port, it is possible to prevent the ring body of the backup ring from entering the gap in the constriction part from the seal member accommodation part.

In the joint according to the twelfth aspect of the present invention, the radial thickness of the ring body of the backup ring is greater than the radial height of the locking surface of the projection.
According to this, the ring main body portion of the backup ring is reliably locked to the locking surface of the projection from the pressing direction of the seal member.

In the joint according to the thirteenth aspect of the present invention, receptacles are provided at both ends of the tubular joint ring,
An insert is provided at the end of the tube,
Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A narrowed portion in which the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing portion is formed in the back of the socket than the seal member housing portion;
In the outer peripheral surface of the insertion opening, a separation preventing projection exposed to the outside of the socket and protruding radially outward is provided.
A release preventing means is provided which engages with the release preventing projection to prevent the insertion port from moving in the release direction for release from the receptacle;
Inside the receptacle, a backup ring is provided to prevent the seal member from entering the narrowed portion from the seal member accommodation portion,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is formed in an annular shape, has a plurality of cut portions in the circumferential direction, is provided in the ring main body portion, is radially deformable, and has an inner peripheral surface of the socket and a slot It abuts on any other surface of the outer peripheral surface.

According to this, when the detachment preventing means engages with the detachment preventing projection, the insertion port is prevented from moving in the detachment direction, and the insertion port can be prevented from being detached from the receptacle.
In addition, even when the gap in the constriction part is increased due to manufacturing tolerances of the socket and the insertion port, the ring main body of the backup ring can be prevented from entering the gap in the constriction part from the seal member accommodation part. In addition, the sealing member can be reliably prevented from entering the narrowed portion from the sealing member accommodation portion.
Further, since the main body pressing portion can be easily curved in an annular shape, the backup ring can be easily attached to the joint.

  As described above, according to the present invention, the seal member can be reliably prevented from entering the narrowed portion from the seal member accommodation portion.

It is a figure of the pipeline provided with the coupling in a 1st embodiment of the present invention. FIG. It is an expanded sectional view of a socket and a slot of a joint equally. It is an expanded sectional view of the backup ring with which the joint was equipped equally. It is a front view of the same backup ring, and shows the natural state which is not attached to a joint. It is an XX arrow line view in FIG. Similarly, it is a partially enlarged front view of a backup ring, and shows a linearly extended state in a natural state where it is not attached to a joint. Similarly, it is a partially enlarged front view of the backup ring, and shows a state of being curved in an annular shape in a natural state where it is not attached to the joint. It is a YY arrow line view in FIG. It is a figure which similarly shows the connection method of the pipe | tube which used the coupling, and shows the state which connected one pipe | tube. It is a figure which shows the connection method of the pipe | tube which used the coupling similarly, and shows the state which carried out external fitting of the press means, the detachment prevention means, and the joint ring to one pipe, and was made to move to one direction. It is sectional drawing in the state which fitted the pressing means, the detachment prevention means, and the joint ring on one pipe | tube, and was moved to one direction. It is a figure which similarly shows the connection method of the pipe | tube which used the coupling, and shows the state which connected the other pipe | tube. It is a figure which similarly shows the connection method of the pipe | tube which used the coupling, and shows the state which externally fitted the press means and the detachment prevention means to the other pipe | tube. Similarly, it is a figure which shows the connection method of the pipe | tube which used the coupling, and shows the state which moved the joint ring to the other direction. It is a figure which similarly shows the connection method of the pipe | tube which used the coupling, and shows the state which set the press means and the detachment prevention means. It is sectional drawing which shows the magnitude correlation with the internal diameter of the receiving part protrusion of a coupling | joint, and the outer diameter of the protrusion part for detachment | leave prevention equally in the same. It is an expanded sectional view of the backup ring with which the joint in a 2nd embodiment of the present invention was equipped. Similarly, it is a partially enlarged front view of the backup ring, and shows a state of being curved in an annular shape in a natural state where it is not attached to the joint. It is an XX arrow line view in FIG. It is sectional drawing of the conventional coupling. It is sectional drawing of another conventional coupling.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First Embodiment

  In the first embodiment, as shown in FIG. 1, 1 is a pipe such as a water pipe embedded so as to cross the road 2, and the pipe 1 is disposed on both sides of the road 2 And the other conduit 4 disposed below the road 2. One pipe 6 is connected to one pipe 3 and the other pipe 7 is connected to the other pipe 4.

  One pipe 6 and the other pipe 7 are connected via a joint 9. As shown in FIGS. 2 to 4, the joint 9 has a socket 10 provided at the end of the tubes 6 and 7, a cylindrical joint ring 11, and a socket provided at both ends of the joint ring 11. 12, an annular seal member 13 for sealing the gap between the insertion port 10 and the reception port 12, and a seal member for accommodating the seal member 13 between the outer peripheral surface of the insertion port 10 and the inner peripheral surface of the reception port 12 The housing portion 14, the pressing means 15 for pressing the seal member 13 from the opening end of the receptacle 12 to the back, the detachment preventing projection 16 provided on the entire outer peripheral surface of the insertion slot 10, and the detachment preventing protrusion A backup ring 18 or the like is provided with a separation preventing means 17 which engages with the portion 16 and prevents the insertion port 10 from moving in the separation direction A in which the insertion port 10 is separated from the reception port 12.

The mouthpiece 10 is inserted into the receptacle 12. For example, a rubber ring or the like is used for the sealing member 13. On the inner peripheral surface of the receptacle 12, a receptacle projection 20 (an example of a projection) projecting radially inward is formed over the entire circumference. The receiving protrusion 20 is formed on the inner side of the receiving hole 12 than the sealing member accommodating portion 14, and a narrowed portion 21 is formed between the receiving protrusion 20 and the insertion port 10. As shown in FIG. 4, the gap 22 in the radial direction B between the inner circumferential surface of the receiving protrusion 20 and the outer circumferential surface of the insertion opening 10 corresponds to the inner circumferential surface of the receiving opening 12 and the insertion opening 10 in the sealing member housing 14. The distance 23 is smaller than the distance 23 in the radial direction B with the outer circumferential surface of
The receiving protrusion 20 has a locking surface 20 a orthogonal to the tube axis 31 on the near side in the tube axis direction C.

  The pressing means 15 includes an annular push ring 27, an annular split ring 28 provided between the seal member 13 and the push ring 27, and a plurality of bolts 29 for fastening the flange portion of the receptacle 12 and the push ring 27. And a nut 30 (an example of a fastener). The push ring 27 and the split ring 28 are fitted around the insert 10. Further, the pressing ring 27 is provided with a plurality of centering bolts 32 for aligning the center of the pressing ring 27 with the tube axis 31 of the insertion opening 10. By tightening the nut 30, the push ring 27 approaches the receptacle 12 along the tube axis 31 and pushes the seal member 13 into the back of the receptacle 12 via the split ring 28.

  As shown in FIG. 2, the detachment preventing projection 16 is formed of a bead of welding, is exposed to the outside of the socket 12, and protrudes radially outward from the outer peripheral surface of the insertion port 10. The detachment prevention means 17 has an annular insertion ring 34 and an annular lock ring 35. The insertion ring 34 and the lock ring 35 are externally fitted to the insertion port 10. The insertion ring 34 is fastened to the receptacle 12 via the plurality of bolts 29 and nuts 36 (an example of a fastener), and is positioned on the side of the detachment direction A with respect to the detachment preventing projection 16. There is. The lock ring 35 is a split ring which is cut at one place, and is provided between the detachment preventing projection 16 and the insertion ring 34. The cut portion of the lock ring 35 is connected by a connector 35a.

  Further, the insertion ring 34 is provided with a plurality of centering bolts 37 for aligning the center of the insertion ring 34 with the tube axis 31 of the insertion hole 10. When the insertion port 10 tries to move in the disengaging direction A, the disengaging projection 16 is engaged with the lock ring 35 in the disengaging direction A, and the lock ring 35 is engaged with the insertion ring 34 in the disengaging direction A. The movement of the insertion port 10 in the removal direction A is blocked, and the insertion port 10 can be prevented from being inadvertently removed from the receiving port 12.

  As shown in FIGS. 4 to 9, the backup ring 18 is a ring for preventing the seal member 13 from entering the narrow portion 21 from the seal member accommodation portion 14, and one part is cut. It is a ring of The back-up ring 18 is a ring on the ring main body 40 fitted between the back end of the seal member 13 in the tube axial direction C and the narrowed portion 21 and the inner peripheral surface (one example of one surface) of the receiving port 12 A plurality of main body pressing portions 41 and 42 for pressing the main body portion 40 are provided. The backup ring 18 is made of a flexible material that can be bent in an annular shape, and is, for example, a resin ring using nylon 6 or the like.

  As shown in FIG. 9, both the main body pressing parts 41 and 42 are deformable annular thin plates, provided at both ends of the ring main body 40 in the tube axial direction C and on the inner peripheral side, They face each other in the cardiac direction C.

  Further, in the natural state where the joint 9 is not attached, the main body pressing parts 41 and 42 have a distance D1 between the free ends 41a and 42a between the base ends 41b and 42b attached to the ring main body 40. It inclines so as to expand in the tube axial direction C more than the distance D2. Further, in the natural state in which the joint 9 is not attached, the distance D1 is longer than the length E of the ring main body 40 in the tube axial direction C.

  Furthermore, in the natural state where the joint 9 is not attached, the length F of the main body pressing portions 41 and 42 in the radial direction B is larger than the thickness T of the ring main body portion 40 in the radial direction B. Further, as shown in FIG. 9, in the natural state where the joint 9 is not attached, the cross-sectional shape of the backup ring 18 intersecting the virtual plane 46 (see FIG. 5) including the pipe axis 31 is the pipe axis 31 From the backup ring 18 to the imaginary straight line 47 in the radial direction B. The ring body 40 has a rectangular cross-sectional shape.

As shown in FIGS. 5 and 7, each of the main body pressing portions 41 and 42 has a plurality of notches 44 at a plurality of locations in the circumferential direction G. The notches 44 are open at the inner peripheral ends of the main body pressing portions 41 and 42. Further, as shown in FIG. 4 and FIG. 9, the thickness T of the ring main body 40 is larger than the height H in the radial direction B of the locking surface 20 a of the receiving protrusion 20.
Hereinafter, the operation in the above configuration will be described.

  As shown in FIG. 2, in a state in which one pipe 6 and the other pipe 7 are connected via the joint 9, the push ring 27 is received along the pipe axis 31 by tightening the nut 30. , And push the seal member 13 into the back of the socket 12 via the split ring 28. Under the present circumstances, as shown in FIG. 4, the ring main-body part 40 of the backup ring 18 is inserted between the back end part of the sealing member 13 and the receiving part protrusion 20, and the restoring force of the main body pressing parts 41 and 42 ( Is pressed against the inner peripheral surface (an example of one surface) of the receiving port 12 and engaged with the locking surface 20a (the front side of the narrowed portion 21) of the receiving protrusion 20 from the pressing direction J of the sealing member 13. It has been stopped.

  Further, both the main body pressing portions 41 and 42 are in pressure contact with the outer peripheral surface of the opening 10, and one main body pressing portion 41 is curved in an L shape and the outer peripheral surface (other surface) of the opening 10 and the seal member 13 The other main body pressing portion 42 is curved and rushes into the narrowed portion 21.

  Thereby, even when the gap (spacing 22) of the narrowed portion 21 is increased due to manufacturing tolerances of the insertion port 10 and the receiving port 12, the ring main body 40 of the backup ring 18 is separated from the sealing member accommodating portion 14 Can be prevented from entering the

  Thus, when the ring main body portion 40 is pressed against the inner peripheral surface of the receptacle 12 and both the main body pressing portions 41 and 42 are in pressure contact with the outer peripheral surface of the opening 10, the gap of the narrowed portion 21 is enlarged. Alternatively, even in the case of contraction, the seal member 13 can be reliably prevented from entering the narrowed portion 21 from the seal member accommodation portion 14.

  In addition, since the two main body pressing portions 41 and 42 are provided in the ring main body portion 40, the ring main body portion 40 is strongly pressed against the inner peripheral surface of the receiving port 12, and the ring main body portion 40 is It is possible to prevent separation from between the back end of the seal member 13 and the receiving projection 20 apart from the circumferential surface.

  Further, since the free end portions 41a and 42a of the main body pressing portions 41 and 42 are respectively in pressure contact with the outer peripheral surface of the insertion port 10, the ring main body portion 40 can be attached in a stable posture.

  Further, since the thickness T (see FIG. 9) of the ring main body 40 is larger than the height H of the locking surface 20 a of the receiving projection 20, the ring main body 40 receives the opening from the pressing direction J of the seal member 13. The locking surface 20 a of the projection 20 is reliably locked.

  Further, in order to attach the backup ring 18 to the joint 9, the cutting portion 45 (see FIGS. 5 and 6) of the backup ring 18 is enlarged and the backup ring 18 is externally fitted to the insertion port 10. Under the present circumstances, as shown in FIG. 9, since the cross-sectional shape of the backup ring 18 is symmetrical with respect to the straight line 47 in the natural state before externally fitting to the insertion port 10, the backup ring 18 is externally fitted to the insertion port 10 When doing this, it is possible to prevent the mounting direction of the backup ring 18 from being mistaken.

Further, as shown in FIG. 7, since the main body pressing portions 41 and 42 each have a plurality of cut portions 44, the main body pressing portions 41 and 42 can be easily curved in an annular shape, and the backup ring 18 is Can be easily fitted over the insert 10.
Next, a method of connecting pipes using the joint 9 will be described below.

As shown in FIG. 1, since the road 2 does not exist above one of the pipelines 3, the ground is cut and one pipeline 3 is laid. Moreover, since the road 2 exists above the other pipeline 4, the ground is not cut and the other pipeline 4 is laid using a propulsion method.
Thereafter, the straight pipe is cut to an appropriate length to form one pipe 6, and welding is performed on the outer peripheral surface of the insertion port 10 of one pipe 6 to form a protrusion 16 for detachment prevention (see FIG. 2) Do.

  Next, as shown in FIGS. 10 and 11, one pipe 6 is connected to the end of one pipe line 3, and one seal member 13, the push ring 27, the split ring 28, the insertion ring 34 and the lock ring 35 is fitted on one of the tubes 6.

Next, as shown in FIG. 11 and FIG. 12, the joint ring 11 is externally fitted to the insertion port 10 of one of the pipes 6 and moved in one direction K along the pipe axis 31 to Overlay on the outside.
Next, the straight pipe is cut to an appropriate length to form the other pipe 7, and welding is performed on the outer peripheral surface of the insertion port 10 of the other pipe 7 to form the detachment preventing projection 16 (see FIG. 2). Form.

  Next, as shown in FIG. 13, the other pipe 7 is connected to the end of the other pipe 4, and as shown in FIG. 14, the other seal member 13, the push ring 27, the split ring 28 and the insertion ring 34 and lock ring 35 are fitted on the other tube 7.

  Next, alignment adjustment of one tube 6 and the other tube 7 is performed, and thereafter, as shown in FIG. 15, the joint ring 11 is moved along the tube axis 31 in the other direction M to The insertion port 10 of the pipe 7 is inserted into the other receiving port 12 of the joint ring 11, and the insertion port 10 of one pipe 6 is inserted into one receiving port 12 of the joint ring 11.

  Thereafter, the backup rings 18 are externally fitted to the insertion holes 10 of the one and the other pipes 6 and 7, respectively, and the push ring 27 is fastened to the socket 12 using the bolt 29 and the nut 30, and the nut 30 is tightened. The seal member 13 and the backup ring 18 are pushed into the inside of the receptacle 12 via the split ring 28.

  Thereafter, as shown in FIG. 16, the lock ring 35 and the insertion ring 34 are moved to the proper attachment position, and the insertion ring 34 is fastened to the socket 12 using the bolt 29 and the nut 36. As a result, as shown in FIG. 2, the pressing means 15 and the detachment preventing means 17 are set at proper positions, and one pipe 3 and the other pipe 4 are connected via the joint 9.

  In the connection method as described above, as shown in FIG. 12, the joint ring 11 is externally fitted to the insertion port 10 of one of the pipes 6, and moved in one direction K along the pipe axis 31 to one of the pipes. As shown in FIG. 17, the inner diameter Di of the receiving protrusion 20 is inserted into the insertion hole 10 so that the detachment preventing protrusion 16 of the insertion hole 10 does not abut on the receiving protrusion 20. It is necessary to make it larger than the outer diameter Do of the protrusion part 16 for detachment | leave prevention of this.

For this reason, as shown in FIG. 2, when one pipe 6 and the other pipe 7 are connected by the joint 9, a large gap (interval 22) is formed in the narrowed portion 21 as shown in FIG. By the operation and effect as described above, it is possible to prevent the ring main body 40 of the backup ring 18 from entering the gap of the narrowed portion 21 from the seal member accommodating portion 14.
Second Embodiment

  In the second embodiment, as shown in FIG. 18, an insertion protrusion 61 (an example of a protrusion) protruding outward in the radial direction is formed over the entire circumference on the outer peripheral surface of the insertion hole 10. The narrowed portion 21 is formed between the insertion protrusion 61 and the inner circumferential surface of the socket 12.

As shown in FIGS. 19 and 20, the backup ring 62 has a ring main body 40 and main body pressing parts 41 and 42, and the main body pressing parts 41 and 42 are provided on the outer peripheral side of the ring main body 40. As shown in FIG. 18, the ring main body 40 is fitted between the back end of the seal member 13 and the insertion protrusion 61, and the locking of the insertion protrusion 61 from the pressing direction J of the seal member 13. It is locked to the surface 61a.
The main body pressing portions 41 and 42 are in pressure contact with the inner circumferential surface of the socket 12 and press the ring main body portion 40 against the outer circumferential surface of the insertion port 10.

  According to this, even when the gap (spacing 22) of the narrowed portion 21 becomes large due to the manufacturing tolerance of the insertion port 10 and the receiving port 12, the ring main body portion 40 of the backup ring 62 It is possible to prevent the sealing member 13 from entering the clearance from the sealing member accommodation portion 14 reliably from the sealing member accommodation portion 14 as in the first embodiment described above. Action and effect are obtained.

  Although the two main body pressing portions 41 and 42 are provided on the ring main body portion 40 of the backup ring 62 in each of the above embodiments, three or more main body pressing portions may be provided.

3 One pipe 4 Other pipe 6 One pipe 7 The other pipe 9 Joint 10 Fitting 11 Fitting 11 Joint ring 12 Socket 14 Seal member housing 15 Pressing means 16 Protrusion for separation prevention 17 Separation prevention means 18 Backup ring 20 socket projection (projection)
20a Locking surface 21 Narrowing portion 31 Tube axis 40 Ring body portion 41, 42 Body pressing portion 41a, 42a Free end portion 41b, 42b Base end portion 44 Notched portion 46 Flat surface 47 Straight line 61 Insertion projection (projection)
61a Locking surface 62 Backup ring A Disengaging direction B Radial direction C Tube axial direction D1 Distance between free ends D2 Distance between proximal ends E Length of ring body F Length of main body pressing H Locking surface Radial height J indentation direction K one direction M other direction T thickness of ring body in radial direction

Claims (13)

Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A backup used in a joint in which a narrow portion where the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing is deeper than the seal housing. A ring,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is annularly formed, has a plurality of cut portions in the circumferential direction, is provided in the ring main body portion, is radially deformable, and has an inner peripheral surface of the socket and a slot A backup ring characterized in that it abuts on any other surface of the outer peripheral surface. The backup ring according to claim 1, wherein the main body pressing portion is provided at a plurality of locations of the ring main body portion in the axial direction of the tube. Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A backup used in a joint in which a narrow portion where the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing is deeper than the seal housing. A ring,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is provided on the ring main body portion, is radially deformable, and abuts on the other of the inner peripheral surface of the socket and the outer peripheral surface of the insertion port,
At least two body pressing parts are provided opposite to each other in the axial direction of the tube and provided on the ring body;
In the natural state where the joint is not attached, both body pressing parts are inclined such that the distance between the free ends is larger in the tube axial direction than the distance between the base ends attached to the ring body. A backup ring characterized by The natural distance not attached to the joint, characterized in that the distance between the free ends of the two main body pressing portions in the axial direction is longer than the length of the ring main portion in the axial direction. Backup ring. The backup ring according to claim 3 or 4, wherein the main body pressing portion is formed in a ring shape, and has a plurality of cut portions in a circumferential direction . The length of the main body pressing portion in the radial direction is larger than the thickness of the ring main body portion in the radial direction in the natural state in which the joint is not attached. backup ring. In the natural state that is not attached to the joint, the cross-sectional shape of the backup ring intersecting the plane including the tube axis is symmetrical with respect to the radial straight line passing from the tube axis to the backup ring. The backup ring according to any one of claims 1 to 6 . A joint provided with the backup ring according to any one of claims 1 to 7,
Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A joint characterized in that a narrowed portion in which the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing portion is formed in the back of the socket than the seal member housing portion. . A projection projecting radially inward is formed on the inner peripheral surface of the receptacle,
The constriction is formed between the projection and the mouthpiece,
The ring body portion of the backup ring is fitted between the back end of the seal member and the projection, and is engaged with the projection from the pressing direction of the seal member,
The joint according to claim 8, wherein the main body pressing portion is in contact with the outer peripheral surface of the insertion port, and presses the ring main body portion against the inner peripheral surface of the socket . In the outer peripheral surface of the insertion opening, a protrusion protruding outward in the radial direction is formed,
The constriction is formed between the projection and the socket,
The ring body portion of the backup ring is fitted between the back end of the seal member and the projection, and is engaged with the projection from the pressing direction of the seal member,
The joint according to claim 8, wherein the main body pressing portion is in contact with the inner peripheral surface of the socket, and presses the ring main body portion against the outer peripheral surface of the insertion port . The protrusion has a locking surface orthogonal to the tube axis on the near side in the tube axis direction,
The joint according to claim 9 or 10, wherein the ring body portion of the backup ring is locked to the locking surface of the projection from the pressing direction of the seal member . The joint according to claim 11, wherein the radial thickness of the ring body portion of the backup ring is larger than the radial height of the locking surface of the projection . A receptacle is provided at both ends of the tubular joint ring,
An insert is provided at the end of the tube,
Insert is inserted into the socket,
An annular seal member for sealing a gap between the inlet and the inlet, a seal member accommodating portion for accommodating the seal member between the inner peripheral surface of the inlet and the outer peripheral surface of the inlet, and the seal member And pressing means for pressing backward from the open end,
A narrowed portion in which the distance between the inner circumferential surface of the socket and the outer circumferential surface of the inlet in the radial direction is narrower than the seal member housing portion is formed in the back of the socket than the seal member housing portion;
In the outer peripheral surface of the insertion opening, a separation preventing projection exposed to the outside of the socket and protruding radially outward is provided.
A release preventing means is provided which engages with the release preventing projection to prevent the insertion port from moving in the release direction for release from the receptacle;
Inside the receptacle, a backup ring is provided to prevent the seal member from entering the narrowed portion from the seal member accommodation portion,
The back-up ring has a ring main body portion fitted between the back end of the seal member in the axial direction and the narrow portion, and the ring main body on one of the inner peripheral surface of the socket and the outer peripheral surface of the inlet. And a main body pressing unit for pressing the unit,
The ring main body portion is locked on the front side of the narrowed portion in the axial direction of the tube from the pressing direction of the seal member in a state of being pressed against the one surface.
The main body pressing portion is formed in an annular shape, has a plurality of cut portions in the circumferential direction, is provided in the ring main body portion, is radially deformable, and has an inner peripheral surface of the socket and a slot A joint characterized in that the joint abuts on any other surface of the outer peripheral surface.

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