Ring body, pipe joint, and method for joining pipes using said ring body

Abstract

The ring body (40) has: an annular ring main body section (41) that can be inserted between the inner peripheral surface (22a) of the socket protrusion (22) and the outer peripheral surface (3a) of the socket (3); and a plurality of gap maintaining sections (42) that can be inserted between the socket sealing surface (21) and the outer peripheral surface (3a) of the socket (3). The plurality of interval maintaining parts (42) are arranged on the ring main body part (41) at specified intervals in the circumferential direction of the pipe. The plurality of interval maintaining parts (42) are inserted between the socket sealing surface (21) and the outer peripheral surface (3a) of the socket (3), so that the interval (52) between the socket sealing surface (21) and the outer peripheral surface (3a) of the socket (3) is maintained to be a specified size capable of being pressed into the sealing ring. A retreat space into which the tip of the compressed seal ring can enter is formed between one of the adjacent interval maintaining parts (42) and the other interval maintaining part (42) and closer to the opening end of the socket than the ring main body part (41).

Description

Technical Field

[0001] The present invention relates to a ring body provided in a pipe joint having a lock ring and a seal ring, a pipe joint provided with the ring body, and a method for joining pipes using the ring body. Background Art

[0002] In the past, as such a ring body, Fig.21 , Fig. 22 As shown, there is a ring body 204 provided on the pipe joint 201. The socket 207 of the first pipe 206 of the pipe joint 201 is inserted into the socket 209 of the second pipe 208. The lock ring 202 is received in the lock ring receiving groove 210 formed on the inner periphery of the socket 209.

[0003] The seal ring 203 is compressed in the pipe radial direction 211 at a portion closer to the open end of the socket 209 than the lock ring 202 is, thereby sealing between the outer peripheral surface of the socket 207 and the inner peripheral surface of the socket 209 .

[0004] The socket 209 has, on its inner periphery, a socket sealing surface 212 to which the outer peripheral surface of the seal ring 203 is pressed over the entire periphery, and a socket protrusion 213 protruding from the inner portion of the socket sealing surface 212 toward the inner side in the pipe radial direction.

[0005] The ring body 204 includes an annular ring body 214 that can be inserted between the inner circumference of the socket protrusion 213 and the outer circumference of the insertion hole 207 , and an anti-deviating member 215 that prevents the ring body 214 from deviating toward the opening end of the socket 209 .

[0006] When the first tube 206 and the second tube 208 are connected, first, the locking ring 202 is accommodated in the locking ring accommodating groove 210. Then, the socket 207 is inserted into the socket 209. Then, the ring body 204 is inserted from the open end of the socket 209 between the socket sealing surface 212 and the outer peripheral surface of the socket 207, and the ring body 214 of the ring body 204 is pressed between the inner peripheral surface of the socket protrusion 213 and the outer peripheral surface of the socket 207.

[0007] Then, the sealing ring 203 is pressed into between the sealing surface 212 of the socket 209 and the outer peripheral surface of the socket 207. Fig. 22 As shown, since the ring body 214 of the ring body 204 is inserted between the inner circumference of the socket protrusion 213 and the outer circumference of the plug 207, the interval 216 between the socket sealing surface 212 and the outer circumference of the plug 207 in the pipe radial direction 211 is maintained at a specified size that allows the sealing ring 203 to be pressed in.

[0008] The ring body 204 as described above can be referred to Japanese Patent Application Laid-Open No. 2021-67282. Summary of the invention

[0009] Problems to be solved by the invention

[0010] In the above-mentioned conventional form, when the first tube 206 and the second tube 208 are connected, as shown in FIG. Fig.23 As shown, there is a possibility that the amount of insertion of the ring body 204 is insufficient, and the ring main body 214 does not reach between the inner peripheral surface of the socket protrusion 213 and the outer peripheral surface of the socket 207, but is disposed between the socket sealing surface 212 and the outer peripheral surface of the socket 207 before the socket protrusion 213. In this case, a portion is generated in which the interval 216 between the socket sealing surface 212 and the outer peripheral surface of the socket 207 in the pipe radial direction 211 is narrower than the specified size that can press the seal ring 203. Therefore, when the seal ring 203 is pressed between the socket sealing surface 212 and the outer peripheral surface of the socket 207, there is a problem that the seal ring 203 is excessively compressed in the pipe radial direction 211, and the operation of pressing the seal ring 203 between the socket sealing surface 212 and the outer peripheral surface of the socket 207 becomes difficult.

[0011] The object of the present invention is to provide a ring body and a method for joining a pipe using the ring body. When the ring body is inserted between the sealing surface of the socket and the outer peripheral surface of the plug, even if the insertion amount of the ring body is insufficient, the sealing ring can be prevented from being excessively compressed in the radial direction of the pipe by maintaining the interval between the sealing surface of the socket and the outer peripheral surface of the plug in the radial direction of the pipe to an appropriate size for pressing the sealing ring.

[0012] Means for solving problems

[0013] The ring body of the present invention is a ring body provided in a pipe joint, and is characterized in that:

[0014] The pipe joint has:

[0015] a socket formed in the first tube;

[0016] A receiving port, the receiving port being formed on the second pipe;

[0017] A locking ring receiving groove, wherein the locking ring receiving groove is formed on the inner circumference of the receiving interface;

[0018] a locking ring received in a locking ring receiving groove; and

[0019] A sealing ring is compressed in the pipe radial direction at a position closer to the open end of the socket than the locking ring to seal the outer periphery of the spigot and the inner periphery of the socket.

[0020] The socket has a socket sealing surface on the inner periphery to which the outer peripheral surface of the sealing ring is pressed over the entire periphery, and a socket protrusion protruding from the inner part of the socket sealing surface toward the inner side in the pipe radial direction.

[0021] The inner diameter of the socket sealing surface is larger than the inner diameter of the socket protrusion.

[0022] A socket engaging portion is formed on the outer periphery of the socket.

[0023] When the socket is inserted into the socket, the socket engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the socket, thereby preventing the socket from being disengaged from the socket.

[0024] The ring body has:

[0025] an annular ring body portion, the ring body portion being insertable between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the socket; and

[0026] A plurality of interval maintaining parts, wherein the plurality of interval maintaining parts can be inserted between the sealing surface of the receiving interface and the outer peripheral surface of the socket,

[0027] The plurality of interval maintaining portions are provided on the ring body at predetermined intervals in the tube circumferential direction.

[0028] The plurality of interval maintaining parts are inserted between the sealing surface of the receiving port and the outer peripheral surface of the insert, thereby maintaining the interval between the sealing surface of the receiving port and the outer peripheral surface of the insert in the pipe radial direction to a predetermined size capable of pressing in the sealing ring.

[0029] A retreat space into which the top end of the compressed seal ring can enter is formed between one spacing maintaining portion and the other spacing maintaining portion adjacent to each other in the circumferential direction of the pipe and closer to the opening end of the socket than the ring body.

[0030] Thus, when the first tube and the second tube are joined, the spigot is inserted into the socket, the ring body is inserted from the open end of the socket into between the socket sealing surface and the outer peripheral surface of the spigot, and the main body of the ring body is pressed into between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the spigot. Thus, the ring body is installed in the standard position, the interval maintaining portion of the ring body is arranged between the socket sealing surface and the outer peripheral surface of the spigot, and the interval between the socket sealing surface and the outer peripheral surface of the spigot in the pipe radial direction is maintained to a specified size that allows the sealing ring to be pressed in.

[0031] Thus, when the sealing ring is pressed from the open end of the socket into between the sealing surface of the socket and the outer peripheral surface of the plug, the sealing ring will not be over-compressed in the radial direction of the pipe, and the sealing ring can be easily pressed from the open end of the socket into between the sealing surface of the socket and the outer peripheral surface of the plug.

[0032] In addition, even if the amount of insertion of the ring body is insufficient, the main body of the ring does not reach between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the spigot, but is arranged between the socket sealing surface in front of the socket protrusion and the outer peripheral surface of the spigot, the interval maintaining portion is also arranged between the socket sealing surface and the outer peripheral surface of the spigot. Therefore, the interval between the socket sealing surface and the outer peripheral surface of the spigot in the pipe radial direction is maintained at a predetermined size that allows the sealing ring to be pressed in.

[0033] Thus, even when the insertion amount of the ring body is insufficient, the sealing ring will not be excessively compressed in the pipe radial direction, and the sealing ring can be easily pressed from the opening end of the socket into between the socket sealing surface and the outer peripheral surface of the spigot.

[0034] In addition, when the first tube and the second tube are bent and joined, a portion is generated where the interval between the sealing surface of the receiving port and the outer peripheral surface of the insert in the tube radial direction is narrower than the predetermined size. In this case, even if a portion of the sealing ring pressed between the sealing surface of the receiving port and the outer peripheral surface of the insert is over-compressed in the tube radial direction, the over-compressed portion of the sealing ring enters the retreat space of the ring body, which can prevent the sealing ring from being under-pressed.

[0035] According to the ring body of the present invention, preferably, the outer diameter of the spacing maintaining portion is larger than the outer diameter of the ring main body, and the spacing maintaining portion has a snap-fitting surface hooked on the socket protrusion in the insertion direction of the socket, and the snap-fitting surface extends from the outer peripheral surface of the ring main body to the outside in the radial direction of the pipe.

[0036] Thus, when the first tube and the second tube are connected, the ring body is inserted from the opening end of the socket into between the socket sealing surface and the outer peripheral surface of the plug, and the main body of the ring is pressed into between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the plug. At this time, the ring body is hooked on the socket protrusion in the insertion direction of the plug by the engagement surface of the ring body, so that the ring body is arranged in the standard position, and the position of the ring body will not deviate from the standard position to the inner side of the socket.

[0037] According to the ring body of the present invention, preferably, when the engaging surface of the spacing maintaining portion is hooked on the socket protrusion, the inner end of the ring body portion in the axial direction of the tube is located closer to the socket opening end than the inner end of the socket protrusion.

[0038] Thus, when the ring body is set at the standard position, the engaging surface of the interval maintaining portion is hooked on the socket protrusion, and the inner end of the ring body is located closer to the socket opening end than the inner end of the socket protrusion. Therefore, the contact between the ring body and the locking ring can be prevented, and the ring body can be prevented from being damaged.

[0039] The pipe joint provided with the ring body of the present invention is characterized by having:

[0040] a socket formed in the first tube;

[0041] A receiving port, the receiving port being formed on the second pipe;

[0042] A locking ring receiving groove, wherein the locking ring receiving groove is formed on the inner circumference of the receiving interface;

[0043] a locking ring received in a locking ring receiving groove; and

[0044] A sealing ring is compressed in the pipe radial direction at a position closer to the open end of the socket than the locking ring to seal the outer periphery of the spigot and the inner periphery of the socket.

[0045] The socket has a socket sealing surface on the inner periphery to which the outer peripheral surface of the sealing ring is pressed over the entire periphery, and a socket protrusion protruding from the inner part of the socket sealing surface toward the inner side in the pipe radial direction.

[0046] The inner diameter of the socket sealing surface is larger than the inner diameter of the socket protrusion.

[0047] A socket engaging portion is formed on the outer periphery of the socket.

[0048] When the socket is inserted into the socket, the socket engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the socket, thereby preventing the socket from being disengaged from the socket.

[0049] The ring body is arranged between the locking ring and the sealing ring.

[0050] According to the pipe joint of the present invention, it is preferred that the first pipe is joined straightly with respect to the second pipe.

[0051] According to the pipe joint of the present invention, it is preferred that the first pipe is joined to the second pipe in a bent manner.

[0052] According to the pipe joint of the present invention, preferably, a gap is formed between the ring body and the sealing ring.

[0053] According to the pipe joint of the present invention, preferably, the sealing ring is connected to the ring body.

[0054] The method for joining pipes using the ring body of the present invention is characterized in that:

[0055] Place the locking ring in the locking ring receiving groove.

[0056] Insert the socket into the socket, so that the socket engagement portion passes from the vicinity of the socket opening end of the locking ring to the inner side of the socket.

[0057] Insert the ring from the opening end of the socket into the space between the sealing surface of the socket and the outer peripheral surface of the socket.

[0058] Press the sealing ring from the opening end of the socket into between the sealing surface of the socket and the outer peripheral surface of the socket.

[0059] Thus, by inserting the ring body between the sealing surface of the socket and the outer peripheral surface of the plug and setting it in the standard position, the spacing maintaining portion of the ring body is clamped between the sealing surface of the socket and the outer peripheral surface of the plug, and the spacing between the sealing surface of the socket and the outer peripheral surface of the plug in the radial direction of the pipe is maintained at a specified size that allows the sealing ring to be pressed in.

[0060] Even if the insertion amount of the ring body is insufficient, the interval maintaining portion is sandwiched between the sealing surface of the socket and the outer peripheral surface of the spigot, so that the interval between the sealing surface of the socket and the outer peripheral surface of the spigot in the pipe radial direction is maintained at a predetermined size that allows the sealing ring to be pressed in. Thus, the sealing ring can be easily pressed from the opening end of the socket into between the sealing surface of the socket and the outer peripheral surface of the spigot.

[0061] Effects of the Invention

[0062] As described above, according to the present invention, when the ring body is inserted between the sealing surface of the receiving port and the outer peripheral surface of the spigot, even if the insertion amount of the ring body is insufficient, the interval maintaining portion is sandwiched between the sealing surface of the receiving port and the outer peripheral surface of the spigot. Therefore, the interval between the sealing surface of the receiving port and the outer peripheral surface of the spigot in the pipe radial direction is maintained at a predetermined size that allows the sealing ring to be pressed in. Thus, the sealing ring can be easily pressed in between the sealing surface of the receiving port and the outer peripheral surface of the spigot. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a cross-sectional view of the pipe joint according to the first embodiment of the present invention, and shows a cross section of a gap maintaining portion of a ring body.

[0064] Figure 2 1 is a cross-sectional view of the pipe joint, showing a cross section of the ring body portion of the ring body.

[0065] Figure 3 This is a diagram showing a lock ring provided in the pipe joint when its diameter is expanded.

[0066] Figure 4 It is a perspective view of a ring body provided in the pipe joint.

[0067] Figure 5 It is a front view of the ring body provided in the pipe joint.

[0068] Figure 6 It is a side view of the ring body provided in the pipe joint.

[0069] Figure 7 yes Figure 5 XX section view in.

[0070] Figure 8 yes Figure 5 The YY view in the diagram.

[0071] Fig. 9 yes Figure 5ZZ section view in.

[0072] Fig.10 It is a partially enlarged cross-sectional view of a pipe joint provided with a ring body, showing a cross section of a spacing maintaining portion when the ring body is installed in a standard position.

[0073] Fig.11 It is a partially enlarged cross-sectional view of a pipe joint provided with a ring body, showing a cross section of the ring body portion when the ring body is installed in a standard position.

[0074] Fig.12 This is a diagram showing a method of joining pipes using a ring body, showing a situation in which the diameter of a lock ring is expanded and the socket is inserted into the socket.

[0075] Fig.13 This is a diagram showing a method of joining pipes using a ring body, and shows a situation in which a lock ring is reduced in diameter to embrace the outer circumference of a socket.

[0076] Fig.14 This is a diagram showing a method of joining pipes using a ring body, and shows a state when the ring body is inserted and set in a standard position.

[0077] Fig.15 It is a partially enlarged cross-sectional view of a pipe joint including a ring body, showing a cross section of a gap maintaining portion when the insertion amount of the ring body is insufficient.

[0078] Fig.16 It is a cross-sectional view of a pipe joint according to a second embodiment of the present invention.

[0079] Fig.17 It is a partially enlarged cross-sectional view of a pipe joint having a ring body, showing a state when the ring body is set in a standard position.

[0080] Fig.18 This is a partially enlarged cross-sectional view of a pipe joint having a ring body, showing the state when a seal ring is pressed in.

[0081] Fig.19 It is a partially enlarged cross-sectional view of a pipe joint including a ring body according to a third embodiment of the present invention, and shows a cross section of a spacing maintaining portion of the ring body.

[0082] Fig. 20 It is a partially enlarged cross-sectional view of a pipe joint including a ring body, showing a cross section of a ring main body portion of the ring body.

[0083] Fig.21 It is a cross-sectional view of a pipe joint including a conventional ring body.

[0084] Fig. 22 It is a partially enlarged cross-sectional view of a pipe joint having a ring body, showing a state when the ring body is set in a standard position.

[0085] Fig.23It is a partially enlarged cross-sectional view of a pipe joint having a ring body, showing a situation when the insertion amount of the ring body is insufficient. DETAILED DESCRIPTION

[0086] Hereinafter, embodiments of the present invention will be described with reference to the drawings. (First embodiment)

[0087] like Figure 1 , Figure 2 As shown, the pipe joint 1 includes a spigot 3 formed on a first pipe 2 and a socket 5 formed on a second pipe 4, and the spigot 3 is inserted into the socket 5. For example, ductile iron pipes are used for these pipes 2 and 4.

[0088] A locking ring receiving groove 7 is formed on the inner circumferential surface of the receiving port 5 over the entire circumference. A locking ring 8 is received in the locking ring receiving groove 7. Figure 3 As shown, the lock ring 8 is a split ring cut at one location along the circumferential direction. The lock ring 8 has the following elasticity: the diameter is enlarged by enlarging the interval 12 between the cut ends at the cut portion 11 by using the expander 13, and the diameter is reduced and returned to the original diameter by removing the expander 13 from the cut portion 11.

[0089] like Figure 1 , Figure 2 As shown, a socket protrusion 15 is formed all around the outer periphery of the socket 3. The socket protrusion 15 is hooked on the lock ring 8 from the inner side of the socket in the disengagement direction 6 of the socket 3, thereby preventing the socket 3 from being disengaged from the socket 5.

[0090] A seal ring 19 is provided at a position closer to the opening end of the socket 5 than the lock ring 8. The seal ring 19 is compressed in the pipe radial direction 17 to seal between the outer peripheral surface 3a of the socket 3 and the inner peripheral surface of the socket 5. The seal ring 19 is a rubber ring.

[0091] The socket 5 has, on its inner periphery, a socket sealing surface 21 to which the outer peripheral surface of the seal ring 19 is pressed over the entire periphery, and a socket protrusion 22 protruding from the inner portion of the socket sealing surface 21 toward the inner side in the pipe radial direction.

[0092] like Figure 1 , Fig.10 As shown, the socket sealing surface 21 has a tapered surface 25 that gradually decreases in diameter from the opening end surface 24 of the socket 5 to the inside and an inner peripheral surface 26 that extends inward from the inner end of the tapered surface 25. The inner peripheral surface 26 is formed with the same inner diameter in the axial direction 27 of the pipe and is parallel to the outer peripheral surface 3a of the socket 3.

[0093] The socket protrusion 22 is formed in a circular shape over the entire circumference between the inner circumferential surface 26 of the socket sealing surface 21 and the lock ring receiving groove 7. The socket protrusion 22 has a first end surface 22b from the inner end of the inner circumferential surface 26 of the socket sealing surface 21 to the inner circumferential surface 22a of the socket protrusion 22 and a second end surface 22c from the inner circumferential surface 22a to the lock ring receiving groove 7.

[0094] The first end face 22b of the socket protrusion 22 is a tapered face that decreases in diameter as it approaches the inner circumferential face 22a of the socket protrusion 22 from the inner end of the inner circumferential face 26 of the socket sealing face 21. In addition, the second end face 22c of the socket protrusion 22 is a face facing the inner side of the socket 5, and is located at the inner end of the socket protrusion 22 in the pipe axial direction 27. The inner diameter of the inner circumferential face 26 of the socket sealing face 21 is set larger than the inner diameter of the socket protrusion 22.

[0095] like Figure 1 , Figure 2 As shown, a pressure ring 30 for pressing the sealing ring 19 into the inner side of the socket 5 is provided at the open end of the socket 5. The pressure ring 30 has a contact portion 32 that contacts the open end face 24 of the socket 5 in the insertion direction 31 of the sealing ring 19. The pressure ring 30 is connected to the open end of the socket 5 by a plurality of bolts 33 and nuts 34.

[0096] A ring body 40 is provided between the locking ring 8 and the sealing ring 19 in the axial direction 27 of the tube. Figure 4~Figure 6 As shown, the ring body 40 is made of a material such as an elastic resin. The ring body 40 has an annular ring main body 41 that can be inserted between the inner circumferential surface 22a of the socket protrusion 22 and the outer circumferential surface 3a of the socket 3, and a plurality of interval maintaining portions 42 that can be inserted between the inner circumferential surface 26 of the socket sealing surface 21 and the outer circumferential surface 3a of the socket 3. The ring body 40 is a ring with a split structure in the circumferential direction, and any interval maintaining portion 42 is cut in the center.

[0097] like Figure 7 As shown in FIG. 4 , the ring body portion 41 has a quadrilateral cross section. Figure 4~Figure 6 As shown, the plurality of interval maintaining portions 42 are provided integrally on the ring body portion 41 at predetermined intervals in the tube circumferential direction 44. Figure 8 , Fig. 9 As shown, the interval maintaining portion 42 is a protrusion that protrudes from the ring body portion 41 to a position close to the opening end of the socket and protrudes outward in the pipe radial direction than the ring body portion 41. The interval maintaining portion 42 has a snap-fit ​​surface 45 that is hooked on the first end surface 22b of the socket protrusion 22 in the insertion direction 31 of the socket 3.

[0098] The engagement surface 45 is a tapered surface that projects outward in the pipe radial direction 17 from the outer circumferential surface of the ring body 41 and gradually increases in diameter as it approaches the outer circumferential surface of the spacing maintaining portion 42 .

[0099] The inner diameter d1 of the space maintaining portion 42 is the same as the inner diameter d2 of the ring body portion 41 . The outer diameter D1 of the space maintaining portion 42 is larger than the outer diameter D2 of the ring body portion 41 .

[0100] A retreat space 46 into which the tip of the compressed seal ring 19 can enter is formed between one and the other adjacent space maintaining portions 42 in the tube circumferential direction 44 and closer to the socket opening end than the ring body 41 .

[0101] like Fig.10 , Fig.11 As shown, when the engaging surface 45 of the spacing maintaining portion 42 is hooked on the first end surface 22b of the socket protrusion 22, the inner end surface 41a of the ring body 41 is located closer to the socket opening end than the second end surface 22c of the socket protrusion 22.

[0102] Next, a method for joining the first pipe 2 and the second pipe 4 in the pipe joint 1 described above will be described.

[0103] like Fig.12 As shown, the ring body 40, the sealing ring 19 and the pressure ring 30 are pre-embedded in the outer periphery of the first tube 2. In addition, the locking ring 8 is received in the locking ring receiving groove 7 of the second tube 4. Then, as shown in FIG. Figure 3 As shown in FIG. 1 , the space 12 of the cut portion 11 of the lock ring 8 is enlarged by using the expander 13 to expand the diameter of the lock ring 8. Fig.12 As shown, the L-shaped diameter-enlarged retainer 50 is inserted into the cut portion 11 of the lock ring 8, and the expander 13 is removed to maintain the lock ring 8 in the expanded diameter state.

[0104] Then, the socket 3 is inserted into the socket 5, and the socket projection 15 is passed from the socket opening end of the locking ring 8 to the inner side of the socket 52. At this time, the locking ring 8 is maintained in an expanded state by the enlarged diameter retainer 50, so the socket projection 15 is easy to pass through the inner periphery of the locking ring 8.

[0105] Then, if Fig.13 As shown, by removing the enlarged diameter retainer 50 from the cut portion 11 of the lock ring 8, the interval 12 of the cut portion 11 returns to its original size due to the elasticity of the lock ring 8, and the lock ring 8 shrinks in diameter to embrace the outer periphery of the socket 3.

[0106] At this time, when the tube axis of the first tube 2 is offset in the tube radial direction 17 relative to the tube axis of the second tube 4, a portion is generated in which the interval 52 between the inner peripheral surface 26 of the receiving port sealing surface 21 and the outer peripheral surface 3a of the socket 3 in the tube radial direction 17 is narrower than the prescribed size required for pressing the seal ring 19. Hereinafter, the portion narrowed as described above is referred to as a narrow portion. At a portion on the opposite side of the narrow portion at 180° in the tube circumferential direction 44, the interval 52 is expanded than the prescribed size.

[0107] For example, in Fig.13 , a narrow portion is generated in the upper part of the horizontal pipes 2 and 4. In this case, the interval 52 is expanded more than a predetermined size in the lower part of the pipes 2 and 4.

[0108] Then, if Fig.14 As shown, the ring body 40 is moved in the pipe axial direction 27, inserted from the open end of the socket 5 into between the socket sealing surface 21 and the outer peripheral surface 3a of the socket 3, and installed in the standard position.

[0109] Therefore, if Fig.10 , Fig.11 As shown, the main body 41 of the ring body 40 is inserted between the inner circumference 22 a of the socket protrusion 22 and the outer circumference 3 a of the socket 3 , and the engaging surface 45 of the ring body 40 is hooked on the first end surface 22 b of the socket protrusion 22 .

[0110] At this time, by inserting the spacing maintaining portion 42 of the ring body 40 between the inner circumferential surface 26 of the socket sealing surface 21 and the outer circumferential surface 3a of the plug 3, the spacing 52 between the inner circumferential surface 26 of the socket sealing surface 21 and the outer circumferential surface 3a of the plug 3 in the pipe radial direction 17 is maintained at a specified size required for pressing the sealing ring 19.

[0111] Therefore, even if the above Fig.13 As shown in the figure, a narrow part is generated when the socket 3 is inserted into the receiving port 5, and then the narrow part is formed by the above-mentioned Fig.14 As shown, the ring body 40 is installed in the standard position, such as Fig.10 , Fig.11 As shown, the gap 52 between the inner peripheral surface 26 of the socket sealing surface 21 and the outer peripheral surface 3 a of the socket 3 in the pipe radial direction 17 can be maintained at a predetermined size required for press-fitting the seal ring 19 over the entire circumference.

[0112] The engagement surface 45 of the ring body 40 is hooked on the first end surface 22 b of the socket protrusion 22 , so that the ring body 40 is installed in the standard position, and the position of the ring body 40 does not deviate from the standard position to the inner side of the socket 5 .

[0113] Then, insert the sealing ring 19 from the open end of the socket 5 between the socket sealing surface 21 and the outer peripheral surface 3a of the socket 3, use the bolts 33 and the nuts 34 to connect the pressure ring 30 to the open end of the socket 5, and screw the bolts 33 and the nuts 34 until the contact portion 32 of the pressure ring 30 is in contact with the open end surface 24 of the socket 5.

[0114] At this time, as described above, since the interval 52 between the inner peripheral surface 26 of the socket sealing surface 21 and the outer peripheral surface 3a of the spigot 3 is maintained at a predetermined size required for pressing the sealing ring 19, when the sealing ring 19 is pressed between the socket sealing surface 21 and the outer peripheral surface 3a of the spigot 3, the sealing ring 19 is not excessively compressed in the pipe radial direction 17. Thus, the sealing ring 19 can be easily pressed from the opening end of the socket 5 between the socket sealing surface 21 and the outer peripheral surface 3a of the spigot 3.

[0115] Therefore, if Figure 1 , Figure 2 As shown, by joining the first tube 2 and the second tube 4 and installing the sealing ring 19, the first tube 2 is centered relative to the second tube 4, and the tube axis of the first tube 2 coincides with the tube axis of the second tube 4. In such a centered state, a small gap is generated substantially uniformly over the entire circumference between the outer peripheral surface of the ring main body portion 41 of the ring body 40 and the inner peripheral surface 22a of the socket protrusion 22, and between the outer peripheral surface of the interval maintaining portion 42 and the inner peripheral surface 26 of the socket sealing surface 21.

[0116] In the method for joining the pipes 2 and 4 using such a ring body 40, when the ring body 40 is inserted between the receiving end sealing surface 21 and the outer peripheral surface 3a of the socket 3, as shown in FIG. Fig.15 As shown, sometimes the insertion amount of the ring body 40 is insufficient, and the ring body portion 41 does not reach between the inner peripheral surface 22a of the socket protrusion 22 and the outer peripheral surface 3a of the socket 3, but is arranged between the inner peripheral surface 26 of the socket sealing surface 21 closer to the socket protrusion 22 and the outer peripheral surface 3a of the socket 3. Even in such a case, since the interval maintaining portion 42 is inserted between the inner peripheral surface 26 of the socket sealing surface 21 and the outer peripheral surface 3a of the socket 3, the interval 52 between the inner peripheral surface 26 of the socket sealing surface 21 and the outer peripheral surface 3a of the socket 3 in the pipe radial direction 17 is also maintained at a predetermined size required for pressing the sealing ring 19.

[0117] Thus, even when the insertion amount of the ring body 40 is insufficient, when the sealing ring 19 is pressed between the sealing surface 21 of the socket and the outer peripheral surface 3a of the plug 3, the sealing ring 19 will not be overly compressed in the pipe radial direction 17, and the sealing ring 19 can be easily pressed from the open end of the socket 5 between the sealing surface 21 of the socket and the outer peripheral surface 3a of the plug 3.

[0118] like Fig.15As shown, even when the insertion amount of the ring body 40 is insufficient, by pressing the sealing ring 19 between the sealing surface 21 of the socket 5 and the outer peripheral surface 3a of the plug 3, the ring body 40 is also pressed toward the inner side of the socket 5 by the sealing ring 19 until the ring body 41 reaches between the inner peripheral surface 22a of the socket protrusion 22 and the outer peripheral surface 3a of the plug 3.

[0119] like Fig.10 , Fig.11 As shown, when the ring body 40 is installed in the standard position, the engaging surface 45 of the interval maintaining portion 42 is hooked on the first end surface 22b of the socket protrusion 22, and the inner end surface 41a of the ring body 41 is located closer to the socket opening end than the second end surface 22c of the socket protrusion 22. Therefore, the contact between the ring body 41 and the locking ring 8 can be prevented, and the ring body 41 can be prevented from being damaged.

[0120] In the first embodiment described above, if Fig.13 As shown, a case where a narrow portion is generated at the upper portion of the horizontal tubes 2 and 4 and the interval 52 is expanded than a predetermined size at the lower portion of the tubes 2 and 4 is exemplified. However, even if a narrow portion is generated at a portion other than the upper portion (for example, the lower portion) of the horizontal tubes 2 and 4 and the interval 52 is expanded than a predetermined size at a portion other than the lower portion (for example, the upper portion) of the tubes 2 and 4, the same action and effect can be obtained. (Second embodiment)

[0121] In the first embodiment described above, if Figure 2 , the first tube 2 is connected to the second tube 4 in a straight manner. Fig.16 As shown in FIG. 1 , a case where the first pipe 2 is bent upward and joined to the second pipe 4 in the horizontal direction will be described.

[0122] like Fig.14 As shown, the socket 3 is inserted into the socket 5, and then the ring body 40 is moved in the pipe axial direction 27, inserted from the open end of the socket 5 between the socket sealing surface 21 and the outer peripheral surface 3a of the socket 3, and installed in the standard position.

[0123] Therefore, if Fig.10 , Fig.11 As shown, the main body 41 of the ring body 40 is inserted between the inner circumference 22 a of the socket protrusion 22 and the outer circumference 3 a of the socket 3 , and the engaging surface 45 of the ring body 40 is hooked on the first end surface 22 b of the socket protrusion 22 .

[0124] Then, if Fig.17As shown, the first tube 2 is bent upward relative to the horizontal second tube 4. Thus, the interval 52 between the inner peripheral surface 26 of the receiving end sealing surface 21 and the outer peripheral surface 3a of the socket 3 is narrower than the predetermined size at the upper part of the tubes 2 and 4, and becomes wider at the lower part of the tubes 2 and 4.

[0125] Then, the sealing ring 19 is pressed into between the sealing surface 21 of the socket 5 and the outer peripheral surface 3a of the socket 3 from the opening end of the socket 5. Fig.18 As shown, even if the seal ring 19 on the upper portion of the pipe 2 or 4 is over-compressed in the pipe radial direction 17 , the over-compressed portion of the seal ring 19 enters the escape space 46 of the ring body 40 , thereby preventing the seal ring 19 from being under-pressed.

[0126] In the above-mentioned second embodiment, the case where the first tube 2 is bent upward relative to the second tube 4 in the horizontal direction is exemplified, but the same action and effect can be obtained when the first tube 2 is bent downward (or in a direction other than this) relative to the second tube 4 in the horizontal direction. (Third Embodiment)

[0127] In the first embodiment described above, if Figure 1 As shown in FIG. 1 , when the ring body 40 is inserted to the standard position, a gap is generated between the ring body 40 and the seal ring 19. In contrast, in the third embodiment described below, as shown in FIG. Fig.19 As shown, the distance C from the opening end surface 24 of the socket 5 to the socket protrusion 22 is set shorter than that of the first embodiment, and when the ring body 40 is inserted to the standard position, the seal ring 19 is in contact with the ring body 40.

[0128] In this case, the seal ring 19 is compressed in the pipe radial direction 17, and is sandwiched between the interval maintaining portion 42 of the ring body 40 and the pressure ring 30, and is also compressed in the pipe axial direction 27. Fig. 20 As shown, since the ring body 40 is provided with a retreat space 46, a sufficiently large space required to prevent excessive compression of the sealing ring 19 is ensured between the receiving interface sealing surface 21 and the outer peripheral surface 3a of the socket 3. Therefore, by the top end of the sealing ring 19 entering the retreat space 46 of the ring body 40, the sealing ring 19 can be prevented from being excessively compressed between the receiving interface sealing surface 21 and the outer peripheral surface 3a of the socket 3.

[0129] This prevents excessive compression as described above and shortens the distance C from the opening end surface 24 of the socket 5 to the socket protrusion 22 compared to the first embodiment, thereby shortening the length of the socket 5 in the pipe axial direction 27 .

[0130] In the above-mentioned embodiments, the ring body 40 is provided as a split structure, but the ring body 40 may be split into a plurality of arc-shaped ring segments and the adjacent ring segments may be joined together by a connecting member to assemble the annular ring body 40 .

Claims

1. A ring body, which is arranged on a pipe joint, characterized in that: The pipe joint has: a socket formed in the first tube; A receiving port, the receiving port being formed on the second pipe; A locking ring receiving groove, wherein the locking ring receiving groove is formed on the inner circumference of the receiving interface; A locking ring, the locking ring being received in the locking ring receiving groove; as well as A sealing ring is compressed in the pipe radial direction at a position closer to the open end of the socket than the locking ring to seal the outer periphery of the spigot and the inner periphery of the socket. The socket has a socket sealing surface on the inner periphery to which the outer peripheral surface of the sealing ring is pressed over the entire periphery, and a socket protrusion protruding from the inner part of the socket sealing surface toward the inner side in the pipe radial direction. The inner diameter of the socket sealing surface is larger than the inner diameter of the socket protrusion. A socket engaging portion is formed on the outer periphery of the socket. When the socket is inserted into the socket, the socket engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the socket, thereby preventing the socket from being disengaged from the socket. The ring body has: an annular ring body portion, the ring body portion being insertable between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the socket; and A plurality of interval maintaining parts, wherein the plurality of interval maintaining parts can be inserted between the sealing surface of the receiving interface and the outer peripheral surface of the socket, The plurality of interval maintaining portions are provided on the ring body at predetermined intervals in the tube circumferential direction. The plurality of interval maintaining parts are inserted between the sealing surface of the receiving port and the outer peripheral surface of the insert, thereby maintaining the interval between the sealing surface of the receiving port and the outer peripheral surface of the insert in the pipe radial direction to a predetermined size capable of pressing in the sealing ring. A retreat space into which the top end of the compressed seal ring can enter is formed between one spacing maintaining portion and the other spacing maintaining portion adjacent to each other in the circumferential direction of the pipe and closer to the opening end of the socket than the ring body.

2. The ring body according to claim 1, characterized in that: The outer diameter of the spacer maintaining portion is larger than the outer diameter of the ring main body portion. The interval maintaining portion has an engaging surface hooked on the protruding portion of the receiving port in the insertion direction of the socket. The engagement surface protrudes outward in the pipe radial direction from the outer peripheral surface of the ring body.

3. The ring body according to claim 2, characterized in that: When the engaging surface of the spacing maintaining portion is hooked on the socket protrusion, the inner end of the ring body portion in the axial direction of the pipe is located closer to the socket opening end than the inner end of the socket protrusion.

4. A pipe joint, comprising the ring body according to any one of claims 1 to 3, characterized in that: have: a socket formed in the first tube; A receiving port, the receiving port being formed on the second pipe; A locking ring receiving groove, wherein the locking ring receiving groove is formed on the inner circumference of the receiving interface; A locking ring, the locking ring being received in the locking ring receiving groove; as well as A sealing ring is compressed in the pipe radial direction at a position closer to the open end of the socket than the locking ring to seal the outer periphery of the spigot and the inner periphery of the socket. The socket has a socket sealing surface on the inner periphery to which the outer peripheral surface of the sealing ring is pressed over the entire periphery, and a socket protrusion protruding from the inner part of the socket sealing surface toward the inner side in the pipe radial direction. The inner diameter of the socket sealing surface is larger than the inner diameter of the socket protrusion. A socket engaging portion is formed on the outer periphery of the socket. When the socket is inserted into the socket, the socket engaging portion is hooked on the locking ring from the inner side of the socket in the disengagement direction of the socket, thereby preventing the socket from being disengaged from the socket. The ring body is arranged between the locking ring and the sealing ring.

5. The pipe joint according to claim 4, characterized in that: The first tube is joined straightly relative to the second tube.

6. The pipe joint according to claim 4, characterized in that: The first tube is curvedly joined relative to the second tube.

7. The pipe joint according to claim 4, characterized in that: A gap is formed between the ring body and the sealing ring.

8. The pipe joint according to claim 4, characterized in that: The sealing ring is connected to the ring body.

9. A method for joining pipes, wherein the method is a method for joining pipes using the ring body according to any one of claims 1 to 3, characterized in that: Place the locking ring in the locking ring receiving groove. Insert the socket into the socket, so that the socket engagement portion passes from the vicinity of the socket opening end of the locking ring to the inner side of the socket. Insert the ring from the opening end of the socket into the space between the sealing surface of the socket and the outer peripheral surface of the socket. Press the sealing ring from the opening end of the socket into between the sealing surface of the socket and the outer peripheral surface of the socket.

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