Ring body and pipe joining method using ring body

Abstract

To prevent a seal ring from being excessively compressed in a pipe diameter direction even if an amount of insertion of a ring unit is insufficient when the ring unit is inserted between a receptacle seal surface and an external peripheral surface of an insertion port.SOLUTION: A ring unit 40 includes: an annular ring body part 41 insertable between an internal peripheral surface 22a of a receptacle protrusion 22 and an external peripheral surface 3a of an insertion port 3; and a plurality of interval retaining parts 42 insertable between a receptacle seal surface 21 and the external peripheral surface 3a of the insertion port 3. The interval retaining parts 42 are arranged at the ring body part 41 at a prescribed interval in a pipe circumferential direction, and are sandwiched between the receptacle seal surface 21 and the external peripheral surface 3a of the insertion port 3, thus maintaining an interval 52 between the receptacle seal surface 21 and the external peripheral surface 3a of the insertion port 3 at a prescribed interval into which a seal ring can be pushed. An escape space which the compressed seal ring can enter is formed between one interval retaining part 42 and another interval retaining part 42 which neighbor each other, and at a receptacle opening end side of the ring main body part 41.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a ring body provided between a lock ring and a seal ring of a pipe joint having the lock ring and the seal ring, and to a method of joining pipes using the ring body. [Background technology]

[0002] A conventional ring body of this type is a ring body 204 provided between a lock ring 202 and a seal ring 203 of a pipe fitting 201, as shown in Figures 21 and 22. In this pipe fitting 201, an insertion port 207 of one pipe 206 is inserted into a socket 209 of the other pipe 208. The lock ring 202 is received in a lock ring receiving groove 210 formed on the inner periphery of the socket 209.

[0003] The seal ring 203 is compressed in the pipe diameter direction 211 on the opening end side of the socket 209 closer to the lock ring 202 to seal between the outer peripheral surface of the insertion port 207 and the inner peripheral surface of the socket 209 .

[0004] The socket 209 has a socket seal surface 212 on its inner periphery against which the outer periphery of the seal ring 203 is pressed over the entire periphery, and a socket protrusion 213 that protrudes radially inward from the deepest part of the socket seal surface 212.

[0005] The ring body 204 has a circular ring main body portion 214 that can be inserted between the inner surface of the receiving port protrusion 213 and the outer surface of the insertion port 207, and a slip prevention member 215 that prevents the ring main body portion 214 from slipping toward the opening end of the receiving port 209.

[0006] When joining pipes 206, 208, first, lock ring 202 is accommodated in lock ring accommodating groove 210, then insertion port 207 is inserted into socket 209, and then ring body 204 is inserted from the opening end of socket 209 between socket seal surface 212 and the outer peripheral surface of socket 207, and ring main body 214 of ring body 204 is pushed between the inner peripheral surface of socket protrusion 213 and the outer peripheral surface of socket 207.

[0007] Thereafter, seal ring 203 is pressed into the gap between socket seal surface 212 and the outer peripheral surface of insertion port 207 from the open end of socket 209. At this time, as shown in Figure 22, ring main body 214 of ring body 204 is inserted between the inner peripheral surface of socket protrusion 213 and the outer peripheral surface of insertion port 207, so that gap 216 between socket seal surface 212 and the outer peripheral surface of insertion port 207 in pipe diameter direction 211 is maintained at a predetermined size that allows seal ring 203 to be pressed in.

[0008] The ring body 204 as described above is described in, for example, Patent Document 1 below. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent Publication No. 2021-67282 Summary of the Invention [Problem to be solved by the invention]

[0010] However, with the above-described conventional design, when joining pipes 206 and 208, as shown in Figure 23, the insertion depth of ring body 204 may be insufficient, causing ring body 214 to fail to reach the gap between the inner peripheral surface of socket protrusion 213 and the outer peripheral surface of insertion port 207, resulting in the risk of ring body 214 being set between socket seal surface 212 and the outer peripheral surface of insertion port 207, which is located before socket protrusion 213. In this case, gap 216 between socket seal surface 212 and the outer peripheral surface of insertion port 207 in pipe radial direction 211 becomes narrower than the predetermined size required to press seal ring 203 into place. Therefore, when pressing seal ring 203 into place between socket seal surface 212 and the outer peripheral surface of insertion port 207, seal ring 203 is excessively compressed in pipe radial direction 211, making it difficult to press seal ring 203 into place between socket seal surface 212 and the outer peripheral surface of insertion port 207.

[0011] The present invention aims to provide a ring body and a method for joining pipes using a ring body that can prevent the seal ring from being excessively compressed in the pipe radial direction by maintaining the distance between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe radial direction at a predetermined size (appropriate size) that allows the seal ring to be pushed in, even if the insertion amount of the ring body is insufficient when inserting the ring body between the receiving port seal surface and the outer peripheral surface of the insertion port. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides a pipe fitting in which the insertion port of one pipe is inserted into the receiving port of the other pipe, A lock ring receiving groove is formed on the inner periphery of the socket. The lock ring is accommodated in the lock ring accommodating groove, A seal ring is provided on the open end side of the socket relative to the lock ring, and is compressed in the pipe diameter direction to seal between the outer periphery of the insertion port and the inner periphery of the socket. The socket has, on its inner periphery, a socket seal surface against which the outer periphery of the seal ring is pressed over the entire periphery, and a socket protrusion protruding radially inward from the deepest part of the socket seal surface, The inner diameter of the receiving port seal surface is larger than the inner diameter of the receiving port protrusion, An insertion port engaging portion is formed on the outer periphery of the insertion port, A ring body provided between a lock ring and a seal ring of a pipe fitting, which can prevent the insertion port from being removed from the insertion port by having an insertion port engagement portion engage with the lock ring from the back side of the insertion port in the removal direction of the insertion port, The connector has an annular ring body that can be inserted between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the insertion port, and a plurality of spacing maintaining portions that can be inserted between the socket seal surface and the outer peripheral surface of the insertion port, The gap maintaining portions are provided on the ring body at predetermined intervals in the pipe circumferential direction, and are sandwiched between the receiving port seal surface and the outer peripheral surface of the insertion port, thereby maintaining the gap between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe radial direction at a predetermined size that allows the seal ring to be pressed in, An escape space is formed between adjacent spacing maintaining portions in the circumferential direction of the pipe, and closer to the receiving port opening end than the ring main body portion, into which the compressed seal ring can enter.

[0013] According to this, when joining pipes, the spigot is inserted into the socket, the ring body is inserted from the open end of the socket between the socket seal surface and the outer peripheral surface of the socket, and the ring body of the ring body is pressed between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the socket. This sets the ring body in the correct position, and the spacing maintaining portion of the ring body is sandwiched between the socket seal surface and the outer peripheral surface of the socket, maintaining the spacing between the socket seal surface and the outer peripheral surface of the socket in the pipe diameter direction at a predetermined size that allows the seal ring to be pressed in.

[0014] This means that when the seal ring is pushed from the open end of the receiving port between the receiving port seal surface and the outer peripheral surface of the insertion port, the seal ring is not excessively compressed in the pipe diameter direction, and the seal ring can be easily pushed from the open end of the receiving port between the receiving port seal surface and the outer peripheral surface of the insertion port.

[0015] Furthermore, even if the insertion depth of the ring body is insufficient and the ring main body does not reach the gap between the inner surface of the receiving port protrusion and the outer surface of the insertion port, and is instead set between the receiving port seal surface located before the receiving port protrusion and the outer surface of the insertion port, the spacing maintaining portion is sandwiched between the receiving port seal surface and the outer surface of the insertion port, so the spacing between the receiving port seal surface and the outer surface of the insertion port in the pipe diameter direction is maintained at a predetermined size that allows the seal ring to be pushed in.

[0016] This means that even if the insertion depth of the ring body is insufficient, the seal ring will not be excessively compressed in the pipe diameter direction, and the seal ring can be easily pushed from the opening end of the receiving port between the receiving port seal surface and the outer peripheral surface of the insertion port.

[0017] Furthermore, when pipes are bent and joined together, there are places where the distance between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe diameter direction becomes narrower than the above-mentioned specified size, and even if part of the seal ring pressed between the receiving port seal surface and the outer peripheral surface of the insertion port is overly compressed in the pipe diameter direction, the overly compressed part of the seal ring enters the escape space of the ring body, thereby preventing the seal ring from being pressed in insufficiently.

[0018] In addition, in the ring body of the present invention, the outer diameter of the gap maintaining portion is larger than the outer diameter of the ring main body portion, The spacing maintaining portion has an engaging surface that engages with the socket protrusion in the insertion direction of the insertion port, The engagement surface projects outward in the pipe radial direction from the outer peripheral surface of the ring body.

[0019] When joining pipes, the ring body is inserted from the open end of the socket between the socket seal surface and the outer circumferential surface of the socket, and the ring body is pressed into the gap between the inner circumferential surface of the socket protrusion and the outer circumferential surface of the socket. At this time, the engagement surface of the ring body engages with the socket protrusion in the insertion direction of the socket, so that the ring body is set in the correct position and will not shift further back into the socket than the correct position.

[0020] In addition, in the ring body of the present invention, when the engagement surface of the spacing maintaining portion is engaged with the receiving port protrusion, the rear end of the ring main body portion in the pipe axis direction is located closer to the receiving port opening end than the rear end of the receiving port protrusion.

[0021] As a result, when the ring body is set in the correct position, the engagement surface of the spacing maintaining portion engages with the receiving port protrusion, and the rear end of the ring main body is positioned closer to the receiving port opening end than the rear end of the receiving port protrusion, thereby preventing contact between the ring main body and the lock ring and preventing damage to the ring main body.

[0022] The present invention also provides a method for joining pipes using the ring body, comprising: The lock ring is accommodated in the lock ring accommodating groove, Insert the insertion port into the socket, and pass the insertion port engagement part from the socket opening end side of the lock ring to the socket back side, The ring body is inserted from the open end of the receiving port between the receiving port seal surface and the outer peripheral surface of the insertion port, The seal ring is pressed into the opening end of the socket between the socket seal surface and the outer peripheral surface of the insertion port.

[0023] By inserting the ring body between the receiving port seal surface and the outer peripheral surface of the insertion port and setting it in the correct position, the spacing maintaining portion of the ring body is sandwiched between the receiving port seal surface and the outer peripheral surface of the insertion port, and the spacing between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe diameter direction is maintained at a predetermined size that allows the seal ring to be pushed in.

[0024] Furthermore, even if the insertion depth of the ring body is insufficient, the spacing maintaining portion is sandwiched between the receiving port seal surface and the outer peripheral surface of the insertion port, so the spacing between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe diameter direction is maintained at a predetermined size that allows the seal ring to be pushed in.

[0025] This allows the seal ring to be easily pushed into the gap between the receiving port seal surface and the outer peripheral surface of the insertion port from the open end of the receiving port even if the insertion depth of the ring body is insufficient. [Effects of the Invention]

[0026] As described above, according to the present invention, even if the insertion distance of the ring body is insufficient when inserting the ring body between the receiving port seal surface and the outer peripheral surface of the insertion port, the gap maintaining portion is sandwiched between the receiving port seal surface and the outer peripheral surface of the insertion port, so the gap between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe diameter direction is maintained at a predetermined size that allows the seal ring to be pushed in. This makes it easy to push the seal ring between the receiving port seal surface and the outer peripheral surface of the insertion port. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view of a pipe joint according to a first embodiment of the present invention, showing a cross section of a gap maintaining portion of a ring body. [Figure 2]FIG. 4 is a cross-sectional view of the pipe joint of the first embodiment, showing a cross-section of a ring body portion of a ring body. [Figure 3] 10 is a view showing the state in which the diameter of the lock ring provided in the pipe joint is expanded. FIG. [Figure 4] 10 is a three-dimensional view of a ring body provided in the pipe joint of the first embodiment. FIG. [Figure 5] FIG. 2 is a front view of a ring body provided in the pipe joint according to the first embodiment. [Figure 6] 10 is a side view of a ring body provided in the pipe joint according to the first embodiment. FIG. [Figure 7] FIG. 6 is a view taken along the arrow XX in FIG. 5. [Figure 8] FIG. 6 is a view taken along the arrow YY in FIG. 5. [Figure 9] FIG. 6 is a view taken along arrow ZZ in FIG. 5. [Figure 10] 10 is an enlarged cross-sectional view of a gap maintaining portion of a ring body provided in the pipe joint of the first embodiment, showing the state when the ring body is set in the normal position. FIG. [Figure 11] 10 is an enlarged cross-sectional view of a ring body of a ring body provided in the pipe joint of the first embodiment, showing the state when the ring body is set in a normal position. FIG. [Figure 12] This is a diagram showing the same method of joining pipes using a ring body, and shows the state when the lock ring is expanded and the insertion port is inserted into the receiving port. [Figure 13] This is a diagram showing a method of joining pipes using a ring body, showing the state when the lock ring is reduced in diameter and hugged to the outer circumference of the insertion port. [Figure 14] 10 is a diagram showing a method of joining pipes using a ring body in accordance with the first embodiment, showing the state when the ring body is inserted and set in the correct position. FIG. [Figure 15] 10 is an enlarged cross-sectional view of a gap maintaining portion of the ring body provided in the pipe joint in accordance with the first embodiment, showing the state when the insertion amount of the ring body is insufficient. FIG. [Figure 16] FIG. 4 is a cross-sectional view of a pipe joint according to a second embodiment of the present invention. [Figure 17] 10 is an enlarged cross-sectional view of a ring body provided in the pipe joint of the first embodiment, showing the state when the ring body is set in a normal position. FIG. [Figure 18] 10 is an enlarged cross-sectional view of a ring body provided in the pipe joint of the first embodiment, showing the state when the seal ring is pressed in. FIG. [Figure 19] FIG. 10 is a cross-sectional view of a pipe joint according to a third embodiment of the present invention, showing a cross section of a gap maintaining portion of a ring body. [Figure 20] FIG. 4 is a cross-sectional view of the pipe joint of the first embodiment, showing a cross-section of a ring body portion of a ring body. [Figure 21] FIG. 10 is a cross-sectional view of a pipe joint provided with a conventional ring body. [Figure 22] 10 is an enlarged cross-sectional view of a ring body provided in the pipe joint of the first embodiment, showing the state when the ring body is set in a normal position. FIG. [Figure 23] 10 is an enlarged cross-sectional view of a ring body provided in the pipe joint of the first embodiment, showing the state when the insertion amount of the ring body is insufficient. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0029] (First embodiment) As shown in Figures 1 and 2, reference numeral 1 denotes a pipe joint with a separation prevention function, in which the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4. These pipes 2, 4 are made of, for example, ductile iron pipes.

[0030] A lock ring receiving groove 7 is formed around the entire inner circumferential surface of the socket 5. A lock ring 8 is received in the lock ring receiving groove 7. As shown in Figure 3, the lock ring 8 is a ring with a split structure cut in one place, and has an elasticity such that the diameter can be expanded by expanding the width 12 of the cut portion 11 with an expander 13, and the diameter can be reduced and returned to its original diameter by removing the expander 13 from the cut portion 11.

[0031] 1 and 2, a socket protrusion 15 (an example of a socket engagement portion) is formed around the entire outer periphery of the socket 3. The socket protrusion 15 engages with the lock ring 8 from the back side of the socket in the removal direction 6 of the socket 3, thereby preventing the socket 3 from being removed from the socket 5.

[0032] A seal ring 19 is provided closer to the open end of the socket 5 than the lock ring 8 and is compressed in the pipe diameter direction 17 to seal between the outer peripheral surface 3a of the insertion port 3 and the inner peripheral surface of the socket 5. The seal ring 19 is a rubber ring (rubber ring).

[0033] The receiving port 5 has, on its inner periphery, a receiving port seal surface 21 against which the outer surface of the seal ring 19 is pressed all around, and a receiving port protrusion 22 that protrudes from the deepest part of the receiving port seal surface 21 inward in the pipe diameter direction.

[0034] 1 and 10, the receiving port sealing surface 21 has a tapered portion 25 that gradually reduces in diameter from the opening end surface 24 of the receiving port 5 toward the rear, and a straight portion 26 that extends toward the rear from the rear end of the tapered portion 25. The straight portion 26 is formed with the same inner diameter in the pipe axis direction 27 and is parallel to the outer peripheral surface 3a of the insertion port 3.

[0035] The receiving port protrusion 22 is formed in a circular ring shape around the entire circumference between the straight portion 26 of the receiving port seal surface 21 and the lock ring accommodating groove 7, and has one end face 22b that extends from the inner end of the straight portion 26 to the inner surface 22a of the receiving port protrusion 22, and the other end face 22c that faces from the inner surface 22a to the lock ring accommodating groove 7.

[0036] One end face 22b of socket projection 22 is a tapered surface whose diameter decreases as it approaches inner circumferential surface 22a of socket projection 22 from the inner end of straight portion 26. The other end face 22c of socket projection 22 is a surface facing the interior of the socket, and is located at the inner end of socket projection 22 in pipe axis direction 27. The inner diameter of straight portion 26 of socket seal surface 21 is set larger than the inner diameter of socket projection 22.

[0037] 1 and 2, a press ring 30 is provided at the open end of the socket 5 to press the seal ring 19 into the back of the socket. The press ring 30 has an abutment portion 32 that abuts against the open end surface 24 of the socket 5 in the insertion direction 31 of the seal ring 19, and is connected to the open end of the socket 5 with a plurality of bolts 33 and nuts 34.

[0038] A ring body 40 is provided between the lock ring 8 and the seal ring 19 in the pipe axis direction 27. As shown in Figures 4 to 6, the ring body 40 is made of an elastic material such as resin, and has an annular ring main body portion 41 that can be inserted between the inner peripheral surface 22a of the socket protrusion 22 and the outer peripheral surface 3a of the insertion port 3, and a plurality of spacing maintaining portions 42 that can be inserted between the straight portion 26 of the socket seal surface 21 and the outer peripheral surface 3a of the insertion port 3, and is a ring with a single split structure in which one of the spacing maintaining portions 42 is cut off.

[0039] As shown in Fig. 7, ring main body 41 has a rectangular cross section. Also, as shown in Figs. 4 to 6, gap maintaining portions 42 are provided integrally with ring main body 41 at predetermined intervals in pipe circumferential direction 44, and as shown in Figs. 8 and 9, are protrusions that protrude from ring main body 41 toward the socket opening end and protrude further outward in the pipe radial direction than ring main body 41, and have engagement surface 45 that engages with one end surface 22b of socket protrusion 22 in insertion direction 31 of insertion port 3.

[0040] The engagement surface 45 extends outward in the pipe diameter direction 17 from the outer peripheral surface of the ring main body 41, and is a tapered surface whose diameter increases as it approaches the outer peripheral surface of the gap maintaining portion 42 from the outer peripheral surface of the ring main body 41.

[0041] The inner diameter d1 of the gap maintaining portion 42 is the same as the inner diameter d2 of the ring main body 41, and the outer diameter D1 of the gap maintaining portion 42 is larger than the outer diameter D2 of the ring main body 41.

[0042] Between adjacent spacing maintaining portions 42 in the pipe circumferential direction 44 and on the receiving port opening end side of the ring main body portion 41, an escape space 46 is formed into which the compressed seal ring 19 can enter.

[0043] As shown in Figures 10 and 11, when the engagement surface 45 of the spacing maintaining portion 42 abuts and engages with one end face 22b of the receiving port protrusion 22, the rear end face 41a of the ring main body portion 41 is positioned closer to the receiving port opening end than the other end face 22c (rear end) of the receiving port protrusion 22.

[0044] A method for joining the pipes 2 and 4 in the pipe joint 1 described above will now be described.

[0045] As shown in Figure 12, the ring body 40, seal ring 19, and press ring 30 are fitted onto one of the tubes 2 in advance. The lock ring 8 is then placed (set) into the lock ring receiving groove 7 of the other tube 4. Then, as shown in Figure 3, the width 12 of the cut portion 11 of the lock ring 8 is expanded with an expander 13 to expand the diameter of the lock ring 8. Next, as shown in Figure 12, an L-shaped diameter expansion holder 50 is inserted into the cut portion 11 of the lock ring 8, and the expander 13 is removed, leaving the lock ring 8 in its expanded state.

[0046] Thereafter, insert port 3 into socket 5, and pass port protrusion 15 from the socket opening end side to the back side of the socket of lock ring 8. At this time, because lock ring 8 is maintained in an expanded diameter state by diameter expansion holder 50, insert port protrusion 15 easily passes through the inner circumference of lock ring 8.

[0047] 13, the diameter expansion holder 50 is removed to reduce the diameter of the lock ring 8. As a result, the lock ring 8 clings to the outer periphery of the insertion port 3.

[0048] In this case, if the pipe axis of one pipe 2 is misaligned in the pipe diameter direction 17 with respect to the pipe axis of the other pipe 4, a location (hereinafter referred to as a narrow location) will occur where the gap 52 between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 in the pipe diameter direction 17 is narrower than the predetermined size required to press in the seal ring 19. Note that at the location on the opposite side, 180° away from the narrow location in the pipe circumferential direction 44, the gap 52 will be wider than the predetermined size.

[0049] For example, FIG. 13 shows a state in which a narrowed portion occurs in the upper part of the pipes 2, 4, and in this case, the gap 52 in the lower part of the pipes 2, 4 becomes larger than the predetermined size.

[0050] Then, as shown in Figure 14, the ring body 40 is moved in the pipe axis direction 27 and inserted from the open end of the receiving port 5 between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, and set in the correct position.

[0051] As a result, as shown in Figures 10 and 11, the ring main body 41 of the ring body 40 is inserted between the inner surface 22a of the receiving port protrusion 22 and the outer surface 3a of the insertion port 3, and the engagement surface 45 of the ring body 40 abuts and engages with one end surface 22b of the receiving port protrusion 22.

[0052] At this time, the spacing maintaining portion 42 of the ring body 40 is sandwiched between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, so that the spacing 52 between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 in the pipe diameter direction 17 is maintained at a predetermined size required to push in the seal ring 19.

[0053] As a result, even if a narrow spot occurs when the insertion port 3 is inserted into the receiving port 5 as shown in Figure 13 above, by subsequently setting the ring body 40 to the correct position as shown in Figure 14 above, the distance 52 between the straight portion 26 of the receiving port seal surface 21 in the pipe diameter direction 17 and the outer surface 3a of the insertion port 3 can be maintained at the specified size required to push in the seal ring 19, as shown in Figures 10 and 11.

[0054] Furthermore, by engaging the engagement surface 45 of the ring body 40 with one end surface 22b of the receiving port protrusion 22, the ring body 40 is set in the correct position, and the position of the ring body 40 will not shift further back into the receiving port 5 than the correct position.

[0055] Then, the seal ring 19 is inserted from the opening end of the receiving port 5 between the receiving port seal surface 21 and the outer surface 3a of the insertion port 3, and the pressure ring 30 is connected to the opening end of the receiving port 5 using a bolt 33 and a nut 34, and the bolt 33 and the nut 34 are tightened until the abutment portion 32 of the pressure ring 30 abuts against the opening end surface 24 of the receiving port 5.

[0056] In this case, as described above, the distance 52 between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 is maintained at a predetermined size required to push in the seal ring 19, so when the seal ring 19 is pushed between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, the seal ring 19 is not excessively compressed in the pipe diameter direction 17, and the seal ring 19 can be easily pushed in between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 from the open end of the receiving port 5.

[0057] 1 and 2, when the pipes 2 and 4 are joined together and the seal ring 19 is attached, one pipe 2 is centered relative to the other pipe 4, and the pipe axis of one pipe 2 coincides with the pipe axis of the other pipe 4. In this centered state, slight gaps are generated approximately evenly around the entire circumference between the outer circumferential surface of the ring main body portion 41 of the ring body 40 and the inner circumferential surface 22a of the socket protrusion 22, and between the outer circumferential surface of the gap maintaining portion 42 and the straight portion 26 of the socket seal surface 21.

[0058] In such a method of joining pipes 2, 4 using a ring body 40, when the ring body 40 is inserted between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, as shown in Figure 15, the insertion depth of the ring body 40 is insufficient, and the ring main body portion 41 does not reach between the inner peripheral surface 22a of the receiving port protrusion 22 and the outer peripheral surface 3a of the insertion port 3.Even if the ring body 40 is set between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, which is closer to the receiving port protrusion 22, the spacing maintaining portion 42 is sandwiched between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, so the spacing 52 between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 in the pipe diameter direction 17 is maintained at the specified size required to push in the seal ring 19.

[0059] As a result, even if the insertion depth of the ring body 40 is insufficient, when the seal ring 19 is pushed between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, the seal ring 19 is not excessively compressed in the pipe diameter direction 17, and the seal ring 19 can be easily pushed from the opening end of the receiving port 5 between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3.

[0060] Furthermore, even if the insertion depth of the ring body 40 is insufficient as shown in Figure 15 above, by pushing the seal ring 19 between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, the ring body 40 is pushed toward the back of the receiving port by the seal ring 19 until the ring main body 41 reaches between the inner peripheral surface 22a of the receiving port protrusion 22 and the outer peripheral surface 3a of the insertion port 3.

[0061] Furthermore, as shown in Figures 10 and 11, when the ring body 40 is set in the correct position, the engagement surface 45 of the spacing maintaining portion 42 engages with one end face 22b of the receiving port protrusion 22, and the rear end face 41a of the ring main body portion 41 is positioned closer to the receiving port opening end than the other end face 22c (rear end) of the receiving port protrusion 22, thereby preventing contact between the ring main body portion 41 and the lock ring 8 and preventing damage to the ring main body portion 41.

[0062] In the first embodiment described above, as shown in Figure 13, an example is given of a case where a narrowed area occurs in the upper part of the pipes 2, 4 and the distance 52 in the lower part of the pipes 2, 4 is wider than the specified size, but the same action and effect can be obtained even if a narrowed area occurs other than the upper part of the pipes 2, 4 (for example, the lower part) and the distance 52 in the lower part of the pipes 2, 4 (for example, the upper part) is wider than the specified size.

[0063] (Second embodiment) In the first embodiment described above, one pipe 2 is joined straight to the other pipe 4 as shown in FIG. 2, but in the second embodiment described below, a case will be described in which one pipe 2 is joined by bending it upward relative to the other pipe 4 as shown in FIG. 16.

[0064] As shown in Figure 14, the insertion port 3 is inserted into the receiving port 5, and then the ring body 40 is moved in the pipe axis direction 27 and inserted from the open end of the receiving port 5 between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3, and set in the correct position.

[0065] As a result, as shown in Figures 10 and 11, the ring main body 41 of the ring body 40 is inserted between the inner surface 22a of the receiving port protrusion 22 and the outer surface 3a of the insertion port 3, and the engagement surface 45 of the ring body 40 abuts and engages with one end surface 22b of the receiving port protrusion 22.

[0066] 17, one pipe 2 is bent upward relative to the other pipe 4. As a result, the distance 52 between the straight portion 26 of the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 becomes narrower than the predetermined size at the upper part of the pipes 2 and 4, and becomes wider at the lower part of the pipes 2 and 4.

[0067] Thereafter, when the seal ring 19 is pushed into the space between the receiving port seal surface 21 and the outer peripheral surface 3a of the insertion port 3 from the open end of the receiving port 5, even if the seal ring 19 is excessively compressed in the pipe diameter direction 17 at the top of the pipes 2, 4 as shown in Figure 18, the excessively 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 pushed in insufficiently.

[0068] In the above second embodiment, an example is shown in which one pipe 2 is bent upward relative to the other pipe 4, but the same action and effect can be obtained even if one pipe 2 is bent downward (or in another direction) relative to the other pipe 4.

[0069] (Third embodiment) In the first embodiment described above, as shown in Figure 1, when the ring body 40 is inserted to the correct position, a gap is created between the ring body 40 and the seal ring 19. However, in the third embodiment described below, as shown in Figure 19, the distance C from the opening end face 24 of the receiving port 5 to the receiving port protrusion 22 is shorter than in the first embodiment, and the seal ring 19 is set to abut against the ring body 40 when the ring body 40 is inserted to the correct position.

[0070] In this case, the seal ring 19 is compressed in the pipe diameter direction 17, and is also compressed in the pipe axis direction 27 by being sandwiched between the gap maintaining portion 42 of the ring body 40 and the pressure ring 30. At this time, because the escape space 46 is formed in the ring body 40, a sufficiently large space necessary for compressing the seal ring 19 is secured between the socket seal surface 21 and the outer peripheral surface 3a of the insertion port 3, and as shown in Figure 20, the tip of the seal ring 19 enters the escape space 46 of the ring body 40, thereby preventing the seal ring 19 from being excessively compressed between the socket seal surface 21 and the outer peripheral surface 3a of the insertion port 3.

[0071] This makes it possible to reduce the distance C from the open end face 24 of the socket 5 to the socket protrusion 22 and to reduce the length of the socket 5 in the pipe axis direction 27 compared to the first embodiment.

[0072] In each of the above embodiments, the ring body 40 has a single split structure, but the ring body 40 may also be split into multiple arc-shaped ring pieces, and adjacent ring pieces may be connected together with connecting members to assemble the annular ring body 40. [Explanation of symbols]

[0073] 1 Pipe fittings 2 One of the tubes 3 Insertion port 3a Outer surface of insertion port 4 The other tube 5 socket 6. Departure direction 7 Lock ring receiving groove 8 Lock ring 15 Insertion port protrusion (insertion port engagement part) 17 Pipe diameter direction 19 Seal ring 21 Receiver seal surface 22 Socket protrusion 22a Inner surface of socket protrusion 22c Other end face of socket protrusion (rear end of socket protrusion) 24 Open end face 31 Insertion direction 40 Ring body 41 Ring body 41a Back end surface of ring body 42 Spacing maintenance unit 44 Circumferential direction 45 Engagement surface 46 Escape Space 52 interval D1 Outer diameter of the gap maintaining part D2 Outer diameter of ring body

Claims

1. The spigot of one pipe is inserted into the socket of the other pipe, A lock ring receiving groove is formed on the inner periphery of the socket. The lock ring is accommodated in the lock ring accommodating groove, A seal ring is provided on the open end side of the socket relative to the lock ring, and is compressed in the pipe diameter direction to seal between the outer periphery of the insertion port and the inner periphery of the socket. The socket has, on its inner periphery, a socket seal surface against which the outer periphery of the seal ring is pressed over the entire periphery, and a socket protrusion protruding radially inward from the deepest part of the socket seal surface, The inner diameter of the receiving port seal surface is larger than the inner diameter of the receiving port protrusion, An insertion port engaging portion is formed on the outer periphery of the insertion port, A ring body provided between a lock ring and a seal ring of a pipe fitting, which can prevent the insertion port from being removed from the insertion port by having an insertion port engagement portion engage with the lock ring from the back side of the insertion port in the removal direction of the insertion port, The connector has an annular ring body that can be inserted between the inner peripheral surface of the socket protrusion and the outer peripheral surface of the insertion port, and a plurality of spacing maintaining portions that can be inserted between the socket seal surface and the outer peripheral surface of the insertion port, The gap maintaining portions are provided on the ring body at predetermined intervals in the pipe circumferential direction, and are sandwiched between the receiving port seal surface and the outer peripheral surface of the insertion port, thereby maintaining the gap between the receiving port seal surface and the outer peripheral surface of the insertion port in the pipe radial direction at a predetermined size that allows the seal ring to be pressed in, A ring body characterized in that an escape space into which a compressed seal ring can enter is formed between adjacent spacing maintaining portions in the circumferential direction of the pipe and on the side closer to the receiving port opening end than the ring main body.

2. The outer diameter of the spacing maintaining portion is larger than the outer diameter of the ring main body portion, The spacing maintaining portion has an engaging surface that engages with the socket protrusion in the insertion direction of the insertion port, 2. The ring body according to claim 1, wherein the engagement surface projects outward in the pipe radial direction from the outer peripheral surface of the ring body.

3. 3. A ring body according to claim 2, wherein when the engagement surface of the spacing maintaining portion is engaged with the receiving port protrusion, the innermost end of the ring body in the axial direction of the pipe is positioned closer to the receiving port opening end than the innermost end of the receiving port protrusion.

4. A method for joining pipes using the ring body according to any one of claims 1 to 3, The lock ring is accommodated in the lock ring accommodating groove, Insert the insertion port into the socket, and pass the insertion port engagement part from the socket opening end side of the lock ring to the socket back side, The ring body is inserted from the open end of the receiving port between the receiving port seal surface and the outer peripheral surface of the insertion port, A method for joining pipes, characterized in that a seal ring is pressed into between the receiving port seal surface and the outer peripheral surface of the insertion port from the open end of the receiving port.

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