Press ring, pipe joint, and pipe joining method

Abstract

To provide a push ring capable of improving workability in joining pipes even when a work space between the work position and an obstacle is narrow.SOLUTION: In a push ring 14 which is externally fitted to an insertion port, opposed to an opening end face of a socket from an outer side and connected to the socket by means of a plurality of fasteners, and presses a seal material toward a depth side of the socket, a pressing face for pressing the seal material, and a plurality of fastener insertion holes 21 to which the fasteners are inserted, are formed on a push ring main body 14a, the push ring main body 14a has a uniform interval region 29 where an interval between the fastener insertion holes 21 in a circumferential direction A is maintained bo be a uniform interval S1, and an enlarged interval region 30 where an interval S2 between any mutually adjacent, in the circumferential direction A, two of the fastener insertion holes 21, is enlarged with respect to the uniform interval S1. and a reinforcement member 23 is disposed in the enlarged interval region 30.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a press ring used in a pipe joint having a socket and a spigot, a pipe joint equipped with a press ring, and a method for joining pipes using a press ring. [Background technology]

[0002] Conventionally, an example of this type of pipe fitting is shown in Figure 19, in which the insertion port 102 of one pipe 101 is inserted into the receiving port 104 of the other pipe 103, a sealing member 105 is inserted between the outer periphery of the insertion port 102 and the inner periphery of the receiving port 104, and a pressure ring 106 is fitted onto the outside of the insertion port 102 so as to face the open end face 107 of the receiving port 104 from the outside, and is connected to the receiving port 104 by a number of bolts 108 and nuts 109.

[0003] The press ring 106 has a circular press ring body 110, a pressing surface 111 that comes into contact with the seal member 105 to press the seal member 105, a plurality of protrusions 112 that come into contact with the open end face 107 of the socket 104, and a plurality of bolt insertion holes 113 through which the bolts 108 are inserted. The pressing surface 111 and the protrusions 112 are provided on the same side of the press ring body 110 (i.e., the side facing the socket 104). Furthermore, the protrusions 112 come into contact with the open end face 107 of the socket 104, thereby maintaining a predetermined distance between the pressing surface 111 and the open end face 107 of the socket 104.

[0004] 20 , the intervals G between the bolt insertion holes 113 in the circumferential direction A of the press ring 106 are all kept uniform. The bolts 108 are inserted into the bolt insertion holes 113 of the press ring 106, and by tightening the nuts 109, the pressing surfaces 111 of the press ring 106 come into contact with the seal member 105, forcing the seal member 105 into the gap between the outer periphery of the insertion port 102 and the inner periphery of the receiving port 104.

[0005] The above-described press ring 106 and pipe joint 100 are described in, for example, Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2014-5868 Summary of the Invention [Problem to be solved by the invention]

[0007] 21, when a groove 114 is formed in the ground 116 and the pipes 101, 103 are joined inside the groove 114, the narrow distance H between the bolt insertion hole 113 located directly below the pipes 101, 103 and the bottom 115 of the groove 114 makes it difficult to insert the bolt 108 into the bolt insertion hole 113 located directly below the pipes 101, 103 and tighten the nut 109, reducing the workability when joining the pipes 101, 103. For this reason, it is necessary to ensure a wide distance H between the bolt insertion hole 113 located directly below the pipes 101, 103 and the bottom 115 of the groove 114, which requires a large work space.

[0008] Further, not only when the pipes 101, 103 are joined together inside the groove 114 as described above, but also when the pipes 101, 103 are joined together along an obstacle such as a wall to form a pipeline, the narrow gap between the bolt insertion hole 113 located on the side where the obstacle exists and the obstacle makes it difficult to insert the bolt 108 into the bolt insertion hole 113 located on the side where the obstacle exists and tighten the nut 109, reducing the ease of operation when joining the pipes 101, 103. For this reason, it is necessary to ensure a wide gap between the bolt insertion hole 113 located on the side where the obstacle exists and the obstacle, which requires a large working space.

[0009] An object of the present invention is to provide a press ring, a pipe joint, and a pipe joining method that can improve workability when joining pipes even if the working space between the pipes and an obstacle is narrow. [Means for solving the problem]

[0010] In order to achieve the above object, the first invention provides a device for inserting a plug into a socket, The seal member is used in a pipe joint in which the seal member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, A press ring is fitted onto the insertion port so as to face the open end surface of the receiving port from the outside and is connected to the receiving port by a plurality of fasteners to press the seal member into the inner side of the receiving port, The pressing ring body is formed with a pressing surface for pressing the seal member and a plurality of fastener insertion holes through which fasteners are inserted, the press ring body has an even spacing region in which the spacing between the fastener insertion holes in the circumferential direction is kept even, and an expanded spacing region in which the spacing between any two adjacent fastener insertion holes in the circumferential direction is expanded beyond the even spacing, A reinforcing member is provided in the enlarged gap region.

[0011] According to this, when there is an obstacle that hinders the joining work of joining pipes, the insert is inserted into the socket, and with the expanded gap area of ​​the press ring positioned on the side where the obstacle is present, the fastener is inserted into the fastener insertion hole and tightened. This connects the press ring to the socket and inserts the seal member between the outer periphery of the insert and the inner periphery of the socket.

[0012] In such pipe joining operations, since the enlarged gap region of the pressure ring is located on the side of the obstacle as described above, the fastener insertion holes in the enlarged gap region are located at positions distributed in the circumferential direction of the pressure ring rather than at the position closest to the obstacle. This increases the distance between the fastener insertion holes in the enlarged gap region and the obstacle, improving workability when joining pipes even if the working space between the pressure ring and the obstacle is narrow.

[0013] Furthermore, since the expanded gap region of the pressure ring is maintained with sufficient rigidity by the reinforcing member, even if a reaction force of the sealing member acts on the pressure ring, the expanded gap region of the pressure ring can be prevented from bending due to the reaction force.

[0014] The press ring in the second invention has an expanded gap region located on the side where there is an obstacle that hinders the joining operation of joining pipes together.

[0015] In the third aspect of the present invention, the reinforcing member is provided on the surface of the press ring body opposite the pressing surface, and is located radially outward from the inner periphery of the press ring body. A step is formed between the inner periphery of the pressure ring body and the inner periphery of the reinforcing member.

[0016] According to this, after the insertion port of one pipe is inserted into the receiving port of the other pipe to join them, when one pipe is bent relative to the other pipe due to an earthquake or the like, the bending angle until the one pipe comes into contact with the reinforcing member of the pressure ring increases, and the load applied to the pressure ring when one pipe is bent relative to the other pipe is reduced.

[0017] In addition, when multiple fasteners are inserted into multiple fastener insertion holes to connect the pressure ring to the socket, the fasteners are tightened one-sidedly, so even if the pressure ring is tilted relative to one of the pipes, the angle of inclination until the reinforcing member of the pressure ring comes into contact with the one of the pipes increases. This makes it easy to connect the pressure ring to the socket by tightening multiple fasteners one-sidedly.

[0018] In the fourth aspect of the present invention, the reinforcing member is provided on the surface of the press ring body opposite to the pressing surface, and is located radially outward of the inner periphery of the press ring body. A tapered portion is formed between the inner periphery of the pressing ring body and the inner periphery of the reinforcing member, The tapered portion is inclined radially outward in the direction in which the insertion port is separated from the receiving port.

[0019] According to this, after the insertion port of one pipe is inserted into the receiving port of the other pipe to join them, when one pipe is bent relative to the other pipe due to an earthquake or the like, the bending angle until the one pipe comes into contact with the reinforcing member of the pressure ring increases, and the load applied to the pressure ring when one pipe is bent relative to the other pipe is reduced.

[0020] In addition, when multiple fasteners are inserted into multiple fastener insertion holes to connect the pressure ring to the socket, the fasteners are tightened one-sidedly, so even if the pressure ring is tilted relative to one of the pipes, the angle of inclination until the reinforcing member of the pressure ring comes into contact with the one of the pipes increases. This makes it easy to connect the pressure ring to the socket by tightening multiple fasteners one-sidedly.

[0021] In the press ring according to the fifth invention, the reinforcing member is provided across two adjacent fastener insertion holes in the enlarged gap region.

[0022] As a result, the area between the two fastener insertion holes in the enlarged spacing area of ​​the pressure ring is maintained with sufficient rigidity by the reinforcing member, so that when a fastener is inserted through the fastener insertion hole in the enlarged spacing area and tightened, even if a high load is generated between the two fastener insertion holes in the enlarged spacing area, deformation or damage to the enlarged spacing area of ​​the pressure ring can be prevented.

[0023] The sixth invention is a pipe joint provided with the press ring according to any one of the first to fifth inventions, The insert is inserted into the socket, A seal member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, The press ring is fitted onto the insertion port so as to face the open end surface of the receiving port from the outside, and is connected to the receiving port by a plurality of fasteners in a state in which the expanded gap region is positioned on the side where an obstacle that hinders the pipe joining operation is present, The pressing surface of the pressing ring abuts against the seal member, The fastener is inserted into the fastener insertion hole of the press ring.

[0024] The seventh invention is a method for joining pipes using the press ring according to any one of the first to fifth inventions, The insertion port is inserted into the receiving port, and the expanded spacing area of ​​the pressure ring is positioned on the side where there is an obstacle that hinders the pipe joining work.The fastener is then inserted into the fastener insertion hole of the pressure ring and tightened, connecting the pressure ring to the receiving port and inserting a sealing member between the outer periphery of the insertion port and the inner periphery of the receiving port.

[0025] The method of joining pipes in the eighth invention involves inserting the spigot into the receiving port, bending the spigot at an angle relative to the receiving port, and then inserting a fastener into the fastener insertion hole of the spigot and tightening it to connect the spigot to the receiving port. Effect of the Invention

[0026] As described above, according to the present invention, it is possible to improve the workability when joining pipes even if the working space between the pressure ring and the obstacle is narrow. Furthermore, since the expanded gap area of ​​the pressure ring is kept sufficiently rigid by the reinforcing member, even if the reaction force of the sealing member acts on the pressure ring, the expanded gap area of ​​the pressure ring can be prevented from being deflected by the reaction force. [Brief description of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view of a pipe joint provided with a pressing ring in a first embodiment of the present invention. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] XX arrow view in FIG. 3. [Figure 6] 4 is a view taken along the arrow YY in FIG. 3. [Figure 7] FIG. 4 is a view taken along the arrow ZZ in FIG. [Figure 8] FIG. 4 is a front perspective view of the press ring of the pipe joint according to the first embodiment. [Figure 9] FIG. 4 is a perspective view of the rear side of the press ring of the pipe joint according to the first embodiment. [Figure 10] FIG. 11 is a schematic diagram showing a joining operation for joining pipes of a pipe joint inside a groove formed in the ground. [Figure 11] FIG. 4 is a cross-sectional view of the pipe joint of the same embodiment, showing a state in which one pipe is bent relative to the other pipe after the pipes are joined. [Figure 12] 13 is an enlarged view of a portion of the cross-sectional view of the pipe joint in FIG. 12. [Figure 13]FIG. 11 is a cross-sectional view of the pipe joint of the same embodiment, showing the state when one-sided tightening is performed to connect the press ring to the socket when joining pipes. [Figure 14] FIG. 14 is an enlarged view of a portion of the cross-sectional view in FIG. [Figure 15] FIG. 11 is a cross-sectional view of a pipe joint provided with a press ring in a second embodiment of the present invention. [Figure 16] FIG. 13 is a schematic diagram showing how pipes of a pipe joint of a riser piping laid in the vertical direction along the wall of a building are joined together in the third embodiment of the present invention. [Figure 17] 13 is a cross-sectional view showing a pipe joining method in a fourth embodiment of the present invention, illustrating how a press ring is connected to a socket in a state in which the insertion socket is bent relative to the socket. FIG. [Figure 18] FIG. 18 is an enlarged view of a portion of the cross-sectional view in FIG. [Figure 19] FIG. 1 is a cross-sectional view of a pipe joint equipped with a conventional press ring. [Figure 20] FIG. [Figure 21] FIG. 1 is a schematic diagram showing how pipes of a conventional pipe joint are joined together inside a groove formed in the ground. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0029] (First embodiment) In the first embodiment, as shown in Fig. 1, reference numeral 1 denotes a pipe joint for joining cast iron pipes together, with a spigot 3 provided at the end of one pipe 2 being inserted into a socket 5 provided at the end of the other pipe 4. An annular rubber ring 7 (an example of a sealing member) is inserted and positioned between the outer periphery of the spigot 3 and the inner periphery of the socket 5.

[0030] A lock ring groove 9 is formed around the entire periphery of the inner periphery of the socket 5, further back than the rubber ring 7. A lock ring 10 that is split in the circumferential direction is provided in the lock ring groove 9.

[0031] The insertion port 3 has a protrusion 11 around the entire circumference on the outer periphery of its tip portion, which can be engaged with a lock ring 10 from the back side of the receiving port 5.

[0032] A backup ring 13 , which is split in the circumferential direction, is fitted onto the insertion port 3 and is adjacent to the lock ring 10 .

[0033] The socket 5 has a flange portion 5a at its tip. The flange portion 5a is formed with a plurality of bolt holes 12. For example, in Fig. 2, eight bolt holes 12 are formed in the flange portion 5a, and any two of the bolt holes 12 are positioned on a vertical line.

[0034] A press ring 14 that presses the rubber ring 7 into the back of the socket 5 is fitted onto the insertion port 3 and faces the open end surface 15 of the socket 5 from the outside. The press ring 14 has an annular press ring body 14a and is connected to the socket 5 by a plurality (e.g., seven) of T-head bolts 16 (an example of a fastener) and nuts 17 (an example of a fastener). As shown in Figs. 3 to 9, the press ring body 14a has a plurality of protrusions 14b that protrude radially outward on its outer periphery.

[0035] The pressure ring body 14a is provided with a pressing surface 19 that presses the rubber ring 7, a plurality of bolt insertion holes 21 (one example of fastener insertion holes) through which the T-head bolts 16 are inserted, a reinforcing member 23, and first and second protrusions 24, 25. The protrusions 14b of the pressure ring body 14a are formed to correspond to the bolt insertion holes 21.

[0036] The pressure ring body 14a has an even spacing region 29 and an enlarged spacing region 30. In the even spacing region 29, the spacing between the bolt insertion holes 21 in the circumferential direction A is maintained at an even spacing S1. In the enlarged spacing region 30, the spacing S2 between any two adjacent bolt insertion holes 21 is enlarged from the even spacing S1.

[0037] For example, in Figures 3 and 4, seven bolt insertion holes 21 are formed in the pressure wheel body 14a, the distribution angle B1 of each bolt insertion hole 21 in the evenly spaced region 29 is 45°, and the distribution angle B2 of both bolt insertion holes 21 in the enlarged spacing region 30 is 90°.

[0038] The reinforcing member 23 is an arc-shaped member provided on the surface 32 opposite the pressing surface 19, and is provided between two adjacent bolt insertion holes 21 in the expanded spacing region 30, and is located outside the inner circumference 14c of the pressing ring body 14a in the radial direction D.

[0039] 1 and 7, a tapered portion 34 is formed between the inner periphery 14c of the pressing ring body 14a and the inner periphery 23a of the reinforcing member 23 over the entire length of the reinforcing member 23. The tapered portion 34 is inclined outward in the radial direction D toward the direction C in which the insertion port 3 is separated from the receiving port 5.

[0040] As shown in FIG. 4 , both ends 23b of the reinforcing member 23 extend from within the enlarged spacing region 30 beyond two radial straight lines 36 connecting the center of the pressure ring 14 and the centers of both bolt insertion holes 21 in the enlarged spacing region 30, and into the even spacing region 29.

[0041] The first and second protrusions 24, 25 each come into contact with the open end surface 15 of the socket 5, and of these, a plurality of first protrusions 24 are provided, and are positioned outward of each bolt insertion hole 21 in the radial direction D of the press ring 14. The second protrusions 25 are positioned inward of each bolt insertion hole 21 in the radial direction D of the press ring 14, and are formed in an annular shape so as to surround the periphery of the pressing surface 19. As shown in FIG. 1, the end of the rubber ring 7 is fitted into the inner side of the second protrusions 25 of the press ring 14 in the radial direction D and comes into contact with the pressing surface 19.

[0042] 1, 3, and 4, the pressure ring 14 is connected to the socket 5 so that the expanded gap region 30 is located directly below one of the pipes 2. As shown in Fig. 10, the pipes 2, 4 are joined inside a groove 39 formed by excavating the ground 38, and at this time, the bottom 40 of the groove 39 becomes an obstacle that hinders the joining work of the pipes 2, 4. In other words, the pressure ring 14 is connected to the socket 5 by multiple T-head bolts 16 and nuts 17 with the expanded gap region 30 located on the side where the bottom 40 of the groove 39 (an example of an obstacle) exists.

[0043] A method for joining the pipes 2, 4 using the pressure ring 14 will be described below.

[0044] First, the pressure ring 14, rubber ring 7, and backup ring 13 are fitted onto the insertion port 3 of one of the pipes 2, and the lock ring 10 is attached to the lock ring groove 9 of the receiving port 5 of the other pipe 4, which is already disposed inside the groove 39, and the lock ring 10 is expanded in diameter using a diameter expander (not shown).

[0045] Then, inside the groove 39, the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4. At this time, since the lock ring 10 has an expanded diameter, the protrusion 11 of the insertion port 3 passes through the inner periphery of the lock ring 10 from the open end face 15 side of the receiving port 5 to the back side.

[0046] Thereafter, the diameter expander (not shown) is removed, whereby the lock ring 10 contracts in diameter and hugs the outer periphery of the insertion port 3.

[0047] Next, the backup ring 13 is moved in the axial direction E and inserted into the socket 5 so as to be adjacent to the lock ring 10. Furthermore, the rubber ring 7 is moved in the axial direction E so as to be positioned in front of the opening end face 15 of the socket 5.

[0048] Then, with the expanded gap area 30 of the pressure ring 14 positioned directly below one of the pipes 2, as shown in Figure 10, the T-head bolt 16 is inserted through the bolt hole 12 of the receiving port 5 and the bolt insertion hole 21 of the pressure ring 14, and the nut 17 is screwed onto the T-head bolt 16. The nut 17 is then tightened until the first and second protrusions 24, 25 of the pressure ring 14 abut against the opening end face 15 of the receiving port 5.

[0049] As a result, as shown in Figure 1, the pressure ring 14 is connected to the receiving port 5, and the pressure surface 19 of the pressure ring 14 presses the rubber ring 7 and inserts it between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5, thereby joining one tube 2 to the other tube 4.

[0050] 3, 4 and 10, the enlarged spacing region 30 of the pressure ring 14 is located directly below one of the pipes 2, so the bolt insertion hole 21 in the enlarged spacing region 30 is not located directly below one of the pipes 2, but is located at a position further in the circumferential direction A of the pressure ring 14 than directly below one of the pipes 2. This enlarges the distance H between the bolt insertion hole 21 in the enlarged spacing region 30 and the bottom 40 of the groove 39, so that even if the working space between the pressure ring 14 and the bottom 40 of the groove 39 is narrow, the workability when joining the pipes 2, 4 can be improved.

[0051] In addition, because the reinforcing member 23 maintains the expanded spacing region 30 of the pressure ring 14 with sufficient rigidity, the expanded spacing region 30 of the pressure ring 14 can be prevented from bending due to the reaction force even if the reaction force of the rubber ring 7 acts on the pressure ring 14. Furthermore, when the T-head bolt 16 is inserted through the bolt insertion hole 21 in the expanded spacing region 30 of the pressure ring 14 and the bolt hole 12 of the socket 5 and tightened with the nut 17, even if a high load is generated between the two bolt insertion holes 21 in the expanded spacing region 30, the expanded spacing region 30 can be prevented from being deformed or damaged.

[0052] In addition, after the pipes 2 and 4 are joined together as described above, when one pipe 2 is bent relative to the other pipe 4 due to an earthquake or the like, the bending angle α at which one pipe 2 contacts the reinforcing member 23 of the pressure ring 14 increases as shown in Figures 11 and 12. This reduces the load applied to the pressure ring 14 when one pipe 2 is bent relative to the other pipe 4.

[0053] In the above-mentioned method of joining the pipes 2 and 4, when the T-head bolt 16 is inserted through the bolt hole 12 of the socket 5 and the bolt insertion hole 21 of the pressure ring 14 to connect the pressure ring 14 to the socket 5, the uppermost T-head bolt 16 and nut 17 are first tightened, and then the lower T-head bolts 16 and nuts 17 are tightened in sequence, as shown in Fig. 13, so-called "one-sided tightening". In this way, by tightening the T-head bolt 16 and the nut 17 one-sidedly, even if the pressure ring 14 is inclined relative to one of the pipes 2, the inclination angle β until the reinforcing member 23 of the pressure ring 14 comes into contact with one of the pipes 2 increases. This makes it easy to connect the pressure ring 14 to the socket 5 by tightening multiple T-head bolts 16 and nuts 17 one-sidedly. (Second embodiment) 15, in the second embodiment, the reinforcing member 23 is located outward in the radial direction D from the inner periphery 14c of the press ring body 14a. A step 50 is formed between the inner periphery 14c of the press ring body 14a and the inner periphery 23a of the reinforcing member 23 over the entire length of the reinforcing member 23. The step 50 has a step surface parallel to the radial direction D.

[0054] According to this, as in the first embodiment described above, after the pipes 2 and 4 are joined together, when one pipe 2 is bent relative to the other pipe 4 due to an earthquake or the like, the bending angle α at which the one pipe 2 comes into contact with the reinforcing member 23 of the push ring 14 increases.

[0055] In addition, in the method of joining pipes 2, 4, when the T-head bolt 16 is inserted into the bolt hole 12 of the receiving port 5 and the bolt insertion hole 21 of the pressure ring 14 to connect the pressure ring 14 to the receiving port 5, by tightening the T-head bolt 16 and the nut 17 on one side, even if the pressure ring 14 is inclined relative to one of the pipes 2, the inclination angle β until the reinforcing member 23 of the pressure ring 14 comes into contact with the one of the pipes 2 is increased. (Third embodiment) In the first embodiment described above, as shown in FIG. 10 , the bottom 40 of the groove 39 is an obstacle that impedes the joining operation of the pipes 2, 4, and the pressure ring 14 is connected to the receiving port 5 by a plurality of T-head bolts 16 and nuts 17 with the expanded spacing area 30 positioned on the side where the bottom 40 of the groove 39 is located, but the obstacle is not limited to the bottom 40 of the groove 39.

[0056] For example, in the third embodiment described below, when the pipes 2, 4 are rising pipes laid vertically and surrounded on three sides by building walls 55-57 as shown in Fig. 16, the wall 55 closest to the pipes 2, 4 is regarded as an obstacle. In this case, the pressure ring 14 is connected to the socket 5 by a plurality of T-head bolts 16 and nuts 17 with the expanded gap area 30 positioned on the side where the wall 55 exists.

[0057] According to this, when joining the pipes 2, 4 together, the enlarged spacing region 30 of the pressure ring 14 is located on the wall 55 side, so the two bolt insertion holes 21 in the enlarged spacing region 30 are located at positions distributed in the circumferential direction A of the pressure ring 14 rather than the positions closest to the wall 55. This increases the interval H between the bolt insertion holes 21 in the enlarged spacing region 30 and the wall 55, improving the workability when joining the pipes 2, 4 together even if the work space is narrow. (Fourth embodiment) In the first embodiment described above, as shown in Figure 1, when joining pipes 2 and 4, the insertion port 3 is aligned with the receiving port 5, and the T-head bolt 16 is inserted into the bolt hole 12 of the receiving port 5 and the bolt insertion hole 21 of the pressure ring 14, and the nut 17 is tightened to connect the pressure ring 14 to the receiving port 5 in a straight state. However, the joining method is not limited to this, and for example, in the fourth embodiment described below, as shown in Figures 17 and 18, the insertion port 3 is inserted into the receiving port 5, and the insertion port 3 is bent diagonally with respect to the receiving port 5, and the T-head bolt 16 is inserted into the bolt hole 12 of the receiving port 5 and the bolt insertion hole 21 of the pressure ring 14, and the nut 17 is tightened to connect the pressure ring 14 to the receiving port 5.

[0058] In each of the above-described embodiments, as shown in Figures 3 and 4, seven bolt insertion holes 21 are formed in the pressure ring 14, but this is not limited to seven and may be, for example, a number obtained by subtracting 1 from a multiple of 4 (11 or 15, etc.).

[0059] In each of the above-described embodiments, as shown in FIG. 4, both end portions 23b of the reinforcing member 23 extend from within the expanded spacing region 30 beyond the two straight lines 36 into the even spacing region 29, but may also be formed between the two straight lines 36 without extending beyond the two straight lines 36.

[0060] In the first embodiment, the pressure ring 14 is formed with a tapered portion 34 as shown in Fig. 1, and in the second embodiment, the pressure ring 14 is formed with a stepped portion 50 as shown in Fig. 15, but it is also possible to make the inner periphery 14c of the pressure ring main body 14a and the inner periphery 23a of the reinforcing member 23 have the same diameter and to make the inner periphery 14c of the pressure ring main body 14a and the inner periphery 23a of the reinforcing member 23 flush with each other without forming the tapered portion 34 or the stepped portion 50. However, forming the tapered portion 34 and the stepped portion 50 as described above has the advantage that the bending angle α (see Fig. 11) of the tubes 2, 4 and the inclination angle β (see Fig. 13) of the pressure ring 14 can be made larger than when the tapered portion 34 and the stepped portion 50 are not formed. [Explanation of symbols]

[0061] 1 Pipe fittings 3 Insertion port 5 socket 7 Rubber ring (sealing material) 14 Push Ring 14a Push Ring Body 14c Inner circumference of the push ring body 15 Open end face 16 Bolts (fasteners) 17 Nut (fastener) 19 Pressing surface 21 Bolt insertion hole (fastener insertion hole) 23 Reinforcement members 23a Inner circumference of reinforcing member 29 Evenly spaced areas 30 Expanded Spacing Area 32 Opposite side 34 Tapered section 40 Bottom (obstacle) 50 Step 55 Wall (Obstacle) A Circumferential direction C. Departure direction D Radial direction S1 Evenly spaced S2 interval

Claims

1. The insert is inserted into the socket, The seal member is used in a pipe joint in which the seal member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, A press ring is fitted onto the insertion port so as to face the open end surface of the receiving port from the outside and is connected to the receiving port by a plurality of fasteners to press the seal member into the inner side of the receiving port, The pressing ring body is formed with a pressing surface for pressing the seal member and a plurality of fastener insertion holes through which fasteners are inserted, the press ring body has an even spacing region in which the spacing between the fastener insertion holes in the circumferential direction is kept even, and an expanded spacing region in which the spacing between any two adjacent fastener insertion holes in the circumferential direction is expanded beyond the even spacing, A pressure ring characterized in that a reinforcing member is provided in the enlarged gap region.

2. 2. The press ring according to claim 1, wherein the expanded gap area is located on a side where an obstacle that hinders a joining operation for joining the pipes is present.

3. The reinforcing member is provided on a surface of the pressure ring body opposite to the pressing surface, and is located radially outward of an inner periphery of the pressure ring body, 3. The pressure ring according to claim 1, wherein a step is formed between an inner periphery of the pressure ring body and an inner periphery of the reinforcing member.

4. The reinforcing member is provided on a surface of the pressure ring body opposite to the pressing surface, and is located radially outward of an inner periphery of the pressure ring body, A tapered portion is formed between the inner periphery of the pressing ring body and the inner periphery of the reinforcing member, 3. The press ring according to claim 1, wherein the tapered portion is inclined radially outward in a direction in which the insertion port is separated from the receiving port.

5. 5. The press ring according to claim 1, wherein the reinforcing member is provided across two adjacent fastener insertion holes in the enlarged spacing region.

6. A pipe joint provided with the pressure ring according to any one of claims 1 to 5, The insert is inserted into the socket, A seal member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, The press ring is fitted onto the insertion port so as to face the open end surface of the receiving port from the outside, and is connected to the receiving port by a plurality of fasteners in a state in which the expanded gap region is positioned on the side where an obstacle that hinders the pipe joining operation is present, The pressing surface of the pressing ring abuts against the seal member, A pipe joint characterized in that a fastener is inserted into a fastener insertion hole of a pressure ring.

7. A method for joining pipes using the press ring according to any one of claims 1 to 5, A method of joining pipes, characterized in that a plug is inserted into a receiving port, and the expanded spacing area of ​​the pressure ring is positioned on the side where an obstacle that hinders the pipe joining operation is present, and then a fastener is inserted into the fastener insertion hole of the pressure ring and tightened, thereby connecting the pressure ring to the receiving port and inserting a sealing member between the outer periphery of the plug and the inner periphery of the receiving port.

8. A method for joining pipes as described in claim 7, characterized in that the push ring is connected to the socket by inserting the insertion port into the socket and bending the insertion port diagonally relative to the socket, and then inserting a fastener into the fastener insertion hole of the push ring and tightening it.

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