Pressing wheel, pipe joint, and pipe joining method

Abstract

To provide a push ring capable of increasing an inclination angle in joining pipes, and sufficiently inserting a seal member into between an outer periphery of an insertion port and an inner periphery of a socket.SOLUTION: In a push ring 14 used in a pipe joint 1 in which a seal member 7 is inserted into between an outer periphery of an insertion port 3 and an inner periphery of a socket 5, externally fitted to the insertion port 3, opposed to an opening end face 15 of the socket 5 from an outer side, connected to the socket 5 by a plurality of fasteners 16, 17, and pushing the seal member 7 toward a depth side of the socket 5, a pressing face 19 for pressing the seal member 7, a plurality of fastener insertion holes 21 to which the fasteners 16 are inserted, and a first contact portion 24 contacting the opening end face 15 of the socket 5, are formed on an annular push ring main body 14a, a taper face 29 is formed over the whole periphery of an inner periphery 14c of the push ring main body 14a, and the taper face 29 is gradually expanded in diameter as proceeding from a side near the pressing face 19 toward an opposite side away from the pressing face, and reaches a face 32 at a side opposite to the pressing face 19.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pressing ring used for a pipe joint having a receiving port and an insertion port, a pipe joint provided with the pressing ring, and a method for joining pipes using the pressing ring.

Background Art

[0002] Conventionally, as this type of pipe joint, for example, as shown in FIG. 16, the insertion port 112 of one pipe 111 is inserted into the receiving port 114 of the other pipe 113, a rubber seal member 115 is inserted between the outer periphery of the insertion port 112 and the inner periphery of the receiving port 114, and a pressing ring 116 is externally fitted to the insertion port 112 and faces the opening end face 117 of the receiving port 114 from the outside, and is connected to the receiving port 114 by a plurality of bolts 118 and nuts 119.

[0003] The pressing ring 116 has an annular pressing ring body 116a, a pressing surface 120 that abuts against the seal member 115 and presses the seal member 115, abutting portions 121, 122 that abut against the opening end face 117 of the receiving port 114, and a plurality of bolt insertion holes 123 through which the bolts 118 are inserted. The pressing surface 120 and the abutting portions 121, 122 are provided on the same side of the pressing ring body 116a (the side facing the receiving port 114). Further, when the abutting portions 121, 122 abut against the opening end face 117 of the receiving port 114, the distance from the pressing surface 120 to the opening end face 117 of the receiving port 114 is maintained at a predetermined distance.

[0004] The bolt 118 is inserted through the bolt insertion hole 123 of the pressing ring 116, and by tightening the nut 119, the pressing surface 120 of the pressing ring 116 abuts against the seal member 115 and presses the seal member 115 into the space between the outer periphery of the insertion port 112 and the inner periphery of the receiving port 114.

[0005] Incidentally, the pressing ring 116 and the pipe joint 110 as described above are described in, for example, Patent Document 1 below.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the above conventional form, when forming a curved pipeline 124 by joining a plurality of pipes 111 and 113 as shown in FIG. 17, as shown in FIG. 18, with the pipe axis 111a of one pipe 111 inclined with respect to the pipe axis 113a of the other pipe 113, these pipes 111 and 113 are joined to each other.

[0008] At this time, as shown in FIG. 18, when the outer circumference of one pipe 111 abuts against the corner portion 128 between the inner circumference 116b of the pressing ring 116 and the surface 126 on the opposite side of the pressing surface 120, it is difficult to further increase the inclination angle α of the pipe axis 111a of one pipe 111 with respect to the pipe axis 113a of the other pipe 113. Note that increasing the diameter (inner diameter) of the inner circumference 116b of the pressing ring 116 makes it possible to increase the inclination angle α. However, in this case, the gap 125 (see FIG. 16) between the inner circumference 116b of the pressing ring 116 and the outer circumference of one pipe 111 also expands. Therefore, there is a risk that the sealing member 115 enters the gap 125 from the pressing surface 120 of the pressing ring 116 and cannot be sufficiently inserted between the outer circumference of the insertion port 112 and the inner circumference of the receiving port 114.

[0009] An object of the present invention is to provide a pressing ring, a pipe joint, and a pipe joining method capable of increasing the inclination angle when joining pipes at an inclination and being able to sufficiently insert a sealing member between the outer circumference of the insertion port and the inner circumference of the receiving port.

Means for Solving the Problems

[0010] To achieve the above object, the first invention of the present invention is used for a pipe joint in which an insertion port is inserted into a receiving port and , and a sealing member is inserted between the outer circumference of the insertion port and the inner circumference of the receiving port. A pressing ring that is externally fitted into an insertion port, faces the opening end surface of a receiving port from the outside, and is connected to the receiving port by a plurality of fasteners to push a sealing member into the back side of the receiving port. An annular pressing ring body is formed with a pressing surface for pressing the sealing member, a plurality of fastener insertion holes through which the fasteners are inserted, and a first contact portion that contacts the opening end surface of the receiving port. A tapered surface is formed on the inner circumference of the pressing ring body a straight surface connected to the tapered surface on the side closer to the pressing surface than the tapered surface over the entire circumference. The tapered surface 、 has a diameter that increases from the side closer to the pressing surface to the far side opposite. is a conical circumferential surface that The straight surface is a cylindrical circumferential surface having a constant inner diameter and extending in the axial direction of the pressing ring When the insertion port is inserted into the receiving port with one of the pipe axes of the insertion port and the receiving port inclined with respect to the other pipe axis and the outer periphery of the insertion port contacts the inner periphery of the pressing ring, the outer periphery of the insertion port contacts the boundary portion where the tapered surface and the straight surface are connected It is such.

[0011] According to this, with the insertion port of one pipe inserted into the receiving port of the other pipe in a state where the pipe axis of the insertion port is inclined with respect to the pipe axis of the receiving port of the other pipe, and the fasteners are inserted through the fastener insertion holes of the pressing ring and tightened, the pressing ring is connected to the receiving port and the sealing member is inserted between the outer circumference of the insertion port and the inner circumference of the receiving port, and one pipe and the other pipe can be joined.

[0012] At this time, since a tapered surface is formed on the inner circumference of the pressing ring body, the contact point when the outer circumference of one pipe abuts against the inner circumference of the pressing ring is closer to the pressing surface than the corner portion between the inner circumference of the pressing ring and the surface on the opposite side of the pressing surface. As a result, it is possible to increase the inclination angle of the pipe axis of one pipe with respect to the pipe axis of the other pipe when the outer circumference of one pipe abuts against the inner circumference of the pressing ring, and when joining a plurality of pipes while inclining them to form a curved pipeline, the number of pipes can be reduced. Further, when the insertion port is inserted into the receiving port with the pipe axis of the insertion port of one pipe inclined with respect to the pipe axis of the receiving port of the other pipe and the one pipe and the other pipe are joined, the outer periphery of the one pipe does not contact the inner peripheral edge of the pressing surface of the pressing ring, but contacts the boundary portion between the straight surface and the tapered surface on the inner periphery of the pressing ring. Thereby, it is possible to prevent the inner peripheral edge of the pressing surface of the pressing ring from being damaged, and the sealing member can be sufficiently inserted between the outer periphery of the insertion port and the inner periphery of the receiving port by the pressing surface of the pressing ring

[0013] Also, since it is not necessary to increase the inner diameter of the pressing ring in order to increase the inclination angle, the gap between the inner circumference of the pressing ring and the outer circumference of one pipe does not expand, and it is possible to suppress the sealing member from entering the gap from the pressing surface of the pressing ring. As a result, the sealing member can be sufficiently inserted between the outer circumference of the insertion port and the inner circumference of the receiving port.

[0014] In the second invention, the pressing ring has a second contact portion that is separate from the first contact portion and contacts the opening end surface of the receiving port, and is formed on the pressing ring body. The first contact portion is a convex portion located radially outside the fastener insertion hole. The second contact portion is a convex portion that is located radially inside the fastener insertion hole and is formed so as to surround the periphery of the pressing surface. A recess into which the end portion of the sealing member can be inserted is formed radially inside the second contact portion.

[0015] According to this, when the first and second contact portions of the pressing ring contact the opening end surface of the receiving port, the distance from the pressing surface to the opening end surface of the receiving port is maintained at a predetermined distance. Further, when the pressing ring is pushed into the space between the outer periphery of the insertion port and the inner periphery of the receiving port, since the end portion of the sealing member is fitted into the recess of the pressing ring, the end portion of the sealing member is fixed to the pressing ring without displacement in the radial direction. Thereby, the sealing member can be reliably inserted between the outer periphery of the insertion port and the inner periphery of the receiving port.

[0018] The fourth invention is a pipe joint including the pressing ring according to any one of the first to third inventions, In a state where the insertion port is inserted into the receiving port, one of the pipe axes of the insertion port and the receiving port is inclined with respect to the other pipe axis, The sealing member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, The pressing ring is externally fitted to the insertion port and faces the opening end surface of the receiving port from the outside, and is connected to the receiving port by a plurality of fasteners, The pressing surface of the pressing ring abuts against the sealing member, The fastener is inserted through the fastener insertion hole of the pressing ring.

[0019] The fifth invention is a pipe joining method using the pressing ring according to any one of the first to third inventions, With one of the pipe axes of the insertion port and the receiving port inclined with respect to the other pipe axis, the insertion port is inserted into the receiving port. The fastening member is inserted through the fastening member insertion hole of the pressing ring and tightened, thereby connecting the pressing ring to the receiving port and inserting the sealing member between the outer periphery of the insertion port and the inner periphery of the receiving port.

[0020] According to this, before inserting the sealing member between the outer periphery of the insertion port and the inner periphery of the receiving port, the insertion port is inserted into the receiving port in a state where one of the pipe axes of the insertion port and the receiving port is inclined with respect to the other pipe axis. Therefore, the force required when inclining the insertion port with respect to the receiving port is reduced.

[0021] Instead of the above-described pipe joining method, for example, first, the insertion port is inserted into the receiving port in a state where the pipe axes of either the insertion port or the receiving port are aligned in a straight line without being inclined with respect to the other pipe axis. Next, the sealing member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port. Thereafter, when one of the pipe axes of the insertion port and the receiving port is inclined with respect to the other pipe axis, there is a problem that the force required to incline one of the insertion port and the receiving port with respect to the other increases because it resists the sealing member.

Advantages of the Invention

[0022] As described above, according to the present invention, it is possible to increase the inclination angle when joining pipes while inclining them, and it is possible to sufficiently insert the sealing member between the outer periphery of the insertion port and the inner periphery of the receiving port.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0025] (First Embodiment) In the first embodiment, as shown in FIGS. 1 and 2, 1 is a pipe joint for joining pipes 2 and 4 made of cast iron. An insertion port 3 provided at the end of one pipe 2 is inserted into a receiving port 5 provided at the end of the other pipe 4. An annular rubber ring 7 (an example of a sealing member) is inserted and disposed between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5.

[0026] Inside the inner circumference of the receiving port 5 and deeper inside the receiving port 5 than the rubber ring 7, a locking ring groove 9 is formed over the entire circumference. A circumferentially spaced locking ring 10 is provided in the locking ring groove 9.

[0027] The insertion port 3 has, on the outer circumference of its tip portion, a protrusion 11 that can engage with the locking ring 10 over the entire circumference from the deeper side of the receiving port 5.

[0028] Also, a circumferentially spaced backup ring 13 is externally fitted to the insertion port 3 and is adjacent to the locking ring 10.

[0029] The receiving port 5 has a flange portion 5a at its tip. A plurality of bolt holes 12 are formed in the flange portion 5a. For example, in FIG. 3, eight bolt holes 12 are formed in the flange portion 5a at equal angles.

[0030] An extrusion ring 14 for pushing the rubber ring 7 deeper into the receiving port 5 is externally fitted to the insertion port 3 and faces the opening end face 15 of the receiving port 5 from the outside. The extrusion ring 14 has an annular extrusion ring body 14a and is connected to the receiving port 5 by a plurality (e.g., eight) of T-head bolts 16 (an example of a fastening tool) and nuts 17 (an example of a fastening tool). As shown in FIGS. 4 to 6, the extrusion ring body 14a has a plurality of protrusions 14b protruding radially outward on its outer peripheral portion.

[0031] The extrusion ring body 14a is provided with a pressing surface 19 for pressing the rubber ring 7, a plurality (e.g., eight) of bolt insertion holes 21 (an example of a fastening tool insertion hole) through which the T-head bolts 16 are inserted, and first and second contact portions 24, 25 that contact the opening end face 15 of the receiving port 5. Note that the protrusions 14b of the extrusion ring body 14a are formed to correspond to the bolt insertion holes 21.

[0032] A plurality of the first contact portions 24 are provided, and they are convex portions located outside each bolt insertion hole 21 in the radial direction D of the extrusion ring 14.

[0033] Further, the second contact portion 25 is a convex portion that is located inside each bolt insertion hole 21 in the radial direction D of the pressing ring 14 and is formed in an annular shape so as to surround the periphery of the pressing surface 19. A concave portion 27 into which the end portion of the rubber ring 7 can be fitted is formed inside the second contact portion 25 in the radial direction D.

[0034] On the inner circumference 14c of the pressing ring body 14a, a tapered surface 29 and a straight surface 30 are formed over the entire circumference. The tapered surface 29 has a larger diameter from the side closer to the pressing surface 19 to the farther side, and reaches the surface 32 on the side opposite to the pressing surface 19.

[0035] The straight surface 30 has a constant inner diameter d, is parallel to the tube axis 4a of the other tube 4, and is formed with a predetermined width W in the tube axis direction E. The straight surface 30 is located closer to the pressing surface 19 than the tapered surface 29 and reaches the pressing surface 19.

[0036] Hereinafter, a method for joining the tubes 2 and 4 using the pressing ring 14 will be described.

[0037] First, the pressing ring 14, the rubber ring 7, and the backup ring 13 are externally fitted to the insertion port 3 of one tube 2, the locking ring 10 is attached to the locking ring groove 9 of the receiving port 5 of the other tube 4, and the locking ring 10 is expanded using an expander (not shown).

[0038] After that, with the tube axis 2a of one tube 2 inclined with respect to the tube axis 4a of the other tube 4, the insertion port 3 is inserted into the receiving port 5. At this time, since the locking ring 10 is expanded, the protrusion 11 of the insertion port 3 passes through the inner circumference of the locking ring 10 from the side of the opening end face 15 of the receiving port 5 to the back side.

[0039] After that, by removing the expander (not shown), the locking ring 10 contracts and clings to the outer circumference of the insertion port 3.

[0040] Next, as shown in Fig. 8, move the backup ring 13 in the pipe axis direction E and insert it into the inside of the socket 5 so as to be adjacent to the lock ring 10. Further, move the rubber ring 7 in the pipe axis direction E and position it in front of the opening end face 15 of the socket 5.

[0041] Thereafter, insert the T-head bolt 16 through the bolt hole 12 of the socket 5 and the bolt insertion hole 21 of the pressing ring 14, thread the nut 17 onto the T-head bolt 16, and tighten the nut 17 until the first and second contact portions 24, 25 of the pressing ring 14 abut against the opening end face 15 of the socket 5.

[0042] As a result, as shown in Figs. 1 and 2, the pressing ring 14 is connected to the socket 5, and the pressing surface 19 of the pressing 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 socket 5, and the pipe 2 and the other pipe 4 are joined in a state where the pipe axis 2a of one pipe 2 is inclined with respect to the pipe axis 4a of the other pipe 4.

[0043] Hereinafter, the operation in the above configuration and joining method will be described below.

[0044] As shown in Fig. 2, when the first and second contact portions 24, 25 of the pressing ring 14 contact the opening end face 15 of the socket 5, the distance from the pressing surface 19 to the opening end face 15 of the socket 5 is maintained at a predetermined distance. Further, when the pressing ring 14 pushes the rubber ring 7 between the outer periphery of the insertion port 3 and the inner periphery of the socket 5, since the end portion of the rubber ring 7 is fitted into the concave portion 27 (see Figs. 6 and 7) of the pressing ring 14, the end portion of the rubber ring 7 is fixed to the pressing ring 14 without displacement in the radial direction D. Thereby, the rubber ring 7 can be surely inserted between the outer periphery of the insertion port 3 and the inner periphery of the socket 5.

[0045] Further, as shown in FIGS. 1, 2, 6, and 7, since the tapered surface 29 and the straight surface 30 are formed on the inner periphery 14c of the pressing ring body 14a, when the outer periphery of one pipe 2 abuts against the inner periphery 14c of the pressing ring 14, the outer periphery of one pipe 2 abuts against the boundary portion 36 between the tapered surface 29 and the straight surface 30. This boundary portion 36 is closer to the pressing surface 19 than the corner portion 37 between the inner periphery 14c of the pressing ring 14 and the surface 32 on the opposite side of the pressing surface 19. Therefore, it is possible to increase the inclination angle α (see FIG. 1) of the pipe axis 2a of one pipe 2 with respect to the pipe axis 4a of the other pipe 4 when the outer periphery of one pipe 2 abuts against the inner periphery 14c of the pressing ring 14. As a result, when joining a plurality of pipes while inclining them to form a curved pipeline (see FIG. 17), the number of pipes can be reduced.

[0046] Furthermore, since the inclination angle α (see FIG. 1) can be increased as described above, even when the pipeline bends due to an earthquake or the like, one pipe 2 and the other pipe 4 can bend at a large inclination angle α, thereby reducing the load applied to the pressing ring 14.

[0047] Also, the outer periphery of one pipe 2 does not abut against the inner peripheral edge 19a (see FIGS. 6 and 7) of the pressing surface 19 of the pressing ring 14, but abuts against the boundary portion 36, so that damage to the inner peripheral edge 19a of the pressing surface 19 can be prevented. As a result, the rubber ring 7 can be sufficiently inserted between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5 by the pressing surface 19 of the pressing ring 14.

[0048] Also, since it is not necessary to increase the inner diameter d of the pressing ring 14 (that is, the inner diameter d of the straight surface 30) in order to increase the inclination angle α, the gap 34 (see FIG. 1) between the straight surface 30 of the inner periphery 14c of the pressing ring 14 and the outer periphery of one pipe 2 does not expand, and it is possible to suppress the rubber ring 7 from entering the gap 34 from the pressing surface 19 of the pressing ring 14. As a result, the rubber ring 7 can be sufficiently inserted between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5.

[0049] Also, according to the above-described pipe joining method, as shown in FIG. 8, before inserting the rubber ring 7 between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5, with the pipe axis 2a of one pipe 2 inclined with respect to the pipe axis 4a of the other pipe 4, when inserting the insertion port 3 into the receiving port 5, the force required to incline the insertion port 3 with respect to the receiving port 5 is reduced.

[0050] In addition, if it is not the above-described pipe joining method, for example, first, with the pipe axis 2a of one pipe 2 aligned in a straight line without being inclined with respect to the pipe axis 4a of the other pipe 4, insert the insertion port 3 into the receiving port 5, then insert the rubber ring 7 between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5, and then, when inclining the pipe axis 2a of one pipe 2 with respect to the pipe axis 4a of the other pipe 4, since the insertion port 3 (one pipe 2) is inclined with respect to the receiving port 5 (the other pipe 4) against the resistance of the rubber ring 7, there is a problem that the force required to incline the insertion port 3 with respect to the receiving port 5 increases.

[0051] (Second Embodiment) In the second embodiment, as shown in FIGS. 10 to 14, the pressing ring body 14a has an equal interval region 59 and an enlarged interval region 60. In the equal interval region 59, the interval between the bolt insertion holes 21 in the circumferential direction A is maintained at an equal interval S1. In the enlarged interval region 60, the interval S2 between any two adjacent bolt insertion holes 21 is enlarged compared to the equal interval S1.

[0052] For example, in FIGS. 10 and 11, seven bolt insertion holes 21, which is one less than the number (eight) of bolt holes 12 in the flange portion 5a of the receiving port 5, are formed in the pressing ring body 14a. The distribution angle B1 of each bolt insertion hole 21 in the equal interval region 59 is 45°, and the distribution angle B2 of the two bolt insertion holes 21 in the enlarged interval region 60 is 90°.

[0053] On the surface 32 on the side opposite to the pressing surface 19 of the pressing wheel body 14a, an arcuate reinforcing member 62 is provided. This reinforcing member 62 is provided across two bolt insertion holes 21 adjacent to each other in the enlarged interval region 60, and is located outside in the radial direction D from the straight surface 30 of the pressing wheel body 14a as shown in FIG. 12.

[0054] As shown in FIGS. 9 to 11, the pressing wheel 14 is connected to the receiving port 5 such that the enlarged interval region 60 is located directly below one of the pipes 2. Incidentally, as shown in FIG. 15, the pipes 2 and 4 are joined inside a groove 65 formed by excavating the ground 64. At this time, the bottom 66 of the groove 65 becomes an obstacle that hinders the joining operation of the pipes 2 and 4. That is, the pressing wheel 14 is connected to the receiving port 5 by a plurality of T-head bolts 16 and nuts 17 in a state where the enlarged interval region 60 is located on the side where the bottom 66 (an example of an obstacle) of the groove 65 exists.

[0055] Hereinafter, the operation of the above configuration will be described.

[0056] Similar to the first embodiment described above, since the tapered surface 29 is formed on the inner circumference 14c of the pressing wheel 14, it is possible to increase the inclination angle α of the pipe axis 2a of one pipe 2 with respect to the pipe axis 4a of the other pipe 4 when the outer circumference of one pipe 2 abuts on the inner circumference 14c of the pressing wheel 14.

[0057] In addition, since it is not necessary to increase the inner diameter d of the pressing wheel 14 in order to increase the inclination angle α, the gap 34 between the straight surface 30 of the pressing wheel 14 and the outer circumference of one pipe 2 does not expand, and it is possible to suppress the rubber ring 7 from entering the gap 34 from the pressing surface 19 of the pressing wheel 14.

[0058] Also, as shown in FIGS. 10, 11, and 15, since the enlarged interval region 60 of the pressing ring 14 is located directly below one of the pipes 2, the bolt insertion holes 21 of the enlarged interval region 60 do not exist directly below one of the pipes 2, but are distributed in the circumferential direction A of the pressing ring 14 at a position shifted from directly below one of the pipes 2. As a result, the distance H between the bolt insertion holes 21 in the enlarged interval region 60 and the bottom 66 of the groove 65 increases, so that even if the working space between the pressing ring 14 and the bottom 66 of the groove 65 is narrow, the workability when joining the pipes 2 and 4 can be improved.

[0059] Further, since the enlarged interval region 60 of the pressing ring 14 is maintained at sufficient rigidity by the reinforcing member 62, even if the reaction force of the rubber ring 7 acts on the pressing ring 14, it is possible to prevent the enlarged interval region 60 of the pressing ring 14 from being deflected by the reaction force. Furthermore, when the T-head bolt 16 is inserted through the bolt insertion holes 21 in the enlarged interval region 60 of the pressing ring 14 and the bolt holes 12 of the socket 5 and tightened with the nut 17, even if a high stress is generated between the two bolt insertion holes 21 in the enlarged interval region 60, it is possible to prevent the enlarged interval region 60 from being deformed or damaged.

[0060] In the second embodiment described above, as shown in FIGS. 10 and 11, seven bolt insertion holes 21 are formed in the pressing ring 14, but the number is not limited to seven, and for example, the number obtained by subtracting 1 from a multiple of 4 (11 or 15, etc.) may be used.

Explanation of Reference Numerals

[0061] 1 Pipe joint 2a Pipe axis 3 Insertion port 4a Pipe axis 5 Socket 7 Rubber ring (sealing member) 14 Pressing ring 14a Pressing ring body 14c Inner circumference of the pressing ring body 15 Open end face 16 Bolt (fastening tool) 17 Nut (fastening tool) 19 Pressing surface 21 Bolt insertion hole (fastening tool insertion hole) 24 First contact part 25 Second contact part 27 Concave part 29 Tapered surface 30 Straight surface 32 Opposite side surface D Radial direction d Constant inner diameter E Tube axis direction W Predetermined width

Claims

1. A pipe joint used when an insertion port is inserted into a receiving port and a sealing member is inserted between the outer circumference of the insertion port and the inner circumference of the receiving port, An pressing ring that is externally fitted to the insertion port, faces the opening end face of the receiving port from the outside, and is connected to the receiving port by a plurality of fastening members to push the sealing member toward the inner side of the receiving port, An annular pressing ring body is formed with a pressing surface for pressing the sealing member, a plurality of fastening member insertion holes through which the fastening members are inserted, and a first contact portion that contacts the opening end face of the receiving port, A tapered surface is formed on the inner circumference of the pressing ring body over the entire circumference, and a straight surface connected to the tapered surface is formed on the side closer to the pressing surface than the tapered surface, The tapered surface is a conical circumferential surface that expands in diameter from the side closer to the pressing surface to the far side, The straight surface is a cylindrical circumferential surface having a constant inner diameter and extending in the axial direction of the pressing ring, When the insertion port is inserted into the receiving port with one of the pipe axes of the insertion port and the receiving port inclined with respect to the other pipe axis, and the outer circumference of the insertion port abuts against the inner circumference of the pressing ring, the outer circumference of the insertion port abuts against the boundary portion where the tapered surface and the straight surface are connected. A pressing ring characterized by this.

2. A second contact portion that is separate from the first contact portion and contacts the opening end face of the receiving port is formed on the pressing ring body, The first contact portion is a convex portion located outside the fastening member insertion hole in the radial direction, The second contact portion is a convex portion that is located inside the fastening member insertion hole in the radial direction and is formed so as to surround the periphery of the pressing surface, The pressing ring according to claim 1, wherein a concave portion into which an end portion of the sealing member can be fitted is formed inside the second contact portion in the radial direction.

3. The inclination angle between the pipe axis of the insertion port and the pipe axis of the receiving port is a predetermined angle, The tapered surface of the pressing ring is inclined at an angle equal to or greater than the predetermined angle with respect to the axis of the pressing ring, and the diameter of the end portion of the tapered surface on the side far from the opening end face of the receiving port is smaller than the diameter of the end portion on the outer side in the radial direction of the pressing ring on the pressing surface. The pressing ring according to claim 1, characterized by this.

4. A pipe joint provided with the pressing ring according to any one of claims 1 to 3 above, With the insertion port inserted into the receiving port, one of the pipe axes of the insertion port and the receiving port is inclined with respect to the other pipe axis, A sealing member is inserted between the outer circumference of the insertion port and the inner circumference of the receiving port, The pressing ring is externally fitted to the insertion port, faces the opening end face of the receiving port from the outside, and is connected to the receiving port by a plurality of fastening members, The pressing surface of the pressing ring abuts against the sealing member, A pipe joint characterized in that a fastener is inserted through a fastener insertion hole of a pressing ring.

5. A method for joining pipes using the pressing ring according to any one of claims 1 to 2 above, with one of the pipe axes of the insertion port and the receiving port inclined with respect to the other pipe axis, inserting the insertion port into the receiving port, characterized in that a fastener is inserted through a fastener insertion hole of a pressing ring and tightened to connect the pressing ring to the receiving port and insert a sealing member between the outer periphery of the insertion port and the inner periphery of the receiving port.

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