Pressing wheel, pipe joint, and pipe joining method

Abstract

To provide a push ring capable of increasing an inclination angle at the time when pipes are connected in an inclined manner, and capable of preventing deformation of a push ring body.SOLUTION: An annular push ring body 35 is formed with a pressing surface 36 that presses a sealing member 15, a plurality of fastener insertion holes 37 through which fasteners 22 are inserted, and a contact part 38 that contacts an opening end surface 21 of a socket 5. A first tapered surface 47 is formed along the entire inner circumference of the push ring body 35. The first tapered surface 47 expands in diameter from a side closer to the pressing surface 36 toward the opposite side. The contact part 38 is provided in a region from an outer peripheral edge of the pressing surface 36 in a radial direction of the push ring body 35 to an outer peripheral edge 39 of the push ring body 35, except for the fastener insertion holes 37.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. 18, 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 contacts the seal member 115 and presses the seal member 115, first and second contact portions 121, 122 that contact 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 first and second contact portions 121, 122 are provided on the same side of the pressing ring body 116a (the side facing the receiving port 114).

[0004] Among these, the first contact portion 121 is outside the bolt insertion hole 123 in the radial direction 124, and the second contact portion 122 is inside the bolt insertion hole 123 in the radial direction 124. When these first and second contact portions 121, 122 contact 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.

[0005] 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 contacts the seal member 115 and presses the seal member 115 between the outer periphery of the insertion port 112 and the inner periphery of the receiving port 114.

[0006] Incidentally, the pressing ring 116 and the pipe joint 110 as described above are described, for example, in Patent Document 1 below. [Prior Art Document] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2021-67282 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] However, in the above conventional form, when forming a curved pipeline 130 by joining a plurality of pipes 111 and 113 as shown in FIG. 19, as shown in FIG. 20, while inclining the pipe axis 111a of one pipe 111 with respect to the pipe axis 113a of the other pipe 113, these pipes 111 and 113 are joined together.

[0009]

[0010]

[0011] ​​The 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 with inclination, inserting a sealing member sufficiently between the outer periphery of the insertion port and the inner periphery of the receiving port, and further preventing deformation of the pressing ring body.

Means for Solving the Problems

[0012] In order 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 periphery of the insertion port and the inner periphery of the receiving port. A pressing ring that is externally fitted to the insertion port, faces the opening end surface 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 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 fastening member insertion holes through which the fastening members are inserted, and a contact portion that contacts the opening end surface of the receiving port. The fastening member insertion holes are located between the pressing surface and the outer peripheral edge of the pressing ring body in the radial direction of the pressing ring body. A first tapered surface a straight surface connected to the first tapered surface on a side closer to the pressing surface than the first tapered surface, and is formed over the entire circumference on the inner periphery of the pressing ring body. The first tapered surface 、 has a diameter that increases from the side closer to the pressing surface to the farther opposite side. 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 the tube axis of either the insertion port or the receiving port inclined with respect to the tube axis of the other, and the outer periphery of the insertion port abuts against the inner periphery of the pressing ring, the outer periphery of the insertion port abuts against the boundary portion where the first tapered surface and the straight surface are connected. When the insertion port is inserted into the receiving port with the tube axis of the insertion port of one tube inclined with respect to the tube axis of the receiving port of the other tube, and the two tubes are joined, the outer periphery of one tube does not abut against the inner peripheral edge of the pressing surface of the pressing ring, but abuts against 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. The contact portion is provided so as to surround at least the periphery of each fastening member insertion hole.

[0013] According to this, 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, the insertion port is inserted into the receiving port, and the fastening member is inserted through the fastening member insertion hole of the pressing ring and tightened, whereby the pressing ring is connected to the receiving port and the sealing member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port, and one pipe and the other pipe can be joined.

[0014] At this time, since a tapered surface is formed on the inner circumference of the pressing ring body, when the outer circumference of one pipe abuts against the inner circumference of the pressing ring, the contact portion is closer to the pressing surface than the corner portion between the inner circumference of the pressing ring and the surface on the side opposite to 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. When joining a plurality of pipes while inclining them to form a curved pipeline, the number of pipes can be reduced.

Figure 1

[0015] In addition, 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.

[0016] Further, when the contact portion contacts 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. At this time, even if the fastening member is tightened too much and an excessive tightening force acts on the pressing ring body, since the contact portion is provided so as to surround at least the periphery of each fastening member insertion hole, it is possible to prevent the pressing ring body from deforming around the fastening member insertion hole.

[0017] In the pressing ring according to the second invention, the contact portion is provided in a region between the fastening member insertion hole and the adjacent fastening member insertion hole in the circumferential direction of the pressing ring body.

[0018] According to this, even if the fastening member is tightened too much and an excessive tightening force acts on the pressing ring body, it is possible to prevent the pressing ring body from deforming in the region between the fastening member insertion hole and the adjacent fastening member insertion hole.

[0019] In the pressing ring according to the third invention, the contact portion is provided in a region from the outer peripheral edge of the pressing surface in the radial direction of the pressing ring body to the outer peripheral edge of the pressing ring body, excluding the fastening member insertion hole.

[0020] According to this, even if the fastener is tightened too much and an excessive tightening force acts on the pressing ring body, it is possible to prevent the pressing ring body from deforming in the region from the outer peripheral edge of the pressing surface to the outer peripheral edge of the pressing ring body.

[0023] The fifth invention is a pipe joint including the pressing ring according to any one of the first to fourth inventions, a second tapered surface that tapers toward the inner side of the receiving port is formed on the inner circumference of the receiving port, a seal member insertion space is formed over the entire circumference between the second tapered surface and the outer circumference of the insertion port, a seal member is inserted into the seal member insertion space, the seal member has a valve portion that is compressed in the pipe diameter direction at one end in the insertion direction and exhibits a sealing function, a guide portion for guiding the valve portion of the seal member from the opening end surface of the receiving port into the seal member insertion space is formed on the inner circumference of the receiving port, the guide portion has a third tapered surface that tapers toward the inner side of the receiving port, the third tapered surface is formed between the opening end surface of the receiving port and the second tapered surface in the pipe axis direction, the inclination angle of the third tapered surface with respect to the pipe axis is larger than the inclination angle of the second tapered surface with respect to the pipe axis.

[0024] According to this, when the seal member is pushed into the seal member insertion space by the pressing ring, the valve portion of the seal member is guided from the opening end surface of the receiving port into the seal member insertion space by the third tapered surface of the guide portion.

[0025] Thus, when the pressing ring is fastened to the receiving port and the fastener is tightened on one side, even if the seal member extends and loosens, the valve portion of the seal member is guided from the opening end surface of the receiving port into the seal member insertion space by the third tapered surface of the guide portion, so that the seal member can be surely pushed into the seal member insertion space by the pressing ring.

[0026] In the pipe joint according to the sixth invention, the fastener insertion hole of the pressing ring is located outside the pressing surface in the radial direction of the pressing ring body, The contact portion of the pressing ring is provided in a region from the outer peripheral edge of the pressing surface in the radial direction of the pressing ring body to the outer peripheral edge of the pressing ring body, excluding the fastener insertion hole. The pressing surface is formed in a recess surrounded by the contact portion. The other end of the sealing member is fitted into the recess of the pressing ring.

[0027] According to this, when the pressing ring pushes the sealing member into the sealing member insertion space, since the other end of the sealing member is fitted into the recess of the pressing ring, it is fixed to the pressing ring without displacement in the radial direction. Thereby, the sealing member can be surely inserted into the sealing member insertion space.

[0028] The pipe joint according to the seventh invention is such that a gap is formed by the inner peripheral surface of the contact portion of the pressing ring, the third tapered surface of the receiving port, and the outer peripheral surface of the sealing member.

[0029] According to this, when the sealing member is pushed into the sealing member insertion space by the pressing ring, even if the sealing member is deformed outward in the radial direction, the sealing member escapes into the gap, thereby preventing the sealing member from being sandwiched between the contact portion of the pressing ring and the opening end surface of the receiving port.

[0030] The pipe joint according to the eighth invention is such that the diameter of the end portion of the third tapered surface on the opening end surface side of the receiving port is smaller than the inner diameter of the contact portion of the pressing ring.

[0031] According to this, when the sealing member is pushed into the sealing member insertion space by the pressing ring, the gap formed between the sealing member and the third tapered surface becomes smaller. Therefore, even when the fastener is singly tightened when the pressing ring is fastened to the receiving port, it is possible to prevent the sealing member from being turned up due to the single tightening and to prevent the sealing member from being sandwiched between the contact portion of the pressing ring and the opening end surface of the receiving port.

[0032] The ninth invention is a method for joining pipes using the pressing ring according to any one of the first to fourth inventions, With one of the pipe axes of either the insertion port or the receiving port inclined with respect to the other pipe axis, the insertion port is inserted into the receiving port, By inserting the fastener through the fastener insertion hole of the pressing ring and tightening it, the pressing ring is connected to the receiving port and the sealing member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port.

[0033] 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 with one of the pipe axes of either the insertion port or the receiving port inclined with respect to the other pipe axis, so that the force required when inclining the insertion port with respect to the receiving port is reduced.

[0034] Instead of the above-described pipe joining method, for example, first, the insertion port is inserted into the receiving port in a state where one of the pipe axes of either the insertion port or the receiving port is made straight without inclining it 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. Then, if one of the pipe axes of either the insertion port or the receiving port is inclined with respect to the other pipe axis, there is a problem that the force required when inclining one of the insertion port and the receiving port with respect to the other increases because it resists the sealing member and inclines one of the insertion port and the receiving port with respect to the other.

Effect of the Invention

[0035] As described above, according to the present invention, the inclination angle when joining pipes while inclining them can be increased, and the sealing member can be sufficiently inserted between the outer periphery of the insertion port and the inner periphery of the receiving port. Furthermore, deformation of the pressing ring body can be prevented.

Brief Description of the Drawings

[0036]

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

Figure 19

Figure 20

Embodiments for Carrying Out the Invention

[0037] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0038] (First Embodiment) In the first embodiment, as shown in FIGS. 1 to 3, 1 is a pipe joint, and in this pipe joint 1, an insertion port 3 formed in one pipe 2 is inserted into a receiving port 5 formed in the other pipe 4.

[0039] On the inner circumference of the receiving port 5, a second tapered surface 8 that tapers inward toward the back side of the receiving port 5, a receiving port protrusion 10, and a lock ring accommodation groove 11 are formed. A seal member insertion space 14 is formed over the entire circumference between the second tapered surface 8 and the outer circumference of the insertion port 3. An annular seal member 15 that seals between the inner circumference of the receiving port 5 and the outer circumference of the insertion port 3 is inserted into the seal member insertion space 14. The seal member 15 is a rubber ring and has a valve portion 16 provided at one end in the insertion direction 18 and a base portion 17 provided integrally with the valve portion 16.

[0040] The valve portion 16 has a circular cross-section, and the base portion 17 has a trapezoidal cross-section. In a state where the seal member 15 is inserted into the seal member insertion space 14, the valve portion 16 is compressed in the pipe diameter direction 19 to exhibit a sealing function.

[0041] A plurality of bolt holes 25 through which T-head bolts 22 are inserted are formed in the receiving port 5.

[0042] The lock ring accommodation groove 11 is formed on the back side of the receiving port 5 rather than the seal member insertion space 14, and a lock ring 26 is accommodated in the lock ring accommodation groove 11. The lock ring 26 is a split-ring structure with one part cut, and it has elasticity such that it expands in diameter by expanding the width of the cut portion with an expander (not shown) and returns to its original diameter by removing the expander from the cut portion.

[0043] The insertion port 3 penetrates through the seal member 15, the lock ring 26, and the backup ring 29. An insertion port protrusion 27 is formed over the entire circumference on the outer periphery of the tip of the insertion port 3. The insertion port protrusion 27 can engage with the lock ring 26 from the inner side of the receiving port 5 in the separation direction 28 of one pipe 2, thereby preventing the insertion port 3 from separating from the receiving port 5 during an earthquake or the like.

[0044] The receiving port protrusion 10 protrudes inward in the pipe diameter direction 19 from the inner circumference of the receiving port 5 and is formed over the entire circumference between the seal member insertion space 14 and the lock ring accommodation groove 11. The backup ring 29 is externally fitted to the insertion port 3 and is disposed between the inner circumference of the receiving port protrusion 10 and the outer circumference of the insertion port 3 and adjacent to the lock ring 26. Further, the backup ring 29 is a split ring structure with one part cut, and is made of a material such as an elastic resin.

[0045] Also, a guide portion 31 for guiding the valve portion 16 of the seal member 15 from the opening end face 21 of the receiving port 5 to the seal member insertion space 14 is formed on the inner circumference of the receiving port 5. The guide portion 31 has a third tapered surface 32 that tapers inward toward the inner side of the receiving port 5. The third tapered surface 32 is formed over the entire circumference between the opening end face 21 of the receiving port 5 and the second tapered surface 8 in the pipe axis direction 50. As shown in FIG. 4, the inclination angle B of the third tapered surface 32 with respect to the pipe axis 4a of the other pipe 4 is larger than the inclination angle C of the second tapered surface 8 with respect to the pipe axis 4a.

[0046] A pressing ring 20 for pushing the seal member 15 from the opening end face 21 of the receiving port 5 into the seal member insertion space 14 is externally fitted to the insertion port 3 and faces the opening end face 21 of the receiving port 5 from the outside. The pressing ring 20 is fastened to the receiving port 5 via a plurality of T-head bolts 22 (an example of a fastening tool) and nuts 23 (an example of a fastening tool). As shown in FIGS. 5 to 8, the pressing ring 20 has an annular pressing ring body 35, a pressing surface 36 for pressing the seal member 15, a plurality of bolt insertion holes 37 (fastening tool insertion holes) through which the T-head bolts 22 are inserted, and a contact portion 38 that contacts the opening end face 21 of the receiving port 5.

[0047] The pressing wheel body 35 has a plurality of protruding portions 40 that protrude radially outward on the outer peripheral portion. The pressing surface 36 is formed in an annular shape along the inner circumference 41 of the pressing wheel body 35.

[0048] Also, each bolt insertion hole 37 is located between the pressing surface 36 and the outer peripheral edge 39 of the pressing wheel body 35 in the radial direction 46 of the pressing wheel body 35. Incidentally, the protruding portions 40 of the pressing wheel body 35 are arranged so as to correspond to the bolt insertion holes 37.

[0049] The contact portion 38 is provided in the entire region from the outer peripheral edge 42 of the pressing surface 36 to the outer peripheral edge 39 of the pressing wheel body 35 in the radial direction 46 of the pressing wheel body 35, excluding the bolt insertion holes 37. The pressing surface 36 is formed in a recess 43 surrounded by the contact portion 38, and is recessed by one step from the surface of the contact portion 38 in the thickness direction 55 of the pressing wheel body 35 (the same direction as the tube axis direction 50 in FIGS. 7 and 8). The inner peripheral surface 44 of the contact portion 38 is a tapered surface that expands in diameter as it approaches the insertion direction 18 (see FIG. 3).

[0050] The contact portion 38 and the recess 43 are formed on the joint surface side of the pressing wheel 20 that faces the opening end surface 21 of the receiving port 5.

[0051] The base portion 17 (the other end portion) of the seal member 15 is fitted into the recess 43 of the pressing wheel 20. A gap 45 surrounded by the inner peripheral surface 44 of the contact portion 38 of the pressing wheel 20, the third tapered surface 32 of the receiving port 5, and the outer peripheral surface of the base portion 17 of the seal member 15 is formed over the entire circumference.

[0052] As shown in FIG. 3, the diameter D2 of the end portion of the third tapered surface 32 on the opening end surface 21 side of the receiving port 5 is smaller than the inner diameter D1 of the contact portion 38.

[0053] As shown in FIGS. 6 to 8, a first tapered surface 47 and a straight surface 48 are formed over the entire circumference on the inner circumference 41 of the pressing wheel body 35. The first tapered surface 47 expands in diameter from the side closer to the pressing surface 36 to the opposite far side, and reaches the surface 49 on the side opposite to the pressing surface 36.

[0054] The straight surface 48 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 50. It is located closer to the pressing surface 36 than the first tapered surface 47 and reaches the pressing surface 36.

[0055] The method of joining the tubes 2 and 4 using the pressing ring 20 will be described below. First, the pressing ring 20, the seal member 15, and the backup ring 29 are externally fitted to the insertion port 3 of one tube 2. The locking ring 26 is attached to the locking ring accommodation groove 11 of the receiving port 5 of the other tube 4, and the locking ring 26 is expanded using an expander (not shown).

[0056] After that, with the tube axis 2a of the insertion port 3 inclined with respect to the tube axis 4a of the receiving port 5, the insertion port 3 is inserted into the receiving port 5. At this time, since the locking ring 26 is expanded, the insertion port protrusion 27 passes through the inner circumference of the locking ring 26 from the side of the opening end face 21 of the receiving port 5 to the inner side.

[0057] After that, by removing the expander (not shown), the locking ring 26 contracts and clamps the outer circumference of the insertion port 3.

[0058] Next, as shown in FIG. 9, the backup ring 29 is moved in the tube axis direction 50 and inserted into the inside of the receiving port 5 and adjacent to the locking ring 26. Further, the seal member 15 is moved in the tube axis direction 50 and positioned in front of the opening end face 21 of the receiving port 5.

[0059] After that, the T-head bolt 22 is inserted through the bolt hole 25 of the receiving port 5 and the bolt insertion hole 37 of the pressing ring 20, and the nut 23 is screwed onto the T-head bolt 22. The nut 23 is tightened until the contact portion 38 of the pressing ring 20 abuts against the opening end face 21 of the receiving port 5.

[0060] As a result, as shown in FIGS. 1 and 2, the pressing ring 20 is connected to the receiving port 5, the pressing surface 36 of the pressing ring 20 presses the seal member 15 and inserts it into the seal member insertion space 14, and the tube 2 and the other tube 4 are joined with the tube axis 2a of the insertion port 3 inclined with respect to the tube axis 4a of the receiving port 5.

[0061] The operations in the above configuration and joining method will be described below.

[0062] As shown in FIG. 2, when the contact portion 38 of the pressing ring 20 contacts the opening end face 21 of the receiving port 5, the distance from the pressing surface 36 of the pressing ring 20 to the opening end face 21 of the receiving port 5 is maintained at a predetermined distance.

[0063] At this time, even if the T-head bolt 22 and the nut 23 are tightened too much and an excessive tightening force acts on the pressing ring body 35, it is possible to prevent the pressing ring body 35 from deforming in the entire region from the outer peripheral edge 42 of the pressing surface 36 to the outer peripheral edge 39 of the pressing ring body 35.

[0064] When the seal member 15 is pushed into the seal member insertion space 14 by the pressing ring 20, the other end of the seal member 15 is fitted into the concave portion 43 of the pressing ring 20, so that it is fixed to the pressing ring 20 without displacement in the radial direction 46. Thereby, the seal member 15 can be surely inserted into the seal member insertion space 14.

[0065] Also, as shown in FIG. 9, when the seal member 15 is pushed into the seal member insertion space 14 by the pressing ring 20, the valve portion 16 of the seal member 15 is guided from the opening end face 21 of the receiving port 5 to the seal member insertion space 14 by the third tapered surface 32 of the guide portion 31.

[0066] At this time, when the T-head bolt 22 and the nut 23 are tightened one by one from the upper ones to the lower ones in order when the pressing ring 20 is fastened to the receiving port 5, even if the seal member 15 stretches and loosens, the valve portion 16 is guided from the opening end face 21 of the receiving port 5 to the seal member insertion space 14 by the third tapered surface 32 of the guide portion 31, and the seal member 15 can be surely pushed into the seal member insertion space 14 by the pressing ring 20.

[0067] Thus, it is not necessary to tighten all the T-head bolts 22 and nuts 23 so that their tightening torques are uniform, eliminating the need to manage the tightening torques of the T-head bolts 22 and nuts 23, and shortening the time required for the tightening operation of the T-head bolts 22 and nuts 23.

[0068] Also, when the pressing ring 20 presses the seal member 15 into the seal member insertion space 14, as shown in FIG. 10, even if the seal member 15 deforms outward in the pipe diameter direction 19, the seal member 15 can escape into the gap 45, preventing the seal member 15 from being sandwiched between the contact portion 38 of the pressing ring 20 and the opening end face 21 of the receiving port 5.

[0069] Also, as shown in FIGS. 1 to 3, 7, and 8, since the first tapered surface 47 and the straight surface 48 are formed on the inner circumference 41 of the pressing ring body 35, when the outer circumference of one pipe 2 abuts against the inner circumference 41 of the pressing ring 20, the outer circumference of one pipe 2 abuts against the boundary portion 51 between the first tapered surface 47 and the straight surface 48. This boundary portion 51 is closer to the pressing surface 36 than the corner portion 52 between the inner circumference 41 of the pressing ring 20 and the surface 49 on the opposite side of the pressing surface 36. 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 circumference of one pipe 2 abuts against the inner circumference 41 of the pressing ring 20. Thereby, when joining a plurality of pipes while inclining them to form a curved pipeline (see FIG. 19), the number of pipes can be reduced.

[0070] 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 20.

[0071] Further, since the outer periphery of one of the tubes 2 does not contact the inner peripheral edge 53 (see FIGS. 7 and 8) of the pressing surface 36 of the pressing ring 20 and contacts the boundary portion 51, damage to the inner peripheral edge 53 of the pressing surface 36 can be prevented. As a result, the seal member 15 can be sufficiently inserted into the seal member insertion space 14 by the pressing surface 36 of the pressing ring 20.

[0072] Also, since it is not necessary to increase the inner diameter d of the pressing ring 20 (i.e., the inner diameter d of the straight surface 48) in order to increase the inclination angle α, the gap 54 (see FIG. 1) between the straight surface 48 of the inner periphery 41 of the pressing ring 20 and the outer periphery of one of the tubes 2 does not expand, and it is possible to suppress the seal member 15 from entering the gap 54 from the pressing surface 36 of the pressing ring 20. As a result, the seal member 15 can be sufficiently inserted into the seal member insertion space 14.

[0073] Further, according to the above-described tube joining method, as shown in FIG. 9, before inserting the seal member 15 into the seal member insertion space 14, the insertion port 3 is inserted into the receiving port 5 in a state where the tube axis 2a of one of the tubes 2 is inclined with respect to the tube axis 4a of the other tube 4. Therefore, the force required to incline the insertion port 3 with respect to the receiving port 5 is reduced.

[0074] However, if the tube joining method is not as described above, for example, first, the insertion port 3 is inserted into the receiving port 5 with the tube axis 2a of one of the tubes 2 aligned straight without inclining it with respect to the tube axis 4a of the other tube 4, and then the seal member 15 is inserted into the seal member insertion space 14. After that, when the tube axis 2a of one of the tubes 2 is inclined with respect to the tube axis 4a of the other tube 4, there is a problem that the force required to incline the insertion port 3 with respect to the receiving port 5 increases because the insertion port 3 (one of the tubes 2) is inclined with respect to the receiving port 5 (the other tube 4) against the resistance of the seal member 15.

[0075] Also, as shown in FIG. 3, since the diameter D2 of the end portion of the third tapered surface 32 on the opening end surface 21 side of the receiving port 5 is smaller than the inner diameter D1 of the contact portion 38, as shown in FIG. 11, when the seal member 15 is pushed into the seal member insertion space 14 by the pressing ring 20, the gap 56 formed between the seal member 15 and the third tapered surface 32 becomes smaller.

[0076] Therefore, when the T-head bolt 22 and the nut 23 are semi-fastened when fastening the pressing ring 20 to the receiving port 5, as shown in FIG. 12, even if the pressed seal member 15 escapes into the gap 56, it is possible to suppress the curling up of the seal member 15 due to semi-fastening. Thereby, it is possible to prevent the seal member 15 from being sandwiched between the contact portion 38 of the pressing ring 20 and the opening end face 21 of the receiving port 5.

[0077] Incidentally, as a reference example, as shown in FIG. 13, if the magnitude relationship between the inner diameter D1 of the contact portion 38 and the diameter D2 of the end portion of the third tapered surface 32 is reversed, that is, when the diameter D2 is larger than the inner diameter D1, when the seal member 15 is pushed into the seal member insertion space 14 by the pressing ring 20, the gap 56 formed between the seal member 15 and the third tapered surface 32 becomes large.

[0078] Therefore, when the T-head bolt 22 and the nut 23 are semi-fastened when fastening the pressing ring 20 to the receiving port 5, as shown in FIG. 14, the pressed seal member 15 escapes into the gap 56, and there is a risk that the seal member 15 curls up and the inner peripheral surface of the seal member 15 is separated from the outer peripheral surface of the insertion port 3 in the pipe diameter direction 19. Thus, when the seal member 15 curls up, problems such as the seal member 15 being sandwiched between the contact portion 38 of the pressing ring 20 and the opening end face 21 of the receiving port 5 are likely to occur. (Second Embodiment) In the second embodiment, as shown in FIGS. 15 and 16, the contact portions 38 of the pressing ring 20 are formed in a plurality of annular shapes so as to surround the periphery of each bolt insertion hole 37 on the pressing ring body 35.

[0079] According to this, when the contact portion 38 contacts the opening end face 21 of the receiving port 5, the distance from the pressing surface 36 to the opening end face 21 of the receiving port 5 is maintained at a predetermined distance. At this time, even if the T-head bolt 22 and the nut 23 are tightened too much and an excessive tightening force acts on the pressing ring body 35, it is possible to prevent the pressing ring body 35 from deforming around the bolt insertion hole 37. (Third Embodiment) In the third embodiment, as shown in FIG. 17, the contact portion 38 is formed in an annular shape so as to surround the periphery of each bolt insertion hole 37, and is also formed in the region between the bolt insertion hole 37 and the adjacent bolt insertion hole 37 in the circumferential direction 57 of the pressing ring body 35.

[0080] According to this, even if the T-head bolt 22 and the nut 23 are tightened too much and an excessive tightening force acts on the pressing ring body 35, it is possible to prevent the pressing ring body 35 from deforming in the region between the bolt insertion hole 37 and the adjacent bolt insertion hole 37.

[0081] In each of the above embodiments, as shown in FIG. 1, the pipe joint 1 in which the insertion port 3 is joined to the receiving port 5 in an inclined state is shown, but a pipe joint 1 in which the receiving port 5 is joined to the insertion port 3 in an inclined state may also be used. Further, the pressing ring 20 shown in each of the above embodiments may be used for a pipe joint in which the insertion port 3 and the receiving port 5 are joined in a straight line without being inclined.

Explanation of Reference Numerals

[0082] 1 Pipe joint 2a Pipe axis 3 Insertion port 4a Pipe axis 5 Receiving port 8 Second tapered surface 14 Seal member insertion space 15 Seal member 16 Valve portion 18 Insertion direction 19 Pipe diameter direction 20 Pressing ring 21 Opening end face 22 T-head bolt (fastener) 23 Nut (fastener) 31 Guide portion 32 Third tapered surface 35 Pressing ring body 36 Pressing surface 37 Bolt insertion hole (fastener insertion hole) 38 Contact portion 39 Outer peripheral edge of the pressing ring body 42 Outer peripheral edge of the pressing surface 43 Concave portion 44 Inner peripheral surface of the contact portion 45 Gap 46 Radial direction 47 First tapered surface 48 Straight surface 50 Axial direction of the tube 57 Circumferential direction of the pressing wheel body B Inclination angle of the third tapered surface C Inclination angle of the second tapered surface D1 Inner diameter of the contact portion D2 Diameter of the third tapered surface d Inner diameter

Claims

1. It is used for a pipe joint in which an insertion port is inserted into a receiving port, and a sealing member is inserted between the outer periphery of the insertion port and the inner periphery of the receiving port. An abutting 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 fasteners to push the sealing member toward the back side of the receiving port. An annular abutting 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 contact portion that contacts the opening end face of the receiving port. The fastener insertion holes are located between the pressing surface and the outer peripheral edge of the abutting ring body in the radial direction of the abutting ring body. A first tapered surface is formed on the inner periphery of the abutting ring body over the entire circumference, and a straight surface connected to the first tapered surface on the side closer to the pressing surface than the first tapered surface is formed over the entire circumference. The first 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 abutting 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 abuts against the inner periphery of the abutting ring, the outer periphery of the insertion port abuts against the boundary portion where the first tapered surface and the straight surface are connected. The contact portion is provided so as to surround at least the periphery of each fastener insertion hole. The abutting ring is characterized by this.

2. The contact portion is provided in a region between the fastener insertion hole and the adjacent fastener insertion hole in the circumferential direction of the abutting ring body. The abutting ring according to claim 1 is characterized by this.

3. The contact portion is provided in a region from the outer peripheral edge of the pressing surface to the outer peripheral edge of the abutting ring body in the radial direction of the abutting ring body, excluding the fastener insertion holes. The abutting ring according to claim 1 or claim 2 is characterized by this.

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

5. A pipe joint including the abutting ring according to any one of claims 1 to 3 above. A second tapered surface that reduces in diameter toward the back side of the receiving port is formed on the inner periphery of the receiving port. A sealing member insertion space is formed over the entire circumference between the second tapered surface and the outer periphery of the insertion port. The sealing member is inserted into the sealing member insertion space. The sealing member has a valve portion at one end in the insertion direction, which is compressed in the pipe diameter direction to exhibit a sealing function. A guiding portion for guiding the valve portion of the sealing member from the opening end surface of the receiving port into the sealing member insertion space is formed on the inner circumference of the receiving port. The guiding portion has a third tapered surface whose diameter decreases toward the back side of the receiving port. The third tapered surface is formed between the opening end surface of the receiving port and the second tapered surface in the pipe axis direction. A pipe joint characterized in that the inclination angle of the third tapered surface with respect to the pipe axis is larger than the inclination angle of the second tapered surface with respect to the pipe axis.

6. The fastening tool insertion hole of the pressing ring is located outside the pressing surface in the radial direction of the pressing ring body. The contact portion of the pressing ring is provided in a region from the outer peripheral edge of the pressing surface in the radial direction of the pressing ring body to the outer peripheral edge of the pressing ring body, excluding the fastening tool insertion hole. The pressing surface is formed in a recess surrounded by the contact portion. The pipe joint according to claim 5, characterized in that the other end of the sealing member is fitted into the recess of the pressing ring.

7. A pipe joint according to claim 6, characterized in that a gap is formed by the inner peripheral surface of the contact portion of the pressing ring, the third tapered surface of the receiving port, and the outer peripheral surface of the sealing member.

8. A pipe joint according to claim 7, characterized in that the diameter of the end portion of the third tapered surface on the opening end surface side of the receiving port is smaller than the inner diameter of the contact portion of the pressing ring.

9. A pipe joining method using the pressing ring according to any one of claims 1 to 3, while inclining the pipe axis of either the insertion port or the receiving port with respect to the other pipe axis, inserting the insertion port into the receiving port, and inserting a fastening tool through the fastening tool insertion hole of the pressing ring and tightening it to connect the pressing ring to the receiving port and insert the sealing member between the outer circumference of the insertion port and the inner circumference of the receiving port.

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