Pipe joint, press ring and pipe joining method

Abstract

To provide a pipe joint which can surely push a seal member into a seal member insertion space by a push ring, and can prevent the deformation of the push ring.SOLUTION: In a pipe joint, a seal member insertion space 14 is formed between a first tapered face 8 of a receptacle 5 and an external periphery of an insertion port 3, a seal member 15 is inserted into the seal member insertion space 14, and a push ring 17 for pushing the seal member 15 into the seal member insertion space 14 is externally fit to the insertion port 3. The seal member 15 has a valve part 26 at one end part, a guide part 29 for guiding the valve part 26 to the seal member insertion space 14 from an opening end face 16 of the receptacle 5 is formed at an internal periphery of the receptacle 5, the guide part 29 has a second tapered face 30, and an inclination angle of the second tapered face 30 is larger than an inclination angle of the first tapered face 8.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pipe joint in which a spigot formed on one pipe is inserted into a socket formed on the other pipe, a press ring used in this pipe joint, and a method for joining pipes. [Background technology]

[0002] Conventionally, as a pipe fitting of this type, for example, as shown in Figure 16, a pipe fitting 110 is known in which an insertion port 102 formed in one pipe 101 is inserted into a receiving port 104 formed in the other pipe 103, a first tapered surface 105 which narrows in diameter toward the back of the receiving port 104 is formed on the inner circumference of the receiving port 104, a seal member insertion space 106 is formed around the entire circumference between the first tapered surface 105 and the outer periphery of the insertion port 102, an annular seal member 107 which seals between the inner circumference of the receiving port 104 and the outer periphery of the insertion port 102 is inserted into the seal member insertion space 106, and a push ring 109 which presses the seal member 107 from the opening end face 108 of the receiving port 104 into the seal member insertion space 106 is fitted around the insertion port 102 and faces the opening end face 108 of the receiving port 104 from the outside.

[0003] Further inside the socket 104 than the seal member insertion space 106, a socket protrusion 111 is formed around the entire circumference, protruding inward from the inner periphery of the socket 104 in the pipe radial direction B. Further inside the socket 104 than the socket protrusion 111, a lock ring 112 is housed.

[0004] Insertion port 102 passes through lock ring 112, and insertion port protrusion 113 is formed around the entire outer periphery of the tip of insertion port 102. Insertion port protrusion 113 can engage with lock ring 112 from the back side of socket 104 in removal direction A of one pipe 101, thereby preventing insertion port 102 from coming off socket 104 in the event of an earthquake or the like.

[0005] 16 and 17, the pressure ring 109 is fastened to the socket 104 via a plurality of bolts 114 and nuts 115. The bolts 114 are inserted into bolt insertion holes 116 formed in the pressure ring 109, and these bolts 114, nuts 115 and bolt insertion holes 116 are each formed at a predetermined interval in the pipe circumferential direction G. In addition, the pressure ring 109 is provided with a plurality of protrusions 117. Each of these protrusions 117 is located outside the bolt insertion holes 116 in the pipe radial direction B.

[0006] The seal member 107 has a valve portion 118 at one end in the insertion direction C that is compressed in the pipe radial direction B to exert a sealing function.

[0007] According to this, the sealing member 107 and the pressing ring 109 are fitted onto one of the pipes 101, the insertion port 102 is inserted into the receiving port 104, and centering is performed to align the axis of one of the pipes 101 with the axis of the other pipe 103. In this state, the bolt 114 and the nut 115 are tightened, and the sealing member 107 is pressed into the sealing member insertion space 106 from the open end face 108 of the receiving port 104 by the pressing ring 109.

[0008] 16, by tightening the bolt 114 and nut 115 until the protrusion 117 of the press ring 109 abuts against the open end surface 108 of the socket 104, it is possible to prevent the seal member 107 from being pressed with excessive force. In this way, one pipe 101 is joined to the other pipe 103.

[0009] Incidentally, the above-mentioned pipe joint is described, for example, in Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent Publication 2010-286110 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the above conventional type, when one pipe 101 is joined to the other pipe 103, for example, as shown in Fig. 17, first, the bolt 114 and nut 115 at the top M1 of the pipe joint 110 are tightened, then the bolts 114 and nuts 115 at the lower M2 to M4 are tightened in sequence, and finally the bolt 114 and nut 115 at the bottom M5 of the pipe joint 110 are tightened in an unbalanced manner without controlling the tightening torque. This may cause a problem that the seal member 107 stretches and loosens downward at the bottom of the pipe joint 110, making it impossible to insert the valve portion 118 of the seal member 107 into the seal member insertion space 106. Therefore, in the conventional type, it is necessary to tighten all the bolts 114 and nuts 115 so that the tightening torque is uniform, and it takes time to tighten the bolts 114 and nuts 115.

[0012] Moreover, if the bolt 114 and the nut 115 are tightened too much, an excessive tightening force acts on the pressure ring 109, and as shown in Fig. 18, there is a risk that the inner circumference side of the pressure ring 109 will deform and approach the opening end face 108 of the socket 104. Furthermore, after the insertion port 102 is inserted into the socket 104, when the insertion port 102 is bent at a predetermined bending angle θ with respect to the socket 104 as shown in Fig. 19, the outer circumference of the insertion port 102 will come into contact with the inner circumference of the pressure ring 109, and the inner circumference side of the pressure ring 109 will deform and approach the opening end face 108 of the socket 104.

[0013] An object of the present invention is to provide a pipe fitting, a pressure ring, and a method of joining pipes that enable a seal member to be reliably pressed into a seal member insertion space with a pressure ring, that is capable of preventing deformation of the pressure ring, and that eliminates the need to manage the tightening torque of the fastener. [Means for solving the problem]

[0014] In order to achieve the above object, the first invention is a pipe fitting in which a spigot formed on one pipe is inserted into a socket formed on the other pipe, A required space is formed between the outer periphery of the insertion port end and the inner periphery of the receiving port at the back side, so that one tube can be bent relative to the other tube. A first tapered surface that narrows toward the back of the socket is formed on the inner circumference of the socket, A seal member insertion space is formed around the entire circumference between the first tapered surface and the outer periphery of the insertion port, An annular seal member that seals between the inner circumference of the receiving port and the outer circumference of the insertion port is inserted into the seal member insertion space. 、 A pressing ring for pressing the seal member into the seal member insertion space from the open end face of the receiving port is fitted onto the insertion port and faces the open end face of the receiving port from the outside; Even when one tube is bent relative to the other, A pipe joint in which a press ring is fastened to a socket via a plurality of fasteners, The seal member has a valve portion at one end in the insertion direction, the valve portion being compressed in the pipe radial direction to provide a sealing function, A guide portion for guiding the valve portion of the seal member from the open end face of the receiving port into the seal member insertion space is formed on the inner periphery of the receiving port, The guide portion has a second tapered surface that decreases in diameter toward the back of the socket, The second tapered surface is formed between the opening end surface of the receiving port and the first tapered surface in the pipe axial direction, The inclination angle of the second tapered surface with respect to the tube axis is larger than the inclination angle of the first tapered surface with respect to the tube axis. Ku, The press ring is provided with a fastener insertion hole through which the fastener is inserted, a first annular protrusion that abuts against the open end surface of the socket, and a recess surrounded by the first protrusion, The first protrusion is formed on the inside of the fastener insertion hole in the pipe radial direction, When the seal member is inserted into the seal member insertion space while being fitted onto the insertion port, The other end of the seal member in the removal direction is fitted into the recess of the press ring, a valve center portion between an inner periphery and an outer periphery in a pipe diameter direction of the valve portion of the seal member is located inside in the pipe diameter direction with respect to an end portion of the second tapered surface on the opening end face side of the receiving port; a diameter of an end of the second tapered surface on the open end surface side of the receiving port is smaller than an inner diameter of the first protrusion of the press ring; When one tube is bent relative to the other tube, a minimum gap occurs between the outer periphery of the insertion port and the inner periphery of the receiving port, which is the minimum allowable gap. Even in the minimum gap portion, the other end of the seal member is kept fitted in the recess, Even in the minimum gap portion, the relationship is maintained in which the center of the valve is located radially inward of the end of the second tapered surface on the open end face side of the receiving port. It is something.

[0015] According to this, when the seal member is pressed into the seal member insertion space by the pressing ring, the valve portion of the seal member is guided from the open end face of the receiving port into the seal member insertion space by the second tapered surface of the guide portion.

[0016] As a result, even if the fasteners are unbalanced when fastening the press ring to the socket and the seal member stretches and becomes loose, the valve portion of the seal member is guided from the open end face of the socket to the seal member insertion space by the second tapered surface of the guide portion, so the seal member can be reliably pushed into the seal member insertion space by the press ring. This means that it is not necessary to tighten all the fasteners so that the tightening torque is uniform, there is no need to manage the tightening torque of the fasteners, and the time required for the work of tightening the fasteners can be reduced.

[0018] Also Since the valve center portion of the sealing member is located radially inward of the end portion of the second tapered surface, even if the sealing member stretches in the radial direction of the pipe by unevenly tightening the fastener when fastening the press ring to the receiving port, the valve portion of the sealing member is reliably guided from the open end face of the receiving port into the sealing member insertion space by the second tapered surface of the guide portion.

[0020] Also If the axis of one pipe is misaligned in the pipe diameter direction relative to the axis of the other pipe, or one pipe is bent relative to the other pipe, causing a minimum gap portion, the valve center of the seal member is located radially inward of the end of the second tapered surface, even in the minimum gap portion. As a result, even if the fastener is unevenly tightened when fastening the press ring to the socket, the valve portion of the seal member is reliably guided from the open end face of the socket to the seal member insertion space by the second tapered surface of the guide portion.

[0022] moreover When the seal member is pressed into the seal member insertion space by the pressure ring, the other end of the seal member is fitted into the recess of the pressure ring, thereby preventing the other end of the seal member from shifting in the pipe diameter direction and being turned over.

[0023] This 2 In the pipe joint of the invention, a gap is formed which is surrounded by the inner peripheral surface of the first projection, the second tapered surface, and the outer peripheral surface of the seal member.

[0024] According to this, even if the sealing member deforms outward in the pipe diameter direction when the sealing member is pushed into the sealing member insertion space with the pressure ring, the sealing member escapes into the gap, thereby preventing the sealing member from being pinched between the first protrusion of the pressure ring and the opening end face of the receiving port.

[0025] This 3 The present invention is a press ring used in the pipe joint according to the fourth or fifth invention, A second protrusion is formed to abut against the open end surface of the socket, The second protrusion is formed further outward than the first protrusion in the pipe radial direction.

[0026] According to this, when the fastener is inserted into the fastener insertion hole and the pressure ring is fastened to the receiving port, even if an excessive fastening force is applied to the pressure ring, the first protrusion and the second protrusion are each in contact with the open end face of the receiving port, thereby preventing deformation of the pressure ring.

[0027] Furthermore, after the insertion port is inserted into the receiving port, when the insertion port is bent at a predetermined angle relative to the receiving port, even if the outer periphery of the insertion port abuts the inner periphery of the pressure ring, the first protrusion and the second protrusion each abut against the opening end face of the receiving port, thereby preventing deformation of the pressure ring.

[0028] This 4 The press ring in the present invention has a plurality of fastener insertion holes and a plurality of second protrusions formed at predetermined intervals in the pipe circumferential direction, The second protrusion is formed outside the fastener insertion hole in the pipe radial direction, A plurality of outer peripheral recesses recessed inwardly in the pipe radial direction are formed on the outer peripheral edge of the press ring, The outer peripheral recess extends from the outer peripheral edge of the press ring between the fastener insertion hole and the adjacent fastener insertion hole.

[0029] According to this, since a plurality of outer peripheral recesses are formed on the outer peripheral edge of the press ring, the press ring can be made lighter in weight than a press ring that does not have outer peripheral recesses.

[0030] This5 The press ring in the present invention is configured so that the width in the pipe diameter direction from the inner periphery to the outer periphery of the first protrusion is equal to or greater than the width in the pipe diameter direction from the outer periphery of the first protrusion to the outer periphery recess.

[0031] This makes it possible to maintain sufficient strength of the pressure ring even if a plurality of outer peripheral recesses are formed on the outer peripheral edge of the pressure ring.

[0032] This 6 The invention is a pipe fitting in which a spigot formed on one pipe is inserted into a socket formed on the other pipe, A required space is formed between the outer periphery of the insertion port end and the inner periphery of the receiving port at the back side, so that one tube can be bent relative to the other tube. A first tapered surface that narrows toward the back of the socket is formed on the inner circumference of the socket, A seal member insertion space is formed around the entire circumference between the first tapered surface and the outer periphery of the insertion port, An annular seal member that seals between the inner periphery of the receiving port and the outer periphery of the insertion port is inserted into the seal member insertion space, A pressing ring for pressing the seal member into the seal member insertion space from the open end face of the receiving port is fitted onto the insertion port and faces the open end face of the receiving port from the outside; The press ring is fastened to the socket via a plurality of fasteners, The seal member has a valve portion at one end in the insertion direction, the valve portion being compressed in the pipe radial direction to provide a sealing function, A guide portion for guiding the valve portion of the seal member from the open end face of the receiving port into the seal member insertion space is formed on the inner periphery of the receiving port, The guide portion has a second tapered surface that decreases in diameter toward the back of the socket, The second tapered surface is formed between the opening end surface of the receiving port and the first tapered surface in the tube axial direction. And, the inclination angle of the second tapered surface with respect to the tube axis is larger than the inclination angle of the first tapered surface with respect to the tube axis; The press ring is provided with a fastener insertion hole through which a fastener is inserted, a first annular protrusion that abuts against the open end face of the receiving port and is formed on the inside of the fastener insertion hole in the pipe radial direction, and a recess surrounded by the first protrusion, The diameter of the end of the second tapered surface on the open end face side of the receiving port is smaller than the inner diameter of the first protrusion of the press ring. A method for joining pipes in a pipe joint, comprising the steps of: With the seal member and the press ring fitted onto one of the pipes, the insertion port is inserted into the receiving port of the other pipe; The other end of the seal member in the removal direction is fitted into a recess formed in the press ring, and the valve center between the inner and outer peripheries in the pipe diameter direction of the valve part of the seal member is positioned inside in the pipe diameter direction from the end of the second tapered surface on the side of the opening end face of the socket. In this state, the fastener is tightened and the seal member is pushed into the seal member insertion space from the opening end face of the socket with the press ring. fruit, When one tube is bent relative to the other tube, a minimum gap occurs between the outer periphery of the insertion port and the inner periphery of the receiving port, which is the minimum allowable gap. The other end of the sealing member is fitted into the recess even in the smallest gap portion, Even in the minimum gap portion, the valve center portion of the valve portion is positioned radially inward from the end portion of the second tapered surface on the side of the opening end face of the receiving port. It is something. Effect of the Invention

[0034] As described above, according to the present invention, when the seal member is pushed into the seal member insertion space by the press ring, the valve portion of the seal member is guided from the open end face of the socket into the seal member insertion space by the second tapered surface of the guide portion. As a result, when the fastener is one-sidedly tightened to fasten the press ring to the socket, even if the seal member stretches and becomes loose, the valve portion of the seal member is guided from the open end face of the socket into the seal member insertion space by the second tapered surface of the guide portion, so the seal member can be reliably pushed into the seal member insertion space by the press ring. In addition, it is not necessary to tighten all fasteners so that the tightening torque is uniform, eliminating the need to manage the tightening torque of the fasteners and shortening the time required for the fastener tightening operation. [Brief description of the drawings]

[0035] [Figure 1] 1 is a cross-sectional view of an upper portion of a pipe joint according to a first embodiment of the present invention. [Diagram 2] 11 is a partially enlarged cross-sectional view of the insertion port, the receiving port, the seal member, and the press ring of the pipe joint of the first embodiment, showing the state immediately before the seal member is inserted into the seal member insertion space. 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] 4 is a cross-sectional view showing a method of joining pipes in the pipe joint of the first embodiment. FIG. [Figure 8] 4 is a cross-sectional view showing a method of joining pipes in the pipe joint of the first embodiment. FIG. [Figure 9] 5 is a partially enlarged cross-sectional view showing the method of joining pipes in the pipe joint of the first embodiment, illustrating a state when the seal member starts to be inserted into the seal member insertion space. FIG. [Figure 10] 10 is a partially enlarged cross-sectional view showing a method of joining pipes in a pipe joint according to the first embodiment, illustrating a state in which a seal member is being inserted into a seal member insertion space. FIG. [Figure 11] 5 is a partially enlarged cross-sectional view showing a method of joining pipes in the pipe joint of the first embodiment, illustrating a state in which a seal member is inserted into a seal member insertion space. FIG. [Figure 12] FIG. 11 is a diagram showing pipes bent and joined by a pipe joint in a second embodiment of the present invention. [Figure 13] FIG. 4 is a cross-sectional view of the lower part of the pipe joint according to the first embodiment. [Figure 14] 4 is a cross-sectional view showing a method of joining pipes in the pipe joint of the first embodiment. FIG. [Figure 15] FIG. 15 is a cross-sectional view showing a method of joining pipes in the pipe joint of the first embodiment, which is an enlarged view of a portion of FIG. [Figure 16] FIG. 1 is a cross-sectional view of the upper part of a conventional pipe joint. [Figure 17] FIG. 2 is a view of the pipe joint as viewed from the axial direction of one of the pipes. [Figure 18] FIG. 11 is a cross-sectional view of the upper part of the pipe joint of the same embodiment, showing how the pressing ring is deformed. [Figure 19] 13 is a cross-sectional view of the lower part of the pipe joint when the pipes are bent and joined, showing how the pressure ring is deformed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0037] (First embodiment) In the first embodiment, as shown in Figures 1 and 2, 1 is a pipe fitting, and in this pipe fitting 1, a spigot 3 formed in one pipe 2 is inserted into a socket 5 formed in the other pipe 4.

[0038] The inner circumference of the socket 5 is formed with a first tapered surface 8, a straight surface 9, a socket protrusion 10, and a lock ring accommodating groove 11. The first tapered surface 8 narrows in diameter toward the back of the socket 5. The straight surface 9 is parallel to the pipe axis 13 of the pipe 4, and continues from the back end of the first tapered surface 8 to the back side of the socket 5.

[0039] A seal member insertion space 14 is formed around the entire circumference between the first tapered surface 8 and the outer periphery of the insertion port 3. An annular seal member 15 that seals between the inner periphery of the receiving port 5 and the outer periphery of the insertion port 3 is inserted into the seal member insertion space 14.

[0040] A pressure ring 17 that presses the seal member 15 from the opening end face 16 of the socket 5 into the seal member insertion space 14 is fitted onto the insertion port 3 and faces the opening end face 16 of the socket 5 from the outside. The pressure ring 17 is fastened to the socket 5 via a number of T-head bolts 19 (an example of a fastener) and nuts 20 (an example of a fastener).

[0041] The socket 5 is formed with a plurality of bolt holes 21 through which the T-head bolts 19 are inserted.

[0042] The lock ring accommodating groove 11 is formed on the rear side of the seal member insertion space 14 in the receiving port 5, and a lock ring 22 is accommodated in the lock ring accommodating groove 11. The lock ring 22 is a ring with a single split structure cut in one place, and has elasticity such that the diameter can be expanded by expanding the width of the cut part with a diameter expander (not shown), and the diameter can be reduced and returned to the original diameter by removing the diameter expander from the cut part.

[0043] The insertion port 3 passes through the lock ring 22, and an insertion port protrusion 23 is formed around the entire outer periphery of the tip of the insertion port 3. The insertion port protrusion 23 can engage with the lock ring 22 from the back side of the socket 5 in the removal direction A of one of the pipes 2, thereby preventing the insertion port 3 from coming off the socket 5 in the event of an earthquake or the like.

[0044] The socket protrusion 10 protrudes inward in the pipe diameter direction B from the inner periphery of the socket 5, and is formed over the entire periphery between the seal member insertion space 14 and the lock ring accommodating groove 11. A centering ring 24 is fitted between the inner periphery of the socket protrusion 10 and the outer periphery of the insertion port 3. The centering ring 24 is a ring with a one-piece structure cut at one point, and is made of an elastic material such as resin.

[0045] The seal member 15 is a rubber ring and has a valve portion 26 with a circular cross section provided at one end in the insertion direction C, and a base portion 27 with a trapezoidal cross section provided integrally with the valve portion 26. As shown in Fig. 1, when the seal member 15 is inserted into the seal member insertion space 14, the valve portion 26 is compressed in the pipe radial direction B to exert a sealing function.

[0046] A guide portion 29 that guides the valve portion 26 of the seal member 15 from the opening end face 16 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 29 has a second tapered surface 30 that narrows in diameter toward the back of the receiving port 5. The second tapered surface 30 is formed over the entire circumference in the tube axis direction E between the opening end face 16 of the receiving port 5 and the first tapered surface 8. As shown in FIG. 1, the inclination angle α2 of the second tapered surface 30 with respect to the tube axis 13 is greater than the inclination angle α1 of the first tapered surface 8 with respect to the tube axis 13.

[0047] As shown in Figures 3 to 6, the pressure ring 17 has a plurality of bolt insertion holes 32 (an example of a fastener insertion hole) through which the T-head bolt 19 is inserted, a circular first protrusion 33 that abuts against the opening end face 16 of the receiving port 5, a plurality of second protrusions 34 that abut against the opening end face 16, and a recess 35 surrounded by the first protrusions 33.

[0048] The first protrusion 33 , the second protrusion 34 and the recess 35 are formed on the joint surface side of the press ring 17 that faces the open end surface 16 of the socket 5 .

[0049] The first protrusion 33 is formed inward of the bolt insertion hole 32 in the pipe radial direction B. As shown in Figures 1 and 9, the other end of the base 27 of the seal member 15 in the removal direction A is fitted into the recess 35 of the press ring 17.

[0050] 3 and 4, the bolt insertion holes 32 and the second protrusions 34 are formed at a predetermined interval in the pipe circumferential direction G, and further, the second protrusions 34 are formed outward of the bolt insertion holes 32 in the pipe radial direction B. As shown in Fig. 5, the height h1 of the first protrusions 33 and the height h2 of the second protrusions 34 are the same.

[0051] The outer circumferential edge of the pressure ring 17 is formed with a plurality of outer circumferential recesses 37 recessed inward in the pipe radial direction B. As shown in Figures 3 and 4, the outer circumferential recesses 37 extend from the outer circumferential edge of the pressure ring 17 into between the bolt insertion holes 32 and the adjacent bolt insertion holes 32.

[0052] The width W1 in the pipe radial direction B from the inner periphery to the outer periphery of the first protrusion 33 is configured to be equal to or larger than the width W2 in the pipe radial direction B from the outer periphery of the first protrusion 33 to the outer periphery recess 37. The inner peripheral surface 33a of the first protrusion 33 of the press ring 17 is a tapered surface that expands in diameter in the insertion direction C. As shown in FIG. 2, the diameter D2 of the end 30a of the second tapered surface 30 on the side of the opening end surface 16 of the receiving port 5 is smaller than the inner diameter D1 of the first protrusion 33 of the press ring 17.

[0053] As shown in FIGS. 1 and 11, a gap 39 surrounded by the inner peripheral surface 33a of the first protrusion 33, the second tapered surface 30, and the outer peripheral surface of the base portion 27 of the seal member 15 is formed over the entire periphery.

[0054] Furthermore, as shown in Figures 2 and 9, when the sealing member 15 is inserted into the sealing member insertion space 14 while being fitted onto the insertion port 3, the valve center portion 41 between the inner and outer circumferences in the pipe radial direction B of the valve portion 26 of the sealing member 15 is positioned inside in the pipe radial direction B relative to the end portion 30a of the second tapered surface 30 on the opening end face 16 side of the receiving port 5.

[0055] A method for joining the pipes 2, 4 in the above pipe joint 1 will now be described.

[0056] First, the lock ring 22 is accommodated in the lock ring accommodating groove 11, and the width of the cut portion of the lock ring 22 is enlarged using a diameter expander (not shown), thereby expanding the diameter of the lock ring 22.

[0057] Next, with the centering ring 24, the seal member 15, and the press ring 17 fitted onto the outside of one of the pipes 2, the insertion port 3 of one of the pipes 2 is inserted into the receiving port 5 of the other pipe 4. At this time, because the diameter of the lock ring 22 has been expanded using the diameter expander as described above, the insertion port protrusion 23 passes through the inner circumference of the lock ring 22 from the open end face 16 of the receiving port 5 and reaches the rear side of the lock ring 22 into the receiving port 5.

[0058] Thereafter, the expander is removed from the cut portion of the lock ring 22, whereby the lock ring 22 contracts in diameter and hugs the outer periphery of the insertion port 3.

[0059] 7, the centering ring 24 is slid in the pipe axis direction E and inserted between the inner circumference of the socket protrusion 10 and the outer circumference of the insertion port 3. This causes the insertion port 3 to be centered with respect to the socket 5, and the misalignment between the axis of one pipe 2 and the axis of the other pipe 4 is almost eliminated.

[0060] Furthermore, as shown in Figures 8 and 9, the other end of the base 27 of the sealing member 15 in the removal direction A is fitted into the recess 35 of the pressure ring 17, the T-head bolt 19 is inserted into the bolt hole 21 of the receiving port 5 and the bolt insertion hole 32 of the pressure ring 17, the nut 20 is tightened onto the T-head bolt 19, and the pressure ring 17 pushes the sealing member 15 from the opening end face 16 of the receiving port 5 into the sealing member insertion space 14.

[0061] At this time, as shown in FIGS. 9 and 10, the valve portion 26 of the seal member 15 is guided by the second tapered surface 30 of the guide portion 29 from the open end surface 16 of the socket 5 into the seal member insertion space 14 .

[0062] Furthermore, as shown in Figure 9, the valve center portion 41 of the sealing member 15 is located further inward in the pipe radial direction B than the end portion 30a of the second tapered surface 30. Therefore, if the T-head bolts 19 and nuts 20 are tightened one-sidedly from the uppermost to the lowermost when fastening the pressure ring 17 to the receiving port 5, even if the sealing member 15 stretches and becomes loose, the valve portion 26 will be reliably guided from the opening end face 16 of the receiving port 5 into the sealing member insertion space 14 by the second tapered surface 30 of the guide portion 29, and the sealing member 15 can be reliably pushed into the sealing member insertion space 14 by the pressure ring 17.

[0063] This eliminates the need to tighten all the T-head bolts 19 and nuts 20 to a uniform tightening torque, eliminates the need to manage the tightening torque of the T-head bolts 19 and nuts 20, and shortens the time required to tighten the T-head bolts 19 and nuts 20.

[0064] In addition, when the sealing member 15 is pressed into the sealing member insertion space 14 by the pressure ring 17, the other end of the sealing member 15 is fitted into the recess 35 of the pressure ring 17, so that the other end of the sealing member 15 can be prevented from shifting in the pipe radial direction B and being turned over.

[0065] Furthermore, as shown in Figure 11, even if the sealing member 15 deforms outward in the pipe radial direction B, the sealing member 15 escapes into the gap 39, thereby preventing the sealing member 15 from being pinched between the first protrusion 33 of the press ring 17 and the opening end face 16 of the receiving port 5.

[0066] Furthermore, as shown in FIG. 1, when T-head bolt 19 is inserted through bolt hole 21 of receiving port 5 and bolt insertion hole 32 of pressure ring 17, and nut 20 is tightened to fasten pressure ring 17 to receiving port 5, the first protrusion 33 and the second protrusion 34 are each in contact with the opening end face 16 of receiving port 5, so that deformation of pressure ring 17 can be prevented even if an excessive fastening force is applied to pressure ring 17.

[0067] In addition, as shown in Figures 3 and 4, multiple outer peripheral recesses 37 are formed on the outer periphery of the pressure ring 17, making the pressure ring 17 lighter than a pressure ring that does not have outer peripheral recesses 37 formed.

[0068] Furthermore, as shown in Figures 3 and 6, the pressure ring 17 is configured so that the width W1 from the inner circumference to the outer circumference of the first protrusion 33 is greater than or equal to the width W2 from the outer circumference of the first protrusion 33 to the outer circumference recess 37. Therefore, even if multiple outer circumference recesses 37 are formed on the outer circumference of the pressure ring 17, the strength of the pressure ring 17 can be sufficiently maintained.

[0069] (Second embodiment) In the above-mentioned first embodiment, as shown in Fig. 1, one pipe 2 is joined to the other pipe 4 straight without bending, but in the second embodiment described below, as shown in Fig. 12 and Fig. 13, one pipe 2 is bent at a predetermined bending angle θ and joined to the other pipe 4. In this case, one pipe 2 is inclined so that the end on the insertion port 3 side is higher than the opposite end.

[0070] When joining one pipe 2 to the other pipe 4 in such a bent pipe joint 1, with the centering ring 24, sealing member 15 and pressure ring 17 fitted onto the outside of one pipe 2, the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4.

[0071] Then, as shown in Figure 14, the centering ring 24 is slid in the pipe axis direction E and inserted between the inner circumference of the receiving port protrusion 10 and the outer circumference of the insertion port 3, and then one pipe 2 is bent relative to the other pipe 4 at a predetermined bending angle θ.

[0072] At this time, since the insertion port 3 is supported by the centering ring 24 and bent at a predetermined bending angle θ, a minimum gap portion 43, where the gap between the outer periphery of the insertion port 3 and the inner periphery of the receiving port 5 is the smallest within the allowable range, is generated at the bottom of the pipe fitting 1.

[0073] In this state, the other end of the base 27 of the sealing member 15 is fitted into the recess 35 of the pressure ring 17, the T-head bolt 19 is inserted into the bolt hole 21 of the receiving port 5 and the bolt insertion hole 32 of the pressure ring 17, the nut 20 is tightened onto the T-head bolt 19, and the pressure ring 17 is used to push the sealing member 15 from the opening end face 16 of the receiving port 5 into the sealing member insertion space 14.

[0074] At this time, as shown in FIG. 15, the valve portion 26 of the seal member 15 is guided by the second tapered surface 30 of the guide portion 29 from the open end surface 16 of the socket 5 into the seal member insertion space 14 .

[0075] Furthermore, if the T-head bolts 19 and nuts 20 are tightened unevenly from the top to the bottom when fastening the press ring 17 to the receiving port 5, even in the minimum gap portion 43 as described above, the valve center portion 41 of the sealing member 15 is located inside the end portion 30a of the second tapered surface 30 in the pipe radial direction B, so that the valve portion 26 is reliably guided from the opening end face 16 of the receiving port 5 into the sealing member insertion space 14 by the second tapered surface 30 of the guide portion 29, and the sealing member 15 can be reliably pushed into the sealing member insertion space 14 by the press ring 17.

[0076] Furthermore, as shown in FIG. 13, even if the outer periphery of the bent insertion port 3 abuts against the inner periphery of the pressure ring 17, the first protrusion 33 and the second protrusion 34 each abut against the opening end face 16 of the receiving port 5, thereby preventing deformation of the pressure ring 17. [Explanation of symbols]

[0077] 1 Pipe fittings 2 One tube 3 Insertion port 4 The other tube 5 socket 8 First tapered surface 13 Tube axis 14. Sealing member insertion space 15 Sealing material 16 Open end face 17 Push Ring 19 T-head bolt (fastener) 20 Nut (fastener) 26 Valve section 29 Information Department 30 Second tapered surface 30a End of second tapered surface 32 Bolt hole (fastener hole) 33 First protrusion 33a: inner circumferential surface of the first protrusion 34 Second protrusion 35 Recess 37 Outer periphery recess 39 Gap 41 Valve center 43 Minimum gap A Departure direction B Pipe diameter direction C Insertion direction D1 Inner diameter of the first protrusion D2 Diameter of the end of the second tapered surface E Tube axis direction W1: Width in the pipe diameter direction from the inner circumference to the outer circumference of the first protrusion W2: The width in the pipe diameter direction from the outer periphery of the first protrusion to the outer periphery recess α1 Inclination angle of the first tapered surface α2 Inclination angle of the second tapered surface

Claims

1. A spigot formed on one tube is inserted into a socket formed on the other tube; A required space is formed between the outer periphery of the insertion port end and the inner periphery of the receiving port at the back side, so that one tube can be bent relative to the other tube. A first tapered surface that narrows toward the back of the socket is formed on the inner circumference of the socket, A seal member insertion space is formed around the entire circumference between the first tapered surface and the outer periphery of the insertion port, An annular seal member that seals between the inner periphery of the receiving port and the outer periphery of the insertion port is inserted into the seal member insertion space, A pressing ring for pressing the seal member into the seal member insertion space from the open end face of the receiving port is fitted onto the insertion port and faces the open end face of the receiving port from the outside; Even when one tube is bent relative to the other, A pipe joint in which a press ring is fastened to a receiving port via a plurality of fasteners, the seal member having a valve portion at one end in an insertion direction, the valve portion being compressed in a pipe radial direction to exert a sealing function, A guide portion for guiding the valve portion of the seal member from the open end face of the receiving port into the seal member insertion space is formed on the inner periphery of the receiving port, The guide portion has a second tapered surface that narrows toward the back of the socket, the second tapered surface is formed between the opening end surface of the receiving port and the first tapered surface in the tube axial direction; the inclination angle of the second tapered surface with respect to the tube axis is larger than the inclination angle of the first tapered surface with respect to the tube axis; The press ring is provided with a fastener insertion hole through which the fastener is inserted, a first annular protrusion that contacts the open end surface of the socket, and a recess surrounded by the first protrusion, The first protrusion is formed on the inside of the fastener insertion hole in the pipe radial direction, When the seal member is inserted into the seal member insertion space while being fitted onto the insertion port, The other end of the seal member in the removal direction is fitted into the recess of the press ring, a valve center portion between an inner periphery and an outer periphery in a pipe diameter direction of the valve portion of the seal member is located inside in the pipe diameter direction with respect to an end portion of the second tapered surface on the opening end face side of the receiving port, a diameter of an end of the second tapered surface on the open end surface side of the receiving port is smaller than an inner diameter of the first protrusion of the press ring; When one tube is bent relative to the other tube, a minimum gap occurs between the outer periphery of the insertion port and the inner periphery of the receiving port, which is the minimum allowable gap. Even in the minimum gap portion, the other end of the seal member is kept fitted in the recess, A pipe fitting characterized in that even in the minimum gap portion, the valve center is maintained at a position radially inward of the end of the second tapered surface on the opening end face side of the receiving port.

2. 2. A pipe joint according to claim 1, wherein a gap is formed surrounded by an inner peripheral surface of the first projection, the second tapered surface, and an outer peripheral surface of the seal member.

3. A pressure ring for use in the pipe joint according to claim 1 or 2, A second protrusion is formed to abut on an open end surface of the socket, A press ring characterized in that the second protrusion is formed outside the first protrusion in a pipe radial direction.

4. A plurality of fastener insertion holes and a plurality of second protrusions are formed at predetermined intervals in a circumferential direction of the pipe, The second protrusion is formed outside the fastener insertion hole in the pipe radial direction, A plurality of outer peripheral recesses recessed inwardly in the pipe radial direction are formed on the outer peripheral edge of the press ring, 4. The pressure ring according to claim 3, wherein the outer peripheral recess extends from the outer peripheral edge of the pressure ring to between the fastener insertion hole and the adjacent fastener insertion hole.

5. 5. The press ring according to claim 4, characterized in that the width in the pipe diameter direction from the inner periphery to the outer periphery of the first protrusion is equal to or greater than the width in the pipe diameter direction from the outer periphery of the first protrusion to the outer peripheral recess.

6. A spigot formed on one tube is inserted into a socket formed on the other tube; A required space is formed between the outer periphery of the insertion port end and the inner periphery of the receiving port at the back side, so that one tube can be bent relative to the other tube. A first tapered surface that narrows toward the back of the socket is formed on the inner circumference of the socket, A seal member insertion space is formed around the entire circumference between the first tapered surface and the outer periphery of the insertion port, An annular seal member that seals between the inner periphery of the receiving port and the outer periphery of the insertion port is inserted into the seal member insertion space, A pressing ring for pressing the seal member into the seal member insertion space from the open end face of the receiving port is fitted onto the insertion port and faces the open end face of the receiving port from the outside; The press ring is fastened to the socket via a plurality of fasteners, The seal member has a valve portion at one end in the insertion direction, the valve portion being compressed in the pipe radial direction to provide a sealing function, A guide portion for guiding the valve portion of the seal member from the open end face of the receiving port into the seal member insertion space is formed on the inner periphery of the receiving port, The guide portion has a second tapered surface that narrows toward the back of the socket, the second tapered surface is formed between the opening end surface of the receiving port and the first tapered surface in the tube axial direction; the inclination angle of the second tapered surface with respect to the tube axis is larger than the inclination angle of the first tapered surface with respect to the tube axis; The press ring is provided with a fastener insertion hole through which the fastener is inserted, a first annular protrusion that abuts against the open end face of the socket and is formed on the inside of the fastener insertion hole in the pipe radial direction, and a recess surrounded by the first protrusion, A method for joining pipes in a pipe fitting, in which a diameter of an end of a second tapered surface on an open end face side of a receiving port is smaller than an inner diameter of a first protrusion of a press ring, With the seal member and the press ring fitted onto one of the pipes, the insertion port is inserted into the receiving port of the other pipe; the other end of the seal member in the removal direction is fitted into a recess formed in the press ring, and the valve center portion between the inner and outer peripheries in the pipe diameter direction of the valve portion of the seal member is positioned inside in the pipe diameter direction relative to the end portion of the second tapered surface on the side of the opening end face of the socket, and the fastener is tightened in this state to push the seal member into the seal member insertion space from the opening end face of the socket with the press ring; When one tube is bent relative to the other tube, a minimum gap occurs between the outer periphery of the insertion port and the inner periphery of the receiving port, which is the minimum allowable gap. The other end of the sealing member is fitted into the recess even in the smallest gap portion, A method for joining pipes, characterized in that even in the minimum gap portion, the valve center portion of the valve portion is positioned radially inward of the end portion of the second tapered surface on the opening end face side of the receiving port.

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