Pipe joint, compression ring and method of joining pipes

Abstract

A pipe joint in which a seal member insertion space 14 is formed between a first taper surface 8 of a receiving port 5 and the outer periphery of a plug-in port 3, a seal member 15 is inserted into the seal member insertion space 14, and an outer ring 17 that presses the seal member 15 into the seal member insertion space 14 is fitted to the plug-in port 3, wherein the seal member 15 has a valve portion 26 at one end portion, a guide portion 29 that guides the valve portion 26 from an open end surface 16 of the receiving port 5 to the seal member insertion space 14 is formed on the inner periphery of the receiving port 5, and the guide portion 29 has a second taper surface 30 that has a larger inclination angle than the inclination angle of the first taper surface 8.

Description

Technical Field

[0001] The present invention relates to a pipe fitting for inserting an inlet of a pipe formed on one side into a socket of a pipe formed on the other side, a pressure ring used in the pipe fitting, and a method of pipe joining. Background Technology

[0002] Previously, it was known that Figure 16 The pipe fitting 110 is as shown. The pipe fitting 110 is configured as follows: An insertion port 102 formed on one side of the pipe 101 is inserted into a receiving port 104 formed on the other side of the pipe 103. A first conical surface 105, which narrows towards the inner side of the receiving port 104, is formed on the inner circumference of the receiving port 104. A sealing member insertion space 106 is formed circumferentially between the first conical surface 105 and the outer circumference of the insertion port 102. An annular sealing member 107, which seals between the inner circumference of the receiving port 104 and the outer circumference of the insertion port 102, is inserted into the sealing member insertion space 106. The sealing member 107 is pressed from the open end face 108 of the receiving port 104 into the sealing member insertion space 106, where a pressure ring 109 is fitted over the insertion port 102 and faces the open end face 108 of the receiving port 104 from the outside.

[0003] Furthermore, a socket protrusion 111 is formed throughout the entire circumference of the socket 104, protruding inward from the inner circumference of the socket 104 in the pipe diameter direction B, at a position further inside the socket 104 than the sealing member insertion space 106. A locking ring 112 is accommodated at a position further inside the socket 104 than the socket protrusion 111.

[0004] The insertion port 102 passes through the locking ring 112, and the insertion port protrusion 113 is formed around the entire circumference of the front end of the insertion port 102. The insertion port protrusion 113 can engage with the locking ring 112 from the inside of the receiving port 104 in the disengagement direction 120 of one of the pipes 101. Thus, the insertion port 102 can be prevented from disengaging from the receiving port 104 in the event of an earthquake or other similar event.

[0005] like Figure 16 , Figure 17 As shown, the pressure ring 109 is fastened to the socket 104 by a plurality of bolts 114 and nuts 115. The bolts 114 are inserted into bolt insertion holes 116 formed in the pressure ring 109. These bolts 114, nuts 115, and bolt insertion holes 116 are formed at predetermined intervals in the circumferential direction G. In addition, a plurality of protrusions 117 are provided on the pressure ring 109. These protrusions 117 are located on the outer side of the bolt insertion holes 116 in the circumferential direction B.

[0006] The sealing member 107 has a valve portion 118 at one end in the insertion direction C, which is compressed in the pipe diameter direction B to perform a sealing function.

[0007] Thus, the sealing member 107 and the pressure ring 109 are externally embedded in one of the tubes 101, the insertion port 102 is inserted into the receiving port 104, and centering is performed so that the axis of one tube 101 is aligned with the axis of the other tube 103. In this state, the bolts 114 and nuts 115 are tightened, and the pressure ring 109 is used to press the sealing member 107 from the open end face 108 of the receiving port 104 into the sealing member insertion space 106.

[0008] like Figure 16 As shown, by tightening the bolts 114 and nuts 115 to abut the protrusion 117 of the pressure ring 109 against the open end face 108 of the socket 104, it is possible to prevent the sealing member 107 from being pressed by excessive force. Thus, one pipe 101 is joined to the other pipe 103.

[0009] Regarding the aforementioned pipe fitting 110, please refer to Japanese Patent Application Publication No. 2010-286110. Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, in the aforementioned conventional configurations, when connecting one tube 101 to the other tube 103, for example... Figure 17 As shown, first, the bolt 114 and nut 115 at the uppermost 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. Finally, the bolt 114 and nut 115 at the lowermost M5 of the pipe joint 110 are tightened. When tightening is performed unilaterally in this order without managing the tightening torque, the sealing member 107 may sometimes elongate, and at the lower part of the pipe joint 110, the sealing member 107 may sometimes loosen downwards. When the sealing member 107 loosens, there may be a problem where the valve portion 118 of the sealing member 107 cannot be inserted into the sealing member insertion space 106. Therefore, in conventional designs, it is necessary to tighten all the bolts 114 and nuts 115 in a way that ensures a uniform tightening torque, and the tightening operation of the bolts 114 and nuts 115 takes time.

[0012] Additionally, when bolt 114 and nut 115 are overtightened, excessive tightening force will act on pressure ring 109, such as... Figure 18 As shown, the inner circumferential side of the pressure ring 109 may deform and approach the open end face 108 of the receiving interface 104. Furthermore, after the insertion port 102 is inserted into the receiving interface 104, as... Figure 19As shown, when the insertion port 102 is bent relative to the receiving port 104 at a specified bending angle θ, the outer periphery of the insertion port 102 abuts against the inner periphery of the pressure ring 109, and the inner periphery of the pressure ring 109 may deform and approach the opening end face 108 of the receiving port 104.

[0013] The purpose of this invention is to provide a pipe fitting, a pressure ring, and a method for joining pipes, which can reliably press a sealing member into a sealing member insertion space using a pressure ring, prevent deformation of the pressure ring, and eliminate the need for managing the tightening torque of the fastening connection.

[0014] Methods for solving problems

[0015] The pipe fitting of the present invention is characterized in that: the insertion port of a pipe formed on one side is inserted into the receiving port of a pipe formed on the other side.

[0016] The first conical surface, which tapers towards the inner side of the bearing interface, is formed on the inner circumference of the bearing interface.

[0017] A sealing member insertion space is formed throughout the entire circumference between the first conical surface and the outer periphery of the insertion port. An annular sealing member, which seals the inner periphery of the receiving interface and the outer periphery of the insertion port, is inserted into the sealing member insertion space.

[0018] The sealing member is pressed into the insertion space of the sealing member through the open end face of the socket. The pressure ring is fitted into the insertion port and faces the open end face of the socket from the outside.

[0019] The pressure ring is securely connected to the bearing interface via multiple fastening fasteners.

[0020] The sealing member has a valve portion at one end in the insertion direction, which is compressed in the pipe diameter direction to perform a sealing function.

[0021] The valve portion of the sealing member is guided from the open end face of the socket to the guide portion of the sealing member insertion space, which is formed on the inner circumference of the socket.

[0022] The guide section has a second conical surface that narrows in diameter as it approaches the inner side of the bearing interface.

[0023] The second conical surface is formed in the direction of the tube axis between the open end face of the bearing interface and the first conical surface.

[0024] The inclination angle of the second conical surface relative to the tube axis is greater than that of the first conical surface relative to the tube axis.

[0025] Therefore, when the sealing member is pressed into the sealing member insertion space using the pressure ring, the valve part of the sealing member is guided from the open end face of the socket to the sealing member insertion space using the second conical surface of the guide.

[0026] Therefore, even if the sealing member elongates and loosens due to unilateral tightening of the fastening connection when the pressure ring is fastened to the socket, the valve portion of the sealing member can still be guided from the open end face of the socket to the sealing member insertion space using the second conical surface of the guide portion. Thus, the sealing member can be reliably pressed into the sealing member insertion space using the pressure ring. Consequently, it is not necessary to tighten all fastening connections in a manner that ensures uniform tightening torque, and there is no need to manage the tightening torque of the fastening connections, thereby reducing the time required for tightening the fastening connections.

[0027] According to the pipe fitting of the present invention, it is preferred that when the sealing member is inserted into the sealing member insertion space in a state where it is externally embedded in the insertion port, the valve center portion of the valve part of the sealing member is located on the inner side of the end of the second conical surface on the side of the opening end face of the bearing interface in the pipe diameter direction between the inner and outer circumferences of the valve part.

[0028] Therefore, since the valve center of the sealing member is located inside the end of the second conical surface in the pipe diameter direction, even if the sealing member is stretched and loosened in the pipe diameter direction when the pressure ring is fastened to the socket by tightening the fastening connection on one side, the valve part of the sealing member can be reliably guided from the open end face of the socket to the sealing member insertion space by the second conical surface of the guide.

[0029] According to the pipe fitting of the present invention, it is preferable that, in the case of a minimum gap portion in which the gap between the outer periphery of the insertion port and the inner periphery of the socket is the minimum value within the allowable range, the minimum gap portion is also maintained such that: the valve center portion is located in the pipe diameter direction at the end of the second conical surface that is closer to the opening end face of the socket.

[0030] Therefore, by offsetting the axis of one pipe relative to the axis of the other pipe along the pipe diameter direction, or by bending one pipe relative to the other pipe, in the case of a minimum clearance portion, the valve center of the sealing member will be located in the pipe diameter direction at a position closer to the end of the second conical surface in the minimum clearance portion. Thus, even if the fastening connection is tightened on one side when the pressure ring is fastened to the socket, the valve portion of the sealing member can be reliably guided from the open end face of the socket to the sealing member insertion space using the second conical surface of the guide portion.

[0031] According to the pipe fitting of the present invention, preferably, the pressure ring is provided with a fastening connector insertion hole for inserting a fastening connector, an annular first protrusion that abuts against the open end face of the socket, and a recess surrounded by the first protrusion.

[0032] The first protrusion is formed in the pipe diameter direction at a position that is more inner than the insertion hole of the fastening connector.

[0033] The other end of the sealing member in the disengagement direction is embedded into the recess of the pressure ring.

[0034] The diameter of the end of the second conical surface on the open end face of the bearing is smaller than the inner diameter of the first protrusion of the pressure ring.

[0035] Therefore, when the sealing member is pressed into the sealing member insertion space using the pressure ring, since the other end of the sealing member is embedded in the recess of the pressure ring, it is possible to prevent the other end of the sealing member from shifting and curling along the pipe diameter direction.

[0036] According to the pipe fitting of the present invention, preferably, the pipe fitting has a gap surrounded by the inner peripheral surface of the first protrusion, the second conical surface, and the outer peripheral surface of the sealing member.

[0037] Therefore, when the sealing member is pressed into the sealing member insertion space using the pressure ring, even if the sealing member deforms outward in the pipe diameter direction, the sealing member can be prevented from being clamped between the first protrusion of the pressure ring and the open end face of the socket by allowing the sealing member to retract into the gap.

[0038] The pressure ring used in the pipe fitting of the present invention is characterized in that: the pressure ring has a second protrusion that abuts against the open end face of the socket.

[0039] The second protrusion is formed on the outer side of the first protrusion in the pipe diameter direction.

[0040] Therefore, when the fastening connector is inserted into the fastening connector insertion hole and the pressure ring is fastened to the bearing interface, even if an excessive fastening force is applied to the pressure ring, the first protrusion and the second protrusion abut against the open end face of the bearing interface, thus preventing deformation of the pressure ring.

[0041] Furthermore, after the insertion port is inserted into the receiving port, when the insertion port is bent at a specified angle relative to the receiving port, even if the outer periphery of the insertion port abuts against the inner periphery of the pressure ring, deformation of the pressure ring can be prevented by having the first protrusion and the second protrusion abut against the open end face of the receiving port, respectively.

[0042] According to the pressure ring of the present invention, preferably, a plurality of fastening connection through holes and a plurality of second protrusions are formed at predetermined intervals in the circumferential direction of the tube.

[0043] The second protrusion is formed in the pipe diameter direction at a position further outward than the insertion hole of the fastening connector.

[0044] Multiple peripheral recesses are formed on the outer periphery of the pressure ring, and these multiple peripheral recesses are recessed inward in the pipe diameter direction.

[0045] The outer peripheral recess enters from the outer periphery of the pressure ring between the fastening connector insertion hole and the adjacent fastening connector insertion hole.

[0046] Therefore, since multiple peripheral recesses are formed on the outer periphery of the pressure ring, the pressure ring can be made lighter compared to pressure rings without peripheral recesses.

[0047] According to the pressure ring of the present invention, it is preferable that the width of the pressure ring in the pipe diameter direction from the inner periphery of the first protrusion to the outer periphery is greater than or equal to the width in the pipe diameter direction from the outer periphery of the first protrusion to the outer peripheral recess.

[0048] Therefore, even if multiple peripheral recesses are formed on the outer periphery of the pressure ring, the strength of the pressure ring can be fully maintained.

[0049] The pipe joining method of the present invention is a pipe joining method in a pipe joint, wherein an insertion port formed on one side of a pipe is inserted into a receiving port formed on the other side of a pipe.

[0050] The first conical surface, which tapers towards the inner side of the bearing interface, is formed on the inner circumference of the bearing interface.

[0051] A sealing member insertion space is formed throughout the entire circumference between the first conical surface and the outer periphery of the insertion port. An annular sealing member, which seals the inner periphery of the receiving interface and the outer periphery of the insertion port, is inserted into the sealing member insertion space.

[0052] The sealing member is pressed into the insertion space of the sealing member through the open end face of the socket. The pressure ring is fitted into the insertion port and faces the open end face of the socket from the outside.

[0053] The pressure ring is securely connected to the bearing interface via multiple fastening fasteners.

[0054] The sealing member has a valve portion at one end in the insertion direction, which is compressed in the pipe diameter direction to perform a sealing function.

[0055] The valve portion of the sealing member is guided from the open end face of the socket to the guide portion of the sealing member insertion space, which is formed on the inner circumference of the socket.

[0056] The guide section has a second conical surface that narrows in diameter as it approaches the inner side of the bearing interface.

[0057] The second conical surface is formed in the direction of the tube axis between the open end face of the bearing interface and the first conical surface.

[0058] The characteristic is that, in the joining method of the tube,

[0059] With the sealing member and pressure ring externally embedded in one of the pipes, the insertion port is inserted into the socket of the other pipe.

[0060] The other end of the sealing member in the disengagement direction is inserted into the recess formed in the pressure ring.

[0061] With the valve center of the valve part of the sealing member positioned in the pipe diameter direction between the inner and outer circumferences of the valve section, and the end of the valve located inside the opening end face of the second conical surface of the socket, the fastening connector is tightened, and the sealing member is pressed into the sealing member insertion space from the opening end face of the socket using the pressure ring.

[0062] According to the pipe joining method of the present invention, it is preferable to insert the insertion port into the receiving port of the other pipe.

[0063] When the minimum gap portion is generated where the gap between the outer periphery of the insertion port and the inner periphery of the socket is within the minimum allowable range, the other end of the sealing member is embedded into the recess of the pressure ring. In the minimum gap portion, the valve center portion of the valve part is also positioned in the pipe diameter direction at a position that is more inward than the end of the socket opening face of the second conical surface.

[0064] Invention Effects

[0065] As described above, according to the present invention, when the sealing member is pressed into the sealing member insertion space using a pressure ring, the valve portion of the sealing member is guided from the open end face of the socket into the sealing member insertion space using the second conical surface of the guide portion. Therefore, even when the pressure ring is fastened to the socket by unilateral tightening of the fastening connection, the valve portion of the sealing member can still be guided from the open end face of the socket into the sealing member insertion space using the second conical surface of the guide portion, thus reliably pressing the sealing member into the sealing member insertion space using the pressure ring. Furthermore, since it is not necessary to tighten all fastening connections in a manner that ensures uniform tightening torque, there is no need to manage the tightening torque of the fastening connections, and the time required for tightening the fastening connections can be shortened. Attached Figure Description

[0066] Figure 1 This is a cross-sectional view of the upper part of the pipe fitting according to the first embodiment of the present invention.

[0067] Figure 2 This is a partially enlarged sectional view of the pipe fitting's insertion port, socket, sealing member, and pressure ring, showing the situation just before the sealing member is inserted into the sealing member insertion space.

[0068] Figure 3 This is the front view of the pressure ring of the pipe fitting.

[0069] Figure 4 This is a rear view of the pressure ring of the pipe fitting.

[0070] Figure 5 yes Figure 3 XX-direction view.

[0071] Figure 6 yes Figure 3 The YY-direction view.

[0072] Figure 7 This is a cross-sectional view showing the method of joining the pipes in the pipe fitting.

[0073] Figure 8 This is a cross-sectional view showing the method of joining the pipes in the pipe fitting.

[0074] Figure 9 This is a partially enlarged cross-sectional view showing the method of joining the pipes in the pipe fitting, illustrating the initial insertion of the sealing member into the sealing member insertion space.

[0075] Figure 10 This is a partially enlarged cross-sectional view showing the method of joining the pipes in the pipe fitting, illustrating the insertion of the sealing member into the middle of the sealing member insertion space.

[0076] Figure 11 This is a partially enlarged cross-sectional view showing the method of joining the pipes in the pipe fitting, illustrating the insertion of the sealing member into the sealing member insertion space.

[0077] Figure 12 This is a diagram showing a pipe after it has been bent and joined using the pipe fitting according to the second embodiment of the present invention.

[0078] Figure 13 This is a cross-sectional view of the lower part of the pipe fitting.

[0079] Figure 14 This is a cross-sectional view showing the method of joining the pipes in the pipe fitting.

[0080] Figure 15 This is a cross-sectional view showing the method of joining the pipes in the pipe fitting. Figure 14 A portion of the image is shown in magnified form.

[0081] Figure 16 This is a cross-sectional view of the upper part of a conventional pipe fitting.

[0082] Figure 17 This is a diagram of the pipe joint viewed from the pipe axis direction of one side of the pipe.

[0083] Figure 18 This is a cross-sectional view of the upper part of the pipe fitting, showing the condition after the pressure ring is deformed.

[0084] Figure 19 This is a cross-sectional view of the lower part of the pipe fitting after the pipe has been bent and joined, showing the situation after the pressure ring has deformed. Detailed Implementation

[0085] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0086] (First Implementation)

[0087] In the first embodiment, such as Figure 1 , Figure 2 As shown, the pipe fitting 1 is configured to insert the insertion port 3 of the pipe 2 formed on one side into the receiving port 5 of the pipe 4 formed on the other side.

[0088] A first conical surface 8, a straight surface 9, a socket protrusion 10, and a locking ring receiving groove 11 are formed on the inner periphery of the socket 5. The first conical surface 8 is more constricted towards the inner side of the socket 5. The straight surface 9 is parallel to the pipe axis 13 of the pipe 4 and extends continuously from the inner end of the first conical surface 8 to the inner side of the socket 5.

[0089] A sealing member insertion space 14 is formed throughout the entire circumference between the first conical surface 8 and the outer periphery of the insertion port 3. An annular sealing member 15, which seals the inner periphery of the receiving interface 5 and the outer periphery of the insertion port 3, is inserted into the sealing member insertion space 14.

[0090] The sealing member 15 is pressed from the open end face 16 of the socket 5 into the sealing member insertion space 14, where the pressure ring 17 is externally embedded in the insertion port 3, facing the open end face 16 of the socket 5 from the outside. The pressure ring 17 is fastened to the socket 5 by a plurality of T-head bolts 19 (an example of a fastening connection) and nuts 20 (an example of a fastening connection).

[0091] Multiple bolt holes 21 are formed in the receiving interface 5 for T-head bolts 19 to be inserted.

[0092] A locking ring receiving groove 11 is formed on the inner side of the bearing interface 5, closer to the sealing member insertion space 14. A locking ring 22 is received in the locking ring receiving groove 11. The locking ring 22 is a ring with a cut-off section. The locking ring 22 has the elasticity to be expanded by using an expander (not shown) to widen the cut section, and to be reduced in diameter and restored to its original diameter by removing the expander from the cut section.

[0093] The insertion port 3 passes through the locking ring 22. An insertion port protrusion 23 is formed all around the outer periphery of the front end of the insertion port 3. The insertion port protrusion 23 can engage with the locking ring 22 from the inside of the receiving interface 5 in the disengagement direction 25 of one of the pipes 2, thereby preventing the insertion port 3 from disengaging from the receiving interface 5 in the event of an earthquake or the like.

[0094] The socket protrusion 10 protrudes inward from the inner circumference of the socket 5 in the pipe diameter direction B, and is formed throughout the entire circumference between the sealing member insertion space 14 and the locking ring receiving groove 11. A centering ring 24 is embedded between the inner circumference of the socket protrusion 10 and the outer circumference of the insertion port 3. The centering ring 24 is a ring with a cut-off section and is made of an elastic resin or similar material.

[0095] The sealing member 15 is a rubber ring, having a valve portion 26 with a circular cross-section at one end in the insertion direction C, and a base portion 27 integrally formed with the valve portion 26 and having a trapezoidal cross-section. For example... Figure 1 As shown, when the sealing member 15 is inserted into the sealing member insertion space 14, the valve part 26 is compressed in the pipe diameter direction B to perform the sealing function.

[0096] A guide portion 29, forming on the inner circumference of the socket 5, guides the valve portion 26 of the sealing member 15 from the open end face 16 of the socket 5 to the sealing member insertion space 14. The guide portion 29 has a second conical surface 30 that tapers towards the inner side of the socket 5. The second conical surface 30 is formed circumferentially throughout the socket 5 between the open end face 16 and the first conical surface 8 in the axial direction E. Figure 1 As shown, the inclination angle α2 of the second conical surface 30 relative to the tube axis 13 is greater than the inclination angle α1 of the first conical surface 8 relative to the tube axis 13.

[0097] like Figures 3-6 As shown, the pressure ring 17 is provided with a plurality of bolt insertion holes 32 (an example of fastening connector insertion holes) for T-head bolts 19 to be inserted, an annular first protrusion 33 that abuts against the open end face 16 of the bearing interface 5, a plurality of second protrusions 34 that abut against the open end face 16, and a recess 35 surrounded by the first protrusion 33.

[0098] The first protrusion 33, the second protrusion 34, and the recess 35 are formed on the mating surface side of the pressure ring 17 facing the open end face 16 of the receiving interface 5.

[0099] The first protrusion 33 is formed in the pipe diameter direction B at a position inside the bolt insertion hole 32. For example... Figure 1 , Figure 9 As shown, the other end of the base 27 of the sealing member 15 in the disengagement direction 25 is embedded in the recess 35 of the pressure ring 17.

[0100] like Figure 3 , Figure 4 As shown, the bolt insertion hole 32 and the second protrusion 34 are formed at predetermined intervals in the circumferential direction G. Furthermore, the second protrusion 34 is formed in the radial direction B at a position further outward than the bolt insertion hole 32. Figure 5As shown, the height h1 of the first protrusion 33 is the same as the height h2 of the second protrusion 34.

[0101] Multiple peripheral recesses 37 are formed on the outer periphery of the pressure ring 17, and the multiple peripheral recesses 37 are recessed inward in the pipe diameter direction B. Figure 3 , Figure 4 As shown, the outer peripheral recess 37 enters from the outer periphery of the pressure ring 17 between the bolt insertion hole 32 and the adjacent bolt insertion hole 32.

[0102] The width W1 of the pipe diameter direction B from the inner periphery to the outer periphery of the first protrusion 33 is greater than or equal to the width W2 of the pipe diameter direction B from the outer periphery of the first protrusion 33 to the outer periphery recess 37.

[0103] The inner circumferential surface 33a of the first protrusion 33 of the pressure ring 17 is a conical surface that expands in diameter as it moves towards the insertion direction C. For example... Figure 2 As shown, the diameter D2 of the end 30a of the second conical surface 30 on the side of the opening end face 16 of the receiving interface 5 is smaller than the inner diameter D1 of the first protrusion 33 of the pressure ring 17.

[0104] like Figure 1 , Figure 11 As shown, the gap 39, which is surrounded by the inner peripheral surface 33a of the first protrusion 33, the second conical surface 30, and the outer peripheral surface of the base 27 of the sealing member 15, is formed all around the circumference.

[0105] In addition, such as Figure 2 , Figure 9 As shown, when the sealing member 15 is inserted into the sealing member insertion space 14 with its outer portion embedded in the insertion port 3, the valve center portion 41 of the valve portion 26 of the sealing member 15 is located in the pipe diameter direction B, inside the end 30a of the second conical surface 30 on the side of the opening end face 16 of the bearing interface 5. Here, the valve center portion 41 refers to the central portion between the inner and outer circumferences of the valve portion 26 in the pipe diameter direction B.

[0106] The following describes the connection method of pipes 2 and 4 in the above-mentioned pipe joint 1.

[0107] First, the locking ring 22 is housed in the locking ring receiving groove 11, and the width of the cut portion of the locking ring 22 is enlarged by using a diameter expander (not shown), thereby enlarging the diameter of the locking ring 22.

[0108] Next, with the centering ring 24, sealing member 15, and pressure ring 17 externally fitted onto one of the pipes 2, the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4. At this time, since the locking ring 22 is enlarged using an expander as described above, the insertion port protrusion 23 passes through the inner circumference of the locking ring 22 from the opening end face 16 of the receiving port 5 to a position closer to the inside of the receiving port 5 than the locking ring 22.

[0109] Then, by removing the expander from the cut portion of the locking ring 22, the locking ring 22 is reduced in diameter and held tightly around the outer periphery of the insertion port 3.

[0110] Next, as Figure 7 As shown, the centering ring 24 is slid along 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 centers the insertion port 3 relative to the socket 5, so that the axis of one pipe 2 is almost offset from the axis of the other pipe 4.

[0111] Moreover, such as Figure 8 , Figure 9 As shown, the other end of the base 27 of the sealing member 15 in the disengagement direction 25 is inserted into the recess 35 of the pressure ring 17, the T-head bolt 19 is inserted into the bolt hole 21 of the socket 5 and the bolt insertion hole 32 of the pressure ring 17, the nut 20 is tightened with the T-head bolt 19, and the sealing member 15 is pressed from the open end face 16 of the socket 5 into the sealing member insertion space 14 by the pressure ring 17.

[0112] At this time, as Figure 9 , Figure 10 As shown, the valve portion 26 of the sealing member 15 is guided from the open end face 16 of the receiving interface 5 to the sealing member insertion space 14 by the second conical surface 30 of the guide portion 29.

[0113] In addition, such as Figure 9 As shown, since the valve center 41 of the sealing member 15 is located in the pipe diameter direction B, which is inside the end 30a of the second conical surface 30, when the pressure ring 17 is fastened to the socket 5, even if the sealing member 15 elongates and loosens, the valve part 26 can be reliably guided from the opening end face 16 of the socket 5 to the sealing member insertion space 14 by the second conical surface 30 of the guide part 29, and the sealing member 15 can be reliably pressed into the sealing member insertion space 14 by the pressure ring 17.

[0114] Therefore, it is not necessary to tighten all T-head bolts 19 and nuts 20 in a way that ensures uniform tightening torque, and there is no need to manage the tightening torque of T-head bolts 19 and nuts 20, which can shorten the time required for tightening T-head bolts 19 and nuts 20.

[0115] In addition, when the sealing member 15 is pressed into the sealing member insertion space 14 using the pressure ring 17, since the other end of the sealing member 15 is embedded in the recess 35 of the pressure ring 17, it is possible to prevent the other end of the sealing member 15 from shifting and curling along the pipe diameter direction B.

[0116] In addition, such as Figure 11 As shown, even if the sealing member 15 deforms outward in the pipe diameter direction B, by causing the sealing member 15 to retract toward the gap 39, it is possible to prevent the sealing member 15 from being clamped between the first protrusion 33 of the pressure ring 17 and the open end face 16 of the socket 5.

[0117] In addition, such as Figure 1 As shown, when the T-head bolt 19 is inserted into the bolt hole 21 of the socket 5 and the bolt insertion hole 32 of the pressure ring 17 and the nut 20 is tightened to secure the pressure ring 17 to the socket 5, even if an excessive tightening force is applied to the pressure ring 17, the deformation of the pressure ring 17 can be prevented because the first protrusion 33 and the second protrusion 34 respectively abut against the open end face 16 of the socket 5.

[0118] In addition, such as Figure 3 , Figure 4 As shown, since multiple peripheral recesses 37 are formed on the outer periphery of the pressure ring 17, the pressure ring 17 can be made lighter compared to a pressure ring without peripheral recesses 37.

[0119] In addition, such as Figure 3 , Figure 6 As shown, since the pressure ring 17 is configured such that the width W1 from the inner periphery of the first protrusion 33 to the outer periphery is greater than or equal to the width W2 from the outer periphery of the first protrusion 33 to the outer peripheral recess 37, the strength of the pressure ring 17 can be adequately maintained even if multiple outer peripheral recesses 37 are formed on the outer periphery of the pressure ring 17.

[0120] (Second Implementation)

[0121] In the first embodiment described above, such as Figure 1 As shown, one pipe 2 is joined straight to the other pipe 4 without bending, but in the second embodiment described below, as... Figure 12 , Figure 13 As shown, one tube 2 can also be joined to the other tube 4 while bent at a specified bending angle θ. In this case, one tube 2 is tilted such that the end on the insertion port 3 side is positioned higher than the end on the opposite side.

[0122] The construction of the pipe joint 1, which joins the pipes 2 and 4 together after bending them in this way, is similar to the construction of the pipe joint 1 in the first embodiment described earlier (see reference). Figure 1 )same.

[0123] In the pipe fitting 1 of the second embodiment, when one pipe 2 is joined to the other pipe 4, the insertion port 3 of one pipe 2 is inserted into the receiving port 5 of the other pipe 4 while the centering ring 24, the sealing member 15 and the pressure ring 17 are externally embedded in one pipe 2.

[0124] And, as Figure 14 As shown, after the centering ring 24 is slid along the tube axis direction E and inserted between the inner circumference of the receiving port protrusion 10 and the outer circumference of the insertion port 3, one tube 2 is bent relative to the other tube 4 at a specified bending angle θ.

[0125] At this time, since the insertion port 3 is supported by the centering ring 24 and bent at a specified bending angle θ, the minimum gap portion 43, which is the minimum allowable value of the gap between the outer periphery of the insertion port 3 and the inner periphery of the receiving interface 5, will be generated at the lower part of the pipe fitting 1.

[0126] In this state, the other end of the base 27 of the sealing member 15 is inserted into the recess 35 of the pressure ring 17, and the T-head bolt 19 is inserted through the bolt hole 21 of the socket 5 and the bolt insertion hole 32 of the pressure ring 17. The nut 20 is tightened with the T-head bolt 19, and the sealing member 15 is pressed from the open end face 16 of the socket 5 into the sealing member insertion space 14 by the pressure ring 17.

[0127] At this time, as Figure 15 As shown, the valve portion 26 of the sealing member 15 is guided from the open end face 16 of the receiving interface 5 to the sealing member insertion space 14 by the second conical surface 30 of the guide portion 29.

[0128] Furthermore, when the pressure ring 17 is fastened to the socket 5, even in the case of single-sided tightening where the T-head bolts 19 and nuts 20 are tightened sequentially from the upper T-head bolts 19 and 20 to the lower T-head bolts 19 and 20, the valve center portion 41 of the sealing member 15 will be located in the pipe diameter direction B at a position closer to the end 30a of the second conical surface 30. Therefore, the valve portion 26 can be reliably guided from the opening end face 16 of the socket 5 to the sealing member insertion space 14 using the second conical surface 30 of the guide portion 29, and the sealing member 15 can be reliably pressed into the sealing member insertion space 14 using the pressure ring 17.

[0129] In addition, such as Figure 13 As shown, even when the outer periphery of the bent insertion port 3 abuts against the inner periphery of the pressure ring 17, deformation of the pressure ring 17 can be prevented by having the first protrusion 33 and the second protrusion 34 abut against the opening end face 16 of the receiving interface 5, respectively.

Claims

1. A pipe fitting in which an insertion port formed on one side of a pipe is inserted into a socket formed on the other side of a pipe, wherein a first conical surface that narrows towards the inner side of the socket is formed on the inner circumference of the socket. A sealing member insertion space is formed throughout the entire circumference between the first conical surface and the outer periphery of the insertion port. An annular sealing member, which seals the inner periphery of the receiving interface and the outer periphery of the insertion port, is inserted into the sealing member insertion space. The sealing member is pressed into the insertion space of the sealing member through the open end face of the socket. The pressure ring is fitted into the insertion port and faces the open end face of the socket from the outside. The pressure ring is securely connected to the bearing interface via multiple fastening fasteners. Its features are, The sealing member has a valve portion at one end in the insertion direction, which is compressed in the pipe diameter direction to perform a sealing function. The valve portion of the sealing member is guided from the open end face of the socket to the guide portion of the sealing member insertion space, which is formed on the inner circumference of the socket. The guide section has a second conical surface that narrows in diameter as it approaches the inner side of the bearing interface. The second conical surface is formed in the direction of the tube axis between the open end face of the bearing interface and the first conical surface. The inclination angle of the second conical surface relative to the tube axis is larger than that of the first conical surface relative to the tube axis. The pressure ring is provided with a fastening connector insertion hole for fastening connectors to pass through, an annular first protrusion that abuts against the open end face of the bearing interface, and a recess surrounded by the first protrusion. The first protrusion is formed in the pipe diameter direction at a position that is more inner than the insertion hole of the fastening connector. When the sealing member is inserted into the sealing member insertion space with its outer portion already inserted into the insertion port, the other end of the sealing member in the disengagement direction is embedded into the recess of the pressure ring. The valve center of the valve part of the sealing member, located on the inner side of the end of the second conical surface on the side of the opening end face of the bearing interface in the pipe diameter direction, is between the inner and outer circumferences of the valve part. The diameter of the end of the second conical surface on the open end face of the bearing is smaller than the inner diameter of the first protrusion of the pressure ring. In the case where the minimum gap between the outer periphery of the insertion port and the inner periphery of the socket is generated by offsetting the axis of one pipe relative to the axis of the other pipe in the pipe diameter direction or by bending one pipe relative to the other pipe, the minimum gap is maintained in the minimum gap portion as follows: the valve center is located in the pipe diameter direction at a position that is more inward than the end of the socket opening face of the second conical surface.

2. The pipe fitting according to claim 1, characterized in that, The pipe joint has a gap surrounded by the inner peripheral surface of the first protrusion, the second conical surface, and the outer peripheral surface of the sealing member.

3. A pressure ring, said pressure ring being used in the pipe fitting according to claim 1 or 2, characterized in that, The pressure ring has a second protrusion that abuts against the open end face of the bearing interface. The second protrusion is formed on the outer side of the first protrusion in the pipe diameter direction.

4. The pressure ring according to claim 3, characterized in that, Multiple fastening connector through holes are formed at predetermined intervals in the circumferential direction of the pipe, and multiple second protrusions are formed at predetermined intervals in the circumferential direction of the pipe. The second protrusion is formed in the pipe diameter direction at a position further outward than the insertion hole of the fastening connector. Multiple peripheral recesses are formed on the outer periphery of the pressure ring, and these multiple peripheral recesses are recessed inward in the pipe diameter direction. The outer peripheral recess enters from the outer periphery of the pressure ring between the fastening connector insertion hole and the fastening connector insertion hole adjacent to the fastening connector insertion hole.

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

6. A method for joining pipes, which is a method for joining pipes in a pipe fitting, wherein an insertion port formed on one side of a pipe is inserted into a socket formed on the other side of a pipe, and a first conical surface that narrows towards the inner side of the socket is formed on the inner circumference of the socket. A sealing member insertion space is formed throughout the entire circumference between the first conical surface and the outer periphery of the insertion port. An annular sealing member, which seals the inner periphery of the receiving interface and the outer periphery of the insertion port, is inserted into the sealing member insertion space. The sealing member is pressed into the insertion space of the sealing member through the open end face of the socket. The pressure ring is fitted into the insertion port and faces the open end face of the socket from the outside. The pressure ring is securely connected to the bearing interface via multiple fastening fasteners. The sealing member has a valve portion at one end in the insertion direction, which is compressed in the pipe diameter direction to perform a sealing function. The valve portion of the sealing member is guided from the open end face of the socket to the guide portion of the sealing member insertion space, which is formed on the inner circumference of the socket. The guide section has a second conical surface that narrows in diameter as it approaches the inner side of the bearing interface. The second conical surface is formed in the direction of the tube axis between the open end face of the bearing interface and the first conical surface. The inclination angle of the second conical surface relative to the tube axis is larger than that of the first conical surface relative to the tube axis. The pressure ring is provided with a fastening connector insertion hole for fastening connectors to pass through, an annular first protrusion that abuts against the open end face of the socket and is formed in the pipe diameter direction at a position inside the fastening connector insertion hole, and a recess surrounded by the first protrusion. The diameter of the end of the second conical surface on the open end face of the bearing is smaller than the inner diameter of the first protrusion of the pressure ring. Its features are, With the sealing member and pressure ring externally embedded in one of the pipes, the insertion port is inserted into the socket of the other pipe. The other end of the sealing member in the disengagement direction is inserted into the recess formed in the pressure ring. With the valve center portion of the valve part of the sealing member located in the pipe diameter direction between the inner and outer circumferences, and the end of the valve center portion of the valve part located in the pipe diameter direction closer to the open end face of the second conical surface of the socket, the fastening connector is tightened. The pressure ring is used to press the sealing member from the open end face of the socket into the sealing member insertion space. In cases where the minimum clearance portion between the outer circumference of the insertion port and the inner circumference of the socket is created by offsetting the axis of one pipe relative to the axis of the other pipe along the pipe diameter direction or by bending one pipe relative to the other pipe, the clearance is within the minimum allowable range. In the minimum clearance section, the valve center of the valve section is positioned in the pipe diameter direction at an inner side of the end of the second conical surface's socket opening face.

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