CN118119786A - Compression ring, pipe joint, and pipe joining method - Google Patents

Abstract

A compression ring (20) is provided in a pipe joint (1), in which a seal member (15) is inserted between the outer periphery of a socket (3) and the inner periphery of a socket (5), the compression ring is externally fitted to the socket (3) and faces the open end face (21) of the socket (5) from the outside, and the seal member (15) is pressed into the inner side of the socket (5) by connecting a plurality of fasteners (22, 23) to the socket (5). The pressure ring (20) has: a pressing surface (36) for pressing the sealing member (15); a plurality of fastener insertion holes (37) through which fasteners (22) are inserted; a contact part (38) which is in contact with the opening end surface (21) of the socket (5); and a tapered surface (47) formed on the inner periphery (41) of the pressure ring. The tapered surface (47) expands in diameter as it approaches the opposite side from the side closer to the pressing surface (36) to the side farther from the pressing surface.

Description

Compression ring, pipe joint, and pipe joining method

Technical Field

The present invention relates to a press ring for a pipe joint having a socket and a spigot, a pipe joint provided with the press ring, and a pipe joining method using the press ring.

Background

Conventionally, in such a pipe joint, for example, as shown in fig. 31, a socket 112 of a first pipe 111 is inserted into a socket 114 of a second pipe 113. A rubber seal member 115 is interposed between the outer periphery of the socket 112 and the inner periphery of the mouthpiece 114. The pressing ring 116 is externally fitted to the socket 112 and faces an open end surface 117 of the socket 114 from the outside. The press ring 116 is coupled to the socket 114 by a plurality of bolts 118 and nuts 119.

The pressing ring 116 has an annular main body 116a, a pressing surface 120 that presses the sealing member 115 by abutting against the sealing member 115, abutting portions 121 and 122 that abut against the opening end surface 117 of the socket 114, and a plurality of bolt insertion holes 123 through which bolts 118 are inserted. By tightening the nut 119 to the bolt 118, the pressing surface 120 of the pressing ring 116 presses the seal member 115 between the outer periphery of the socket 112 and the inner periphery of the socket 114.

As for the pressure ring 116 and the pipe joint 110, japanese patent application laid-open No. 2021-67282 can be referred to.

Disclosure of Invention

Problems to be solved by the invention

In the conventional form described above, when the plurality of pipes 111 and 113 are joined to each other to form the bent pipe 130 as shown in fig. 32, the pipes 111 and 113 are joined to each other in a state in which the pipe axis 111a of the first pipe 111 is inclined with respect to the pipe axis 113a of the second pipe 113 as shown in fig. 33.

However, as shown in fig. 33, the pressing ring 116 has a corner 128 where the inner periphery 116b of the pressing ring 116 intersects with the surface 126 on the opposite side of the pressing surface 120. When the outer periphery of the first tube 111 comes into contact with the corner 128, it is difficult to further increase the inclination angle α of the tube axis 111a of the first tube 111 with respect to the tube axis 113a of the second tube 113.

In addition, when the diameter (inner diameter) of the inner periphery 116b of the pressure ring 116 is increased, the inclination angle α can be increased, but in this case, the gap 129 (see fig. 31) between the inner periphery 116b of the pressure ring 116 and the outer periphery of the first pipe 111 is also increased. Therefore, the seal member 115 is easily inserted into the gap 129 from the pressing surface 120 of the pressing ring 116, and the seal member 115 may not be sufficiently inserted between the outer periphery of the socket 112 and the inner periphery of the socket 114.

The invention aims to provide a compression ring, a pipe joint and a pipe joining method, wherein the inclination angle of the pipe joint when the pipes are joined obliquely can be increased, and a sealing member can be sufficiently inserted between the outer periphery of a socket and the inner periphery of a bell mouth.

Means for solving the problems

The present invention provides a press ring provided in a pipe joint in which a socket is inserted into a socket and a seal member is inserted between an outer periphery of the socket and an inner periphery of the socket, the press ring being externally fitted into the socket so as to face an opening end face of the socket from an outside, and the press ring being coupled to the socket by a plurality of fasteners so as to press the seal member into a back side of the socket, the press ring comprising:

a pressing surface that presses the sealing member;

A plurality of fastener insertion holes through which fasteners are inserted;

a contact portion that contacts an opening end surface of the socket; and

A tapered surface formed on an inner periphery of the pressure ring,

The tapered surface expands in diameter as it approaches the opposite side from the pressing surface.

Thus, the socket is inserted into the socket in a state in which the pipe axis of the socket of the first pipe is inclined with respect to the pipe axis of the socket of the second pipe, and the fastener is inserted into the fastener insertion hole of the press ring and tightened. Thereby, the pressure ring and the socket can be coupled, and the sealing member can be inserted between the outer periphery of the socket and the inner periphery of the socket, so that the first pipe and the second pipe can be joined.

In this case, since the tapered surface is formed on the inner periphery of the pressure ring, the contact portion in the case where the outer periphery of the first pipe contacts the inner periphery of the pressure ring is a portion closer to the pressure surface than the corner portion of the surface opposite to the pressure surface of the inner periphery of the pressure ring. Thus, the inclination angle of the pipe axis of the first pipe with respect to the pipe axis of the second pipe when the outer periphery of the first pipe is in contact with the inner periphery of the pressing ring can be increased. Therefore, in the case where a plurality of pipes are joined to each other so as to form a curved pipeline, it is not necessary to form each pipe to be short, and therefore the number of pipes can be reduced.

Further, since it is not necessary to increase the inner diameter of the pressure ring in order to increase the inclination angle, the gap between the inner periphery of the pressure ring and the outer periphery of the first pipe does not increase, and the entry of the seal member into the gap from the pressing surface of the pressure ring can be suppressed. Thereby, the seal member can be sufficiently inserted between the outer periphery of the socket and the inner periphery of the socket.

According to the present invention, it is preferable that the pressing ring has an inner peripheral surface formed on the inner periphery, the inner peripheral surface having a constant inner diameter, and being located closer to the pressing surface than the tapered surface.

Thus, when the socket is inserted into the socket in a state where the pipe axis of the socket of the first pipe is inclined with respect to the pipe axis of the socket of the second pipe, the first pipe is joined to the second pipe, and the outer periphery of the first pipe is not in contact with the inner periphery of the pressing surface of the pressing ring, but in contact with the boundary portion between the inner periphery of the pressing ring and the tapered surface. This can prevent the inner peripheral edge of the pressing surface of the pressure ring from being damaged, and the sealing member can be sufficiently inserted between the outer periphery of the socket and the inner periphery of the socket by the pressing surface of the pressure ring.

According to the press ring of the present invention, it is preferable that the contact portion is provided so as to surround at least the periphery of each fastener insertion hole.

Thus, the contact portion is in contact with the opening end face of the socket, and the interval from the pressing surface to the opening end face of the socket is maintained at a predetermined interval. In this case, even if the fastener is excessively tightened to apply an excessive tightening force to the press ring, the press ring can be prevented from being deformed around the fastener insertion hole.

According to the press ring of the present invention, the contact portion is preferably provided in a region from the periphery of the pressing surface to the outer periphery of the press ring in the radial direction except for the fastener insertion hole.

Thus, even if the fastener is excessively tightened to apply an excessive tightening force to the press ring, the press ring can be prevented from being deformed in a region from the outer peripheral edge of the pressing surface to the outer peripheral edge of the press ring.

According to the press ring of the present invention, it is preferable that the contact portion has a first contact portion and a second contact portion,

The first contact portion is a first convex portion located radially outside the fastener insertion hole,

The second contact portion is a second convex portion which is located radially inward of the fastener insertion hole and formed so as to surround the periphery of the pressing surface,

A recess into which an end portion of the seal member can be fitted is formed on the inner side in the radial direction of the second contact portion.

Thus, the first contact portion and the second contact portion of the pressing ring are brought into contact with the opening end face of the socket, and the interval from the pressing surface to the opening end face of the socket is maintained at a predetermined interval. When the pressing ring presses the sealing member between the outer periphery of the socket and the inner periphery of the socket, the end portion of the sealing member is fitted into the concave portion of the pressing ring, and therefore the end portion of the sealing member is fixed to the pressing ring without being displaced in the radial direction. Thus, the seal member can be reliably inserted between the outer periphery of the socket and the inner periphery of the socket.

The pipe joint with the compression ring is characterized in that a sealing surface which reduces the diameter towards the inner side of the socket is formed on the inner periphery of the socket,

A seal member insertion space is formed over the entire circumference between the seal surface and the outer periphery of the socket,

The sealing member is inserted into the sealing member insertion space,

The end of the sealing member in the insertion direction has a valve portion compressed in the pipe diameter direction to perform a sealing function,

A guide surface for guiding the valve portion of the sealing member from the opening end of the socket toward the sealing member insertion space is formed on the inner periphery of the socket,

The guide surface is a tapered surface which reduces in diameter as it goes toward the inner side of the socket, is formed between the opening end surface of the socket and the sealing surface in the tube axis direction,

The guide surface has a larger inclination angle with respect to the pipe axis than the seal surface.

Thus, 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 by the guide surface from the opening end of the socket toward the seal member insertion space. In this way, even when the fastener is fastened on one side to stretch and loosen the seal member when the pressing ring is fastened to the socket, the valve portion of the seal member is guided by the guide surface from the opening end surface of the socket toward the seal member insertion space, and therefore the seal member can be reliably pressed into the seal member insertion space by the pressing ring.

According to the pipe joint of the present invention, it is preferable that the fastener insertion hole of the pressure ring is located at a position closer to the outer side of the pressure ring main body in the radial direction than the pressing surface,

The contact portion of the press ring is provided in a region from the periphery of the pressing surface to the outer periphery of the press ring in the radial direction of the press ring main body except for the fastener insertion hole,

The pressing surface is formed in the recess surrounded by the contact portion,

The end of the sealing member is fitted into the recess of the pressure ring.

Thus, when the pressing ring presses the seal member into the seal member insertion space, the end portion of the seal member is fitted into the concave portion of the pressing ring, and is fixed to the pressing ring without being displaced in the radial direction. Thus, the seal member can be reliably inserted into the seal member insertion space.

According to the pipe joint of the present invention, it is preferable that a gap is formed which is surrounded by an inner peripheral surface of the contact portion of the pressure ring, a guide surface of the socket, and an outer peripheral surface of the seal member.

Thus, even if the seal member is deformed outward in the radial direction when the seal member is pushed into the seal member insertion space by the pressing ring, the seal member is retracted into the gap, and the seal member can be prevented from being sandwiched between the contact portion of the pressing ring and the opening end surface of the socket.

According to the pipe joint of the present invention, it is preferable that the diameter of the end portion of the guide surface on the opening end surface side of the socket is smaller than the inner diameter of the contact portion of the pressure ring.

Thus, when the seal member is pressed into the seal member insertion space by the pressing ring, the gap formed between the seal member and the guide surface becomes smaller. Therefore, even when the fastener is fastened on one side when the pressure ring is fastened to the socket, the seal member can be prevented from tilting due to the fastening on one side, and the seal member can be prevented from being sandwiched between the contact portion of the pressure ring and the opening end surface of the socket.

According to the pipe joint of the present invention, it is preferable that in a state where the socket is inserted into the socket, the pipe axis of either one of the socket and the socket is inclined with respect to the pipe axis of the other,

A sealing member is interposed between the outer periphery of the socket and the inner periphery of the mouthpiece,

The compression ring is externally embedded in the socket and is opposite to the opening end face of the socket from the outer side, and is connected with the socket through a plurality of fasteners,

The pressing surface of the pressing ring is abutted with the sealing component,

The fastener is inserted into the fastener insertion hole of the compression ring.

The method for joining pipes using the pressure ring according to the present invention is characterized in that the socket is inserted into the socket in a state in which one of the socket and the socket is inclined with respect to the other,

The press ring is coupled to the socket by inserting and tightening the fastener through the fastener insertion hole of the press ring, and the seal member is inserted between the outer periphery of the socket and the inner periphery of the socket.

According to this joining method, the socket is inserted into the socket in a state where the pipe axis of either one of the socket and the socket is inclined with respect to the pipe axis of the other, before the seal member is inserted between the outer periphery of the socket and the inner periphery of the socket, so that the force required for inclining the socket with respect to the socket is reduced.

As another joining method other than the above-described joining method of pipes, for example, first, the socket is inserted into the socket in a state where one pipe axis of the socket and the socket is aligned with respect to the other pipe axis, not inclined. Next, a sealing member is inserted between the outer periphery of the socket and the inner periphery of the mouthpiece. Then, either one of the socket and the spigot can be tilted with respect to the other. However, in such other joining methods, after the seal member is inserted between the outer periphery of the socket and the inner periphery of the socket, one of the socket and the socket is tilted against the seal member with respect to the other, and therefore there is a problem in that a large force is required when tilting one of the socket and the socket with respect to the other.

Effects of the invention

As described above, according to the present invention, the inclination angle at which the pipes are joined obliquely to each other can be increased, and the seal member can be sufficiently inserted between the outer periphery of the socket and the inner periphery of the socket.

Drawings

Fig. 1 is a cross-sectional view of a pipe joint according to a first embodiment of the present invention.

Fig. 2 is an enlarged partial cross-sectional view of the pipe joint.

Fig. 3 is an enlarged partial cross-sectional view of the pipe joint, showing a state immediately before the sealing member is inserted between the inner periphery of the socket and the outer periphery of the spigot.

Fig. 4 is an enlarged partial cross-sectional view of the socket of the pipe joint.

Fig. 5 is a front view of the compression ring of the pipe joint.

Fig. 6 is a rear view of the compression ring of the pipe joint.

Fig. 7 is an X-X cross-sectional view of fig. 5.

Fig. 8 is a Y-Y cross-sectional view of fig. 5.

Fig. 9 is a cross-sectional view showing a method of joining pipes of the pipe joint, and shows a case where a seal member is pressed between an inner periphery of a socket and an outer periphery of a spigot by a pressing ring.

Fig. 10 is a cross-sectional view showing a case where the sealing member of the pipe joint is deformed outward and retreated toward the gap.

Fig. 11 is a cross-sectional view showing a method of joining pipes of the pipe joint, and shows a case where a seal member is pressed between an inner periphery of a socket and an outer periphery of a spigot by a pressing ring.

Fig. 12 is a cross-sectional view showing a method of joining pipes of the pipe joint, and shows a case where a seal member is pressed between an inner periphery of a socket and an outer periphery of a spigot by a pressing ring.

Fig. 13 is a cross-sectional view showing a reference example of the first embodiment of the present invention, in which a seal member is pressed between the inner periphery of a socket and the outer periphery of a socket by a pressing ring.

Fig. 14 is a cross-sectional view showing this reference example, and shows a case where a seal member is pressed between the inner periphery of the socket and the outer periphery of the spigot by a pressing ring.

Fig. 15 is a cross-sectional view of a pipe joint according to a second embodiment of the present invention.

Fig. 16 is an enlarged front view of a part of the pressure ring of the pipe joint.

Fig. 17 is a partially enlarged front view of a compression ring of a pipe joint according to a third embodiment of the present invention.

Fig. 18 is a cross-sectional view of a pipe joint according to a fourth embodiment of the present invention.

Fig. 19 is a front view of the socket of the pipe joint.

Fig. 20 is a front view of the compression ring of the pipe joint.

Fig. 21 is a perspective view of a compression ring of the pipe joint.

Fig. 22 is an X-X cross-sectional view of fig. 20.

Fig. 23 is a Y-Y sectional view of fig. 20.

Fig. 24 is a cross-sectional view of a pipe joint according to a fifth embodiment of the present invention.

Fig. 25 is a front view of the compression ring of the pipe joint.

Fig. 26 is a rear view of the compression ring of the pipe joint.

Fig. 27 is a Z-Z cross-sectional view in fig. 25.

Fig. 28 is a perspective view of the front side of the pressure ring of the pipe joint.

Fig. 29 is a perspective view of the back side of the pressure ring of the pipe joint.

Fig. 30 is a schematic view showing a case of pipe joining work performed in a groove formed in the ground.

Fig. 31 is a cross-sectional view of a conventional pipe joint, showing a case where pipes are joined in a straight line.

Fig. 32 is a view of a bent pipe line formed by joining a plurality of pipes.

Fig. 33 is a cross-sectional view of the pipe joint, showing a state in which pipes are joined in an inclined state to each other.

Detailed Description

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

(First embodiment)

In the first embodiment, as shown in fig. 1 to 3, a pipe joint 1 has a socket 3 formed in a first pipe 2 and a socket 5 formed in a second pipe 4, and the socket 3 is inserted into the socket 5.

A tapered sealing surface 8, a socket projection 10, and a lock ring receiving groove 11, which reduce in diameter as going to the inner side of the socket 5, are formed on the inner periphery of the socket 5. A seal member insertion space 14 is formed over the entire circumference between the seal surface 8 and the outer circumference of the socket 3. An annular sealing member 15 sealing between the inner periphery of the socket 5 and the outer periphery of the spigot 3 is inserted into the sealing member insertion space 14. The seal member 15 is a rubber ring, and has a valve portion 16 provided at one end in the insertion direction 18 and a base portion 17 integrally provided with the valve portion 16.

The valve portion 16 is circular in cross section. The base 17 is trapezoidal in cross section. In a state where the seal member 15 is inserted into the seal member insertion space 14, the valve portion 16 is compressed in the radial direction 19 to perform a sealing function.

The socket 5 has a plurality of bolt holes 25 through which the T-head bolts 22 are inserted.

The lock ring receiving groove 11 is formed at a position on the inner side of the socket 5 than the seal member insertion space 14. The lock ring 26 is accommodated in the lock ring accommodation groove 11. The lock ring 26 is a ring of a split structure in which one portion in the circumferential direction is cut. The lock ring 26 has elasticity such that the width of the cut portion is enlarged by an expander (not shown) to expand the diameter, and the diameter is reduced and returned to the original diameter by removing the expander from the cut portion.

The socket 3 penetrates the sealing member 15, the locking ring 26 and the support ring 29. A socket protrusion 27 is formed on the outer periphery of the distal end portion of the socket 3 over the entire circumference. The socket projection 27 can engage with the lock ring 26 from the inner side of the socket 5 in the disengaging direction 28 of the first pipe 2. Thereby, the socket 3 is prevented from being detached from the socket 5 when an earthquake or the like occurs.

The receiving protrusion 10 protrudes inward in the radial direction 19, and is formed over the entire circumference between the seal member insertion space 14 and the lock ring housing groove 11. The support ring 29 is fitted to the socket 3, and is disposed between the inner periphery of the socket protrusion 10 and the outer periphery of the socket 3, and adjacent to the lock ring 26. The support ring 29 is a ring of a one-divided structure in which one portion in the circumferential direction is cut, and is made of a material such as a resin having elasticity.

A guide surface 31 for guiding the valve portion 16 of the seal member 15 from the opening end surface 21 of the socket 5 to the seal member insertion space 14 is formed on the inner periphery of the socket 5. The guide surface 31 is a tapered surface that reduces in diameter as it goes toward the inner side of the socket 5, and is formed over the entire circumference between the opening end surface 21 of the socket 5 and the seal surface 8 in the tube axis direction 50. As shown in fig. 4, the inclination angle B of the guide surface 31 with respect to the pipe axis 4a of the second pipe 4 is larger than the inclination angle C of the sealing surface 8 with respect to the pipe axis 4 a.

The seal member 15 is fitted to the socket 3 from the outside of the socket 5 to the opening end surface 21 of the socket 5 by the pressing ring 20 pressed from the opening end surface 21 of the socket 5 to the inside of the socket 5. The press ring 20 is connected to the socket 5 in the circumferential direction via a plurality of T-head bolts 22 (one example of a fastener) and nuts 23 (one example of a fastener).

As shown in fig. 5 to 8, the pressing ring 20 includes an annular main body 35, a pressing surface 36 for pressing the seal member 15, a plurality of bolt insertion holes 37 (an example of fastener insertion holes) through which the T-head bolts 22 are inserted, and a contact portion 38 that contacts the opening end surface 21 of the socket 5. The pressing ring 20 has a plurality of protruding portions 40 protruding radially outward on the outer peripheral portion. The pressing surface 36 is formed in an annular shape along the inner periphery 41 of the pressing ring 20.

Each bolt insertion hole 37 is located between the pressing surface 36 and the outer peripheral edge 39 of the pressing ring 20 in the radial direction 19 of the pressing ring 20. The protruding portion 40 is disposed so as to correspond to the bolt insertion hole 37.

The contact portion 38 is provided over the entire region from the periphery of the pressing surface 36 to the outer peripheral edge 39 of the pressing ring 20 in the radial direction 19 of the pressing ring 20 except for the bolt insertion hole 37. Here, the periphery of the pressing surface 36 is the largest diameter portion of the inner peripheral surface 44 of the contact portion 38 described below. The pressing surface 36 is formed in a recess 43 surrounded by the contact portion 38, and is recessed a distance from the surface of the contact portion 38 in the thickness direction 55 of the pressing ring 20. The inner peripheral surface 44 of the contact portion 38 is a tapered surface that expands in diameter as it goes toward the insertion direction 18 (see fig. 3). The contact portion 38 and the recess 43 are formed on one surface side of the pressing ring 20 facing the opening end surface 21 of the socket 5.

As shown in fig. 2, the base 17 (end) of the seal member 15 is fitted into the recess 43 of the pressure ring 20. A gap 45 surrounded by the inner peripheral surface 44 of the contact portion 38 of the pressure ring 20, the guide surface 31 of the socket 5, and the outer peripheral surface of the base 17 of the seal member 15 is formed over the entire circumference.

As shown in fig. 3, the diameter D2 of the guide surface 31 at the opening end surface 21 of the socket 5 is smaller than the inner diameter D1 of the contact portion 38 of the press ring 20.

As shown in fig. 6 to 8, tapered surfaces 47 and inner peripheral surfaces 48 are formed on the entire inner periphery 41 of the pressure ring 20. The tapered surface 47 expands in diameter from the side closer to the pressing surface 36 toward the opposite side away from the pressing surface 36, and reaches a surface 49 on the opposite side from the pressing surface 36.

The inner circumferential surface 48 has a constant inner diameter d, is parallel to the tube axis 4a of the second tube 4, and is formed with a predetermined width W in the tube axis direction 50. The inner peripheral surface 48 is located closer to the pressing surface 36 than the tapered surface 47, and reaches the pressing surface 36.

A method of joining the pipes 2 and 4 using the pressure ring 20 will be described below.

First, the compression ring 20, the seal member 15, and the support ring 29 are fitted to the socket 3 of the first pipe 2, the lock ring 26 is mounted in the lock ring receiving groove 11 of the socket 5 of the second pipe 4, and the lock ring 26 is expanded in diameter by using an expander (not shown).

Then, the socket 3 is inserted into the socket 5 in a state where the pipe axis 2a of the socket 3 is inclined with respect to the pipe axis 4a of the socket 5. At this time, since the lock ring 26 is expanded in diameter, the spigot 27 passes through the inner periphery of the lock ring 26 toward the inside of the socket 5.

Then, by removing the expander (not shown), the lock ring 26 is contracted to be held tightly around the outer periphery of the socket 3.

Next, as shown in fig. 9, the support ring 29 is moved in the pipe axis direction 50 and inserted into the socket 5, adjacent to the lock ring 26. The seal member 15 is moved in the tube axial direction 50 so as to be positioned in front of the opening end surface 21 of the socket 5.

Then, the T-head screw 22 is inserted into the bolt hole 25 of the socket 5 and the screw insertion hole 37 of the press ring 20. Then, the nut 23 is screwed with the T-head screw 22, and the nut 23 is tightened until the contact portion 38 of the pressing ring 20 abuts against the opening end surface 21 of the socket 5.

As a result, as shown in fig. 1 and 2, the pressure ring 20 is coupled to the socket 5, and the pressing surface 36 of the pressure ring 20 presses the seal member 15 and is inserted into the seal member insertion space 14, whereby the first pipe 2 and the second pipe 4 are joined in a state where the pipe axis 2a of the socket 3 is inclined with respect to the pipe axis 4a of the socket 5.

The structure of the pipe joint 1 and the operation and effects of the joining method of the pipes 2 and 4 will be described below.

As shown in fig. 1 to 3, 7, and 8, since the tapered surface 47 and the inner peripheral surface 48 are formed on the inner periphery 41 of the pressure ring 20, when the outer periphery of the first pipe 2 abuts against the inner periphery 41 of the pressure ring 20, the outer periphery of the first pipe 2 abuts against the boundary portion 51 between the tapered surface 47 and the inner peripheral surface 48. The boundary portion 51 is located closer to the pressing surface 36 than the corner 52 of the surface 49 opposite to the pressing surface 36 of the inner periphery 41 of the pressing ring 20. Therefore, the inclination angle α (see fig. 1) of the pipe axis 2a of the first pipe 2 with respect to the pipe axis 4a of the second pipe 4 when the outer periphery of the first pipe 2 is in contact with the inner periphery 41 of the pressure ring 20 can be increased. In this way, when a plurality of pipes are joined to each other in an inclined manner to form a curved pipeline (see fig. 32), a plurality of shorter pipes are not required, and therefore the number of pipes can be reduced.

Since the inclination angle α can be increased as described above, even when the pipe line is buckled by an earthquake or the like, the first pipe 2 and the second pipe 4 can be buckled at a large inclination angle α. This can reduce the load applied to the pressure ring 20.

The outer periphery of the first pipe 2 is not in contact with the inner peripheral edge 53 (see fig. 7 and 8) of the pressing surface 36 of the pressure ring 20, and is in contact with the boundary portion 51 as shown in fig. 2, so that damage to the inner peripheral edge 53 of the pressing surface 36 can be prevented. Thereby, the seal member 15 can be sufficiently inserted into the seal member insertion space 14 by the pressing surface 36 of the pressing ring 20.

There is no need to increase the inner diameter d of the pressure ring 20 (i.e., the inner diameter d of the inner peripheral surface 48) in order to increase the inclination angle α. Therefore, the gap 54 (see fig. 1) between the inner peripheral surface 48 of the inner periphery 41 of the pressure ring 20 and the outer periphery of the first pipe 2 is not widened, and the entry of the seal member 15 into the gap 54 from the pressing surface 36 of the pressure ring 20 can be suppressed. Thereby, the seal member 15 can be sufficiently inserted into the seal member insertion space 14.

As shown in fig. 2, the contact portion 38 of the pressing ring 20 contacts the opening end surface 21 of the socket 5, so that the interval from the pressing surface 36 of the pressing ring 20 to the opening end surface 21 of the socket 5 is maintained at a predetermined interval.

At this time, even if excessive tightening force is applied to the press ring 20 by excessively tightening the T-head screw 22 and the nut 23, the press ring 20 can be prevented from being deformed over the entire region from the outer peripheral edge 42 of the pressing surface 36 to the outer peripheral edge 39 of the press ring 20.

As shown in fig. 9, when the seal member 15 is pressed into the seal member insertion space 14 using the press ring 20, the end portion of the seal member 15 is fitted into the recess 43 of the press ring 20, and is thus fixed to the press ring 20 without being displaced in the radial direction 19. Thereby, the sealing member 15 can be reliably inserted into the sealing member insertion space 14.

When the seal member 15 is pressed into the seal member insertion space 14 by the pressing ring 20, the valve portion 16 of the seal member 15 is guided from the opening end surface 21 of the socket 5 to the seal member insertion space 14 by the guide surface 31.

When the T-head bolt 22 and the nut 23 are fastened to each other from above to below in this order when the pressure ring 20 is coupled to the socket 5, the valve portion 16 is guided from the opening end surface 21 of the socket 5 to the seal member insertion space 14 by the guide surface 31 even if the seal member 15 is stretched and loosened, and therefore the seal member 15 can be reliably pushed into the seal member insertion space 14 by the pressure ring 20.

Accordingly, it is unnecessary to perform tightening so that tightening torques of all the T-bolts 22 and nuts 23 become uniform, and it is unnecessary to manage tightening torques of the T-bolts 22 and nuts 23, so that it is possible to shorten the time required for tightening the T-bolts 22 and nuts 23.

When the seal member 15 is pressed into the seal member insertion space 14 by the pressing ring 20, as shown in fig. 10, even if the seal member 15 is deformed outward in the radial direction 19, the seal member 15 can retreat toward the gap 45. This prevents the seal member 15 from being sandwiched between the contact portion 38 of the pressure ring 20 and the opening end surface 21 of the socket 5.

According to the above-described pipe joining method, as shown in fig. 9, the socket 3 is inserted into the socket 5 in a state where the pipe axis 2a of the first pipe 2 is inclined with respect to the pipe axis 4a of the second pipe 4 before the seal member 15 is inserted into the seal member insertion space 14. Therefore, the force required to tilt the socket 3 with respect to the socket 5 may be small.

Instead of the above-described pipe joining method, other joining methods may be performed as follows. That is, first, the socket 3 is inserted into the socket 5 in a state where the pipe axis 2a of the first pipe 2 is aligned with the pipe axis 4a of the second pipe 4, not inclined. Next, the sealing member 15 is inserted into the sealing member insertion space 14. Then, the pipe axis 2a of the first pipe 2 may be inclined with respect to the pipe axis 4a of the second pipe 4. However, in such other joining method, after the sealing member 15 is inserted into the sealing member insertion space 14, the socket 3 (the first pipe 2) is tilted with respect to the socket 5 (the second pipe 4) against the sealing member 15, so there is a problem that the force required to tilt the socket 3 is large.

Since the diameter D2 of the end portion of the guide surface 31 at the opening end surface 21 of the socket 5 is smaller than the inner diameter D1 of the contact portion 38 as shown in fig. 3, the gap 56 formed between the seal member 15 and the guide surface 31 becomes smaller when the seal member 15 is pressed into the seal member insertion space 14 by the pressing ring 20 as shown in fig. 11.

Therefore, when the T-head bolt 22 and the nut 23 are fastened on one side when the pressure ring 20 is fastened to the socket 5, as shown in fig. 12, even if the pressed sealing member 15 retreats toward the gap 56, the sealing member 15 can be prevented from tilting due to the fastening on one side. This prevents the seal member 15 from being sandwiched between the contact portion 38 of the pressure ring 20 and the opening end surface 21 of the socket 5.

As a reference example, as shown in fig. 13, if the relationship between the inner diameter D1 of the contact portion 38 and the diameter D2 of the end portion of the guide surface 31 is reversed, that is, if the diameter D2 is larger than the inner diameter D1, the gap 56 formed between the seal member 15 and the guide surface 31 increases when the seal member 15 is pressed into the seal member insertion space 14 by the pressing ring 20.

Therefore, when the T-head screw 22 and the nut 23 are fastened on one side at the time of connecting the compression ring 20 to the socket 5, as shown in fig. 14, the pressed sealing member 15 is retracted toward the gap 56, and the sealing member 15 may tilt, so that the inner peripheral surface of the sealing member 15 may be separated from the outer peripheral surface of the socket 3 in the radial direction 19. When the seal member 15 is tilted in this way, a problem is likely to occur in that the seal member 15 is sandwiched between the contact portion 38 of the pressing ring 20 and the opening end surface 21 of the socket 5.

(Second embodiment)

In the second embodiment, as shown in fig. 15 and 16, a plurality of annular contact portions 38 surrounding the periphery of each bolt insertion hole 37 are formed in the pressing ring 20.

Thus, the contact portion 38 contacts the opening end surface 21 of the socket 5, and the interval from the pressing surface 36 to the opening end surface 21 of the socket 5 is maintained at a predetermined interval. At this time, even if the T-head screw 22 and the nut 23 are excessively tightened to apply an excessive tightening force to the pressing ring 20, the pressing ring 20 can be prevented from being deformed around the bolt insertion hole 37.

(Third embodiment)

In the third embodiment, as shown in fig. 17, the contact portion 38 is formed in an annular shape so as to surround the periphery of each bolt insertion hole 37, and is also formed in the region between the bolt insertion hole 37 and its adjacent bolt insertion hole 37 in the circumferential direction 57.

Accordingly, even if the T-head screw 22 and the nut 23 are excessively tightened to apply an excessive tightening force to the pressing ring 20, the pressing ring 20 can be prevented from being deformed in the region between the bolt insertion hole 37 and the adjacent bolt insertion hole 37.

(Fourth embodiment)

A fourth embodiment will be described below with reference to fig. 18 to 23. As shown in fig. 18, the socket 5 has a flange portion 5a at the tip end. The flange 5a has a plurality of bolt holes 25. For example, in fig. 19, eight bolt holes 25 are formed in the flange portion 5a at equal angular distributions.

The pressing ring 20 has an annular main body 35, a pressing surface 36 for pressing the seal member 15, a plurality of (e.g., eight) bolt insertion holes 37 through which the T-head bolts 22 are inserted, and a first contact portion 81 and a second contact portion 82 that contact the opening end surface 21 of the socket 5.

As shown in fig. 20 to 23, the first contact portion 81 is a plurality of protruding portions provided in the press ring 20 and located outside the bolt insertion holes 37 in the radial direction 19 of the press ring 20.

The second contact portion 82 is a convex portion which is located inside the bolt insertion holes 37 in the radial direction 19 of the pressing ring 20 and is formed in an annular shape so as to surround the periphery of the pressing surface 36. A recess 43 into which the base 17 (end portion) of the seal member 15 can be fitted is formed on the inner side in the radial direction 19 of the second contact portion 82.

As a result, as shown in fig. 18, the first contact portion 81 and the second contact portion 82 of the pressing ring 20 are brought into contact with the opening end surface 21 of the socket 5, and the interval from the pressing surface 36 to the opening end surface 21 of the socket 5 is maintained at a predetermined interval. When the pressing ring 20 presses the seal member 15 into the seal member insertion space 14, the end portion of the seal member 15 is fitted into the recess 43 (see fig. 22 and 23) of the pressing ring 20, and therefore the end portion of the seal member 15 is fixed to the pressing ring 20 without being displaced in the radial direction 19. Thereby, the sealing member 15 can be reliably inserted into the sealing member insertion space 14.

(Fifth embodiment)

The fifth embodiment will be described below with reference to fig. 24 to 30. The pressure ring 20 has equally spaced areas 86 and enlarged spaced areas 87. In the uniform interval region 86, the interval between the bolt insertion holes 37 in the circumferential direction 57 is kept at the uniform interval S1. In the enlarged spacing region 87, the spacing S2 between any two adjacent bolt insertion holes 37 is enlarged as compared with the above-described uniform spacing S1.

For example, in fig. 25 and 26, seven bolt insertion holes 37, one less than the number of bolt holes 25 (eight (see fig. 19)) of the flange portion 5a of the socket 5, are formed in the press ring 20. The distribution angle E1 of each bolt insertion hole 37 in the uniform interval region 86 is 45 °. The distribution angle E2 of the two bolt insertion holes 37 in the enlarged spacing area 87 is 90 °.

A circular arc-shaped reinforcing member 88 is provided on the surface 49 of the pressing ring 20 opposite to the pressing surface 36. The reinforcing member 88 is provided across between the adjacent two bolt insertion holes 37 in the enlarged spacing region 87. As shown in fig. 27, the reinforcing member 88 is located outside the inner peripheral surface 48 of the pressure ring 20 in the radial direction 19.

As shown in fig. 24 to 26, the pressure ring 20 is connected to the socket 5 so that the enlarged spacing area 87 is located immediately below the first pipe 2. As shown in fig. 30, the pipes 2 and 4 are joined together in the groove 90 formed by digging the ground 89, and at this time, the bottom 91 of the groove 90 becomes an obstacle that hinders the joining operation of the pipes 2 and 4. That is, the pressing ring 20 is coupled to the socket 5 by the plurality of T-head bolts 22 and nuts 23 in a state where the enlarged spacing area 87 faces the bottom 91 of the groove 90.

Hereinafter, the operation of the above structure will be described.

As shown in fig. 25, 26, and 30, the enlarged spacing area 87 of the press ring 20 is located directly below the first pipe 2, and therefore the bolt insertion hole 37 of the enlarged spacing area 87 is located at a position that is not located directly below the first pipe 2 and is distributed in the circumferential direction 57 of the press ring 20 than directly below the first pipe 2. Accordingly, the vertical distance H between the bolt insertion hole 37 of the enlarged space area 87 and the bottom 91 of the groove 90 increases, and therefore, even if the working space between the press ring 20 and the bottom 91 of the groove 90 is narrow, the workability in joining the pipes 2 and 4 can be improved.

Further, since the enlarged spacing region 87 of the pressure ring 20 is held to be sufficiently rigid by the reinforcing member 88, even if the reaction force of the seal member 15 acts on the pressure ring 20, the enlarged spacing region 87 of the pressure ring 20 can be prevented from being deflected by the reaction force. Further, when the T-head screw 22 is inserted into the bolt insertion hole 37 of the enlarged spacing area 87 of the press ring 20 and the bolt hole 25 of the socket 5 and tightened with the nut 23, even if a high stress is generated between the two bolt insertion holes 37 of the enlarged spacing area 87, the enlarged spacing area 87 can be prevented from being deformed or damaged.

In the fifth embodiment, as shown in fig. 25 and 26, seven bolt insertion holes 37 are formed in the pressing ring 20, but the number is not limited to seven. For example, the number of bolt insertion holes 37 of the press ring 20 having 12 bolt insertion holes 37 shown in fig. 5 and 6 as the first embodiment may be reduced by one, and 11 bolt insertion holes 37 may be formed in the press ring 20.

In the first to fifth embodiments described above, the pipe joint 1 is shown in which the socket 3 is joined in a state of being inclined with respect to the spigot 5 as shown in fig. 1 and 24, but the pipe joint 1 may be joined in a state in which the spigot 5 is inclined with respect to the socket 3. The pressure ring 20 according to the first to fifth embodiments may be used in a pipe joint in which the socket 3 and the spigot 5 are joined in a straight line without being inclined.

In the first to fifth embodiments described above, the tapered surface 47 and the inner peripheral surface 48 are formed on the inner periphery 41 of the pressing ring 20, but only the tapered surface 47 may be formed without forming the inner peripheral surface 48.

In the first to fourth embodiments, the intervals between the bolt insertion holes 37 of the press ring 20 are all kept at equal intervals, but the press ring 20 of the first to fourth embodiments may be replaced with the press ring 20 having the equal interval regions 86 and the enlarged interval regions 87 shown in fig. 25 and 26 of the fifth embodiment.

Claims (11)

1. A pressure ring provided in a pipe joint, in which a socket is inserted into a socket and a sealing member is inserted between an outer periphery of the socket and an inner periphery of the socket, the pressure ring being externally fitted into the socket so as to face an opening end face of the socket from an outside, and the pressure ring being connected to the socket by a plurality of fasteners so as to press the sealing member into an inner side of the socket,

The pressure ring has:

a pressing surface that presses the sealing member;

A plurality of fastener insertion holes through which fasteners are inserted;

a contact portion that contacts an opening end surface of the socket; and

A tapered surface formed on an inner periphery of the pressure ring,

The tapered surface expands in diameter as it approaches the opposite side from the pressing surface.

2. The pressure ring of claim 1, wherein the pressure ring comprises a plurality of pressure rings,

The pressure ring has an inner peripheral surface formed on an inner periphery,

The inner peripheral surface has a constant inner diameter and is located closer to the pressing surface than the tapered surface.

3. A pressure ring as claimed in claim 1 or 2, characterized in that,

The contact portion is provided so as to surround at least the periphery of each fastener insertion hole.

4. A compression ring according to claim 3, wherein,

The contact portion is provided in a region from the periphery of the pressing surface to the outer periphery of the pressing ring in the radial direction except for the fastener insertion hole.

5. A pressure ring as claimed in claim 1 or 2, characterized in that,

The contact portion has a first contact portion and a second contact portion,

The first contact portion is a convex portion located radially outside the fastener insertion hole,

The second contact portion is a convex portion which is located radially inward of the fastener insertion hole and formed so as to surround the periphery of the pressing surface,

A recess into which an end portion of the seal member can be fitted is formed on the inner side in the radial direction of the second contact portion.

6. A pipe joint provided with the pressure ring as claimed in claim 1, characterized in that,

A sealing surface which reduces in diameter towards the inner side of the socket is formed on the inner periphery of the socket,

A seal member insertion space is formed over the entire circumference between the seal surface and the outer periphery of the socket,

The sealing member is inserted into the sealing member insertion space,

The end of the sealing member in the insertion direction has a valve portion compressed in the pipe diameter direction to perform a sealing function,

A guide surface for guiding the valve portion of the sealing member from the opening end of the socket toward the sealing member insertion space is formed on the inner periphery of the socket,

The guide surface is a tapered surface which reduces in diameter as it goes toward the inner side of the socket, is formed between the opening end surface of the socket and the sealing surface in the tube axis direction,

The guide surface has a larger inclination angle with respect to the pipe axis than the seal surface.

7. A pipe joint according to claim 6, wherein,

The fastener insertion hole of the pressing ring is positioned at a position closer to the outer side of the pressing surface in the radial direction of the pressing ring main body,

The contact portion of the press ring is provided in a region from the periphery of the pressing surface to the outer periphery of the press ring in the radial direction of the press ring main body except for the fastener insertion hole,

The pressing surface is formed in the recess surrounded by the contact portion,

The end of the sealing member is fitted into the recess of the pressure ring.

8. A pipe joint according to claim 7, wherein,

The pipe joint is formed with a gap surrounded by an inner peripheral surface of a contact portion of the pressure ring, a guide surface of the socket, and an outer peripheral surface of the seal member.

9. A pipe joint according to claim 8, wherein,

The diameter of the end of the guide surface on the opening end surface side of the socket is smaller than the inner diameter of the contact portion of the pressing ring.

10. Pipe joint according to any one of claims 6 to 9, characterized in that,

In a state where the socket is inserted into the socket, the pipe axis of either the socket or the socket is inclined with respect to the pipe axis of the other,

A sealing member is interposed between the outer periphery of the socket and the inner periphery of the mouthpiece,

The compression ring is externally embedded in the socket and is opposite to the opening end face of the socket from the outer side, and is connected with the socket through a plurality of fasteners,

The pressing surface of the pressing ring is abutted with the sealing component,

The fastener is inserted into the fastener insertion hole of the compression ring.

11. A method of joining pipes using the press ring according to claim 1, characterized in that,

The socket is inserted into the socket in a state that the pipe axis of either one of the socket and the socket is inclined relative to the pipe axis of the other,

The press ring is coupled to the socket by inserting and tightening the fastener through the fastener insertion hole of the press ring, and the seal member is inserted between the outer periphery of the socket and the inner periphery of the socket.