Pipe connection prevention structure

Abstract

To suppress a pipe support part on one end side of a collar from lifting up due to the tightening reaction force for biting an anti-loosening claw into an outer peripheral surface of a spigot, to stabilize a separation prevention function of the anti-loosening claw.SOLUTION: An opposing portion of a collar 3 and a socket is provided with a first separation prevention part that prevents further relative separation movement in a contact manner when the socket and a spigot move relatively separately from each other by a set separation distance. A pipe support part 30D at one end side of the collar 3 in a pipe axial direction is provided with a second separation prevention part 5 that comprises a biting guide part for guiding an anti-loosening claw to a biting side as the socket and the spigot move relatively separately from each other. The collar 3 comprises a plurality of split collar bodies 30, and a fastener 31 that fastens both flange parts 30F of the split collar bodies 30 in a sealed state, which face each other in a pipe circumferential direction. On split surfaces 30G of both flange parts 30F, a metal touch surface 36 is formed at least on the one end side where the second separation prevention part 5 is present.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a pipe connection prevention structure and an assembly method thereof, in which a metal collar with a split structure that hermetically surrounds the mating connection between the insertion port of one pipe section and the receiving port of the other pipe section is fitted over both pipe sections, and a first separation prevention portion is provided at the portion facing the insertion port and the receiving port of the other pipe section in the pipe axial direction, which abuts from the pipe axial direction to prevent further relative separation when the receiving port and the insertion port move relatively apart by a set distance, and a second separation prevention portion is provided on the pipe support portion side at one end of the collar in the pipe axial direction, which has a removal prevention claw that can bite into the outer peripheral surface of the insertion port and a bite-in guide portion that guides the removal prevention claw toward the bite-in side as the receiving port and the insertion port move relatively apart. [Background technology]

[0002] In the above-mentioned pipe connection separation prevention structure, the first separation prevention section, located at the position where the collar and the socket side of the other pipe section face each other in the pipe axial direction, allows relative separation movement between the socket and the socket by a set distance when a separation force due to an earthquake, uneven settlement, etc. acts on the mating connection between the socket and the socket. This makes it possible to absorb large separation forces acting on the mating connection between the socket and the socket. At the same time, relative separation movement between the socket and the collar beyond the set separation distance can be reliably prevented, so the socket will not come loose from the pipe support section on the other end of the collar.

[0003] The second anti-detachment part's bite guide, provided on the pipe support part side at one end of the collar in the pipe axial direction, guides the anti-detachment claw toward the bite side as the socket and insertion port move relative to each other, so that the insertion port of one pipe part and the pipe support part at one end of the collar are firmly fixed together via the second anti-detachment part. This firmly prevents the socket from moving out of the pipe support part at the other end of the collar, and prevents the insertion port from moving out of the pipe support part at one end of the collar.

[0004] A conventional collar used in a structure for preventing separation of a pipe connection, as disclosed in Patent Document 1, for example, comprises a split collar body with a two-part structure that can be fitted to the insertion port and the receiving port via a packing, and bolts and nuts that fasten both flange parts of the split collar body that face each other in the circumferential direction of the pipe. A gap is formed between the split surfaces of the flange parts of the split collar body that face each other in the circumferential direction of the pipe, and by tightening the bolts and nuts, the packing is compressed to a watertight state and the anti-pullout claws are forced to bite into the outer peripheral surface of the insertion port. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4382226 Summary of the Invention [Problem to be solved by the invention]

[0006] In conventional collars, when the retaining claws bite into the outer periphery of the insertion port during the bolt and nut tightening operation, the reaction force of the retaining claws causes the pipe support portion on one end of the collar to lift up from the outer periphery of the insertion port. As a result, the separation prevention function of the retaining claws housed in the pipe support portion on one end of the collar becomes unstable, which is an inconvenience. In particular, in a separation prevention structure for a pipe connection where the second separation prevention portion is equipped with a pressure bolt that presses the retaining claws against the outer periphery of the insertion port, the reaction force of the pressure bolt tends to cause the pipe support portion on one end of the collar to lift up from the outer periphery of the insertion port.

[0007] In view of this situation, the main objective of the present invention is to provide a pipe connection part separation prevention structure and a useful assembly method that can stabilize the separation prevention function of the anti-pullout claws by rationally modifying both split joint ring bodies to suppress the lift-up of the pipe support part on one end of the joint ring caused by the tightening reaction force used to dig the anti-pullout claws into the outer peripheral surface of the insertion port, thereby preventing the anti-pullout claws from coming loose. [Means for solving the problem]

[0008] A first characteristic configuration of the present invention is a separation prevention structure for a pipe connection section, in which a metal collar having a split structure that hermetically surrounds the fitting connection section between the insertion port of one pipe section and the receiving port of the other pipe section is fitted over both pipe sections, and a first separation prevention section is provided at a portion where the collar and the receiving port side of the other pipe section face each other in the pipe axial direction, the first separation prevention section abuts from the pipe axial direction to prevent further relative separation when the receiving port and the insertion port move relatively apart by a set distance, and a pipe support section at one end of the collar in the pipe axial direction is provided with a second separation prevention section that includes a stopper claw that can bite into the outer peripheral surface of the insertion port and a bite guide section that guides the stopper claw toward the bite side as the receiving port and the insertion port move relatively apart, The joint ring comprises a plurality of split joint ring bodies that can be fitted to the insertion port and the receiving port via gaskets, and a fastening device that fastens both flange portions of the split joint ring bodies that face each other in the circumferential direction of the pipe in a sealed state, and the split surfaces of the flange portions of both split joint ring bodies that face each other in the circumferential direction of the pipe are formed with metal touch surfaces that come into surface contact by the fastening operation of the fastening device, at least on one end side where the second separation prevention portion is located.

[0009] According to the above configuration, when the flanges of the two split joint rings facing each other in the pipe circumferential direction are fastened together with a fastener, at least the metal-touch surface of the split surfaces of the flanges of the two split joint rings, on the one end side where the second separation prevention portion is located, comes into surface contact. Therefore, even if a tightening reaction force acts on the pipe support portion on the one end side of the joint ring where the second separation prevention portion is located, causing the anti-pullout claw to bite into the outer peripheral surface of the insertion port, the metal-touch surface on the one end side of the split surfaces of the flanges of the split joint ring can strongly prevent the pipe support portion on the one end side from lifting up from the outer peripheral surface of the insertion port. Therefore, by simply making a rational modification to form a metal touch surface on at least one end side of the split surface of the flange portion of the split joint ring body, it is possible to suppress the lifting of the pipe support portion on one end side of the joint ring caused by the tightening reaction force that causes the anti-pullout claw to bite into the outer peripheral surface of the insertion port, thereby stabilizing the anti-pullout claw's function of preventing separation.

[0010] A second characteristic configuration of the present invention is that the metal touch surface is formed on a portion of the divided surfaces of the two flange portions of the split joint ring body that is located away from the mounting area of ​​the gasket toward one end.

[0011] According to the above configuration, there is no metal-to-metal surface at the split surfaces of the flanges of the split joint rings in the area where the packing is to be attached. Therefore, when the flanges of the two split joint rings are fastened together with a fastener, the fastening torque can be controlled in the area where the packing is to be attached so that the packing can exhibit high sealing performance.

[0012] A third characteristic configuration of the present invention is that the metal touch surface has a first metal touch surface at a portion of the divided surfaces of both flange portions of the split joint ring body that is offset from one end side of the mounting area for the packing, and a second metal touch surface at a portion that is offset from the other end side of the mounting area for the packing, and the area of ​​the first metal touch surface is configured to be larger than the area of ​​the second metal touch surface.

[0013] According to the above configuration, when the flanges of the two split joint rings facing each other in the pipe circumferential direction are fastened together with a fastener, the split surfaces of the flanges of the two split joint rings come into surface contact with each other, with the first metal-touch surface having a larger area at one end and the second metal-touch surface having a smaller area at the other end. Therefore, the cooperation of the first and second metal-touch surfaces more effectively prevents the pipe support part at one end of the joint ring, where the second separation prevention part is located, from lifting up from the outer circumferential surface of the insertion port, even if a tightening reaction force acts on the pipe support part at one end of the joint ring, which is where the second separation prevention part is located, to force the anti-pullout claws into the outer circumferential surface of the insertion port.

[0014] The fourth characteristic configuration of the present invention is that the pipe support portion on one end side of the joint ring is provided with a claw storage portion that stores multiple anti-pullout claws along a semi-circumferential direction, and a push bolt is screwed into the claw storage portion to press each of the anti-pullout claws toward the outer surface of the insertion hole, and among the fastening bolts of the fastener, the fastening bolt located at one end of each of the two flange portions of the split joint ring body is arranged at the radially outermost part of the metal touch surface outside the operating space of the push bolt located at the end in the circumferential direction of the pipe.

[0015] According to the above configuration, the flanges of the two split joint rings facing each other in the circumferential direction of the pipe are fastened together with the fastening bolts of the fastener, and then the push bolts are screwed in to engage the retaining claws with the outer circumferential surface of the insertion port. At this time, the fastening bolts located at one end of the two flanges are located at the radially outermost part of the metal-to-metal surface outside the operating space of the push bolts located at the circumferential ends of the pipe, so that the push bolts located at the circumferential ends can be easily screwed in without being obstructed by the fastening bolts.

[0016] A fifth characteristic configuration of the present invention is that the split joint ring body is provided with a first packing groove in the pipe axial direction formed on the dividing surfaces of the two flange portions, a second packing groove in the pipe circumferential direction formed on the inner surface of the pipe support portion on one end side in a state continuous with one end of both the first packing grooves, and a third packing groove in the pipe circumferential direction formed on the inner surface of the pipe support portion on the other end side in a state continuous with the other end of both the first packing grooves, and the second packing groove is arranged overlapping in the pipe axial direction with the side wall main body portion of the side wall portion on the one end side where the second separation prevention portion of the split joint ring body is located, excluding the reinforcing rib formed on the outer surface of this portion.

[0017] According to the above configuration, when a tightening reaction force acts on the pipe support part at one end of the joint ring where the second separation prevention part is located, causing the anti-pullout claw to bite into the outer peripheral surface of the insertion port, the pipe support part at one end tries to deform in a direction that causes it to lift up from the outer peripheral surface of the insertion port, but the amount of deformation is small in the area where the side wall part at one end of the split joint ring is located. Therefore, by arranging the second packing groove overlapping in the pipe axial direction with the side wall main body part of the side wall part at one end of the split joint ring, excluding the reinforcing rib formed on the outer surface of this, it is possible to suppress fluctuations in the surface pressure of the packing part in the pipe circumferential direction of the pipe of the packing installed in the second packing groove.

[0018] A sixth characteristic feature of the present invention is that the third packing grooves are formed in two rows spaced apart from each other in the axial direction of the pipe.

[0019] According to the above configuration, the first separation prevention section, provided at the location where the collar and the socket side of the other pipe section face each other in the pipe axial direction, allows the socket and the socket to move relative to each other by a set distance when a separation force due to an earthquake, uneven settlement, or the like acts on the mating connection between the socket and the socket. Accordingly, the circumferential packing portion of the packing installed in the third packing groove of the pipe support section on the other end slides along the outer circumferential surface of the other pipe section. Because these third packing grooves are formed in two rows spaced apart in the pipe axial direction, even if the circumferential packing portion of the packing installed in one third packing groove wears and the surface pressure drops locally, the expected sealing performance can be maintained by the circumferential packing portion of the packing installed in the other third packing groove.

[0020] A seventh characteristic configuration of the present invention is a method for assembling the separation prevention structure for a pipe connection portion according to any one of the first to sixth characteristic configurations, The method comprises the steps of: a collar exteriorizing process in which the split collar body of the collar, which has the anti-pullout claw stored in a claw storage section formed in the pipe support section on one end side and a push bolt screwed in to press the anti-pullout claw in the claw storage section toward the outer surface of the insertion port, is exteriorized around both pipe sections in a state where it seals and surrounds the mating connection between the insertion port of one pipe section and the receiving port of the other pipe section; a collar fastening process in which the two flange portions of the split collar body facing each other in the pipe circumferential direction are fastened together with the fastener; and a push bolt operating process in which the push bolt is used to press the anti-pullout claw in the claw storage section into a set engagement state.

[0021] According to the above configuration, in the step of fastening the split rings after the step of sheathing the split rings, the flanges of the split rings that are sheathed over both pipe sections are fastened together with fasteners to hermetically surround the fitting connection between the insertion port and the receiving port. This allows the packings interposed between the outer circumferential surfaces of both pipe sections and the split rings to be set in a state that provides high sealing performance. Next, after the connecting ring fastening step, a pressing bolt operation step is carried out. When the pressing bolt is used to press the anti-pullout claws in the claw storage section to the set bite state, even if the tightening reaction force of the pressing bolt acts on the pipe support section on one side of the connecting ring where the second separation prevention section is located, the metal-to-metal surface on at least one side of the divided surface of the flange section of the split connecting ring body can strongly prevent the pipe support section on one side from lifting up from the outer surface of the insertion port. Therefore, while maintaining the high sealing performance of the gasket, the lifting of the pipe support part on one end of the sleeve caused by the tightening reaction force of the push bolt that digs the anti-pullout claw into the outer peripheral surface of the insertion port can be suppressed, thereby stabilizing the anti-pullout claw's function of preventing separation. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a plan view of a pipe connection portion separation prevention structure showing a first embodiment; [Figure 2] Side view of the structure to prevent detachment of the pipe connection [Figure 3] Cross-sectional view of the pipe connection separation prevention structure when assembled [Figure 4] Cross-sectional view of the anti-detachment structure of the pipe connection when it is detached [Figure 5] Front view of split joint ring body [Figure 6] VI-VI arrow view of Figure 5 [Figure 7] Arrow view of line VII-VII in Figure 5 [Figure 8] Enlarged cross-sectional view of the second separation prevention part [Figure 9] FIG. 10 is an enlarged cross-sectional view of a second separation prevention portion showing a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment of the present invention will be described with reference to the drawings. [First embodiment] 1 to 4 show a separation prevention structure for a pipe connection part used in a fluid piping system. In this separation prevention structure for a pipe connection part, an insertion port 1A of a fluid pipe 1, which is an example of one pipe part, and a socket 2A of a fluid pipe 2, which is an example of the other pipe part, are connected by a fitting connection part 20. A collar 3 having a split structure that hermetically surrounds this fitting connection part 20 is fitted over both fluid pipes 1 and 2. At the location where the bushing 3 and the receiving port 2A of the other fluid pipe 2 face each other in the pipe axis direction, as shown in Figures 3 and 4, a first separation prevention part 4 is provided which abuts from the pipe axis direction to prevent further relative separation movement when the receiving port 2A and the insertion port 1A move relative to each other by a set separation distance. As shown in Figures 3, 4 and 8, the pipe support portion 30D at one end side of the pipe axis direction of the fitting ring 3 is provided with a second removal prevention portion 5 equipped with a removal prevention claw 52 that can bite into the outer peripheral surface 1a of the insertion port 1A and a bite-in guide portion 50 that guides the removal prevention claw 52 toward the bite-in side as the receiving port 2A and the insertion port 1A move away from each other.

[0024] In the above-described structure for preventing separation of a pipe connection, fluid pipes 1 and 2 are used as an example of the pipe portion, but various types of pipe portions have been used in the past. For example, although not shown, examples include a branch pipe portion of a split T-shaped pipe with a divided structure that is fixed to the exterior of the fluid pipe in a sealed state, a branch pipe portion formed integrally with the fluid pipe and protruding, and a pipe portion that constitutes part of fluid equipment. Furthermore, the fluid pipes 1 and 2 in this embodiment are ductile cast iron pipes that constitute water pipes for transporting clean water, which is an example of a fluid, but other cast iron pipes, steel pipes, etc. can also be used. Fluids other than clean water include industrial water and gas.

[0025] As shown in Figures 3 and 4, the mating connection 20 between the outlet 1A of one fluid pipe 1 and the socket 2A of the other fluid pipe 2 is composed of a K-shaped mechanical joint. In this K-shaped mechanical joint, an annular rubber ring 21 for sealing is attached between the outer peripheral surface 1a of the outlet 1A and the tapered inner peripheral surface 2a of the socket 2A. A pressing ring 22 with a pressing portion 22a that can press the rubber ring 21 from the pipe axial direction is attached to the exterior of the outlet 1A. A flange portion 22b of the pressing ring 22 and a flange portion 2b of the socket 2A are fastened from the pipe axial direction by a first fastener 23. The first fastener 23 is composed of multiple T-head bolts 23A and nuts 23B arranged at predetermined intervals around the pipe. By the fastening operation of the first fastener 23, the rubber ring 21 is sealed (watertight) by the pressing portion 22a of the pressing ring 22 which is pulled and fixed to the flange portion 2b of the socket 2A. The seal is then compressed to maintain its tight seal.

[0026] 3 and 4, the first separation prevention portion 4 comprises a plurality of T-head bolts 23A of the first fastener 23, and a separation prevention wall portion 30e formed on the side wall portion 30C on the other end side of each split joint ring body 30 constituting the joint ring 3, at a position facing the head 23a of the T-head bolt 23A in the pipe axis direction. The bolt abutment surface on the inner side of this separation prevention wall portion 30e and the abutment surface of the head 23a of each T-head bolt 23A are each configured in a vertical plane perpendicular or approximately perpendicular to the pipe axis. When the joint ring 3 is fitted over both fluid pipes 1, 2, it is assembled so that the tip of each T-head bolt 23A abuts against the inner surface of the side wall 30B at one end of both split joint ring bodies 30. The distance between the abutting surface of the head 23a of the T-head bolt 23A at the time of this assembly and the abutting surface of the separation prevention wall 30e on the side wall 30C at the other end becomes the set separation distance that allows relative separation movement between the insertion port 1A and the receiving port 2A.

[0027] 3 and 4, when a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection 20 between the spigot 1A and the socket 2A, the fitting connection 20 allows relative separation movement between the spigot 1A and the socket 2A up to a set separation distance. This makes it possible to absorb large separation forces acting on the fitting connection 20 between the spigot 1A and the socket 2A. At the same time, relative separation movement between the socket 2A and the joint ring 3 that exceeds the set separation distance can be reliably prevented by the heads 23a of the T-head bolts 23A of the fitting connection 20 abutting against the separation prevention wall 30e on the side wall 30C on the other end side of both split joint ring bodies 30.

[0028] As shown in Figures 3, 4 and 8, the second separation prevention section 5 is provided with a claw storage section 51 formed in the pipe support section 30D on one end side of both split joint ring bodies 30 so as to open radially inward, a plurality of anti-pullout claws 52 stored in the claw storage section 51 along the circumferential direction of the pipe, and a push bolt 53 that presses each of the anti-pullout claws 52 toward the outer surface 1a of the insertion port 1A. Claw portions 52a with triangular cross sections extending along the pipe circumferential direction are formed at two locations on the inner peripheral surface of the retention claw 52 in the pipe axial direction. A pressed surface 52b in the center of the outer surface of the retention claw 52 in the pipe circumferential direction is formed as an inclined surface whose diameter increases toward the socket 2A side. A screw hole 54 is formed in the ceiling wall 51a of the claw storage section 51 in a direction perpendicular to the pressed surface 52b of the retention claw 52. A pressing bolt 53 is screwed into this screw hole 54. The inclined surface of the anti-pullout claw 52, ​​which is the pressed surface 52b, and the tip of the push bolt 53 that abuts against this from a direction perpendicular to it form a biting guide portion 50 that guides the anti-pullout claw 52 toward the biting side by a wedge effect as the receiving port 2A and the insertion port 1A move away from each other.

[0029] 1 to 4, the collar 3 is made of a cast iron split collar 30 having a two-part structure that can be freely fitted over both fluid pipes 1 and 2 while surrounding the fitting connection portions 20 of both fluid pipes 1 and 2. Both split collars 30 are formed to have the same shape. As shown in Figures 1 to 4, the split joint ring 30 primarily comprises a semi-cylindrical peripheral wall 30A with a diameter larger than that of the socket 2A, semi-annular side walls 30B and 30C extending radially inward from both ends of the peripheral wall 30A in the pipe axis direction, and semi-cylindrical tube support members 30D and 30E extending radially outward from the inner diameter ends of each side wall 30B and 30C in the pipe axis direction. The side wall 30B at one end, which faces the socket 1A, is vertically oriented perpendicular or nearly perpendicular to the pipe axis. The side wall 30C at the other end, which faces the socket 2A, is tapered, gradually decreasing in diameter toward the tube support member 30E.

[0030] As shown in Figures 1, 2, and 1 to 4, flanges 30F that protrude horizontally outward are integrally formed at both circumferential ends of both split joint rings 30 of the joint ring 3. The flanges 30F of both split joint rings 30 are fixedly connected in a sealed (watertight) state by fastening second fasteners 31 equipped with a plurality of fastening bolts 31A and nuts 31B. As shown in Figures 3 to 5, both split joint rings 30 are provided with annular packings 33 that seal an enclosed space 32 formed between the inner peripheral surface 30a of the joint ring 3 and the outer peripheral surfaces 1a, 2c of both fluid pipes 1, 2 including the fitting connection portion 20 in a watertight state.

[0031] As shown in FIGS. 3 to 5, the packing 33 is fitted into annular packing grooves 35 formed in each of the split joint ring bodies 30. As shown in FIGS. The packing grooves 35 include a first packing groove 35A formed along the pipe axis on the dividing surfaces 30G of both flange portions 30F; a second packing groove 35B formed along the pipe circumferential direction on the inner surface of the pipe support portion 30D on one end facing the semi-peripheral surface of the insertion port 1A; and two third packing grooves 35C formed along the pipe circumferential direction at a distance from each other along the pipe axis on the inner surface of the pipe support portion 30E on the other end facing the semi-peripheral surface of the fluid pipe 2 on the receiving port 2A side. Both pipe circumferential ends of the second packing groove 35B are continuous with one end of both first packing grooves 35A. Both pipe circumferential ends of the two third packing grooves 35C are continuous with the other end of both first packing grooves 35A.

[0032] As an overall view of the packing 33 is omitted, the packing will be described with the reference numerals also attached to the packing grooves 35 in Fig. 6. The packing 33 is configured by integrally molding a first packing portion 33A along the pipe axis direction that is fitted into both first packing grooves 35A, a second packing portion 33B along the pipe circumferential direction on one end side that is fitted into second packing grooves 35B, and a third packing portion 33C along the pipe circumferential direction on the other end side that is fitted into two third packing grooves 35C.

[0033] The first separation prevention member 4, located at the axially opposing positions of the collar 3 and the socket 2A of the other fluid pipe 2, allows relative separation movement between the socket 1A and the socket 2A by a set distance when a separation force due to an earthquake, uneven settlement, or the like acts on the mating connection 20 between the socket 1A and the socket 2A. Accordingly, the third packing portion 33C of the packing 33 attached to the third packing groove 35C of the pipe support portion 30E on the other end slides along the outer circumferential surface 2c of the other fluid pipe 2. Because the third packing groove 35C and the third packing portion 33C are formed in two rows spaced apart in the axial direction, even if one third packing portion 33C wears or deforms, causing a localized decrease in surface pressure, the other third packing portion 33C can maintain the intended sealing performance.

[0034] The second packing groove 35B of the packing groove 35 is arranged overlapping the side wall body 30B on the one end side where the second separation prevention portion 5 of the split joint ring body 30 is located, excluding the reinforcing rib 30b formed on the outer surface thereof, in the pipe axial direction.

[0035] When the tightening reaction force of the push bolt 53 that presses the retaining claws 52 into the outer peripheral surface 1a of the insertion opening 1A acts on the pipe support portion 30D at one end of each of the split joint rings 30, the pipe support portion 30D at one end tends to deform in a direction that causes it to lift up from the outer peripheral surface 1a of the insertion opening 1A, but the amount of deformation is small in the area where the side wall portion 30B at one end of the split joint ring 30 is located. Therefore, by arranging the second packing groove 35B to overlap in the pipe axial direction with the side wall main body portion of the side wall portion 30B at one end of the split joint ring 30, excluding the reinforcing rib 30b formed on the outer surface of this, it is possible to suppress fluctuations in the surface pressure of the second packing portion 33B of the packing 33 attached to the second packing groove 35B.

[0036] 2 and 6, the split surfaces 30G of both flange portions 30F of the split joint ring body 30 are provided with metal-to-metal surfaces 36, which are in surface contact with each other when the multiple fastening bolts 31A and nuts 31B constituting the second fastener 31 are fastened, at least at one end where the second separation prevention portion 5 is present. The area of ​​the metal-to-metal surfaces 36 is indicated by a light gray pattern in FIG. 6.

[0037] When the flange portions 30F of both split joint rings 30 facing each other in the pipe circumferential direction are fastened together with the second fasteners 31, at least the metal touch surfaces 36 of the split surfaces 30G of the flange portions 30F of both split joint rings 30 on one end side where the second separation prevention portion 5 is located come into surface contact. Therefore, even if the tightening reaction force of the push bolt 53 for driving the anti-pullout claws 52 into the outer peripheral surface 1a of the insertion port 1A acts on the pipe support portion 30D on one end side of both split joint rings 30 where the second separation prevention portion 5 is located, the metal touch surfaces 36 on at least one end side of the split surfaces 30G of the flange portions 30F of both split joint rings 30 can strongly prevent the pipe support portion 30D on one end side from lifting up from the outer peripheral surface 1a of the insertion port 1A. Therefore, by simply making a rational modification to form a metal touch surface 36 on at least one end side of the split surface 30G at the flange portion 30F of both split joint ring bodies 30, it is possible to suppress the lifting of the pipe support portion 30D on one end side of the joint ring 3 caused by the tightening reaction force of the push bolt 53, thereby stabilizing the separation prevention function of the anti-pullout claw 52 and maintaining stable sealing properties.

[0038] In this embodiment, as shown in Figures 2 and 5, the metal touch surface 36 is composed of a first metal touch surface 36A at a portion of the split surface 30G of both flange portions 30F of the split joint ring body 30 that is offset from the mounting area of ​​the first packing portion 33A of the packing 33 (hereinafter referred to as the packing mounting area) to one end side in the pipe axis direction, and a second metal touch surface 36B at a portion that is offset from the packing mounting area to the other end side in the pipe axis direction. Specifically, the first metal touch surface 36A is formed at a location offset toward one end from the claw storage portion 51 formed in the pipe support portion 30D on one end side of both split joint ring bodies 30. The second metal touch surface 36B is formed at a location offset toward the other end from the third packing portion 33C. The area of ​​the first metal touch surface 36A is configured to be larger than the area of ​​the second metal touch surface 36B on the other end side.

[0039] 2 and 5, the portion of the split surfaces 30G of the flange portions 30F of both split joint rings 30 that is located between the first metal touch surface 36A and the second metal touch surface 36B is configured as a non-contact surface 37. Therefore, when the flange portions 30F of both split joint rings 30 are fastened together with the second fasteners 31, a gap is generated between the non-contact surfaces 37 of the split surfaces 30G of both flange portions 30F that face each other in the pipe circumferential direction in the packing installation area.

[0040] When the flange portions 30F of the two split joint rings 30 facing each other in the pipe circumferential direction are fastened together with the second fasteners 31, the first metal touch surface 36A with a large area on one end and the second metal touch surface 36B with a small area on the other end of the split surfaces 30G of the flange portions 30F of the two split joint rings 30 come into surface contact. Therefore, the cooperation of the first metal touch surface 36A and the second metal touch surface 36B more effectively prevents the pipe support portion 30D on one end of the two split joint rings 30 from lifting up from the outer peripheral surface 1a of the insertion port 1A, even if the tightening reaction force of the push bolt 53 that presses the retaining claws 52 into the outer peripheral surface 1a of the insertion port 1A acts on the pipe support portion 30D on one end of the two split joint rings 30.

[0041] Furthermore, the portion of the split surface 30G on the flange portion 30F of each of the split joint rings 30 that corresponds to the packing installation area is configured as a non-contact surface 37. Therefore, when the flange portions 30F of each of the split joint rings 30 are fastened with the second fastener 31, the portion that corresponds to the packing installation area can be set to an appropriate compressed state in which the packing 33 exhibits high sealing performance by controlling the torque of the fastening force.

[0042] A plurality of bolt insertion holes 38 for the fastening bolts 31A of the second fastener 31 are formed in the flange portions 30F of both split joint ring bodies 30. In the packing attachment region between the first metal touch surface 36A and the second metal touch surface 36B, a plurality of bolt insertion holes 38 are arranged at a predetermined pitch along the pipe axial direction. Two bolt insertion holes 38 are arranged in the first metal touch surface 36A along the pipe radial direction, at positions spaced toward one end from the screw holes 54 for the press bolts 53 formed in the ceiling wall 51a of the claw storage section 51. Of these, the bolt insertion hole 38 located on the outermost side in the pipe radial direction of the first metal touch surface 36A is located in a position radially outward from the operation space of the press bolts 53 located at the end in the pipe circumferential direction.

[0043] Then, the flange portions 30F of the two split joint ring bodies 30 facing each other in the pipe circumferential direction are fastened together with the fastening bolts 31A and nuts 31B of the second fasteners 31, and then the press bolts 53 are screwed in to engage the retaining claws 52 into the outer peripheral surface 1a of the insertion port 1A. At this time, the fastening bolts 31A and nuts 31B at one end of the two flange portions 30F and located on the outermost side in the pipe diameter direction of the first metal touch surface 36A are positioned radially outward from the operating space of the press bolts 53 located at the end in the pipe circumferential direction. As a result, when the press bolts 53 located at the end in the circumferential direction are rotated with a rotary operating tool such as a box wrench, the rotary operating tool does not interfere with the fastening bolts 31A and nuts 31B located on the outermost side in the pipe diameter direction of the first metal touch surface 36A, and the press bolts 53 can be easily screwed in without being hindered by the fastening bolts 31A and nuts 31B.

[0044] Next, a method for assembling the connection portion separation prevention structure will be described. In this method, the steps of preparing the collar 3, the collar exterior mounting step, the collar fastening step, and the push bolt operation step are carried out in this order. (1) Preparation process for the connecting ring 3 Packings 33 are fitted into the packing grooves 35 of both split joint ring bodies 30 that make up the joint ring 3, and a plurality of retaining claws 52 are housed along the circumferential direction of the pipe in the claw storage section 51 of the pipe support section 30D on one end side. A press bolt 53 is screwed into a screw hole 54 formed in the ceiling wall 51a of the claw storage section 51.

[0045] (2) Ring exterior process The two split joint ring bodies 30 of the joint ring 3 are fitted over both fluid pipes 1, 2 in a state where they hermetically surround the mating connection 20 between the insertion port 1A of one fluid pipe 1 and the socket port 2A of the other fluid pipe 2. At this time, the ends of the T-head bolts 23A of the first fasteners 23 are assembled in a state where they abut against the inner surface of the side wall portion 30B on one end side of both split joint ring bodies 30. The distance between the abutting surface of the head 23a of the T-head bolt 23A at the time of this assembly and the abutting surface of the separation prevention wall portion 30e on the side wall portion 30C on the other end side becomes the set separation distance that allows relative separation movement between the insertion port 1A and the socket port 2A.

[0046] (3) Collar fastening process Next, the flange portions 30F of the two split joint rings 30, which face each other in the circumferential direction of the pipe, are fastened together using the fastening bolts 31A and nuts 31B of the second fasteners 31. This fastening operation brings the split surfaces 30G of the flange portions 30F of the two split joint rings 30, the first metal-touch surface 36A with a large area at one end and the second metal-touch surface 36B with a small area at the other end, into surface contact. Because the non-contact surface 37 is formed between the first metal-touch surface 36A and the second metal-touch surface 36B at this split surface 30G, a gap is generated between the non-contact surface 37 corresponding to the packing installation area. Therefore, when fastening the flange portions 30F of the two split joint rings 30 with the second fasteners 31, the packing 33 is set to an appropriate compressed state to provide high sealing performance in the area corresponding to the packing installation area by torque management of the fastening force.

[0047] (4) Push bolt operation process The tip of the pressing bolt 53 screwed into each screw hole 54 in the ceiling wall 51a of the claw storage section 51 abuts perpendicularly against the pressed surface 52b, which is the inclined surface of the retaining claw 52. Each pressing bolt 53 in this abutting state is screwed in toward the tightening side, and the retaining claw 52 in the claw storage section 51 is set to the set biting state. Even if the tightening reaction force of the push bolt 53 acts, the cooperation of the first metal touch surface 36A and the second metal touch surface 36B can more effectively prevent the pipe support portion 30D on one end side of both split joint ring bodies 30 from floating up from the outer peripheral surface 1a of the insertion port 1A. Therefore, while maintaining the high sealing performance of the gasket 33, the lifting up of the pipe support portion 30D on one end side of the two split joint ring bodies 30 caused by the tightening reaction force of the push bolt 53 for driving the anti-pullout claw 52 into the outer peripheral surface 1a of the insertion port 1A can be suppressed, thereby stabilizing the detachment prevention function of the anti-pullout claw 52.

[0048] The pipe support portion 30D on one end side of each split joint ring 30, and the end inner peripheral surface 30d located closer to the one end than the claw storage portion 51, are configured as a tapered surface with a larger diameter toward the one end. This is to accommodate curved joints.

[0049] Second Embodiment 9 shows an improved screw structure for the press bolt 53 of the second separation prevention section 5. In this screw structure, a blind hole 60 without a female thread, through which the press bolt 53 can be freely inserted, is formed in the ceiling wall 51a of the claw storage section 51 in the pipe support section 30D on one end side of both split joint ring bodies 30. A screw storage section 62 is formed in communication with the blind hole 60 at a portion on the inner side in the pipe diameter direction, and stores a screw member 61 with a female thread (not shown) that screws into the press bolt 53 in a detachable but non-rotatable state.

[0050] In this embodiment, a JIS-compliant hexagonal nut is used as the screw member 61. The screw storage section 62 has a first passage section 62A that opens perpendicular to the pipe axis with a passage width slightly larger than the diagonal distance of the hexagonal nut, and a second passage section 62B that is inclined perpendicular to the center line of the through hole 60 at the rear of the first passage section 62A. The vertical inner wall surface 62a of the first passage section 62A on the side wall section 30B side and the inclined inner wall surface 62b of the second passage section 62B on the side wall section 30B side are bent in a dogleg shape. The hexagonal nut is inserted vertically from the first passage section 62A and rotates within the second passage section 62B into an installed position along the inner surface of the ceiling wall 51a. In this installed position, the hexagonal nut is locked and secured at or near the bend between the vertical inner wall surface 62a and the inclined inner wall surface 62b.

[0051] For example, when forming threaded holes 54 in the ceiling wall 51a of the claw storage section 51 as in the first embodiment, the threaded holes 54 are inclined relative to the pipe axis and multiple threaded holes are formed at a predetermined pitch around the pipe of the pipe support section 30D of the split joint ring 30. This requires highly accurate positioning of the heavy pipe support section 30D using a special jig and threading. This requires a large number of steps for threading, increasing the cost of the split joint ring 30. However, in the second embodiment described above, it is sufficient to simply form a blind hole 60 in the ceiling wall 51a of the claw storage section 51 and store a screw member 61, such as a hexagonal nut, in the screw storage section 62 that communicates with the blind hole 60. This eliminates the need for a special jig for threading and reduces the number of steps, thereby reducing the cost of the split joint ring 30. The other configurations are the same as those described in the first embodiment, so the same components are denoted by the same numbers as in the first embodiment and the description thereof will be omitted.

[0052] Other Embodiments (1) In each of the above-described embodiments, a K-type mechanical joint is used as an example of the fitting connection 20 between the inlet 1A of one fluid pipe 1 and the socket 2A of the other fluid pipe 2. However, a push-on type T-type mechanical joint may also be used, which can be joined simply by attaching a rubber ring 21 to the inner surface of the socket 2A and inserting the tapered inlet 1A.

[0053] (2) In each of the above-described embodiments, the metal touch surface 36 is composed of a first metal touch surface 36A at a location offset from the packing mounting area toward one end in the pipe axis direction, and a second metal touch surface 36B at a location offset from the packing mounting area toward the other end in the pipe axis direction, but it may also be implemented with only the first metal touch surface 36A. Furthermore, the entire split surface 30G of the flange portion 30F of each of the split joint ring bodies 30 may be formed as the metal touch surface . [Explanation of symbols]

[0054] 1. One pipe section (fluid pipe) 1A socket 1a Outer surface 2. The other pipe section (fluid pipe) 2A socket 3 Collars 4 1st disengagement prevention part 5 Second disengagement prevention part 30 Split joint ring body 30D pipe support part 30F flange 30G split plane 31 Fastener (second fastener) 31A Fastening bolt 33 Gasket 35 packing groove 35A First packing groove 35B Second packing groove 35C 3rd packing groove 36 Metal touch surface 36A 1st metal touch surface 36B Second metal touch surface 50 Biting guide part 51 Claw storage section 52 Anti-pullout claw 53 Push Bolt

Claims

1. a metal collar having a split structure that hermetically surrounds the fitting connection between the insertion port of one pipe section and the receiving port of the other pipe section, the metal collar having a split structure being fitted over both pipe sections, the metal collar having a split structure that hermetically surrounds the fitting connection between the insertion port of one pipe section and the receiving port of the other pipe section, the metal collar ... The flanges of the flanges are arranged in a sealed manner around the pipe, and the flanges of the flanges are arranged in a sealed manner around the pipe. The split joint ring is provided with a semi-cylindrical peripheral wall portion having a diameter larger than that of the receiving port, a semi-annular side wall portion extending integrally from one end side of the peripheral wall portion radially inward, and a semi-cylindrical pipe support portion extending integrally from the inner diameter side end of the side wall portion to one end side and constituting the pipe support portion at one end side of the joint ring, and the divided surfaces of both flange portions of the split joint ring facing each other in the pipe circumferential direction are formed with metal touch surfaces that come into surface contact by the fastening operation of the fastener, at least at the one end side where the second separation prevention portion is present, and the metal touch surfaces are not formed at the divided surfaces of the both flange portions of the split joint ring corresponding to the installation area of ​​the packing, The pipe support portion on one end side of the connecting ring is provided with a claw storage portion that stores multiple anti-pullout claws circumferentially around the pipe, and a push bolt is screwed into the claw storage portion to press each of the anti-pullout claws toward the outer peripheral surface of the insertion port.The inner peripheral surface of the pipe support portion on one end side of the connecting ring, which is adjacent to the claw storage portion and closer to the one end than the claw storage portion, is a tapered surface with a larger diameter toward the one end, thereby preventing separation of the pipe connection portion.

2. The split joint ring includes: a first packing groove formed in the dividing surface of each of the flange portions in the pipe axial direction; a second packing groove formed in the pipe circumferential direction on the inner surface of the pipe support portion on one end side in a state continuous with one end of each of the first packing grooves; and a third packing groove formed in the pipe circumferential direction on the inner surface of the pipe support portion on the other end side in a state continuous with the other end of each of the first packing grooves, 2. The pipe connection part separation prevention structure according to claim 1, wherein the second packing groove is located on the inner peripheral surface of the pipe support part on one end side of the connecting ring, closer to the other end side than the claw housing part.

3. The second packing groove is located within the wall thickness of the side wall main body, excluding the reinforcing rib formed on the outer surface of the side wall portion on the one end side where the second separation prevention portion of the split joint ring is located, in the pipe axial direction, and is arranged overlapping with the side wall main body.

Images