JP7543500B2 - Pipe connection part has a structure to prevent separation - Google Patents

Description

The present invention relates to a structure for preventing separation of a pipe connection, in which a joint ring of a split structure that surrounds in a sealed state the fitting 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 separation movement prevention means is provided at the portion that faces the joint ring and the receiving port of the other pipe section in the pipe axial direction to prevent the relative separation movement between the receiving port and the joint ring beyond a certain level.

The pipe attachment structure shown in Patent Document 1 is an example of a structure for preventing the above-mentioned pipe connection from coming loose. In this pipe attachment structure, the fitting connection between the insertion port of one pipe section and the receiving port of the other pipe section is composed of a K-shaped mechanical joint. In this mechanical joint, a sealant such as a rubber ring is attached between the outer peripheral surface of the insertion port and the tapered inner peripheral surface of the receiving port, and the flange portion of the pressing ring, which has a pressing portion that can press the sealant from the axial direction of the pipe, and the flange portion of the receiving port are tightened and connected with bolts and nuts. This tightening connection compresses the sealant into a watertight state by the pressing portion of the pressing ring, which is pulled and fixed to the flange portion of the receiving port, and maintains that watertight state.

In addition, the connecting ring of a split structure that surrounds the mechanical joint, which is the mating connection part, in a sealed state has as its main components a cylindrical peripheral wall portion having a larger diameter than the receiving port, annular side wall portions extending radially inwardly from both ends of the peripheral wall portion in the pipe axial direction, and pipe support portions extending integrally outwardly along the pipe axial direction from the inner diameter side ends of each side wall portion.
The inner peripheral surfaces of both pipe support parts of the collar are provided with seal parts fitted with a seal material that seals between the inner peripheral surfaces of both pipe parts.

The separation movement prevention means is configured so that the inner diameter of the pipe support part on the other end side of the joint ring, which is the receiving port side, is smaller than the maximum outer diameter of the tapered part of the receiving port, and when the insertion port and the receiving port are separated, the pipe support part on the other end side of the joint ring abuts against the tapered part of the receiving port from the tube axis direction, preventing further separation movement.

A separation prevention part with a split structure having a locking member that bites into the outer peripheral surface is clamped and fixed to the outer peripheral surface of the insertion port located inside the joint ring, and the outer diameter of this separation prevention part is formed to be larger than the inner diameter of the pipe support part on one end side of the joint ring that is the insertion port side, so that when the insertion port and the receiving port are separated, the separation prevention part clamped and fixed to the insertion port abuts against the pipe support part on one end side of the joint ring from the pipe axis center direction, preventing further separation movement.

JP 2016-138637 A

In the pipe attachment structure shown in Patent Document 1, when the insertion port and the receiving port are separated, the separation prevention part clamped and fixed to the insertion port only contacts the pipe support part on one end of the collar from the pipe axial direction, and does not have the function of preventing bending between the insertion port and the pipe support part on one end of the collar. Therefore, when the insertion port and the receiving port are separated, the insertion port and the pipe support part on one end of the collar bend significantly, causing a localized decrease in the circumferential sealing ability of the seal part provided on the inner surface of the pipe support part on one end of the collar, resulting in the inconvenience of fluid leakage from the area where the sealing ability has decreased.

In view of this situation, the main objective of the present invention is to provide a structure for preventing separation of a pipe connection that can reliably restrict further separation movement when the insertion port and the receiving port are separated, while maintaining the bending state between the insertion port and the pipe support portion on one end of the joint ring within an appropriate range, thereby suppressing fluid leakage caused by localized deterioration of the sealing ability in the circumferential direction of the seal portion.

A first characteristic feature of the present invention is a separation prevention structure for pipe connection parts, in which a joint ring of a split structure surrounding in a sealed state a fitting connection part between an insertion port of one pipe part and a receiving port of the other pipe part is fitted over both pipe parts, and a separation movement prevention means is provided at a portion facing the joint ring and the receiving port side of the other pipe part in the pipe axial direction for abutting against the receiving port and the joint ring to prevent relative separation movement between the receiving port and the joint ring beyond a certain level,
One of the pipe sections is provided with a reinforcing and fixing means of a split structure which includes a connecting section which is fixedly connected to the pipe support section at one end in the pipe axial direction of the joint ring which is externally supported by the connecting section, and a pull-out prevention section which increases in resistance to pull-out between the connecting section and the outer peripheral surface of the insertion hole as the insertion hole moves away from the pipe support section at one end of the joint ring.

According to the above configuration, when a separation force due to an earthquake, uneven subsidence, etc. acts on the fitting connection between the insertion port and the receiving port, the separation movement prevention means provided at opposing positions in the pipe axial direction between the receiving port side of the other pipe part and the connecting ring can abut and prevent relative separation movement between the receiving port of the other pipe part and the connecting ring beyond a certain level.
Between the insertion hole of one of the pipe sections and the joint ring, a connecting portion of the reinforcing means having a split structure provided at the insertion hole is fixedly connected to the pipe support portion at one end of the joint ring. Furthermore, the anti-pullout resistance of the anti-pullout portion of the reinforcing means increases between the outer circumferential surface of the insertion hole as the insertion hole moves away from the pipe support portion at one end of the joint ring. Therefore, as a whole, the insertion hole of one of the pipe sections and the pipe support portion at one end of the joint ring are firmly fixedly connected as one body via the reinforcing means.
This makes it possible to firmly prevent the receiving port from moving out of the pipe support portion on the other end of the collar, and the insertion port from moving out of the pipe support portion on one end of the collar, even if the insertion port and the receiving port become separated.

In addition, the pipe support part on one end of the joint ring and the anti-removal part of the reinforcing fixing means support the insertion port of the pipe at two points spaced apart in the pipe axial direction, so that when the insertion port and the receiving port separate, bending of the insertion port and the pipe support part on one end of the joint ring can be suppressed.

As a result, when the insertion port and the receiving port are separated, the separation prevention means and the reinforcing and fixing means work together to reliably restrict further separation movement, while maintaining the bending state between the insertion port and the pipe support part on one end side of the joint ring within an appropriate range, thereby suppressing fluid leakage caused by localized deterioration in sealing in the circumferential direction of the seal part.

The second characteristic feature of the present invention is that the separation prevention means is composed of a separation prevention part that can come into contact with the outer circumferential surface of the receiving port, which is formed on the inner circumferential surface of the pipe support part on the other end side of the pipe axis direction of the joint ring, and at a location that is offset toward the center of the pipe axis direction of the joint ring from the seal part that seals between the outer circumferential surface of the other pipe part.

According to the above configuration, when a separation force due to an earthquake, uneven subsidence, etc. acts on the fitting connection between the insertion port and the receiving port, the separation prevention portion formed on the inner surface of the pipe support portion on the other end of the coupling ring abuts against the outer surface of the receiving port, preventing further separation between the two.
In this case, when the separation prevention portion of the collar abuts against the tapered portion of the outer circumferential surface of the receiving port, a force is generated to push open the split surfaces of the collar of the split structure. However, in the present invention, the separation prevention portion of the collar is formed at a position offset toward the center of the collar in the pipe axis direction from the seal portion, so the push-open force is reduced by the offset amount, and it is possible to suppress the occurrence of fluid leakage due to a decrease in the sealing performance of the seal portion caused by the split surfaces of the collar being pushed open.

Furthermore, when the insertion port and the receiving port separate and the pipe support part on the other end of the collar and the receiving port of the other pipe part bend, the pipe part on the receiving port side is supported at two points: the seal part on the pipe support part on the other end side and the separation prevention part that is displaced from it toward the center of the pipe axis of the collar, so bending of both can be suppressed. This keeps the bending state of the pipe part on the receiving port side and the pipe support part on the other end side of the collar within an appropriate range, suppressing fluid leakage caused by localized deterioration in sealing ability in the circumferential direction of the seal part.

The third characteristic feature of the present invention is that the separation prevention means comprises an abutment surface formed on the inner surface of the side wall portion on the other end side of the joint ring in the pipe axis direction and an abutment member fixed to the receiving port side in a state facing the abutment surface in the pipe axis direction, and the abutment surface of the joint ring and the abutment surface of the abutment member are formed in an orthogonal plane perpendicular to the pipe axis.

According to the above configuration, when a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection between the insertion port and the receiving port, the abutment surface formed on the inner surface of the side wall portion at the other end of the collar and the abutment member fixed to the receiving port side abut from the pipe axis center, preventing further separation movement between the pipe part on the receiving port side and the collar. At this time, since the abutment surface of the collar and the abutment surface of the abutment member on the receiving port side are formed on an orthogonal plane perpendicular to the pipe axis center, the abutment surface of the collar and the abutment surface of the abutment member are in a surface contact state along the orthogonal direction. This makes it possible to reliably receive the separation force and improve the separation prevention effect, and also reduces the pushing-opening force of the split joint acting on the collar when abutting, suppressing a decrease in the sealing performance at the split joint of the collar.

The fourth characteristic feature of the present invention is that the distance from the abutment position of the separation prevention part to the seal retaining groove of the seal part is configured to be greater than the thickness dimension in the pipe axial direction of the inner partition wall of the seal retaining groove of the seal part that seals between the inner circumferential surface of the pipe support part on one end side of the joint ring and the outer circumferential surface of one of the pipe parts.

According to the above configuration, the thickness dimension corresponding to the distance from the contact position of the separation prevention part of the joint ring to the seal retaining groove of the seal part is configured to be larger than the thickness dimension of the partition wall on the inner side of the seal retaining groove in the pipe support part on one end side of the joint ring, so that the separation prevention part that abuts on the outer circumferential surface of the receiving port can be configured to be sturdy. Moreover, it is possible to further suppress the occurrence of fluid leakage due to a decrease in the sealing property of the seal part caused by pushing open the divided surface of the joint ring.

The fifth characteristic feature of the present invention is that an elastic seal is provided on the inner circumferential surface of the pipe support part on the other end side of the joint ring, at a location offset from the separation prevention part toward the center of the pipe axis direction of the joint ring, to seal between the separation prevention part and the outer circumferential surface of the receiving port when the separation prevention part is in contact with the outer circumferential surface of the receiving port.

According to the above configuration, when a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection between the insertion port and the receiving port, the separation prevention part formed on the inner peripheral surface of the pipe support part on the other end of the joint ring abuts against the outer peripheral surface of the receiving port, preventing further separation between the two. At this time, the coating protective layer such as powder coating formed on the outer peripheral surface of the receiving port where the separation prevention part abuts is damaged, but since the elastic seal material provided at a position offset toward the center of the pipe axis of the joint ring from the separation prevention part seals the gap with the outer peripheral surface of the receiving port, no fluid will flow into the damaged part of the coating protective layer, and the progression of corrosion of the receiving port at the damaged part of the coating protective layer can be suppressed.

The sixth characteristic feature of the present invention is that the connecting portion of the reinforcing fixing means is composed of an engaging protrusion that is detachably engaged from the outer radial side of the pipe with an engaging recess formed on the outer circumferential surface of the pipe support portion on one end side of the joint ring.

According to the above configuration, the engagement protrusion constituting the connecting portion of the reinforcing fixing means is engaged from the outer side in the pipe diameter direction with the engagement recess formed on the outer circumferential surface of the pipe support portion on one end side of the joint ring, so that when the insertion port and the receiving port are separated, bending between the insertion port of one pipe portion and the pipe support portion on one end side of the joint ring can be suppressed. This makes it possible to maintain the bending state between the insertion port of the pipe portion and the pipe support portion on one end side of the joint ring within an appropriate range and suppress fluid leakage caused by localized deterioration in sealing ability in the circumferential direction of the seal portion.

The seventh characteristic feature of the present invention is that the abutment member is composed of a clamping ring with a split structure that can be clamped and fixed to the bent portion that spans the tapered outer peripheral surface portion and the straight outer peripheral surface portion of the outer peripheral surface of the socket.

According to the above configuration, when a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection between the insertion port and the receiving port, the abutment surface formed on the inner surface of the side wall portion at the other end of the coupling ring abuts against the abutment surface of the clamping ring that is clamped and fixed to the bent portion of the outer circumferential surface of the receiving port from the direction of the pipe axis. The clamping ring abuts against the tapered outer circumferential surface portion of the outer circumferential surface of the receiving port, and can firmly withstand the separation force. At the same time, since the abutment surface of the coupling ring and the abutment surface of the clamping ring are in a surface abutment state along a direction perpendicular to the pipe axis, the pushing-open force acting on the coupling ring at the time of abutment is reduced, and the deterioration of the sealing performance at the split joint of the coupling ring can be suppressed.

FIG. 1 is a partial cross-sectional view showing a first embodiment of a pipe connection portion separation prevention structure in an exploded state; Overall cross-sectional view when assembled Enlarged cross-sectional view of the main parts when assembled Overall cross-sectional view when removed 5A and 5B are overall cross-sectional views showing a second embodiment of a structure for preventing separation of a pipe connection portion during assembly and during separation, respectively; FIG. 13 is an enlarged view of a main portion showing a third embodiment of a structure for preventing separation of a connection portion; 13A and 13B are overall cross-sectional views showing a fourth embodiment of a structure for preventing separation of a pipe connection portion when assembled and when separated, respectively; 13A and 13B are enlarged views of the T-head bolt side showing two other examples of the fourth embodiment. 13A and 13B are overall cross-sectional views showing a fifth embodiment of a structure for preventing separation of a pipe connection portion when assembled and when separated, respectively; 13A and 13B are overall cross-sectional views showing a sixth embodiment of a structure for preventing separation of a pipe connection portion when assembled and when separated, respectively; FIG. 13 is an overall cross-sectional view showing a seventh embodiment of the structure for preventing separation of a pipe connection portion during assembly. 13A and 13B are overall cross-sectional views showing an eighth embodiment of a structure for preventing separation of a pipe connection portion when assembled and when separated, respectively;

First Embodiment
1 and 2 show a separation prevention structure for a pipe connection used in a fluid transport piping system. In this separation prevention structure for a pipe connection, an insertion port 1A of a fluid pipe 1, which is an example of one pipe portion, and a receiving port 2A of a fluid pipe 2, which is an example of the other pipe portion, are connected by a fitting connection portion 20, and a collar 30 of a split structure that surrounds the fitting connection portion 20 in a sealed state is fitted over both fluid pipes 1 and 2.
In addition, at the portion facing the collar 30 and the receiving port 2A of the other fluid pipe 2 in the pipe axial direction, a separation movement prevention means 40 is provided which abuts against the receiving port 2A of the other fluid pipe 2 and the collar 30 to prevent relative separation movement between them beyond a certain level.

In the above-mentioned structure for preventing separation of a pipe connection, the fluid pipes 1 and 2 are given as examples of pipe parts, but various types of pipe parts have been available in the past. For example, although not shown, examples include a branch pipe part of a split T-shaped pipe with a divided structure that is fixed to the exterior of a fluid pipe in a sealed state, a branch pipe part that is integrally formed and protrudes from the fluid pipe, and a pipe part that constitutes a part of a fluid equipment.
Furthermore, the fluid pipes 1 and 2 in the present embodiment are ductile cast iron pipes constituting water pipes for transporting clean water, which is an example of a fluid, but other cast iron pipes, steel pipes, etc. may also be used.
As the fluid, in addition to tap water, industrial water, gas, etc. can be mentioned.

The fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2 is composed of a K-shaped mechanical joint as shown in Figures 1 to 3. In this K-shaped mechanical joint, a first seal member 21 such as a rubber ring is attached between the outer peripheral surface 1a of the insertion port 1A and the tapered inner peripheral surface 2a of the receiving port 2A. A split-structured pressing ring 22 with a pressing portion 22a that can press the first seal member 21 from the pipe axis direction is attached to the insertion port 1A. The flange portion 22b of the pressing ring 22 and the flange portion 2b of the receiving port 2A are tightened and connected from the pipe axis direction by a T-head bolt 23 and a nut 24. This tightening connection compresses the first seal member 21 into a watertight state (sealed state) by the pressing portion 22a of the pressing ring 22 that is pulled and fixed to the flange portion 2b of the receiving port 2A, and maintains the watertight state.

As shown in Figures 2 and 3, the collar 30 is composed of two split collar cases 30A, 30B made of cast iron with a two-part structure that can be freely fitted to both fluid pipes 1, 2 while surrounding the fitting connection parts 20 of both fluid pipes 1, 2. The collar 30 mainly comprises a cylindrical peripheral wall part 30a with a diameter larger than the receiving port 2A, annular side wall parts 30b, 30c that are integrally extended radially inward from both ends of the peripheral wall part 30a in the pipe axis direction, and cylindrical pipe support parts 30d, 30e that are integrally extended outward along the pipe axis direction from the inner diameter side ends of each side wall part 30b, 30c.

1, connecting flanges 30C are integrally formed at both circumferential ends of the two split collar cases 30A, 30B of the collar 30 for fixedly connecting them to each other via fastening means such as bolts 31 and nuts 32. A seal 35 (see FIG. 2) is provided at the divided surfaces of the two split collar cases 30A, 30B for watertightly sealing an enclosed space 33 formed between an inner peripheral surface 30f (see FIG. 2) of the collar 30 and outer peripheral surfaces 1a, 2c of the two fluid pipes 1, 2 including the fitting connection portion 20 from the outside.
2 and 3, the seal portion 35 is configured by fitting a second seal member 37 such as an annular gasket into an annular seal retaining groove 36 formed on each of the divided surfaces of the split collar cases 30A, 30B. The second seal members 37 contact each other in a watertight manner from the pipe radial direction at both circumferential ends of the split collar cases 30A, 30B, and contact the outer circumferential surfaces 1a, 2c of the fluid pipes 1, 2 in a watertight manner at both pipe support portions 30d, 30e of the collar 30 along the pipe circumferential direction.

As shown in Figures 2 to 4, the separation movement prevention means 40 is configured by forming a separation prevention portion 41 with a circular abutment surface 41a that can abut against the outer circumferential surface 2c of the receiving port 2A from the pipe axial direction, on the inner surface of the pipe support portion 30e on the other end side of the joint ring 30 in the pipe axial direction, and at a position offset toward the center of the joint ring 30 in the pipe axial direction from the pipe circumferential seal groove portion 36a of the seal retaining groove 36 formed on the inner surface of the pipe support portion 30e and the pipe circumferential seal portion 37a of the second seal member 37 attached thereto.
The separation prevention portion 41 is formed on the inner peripheral surface of the pipe support portion 30e on the other end side with a diameter smaller than the inner diameter of the partition walls 30g located on both sides in the pipe axial direction of the pipe circumferential seal groove portion 36a. In other words, the inner peripheral surface of the separation prevention portion 41 is formed to protrude radially inward from the inner peripheral surfaces of the partition walls 30g located on both sides of the pipe circumferential seal groove portion 36a, and the separation prevention portion 41 is formed integrally with one of the partition walls 30g, and is configured to have a reinforced structure in which the thickness in the pipe axial direction from the abutment surface 41a of the separation prevention portion 41 to the seal portion 35 is also large.
Furthermore, the contact surface 41a of the removal prevention portion 41 is formed at an inclination angle that is the same or approximately the same as the inclination angle of the tapered contact portion 2d of the outer peripheral surface 2c of the socket 2A.

When a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2, the abutment surface 41a of the separation prevention portion 41 provided at the opposing positions in the pipe axis direction between the receiving port 2A of the other fluid pipe 2 and the pipe support portion 30e on the other end side of the collar 30 comes into contact with the tapered abutment portion 2d on the outer circumferential surface 2c of the receiving port 2A, thereby preventing a certain amount of relative separation movement between the receiving port 2A of the other fluid pipe 2 and the pipe support portion 30e on the other end side of the collar 30.

2 and 3, the initial assembly state is when the tip of the T-head bolt 23 of the fitting connection portion 20 abuts against the inner surface of the side wall portion 30b at one end of the joint ring 30. Also, the maximum separation movement state is when the abutment surface 41a of the separation prevention portion 41 formed on the pipe support portion 30e at the other end of the joint ring 30 abuts against the tapered abutment portion 2d of the outer circumferential surface 2c of the socket 2A, as shown in FIG.
As a result, as shown in Figure 4, in the initial assembly state, the distance L from the tip position of the T-head bolt 23 or the inner surface of the side wall portion 30b on one end side of the connecting ring 30 to the tip position of the T-head bolt 23 in the maximum disengagement movement state becomes the maximum disengagement movement distance, and in the maximum disengagement movement state, the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2 are in a disengaged state in which they have come out.

As described above, when a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection portion 20 between the insertion port 1A and the receiving port 2A, and the abutment surface 41a of the separation prevention portion 41 formed on the inner peripheral surface side of the pipe support portion 30e on the other end side of the joint ring 30 abuts against the tapered abutment portion 2d of the outer peripheral surface 2c of the receiving port 2A, a force is generated to push open the divided surface of the joint ring 30 of the split structure. However, in the present invention, the separation prevention portion 41 of the joint ring 30 is formed at a portion offset toward the center of the pipe axis direction of the joint ring 30 from the pipe circumferential seal groove portion 36a of the seal portion 35, so that the pushing force is reduced by the amount of the offset, and the occurrence of fluid leakage due to the decrease in sealing property (decrease in surface pressure) of the seal portion 35 caused by the split surface of the joint ring 30 being pushed open can be suppressed.

Furthermore, as shown in Figure 3, the distance L1 from the abutment surface 41a, which is the abutment position of the separation prevention portion 41, to the pipe circumferential seal groove portion 36a of the seal retaining groove 36 formed on the inner surface of the pipe support portion 30e on the other end side is configured to be larger than the pipe axial thickness dimension of the inner partition wall 30h, which is the pipe axial center side of the joint ring 30, among the partition walls 30h on both sides in the pipe axial direction of the pipe circumferential seal groove portion 36a of the seal retaining groove 36 formed on the inner surface of the pipe support portion 30d on the one end side.
As shown in Figure 3, the thickness dimension corresponding to the distance L1 from the abutment surface 41a of the anti-detachment portion 41 of the joint ring 30 to the pipe circumferential seal groove portion 36a of the seal portion 35 is configured to be larger than the thickness dimension in the pipe axial direction of the partition wall 30h of the pipe circumferential seal groove portion 36a at the pipe support portion 30d on one end side of the joint ring 30, so that the anti-detachment portion 41 abutting against the outer peripheral surface 2c of the receiving port 2A can be configured to be sturdy.

As shown in Figs. 1 to 4, an earthquake-resistant reinforcing bracket 50 having a split structure is provided, which is an example of a reinforcing and fixing means for integrally fixing one of the fluid pipes 1 and the pipe support portion 30d at one end of the flange 30 in the pipe axial direction. As shown in Fig. 1, this earthquake-resistant reinforcing bracket 50 is provided with a pair of split metal clamping members 51 that are split into two in the pipe circumferential direction and are clamped and fixed to the insertion port 1A of one of the fluid pipes 1 from the pipe diameter direction so that they can be freely attached and detached. The pair of split clamping members 51 are firmly clamped and fixed to the insertion port 1A of the fluid pipe 1 by tightening and connecting the flange portions 51A provided at both ends in the pipe circumferential direction with bolts 48 and nuts 49.

As shown in Figures 2 to 4, the earthquake-resistant reinforcement bracket 50 is provided with a connecting portion 52 that is fixedly connected to the pipe support portion 30d on one end side of the joint ring 30, and a pull-out prevention portion 55 that increases in resistance to pull-out between the connecting portion 52 and the outer peripheral surface 1a of the insertion port 1A as the insertion port 1A moves away from the pipe support portion 30d on one end side of the joint ring 30.
The connecting portion 52 is composed of an annular engaging recess 53 that is formed on the outer circumferential surface of the pipe support portion 30d on one end side and opens radially outward, and an engaging protrusion 54 that is detachably engaged with the engaging recess 53 from the outer side in the pipe radial direction. Of these, the engaging protrusion 54 is integrally formed to protrude along the pipe axis direction from multiple points in the pipe circumferential direction of both split clamping members 51.
When attaching the earthquake-resistant reinforcement bracket 50 to the insertion port 1A of the fluid pipe 1, as shown in Figures 1 and 2, the engaging protrusions 54 formed integrally with both split clamping members 51 are engaged with the engaging recesses 53 of the pipe support portion 30d on one end side from the outer side in the pipe diameter direction, and in this state the flange portions 51A of the two split clamping members 51 are tightened and connected to each other with bolts 48 and nuts 49.

1 and 2, the retaining portion 55 includes a claw housing portion 56 formed on the inner peripheral surface of each of the divided clamping members 51 and opening radially inward, and a claw member 57 housed in the claw housing portion 56 so as to be movable radially inward in the pipe direction. The inner surface of the claw member 57 is formed with multiple rows of sharp tapered blade portions along the pipe circumferential direction and capable of biting into the outer peripheral surface 1a of the insertion port 1A.
The outer surface of the claw member 57 and the ceiling surface of the claw storage section 56 are configured as inclined surfaces which cause the claw member 57 to bite into and move radially inward as the claw member 57 moves away from the claw storage section 56 of each split clamping member 51 and the claw member 57 stored in the claw storage section 56 while biting into the outer peripheral surface 1a of the insertion port 1A in the pipe axial direction.

When a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection part 20 between the insertion 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2, the connecting part 52 of the seismic reinforcement metal fitting 50 with a split structure provided at the insertion 1A is fixedly connected to the pipe support part 30d at one end of the joint ring 30 between the insertion 1A of one fluid pipe 1 and the joint ring 30. Furthermore, the claw member 57 of the slip-out prevention part 55 of the seismic reinforcement metal fitting 50 bites into the outer circumferential surface 1a of the insertion 1A as the insertion 1A moves away from the pipe support part 30d at one end of the joint ring 30, thereby increasing the slip-out prevention resistance. Therefore, as a whole, the insertion 1A of one fluid pipe 1 and the pipe support part 30d at one end of the joint ring 30 are firmly fixedly connected together via the seismic reinforcement metal fitting 50.
As a result, even if the insertion port 1A and the receiving port 2A separate, as shown in Figure 4, it is possible to firmly prevent the receiving port 2A from moving out of the pipe support portion 30e on the other end side of the joint ring 30, and the insertion port 1A from moving out of the pipe support portion 30d on one end side of the joint ring 30.

In addition, the pipe support part 30d on one end of the joint ring 30 and the anti-reinforcement part 55 of the seismic reinforcement bracket 50 support the insertion port 1A of the fluid pipe 1 at two locations spaced apart in the pipe axial direction, so that bending of the insertion port 1A and the pipe support part 30d on one end of the joint ring 30 can be suppressed when the insertion port 1A and the receiving port 2A separate, as shown in Figure 4.

Furthermore, since the engagement projections 54 constituting the connecting portion 52 of the earthquake-resistant reinforcing bracket 50 are engaged from the outer side in the pipe diameter direction with the engagement recesses 53 formed on the outer peripheral surface of the pipe support portion 30d on one end side of the collar 30, when the insertion port 1A and the receiving port 2A are separated, bending of the insertion port 1A of one fluid pipe 1 and the pipe support portion 30d on one end side of the collar 30 can be suppressed. This makes it possible to maintain the bending state of the insertion port 1A of the fluid pipe 1 and the pipe support portion 30d on one end side of the collar 30 within an appropriate range and suppress fluid leakage caused by a local decrease in sealing ability in the circumferential direction of the seal portion 35.
Second Embodiment
In the structure for preventing separation of a pipe connection shown in Fig. 5, the fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2 is composed of a T-shaped mechanical joint. This T-shaped mechanical joint is configured by fitting a third seal member 61 such as a rubber ring that is compressed watertightly between the outer peripheral surface 1a of the insertion port 1A that is fitted and connected, into an annular seal retaining groove 60 that opens radially inward and is formed on the inner peripheral surface of the receiving port 2A.
The other configurations are the same as those described in the first embodiment, so the same components are given the same reference numbers as in the first embodiment and the description thereof is omitted.

Third Embodiment
In the structure for preventing separation of a pipe connection shown in Fig. 6, the fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2 is composed of a T-shaped mechanical joint. In this structure for preventing separation of a pipe connection, an improvement is shown in the separation prevention means 40 for abutting and preventing a certain degree of relative separation movement between the receiving port 2A of the other fluid pipe 2 and the collar 30. In this embodiment, too, a separation prevention part 41 having an annular abutment surface 41a that can abut against the tapered abutment part 2d of the outer circumferential surface 2c of the receiving port 2A from the pipe axial direction is formed on the inner circumferential surface side of the pipe support part 30e on the other end side of the collar 30 in the pipe axial direction and at a position offset toward the center of the collar 30 in the pipe axial direction from the pipe circumferential seal groove part 36a of the seal retaining groove 36 formed on the inner circumferential surface of the pipe support part 30e and the pipe circumferential seal part 37a of the second seal member 37 attached thereto.

On the inner surface of the pipe support portion 30e on the other end side of the joint ring 30, and at a portion offset toward the center of the pipe axis direction of the joint ring 30 more than the separation prevention portion 41, a ring-shaped elastic sealing material 43 is provided to seal between the separation prevention portion 41 and the outer peripheral surface 2c of the receiving port 2A when the abutment surface 41a of the separation prevention portion 41 abuts against the tapered abutment portion 2d of the outer peripheral surface 2c of the receiving port 2A.
The abutment surface 41a of the separation prevention portion 41 and the second seal retaining groove 44 which retains the elastic sealing material 43 are formed on the inner surface of the side wall portion 30c on the other end side of the joint ring 30, and the thickness of the side wall portion 30c on the other end side in the pipe axis direction is configured to be greater than the thickness of the side wall portion 30b on one end side of the joint ring 30 in the pipe axis direction (see Figure 2 of the first embodiment and Figure 5 of the second embodiment).

When a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection portion 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2, the abutment surface 41a of the separation prevention portion 41 formed on the inner peripheral surface of the pipe support portion 30e on the other end side of the collar 30 abuts against the tapered abutment portion 2d of the outer peripheral surface 2c of the receiving port 2A, preventing further separation between the two. At this time, the coating protective layer such as powder coating formed on the outer peripheral surface 2c of the receiving port 2A with which the abutment surface 41a of the separation prevention portion 41 abuts is damaged, but since the elastic seal material 43 provided at a portion displaced toward the center of the collar 30 in the pipe axis direction from the abutment surface 41a of the separation prevention portion 41 seals the gap with the outer peripheral surface 2c of the receiving port 2A, no fluid flows into the damaged portion of the coating protective layer, and the progress of corrosion of the receiving port 2A at the damaged portion of the coating protective layer can be suppressed.
The other configurations are the same as those described in the second embodiment, so the same components are denoted by the same reference numbers as in the first embodiment and the description thereof will be omitted.

Fourth Embodiment
In the separation prevention structure for a pipe connection shown in Figure 7, the fitting connection part 20 between the insertion port 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 separation prevention structure for a pipe connection, an improvement is shown in the separation prevention means 40 which abuts and prevents the socket 2A of the other fluid pipe 2 and the collar 30 from moving relative to each other beyond a certain level.
In this embodiment, the separation movement prevention means 40 is configured such that a plurality of metal T-head bolts 23, which are arranged at predetermined intervals around the pipe, among the constituent members of the K-shaped mechanical joint that makes up the mating connection portion 20, also serve as abutment members 45 fixed to the receiving port 2A side, and the flat top surface 23a of the head 23A of each T-head bolt 23 is configured as the abutment surface 45a of the abutment member 45.

Furthermore, the inner surface of the side wall portion 30 c on the other end side of the joint ring 30 in the pipe axial direction, which faces the heads 23 A of the T-head bolts 23 in the pipe axial direction, is configured as a contact surface 46 .
The abutment surface 46 formed on the inner surface of this side wall portion 30c and the abutment surface 45a of the abutment member 45 formed by the top surface 23a of the head 23A of each T-head bolt 23 are each formed on an orthogonal plane perpendicular to the pipe axis.

When a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the socket 2A of the other fluid pipe 2, the abutment surface 46 formed on the inner surface of the side wall 30c at the other end of the collar 30 and the abutment surface 45a of the abutment member 45 composed of the abutment surfaces 45a of the heads 23A of the T-head bolts 23 fixed to the socket 2A side come into face-to-face contact from the pipe axial direction, preventing further separation between the socket 2A of the fluid pipe 2 and the collar 30. This face-to-face contact between the abutment surface 46 of the collar 30 and the abutment surface 45a of the abutment member 45 composed of the abutment surfaces 45a of the T-head bolts 23 can reliably receive the separation force, improving the separation prevention effect.
The other configurations are the same as those described in the first embodiment, so the same components are given the same reference numbers as in the first embodiment and the description thereof is omitted.

In addition, in the above-mentioned fourth embodiment, the flat top surface 23a of the head 23A of each T-head bolt 23 is configured as the abutment surface 45a of the abutment member 45, but as shown in Figure 8 (a), the head 23A of each T-head bolt 23 may be integrally formed with an abutment member 45 having an abutment surface 45a that can abut against the abutment surface 46 of the side wall portion 30c of the joint ring 30 from the pipe axial direction.
In this case, too, the contact surface 46 of the collar 30 and the contact surface 45a of the contact member 45 of each T-head bolt 23 on the socket 2A side are formed on an orthogonal plane perpendicular to the pipe axis, so that the contact surface 46 of the collar 30 and the contact surface 45a of the contact member 45 of each T-head bolt 23 come into surface contact with each other, reliably receiving the separation force and improving the separation prevention effect.

Furthermore, as shown in FIG. 8(b), an abutment member 45 having an abutment surface 45a that can abut against the abutment surface 46 of the side wall portion 30c of the joint ring 30 from the pipe axial direction may be fitted and fixed to the head 23A of each T-head bolt 23 as an attachment.
In this case, too, the contact surface 46 of the collar 30 and the contact surface 45a of the contact member 45B of each T-head bolt 23 on the socket 2A side are formed on an orthogonal plane perpendicular to the pipe axis, so that the contact surface 46 of the collar 30 and the contact surface 45a of the contact member 45B of each T-head bolt 23 come into surface contact with each other, reliably receiving the separation force and improving the separation prevention effect.

Fifth Embodiment
In the pipe connection prevention structure shown in Figure 9, the fitting connection part 20 between the insertion port 1A of one fluid pipe 1 and the socket 2A of the other fluid pipe 2 is composed of a T-shaped mechanical joint. In this pipe connection prevention structure, an improvement is shown in the separation movement prevention means 40 that abuts and prevents the relative separation movement between the socket 2A of the other fluid pipe 2 and the collar 30 beyond a certain level.
In the separation movement prevention means 40 of this embodiment, a metal abutment band 70 having a split structure (a two-split structure in this embodiment) that is clamped and fixed to the socket 2A of the fluid pipe 2 from the outside in the pipe diameter direction is used as an example of the abutment member 45 fixed to the socket 2A side of the other fluid pipe 2. The abutment band 70 is provided with an annular first positioning portion 70b that abuts against the end face on the connection port side of the socket 2A and a second positioning portion 70c that abuts against a tapered portion of the outer circumferential surface 2c of the socket 2A. Therefore, when the abutment band 70 is fastened and fixed to the outer circumferential surface of the socket 2A, the first positioning portion 70b and the second positioning portion 70c prevent the abutment band 70 from moving in the pipe axial direction.

The tip surface 70a of the second positioning portion 70c of the abutment band 70 constitutes the abutment surface 45a of the abutment member 45, and the inner surface portion of the side wall portion 30c on the other end side of the joint ring 30 in the pipe axis direction that faces the abutment surface 45a constituted by the tip surface 70a of the second positioning portion 45c of the abutment band 70 in the pipe axis direction constitutes the abutment surface 46.

In this case, too, the abutment surface 46 of the collar 30 and the abutment surface 45a formed by the tip surface 70a of the abutment band 70 fixed to the socket 2A are formed on an orthogonal plane perpendicular to the pipe axis, so that the abutment surface 46 of the collar 30 and the abutment surface 45a of the abutment band 70 come into surface contact with each other, reliably receiving the separation force and improving the separation prevention effect.
The other configurations are the same as those described in the first embodiment, so the same components are given the same reference numbers as in the second embodiment and the description thereof is omitted.

Sixth Embodiment
In the pipe connection prevention structure shown in Figure 10, the fitting connection part 20 between the insertion port 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 pipe connection prevention structure, an improvement is shown in the separation movement prevention means 40 that abuts and prevents the relative separation movement between the socket 2A of the other fluid pipe 2 and the collar 30 beyond a certain level.
The separation movement preventing means 40 in this embodiment is an example of the abutment member 45 fixed to the socket 2A side of the other fluid pipe 2, and uses a metallic socket band 71 that is clamped and fixed in a state of being engaged from the outside in the pipe diameter direction with respect to the flange portion 2b of the socket 2A. A tip surface 71a of this socket band 71 constitutes the abutment surface 45a of the abutment member 45, and the inner surface of the side wall portion 30c on the other end side in the pipe axial direction of the joint ring 30 that faces in the pipe axial direction to the abutment surface 45a constituted by the tip surface 71a of the socket band 71 constitutes the abutment surface 46.

In this case, the abutment surface 45a, which is composed of the abutment surface 46 of the collar 30 and the tip surface 71a of the socket band 71 fixed to the socket 2A, is formed on an orthogonal surface perpendicular to the pipe axis. This allows the abutment surface 46 of the collar 30 and the abutment surface 45a of the socket band 71 to come into surface contact with each other, thereby reliably receiving the separation force and improving the separation prevention effect.
The other configurations are the same as those described in the first embodiment, so the same components are given the same reference numbers as in the first embodiment and the description thereof is omitted.

Seventh Embodiment
In the structure for preventing separation of a pipe connection shown in Fig. 11, the fitting connection part 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2 is composed of a K-shaped mechanical joint. In this structure for preventing separation of a pipe connection, an improvement is shown in which an earthquake-resistant reinforcing metal fitting (one example of a reinforcing and fixing means) 50 of a split structure is shown, which integrally and fixedly connects one fluid pipe 1 and a pipe support part 30d on one end side of a collar 30 in the pipe axial direction.
In this embodiment of the earthquake-resistant reinforcement fitting 50, an extension pipe support portion 30j having an annular space opening radially inward is integrally formed on the end side of the pipe support portion 30d on one end side in the pipe axial direction of the joint ring 30, which is located closer to the earthquake-resistant reinforcement fitting 50 than the pipe circumferential seal groove portion 36a of the seal retaining groove 36 formed on its inner surface and the pipe circumferential seal portion 37a of the second seal member 37 attached thereto.

A ring-shaped engagement recess 53 that opens radially outward is formed on the outer circumferential surface of the pipe support portion 30d on one end side, including the extension pipe support portion 30j, and an engagement protrusion 54 integrally formed on both split clamping members 51 of the earthquake-resistant reinforcement bracket 50 is engaged from the outside in the pipe radial direction with the outer end portion of the engagement recess 53 in the range corresponding to the extension pipe support portion 30j.

In this embodiment, the engagement position of the engagement protrusion 54 of the earthquake-resistant reinforcing bracket 50 with the pipe support portion 30d at one end of the joint ring 30 is separated from the pipe circumferential seal groove portion 36a of the seal retaining groove 36 formed on the inner surface of the pipe support portion 30d and the pipe circumferential seal portion 37a of the second seal member 37 attached thereto toward the outer end side. Therefore, as shown in FIG. 4, when the insertion port 1A and the receiving port 2A are separated, bending of the insertion port 1A and the pipe support portion 30d at one end of the joint ring 30 can be suppressed. This maintains the bending state of the insertion port 1A of the fluid pipe 1 and the pipe support portion 30d at one end of the joint ring 30 within an appropriate range, and suppresses leakage of fluid caused by a local decrease in sealing ability in the circumferential direction of the pipe circumferential seal groove portion 36a of the seal portion 35.

Eighth embodiment
In the structure for preventing separation of a pipe connection shown in Figure 12, the fitting connection 20 between the insertion port 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 structure for preventing separation of a pipe connection, an improvement is shown in the separation prevention means 40 which abuts and prevents the socket 2A of the other fluid pipe 2 and the collar 30 from moving relative to each other beyond a certain level.
In the separation movement prevention means 40 of this embodiment, a metal clamping ring 80 having a split structure (two-split structure in this embodiment) that can be detachably clamped and fixed from the outside in the pipe diameter direction to the bent portion extending from the tapered outer peripheral surface portion 2e to the straight outer peripheral surface portion 2f on the outer peripheral surface 2c of the socket 2A is used as an example of the abutment member 45 fixed to the socket 2A side of the other fluid pipe 2. The clamping ring 80 is provided with a semicircular split ring 80A that is split into two in the pipe circumferential direction. The pair of split rings 80A are firmly clamped and fixed to the bent portion of the socket 2A by fastening and connecting connecting pieces 80B provided on both ends in the pipe circumferential direction with bolts 81.
One end surface 80a of the clamping ring 80 in the pipe axis direction is configured as a tapered end surface that abuts on the tapered outer peripheral surface portion 2e of the outer peripheral surface 2c of the socket 2A in a face-to-face contact state. The other end surface 80b of the clamping ring 80 in the pipe axis direction includes the other end surface of the split ring 80A in the pipe axis direction and the other end surface of the connecting piece 80B in the pipe axis direction, and is configured as the abutment surface 45a of the abutment member 45. The inner surface of the side wall portion 30c on the other end side in the pipe axis direction of the joint ring 30 is configured as the abutment surface 46 that can abut from the pipe axis direction against the abutment surface 45a configured by the other end surface 80b of the clamping ring 80. The abutment surface 46 configured by the inner surface of the side wall portion 30c of the joint ring 30 and the abutment surface 45a configured by the other end surface 80b of the clamping ring 80 are formed in an orthogonal plane perpendicular to the pipe axis.

When a separation force due to an earthquake, uneven settlement, or the like acts on the fitting connection 20 between the insertion port 1A of one fluid pipe 1 and the receiving port 2A of the other fluid pipe 2, the abutment surface 46 formed on the inner surface of the side wall portion 30c on the other end side of the joint ring 30 abuts from the pipe axial direction against the abutment surface 45a of the clamping ring 80 that is clamped and fixed to the bent portion of the outer circumferential surface 2c of the receiving port 2A. The tapered one end face 80a of the clamping ring 80 abuts in a face-to-face state from the pipe axial direction against the tapered outer circumferential surface portion 2e of the outer circumferential surface 2c of the receiving port 2A, and can firmly withstand the separation force. At the same time, since the abutment surface 46 of the collar 30 and the abutment surface 45a of the clamping ring 80 are in a face-to-face contact state along a direction perpendicular to the pipe axis, the pushing-open force acting on the split joint of the collar 30 during abutment is reduced, thereby suppressing a decrease in sealing performance at the split joint of the collar 30 (a decrease in the surface pressure of the second seal member 37).
The other configurations are the same as those described in the first embodiment, so the same components are given the same reference numbers as in the first embodiment and the description thereof is omitted.

Other embodiments
(1) In the first embodiment described above, as shown in FIG. 3, in the initial assembly state in which the tip of the T-head bolt 23 of the K-type mechanical joint is in contact with or close to the inner surface of the side wall portion 30b at one end of the joint ring 30, an expansion allowance is formed between the abutment surface 41a of the separation prevention portion 41 of the joint ring 30 and the tapered abutment portion 2d of the outer peripheral surface 2c of the socket 2A. However, this expansion allowance may be reduced or made smaller.

(2) In the first embodiment described above, the contact surface 41a of the separation prevention portion 41 formed on the inner peripheral surface side of the pipe support portion 30e on the other end side of the joint ring 30 is configured to directly contact the tapered contact portion 2d of the outer peripheral surface 2c of the receiving port 2A, but the contact surface 41a of the separation prevention portion 41 may be configured with an elastic body.

(3) In the first embodiment described above, the connecting portion 52 of the earthquake-resistant reinforcing bracket 50 is configured from an annular engaging recess 53 that is formed on the outer circumferential surface of the pipe support portion 30d at one end and opens radially outward, and an engaging protrusion 54 that is freely engaged and disengaged with the engaging recess 53 from the outer side in the pipe radial direction, but is not limited to this configuration. For example, the connecting portion 52 of the earthquake-resistant reinforcing bracket 50 may be configured from a bolt and nut that fixedly connects the pipe support portion 30d at one end of the joint ring 30 to both split clamping members 51.

1. One pipe section (fluid pipe)
1A Inlet 2 Other pipe section (fluid pipe)
2A Socket 2c Outer circumferential surface 2e Tapered outer circumferential surface portion 2f Straight outer circumferential surface portion 20 Fitting connection portion 30 Joint ring 30c Side wall portion 30d Tube support portion on one end side 30e Tube support portion on the other end side 35 Seal portion 36 Seal retaining groove 40 Separation prevention means 41 Separation prevention portion 41a Contact surface 43 Elastic seal material 45 Contact member 45a Contact surface 50 Reinforcement fixing means (earthquake-resistant reinforcement metal fitting)
52 Connecting portion 53 Engagement recess 54 Engagement protrusion 55 Removal prevention portion 70 Contact band (contact member)
71 Socket band (contact member)
80 Clamping ring (contact member)

Claims (5)

a split joint ring that surrounds in a sealed state a fitting connection between an insertion port of one pipe portion and a receiving port of the other pipe portion and is fitted over both pipe portions ; a reinforcing and fixing means is provided that has a split clamping member of a split structure that is clamped and fixed to the insertion port in a pipe diameter direction; the split clamping member is provided with a pull-out prevention portion that increases in pull-out prevention resistance between the split clamping member and an outer peripheral surface of the insertion port as the insertion port moves away from the pipe support portion on one end of the joint ring, and a connecting portion that is fixedly connected to the pipe support portion on one end of the joint ring ,
A detachment prevention structure for a pipe connection portion, in which the pipe support portion on one end side of the connecting ring is formed with an extension pipe support portion having an annular space opening toward the inside in the pipe diameter direction, and the connecting portion of the reinforcing fixing means is provided with an engagement recess formed on the outer surface of the pipe support portion on one end side including the extension pipe support portion, and an engagement protrusion provided on the split clamping member in a state in which it engages with the engagement recess from the outside in the pipe diameter direction, and a detachment movement prevention means is provided at the portion opposing the connecting ring and the receiving port side in the pipe axial direction, which prevents relative detachment movement beyond a certain level by abutment between the connecting ring and the abutment portion on the receiving port side. A pipe connection portion separation prevention structure as described in claim 1, wherein an outer wall is formed at the outer end of the extension pipe support portion, protruding inward and outward in the pipe radial direction while partitioning the outer end sides of the annular space and the engagement recess. 3. A structure for preventing separation of a pipe connection portion as described in claim 2, wherein a seal portion is provided to seal between the inner circumferential surface of the pipe support portion on one end side of the collar and the outer circumferential surface of one of the pipe portions, the seal portion being configured by fitting a second seal member into annular seal retaining grooves formed in each of the split collar cases of the collar, and a pipe circumferential seal groove portion of the seal retaining groove formed on the inner circumferential surface of the pipe support portion on one end side and the annular space are partitioned by a partition wall . 4. A pipe connection section separation prevention structure according to claim 2, wherein an outer wall is formed on an outer end side of said pipe support section on the other end side of said joint ring, said outer wall projecting inwardly and outwardly in a pipe diameter direction. The detachment prevention structure for a pipe connection portion according to any one of claims 1 to 4, wherein the detachment prevention means comprises an abutment surface formed on the inner surface of a side wall portion on the other end side of the connecting ring in the pipe axis direction, and an abutment member fixed to the receiving port side in a state facing the abutment surface in the pipe axis direction, the abutment surface of the side wall portion being formed on an orthogonal plane perpendicular to the pipe axis, and the abutment portion of the abutment member being formed on an abutment surface that abuts against the abutment surface of the side wall portion in a surface-to-surface manner from the pipe axis direction.

Images