JPS6120758B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an earthquake-resistant pipe joint having an earthquake-resistant function.

BACKGROUND TECHNOLOGY Earthquake resistance is achieved by allowing movement within a certain range in the axial direction of the tube between the receptacle and the insertion port, but reliably preventing them from slipping out of each other due to further movement. It has this function and also has excellent sealing performance.
Moreover, as a conventional earthquake-resistant pipe joint with a simple structure and simple joining work, as shown in Fig. An annular groove 5 is provided on the inner surface of the socket 3 on the back side of the installation position of the seal packing 4 disposed in the socket 3, and the annular groove 5 is capable of engaging with the protrusion 2 and is connected to the socket 3.
A split lock ring 7 having a tapered surface 6 facing the back side of the socket 3 is fitted on the side surface on the opening side, and a lock ring 7 on the back side of the socket 3 is inserted between the lock ring 7 and the seal packing 4. A back-up ring 8 having a triangular cross section is provided, the side surface of which is in contact with the tapered surface 6 of the lock ring 7, and the side surface of the opening side of the socket 3 is in contact with the side surface of the seal packing 4 on the back side of the socket 3. 2 and the lock ring 7 prevents the socket 3 from coming off from the socket 1, and a particularly large pull-out force in the tube axis direction or a pull-out force biased in the circumferential direction is applied to the lock ring 7. In this case, the backup spring 8 reliably prevents the diameter of the lock ring 7 from decreasing, and the socket 3
A method has been proposed that more reliably prevents mutual slippage. Note that 9 is connected to the flange portion 1 of the socket 3 by means of T-shaped bolts 10 and nuts 11.
This is a press ring that is attached to the seal packing 2 and presses the seal packing 4.

Problems to be Solved by the Invention However, due to the dimensional tolerances of the socket 3 and the socket 1, the gap in the annular space between the inner surface of the socket 3 and the outside surface of the socket 1 differs depending on the individual pipe joint. The thickness of the back-up spring 8 in the radial direction must be made approximately equal to the minimum value of the gap in the annular space, and the lock ring 7 must be inserted from the annular space to the back side of the socket 3, so its diameter The thickness in this direction had to be made thinner than the minimum value of the gap between the annular spaces. Therefore, if the gap in the annular space is thick, the area of the contact surfaces between the lock ring 7 and the back-up ring 8 will be very small. Conventionally, the back-up spring 8 was usually made of hard rubber or cloth impregnated with rubber, but if the area of the contact surface is small, the socket 3
Due to the relative movement between the sockets 1, the back-up spring 8 moves to the back side of the socket 3 relative to the lock ring 7, causing a problem in fulfilling its function of preventing the lock ring 7 from shrinking in diameter.

In addition, if the gap between the annular space between the inner surface of the socket 3 and the outer surface of the socket 1 is standard or thick, the outer peripheral edge of the side surface of the seal packing on the back side of the socket 3 is covered with a back-up spring 8. Therefore, the outer peripheral edge portion was directly exposed to the fluid in the pipe, and depending on the nature of the fluid in the pipe, there was a risk that the seal packing would be damaged.

In view of the above points, the present invention has been developed to ensure that the engagement area between the lock ring and the back-up spring is at least determined by the dimensional tolerance between the socket sockets, and that the fluid in the pipe can be prevented from slipping out between the socket sockets. The purpose of this invention is to provide an earthquake-resistant pipe joint that can prevent damage to the seal packing due to contact with the pipes, and one embodiment thereof will be described below with reference to the drawings.

This is the purpose.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention forms an annular protrusion on the outer surface of the tip of the socket and a seal packing disposed between the socket and the socket. An annular groove is provided on the inner surface of the socket located on the back side of the installation position, and a tapered surface facing the back side of the socket is formed in the annular groove on the side surface on the socket opening side that can engage with the protrusion. A split lock ring is fitted between the lock ring and the seal packing, and a radial thickness is larger than the maximum value of the gap in the annular space between the inner surface of the socket and the outer surface of the socket. A back-up ring is provided which integrally includes an annular body consisting of a body and a metal or hard synthetic resin ring divided into multiple parts in the circumferential direction and fixed to the side surface of the annular body on the back side of the socket. A tapered surface that comes into contact with the tapered surface of the lock ring is formed on the side surface on the back side of the socket.

Effect With such a device, even if the gap in the annular space becomes thicker due to the dimensional tolerance between the socket and the socket, and the area of the contact surface between the lock ring and the metal or hard synthetic resin ring becomes smaller, the metal or Since the hard synthetic resin ring is rigid and does not deform, there is no risk that the back-up ring will deform due to relative movement between the sockets and move further into the socket than the locking ring. When a large pull-out force in the tube axis direction or a pull-out force biased in the circumferential direction is applied, the metal or hard synthetic resin ring portion of the back-up spring reliably prevents the lock ring from shrinking in diameter, and the socket and socket are mutually connected. It is possible to reliably prevent slippage. Moreover, since the radial thickness of the annular body portion of the back-up spring is larger than the maximum value of the gap in the annular space, not only when the gap in the annular space is thin or standard, but also when the annular space Even if the gap is thick, the entire side of the seal packing on the back side of the socket is covered by the annular body part of the back-up spring, so the seal packing is not directly exposed to the fluid in the pipe. Therefore, no matter what properties the fluid in the pipe has, there is no risk of damage to the seal packing.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

In Figure 2, 13 is the socket, 14 is the socket,
An annular protrusion 15 is formed on the outer surface of the tip of the socket 14 . This protrusion 15 is a ring-shaped member made of ductile cast iron, steel, or the like and fixed to the socket 14 by welding. This protrusion 15 may be formed integrally with the socket 14. On the other hand, socket 13
A tapered surface 17 is formed on the inner surface of the opening end, on which a seal packing 16 is installed, and an annular groove 18 is formed on the inner side of the tapered surface 17. Numeral 19 is a lock ring that can be inserted into the inner side of the socket 13 from the annular space between the inner surface of the socket 13 and the outer surface of the socket 14, and is fitted in the annular groove 18 with a biasing force for expanding the diameter in one piece. . The annular groove 18 has such a depth that the inner peripheral portion of the lock ring 19 fitted therein can engage with the protrusion 15 at the tip of the insertion port 14 in the tube axis direction. The lock ring 19 is made of ductile cast iron, steel, or the like, and has a tapered surface 20 formed on its side surface on the opening side of the socket 13 toward the back of the socket 13, that is, toward the tip of the socket 14. Between the lock ring 19 and the seal packing 16, there is provided an annular body 21 made of an elastic material such as rubber and having a radial thickness greater than the maximum gap of the annular space, and a receiving member for the annular body 21. A back-up spring 23 consisting of a metal or hard synthetic resin ring 22 divided into a plurality of parts in the circumferential direction is fixed to the side surface on the back side of the mouth 13 with an adhesive or the like. As shown in detail in FIGS. 3 and 4, the annular body 21 and the metal or hard synthetic resin ring 22 constituting the back-up spring 23 have inner peripheral surfaces flush with each other, and are made of metal or hard synthetic resin. A tapered surface 24 that comes into contact with the tapered surface of the lock ring 19 is formed on the side surface of the synthetic resin ring 22 on the back side of the socket 13 . Further, the outer peripheral surface 25 of the annular body 21 is formed into a tapered shape substantially parallel to the tapered surface 24 of the metal or hard synthetic resin ring 22. Reference numeral 26 denotes a two-part push ring that presses the seal packing 16, and a T-shaped bolt 2 is inserted through a hole provided in the flange portion 27 of the socket 13 and a hole provided in the push ring 26.
8 and a nut 29, and by tightening the bolt 28 and nut 29, a pressing force acts on the seal packing 16, and the socket 13
The sealing property between the insertion port 14 and the insertion port 14 is ensured. The radial thickness of the metal or hard synthetic resin ring 22 is as follows:
As shown in FIG. 5A, the thickness is such that it can be inserted from the annular space to the back side of the socket 13 when the gap in the annular space is the minimum. The thickness of the annular body 21 in the radial direction is larger than the maximum gap of the annular space as shown in FIG. 5C, but since the annular body 21 is made of an elastic material such as rubber, Not only when the gap between the annular spaces is standard as shown in FIG. 5A, but also when the gap between the annular spaces is the minimum as shown in FIG. . Note that 30 is a stepped surface at the back end of the socket 13.

To explain the connection work, from the tip side of the socket 14, the seal packing 16, back-up ring 23, and split locking ring 19 are installed in this order and left in the socket 14.
4 into the socket 13. Next, when the split lock ring 19 is pushed into the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 in the axial direction, the split lock ring 19 is fitted into the annular groove 18 due to its diameter expansion biasing force. be done. Next Backup Spring 23
is pushed into the annular space in the axial direction. At this time,
If the outer circumferential surface 25 of the annular body 21 is formed into a tapered shape as in this embodiment, the backup ring 23 can be easily pushed into the annular space even if the gap in the annular space is thin. Next, after pushing the seal packing 16 into the annular space in the axial direction, a push ring 26 is applied to the back surface of the seal packing 16, and then the push ring 26 and the flange portion 27 of the socket 13 are connected with bolts 28 and nuts 29. By fastening, the joining is completed. In this way, the joint connection can be completed and the sealing performance is perfect.

Thus, after the joining work is completed, the protrusion 15 at the tip of the socket 14 can be moved between the step surface 30 at the back end of the socket 13 and the lock ring 19, and the projection 15 at the tip of the socket 14 can be moved between the socket 13 and the socket 14 within this range. Movement in the tube axis direction is allowed,
Further, the engagement between the protrusion 15 and the lock ring 19 prevents the device from being pulled out. Therefore, it has an earthquake-resistant function. Also, since the part of the back-up spring 23 that comes into contact with the lock ring 19 is made of metal or hard synthetic resin ring 22, if the gap in the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 is thin or standard. , when a particularly large pull-out force in the direction of the tube axis is applied to the lock ring 19, the metal or hard synthetic resin ring 22 of the back-up spring 23
Not only can the diameter of the lock ring 19 be reliably prevented from shrinking by the portion, and the lock ring 19 can be reliably prevented from coming off between the sockets 13 and the sockets 14, but even if the gap in the annular space is thick, the taper of the lock ring 19 can be prevented. Although the area of the contact surface between the surface 20 and the tapered surface 24 of the metal or hard synthetic resin ring 22 of the back-up spring 23 is very small, the metal or hard synthetic resin ring 22 is rigid and does not deform, so the socket 13
Due to the relative movement between the sockets 14, the back-up spring 23 is deformed and becomes closer to the socket 1 than the lock ring 19.
3.There is no risk of movement to the back side, and therefore, when a particularly large pull-out force in the tube axis direction or pull-out force biased in the circumferential direction is applied to the lock ring 19, the metal or hard synthetic resin ring 22 of the back-up spring 23 This portion reliably prevents the lock ring 19 from shrinking in diameter, thereby reliably preventing it from coming off between the sockets 13 and 14. Moreover, since the radial thickness of the annular body 21 portion of the back-up spring 19 is larger than the maximum value of the gap in the annular space, it goes without saying that the gap in the annular space is thin or standard. Even when the gap in the annular space is thick, the entire side surface of the seal packing 16 on the back side of the socket 13 is covered by the annular body 21 portion of the back-up spring 23, so that the seal packing 16 is not directly exposed to the fluid in the pipe. Therefore, there is no risk that the seal packing 16 will be damaged, no matter what properties the fluid in the pipe has.

Note that if the protrusion 15 at the tip of the socket 14 is attached immediately before joining the joint, or if the mounting structure is removable, the inner circumferential surface of the push ring 26 may be brought close to the outer surface of the socket 14 even if the push ring 26 is formed integrally. Since the inner periphery of the seal packing 16 can be brought into contact with almost the entire surface of the back surface of the seal packing 16, it is possible to omit dividing the press ring 26 into two.

Maximum Value of Gap As explained above, according to the earthquake-resistant pipe joint according to the present invention, it is possible to reliably prevent the socket sockets from coming out based on the dimensional tolerance between the socket sockets, and also to Damage to the seal packing due to contact with the fluid in the pipe can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional earthquake-resistant pipe joint, Figs. 2 to 5 show an embodiment of the present invention, Fig. 2 is a longitudinal sectional view thereof, and Fig. 3 is a front view of a back-up spring. , Fig. 4 is a sectional view taken along the - line in Fig. 3, and Figs. 5 A to C show the back-up spring, lock ring, and seal packing due to changes in the gap in the annular space between the inner surface of the receptacle and the outer surface of the receptacle. FIG. 13...Socket, 14...Socket, 15...Protrusion,
16... Seal packing, 18... Annular groove, 1
9... Lock ring, 20... Tapered surface, 21...
... cyclic body, 22 ... metal or hard synthetic resin ring,
23...Backup spring, 24...Tapered surface.

Claims (1)

[Claims] 1. Forming an annular protrusion on the outer surface of the tip of the socket, and providing an annular groove on the inner surface of the socket located on the back side of the installation position of the seal packing placed between the socket and the socket, A split lock ring that can engage with the protrusion and has a tapered surface toward the back of the socket on the side surface on the opening side of the socket is fitted into this annular groove, and the lock ring and the seal packing are connected to each other. an annular body made of an elastic body whose radial thickness is larger than the maximum gap of the annular space between the inner surface of the socket and the outer surface of the socket; A back-up ring is provided which integrally has a plurality of fixed metal or hard synthetic resin rings in the circumferential direction, and the metal or hard synthetic resin ring has a backside surface on the back side of the socket that comes into contact with the tapered surface of the lock ring. An earthquake-resistant pipe joint characterized by forming a tapered surface.