JPS624592B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pipe joint having an earthquake-resistant function.

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 movement beyond that range. It has this function and also has excellent sealing performance.
Moreover, as an earthquake-resistant pipe joint with a simple structure and easy joining work, as shown in Fig. 1, an annular protrusion 2 is formed on the outer surface of the tip of the socket 1 and placed between the socket 3 and the socket 1. 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, and a ring groove 5 is provided in the annular groove 5 that can be engaged with the protrusion 2 and is provided on the side surface of the opening of the socket 3. A split lock ring 7 having a tapered surface 6 toward the back of the mouth 3 is fitted, and between the lock ring 7 and the seal packing 4,
A back up spring 8 having a triangular cross section, the side surface on the back side of the socket 3 is in contact with the tapered surface 6 of the lock ring 7, and the side surface on the opening side of the socket 3 is in contact with the side surface on the back side of the socket 3 of the seal packing 4. The engagement between the protrusion 2 and the lock ring 7 prevents the socket 3 from slipping out of the socket 1, and also prevents the lock ring 7 from being subjected to a particularly large pull-out force in the tube axis direction or deviation in the circumferential direction. It has been proposed that when a pull-out force is applied, the back-up spring 8 reliably prevents the diameter of the lock ring 7 from shrinking, thereby more reliably preventing the lock ring 7 from slipping out between the sockets 3 and 1. . Note that 9 is a press ring that is attached to the flange portion 12 of the socket 3 by T-shaped bolts 10 and nuts 11 and presses the seal packing 4.

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 fittings. The thickness must be made approximately equal to the minimum value of the gap in the annular space, and since the lock ring 7 must be inserted from the annular space to the back side of the socket 3, its radial thickness must be made to match the minimum value of the gap in the annular space. We had no choice but to make it thinner than the minimum value of the gap. 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 was small, the relative movement between the sockets 3 and 1 would be affected. Yotsute Backup Spring 8
moves to the back of the socket 3 from the locking ring 7,
There was a problem in fulfilling the function of preventing the lock ring 7 from contracting in diameter.

In view of the above points, the present invention provides an earthquake-resistant pipe joint in which 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 which can reliably prevent slippage between the socket sockets. To this end, the present invention forms an annular protrusion on the outer surface of the tip of the socket, and also forms a ring-shaped projection on the outer surface of the tip of the socket, and also forms a ring-shaped protrusion at the back of the installation position of the seal packing located between the socket and the socket. An annular groove is provided on the inner surface of the socket, and the annular groove has a tapered surface facing toward the back of the socket on the side surface on the opening side of the socket, which is engageable with the protrusion. A locking ring is fitted, and a tapered surface that contacts the tapered surface of the locking ring is formed between the locking ring and the seal packing on the side surface on the back side of the socket, and the side surface on the side of the socket opening is connected to the seal packing. A back-up spring made of metal or hard synthetic resin is provided in one piece that comes into contact with the packing and can slide in the circumferential direction to expand the diameter in the radial direction and has a biasing force for reducing the diameter. The side surface of the ring on the socket opening side is provided with a plate that covers the divided portion of the back-up spring. According to this structure, the back-up spring is made of metal or hard synthetic resin. Since it is rigid and does not deform, there is no risk that the back-up spring will deform due to relative movement between the socket and the socket and move further into the socket than the lock ring. When a pull-out force in the direction or a pull-out force biased in the circumferential direction is applied, the back-up spring reliably prevents the diameter of the lock ring from shrinking, and it is possible to reliably prevent the lock ring from coming off between the socket and the socket. In addition, since the back-up spring is a single piece, it can slide in the circumferential direction and expand the diameter in the radial direction, and has a biasing force for reducing the diameter. It can be expanded and installed securely. One embodiment will be described below 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, a tapered surface 21 is formed on the side surface on the back side of the socket 13, which contacts the tapered surface 20 of the lock ring 19, and the side surface on the opening side of the socket 13 is formed on the side surface on the back side of the socket 13. Backup spring 2 that comes into contact with seal packing 16
2 is placed. This Backup Spring 2
2 is made of metal such as ductile cast iron or steel, or hard synthetic resin, and has a biasing force for diameter reduction in one piece, and a third
As shown in detail in the figure, the backup spring 2
A plate body 24 is provided to cover the two divided portions 23. Two side surfaces 25 and 26 of this plate body 24, which face each other in the circumferential direction of the back-up ring 22, are formed in a tapered shape with a wide hem, and one side surface 25 is attached to the back-up spring by welding, adhesion, etc. 2
It is fixed to the side surface on the opening side of the socket 13 of No. 2, and the other side surface 26 is free. For this reason, the end of the back-up spring 22 and the free end of the plate 24 are configured to slide when fitted into the socket 14. Reference numeral 27 denotes a two-split press ring that presses the seal packing 16, and a T-shaped bolt 29 and nut 30 are inserted into the hole provided in the flange portion 28 of the socket 13 and the hole provided in the press ring 27. It is attached by the bolt 29 and nut 30.
By tightening, a pressing force acts on the seal packing 16, and the sealing performance between the socket 13 and the socket 14 is ensured. Note that the backup spring 22
As shown in FIG. 4A, when the gap in the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 is the minimum, As thick as possible. Further, 31 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 22, and split locking ring 19 are fitted in this order, and the socket 1 is 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 22
When the lock ring 19 is pushed into the annular space in the axial direction, the end of the back-up spring 22 and the free end of the plate 24 slide and expand according to the outer diameter of the socket 14, ensuring that the lock ring 19 is inserted into the annular groove 18. Push up. After that, after pushing the seal packing 16 into the annular space in the axial direction, a push ring 27 is applied to the back of the seal packing 16, and then the push ring 27 and the socket 1
The flange part 28 of No. 3 is connected to the bolt 29 and nut 30.
The joining is completed by fastening with. 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 31 at the rear 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,
Moreover, 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. In addition, since the back-up spring 22 is made of metal or hard synthetic resin, the socket 13
If the gap in the annular space between the inner surface and the outer surface of the socket 14 is thin as shown in FIG. 4A or standard as shown in FIG. Of course, when a pull-out force biased in the direction is applied, the back-up spring 22 reliably prevents the diameter of the lock ring 19 from shrinking, and it is possible to reliably prevent the lock ring 19 from coming off between the sockets 13 and 14. , even when the gap between the annular spaces is thick as shown in FIG. is made of metal and is rigid and does not deform, so there is no risk that the back up spring 22 will deform due to relative movement between the socket 13 and the socket 14 and move further into the socket 13 than the lock ring 19. Therefore, when 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 19, the back-up spring 22 reliably prevents the lock ring 19 from shrinking in diameter, and the socket 13 is inserted into the socket 13. 14. It is possible to reliably prevent mutual slippage. Moreover, the socket 1 of the back-up spring 22
3. On the side of the opening side, there is a back-up spring 22.
Since the plate body 24 covering the divided part 23 is fixed, a part of the seal packing 16 covers the divided part 23.
3, and therefore there is no risk of damage to the seal packing 16.

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 circumference of the push ring 27 may be brought close to the outer surface of the socket 14 even if the press ring 27 is formed integrally. Since the inner circumferential portion of the seal packing 16 can be brought into contact with almost the entire rear surface thereof, it is possible to omit dividing the press ring 27 into two.

As explained above, according to the earthquake-resistant pipe joint according to the present invention, since the back-up spring made of metal or hard resin is provided, even if the gap in the annular space between the inner surface of the socket and the outer surface of the socket is large. However, it can reliably prevent slippage between the socket and socket, and the back-up spring can slide in the circumferential direction and expand the diameter in the radial direction, and has a biasing force for reducing the diameter. Although it is rigid, it expands according to the outer diameter of the insertion port, allowing for secure installation.
Since a plate is provided on the side surface of the back-up spring on the side of the socket opening to cover the divided portion of the back-up spring, damage to the seal packing due to entry into the divided portion of the back-up spring 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 4 show an embodiment of the present invention, Fig. 2 is a longitudinal sectional view thereof, and Fig. 3 is a divided portion of a back-up spring. The side views of the vicinity and FIGS. 4A to 4C are longitudinal cross-sectional views illustrating changes in the state of contact between the lock bolt and the back-up spring due to changes in the gap in the annular space between the inner surface of the socket and the outer surface of the socket. . 13...Socket, 14...Socket, 15...Protrusion, 16...
Seal packing, 18... Annular groove, 19... Lock ring, 20, 21... Tapered surface, 22... Backup spring, 23... Backup spring divided portion, 24... Plate body.

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. A tapered surface that abuts the tapered surface of the lock ring is formed on the side surface on the back side of the socket, and a side surface on the side of the socket opening abuts on the seal packing.
A back-up spring made of metal or hard synthetic resin that can slide in the circumferential direction to expand the diameter in the radial direction and has a biasing force for reducing the diameter is provided in the socket opening side of the back-up spring. An earthquake-resistant pipe joint characterized in that a plate body is provided on a side surface to cover a divided portion of the back-up spring.