JPS623356B2 - - Google Patents

Description

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

BACKGROUND TECHNOLOGY Earthquake resistance is achieved by allowing movement within a certain range in the tube axis direction between the receptacle and the insertion port, but reliably preventing them from slipping out of each other due to further movement. As shown in FIG. 1, an annular protrusion 2 is formed on the outer surface of the tip of the insertion port 1 as an earthquake-resistant pipe joint that has such functions, has excellent sealing performance, and is easy to construct and connect. 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 arranged between the socket 3 and the socket 1, and the annular groove 5 engages with the protrusion 2. A split lock ring 7, which is possible and has a tapered surface 6 toward the back of the socket 3 formed on the side surface on the opening side of the socket 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. When a pull-out force is applied, the back-up spring 8 reliably prevents the lock ring 7 from contracting in diameter, and
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, according to the above-mentioned conventional configuration, due to the dimensional tolerance 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 is smaller than that of the individual pipes. Since the thickness varies depending on the joint, it is necessary to make the radial thickness of the back-up spring 8 approximately equal to the minimum value of the gap in the annular space.

Further, since the lock ring 7 must be inserted into the inner side of the socket 3 from the annular space, its radial thickness must be made thinner than the minimum value of the gap in the annular space. Therefore, when the gap in the annular space is wide, the area of the contact surface between the lock ring 7 and the back up spring 8 becomes very small, and therefore, the back up is caused by the relative movement between the socket 3 and the back up spring 1. There was a problem in that the coupling ring 8 moved to the back side of the socket 3 relative to the locking ring 7, and the function of preventing the diameter of the locking ring 7 from decreasing.

In view of the above-mentioned points, the present invention aims to provide an earthquake-resistant pipe joint that can reliably prevent slippage between sockets and sockets.

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, an annular body that abuts both the inner peripheral surface of the lock ring and the tapered surface is fitted inside the lock ring, and between the annular body and the seal packing, A back-up spring is provided that comes into contact with both of them.

Effect: According to this configuration, even if the gap in the annular space formed between the inner surface of the socket and the outer surface of the socket is wide, the back-up spring and the lock ring are Compared to the case where the lock ring and the lock ring directly contact each other, the lock ring and the lock ring engage with each other through a tapered surface having a wider area corresponding to the thickness of the annular body portion that contacts the inner circumferential surface of the lock ring.
Therefore, 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 annular body, and the diameter reduction of the lock ring will be reliably prevented and the This ensures that no gaps are left in between.

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. Note that this protrusion 15 may be formed integrally with the socket 14. On the other hand, a tapered surface 17 is formed on the inner surface of the socket 13 at an open end thereof, on which a seal packing 16 is installed, and an annular groove 18 is formed on the inner side thereof. 1
Numeral 9 is a lock ring that can be inserted into the back 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 into the annular groove 18 with a biasing force for expanding the diameter when it is divided into 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. The lock ring 19 also includes a cylindrical portion 21 that abuts the entire inner circumferential surface of the lock ring 19, and
An annular body 2 having a substantially doglegged cross section and a tapered portion 22 extending from the end on the opening side of the socket 13 along the tapered surface 20 and abutting substantially the entire surface of the tapered surface 20.
3 is fitted inside, and between the annular body 23 and the seal packing 16, a tapered surface 24 that comes into contact with the tapered part 22 of the annular body 23 is formed on the back side surface of the socket 13, In addition, a back-up spring 25 is arranged whose side surface on the opening side of the socket 13 comes into contact with the side surface of the seal packing 16 on the back side of the socket 13. The annular body 23 is made of a hard material such as ductile cast iron or steel, has a biasing force for diameter expansion when divided into one piece, and extends from the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 to the back side of the socket 13. It can be inserted and is pressed against the lock ring 19 by its diameter expansion biasing force. The back-up spring 25 may be made of hard rubber, cloth impregnated with rubber, hard synthetic resin, or
Alternatively, it is made of metal or the like, and is formed in one piece or in pieces. Reference numeral 26 denotes a two-part push ring that presses the seal packing 16. A T-shaped bolt 28 and a nut 29 are inserted into the hole provided in the flange portion 27 of the socket 13 and the hole provided in the push ring 26. By tightening the bolt 28 and nut 29, a pressing force is applied to the seal packing 16, and the socket 13 and the socket 14 are
Sealing performance is ensured. Note that the annular body 23
As shown in FIG. 3A, 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, the radial dimension of The size is as large as possible, and the thickness is such that the cylindrical portion 21 can be inserted into the gap between the outer surface of the socket 14 and the inner peripheral surface of the lock ring 19. Further, the thickness of the back-up spring 25 in the radial direction is
As shown in FIG. A, when the gap in the annular space is minimum, the backing ring 25 has a thickness that allows insertion into the back of the socket 13 from the annular space. Tapered surface 2
Lock ring 19 instead of directly touching 0.
Since the gap contacts the tapered portion 22 of the annular body 23 that fits into the annular body 23, the gap between the annular spaces is standard as shown in FIG. Even when the gap is maximum, the area of the contact surface between the back-up spring 25 and the annular body 23 is sufficiently large. 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 insertion port 14, the seal packing 16, the back-up ring 25, the annular body 23, and the split locking ring 1.
9 are fitted onto the outside in this order and left in the socket 14, and then the socket 14 is inserted into the socket 13. Then,
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 fits into the annular groove 18 due to its diameter expansion biasing force. be done. Next, when the annular body 23 is pushed into the annular space in the axial direction, the annular body 23 is pushed into the locking ring 1 by its diameter expansion biasing force.
Press onto the inner surface of 9. After this, the back spring 25 and the seal packing 16 are pushed into the annular space in the axial direction, and then the push ring 26 is applied to the back of the seal packing 16, and then the push ring 26 and the flange portion 27 of the socket 13 are bolted together. 28 and nut 29, 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 lock ring from coming off. In addition, the back-up spring 25 is further provided with a seal packing 16 on the side surface of the lock ring 19 so that the pressing force of the seal packing 16 effectively acts as seal surface pressure.
Only a portion of the surface is pressed against the surface, so that the surface is not damaged. In addition, if the gap between the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 is narrow or standard, 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, Then, the annular body 2 is removed by the back up spring 25.
3, the lock ring 19 is reliably prevented from shrinking in diameter, and it is possible to reliably prevent the lock ring 19 from coming off between the sockets 13 and 14. Even if the space is wide, the area of the contact surface between the tapered surface 24 of the back-up ring 25 and the tapered portion 22 of the annular body 23 that fits inside the lock ring 19 is sufficiently large, so that the socket 1
There is no risk that the back-up spring 25 will be deformed by the relative movement between the three sockets 14 and move further into the socket 13 than the annular body 23, and therefore a particularly large pull-out force in the tube axis direction will be applied to the lock ring 19. When a pull-out force biased in the circumferential direction is applied, the back-up spring 25 reliably prevents the lock ring 19 from contracting in diameter via the annular body 23, and the socket 13
It is possible to reliably prevent slippage between the insertion ports 14.
Therefore, it has an earthquake-resistant function.

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

Further, in the above embodiment, an example was explained in which the cylindrical portion 21 of the annular body 23 was configured to abut the entire inner circumferential surface of the lock ring 19. No. 13 may be used as long as it comes into contact with the vicinity of the end on the opening side.

Effects of the Invention As explained above, according to the earthquake-resistant pipe joint according to the present invention, even when the gap in the annular space between the inner surface of the socket and the outer surface of the socket is large, it is possible to ensure that the socket and the socket can be pulled out from each other. can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a conventional earthquake-resistant pipe joint, Fig. 2 and Fig. 3 show an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view thereof, and Fig. 3 A to C are inner surfaces of the socket. FIG. 4 is a longitudinal cross-sectional view illustrating a change in the state of contact between the back-up spring and the annular body due to a change in the gap in the annular space between the annular body and the outer surface of the insertion port. 13...Socket, 14...Socket, 15...Protrusion, 16...
Seal packing, 18... Annular groove, 19... Lock ring, 20... Tapered surface, 23... Annular body, 25...
Back at Spring.

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 inner peripheral surface of the lock ring is fitted into the lock ring. and the tapered surface, and a back-up spring is provided between the annular body and the seal packing, and the back-up spring comes into contact with both of them. Fittings.