JPS623355B2 - - 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 axial direction of the tube between the socket and the insertion port, but reliably preventing them from coming out 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. Even when a pull-out force is applied, the back-up spring 8 reliably prevents the diameter of the lock ring 7 from shrinking.
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 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 Since the thickness varies depending on the pipe joint, the radial thickness of the back-up spring 8 has to be approximately equal to the minimum value of the gap in the annular space. Therefore, if the gap in the annular space is thick, the area of the contact surface between the locking ring 7 and the backup spring 8 will be very small, and therefore, the relative movement between the socket 3 and the socket 1 will cause the backup The ring 8 moved further into the socket 3 than the lock ring 7, causing a problem in fulfilling the function of preventing the lock ring 7 from shrinking in diameter.

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 7 is fitted, and a tapered surface that contacts the tapered surface of the lock ring is formed on the back side of the socket between the lock ring 7 and the seal packing. A back-up spring is provided in which a recess is formed on the side surface and extends all the way around the circumference.

Effect According to this configuration, when the annular space between the inner surface of the socket and the outer surface of the socket is narrow, the back-up spring is compressed between the inner surface of the socket and the outer surface of the socket. By crushing the concave portion, it is relatively easily deformed to become thinner and inserted into this annular space. As a result, the back-up spring prevents the lock ring from shrinking in diameter, thereby reliably preventing the lock ring from slipping out between the receptacles. In addition, if the gap in the annular space is sufficiently wide, the backup spring will be installed without being compressed, and will come into contact with the locking ring with a large surface that leaves room for compression. ,
This also reliably prevents the lock ring from slipping out between the socket and the socket due to its diameter reduction.

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 material of the lock ring 19 is ductile cast iron or steel. Also, socket 1 of lock ring 19
3. On the side of the opening side, there is a socket 13 on the back side, that is, the socket 1.
4 A tapered surface 20 is formed toward the tip side, and a lock ring 1 is formed on the back side of the socket 13 between the lock ring 19 and the seal packing 16.
A back-up spring 2 in which a tapered surface 21 is formed in contact with the tapered surface 20 of No. 9, and a recessed portion 22 is formed in the side surface on the opening side of the socket 13 over the entire circumferential direction.
3 is placed. The back-up spring 23 is made of a material that does not easily undergo plastic deformation, such as hard rubber, cloth impregnated with rubber, hard synthetic resin, or metal, and is formed as one piece or in pieces. 24 presses the seal packing 16 2
Attach the flange portion 25 of the socket 13 with a split press ring.
It is attached by a T-shaped bolt 26 and nut 27 inserted through a hole provided in the push ring 24 and a hole provided in the press ring 24.
By tightening 7, the seal packing 16
A pressing force acts on the socket 13 and the socket 14 to ensure a tight seal. In addition, the above-mentioned Backup Spring 2
The radial thickness of the back-up spring 2 is approximately equal to the standard gap of the annular space between the inner surface of the socket 13 and the outer surface of the socket 14, as shown in FIG. 3B.
3 has a recess 22 formed in the side surface on the opening side of the socket 13, which extends all the way around the circumference, so it can be relatively easily deformed to become thinner, and therefore the socket 13 can be deformed to become thinner as shown in FIG. 3A. Even if the gap in the annular space between the inner surface of the opening 13 and the outer surface of the socket 14 is narrow, the back-up spring 23 can be inserted into the annular space. In addition, since the thickness of the back-up spring 23 is thicker than the conventional one, the socket 13 is
Even if the gap in the annular space between the inner surface and the outer surface of the socket 14 is thick, the area of the contact surface between the lock ring 19 and the back-up spring 23 is sufficiently large. Note 2
Reference numeral 8 denotes a step surface at the far end of the socket 13.

To explain the connection work, from the tip side of the socket 14, the seal packing 16, the back-up ring 23, and the split lock 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. After that, the back spring 23 and the seal packing 16 are pushed into the annular space in the axial direction, and then the press ring 24 is applied to the back of the seal packing 16, and then the back ring 24 and the flange part 25 of the socket 13 are bolt 26 and nut 2
7, 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 28 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. In addition, the back-up spring 23 is designed so that the pressing force of the seal packing 16 effectively acts as sealing surface pressure, and furthermore, only a part of the seal packing 16 comes into pressure contact with the side surface of the lock ring 19, so that its surface is not damaged. I'll make sure it doesn't exist. In addition, 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 tube axis direction or a pull-out force biased in the circumferential direction is applied to the lock ring 19, To,
Locking ring 1 by back up spring 23
9 is reliably prevented from shrinking in diameter, and the socket 13 and the socket 14 are reliably prevented from slipping out from each other, the gap in the annular space between the inner surface of the socket 13 and the outer surface of the socket 14 is thick. Even if the contact surface area between the lock ring 19 and the back up spring 23 is sufficiently large, and the socket 13 of the back up spring 23
A seal packing 16 is in contact with the side surface on the opening side, and the backing spring 23 is not easily deformed to become thinner.
There is no risk that the back-up spring 23 will be deformed due to the relative movement between the three sockets 14 and move further into the socket 13 than the lock ring 19, and therefore the lock ring 19 will not be subject to a particularly large pull-out force in the tube axis direction. Even when a circumferentially biased pull-out force is applied,
Locking ring 1 by back up spring 23
9 is reliably prevented from shrinking in diameter, and the receptacle 13 and the receptacle 14 are reliably prevented from slipping out from each other. Therefore, it has an earthquake-resistant function.

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 periphery of the push ring 24 may be brought close to the outer circumferential surface of the socket 14 even if the press ring 24 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 24 into two.

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 sectional view of a conventional earthquake-resistant pipe joint, Figs. 2 and 3 show an embodiment of the present invention, Fig. 2 is a longitudinal sectional view thereof, and Figs. 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 lock ring and the back-up ring due to a change in the gap in the annular space between the lock ring 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... Concave portion, 2
3... Backup 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 lock ring and the seal packing are connected to each other. and a back-up ring having a tapered surface in contact with the tapered surface of the lock ring on the side surface on the back side of the socket, and a recess extending all the way around in the circumferential direction on the side surface on the side of the socket opening. Earthquake-resistant pipe fittings featuring: