JP2002005360A - Detachment preventive pipe coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a possibility of deforming or twisting a lock ring due to force applied for preventing detachment when a spigot projecting part is engaged to the lock ring. SOLUTION: This pipe coupling for preventing extraction of a spigot 1 by engaging the lock ring 3 stored in an inside face of a socket 5 to a spigot projecting part 1a formed on an outside face of the spigot 1 is provided with a cut-out part for receiving the spigot projecting part 1a on a surface facing to the spigot projecting part 1a of the lock ring 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint for preventing separation.

[0002]

2. Description of the Related Art A seismic pipe joint having a structure as shown in FIGS. 4 and 5 is known as a seismic pipe joint for a metal pipe such as a ductile cast iron pipe.

[0003] In a pipe joint 10 shown in FIG. 4, a lock ring accommodating groove 5b is formed in the inner surface of a receiving port 5, and after the lock ring 3 is mounted in the lock ring accommodating groove 5b, the distal end of the joint exceeds the lock ring 3 portion. The insertion port 1 having the insertion projection 1a is inserted into the opening, and the sealing rubber ring 2 and the backup ring 6 previously entrusted to the outer surface are fitted into the opening of the receiving port 5 together. When the pressing ring 7 is tightened with a nut 7a which is screw-fitted to a screw which is screw-fitted, the sealing rubber ring 2 is compressed and sealed, and when a release force is applied to the joint portion 10, the insertion projection 1a is formed. This is a so-called mechanical type earthquake-resistant joint in which the lock ring 3 and the lock ring 3 are engaged as shown in the figure to prevent the joint from coming off.

[0005] The pipe joint 10 shown in FIG. 5 has a sealing rubber ring storage groove 5 a and a lock ring storage groove 5 b formed on the inner surface of the receiving port 5, and the sealing rubber ring 2 is connected to the sealing rubber ring storage groove 5.
After the lock ring 3 is mounted on the lock ring storage groove 5b through the centering rubber 4, the seal ring 2 and the insertion ring 1a having the insertion protrusion 1a at the tip end beyond the lock ring 3 are attached. A so-called slip-on type earthquake-resistant joint in which the insertion projection 1a and the lock ring 3 are engaged to prevent the insertion when the opening 1 is inserted and a release force acts on the joint portion 10. It is.

[0005]

By the way, an external force such as at the time of a large earthquake acts on the pipe joint 10 shown in FIG. 4 or FIG. 5 so that the insertion port 1 comes out and the insertion projection 1a is engaged with the lock ring 3. When the lock ring 3 is prevented from slipping out of the slot, the lock ring 3 has a lock ring storage groove 5b as shown in FIG.
A force F from the inner wall and a force R applied from the insertion projection 1a act, but the axes of these forces do not coincide, and the lock ring 3
, A rotational force T indicated by an arrow is generated, and there is a concern that the lock ring 3 is deformed or twisted as indicated by a dotted line.

SUMMARY OF THE INVENTION The object of the present invention is to solve the above problem and to prevent the lock ring from being deformed or twisted by a force acting when the insertion projection engages with the lock ring. Things.

[0007]

According to a first aspect of the present invention, a lock ring accommodated in an inner surface of a socket is engaged with an insertion projection formed on an outer surface of the insertion port. In the pipe joint which aims to prevent the opening of the insertion port by the surface of the lock ring facing the insertion projection,
A notch for receiving the insertion projection is provided.

Therefore, according to the present invention, when the insertion hole comes out and the insertion protrusion engages with the lock ring and an axial force acts on the lock ring, the insertion into the notch of the lock ring surface on the insertion protrusion side. The mouth projection enters and is radially supported from the inner surface of the lock ring, thereby preventing the lock ring from being deformed.

[0009]

Next, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of a main part showing a separation preventing pipe joint of the present invention.

In FIG. 1, members denoted by the same reference numerals as those in FIGS. 4 and 5 indicate the same or corresponding members, and therefore detailed description is omitted by attaching the same reference numerals. In FIG. 1, a lock ring 3 housed in a lock ring housing groove 5b on an inner surface of a receiving hole 5 formed at one end of a ductile cast iron pipe.
Is made of steel or cast iron, and receives the insertion projection 1a on the side surface 3a of the lock ring 3 facing the insertion projection 1a of another ductile cast iron tube housed in the receiving port 5. A notch 3b is formed.

The height H of the notch 3b is only required to be substantially equal to the height h of the insertion projection 1a, and the accuracy need not be so high. Next, the operation of the detachment preventing pipe joint will be described with reference to the pipe joint shown in FIG. 4 as an example.

When an external force in the axial direction acts on the pipe due to a large earthquake or the like and the insertion projection 1a engages with the lock ring 3 as shown in FIG. 3 enters the lower notch 3b.

Therefore, at this time, the lock ring 3 is rotated around the lock ring 3 by the force F from the inner wall of the lock ring storage groove 5b and the force R from the insertion projection 1a, as shown in FIG. Is generated, but the upper surface of the insertion projection 1a enters the notch 3b of the lock ring 3 to support the rotational force at this portion, and the drag R
1 prevents rotation.

Therefore, even if the forces F and R in the opposite directions in which the axes do not coincide with each other, the lock ring 3 is engaged with the insertion projection 1a without being rotated by the force R1 in the direction perpendicular thereto, thereby preventing the lock ring 3 from coming out. Do.

The above operation is exactly the same for the slip-on type seismic joint shown in FIG. 5, and the inserted projection 1a of the inserted opening 1 enters the notch 3b of the lock ring 3 so that the axes coincide with each other. Even if the forces F and R in the opposite directions are not applied, the rotation of the lock ring 3 is prevented by the force R1 supported by the insertion protrusion 1a entering the notch 3b of the lock ring 3.

[0016]

As described above, the anti-separation pipe joint of the present invention exhibits an anti-seismic function. When the insertion projection engages with the lock ring on the inner surface of the receiving port, the lock ring is unnatural. Since the force to rotate the lock ring does not work, the function of preventing the lock ring from being disengaged is surely exerted without impairment, and the reliability of these seismic joints is increased.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of a separation-preventing pipe joint according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the earthquake-resistant joint according to the embodiment.

FIG. 3 is an operation explanatory enlarged view of the detachment prevention pipe joint according to the embodiment;

FIG. 4 is a cross-sectional view of a conventional mechanical type earthquake-resistant joint.

FIG. 5 is a sectional view of a conventional slip-on type seismic joint.

FIG. 6 is an explanatory view of an operation of a conventional separation preventing pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insert 1a Insert protrusion 2 Seal rubber ring 3 Lock ring 3a Surface facing the lock protrusion 3b Notch for receiving the insert protrusion 4 Centering rubber 5 Receptacle 5b Lock ring storage Groove 10 Seismic joint

Claims (1)

[Claims] 1. A pipe joint in which a lock ring housed on an inner surface of a socket is engaged with an insertion projection formed on an outer surface of the insertion hole to prevent the insertion hole from coming off. A detachment prevention pipe joint comprising a notch for receiving the insertion projection on a surface facing the projection.