JP2001317683A - Pipe joint having function of preventing flaw in spigot projection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an end face corrosion preventing protective coating overlaying a spigot projection from being damaged by a lock ring cover covering a lock ring even when a spigot is moved in a withdrawal direction. SOLUTION: A lock ring 13 fixed to the internal surface of a socket 10 of a pipe joint is covered with a taper cylinder 2 that uniformly covers the internal surface of the lock ring 13 from the socket opening-side face to the internal surface thereof. The socket back-side end of the taper cylinder 2 is extended beyond the lock ring 13, and the extended end 2d is bent radially outward of the pipe. That end of a protective covering 1c overlaying the external surface of a projection 1a of a spigot 1 which faces the lock ring 13 after inserted in the socket 10 is allowed to slide between the bent extended end 2d and the internal surface of the socket 10 when the spigot l is moved in a withdrawal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a pipe joint having a function of preventing an insertion projection from being damaged.

[0002]

2. Description of the Related Art As a pipe joint for a metal pipe such as a ductile cast iron pipe, a pipe joint as shown in FIG. 5 is known.

In this pipe joint 10, a sealing rubber ring storage groove 11a and a lock ring storage groove 11b are formed on the inner surface of a receiving port 11, and as shown, the sealing rubber ring 12 is connected to the sealing rubber ring storage groove 11a. After the centering rubber 14 and the lock ring 13 are attached to the lock ring storage groove 11b,
The insertion protrusion 1a of the lock ring 1 as shown in FIG.
When the release force is applied to the joint portion 10, the insertion protrusion 1a is pressed against the three portions and inserted beyond the insertion protrusion 1a.
The lock ring 13 is engaged with the lock ring 13 to prevent the lock ring 13 from coming off.

[0004]

When the pipe joint 10 is joined, as shown in FIG.
Is inserted into the socket 11 while pushing the lock ring 13 by the tapered portion 1b.
3, there is a problem in that the anticorrosion coating on the outer surface of the tapered portion 1b is scratched and the insertion projection 1a is inferior in corrosion protection.

[0005] In order to solve such a problem, as shown in FIG.
A lock ring cover 15 made of polyethylene or the like having low friction is put on to reduce the contact force with the insertion projection 1a forcibly inserted.

Incidentally, a heat-shrinkable tube or the like may be put on the tip of the insertion slot 1 inserted as described above as a protective coating 1c for protecting the end face. When the insertion protrusion 1a comes into contact with the lock ring 13, the extension 15a of the cover 15 covered by the lock ring 13 is attached to the end of the protective coating 1c covered by the insertion protrusion 1a. As a result, the protective coating 1c is crushed as shown by the reference numeral 1d in FIG. 8, and is further peeled off or displaced, and there is a concern that the end face corrosion protection function of the protective coating 1c is impaired.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problem and to prevent the protective film for protecting the end face from being damaged at all even when the insertion opening moves in the exit direction.

[0008]

In order to achieve the above object, according to the present invention, a lock ring attached to an inner surface of a socket of a pipe joint uniformly covers an inner surface from a side surface of an opening of the socket to the inner surface of the lock ring. The tapered tubular body to be covered is covered, and the receiving port inner end of the tapered tubular body is extended from the lock ring,
The extension end is bent outward in the radial direction of the pipe, while the lock ring side end of the protective cover material for covering the outer surface of the projection of the insertion hole inserted into the reception hole comes out of the insertion hole. When it moves in the direction, it can slide between the bent extension end and the inner surface of the receptacle.

Therefore, according to the present invention, even if the insertion projection engages with the lock ring, the lock ring cover rides on the end face anticorrosion coating covering the insertion projection. Therefore, adverse effects such as peeling do not occur.

[0010]

Next, an embodiment of the present invention will be described. FIG. 1 is an explanatory perspective view of a lock ring cover of the present invention, FIG. 2 is a sectional view of a pipe joint having a function of preventing an insertion projection from being damaged according to an embodiment, and FIGS. FIG.

In FIG. 1, reference numeral 2 denotes a lock ring cover, and as shown in FIG. 2, a side surface 2a of the lock ring 13 along the receiving opening side 13a passes through an inclined surface 2b along the inclined surface 13b of the lock ring 13. Lock ring inner surface 13
A cylindrical inner surface 2c is formed along the inner surface 2c, and the end 2d of the cylindrical inner surface on the insertion projection side is bent radially outward.

As shown in FIG. 1, the whole is divided into one and can be reduced in diameter and expanded together with the lock ring 13, and the whole is integrally formed of a slippery resin such as polyethylene resin.

The side wall 2a of the lock ring cover 2 on the opening side of the receiving opening is made thicker in the axial direction T so that the side surface 2a is not deformed or twisted at the split portion due to friction at the time of insertion of the insertion opening. It is reinforced by.

The inner surface portion 13c of the lock ring 13
The thickness t (FIG. 1) of the cylindrical portion 2c extending along the length is a thickness that does not cause breakage when the insertion projection 1a is inserted, and the engagement amount of the lock ring 13 with the insertion projection 1a is sufficient. And the wall thickness t is specifically 200 to 50.
0 μm.

Next, the connection state of the pipe joint having the function of preventing the insertion projection from being damaged will be described. As shown in FIG.
After the centering rubber 14 is mounted in the lock ring storage groove 11b on the inner surface of the inner ring 0, the lock ring 13 fitted with the lock ring cover 2 is mounted.

Next, the insertion port 1 covered with the end face anticorrosion coating 1c is inserted. At this time, the end face anticorrosion coating 1c of the insertion projection 1a is locked through the tapered portion 2b and the inner surface 2c of the lock ring cover 2. The contact with the ring 13 prevents the anticorrosion coating 1c from being damaged by the lock ring 13.

The lock ring cover 2 is placed on the inner surface of the receiving port 11 while being fitted to the outer surface of the lock ring 13 even after the insertion port 1 is connected.
Since d is bent outward in the radial direction, the insertion port moves in the exit direction, such as during an earthquake, and the insertion projection 1a and the lock ring 1
Even when it comes to a situation where it comes into contact with the end portion 3, as shown in FIG. 4, the end portion of the lock ring cover 2 covers the insertion projection 1a by the guide function of the bent portion 2d.
c, and the end surface is used as the anticorrosion coating 1c.
The detrimental effect of breaking or peeling off is prevented.

Therefore, according to the lock ring cover of this embodiment, the opening 1 can be inserted without damaging the anticorrosion coating 1c.
Can be inserted into the receptacle 11, and when the function of preventing the lock ring from being operated after connection is established, the lock ring cover 2 rides on the anticorrosion coating on the end face.
Is not broken.

[0019]

As described above, according to the lock ring cover of the present invention, when the pipe is connected, the insertion port can be connected without damaging the anticorrosion coating, and after the connection, the anti-seismic function is exhibited and the lock is achieved. When the ring and the insertion projection come into contact,
Since the lock ring cover rides on the end face anticorrosion coating of the opening, the end face anticorrosion coating is protected, and the pipe connection state after the seismic function is exhibited is also maintained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a lock ring cover applied to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a pipe joint according to an embodiment, which has a function of preventing an insertion projection from being damaged.

FIG. 3 is an explanatory sectional view of a main part showing a connection state of a pipe joint having a function of preventing an insertion projection from being damaged according to an embodiment;

FIG. 4 is a cross-sectional view of a principal part illustrating a connection state of a pipe joint having a function of preventing an insertion projection from being damaged according to an embodiment;

FIG. 5 is a sectional view of a conventional pipe joint.

FIG. 6 is a cross-sectional view of an essential part illustrating a connection state of a conventional pipe joint.

FIG. 7 is a cross-sectional view of an essential part showing a connection state of a conventional pipe joint.

FIG. 8 is a cross-sectional view of a relevant part illustrating a connection state of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insert 1a Insert projection 2 Lock ring cover 2a Side surface on the opening side of receiving opening 2b Tapered portion 2c Cylindrical portion 2d Bending portion 10 Receiving opening 13 Lock ring

Claims (1)

[Claims] 1. A lock ring attached to an inner surface of a socket of a pipe fitting is covered with a tapered cylindrical body that uniformly covers an inner surface from a side surface of the socket opening to an inner surface of the lock ring. A side end of the protective ring is extended from the lock ring, and the extended end is bent radially outward of the pipe, while a protective cover material for covering a projection outer surface of an insertion hole inserted into the socket. The lock ring side end can be slid between the bent extended end and the inner surface of the receptacle when the insertion port moves in the exit direction, thereby preventing the insertion projection from being damaged. A pipe fitting with functions.