JP3137567B2 - Captive fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip-on type separation-preventing pipe joint capable of joining a receptacle to a receptacle by inserting the receptacle into the receptacle.

[0002]

2. Description of the Related Art Conventionally, as this kind of separation preventing pipe joint, for example, there is one shown in FIG. That is, 31 is a ductile cast iron pipe, a receiving port 32 is formed at one end, and an insertion port 33 is formed at the other end, and the insertion port 33 of one pipe 31 is connected to the other pipe 31. The tube 31 can be inserted into the socket 32
Are joined together. On the inner peripheral surface of the receiving port 32, a seal material accommodating groove 34, and a lock ring accommodating groove 35 located on the back side of the seal material accommodating groove 34 are formed. Is provided with a rubber ring 36 for sealing between the inner peripheral surface of the receiving port 32 and the outer peripheral surface of the insertion port 33. Further, a metal lock ring 37 is mounted in the lock ring receiving groove 35, and a lock ring is provided between an outer peripheral side of the lock ring 37 and an inner peripheral side of the lock ring receiving groove 35.
A centering rubber ring 38 for centering 37 is fitted. A projection 39 is formed on the outer periphery of the distal end of the insertion opening 33 so as to engage with the lock ring 37 and prevent the insertion opening 33 from being detached from the receiving opening 32.

According to this, when the insertion opening 33 is inserted into the reception opening 32, the lock ring 37 is pushed to the rear side of the reception opening 32 by the projection 39, and the rear side surface 37a of the lock ring 37 is locked in the lock ring receiving groove.
The projection 39 penetrates the lock ring 37 in a state of being in contact with the rear side surface 35a of the 35, and the insertion port 33 and the receiving port 32 are joined.

[0004]

In the aforementioned conventional type of disengagement-preventive pipe joint, when the insertion port 33 and the receiving port 32 are joined, the outer peripheral side of the lock ring 37 and the inner peripheral side of the lock ring receiving groove 35 are connected. Although the space is insulated through a centering rubber ring 38, the inner surface 37a of the lock ring 37 comes into contact with the inner surface 35a of the lock ring receiving groove 35.
And the opening 33 are electrically connected, and the stray current flows from the one tube 31 to the other tube 31 via the lock ring 37. Therefore, a plurality of pipes 31 can be formed by using a conventional type separation prevention pipe joint.
When these were joined, there was a possibility that a stray current would flow in the pipeline to cause corrosion.

Accordingly, an object of the present invention is to prevent a stray current from flowing from one tube to another via a lock ring.

[0006]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a sealing material receiving groove is provided on an inner peripheral surface of a receiving port. An annular seal that forms a lock ring receiving groove located on the inner side than the inner side and seals between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port inserted into the receiving port in the sealing material receiving groove. A lock ring is inserted into the lock ring accommodating groove, and a lock ring through which an insertion hole can penetrate is attached, and the lock ring is centered between an outer peripheral side of the lock ring and an inner peripheral side of the lock ring accommodating groove. In a detachment prevention pipe joint, a centering member for performing the above operation is fitted, and a projection is provided on an outer periphery of a distal end of the insertion opening so as to engage with a lock ring and prevent the insertion opening from being removed from the receiving opening. And the centering member are each formed of an insulating material, and the lock ring Insulating space is formed between the front side surface of the front side and the locking ring receiving groove, seen write fitted an insulating ring between the inner side surface of the rear side and the locking ring receiving groove of the locking ring, the protrusion Sealing material and lock
It is configured to be able to penetrate the ring and the insulating ring .

According to this, the outer peripheral side of the lock ring and the inner peripheral side of the lock ring receiving groove are insulated through the centering member, and the front side surface of the lock ring and the front side surface of the lock ring receiving groove are insulated. It is insulated through the space, and the back side of the lock ring and the back side of the lock ring receiving groove are insulated through the insulating ring. For this reason, the receptacle of one tube and the insertion opening of the other tube are insulated, and stray current can be prevented from flowing from one tube to the other tube via the lock ring.

[0008]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. Reference numeral 1 denotes a ductile cast iron pipe, in which a receiving port 2 is formed at one end and an insertion port 3 is formed at the other end, and the insertion port 3 of one pipe 1 is connected to the other pipe 1.
The pipes 1 are joined to each other by inserting the pipes 1 into the receiving ports 2.
On the inner peripheral surface of the receiving port 2, a seal material accommodating groove 4 and a lock ring accommodating groove 5 located on the inner side of the seal material accommodating groove 4 are formed. In the sealing material accommodation groove 4,
An annular sealing material 6 for sealing between the inner peripheral surface of the receiving port 2 and the outer peripheral surface of the insertion port 3 is mounted.

The lock ring receiving groove 5 has a trapezoidal cross section, and the front side face 5 of the lock ring receiving groove 5 is formed.
a is formed in a tapered shape over the entire circumference. The lock ring receiving groove 5 is provided with a lock ring 7 through which the insertion opening 3 can pass. A centering ring 8 (an example of a centering member) for centering the lock ring 7 is fitted between the outer peripheral side of the lock ring 7 and the inner peripheral side of the lock ring housing groove 5. .

The lock ring 7 is a metal (for example, a cast iron) ring having a rectangular cross section and a tapered surface 10 formed on the entire front side of the inner peripheral portion. It has a split structure. The sealing member 6 and the centering ring 8 are each made of rubber, which is an example of an insulating material, so as to be elastically deformable. Of these, the centering ring 8 has a rectangular structure with a rectangular cross section, and has a split structure in which one portion in the circumferential direction is cut, and is bonded to the outer peripheral surface of the lock ring 7. .

An insulating space 11 is formed between the front side surface 7a of the lock ring 7 and the front side surface 5a of the lock ring receiving groove 5. An insulating ring 12 is fitted between the rear side surface 7b of the lock ring 7 and the rear side surface 5b of the lock ring housing groove 5, and the outer peripheral portion of the insulating ring 12 is It is fitted between the side surface 8b and the rear side surface 5b of the lock ring housing groove 5. This insulating ring 12 is formed in a thin annular shape in the tube axis direction, and is made of fluororesin (polytetrafluoroethylene or the like).
It has flexibility and slipperiness because it is made of

A projection 14 is formed on the outer periphery of the distal end of the insertion opening 3 to engage with the lock ring 7 in the tube axis direction to prevent the insertion opening 3 from being detached from the receiving opening 2. At the tip of the projection 14, a tapered surface 15 with a taper is formed over the entire circumference.

According to this, when the receiving port 2 and the insertion port 3 are joined, first, the insulating ring 12 is deformed and fitted into the back side of the lock ring receiving groove 5, and then the centering ring 8 and the lock The ring 7 is fitted into the lock ring receiving groove 5.
Then, the sealing material 6 is housed in the sealing material housing groove 4.

In this state, when the insertion port 3 of one tube 1 is inserted into the receiving port 2 of the other tube 1, the projection 14 becomes the sealing material 6.
When the protrusion 14 is further pushed into the inner peripheral side of the lock ring 7, the lock ring 7 is pushed by the protrusion 14 to the rear side of the socket 2, and the inner side surface 7 b of the lock ring 7 and the insulating ring 12 and the back side surface 5b of the lock ring housing groove 5 are in close contact with each other, and an insulating space 11 is provided between the front side surface 7a of the lock ring 7 and the front side surface 5a of the lock ring housing groove 5.
Is formed, and the tapered surface 15 comes into contact with the tapered surface 10 so that the diameter of the lock ring 7 is elastically expanded, so that the protrusion 14 penetrates the lock ring 7. Thereafter, the lock ring 7 returns to the original state, and is securely fitted on the outer periphery of the insertion opening 3.

In the receiving port 2 and the insertion port 3 thus joined, the outer peripheral side of the lock ring 7 and the inner peripheral side of the lock ring receiving groove 5 are insulated through the centering ring 8, and the lock ring 7 is insulated from the front side surface 5a of the lock ring accommodating groove 5 through an insulating space 11,
The back side surface 7b of the lock ring 7 and the back side surface 5b of the lock ring housing groove 5 are insulated through an insulating ring 12. For this reason, the receiving port 2 of one tube 1 and the insertion port 3 of the other tube 1 are insulated, and stray current flows through the lock ring 7 to the one tube 1.
From the other pipe 1 to the other pipe 1 can be prevented.

Further, in the above-described embodiment, before inserting the insertion opening 3 into the receiving opening 2, it is only necessary to attach the insulating ring 12 in advance similarly to the centering ring 8 and the lock ring 7, The joining operation between the mouth 3 and the receiving port 2 can be performed without much difference from the conventional one, and there is no need to largely change the procedure of the joining operation.

Further, since the insulating ring 12 is made of fluororesin, the lock ring 7 easily slides on the insulating ring 12 in the pipe diameter direction. Therefore, the frictional resistance of the insulating ring 12 acting on the lock ring 7 is reduced, so that when the projection 14 penetrates the lock ring 7, the lock ring 7 can easily return to its original state after its diameter is expanded. .

In the above embodiment, the insulating ring 12 is made of a fluororesin such as polytetrafluoroethylene, but a plastic material may be used. Further, the insulating ring 12 may have a split structure in which one portion in the circumferential direction is cut.

[0019]

As described above, according to the first aspect of the present invention, the outer peripheral side of the lock ring and the inner peripheral side of the lock ring receiving groove are insulated through the centering member, The front side of the lock ring and the front side of the lock ring receiving groove are insulated through an insulating space, and the back side of the lock ring and the back side of the lock ring receiving groove are insulated through an insulating ring. For this reason, the receiving port of one tube and the insertion port of the other tube are insulated, and stray current can be prevented from flowing from one tube to the other tube via the lock ring. When the pipes are joined, it is possible to prevent a stray current from flowing through the pipes to cause corrosion.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a detachment prevention pipe joint according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view around a lock ring housing groove.

FIG. 3 is a front view of an insulating ring.

FIG. 4 is a cross-sectional view of a conventional separation prevention pipe joint.

[Explanation of symbols]

 2 Receiving port 3 Insertion opening 4 Seal material accommodating groove 5 Lock ring accommodating groove 5a Front side surface 5b Back side surface 6 Seal material 7 Lock ring 7a Front side surface 7b Back side surface 8 Centering ring (member for centering) 11 Insulating space 12 Insulation ring 14 protrusion

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16L 25/00 F16L 9/02 F16L 25/02

Claims (1)

(57) [Claims] A seal material accommodating groove and a lock ring accommodating groove located deeper than the seal material accommodating groove are formed on an inner peripheral surface of the receiving port. Attach an annular sealing material that seals between the inner peripheral surface and the outer peripheral surface of the insertion hole inserted into the receptacle, and install a lock ring through which the insertion hole can be inserted in the lock ring receiving groove, A centering member for centering the lock ring is fitted between the outer peripheral side of the lock ring and the inner peripheral side of the lock ring accommodating groove. In a detachment prevention pipe joint provided with a protrusion for preventing the insertion of the insertion hole from the mouth, the sealing material and the centering member are each formed of an insulating material, and the front side surface of the lock ring and the front side of the lock ring receiving groove are provided. Form an insulating space between the side and the lock See write fitted an insulating ring between the inner side surface of the rear side and the locking ring receiving groove of the ring, the protrusion
The seal material, lock ring and insulation ring can be penetrated.
A detachable pipe fitting characterized by being formed.