JPS6337590Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electrically conductive pipe joint with improved current conductivity.

For example, buried conduits buried under the ground are subject to chemical corrosion due to the soil environment or electrical corrosion due to stray currents, macro cells, and the like. Anti-corrosion coatings and cathodic protection are used to prevent these, but when using cathodic protection, the target pipes must be electrically conductive and must be insulated at the joints. In some cases, it is difficult to apply cathodic protection to the entire pipeline.

In addition, buried pipes often require construction work such as replacement or relocation, but in such cases,
It is necessary to accurately determine the location of buried conduits. A commonly used method for detecting the location of buried conduits from the ground without digging is to pass a current at a specific frequency through the buried conduit and use a detector to detect the magnetic field generated by this, but in this case as well. The target buried pipeline must be electrically conductive. If such location detection is required for a non-conducting buried pipe, a method is used to bury a detection wire parallel to the pipe when it is buried, but if the pipe can be made electrically conductive, , such a detection wire becomes unnecessary. Making the pipe electrically conductive in this way is useful for installing cathodic protection and investigating the buried location from the ground, but generally the outer surface of the buried pipe is coated with anti-corrosion coating such as polyethylene, which is in close contact with the pipe body. This anti-corrosion coating is interposed between the pipe and the joint body, causing an increase in electrical resistance. In order to make such cladding conductive at the joint, it is necessary to peel off the sheathing near the joint and remove the adhesive, but this increases the work required to peel off the sheathing or prevent corrosion on the peeled surface, reducing construction efficiency. This results in a decrease in

This idea was created in view of the above-mentioned circumstances.
The purpose of this is to be able to penetrate the anti-corrosion coating and obtain good electrical conductivity simply by screwing the fitting body, without peeling off the anti-corrosion coating. It is an object of the present invention to provide an electrically conductive pipe joint that can securely seal between the joint body and the connecting pipe using a gasket and prevent the connecting pipe from being pulled out even if conductivity is obtained.

In order to achieve the above object, the present invention forms a second tapered surface 8 that gradually increases in diameter toward the abutment tool 5 side in the inner hole of the tightening ring 7 on the abutment tool 5 side,
A holding belt 11a is provided between the second tapered surface 8, the abutting tool 5, and the connecting pipe 2, and a second tapered surface 8 of the tightening ring 7 held by the holding belt 11a.
A plurality of spheres 9 are bitten into the anti-corrosion coating layer of the connecting pipe 2 by pressure from the rear surface 1 of the axial piece 10a.
The taper formed at 0a' is slidably brought into contact with the second tapered surface 8 of the tightening ring 7, and the radial piece 10
The sharp tip 10b' formed at the tip of b breaks through the anti-corrosion coating layer 2b of the connecting tube 2 by pressure from the second tapered surface 8 of the tightening ring 7 and bites into the metal part 2a of the connecting tube 2. The L-shaped conductive member 10 is provided.

Hereinafter, the present invention will be explained based on an embodiment shown in the drawings. The drawing shows an example in which connecting pipes 2, 2 are inserted into inner holes 3, 3 of one joint body 1 from both sides and connected.

That is, at the back of the inner hole 3 of the joint body 1 into which the connecting pipe 2 is inserted, a first tapered surface 4 is formed whose diameter gradually increases toward the open end 1b side, and the first tapered surface 4 is connected to the first tapered surface 4. A gasket 6 is housed between the gasket 6 and the connecting pipe 2, a stopper 5 is disposed on the open end 1b side of the joint main body 1 of the gasket 6, and a stopper 5 is arranged on the first tapered surface 4 of the joint main body 1. A clamping ring 7 having electrical conductivity and pressing the gasket 6 through the joint body 1 is screwed onto the joint body 1. A second tapered surface 8 whose diameter gradually increases toward the abutment tool 5 side is formed in the inner hole of the tightening ring 7 on the abutment tool 5 side, and this second tapered surface 8 and the abutment tool A holding belt 11a and a plurality of rings held by the holding belt 11a and bitten into the anticorrosion coating layer of the connecting pipe 2 by pressure from the second tapered surface 8 of the tightening ring 7 are provided between the connecting pipe 2 and the connecting pipe 2. The axial piece 10a is arranged on the holding belt surface between the spheres 9... and the spheres 9...
A taper formed on the back surface 10a' is slidably abutted on the second tapered surface 8 of the tightening ring 7, and a sharp tip 10 is formed at the tip of the radial piece 10b.
L-shaped conductive member 1 which breaks through the anti-corrosion coating layer 2b of the connecting pipe 2 and bites into the metal part 2a of the connecting pipe 2 by pressure from the second tapered surface 8 of the tightening ring 7.
0.

That is, the holding belt 11a, for example,
As shown in the figure, it is made of soft rubber, for example, and is wrapped around the outer circumference of the connecting pipe 2 in a ring shape, and a required number of steel spheres 9 are embedded at intervals in the longitudinal direction (circumferential direction), and the spheres 9, An L-shaped conductive member 10 is mounted on the surface of the holding belt 11a between the two. As shown in FIGS. 3 and 4, the L-shaped conductive member 10 is approximately L-shaped when viewed from the side, and as shown in FIG. The attached ring 7 is tapered in the opposite direction to the second tapered surface 8 so as to directly contact and fit into the second tapered surface 8, and in this state, the sharpened shape formed at the tip of the radial piece 10b The tip 10b' is directed toward the outer peripheral surface of the connecting tube 2. This L-shaped conductive member 10 has good electrical conductivity and high mechanical strength, for example.
A material such as SS41 is used. It should be noted that this L-shaped conductive member 10 can be expected to have an electrically conductive effect even with just one, but in order to ensure that it has a reliable electrically conductive effect even when the connecting pipe 2 is bent with respect to the joint body 1. It is better to provide them at multiple locations at appropriate intervals in the circumferential direction. Furthermore, by curving the radial piece tip 10b' of the L-shaped conductive member 10 with a smaller curvature than the outer circumference of the connecting pipe 2, as shown in FIG. It makes it easy to bite into.

Further, the clamping ring 7 and the joint body 1 against which the L-shaped conductive member 10 comes into contact are made of materials with good electrical conductivity, so that the current from the L-shaped conductive member 10 can easily flow. ing.

Further, the abutting tool 5 is formed into a ring shape of a plastic material having high mechanical strength and good lubricity, for example, and the tightening force from the tightening ring 7 is transmitted to the gasket 6 via the abutting tool 5. It is becoming more and more common.

Thus, the connecting pipe 2 is inserted into the inner hole 3 of the joint body 1, and the outer peripheral thread 7a formed on the outer periphery of the tightening ring 7 is inserted into the inner peripheral thread 1a formed on the inner periphery of the joint main body 1. Screw them together, and in this state, connect the joint body 1.
By screwing in the tightening ring 7, the tightening ring 7 is axially screwed in the direction of the arrow A shown in the figure, and the second tapered surface 8 is attached to the rear surface 1 of the L-shaped conductive member 10 in the axial direction.
Press 0a'. Due to the pressure by the second tapered surface 8, the radial piece 10 of the L-shaped conductive member 10
b moves in the radial direction in the direction of arrow B in accordance with the taper of the second tapered surface 8, and the tip 10b' of the radial piece bites into the outer circumferential surface of the connecting pipe 2. Due to this biting of the radial piece tip 10b', the anticorrosion coating layer 2b covering the outer peripheral surface of the connecting pipe 2 is broken, and the radial piece tip 10b' of the L-shaped conductive member 10 is broken.
b' directly contacts and bites into the metal part 2a of the connecting pipe 2, and in this state, the current flowing through the pipe passes through the metal part 2a, the L-shaped conductive member 10, and the tightening ring 7, and It flows from this joint body 1 through the adjacent tightening ring 7 and L-shaped conductive member 10 to the adjacent metal portion 2a. This makes it easier for the anticorrosion current to flow through the pipe at the joint of the pipe, and corrosion (electrolytic corrosion) can be reliably prevented.

In addition, in this state, the sphere 9 is interposed between the second tapered surface 8 and the connecting tube 2 and acts as a wedge to prevent the connecting tube 2 from coming off. Gasket 6 via tool 5
In order to press the gasket 6, the first tapered surface 4
The connecting pipe 2 and the joint body 1 are firmly sealed.

In the above embodiment, an example was explained in which the connecting pipes 2, 2 are connected to the joint body 1, but the present invention also applies if the joint body provided integrally with one connecting pipe is connected to the other connecting pipe. can be carried out.

As explained above, according to the configuration of the present invention,
When the tightening ring 7 is screwed into the joint body 1, the second tapered surface 8 of the tightening ring 7 causes the L-shaped conductive member 1 to tighten.
0 and the sphere 9 are pressed toward the connecting tube 2, and the sharp tip 10b' of the L-shaped conductive member 10 breaks through the anticorrosive coating layer 2b of the connecting tube 2 and bites into the metal part 2a of the connecting tube 2. The sphere 9 also bites into the anti-corrosion coating layer 2b of the connecting tube 2, and can simultaneously provide electrical continuity between the joint body and the connecting tube and prevent the connecting tube from slipping out. Therefore, even if an electrically conductive member is added within the joint body, no trouble is caused in the connection work. Moreover, the back surface 10 of the axial piece 10a of the L-shaped conductive member
a' is slidably tapered on the second tapered surface 8 of the tightening ring, so when the tightening ring 7 is screwed into the joint body 1, the second tapered surface 8 of the tightening ring 7 enters the taper. This ensures that the L-shaped conductive member 10
The sharp tip 10b' of the connecting tube 2 can be bitten into the connecting tube 2, thereby ensuring good and reliable electrical continuity between the connecting tube and the joint body.

On the other hand, when the tightening ring 7 is screwed into the joint body 1, the tip of the tightening ring 7 can reliably press the gasket via the stopper without being affected by the presence of the L-shaped conductive member 10. . Therefore, sealing between the joint body and the connecting pipe can be ensured.

Furthermore, in the case of the configuration of the present invention, the electrically conductive member 10
is L-shaped and placed on the holding belt 11a surface between the holding belts 11a holding a plurality of spheres 9. 10, the second tapered surface 8 of the clamping ring 7, and the connecting pipe 2, there is almost no need to enlarge the space (in the case of the embodiment, it is not necessary to increase the space at all). can also be prevented.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal side view, FIG. 2 is a side view of a holding belt with a sphere and an L-shaped conductive member arranged, and FIG. 3 is a side view of the L-shaped conductive member. FIG. 4 is a front view of the L-shaped conductive member. 1... Joint body, 1a... Inner peripheral threaded part of the joint body, 1b... Open end of the joint body, 2... Connection pipe,
2a... Steel main pipe of the connecting pipe, 2b... Corrosion-proof coating layer of the connecting pipe, 3... Inner hole of the joint body, 4... First tapered surface, 5... Fitting tool, 6... Gasket, 7 …
... Tightening ring, 8 ... Second tapered surface, 9 ... Sphere, 1
0... L-shaped conductive member, 10a... Axial piece of L-shaped conductive member, 10a'... Back side of axial piece of L-shaped conductive member, 10b... Radial piece of L-shaped conductive member, 10b '... End of radial piece of L-shaped conductive member, 11a... Holding belt.

Claims (1)

[Scope of utility model registration request] A first tapered surface 4 whose diameter gradually increases toward the open end side of the joint body 1 is formed at the back of the inner hole of the joint body 1 into which the connecting pipe 2 having an anticorrosive coating layer on the outer peripheral surface is inserted. A gasket 6 is housed between the first tapered surface 4 and the connecting pipe 2, and a stopper 5 is disposed on the open end side of the joint body 1 of the gasket 6, and the first taper of the joint body 1 is disposed on the open end side of the joint body 1. A clamping ring 7 having electrical conductivity that presses the gasket 6 on the surface 4 via the abutment 5 is screwed onto the joint body 1, and the clamping ring 7 A second tapered surface 8 whose diameter gradually increases toward the abutting tool 5 side is formed in the inner hole on the tool 5 side, and a second tapered surface 8 is formed between the second tapered surface 8 and the abutting tool 5 and the connecting pipe 2. ,
A holding belt 11a, a plurality of spheres 9 held by the holding belt 11a and bitten into the anticorrosion coating layer of the connecting pipe 2 by pressure from the second tapered surface 8 of the tightening ring 7, and the spheres 9. The taper formed on the back surface 10a' of the axial piece 10a is slidably abutted on the second tapered surface 8 of the tightening ring 7, and the tip of the radial piece 10b The sharp tip 10b' formed in the second
Electrical conductivity characterized by comprising an L-shaped conductive member 10 that pierces the anti-corrosion coating layer 2b of the connecting pipe 2 and bites into the metal part 2a of the connecting pipe 2 by pressure from the tapered surface 8. pipe fittings.