JPH0443797Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an end plug for pinhole inspection of corrugated pipes.

[Conventional technology and its problems]

Generally, if there are pinholes in the corrugated pipes used for many cables, water will leak through the pinholes.
In view of the fact that the various properties of the cable are severely degraded and it becomes unusable, the presence or absence of pinholes is inspected. This inspection is performed by closing both ends of the corrugated pipe to seal in high-pressure gas, and detecting the degree of leakage (degree of pressure drop).

A conventional end plug for closing the end of the corrugated pipe during this inspection is disclosed in Japanese Utility Model Application No. 102081/1981 and shown in FIG. 2. That is, an elastic plug 2 screwed into a corrugated pipe 1
The conduction pipe 3 with a valve 4 is hermetically penetrated through the conduction pipe 3, a flange 5 is provided at the tip of the conduction pipe 3, and a holding plate 6 is movably inserted into the other end on the valve 4 side.
The retaining plate 6 can be tightened in the distal direction with a nut 7, and as shown in the same figure, the elastic plug 2 with flanges 5 and retaining plates 6 applied to both ends of the elastic plug 2 is attached to the corrugated pipe 1. By tightening both the flange 5 and the holding plate 6 with the nut 7, the elastic plug 2 is bulged radially outward and is pressed into contact with the inner surface of the corrugated pipe 1 to seal it.

However, since this terminal plug screws the elastic plug 2 into the corrugated pipe 1, there is no problem if the corrugated pipe 1 has a large diameter, but if the corrugated pipe 1 has a small diameter (for example, an inner diameter,
25mmφ or less), they cannot be screwed in smoothly and workability is poor, and if they are screwed in forcibly, the threads of both 1 and 2 will not fit tightly, causing problems with airtightness. If there is a problem in airtightness, the degree of decrease in the sealed gas tends to be large regardless of the presence or absence of pinholes, and the reliability of the test results decreases. Therefore, when the corrugated pipe 1 has a small diameter, the conduit pipe 3 with the valve 4 is soldered to the terminal end, and this operation is extremely complicated.

Furthermore, when the inside of the corrugated pipe 1 is made to have a high pressure, the corrugated pipe 1 also expands and expands in diameter, but since the elastic plug 2 is in pressure contact with the inner surface of the corrugated pipe 1 to maintain airtightness, the pressure contact force is reduced due to the expansion of the diameter. It weakens and the airtightness deteriorates. Deterioration of airtightness leads to a decrease in reliability of test results, as described above.

[Purpose of invention]

With the above points in mind, the present invention aims to provide a terminal stopper that is easy to attach to a small-diameter corrugated pipe and does not deteriorate airtightness.

[Means to achieve the purpose]

In order to achieve the above object, in the terminal stopper of the present invention, a closing plate having a valved conduction pipe connected and fixed in an airtight manner is attached to one end face of the cylindrical elastic stopper screwed into the outer surface of the corrugated pipe. In addition to covering the opening, an annular holding plate that is inserted into the corrugated pipe is applied to the other end surface of the elastic stopper, and a cylindrical body shorter than the length of the elastic stopper is inserted into the outer surface of the elastic stopper. The closing plate and the holding plate are fastened to each other by bolts and nuts extending in the direction of the cylinder axis of the elastic stopper so that the plates can be expanded and contracted.

[Effect]

In the terminal plug according to the present invention constructed in this way, when the elastic plug is screwed onto the outer surface of one end of the corrugated pipe and the holding plate and the closing plate at both ends are tightened with bolts and nuts, both plates are pressed against both end surfaces of the elastic plug. One end surface of the elastic stopper is sealed by the closed plate, and
The elastic stopper is compressed. During this compression, since there is a cylindrical body on the outer surface, the elastic plug swells inward and comes into pressure contact with the outer surface of the corrugated pipe, creating an airtight state.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the attached figures.

As shown in FIG. 1, the terminal plug A according to the present invention
is used as a pair with a terminal stopper B which does not have a conduction tube 13, which will be described later. This terminal plug A includes a cylindrical elastic plug 11 screwed into the outer surface of the corrugated pipe 10,
A closing plate 14 to which a conduit pipe 13 with a valve 12 is connected and fixed in an airtight manner, a cylindrical body 15 fixed to this closing plate 14 by welding or the like, and an inward flange that is slidably fitted into this cylindrical body 15. 16 and a cylindrical body 17. On the other hand, the terminal plug B has the same structure except that the conduit tube 13 is not provided.

The elastic stopper 11 is made of soft rubber, and the closure plate 1
It is fixed to one side of 4 with adhesive or the like. Note that if the inner surface of the elastic plug 11 is tapered so that one side (closed plate 14 side) has a smaller diameter than the outer diameter of the corrugated pipe 10 and the other end has a larger diameter, the elastic plug 11 can be easily screwed into the corrugated pipe 10. , and the pressure contact force is increased by screwing.

The conduit 13 communicating with the other surface of the closing plate 14 is fixed to the closing plate 14 via a nut 18, and the nut 1
8 with a spanner or the like and turn it to screw the elastic plug 11 into the corrugated pipe 10. The valve 12 provided in the conduction pipe 13 is a check valve that flows in the direction of the elastic stopper 11, and prevents the gas from being discharged from the conduction pipe 13 when gas is pressurized into the corrugated gate 10, which will be described later.

The cylindrical body 15 is fitted into the elastic stopper 11, and its length together with the other cylindrical body 17 is made shorter than that of the elastic stopper 11. Further, a required number of bolts 19 in the axial direction of the elastic plug 11 are welded to one end of the outer peripheral surface of the cylinder body 17 at equal intervals, and these bolts 19 are connected to the closure plate 1.
A nut 20 is inserted through the outer periphery of 4 and screwed into the nut 20.

In addition, in this embodiment, the flange 16 of the cylindrical body 17 serves as a presser plate in the "claims",
It is applied to the other side of the elastic stopper 11 as shown.

The embodiment is configured as described above, and its operation will be explained next.

When inspecting the pinhole in the corrugated pipe 10, first, with the nut 20 of the bolt 19 loosened, most of the elastic plug 11 is screwed into one end of the corrugated pipe 10 through the nut 18.
9. When the nut 20 is tightened, the space between the closing plate 14 and the flange 16 is narrowed and the elastic stopper 11 is compressed, as shown from the chain line to the solid line in the figure. During this compression, since the cylindrical body 15 is on the outer surface of the elastic plug 11, the elastic plug 11
1 bulges inward and presses onto the outer surface of the corrugated pipe 10 to create an airtight state, completing the installation of the terminal plug A.

On the other hand, a terminal stopper B is similarly attached to the other end of the corrugated pipe 10, and the inside of the corrugated pipe 10 is sealed by both stoppers A and B.

Next, pressure fluid, such as air, is blown into the sealed corrugated pipe 10 from the conduction pipe 13 to obtain a predetermined internal pressure, and after a predetermined time, the internal pressure is detected,
The presence or absence of a pinball is detected based on the degree of decrease. During this action, even if the corrugated pipe 10 bulges due to internal pressure, the bulge further increases the pressure contact with the elastic plug, improving airtightness.

[Effect of idea]

As explained above, according to the terminal plug of the present invention,
With the above configuration, the corrugated pipe is sealed by pressure contact from its outer surface, so it can be easily installed even on small diameter pipes, and has high airtightness.
Increase the reliability of pinhole inspection results.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an embodiment of the terminal plug according to the present invention, and FIG. 2 is a schematic sectional view of a conventional example. 1, 10...corrugated pipe, 11...cylindrical elastic plug, 12...valve, 13...conducting pipe, 14...
Closure plate, 15... Cylindrical body, 16... Flange, 17
...Cylinder.

Claims (1)

[Scope of utility model registration request] A closing plate 14 in which a conduit tube 13 with a valve 12 is connected and fixed in an airtight manner is applied to one end surface of a cylindrical elastic stopper 11 that is screwed into the outer surface of the corrugated pipe 10, covering the opening in the one end surface. An annular holding plate 16 that is inserted into the corrugated pipe 10 is applied to the other end surface of the elastic stopper 11.
A cylindrical body 15 shorter than the length of the cylindrical body 15 is fitted onto the outer surface of the elastic plug 11, and the closing plate 14 and the holding plate 16 can be expanded and contracted between the two plates 14 and 16 by bolts and nuts 19 and 20 in the axial direction of the elastic plug 11. A terminal plug for pinhole inspection of corrugated pipes, which is fastened to a corrugated tube.