JPH0350485B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cable entry hole inspection device.

[Conventional technology and its problems] When inspecting conduits such as underground power transmission lines, underground distribution lines, and communication cables, if there are holes in the conduit, the holes are used to carry out "testing". They were able to perform tasks such as "Threading a stick" or "Threading a TV camera."

However, if there are no holes, there is no proper inspection method, and the current situation is that they are left untreated.

The present invention solves these conventional problems, and
It is an object of the present invention to provide a cable entry hole inspection device that can easily and quickly inspect a cable entry hole with a cable inserted therein.

[Means for solving problems]

The cable entry hole inspection device of the present invention includes an insertion guide tube made of synthetic resin that is flexible and has no seams; an inspection cylinder having an injection tube for injecting fresh water into the guide tube and having a transparent part; inserted from the base end side of the inspection cylinder into the insertion guide tube;
an image guide provided on the outer circumference along the longitudinal direction with a scale that can be observed from the transparent part of the inspection cylinder; covering the image guide at or near the base end of the inspection cylinder; and a longitudinally expandable sealing member.

[Effect]

If configured as described above, the insertion guide tube is flexible and has no joints, so it is easy to insert into the cable entry hole, and it is also easy to insert the image guide into the insertion guide tube. Further, since fresh water is injected into the insertion guide tube, the suspended water can be washed away from the cable entry hole, and the distal end portion of the image guide, that is, the objective portion, is constantly washed. Furthermore, since the image guide is provided with a scale, it is possible to know the dimension from the front end surface of the image guide to the step or crack created in the cable entry hole.

〔Example〕

Hereinafter, the present invention will be explained in detail based on drawings showing examples.

FIG. 1 shows a cable entry hole inspection device according to the present invention, and this inspection device includes an insertion guide tube 2 inserted into the cable entry hole 1, and
An inspection cylinder 5 whose distal end 4 is fixed to the base end 3 of the
and an image guide 6 inserted from the base end side of the inspection cylinder 5 and inserted into the insertion guide tube 2.
and the base end 7 of the inspection cylinder 5 to the base end 7
A sealing member 8 that covers the nearby image guide 6
It is equipped with. Note that this image guide is of a direct view type in the illustrated example.

The insertion guide tube 2 is made of flexible and seamless synthetic resin, such as crosslinked polyethylene. In other words, this insertion guide tube 2
is easy to insert into cable entry hole 1,
The wire can be inserted even if the wire entry hole 1 is bent.

The inspection cylinder 5 has a branch pipe 9 and a transparent part, and the base end 3 of the insertion guide tube 2 is fitted into the distal end 4 of the inspection cylinder 5, and the joint part is connected to a fixing member 10 such as an adhesive tape. The inspection cylinder 5 and the insertion guide tube 2 are integrally connected. The transparent portion is formed by making the inspection cylinder 5 transparent. In other words, the entire inspection cylinder 5 is a transparent part. An injection tube 11 such as a rubber hose for injecting clean water into the insertion guide tube 2 is attached to the branch tube 9. That is, the injection tube 11 is externally fitted onto the branch tube 9, and the injection tube 11 is attached to the branch tube 9 by tightening the injection tube 11 with a tightening member 12 such as a stop band.
Note that the branch pipe 9 is provided with an on-off valve (not shown), and the flow rate of fresh water from the injection pipe 11 to the insertion guide pipe 2 is adjusted by the valve.

Thus, the image guide 6 includes an image guide main body, an objective section attached to the distal end of the image guide main body and having an objective lens, and an eyepiece section attached to the base end of the image guide main body and having an eyepiece lens. The image guide main body is made up of an optical fiber strand consisting of a core and a cladding, and a coating layer made of a synthetic resin or the like that covers the optical fiber strand. Then, the image of the observation section is transmitted to the image guide body through the objective lens of the objective section, transmitted to the eyepiece section, and observed through the eyepiece lens of the eyepiece section. In addition, a scale is provided on the outer peripheral surface 13 of the image guide 6 along the longitudinal direction, and the image guide 6 is inserted into the insertion guide tube 2 inserted into the cable entry hole 1 which has a step as shown in FIG. When inserted, the cable entry hole 1
from the stepped portion 23 of the image guide 6 to the distal end surface 2 of the image guide 6.
Dimensions L up to 7 can be measured. That is,
A mark portion 17 consisting of a circle 15 and arrows 16, 16 is written on the inspection cylinder 5 at a certain distance from the distal end surface 26 of the insertion guide tube 2. It is set so that the above-mentioned dimension L can be measured by reading the numerical value on the scale 14 of the guide 6. Of course, the dimension from the cable entry hole 1 to the stepped portion 23 can be measured.

Further, the sealing member 8 is made of a cell body made of rubber, synthetic resin, etc., which is expandable and contractible in the longitudinal direction, and the distal end thereof is connected to the proximal end of the inspection cylinder 5 by a tightening member 18 such as a stopper band. 7, and its proximal end is attached to the image guide 6 near the proximal end 7 of the inspection cylinder 5 with a fastening member 19 such as a stop band.

Then, only the tightening member 19 on the proximal end side is slightly loosened, and the sealing member 8 and the image guide 6
are pushed toward the distal end as shown by arrows A and B, respectively, to reduce the length of the sealing member 8, and then, while maintaining the image guide 6 as it is, only the sealing member 8 is pushed as shown by arrow C. If the length of the sealing member 8 is extended by pulling the image guide 6 as shown in FIG.
is pushed out in the direction of arrow A. Therefore, by repeating this movement, the image guide 6 can be sequentially inserted into the insertion guide tube 2. Further, while holding the image guide 6, only the sealing member 8 is pushed toward the distal end side as shown by arrow A to reduce the length of the sealing member 8, and then the sealing member 8 and the image guide 6 are When pulled toward the proximal end as shown by arrows C and D, the length of the sealing member 8 is extended and the image guide 6 is pulled in the direction of arrow D.
Therefore, by repeating this movement, the insertion guide tube 2
The image guide 6 inserted can be pulled out. In addition, when inserting or withdrawing the image guide 6 into the insertion guide tube 2, this insertion guide tube 2
There are no seams, so it's easy to do.

Next, an inspection method for inspecting the cable entry hole 1 using the inspection device configured as described above will be explained.

First, the above-mentioned sealing member 8 is inserted into the insertion guide tube 2.
Insert the image guide 6 in advance using the image guide 6, firmly tighten the tightening members 18 and 19 on both ends of the sealing member 8, respectively, to seal the proximal end 7 of the inspection cylinder 5, and then close the guide tube. 2 and image guide 6 into the cable entry hole 1, and insert the injection tube 11 into the cable entry hole 1.
While injecting clean water into the insertion guide tube 2 as shown by arrow E, the cable entry hole 1 is observed using the image guide 6. That is, by injecting clean water into the insertion guide tube 2, the suspended water in the cable entry hole 1 can be washed away, and the distal end of the image guide 6, that is, the objective part, can be washed, and the image guide 6 can be cleaned. The image of the observation part of the cable entry hole 1 can always be made clear.

Therefore, as described above, the image guide 6 inserted into the insertion guide tube 2, as shown in FIG.
Even if it cannot be fixed directly above the cable 20, the image guide 6 does not fall into the narrow gap between the inner circumferential wall 21 of the cable entry hole 1 and the outer circumferential surface 22 of the cable 20, and the image guide 6 can secure a wide field of view.

With this inspection device, in order to measure the step dimension F of the cable entry hole 1 with a step as shown in FIG. , gradually pull back only the image guide 6, and insert the insertion guide tube 2 into the image seen at the eyepiece of the image guide 6.
If you stop pulling back the image guide 6 when point G on the inner circumferential surface 24 of the insertion guide tube 2 is photographed, this image will include point G and the inner circumferential surface 24 of the insertion guide tube 2, as shown in FIG. The H point of the step portion 23 appears, and the step dimension F can be determined. That is, the maximum dimension of the image at this time is the dimension J from point G to point N in FIG. (known)], and this dimension J and the dimension K from point H to point G in this image - that is, from the inner circumferential surface 24 of the insertion guide tube 2 to the inner circumferential surface 25 of the cable entry hole 1 in FIG. If we find the ratio x-, that is, x=K/J-, the dimension from the stepped portion 23 to the left side in the example, the above equation () becomes K=2xLtanα/2...(), and the dimension K can be found.

Therefore, by adding the wall thickness dimension M (known) of the insertion guide tube 2 to this dimension K, the step dimension F can be determined.

The present invention is not limited to the illustrated embodiment, and the design may be changed without departing from the gist of the present invention. For example, the image guide 6 may be of a side-viewing type, and if it is a side-viewing type, You can find cracks that are difficult to find with direct viewing.

Moreover, the inspection cylinder 5 is not formed from a transparent body,
It is also possible to form it from a cylindrical body having only a partially transparent part. Furthermore, the sealing member 8 is not limited to the alveolar body,
It expands and contracts in the longitudinal direction, and the distal end side is brought into close contact with the proximal end 7 of the inspection cylinder 5, the proximal end is brought into close contact with the image guide 6, and the proximal end 7 of the inspection cylinder 5 is sealed. Good to have. For example, it may be a cylindrical body made of elastic rubber or the like with no irregularities on the side surface.

〔Effect of the invention〕

The cable entry hole inspection device of the present invention is such that the insertion guide tube 2 can be easily inserted into the cable entry hole 1, the image guide 6 can be easily inserted into the insertion guide tube 2, and the cable entry hole can be easily inserted with clean water. 1 can be washed away, and the tip of the image guide 6, that is, the objective part, can be constantly washed, and the image of the cable entry hole 1 produced by the image guide 6 can always be made clear. In addition, it is possible to know the dimension from the tip surface 26 of the image guide 6 to the step or crack that has occurred in the cable entry hole 1, and the position of the step or crack can be known, and in the case of a step, the step dimension F can be determined. be able to. Therefore, by using this inspection device, even if the wire entry hole 1 into which the cable 20 is inserted is bent, or if the wire entry hole 1 is filled with suspended water, the wire entry hole 1 can be easily and quickly inspected. 1 can be inspected.

[Brief explanation of drawings]

Fig. 1 is an enlarged cross-sectional view of essential parts showing an embodiment of the present invention, Fig. 2 is a simplified cross-sectional view of the insertion guide tube and image guide inserted into the cable entry hole, and Fig. 3 is the step size. FIG. 4 is an enlarged cross-sectional view of the distal end of this inspection device in the measurement state, and FIG. 4 is a simplified image guide image of the state in FIG. 3. 2... Insertion guide tube, 3... Proximal end, 4... Distal end, 5... Inspection cylinder, 6... Image guide, 7... Proximal end, 8... Sealing member, 11... Injection pipe, 13... outer peripheral surface.

Claims (1)

[Scope of Claims] 1. An insertion guide tube made of synthetic resin that is flexible and has no joints, the distal end of which is fixed to the proximal end of the insertion guide tube, and fresh water is provided in the insertion guide tube. an inspection tube that is attached with an injection tube for injecting the same and has a transparent part; and the inspection tube is inserted from the base end side of the inspection tube into the insertion guide tube, and the inspection tube is attached to the outer peripheral surface of the inspection tube. An image guide provided with a scale that can be observed from the transparent part of the inspection cylinder along the longitudinal direction, and a longitudinally expandable image guide that covers the image guide at or near the proximal end of the inspection cylinder. A cable entry hole inspection device comprising: a sealing member;