JPH0350484B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for inspecting a cable entry hole.

[Conventional technology and its problems]

Conventionally, when inspecting underground power transmission line conduits, if there are holes in the conduit, it is possible to use the holes to conduct inspections by ``passing a test rod'' or ``passing a TV camera through.'' did it. However, in cases where there are no holes (in the case of a so-called full-hole pipe), there is currently no effective inspection method and the pipeline is left unattended.Therefore, there has been a desire to develop an effective inspection method.

The present invention solves these conventional problems, and
To provide a cable entry hole inspection method that allows easy and quick inspection of the cable entry hole, whether the entry hole into which the cable is inserted is bent or filled with suspended water. The purpose is to provide.

[Means for solving problems]

The first method of inspecting the cable entry hole of the present invention is as follows:
A flexible and seamless insertion guide tube made of synthetic resin is inserted into the cable entry hole, and then an image guide is inserted into the insertion guide tube from the proximal end of the insertion guide tube. ,
While injecting fresh water to wash away the suspended water in the cable entry hole and wash the tip of the image guide, the cable entry hole is observed using the image guide.

In addition, in the cable entry hole inspection method according to the second aspect of the present invention, an image guide is inserted in advance into an insertion guide tube made of synthetic resin that is flexible and has no seams, and the image guide is inserted into the insertion guide tube and the image guide. The guide is integrally inserted into the cable entry hole, and fresh water is injected from the proximal end of the insertion guide tube to wash away the suspended water in the cable entry hole and wash the distal end of the image guide. Observe the cable entry hole using the image guide.

[Effect]

If carried out as in the first or second method of the present invention,
Since there is no seam in the insertion guide tube, the image guide can be smoothly inserted into the insertion guide tube.
In addition, the insertion guide tube has flexibility and is stronger than the image guide, and is easy to insert into the cable entry hole.The image guide is protected by the insertion guide tube, and is inside the cable entry hole. This prevents injury.

〔Example〕

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

FIG. 1 shows a cable entry hole inspection device used in the method according to the present invention. The inspection device main body 4 is attached to the inspection device main body 4, and the image guide 5 is inserted into the insertion guide tube 2 from the proximal end 3 side of the insertion guide tube 2 via the inspection device main body 4. Note that this image guide is exemplified as a direct view type.

The insertion guide tube 2 is made of flexible and seamless synthetic resin, such as crosslinked polyethylene. The inspection device main body 4 is made of a cylindrical body having a branch pipe 6, into which the proximal end 3 of the insertion guide tube 2 is fitted, and the joint part is secured with a tightening band, clip, etc. The insertion guide tube 2 and the inspection device main body 4 are fixed to each other by a mounting member 7, so that the insertion guide tube 2 and the inspection device body 4 are integrated. Further, a piping 8 such as a rubber hose for injecting clean water into the inspection device main body 4 and the insertion guide tube 2 is attached to the branch pipe 6 with a tightening member 11 such as a stop band. Also,
The proximal end of the inspection device body 4 is a small diameter portion 9, and an image of the small diameter portion 9 and the vicinity of the small diameter portion 9 is shown below with the image guide 5 inserted into the inspection device body 4 and the insertion guide tube 2. The guide 5 and the seal member 1
Coated with 0. 12 is a tightening member such as a stopper band for attaching the seal member 10 to the small diameter portion 9;
This is a tightening member such as a stop band for attaching to the The branch pipe 6 is provided with an on-off valve (not shown), which adjusts the flow rate of fresh water from the pipe 8 and also opens and closes the flow of fresh water.

Although detailed illustrations are omitted, the image guide 5 includes an image guide body, an objective portion attached to the tip of the image guide body and having an objective lens, and an eyepiece attached to the base end of the image guide body. The image guide body consists of an optical fiber consisting of a core and a cladding, and a coating layer made of a synthetic resin or the like that covers the optical fiber. Then, the image of the observation section is transmitted to the eyepiece section by entering the image guide body through the objective lens of the objective section,
Observation is made through the eyepiece of the eyepiece.

Next, an inspection method for inspecting the cable entry hole 1 using the above-mentioned inspection device will be explained.

First, the insertion guide tube 2 of this inspection device with the insertion guide tube 2 and piping 8 attached to the inspection device main body 4 is inserted into the cable entry hole 1 from the tip 14 side of the insertion guide tube 2, and then, Insert the image guide 5 into the insertion guide tube 2 from the small diameter part 9 of the inspection device main body 4 and attach the seal member 10, while injecting clean water from the piping 8 into the insertion guide tube 2 as shown by arrow X. , the image guide 5
Observe the cable entry hole 1. That is, by injecting fresh water into the insertion guide tube 2, the fresh water is injected into the cable entry hole 1 from the tip 14 of the insertion guide tube 2, washes away the suspended water in the cable entry hole, and cleans the tip of the image guide. -In other words,
The objective part can be cleaned, and the image of the observation part of the cable entry hole 1 by the image guide 5 can always be made clear.

In addition, the image guide 5 is inserted into the insertion guide tube 2 in advance, and the guide tube 2 and the image guide 5 are inserted into the cable entry hole 1 as one body, and fresh water is poured into the insertion guide tube 2 from the piping 8. It is also preferable to observe the cable entry hole 1 using the image guide 5 while injecting it as indicated by the arrow X.

Therefore, as described above, the image guide 5 inserted into the insertion guide tube 2 is as shown in FIG.
Even if the image guide 5 cannot be fixed directly above the cable 15, it does not fall into the narrow gap between the inner circumferential wall 16 of the cable entry hole 1 and the outer circumferential surface 17 of the cable 15, and the image guide 5 can secure a wide field of view. However, as shown in FIG. 9, only the image guide 5 is inserted into the cable entry hole 1 without using the insertion guide tube 2.
If the cable is inserted into the cable entry hole 1, it will fall into the narrow gap between the inner peripheral wall 16 of the cable entry hole 1 and the outer peripheral surface 17 of the cable 15, and the field of view of the image guide 5 will be narrow, making it impossible to accurately observe the cable entry hole 1.

Therefore, in order to measure the step dimension A of the cable entry hole 1 with a step as shown in FIG. , only the image guide 5 is gradually pulled back, and when point E on the inner circumferential surface 19 of the insertion guide tube 2 is reflected in the image seen at the eyepiece of the image guide 5, the image guide 5 is pulled back. When the pullback is stopped, this image shows points E, F, and G on the inner circumferential surface 19 of the insertion guide tube 2, and the cable entry hole 1, as shown in FIG.
H point on the inner circumferential surface 20 appears, and the step size A can be determined. That is, the inner diameter dimension B of the insertion guide tube 2, the wall thickness dimension C of the insertion guide tube 2, and the viewing angle of the image guide 5 are known, and the wall thickness dimension C of the insertion guide tube 2 is subtracted from the step dimension A. The accurate dimension D can be determined by determining the ratio between the inner diameter dimension Ba and the dimension Da of the insertion guide tube 2 shown in the above image. Therefore, the step dimension A can be determined by adding the dimension D to the wall thickness dimension C.

It is also preferable to attach a distal end attachment 21 as shown in FIGS. 5 to 8 to the distal end of the insertion guide tube 2. These attachments 21
is the cable 15 inserted into the cable entry hole 1.
It is used when the diameter of the cable is small, and prevents the insertion guide tube 2 from falling into the narrow gap between the inner circumferential surface 16 of the wire entry hole 1 and the outer circumferential surface 17 of the cable 15, as shown in FIG. However, even when the diameter of the cable 15 is small, the image guide 5 is designed to ensure a wide field of view.

Specifically, the attachment 21 shown in FIG.
has a structure of a pair of halves, which are fitted into the insertion guide tube 2, and are made of a shaped material such as plastic with a streamlined outer circumferential surface, and both ends are attached with adhesive tape, fastening bands, etc. Members 40, 40
The insertion guide tube 2 and this attachment 21 are attached to the insertion guide tube 2 at . Reference numeral 22 denotes a pawl member fixed along the circumferential direction to the outer circumferential surface 23 of the insertion guide tube 2, and a concave circumferential groove 25 provided on the inner circumferential surface of the attachment 21.
This prevents the attachment 21 from shifting in the longitudinal direction.

Further, the attachment 21 shown in FIG. 6 has a recess 26 formed in the outer circumferential surface 23 of the insertion guide tube 2.
A fixing device 27 such as a screw attached to the attachment 21 is fitted into the recess 26, so that the attachment 21 and the insertion guide tube 2 are integrated.

Next, the attachment 21 shown in FIG. 7 is formed by arranging attachment forming members 28 made of elastically deformable wire rods or plate spring materials at equal pitches around the circumference, and the outer diameter of the attachment 21 is This makes it possible to reduce the diameter. That is, the attachment forming members 28 are arranged radially when viewed from the distal end surface side of the insertion guide tube 2, and each attachment forming member 28 has a distal end facing the insertion guide tube 2.
is bent toward the proximal end 3 side to form an abutting part 29, and the abutting part 29 is attached to a mounting member 30 such as a tightening band.
Further, the rear end portion of the attachment forming member 28 is attached to the insertion guide tube 2 via a mounting member 30 so as to be slidable in the direction of the arrow. Therefore, when this attachment forming member 28 is pressed as shown by arrow Y, it deforms as shown by the imaginary line, and this attachment 21
The outer diameter dimension of can be reduced.

Next, the attachment 21 shown in FIG. 8 has a threaded part 32 formed on the outer circumferential surface 23 of the insertion guide tube 2, and a threaded hole 33 formed in this attachment 21 is screwed into the threaded part 32. 21 and the insertion guide tube 2 are integrated.

Next, FIG. 11 shows another embodiment of the inspection device, in which the image guide 5 is of a side view type.

In this case, a prism 34 is installed in the objective section of the image guide 5, and the insertion guide tube 2
The image from the window 35 provided in the objective lens 3
The light enters the prism 34 through the prism 34, and the incident image enters the image guide body through the prism 34 and is transmitted to the eyepiece. Reference numeral 37 denotes a distal end member attached to the distal end surface 45 of the insertion guide tube 2, and fixes the distal end portion 39 of the image guide 5 to the insertion guide tube 2. That is, the distal opening of the insertion guide tube 2 is expanded toward the distal side.
The inner peripheral surface of the distal end is a tapered part 47, and a female threaded part 41 is formed on the distal end side, and the distal end member 37
has a threaded portion 42 into which the female threaded portion 41 is threaded, and a fitting hole 38 into which the distal end surface 45 of the image guide 5 is fitted, and the distal end member 37 is threaded into the distal end 14 of the insertion guide tube 2. The fitting hole 38 is provided with a reduced diameter portion 44 having a notch portion 43 and a tapered outer circumferential surface 48 that reduce the inner diameter of the fitting hole 38 in the closed state. Therefore, if this tip member 37 is attached to the insertion guide tube 2, the tip portion 3 of the image guide 5 can be attached to the insertion guide tube 2.
9 is fixed to the distal end 14 of the insertion guide tube 2.
That is, when the insertion guide tube 2 is rotated in the circumferential direction on the proximal end side, the distal end portion 39 of the image guide 5 also rotates to follow the rotation, and the distal end portion of the image guide 5 is oriented in the direction desired for observation. be able to.

Therefore, in order to observe the cable entry hole 1 using the inspection device in this case, first,
As shown in Figure), insert the image guide 5 into the insertion guide tube 2, and
9 is fixed to the distal end 14 of the insertion guide tube 2,
Insert the cable into the cable entry hole 1 as one piece. After that, as in the case of the inspection device main body shown in FIG. It is injected into the cable entry hole 1 from the window 35 as shown by the arrow W. Therefore, with this fresh water, the suspended water in the cable entry hole 1 can be washed away, and the distal end 39 of the image guide, that is, the objective part, can be washed away. The image of the observation section 1 can always be made clear. Also,
In this case, it is possible to discern cracks in the cable entry hole 1 that cannot be seen with a direct viewing type.

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, even in the side-view type inspection device shown in FIG. It is also possible to attach an attachment 21 as shown in Figure 2. If the suspended water in the cable entry hole 1 is extremely cloudy, first insert only the insertion guide tube 2 into the cable entry hole 1, and then pour fresh water into the cable entry hole 1. It is also desirable to insert the image guide 5 after completely replacing the suspended water with fresh water by injecting it into the hole 1.

〔Effect of the invention〕

According to the method of the present invention, since the insertion guide tube 2 has flexibility, it can be easily inserted into the cable entry hole 1 even when the cable entry hole 1 is bent, and the guide tube 2 has no seams. Therefore, the image guide 5 can be smoothly inserted into the insertion guide tube 2.
Furthermore, since the tip of the image guide, that is, the objective section, is washed with fresh water, the image at the observation section of the cable entry hole 1 can always be kept clear. Therefore, even if the wire entry hole 1 into which the cable 15 is inserted is bent or the wire entry hole is filled with suspended water, this method allows the wire entry hole 1 to be easily and quickly inspected. can do. Even in the case of a so-called full-hole channel, the image guide 5 can be pushed through a narrow space and inserted, thereby preventing damage to the image guide 5.

[Brief explanation of drawings]

Figure 1 is a sectional view of the inspection device used in the method according to the present invention, Figure 2 is a simplified cross-sectional view of the insertion guide tube and image guide inserted into the cable entry hole, and Figure 3 is the cable entry hole. Fig. 4 is a simplified image taken by an image guide; Figs. Cross-sectional view of various attached attachments, No. 9
The figure is a simplified cross-sectional view of the image guide inserted into the cable entry hole when the insertion guide tube is not used, and Figure 10 is a simplified cross-sectional view of the insertion guide tube inserted into the cable entry hole when the attachment is attached to the insertion guide tube. FIG. 11 is a cross-sectional view of another embodiment. 1... Cable entry hole, 2... Insertion guide tube,
3... Proximal end, 5... Image guide, 39... Distal end.

Claims (1)

[Claims] 1. An insertion guide tube made of synthetic resin that is flexible and has no joints is inserted into the cable entry hole, and then inserted into the insertion guide tube from the proximal end of the insertion guide tube. , the cable entry hole is observed using the image guide while inserting the image guide and injecting fresh water to wash away the suspended water in the cable entry hole and wash the tip of the image guide. How to check the cable entry hole. 2. Insert the image guide in advance into an insertion guide tube made of synthetic resin that is flexible and has no joints, insert the insertion guide tube and the image guide as one body into the cable entry hole, and The cable entry hole is observed using the image guide while injecting clean water from the proximal end of the insertion guide tube to wash away the suspended water in the cable entry hole and wash the distal end of the image guide. How to check the cable entry hole.