JPH0755018B2 - Inspection device for cable entry hole - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a cable entry hole inspection device.

[Conventional technology and its problems]

Generally, when inspecting pipelines for underground power transmission lines, underground distribution lines, communication cables, etc., if there are holes in the pipelines, use those holes to "test rod thread" or "TV." Through the camera ”and so on. However, if there is no hole (so-called full-pipe line), there is no effective inspection method and it is left unattended, and the development of an effective inspection method has been desired.

The present invention solves such a problem in the related art, and it is possible to easily and quickly inspect the cable entry hole with the cable inserted, and if there is a stepped portion in the entry hole, accurately measure the step size. It is an object of the present invention to provide a device for inspecting a cable entry hole that can be measured at any time.

[Means for solving problems]

The inspection device for the cable entry hole of the present invention projects from the tip surface of the optical fiber body of the optical fiber scope provided with the image guide by a predetermined dimension, and at least the inner peripheral edge of the tip of the tip opening is projected. A distal end cylindrical window portion for observing an observed portion through the optical fiber scope from the distal end opening portion is provided.

[Action]

When inspecting the cable entry hole with the inspection device configured as described above, if there is a step in the cable entry hole, the step size of the step can be measured. That is, when the tip end of the distal cylindrical window portion is abutted against the step portion and the step portion is observed with an optical fiber scope, the inner peripheral edge of the tip end of the cylindrical window portion and the step portion are shown in the image. . Therefore, the diameter dimension of the inner peripheral edge of the tip on this image and the step dimension on the image (the step dimension in this case is the dimension on the image obtained by subtracting the wall thickness dimension of the cylindrical window from the correct step dimension). Therefore, if the ratio of this step dimension to the correct step dimension is added to the wall thickness dimension), the actual diameter and wall thickness of the inner peripheral edge of the tip are known. It is possible to obtain the step size of.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings illustrating examples.

FIG. 1 is a view of the present invention, in which 21 is a cable entry hole insertion body of an inspection device according to the present invention, and the insertion body 21 is inserted into the cable entry hole 1 (see FIGS. 3 and 4). A guide tube 2 and an optical fiber scope 4 having an optical fiber body 3 to be inserted into the insertion guide tube 2 are provided.

The optical fiber scope 4 is composed of the optical fiber main body 3 and an eyepiece (not shown) provided on the proximal end side of the optical fiber main body 3, and the objective lens is attached to the front end of the optical fiber main body 3. An objective unit 6 including 5 is formed. Further, the optical fiber main body 3 includes an insertion tube 7, an image guide 8 to be inserted into the insertion tube 7, and a plurality of light guides 9 ... And the objective lens 5 is connected to the tip of the image guide 8. It is set up. The image guide 8 includes an image guide body including a large number of pixels,
And a coating layer that covers the main body, and the pixel further includes a core and a clad. Further, the light guide is composed of an optical fiber elemental wire including a core and a clad, and a coating layer that covers the elemental wire.

Therefore, the optical fiber scope 4 is provided with the light guide 9
From the observation target portion, the light reflected from the observation target portion is incident on the image guide 8 through the objective lens 5 of the objective portion 6, is transmitted, and the transmitted light is The light enters the eyepiece lens of the eyepiece section. Then, the light that has passed through the eyepiece reaches the cameras connected via a mount (not shown) or the like, and the observed portion is observed. In addition, it is free to observe with naked eyes without using cameras.

Thus, the insertion guide tube 2 has a metallic tip tube portion 10 and a guide tube body 12 connected to the tube portion 10 via a connecting tube 11.
The distal end portion of the optical fiber body 3 is fixed to the tubular portion 10 via the interposition member 13, and the inner peripheral surface 15 of the insertion guide tube 2 and the insertion tube 2 of the optical fiber body 3 are fixed. A flow path 16 is formed between the outer peripheral surface 14 and the outer peripheral surface 14 for allowing a fluid such as fresh water that has flowed in from the proximal end side of the guide tube 2 to flow out from the tip end of the guide tube 2 via the intervening member 13. It In addition,
The guide tube body 12 is made of a flexible and seamless synthetic resin, for example, crosslinked polyethylene. Also,
The connecting pipe 11 is made of synthetic resin or metal.

Further, the intervening member 13 is made of a cylindrical body, and the peripheral wall 17 thereof is
As shown in FIG. 2, through-holes 18 ... In the axial direction, which are arranged at equal pitches around the circumference, are provided. The intervening member 13 is fixed to the large-diameter base portion 37 of the distal end tube portion 10, and the distal end portion of the optical fiber body 3 is inserted and fixed therein. Reference numeral 25 is a screw hole provided in the distal end tube portion 10 for fixing the interposition member 13 and the distal end tube portion 10 to each other, and 29 is an interposition member.
A screw hole provided in 13 for fixing the intervening member 13 and the tip of the optical fiber body 3 to each other. Although screws are respectively screwed into the screw holes 25 and 29, they are omitted in the illustrated example. Further, a tip projecting wall 26 of the connecting pipe 11 is interposed between the interposition member 13 and the tip tubular portion 19.

Then, the distal end portion of the guide tube main body 12 is fitted into the base end small-diameter portion 30 of the connecting pipe 11 to form the insertion guide tube 2 having the optical fiber main body 3 therein. In this case, the axis of the image guide and the axis of the window portion 19 are the same axis, and the outer surface 31 of the guide tube body 12, the outer surface 32 of the connecting tube 11, and the outer surface of the tip tube portion 10 are the same. 33 is continuous. Reference numerals 27 and 28 denote screw holes provided in the guide tube main body 12 and the connecting tube 11, respectively, and connect the guide tube 12 and the connecting tube 11 together.
Also in this case, the screws screwed into the screw holes 27 and 28 are not shown.

Therefore, according to the configuration described above, the distal end cylindrical window portion 19 protruding from the distal end surface 3a of the optical fiber main body 3 by the predetermined dimension L is formed, and the distal end opening portion is formed through the window 34 of the interposing member 13. The observed part can be observed from 35. Further, in this case, the observation of the observed portion through the optical fiber scope 4 has a constant visual field. That is, the optical fiber scope 4
The viewing angle of α is α, and in the image projected by the optical fiber scope 4, as shown in FIG.
It is set so that the inner peripheral edge 36 of the tip of the is exposed. In addition, 24 shown in FIG. 5 is an inner peripheral surface of the window portion 19.

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

First, as shown in FIG.
The cable 20 is inserted into the cable entry hole 1 into which the cable 20 has been entered, and as shown in FIG. 1, the fluid is caused to flow through the flow path 16 as indicated by the arrow, and the fluid is caused to flow out from the window portion 19 through the interposition member 13. That is, by injecting a fluid into the dewdrop 16, the suspended water in the cable entry hole 1 is washed away, and the optical fiber scope 4
It is possible to wash the tip of the optical fiber scope 4 and to make the image of the observation portion of the cable entry hole 1 by the optical fiber scope 4 always clear.

Then, in order to measure the step size A of the cable entry hole 1 in which the step as shown in FIG.
Abut the tip surface 2a of the insertion guide tube 2 against the step portion 22,
As described above, the fluid is caused to flow out from the tip end opening 34 of the window 19 to wash the vicinity of the step portion 22, and thus the step portion 22 is observed by the optical fiber scope 4. Therefore,
The image at this time is, as shown in FIG. 5, the inner peripheral surface of the window portion 19.
24 and the step edge 38 of the cable entry hole 1 appear, and the step dimension A can be obtained. That is, from the step size A, the window
Dimension G obtained by subtracting the wall thickness dimension F of 19 (that is, from point C to D
The dimension to the point) is the dimension Ga on the image, the diameter dimension E of the tip inner peripheral edge 36 of the window 19 (that is, the dimension from the point C to the point B) is the dimension Ea on the image, and Since the diameter dimension E and the wall thickness dimension F of the tip inner peripheral edge 36 of the window portion 19 are known, the actual dimension G can be obtained by obtaining the ratio of the dimension Ea and the dimension Ga from the image and performing the proportional calculation. You can Then, by adding the wall thickness dimension F of the window portion 19 to the actual dimension G, the step dimension A can be obtained. Of course, even when the axis of the image guide of the optical fiber scope 4 and the axis of the window 19 are deviated, the inner peripheral edge 36 of the tip of the window 19 and the step edge 38 of the step 22 are shown in the image. Step difference A
Can be asked.

When the cable entry hole 1 is filled with water, the refractive index of light differs between the atmosphere and the water.
The viewing angle of the optical fiber scope 4 is α in the atmosphere.
Was β in water. And this β
In this case, as shown in FIG. 6, it is set so that a part of the inner peripheral surface 24 of the window 19 is not displayed on the image from the optical fiber scope 4.

Therefore, during inspection of the cable entry hole 1 with this inspection device, if the inner peripheral surface 24 of the window 19 is not shown in the image as shown in FIG. You can see that the water is full. Of course, also in this case, the points B and C of the window portion 19 and the point D of the step portion 22 are displayed in the image, and the step dimension A can be measured. That is, if the ratio between the dimension Fa and the dimension Ga is obtained, the actual dimension G is obtained from the ratio, and the wall thickness dimension F of the window portion 19 is added to the dimension G, the step dimension A can be obtained.

However, according to the above-described embodiment, since the distal end tube portion 10 is made of metal, it does not wear even when the distal end tube portion 10 comes into sliding contact with the inner peripheral surface 23 of the cable entry hole 1, It will be highly durable. Further, the fluid can be made to flow into the entry hole 1, and the image of the observed portion can be made clear. Further, it is convenient because it can be determined whether or not the inside of the cable entry hole 1 is filled with water.

It should be noted that the present invention is not limited to the above-described embodiments, and design changes can be freely made without departing from the scope of the present invention. For example, the insertion guide tube 2 is not formed of three members as in the embodiment, and the distal end is not formed. The tubular portion 10 and the connecting pipe 11 may be integrated as a synthetic resin similar to the guide pipe main body 12 freely, and the distal end tubular portion 10 is detachable, and the distal end tubular portions 10 of various sizes are formed. If they are aligned, various stepped portions 22 of the cable entry hole 1 can be accommodated.

〔The invention's effect〕

The cable entry hole inspection device of the present invention is such that if the tip end of the distal end cylindrical window portion 19 is abutted against the step portion 22 of the cable entry hole 1, the length from the step portion 22 to the tip surface 3a of the optical fiber main body 3 is increased. The size becomes the predetermined size. When the step portion 22 is observed with the optical fiber scope 4 in this state, the inner peripheral edge 36 of the distal end of the cylindrical window portion 19 and the step portion 22 are shown in the image. Therefore, the ratio between the inner peripheral edge dimension on the image and the step dimension (in this case, not the correct step dimension but the step dimension A minus the wall thickness dimension F of the window 19 on the image). If found, the actual step size A can be obtained by proportional calculation.

That is, when this inspection device is used, even when the cable entry hole 1 has a step portion 22, the tip of the cylindrical window portion 19 is abutted against the step portion 22 and the observation can be performed with an optical fiber scope. If so, the step dimension A of the step portion 22 can be measured easily and quickly, and the inspection of the wire entry hole becomes extremely easy.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part showing an embodiment of the present invention.
The figure is a sectional view taken along the line II-II in FIG. 1, FIG. 3 is a simplified transverse sectional view showing a state of being inserted into a cable entry hole, and FIG. FIG. 6 and FIG. 6 are simplified diagrams of images by an optical fiber scope. 3 ... Optical fiber main body, 3a ... Tip surface, 4 ... Optical fiber scope, 8 ... Image guide, 19 ... Tip cylindrical window section, 35 ... Tip opening section, 36 ... Tip inner peripheral edge.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Masami Ishihii 1-12-17 Umeda, Kita-ku, Osaka City, Osaka Prefecture (Umeda Building) Inside the Osaka office of Mitsubishi Cable Industries, Ltd. (72) Inventor Daizo Tanaka, Osaka City, Osaka Prefecture Nishi-Yodogawa-ku, 3-chome, 3-chome, Ryosei Electric Co., Ltd. (72) Inventor Masahiro Fukui, Osaka Prefecture, Osaka 3-chome, 3-chome, Chifune, Nishi-yodogawa-ku, Ryosei Electric Co., Ltd. (72) Inventor, Masayuki Hamada, Osaka Ryosei Denshi Co., Ltd., 3-7-7, Chifune, Nishiyodogawa-ku, Osaka (72) Inventor, Mitsuji Yasuda 4-chome, 3-chome, Ikejiri, Itami City, Hyogo Prefecture Mitsubishi Cable Industries, Ltd. Itami Works

Claims (1)

[Claims] 1. An optical fiber scope having an image guide, which protrudes from a front end surface of an optical fiber main body by a predetermined dimension, and at least the inner peripheral edge of the front end opening is projected from the front end opening. A tip cylindrical window portion for observing an observed portion through the optical fiber scope,
An inspection device for the cable entry hole, which is characterized by being equipped.