JPS63234151A - Fault detecting device for overhead wire - Google Patents

Abstract

PURPOSE:To accurately detect a fault, etc., of even an overhead cable whose diameter is different by moving up and down a coil holder by a holding mechanism corresponding to the external diameter of the overhead wire. CONSTITUTION:A couple of rollers 10 for traveling are coupled on the overhead wire 4 and the coil holder 16 consisting of holder half parts 16A and 16B is arranged between the rollers 10. When the wire 4 is traveled through the through hole 16C of this holder 16, bushes 21 and 21 abut on the peripheral surface of the wire 4, so the holder moves up through suspension shafts 19 and 19. Further, six square coil holes 22 are bored in the holder half parts 16A and 16B and detection coils 23 are fitted movably in the respective coil holes 22. The respective coils 23 are pressed against the peripheral surface of the wire 4 at all times with the elastic force of a coil spring 25. Then when the respective rollers 10 are driven and rotated and a flaw detector moves on the wire 4, an encoder 14 outputs pulses. The respective coils 23, on the other hand, send out difference voltages of detected voltages as detection signal to a fault detecting circuit if the element wire of the wire has a fault or disconnection during the traveling.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a flaw detection device for detecting flaws, breaks, etc. in overhead electric wires.

(Technical Background of the Invention) Since aerial power transmission lines, overhead ground wires, and the like are often installed in high places such as mountainous areas, the wires may melt or break due to lightning. Further, the wires of overhead power transmission lines and the like may be damaged or broken due to long-term use.

For this reason, in the past, workers inspected overhead power lines directly visually or through binoculars, but in mountainous areas, it is difficult to inspect the entire circumferential surface of overhead power lines, and it is difficult to do so manually. However, it is impossible to reliably detect flaws, breaks, etc. in the strands.

Therefore, recently, a flaw detection device is attached to an overhead electric wire, and the flaw detection device is run on the overhead electric wire to detect flaws, breaks, etc. in the wire. That is, as shown in FIGS. 4(A) and CB), this flaw detection device includes a running roller 1 that engages with an overhead electric wire, and a coil through which an overhead electric wire 4 is passed through which a plurality of detection coils 2 are arranged. holder 3, and has a configuration in which each detection coil 2 electromagnetically detects flaws, breaks, etc. in the strands of the overhead electric wire 4 while moving along the overhead electric wire via a running roller l. .

(Problems with Background Art) By the way, in the flaw detection apparatus described above, each detection coil 2 is fixedly attached within a coil holder 3. Therefore, when detecting a flaw or the like on an overhead wire having a predetermined outer diameter, the overhead wire 4 passes through the center position of the coil holder 3. However, in reality, there are dimensional errors between the various parts and there are bent parts in the overhead wire, so the overhead wire 4 passes eccentrically through the center of the coil holder 3. Therefore, there is a drawback that noise is superimposed on the detection signal of the detection coil 2.

In addition, when detecting scratches etc. on the overhead wire 4' having a small diameter, the overhead wire 4' is located above the center position of the coil holder 3, so that the circumferential surface of each detection coil 2 and the overhead wire 4' is The intervals between the two are different, and the detection C bell of each detection coil 2 is different.Furthermore, the overhead wire 4 has a small diameter.
', the distance between the detection coil 2 and the detection coil 2 becomes large, so the detection sensitivity of the detection coil 2 decreases. As shown in the figure, the distance from the detection coil 2 is 1 mm.
, the detection sensitivity (S/N) of the detection coil 2 becomes approximately 1/
2, and when it becomes 3 mm, it decreases to about 2/9. Therefore, in order to accurately detect flaws, etc. on the overhead electric wire 4', the flaw detection circuit must be fine-tuned or adjusted to the outside diameter of the overhead electric wire. Therefore, it is necessary to prepare multiple flaw detection devices equipped with detection coils.

However, as mentioned above, it takes a lot of effort and time to fine-tune the flaw detection circuit, and it is extremely uneconomical to prepare a flaw detection device for each overhead wire with a different diameter. As described above, the influence of noise cannot be avoided, and it requires a great deal of effort on the part of the operator to transport multiple flaw detection devices for use in mountainous areas, etc.

(Objective of the Invention) An object of the present invention is to provide a flaw detection device that can accurately detect flaws, etc. in overhead wires even if they have different diameters.

(Summary of the Invention) The present invention moves a coil holder up and down in accordance with the outer diameter of an overhead electric wire, and presses a plurality of detection coils against the circumferential surface of the overhead electric wire using a suppression mechanism, so that the detection signal level of each detection coil is adjusted to the outer diameter of the overhead electric wire. It is characterized by preventing fluctuations due to changes in the outer diameter of the electric wire and improving detection sensitivity.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

The flaw detection device for overhead wires according to the present invention is shown in FIGS.
As shown in B), a pair of running rollers 1O110 are provided. These running rollers 1O11O are engaged with the overhead electric wires 4H, and have shafts 10a, 1 which rotatably pass through the upper part of the board 28 arranged along the vertical direction.
Fixed to 0a? installed. A sprocket) 11 is attached to each shaft 10a, and a sprocket) 11.11
Another sprocket 12 is disposed in between, and this sprocket 12 is connected to the input shaft of an encoder 13 via a gear mechanism. A geared motor 14 is fixed to the lower part of the board 28, and a sprocket 14a is attached to the output shaft of the geared motor 14. A chain 15 is wound around these sprockets 11.11.12.14a. Therefore, when the gear motor 14 is driven, the sprockets 11 and 11 rotate via the sprocket 14a, so the traveling roller 1O1 rotates.
The flaw detection device of the present invention moves on the overhead wire 4 by rotationally driving the lO. Furthermore, since the sprocket 12 also rotates with this movement, the encoder 13 outputs a number of pulses corresponding to the moving (traveling) distance.

A cylindrical coil holder 16 is arranged between the running rollers 10.10. This coil holder 16
As shown in Figures (A) and CB), the holder half 16A,
It has a two-sided structure consisting of 16B and a holder half 16A.
, 16B are joined to each other via a hinge 17 on the substrate 28 side, and a lock member 18 for closing is attached to the opposite end. Each of the holder half parts 16A, 16B has a recessed portion having a semicircular cross section in the center, and these recessed portions form a through hole 16C through which the overhead electric wire 4 is passed. On both end faces of the upper holder half 16A are bushes 21 for setting the entry and small diameter of the through hole 16C in accordance with the outer diameter of the overhead electric wire 4.
is bolted.

A suspension shaft 19.19 extends upward from the upper surface of the holder half 16A of the coil holder 16. These hanging shafts 19, 19 are vertically movably inserted into each of the brackets 20, 20+7), and a stopper member 19a is attached to the upper end thereof. 20 each bracket
The base of is bolted to the base plate 28. Therefore, when the overhead wire 4 is passed through the through hole 16G, the bushings 21.21 come into contact with the circumferential surface of the overhead wire 4, so that the coil holder 16 moves upward via the hanging shaft 19.19.
The center line of the through hole 16C is kept aligned with the center axis of the overhead electric wire 4.

The holder halves 16A and 16B of the coil holder 16 have six square coil holes 2 with their positions shifted every 60 degrees.
2 is provided. These coil holes 22 are shown in Figure 3 (
As shown in A), it extends in the radial direction of the boulder 16 and communicates with the through hole 16C via the small diameter hole 22a. A detection coil 23 is movably fitted into each coil hole 22 . A stopper member 29 is attached to one end of the detection coil 23, and this stopper member 29 prevents the detection coil 23 from being pulled out toward the through hole 18C. Reinforcement plates 30 and 30 are fixed to each side wall portion of the coil portions 23A and 23B of the detection coil 23. These reinforcing plates 30 are made of abrasion-resistant imide resin, and have tapered portions at their tips. Therefore, when the convex portion of the overhead wire 4 comes into contact with the reinforcing plate 30, 30, the detection coil 23 smoothly retreats into the coil hole 22 via this tapered portion. Each coil hole 22 is closed with a presser plate 24. Recesses 24a and 29a are provided at the center of opposing surfaces of the presser plate 24 and the stopper member 29, and these recesses 24a,
Both ends of the coil spring 25 are engaged with the coil spring 29a. Therefore, each detection coil 23 has a coil spring 25
It is constantly pressed against the circumferential surface of the overhead electric wire 4 due to the elastic force. The coil portions 23A and 23B of the detection coil 23 have a structure in which the coils are embedded in imide resin which has excellent wear resistance.

By the way, at the bottom of the substrate 28, as shown in FIG.
A casing 27 is supported via a letter-shaped support 26,
The housing 27 houses a flaw detection circuit, a drive circuit, a recording section, a receiver, and the like. Therefore, when the drive signal is received by the receiver and the geared motor 14 is driven by the drive circuit,
As described above, the traveling rollers 10 and 10 are driven to rotate, and the flaw detection device of the present invention moves on the overhead wire 4. Also,
As the encoder 13 outputs pulses along with this movement, the pulses are counted by the flaw detection circuit and a distance detection signal is sent to the recording section. Therefore, the recording section records the traveling distance on a magnetic tape or the like. On the other hand, if there is a flaw or disconnection in the strands of the overhead electric wire 4 during running, the coil portions 23A and 23B of each detection coil 23 send out the difference voltage between the detection voltages as a detection signal to the flaw detection circuit. Therefore, since the flaw detection circuit shapes the detection signal into a waveform and outputs it to the recording section, the recording section records the location of the flaw etc. in correspondence with the traveling distance. In this case, since each detection coil 23 is pressed against and in close contact with the peripheral surface of the overhead wire 4, a detection signal with less noise can be sent to the flaw detection circuit.

Now, as shown by the broken line in FIG. 3(A), when detecting scratches on the overhead wire 4' that have a small outer diameter, replace the bushings 21 and 21 attached to the coil holder 16, and Adjust the entry and small diameters of the wires to the outside diameter of the overhead wire 4'.

Therefore, since the bushings 21.21 come into contact with the circumferential surface of the overhead wire 4', the coil holder 16 moves slightly upward via the hanging shaft 19.19, and similarly connects the center line of the through hole 16C to the overhead wire 4'. It is held aligned with the central axis of '. Moreover, since each detection coil 23 is pressed by a coil spring 25, even an overhead electric wire 4' having a small outer diameter is similarly pressed against the circumferential surface of the overhead electric wire 4' and comes into close contact with it. Therefore, even if the outer diameter of the overhead wire to be inspected changes, the detection coil 23 outputs a detection signal of the same level for the same flaw, and most of the noise is added to the detection signal. Therefore, it is possible to accurately detect and record flaws, etc. without making fine adjustments to the flaw detection circuit.

Therefore, by setting the diameter of the through hole 16c of the coil holder 16 large in advance, it is possible to accurately detect flaws, etc. in two or more overhead wires with different outer diameters using a single flaw detection device of the present invention. .

In the above embodiment, a self-propelled flaw detection device equipped with a geared motor 14 has been described, but it goes without saying that the present invention can also be applied to a flaw detection device towed by a self-propelled construction machine.

In order to prevent wear of the detection coil 23, it is preferable to use a coil spring 25 with relatively small elastic force.

(Effects of the Invention) According to the present invention, the coil holder is moved up and down by the holding mechanism in accordance with the outer diameter of the overhead electric wire, and the plurality of detection coils are pressed against the circumferential surface of the overhead electric wire by the suppression mechanism. This makes it possible to prevent noise from entering the detection signal, and also to accurately detect flaws, etc., even in overhead wires with different outer diameters, without making fine adjustments to the flaw detection circuit. Therefore, it is possible to provide a flaw detection device that can detect flaws and the like on overhead ground wires having different outer diameters accurately and with good workability, and also requires less transportation in mountainous areas.

[Brief Description of the Drawings] Figures 1 (A) and (B) are front and side views of a flaw detection device according to the present invention, and Figures 2 (A) and (B) are front views of a coil holder according to the present invention. Figures 3(A) and 3(B) are partial cross-sectional views of the coil holder in Figure 2 and a configuration diagram of the detection coil. Figures 4(A) and CB) are the conventional FIG. 5 is a schematic diagram and a partially sectional view of the flaw detection device, and a diagram showing detection sensitivity characteristics. 4-11-------- Overhead electric wire, 10-------1 running roller, 16-------- Coil holder, 19-1----
---Hanging shaft, 20--------Bracket, 21--Bushing, 22--1--Coil hole, 23--11~---- detection coil. 24----------Part of the plate, (1 other person) France) 4-----------1 Overhead electric wire 10-----1--Roller for ji row 16---- −
---Coil holder f9--1------Hanging T-shaft 20--Bracket 1 Figure (B) 24~ " 2+--Bushing 22-- ----- Coin hole 23 --- 1 --- Detection coil 24 --- 1 --- Pressing temporary 25 --- Coil spring "-j7 2 ■ Figure 3 (B ) Figure 4 P4 (mm)

Claims (1)

[Claims] a running roller that engages on an overhead electric wire; a coil holder through which the overhead electric wire is passed and moves along the overhead electric wire as the running roller rolls; A flaw detection device for overhead electric wires comprising a plurality of detection coils arranged along a circumferential surface, a holding mechanism for holding the coil holder in a vertically movable manner, and a pressure force for pressing each of the detection coils against the circumferential surface of the overhead electric wire. A flaw detection device for overhead electric wires, characterized by having a mechanism.