JPH0413963A - Aerial wire inspecting drvice - Google Patents

Abstract

PURPOSE:To achieve detection of flaws in an aerial wire stably and at a high sensitivity by reducing a change in a clearance between a flaw detecting member and the aerial wire when a wheel runs on a snow-retarding ring on the aerial wire by a plurality of balance-shaped arm. CONSTITUTION:A rotating shaft 21a of a right wheel 21 of a first balance- shaped arm 22 acts as fulcrum and a rotating shaft 21a of a left wheel 21 does as force point to perform an action similar to leverage with an oscillating shaft 22a as working point. when the oscillating shaft 22a exists almost at the center of the first balance-shaped arm 22, a moving value of the oscillating shaft 22a is a half of the moving value of the wheel 21 which runs on snow vetarding ring 13. In the same theory, the moving value of a flaw detecting member 26 at the center of a second balance-shaped arm 23 is a half as much as that of the oscillating shaft 22a of the first balance-shaped arm 22. As a result, when the wheel 21 at the extremely left end runs on the snow retarding ring 13, the moving value of the flaw detecting member 26 is a quarter of the wheel 21.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an overhead wire inspection device for inspecting the outer surface of overhead wires and flaws in strands.

(Prior Art) For example, overhead lines such as AC3R are often installed through mountainous areas, and are frequently damaged by lightning. The degree of damage varies widely, from slight damage to damage such as partial wire breakage, which cannot be left untreated. Breakage of the strands causes corona discharge and reduces the tensile strength of the overhead wire, which may lead to major accidents such as breakage. Therefore, inspection devices that automatically detect flaws over the entire length of overhead wires have been developed.

FIG. 5 shows a schematic configuration diagram of a conventional overhead wire inspection device.

In the figure, this device has a pair of driving wheels 3 so that it can run on the overhead wire 1 by itself, and these driving wheels 3 are moved along the overhead wire 1 by an arrow 10 by a drive unit 4 such as a motor.
It is driven to travel in direction a.

Moreover, several flaw detection coils 5 are provided inside this device, and are positioned by guide wheels 6 that maintain a predetermined distance from the overhead wire 1. This guide wheel 6
is provided so as to trace the outer peripheral surface of the overhead wire 1. The coil holder 7 that supports each flaw detection coil 5 is
Using the hanging bracket 8, move the arrow 1 to the main body case 2 of the device.
It is movably suspended in the 0b direction. This hanging metal fitting 8
absorbs the vertical vibration of the coil holder 7, and the guide wheel 6
At the same time, it acts to maintain the distance between the flaw detection coil 5 and the overhead wire 1 at a predetermined distance.

A control section 9 is provided to process the output signal of the flaw detection coil 5 or to output a predetermined drive signal to the drive section 4. On the other hand, on the rear side of the main case 2,
A camera 11 and a mirror 12 are arranged to sandwich the overhead wire 1.

The above device operates as follows.

First, the drive unit 4 rotates the drive wheel 3 and rotates the main body case 2.
is run at a constant speed along the overhead wire 1 in the direction of the arrow 10a in the figure. While the main body case 2 is running, the flaw detection coil 5 is
While maintaining a predetermined distance from the overhead wire 1, flaw detection is performed on the outer surface of the overhead wire 1 using eddy current or the like. If a flaw exceeding a certain level is detected on the surface of the overhead wire 1, the control section 9 records the detection signal and operates the camera 11 to take a photograph of the outer surface of the overhead wire 1. The mirror 12 is provided for photographing the backside portion of the overhead wire 1 that cannot be directly photographed by the camera 11.

(Problem to be solved by the invention) By the way, in areas where there is a lot of snow in the winter, it is possible to install a snow accretion prevention device called an anti-snow ring on the overhead lines in order to prevent snow from adhering to the overhead lines. It is being done.

FIG. 6 shows the state in which the anti-snow ring is installed.

A bracelet-shaped ring 13 having concave portions on its outer circumferential surface at predetermined intervals is attached to the overhead wire 1 .

FIG. 7 shows a perspective view of this anti-snow ring before it is installed.

As shown in the figure, the anti-snow ring 13 is attached to the overhead wire by fitting its protrusion 13a into the recess 13b.

In order to facilitate this operation, the anti-snow ring 13 is provided with a bent portion 13c. Usually, this is manufactured by integrally molding plastic such as vinyl chloride resin. In addition, the installation interval to the overhead wire is 30cm to 50'c.
It is said to be about m.

If the apparatus shown in FIG. 5 is used to detect flaws in the overhead wire 1 to which the anti-snow ring 13 is attached, the following problem will occur.

First, when the guide wheel 6 that holds the flaw detection coil 5 shown in FIG.
vibrates. When the flaw detection coil 5 performs flaw detection by electromagnetic induction, if the flaw detection coil 5 vibrates, its output signal will be disturbed. This output signal is similar to the output signal when the outer surface of the overhead line 1 is damaged, and there is a possibility that the control section 9 may mistakenly recognize that ``the surface of the overhead line 1 is damaged''.

On the other hand, when the drive wheels 3 shown in FIG. 5 run on the overhead wire 1 and pass over the anti-snow ring 13 shown in FIG. 6, the main body case 2 vibrates. Therefore, at that time, the coil holder 7 also vibrates, and the hanging metal fitting 8 may not be able to absorb the vibration of the flaw detection coil 5 completely.

The present invention has been made in view of the above points, and it is an object of the present invention to provide an overhead wire inspection device that can perform inspections such as flaw detection on overhead wires stably and accurately without errors.

(Means for Solving the Problems) The overhead wire inspection device of the present invention has a pair of wheels rotating in contact with the overhead wires, which are pivotally supported at both ends, and a pair of first wheels oriented in a direction parallel to the overhead wires. a scale-shaped arm, a second scale-shaped arm having a swing shaft located approximately in the center of each of the first scale-shaped arms fixed to both ends; It is characterized by consisting of flaw detection members arranged opposite to each other.

(Function) The above-mentioned device has wheels pivotally supported at both ends of a scale-like arm to ride over the anti-snow ring. In this case, if the flaw detection member is directly supported by a second balance-shaped arm that has a first scale-shaped arm on both ends that supports such a wheel, the flaw detection that occurs when the wheel goes over the anti-snow ring can be avoided. The change in clearance between the member and the overhead wire is reduced to 1/4. If a third scale arm is provided, the reduction will be reduced to 1/8. Thereby, fluctuations in the detection signal can be suppressed within the detection sensitivity.

(Example) Hereinafter, the present invention will be explained in detail using embodiments shown in the drawings.

FIG. 1 shows an embodiment of the overhead wire inspection device of the present invention.

The illustrated device is suspended from a part of the frame that constitutes the main body case 2 of the device shown in FIG.

FIG. 1(a) is a front view of the main part, and FIG. 1(b) is a top view thereof.

In the figure (a), this device is equipped with a pair of wheels 21 on the left and right sides, which rotate in contact with the overhead wire 1, as shown in the figure. A pair of left and right wheels 21 are pivotally supported at both ends of a first scale-shaped arm 22 via a rotating shaft 21a. A pair of first scale-shaped arms 22 are provided on the left and right sides of the device, and both are oriented in a direction parallel to the overhead wire 1. Further, a swing shaft 22a located at the center of the first scale-shaped arm 22 is fixed to both ends of the second scale-shaped arm 2-3. Therefore, at both ends of the second balance-shaped arm 23, each first scale-shaped arm 22 is configured to swing in the direction of the arrow (■) about the swing shaft 22a.

A flaw detection member 26 having a coil 25 housed inside a holder 24 is supported and fixed at the center of the second scale-shaped arm 23 . A support shaft 32 is attached to the upper part of the holder 24 via a swing shaft 31. This support shaft 32 passes through a support angle 35 fixed to the frame 2, and is prevented from being pulled out by a nut 34, while a spring 33 inserted through the support shaft 32 presses the support shaft 32 in the direction of the arrow (■). Each wheel 21 is adjusted so as to contact the overhead wire 1 with an appropriate pressure.

In addition, since the second scale-shaped arm 23 is supported by the swing shaft 31, the second scale-shaped arm 23 is configured to swing in the direction of the arrow (■). :- The apparatus of the present invention having the above configuration operates as follows.

FIG. 2 shows an explanatory diagram of the operating principle of the apparatus of the present invention.

Figures (a) to (c) show different operating states when the four wheels 21 of the device shown in Figure 1 ride over the top surface of the overhead line 1 equipped with the anti-snow ring 13. It shows.

First, as shown in FIG. 3(a), the device moves in the direction of arrow
Suppose it reaches 3. In this case, the first scale arm 22 swings as shown in the figure around its swing shaft 22a,
Furthermore, the swing shaft 22a of the first scale arm 22 is connected to the overhead line 1.
By swinging away from the second scale arm 23, the second scale arm 23 swings in the same direction as shown in the figure.

Then, at the next moment, as shown in FIG. 2(b), the leftmost wheel 21 crosses the anti-snow ring 13, and the first scale arm 22 straddles the anti-snow ring 13. becomes. In this case, the state returns to the same state as when the anti-snow ring 13 is not provided at all.

Then, as shown in FIG. 2(C), when the second wheel 21 from the left passes over the anti-snow ring 13 again, the first scale-shaped arm 22 moves to the position shown in FIG. 2(a). Swings in the opposite direction as shown. As a result, the swing shaft 22a also moves in the direction away from the overhead wire 1, and the second scale arm 23 swings accordingly. Thereafter, the second scale-like arm 23 straddles the anti-snow accretion ring, returning to the same state as in the case without the anti-snow accretion ring 13.

For example, in FIG. 2(a), if we pay attention to the first scale-shaped arm 22, the wheel 2 attached to the right side thereof
The rotary shaft 21a of the wheel 21 on the left side serves as a fulcrum, the rotary shaft 21a of the left wheel 21 serves as a point of effort, and an action similar to that of a lever is performed using its swing shaft 22a as a point of action.

If the swing shaft 22a is located approximately at the center of the first scale arm 22, the amount of movement of the swing shaft 22a will be 1/2 of the amount of movement of the wheel 21 that has run onto the anti-snow ring 13. Based on the same principle, the amount of movement of the flaw detection member 26 located at the center of the second balance arm 23 is
The amount of movement of a is 1/2. As a result, when the leftmost wheel 21 rides on the anti-snow ring 13 as shown in FIG. 2(a), the amount of movement of the flaw detection member 26 is 1/4 of the amount of movement of the wheel 21. Therefore, if the height of the anti-snow accretion ring is set to 4 mm, the amount of movement of the flaw detection member 26 shown in FIG.

The holder 24 of the flaw detection member 26 as shown in FIG. 1 is made of plastic or the like so as not to interfere with the detection operation of the coil 25. Furthermore, the device shown in FIG.
In order to uniformly inspect the outer circumferential surface of the overhead line 1, for example, six units are arranged surrounding the overhead line.

Figure 3 shows the behavior when the operation is as explained in Figure 2.
The change in clearance between the flaw detection member 26 and the overhead wire 1 is shown in a graph. In the graph shown in the figure, the vertical axis represents the clearance in mm, and the horizontal axis represents the distance from the anti-snow ring of the flaw detection member in mm.

As shown in the figure, in the device of the present invention, even when the wheel 21 passes over the anti-snow ring 13, the clearance between the flaw detection member 26 and the overhead wire 1 changes by only about 1 mm. Here, it is assumed that there are scratches on the overhead wire 1 at points A and B in FIG.

FIG. 4 shows a table showing the relationship between the detection sensitivity of the flaw detection member of the apparatus of the present invention and the running conditions.

Further, FIG. 4(b) shows an explanatory diagram of the position of the scratch.

As shown in the figure, it is assumed that the overhead wire 1 has one flaw in a portion X facing the flaw detection member 26 and one flaw in a portion Y inclined at about 45 degrees from there. In such a case, data obtained by measuring the S/N ratio of the signal output from the flaw detection member 26, that is, the detection sensitivity, at points A and B in Fig. 3 is shown in Fig. 3 (a). .

In the same figure (a), cases where the flaw is located directly under the flaw detection member and cases where the flaw is located at an angle of 45° are classified, and the degree of the flaw is further divided into cases where one wire is broken and cases where one wire is broken. It is divided into cases where half is damaged and cases where half is damaged. The results shown in the table are obtained when the driving conditions are normal driving, when the vehicle is above point A, and when the vehicle is above point B.

Note that point A is a point 40 mm away from the difficult-to-snow ring, and point B is 24 mm away from the difficult-to-snow ring. Further, in the case of normal running, the clearance between the flaw detection member and the overhead wire 1 is 6 mm.

As can be seen from this table, there are parts where the S/N ratio decreases due to the influence of changes in clearance, but in all cases the sensitivity is higher than practical sensitivity and the flaw detection function can be fully performed.

Based on the above principle, for example, eight wheels may be provided, and the second
If the balance-shaped arm is supported by a third scale-shaped arm and a flaw detection member is provided in the center of the third scale-shaped arm, it is possible to reduce the variation in clearance to 1/8.

(Effects of the Invention) The overhead wire inspection device of the present invention as described above uses a plurality of scale-like arms to control the clearance between the flaw detection member and the overhead wire when the wheels go over the anti-snow ring on the overhead wire. Since the fluctuation is made sufficiently small, it is possible to perform flaw detection of overhead wires stably and with high sensitivity.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the overhead wire inspection device of the present invention, in which (a) is a front view of the main part, FIG. 1 (b) is a top view of the main part,
Fig. 2 is an explanatory diagram explaining the operating principle of the device of the present invention, Fig. 3 is a graph showing the variation in clearance between the flaw detection member of the device of the present invention and an overhead wire, and Fig. 4 is a demonstration test of the device of the present invention. Figure 5 (a) shows a list of detection sensitivities corresponding to driving conditions, Figure (b) shows an explanatory diagram of flaw locations, and Figure 5 shows a schematic configuration of an example of a conventional overhead wire flaw detection device. 6 is a side view of an overhead line equipped with a snow-resistant ring, and FIG. 7 is a perspective view of the snow-resistant ring. 1---------1 overhead wire, 2-1-------- Body frame, 21--------
---One wheel, 22-----One--First scale arm, 22a,
31-----1 swing axis, 32--1-- 33-1--2nd balance arm, flaw detection member, support shaft, -spring, support angle. (1 other person) Overhead wire 4-frame wheel 1st sword support arm Swing shaft 2 scale-shaped arm 鵠U 音音μ子子 Support shaft spring support angle 21a z γ / 2,)] ? (a) (b) (a) (C) Figure 2

Claims (1)

[Claims] A pair of first balance-shaped arms having a pair of wheels rotating in contact with the overhead line are pivotally supported at both ends thereof and are oriented in a direction parallel to the overhead line, and a pair of first scale-shaped arms located approximately in the center of each of the first balance-shaped arms. An overhead wire inspection device comprising: a second scale-shaped arm having a swing shaft fixed at both ends; and a flaw detection member supported by the second scale-shaped arm and disposed opposite to the overhead wire.