JP3720144B2

JP3720144B2 - Insulated wire defect detection apparatus and defect detection method

Info

Publication number: JP3720144B2
Application number: JP27492396A
Authority: JP
Inventors: 博幸多田
Original assignee: Fujikura Ltd
Current assignee: Fujikura Ltd
Priority date: 1996-10-17
Filing date: 1996-10-17
Publication date: 2005-11-24
Anticipated expiration: 2016-10-17
Also published as: JPH10123195A

Description

【０００１】
【発明の属する技術分野】
本発明は、絶縁電線の欠陥検出装置および欠陥検出方法に係り、特に、架空配電線等の絶縁電線における導体の応力腐食割れや素線切れ等に基づく欠陥部を、高い精度で検出する技術に関するものである。
【０００２】
【従来の技術】
架空配電線等の絶縁電線における導体部分に、応力腐食割れや素線切れ等に基づく欠陥部が生じているか否かを検出する技術として、図４に示すように、絶縁電線１の回りに例えば２個の磁界センサ（サーチコイル）２を１８０度間隔で配して、絶縁電線１に流れる負荷電流によって生じる磁界を検出するとともに、該磁界センサ２の出力を、ローパスフィルタ３，プリアンプ４を経由して差動増幅器５に送り込み、差電圧を別のローパスフィルタ６を経由して電圧計等に出力して計測を行なう方法が知られている。
【０００３】
【発明が解決しようとする課題】
しかし、２個の磁界センサ２で絶縁電線１の磁界を検出した場合、図５に示すように、２個の磁界センサ２が導体１ａの中心に対して等距離に配されている場合には、導体１ａの異常を正確に検出することができるものの、図６に示すように、絶縁電線１に対して２個の磁界センサ２が片寄って配されている場合、あるいは、図７に示すように、絶縁被覆１ｂの表面に有する突条部（ヒレ）等の突出部１ｃが、磁界センサ２を支持している支持構造物Ｓの穴ｈの内壁面に接触することにより、絶縁電線１に片寄りが生じる場合等であると、導体１ａの欠陥の有無に関係なく２個の磁界センサ２の差電圧（Ｖ₂−Ｖ₁）が出力されてしまうため、異常の有無の判別精度が損なわれてしまう。
【０００４】
本発明は、上述の事情に鑑みてなされたもので、以下の目的を達成するものである。
▲１▼絶縁電線の絶縁被覆に、突条部等の突出部が設けられている場合における検出誤差の発生を低減すること。
▲２▼素線断線等の欠陥部の検出感度を向上させること。
【０００５】
【課題を解決するための手段】
互いに対向して形成された一対の突出部を有する絶縁電線の導体に交番電流を流した際に発生する磁界を検出して、導体に異常が生じているか否かを判別する場合に、絶縁電線の回りに、複数の位置決めローラにおける外周部の歯部を対向状態に配して、絶縁電線の表面に位置決めローラの歯車状の歯部を接触または近接させて絶縁電線の位置を設定するとともに、前記突出部と前記歯部との接触により位置決めローラを回転させて、絶縁電線の表面に設けられている突出部を、位置決めローラの外周面の凹部に逃すことにより、絶縁電線における導体の位置の変動を抑制する技術が採用される。交番電流による磁界を検出する手段として磁界センサが配され、該磁界センサが電線挿通穴を有する支持具に取り付けられ、該支持具に、外周部に歯部を有する複数の位置決めローラが、電線挿通穴の内壁に円周方向に間隔を空けて、１８０度離れた位置等に、外周面を対向させた状態に配される。
【０００６】
【発明の実施の形態】
以下、本発明に係る絶縁電線の欠陥検出方法およびその装置の一実施形態について、図１ないし図３を参照して説明する。
図１ないし図３において、符号２は磁界センサ、Ｓは支持具、ｈは電線挿通穴、１１は位置決めローラ、１２は歯部、１３は凹部、１４は回転軸を示している。
【０００７】
前記磁界センサ２は、例えばボビンに細線を密巻きしたものであり、巻き数，巻き径，寸法等が同一特性であるもの（同型のもの）が２個組み合わせて用いられる。
該磁界センサ２は、支持具Ｓにおける電線挿通穴ｈの内壁の近傍に内向状態に配され、図１に示すように、その１組のものが、電線挿通穴ｈに挿入される絶縁電線１の円周方向に１８０度離れた状態に対向配置されている。
なお、磁界センサ２の出力信号は、前述した図４に示す検出回路および方法を適用することにより処理される。
【０００８】
前記支持具Ｓには、一対をなす磁界センサ２に加えて、例えば３個の位置決めローラ１１が、その外周部を電線挿通穴ｈの内壁面から突出させた状態に、絶縁電線１の挿通方向に平行に配した回転軸１４により回転可能に取り付けられている。
【０００９】
前記位置決めローラ１１は、図２等に示すように、外周部が歯車状とされて、歯部１２及び凹部１３を有するものが採用される。
該位置決めローラ１１は、少なくとも一対のものが、電線挿通穴ｈの内壁面に対して突出した状態に配されるとともに、その位置が磁界センサ２に対して絶縁電線１の挿通方向に隣合わせで並べた状態となるように設定され、図１例においては、電線挿通穴ｈにおける円弧状内面ｃにも配されている。
【００１０】
さらに、位置決めローラ１１は、その歯部１２が絶縁電線１の表面に対して接触または近接状態となるように設定されるとともに、凹部１３が、絶縁電線１の突出部１ｃを収容し得る大きさに形成されている。
なお、突出部１ｃは、突条のものが絶縁被覆１ｂと一体に長手方向に沿って形成され、その大きさが、図３におけるＬ，Ｈ寸法が１ｍｍ程度で、曲率Ｒａ，Ｒｂが０．３〜０．４ｍｍ程度である。
【００１１】
したがって、図１に示すように、絶縁電線１を支持具Ｓの電線挿通穴ｈに挿通させると、絶縁電線１の表面に位置決めローラ１１の歯部１２が接触または近接状態となることにより、絶縁電線１と磁界センサ２との位置設定が正確に行なわれ、磁界センサ２の検出値に有意義な差が生じているか否かにより、導体１ａにおける応力腐食割れや素線切れ等の欠陥部の有無が判別される。
【００１２】
一方、絶縁電線１及び支持具Ｓの間で相対的な回転が生じて、絶縁電線１の突出部１ｃが位置決めローラ１１に接触すると、突出部１ｃ等と歯部１２との接触により位置決めローラ１１が回転して、図２に示すように、突出部１ｃ等が凹部１３に収容された退避状態となる。この際にも絶縁電線１の導体１ａと磁界センサ２との相対位置のずれが生じることがなく、導体１ａに欠陥部が生じているか否かを誤差なく検出することができる。
【００１３】
【発明の効果】
本発明に係る絶縁電線の欠陥検出方法およびその装置によれば、磁界センサに位置決めローラを並べて配置し、磁界センサと絶縁電線の表面とを接触または近接状態として、導体の異常の有無を判別するものであるから、以下のような効果を奏する。
（１）位置決めローラで絶縁電線の位置を設定することにより、導体の欠陥部の検出精度を向上させることができる。
（２）位置決めローラに凹部を設けて、絶縁電線における突条部等の突出部を退避させることにより、絶縁電線の絶縁被覆に、突条部が設けられている場合や局部的な突出部が形成されている場合における検出誤差の発生を低減することができる。
（３）位置決めローラを回転させることにより、絶縁電線の挿通を円滑にして、異常の検出作業性を向上させることができる。
【図面の簡単な説明】
【図１】本発明に係る絶縁電線の欠陥検出方法およびその装置の一実施形態を示す正面図である。
【図２】図１における位置決めローラの歯部と絶縁電線の突出部との係合状況を示す正面図である。
【図３】図２における絶縁電線の突出部の拡大図である。
【図４】絶縁電線の欠陥部検出方法の従来技術を示す結線図である。
【図５】図４の磁界センサと絶縁電線との配置状況を示す正面図である。
【図６】図５の磁界センサが絶縁電線に対して片寄った場合の検出状況を示す正面図である。
【図７】図５の絶縁電線が支持構造物の穴内で片寄った場合の検出状況を示す正面図である。
【符号の説明】
１絶縁電線
１ａ導体
１ｂ絶縁被覆
１ｃ突出部
２磁界センサ（サーチコイル）
３ローパスフィルタ
４プリアンプ
５差動増幅器
６ローパスフィルタ
Ｓ支持具
ｈ電線挿通穴
ｃ円弧状内面
１１位置決めローラ
１２歯部
１３凹部
１４回転軸[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insulated wire defect detection device and a defect detection method , and more particularly, to a technique for detecting a defective portion based on stress corrosion cracking of a conductor or a broken wire in an insulated wire such as an overhead distribution line with high accuracy. Is.
[0002]
[Prior art]
As a technique for detecting whether or not a defective portion based on stress corrosion cracking, wire breakage, or the like has occurred in a conductor portion of an insulated wire such as an aerial distribution wire, as shown in FIG. Two magnetic field sensors (search coils) 2 are arranged at intervals of 180 degrees to detect the magnetic field generated by the load current flowing through the insulated wire 1 and the output of the magnetic field sensor 2 is passed through the low-pass filter 3 and the preamplifier 4. Then, a method is known in which the differential amplifier 5 is sent to the differential amplifier 5 and the difference voltage is output to a voltmeter or the like via another low-pass filter 6 for measurement.
[0003]
[Problems to be solved by the invention]
However, when the magnetic field of the insulated wire 1 is detected by the two magnetic field sensors 2, as shown in FIG. 5, when the two magnetic field sensors 2 are arranged at the same distance from the center of the conductor 1a, Although the abnormality of the conductor 1a can be accurately detected, as shown in FIG. 6, when the two magnetic field sensors 2 are arranged offset from the insulated wire 1, or as shown in FIG. Further, the protruding portion 1c such as a ridge (fin) on the surface of the insulating coating 1b comes into contact with the inner wall surface of the hole h of the support structure S supporting the magnetic field sensor 2, so that the insulated wire 1 If the deviation occurs, the difference voltage (V ₂ −V ₁ ) between the two magnetic field sensors 2 is output regardless of whether or not the conductor 1a is defective. It will be.
[0004]
The present invention has been made in view of the above circumstances, and achieves the following objects.
(1) To reduce the occurrence of detection errors when the insulation coating of insulated wires is provided with protrusions such as protrusions.
(2) Improve the detection sensitivity of defective parts such as broken wires.
[0005]
[Means for Solving the Problems]
When detecting the magnetic field generated when an alternating current is passed through a conductor of an insulated wire having a pair of protrusions formed facing each other to determine whether or not an abnormality has occurred in the conductor, the insulated wire Around the outer periphery of the plurality of positioning rollers are arranged in an opposing state, the position of the insulated wire is set by bringing the gear-shaped teeth of the positioning roller into contact with or in proximity to the surface of the insulated wire, The positioning roller is rotated by the contact between the protruding portion and the tooth portion, and the protruding portion provided on the surface of the insulated wire is allowed to escape to the concave portion on the outer peripheral surface of the positioning roller. Technology that suppresses fluctuations is adopted. A magnetic field sensor is arranged as means for detecting a magnetic field due to an alternating current, the magnetic field sensor is attached to a support having a wire insertion hole, and a plurality of positioning rollers having tooth portions on the outer periphery are provided on the support. It is arranged in a state where the outer peripheral surface is opposed to the inner wall of the hole at a position 180 degrees away from the inner wall in the circumferential direction.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of an insulated wire defect detection method and apparatus according to the present invention will be described with reference to FIGS.
1 to 3, reference numeral 2 denotes a magnetic field sensor, S denotes a support, h denotes a wire insertion hole, 11 denotes a positioning roller, 12 denotes a tooth portion, 13 denotes a recess, and 14 denotes a rotating shaft.
[0007]
The magnetic field sensor 2 is formed by, for example, densely winding a thin wire around a bobbin, and a combination of two (the same type) having the same characteristics such as the number of turns, the winding diameter, and the dimensions.
The magnetic field sensor 2 is arranged in an inward state in the vicinity of the inner wall of the wire insertion hole h in the support S, and as shown in FIG. 1, one set of the insulated wire 1 is inserted into the wire insertion hole h. Are opposed to each other in a state of being 180 degrees apart in the circumferential direction.
The output signal of the magnetic field sensor 2 is processed by applying the detection circuit and method shown in FIG.
[0008]
In addition to the pair of magnetic field sensors 2 on the support S, for example, three positioning rollers 11 are inserted in the direction in which the insulated wire 1 is inserted such that the outer peripheral portion protrudes from the inner wall surface of the wire insertion hole h. rotatably attached to the rotary shaft 14 arranged in parallel to the.
[0009]
As the positioning roller 11, as shown in FIG. 2 and the like, an outer peripheral portion having a gear shape and having a tooth portion 12 and a concave portion 13 is employed.
At least a pair of the positioning rollers 11 are arranged in a state protruding from the inner wall surface of the electric wire insertion hole h, and their positions are arranged next to each other in the insertion direction of the insulated wire 1 with respect to the magnetic field sensor 2. In the example of FIG. 1, it is also arranged on the arc-shaped inner surface c in the wire insertion hole h.
[0010]
Further, the positioning roller 11 is set so that the tooth portion 12 is in contact with or close to the surface of the insulated wire 1, and the recessed portion 13 can accommodate the protruding portion 1 c of the insulated wire 1. Is formed.
In addition, the protrusion 1c is formed in the shape of a protrusion along the longitudinal direction integrally with the insulating coating 1b, and the size thereof is about 1 mm in the L and H dimensions in FIG. It is about 3 to 0.4 mm.
[0011]
Therefore, as shown in FIG. 1, when the insulated wire 1 is inserted into the wire insertion hole h of the support S, the teeth 12 of the positioning roller 11 are brought into contact with or close to the surface of the insulated wire 1. Whether or not there is a defective portion such as stress corrosion cracking or wire breakage in the conductor 1a depending on whether or not the position setting between the electric wire 1 and the magnetic field sensor 2 is accurately performed and a significant difference occurs in the detection value of the magnetic field sensor 2 Is determined.
[0012]
On the other hand, when relative rotation occurs between the insulated wire 1 and the support S and the protruding portion 1c of the insulated wire 1 comes into contact with the positioning roller 11, the positioning roller 11 is brought into contact with the protruding portion 1c and the tooth portion 12. Is rotated, and as shown in FIG. 2, the protruding portion 1 c and the like are in the retracted state accommodated in the recess 13. Also in this case, the relative position between the conductor 1a of the insulated wire 1 and the magnetic field sensor 2 does not shift, and it can be detected without error whether or not the conductor 1a has a defective portion.
[0013]
【The invention's effect】
According to the defect detection method and apparatus for an insulated wire according to the present invention, positioning rollers are arranged side by side on a magnetic field sensor, and the presence or absence of an abnormality in the conductor is determined by bringing the magnetic field sensor and the surface of the insulated wire into contact or proximity. Since it is a thing, there exist the following effects.
(1) By setting the position of the insulated wire with the positioning roller, the detection accuracy of the defective portion of the conductor can be improved.
(2) By providing a recess in the positioning roller and retracting the protruding portion such as the protruding portion of the insulated wire, when the protruding portion is provided on the insulating coating of the insulated wire or when the protruding portion is locally It is possible to reduce the occurrence of detection errors when formed.
(3) By rotating the positioning roller, it is possible to smoothly insert the insulated wire and improve the abnormality detection workability.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of an insulated wire defect detection method and apparatus according to the present invention.
2 is a front view showing a state of engagement between a tooth portion of a positioning roller and a protruding portion of an insulated wire in FIG. 1. FIG.
3 is an enlarged view of a protruding portion of the insulated wire in FIG. 2. FIG.
FIG. 4 is a connection diagram showing a prior art of a method for detecting a defective portion of an insulated wire.
5 is a front view showing a state of arrangement of the magnetic field sensor and insulated wires in FIG. 4; FIG.
6 is a front view showing a detection situation when the magnetic field sensor of FIG. 5 is offset from the insulated wire. FIG.
7 is a front view showing a detection situation when the insulated wire of FIG. 5 is offset in the hole of the support structure. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insulated electric wire 1a Conductor 1b Insulation coating 1c Protrusion part 2 Magnetic field sensor (search coil)
3 Low-pass filter 4 Preamplifier 5 Differential amplifier 6 Low-pass filter S Support tool h Electric wire insertion hole c Arc-shaped inner surface 11 Positioning roller 12 Tooth part 13 Concave part 14 Rotating shaft

Claims

Whether or not an abnormality has occurred in the conductor by detecting a magnetic field generated when an alternating current is passed through the conductor (1a) of the insulated wire (1) having a pair of protrusions (1c) formed to face each other This is a device for determining whether or not a support tool (S) having an electric wire insertion hole (h) through which an insulated wire is inserted, and an alternating current flowing in the vicinity of the electric wire insertion hole in the support tool. A magnetic field sensor (2) for detecting a magnetic field to be moved, and a gear-shaped tooth portion (12) is brought into contact with or close to the surface of the inserted insulated wire arranged on the inner wall of the wire insertion hole at a circumferential interval. and a plurality of positioning rollers to set the position of the insulated wire (11) by,
The plurality of positioning rollers are rotatably attached to the support by a rotating shaft (14) arranged in parallel with the insertion direction of the insulated wire, and a gear-like shape is provided on the outer periphery of the positioning roller (11). The teeth (12) and the recesses (13) are alternately formed, the recesses are formed in a size that can accommodate the protruding portions of the insulated wires, and the plurality of positioning rollers (11) A defect of an insulated wire characterized by including at least a pair of positioning rollers arranged in a state where the outer peripheral portion is opposed to the inner wall of the electric wire insertion hole (h) at a position 180 degrees apart in the circumferential direction. Detection device.

When an alternating current is passed through the conductor (1a) of the insulated wire (1) having a pair of protrusions (1c) formed to face each other using the defect detection device for an insulated wire according to claim 1. A method for detecting a generated magnetic field to determine whether or not an abnormality has occurred in a conductor, wherein an outer peripheral tooth portion (12) of a plurality of positioning rollers (11) is opposed to each other around an insulated wire The position of the insulated wire is set by bringing the tooth portion into contact with or close to the surface of the insulated wire, and the positioning roller is rotated by the contact between the protruding portion and the tooth portion, thereby The magnetic field is detected in a state in which fluctuations in the position of the conductor in the insulated wire are suppressed by letting the protrusion (1c) provided on the outer periphery of the positioning roller escape into the recess (13). How to detect insulated wire defects .