JPH0792127A - Method and equipment for measuring crack in insulation coating - Google Patents
Method and equipment for measuring crack in insulation coatingInfo
- Publication number
- JPH0792127A JPH0792127A JP23485893A JP23485893A JPH0792127A JP H0792127 A JPH0792127 A JP H0792127A JP 23485893 A JP23485893 A JP 23485893A JP 23485893 A JP23485893 A JP 23485893A JP H0792127 A JPH0792127 A JP H0792127A
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- Japan
- Prior art keywords
- measuring
- crack
- wire
- measured
- insulation resistance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、絶縁電線の絶縁被覆の
亀裂を非破壊で検出する方法および装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for nondestructively detecting cracks in an insulation coating of an insulated wire.
【０００２】[0002]
【従来の技術】従来、絶縁電線の絶縁被覆の亀裂を検出
する方法あるいは装置として、絶縁電線の表面に複数本
の線状電極を接触させた状態で、芯線と絶縁被覆の間に
電圧を印加し、芯線が露出している箇所に電極が入り込
むと通電することを利用する装置がある（実開昭６１−
１３１６７４）。図１に前記の通電を利用する方法（こ
こでは通電法と名付ける）による検査例を示す。図１に
おいて、３１は絶縁電線の芯線、３２は絶縁被覆、３３
は線状電極、３４は検出器、３５は電源、１２は絶縁被
覆の亀裂部分を示している。線状電極３３が亀裂１２に
入り込んで芯線３１に接触すると、検出器３５に電流が
流れ、亀裂の発生を知ることができる。2. Description of the Related Art Conventionally, as a method or apparatus for detecting cracks in the insulation coating of an insulated wire, a voltage is applied between the core wire and the insulation coating with a plurality of linear electrodes in contact with the surface of the insulated wire. However, there is a device that utilizes electricity when the electrode enters an area where the core wire is exposed (Shokai Sho 61-
131674). FIG. 1 shows an example of an inspection by the above-described method of utilizing energization (herein referred to as energization method). In FIG. 1, 31 is a core wire of an insulated wire, 32 is an insulation coating, 33
Is a linear electrode, 34 is a detector, 35 is a power source, and 12 is a cracked portion of the insulating coating. When the linear electrode 33 enters the crack 12 and comes into contact with the core wire 31, a current flows through the detector 35, and the occurrence of the crack can be known.
【０００３】この方法は、芯線と電極との機械的な接触
を利用するため、亀裂が閉じている状態の割れや微細な
クラックを検出できない。また、芯線をアースに落とす
必要があること、および通電時、芯線に検出電流が流れ
ることから、現用線への適用が困難である等の問題があ
った。Since this method utilizes mechanical contact between the core wire and the electrode, it is impossible to detect cracks in a closed state or fine cracks. Further, there is a problem that it is difficult to apply it to a working wire because it is necessary to drop the core wire to ground and a detection current flows through the core wire when energized.
【０００４】[0004]
【発明が解決しようとする課題】本発明は上記の欠点を
改善するために提案されたものであって、その目的は絶
縁電線を非破壊で測定し、その絶縁被覆の亀裂を、簡易
に把握できる方法および装置を提供することである。DISCLOSURE OF THE INVENTION The present invention has been proposed in order to remedy the above-mentioned drawbacks, and its purpose is to measure non-destructively an insulated wire and to easily detect cracks in the insulating coating. Method and apparatus.
【０００５】[0005]
【課題を解決するための手段】前記課題の解決は、本発
明が次に列挙する新規な特徴的構成手法および手段を採
用することにより達成される。すなわち、本発明の方法
の特徴は、一定の距離を隔てた２つの探触電極、直流電
源、電流検出素子からなる測定回路を用い、絶縁電線被
覆表面の２点間に探触電極を接触させ、絶縁電線の長手
方向に所定の距離だけ移動させながら、時系列に前記測
定回路に流れる電流を測定し（以後、時系列に測定した
電流値を電流波形と呼ぶ）、電流波形が急激に変化する
点の数、すなわち絶縁被覆の絶縁抵抗が変化する点の数
から絶縁被覆の亀裂検出を行う絶縁電線被覆の亀裂検出
方法である。The solution to the above-mentioned problems can be achieved by adopting the novel characteristic construction method and means listed in the following by the present invention. That is, the feature of the method of the present invention is that a probe electrode is brought into contact with two points on the surface of the insulated wire by using a measuring circuit composed of two probe electrodes, a DC power source, and a current detecting element, which are separated by a certain distance. While moving the insulated wire by a predetermined distance in the longitudinal direction, the current flowing through the measuring circuit is measured in time series (hereinafter, the current value measured in time series is called current waveform), and the current waveform changes rapidly. It is a crack detection method for an insulated wire coating, which detects a crack in the insulation coating from the number of points to be applied, that is, the number of points at which the insulation resistance of the insulation coating changes.
【０００６】本発明装置の特徴は、一定の距離を隔てて
２つの探触電極、直流電源、電流検出素子からなる測定
回路を絶縁電線の長手方向に所定の距離だけスライドさ
せることによって、絶縁電線被覆表面の２点間の絶縁抵
抗を時系列に測定する手段と、時系列に測定した絶縁抵
抗を波形（抵抗値波形）として記憶する記憶回路と、抵
抗値波形が急激に変化する点の数を測定することで、絶
縁電線の亀裂を検出する検出回路を備える絶縁電線被覆
の亀裂検出装置である。The device of the present invention is characterized in that a measuring circuit composed of two probe electrodes, a DC power source, and a current detecting element is slid at a predetermined distance in the longitudinal direction of the insulated wire by a predetermined distance. A means for measuring the insulation resistance between two points on the coating surface in time series, a memory circuit for storing the insulation resistance measured in time series as a waveform (resistance value waveform), and the number of points at which the resistance value waveform changes abruptly. Is a crack detection device for an insulated electric wire coating, which is provided with a detection circuit for detecting a crack in the insulated electric wire.
【０００７】[0007]
【作用】測定回路を絶縁電線の表面に接触、移動させる
だけで測定てきるので、迅速かつ容易に非破壊検査が実
施できる。また、測定は絶縁被覆の直流抵抗を求めてい
るので、電線に対する電磁的誘導やノイズがなく、現用
線への適用が可能である。さらに、亀裂の検出は、時系
列に測定した絶縁抵抗の相対的な変化から求めているの
で、絶縁被覆の固有抵抗に依存することがない。Since the measurement can be performed only by bringing the measuring circuit into contact with and moving the surface of the insulated wire, the nondestructive inspection can be carried out quickly and easily. Further, since the measurement requires the DC resistance of the insulation coating, there is no electromagnetic induction or noise to the electric wire, and it can be applied to the working wire. Further, since the crack is detected from the relative change of the insulation resistance measured in time series, it does not depend on the specific resistance of the insulation coating.
【０００８】[0008]
【実施例】添付図面を参照して本発明の実施例を詳細に
説明する。図２は本発明の基本的な考え方を示す図であ
り、図２（ａ）は絶縁電線被覆の亀裂を検出する基本回
路の構成図であり、図２（ｂ）は上記の回路で得られ
る、測定位置と電流との関係を示す波形図である。２つ
の探触電極２１、直流電源３、検流計２２からなる測定
回路を、絶縁電線１１の長手方向に沿って移動させ、各
位置における絶縁被覆を流れる直流電流を測定する。電
極間に亀裂が存在しない場合には、絶縁被覆の抵抗に応
じた固有の電流（Ｉ 0 ）が流れる。電極間に亀裂が存在
する（電極位置がａからａ＋Ｌの範囲）場合には、２つ
の電極を結んでいる絶縁被覆が亀裂位置で分断されるこ
とになるので、電流は図２（ｂ）に示すようにＩ0 から
Ｉn に減少する。Embodiments of the present invention will be described in detail with reference to the accompanying drawings.
explain. FIG. 2 is a diagram showing the basic idea of the present invention.
Fig. 2 (a) shows the basic procedure for detecting cracks in the insulated wire coating.
Fig. 2 (b) is a block diagram of the path obtained by the above circuit.
FIG. 6 is a waveform chart showing the relationship between the measurement position and the current. Two
Measurement of probe electrode 21, DC power supply 3, galvanometer 22
Move the circuit along the longitudinal direction of the insulated wire 11
The DC current flowing through the insulation coating at the location is measured. Electric
If there is no crack between the poles, the resistance of the insulation coating
Specific current (I 0) Flows. There is a crack between the electrodes
If (the electrode position is in the range from a to a + L), two
The insulation coating connecting the electrodes of the
Therefore, the current is I as shown in FIG.0From
InDecrease to.
【０００９】図３は亀裂がない場合（ａ）と、亀裂があ
る場合（ｂ）の電流の違いを説明するための図であり、
図３（ａ−１）は亀裂がない場合の模式図、図３（ａ−
２）はその等価回路図、図３（ｂ−１）は亀裂がある場
合の模式図、図３（ｂ−２）はその等価回路図である。
直流電源３の起電力をＶ、絶縁電線被覆の抵抗値をＲ
ins とすれば、測定回路を流れる電流Ｉ0 は、FIG. 3 shows a case where there is no crack (a) and a case where there is a crack.
FIG. 6 is a diagram for explaining a difference in current in the case (b) of FIG.
Fig.3 (a-1) is a schematic diagram when there is no crack, FIG.
2) is the equivalent circuit diagram, and Fig. 3 (b-1) is the case with cracks.
FIG. 3 (b-2) is a schematic diagram of the case, and its equivalent circuit diagram.
The electromotive force of the DC power supply 3 is V, and the resistance value of the insulated wire coating is R
insThen, the current I flowing through the measurement circuit0Is
【数１】Ｉ0 ＝Ｖ／Ｒins であり、一方、絶縁電線被覆が亀裂の発生により２つに
分断された場合、それら２つの領域の抵抗値をそれぞれ
Ｒins1、Ｒins2、亀裂による抵抗分をＲcrk とすれば、
このとき測定回路に流れる電流Ｉn は、[Equation 1] I 0 = V / R ins . On the other hand, when the insulated wire coating is divided into two due to the occurrence of cracks, the resistance values of these two regions are R ins1 , R ins2 , and the resistance due to the crack, respectively. If the minute is R crk ,
At this time, the current I n flowing through the measuring circuit is
【数２】Ｉn ＝Ｖ／（Ｒins1＋Ｒcrk ＋Ｒins2） となり、ここで、Ｒins1＋Ｒins2＝Ｒins 、また、Ｒ
crk ≫Ｒins であるから、結局、## EQU2 ## I n = V / (R ins1 + R crk + R ins2 ) where R ins1 + R ins2 = R ins and R
crk >> R ins , so after all,
【数３】Ｉn ＝Ｖ／（Ｒins ＋Ｒcrk ）≒Ｖ／Ｒcrk となり、従って、Ｉ0 ≫Ｉn となるため。図２（ｂ）に
示すとおり、電流の急激な減少から亀裂の存在を検知で
きる。Since I n = V / (R ins + R crk ) ≉V / R crk , I 0 >> I n . As shown in FIG. 2B, the presence of cracks can be detected from the rapid decrease in current.
【００１０】図４は本発明による絶縁電線被覆の亀裂検
出方法を実現する亀裂検出装置の構成図である。亀裂検
出装置は、陽探触電極１、陰探触電極２、直流電源３、
電流検出用抵抗４、記憶装置５、演算装置６、出力装置
７から構成される。被測定電線１１は、陽探触電極１お
よび保持用スプリング８と、陰探触電極２および保持用
スプリング８により、それぞれ３方から挟み込まれて測
定に供される。FIG. 4 is a block diagram of a crack detecting device for realizing the crack detecting method for the insulated wire coating according to the present invention. The crack detection device includes a positive probe electrode 1, a negative probe electrode 2, a DC power supply 3,
It is composed of a current detection resistor 4, a storage device 5, an arithmetic device 6, and an output device 7. The measured electric wire 11 is sandwiched by the positive probe electrode 1 and the holding spring 8 and the negative probe electrode 2 and the holding spring 8 from three sides, respectively, and used for the measurement.
【００１１】図５に示す亀裂検出装置の動作フローを、
図４の亀裂検出装置の構成図を用いながら順次説明す
る。測定工程では、直流電源３、探触電極１および２、
保持用スプリング８、電流検出用抵抗４からなる測定回
路を、絶縁電線１１の長手方向に沿って移動させ、回路
を流れる電流を時系列に測定する。なお、本例では、
陽，陰探触電極それぞれが、絶縁電線の外周を３分割す
る位置に配置されているのは、絶縁電線の円周方向に対
する絶縁抵抗のばらつきを平均化するためである。The operation flow of the crack detecting device shown in FIG.
The crack detection device will be sequentially described with reference to the block diagram of FIG. In the measurement process, the DC power source 3, the probe electrodes 1 and 2,
The measurement circuit including the holding spring 8 and the current detection resistor 4 is moved along the longitudinal direction of the insulated wire 11 to measure the current flowing through the circuit in time series. In this example,
Each of the positive and negative probe electrodes is arranged at a position where the outer circumference of the insulated wire is divided into three parts, in order to average the variation in the insulation resistance in the circumferential direction of the insulated wire.
【００１２】信号記憶工程では、時系列に測定した電流
は波形信号として記憶装置５に記憶される。亀裂検出工
程では、演算装置６により波形信号は微分演算される。
図６は、図２（ａ）の波形信号を微分演算した結果であ
る。演算装置６はさらに、微分波形の中から所定のレベ
ル（図６の点線で示す振幅レベル：以後、しきい値と呼
ぶ）を越える箇所を亀裂と見なし、その数をカウントす
る。出力工程は、亀裂の検出結果を出力し表示する。In the signal storage step, the current measured in time series is stored in the storage device 5 as a waveform signal. In the crack detection step, the waveform signal is differentiated by the arithmetic unit 6.
FIG. 6 shows the result of differentiating the waveform signal of FIG. The arithmetic unit 6 further regards a portion exceeding a predetermined level (amplitude level shown by a dotted line in FIG. 6: hereinafter referred to as a threshold) in the differential waveform as a crack, and counts the number. The output step outputs and displays the crack detection result.
【００１３】[0013]
【発明の効果】以上説明したように、本発明によれば、
これまで目視点検に頼っていた亀裂検出を、機械により
簡易かつ迅速に実施できる。また、測定は絶縁被覆の直
流抵抗を求めているので、電線に対する電磁的誘導やノ
イズがなく、現用線への適用が可能である。As described above, according to the present invention,
The crack detection, which has hitherto relied on visual inspection, can be performed simply and quickly by a machine. Further, since the measurement requires the DC resistance of the insulation coating, there is no electromagnetic induction or noise to the electric wire, and it can be applied to the working wire.
【図１】図１は通電法による亀裂検出方法を示す説明図
である。FIG. 1 is an explanatory diagram showing a crack detection method by an energization method.
【図２】図２は本発明の基本的な考え方を示す説明図で
ある。FIG. 2 is an explanatory diagram showing the basic idea of the present invention.
【図３】図３は絶縁被覆の亀裂検出を電気的モデルで表
現した模式図ならびに等価回路図であり、（ａ−１，ａ
−２）は亀裂がない場合、（ｂ−１，ｂ−２）は亀裂が
ある場合をそれぞれ示している。3A and 3B are a schematic diagram and an equivalent circuit diagram in which crack detection of an insulating coating is expressed by an electrical model, and FIG.
-2) shows the case where there is no crack, and (b-1, b-2) shows the case where there is a crack, respectively.
【図４】図４は本発明の亀裂検出装置の構成図である。FIG. 4 is a configuration diagram of a crack detection device of the present invention.
【図５】図５は本発明の処理の流れを示すフローチャー
トである。FIG. 5 is a flowchart showing a processing flow of the present invention.
【図６】図６は図２の絶縁電線を測定した場合に得られ
る微分波形図である。FIG. 6 is a differential waveform diagram obtained when the insulated wire of FIG. 2 is measured.
１ 陽探触電極 ２ 陰探触電極 ３ 直流電源 ４ 電流検出用抵抗 ５ 記憶装置 ６ 演算装置 ７ 出力装置 ８ 保持用スプリング １１ 絶縁電線あるいは被測定電線あるいは被測定線材 １２ 亀裂部分 ２１ 探触電極 ２２ 検流計 ３１ 芯線 ３２ 絶縁被覆 ３３ 線状電極 ３４ 検出器 ３５ 電源 DESCRIPTION OF SYMBOLS 1 Positive probe electrode 2 Negative probe electrode 3 DC power supply 4 Current detection resistance 5 Memory device 6 Computing device 7 Output device 8 Holding spring 11 Insulated wire or measured wire or measured wire 12 Cracked part 21 Probe electrode 22 Galvanometer 31 Core wire 32 Insulation coating 33 Wire electrode 34 Detector 35 Power supply
───────────────────────────────────────────────────── フロントページの続き (72)発明者 進藤 博昭 東京都千代田区内幸町１丁目１番６号 日 本電信電話株式会社内 (72)発明者 増田 順一 東京都千代田区内幸町１丁目１番６号 日 本電信電話株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Shindo 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Junichi Masuda 1-16-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation
Claims (2)
測定方法であって、 前記被測定線材の絶縁抵抗を測定する測定手段と、 前記測定手段の出力を微分処理した結果と所定の絶縁抵
抗変化値を比較する演算部とから構成され、 前記測定手段を前記被測定線材の長手方向に所定長移動
し、前記演算部において所定の絶縁抵抗変化値以上とな
る回数から前記亀裂を測定することを特徴とする絶縁被
覆の亀裂測定方法。1. A measuring method for detecting a crack in an insulating coating of a wire to be measured, comprising: a measuring means for measuring an insulation resistance of the wire to be measured; a result obtained by differentiating an output of the measuring means; It comprises a calculation unit for comparing the resistance change value, the measurement means is moved a predetermined length in the longitudinal direction of the wire to be measured, the crack is measured from the number of times the predetermined insulation resistance change value or more in the calculation unit. A method for measuring cracks in an insulating coating, which is characterized by the above.
する第１および第２の探触電極と、前記第１および第２
の探触電極を介して前記絶縁被覆に絶縁抵抗測定用電圧
を印加する測定用電源と、 前記第１の探触電極に一端が接続され、他端が前記測定
用電源に接続される電流検出素子から構成される測定部
と、 前記測定部の出力の微分処理部と、前記微分処理部の出
力と所定の絶縁抵抗変化値を比較する比較部から構成さ
れる演算部と、 前記演算部の出力を表示する表示部とからなることを特
徴とする絶縁被覆の亀裂測定装置。2. The first and second probe electrodes contacting the insulating coating of the wire to be measured at predetermined intervals, and the first and second probe electrodes.
Measuring power source for applying an insulation resistance measuring voltage to the insulating coating through the probe electrode, and a current detector having one end connected to the first probe electrode and the other end connected to the measuring power source. A measuring unit configured of an element, a differential processing unit of the output of the measuring unit, a computing unit configured of a comparing unit that compares a predetermined insulation resistance change value with the output of the differential processing unit, and a computing unit of the computing unit. A crack measuring device for insulating coating, comprising: a display unit for displaying an output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23485893A JPH0792127A (en) | 1993-09-21 | 1993-09-21 | Method and equipment for measuring crack in insulation coating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23485893A JPH0792127A (en) | 1993-09-21 | 1993-09-21 | Method and equipment for measuring crack in insulation coating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0792127A true JPH0792127A (en) | 1995-04-07 |
Family
ID=16977457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23485893A Pending JPH0792127A (en) | 1993-09-21 | 1993-09-21 | Method and equipment for measuring crack in insulation coating |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0792127A (en) |
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|---|---|---|---|---|
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| CN109208009A (en) * | 2018-09-26 | 2019-01-15 | 江苏清源管道技术有限公司 | A kind of pipeline corrosion protection system of metro area |
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1993
- 1993-09-21 JP JP23485893A patent/JPH0792127A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1455181A1 (en) * | 2003-02-14 | 2004-09-08 | Alcan Technology & Management Ltd. | Non-destructive testing of composite conductor rails |
| CN109208009A (en) * | 2018-09-26 | 2019-01-15 | 江苏清源管道技术有限公司 | A kind of pipeline corrosion protection system of metro area |
| CN109142454A (en) * | 2018-09-27 | 2019-01-04 | 中国科学院合肥物质科学研究院 | A kind of pipeline leak detection method continuously detected based on canal electrical resistance |
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