JPH05281198A - Eddy current flaw detection device - Google Patents
Eddy current flaw detection deviceInfo
- Publication number
- JPH05281198A JPH05281198A JP7982392A JP7982392A JPH05281198A JP H05281198 A JPH05281198 A JP H05281198A JP 7982392 A JP7982392 A JP 7982392A JP 7982392 A JP7982392 A JP 7982392A JP H05281198 A JPH05281198 A JP H05281198A
- Authority
- JP
- Japan
- Prior art keywords
- eddy current
- magnetic field
- magnetic
- coil
- inspected
- 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.)
- Pending
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、被検査磁性体に渦電流
を流して被検査磁性導体の探傷を行う渦電流探傷装置に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an eddy current flaw detector for inspecting a magnetic conductor to be inspected by applying an eddy current to a magnetic substance to be inspected.
【０００２】[0002]
【従来の技術】従来の渦電流探傷装置は、例えば特公昭
５８−８３２５２号公報等で紹介されているように、被
検査磁性体の表面に渦電流発生電流を配置し、この渦電
流発生電極から被検査磁性体に数１０キロヘルツ（通常
５０キロヘルツ）の交流磁界を印加し、被検査磁性体の
傷による渦電流抵抗変化をインピーダンスの変化として
検出している。2. Description of the Related Art A conventional eddy current flaw detector has an eddy current generating electrode arranged on the surface of a magnetic material to be inspected, as disclosed in Japanese Patent Publication No. 58-83252. Therefore, an alternating magnetic field of several tens of kilohertz (normally 50 kilohertz) is applied to the magnetic material to be inspected, and eddy current resistance change due to scratches on the magnetic material to be inspected is detected as a change in impedance.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら従来の渦
電流探傷装置は、被検査磁性体に生じた初期の極く小さ
な傷を探傷する場合、この傷によって渦電流を妨げる割
合が小さいため、感度良くこれを識別することができな
かった。However, in the conventional eddy current flaw detector, when detecting an initial very small flaw generated in the magnetic substance to be inspected, the proportion of the eddy current interrupted by this flaw is small, and therefore the sensitivity is high. I could not identify this.
【０００４】本発明の目的とするところは、十分な検出
感度をもち安定した探傷を行なうことができる渦電流探
傷装置を提供することにある。An object of the present invention is to provide an eddy current flaw detector having sufficient detection sensitivity and capable of performing stable flaw detection.
【０００５】[0005]
【課題を解決するための手段】本発明は上記目的を達成
するために、被検査磁性体上に渦電流発生電極を配置
し、この渦電流発生電極によって上記被検査磁性体に渦
電流を発生させて、上記被検査磁性体の探傷を行なう渦
電流探傷装置において、上記渦電流の発生部を鎖交する
バイアス磁界を発生する磁界発生装置と、この磁界発生
装置のバイアス磁界を調整する調整装置を設けたことを
特徴とする。In order to achieve the above object, the present invention arranges an eddy current generating electrode on a magnetic material to be inspected, and the eddy current generating electrode generates an eddy current in the magnetic material to be inspected. In the eddy current flaw detector for flaw detection of the magnetic body to be inspected, a magnetic field generator for generating a bias magnetic field interlinking the eddy current generator and an adjusting device for adjusting the bias magnetic field of the magnetic field generator. Is provided.
【０００６】[0006]
【作用】本発明による渦電流探傷装置は上述の如く構成
したため、渦電流発生電極の先端、すなわち被検査磁性
体の探傷部分に磁界発生装置によってバイアス磁界を印
加し、損傷部の傷などによる漏洩磁束を発生させるので
小さな傷でも感度良く探傷することができる。しかも磁
気飽和曲線における飽和磁界よりも小さくなるように調
整装置によって調整した磁界を被検査磁性体に与えるこ
とができるため、ノイズの発生を防止することができ
る。Since the eddy current flaw detector according to the present invention is configured as described above, a bias magnetic field is applied by the magnetic field generator to the tip of the eddy current generating electrode, that is, the flaw detection portion of the magnetic material to be inspected, and leakage due to flaws in the damaged portion occurs. Since magnetic flux is generated, even small scratches can be detected with high sensitivity. Moreover, since the magnetic field adjusted by the adjusting device so as to be smaller than the saturation magnetic field in the magnetic saturation curve can be applied to the magnetic material to be inspected, the generation of noise can be prevented.
【０００７】[0007]
【実施例】以下本発明の一実施例による渦電流探傷装置
を図面によって説明する。図１および図２は本発明の一
実施例による渦電流探傷装置の基本構成を示す正面図お
よび斜視図である。略コ字状に成された磁極２には、図
示しない電源に接続されたコイル３が巻回されて磁界発
生装置８が構成され、この磁界発生装置８は開放側に設
けた被検査磁性体４にバイアス磁界７を与えている。コ
イル３の電源には、例えばコイル３への電流を制御する
調整装置９が接続されている。磁界発生装置８によるバ
イアス磁界７を鎖交する位置には、損傷部５から発生す
る漏洩磁束６を検出する渦電流発生電極１が配置されて
おり、この渦電流発生電極１には励磁コイル１ａと検出
コイル１ｂが取付けられている。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An eddy current flaw detector according to an embodiment of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a perspective view showing a basic configuration of an eddy current flaw detector according to an embodiment of the present invention. A magnetic field generator 8 is constructed by winding a coil 3 connected to a power source (not shown) around the magnetic pole 2 formed in a substantially U-shape. The magnetic field generator 8 is a magnetic body to be inspected provided on the open side. Bias magnetic field 7 is applied to No. 4. To the power source of the coil 3, for example, an adjusting device 9 that controls the current to the coil 3 is connected. An eddy current generating electrode 1 for detecting a leakage magnetic flux 6 generated from the damaged portion 5 is arranged at a position where the bias magnetic field 7 generated by the magnetic field generating device 8 intersects, and the eddy current generating electrode 1 has an exciting coil 1a. And the detection coil 1b are attached.
【０００８】被検査磁性体４の探傷を行なう場合、磁界
発生装置８を被検査磁性体４の対象部に接近させる。こ
のとき被検査磁性体４の材質や厚さ等によって決まる磁
気飽和曲線における飽和磁界よりも小さくなるように調
整装置９によって調整したバイアス磁界７を与えるよう
にする。バイアス磁界７が飽和磁界に達すると、渦電流
発生電極１にはノイズが検出されてしまうが、調整装置
９によってこれが防止されている。渦電流発生電極１を
上述した位置に配置すると、渦電流発生電極１は磁界発
生装置８の磁気吸引力によって被検査磁性体４に吸着し
た状態となる。渦電流発生電極１には、渦電流発生用コ
イル１ａと検出用コイル１ｂが巻回されており、渦電流
発生用コイル１ａに交流定電圧電流を流すことにより、
被検査磁性体４に渦電流を生じさせる。この交流定電圧
電流と渦電流によって検出用コイル１ｂには電流が流
れ、これが検出される。被検査磁性体４に傷がある場
合、損傷部５から発生する漏洩磁束６も変化するので、
検出コイル１ｂの感度の最も高いところを探しつつ探傷
を行なう。When performing flaw detection on the magnetic body 4 to be inspected, the magnetic field generator 8 is brought close to the target portion of the magnetic body 4 to be inspected. At this time, the bias magnetic field 7 adjusted by the adjusting device 9 so as to be smaller than the saturation magnetic field in the magnetic saturation curve determined by the material and thickness of the magnetic material 4 to be inspected is applied. When the bias magnetic field 7 reaches the saturation magnetic field, noise is detected in the eddy current generating electrode 1, but this is prevented by the adjusting device 9. When the eddy current generating electrode 1 is arranged at the above-mentioned position, the eddy current generating electrode 1 is in a state of being attracted to the magnetic body 4 to be inspected by the magnetic attraction force of the magnetic field generator 8. An eddy current generating coil 1a and a detecting coil 1b are wound around the eddy current generating electrode 1, and by applying an alternating constant voltage current to the eddy current generating coil 1a,
An eddy current is generated in the magnetic material 4 to be inspected. A current flows through the detection coil 1b due to the alternating constant voltage current and the eddy current, and this is detected. When the magnetic material 4 to be inspected has a flaw, the leakage magnetic flux 6 generated from the damaged portion 5 also changes,
The flaw detection is performed while searching for the most sensitive portion of the detection coil 1b.
【０００９】図３は、上述した渦電流探傷装置を用いた
場合の検出感度を示す特性図で、横軸に磁界の強さを示
し、縦軸に信号出力の倍率を示し、被検査磁性体４の厚
さ１を２，３，５ミリメートルと変えた場合の特性曲線
を表している。図１に示した調整装置９によってバイア
ス磁界を変化させることにより、０．２テスラーから
０．６テスラーで、約２倍から３倍まで感度を高めるこ
とができるため、従来、十分な感度が得られなかった小
さな傷でも安定した探傷を行なうことができる。特に、
この磁界の強さの範囲は、エレベーターやエスカレータ
ーに使用される各種鋼材の探傷に適しているが、磁界の
強さを変えることによって厚さの異なる被検査磁性体４
においても同様の効果を得ることができる。FIG. 3 is a characteristic diagram showing the detection sensitivity when the above-mentioned eddy current flaw detector is used. The horizontal axis represents the magnetic field strength, the vertical axis represents the signal output magnification, and the magnetic material to be inspected. 4 shows a characteristic curve when the thickness 1 of 4 is changed to 2, 3 and 5 millimeters. By changing the bias magnetic field by the adjusting device 9 shown in FIG. 1, the sensitivity can be increased from about 2 to 3 times at 0.2 to 0.6 Tesler, so that sufficient sensitivity can be obtained conventionally. Stable flaw detection can be performed even with small scratches that were not made. In particular,
This magnetic field strength range is suitable for flaw detection of various steel materials used in elevators and escalators, but the magnetic material to be inspected 4 having different thicknesses by changing the magnetic field strength.
Also in, the same effect can be obtained.
【００１０】[0010]
【発明の効果】以上説明したように本発明は、渦電流の
発生部を鎖交するバイアス磁界を発生する磁界発生装置
と、この磁界発生装置のバイアス磁界を調整する調整装
置を設けたため、被検査磁性体に加える磁束を変化させ
ることにより、損傷部から発生する漏洩磁束を変化させ
て検出コイルの感度の最も高いところで探傷を行なうこ
とができるので、小さな傷でも安定した探傷を行なうこ
とができる。As described above, according to the present invention, the magnetic field generator for generating the bias magnetic field interlinking the eddy current generating portion and the adjusting device for adjusting the bias magnetic field of the magnetic field generator are provided. By changing the magnetic flux applied to the inspection magnetic body, it is possible to change the leakage magnetic flux generated from the damaged part and perform flaw detection at the location where the detection coil has the highest sensitivity, so stable flaw detection can be performed even with small flaws. .
【図１】本発明の一実施例による渦電流探傷装置を示す
正面図である。FIG. 1 is a front view showing an eddy current flaw detector according to an embodiment of the present invention.
【図２】図１に示す渦電流探傷装置の斜視図である。FIG. 2 is a perspective view of the eddy current flaw detector shown in FIG.
【図３】本発明の渦電流探傷装置の検出感度を示す特性
図である。FIG. 3 is a characteristic diagram showing the detection sensitivity of the eddy current flaw detector of the present invention.
１ 渦電流発生電極 ２ 磁極 ４ 被検査磁性体 ８ 磁界発生装置 ９ 調整装置 1 eddy current generating electrode 2 magnetic pole 4 magnetic material to be inspected 8 magnetic field generator 9 adjusting device
Claims (1)
し、この渦電流発生電極によって上記被検査磁性体に渦
電流を発生させて、上記被検査磁性体の探傷を行なう渦
電流探傷装置において、上記渦電流の発生部を鎖交する
バイアス磁界を発生する磁界発生装置と、この磁界発生
装置のバイアス磁界を調整する調整装置を設けたことを
特徴とする渦電流探傷装置。1. An eddy current flaw detector for disposing an eddy current generating electrode on a magnetic material to be inspected, and generating an eddy current in the magnetic material to be inspected by the eddy current generating electrode to detect flaws in the magnetic material to be inspected. An eddy current flaw detector, comprising: a magnetic field generator that generates a bias magnetic field that links the eddy current generator; and an adjusting device that adjusts the bias magnetic field of the magnetic field generator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7982392A JPH05281198A (en) | 1992-04-01 | 1992-04-01 | Eddy current flaw detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7982392A JPH05281198A (en) | 1992-04-01 | 1992-04-01 | Eddy current flaw detection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05281198A true JPH05281198A (en) | 1993-10-29 |
Family
ID=13700932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7982392A Pending JPH05281198A (en) | 1992-04-01 | 1992-04-01 | Eddy current flaw detection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05281198A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007183197A (en) * | 2006-01-10 | 2007-07-19 | Hitachi Ltd | Eddy current flaw sensor |
| GB2475314A (en) * | 2009-11-16 | 2011-05-18 | Innospection Group Ltd | Apparatus and method for inspection of components made of electrically conductive material by partial saturation eddy current testing |
| JP2021502558A (en) * | 2017-11-13 | 2021-01-28 | エクソンモービル リサーチ アンド エンジニアリング カンパニーＥｘｘｏｎ Ｒｅｓｅａｒｃｈ Ａｎｄ Ｅｎｇｉｎｅｅｒｉｎｇ Ｃｏｍｐａｎｙ | Non-destructive material inspection methods and systems |
| US10921286B2 (en) | 2015-04-07 | 2021-02-16 | Innospection Group Limited | In-line inspection tool |
-
1992
- 1992-04-01 JP JP7982392A patent/JPH05281198A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007183197A (en) * | 2006-01-10 | 2007-07-19 | Hitachi Ltd | Eddy current flaw sensor |
| JP4627499B2 (en) * | 2006-01-10 | 2011-02-09 | 株式会社日立製作所 | Eddy current flaw detection sensor |
| GB2475314A (en) * | 2009-11-16 | 2011-05-18 | Innospection Group Ltd | Apparatus and method for inspection of components made of electrically conductive material by partial saturation eddy current testing |
| GB2475314B (en) * | 2009-11-16 | 2013-07-17 | Innospection Group Ltd | Remote environment inspection apparatus and method |
| US9285345B2 (en) | 2009-11-16 | 2016-03-15 | Innospection Group Limited | Electromagnet inspection apparatus with a movable magnet and method for non-destructive testing of electrically conductive test components |
| US10921286B2 (en) | 2015-04-07 | 2021-02-16 | Innospection Group Limited | In-line inspection tool |
| JP2021502558A (en) * | 2017-11-13 | 2021-01-28 | エクソンモービル リサーチ アンド エンジニアリング カンパニーＥｘｘｏｎ Ｒｅｓｅａｒｃｈ Ａｎｄ Ｅｎｇｉｎｅｅｒｉｎｇ Ｃｏｍｐａｎｙ | Non-destructive material inspection methods and systems |
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