JPH01316655A - Eddy current test equipment - Google Patents
Eddy current test equipmentInfo
- Publication number
- JPH01316655A JPH01316655A JP63149580A JP14958088A JPH01316655A JP H01316655 A JPH01316655 A JP H01316655A JP 63149580 A JP63149580 A JP 63149580A JP 14958088 A JP14958088 A JP 14958088A JP H01316655 A JPH01316655 A JP H01316655A
- Authority
- JP
- Japan
- Prior art keywords
- sensor
- coil
- inspected
- eddy current
- scanning
- 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
- 238000012360 testing method Methods 0.000 title description 6
- 238000001514 detection method Methods 0.000 claims abstract description 73
- 230000005284 excitation Effects 0.000 claims abstract description 20
- 238000007689 inspection Methods 0.000 claims description 45
- 230000007547 defect Effects 0.000 claims description 29
- 238000006073 displacement reaction Methods 0.000 claims description 12
- 238000004804 winding Methods 0.000 claims description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 12
- 238000010586 diagram Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000011324 bead Substances 0.000 description 4
- 230000010363 phase shift Effects 0.000 description 4
- 238000013459 approach Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000035945 sensitivity Effects 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000737 Duralumin Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- -1 duralumin Chemical compound 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000002393 scratching effect Effects 0.000 description 1
- 229910001285 shape-memory alloy Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、導電性の被検査体の微小領域における微細な
亀裂、欠陥を非破壊で検査する渦流探傷装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an eddy current flaw detection device that non-destructively inspects minute cracks and defects in minute areas of a conductive object to be inspected.
従来、コイルに流した電流により被検査体の表面に対し
て平行又は垂直な方向の磁界を発生させ、その磁界によ
り被検査体に誘起された渦電流による前記コイルのイン
ピーダンスの変化を検出して、被検査体の微小な亀裂、
凹凸等の欠陥を見出す渦流探傷装置は各種提供されてい
る０例えば、管体の内部を検査する場合には、特開昭６
０−６６１５６号公報にて開示される如く、トーラス状
に巻回したコイルをその中心線を軸方向と平行となして
管体内に内挿し、該コイルにより発生する軸方向の磁界
により、管体の円周方向に渦電流が誘起され、この渦電
流を利用して管体の亀裂等を検出するものであるが、こ
の装置の情報により前記コイルの軸方向幅程度の環状領
域の中に亀裂等が存在することは判るものの、その円周
方向の位置特定が不可能であった。また、被検査体の微
細な亀裂等の位置を微小領域に特定して検査できる渦流
探傷装置としては、実開昭６２−１０８１４８号公報に
て開示される如く、フエライＩ・コアに励磁コイルと検
出コイルを巻回し、該フェライトコアを被検査体の検査
面に対して略垂直に接触又は近接させて移動し、励磁コ
イルによりフェライトコアの先端断面積に略対応する被
検査体の検査面微小領域に発生する渦電流による信号を
検出コイルで検出するものであるが、被検査体の材質が
異なれば検出コイルの出力は変化し、また材質が同じで
あっても溶接部のビード等により被検査体の検査面と各
コイルの間隔が変化すれば検出コイルの出力は更に大き
く変化し、疑似信号が混入する恐れがあるとともに常に
補正する必要がり、更に検出コイルの信号レベルの変動
により検出感度を高めることができないので、信頼性及
び精度の高い検査が困難であった。Conventionally, a magnetic field is generated in a direction parallel or perpendicular to the surface of the object to be inspected using a current passed through a coil, and changes in the impedance of the coil due to eddy currents induced in the object by the magnetic field are detected. , micro cracks in the inspected object,
Various types of eddy current flaw detection equipment are available for detecting defects such as irregularities.For example, when inspecting the inside of a pipe body, the
As disclosed in Japanese Patent No. 0-66156, a toroidally wound coil is inserted into a tube with its center line parallel to the axial direction, and the axial magnetic field generated by the coil causes the tube to An eddy current is induced in the circumferential direction of the coil, and this eddy current is used to detect cracks in the tube body, but the information from this device detects cracks in an annular area about the width of the coil in the axial direction. Although it was known that there were some, it was impossible to specify their circumferential position. In addition, as an eddy current flaw detection device that can identify and inspect the position of minute cracks, etc. in a test object in a minute area, as disclosed in Japanese Utility Model Application Publication No. 108148/1982, there is a Ferrai I core equipped with an excitation coil. A detection coil is wound around the ferrite core, and the ferrite core is moved approximately perpendicularly to or in contact with the inspection surface of the object to be inspected, and the excitation coil is used to generate a microscopic inspection surface of the object to be inspected that approximately corresponds to the cross-sectional area of the tip of the ferrite core. The detection coil detects the signal due to the eddy current generated in the area, but the output of the detection coil will change if the material of the object to be inspected differs, and even if the material is the same, it may be affected by weld beads etc. If the distance between the test surface of the test object and each coil changes, the output of the detection coil will change even more, and there is a risk that spurious signals will be mixed in, requiring constant correction.Furthermore, fluctuations in the signal level of the detection coil will affect the detection sensitivity. Therefore, it has been difficult to perform highly reliable and accurate inspections.
本発明が前述の状況に鑑み、解決しようとするところは
、被検査体の検査面とセンサを非接触で走査し、被検査
体の材質及び溶接部のビード等による構造的な凹凸によ
らず、亀裂、欠陥以外の部分での検出コイルの出力信号
の変動を小さく抑えて検査面の特定微小領域の亀裂、欠
陥を検出でき、検査の信頼性及び精度の高い渦流探傷装
置を提供する点にある。In view of the above-mentioned situation, the present invention aims to solve the problem by scanning the inspection surface of the object to be inspected and the sensor in a non-contact manner, regardless of the material of the object to be inspected and the structural irregularities caused by beads of welded parts. An object of the present invention is to provide an eddy current flaw detection device that can detect cracks and defects in a specific minute region of an inspection surface by suppressing fluctuations in the output signal of a detection coil in areas other than cracks and defects, and has high inspection reliability and accuracy. be.
本発明は、前述の課題解決の為に、被検査体の検査面に
接して走行する走査体と、導電性の被検査体に変動磁界
を与える励磁コイルと、該励磁コイルにより被検査体に
誘起された渦電流による変動磁界を検出する検出コイル
を備えたセンサと、前記検出コイルの出力信号から被検
査体の微小亀裂、欠陥を検出する信号解析手段と、前記
検出コイルの出力信号から前記センサと被検査体との距
離の変化により生じる信号の変化に応じた正負の駆動電
流を発生する制御手段と、前記センサの一端に連結した
永久磁石を前記走査体に弾性体にて釣り合い保持すると
ともに、該永久磁石の周囲に前記制御手段に接続した駆
動コイルを配し、前記センサと被検査体の間隔を自動関
節して検出コイルを常に一定間隔位置に保つ位置調節手
段とよりなる渦流探傷装置を構成した。In order to solve the above-mentioned problems, the present invention includes a scanning body that travels in contact with the inspection surface of an object to be inspected, an excitation coil that applies a fluctuating magnetic field to the conductive object to be inspected, and an excitation coil that applies a variable magnetic field to the object to be inspected. a sensor equipped with a detection coil that detects a changing magnetic field due to an induced eddy current; a signal analysis means that detects microcracks and defects in the object to be inspected from the output signal of the detection coil; control means for generating positive and negative drive currents in accordance with changes in signals caused by changes in the distance between the sensor and the object to be inspected; and a permanent magnet connected to one end of the sensor, balanced with the scanning object by an elastic body. In addition, a drive coil connected to the control means is arranged around the permanent magnet, and a position adjustment means is provided to automatically adjust the distance between the sensor and the object to be inspected to keep the detection coil at a constant distance. Configured the device.
また、前記制御手段は、前記検出コイルの出力を前記セ
ンサと被検査体との間隔変化に応じた直流電圧変化に変
換する変位検出回路と、該変位検出回路の出力電圧を予
め設定した電圧値と比較してその差に応じた正負の出力
を発生する差動回路と、該差動回路の出力に比例した駆
動電流を発注する電流供給回路とで構成した。Further, the control means includes a displacement detection circuit that converts the output of the detection coil into a DC voltage change according to a change in the distance between the sensor and the object to be inspected, and a voltage value that sets the output voltage of the displacement detection circuit in advance. It is constructed of a differential circuit that generates a positive or negative output according to the difference between the two, and a current supply circuit that supplies a drive current proportional to the output of the differential circuit.
そして、前記走査体は、被検査体の検査面に接して回転
移動する転子を走査方向前後に設けるとともに、該前後
転子間に前記センサを下方へ出没自在に配する本体と、
該本体に上設し前記位置調節手段を内装する円筒状の格
納部とで構成した。The scanning body is provided with trochanters that rotate and move in contact with the inspection surface of the object to be inspected at the front and rear in the scanning direction, and a main body in which the sensor is disposed between the front and rear trochanters so as to be freely retractable downward;
A cylindrical storage section is provided above the main body and houses the position adjustment means.
更に、前記位置調節手段は、前記走査体に取付ける円筒
状の収容体内に前記センサに連結した永久磁石をスプリ
ングばねにて釣り合い保持するとともに、該永久磁石の
周囲で前記収容体外周に駆動コイルを巻回して構成した
。Further, the position adjustment means balances and maintains a permanent magnet connected to the sensor in a cylindrical container attached to the scanning body using a spring, and also arranges a driving coil around the permanent magnet on the outer periphery of the container. Constructed by winding.
また、前記走査体に対して、前記位置調節手段を被検査
体の検査面に垂直な方向に移動固定する関節装置を備え
ている。The scanning apparatus also includes a joint device that moves and fixes the position adjusting means in a direction perpendicular to the inspection surface of the object to be inspected relative to the scanning object.
以上の如き内容からなる本発明の渦流探傷装置は、走査
体に位置調節手段に連結したセンサを配し、該センサの
励磁コイルによる変動磁界により被検査体に渦電流を誘
起し、その渦電流による変動磁界を検出コイルにて検出
し、該検出コイルの出力信号を信号解析手段にて解析し
て被検査体の微小亀裂、欠陥を検出すると同時に、検出
コイルの出力信号の位置変動に応じた成分を分岐して制
御手段に入力して、前記センサと被検査体の検査面との
間隔に応じた正負の駆動電流を発生させ、その駆動電流
を前記センサに連結した位置調節手段の永久磁石の周囲
に配した駆動コイルに印加し、走査体に弾性体にて釣り
合い保持された永久磁石及びセンサをその釣り合い位置
から変位させて、検出コイルの平均出力レベルを常に一
定値に保持し、被検査体の検査面の微小亀裂、欠陥の正
確な情報のみ検出できるようになしている。The eddy current flaw detection apparatus of the present invention having the above-mentioned contents includes a sensor connected to a position adjustment means on a scanning body, and an eddy current is induced in the object to be inspected by a fluctuating magnetic field generated by an excitation coil of the sensor, and the eddy current A detection coil detects the changing magnetic field caused by the detection coil, and a signal analysis means analyzes the output signal of the detection coil to detect microcracks and defects in the object to be inspected. A permanent magnet of the position adjustment means that branches the component and inputs it to the control means to generate a positive and negative drive current according to the distance between the sensor and the inspection surface of the object to be inspected, and connects the drive current to the sensor. The average output level of the detection coil is always maintained at a constant value by displacing the permanent magnet and sensor, which are balanced and held by an elastic body on the scanning body, from their balanced position. Only accurate information on microcracks and defects on the inspection surface of the inspection object can be detected.
また、前記センサと被検査体との距離変動により、励磁
コイルに矩形波電流を供給した場合には、検出コイルの
出力信号のパルス幅として現れ、励磁コイルに交流電流
を供給した場合には、検出コイルの出力信号の位相のず
れとして現れるので、前記制御手段の変位検出回路にて
、パルス幅又は位相のずれに応じた直流電圧変化に変換
し、該変位検出回路の出力電圧を差動回路にて予め設定
した電圧値と比較してその差に応じた正負の出力を発生
させ、該差動回路の出力に比例した駆動電流を電流供給
回路で発生させ、この駆動電流にて駆動コイルを作動し
てセンサの位置を調節するものである。In addition, due to distance fluctuations between the sensor and the object to be inspected, when a rectangular wave current is supplied to the excitation coil, it appears as a pulse width of the output signal of the detection coil, and when an alternating current is supplied to the excitation coil, Since this appears as a phase shift in the output signal of the detection coil, the displacement detection circuit of the control means converts it into a DC voltage change according to the pulse width or phase shift, and the output voltage of the displacement detection circuit is converted into a DC voltage change according to the pulse width or phase shift. compares it with a preset voltage value and generates a positive or negative output according to the difference, generates a drive current proportional to the output of the differential circuit in the current supply circuit, and uses this drive current to drive the drive coil. It operates to adjust the position of the sensor.
次に添付図面に示した実施例に基づき更に本発明の詳細
な説明する。Next, the present invention will be further described in detail based on embodiments shown in the accompanying drawings.
第１図は本発明の渦流探傷装置の原理構成を示し、図中
Ａは被検査体、１０は走査体、２０はセンサ、３０は位
置調節手段、４０は信号解析手段、５０は制御手段をそ
れぞれ示している。FIG. 1 shows the principle configuration of the eddy current flaw detection apparatus of the present invention, in which A is the object to be inspected, 10 is the scanning body, 20 is the sensor, 30 is the position adjustment means, 40 is the signal analysis means, and 50 is the control means. are shown respectively.
走査体ｌＯは、被検査体Ａの検査面ａに沿って走行し、
センサ２０の先端を常に検査面ａに近接させて微小亀裂
、欠陥すを走査するもので、箱状本体１１の走査方向前
後に転子１２．１２を回転可能に取付けるとともに、該
転子１２．１２間で本体１１の下方に開口し、センサ２
０を下方へ出没自在に配する凹所１３を形成している。The scanning body 1O runs along the inspection surface a of the inspection object A,
The tip of the sensor 20 is always kept close to the inspection surface a to scan for microcracks and defects. Trochanters 12. 12 and opens below the main body 11, and the sensor 2
A recess 13 is formed in which the 0 is placed so that it can freely appear and retract downward.
尚、該走査体１０の走査速度は、。Incidentally, the scanning speed of the scanning body 10 is as follows.
１０ｍｍ／ｓ以上で行えるようにしている。またここで
、該走査体１０は検査面ａに沿って円滑に走行できるも
のであれば、各種構造のものが採用でき、例えば本体１
１の下面に図示しないスライダーを取付けて検査面ａ上
を摺動するようになすことも可能で、またモータ駆動又
はロボットにより自走するようになすとともに、被検査
体Ａに対する保持装置を備えておけば、検査を迅速に行
えて好ましい。It is designed to be able to do this at a speed of 10 mm/s or more. Here, the scanning body 10 may have various structures as long as it can run smoothly along the inspection surface a. For example, the scanning body 10 may have various structures.
It is also possible to attach a slider (not shown) to the bottom surface of 1 so that it slides on the inspection surface a, or to make it self-propelled by a motor drive or a robot, and to be equipped with a holding device for the object A to be inspected. It is preferable to do so because the test can be carried out quickly.
センサ２０は、第２図に原理的に示すように直径約２１
ｍの棒状のフェライトコア２１にその先端を余して励磁
コイル２２と検出コイル２３を積層巻回し、前者を一次
コイル、後者を二次コイルとなした構造を有し、励磁コ
イル２２に別途用窓した電源にて変動電流夏、を供給し
て導電性の被検査体への検査面ａに変動磁界を与え、そ
れにより検査面ａに誘起された渦電流による変動磁界を
検出コイル２３にて検出し、後述の信号解析手段４０で
その信号を処理して、微小亀裂、欠陥すの有無及び大小
によって異なる渦電流の情報からその微小亀裂、欠陥す
を検査するものである。The sensor 20 has a diameter of approximately 21 mm, as shown in principle in FIG.
It has a structure in which an excitation coil 22 and a detection coil 23 are laminated and wound around a bar-shaped ferrite core 21 with the tip left open, with the former serving as a primary coil and the latter serving as a secondary coil. A variable current is supplied by a windowed power source to apply a variable magnetic field to the inspection surface a of the conductive object to be inspected, and the detection coil 23 detects the variable magnetic field due to the eddy current induced in the inspection surface a. The microcracks and defects are detected and processed by the signal analysis means 40 described later, and the microcracks and defects are inspected from information on eddy currents that differ depending on the presence and size of microcracks and defects.
位置調節手段３０は、円筒状の収容体３１内にＮ極とＳ
極をその軸方向に向けて棒状の永久磁石３２を遊嵌状態
で配するとともに、該収容体３１に対してスプリングバ
ネ３３等の弾性体にて釣り合い保持し、前記永久磁石３
２の周囲で前記収容体３１外周に駆動コイル３４を巻回
固定し、また該永久磁石３２の下端には前記センサ２０
を固定するための連結杆３５を固定して構成した。そし
て、前記収容体３１を走査体１０の本体１１に固定する
とともに、前記連結杆３５を本体１１の凹所Ｉ３内に配
したセンサ２０の上端に固定し、前記駆動コイル３４に
後述の制御手段５０から供給された電流にて前記永久磁
石３２及びセンサ２０をスプリングばね３３の釣り合い
位置から変位させるようになしている。尚、前記永久磁
石３２はスプリングばね３３にて収容体３１に釣り合い
保持したが、その伯の弾性体、例えば板バネ、合成ゴム
にて釣り合い保持することも可能であり、更に高速応答
性のステンピングモータ、圧電素子を用いたアクチュエ
ータ又は形状記憶合金等により前記センサ２０を駆動変
位させることも可能である。The position adjustment means 30 has an N pole and an S pole in a cylindrical container 31.
A rod-shaped permanent magnet 32 is disposed in a loosely fitted state with its pole facing in the axial direction, and is balanced against the housing 31 by an elastic body such as a spring spring 33.
A driving coil 34 is wound and fixed around the outer periphery of the housing 31 around the permanent magnet 32, and the sensor 20 is attached to the lower end of the permanent magnet 32.
A connecting rod 35 for fixing is fixed. Then, the housing body 31 is fixed to the main body 11 of the scanning body 10, the connecting rod 35 is fixed to the upper end of the sensor 20 arranged in the recess I3 of the main body 11, and the drive coil 34 is connected to the control means described below. The permanent magnet 32 and the sensor 20 are displaced from the balanced position of the spring 33 by the current supplied from the magnet 50. Although the permanent magnet 32 is held in balance with the container 31 by a spring 33, it is also possible to hold the permanent magnet 32 in balance with an elastic body such as a leaf spring or synthetic rubber. It is also possible to drive and displace the sensor 20 using a ping motor, an actuator using a piezoelectric element, a shape memory alloy, or the like.
信号解析手段４０は、前記センサ２０の構造及び励磁コ
イル２２に供給する電流波形により、検出コイル２３で
検出する信号波形が異なるので、それに応じた回路構成
をしなければならない。本実施例では第３図＋ａｌ、
（ｂ）に示すように、前記励磁コイル２２には約１ｋｌ
ｌｚ、パルス幅約０．２ｍｓの矩形波電流Ｉｔを供給し
て検査面ａに略垂直方向に変動磁界を与え、矩形波電流
■（の立ち上がり及び立ち下がり時に数１０ｐ３のパル
ス幅のパルス波形電圧ｖ２が検出コイル２３から得られ
る。このパルス波形電圧′Ｌｒ２は、矩形波電流■、の
急激な変化時に検査面ａに誘起され、その後被検査体Ａ
の電気抵抗により減衰する渦電流に起因し、検査面ａに
微小亀裂、欠陥すが存在する場合には減衰速度が変化し
、更に電気抵抗率の異なる材質が存在する場合にも減衰
速度は変化する。従って、該信号解析手段４０は、検出
コイル２３のパルス波形電圧Ｖ２の減衰時間を微小亀裂
、欠陥すの存否両場合について比較して微小亀裂、欠陥
すを検出し、その結果を表示器又は発音器で確認できる
ようになしたものである。尚、走査体１０の走査速度を
１０ｍｍ八とした場合には、サンプリング周波数１ｋＨ
ｚであるから、微小亀裂、欠陥すを直径２ｆｉのフェラ
イトコア２１の先端が通過するまでに、この微小亀裂、
欠陥すによる信号を約２００回検出することになり、十
分な精度で検出が可能であり、実際的には走査速度１０
０ｍｍ／ｓ程度まで可能である。Since the signal waveform detected by the detection coil 23 differs depending on the structure of the sensor 20 and the current waveform supplied to the excitation coil 22, the signal analysis means 40 must have a circuit configuration corresponding to this. In this embodiment, Fig. 3+al,
As shown in (b), the excitation coil 22 has approximately 1 kl.
lz, a rectangular wave current It with a pulse width of about 0.2 ms is supplied to give a varying magnetic field in a substantially perpendicular direction to the inspection surface a, and a pulse waveform voltage with a pulse width of several tens of p3 is generated at the rise and fall of the rectangular wave current (). v2 is obtained from the detection coil 23. This pulse waveform voltage 'Lr2 is induced on the inspection surface a at the time of a sudden change in the rectangular wave current (2), and is then applied to the inspection object A.
Due to eddy currents that attenuate due to the electrical resistance of do. Therefore, the signal analysis means 40 detects microcracks and defects by comparing the attenuation time of the pulse waveform voltage V2 of the detection coil 23 in both the presence and absence of microcracks and defects, and displays the results on a display or a sounder. It was made so that it could be confirmed with a device. In addition, when the scanning speed of the scanning body 10 is 10 mm, the sampling frequency is 1 kHz.
z, by the time the tip of the ferrite core 21 with a diameter of 2fi passes through the microcrack,
The signal due to the defect will be detected approximately 200 times, and detection is possible with sufficient accuracy, and in practice, a scanning speed of 10
It is possible up to about 0 mm/s.
制御手段５０は、前記検出コイル２３の出力信号からそ
の信号し・ベルの高低に応じて前記位置調節手段３０の
駆動コイル３４に供給する正負の駆動電流■。The control means 50 generates a signal from the output signal of the detection coil 23 and supplies positive and negative drive currents to the drive coil 34 of the position adjustment means 30 according to the height of the bell.
（第３図＋ｄ）に示す）を発生するもので、第１図に示
すように検出コイル２３の出力信号から前記センサ２０
と被検査体Ａとの間隔に応じた直流電圧を発生ずる変位
検出回路５１と、該変位検出回路５１の出力電圧ｙｃ
（第３図（Ｃ）に示す）を定電圧電源５２の電圧を可
変抵抗器５３で分圧して予め設定した電圧値Ｖｔ と比
較してその差に応じた正負の出力を発生する差動回路５
４と、外部電源にて士■ボルトで付勢され、該差動回路
５４の出力に比例した駆動電流Ｉ。を発生する電流供給
回路５５とから構成した。(shown in Figure 3+d)), and as shown in Figure 1, the sensor 2
and a displacement detection circuit 51 that generates a DC voltage according to the distance between
(shown in FIG. 3(C)) is a differential circuit that divides the voltage of a constant voltage power supply 52 using a variable resistor 53, compares it with a preset voltage value Vt, and generates a positive or negative output according to the difference. 5
4, and a drive current I which is energized by an external power supply at 1 volts and is proportional to the output of the differential circuit 54. The current supply circuit 55 generates a current.
尚、前記信号解析手段４０と制御手段５０に分岐する前
段に適宜増幅器５６を配し、分岐することによる検出コ
イル２３の信号の電流電圧降下及びインピーダンスの調
整を行っている。尚、励磁コイル２２に供給する変動電
流が矩形波と交流の場合では、検出コイル２３に生じる
出力電圧波形は異なり、当然その信号を処理する回路も
若干異なる。即ら、前記した矩形波電流■、の場合には
、センサ２０と被検査体Ａとの距離の変化は検出コイル
２３の出力信号のパルス幅の変化として現れるので、そ
の信号をコンパレータによりそのパルス幅に応じた矩形
波に変換し、その矩形波を整流平滑化して、距離の変化
に応じた直流電圧変化に変換できるように前記変位検出
回路５１は構成する。また、交流電流の場合には、セン
サ２０と被検査体Ａとの距離の変化は検出コイル２３の
出力信号の位相のずれとして現れるので、差動増幅器に
て位相差に応じた矩形波に変換し、前記同様にこの矩形
波を直流電圧変化にに変換できるように前記変位検出回
路５１を構成する。Incidentally, an amplifier 56 is appropriately arranged before branching to the signal analysis means 40 and the control means 50 to adjust the current voltage drop and impedance of the signal of the detection coil 23 due to the branching. Note that when the fluctuating current supplied to the excitation coil 22 is a rectangular wave or an alternating current, the output voltage waveform generated at the detection coil 23 is different, and naturally the circuit that processes the signal is also slightly different. That is, in the case of the above-mentioned rectangular wave current (2), a change in the distance between the sensor 20 and the object A to be inspected appears as a change in the pulse width of the output signal of the detection coil 23. The displacement detection circuit 51 is configured to convert into a rectangular wave according to the width, rectify and smooth the rectangular wave, and convert it into a DC voltage change according to a change in distance. In the case of alternating current, a change in the distance between the sensor 20 and the object A to be inspected appears as a phase shift in the output signal of the detection coil 23, so a differential amplifier converts it into a rectangular wave according to the phase difference. However, similarly to the above, the displacement detection circuit 51 is configured so as to be able to convert this rectangular wave into a DC voltage change.
しかして、被検査体Ａの検査面ａに溶接のビード等によ
る凹凸が存在する場合には、該検査面ａとセンサ２０と
の間隔が変化し、間隔が大きいと変位検出回路５１の変
位検出信号レヘルは低く、間隔が小さいと逆に高くなる
が、前記制御手段５０により、信号レベルが低くなると
センサ２０を検査面ａに近づけ、高くなると遠ざける方
向に永久磁石３２が変位するように駆動コイル３４に駆
動電流Ｉ０が供給されるので、前記検出コイル２３の信
号レベルは検査面ａの凹凸によらず常に略一定値に維持
され、従って検出感度が常にｒ＆通な状態で検査が可能
となる。If there are irregularities due to welding beads or the like on the inspection surface a of the object A, the distance between the inspection surface a and the sensor 20 changes, and if the distance is large, the displacement detection circuit 51 detects the displacement. The signal level is low, and conversely becomes high when the interval is small. However, the control means 50 controls the drive coil so that the permanent magnet 32 is displaced in the direction in which the sensor 20 is brought closer to the inspection surface a when the signal level is low, and moved away from it when the signal level is high. 34 is supplied with the drive current I0, the signal level of the detection coil 23 is always maintained at a substantially constant value regardless of the unevenness of the inspection surface a, and therefore inspection can be performed with the detection sensitivity always being r&. .
ところで、前記励磁コイル２２に矩形波電流１１を供給
する場合、前記センサ２０がアルミニウムや銅に接近す
れば検出コイル２３のパルス波形電圧ｖ２のパルス幅は
小さくなり、合金や鋼に接近すれば逆に大きくなる傾向
にあり、微小亀裂、欠陥すに接近すれば大きくなる傾向
にある。一方、前記励磁コイル２２に交流電流を供給す
る場合、前記センサ２０が微小亀裂、欠陥すに接近する
場合には、検出コイル２３の出力信号の振幅変化（一般
に増大）として現れる。従って、励磁コイル２２に供給
するｉｔ電流は、アルミニウム（ジュラルミン等を含む
）やステンレスに対しては矩形波が好ましく、また鉄、
鋼には交流電流が好ましい。By the way, when the rectangular wave current 11 is supplied to the excitation coil 22, if the sensor 20 approaches aluminum or copper, the pulse width of the pulse waveform voltage v2 of the detection coil 23 becomes smaller, and vice versa if the sensor 20 approaches an alloy or steel. It tends to get larger as it gets closer to microcracks and defects. On the other hand, when an alternating current is supplied to the excitation coil 22, when the sensor 20 approaches a micro-crack or defect, this appears as an amplitude change (generally an increase) in the output signal of the detection coil 23. Therefore, it is preferable that the IT current supplied to the excitation coil 22 be a rectangular wave for aluminum (including duralumin, etc.) and stainless steel;
Alternating current is preferred for steel.
更に本発明を詳説すれば、第４図に示す如（前記走査体
１０の凹所１３の上部には、前記連結杆３５を挿通し左
右のガタつきなくスライド移動できるように案内孔１４
を形成し、また本体１１の上方には中空円筒状の格納部
１５を固定し、該格納部１５内に前記位ｒ１１ｍ節手段
３０を内挿し、格納部１５の外方側面から螺合したビス
１６にて前記収容体３１を押圧固定している。ここで、
前記収容体３１を格納部１５に対する挿入深さを調節し
て、前記スプリングバネ３３による釣り合い状態で前記
センサ２０の先端と検査面ａとの間隔を設定することが
できる。To further explain the present invention in detail, as shown in FIG.
A hollow cylindrical storage part 15 is fixed above the main body 11, and the above-mentioned joint means 30 is inserted into the storage part 15, and a screw screwed from the outer side surface of the storage part 15 is inserted. At 16, the container 31 is pressed and fixed. here,
By adjusting the depth of insertion of the container 31 into the storage section 15, the distance between the tip of the sensor 20 and the inspection surface a can be set in a balanced state by the spring spring 33.
また、前記センサ２０は、本実施例ではフェライトコア
２１に励磁コイル２２と検出コイル２３をｆａ層巻回し
た二つの同一な単位センサ２０ａ 、 ２０ｂをセンサ
容器２４内に配し、該センサ容器２４から下方へ突出さ
せたそれぞれのフェライトコア２１．２１の先端間隔を
約２ｆｉに設定してモールド固定し構成している。尚、
微小亀裂、欠陥すの大きさは前記間隔（２鶴）より道か
に小さく、また被検査体Ａの位置による材質の変化は前
記間隔程度より広い範囲で緩やかに変化することが知ら
れているので、前記フェライトコア２１の直径、及び両
フェライトコア２１、２１の間隔を約２鰭に設定するこ
とにより、単位センサ２０ａ、２０ｂの何れか一方のみ
に微小亀裂、欠陥すの信号が検出されることになり、そ
の他の緩やかな変化によっては殆ど影習されないので、
高感度の検査が可能となった。Further, in this embodiment, the sensor 20 includes two identical unit sensors 20a and 20b in which an excitation coil 22 and a detection coil 23 are wound in a fa layer around a ferrite core 21, arranged in a sensor container 24. The tips of the ferrite cores 21 and 21 that protrude downward from each other are fixed by molding with the interval between their tips set to about 2fi. still,
It is known that the size of microcracks and defects is much smaller than the above-mentioned interval (2 cranes), and that the material quality changes depending on the position of the object A to be inspected, which changes gradually over a wider range than the above-mentioned interval. Therefore, by setting the diameter of the ferrite core 21 and the interval between the two ferrite cores 21, 21 to approximately 2 fins, a signal indicating a micro-crack or defect can be detected only in either one of the unit sensors 20a, 20b. Therefore, since it is hardly affected by other gradual changes,
Highly sensitive testing has become possible.
そして、二つの単位センサ２０ａ、２０ｂを用いた本実
施例では、第５図に示すようにそれぞれの励磁コイル２
２．２２に電源６０から矩形波電流■ｔ （第６図（Ａ
））を供給し、一方の単位センサ２０ａの検出コイル２
３の出力電圧υ。４．（第６図（Ｂ））と他方の単位セ
ンサ２０ｂの検出コイル２３の出力電圧υ。２２（第６
図（Ｃ））を、定電圧電源４１の電圧を可変抵抗器４２
で分圧して予め設定した電圧値Ｖｓを閾値とするコンパ
レータ４３．４４にそれぞれ入力し、渦電流の減衰速度
に対応したパルス幅を有する矩形波電圧′Ｕ１ （第６
図（Ｄ）） とυ２ （第６図（Ｅ））を発生させ、そ
れらを差動回路４５に入力してそれぞれの矩形波電圧Ｖ
ｔ ＋υ２のパルス幅の差に対応した差動出力ＶＯ（第
６図（Ｆ、） ）を得るのである。そして、前記単位セ
ンサ２０ａ、 ２０ｂのいずれか一方の検出コイル２３
には、前記制御手段５０が接続されている。In this embodiment using two unit sensors 20a and 20b, each exciting coil 2
2. At 22, the square wave current ■t from the power supply 60 (Fig. 6 (A
)) and detecting coil 2 of one unit sensor 20a.
3 output voltage υ. 4. (FIG. 6(B)) and the output voltage υ of the detection coil 23 of the other unit sensor 20b. 22 (6th
(C)), the voltage of the constant voltage power supply 41 is changed to the variable resistor 42.
A rectangular wave voltage 'U1 (sixth
(D)) and υ2 (Fig. 6 (E)), input them to the differential circuit 45, and generate the respective rectangular wave voltages V.
A differential output VO (FIG. 6(F,)) corresponding to the difference in pulse width of t + υ2 is obtained. Then, the detection coil 23 of either one of the unit sensors 20a, 20b
The control means 50 is connected to.
以上は、一方の単位センサ２０ａのフェライトコア２１
は微小亀裂、欠陥すの上方に位置し、他方の単位センサ
２０ｂのフェライトコア２１は位置しない場合を想定し
たもので、従って矩形波電圧υ、の・パルス幅は矩形波
電圧′Ｕ２より短く異なるため、差動出力υ。が得られ
て微小亀裂、欠陥すの存在が確認されるのである。また
、微小亀裂、欠陥すが存在しない場合には、両単位セン
サ２０ａ、２０ｂから全く同じ信号が検出され、差動出
力Ｖ。は全く得られず、微小亀裂、欠陥すの不在が確認
されるのである。更に、前記差動出力Ｖ。のパルス幅を
測定することにより、微小亀裂、欠陥すの大きさも検出
でき、それらの結果を別途構成した位置検出手段の情報
とともに表示器に示すと同時に、記ｔΩ手段で記憶する
ことも可能である。そのうえ、微小亀裂、欠陥すの存在
する検査面ａ上に、前記差動出力υ。に連動させたソレ
ノイドにより駆動されるマーカー等で印を付けるように
することも実用的である。The above describes the ferrite core 21 of one unit sensor 20a.
is located above a micro-crack or defect, and the ferrite core 21 of the other unit sensor 20b is not located. Therefore, the pulse width of the rectangular wave voltage υ is shorter than the rectangular wave voltage 'U2. Therefore, the differential output υ. This confirms the presence of microcracks and defects. In addition, when there are no microcracks or defects, exactly the same signal is detected from both unit sensors 20a and 20b, and the differential output V is generated. No defects were obtained at all, and the absence of microcracks and defects was confirmed. Furthermore, the differential output V. By measuring the pulse width, it is possible to detect the size of microcracks and defects, and the results can be displayed on the display together with information from a separately configured position detection means, and at the same time can be stored in the memory using the recording means. be. Moreover, the differential output υ is applied to the inspection surface a where microcracks and defects exist. It is also practical to mark the area with a marker or the like driven by a solenoid linked to the area.
また、他の実施例として、第７図及び第８図に示すよう
に、パイプ状の被検査体Ａの外面及び内面の検査面ａを
その円周方向に沿って走査する場合に便利なように、走
査体１０の本体１１下面を検査面ａの曲率に応じて設定
することも一剋様である。In addition, as another embodiment, as shown in FIGS. 7 and 8, it is convenient to scan the inspection surface a of the outer surface and inner surface of the pipe-shaped object A to be inspected along its circumferential direction. Furthermore, it is also a good practice to set the lower surface of the main body 11 of the scanning body 10 according to the curvature of the inspection surface a.
更に第９図に示すように、位置調節手段３０の収容体３
１の内部に配する永久磁石３２の上下両端をそれぞれス
プリングバネ３３．３３にて上下対称に釣り合い保持す
ることにより、走査体ＩＯを上下反転させて走査する場
合にも精度よく前記永久磁石３２、部ちセンサ２０を変
位させることができる。また、前記格納部１５の中空内
面の軸方向に縦溝１７を形成するとともに、該縦溝１７
内に格納部１５外に配したロック機構を有する操作輪１
８に連係させた回転可能なピニオン１９を一部突出させ
、そして前記収容体３１の外面軸方向に固定したランク
３６を前記縦溝１７内に配してピニオン１９と噛合させ
、前記操作輪１８を回転させることにより収容体３１を
格納部１５に対して軸方向に移動させるようになした調
節装置を設ければ、センサ２０と検査面ａの初期の間隔
設定が容易である。Furthermore, as shown in FIG. 9, the housing 3 of the position adjustment means 30
By holding the upper and lower ends of the permanent magnet 32 disposed inside the device 1 in a vertically symmetrical manner using spring springs 33 and 33, the permanent magnets 32 and The position sensor 20 can be displaced. Further, a vertical groove 17 is formed in the axial direction of the hollow inner surface of the storage portion 15, and the vertical groove 17
An operating wheel 1 having a locking mechanism disposed inside and outside a storage section 15
A rotatable pinion 19 linked to the rotatable pinion 19 is partially protruded, and a rank 36 fixed in the axial direction of the outer surface of the housing body 31 is disposed within the longitudinal groove 17 and meshed with the pinion 19. If an adjusting device is provided that moves the container 31 in the axial direction with respect to the storage section 15 by rotating the sensor 20, it is easy to set the initial distance between the sensor 20 and the inspection surface a.
更に、第１０図に示すように、位置調節手段３０の収容
体３１の外周で前記永久磁石３２の両極端部位置に間隔
を隔てて駆動コイル３４．３４を配し、それぞれの駆動
コイル３４．３４に互いに逆掻性になるように前記制御
手段５０に接続して、その駆動電流■。によって前記永
久磁石３２をより安定に変位させるようになすことも一
態様である。Furthermore, as shown in FIG. 10, drive coils 34, 34 are arranged at intervals at both ends of the permanent magnet 32 on the outer periphery of the container 31 of the position adjusting means 30, and each drive coil 34, 34 and the drive current (1) is connected to the control means 50 so as to have a reverse scratching property with respect to each other. One embodiment is to displace the permanent magnet 32 more stably by using the above-mentioned method.
以上にしてなる本発明の渦流探傷装置によれば、励磁コ
イルによる変動磁界により被検査体の検査面に誘起され
た渦電流による変動磁界を検出コイルで検出し、その出
力信号を分岐して一方を信号解析手段に入力して微小亀
裂、欠陥に関する情報を検出し、他方を制御手段に入力
してセンサと被検査体との距離に応じた正負の駆動電流
を発生させ、その駆動電流を位置調節手段の駆動コイル
に ７供給したので、被検査体の検査面に溶接のビー
ド等による凹凸が存在する場合にも前記検出コイルの信
号レベルは検査面の凹凸によらず常に略一定値に維持さ
れ、従って検査面の凹凸及び材質の違いによる影響を排
除して、真に微小亀裂、欠陥の情報のみを検出すること
ができ、しかも検出感度が常に高く最適な状態で検査が
可能となる。According to the eddy current flaw detection apparatus of the present invention as described above, the detection coil detects the varying magnetic field due to the eddy current induced on the inspection surface of the object to be inspected by the varying magnetic field generated by the excitation coil, and the output signal is branched to one side. is input into the signal analysis means to detect information on microcracks and defects, and the other is input into the control means to generate positive and negative drive currents depending on the distance between the sensor and the object to be inspected. 7 is supplied to the drive coil of the adjustment means, so even if there are irregularities such as weld beads on the inspection surface of the object to be inspected, the signal level of the detection coil is always maintained at a substantially constant value regardless of the irregularities of the inspection surface. Therefore, it is possible to eliminate the effects of irregularities on the inspection surface and differences in materials, and truly detect only information on microcracks and defects.Moreover, detection sensitivity is always high, and inspection can be performed under optimal conditions.
また、走査体の本体の走査方向前後に転子を設け、該転
子間にセンサを配したことにより、被検査体の検査面に
対してセンサの方向を常に安定して維持でき、センサの
検査面に対する角度のバラツキによる検出コイルの信号
レベルの変化を防止できるとともに、走査作業が迅速に
行える。In addition, by providing trochanters before and after the scanning direction of the main body of the scanning object and placing the sensor between the trochanters, the direction of the sensor can always be maintained stably with respect to the inspection surface of the object to be inspected. Changes in the signal level of the detection coil due to variations in angle with respect to the inspection surface can be prevented, and scanning operations can be performed quickly.
更に、走査体の本体上部に格納部を設け、該格納部内に
配した位置調節手段の収容体を検査面に垂直な方向に移
動固定できる調節装置を設ければ、センサと検査面の間
隔をセンサが弾性体により釣り合い保持された状態で調
節することが可能で、実用土掻めて便利である。Furthermore, if a storage section is provided in the upper part of the main body of the scanning body, and an adjustment device is provided that can move and fix the container for the position adjustment means arranged in the storage section in a direction perpendicular to the inspection surface, the distance between the sensor and the inspection surface can be reduced. The sensor can be adjusted while being balanced by an elastic body, which is convenient for practical use.
第１図は本発明の渦流探傷装置を一部プロ、／り図で示
した簡略断面図、第２図はセンサと渦電流の関係を示し
た説明図、第３図は各ポイントでの信号を示す波形図、
第４図は走査体及び位置調節手段の実施例を示す断面図
、第５図は信号解析手段の回路図、第６図はその各ポイ
ントでの信号の波形図、第７図及び第８図は走査体の他
の実施例を示す簡略側面図、第９図は走査体の格納部及
び位置調節手段の他の実施例を示す断面図、第１０図は
位置調節手段の他の実施例を示す断面図である。
Ａ：被検査体、ａ：検査面、ｂ＝微小亀裂、欠陥、ｌＯ
：走査体、１１：本体、１２：転子、１３：凹所、１４
：案内孔、１５：格納部、１６：ビス、１７：縦溝、１
８：操作輪、１９：ピニオン、２０：センサ、２０ａ、
２０ｂ：単位センサ、２１：フェライトコア、２２：励
磁コイル、２３：検出コイル、２４：センサ容器、３０
：位置調節手段、３１：収容体、３２：永久磁石、３３
ニスプリングバネ、３４：駆動コイル、３５：連結杆、
３６：ランク、４０：信号解析手段、４１：定電圧電源
、４２：可変抵抗器、４３，４４：コンパレータ、４５
：差動回路、５０：制御手段、５１：変位検出回路、５
２：定電圧電源、５３：可変抵抗器、５４：差動回路、
５５：電流供給回路、５６：増幅器、６０：電源。
特許出願人 株式会社日本非破壊計測研究所第１０図
第４図
第１図
第３図
第８図 第７図
第 ５ｒＸｉ
第６図Fig. 1 is a simplified cross-sectional view of the eddy current flaw detection device of the present invention, partially shown in a cross-sectional diagram, Fig. 2 is an explanatory diagram showing the relationship between the sensor and eddy current, and Fig. 3 is a signal at each point. A waveform diagram showing
FIG. 4 is a sectional view showing an embodiment of the scanning body and position adjustment means, FIG. 5 is a circuit diagram of the signal analysis means, FIG. 6 is a signal waveform diagram at each point, and FIGS. 7 and 8. 9 is a simplified side view showing another embodiment of the scanning body, FIG. 9 is a sectional view showing another embodiment of the storage section and position adjustment means of the scanning body, and FIG. 10 is a simplified side view showing another embodiment of the position adjustment means. FIG. A: object to be inspected, a: inspection surface, b = microcrack, defect, lO
: scanning body, 11: main body, 12: trochanter, 13: recess, 14
: Guide hole, 15: Storage part, 16: Screw, 17: Vertical groove, 1
8: Operation wheel, 19: Pinion, 20: Sensor, 20a,
20b: unit sensor, 21: ferrite core, 22: excitation coil, 23: detection coil, 24: sensor container, 30
: Position adjustment means, 31: Container, 32: Permanent magnet, 33
spring spring, 34: drive coil, 35: connecting rod,
36: Rank, 40: Signal analysis means, 41: Constant voltage power supply, 42: Variable resistor, 43, 44: Comparator, 45
: Differential circuit, 50: Control means, 51: Displacement detection circuit, 5
2: Constant voltage power supply, 53: Variable resistor, 54: Differential circuit,
55: Current supply circuit, 56: Amplifier, 60: Power supply. Patent Applicant: Japan Non-Destructive Measurement Laboratory Co., Ltd. Figure 10 Figure 4 Figure 1 Figure 3 Figure 8 Figure 7 5rXi Figure 6
Claims (1)
性の被検査体に変動磁界を与える励磁コイルと、該励磁
コイルにより被検査体に誘起された渦電流による変動磁
界を検出する検出コイルを備えたセンサと、 前記検出コイルの出力信号から被検査体の微小亀裂、欠
陥を検出する信号解析手段と、 前記検出コイルの出力信号から前記センサと被検査体と
の距離の変化により生じる信号の変化に応じた正負の駆
動電流を発生する制御手段と、前記センサの一端に連結
した永久磁石を前記走査体に弾性体にて釣り合い保持す
るとともに、該永久磁石の周囲に前記制御手段に接続し
た駆動コイルを配し、前記センサと被検査体の間隔を自
動調節して検出コイルを常に一定間隔位置に保つ位置調
節手段と、 よりなる渦流探傷装置。 ２）前記制御手段として、前記検出コイルの出力を前記
センサと被検査体との間隔変化に応じて直流電圧変化に
変換する変位検出回路を有し、該変位検出回路の出力電
圧を予め設定した電圧値と比較してその差に応じた正負
の出力を発生する差動回路を備え、該差動回路の出力に
比例した駆動電流を発生する電流供給回路を有する制御
手段を用いてなる特許請求の範囲第１項記載の渦流探傷
装置。 ３）前記走査体として、被検査体の検査面に接して回転
移動する転子を走査方向前後に設けるとともに、該前後
転子間に前記センサを下方へ出没自在に配する本体と、
該本体に上設し前記位置調節手段を内装する円筒状の格
納部とよりなる走査体を用いてなる特許請求の範囲第１
項記載の渦流探傷装置。 ４）前記位置調節手段として、前記走査体に取付ける円
筒状の収容体内に前記センサに連結した永久磁石をスプ
リングばねにて釣り合い保持するとともに、該永久磁石
の周囲で前記収容体外周に駆動コイルを巻回してなる位
置調節手段を用いてなる特許請求の範囲第１項記載の渦
流探傷装置。 ５）前記走査体に対して、前記位置調節手段を被検査体
の検査面に垂直な方向に移動固定する調節装置を備えて
なる特許請求の範囲第１項記載の渦流探傷装置。[Claims] 1) A scanning body that travels in contact with the inspection surface of the object to be inspected, an excitation coil that applies a fluctuating magnetic field to the conductive object to be inspected, and a vortex induced in the object by the excitation coil. A sensor equipped with a detection coil that detects a changing magnetic field caused by an electric current; A signal analysis means that detects microcracks and defects in the object to be inspected from the output signal of the detection coil; A sensor that detects the sensor and the object to be inspected from the output signal of the detection coil. A control means that generates positive and negative drive currents in response to changes in signals caused by changes in distance from the body, and a permanent magnet connected to one end of the sensor that is kept in balance with the scanning body by an elastic body; An eddy current flaw detection device comprising: a drive coil connected to the control means arranged around a magnet; and a position adjustment means that automatically adjusts the distance between the sensor and the object to be inspected to always keep the detection coil at a constant distance position. 2) The control means includes a displacement detection circuit that converts the output of the detection coil into a DC voltage change according to a change in the distance between the sensor and the object to be inspected, and the output voltage of the displacement detection circuit is set in advance. A patent claim that uses a control means that includes a differential circuit that compares voltage values and generates a positive or negative output according to the difference, and has a current supply circuit that generates a drive current proportional to the output of the differential circuit. The eddy current flaw detection device according to item 1. 3) as the scanning body, a main body in which a trochanter that rotates and moves in contact with the inspection surface of the object to be inspected is provided at the front and rear in the scanning direction, and the sensor is disposed between the front and rear trochanters so as to be freely retractable downward;
Claim 1, which uses a scanning body comprising a cylindrical storage section installed above the main body and housing the position adjustment means therein.
The eddy current flaw detection device described in section. 4) As the position adjustment means, a permanent magnet connected to the sensor is balanced and held by a spring in a cylindrical container attached to the scanning body, and a drive coil is installed around the permanent magnet on the outer periphery of the container. An eddy current flaw detection device according to claim 1, which uses a position adjustment means formed by winding. 5) The eddy current flaw detection apparatus according to claim 1, further comprising an adjusting device for moving and fixing the position adjusting means in a direction perpendicular to the inspection surface of the object to be inspected with respect to the scanning object.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63149580A JPH01316655A (en) | 1988-06-16 | 1988-06-16 | Eddy current test equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63149580A JPH01316655A (en) | 1988-06-16 | 1988-06-16 | Eddy current test equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01316655A true JPH01316655A (en) | 1989-12-21 |
Family
ID=15478304
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63149580A Pending JPH01316655A (en) | 1988-06-16 | 1988-06-16 | Eddy current test equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01316655A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0592712U (en) * | 1992-05-13 | 1993-12-17 | 新日本製鐵株式会社 | Magnetizing device for magnetic particle inspection of rolling rolls |
| JPH0633065U (en) * | 1992-10-06 | 1994-04-28 | 川重検査サービス株式会社 | Gap type magnetic flaw detector |
| JP2009002945A (en) * | 2007-06-12 | 2009-01-08 | Ge Inspection Technologies Ltd | Automatic lift-off compensation for pulsed eddy current inspection |
| JP2010230349A (en) * | 2009-03-26 | 2010-10-14 | Honda Motor Co Ltd | Work hardness sensor |
| JP2013076700A (en) * | 2011-09-29 | 2013-04-25 | Abb Technology Ag | Method and arrangement for crack detection in metallic material |
| CN109444259A (en) * | 2018-12-21 | 2019-03-08 | 核动力运行研究所 | A kind of heterotype tubing absorption type eddy current array probe |
| JP2021096187A (en) * | 2019-12-18 | 2021-06-24 | 日本製鉄株式会社 | Steel product surface layer inspection device |
| JP2023009219A (en) * | 2019-03-06 | 2023-01-19 | サガワ産業株式会社 | Nondestructive inspection system |
-
1988
- 1988-06-16 JP JP63149580A patent/JPH01316655A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0592712U (en) * | 1992-05-13 | 1993-12-17 | 新日本製鐵株式会社 | Magnetizing device for magnetic particle inspection of rolling rolls |
| JPH0633065U (en) * | 1992-10-06 | 1994-04-28 | 川重検査サービス株式会社 | Gap type magnetic flaw detector |
| JP2009002945A (en) * | 2007-06-12 | 2009-01-08 | Ge Inspection Technologies Ltd | Automatic lift-off compensation for pulsed eddy current inspection |
| JP2010230349A (en) * | 2009-03-26 | 2010-10-14 | Honda Motor Co Ltd | Work hardness sensor |
| JP2013076700A (en) * | 2011-09-29 | 2013-04-25 | Abb Technology Ag | Method and arrangement for crack detection in metallic material |
| US9103802B2 (en) | 2011-09-29 | 2015-08-11 | Abb Technology Ag | Method and arrangement for crack detection in a metallic material |
| CN109444259A (en) * | 2018-12-21 | 2019-03-08 | 核动力运行研究所 | A kind of heterotype tubing absorption type eddy current array probe |
| CN109444259B (en) * | 2018-12-21 | 2024-02-20 | 核动力运行研究所 | Special-shaped pipe adsorption type eddy current array probe |
| JP2023009219A (en) * | 2019-03-06 | 2023-01-19 | サガワ産業株式会社 | Nondestructive inspection system |
| JP2021096187A (en) * | 2019-12-18 | 2021-06-24 | 日本製鉄株式会社 | Steel product surface layer inspection device |
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