JP2003066009A - Eddy current flaw detector - Google Patents
Eddy current flaw detectorInfo
- Publication number
- JP2003066009A JP2003066009A JP2001255172A JP2001255172A JP2003066009A JP 2003066009 A JP2003066009 A JP 2003066009A JP 2001255172 A JP2001255172 A JP 2001255172A JP 2001255172 A JP2001255172 A JP 2001255172A JP 2003066009 A JP2003066009 A JP 2003066009A
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- Prior art keywords
- exciting coils
- coils
- eddy current
- coil
- exciting
- 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 Magnetic Means (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えば鋼材などの
表面傷を検出するための渦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 detecting surface flaws such as steel.
【０００２】[0002]
【従来の技術】渦流探傷方式には、各種の方法があるが
工業的に活用されている方式として、相互誘導形自己比
較方式がある。係る探傷方式には、図７(Ａ)に示すよう
な渦流探傷装置６０が用いられる。渦流探傷装置６０
は、単一の励磁コイル６４および一対の互いに逆巻きの
検出コイル６１，６２を含む。図７(Ａ)に示すように、
鋼材などの被検査材６６に近接して探傷装置６０を配置
し、励磁コイル６４に交流電流を通電すると、係る励磁
コイル６４の軸心方向に沿って形成される磁界に基づく
電磁誘導により、被検査材６６の表面には渦電流６８が
形成される。係る渦電流６８も被検査材６６の表面付近
に新たに磁界を形成するため、検出コイル６１，６２の
両端に電圧Ｖ１，Ｖ２が生じる。2. Description of the Related Art There are various types of eddy current flaw detection methods, but as an industrially utilized method, there is a mutual induction type self comparison method. An eddy current flaw detector 60 as shown in FIG. 7A is used for the flaw detection method. Eddy current flaw detector 60
Includes a single excitation coil 64 and a pair of counter-wound detection coils 61, 62. As shown in FIG. 7 (A),
When the flaw detector 60 is arranged in the vicinity of the material 66 to be inspected such as steel and an alternating current is applied to the exciting coil 64, electromagnetic induction based on a magnetic field formed along the axial direction of the exciting coil 64 causes An eddy current 68 is formed on the surface of the inspection material 66. The eddy current 68 also forms a new magnetic field near the surface of the material 66 to be inspected, so that the voltages V1 and V2 are generated across the detection coils 61 and 62.
【０００３】図７(Ａ)に示すように、被検査材６６の表
面に傷がなく健全である場合、検出コイル６１，６２の
電圧Ｖ１，Ｖ２は等しいため、両者を引き算すると、減
算値は０(ゼロ)になる。一方、図７(Ｂ)に示すように、
被検査材６６の表面に傷７０があると、渦電流６８は係
る傷７０を迂回しようとする。この結果、傷７０付近の
渦電流６８には乱れ６９が生じる。このため、係る乱れ
６９に接近する検出コイル６２および離れた位置の検出
コイル６１の両端に生じる電圧Ｖ２，Ｖ１は、互いに相
違する。従って、係る電圧Ｖ１，Ｖ２を図示しない減算
回路に送り、両者間で差を生じた対応する表面に傷７０
が存在していることを検出できる。As shown in FIG. 7 (A), when the surface of the material 66 to be inspected is not damaged and is sound, the voltages V1 and V2 of the detection coils 61 and 62 are equal. It becomes 0 (zero). On the other hand, as shown in FIG.
If there is a flaw 70 on the surface of the material 66 to be inspected, the eddy current 68 tries to bypass the flaw 70. As a result, turbulence 69 is generated in the eddy current 68 near the flaw 70. Therefore, the voltages V2 and V1 generated at both ends of the detection coil 62 approaching the turbulence 69 and the detection coil 61 at the distant position are different from each other. Therefore, the voltages V1 and V2 are sent to a subtraction circuit (not shown), and the scratches 70 are formed on the corresponding surfaces where a difference is generated between the two.
Can be detected.
【０００４】ところで、前記被検査材６６の傷７０と検
出コイル６１，６２相互との向き関係によっては、電圧
Ｖ１，Ｖ２の変化が小さいため、傷７０を検出できなく
なる場合がある。これを解決するため、単一の励磁コイ
ルに対し、４個の検出コイルを並列に配置する渦流探傷
装置も提案されている。即ち、４個の検出コイルのう
ち、互いに対角位置にある１対の検出コイルを互いに逆
巻きで且つ一端にて接続すると共に、係る１対ずつ２組
の検出コイルを、励磁コイルと共に被検査材の表面に接
近させ、１対２組の検出コイルそれぞれに生じる誘導電
流を基に、傷の有無を検出するものである。係る渦流探
傷装置によれば、傷の方向に拘わらず検出が可能となる
(特開平１０−３００７２４号公報参照)。By the way, depending on the direction relationship between the flaw 70 of the material 66 to be inspected and the detection coils 61 and 62, the changes in the voltages V1 and V2 may be small, so that the flaw 70 may not be detected. In order to solve this, an eddy current flaw detection device in which four detection coils are arranged in parallel with respect to a single excitation coil has also been proposed. That is, of the four detection coils, a pair of detection coils which are diagonally opposite to each other are reversely wound and connected at one end, and two pairs of such detection coils are paired with the exciting coil together with the material to be inspected. The presence or absence of a flaw is detected based on the induced current generated in each of the one-to-two pairs of detection coils by approaching the surface of the. According to the eddy current flaw detector, it is possible to detect regardless of the direction of the flaw.
(See Japanese Patent Laid-Open No. 10-300724).
【０００５】[0005]
【発明が解決すべき課題】しかしながら、上述した渦流
探傷装置では、１対ずつ２組の検出コイル何れかを選択
して切り替えるため、検出コイル側の配線が複雑な回路
になると共に、各検出コイル自体に生じる誘導電流の電
圧は、励磁電圧に比べて非常に微弱であるため、上記配
線や切替回路からのノイズの影響を受け易くなる。特
に、被検査材が比較的傷信号を得にくい非磁性鋼や熱間
加熱状態の鋼材の場合は、傷信号の検出が困難になる、
という問題があった。本発明は、以上に説明した従来の
技術における問題点を解決し、被検査材の材質や傷の方
向性などに関わりなく精度良く安定した傷の検出ができ
ると共に、検出コイルの回路も簡略化できる渦流探傷装
置を提供する、ことを課題とする。However, in the above-mentioned eddy current flaw detector, one pair of two detection coils is selected and switched, so that the wiring on the side of the detection coil becomes a complicated circuit and each detection coil is detected. Since the voltage of the induced current generated in itself is extremely weak as compared with the excitation voltage, it is easily affected by noise from the wiring and the switching circuit. In particular, if the material to be inspected is a non-magnetic steel or a steel material that is hot-heated, it is difficult to detect the scratch signal,
There was a problem. The present invention solves the above-mentioned problems in the conventional technique, enables accurate and stable detection of scratches regardless of the material of the inspected material, the direction of the scratches, etc., and simplifies the circuit of the detection coil. An object of the present invention is to provide an eddy current flaw detector that can be used.
【０００６】[0006]
【課題を解決するための手段】本発明は、単一の検出コ
イルに対し複数の励磁コイルを配置し、複数の励磁コイ
ル毎に被検査材に誘導される複数の渦電流間の差の有無
を上記検出コイルにより検出する、ことに着想して成さ
れたものである。即ち、本発明の渦流探傷装置(請求項
１)は、軸心方向が互いに平行で且つ巻き付け方向が逆
向きの複数の励磁コイルと、係る複数の励磁コイルとほ
ぼ同軸心で配置した単一の検出コイルと、を備え、上記
複数の励磁コイルにより被検査材の表面に個別に誘導さ
れる複数の渦電流間の差を上記検出コイルを介して検出
可能としている、ことを特徴とする。According to the present invention, a plurality of exciting coils are arranged with respect to a single detecting coil, and there is a difference between a plurality of eddy currents induced in a material to be inspected for each of the plurality of exciting coils. This is made with the idea that the detection coil is detected by the above. That is, the eddy-current flaw detector according to the present invention (claim 1) has a plurality of exciting coils whose axial directions are parallel to each other and whose winding directions are opposite to each other, and a single single coil arranged substantially coaxially with the plural exciting coils. A detection coil, and a difference between a plurality of eddy currents individually induced on the surface of the material to be inspected by the plurality of excitation coils can be detected through the detection coil.
【０００７】これによれば、複数の励磁コイル毎に被検
査材の表面に個別に誘導される複数の渦電流相互間の差
を単一の検出コイルにより検出できる。即ち、被検査材
の表面に傷がない場合、複数の渦電流は互いに逆向きで
且つ同じ電流および電圧で、これらによる磁界も互いに
打ち消し合うため、検出コイルには電圧が生じない。こ
れに対し、被検査材の表面に傷がある場合、複数の渦電
流のうち、傷が掛かる位置の渦電流は乱れたりするなど
の変化を生じるため、健全な表面に生じる渦電流との間
で差が生じる。係る差に基づき検出コイルには電圧が発
生するため、傷の検出を確実に行うことができる。しか
も、検出コイルは単一であるため、従来の複数の検出コ
イルを用いる渦流探傷装置に比べ、係る検出コイル側の
配線が簡素な回路になるので、例えば非磁性鋼の被検査
材であっても、安定した検出精度を得ることが可能とな
る。尚、上記複数の励磁コイルには、１組１対で合計２
個の励磁コイルの他、次述する２組２対で合計４個、３
組３対で合計６個、または４組４対で合計８個の励磁コ
イルなども含まれる。また、「前記渦電流間の差」は、検
出コイルに流れる誘導電流および電圧の値の少なくとも
一方により検出される。更に、複数の励磁コイルは、軟
磁性のコアの先端部において、２本または４本の突出部
分ごとに個別に巻き付ける形態の他、後述するように薄
く柔軟な絶縁板の表面や裏面に単一の検出コイルも含め
てプリント配線された形態も含まれる。According to this, the difference between the plurality of eddy currents individually induced on the surface of the material to be inspected for each of the plurality of exciting coils can be detected by the single detecting coil. That is, when there is no scratch on the surface of the material to be inspected, the plurality of eddy currents are in opposite directions and have the same current and voltage, and the magnetic fields due to them cancel each other out, so that no voltage is generated in the detection coil. On the other hand, if there is a scratch on the surface of the material to be inspected, the eddy current at the scratched position of the multiple eddy currents will change, such as being disturbed. Makes a difference. Since a voltage is generated in the detection coil based on the difference, it is possible to surely detect the scratch. Moreover, since the single detection coil is used, the wiring on the side of the detection coil is a simpler circuit than that of the conventional eddy current flaw detector using a plurality of detection coils. Also, it becomes possible to obtain stable detection accuracy. It should be noted that the above plurality of exciting coils have a total of 2 in one pair.
In addition to the individual exciting coils, the following two pairs and two pairs make a total of four, 3
It also includes a total of 6 exciting coils in 3 pairs of pairs, or a total of 8 exciting coils in 4 pairs of 4 pairs. The "difference between the eddy currents" is detected by at least one of the values of the induced current and the voltage flowing in the detection coil. Furthermore, the plurality of exciting coils are individually wound on the front and back surfaces of a thin and flexible insulating plate in addition to the form in which two or four protruding portions are individually wound at the tip of the soft magnetic core. A form in which printed wiring is included including the detection coil of is also included.
【０００８】また、本発明には、前記複数の励磁コイル
は、４個の励磁コイルからなり、これら４個の励磁コイ
ルを軸心方向が互いに平行で且つ隣接するように配置す
ると共に、互いに対角位置にある２組の励磁コイルを各
組ごとの励磁コイルを巻き付け方向が逆向きで且つ一端
で接続するか、互いに隣接する位置にある２組の励磁コ
イルを各組ごとの励磁コイルを巻き付け方向が逆向きで
且つ一端で接続している、渦流探傷装置(請求項２)も含
まれる。これによれば、互いに対角位置または隣接位置
にある２組２対の励磁コイルにより、各組の対の励磁コ
イルごとに、あるいは各組ごとに合成され且つ誘導され
る被検査材の一対の渦電流間の差を、検出コイルにより
容易に検出可能となる。従って、種々の方向に沿った傷
を一層確実に検出することが可能になる。Further, according to the present invention, the plurality of exciting coils are composed of four exciting coils, and the four exciting coils are arranged such that their axial directions are parallel to each other and adjacent to each other, and are opposed to each other. Wind two sets of exciting coils at angular positions, connect the exciting coils of each set in opposite directions and connect at one end, or wind two sets of exciting coils at mutually adjacent positions with each set of exciting coils. An eddy current flaw detector (claim 2) having opposite directions and connected at one end is also included. According to this, two pairs of exciting coils located at diagonal positions or adjacent positions to each other are used for each pair of exciting coils, or for each pair of the inspected material to be synthesized and induced. The difference between the eddy currents can be easily detected by the detection coil. Therefore, it becomes possible to detect the scratches along various directions more reliably.
【０００９】更に、本発明には、前記複数の励磁コイル
がほぼ同一平面内に併設されると共に、係る複数の励磁
コイルとほぼ同軸心且つ隣接(近接)する平面内に前記検
出コイルが重複して配置されている、渦流探傷装置(請
求項３)も含まれる。これによれば、例えば２組２対の
励磁コイルを例えば絶縁板の表面にプリント配線技術に
より形成するプリント基板化することで、同一平面で且
つ互いに併設することができる。また、同じ絶縁板の裏
面または隣接する絶縁板の表面に検出コイルを重複して
配置することにより、コンパクトな構造となる。従っ
て、多チャンネルコイルの製作が容易になり、柔軟なプ
リント基板を用いた場合、被検査材に対しフレキシブル
な倣いによる走査が可能となる。しかも、従来の軟磁性
のコアを用いるプローブ型の探傷装置に比べ、全体とし
て薄い装置構成となるので、狭いスペースの環境でも容
易に適用可能となる。尚、複数の励磁コイルを同じ絶縁
板の表面および裏面に形成する形態も、上記「ほぼ同一
平面内」に含まれる。Further, according to the present invention, the plurality of exciting coils are provided side by side in substantially the same plane, and the detecting coils overlap in a plane substantially coaxial with and adjacent to (adjacent to) the plurality of exciting coils. Also included is an eddy current flaw detector (claim 3), which is arranged as follows. According to this, for example, by forming two sets of two pairs of exciting coils into a printed circuit board formed on the surface of an insulating plate by a printed wiring technique, for example, they can be placed side by side on the same plane. In addition, the detection coil is arranged on the back surface of the same insulating plate or the front surface of the adjacent insulating plate so as to be overlapped, whereby a compact structure is obtained. Therefore, the multi-channel coil can be easily manufactured, and when a flexible printed circuit board is used, it is possible to scan the material to be inspected by a flexible copying. Moreover, since the device configuration is thin as a whole as compared with the conventional probe type flaw detection device using the soft magnetic core, it can be easily applied even in an environment of a narrow space. It should be noted that a form in which a plurality of exciting coils are formed on the front surface and the back surface of the same insulating plate is also included in the "approximately in the same plane".
【００１０】加えて、本発明には、前記複数の励磁コイ
ルおよび単一の検出コイルからなる探傷区分を複数有
し、各探傷区分における複数の励磁コイルが互いにほぼ
同一平面内に併設されると共に、各探傷区分における単
一の検出コイルが互いに同一平面内に併設され且つ同じ
探傷区分における複数の励磁コイルと重複している、渦
流探傷装置(請求項４)も含まれる。これによれば、例え
ば２組２対で合計４個の励磁コイルおよび１つの検出コ
イルからなる探傷区分を、各探傷区分ごとの励磁コイル
および検出コイルを、例えば２枚の平行な絶縁板の表面
に重複して配置することにより、一度に被検査材におけ
る広い範囲の表面を精度および効率良く探傷することが
可能となる。従って、探傷効率を高めると共に、被検査
材を支持または搬送する設備などを扱う検査工程も簡略
化することが可能となる。In addition, the present invention has a plurality of flaw detection sections composed of the plurality of excitation coils and a single detection coil, and the plurality of excitation coils in each flaw detection section are provided side by side in substantially the same plane. Also included is an eddy current flaw detection device (claim 4), in which a single detection coil in each flaw detection section is provided in the same plane as each other and overlaps with a plurality of exciting coils in the same flaw detection section. According to this, for example, a flaw detection section including a total of four excitation coils and one detection coil in two pairs and two pairs, the excitation coil and the detection coil for each flaw detection section, for example, the surface of two parallel insulating plates By arranging the surfaces overlapping with each other, it is possible to detect the surface of a wide range of the material to be inspected with high accuracy and efficiency at one time. Therefore, it is possible to improve the flaw detection efficiency and to simplify the inspection process for handling the equipment or the like that supports or conveys the material to be inspected.
【００１１】[0011]
【発明の実施の形態】以下において、本発明の実施に好
適な形態を図面と共に説明する。図１(Ａ)は、本発明の
１形態の渦流探傷装置１における要部を示す。渦流探傷
装置１は、図１(Ａ)に示すように、軟磁性材からなり円
柱形を呈するコア２と、係るコア２の周面に巻き付けた
検出コイル３と、コア２の先端面から所要長さで形成さ
れ且つ平面視で十字形に交叉する細溝２ａ，２ｂと、こ
れらにより４分割された４分の１の円弧部分２ｃ〜２ｆ
ごとに巻き付けた励磁コイルの組４，５とを含む。上記
コア２は、純鉄またはフェライトなどからなる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1A shows a main part of an eddy current flaw detector 1 according to one embodiment of the present invention. As shown in FIG. 1 (A), the eddy current flaw detection apparatus 1 requires a core 2 made of a soft magnetic material and having a cylindrical shape, a detection coil 3 wound around the peripheral surface of the core 2, and a tip end surface of the core 2. Fine grooves 2a and 2b formed in a length and intersecting in a cross shape in a plan view, and quarter arc portions 2c to 2f divided into four by these.
And a set of exciting coils 4 and 5 wound around each. The core 2 is made of pure iron or ferrite.
【００１２】また、励磁コイルの組４は、図１(Ｂ)，
(Ｃ)に示すように、対角位置にある円弧部分２ｃ，２ｅ
に個別に巻き付けられ且つ互いに逆向きである一対の励
磁コイル６，８からなり、励磁コイルの組５は、残りの
対角位置にある円弧部分２ｄ，２ｆに個別に巻き付けら
れ且つ互いに逆向きである一対の励磁コイル７，９から
なる。励磁コイル６，８および励磁コイル７，９は、図
１(Ｃ)に示すように、それぞれの一端を細溝２ａ，２ｂ
の最深部で各組４，５ごとに接続され、それぞれの他端
はコア２の外部に導出している。尚、検出コイル３と励
磁コイル６〜９は、線径が約０．１５ｍｍの銅線などの
周囲にエナメルを被覆した導線をコイル形状に巻き付け
たものである。また、検出コイル３は、コア２と同軸心
であり、図１(Ａ)で励磁コイル６〜９の外周側に同じレ
ベルで配置しても良い。更に、励磁コイル６〜９は、軸
心方向が互いに平行であり、且つコア２および検出コイ
ル３の軸心と平行(ほぼ同軸心)である。Further, the exciting coil set 4 is shown in FIG.
As shown in (C), the circular arc portions 2c and 2e located at diagonal positions
A pair of exciting coils 6 and 8 which are individually wound around and opposite to each other, and a set 5 of exciting coils is individually wound around the arcuate portions 2d and 2f at the remaining diagonal positions and opposite to each other. It consists of a pair of exciting coils 7 and 9. As shown in FIG. 1C, the exciting coils 6 and 8 and the exciting coils 7 and 9 have fine grooves 2a and 2b at one end thereof.
Is connected to each of the groups 4 and 5 at the deepest portion, and the other ends of the groups are led to the outside of the core 2. The detection coil 3 and the excitation coils 6 to 9 are formed by winding a conductor wire, such as a copper wire having a wire diameter of about 0.15 mm, coated with enamel in a coil shape. Further, the detection coil 3 is coaxial with the core 2 and may be arranged at the same level on the outer peripheral side of the exciting coils 6 to 9 in FIG. 1 (A). Further, the exciting coils 6 to 9 have their axes parallel to each other, and are parallel (substantially coaxial) to the axes of the core 2 and the detection coil 3.
【００１３】以上の渦流探傷装置１を、平面視により概
略化する図２(Ａ)のようになる。また、渦流探傷装置１
における電気回路の概略は、図２(Ｂ)に示す通りであ
る。図２(Ｂ)の右側に示すように、検出コイル３は、両
端をアンプ(増幅器)１８に接続され、係るアンプ１８に
よって増幅された信号は、図示しない検波回路などで従
来の渦流探傷装置と同様に処理される。また、励磁コイ
ル６，８の組４および励磁コイル７，９の組５は、図２
(Ｂ)に示すように、それぞれの一端を所定周波数の電流
を供給する発振器１２，１３に導線１０，１１を介して
接続され、それぞれの他端はアース１６，１７される。The above-mentioned eddy current flaw detector 1 is shown in FIG. Also, the eddy current flaw detection device 1
An outline of the electric circuit in FIG. 2 is as shown in FIG. As shown on the right side of FIG. 2B, both ends of the detection coil 3 are connected to an amplifier (amplifier) 18, and the signal amplified by the amplifier 18 is compared with a conventional eddy current flaw detector by a detection circuit (not shown). It is processed in the same way. The set 4 of exciting coils 6 and 8 and the set 5 of exciting coils 7 and 9 are shown in FIG.
As shown in (B), one end of each is connected to oscillators 12 and 13 for supplying a current of a predetermined frequency via conductors 10 and 11, and the other ends thereof are grounded 16 and 17, respectively.
【００１４】但し、組５の励磁コイル７，９の一端およ
び導線１１の間には、電子スイッチ１４が介在し、係る
スイッチ１４は、バイパス線１５を介して導線１０の中
間と結線可能とされる。即ち、電子スイッチ１４を切り
替えることにより、組５の励磁コイル７，９は、発振器
１２または発振器１３の何れか一方と接続可能とされる
ため、異なる励磁パターンが選択できる。もちろん、組
４の励磁コイル６，８も同様に発振器１２，１３の何れ
かに接続できるよう切替可能としても良い。尚、励磁コ
イル６，８の組４および励磁コイル７，９の組５は、何
れか一方の組４，５に常に通電され且つ交互に切替られ
るか、双方の組４，５が平行に通電される。また、発振
器１２，１３は、互いに逆位相の電流を発振する。However, an electronic switch 14 is interposed between one end of the exciting coils 7 and 9 of the set 5 and the conductor wire 11, and the switch 14 can be connected to the middle of the conductor wire 10 via a bypass wire 15. It That is, by exchanging the electronic switch 14, the excitation coils 7 and 9 of the set 5 can be connected to either the oscillator 12 or the oscillator 13, so that different excitation patterns can be selected. Of course, the exciting coils 6 and 8 of the set 4 may also be switchable so as to be connected to either of the oscillators 12 and 13. The set 4 of the exciting coils 6 and 8 and the set 5 of the exciting coils 7 and 9 are always energized to one of the sets 4 and 5 and switched alternately, or both sets 4 and 5 are energized in parallel. To be done. Further, the oscillators 12 and 13 oscillate currents having mutually opposite phases.
【００１５】以上のような渦流探傷装置１の作用につい
て、図３に基づき説明する。図３(Ａ)に示すように、前
記コア２(図示せず)に配置した検出コイル３および励磁
コイル６，８(７，９)の組４(５)を、鋼材(被検査材)Ｗ
の表面に接近させる。係る状態で、交流電源から前記発
振器１２を経て組４の励磁コイル６，８に所定周波数の
交流電流を通電する。尚、図３(Ａ)では、検出コイル３
を便宜上鋼材Ｗに隣接させた。すると、励磁コイル６，
８ごとにその軸心方向に沿った磁界がそれぞれ形成さ
れ、図３(Ａ)に示すように、これらの磁界に対応した位
置の鋼材Ｗの表面に、一対の渦電流ｖｅ１，ｖｅ２が個
別に誘導される。The operation of the eddy current flaw detector 1 as described above will be described with reference to FIG. As shown in FIG. 3 (A), a set 4 (5) of the detection coil 3 and the exciting coils 6, 8 (7, 9) arranged on the core 2 (not shown) is connected to a steel material (material to be inspected) W
Close to the surface of. In such a state, an alternating current having a predetermined frequency is applied to the exciting coils 6 and 8 of the set 4 from the alternating current power supply through the oscillator 12. In FIG. 3A, the detection coil 3
Was adjacent to the steel material W for convenience. Then, the exciting coil 6,
A magnetic field is formed along the axial direction of each of the eight, and a pair of eddy currents ve1 and ve2 are individually formed on the surface of the steel material W at positions corresponding to these magnetic fields, as shown in FIG. 3 (A). Be induced.
【００１６】渦電流ｖｅ１，ｖｅ２は、傷のない表面に
形成された場合、向きが互いに逆で且つ同じ電圧および
電流値となる。このため、渦電流ｖｅ１，ｖｅ２によ
り、鋼材Ｗの表面から検出コイル３内に向けて新たに誘
導される一対の磁界の各磁束は、互いに逆向きで且つ同
じ大きさである。この結果、図３(Ａ)に示すように、検
出コイル３の両端間で出力される電圧Ｖは０(ゼロ)とな
る。また、残りの組５の励磁コイル７，９に通電するよ
う切替えた際にも、検出コイル３の両端間で電圧Ｖが出
力されないことにより、同じ表面において異なる向きの
傷が存在しないことも検出できる。尚、前記スイッチ１
４により前記発振器１２，１３の何れかと接続し、励磁
コイル７，９の励磁パターン(周波数や位相)を変更して
も良い。従って、図３(Ａ)に示すように、組４，５の励
磁コイル６〜９に通電しても、検出コイル３の両端間で
出力される電圧Ｖが０(ゼロ)であることにより、検査対
象とした鋼材Ｗの表面に傷がないことを検出することが
できる。When the eddy currents ve1 and ve2 are formed on a surface having no scratch, they have opposite directions and have the same voltage and current value. Therefore, the magnetic fluxes of the pair of magnetic fields newly induced from the surface of the steel material W toward the inside of the detection coil 3 by the eddy currents ve1 and ve2 are in opposite directions and have the same magnitude. As a result, as shown in FIG. 3A, the voltage V output between both ends of the detection coil 3 becomes 0 (zero). Further, even when the energizing coils 7 and 9 of the remaining set 5 are switched to be energized, it is also detected that the voltage V is not output between both ends of the detection coil 3 so that there are no scratches in different directions on the same surface. it can. The switch 1
4, the oscillator 12 or 13 may be connected to change the excitation pattern (frequency or phase) of the excitation coils 7 and 9. Therefore, as shown in FIG. 3A, even if the exciting coils 6 to 9 of the sets 4 and 5 are energized, the voltage V output between both ends of the detection coil 3 is 0 (zero), It is possible to detect that the surface of the steel material W to be inspected has no scratch.
【００１７】ところで、図３(Ｂ)に示すように、組４の
励磁コイル６，８に通電し、これらにより形成される磁
界に応じて鋼材Ｗの表面に誘導される渦電流ｖｅ１，ｖ
ｅ２のうち、図示で右側の渦電流ｖｅ２に傷Ｋが掛かる
場合がある。すると、渦電流ｖｅ２は、傷Ｋを迂回して
流れたりして変化する。このため、渦電流ｖｅ１，ｖｅ
２により誘導され且つ検出コイル３を貫通する一対の磁
界には差が生じ、係る差により検査コイル３の両端間に
電圧Ｖが発生する。By the way, as shown in FIG. 3B, eddy currents ve1 and v2 induced on the surface of the steel material W according to the magnetic field formed by energizing the exciting coils 6 and 8 of the set 4
Of the e2, the eddy current ve2 on the right side in the figure may be scratched K. Then, the eddy current ve2 changes by flowing around the flaw K. Therefore, the eddy currents ve1 and ve
A pair of magnetic fields induced by 2 and penetrating the detection coil 3 has a difference, and a voltage V is generated across the inspection coil 3 due to the difference.
【００１８】また、組５の励磁コイル７，９に通電する
よう切替えた際に、検出コイル３の両端間に電圧Ｖが発
生することもある。係る電圧Ｖは、前記アンプ１８によ
り増幅された後に出力される。この結果、図３(Ｂ)に示
すように、組４の励磁コイル６，８または組５の励磁コ
イル７，９の何れかに通電した際、検出コイル３の両端
間で電圧Ｖが出力されることにより、種々の方向に沿っ
た傷Ｋを確実に検出することが可能となる。従って、以
上のような渦流探傷装置１によれば、例えば非磁性鋼の
被検査材であっても、傷Ｋの検出を精度良く確実に行う
ことができる。Further, when the excitation coils 7 and 9 of the set 5 are switched to be energized, a voltage V may be generated across the detection coil 3. The voltage V is output after being amplified by the amplifier 18. As a result, as shown in FIG. 3 (B), when either of the exciting coils 6 and 8 of the set 4 or the exciting coils 7 and 9 of the set 5 is energized, the voltage V is output across the detection coil 3. By doing so, it becomes possible to reliably detect the scratch K along various directions. Therefore, according to the eddy current flaw detection apparatus 1 as described above, it is possible to detect the flaw K with high accuracy and reliability even for a material to be inspected, for example, non-magnetic steel.
【００１９】図４は、本発明の異なる形態の渦流探傷装
置２０に関する。図４(Ａ)に示すように、渦流探傷装置
２０は、ポリイミド樹脂からなる厚みが約１００μｍで
柔軟な絶縁板２１，３４の表面(同一平面)や裏面(同一
平面)に励磁コイル２３〜２６，２９〜３２を含むプリ
ント配線２２，２８や、あるいは検出コイル３６，３８
を形成したプリント基板を備えている。尚、上記絶縁板
２１，３４も図示せぬ絶縁層を介して一体に積層され、
且つ図示しないプローブの先端に取り付けられた状態
で、図４(Ａ)に示すように、鋼材(被検査材)Ｗの表面付
近に配置される。また、プリント配線２２，２８は、公
知の金属メッキやフォトリソグラフィ技術で角形渦巻き
状パターンに形成される。FIG. 4 relates to an eddy current flaw detector 20 of a different form according to the present invention. As shown in FIG. 4 (A), the eddy current flaw detector 20 includes excitation coils 23 to 26 on the front surface (same plane) or back surface (same plane) of flexible insulating plates 21 and 34 made of polyimide resin and having a thickness of about 100 μm. , 29 to 32, or the detection coils 36 and 38.
And a printed circuit board on which is formed. The insulating plates 21 and 34 are also integrally laminated via an insulating layer (not shown),
Further, as shown in FIG. 4 (A), it is arranged near the surface of the steel material (material to be inspected) W while being attached to the tip of a probe (not shown). The printed wirings 22 and 28 are formed in a square spiral pattern by a known metal plating or photolithography technique.
【００２０】図４(Ｂ)に示すように、絶縁板２１の表面
のプリント配線２２のうち、対角に位置する角形渦巻き
状の励磁コイル２３，２６は、それぞれ一端を端子２７
に接続され、残りの対角に位置する励磁コイル２４，２
５は、中央付近で互いに一端を接続される。また、絶縁
板２１の裏面のプリント配線２８のうち、対角に位置す
る励磁コイル２９，３２は、中央付近で互いに一端を接
続され、残りの対角に位置する励磁コイル３０，３１
は、それぞれ一端を端子３３に接続される。更に、励磁
コイル２３，２９、励磁コイル２４，３０、励磁コイル
２５，３１、および励磁コイル２６，３２は、図４(Ｂ)
中の破線で示すスルーホール配線により、それぞれの他
端同士を互いに接続されている。即ち、端子２７，２７
間には、励磁コイル２３，２９，３２，２６が接続さ
れ、端子３３，３３間には、励磁コイル３１，２５，２
４，３０が接続されている。加えて、図４(Ｂ)の下方に
示すように、絶縁板３４の表・裏面には、一端が破線で
示す配線により接続され、且つ他端が端子３７，３７に
接続された角形渦巻き状パターンの検出コイル３６，３
８が形成されている。係る検出コイル３６，３８は一体
であり、図４(Ｂ)中の破線で示すスルーホール配線によ
り接続されている。また、検出コイル３６，３８は、励
磁コイル２３〜２６，２９〜３２と平面視でほぼ同軸心
であり且つ重複した位置にある。As shown in FIG. 4 (B), of the printed wirings 22 on the surface of the insulating plate 21, the rectangular spiral excitation coils 23 and 26 located diagonally have one end at a terminal 27.
Excitation coils 24 and 2 connected to the
5 are connected at one end to each other near the center. In the printed wiring 28 on the back surface of the insulating plate 21, the exciting coils 29 and 32 located diagonally are connected to each other at one end in the vicinity of the center, and the exciting coils 30 and 31 located diagonally to the rest.
Each has one end connected to the terminal 33. Further, the exciting coils 23 and 29, the exciting coils 24 and 30, the exciting coils 25 and 31, and the exciting coils 26 and 32 are as shown in FIG.
The other ends are connected to each other by a through-hole wiring shown by a broken line inside. That is, the terminals 27, 27
Exciting coils 23, 29, 32, 26 are connected between them, and exciting coils 31, 25, 2 are interposed between terminals 33, 33.
4, 30 are connected. In addition, as shown in the lower part of FIG. 4 (B), one side of the insulating plate 34 is connected to the front and back sides by wiring shown by a broken line, and the other end is connected to the terminals 37, 37. Pattern detection coils 36, 3
8 is formed. The detection coils 36 and 38 are integrated and are connected by the through-hole wiring shown by the broken line in FIG. 4 (B). Further, the detection coils 36 and 38 are substantially coaxial with the exciting coils 23 to 26 and 29 to 32 in a plan view, and are located at overlapping positions.
【００２１】例えば、鋼材Ｗの表面に図４(Ｂ)に示す縦
方向の傷Ｋが存在するとする。図４(Ｂ)において、端子
２７，２７および端子３３，３３間に通電し、励磁コイ
ル２３などや励磁コイル３０などをそれぞれ同位相で励
磁する。すると、図４(Ｂ)でプリント配線２２，２８の
左側に位置し太線で示す励磁コイル２３，２５，２９，
３１から個別に生じる磁界は、図４(Ｃ)の上方に示すよ
うに、対応する鋼材Ｗの表面に丸い太線の矢印で示す渦
電流ｕ１，ｕ２を生じさせる。これらのうち、同位相の
渦電流は互いに隣り合う部分で打ち消し合うため、渦電
流ｕ１，ｕ２は、縦長の大きな渦電流Ｕ１に合成され
る。同時に、図４(Ｂ)でプリント配線２２，２８の右側
に位置し細線で示す励磁コイル２４，２６，３０，３２
から個別に生じる磁界は、図４(Ｃ)に示すように、対応
する鋼材Ｗの表面に丸い細線の矢印の渦電流ｕ３，ｕ４
を生じさせる。これらも、上記と同様に縦長の大きな渦
電流Ｕ２に合成される。For example, it is assumed that the surface of the steel material W has a vertical flaw K shown in FIG. 4 (B). In FIG. 4B, the terminals 27, 27 and the terminals 33, 33 are energized to excite the exciting coil 23 and the exciting coil 30 in the same phase. Then, in FIG. 4B, the exciting coils 23, 25, 29, which are located on the left side of the printed wirings 22, 28 and are shown by thick lines,
The magnetic fields individually generated from 31 generate eddy currents u1 and u2 indicated by the arrows with thick round lines on the surface of the corresponding steel material W, as shown in the upper part of FIG. 4 (C). Of these, in-phase eddy currents cancel each other out in adjacent portions, so that the eddy currents u1 and u2 are combined into a vertically long eddy current U1. At the same time, the exciting coils 24, 26, 30, 32 located on the right side of the printed wirings 22, 28 shown in FIG.
As shown in FIG. 4 (C), the magnetic fields individually generated from the eddy currents are eddy currents u3 and u4 indicated by arrows with round thin lines on the surface of the corresponding steel material W.
Cause These are also combined into a large vertically long eddy current U2 as described above.
【００２２】以上の渦電流Ｕ１，Ｕ２により、鋼材Ｗの
表面には、図４(Ｃ)の下方に示すように、縦長で互いに
逆向きの渦電流Ｖ１，Ｖ２がそれぞれ誘導される。鋼材
Ｗのうち、傷のない表面では、渦電流Ｖ１，Ｖ２は、向
きが互いに逆で且つ同じ電圧および電流値となる。この
ため、渦電流Ｖ１，Ｖ２により、鋼材Ｗの表面から新た
に誘導され且つ検出コイル３６，３８を貫通する一対の
磁界は、互いに逆向きで且つ同じ大きさであるので、互
いに打ち消し合う。この結果、検出コイル３６，３８の
端子３７，３７間に電圧を生じないため、縦方向の傷Ｋ
のないことが判明する。一方、図４(Ｃ)に示すように、
渦電流Ｖ２に傷Ｋが掛かると、これを迂回すべく乱れ３
９が生じ、渦電流Ｖ２は小さくなったりその位相が変化
する。このため、渦電流Ｖ１，Ｖ２によって誘導される
一対の磁界には差が生じ、係る差により検査コイル３
６，３８の端子３７，３７間で電圧が出力される。この
結果、縦方向の傷Ｋを確実に検出することができる。By the above eddy currents U1 and U2, vertically long eddy currents V1 and V2 which are opposite to each other are induced on the surface of the steel material W, as shown in the lower part of FIG. 4 (C). The eddy currents V1 and V2 have opposite directions and have the same voltage and current value on the surface of the steel material W having no scratch. Therefore, the pair of magnetic fields newly induced from the surface of the steel material W by the eddy currents V1 and V2 and penetrating the detection coils 36 and 38 are in opposite directions and have the same magnitude, and thus cancel each other out. As a result, since no voltage is generated between the terminals 37 and 37 of the detection coils 36 and 38, the scratch K in the vertical direction is generated.
It turns out that there is no. On the other hand, as shown in FIG.
When the eddy current V2 is damaged K, it is disturbed to bypass it 3
9 occurs, the eddy current V2 becomes smaller and the phase thereof changes. Therefore, a difference occurs between the pair of magnetic fields induced by the eddy currents V1 and V2, and due to the difference, the inspection coil 3
A voltage is output between the terminals 37, 37 of 6, 38. As a result, it is possible to reliably detect the scratch K in the vertical direction.
【００２３】例えば、鋼材Ｗの表面に図５(Ａ)に示す横
方向の傷Ｋが存在するとする。図５(Ａ)において、端子
２７，２７間および端子３３，３３間に通電し、励磁コ
イル２３などや励磁コイル３０などをそれぞれ逆位相で
励磁する。すると、図５(Ａ)でプリント配線２２，２８
の上側に位置し太線で示す励磁コイル２３，２４，２
９，３０から生じる磁界は、図５(Ｂ)に示すように、対
応する鋼材Ｗの表面に丸い太線の矢印の渦電流ｕ１，ｕ
３を生じさせる。これらのうち、同位相の渦電流は互い
に隣り合う部分で打ち消し合うため、渦電流ｕ１，ｕ３
は、横長の大きな渦電流Ｕ３に合成される。同時に、図
５(Ａ)でプリント配線２２，２８の下側に位置し細線で
示す励磁コイル２５，２６，３１，３２から生じる磁界
は、図５(Ｂ)に示すように、対応する鋼材Ｗの表面に丸
い細線の矢印の渦電流ｕ２，ｕ４を生じさせる。これら
も上記と同様に、横長の大きな渦電流Ｕ４に合成され
る。For example, it is assumed that the surface of the steel material W has a lateral flaw K shown in FIG. 5 (A). In FIG. 5A, the terminals 27, 27 and the terminals 33, 33 are energized to excite the exciting coil 23 and the exciting coil 30 in opposite phases. Then, as shown in FIG.
Exciting coils 23, 24, 2 located on the upper side of and shown by thick lines
As shown in FIG. 5 (B), the magnetic fields generated from the magnets 9 and 30 generate eddy currents u1 and u indicated by arrows with round thick lines on the surface of the corresponding steel material W.
Gives rise to 3. Of these, eddy currents of the same phase cancel each other out in the portions adjacent to each other, so that eddy currents u1 and u3
Are combined into a horizontally large eddy current U3. At the same time, the magnetic field generated from the exciting coils 25, 26, 31, 32 located below the printed wirings 22, 28 in FIG. 5 (A) and shown by the thin lines is, as shown in FIG. 5 (B), the corresponding steel material W. Eddy currents u2 and u4 indicated by round thin arrows are generated on the surface of. Similar to the above, these are also combined into the horizontally long eddy current U4.
【００２４】以上の渦電流Ｕ３，Ｕ４により、鋼材Ｗの
表面には、図５(Ｂ)の下方に示すように、横長で互いに
逆向きの渦電流Ｖ３，Ｖ４がそれぞれ誘導される。鋼材
Ｗのうち、傷のない表面では、渦電流Ｖ３，Ｖ４は、向
きが互いに逆で且つ同じ電圧および電流値となる。この
ため、渦電流Ｖ３，Ｖ４により、前記鋼材Ｗの表面から
新たに誘導され且つ検出コイル３６，３８を貫通する一
対の磁界は、互いに逆向きで且つ同じ強度であるため、
互いに打ち消し合う。この結果、検出コイル３６，３８
の端子３７，３７間で電圧が出力されないことにより、
横方向の傷Ｋのないことが判明する。Due to the above eddy currents U3 and U4, laterally long eddy currents V3 and V4 which are opposite to each other are induced on the surface of the steel material W, as shown in the lower part of FIG. 5B. The eddy currents V3 and V4 have opposite directions and have the same voltage and current value on the surface of the steel material W having no scratch. Therefore, the pair of magnetic fields newly induced from the surface of the steel material W by the eddy currents V3 and V4 and penetrating the detection coils 36 and 38 are in opposite directions and have the same strength.
Cancel each other out. As a result, the detection coils 36, 38
Since no voltage is output between terminals 37 and 37 of
It turns out that there are no lateral scratches K.
【００２５】一方、図５(Ｂ)の下方に示すように、渦電
流Ｖ４に傷Ｋが掛かると、これを迂回すべく乱れ３９が
生じ、渦電流Ｖ４は小さくなったりその位相が変化す
る。このため、渦電流Ｖ３，Ｖ４により誘導される一対
の磁界には差が生じ、係る差により検査コイル３６，３
８の端子３７，３７間に電圧が生じる。この結果、横方
向の傷Ｋを確実に検出することができる。従って、以上
のような渦流探傷装置２０によれば、例えば非磁性鋼か
らなる被検査材であっても、各種の傷Ｋの検出を精度良
く確実に行うことができる。On the other hand, as shown in the lower part of FIG. 5 (B), when the eddy current V4 is damaged, a turbulence 39 is generated to bypass the damage K, and the eddy current V4 becomes smaller or its phase changes. Therefore, a difference occurs between the pair of magnetic fields induced by the eddy currents V3 and V4, and the inspection coils 36 and 3 are caused by the difference.
A voltage is generated between the eight terminals 37, 37. As a result, it is possible to reliably detect the scratch K in the lateral direction. Therefore, according to the eddy current flaw detector 20 as described above, it is possible to accurately and surely detect various flaws K even if the material to be inspected is made of non-magnetic steel, for example.
【００２６】図６は、前記渦流探傷装置２０の応用形態
の渦流探傷装置４０を示す。渦流探傷装置４０は、前記
と同様の絶縁板４１の表面(同一平面)に形成した励磁コ
イル４２ａ〜４２ｄ、４４ａ〜４４ｄ、４５ａ〜４５
ｄ、４６ａ〜４６ｄ、４８ａ〜４８ｄ、および絶縁板５
１の表面(同一平面)に形成した検出コイル５２〜５８を
含む。励磁コイル４２ａ〜４２ｄおよび検出コイル５２
は、平面視でほぼ同軸心で且つ重複可能に積層され、探
傷区分Ｔ１を形成する。同様にして、励磁コイル４４ａ
〜４４ｄと検出コイル５４、励磁コイル４５ａ〜４５ｄ
と検出コイル５５、励磁コイル４６ａ〜４６ｄと検出コ
イル５６、および励磁コイル４８ａ〜４８ｄと検出コイ
ル５８は、探傷区分Ｔ２〜Ｔ５を形成し、平面視でほぼ
同軸心で且つ互いに重複して積層される。尚、絶縁板４
１，５１は、単一の同じ絶縁板における表面および裏面
を用いても良い。FIG. 6 shows an eddy current flaw detector 40 which is an application of the eddy current flaw detector 20. The eddy current flaw detector 40 includes exciting coils 42a to 42d, 44a to 44d, 45a to 45 formed on the surface (same plane) of the insulating plate 41 as described above.
d, 46a to 46d, 48a to 48d, and the insulating plate 5
It includes the detection coils 52 to 58 formed on the surface 1 (on the same plane). Excitation coils 42a to 42d and detection coil 52
Are stacked so as to be substantially coaxial with each other in a plan view and to be overlapped with each other to form a flaw detection section T1. Similarly, the exciting coil 44a
To 44d, the detection coil 54, and the excitation coils 45a to 45d
The detection coil 55, the excitation coils 46a to 46d and the detection coil 56, and the excitation coils 48a to 48d and the detection coil 58 form flaw detection sections T2 to T5, and are substantially coaxial with each other in plan view and are laminated so as to overlap each other. It Insulation plate 4
The front and back surfaces of a single insulating plate may be used as 1, 51.
【００２７】探傷区分Ｔ１の励磁コイル４２ａ〜４２ｄ
を例に取ると、対角位置にある励磁コイル４２ａ，４２
ｂおよび励磁コイル４２ｃ，４２ｄは、互いに一端で接
続され且つ他端で図示しない交流電源に接続されてい
る。また、図６に示すように、絶縁板４１の上列の励磁
コイル４２ａ〜４２ｄ、４４ａ〜４４ｄ、４５ａ〜４５
ｄに対し、下列の励磁コイル４６ａ〜４６ｄ、４８ａ〜
４８ｄは、図示で右側に約２分の１程度ずれた位置にあ
り、検出コイル５６，５８も同様にずれている。尚、図
６で励磁コイルが３列である場合は、上下の隣接する励
磁コイル同士は左右方向に約３分の１程度ずらされ、且
つ検出コイルも同様にずらされる。探傷区分Ｔ１を例に
取ると、対角位置にある励磁コイル４２ａ，４２ｂおよ
び励磁コイル４２ｃ，４２ｄに同位相で通電することに
より、図示しない被検査材の表面に縦長または横長の一
対の渦電流が誘導され、何れかに前記傷Ｋが掛かること
により、前記同様に検出コイル５２に誘導電流が流れ、
傷Ｋが検出される。Exciting coils 42a to 42d of the flaw detection section T1
Taking the example as an example, the exciting coils 42a, 42 located at diagonal positions
b and the exciting coils 42c and 42d are connected to each other at one end and to an AC power source (not shown) at the other end. In addition, as shown in FIG. 6, the exciting coils 42a to 42d, 44a to 44d, 45a to 45 in the upper row of the insulating plate 41 are arranged.
With respect to d, the exciting coils 46a to 46d, 48a to
48d is located at a position displaced to the right by about one-half in the figure, and the detection coils 56 and 58 are also displaced in the same manner. When the exciting coils are arranged in three rows in FIG. 6, the upper and lower adjacent exciting coils are shifted from each other in the horizontal direction by about 1/3, and the detection coils are also shifted in the same manner. Taking the flaw detection section T1 as an example, by energizing the exciting coils 42a, 42b and the exciting coils 42c, 42d at diagonal positions in the same phase, a pair of vertically or horizontally long eddy currents are applied to the surface of the inspection material (not shown). Is induced, and the wound K is applied to any of them, an induced current flows in the detection coil 52 in the same manner as described above,
The scratch K is detected.
【００２８】また、励磁コイル４２ａ，４２ｂと励磁コ
イル４２ｃ，４２ｄとに流す電流の位相を逆にすること
により、横方向または縦方向の傷Ｋが容易に検出され
る。同時に、探傷区分Ｔ２〜Ｔ５でも以上と同様な探傷
作用が行われる。従って、以上のような渦流探傷装置４
０によれば、各種の材質からなる被検査材における広い
範囲の表面を効率良く検査することができ、且つ種々の
傷も精度良く検出することが可能となる。尚、絶縁板４
１，５１は、平坦な表面または表・裏面に限らず、例え
ば検査材が棒鋼のような円柱体である場合、係る検査材
の外周面に倣ったアール面を有するものとしても良い。
また、絶縁板４１で上列の励磁コイル４２ａ〜４２ｄな
どおよび下列の励磁コイル４６ａ〜４６ｄなどを、前述
した電子スイッチにより順次切り替えて走査する探傷方
式にしても良い。Further, by making the phases of the currents flowing through the exciting coils 42a and 42b and the exciting coils 42c and 42d opposite to each other, the flaw K in the horizontal direction or the vertical direction can be easily detected. At the same time, the same flaw detection action as above is performed in the flaw detection sections T2 to T5. Therefore, the eddy current flaw detection device 4 as described above
According to 0, it is possible to efficiently inspect a wide range of surfaces of a material to be inspected made of various materials, and it is possible to detect various scratches with high accuracy. Insulation plate 4
1, 51 are not limited to the flat surface or the front and back surfaces, and when the inspection material is a columnar body such as a steel bar, for example, it may have a rounded surface following the outer peripheral surface of the inspection material.
Alternatively, the insulating plate 41 may be of a flaw detection system in which the upper row excitation coils 42a to 42d and the lower row excitation coils 46a to 46d are sequentially switched by the above-described electronic switch to perform scanning.
【００２９】本発明は、以上において説明した各形態に
限定されるものではない。例えば、渦流探傷装置１，２
０，４０および前記鋼材(被検査材)Ｗは、何れか一方を
他方に対して相対的に移動可能としても良い。また、１
つの検出コイルに対して、３組３対で合計６個、または
４組４対で合計８個の励磁コイルを隣接または垂直方向
に積層し、各組で対の励磁コイルを順次ずらして励磁す
ることも可能である。更に、前記渦流探傷装置２０，４
０における励磁コイル２３，４２ａなどや検出コイル３
６，５２などを、円形の渦巻き状パターンに形成しても
良い。尚、本発明の渦流探傷装置１などは、鋼材以外の
非鉄金属や合金からなる被検査材に対しても、適用可能
である。The present invention is not limited to each of the forms described above. For example, eddy current flaw detectors 1 and 2
Any one of 0 and 40 and the steel material (material to be inspected) W may be movable relative to the other. Also, 1
With respect to one detection coil, a total of 6 exciting coils in 3 pairs of 3 pairs, or a total of 8 exciting coils in 4 pairs of 4 pairs are laminated in the adjacent or vertical direction, and the exciting coils of each pair are sequentially shifted and excited. It is also possible. Further, the eddy current flaw detection devices 20, 4
Excitation coil 23, 42a, etc. at 0 and detection coil 3
6, 52 and the like may be formed in a circular spiral pattern. The eddy current flaw detector 1 of the present invention can also be applied to inspected materials made of non-ferrous metals or alloys other than steel.
【００３０】[0030]
【発明の効果】以上に説明した本発明の渦流探傷装置
(請求項１)によれば、複数の励磁コイル毎に被検査材の
表面に個別に誘導される複数の渦電流相互間の差を検出
コイルにより確実に検出できると共に、検出コイルは単
一であるため、係るコイル側の配線が簡素な回路になる
ので、安定した検出精度を得ることが可能となる。ま
た、請求項２の渦流探傷装置によれば、各組の対の励磁
コイルごとに、または各組ごとに合成され且つ誘導され
る被検査材の一対の渦電流間の差を検出コイルにより容
易に検出できるため、種々の方向に沿った傷を一層確実
に検出することができる。The eddy current flaw detector of the present invention described above
According to (Claim 1), the difference between the plurality of eddy currents individually induced on the surface of the material to be inspected for each of the plurality of exciting coils can be reliably detected by the detecting coil, and the single detecting coil is used. Therefore, since the wiring on the coil side is a simple circuit, stable detection accuracy can be obtained. Further, according to the eddy current flaw detector of claim 2, the difference between the pair of eddy currents of the material to be inspected, which is synthesized and induced for each pair of exciting coils of each set or for each pair, can be easily detected by the detecting coil. Therefore, it is possible to more reliably detect the scratches along various directions.
【００３１】更に、請求項３の渦流探傷装置によれば、
多チャンネルコイル化や被検査材とのフレキシブルな倣
い走査が容易となると共に、全体的に薄い装置構成とな
って狭いスペースの環境でも容易に適用可能となる。加
えて、請求項４の渦流探傷装置によれば、複数の探傷区
分を、各区分毎の励磁コイルと検出コイルとを、例えば
絶縁板の表・裏面で重複・配置することで、一度に被検
査材における広い範囲の表面を効率良く探傷することが
可能となる。Further, according to the eddy current flaw detector of claim 3,
In addition to facilitating multi-channel coil formation and flexible scanning with the material to be inspected, the overall device configuration is thin and can be easily applied even in an environment with a narrow space. In addition, according to the eddy current flaw detector of claim 4, a plurality of flaw detection sections are provided at a time by overlapping and arranging the exciting coil and the detection coil for each section, for example, on the front and back surfaces of the insulating plate. It is possible to efficiently detect a wide range of surfaces in the inspection material.
【図１】(Ａ)は本発明の渦流探傷装置における１形態を
示す概略図、(Ｂ)は(Ａ)中のＢ−Ｂ線に沿った視角の断
面図、(Ｃ)は(Ｂ)の励磁コイルの配線を示す概略図。FIG. 1A is a schematic view showing one embodiment of an eddy current flaw detector of the present invention, FIG. 1B is a cross-sectional view taken along the line BB in FIG. 1A, and FIG. Schematic showing the wiring of the exciting coil of FIG.
【図２】(Ａ)は図１の渦流探傷装置における検出コイル
および励磁コイルの配線を示す概略図、(Ｂ)は係る装置
の電気回路を示す概略図。2A is a schematic view showing wiring of a detection coil and an excitation coil in the eddy current flaw detection apparatus of FIG. 1, and FIG. 2B is a schematic view showing an electric circuit of the apparatus.
【図３】(Ａ)，(Ｂ)は図１の渦流探傷装置の作用を示す
概略図。3A and 3B are schematic diagrams showing the operation of the eddy current flaw detector of FIG.
【図４】(Ａ)は異なる形態の渦流探傷装置を示す概略
図、(Ｂ)は係る装置の検出コイルおよび励磁コイルの配
線を示す概略図、(Ｃ)は係る装置の作用を示す概略図。FIG. 4A is a schematic view showing an eddy current flaw detection device of a different form, FIG. 4B is a schematic view showing wiring of a detection coil and an excitation coil of the device, and FIG. 4C is a schematic view showing an operation of the device. .
【図５】(Ａ)は図４(Ａ)の渦流探傷装置の検出コイルお
よび励磁コイルの異なる状態を示す概略図、(Ｂ)は係る
状態における作用を示す概略図。5A is a schematic diagram showing different states of a detection coil and an exciting coil of the eddy current flaw detector of FIG. 4A, and FIG. 5B is a schematic diagram showing an action in such a state.
【図６】図４(Ａ)の渦流探傷装置の応用形態を示す概略
図。FIG. 6 is a schematic diagram showing an applied form of the eddy current flaw detector of FIG. 4 (A).
【図７】(Ａ)，(Ｂ)は従来の渦流探傷装置およびその作
用を示す概略図。7A and 7B are schematic diagrams showing a conventional eddy current flaw detector and its operation.
１，２０，４０……………………………………………渦
流探傷装置
３，３６，３８，５２〜５８……………………………検
出コイル
６〜９，２３〜２６，２９〜３２，４２ａ〜４８ｄ…励
磁コイル
Ｔ１〜Ｔ５…………………………………………………探
傷区分
Ｗ……………………………………………………………鋼
材(被検査材)
ｖｅ１，ｖｅ２，Ｖ１〜Ｖ４……………………………渦
電流1, 20, 40 ……………………………………………… Eddy current flaw detector 3, 36, 38, 52 ～ 58 ……………………… Detecting coils 6-9 , 23 to 26, 29 to 32, 42a to 48d ... Exciting coils T1 to T5 ......................................................................................... ………………………………… Steel materials (materials to be inspected) ve1, ve2, V1-V4 …………………………… Eddy current
Claims (4)
が逆向きの複数の励磁コイルと、係る複数の励磁コイル
とほぼ同軸心で配置した単一の検出コイルと、を備え、
上記複数の励磁コイルにより被検査材の表面に個別に誘
導される複数の渦電流間の差を上記検出コイルを介して
検出可能としている、 ことを特徴とする渦流探傷装置。1. A plurality of exciting coils whose axial directions are parallel to each other and whose winding directions are opposite to each other, and a single detecting coil arranged substantially coaxially with the plurality of exciting coils,
An eddy current flaw detection device characterized in that a difference between a plurality of eddy currents individually induced on the surface of a material to be inspected by the plurality of exciting coils can be detected through the detection coil.
ルからなり、これら４個の励磁コイルを軸心方向が互い
に平行で且つ隣接するように配置すると共に、互いに対
角位置にある２組の励磁コイルを各組ごとの励磁コイル
を巻き付け方向が逆向きで且つ一端で接続するか、互い
に隣接する位置にある２組の励磁コイルを各組ごとの励
磁コイルを巻き付け方向が逆向きで且つ一端で接続して
いる、 ことを特徴とする請求項１に記載の渦流探傷装置。2. The plurality of exciting coils are composed of four exciting coils. The four exciting coils are arranged such that their axial center directions are parallel to each other and adjacent to each other, and they are at diagonal positions with respect to each other. Set the exciting coils of each set so that the winding direction of each set is opposite and connect at one end, or set two exciting coils at the positions adjacent to each other so that the exciting coils of each set are wound in opposite directions. The eddy current flaw detection apparatus according to claim 1, wherein the eddy current flaw detection apparatus is connected at one end.
併設されると共に、係る複数の励磁コイルとほぼ同軸心
で且つ隣接する平面内に前記検出コイルが重複して配置
されている、 ことを特徴とする請求項１または２に記載の渦流探傷装
置。3. The plurality of exciting coils are arranged side by side in substantially the same plane, and the detecting coils are arranged in a plane substantially coaxial with and adjacent to the plurality of exciting coils in an overlapping manner. The eddy-current flaw detection device according to claim 1 or 2.
イルからなる探傷区分を複数有し、各探傷区分における
複数の励磁コイルが互いにほぼ同一平面内に併設される
と共に、各探傷区分における単一の検出コイルが互いに
同一平面内に併設され且つ同じ探傷区分における複数の
励磁コイルと重複している、 ことを特徴とする請求項３に記載の渦流探傷装置。4. A plurality of flaw detection sections composed of the plurality of excitation coils and a single detection coil are provided, and the plurality of excitation coils in each flaw detection section are provided side by side in substantially the same plane with each other. 4. The eddy current flaw detection apparatus according to claim 3, wherein one detection coil is provided in the same plane as each other and overlaps with a plurality of exciting coils in the same flaw detection section.
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|---|---|---|---|
| JP2001255172A JP2003066009A (en) | 2001-08-24 | 2001-08-24 | Eddy current flaw detector |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001255172A JP2003066009A (en) | 2001-08-24 | 2001-08-24 | Eddy current flaw detector |
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| Publication Number | Publication Date |
|---|---|
| JP2003066009A true JP2003066009A (en) | 2003-03-05 |
Family
ID=19083195
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Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005114165A1 (en) * | 2004-05-21 | 2005-12-01 | Nihon University | Eddy current flaw inspecting probe and eddy current flaw inspecting apparatus |
| JP2005351890A (en) * | 2004-05-27 | 2005-12-22 | General Electric Co <Ge> | Omnidirectional eddy current probe and inspection system |
| JP2006250911A (en) * | 2005-03-14 | 2006-09-21 | Osaka Univ | Electromagnetic ultrasonic probe |
| JP2008197016A (en) * | 2007-02-14 | 2008-08-28 | Mitsubishi Heavy Ind Ltd | Sensor element and eddy current flaw detection probe |
| JP2009014651A (en) * | 2007-07-09 | 2009-01-22 | Canon Inc | Magnetic detection element and detection method |
| JP2010019565A (en) * | 2008-07-08 | 2010-01-28 | Hitachi-Ge Nuclear Energy Ltd | Eddy current flaw detecting probe |
| JP2013195202A (en) * | 2012-03-19 | 2013-09-30 | Hitachi Ltd | Eddy current inspection device, eddy current inspection probe, and eddy current inspection method |
| KR101364684B1 (en) * | 2012-08-06 | 2014-02-21 | 남진택 | Unit for Detecting Magnetic Leakage Flux Using Electromagnetic Induction and Non-destructive Testing System and Method Using th Same |
| CN110187004A (en) * | 2019-05-08 | 2019-08-30 | 兰州理工大学 | A kind of different swirl sensor that the biparting shape of vertical angles is picked up |
| CN111879849A (en) * | 2020-07-16 | 2020-11-03 | 南昌航空大学 | Symmetrical non-directional eddy current detection sensor and detection method |
| NL1044407B1 (en) * | 2022-08-30 | 2024-03-12 | Sixpec B V | Eddy current probe with focusing action for non-destructive testing. |
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2001
- 2001-08-24 JP JP2001255172A patent/JP2003066009A/en not_active Withdrawn
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005114165A1 (en) * | 2004-05-21 | 2005-12-01 | Nihon University | Eddy current flaw inspecting probe and eddy current flaw inspecting apparatus |
| JP2005351890A (en) * | 2004-05-27 | 2005-12-22 | General Electric Co <Ge> | Omnidirectional eddy current probe and inspection system |
| JP2006250911A (en) * | 2005-03-14 | 2006-09-21 | Osaka Univ | Electromagnetic ultrasonic probe |
| JP4734522B2 (en) * | 2005-03-14 | 2011-07-27 | 国立大学法人大阪大学 | Electromagnetic ultrasonic probe |
| JP2008197016A (en) * | 2007-02-14 | 2008-08-28 | Mitsubishi Heavy Ind Ltd | Sensor element and eddy current flaw detection probe |
| JP2009014651A (en) * | 2007-07-09 | 2009-01-22 | Canon Inc | Magnetic detection element and detection method |
| JP2010019565A (en) * | 2008-07-08 | 2010-01-28 | Hitachi-Ge Nuclear Energy Ltd | Eddy current flaw detecting probe |
| JP2013195202A (en) * | 2012-03-19 | 2013-09-30 | Hitachi Ltd | Eddy current inspection device, eddy current inspection probe, and eddy current inspection method |
| KR101364684B1 (en) * | 2012-08-06 | 2014-02-21 | 남진택 | Unit for Detecting Magnetic Leakage Flux Using Electromagnetic Induction and Non-destructive Testing System and Method Using th Same |
| CN110187004A (en) * | 2019-05-08 | 2019-08-30 | 兰州理工大学 | A kind of different swirl sensor that the biparting shape of vertical angles is picked up |
| CN111879849A (en) * | 2020-07-16 | 2020-11-03 | 南昌航空大学 | Symmetrical non-directional eddy current detection sensor and detection method |
| NL1044407B1 (en) * | 2022-08-30 | 2024-03-12 | Sixpec B V | Eddy current probe with focusing action for non-destructive testing. |
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