JP3154563B2 - Eddy current generation circuit - Google Patents
Eddy current generation circuitInfo
- Publication number
- JP3154563B2 JP3154563B2 JP22127792A JP22127792A JP3154563B2 JP 3154563 B2 JP3154563 B2 JP 3154563B2 JP 22127792 A JP22127792 A JP 22127792A JP 22127792 A JP22127792 A JP 22127792A JP 3154563 B2 JP3154563 B2 JP 3154563B2
- Authority
- JP
- Japan
- Prior art keywords
- eddy current
- coil
- coils
- signal
- current
- 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.)
- Expired - Fee Related
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、非破壊検査装置に用い
られる電流方向可変型の渦電流発生回路に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable eddy current generating circuit used in a nondestructive inspection apparatus.
【０００２】[0002]
【従来の技術】従来の渦電流センサは、図１５（ａ）に
示すようにコイル１により構成しており、同図（ｂ）に
示すように、このコイル１に高周波電流を流して被検体
２に近付けると、この被検体２が導電性であれば、表面
に渦電流が発生する。被検体２の表面に欠陥等があれ
ば、渦電流の流れが変化し、コイル１のインピーダンス
が変化するので、このインピーダンスの変化から欠陥等
を検出する。2. Description of the Related Art A conventional eddy current sensor comprises a coil 1 as shown in FIG. 15A, and a high-frequency current flows through the coil 1 as shown in FIG. 2, an eddy current is generated on the surface if the subject 2 is conductive. If there is a defect or the like on the surface of the subject 2, the flow of the eddy current changes and the impedance of the coil 1 changes. Therefore, the defect or the like is detected from the change in the impedance.
【０００３】渦電流の発生方向は、コイル１の巻き方に
よって決まり、コイル１に流れる電流の増加方向と反対
方向に発生する。従って、図１５の場合であれば、渦電
流は渦巻状に発生することになる。The direction in which the eddy current is generated is determined by the winding method of the coil 1 and is generated in a direction opposite to the direction in which the current flowing through the coil 1 increases. Therefore, in the case of FIG. 15, the eddy current is generated in a spiral shape.
【０００４】[0004]
【発明が解決しようとする課題】渦電流探傷において
は、渦電流の方向と欠陥の方向とが直交する場合が最も
欠陥検出性が良好となる。In eddy current flaw detection, when the direction of the eddy current and the direction of the defect are perpendicular to each other, the best defect detection is obtained.
【０００５】しかし、従来のセンサでは、上記のように
コイル１の巻き方で渦電流の方向が決まるので、外部コ
ントロールで渦電流の方向を変えることは不可能であ
り、特定の向きの欠陥検出性を向上させることはできな
かった。However, in the conventional sensor, since the direction of the eddy current is determined by the winding method of the coil 1 as described above, it is impossible to change the direction of the eddy current by external control. Could not be improved.
【０００６】本発明は上記の実情を考慮してなされたも
ので、外部コントロールにより被検体上に発生する渦電
流の方向を変えることができ、特定の向きの欠陥検出性
を向上させることができる渦電流発生回路を提供するこ
とを目的とする。The present invention has been made in view of the above circumstances, and the direction of an eddy current generated on a subject can be changed by an external control, thereby improving the detectability of a defect in a specific direction. An object is to provide an eddy current generation circuit .
【０００７】[0007]
【０００８】[0008]
【課題を解決するための手段】本発明に係る渦電流発生
回路は、支持体の一面に第１のコイルと第２のコイルを
独立して設け、これらの第１及び第２のコイルを等角度
で交差させて渦電流発生部を構成すると共に、上記第１
及び第２のコイルの交差部に渦電流検出コイルを設けて
なる渦電流センサと、高周波信号を発生する発振器と、
この発振器から出力される高周波信号を上記渦電流セン
サの第１及び第２のコイルに別個に供給する手段と、渦
電流方向制御信号の値をＳｉｎ曲線の信号に変換するＳ
ｉｎ変換回路と、上記渦電流方向制御信号の値をＣｏｓ
曲線の信号に変換するＣｏｓ変換回路と、上記第１及び
第２のコイルに供給される高周波信号の振幅をそれぞれ
上記Ｓｉｎ変換回路及びＣｏｓ変換回路の出力信号によ
り制御し、上記第１及び第２のコイルにより被検体上に
発生する渦電流の合成電流の方向を可変制御する制御手
段とを具備したことを特徴とする。In the eddy current generating circuit according to the present invention , a first coil and a second coil are independently provided on one surface of a support, and these first and second coils are provided. The eddy current generating section is formed by intersecting the coils of the
An eddy current sensor including an eddy current detection coil provided at the intersection of the second coil and an oscillator that generates a high-frequency signal;
And separately supplying means to high-frequency signal to the first and second coil of the eddy current sensor output from the oscillator, vortex
S for converting the value of the current direction control signal into a signal having a Sin curve
in conversion circuit and the value of the eddy current direction control signal
A Cos conversion circuit for converting the signal into a curve signal;
The amplitude of the high-frequency signal supplied to the second coil
According to the output signals of the Sin conversion circuit and the Cos conversion circuit,
Ri is controlled, characterized in that the direction of the resultant current of the eddy current generated on the object by the first and second coil and a control hand <br/> stage for variably controlled.
【０００９】[0009]
【作用】本発明では、探傷に際してセンサの各コイルに
それぞれ別個に駆動電流を供給し、被検体に近接させ
る。渦電流センサを被検体に近付けた場合、コイルの駆
動電流に応じて被検体上に渦電流が発生する。コイルが
交差する部分においては、各コイルに流れる高周波電流
の位相に応じて渦電流の発生方向が変化し、これに従っ
て合成渦電流の方向も変化する。従って、各コイルに供
給する駆動電流の位相を可変することにより、被検体上
に発生する合成渦電流の方向を任意に設定でき、被検体
上に生じている特定の向きの欠陥についても検出性を向
上することができる。 According to the present invention , a drive current is separately supplied to each coil of the sensor at the time of flaw detection to bring the coil close to the subject. When the eddy current sensor is brought close to the subject, an eddy current is generated on the subject according to the driving current of the coil. In the portion where the coils intersect, the direction of generation of the eddy current changes according to the phase of the high-frequency current flowing through each coil, and the direction of the combined eddy current changes accordingly. Therefore, by changing the phase of the drive current supplied to each coil, the direction of the synthetic eddy current generated on the object can be set arbitrarily, and the defect of a specific direction occurring on the object can be detected. Can be improved.
【００１０】また、本発明では、発振器から出力される
高周波信号の位相を渦電流方向制御信号によって任意に
指定でき、各コイルに駆動電流としてそれぞれ別個に供
給することができる。これにより被検体上に発生する合
成渦電流の方向を任意に可変設定でき、被検体上に生じ
ている特定の向きの欠陥についても確実に検出すること
ができる。Further , in the present invention , the phase of the high-frequency signal output from the oscillator can be arbitrarily designated by the eddy current direction control signal, and can be separately supplied as a drive current to each coil. As a result, the direction of the combined eddy current generated on the subject can be arbitrarily variably set, and a defect of a specific direction occurring on the subject can be reliably detected.
【００１１】[0011]
【実施例】以下、図面を参照して本発明の実施例を説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００１２】図１（ａ）は本発明の一実施例に係る渦電
流センサ１０を示す底面図、同図（ｂ）は側面図であ
る。同図に示すように複数例えば２つのコイル１１，１
２により渦電流発生部を構成している。各コイル１１，
１２の端部（リード線部）は、それぞれ支持体１４の両
端部より外部に導出されて独立に駆動可能である。各コ
イル１１，１２は、支持体１４の下面に平面状に形成さ
れるもので、一定間隔毎に、即ち点線円１５で示す部分
で直交するように巻回し、この点線円１５の部分で発生
する渦電流の方向を外部でコントロールするようにして
いる。この場合、支持体１４の下面には、各点線円１５
の両側に位置するようにそれぞれインシュレータ１６を
一定高さ突出させて設け、このインシュレータ１６を介
してコイル１１，１２を平面状に巻回している。上記イ
ンシュレータ１６は、巻枠の一部をなすもので、例えば
アルミニウム、銅等で形成し、各点線円１５以外のコイ
ル１１，１２の交差部分で発生する磁界が点線円１５で
発生する磁界に影響しないようにしている。FIG . 1A is a bottom view showing an eddy current sensor 10 according to one embodiment of the present invention, and FIG. 1B is a side view . As shown in the figure, a plurality of, for example, two coils 11, 1
2 constitutes an eddy current generator. Each coil 11,
Twelve ends (lead wire parts) are led out from both ends of the support member 14 and can be driven independently. Each of the coils 11 and 12 is formed on the lower surface of the support 14 in a planar shape, and is wound at regular intervals, that is, orthogonally to a portion indicated by a dotted circle 15, and generated at a portion of the dotted circle 15. The direction of the eddy current is controlled externally. In this case, each dotted line 15
The insulators 16 are provided so as to protrude at a constant height so as to be located on both sides of the coil 11, and the coils 11 and 12 are wound in a plane through the insulator 16. The insulator 16 is a part of a bobbin, and is formed of, for example, aluminum, copper, or the like. Try not to affect.
【００１３】そして、上記点線円１５部分に、図１
（ｃ）に示すように渦巻状に形成した渦電流検出コイル
１７を装着する。この渦電流検出コイル１７による検出
信号は、図示しない処理装置へ送られる。この処理装置
は、渦電流検出コイル１７の検出信号から被検体２０上
の欠陥の有無を判定する。FIG. 1 shows the dotted circle 15 in FIG.
An eddy current detection coil 17 formed in a spiral shape as shown in FIG. The detection signal from the eddy current detection coil 17 is sent to a processing device (not shown). This processing device determines the presence or absence of a defect on the subject 20 from the detection signal of the eddy current detection coil 17.
【００１４】上記のように構成した渦電流センサ１０
は、探傷時に際して各コイル１１，１２にそれぞれ別個
に駆動電流を供給し、図１（ｂ）に示すようにコイル１
１，１２を被検体２０に近接させる。The eddy current sensor 10 configured as described above
Supplies a driving current to each of the coils 11 and 12 separately at the time of flaw detection, and as shown in FIG.
1 and 12 are brought close to the subject 20.
【００１５】図２（ａ）は、渦電流センサ１０を被検体
２０に近付けた場合、コイル１１，１２の方向と、それ
によって被検体２０の表面に発生する渦電流Ａ1 ，Ａ2
の方向を示したものである。なお、図２（ａ）では、渦
電流センサ１０の点線円１５の部分のみを示している。
コイル１１，１２の実線矢印の方向に電流が増加したと
すると、各々のコイル１１，１２で発生した渦電流は、
点線Ａ1 ，Ａ2 の位置に発生し、その方向は点線矢印で
示す方向となる。従って、図２（ｂ）に示すように合成
された渦電流ベクトルＡ0 が得られる。FIG. 2 (a) shows that when the eddy current sensor 10 is brought close to the subject 20, the directions of the coils 11, 12 and the eddy currents A1, A2 generated on the surface of the subject 20 by the same.
Is shown. Note that FIG. 2A shows only a portion indicated by a dotted circle 15 of the eddy current sensor 10.
Assuming that the current increases in the direction of the solid arrows of the coils 11 and 12, the eddy current generated in each of the coils 11 and 12 becomes
It occurs at the positions of dotted lines A1 and A2, and its direction is the direction indicated by the dotted arrow. Accordingly, a combined eddy current vector A0 is obtained as shown in FIG.
【００１６】被検体２０の表面に欠陥等があれば、上記
合成渦電流Ａ0 の流れが変化し、渦電流検出コイル１７
の出力が変化するので、処理装置（図示せず）はこの出
力の変化から欠陥等を検出する。If there is a defect or the like on the surface of the subject 20, the flow of the synthetic eddy current A0 changes, and the eddy current detecting coil 17
Since the output of the changes, the processing unit (not shown) the output
Defects and the like are detected from changes in force .
【００１７】コイル１１，１２の駆動電流Ｉ1 ，Ｉ2
を、図３（ａ）（ｂ）に示すように同一の正弦波（高周
波）とすると、ｔ1 時点（正）での渦電流Ａ1 ，Ａ2 及
び合成渦電流Ａ0 は図３（ｃ）に示すようにＡ1a，Ａ2
a，Ａ0aとなり、ｔ2 時点（負）での渦電流Ａ1 ，Ａ2
及び合成渦電流Ａ0 はＡ1b，Ａ2b，Ａ0bとなる。即ち、
この場合の合成渦電流Ａ0 は、Ｘ軸と同一方向となる。The driving currents I1, I2 for the coils 11, 12
Is the same sine wave (high frequency) as shown in FIGS. 3 (a) and 3 (b), the eddy currents A1, A2 and the combined eddy current A0 at time t1 (positive) are as shown in FIG. 3 (c). A1a, A2
a, A0a, and the eddy currents A1, A2 at time t2 (negative)
And the resultant eddy current A0 becomes A1b, A2b, A0b. That is,
In this case, the resultant eddy current A0 is in the same direction as the X axis.
【００１８】次に各コイル１１，１２に供給する電流Ｉ
1 ，Ｉ2 を変えた場合の渦電流Ａ1,A2 及び合成渦電流
Ａ0 の変化を図４ないし図６に示す。図４は、コイル１
２の駆動電流Ｉ2 を零とした場合で、コイル１１による
渦電流Ａ1 と合成渦電流Ａ0 は同一となり、方向は４５
°方向となる。図５は、コイル１１の駆動電流Ｉ1 に対
してコイル１２の駆動電流Ｉ2 の極性を反転させた場合
で、合成渦電流Ａ0 は９０°方向（Ｙ軸方向）となる。
図６は、コイル１１の駆動電流Ｉ1 を零とした場合で、
コイル１２による渦電流Ａ2 と合成渦電流Ａ0 は同一と
なり、方向は１３５°方向となる。Next, the current I supplied to each of the coils 11 and 12
FIGS. 4 to 6 show changes in the eddy currents A1, A2 and the combined eddy current A0 when the values of I and I2 are changed. FIG.
2, the eddy current A1 by the coil 11 and the combined eddy current A0 are the same, and the direction is 45
° direction. FIG. 5 shows a case where the polarity of the drive current I2 of the coil 12 is reversed with respect to the drive current I1 of the coil 11, and the resultant eddy current A0 is in the 90 ° direction (Y-axis direction).
FIG. 6 shows a case where the drive current I1 of the coil 11 is set to zero.
The eddy current A2 by the coil 12 and the combined eddy current A0 are the same, and the direction is 135 °.
【００１９】以上のように、独立した複数の巻き方向の
異なるコイルで渦電流センサ１０を構成し、各コイルを
独立に駆動することにより、合成渦電流の方向を任意に
外部コントロールすることが可能となり、特定の向きの
欠陥検出性を向上させることができる。As described above, the eddy current sensor 10 is constituted by a plurality of independent coils having different winding directions, and by independently driving each coil, the direction of the combined eddy current can be arbitrarily externally controlled. Thus, the detectability of a defect in a specific direction can be improved.
【００２０】次に上記渦電流センサ１０を駆動する渦電
流発生回路について説明する。図７は、渦電流発生回路
の構成を示すブロック図である。同図において、２１は
発振器で、図８に示すようにＶ0 ＝Ｓｉｎ（ωｔ）の正
弦波を発生し、掛算器２４，２５に入力する。Next, an eddy current generating circuit for driving the eddy current sensor 10 will be described. FIG. 7 is a block diagram showing a configuration of the eddy current generation circuit. In the figure, reference numeral 21 denotes an oscillator which generates a sine wave of V0 = Sin (.omega.t) as shown in FIG.
【００２１】２２は図９（ａ）に示すように渦電流方向
制御信号（電圧）Ｖｃの値をＡｓ＝Ｓｉｎ（Ｖｃ）のＳ
ｉｎ曲線の信号に変換するＳｉｎ変換回路で、その変換
出力Ａｓを掛算器２４に入力する。２３は図９（ｂ）に
示すように渦電流方向制御信号Ｖｃの値をＡｃ＝Ｃｏｓ
（Ｖｃ）のＣｏｓ曲線の信号に変換するＣｏｓ変換回路
で、その変換出力Ａｃを掛算器２５に入力する。掛算器
２４は、発振器２１から与えられる信号Ｖ0 の振幅をＳ
ｉｎ変換回路２２の出力信号Ａｓに応じて変え、渦電流
センサ１０のコイル１１に供給する。掛算器２５は、発
振器２１から与えられる信号Ｖ0 の振幅をＣｏｓ変換回
路２３の出力信号Ａｃに応じて変え、渦電流センサ１０
のコイル１２に供給する。Reference numeral 22 denotes the value of the eddy current direction control signal (voltage) Vc as S = Sin (Vc), as shown in FIG.
The Sin conversion circuit converts the converted output As into an in-curve signal and inputs the converted output As to the multiplier 24. Reference numeral 23 denotes the value of the eddy current direction control signal Vc as Ac = Cos as shown in FIG.
A Cos conversion circuit that converts the signal into a signal of a Cos curve of (Vc). The multiplier 24 calculates the amplitude of the signal V0 given from the oscillator 21 by S
It is changed according to the output signal As of the in conversion circuit 22 and is supplied to the coil 11 of the eddy current sensor 10. The multiplier 25 changes the amplitude of the signal V0 supplied from the oscillator 21 according to the output signal Ac of the Cos conversion circuit 23, and
To the coil 12.
【００２２】以下、上記のように構成された渦電流発生
回路の動作について説明する。なお、説明を簡単にする
ため、発振器２１、Ｓｉｎ変換回路２２、Ｃｏｓ変換回
路２３の各出力信号の振幅を「１」とする。図１０ない
し図１４は、制御信号Ｖｃの値を変えた時のコイル１
１，１２の駆動電流Ｉ1 ，Ｉ2 （各図（ａ），（ｂ）に
示す）、各コイル１１，１２によって発生した渦電流Ａ
1 ，Ａ2 及びその合成渦電流Ａ0 （各図（ｃ）に示す）
を示したものである。Hereinafter, the operation of the eddy current generating circuit configured as described above will be described. For the sake of simplicity, it is assumed that the amplitude of each output signal of the oscillator 21, the Sin conversion circuit 22, and the Cos conversion circuit 23 is "1". FIGS. 10 to 14 show the coil 1 when the value of the control signal Vc is changed.
1 and 12 (shown in FIGS. 7A and 7B), the eddy current A generated by the coils 11 and 12, respectively.
1, A2 and its combined eddy current A0 (shown in each figure (c))
It is shown.
【００２３】図１０は、渦電流方向制御信号Ｖｃが「Ｖ
ｃ＝０」の場合で、コイル１１の駆動電流Ｉ1 が零とな
る。コイル１１の駆動電流Ｉ1 が零の場合、渦電流Ａ1
が零となるため、渦電流Ａ2 が合成渦電流Ａ0 となり、
方向は−４５°となる。FIG. 10 shows that the eddy current direction control signal Vc is "V
In the case of "c = 0", the drive current I1 of the coil 11 becomes zero. When the driving current I1 of the coil 11 is zero, the eddy current A1
Becomes zero, the eddy current A2 becomes the combined eddy current A0,
The direction is -45 °.
【００２４】図１１は、渦電流方向制御信号Ｖｃが「Ｖ
ｃ＝π／４」の場合で、コイル駆動電流Ｉ1 ，Ｉ2 は、
同位相で振幅が「０．７」となる。このため各渦電流Ａ
1 ，Ａ2 の大きさは、「Ｖｃ＝０」の場合の渦電流Ａ2
の「０．７」倍の大きさとなる。しかし、合成渦電流Ａ
0 の大きさは、「Ｖｃ＝０」の場合の合成渦電流Ａ0と
同じになり、方向だけが０°方向に変わる。FIG. 11 shows that the eddy current direction control signal Vc is "V
c = π / 4 ”, the coil drive currents I1 and I2 are
The amplitude becomes “0.7” at the same phase. Therefore, each eddy current A
The magnitude of A1 and A2 is the eddy current A2 when "Vc = 0".
Is 0.7 times as large as However, the combined eddy current A
The magnitude of 0 is the same as the combined eddy current A0 in the case of "Vc = 0", and only the direction changes to the 0 ° direction.
【００２５】図１２は、渦電流方向制御信号Ｖｃが「Ｖ
ｃ＝π／２」の場合で、コイル１２の駆動電流Ｉ2 が零
となり、渦電流Ａ1 が合成渦電流Ａ0 となり、方向は４
５°となる。FIG. 12 shows that the eddy current direction control signal Vc is "V
c = π / 2 ”, the drive current I2 of the coil 12 becomes zero, the eddy current A1 becomes the combined eddy current A0, and the direction is 4
5 °.
【００２６】図１３は、渦電流方向制御信号Ｖｃが「Ｖ
ｃ＝３π／４」の場合で、コイル駆動電流Ｉ1 ，Ｉ2
は、逆位相で振幅が「０．７」となり、合成渦電流Ａ0
の方向は９０°となる。FIG. 13 shows that the eddy current direction control signal Vc is "V
c = 3π / 4 ”, the coil drive currents I1, I2
Is the opposite phase, the amplitude is "0.7", and the resultant eddy current A0
Is 90 °.
【００２７】図１４は、渦電流方向制御信号Ｖｃが「Ｖ
ｃ＝π」の場合で、コイル１１の駆動電流Ｉ1 が零、コ
イル１２の駆動電流Ｉ2 が振幅「１」で「Ｖｃ＝０」の
場合とは逆位相となり、合成渦電流Ａ0 の方向は１３５
°となる。上記のように渦電流方向制御信号Ｖｃを変え
ていくと、合成渦電流Ａ0 の振幅は常に一定であるが、
方向だけが順次変化する。これを式で示すと、 Ａ1 ＝ＫＩ1 ＝ＫＶ0 Ｓｉｎ（Ｖｃ） Ａ2 ＝ＫＩ2 ＝ＫＶ0 Ｃｏｓ（Ｖｃ） 但し、Ｋは比例定数となる。合成渦電流Ａ0 の大きさ
は、 （Ａ1 2 ＋Ａ2 2 ）1/2 ＝｜ＫＶ0 ｜｛Sin 2 (Vc)＋Cos 2 (Vc)｝1/2 ＝｜ＫＶ0 ｜ となり、常に一定である。また、方向は、 Ｔａｎ-1（Ｉ1 ／Ｉ2 ）−４５° ＝Ｔａｎ-1｛（Ｖ0 Ｓｉｎ（Ｖｃ）／Ｖ0 Ｃｏｓ（Ｖｃ）｝−４５° ＝Ｖｃ−４５° となり、渦電流方向制御信号Ｖｃでコントロール可能と
なる。FIG. 14 shows that the eddy current direction control signal Vc is "V
c = π ”, the drive current I1 of the coil 11 is zero,
The drive current I2 of the coil 12 has the amplitude "1" and "Vc = 0".
The direction of the combined eddy current A0 is 135
°. Changing the eddy current direction control signal Vc as described above
The amplitude of the resultant eddy current A0 is always constant,
Only the direction changes sequentially. This is represented by the following equation: A1 = KI1 = KV0 Sin (Vc) A2 = KI2 = KV0 Cos (Vc) where K is a proportional constant. The magnitude of the resultant eddy current A0
Is (A1Two + A2Two )1/2 = | KV0 | ｛SinTwo (Vc) + CosTwo (Vc)｝1/2 = | KV0 |, and is always constant. The direction is Tan-1(I1 / I2) -45 ° = Tan-1{(V0 Sin (Vc) / V0 Cos (Vc))} − 45 ° = Vc−45 °, and can be controlled by the eddy current direction control signal Vc.
Become.
【００２８】なお、上記実施例では、２つのコイル１
１，１２を直交させて渦電流センサを構成した場合につ
いて示したが、２つ以上のコイルを用いて渦電流センサ
構成しても良い。即ち、２つ以上の複数のコイルを用い
る場合には、各コイルを点線円１５内で等角度で交差さ
せ、コイルの数に応じて異なった位相の電流を加えるこ
とにより、被検体２０の表面で回転する渦電流を発生さ
せることができる。In the above embodiment, two coils 1
Although the case where the eddy current sensor is configured by making the 1 and 12 orthogonal is shown, the eddy current sensor may be configured by using two or more coils. That is, when two or more coils are used, the coils intersect at equal angles within a dotted circle 15 and currents having different phases are applied according to the number of coils, thereby obtaining the surface of the subject 20. The rotating eddy current can be generated.
【００２９】[0029]
【発明の効果】以上詳記したように本発明によれば、巻
き方向の異なる複数のコイルを設け、所定間隔毎に交差
させて渦電流発生部を構成しているので、各コイルの駆
動電流の位相を可変することにより、被検体上の合成渦
電流の方向を任意に外部コントロールすることが可能と
なり、特定の向きの欠陥についても確実に検出すること
ができる。As described above in detail, according to the present invention, a plurality of coils having different winding directions are provided, and the eddy current generators are formed so as to intersect at predetermined intervals. , The direction of the synthetic eddy current on the subject can be arbitrarily controlled externally, and a defect in a specific direction can be reliably detected.
【図１】 （ａ）は本発明の一実施例に係る渦電流セン
サを示す図、（ｂ）は探傷時の状態を示す図、（ｃ）は
渦電流検出コイルを示す図。1A is a diagram illustrating an eddy current sensor according to an embodiment of the present invention, FIG. 1B is a diagram illustrating a state at the time of flaw detection, and FIG. 1C is a diagram illustrating an eddy current detection coil.
【図２】センサを構成する各コイルの配列方向及び渦電
流の発生方向を示す図。FIG. 2 is a diagram showing an arrangement direction of coils constituting a sensor and a direction in which an eddy current is generated.
【図３】２つのコイルを同一の駆動電流で駆動した場合
の渦電流発生方向を示す図。FIG. 3 is a diagram showing an eddy current generation direction when two coils are driven by the same drive current.
【図４】一方のコイルを駆動電流を零とした場合の渦電
流発生方向を示す図。FIG. 4 is a diagram showing an eddy current generation direction when a driving current of one coil is set to zero.
【図５】２つのコイルの電流極性を変えた場合の渦電流
発生方向を示す図。FIG. 5 is a diagram showing an eddy current generation direction when current polarities of two coils are changed.
【図６】他方のコイルを駆動電流を零とした場合の渦電
流発生方向を示す図。FIG. 6 is a diagram illustrating an eddy current generation direction when the drive current of the other coil is set to zero.
【図７】渦電流センサに駆動する渦電流発生回路の構成
を示すブロック図。FIG. 7 is a block diagram showing a configuration of an eddy current generation circuit driven by the eddy current sensor.
【図８】図７における発振器の出力信号波形を示す図。FIG. 8 is a diagram showing an output signal waveform of the oscillator in FIG. 7;
【図９】図７におけるＳｉｎ変換回路及びＣｏｓ変換回
路の出力信号波形を示す図。FIG. 9 is a diagram showing output signal waveforms of a Sin conversion circuit and a Cos conversion circuit in FIG. 7;
【図１０】渦電流方向制御信号Ｖｃを変えた場合のコイ
ル駆動電流と渦電流の発生状態を示す図。FIG. 10 is a diagram showing a state in which a coil drive current and an eddy current are generated when an eddy current direction control signal Vc is changed.
【図１１】渦電流方向制御信号Ｖｃを変えた場合のコイ
ル駆動電流と渦電流の発生状態を示す図。FIG. 11 is a diagram showing a state of generation of a coil drive current and an eddy current when an eddy current direction control signal Vc is changed.
【図１２】渦電流方向制御信号Ｖｃを変えた場合のコイ
ル駆動電流と渦電流の発生状態を示す図。FIG. 12 is a diagram showing a state in which a coil drive current and an eddy current are generated when an eddy current direction control signal Vc is changed.
【図１３】渦電流方向制御信号Ｖｃを変えた場合のコイ
ル駆動電流と渦電流の発生状態を示す図。FIG. 13 is a diagram showing a state in which a coil drive current and an eddy current are generated when an eddy current direction control signal Vc is changed.
【図１４】渦電流方向制御信号Ｖｃを変えた場合のコイ
ル駆動電流と渦電流の発生状態を示す図。FIG. 14 is a diagram showing a state of generation of a coil drive current and an eddy current when an eddy current direction control signal Vc is changed.
【図１５】（ａ）は従来の渦電流センサを示す構成図、
（ｂ）は探傷時の状態を示す図。FIG. 15A is a configuration diagram showing a conventional eddy current sensor,
(B) is a diagram showing a state at the time of flaw detection.
１０…渦電流センサ、１１，１２…コイル、 １
４…支持体、１５…点線円、 １６…インシ
ュレータ、１７…渦電流検出コイル、２０…被検体、
２１…発振器、 ２２…Ｓｉｎ変換回
路、２３…Ｃｏｓ変換回路、 ２４…掛算器、
２５…掛算器。10: Eddy current sensor, 11, 12: Coil, 1
4 support, 15 dotted circle, 16 insulator, 17 eddy current detection coil, 20 subject
Reference numeral 21: oscillator, 22: Sin conversion circuit, 23: Cos conversion circuit, 24: multiplier,
25 Multiplier.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 清水 直哉 兵庫県神戸市兵庫区和田崎町一丁目１番 １号 三菱重工業株式会社神戸造船所内 (72)発明者 椹木 和人 兵庫県神戸市兵庫区和田崎町一丁目１番 １号 三菱重工業株式会社神戸造船所内 (56)参考文献 特開 平２−269960（ＪＰ，Ａ) 特開 昭63−40850（ＪＰ，Ａ) 実開 昭61−155761（ＪＰ，Ｕ) 特公 平２−49661（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.7，ＤＢ名) G01N 27/72 - 27/90 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Naoya Shimizu 1-1-1, Wadazakicho, Hyogo-ku, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd. 1-1 1-1 Wadazakicho Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) References JP-A-2-269960 (JP, A) JP-A-63-40850 (JP, A) JP, U) JP 2-49661 (JP, B2) (58) Fields surveyed (Int. Cl. 7 , DB name) G01N 27/72-27/90
Claims (1)
イルを独立して設け、これらの第１及び第２のコイルを
等角度で交差させて渦電流発生部を構成すると共に、上
記第１及び第２のコイルの交差部に渦電流検出コイルを
設けてなる渦電流センサと、高周波信号を発生する発振
器と、この発振器から出力される高周波信号を上記渦電
流センサの第１及び第２のコイルに別個に供給する手段
と、渦電流方向制御信号の値をＳｉｎ曲線の信号に変換
するＳｉｎ変換回路と、上記渦電流方向制御信号の値を
Ｃｏｓ曲線の信号に変換するＣｏｓ変換回路と、上記第
１及び第２のコイルに供給される高周波信号の振幅をそ
れぞれ上記Ｓｉｎ変換回路及びＣｏｓ変換回路の出力信
号により制御し、上記第１及び第２のコイルにより被検
体上に発生する渦電流の合成電流の方向を可変制御する
制御手段とを具備したことを特徴とする渦電流発生回
路。A first coil and a second coil are provided on one surface of a support.
It provided independently yl, with by intersecting these first and second coil at equiangular constituting the eddy current generating section, an eddy current detection coil provided at the intersection of the first and second coil An eddy current sensor, an oscillator for generating a high frequency signal, a means for separately supplying a high frequency signal output from the oscillator to the first and second coils of the eddy current sensor, and an eddy current direction control signal. Converts values to Sin curve signals
And a value of the eddy current direction control signal.
A Cos conversion circuit for converting the signal into a signal having a Cos curve;
The amplitudes of the high-frequency signals supplied to the first and second coils are
The output signals of the Sin conversion circuit and the Cos conversion circuit, respectively.
And variably controls the direction of the combined current of the eddy currents generated on the subject by the first and second coils.
An eddy current generation circuit, comprising: a control unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22127792A JP3154563B2 (en) | 1992-08-20 | 1992-08-20 | Eddy current generation circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22127792A JP3154563B2 (en) | 1992-08-20 | 1992-08-20 | Eddy current generation circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06123731A JPH06123731A (en) | 1994-05-06 |
| JP3154563B2 true JP3154563B2 (en) | 2001-04-09 |
Family
ID=16764261
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22127792A Expired - Fee Related JP3154563B2 (en) | 1992-08-20 | 1992-08-20 | Eddy current generation circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3154563B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8570611B2 (en) | 2006-03-22 | 2013-10-29 | Canon Denshi Kabushiki Kaisha | Image reading apparatus, shading correction method therefor, and program for implementing the method |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5669139B2 (en) * | 2010-04-05 | 2015-02-12 | 国立大学法人東京工業大学 | Bioimpedance measurement device |
| JP5581269B2 (en) * | 2011-05-31 | 2014-08-27 | 株式会社日立製作所 | Eddy current inspection apparatus and inspection method using the same |
-
1992
- 1992-08-20 JP JP22127792A patent/JP3154563B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8570611B2 (en) | 2006-03-22 | 2013-10-29 | Canon Denshi Kabushiki Kaisha | Image reading apparatus, shading correction method therefor, and program for implementing the method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06123731A (en) | 1994-05-06 |
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