JPH0357952A - Flaw detection apparatus for surface flaw - Google Patents
Flaw detection apparatus for surface flawInfo
- Publication number
- JPH0357952A JPH0357952A JP19525389A JP19525389A JPH0357952A JP H0357952 A JPH0357952 A JP H0357952A JP 19525389 A JP19525389 A JP 19525389A JP 19525389 A JP19525389 A JP 19525389A JP H0357952 A JPH0357952 A JP H0357952A
- Authority
- JP
- Japan
- Prior art keywords
- flaw
- density
- magnetic force
- magnetic
- subject
- 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
- 238000001514 detection method Methods 0.000 title claims abstract description 48
- 230000005291 magnetic effect Effects 0.000 claims abstract description 61
- BGPVFRJUHWVFKM-UHFFFAOYSA-N N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] Chemical compound N1=C2C=CC=CC2=[N+]([O-])C1(CC1)CCC21N=C1C=CC=CC1=[N+]2[O-] BGPVFRJUHWVFKM-UHFFFAOYSA-N 0.000 abstract description 7
- 239000000463 material Substances 0.000 abstract description 4
- 230000035699 permeability Effects 0.000 abstract description 3
- 230000005294 ferromagnetic effect Effects 0.000 abstract description 2
- 229910000831 Steel Inorganic materials 0.000 description 9
- 239000010959 steel Substances 0.000 description 9
- 238000010586 diagram Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 239000000696 magnetic material Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 239000003302 ferromagnetic material Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000005415 magnetization Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000000877 morphologic effect Effects 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】
く産業上の利用分野〉
本発明は、強磁性を母材とした鋼管や鋼板の表而にある
欠陥や傷（以下，単に傷と言う）を検出し、その位置を
正確に見出す表面傷の探傷装置に関する．
く従来の技術〉
鋼管や鋼板等において、その表面に傷があることはその
特性と品質を低下されるため、傷の検出をすることは、
その製品の品質検査等にて必要事項である．又、これら
の傷を見出したとき、その位置についても正確な検出が
必要である．
このため、従来から探傷方法として、電気抵抗による検
出法、超音波による検出法、磁気的検出法等が提案され
ている．
く発明が解決しようとする課題〉
しかし、傷を検出してもその位置を精度高く見出す方法
は少なく、正確にその位置を測定することは困難であっ
た．
本発明は前記した検出法の中では磁気的検出法に属する
ものであって，ａＡの部分において磁気的特性がその他
の部分に対して独特な変化をすることに着目し、これを
検出し安定正確に、傷の位置を見出す装置を提供しよう
とするものである．
く課題を解決するための手段〉
本発明は、表面に傷をもつ強磁性体を母材とした被検体
の表面から隔てられた位置に置いたほぼ分布一様な密度
の磁力線源より磁力線を被検体に当て、該磁力線の存在
する被検体の表面、又は被検体の表面に近接して配置さ
れた磁力線密度検出器を傷線に直角の方向に移動し、磁
力線密度の変化を検出すると共に、該検出出力を電気的
判定回路に入力し、傷の位置を正確に検出しようとする
ものである．
く作 用〉
本発明は傷の位置を検出するに，検出部を固定し被検体
を回転又は移動させるか、或は被検体を固定し検出部を
同軸に移動させるかして、磁力線密度検出器が傷の上部
を通過するようにして磁力線源より磁力線を当てると、
傷付近での電気的出力が他の部分と相違した独特の変化
をなし、これを検出し電気的判定回路に入力することに
より傷の位置が正確に検出できる。[Detailed description of the invention] Industrial application field> The present invention detects defects and scratches (hereinafter simply referred to as scratches) on the surface of steel pipes and steel plates made of ferromagnetic base material, and locates them. This paper relates to a surface flaw detection device that accurately detects surface flaws. Conventional technology> Scratches on the surface of steel pipes, steel plates, etc. deteriorate their characteristics and quality, so detecting scratches is
This is necessary for quality inspection of the product. Furthermore, when these flaws are found, it is necessary to accurately detect their locations. For this reason, conventional flaw detection methods such as electrical resistance detection, ultrasonic detection, and magnetic detection have been proposed. Problems to be Solved by the Invention> However, even if a flaw is detected, there are few methods for locating it with high accuracy, and it has been difficult to accurately measure its position. The present invention belongs to the magnetic detection method among the above-mentioned detection methods, and focuses on the fact that the magnetic properties of the aA part change uniquely compared to other parts, and detects this and stabilizes it. The aim is to provide a device that can accurately locate the location of a wound. Means for Solving the Problems> The present invention generates magnetic lines of force from a source of magnetic lines of almost uniform density placed at a position separated from the surface of an object made of a ferromagnetic material with scratches on its surface. A magnetic field line density detector placed on the subject and placed on the surface of the subject where the magnetic lines of force exist or in close proximity to the subject's surface is moved in a direction perpendicular to the scratch line to detect changes in the magnetic field line density. , the detection output is input to an electrical judgment circuit to accurately detect the position of the flaw. Function: To detect the position of a flaw, the present invention detects magnetic field line density by fixing the detection part and rotating or moving the subject, or by fixing the subject and moving the detection part coaxially. If you apply magnetic field lines from a magnetic field source so that the device passes over the top of the wound,
The electrical output near the scratch exhibits a unique change different from that in other parts, and by detecting this and inputting it to the electrical determination circuit, the position of the scratch can be accurately detected.
く実施例〉
以下、本発明の実施例を図示の図面に従って説明すれば
次の通りである．
第１図は本発明の概略的構成を示すもので、１は検出部
，２は検出部の出力により傷の位置を正確に判定する電
子回路、３は被検体である鋼管の断面を示し、４は傷を
示すものである．検出部ｌの詳細は第２図に示され、磁
力線源である幅広の永久磁石５の一方の極（図示ではＮ
極）の上面に透磁率の高い材料（例えば電気鉄、或は積
層電気鉄板）よりなる直線状の支持部材６が左右端を下
方に折曲げた折曲げ部７を備えて固定され，又他方の極
（図示ではＳ極）の下面には非磁性体よりなる支持体８
を介して例えばホール素子からなる磁力線密度検出素子
９が被検体３の表面に接触又は近接して設けられ、これ
らの検出部１は図示しないが被検体３をまたぐようにし
て支持され、場合により支持体１は被検体３の周りを回
転若しくは移動する機構を備える．これらの機構は公知
の手段で実施できるものであり、本発明では特に限定し
ない。Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of the present invention, in which 1 is a detection section, 2 is an electronic circuit that accurately determines the position of a flaw based on the output of the detection section, and 3 is a cross section of a steel pipe that is an object to be inspected. 4 indicates a wound. The details of the detection part l are shown in FIG. 2, where one pole (in the figure, N
A linear support member 6 made of a material with high magnetic permeability (for example, electric iron or laminated electric iron plate) is fixed to the upper surface of the pole with bent portions 7 having left and right ends bent downward, and the other side is fixed to the upper surface of the pole. A support 8 made of a non-magnetic material is provided on the bottom surface of the pole (S pole in the figure).
A magnetic force line density detecting element 9 made of, for example, a Hall element is provided in contact with or in close proximity to the surface of the subject 3 through a The support body 1 is equipped with a mechanism for rotating or moving around the subject 3. These mechanisms can be implemented by known means, and are not particularly limited in the present invention.
次に検出部１において、被検体３の表面の磁力線密度分
布が永久磁石５に拘束されず変化し得るためには、永久
磁石５の極面と被検体３の表面の距＃ＩＬは永久磁石５
の幅Ｓに対して等しいか、又はこれより大な程度である
ことが望ましい．又、被検体３を通過しない漏洩磁力線
を減少するために、永久磁石５の側面５′と支持部材６
の折曲げ部７との間隔Ｒは前記した永久磁石５の極面と
被検体３の表面との距ＩＬＬより大であるのが望ましい
．
又、被検体３に広く磁力線１ｏを供給し、且っ磁路が被
検体３より磁気減衰を小とするため、支持部材６の左右
長（２ Ｘ ｗ）は被検体３の半径より大であり、支持
部材６の厚さＴは少なくとも被検体３の厚さ以上である
ことが望ましい．図示の実施例では磁路を形威する支持
部材６の両端は被検体３に向けて折曲げ部７を伴って構
成されるが，周辺情況によっては該折曲げ部７はなくて
もよい．又，支持部材６は直線状でなくても第３図に図
示の如く、湾曲した形状であっても磁路としては問題が
なく、更に磁気的減衰を減ずるよう支持部材６の両端の
折曲げ部７を先端が被検体３の周面に泊った形状とする
こともできる．
尚、支持体８は特に形状の制限はな〈、例えば支持体８
は同時にガイドの役をするよう第３図の鎖線８′で示す
ような形状としてもよい．次に作用を説明すると、第２
図の状態において、仮りに傷４が被検体３にないとする
と、永久磁石５の発生する磁力ｌＩｉｔｔｏは磁路であ
る支持部材６、折曲げ部７、空気、被検体３を通過し、
第４図のように分布する．ここで、磁力線源である永久
磁石５の表面が幅広く、且つ被検体３と隔てられている
ので、支持体８の先端の磁力線密度検出素子９の前後に
おいて該検出素子９を通過する磁力線密度は特に分散、
又は集中することに対して拘束しない．
被検体３に傷がないときは，被検体３の表面のどこでも
前記検出素子９の検出する磁力線密度はほぼ一様である
．しかし、被検体３の表面に傷４が存在すると、そこで
は被検体３の前面の強磁性体が部分的に存在しないで，
検出素子９の検出する磁力線密度は減少し、検出素子９
の出力が減少する．
これをモデル的に示すと第５図に示す溝型の形状を呈す
ることになる．第５図に於て、縦軸は検出磁力線密度、
横軸は位置を示す．尚，第５図の波形は検出素子９が傷
を直角方向に横切ったときのものを示す．
いま、第２図の状態において、検出部１は固定し、被検
体３を図上左方向に回転，又は移動させるか、又は被検
体３を固定して検出部１を右方向に移動させ、磁力線密
度検出素子９が傷４の上部を通過するようにする．測定
においてはこの回転、移動により検出素子９はそれを通
過する磁力線密度を電気的に検出するから、その回転又
は移動に伴なう傷４付近での電気的出力は前述した第５
図の波形となる．
一般に，磁力線密度検出素子９が検出する電気的出力は
傷４以外の場所で常に一定であるとは言えず、被検体３
である鋼管材料内部での透磁率の部分的変動、鋼材加工
の時発生する部分的帯磁，周辺での磁性体の近接、或い
は局部的な加工傷等で出力変化があり得る．
ここで，機械的駆動装置により検出部ｌと被検体３を相
対的に連続移動又は回転させ，被検体３の必要な範囲に
わたる検出素子９の電気的出力の例を第６図に示す．第
６図において、符合１１で示す波形部分は傷の部分にお
ける出力であるが、この傷部の波形ｌ１はその他の場所
における電気的出力波形とその形態特徴に大きな相違が
あることが判明する．即ち，傷以外の場所においてはそ
の電気的出力は大であってもその変化は比較的緩やかで
あるが、傷による出力は傷断面形状により極めて鋭く変
化する．そして，その発生方向は常に磁力線の減少する
極性である．
尚、被検体に存在する傷は必要範囲内で複数のこともあ
り、その全ての位置を高い精度で測定するのが困難のこ
ともあり得る．かかる場合は，必要範囲の測定により傷
波形１１の位置を予備的に検出記憶した上で、次に記憶
した傷波形ｌ１の場所前後を改めて精度高く測定し、傷
の位置を高精度で指定してもよい．
又、傷波形ｌ１の位置が近似的に確定しているときは，
被検体３を固定し、検出部ｌの本体をほぼ傷波形ｌ１の
位置に固定した上で、磁力線密度検出素子９のみを微少
寸法だけ左右に機械的に揺動させるか、又は、被検体３
を固定し検出部ｌの全体を傷波形１１の左右に揺動させ
る方式によってもよい．
以上のように、磁力線密度検出素子９の電気的出力を取
り出して、傷波形１ｌにおける傷の位置を検出するのに
第１［ｆｆｌに示す電子回路２が用いられる．この電子
回路２の動作は第７図に示すが、これは判定の動作を各
個に区分して示したもので、この各動作の順番は限定さ
れない．又場合により不作用、除外できるものもある．
このようにして前記した特徴をもつ波形１１を見出し傷
の位置を確定する．
かくして、検出した傷の位置を記憶し、表示し、或いは
駆動部分に指令してその位置に停止させる等は前記の判
定検出回路の動作と共に、電子回路、コンピュータソフ
トウエアにて容易に具体化することができる．
尚、第８図、第９図は他の実施例を示すもので、磁路を
形或する支持部材６の両側に各１個の永久磁石１２、１
３を配置することによっても可能である．この場合、支
持部材ｌ８の中央部分を下方に突出させた段部ｌ４に非
磁性体よりなる支持体８を介し、先端部に磁力線密度検
出素子９が取付けられている．このとき、支持部材６の
中央部分の段部ｌ４は磁路の一部を構成する．尚、上述
の説明では検出部は１個の磁力線密度検出素子９を取付
けたものとしたが、複数個の検出素子９を配置し、必要
あれば夫々の検出特性に差を与え、被検体３の特性の差
に対応させ，或いは複数の検出素子９の出力の合或演算
により誤差を減少させることが可能となる．又複数の検
出部１を設け、同時に使用する形式としてこれに代わら
せることもできる．
更に、上述した実施例では、磁力線源を永久磁石とした
例を示したが、交流電磁石としても本発明に含まれる．
その場合は磁力線密度検出素子９の出力は交流波形とな
り、その包絡線が記述した各波形となる．
く発明の効果〉
上述のように本発明では、表面に傷をもつ被検体の表面
から隔てられた位置に置いたほぼ分布一様な密度の磁力
線源より磁力線を被検体に当て、該磁力線の存在する被
検体の表面、又は表面に近接して配置された磁力線密度
検出器を，傷線に直角方向に移動し，Ｂｉ力線密度の変
化を検出し、電気的判定回路に入力して傷の位置を検出
するようにしたことで，傷の正確な位置を確実に検出す
ることができる．
しかも、本発明は傷位置での磁力線密度が他の部分に比
して極端に減少し独特の溝型の波形となって検出でき、
この波形は他の場所での波形と明確に区別できる特徴を
もったものであることから、鋼管、又は鋼板の表面に存
する傷の正しい位置を検出することができる．Next, in the detection unit 1, in order for the magnetic field line density distribution on the surface of the subject 3 to change without being restricted by the permanent magnet 5, the distance #IL between the pole face of the permanent magnet 5 and the surface of the subject 3 must be 5
It is desirable that it be equal to or larger than the width S of . In addition, in order to reduce leakage lines of magnetic force that do not pass through the subject 3, the side surface 5' of the permanent magnet 5 and the support member 6
It is preferable that the distance R between the bent portion 7 and the bent portion 7 is larger than the distance ILL between the pole face of the permanent magnet 5 and the surface of the subject 3. In addition, in order to widely supply the lines of magnetic force 1o to the subject 3 and to make the magnetic path have smaller magnetic attenuation than the subject 3, the horizontal length (2 x w) of the support member 6 is larger than the radius of the subject 3. It is desirable that the thickness T of the support member 6 is at least the thickness of the subject 3. In the illustrated embodiment, both ends of the support member 6 forming a magnetic path are provided with bent portions 7 toward the subject 3, but the bent portions 7 may be omitted depending on the surrounding circumstances. In addition, even if the support member 6 is not straight, even if it is curved as shown in FIG. 3, there is no problem with the magnetic path, and both ends of the support member 6 may be bent to further reduce magnetic attenuation. The tip of the portion 7 may be shaped so as to rest on the circumferential surface of the subject 3. Note that there is no particular restriction on the shape of the support 8. For example, the support 8 may be
may also have a shape as shown by chain line 8' in Figure 3 so as to act as a guide at the same time. Next, to explain the effect, the second
In the state shown in the figure, if there is no scratch 4 on the subject 3, the magnetic force generated by the permanent magnet 5 passes through the support member 6, which is a magnetic path, the bending part 7, the air, and the subject 3,
The distribution is shown in Figure 4. Here, since the surface of the permanent magnet 5 that is the magnetic field line source is wide and separated from the subject 3, the density of the magnetic field lines passing through the magnetic field line density detecting element 9 before and after the magnetic field line density detecting element 9 at the tip of the support body 8 is Especially distributed,
Or don't restrict yourself to concentration. When the object 3 has no scratches, the density of magnetic lines of force detected by the detection element 9 is almost uniform everywhere on the surface of the object 3. However, if there is a scratch 4 on the surface of the object 3, the ferromagnetic material on the front surface of the object 3 is partially absent, and
The density of magnetic lines of force detected by the detection element 9 decreases, and the detection element 9
The output of decreases. If this is shown as a model, it will have a groove-shaped shape as shown in Figure 5. In Figure 5, the vertical axis is the detected magnetic field line density,
The horizontal axis shows the position. The waveform in Figure 5 shows the waveform when the detection element 9 crosses the flaw in the right angle direction. Now, in the state shown in FIG. 2, the detection unit 1 is fixed and the subject 3 is rotated or moved to the left in the diagram, or the subject 3 is fixed and the detection unit 1 is moved to the right. Make sure that the magnetic field line density detection element 9 passes over the scratch 4. During measurement, the detection element 9 electrically detects the density of magnetic lines of force passing through it due to this rotation or movement, so the electrical output near the scratch 4 due to the rotation or movement is the same as the fifth point mentioned above.
The waveform is as shown in the figure. In general, it cannot be said that the electrical output detected by the magnetic field line density detection element 9 is always constant at locations other than the wound 4;
Output changes may occur due to local fluctuations in magnetic permeability within the steel pipe material, partial magnetization that occurs during steel processing, proximity to magnetic materials in the surrounding area, or localized machining scratches. FIG. 6 shows an example of the electrical output of the detection element 9 over a necessary range of the subject 3 when the detection unit 1 and the subject 3 are continuously moved or rotated relative to each other by a mechanical drive device. In FIG. 6, the waveform portion indicated by reference numeral 11 is the output at the scratched portion, but it is clear that the waveform l1 at this scratched portion has a large difference in morphological characteristics from the electrical output waveform at other locations. In other words, even if the electrical output is large in areas other than scratches, its change is relatively gradual, but the output due to scratches changes extremely sharply depending on the cross-sectional shape of the scratch. And the direction of its generation is always the decreasing polarity of the magnetic field lines. Note that there may be multiple scratches on the subject within the required range, and it may be difficult to measure all of their positions with high accuracy. In such a case, the position of the flaw waveform 11 is preliminarily detected and memorized by measuring the necessary range, and then the position of the flaw waveform 11 is measured again with high precision around the location of the memorized flaw waveform l1, and the position of the flaw is specified with high precision. You can. Moreover, when the position of the flaw waveform l1 is approximately determined,
After fixing the subject 3 and fixing the main body of the detecting section l approximately at the position of the flaw waveform l1, only the magnetic force line density detection element 9 is mechanically swung left and right by a minute dimension, or
It is also possible to use a method in which the detector l is fixed and the entire detector l is swung to the left and right of the flaw waveform 11. As described above, the electronic circuit 2 shown in the first [ffl] is used to extract the electrical output of the magnetic field line density detection element 9 and detect the position of the flaw in the flaw waveform 1l. The operation of this electronic circuit 2 is shown in FIG. 7, but this shows the judgment operation divided into individual operations, and the order of each operation is not limited. Also, depending on the case, there are some things that have no effect or can be excluded.
In this way, the waveform 11 having the characteristics described above is found and the location of the flaw is determined. Thus, storing and displaying the position of the detected flaw, or instructing the driving part to stop at that position, etc., can be easily realized by electronic circuits and computer software as well as the operation of the judgment detection circuit described above. be able to. 8 and 9 show another embodiment, in which one permanent magnet 12 and one permanent magnet 1 are placed on each side of the support member 6 forming a magnetic path.
This is also possible by placing 3. In this case, a magnetic force line density detecting element 9 is attached to the tip of a stepped portion l4 of the supporting member l8 that projects downward through a supporting body 8 made of a non-magnetic material. At this time, the stepped portion l4 at the center of the support member 6 constitutes a part of the magnetic path. In the above description, it is assumed that the detection unit is equipped with one magnetic field line density detection element 9, but a plurality of detection elements 9 may be arranged, and if necessary, the detection characteristics of each element may be differentiated. It is possible to reduce the error by adapting to the difference in the characteristics of the detection elements 9 or by combining or calculating the outputs of the plurality of detection elements 9. Alternatively, it is also possible to provide a plurality of detection units 1 and use them simultaneously. Further, in the embodiments described above, the magnetic field line source is a permanent magnet, but an AC electromagnet is also included in the present invention.
In that case, the output of the magnetic field line density detection element 9 becomes an alternating current waveform, and its envelope becomes each described waveform. Effects of the Invention> As described above, in the present invention, magnetic lines of force are applied to the subject from a magnetic field line source with a substantially uniform density placed at a position separated from the surface of the subject having scratches on the surface, and the lines of magnetic force are A magnetic field line density detector placed on or near the surface of the object to be examined is moved in a direction perpendicular to the flaw line to detect changes in the Bi field line density, which is input to an electrical judgment circuit to identify the flaw. By detecting the position of the scratch, it is possible to reliably detect the exact position of the scratch. Moreover, in the present invention, the magnetic field line density at the scratch position is extremely reduced compared to other parts, and it can be detected as a unique groove-shaped waveform.
Since this waveform has characteristics that can be clearly distinguished from waveforms at other locations, it is possible to detect the correct location of flaws on the surface of the steel pipe or steel plate.
図面は本発明の実施例を示すもので、第１図は本発明の
概略した構威を示す説明図、第２図は検出部の拡大した
正面図、第３図は検出部の他の実施例を示す正面図、第
４図は磁力線分布を示す説明図、第５図は傷部の波形を
示す説明図、第６図は被検体の必要範囲にわたる電気的
出力の波形を示す説明図、第７図は電子回路の動作を示
す説明図、第８図、第９図は磁力線源の他の実施例を示
す正面図である．
ｌ．，．検出部 ２．．
３．．．被検体 ４．．
５．．．永久磁石 ６．．
８．．．支持体
９．．．磁力線密度検出素子
１１．．．傷波形
１２， １３． ． ．永久磁石
．電子回路
．傷の位置
．支持部材The drawings show embodiments of the present invention; FIG. 1 is an explanatory diagram showing a schematic structure of the present invention, FIG. 2 is an enlarged front view of the detection section, and FIG. 3 is another embodiment of the detection section. A front view showing an example, FIG. 4 is an explanatory diagram showing the magnetic field line distribution, FIG. 5 is an explanatory diagram showing the waveform of the wound part, FIG. 6 is an explanatory diagram showing the waveform of the electrical output over the necessary range of the subject, FIG. 7 is an explanatory diagram showing the operation of the electronic circuit, and FIGS. 8 and 9 are front views showing other embodiments of the magnetic field source. l. 、． Detection part 2. ．． 3. ．． ．． Subject 4. ．． 5. ．． ．． Permanent magnet 6. ．． 8. ．． ．． Support 9. ．． ．． Magnetic field line density detection element 11. ．． ．． Damage waveform 12, 13. ．． ．． permanent magnet. Electronic circuit. Location of the wound. Support member
Claims (1)
置いたほぼ分布一様な密度の磁力線源より磁力線を被検
体に当て、該磁力線の存在する被検体の表面、又は被検
体の表面に近接して配置された磁力線密度検出器を傷線
に直角の方向に移動し、磁力線密度の変化を検出すると
共に、該検出出力を電気的判定回路に入力し傷の位置を
検出することを特徴とした表面傷の探傷装置。1. Apply magnetic lines of force to the subject from a magnetic field line source with a substantially uniform density placed at a location away from the surface of the subject with a scratch on the surface, and then A magnetic field line density detector placed close to the surface is moved in a direction perpendicular to the flaw line to detect changes in the magnetic field line density, and the detection output is input to an electrical determination circuit to detect the position of the flaw. A surface flaw detection device featuring:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19525389A JPH0357952A (en) | 1989-07-26 | 1989-07-26 | Flaw detection apparatus for surface flaw |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19525389A JPH0357952A (en) | 1989-07-26 | 1989-07-26 | Flaw detection apparatus for surface flaw |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0357952A true JPH0357952A (en) | 1991-03-13 |
Family
ID=16338059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19525389A Pending JPH0357952A (en) | 1989-07-26 | 1989-07-26 | Flaw detection apparatus for surface flaw |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0357952A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5782995A (en) * | 1993-11-05 | 1998-07-21 | Citizen Watch Co., Ltd. | Solar battery device and method of fabricating the same |
| EP1327882A1 (en) * | 2000-10-18 | 2003-07-16 | Kawasaki Steel Corporation | Leakage magnetism detecting sensor of magnetic penetration apparatus |
-
1989
- 1989-07-26 JP JP19525389A patent/JPH0357952A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5782995A (en) * | 1993-11-05 | 1998-07-21 | Citizen Watch Co., Ltd. | Solar battery device and method of fabricating the same |
| EP1327882A1 (en) * | 2000-10-18 | 2003-07-16 | Kawasaki Steel Corporation | Leakage magnetism detecting sensor of magnetic penetration apparatus |
| EP1327882A4 (en) * | 2000-10-18 | 2005-04-13 | Jfe Steel Corp | Leakage magnetism detecting sensor of magnetic penetration apparatus |
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