JPH08211023A - Method and apparatus for calibrating sensitivity of steel strip flaw detector - Google Patents
Method and apparatus for calibrating sensitivity of steel strip flaw detectorInfo
- Publication number
- JPH08211023A JPH08211023A JP1755895A JP1755895A JPH08211023A JP H08211023 A JPH08211023 A JP H08211023A JP 1755895 A JP1755895 A JP 1755895A JP 1755895 A JP1755895 A JP 1755895A JP H08211023 A JPH08211023 A JP H08211023A
- Authority
- JP
- Japan
- Prior art keywords
- steel strip
- magnetic
- sensitivity
- magnetic flux
- standard inspection
- 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.)
- Granted
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は鋼帯を圧延方向に磁化し
て鋼帯の内部または表面の欠陥部により生じる漏洩磁束
を多数の感磁素子によって検出する鋼帯欠陥検出装置の
感度較正方法及びその装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of calibrating the sensitivity of a steel strip defect detecting apparatus in which a magnetic flux is generated by magnetizing a steel strip in the rolling direction and causing a magnetic flux leakage caused by defective portions inside or on the surface of the steel strip. And its device.
【０００２】[0002]
【従来の技術】クロムめっき鋼板や冷延鋼板等の鋼帯に
生じるピンホールやガウジ等の表面疵や非金属介在物に
よる内部欠陥等の欠陥部を鋼帯の走行中に検出する鋼帯
欠陥検出装置としては従来より種々提案されている。こ
れらの鋼帯欠陥検出装置に用いられる感磁素子としては
ホール素子、ＳＭＤ素子、Ｕ字型コア付きセンシングコ
イル、コアの磁気ヒステリシス効果を利用した飽和磁束
型センサ、薄いプリント基板に平面状のコイルを形成し
たもの等が用いられている。これらの感磁素子はいずれ
も１個で鋼帯全幅を検査できないので、複数組み合わせ
て使用されることから、検査前後や一定時間経過後に感
度較正を実施して各感磁素子間の検出値の変動を一定レ
ベルに抑えて規定の感度に設定する必要がある。規定の
感度設定は人工の対比欠陥を鋼帯と略同一の材料に加工
するか、自然欠陥の存在している鋼帯を準備して実検査
と同じ条件で検出を行い、感磁素子の検出値が規定範囲
に入るよう増幅ゲインまたは減衰器を操作するのが好ま
しい。2. Description of the Related Art Steel strip defects that detect surface defects such as pinholes and gouges that occur in steel strips such as chrome plated steel sheets and cold rolled steel sheets, and internal defects such as internal defects due to non-metallic inclusions while the steel strip is running. Various detection devices have been proposed in the past. Hall elements, SMD elements, sensing coils with U-shaped cores, saturated magnetic flux type sensors that utilize the magnetic hysteresis effect of the cores, flat coils on thin printed circuit boards are used as magnetic sensing elements used in these steel strip defect detection devices. What is formed is used. Since each of these magnetic sensitive elements cannot inspect the entire width of the steel strip, it is used in multiple combinations. Therefore, sensitivity calibration is performed before and after the inspection or after a certain period of time to detect the detected values between the magnetic sensitive elements. It is necessary to suppress the fluctuation to a certain level and set it to the specified sensitivity. For the specified sensitivity setting, the artificial contrast defect is processed into the same material as the steel strip, or a steel strip with natural defects is prepared and detected under the same conditions as the actual inspection to detect the magnetic sensitive element. It is preferable to operate the amplification gain or attenuator so that the value falls within the specified range.
【０００３】しかしこのような感度較正を行うには、感
磁素子が多すぎて対比欠陥や自然欠陥の準備が大変であ
った。そこで簡便に再現性の良い感度較正法として鋼帯
健全部の地肌ノイズ信号に基づいて感磁素子の検出感度
を較正する装置が提案されている。（例えば、特開平２
−９５２５２号公報）。しかし感磁素子が検出する鋼帯
健全部の地肌ノイズ信号は、圧延ロールの表面粗度と同
じことになるが、圧延ロールの表面は圧延トン数によっ
て徐々に摩耗してゆき、圧延単位の始めと終わりでは変
化するのが常識である。このため表面粗度の変化する鋼
帯の地肌ノイズ信号に基づいて感度較正を行うことは精
度低下の問題があった。また精製ラインのように通板さ
れる鋼帯が必ずしも時系列的にみて連続していない場合
では、直前に通板された鋼帯の地肌ノイズ信号とレベル
が異なる場合も発生し、Ｓ／Ｎ比の確保の点で問題があ
った。However, in order to perform such sensitivity calibration, it was difficult to prepare contrast defects and natural defects because there were too many magnetic sensitive elements. Therefore, an apparatus for calibrating the detection sensitivity of the magnetic sensitive element based on the background noise signal of the steel strip sound part has been proposed as a sensitivity calibration method with good reproducibility. (For example, Japanese Patent Laid-Open No.
-95252 publication). However, the background noise signal of the sound strip of the steel strip detected by the magnetic sensing element is the same as the surface roughness of the rolling roll, but the surface of the rolling roll gradually wears due to the rolling tonnage and the beginning of the rolling unit. It is common sense to change at the end. For this reason, the sensitivity calibration based on the background noise signal of the steel strip whose surface roughness changes has a problem of reduced accuracy. In the case where the steel strip to be stripped is not necessarily continuous in time series as in the refining line, the background noise signal of the strip just before stripping may be different in level from the S / N. There was a problem in securing the ratio.
【０００４】またワイヤを感磁素子の近くに巡らして擬
似漏洩磁束を発生させる方法及び装置が提案されてい
る。（例えば、特開平５−１０９６２号公報）。しかし
アンペールの法則により感磁素子とワイヤの距離の逆自
乗によって発生する磁束の強度は変化するので、厳密な
寸法精度が必要となるが、巻き付け時の寸法精度を確保
するのは難しかった。そこで逆に感磁素子よりかなり離
れた位置にワイヤを巡らせて擬似漏洩磁束を安定させる
ことも考えられるが、通常感磁素子には漏洩磁束の検出
に指向性があるため、実検査時と条件が異なると漏洩磁
束の感磁素子通過経路等が大幅に異なって正確な感度較
正を行うことができなくなるという問題があった。Further, there has been proposed a method and apparatus for generating a pseudo leakage magnetic flux by wrapping a wire near a magnetic sensitive element. (For example, Japanese Patent Laid-Open No. 5-10962). However, since the strength of the magnetic flux generated by the inverse square of the distance between the magnetic sensing element and the wire changes according to Ampere's law, strict dimensional accuracy is required, but it was difficult to secure dimensional accuracy during winding. Therefore, conversely, it may be possible to stabilize the pseudo leakage flux by wrapping the wire at a position far away from the magnetic sensing element, but usually the magnetic sensing element has directivity for detecting the leakage magnetic flux, so it is necessary However, there is a problem in that the path of the magnetic flux passing through the magnetic sensitive element is greatly different and accurate sensitivity calibration cannot be performed.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は前記の
ような問題点を解決し、簡単に精度の高い感度較正を行
うことができる鋼帯欠陥検出装置の感度較正方法及びそ
の装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a method and apparatus for calibrating the sensitivity of a steel strip defect detecting apparatus, which enables simple and highly accurate sensitivity calibration. To do.
【０００６】[0006]
【課題を解決するための手段】本発明は、剛体よりなる
非磁性材に一定の擬似漏洩磁束を生じさせる細線を鋼帯
幅にわたって設けた標準検査体を一定速度で鋼帯欠陥検
出装置の電磁石の磁束中を通過させ、前記標準検査体に
より生じる一定の擬似漏洩磁束を鋼帯幅にわたって配設
される鋼帯欠陥検出装置の多数の感磁素子により検出
し、各感磁素子により検出された検出値を較正装置によ
り比較して各感磁素子の感度変動を較正することを特徴
とする鋼帯欠陥検出装置の感度較正方法及び鋼帯欠陥検
出装置の電磁石と、剛体よりなる非磁性材に一定の擬似
漏洩磁束を生じさせる細線を鋼帯幅にわたって設けると
ともに前記電磁石により生じる磁束中を一定速度で通過
する標準検査体と、該標準検査体の磁束中の通過によっ
て生じる一定の擬似漏洩磁束を検出する鋼帯幅にわたっ
て配設される鋼帯欠陥検出装置の多数の感磁素子と、該
各感磁素子により検出された検出値を比較して各感磁素
子の感度変動を較正する較正装置とよりなることを特徴
とする鋼帯欠陥検出装置の感度較正装置とよりなるもの
である。SUMMARY OF THE INVENTION The present invention provides an electromagnet for a steel strip defect detecting device at a constant speed with a standard inspection body provided with a thin wire for producing a constant pseudo leakage magnetic flux on a non-magnetic material made of a rigid body at a constant speed. Of the standard inspection body, and a constant pseudo leakage magnetic flux generated by the standard inspection body is detected by a large number of magnetic sensitive elements of the steel strip defect detection device arranged over the width of the steel strip, and is detected by each magnetic sensitive element. A method for calibrating the sensitivity of a steel strip defect detection device characterized by calibrating the sensitivity variation of each magnetic sensitive element by comparing detected values with a calibration device, and an electromagnet of the steel strip defect detection device, and a non-magnetic material made of a rigid body. A thin wire that causes a constant pseudo leakage magnetic flux is provided over the width of the steel strip, and a standard inspection body that passes through the magnetic flux generated by the electromagnet at a constant speed, and a constant pseudo body generated by the passage of the standard inspection body in the magnetic flux. Calibrates the sensitivity fluctuation of each magnetic sensitive element by comparing a large number of magnetic sensitive elements of the steel strip defect detecting device arranged across the width of the steel strip for detecting the magnetic flux leakage and the detection values detected by the respective magnetic sensitive elements. And a sensitivity calibrating device for a steel strip defect detecting device.
【０００７】[0007]
【作用】本発明の鋼帯欠陥検出装置の感度較正方法及び
その装置は、一定の擬似漏洩磁束を生じさせる細線を剛
体よりなる非磁性材に設けた鋼帯幅の標準検査体を一定
速度で磁束中に通過させれば、剛体よりなる非磁性材に
設けられた擬似漏洩磁束を生じさせる細線は磁束の吸引
力により変形することなく、磁束を変化させて一定の擬
似漏洩磁束を発生させる。この擬似漏洩磁束は鋼帯全幅
にわたって配設される多数の各感磁素子により検出され
るが、細線による擬似磁束は一定のための感磁素子の感
度にばらつきがあれば、各感磁素子に検出される検出値
は異なることとなる。この検出値のばらつきを較正装置
により修正して感磁素子の感度を規定レベルに補正す
る。The method and apparatus for calibrating the sensitivity of a steel strip defect detecting apparatus according to the present invention uses a standard inspection body of a steel strip width in which a fine wire for producing a constant pseudo leakage flux is provided on a non-magnetic material made of a rigid body at a constant speed. When passing through the magnetic flux, the thin wire that is provided in the non-magnetic material made of a rigid body and causes the pseudo-leakage magnetic flux is not deformed by the attractive force of the magnetic flux, and changes the magnetic flux to generate a constant pseudo-leakage magnetic flux. This pseudo leakage flux is detected by a large number of magnetic sensitive elements arranged over the entire width of the steel strip. The detected values detected will be different. The variation of the detected value is corrected by the calibration device to correct the sensitivity of the magnetic sensing element to the specified level.
【０００８】[0008]
【実施例】次に、本発明を図示の実施例に基づいて詳細
に説明する。１は鋼帯を巻き掛けるブライドルロールで
あり、該ブライドルロール１の若干上方にはブライドル
ロール１を通過する鋼帯を圧延方向に直流磁化させる電
磁石２が配置されている。３は電磁石２の両極間に配設
される多数の感磁素子であり、該感磁素子３は電磁石２
により直流磁化された鋼帯にピンホールやガウジ等の表
面疵や内部の非金属介在物等の欠陥部が存在した場合に
生じる磁束変化すなわち漏洩磁束を検出するものであ
る。４は感度較正を行う際、電磁石２の磁束中に介入さ
れる標準検査体であり、該標準検査体４は直径５６×幅
１２００ｍｍのＳＵＳ３１６製の剛体よりなる非磁性材
のロール５に、軸線方向の凹溝６を形成し、該凹溝６内
に直径０．２ｍｍの強磁性材よりなるピアノ鋼線７等の
細線を張架したうえ、非磁性材よりなる合成樹脂８によ
り埋設したものであり、合成樹脂８によりピアノ鋼線７
を埋設することにより、ピアノ鋼線７はロール５と一体
化された状態となり、防錆と電磁石２の磁力によるピア
ノ鋼線７の中央部がリフトされることを防止している。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the illustrated embodiments. Reference numeral 1 denotes a bridle roll around which a steel strip is wound, and an electromagnet 2 for direct-current magnetizing a steel strip passing through the bridle roll 1 in the rolling direction is arranged slightly above the bridle roll 1. Reference numeral 3 denotes a large number of magnetic sensitive elements arranged between both poles of the electromagnet 2.
Is used to detect a change in magnetic flux, that is, a leakage magnetic flux, which occurs when a surface flaw such as a pinhole or a gouge or a defective portion such as an internal non-metallic inclusion exists in the steel sheet magnetized by direct current. Reference numeral 4 denotes a standard inspection body which is intervened in the magnetic flux of the electromagnet 2 when the sensitivity is calibrated. The standard inspection body 4 is a non-magnetic material roll 5 made of a rigid body made of SUS316 and having a diameter of 56 and a width of 1200 mm. Direction recessed groove 6 is formed, and a fine wire such as a piano steel wire 7 made of a ferromagnetic material having a diameter of 0.2 mm is stretched in the recessed groove 6 and embedded by a synthetic resin 8 made of a non-magnetic material. And synthetic steel 8 is used for piano steel wire 7
By embedding, the piano steel wire 7 is integrated with the roll 5, and the central portion of the piano steel wire 7 is prevented from being lifted due to rust prevention and the magnetic force of the electromagnet 2.
【０００９】９は感磁素子３により検出された標準検査
体４による一定の擬似漏洩磁束の電気信号が入力される
較正装置であり、該較正装置９は図３のブロック図に示
されるように、各感磁素子３により検出された一定の擬
似漏洩磁束の電気信号は対ノイズ性確保のため感磁素子
３の近傍に配置された前置広域増幅器１０により約６０
デシベル程増幅される。そして増幅された擬似漏洩磁束
の電気信号は可変帯域／可変増幅器１１により所定の周
波数帯域のみが増幅される。その後多数の前置広域増幅
器１０の信号は検出端ブロック毎に検波・Ａ／Ｄ変換器
１２により検出端ブロック内の信号を集めたうえ両振れ
信号を片振れ信号に検波し、一定時間または一定周長内
のピーク値をＡ／Ｄ変換して検出端ブロック毎に配置し
たサブデータ処理部１３に入力する。サブデータ処理部
１３は検波・Ａ／Ｄ変換器１２で検出端ブロック毎に信
号が集められるので、注目する感磁素子３に直結する可
変帯域／可変増幅器１１だけが所定の感度で擬似漏洩磁
束を検出し、他の感磁素子３に直結する可変帯域／可変
増幅器１１は感度を絞り、あたかも１チャンネルずつ感
磁素子３の出力をサブデータ処理部１３に取り込まれる
ように制御している。Reference numeral 9 is a calibration device to which an electric signal of a constant pseudo leakage magnetic flux by the standard inspection body 4 detected by the magnetic sensing element 3 is input. The calibration device 9 is as shown in the block diagram of FIG. The electric signal of the constant pseudo leakage magnetic flux detected by each magnetic sensitive element 3 is about 60 by the pre-wide area amplifier 10 arranged near the magnetic sensitive element 3 in order to secure noise resistance.
As much as the decibel is amplified. The variable band / variable amplifier 11 amplifies the amplified electric signal of the pseudo leakage magnetic flux only in a predetermined frequency band. After that, a large number of signals from the pre-wide area amplifiers 10 are detected by the detection / A / D converter 12 for each detection end block, and both swing signals are detected as one-sided swing signals for a certain period of time or a fixed amount. The peak value within the circumference is A / D converted and input to the sub data processing unit 13 arranged for each detection end block. Since the sub-data processing unit 13 collects signals for each detection end block by the detection / A / D converter 12, only the variable band / variable amplifier 11 directly connected to the magnetic sensing element 3 of interest has a predetermined sensitivity to generate the pseudo leakage flux. The variable band / variable amplifier 11 which is directly connected to the other magnetic sensitive element 3 narrows down the sensitivity and controls so that the output of the magnetic sensitive element 3 is taken into the sub-data processing unit 13 as if channel by channel.
【００１０】そしてサブデータ処理部１３はこの擬似漏
洩磁束を所定回数だけ取り込み、平均値を算出する。こ
の結果を上位のメインデータ処理部１４に送り込み、予
めメモリ１５に記憶している感度較正用のデータと製造
ロット毎に入力される板幅や板厚、検査条件等から判断
して、各感磁素子３毎に増幅器のゲイン補正値等を演算
する。この結果は直ちにサブデータ処理部１３に返され
る。サブデータ処理部１３はこれらのデータに基づき可
変帯域／可変増幅器１１のゲインを調整する。感磁素子
３は全部で１４４チャンネルあって９つの検出端ブロッ
クに分かれており、サブデータ処理部１３は１６チャン
ネルの感磁素子３を制御し、メインデータ処理部１４は
９個のサブデータ処理部１３を制御している。そして９
個のサブデータ処理部１３と１個のメインデータ処理部
１４により中央演算部１６が構成されている。１７はモ
ニタ用ＣＲＴ、１８はプリンタである。Then, the sub data processing unit 13 takes in the pseudo leakage magnetic flux a predetermined number of times and calculates an average value. This result is sent to the main data processing unit 14 of the upper level, and is judged from the data for sensitivity calibration stored in the memory 15 in advance and the plate width, plate thickness, inspection condition, etc. input for each manufacturing lot, and each feeling is judged. The gain correction value of the amplifier is calculated for each magnetic element 3. This result is immediately returned to the sub data processing unit 13. The sub data processing unit 13 adjusts the gain of the variable band / variable amplifier 11 based on these data. The magnetic sensing element 3 has 144 channels in total and is divided into nine detection end blocks. The sub-data processing unit 13 controls the magnetic sensing element 3 of 16 channels, and the main data processing unit 14 processes nine sub-data. It controls the unit 13. And 9
The central processing unit 16 is configured by the sub data processing units 13 and the main data processing unit 14. Reference numeral 17 is a monitor CRT, and 18 is a printer.
【００１１】以下、鋼帯欠陥検出装置の感度較正装置の
作用を説明する。鋼帯欠陥検出装置は図６に示されるよ
うに、ブライドルロール１に巻き掛けられる鋼帯を電磁
石２により直流磁化させ、鋼帯の表面疵による漏洩磁束
を感磁素子３により検出するものであるが、検査前後や
一定期間経過後、感度較正を行う際は、図４のフローに
示されるように、鋼帯欠陥検出装置を一旦停止して、非
磁性材に一定の擬似漏洩磁束を生じさせる材質を鋼帯幅
にわたって設けた標準検査体４の剛体よりなる非磁性材
よりなるロール５を鋼帯欠陥検出装置の検出部直下に配
置したうえ、ロール５を一定周速度で回転させる。（こ
の周速度は通板時と同じ速度でも異なる周速度でもよい
が、通板時と周速度が異なる場合は検出値を補正する必
要がある。）このロール５の回転時、電磁石２により直
流磁場を実検査時と同等の条件で印加する。（このとき
の磁化電流は実検査時と異なる場合は検出値の補正を行
う必要がある。）この磁束中を標準検査体４が通過する
と、剛体よりなる非磁性材のロール５の軸線方向に形成
された凹溝６内に非磁性材で埋設されたロール５と一体
化された強磁性材よりなるピアノ鋼線７により、電磁石
２の鉄心から出た磁束は磁気抵抗の小さい経路を通過し
ようとして曲げられる。この曲げられた磁束は一定の擬
似漏洩磁束として感磁素子３により検出される。The operation of the sensitivity calibration device of the steel strip defect detection device will be described below. As shown in FIG. 6, the steel strip defect detection device is one in which a steel strip wound around a bridle roll 1 is DC magnetized by an electromagnet 2, and a magnetic flux leakage due to a surface flaw of the steel strip is detected by a magnetic sensing element 3. However, when sensitivity calibration is performed before and after the inspection or after a certain period of time, as shown in the flow of FIG. 4, the steel strip defect detection device is temporarily stopped to generate a certain pseudo leakage magnetic flux in the non-magnetic material. A roll 5 made of a non-magnetic material made of a rigid body of a standard inspection body 4 whose material is provided across the width of the steel strip is arranged immediately below the detection portion of the steel strip defect detection apparatus, and the roll 5 is rotated at a constant peripheral speed. (This peripheral speed may be the same or different from that at the time of passing the plate, but if the peripheral speed is different from that at the time of passing the plate, it is necessary to correct the detected value.) When the roll 5 is rotated, the DC is applied by the electromagnet 2. The magnetic field is applied under the same conditions as in the actual inspection. (If the magnetizing current at this time is different from that at the time of actual inspection, it is necessary to correct the detection value.) When the standard inspection body 4 passes through this magnetic flux, it moves in the axial direction of the roll 5 of non-magnetic material made of a rigid body. With the piano steel wire 7 made of a ferromagnetic material integrated with the roll 5 embedded with the non-magnetic material in the formed concave groove 6, the magnetic flux emitted from the iron core of the electromagnet 2 will pass through a path having a small magnetic resistance. Can be bent as. The bent magnetic flux is detected by the magnetic sensing element 3 as a constant pseudo leakage magnetic flux.
【００１２】そして各感磁素子３により検出された一定
の擬似漏洩磁束は、電気信号として較正装置９の前置広
域増幅器１０、可変帯域／可変増幅器１１を介して増幅
され、検波・Ａ／Ｄ変換器１２により検波され、Ａ／Ｄ
変換されたうえ、サブデータ処理部１３、メインデータ
処理部１４としての中央演算部１６に取り込む。このと
き各感磁素子３からの検出値を多数回測定して平均値を
算出することにより、精度を高めることができる。そし
て感度較正に先立って、設定されている感度較正用のデ
ータ、例えば、板幅、板圧等の通板材料及び通板速度や
検出感度等の検査条件を中央演算部１６に読み込む。各
感磁素子３の検出値と感度較正用のデータを比較して各
感磁素子３の感度補正量を演算する。この演算結果に基
づき各感磁素子３に対応する可変帯域／可変増幅器１１
のゲインを中央演算部１６の指令で調整する。その後再
度各感磁素子３の検出値を中央演算部１６に取り込ん
で、規定の値に収斂しているかを確認する。収斂してい
なければ再度前記と同様の操作を収斂するまで繰り返せ
ばよい。The constant pseudo leakage magnetic flux detected by each magnetic sensitive element 3 is amplified as an electric signal through the pre-wide area amplifier 10 and the variable band / variable amplifier 11 of the calibration device 9 to perform detection / A / D. A / D detected by the converter 12
After being converted, it is taken into the central processing unit 16 as the sub data processing unit 13 and the main data processing unit 14. At this time, the accuracy can be improved by measuring the detected value from each magnetic sensitive element 3 many times and calculating the average value. Then, prior to the sensitivity calibration, the set sensitivity calibration data, for example, the strip material such as strip width and strip pressure, and inspection conditions such as strip speed and detection sensitivity are read into the central processing unit 16. The detected value of each magnetic sensitive element 3 and the data for sensitivity calibration are compared to calculate the sensitivity correction amount of each magnetic sensitive element 3. Based on the calculation result, the variable band / variable amplifier 11 corresponding to each magnetic sensitive element 3
The gain of is adjusted by a command from the central processing unit 16. After that, the detected values of the respective magnetic sensing elements 3 are again fetched into the central processing unit 16 and it is confirmed whether or not they converge to the specified values. If it is not converged, the same operation as described above may be repeated until it is converged.
【００１３】図５（ａ、ｂ）に鉄製ロール（直径５６×
幅１２００ｍｍ）表面の幅方向に直径０．２ｍｍの対比
欠陥を形成して感磁素子により漏洩磁束を検出した際、
エッジ部と中央部に表れる欠陥信号及びＳＵＳ製ロール
（直径５６×幅１２００ｍｍ）表面に幅方向に幅０．３
ｍｍの凹溝を形成し、直径０．２ｍｍの対比欠陥として
のピアノ鋼線を非磁性体で埋設して感磁素子により漏洩
磁束を検出した際、エッジ部と中央部に表れる欠陥信号
を示す。この両欠陥信号から鉄製ロールでは磁力により
中央部が吸引されてリフトされ、中央部がエッジ部に比
べて感度が上がったものとなっているの対して、ＳＵＳ
製ロールは磁力により吸引されずリフトされることがな
く、磁力の影響を受けるピアノ鋼線は細いうえ非磁性材
で埋設され、ＳＵＳ製ロールと一体化されているため、
吸引されてリフトすることがないので、エッジ部と中央
部で感度は同じであり、感度較正としては適しているこ
とが判る。FIG. 5 (a, b) shows an iron roll (diameter 56 ×
(Width 1200 mm) When a leakage defect is detected by the magnetic sensing element by forming a contrast defect having a diameter of 0.2 mm in the width direction of the surface,
Defect signals appearing in the edge part and the central part and a width of 0.3 in the width direction on the surface of a SUS roll (diameter 56 x width 1200 mm).
When the leak magnetic flux is detected by the magnetic sensitive element when a piano steel wire having a diameter of 0.2 mm and a diameter of 0.2 mm as a contrasting defect is embedded with a non-magnetic material, a defect signal appears at the edge part and the center part. . From these two defect signals, in the iron roll, the central portion is attracted and lifted by the magnetic force, and the central portion has higher sensitivity than the edge portion.
The roll made is not attracted by the magnetic force and is not lifted, and the piano steel wire affected by the magnetic force is thin and embedded with a non-magnetic material, and is integrated with the SUS roll,
Since it is not sucked and lifted, it is understood that the edge portion and the central portion have the same sensitivity, which is suitable for sensitivity calibration.
【００１４】なお、ロール５に凹溝６を２本あるいは４
本形成し、ダミーの非磁性ワイヤを埋め込んで動バラン
スを取ったり、同じ線径あるいは多少線径の異なる強磁
性細線を埋め込んで何本かの信号の平均値で感度較正を
行なったり、大小の信号により感度較正を行ってもよい
ことは勿論である。また実施例では標準検査体４を剛体
よりなる非磁性材のステンレス製のロール５の凹溝６に
ピアノ鋼線７を埋設したものを回転させて一定の擬似漏
洩磁束を発生させているが、剛体よりなる非磁性材より
なるロール５の表面にアモルファス薄帯を貼付したもの
としてもよく、またロール５の代わりに剛体よりなる非
磁性材よりなる板体に凹溝を形成し、該凹溝に強磁性細
線を非磁性材の合成樹脂で埋設したり、剛体よりなる板
体表面にアモルファス薄帯を貼付したものを直線運動さ
せて一定の擬似漏洩磁束を発生させてもよいことは勿論
である。さらに電磁石２はブライドルロール１内に設け
てよいことは勿論である。It should be noted that two or four concave grooves 6 are formed on the roll 5.
Forming a main wire and embedding a dummy non-magnetic wire for dynamic balance, or embedding a ferromagnetic thin wire with the same wire diameter or a slightly different wire diameter and calibrating the sensitivity with the average value of several signals. Of course, sensitivity calibration may be performed by a signal. Further, in the embodiment, the standard inspection body 4 is rotated by rotating the one in which the piano steel wire 7 is embedded in the concave groove 6 of the non-magnetic stainless steel roll 5 made of a rigid body. An amorphous ribbon may be attached to the surface of a roll 5 made of a non-magnetic material made of a rigid body. Alternatively, instead of the roll 5, a concave groove is formed in a plate made of a non-magnetic material made of a rigid body. It is of course possible to embed a ferromagnetic thin wire in a synthetic resin of a non-magnetic material, or linearly move a plate made of a rigid body with an amorphous ribbon attached to generate a constant pseudo leakage flux. is there. Further, it goes without saying that the electromagnet 2 may be provided in the bridle roll 1.
【００１５】[0015]
【発明の効果】本発明は前記説明によって明らかなよう
に、剛体よりなる非磁性材に一定の擬似漏洩磁束を生じ
させる細線を鋼帯幅にわたって設けた標準検査体によ
り、鋼帯全幅にわたって感磁素子の直下で一定の擬似漏
洩磁束を発生させることができので、感磁素子の指向性
に影響されることなく実検査と同等の条件で高精度の感
度較正を行なうことができる。しかも均一な自然欠陥や
対比欠陥を有する鋼帯を準備する必要がないうえに、標
準検査体の一定の擬似漏洩磁束を生じさせる強磁性体よ
りなる細線は剛体よりなる非磁性材に埋設されているた
め錆が発生したり、摩耗することがないうえに、磁束に
より吸引されて変形することがないので、擬似漏洩磁束
がばらついたり変動することがなく、長期間にわたり安
定した感度較正を行なうことができ、また標準検査体の
一定の擬似漏洩磁束を生じさせる細線をアモルファス材
とすれば、腐蝕や摩耗性の心配がないので、非磁性材に
凹溝を形成して合成樹脂等の非磁性材で埋設する必要も
なく、製造コストを低下させことができる。従って、本
発明は従来の問題点を解決した鋼帯欠陥検出装置の感度
較正方法及びその装置として業界の発展に寄与すること
極めて大なものである。As is apparent from the above description, the present invention provides a standard non-magnetic material, which is a rigid non-magnetic material, provided with fine wires for generating a constant pseudo-leakage magnetic flux over the width of the steel strip. Since a constant pseudo leakage magnetic flux can be generated immediately below the element, high-accuracy sensitivity calibration can be performed under the same conditions as in the actual inspection without being affected by the directivity of the magnetic sensing element. Moreover, it is not necessary to prepare a steel strip having uniform natural defects and contrast defects, and the thin wire made of a ferromagnetic material that causes a constant pseudo leakage flux of the standard inspection body is embedded in a non-magnetic material made of a rigid body. Since it does not generate rust or wear due to the presence of magnetic flux, and it is not deformed by being attracted by the magnetic flux, pseudo leakage flux does not fluctuate or fluctuate, and stable sensitivity calibration can be performed over a long period of time. In addition, if the fine wire that produces a constant pseudo leakage magnetic flux of the standard inspection body is made of an amorphous material, there is no concern of corrosion or wear, so a concave groove is formed in the non-magnetic material to make it non-magnetic such as synthetic resin. Since it is not necessary to bury the material, the manufacturing cost can be reduced. Therefore, the present invention greatly contributes to the development of the industry as a method for calibrating the sensitivity of a steel strip defect detecting device and a device therefor which solve the conventional problems.
【図１】本発明の実施例の概略図である。FIG. 1 is a schematic diagram of an embodiment of the present invention.
【図２】本発明の標準検査体の実施例を示す一部切欠斜
視図である。FIG. 2 is a partially cutaway perspective view showing an embodiment of a standard inspection body of the present invention.
【図３】本発明の較正装置のブロック図である。FIG. 3 is a block diagram of a calibration device of the present invention.
【図４】本発明の実施例のフロー図である。FIG. 4 is a flow chart of an embodiment of the present invention.
【図５】鉄製ロールに対比欠陥を形成した場合とＳＵＳ
製ロールにピアノ鋼線を埋設した場合のエッジ部と中央
部に表れる擬似漏洩磁束を示す波形図である。FIG. 5: SUS with contrast defects formed on the iron roll
It is a wave form diagram which shows the pseudo leakage magnetic flux which appears in the edge part and the center part when a piano steel wire is embedded in the roll made.
【図６】鋼帯の欠陥検出を示す概略図である。FIG. 6 is a schematic view showing defect detection of a steel strip.
２ 電磁石 ３ 感磁素子 ４ 標準検査体 ５ ロール ６ 凹溝 ７ 強磁性細線 ９ 較正装置 2 Electromagnet 3 Magnetosensitive element 4 Standard inspection body 5 Roll 6 Recessed groove 7 Ferromagnetic wire 9 Calibration device
───────────────────────────────────────────────────── フロントページの続き (72)発明者 松實 敏幸 愛知県東海市富木島町北広81番地 太平工 業株式会社東海支店内 (72)発明者 青木 伸吾 愛知県東海市富木島町北広81番地 太平工 業株式会社東海支店内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshiyuki Matsuzami 81 Kitahiro, Tomijima-cho, Tokai-shi, Aichi Taihei Kogyo Co., Ltd. (72) Inventor Shingo 81 Kitahiro, Tomi-shi, Tokai-shi, Aichi Pref. Business Tokai Branch
Claims (6)
磁束を生じさせる細線を鋼帯幅にわたって設けた標準検
査体を一定速度で鋼帯欠陥検出装置の電磁石の磁束中を
通過させ、前記標準検査体により生じる一定の擬似漏洩
磁束を鋼帯幅にわたって配設される鋼帯欠陥検出装置の
多数の感磁素子により検出し、各感磁素子により検出さ
れた検出値を較正装置により比較して各感磁素子の感度
変動を較正することを特徴とする鋼帯欠陥検出装置の感
度較正方法。1. A standard inspection body, in which a non-magnetic material made of a rigid body is provided with a thin wire for generating a constant pseudo-leakage magnetic flux over the width of a steel strip, is passed at a constant speed through the magnetic flux of an electromagnet of a steel strip defect detection device, The constant pseudo leakage magnetic flux generated by the standard inspection body is detected by a large number of magnetic sensitive elements of the steel strip defect detection device arranged across the width of the steel strip, and the detected values detected by each magnetic sensitive element are compared by a calibration device. A method for calibrating the sensitivity of a steel strip defect detection device, characterized in that the sensitivity fluctuation of each magnetic sensitive element is calibrated.
なる非磁性材に一定の擬似漏洩磁束を生じさせる細線を
鋼帯幅にわたって設けるとともに前記電磁石による生じ
た磁束中を一定速度で通過する標準検査体と、該標準検
査体の磁束中の通過によって生じる一定の擬似漏洩磁束
を検出する鋼帯幅にわたって配設される鋼帯欠陥検出装
置の多数の感磁素子と、該各感磁素子により検出された
検出値を比較して各感磁素子の感度変動を較正する較正
装置とよりなることを特徴とする鋼帯欠陥検出装置の感
度較正装置。2. An electromagnet of a steel strip defect detection device, and a thin wire for producing a constant pseudo-leakage magnetic flux in a non-magnetic material made of a rigid body are provided over the width of the steel strip and pass through the magnetic flux generated by the electromagnet at a constant speed. Standard inspection body, a large number of magnetic sensitive elements of a steel strip defect detection device arranged over a steel strip width for detecting a constant pseudo leakage magnetic flux generated by passage of the standard inspection body in the magnetic flux, and each of the magnetic sensitive elements A sensitivity calibrating device for a steel strip defect detecting device, comprising: a calibrating device that compares the detection values detected by the above to calibrate the sensitivity fluctuation of each magnetic sensitive element.
させる細線が強磁性材である請求項２に記載の鋼帯欠陥
検出装置の感度較正装置。3. The sensitivity calibration device for a steel strip defect detection device according to claim 2, wherein the thin wire that causes a constant pseudo leakage magnetic flux of the standard inspection body is a ferromagnetic material.
させる細線がアモルファス材である請求項２に記載の鋼
帯欠陥検出装置の感度較正装置。4. The sensitivity calibration device for a steel strip defect detection device according to claim 2, wherein the thin wire that causes a constant pseudo leakage magnetic flux of the standard inspection body is an amorphous material.
ロールと該ロールの軸方向に形成された凹溝内に非磁性
材により埋設された強磁性細線とよりなる請求項２に記
載の鋼帯欠陥検出装置の感度較正装置。5. The standard inspection body comprises a roll of a non-magnetic material made of a rigid body, and a ferromagnetic fine wire embedded in the groove formed in the axial direction of the roll with the non-magnetic material. Sensitivity calibration device for steel strip defect detection device.
りなるロールと該ロールの軸方向に貼付されたアモルフ
ァス細薄帯とよりなるものである請求項２に記載の鋼帯
欠陥検出装置の感度較正装置。6. The steel strip defect detection device according to claim 2, wherein the standard inspection body comprises a roll made of a non-magnetic material made of a rigid body and an amorphous thin strip attached in the axial direction of the roll. Sensitivity calibration device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01755895A JP3272893B2 (en) | 1995-02-06 | 1995-02-06 | Method and apparatus for calibrating sensitivity of steel strip defect detection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP01755895A JP3272893B2 (en) | 1995-02-06 | 1995-02-06 | Method and apparatus for calibrating sensitivity of steel strip defect detection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08211023A true JPH08211023A (en) | 1996-08-20 |
| JP3272893B2 JP3272893B2 (en) | 2002-04-08 |
Family
ID=11947250
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP01755895A Expired - Fee Related JP3272893B2 (en) | 1995-02-06 | 1995-02-06 | Method and apparatus for calibrating sensitivity of steel strip defect detection device |
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| Country | Link |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10197490A (en) * | 1996-12-30 | 1998-07-31 | Tokyo Gas Co Ltd | Method for correcting individual difference of magnetic sensor used for inspection of pipe using leakage flux pig |
| JPH10239093A (en) * | 1997-02-27 | 1998-09-11 | Nkk Corp | Method and device for array sensor sensitivity correction |
| JP2010160068A (en) * | 2009-01-08 | 2010-07-22 | Hitachi Building Systems Co Ltd | Calibration apparatus for flaw detector of wire rope |
| JP2011127922A (en) * | 2009-12-15 | 2011-06-30 | Sumitomo Metal Ind Ltd | Method of eddy current flaw inspection, and gap forming member used for the same |
| WO2022004613A1 (en) * | 2020-07-03 | 2022-01-06 | Ｊｆｅスチール株式会社 | Sensitivity calibration method, inspection device, and magnetic sensor group |
-
1995
- 1995-02-06 JP JP01755895A patent/JP3272893B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10197490A (en) * | 1996-12-30 | 1998-07-31 | Tokyo Gas Co Ltd | Method for correcting individual difference of magnetic sensor used for inspection of pipe using leakage flux pig |
| JPH10239093A (en) * | 1997-02-27 | 1998-09-11 | Nkk Corp | Method and device for array sensor sensitivity correction |
| JP2010160068A (en) * | 2009-01-08 | 2010-07-22 | Hitachi Building Systems Co Ltd | Calibration apparatus for flaw detector of wire rope |
| JP2011127922A (en) * | 2009-12-15 | 2011-06-30 | Sumitomo Metal Ind Ltd | Method of eddy current flaw inspection, and gap forming member used for the same |
| WO2022004613A1 (en) * | 2020-07-03 | 2022-01-06 | Ｊｆｅスチール株式会社 | Sensitivity calibration method, inspection device, and magnetic sensor group |
| JPWO2022004613A1 (en) * | 2020-07-03 | 2022-01-06 |
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| Publication number | Publication date |
|---|---|
| JP3272893B2 (en) | 2002-04-08 |
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