JPH05264704A - Method and apparatus for measuring coercive force of steel plate - Google Patents
Method and apparatus for measuring coercive force of steel plateInfo
- Publication number
- JPH05264704A JPH05264704A JP1327192A JP1327192A JPH05264704A JP H05264704 A JPH05264704 A JP H05264704A JP 1327192 A JP1327192 A JP 1327192A JP 1327192 A JP1327192 A JP 1327192A JP H05264704 A JPH05264704 A JP H05264704A
- Authority
- JP
- Japan
- Prior art keywords
- steel plate
- coercive force
- measured
- detection coil
- excitation
- 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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Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、保磁力測定のために
鋼板からその一部を試料として切り出すことなく鋼板の
保磁力を非接触状態にて測定でき、これにより、鋼板の
機械的性質を検査するために生産ラインにおける走行中
の鋼板の保磁力をオンライン状態で測定できるようにし
た、鋼板の保磁力測定方法及びその装置に関する。This invention can measure the coercive force of a steel sheet in a non-contact state without cutting out a part of the steel sheet as a sample for measuring the coercive force. The present invention relates to a method and apparatus for measuring a coercive force of a steel sheet, which enables the coercive force of a traveling steel sheet in a production line to be measured in an online state for inspection.
【0002】[0002]
【従来の技術】鋼板の保磁力を測定する方法としては、
被測定鋼板から無端環状の試料を切り出し、この試料に
巻き付けた励磁コイル(一次コイル)に励磁電流を流し
て試料中を磁束が環状に通るようにし、試料に巻き付け
た検出コイル(二次コイル)を用いて試料の磁化状態を
調べることにより、図3に示すように、磁束密度Bと磁
界の強さHとの関係を示す B-H曲線(ヒステリシス曲
線)を求め、oc=ofに相当するHの値、すなわち保磁力
HC を測定するという方法がとられている。2. Description of the Related Art As a method for measuring the coercive force of a steel sheet,
An endless annular sample is cut out from the steel plate to be measured, an exciting current is passed through the exciting coil (primary coil) wound around this sample so that the magnetic flux passes through the sample annularly, and a detection coil (secondary coil) wrapped around the sample. As shown in FIG. 3, a BH curve (hysteresis curve) showing the relationship between the magnetic flux density B and the magnetic field strength H is obtained by investigating the magnetization state of the sample using, and H of oc = of A value, that is, the coercive force H C is measured.
【0003】[0003]
【発明が解決しようとする課題】ところで、鋼板の結晶
粒径(結晶粒度)と鋼板の機械的性質とは密接な相関が
ある。また、鋼板の結晶粒径と鋼板の保磁力との間には
密接な相関があり、結晶粒径が大きいほど鋼板の保磁力
は小さくなる。そこで、生産ラインにおける走行中の鋼
板の機械的性質をオンライン状態で検査するために、走
行中の鋼板の保磁力を測定できるようにすることが求め
られている。しかしながら、先に述べた従来の方法で
は、鋼板の保磁力を測定するために、被測定鋼板からそ
の一部を試料として切り出すことが必要となることか
ら、上記の生産ラインにおける走行中の鋼板の保磁力を
オンライン状態において測定できないという問題点があ
る。By the way, there is a close correlation between the crystal grain size (grain size) of a steel sheet and the mechanical properties of the steel sheet. Further, there is a close correlation between the crystal grain size of the steel sheet and the coercive force of the steel sheet, and the larger the crystal grain size, the smaller the coercive force of the steel sheet. Therefore, it is required to be able to measure the coercive force of the running steel sheet in order to inspect the mechanical properties of the running steel sheet in a production line in an online state. However, in the above-mentioned conventional method, in order to measure the coercive force of the steel sheet, it is necessary to cut out a part of the steel sheet to be measured as a sample. There is a problem that the coercive force cannot be measured in the online state.
【0004】そこで、この発明は、保磁力測定のために
鋼板からその一部を試料として切り出すことなく鋼板の
保磁力を非接触状態で測定でき、これにより、鋼板の機
械的性質を検査するために生産ラインにおける走行中の
鋼板の保磁力をオンライン状態で測定できる、鋼板の保
磁力測定方法及びその装置の提供を目的とする。Therefore, according to the present invention, the coercive force of the steel sheet can be measured in a non-contact state without cutting out a part of the steel sheet as a sample for measuring the coercive force, thereby inspecting the mechanical properties of the steel sheet. Another object of the present invention is to provide a method and apparatus for measuring the coercive force of a steel sheet, which can measure the coercive force of a steel sheet during traveling on a production line in an online state.
【0005】[0005]
【課題を解決するための手段】上記の目的を達成するた
めに、この発明による鋼板の保磁力測定方法は、U字型
コアの両脚部それぞれに施され、磁束が、交互に、一方
のコア脚部先端面から出て被測定鋼板中を通って他方の
コア脚部先端面へ入るように直列に接続された励磁コイ
ルと、コア中央部に施された検出コイルとを有する鋼板
励磁装置を、そのU字型コアの両脚部先端面と被測定鋼
板との間に隙間を持たせて配置し、前記鋼板励磁装置の
励磁コイルに交流の励磁電流を流して被測定鋼板を磁化
し、前記鋼板励磁装置の検出コイルに発生する誘起電圧
が磁化半サイクル毎に尖頭値をとった時点を検出するこ
とにより、検出コイルに発生する誘起電圧が先の磁化半
サイクルにおいて尖頭値をとった時点の励磁電流値と検
出コイルに発生する誘起電圧が次の磁化半サイクルにお
いて尖頭値をとった時点の励磁電流値とを検出してこれ
ら励磁電流値の絶対値の平均値を求め、この被測定鋼板
の保磁力に対応する励磁電流値に基づいて被測定鋼板の
保磁力を求めることを特徴とする。In order to achieve the above object, the method of measuring the coercive force of a steel sheet according to the present invention is applied to both legs of a U-shaped core so that magnetic flux is alternately applied to one core. A steel plate excitation device having an exciting coil connected in series so as to come out of the tip end surface of the leg and pass through the steel sheet to be measured to enter the other tip end surface of the core, and a detection coil provided at the center of the core. , The U-shaped core is provided with a gap between the tip surfaces of both leg portions and the steel plate to be measured, and an alternating exciting current is passed through an exciting coil of the steel plate exciting device to magnetize the steel plate to be measured, By detecting the time when the induced voltage generated in the detection coil of the steel plate exciter reached the peak value every magnetization half cycle, the induced voltage generated in the detection coil took the peak value in the previous magnetization half cycle. Exciting current value at the time and generated in the detection coil The exciting current value at the time when the induced voltage takes the peak value in the next magnetization half cycle is detected and the average value of the absolute values of these exciting current values is found, and the exciting current corresponding to the coercive force of this steel sheet to be measured. The coercive force of the steel sheet to be measured is obtained based on the value.
【0006】また、この発明による鋼板の保磁力測定装
置は、a:被測定鋼板との間に隙間を持たせて配置され
るU字型コアを有し、このU字型コアの両脚部それぞれ
に施され、磁束が、交互に、一方のコア脚部先端面から
出て被測定鋼板中を通って他方のコア脚部先端面へ入る
ように直列に接続された励磁コイルを有するとともに、
コア中央部に検出コイルを施してなる鋼板励磁装置と、
b:前記鋼板励磁装置の励磁コイルに交流の励磁電流を
供給する交流定電圧電源と、c:前記交流定電圧電源に
より励磁コイルに励磁電流を流して被測定鋼板を磁化し
た際に、前記鋼板励磁装置の検出コイルに発生する誘起
電圧が磁化半サイクル毎に尖頭値をとった時点を検出す
るピークタイミング検出手段と、d:前記ピークタイミ
ング検出手段からの検出信号に基づいて、検出コイルに
発生する誘起電圧が先の磁化半サイクルにおいて尖頭値
をとった時点の励磁電流値と検出コイルに発生する誘起
電圧が次の磁化半サイクルにおいて尖頭値をとった時点
の励磁電流値とを検出する保磁力対応励磁電流検出手段
と、e:前記保磁力対応励磁電流検出手段によって検出
された前記両励磁電流値の絶対値の平均値を求め、この
被測定鋼板の保磁力に対応する励磁電流値に基づいて被
測定鋼板の保磁力を求める演算手段と、を備えたことを
特徴とする。Further, the apparatus for measuring coercive force of steel sheet according to the present invention has a: U-shaped core arranged with a gap between the steel sheet to be measured and each leg portion of the U-shaped core. The magnetic flux is alternately applied to the core leg portion, and the magnetic flux has alternating excitation coils that are connected in series so as to pass through the steel plate to be measured and enter the tip end surface of the other core leg portion.
A steel plate excitation device having a detection coil in the center of the core,
b: an AC constant voltage power supply for supplying an AC exciting current to the exciting coil of the steel plate exciting device; and c: the steel plate when the measured steel plate is magnetized by passing an exciting current through the exciting coil by the AC constant voltage power supply. Peak timing detection means for detecting the time when the induced voltage generated in the detection coil of the exciter takes a peak value for each half-cycle of magnetization, and d: a detection coil based on the detection signal from the peak timing detection means. The exciting current value when the induced voltage generated had a peak value in the previous magnetization half cycle and the exciting current value when the induced voltage generated in the detection coil had a peak value in the next magnetization half cycle The coercive force-corresponding exciting current detecting means for detecting, e: An average value of absolute values of the two exciting current values detected by the coercive force-corresponding exciting current detecting means is obtained, and the coercive force of the steel sheet to be measured is obtained. Characterized by comprising calculating means for determining the coercive force of the measured steel sheet, a based on the excitation current value corresponding to.
【0007】[0007]
【作用】この発明による鋼板の保磁力測定方法及びその
装置においては、鋼板励磁装置がそのU字型コアの両脚
部先端面と被測定鋼板との間に隙間を持たせて配置され
る。この鋼板励磁装置の励磁コイルに交流の励磁電流を
流して被測定鋼板を磁化すると、鋼板励磁装置の検出コ
イルには、磁化半サイクル毎にその極性が変化し磁束密
度の時間的変化を示すパルス状の誘起電圧が発生する。
この検出コイルに発生する誘起電圧が磁化半サイクル毎
に尖頭値をとった時点が検出される。これにより、検出
コイルに発生する誘起電圧が先の磁化半サイクルにおい
て尖頭値をとった時点の励磁電流値、すなわち、一方の
方向における磁界の強さを変化させて磁束密度をゼロに
する時点の磁界の強さに対応する励磁電流値と、検出コ
イルに発生する誘起電圧が次の磁化半サイクルにおいて
尖頭値をとった時点の励磁電流値、すなわち、他方の方
向における磁界の強さを変化させて磁束密度をゼロにす
るときの磁界の強さに対応する励磁電流値とが検出され
る。そして、これら励磁電流値の絶対値の平均値が求め
られ、この被測定鋼板の保磁力に対応する励磁電流値に
基づいて被測定鋼板の保磁力が求められる。In the method and apparatus for measuring the coercive force of a steel sheet according to the present invention, the steel sheet exciting device is arranged with a gap between the tip surfaces of both legs of the U-shaped core and the steel sheet to be measured. When an alternating exciting current is passed through the exciting coil of this steel plate exciting device to magnetize the steel plate to be measured, the detection coil of the steel plate exciting device changes its polarity every half-cycle of magnetization and produces a pulse indicating a temporal change in magnetic flux density. Induced voltage is generated.
The point in time when the induced voltage generated in the detection coil takes a peak value every magnetization half cycle is detected. As a result, the exciting current value at the time when the induced voltage generated in the detection coil takes the peak value in the previous magnetization half cycle, that is, when the magnetic field strength in one direction is changed to zero the magnetic flux density The exciting current value corresponding to the strength of the magnetic field and the exciting current value at the time when the induced voltage generated in the detection coil takes the peak value in the next magnetization half cycle, that is, the strength of the magnetic field in the other direction, An exciting current value corresponding to the strength of the magnetic field when the magnetic flux density is changed to zero is detected. Then, the average value of the absolute values of these exciting current values is obtained, and the coercive force of the steel sheet to be measured is obtained based on the exciting current value corresponding to the coercive force of the steel sheet to be measured.
【0008】[0008]
【実施例】以下、実施例に基づいてこの発明を説明す
る。図1はこの発明による保磁力測定方法を実施するた
めの保磁力測定装置の構成の一例を示すブロック図であ
る。図2は図1に示す保磁力測定装置の動作を説明する
ためのタイミングチャートである。EXAMPLES The present invention will be described below based on examples. FIG. 1 is a block diagram showing an example of the configuration of a coercive force measuring device for carrying out the coercive force measuring method according to the present invention. FIG. 2 is a timing chart for explaining the operation of the coercive force measuring device shown in FIG.
【0009】図1において、1は鋼板励磁装置である。
この鋼板励磁装置1は、U字型コア2の両脚部それぞれ
に巻線を巻き付けて励磁コイル3a,3bを施すとともに、
コア中央部に巻線を巻き付けて検出コイル4を施してな
るものであって、被測定鋼板Sの上にそのU字型コア2
の両脚部先端面が被測定鋼板Sに対して隙間を持つよう
にして配置される。励磁コイル3a,3bは、後述する交流
定電圧電源5により交流の励磁電流が流された際に、磁
束が、交互に、一方のコア脚部先端面から出て被測定鋼
板S中を通って他方のコア脚部先端面へ入るように直列
に接続されており、それぞれの巻数は、例えば30ターン
である。また、この実施例では検出コイル4の一方の端
子は接地電位(基準電位)とされており、検出コイル4
に発生する誘起電圧(接地電位を基準としたときのコイ
ル両端子間電圧)としては、磁化半サイクル毎にその極
性が交互に変化する正負のパルス状の電圧が発生する。
なお、検出コイル4の巻数は、例えば100 ターンであ
る。In FIG. 1, 1 is a steel plate excitation device.
In this steel plate excitation device 1, windings are wound around both legs of the U-shaped core 2 to apply excitation coils 3a and 3b, and
A detection coil 4 is provided by winding a winding around the center of the core, and the U-shaped core 2 is provided on the steel plate S to be measured.
The front end surfaces of both legs are arranged so as to have a gap with respect to the steel plate S to be measured. When an AC exciting current is applied by an AC constant voltage power source 5 described later, magnetic fluxes of the exciting coils 3a and 3b alternately come out from one tip end surface of the core leg and pass through the steel sheet S to be measured. They are connected in series so as to enter the tip end surface of the other core leg, and the number of turns of each is, for example, 30 turns. In addition, in this embodiment, one terminal of the detection coil 4 is set to the ground potential (reference potential).
As the induced voltage (voltage between both terminals of the coil with reference to the ground potential), a positive and negative pulsed voltage whose polarity alternates every half magnetization cycle is generated.
The number of turns of the detection coil 4 is, for example, 100 turns.
【0010】交流定電圧電源5は、例えば0.1 オームの
抵抗値を有するシャント抵抗を用いた励磁電流検出器6
を介して、直列接続された励磁コイル3a,3bに交流の励
磁電流を供給する電源である。この交流定電圧電源5と
しては、例えば1V,50Hzのものが使用される。励磁
電流検出器6は、励磁コイル3a,3bに流れる交流の励磁
電流を検出し、これに相当する電圧信号を出力する。The AC constant voltage power source 5 is, for example, an exciting current detector 6 using a shunt resistor having a resistance value of 0.1 ohm.
Is a power supply for supplying an alternating exciting current to the exciting coils 3a and 3b connected in series via the. As this AC constant voltage power source 5, for example, one of 1V, 50 Hz is used. The exciting current detector 6 detects an alternating exciting current flowing through the exciting coils 3a and 3b, and outputs a voltage signal corresponding to this.
【0011】7はゲート回路であり、このゲート回路7
は、基準電位であるゼロボルト点に対して設定された正
の微小閾値を検出コイル4に発生する誘起電圧が正の極
性において超えている期間と、ゼロボルト点に対して設
定された負の微小閾値を検出コイル4に発生する誘起電
圧が負の極性において超えている期間とでハイレベル出
力となり、それ以外の期間ではローレベル出力となるも
のである。8は、コイル4に発生する誘起電圧、すなわ
ち検出コイル4の出力を微分する微分器であり、9はゼ
ロ点検出器である。Reference numeral 7 denotes a gate circuit. This gate circuit 7
Is the period during which the induced voltage generated in the detection coil 4 exceeds the positive minute threshold value set for the zero volt point, which is the reference potential, in the positive polarity, and the negative minute threshold value set for the zero volt point. Is a high level output during a period in which the induced voltage generated in the detection coil 4 exceeds the negative polarity, and is a low level output during other periods. Reference numeral 8 is a differentiator that differentiates the induced voltage generated in the coil 4, that is, the output of the detection coil 4, and 9 is a zero-point detector.
【0012】ゼロ点検出器9は、ゲート回路7及び微分
器8の出力が入力され、ゲート回路7の出力がハイレベ
ルの期間において微分器8の出力がゼロボルト点を横切
る時点、つまり、検出コイル4の出力(検出コイル4に
発生する誘起電圧)が正の尖頭値をとった時点と負の尖
頭値をとった時点とをそれぞれ検出し、その時にパルス
信号を出力するものである。ゼロ点検出器9は、検出コ
イル4の出力が正の尖頭値をとったことを検出したと
き、第1サンプルホールド回路10aに第1サンプルホー
ルド指令信号S1を与え、検出コイル4の出力が負の尖頭
値をとったことを検出したとき、第2サンプルホールド
回路10bに第2サンプルホールド指令信号S2を与えるよ
うになっている。この実施例では、ゲート回路7と微分
器8及びゼロ点検出器9は、ピークタイミング検出手段
に相当するものである。The zero point detector 9 receives the outputs of the gate circuit 7 and the differentiator 8, and when the output of the differentiator 8 crosses the zero volt point while the output of the gate circuit 7 is at a high level, that is, the detection coil. The output of 4 (the induced voltage generated in the detection coil 4) takes a positive peak value and a negative peak value, respectively, and a pulse signal is output at that time. When the zero point detector 9 detects that the output of the detection coil 4 has a positive peak value, it gives the first sample hold command signal S1 to the first sample hold circuit 10a, and the output of the detection coil 4 changes. When it is detected that a negative peak value is taken, the second sample hold command signal S2 is given to the second sample hold circuit 10b. In this embodiment, the gate circuit 7, the differentiator 8 and the zero point detector 9 correspond to the peak timing detecting means.
【0013】第1サンプルホールド回路10aは、上記第
1サンプルホールド指令信号S1が与えられたときの励磁
電流検出器6の出力をサンプリングして保持し、この検
出した信号、すなわち、検出コイル4の出力が正の尖頭
値をとった時点における励磁コイル3a,3bの励磁電流値
に相当する信号(IH )を演算回路11に出力するもので
ある。また、第2サンプルホールド回路10bは、上記第
2サンプルホールド指令信号S2が与えられたときの励磁
電流検出器6の出力をサンプリングして保持し、この検
出した信号、すなわち、検出コイル4の出力が負の極大
値をとった時点における励磁コイル3a,3bの励磁電流値
に相当する信号(−IH )を演算回路11に出力するもの
である。この実施例では、励磁電流検出器6及びサンプ
ルホールド回路10a,10bは、保磁力対応励磁電流検出
手段に相当するものである。The first sample and hold circuit 10a samples and holds the output of the exciting current detector 6 when the first sample and hold command signal S1 is given, and holds the detected signal, that is, the detection coil 4 A signal (I H ) corresponding to the exciting current value of the exciting coils 3a and 3b at the time when the output takes a positive peak value is output to the arithmetic circuit 11. The second sample hold circuit 10b samples and holds the output of the exciting current detector 6 when the second sample hold command signal S2 is given, and holds the detected signal, that is, the output of the detection coil 4. There is for outputting excitation coil 3a at the time of taking the negative maximum value, a signal corresponding to the excitation current value of 3b and (-I H) to the arithmetic circuit 11. In this embodiment, the exciting current detector 6 and the sample hold circuits 10a and 10b correspond to the exciting current detecting means corresponding to the coercive force.
【0014】上記の演算手段としての演算回路11は、こ
の実施例では磁化1サイクル毎に、第1サンプルホール
ド回路10aの出力(IH )と第2サンプルホールド回路
10bの出力(−IH )とを用いて、〔(IH )−(−I
H )〕/2の演算を行って被測定鋼板Sの保磁力に対応
する励磁電流値を求め、この保磁力に対応する励磁電流
値に基づいて、予め求めておいた励磁電流と磁界の強さ
との関係から、被測定鋼板Sの保磁力HC を求めるもの
である。なお、この演算回路11からは被測定鋼板Sの保
磁力HC を示す信号が磁化サイクル毎に順次出力される
ようになっている。In the present embodiment, the arithmetic circuit 11 serving as the above-mentioned arithmetic means includes the output (I H ) of the first sample-hold circuit 10a and the second sample-hold circuit every magnetization cycle.
Using the output (-I H ) of 10b, [(I H )-(-I
H )] / 2 is calculated to obtain the exciting current value corresponding to the coercive force of the steel sheet S to be measured, and based on the exciting current value corresponding to this coercive force, the previously determined exciting current and magnetic field strength are calculated. The coercive force H C of the steel plate to be measured S is obtained from the relationship with A signal indicating the coercive force H C of the steel plate S to be measured is sequentially output from the arithmetic circuit 11 every magnetization cycle.
【0015】次に上記保磁力測定装置を用いて行うこの
発明による鋼板の保磁力測定方法を、図1及び図2を参
照しながら、上記装置の動作とともに説明する。被測定
鋼板Sの上に、鋼板励磁装置1をそのU字型コア2の両
脚部先端面と被測定鋼板Sとの間に隙間を持たせて配置
する。交流定電圧電源5により鋼板励磁装置1の励磁コ
イル3a,3bに図2の(e)に示すように交流の励磁電流
を流し、被測定鋼板Sをその中に磁束を通して磁化する
と、鋼板励磁装置1の検出コイル4には、図2の(b)
に示すように、磁化半サイクル毎にその極性が交互に変
化する正負のパルス状の誘起電圧が発生する。この誘起
電圧は、磁束密度(図2の(a)参照)の時間的変化を
示すものである。Next, the method of measuring the coercive force of the steel sheet according to the present invention, which is carried out by using the above-mentioned coercive force measuring device, will be described with reference to FIGS. The steel plate excitation device 1 is arranged on the steel plate to be measured S with a gap between the tip surfaces of both legs of the U-shaped core 2 and the steel plate to be measured S. When an alternating exciting current is applied to the exciting coils 3a and 3b of the steel plate exciting device 1 by the AC constant voltage power source 5 as shown in FIG. 2 (e), and the steel plate to be measured S is magnetized by passing a magnetic flux through it. The detection coil 4 of FIG.
As shown in, a positive and negative pulsed induced voltage whose polarity alternates every half magnetization cycle is generated. This induced voltage shows a temporal change in the magnetic flux density (see FIG. 2A).
【0016】この検出コイル4の出力(検出コイル4に
発生する誘起電圧)がゲート回路7及び微分器8に与え
られ、ゲート回路7からは、図2の(c)に示すよう
に、基準電位であるゼロボルト点に対して設定された正
の微小閾値を検出コイル4の出力が正の極性において超
えている期間と、負の微小閾値を検出コイル4の出力が
負の極性において超えている期間とでハイレベルとなる
出力がゼロ点検出器9に入力される。また、同時に、微
分器8からは、図2の(d)に示す波形の信号がゼロ点
検出器9に入力される。The output of the detection coil 4 (the induced voltage generated in the detection coil 4) is given to the gate circuit 7 and the differentiator 8, and the gate circuit 7 outputs the reference potential as shown in FIG. A period in which the output of the detection coil 4 exceeds the positive minute threshold value set for the zero volt point in the positive polarity and a period in which the output of the detection coil 4 exceeds the negative minute threshold value in the negative polarity. The output which becomes high level by and is input to the zero point detector 9. At the same time, the signal having the waveform shown in FIG. 2D is input from the differentiator 8 to the zero-point detector 9.
【0017】ゼロ点検出器9は、ゲート回路7の出力が
ハイレベルの期間において微分器8の出力がゼロボルト
点を横切る時点、つまり、検出コイル4の出力が正の尖
頭値をとった時点と負の尖頭値をとった時点とをそれぞ
れ検出し、検出コイル4の出力が正の尖頭値をとったこ
とを検出することにより、第1サンプルホールド回路10
aに第1サンプルホールド指令信号S1を与える。一方、
検出コイル4の出力が負の尖頭値をとったことを検出す
ることにより、第2サンプルホールド回路10bに第2サ
ンプルホールド指令信号S2を与える。The zero point detector 9 detects the time when the output of the differentiator 8 crosses the zero volt point while the output of the gate circuit 7 is at a high level, that is, the time when the output of the detection coil 4 has a positive peak value. And the time when the negative peak value is obtained, and by detecting that the output of the detection coil 4 has the positive peak value, the first sample hold circuit 10
The first sample hold command signal S1 is given to a. on the other hand,
By detecting that the output of the detection coil 4 has a negative peak value, the second sample hold command signal S2 is given to the second sample hold circuit 10b.
【0018】第1サンプルホールド回路10aは、上記指
令信号S1が与えられたときの励磁電流検出器6の出力を
サンプリングして保持し、この検出した信号、すなわ
ち、検出コイル4の出力が正の尖頭値をとった時点にお
ける励磁コイル3a,3bの励磁電流値に相当する信号(I
H )を演算回路11に出力する。また、第2サンプルホー
ルド回路10bは、上記指令信号S2が与えられたときの励
磁電流検出器6の出力をサンプリングして保持し、この
検出した信号、すなわち、検出コイル4の出力が負の尖
頭値をとった時点における励磁コイル3a,3bの励磁電流
値に相当する信号(−IH )を演算回路11に出力する。The first sample and hold circuit 10a samples and holds the output of the exciting current detector 6 when the command signal S1 is given, and the detected signal, that is, the output of the detecting coil 4 is positive. A signal corresponding to the exciting current value of the exciting coils 3a and 3b at the time when the peak value is obtained (I
H ) is output to the arithmetic circuit 11. The second sample and hold circuit 10b samples and holds the output of the exciting current detector 6 when the command signal S2 is given, and the detected signal, that is, the output of the detecting coil 4 has a negative peak. outputs exciting coil 3a at the time of taking the head value, a signal corresponding to the excitation current value of 3b and (-I H) to the arithmetic circuit 11.
【0019】演算回路11に第1サンプルホールド回路10
aの出力(IH )と第2サンプルホールド回路10bの出
力(−IH )とが入力されると、演算回路11は、これら
を用いて〔(IH )−(−IH )〕/2の演算を行って
被測定鋼板Sの保磁力に対応する励磁電流値を求め、こ
の保磁力に対応する励磁電流値に基づいて、予め求めて
おいた励磁電流と磁界の強さとの関係から、被測定鋼板
Sの保磁力HC を求め、得られた被測定鋼板Sの保磁力
HC を示す信号を出力する。The arithmetic circuit 11 includes a first sample hold circuit 10
When a output (I H) and the output of the second sample-and-hold circuit 10b (-I H) and is inputted, the arithmetic circuit 11 uses these [(I H) - (- I H) ] / 2 is calculated to obtain the exciting current value corresponding to the coercive force of the steel sheet S to be measured, and based on the exciting current value corresponding to this coercive force, from the previously obtained relation between the exciting current and the magnetic field strength. , determine the coercive force H C of the measured steel sheet S, and outputs a signal indicating the coercive force H C of the measured steel sheet S obtained.
【0020】上記のような動作が磁化サイクル毎に順次
繰り返し行われる。このようにして、保磁力測定のため
に鋼板からその一部を試料として切り出すことなく鋼板
の保磁力を非接触状態で測定できる。これにより、生産
ラインにおける走行中の鋼板の保磁力をオンライン状態
で測定できるので、鋼板の保磁力と鋼板の結晶粒径との
関係を用いて走行中の鋼板の機械的性質の検査をオンラ
イン状態で鋼板の全長にわたって行うことが可能であ
る。The above-described operation is sequentially repeated for each magnetization cycle. In this way, the coercive force of the steel sheet can be measured in a non-contact state without cutting out a part of the steel sheet as a sample for coercive force measurement. As a result, the coercive force of a running steel plate in a production line can be measured online, so the mechanical properties of a running steel plate can be inspected online using the relationship between the coercive force of the steel plate and the grain size of the steel plate. Can be performed over the entire length of the steel sheet.
【0021】なお、上記実施例では、検出コイル4の一
方の端子を接地電位(基準電位)とし、これを基準とし
て検出コイル4に発生する誘起電圧をゲート回路7と微
分器8及びゼロ点検出器9によって構成されるピークタ
イミング検出手段に入力する例について示したが、検出
コイル4に発生する誘起電圧を絶対値回路(絶対値全波
整流回路)に入力し、この絶対値回路の出力をゲート回
路と微分器に入力するようにしてもよい。この場合に
は、検出コイル4に発生する誘起電圧は絶対値回路から
正の極性でもって出力されることになるから、ゲート回
路は正の微小閾値のみを設定するようにしたものでよ
い。In the above embodiment, one terminal of the detection coil 4 is set to the ground potential (reference potential), and the induced voltage generated in the detection coil 4 with this as a reference is detected by the gate circuit 7, the differentiator 8 and the zero point. Although the example of inputting to the peak timing detecting means constituted by the device 9 has been shown, the induced voltage generated in the detecting coil 4 is input to the absolute value circuit (absolute value full wave rectification circuit) and the output of this absolute value circuit is You may make it input into a gate circuit and a differentiator. In this case, since the induced voltage generated in the detection coil 4 is output with a positive polarity from the absolute value circuit, the gate circuit may be configured to set only a positive minute threshold value.
【0022】また、上記実施例では、磁化1サイクル毎
に、先の磁化半サイクルにおける第1サンプルホールド
回路10aの出力(IH )と次の磁化半サイクルにおける
第2サンプルホールド回路10bの出力(−IH )とを用
いて、〔(IH )−(−IH)〕/2の演算を行って被
測定鋼板Sの保磁力に対応する励磁電流値を求め、この
保磁力に対応する励磁電流値に基づいて被測定鋼板Sの
保磁力HC を求めるようにした例について示したが、誤
差を小さくするなどのために、当然のことながら、保磁
力に対応する励磁電流値を磁化の数サイクル分(励磁電
流の数周期分)についての平均値として求めるようにし
てもよい。In the above embodiment, the output (I H ) of the first sample and hold circuit 10a in the previous magnetization half cycle and the output (I H ) of the second sample and hold circuit 10b in the next magnetization half cycle are set for each magnetization cycle. -I H ) is used to calculate [(I H )-(-I H )] / 2 to obtain an exciting current value corresponding to the coercive force of the steel sheet S to be measured, which corresponds to this coercive force. Although the example in which the coercive force H C of the steel sheet to be measured S is obtained based on the exciting current value has been shown, the exciting current value corresponding to the coercive force is naturally magnetized in order to reduce the error. May be calculated as an average value for several cycles (for several cycles of the exciting current).
【0023】[0023]
【発明の効果】以上述べたように、この発明による鋼板
の保磁力測定方法及びその装置は、U字型コアの両脚部
それぞれに施され、磁束が、交互に、一方のコア脚部先
端面から出て被測定鋼板中を通って他方のコア脚部先端
面へ入るように直列に接続された励磁コイルと、コア中
央部に施された検出コイルとを有する鋼板励磁装置を、
そのU字型コアの両脚部先端面と被測定鋼板との間に隙
間を持たせて配置し、励磁コイルに交流の励磁電流を流
して被測定鋼板を磁化し、検出コイルに発生する誘起電
圧が磁化半サイクル毎に尖頭値をとった時点を検出する
ことにより、検出コイルに発生する誘起電圧が先の磁化
半サイクルにおいて尖頭値をとった時点の励磁電流値、
すなわち、一方の方向における磁界の強さを変化させて
磁束密度をゼロにする時点の磁界の強さに対応する励磁
電流値と、検出コイルに発生する誘起電圧が次の磁化半
サイクルにおいて尖頭値をとった時点の励磁電流値、す
なわち、他方の方向における磁界の強さを変化させて磁
束密度をゼロにするときの磁界の強さに対応する励磁電
流値とを検出し、これら励磁電流値の絶対値の平均値を
求め、この被測定鋼板の保磁力に対応する励磁電流値に
基づいて被測定鋼板の保磁力を求めるようにしたもので
ある。したがって、保磁力測定のために鋼板からその一
部を試料として切り出すことなく鋼板の保磁力を非接触
状態で測定できる。これにより、生産ラインにおける走
行中の鋼板の保磁力をオンライン状態で測定できるの
で、鋼板の保磁力と鋼板の結晶粒径との関係を用いて走
行中の鋼板の機械的性質の検査をオンライン状態で鋼板
の全長にわたって行うことが可能である。As described above, the method and apparatus for measuring the coercive force of the steel sheet according to the present invention are applied to both legs of the U-shaped core, and the magnetic flux is alternately applied to the tip end surface of one core leg. A steel plate exciting device having an exciting coil connected in series so as to enter the other end of the core leg through the steel plate to be measured, and a detecting coil provided in the central part of the core,
The U-shaped core is arranged with a gap between the tip surfaces of both legs and the steel plate to be measured, and an alternating exciting current is applied to the exciting coil to magnetize the steel plate to be measured, and an induced voltage generated in the detection coil. By detecting the time when the peak value is taken every magnetization half cycle, the induced voltage value at the time when the induced voltage generated in the detection coil takes the peak value in the previous magnetization half cycle,
That is, the exciting current value corresponding to the magnetic field strength at the time when the magnetic field strength in one direction is changed to zero the magnetic flux density, and the induced voltage generated in the detection coil are peaked in the next magnetization half cycle. The exciting current value at the time when the value is taken, that is, the exciting current value corresponding to the magnetic field strength when changing the magnetic field strength in the other direction to make the magnetic flux density zero, is detected. The mean value of the absolute values is calculated, and the coercive force of the measured steel plate is calculated based on the exciting current value corresponding to the coercive force of the measured steel plate. Therefore, the coercive force of the steel sheet can be measured in a non-contact state without cutting out a part of the steel sheet as a sample for measuring the coercive force. As a result, the coercive force of a running steel plate in a production line can be measured online, so the mechanical properties of a running steel plate can be inspected online using the relationship between the coercive force of the steel plate and the grain size of the steel plate. Can be performed over the entire length of the steel sheet.
【図1】この発明による保磁力測定方法を実施するため
の保磁力測定装置の構成の一例を示すブロック図であ
る。FIG. 1 is a block diagram showing an example of the configuration of a coercive force measuring device for carrying out a coercive force measuring method according to the present invention.
【図2】図1に示す保磁力測定装置の動作を説明するた
めのタイミングチャートである。FIG. 2 is a timing chart for explaining the operation of the coercive force measuring device shown in FIG.
【図3】B-H曲線(ヒステリシス曲線)を示す図であ
る。FIG. 3 is a diagram showing a BH curve (hysteresis curve).
1…鋼板励磁装置 2…U字型コア 3a,3b…励磁コイ
ル 4…検出コイル 5…交流定電圧電源 6…励磁電流検出器 7…ゲート
回路 8…微分器 9…ゼロ点検出器 10a,10b…サ
ンプルホールド回路 11…演算回路 S…被測定鋼板1 ... Steel plate excitation device 2 ... U-shaped core 3a, 3b ... Excitation coil 4 ... Detection coil 5 ... AC constant voltage power source 6 ... Excitation current detector 7 ... Gate circuit 8 ... Differentiator 9 ... Zero point detector 10a, 10b … Sample-hold circuit 11… Arithmetic circuit S… Steel to be measured
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小川 岳夫 神戸市西区美賀多台1−4−1 (72)発明者 赤松 勝 神戸市西区美賀多台1−4−1 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeo Ogawa 1-4-1 Migatadai, Nishi-ku, Kobe (72) Inventor Masaru Akamatsu 1-4-1 Mikatadai, Nishi-ku, Kobe
Claims (2)
磁束が、交互に、一方のコア脚部先端面から出て被測定
鋼板中を通って他方のコア脚部先端面へ入るように直列
に接続された励磁コイルと、コア中央部に施された検出
コイルとを有する鋼板励磁装置を、そのU字型コアの両
脚部先端面と被測定鋼板との間に隙間を持たせて配置
し、前記鋼板励磁装置の励磁コイルに交流の励磁電流を
流して被測定鋼板を磁化し、前記鋼板励磁装置の検出コ
イルに発生する誘起電圧が磁化半サイクル毎に尖頭値を
とった時点を検出することにより、検出コイルに発生す
る誘起電圧が先の磁化半サイクルにおいて尖頭値をとっ
た時点の励磁電流値と検出コイルに発生する誘起電圧が
次の磁化半サイクルにおいて尖頭値をとった時点の励磁
電流値とを検出してこれら励磁電流値の絶対値の平均値
を求め、この被測定鋼板の保磁力に対応する励磁電流値
に基づいて被測定鋼板の保磁力を求めることを特徴とす
る鋼板の保磁力測定方法。1. The U-shaped core is applied to both legs,
Magnetic flux was applied to the core part and the exciting coil connected in series so as to alternately flow out from one core leg tip surface, pass through the steel plate to be measured, and enter the other core leg tip surface. A steel plate excitation device having a detection coil is arranged with a gap between the tip surfaces of both leg portions of the U-shaped core and the steel plate to be measured, and an alternating excitation current is applied to the excitation coil of the steel plate excitation device. By magnetizing the steel sheet to be measured, and detecting the time when the induced voltage generated in the detection coil of the steel plate excitation device reaches the peak value every magnetization half cycle, the induced voltage generated in the detection coil is The exciting current value at the time when the peak value is obtained in the half cycle and the exciting current value at the time when the induced voltage generated in the detection coil takes the peak value in the next magnetization half cycle are detected and these exciting current values are Obtain the average of absolute values and measure Coercivity measurement method of the steel sheet, characterized in that to determine the coercive force of the measured steel sheet on the basis of the excitation current value corresponding to the coercive force of the plate.
配置されるU字型コアを有し、このU字型コアの両脚部
それぞれに施され、磁束が、交互に、一方のコア脚部先
端面から出て被測定鋼板中を通って他方のコア脚部先端
面へ入るように直列に接続された励磁コイルを有すると
ともに、コア中央部に検出コイルを施してなる鋼板励磁
装置と、 b:前記鋼板励磁装置の励磁コイルに交流の励磁電流を
供給する交流定電圧電源と、 c:前記交流定電圧電源により励磁コイルに励磁電流を
流して被測定鋼板を磁化した際に、前記鋼板励磁装置の
検出コイルに発生する誘起電圧が磁化半サイクル毎に尖
頭値をとった時点を検出するピークタイミング検出手段
と、 d:前記ピークタイミング検出手段からの検出信号に基
づいて、検出コイルに発生する誘起電圧が先の磁化半サ
イクルにおいて尖頭値をとった時点の励磁電流値と検出
コイルに発生する誘起電圧が次の磁化半サイクルにおい
て尖頭値をとった時点の励磁電流値とを検出する保磁力
対応励磁電流検出手段と、 e:前記保磁力対応励磁電流検出手段によって検出され
た前記両励磁電流値の絶対値の平均値を求め、この被測
定鋼板の保磁力に対応する励磁電流値に基づいて被測定
鋼板の保磁力を求める演算手段と、を備えたことを特徴
とする鋼板の保磁力測定装置。2. A: A U-shaped core which is arranged with a gap between it and a steel plate to be measured. The U-shaped core is applied to both legs of the U-shaped core. Exciting steel plate that has an exciting coil connected in series so that it exits from the tip surface of the core leg, passes through the steel plate to be measured, and enters the tip surface of the other core leg, and a detection coil is applied to the center of the core. A device, b: an AC constant voltage power supply for supplying an AC excitation current to the excitation coil of the steel plate excitation device, and c: an excitation current is supplied to the excitation coil by the AC constant voltage power supply to magnetize the steel plate to be measured. A peak timing detection means for detecting a time point when an induced voltage generated in a detection coil of the steel plate excitation device takes a peak value for each magnetization half cycle; and d: based on a detection signal from the peak timing detection means, Occurs in the detection coil Detects the exciting current value when the induced voltage takes the peak value in the previous magnetization half cycle and the exciting current value when the induced voltage generated in the detection coil takes the peak value in the next magnetization half cycle Coercive force corresponding exciting current detecting means, e: An average value of absolute values of both exciting current values detected by the coercive force corresponding exciting current detecting means is obtained, and the exciting current value corresponding to the coercive force of the steel sheet to be measured. An apparatus for calculating a coercive force of a steel plate to be measured based on the above, and a coercive force measuring device for a steel plate.
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JP1327192A JPH05264704A (en) | 1992-01-28 | 1992-01-28 | Method and apparatus for measuring coercive force of steel plate |
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JP1327192A JPH05264704A (en) | 1992-01-28 | 1992-01-28 | Method and apparatus for measuring coercive force of steel plate |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103069294A (en) * | 2010-08-11 | 2013-04-24 | 丰田自动车株式会社 | Coercivity performance determination device for coercivity distribution magnet |
RU2483301C1 (en) * | 2011-11-22 | 2013-05-27 | Учреждение Российской академии наук Ордена Трудового Красного Знамени Институт физики металлов Уральского отделения РАН (ИФМ УрО РАН) | Method for local measurement of coercitive force of ferromagnetic objects |
DE112011105011T5 (en) | 2011-03-07 | 2013-11-28 | Toyota Jidosha Kabushiki Kaisha | Apparatus for specifying a coercive force |
-
1992
- 1992-01-28 JP JP1327192A patent/JPH05264704A/en not_active Withdrawn
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103069294A (en) * | 2010-08-11 | 2013-04-24 | 丰田自动车株式会社 | Coercivity performance determination device for coercivity distribution magnet |
DE112011105011T5 (en) | 2011-03-07 | 2013-11-28 | Toyota Jidosha Kabushiki Kaisha | Apparatus for specifying a coercive force |
US8797023B2 (en) | 2011-03-07 | 2014-08-05 | Toyota Jidosha Kabushiki Kaisha | Coercive force specifying apparatus |
DE112011105011B4 (en) * | 2011-03-07 | 2014-08-28 | Toyota Jidosha Kabushiki Kaisha | Apparatus for specifying a coercive force |
RU2483301C1 (en) * | 2011-11-22 | 2013-05-27 | Учреждение Российской академии наук Ордена Трудового Красного Знамени Институт физики металлов Уральского отделения РАН (ИФМ УрО РАН) | Method for local measurement of coercitive force of ferromagnetic objects |
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