JPH0464788B2 - - Google Patents
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- Publication number
- JPH0464788B2 JPH0464788B2 JP58116370A JP11637083A JPH0464788B2 JP H0464788 B2 JPH0464788 B2 JP H0464788B2 JP 58116370 A JP58116370 A JP 58116370A JP 11637083 A JP11637083 A JP 11637083A JP H0464788 B2 JPH0464788 B2 JP H0464788B2
- Authority
- JP
- Japan
- Prior art keywords
- slab
- circuit
- thickness
- amplifier
- ultrasonic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
- Continuous Casting (AREA)
Description
【発明の詳細な説明】
本発明は、電磁超音波を応用して連続鋳造にお
ける鋳片凝固厚みを測定する装置（以下、シエル
厚計という）に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus (hereinafter referred to as a shell thickness gauge) for measuring the solidified thickness of a slab in continuous casting by applying electromagnetic ultrasonic waves.
従来この種の装置として第１図に示すものがあ
つた。図において１は電磁超音波発生器、２は電
磁超音波受信器、７は鋳片、８はパルス発生回
路、９は励磁電源、１０は増幅器、１１はゲート
回路、１２は透過時間測定回路、１３は表面温度
計、１４は鋳片全厚み測定器、１５は凝固厚み演
算回路、１６は出力回路である。一方、第２図は
このシエル厚計における電磁超音波発生、および
受信の原理を示す図である。この図において３は
電磁超音波発生コイル、４は電磁超音波検出コイ
ル、５は磁界を発生させるための励磁コイル、６
は磁気回路を形成するための磁心である。ここで
検出コイル４の出力２１は増幅器１０に接続され
ている。 A conventional device of this type is shown in FIG. In the figure, 1 is an electromagnetic ultrasonic generator, 2 is an electromagnetic ultrasonic receiver, 7 is a slab, 8 is a pulse generation circuit, 9 is an excitation power source, 10 is an amplifier, 11 is a gate circuit, 12 is a transmission time measurement circuit, 13 is a surface thermometer, 14 is a slab total thickness measuring device, 15 is a solidification thickness calculation circuit, and 16 is an output circuit. On the other hand, FIG. 2 is a diagram showing the principle of electromagnetic ultrasonic wave generation and reception in this shell thickness gauge. In this figure, 3 is an electromagnetic ultrasonic generation coil, 4 is an electromagnetic ultrasonic detection coil, 5 is an excitation coil for generating a magnetic field, and 6
is a magnetic core for forming a magnetic circuit. Here, the output 21 of the detection coil 4 is connected to the amplifier 10.
次に動作について説明する。パルス発生回路８
によつてパルス信号を通電された発生コイル３は
コイルのまわりに矢印１７のようにパルス磁界を
発生し、このパルス磁界はレジノの法則により厚
みＤの鋳片７の表面に起電力を誘起し、うず電流
１８を発生させる。このうず電流１８はさらにフ
レミングの左手の法則により矢印１７のパルス磁
界との相互作用によるパルス電磁力を発生させこ
れが鋳片７の表面に超音波振動を起させる。以上
が電磁超音波発生の原理である。 Next, the operation will be explained. Pulse generation circuit 8
The generating coil 3, which is energized with a pulse signal, generates a pulsed magnetic field around the coil as shown by an arrow 17, and this pulsed magnetic field induces an electromotive force on the surface of the slab 7 having a thickness of D according to Resino's law. , generates an eddy current 18. This eddy current 18 further generates a pulsed electromagnetic force due to interaction with the pulsed magnetic field indicated by the arrow 17 according to Fleming's left-hand rule, which causes ultrasonic vibrations on the surface of the slab 7. The above is the principle of electromagnetic ultrasound generation.
次に鋳片７の表面で発生した電磁超音波は鋳片
７の中を矢印１９の向きに進行し、他面に達する
と鋳片７の表面に振動を発生させる。この振動
と、励磁電源９によつて励磁された励磁コイル５
が作る磁界との相互作用により鋳片７の表面に起
電力が発生する。これはフレミングの右手の法則
によるものである。この起電力は鋳片７の表面に
うず電流２０を発生し、このうず電流の作る磁界
がレンツの法則により、検出コイル４に起電力を
誘起し、この起電力信号が受信信号として増幅器
１０によつて増幅され、ゲート回路１１によつて
時間軸上の必要な部分が取り出され、透過時間測
定回路１３に送られる。このゲート回路１１では
通常パルス発生回路のパルス出力タイミング信号
を基準にして時間ゲートが作成される。 Next, the electromagnetic ultrasonic waves generated on the surface of the slab 7 travel inside the slab 7 in the direction of the arrow 19, and when they reach the other side, generate vibrations on the surface of the slab 7. This vibration and the excitation coil 5 excited by the excitation power source 9
An electromotive force is generated on the surface of the slab 7 due to the interaction with the magnetic field created by the slab. This is due to Fleming's right-hand rule. This electromotive force generates an eddy current 20 on the surface of the slab 7, and the magnetic field created by this eddy current induces an electromotive force in the detection coil 4 according to Lenz's law, and this electromotive force signal is sent to the amplifier 10 as a reception signal. The signal is thus amplified, and a necessary portion on the time axis is extracted by the gate circuit 11 and sent to the transmission time measuring circuit 13. In this gate circuit 11, a time gate is normally created based on the pulse output timing signal of the pulse generating circuit.
次に透過時間測定回路１２ではゲート回路１１
から入力された受信信号とパルス出力タイミング
信号の時間差から超音波が鋳片７の一面からその
裏面の他面にまで伝搬するに要する時間ｔを求
め、その結果が凝固厚み演算回路１５に送られ
る。 Next, in the transmission time measuring circuit 12, the gate circuit 11
The time t required for the ultrasonic wave to propagate from one side of the slab 7 to the other side of the back side is calculated from the time difference between the received signal inputted from the block and the pulse output timing signal, and the result is sent to the solidification thickness calculation circuit 15. .
さて、今、鋳片内に未凝固部が残つていると
し、すでに凝固している部分の厚さをｄ＝d1＋d2
とすれば未凝固部の厚さはＤ−ｄのはずであるか
ら凝固部を超音波が伝搬する速度をVs、未凝固
部を超音波が伝搬する速度をVeとすれば鋳片全
体を超音波が透過する透過時間ｔは
ｔ＝ｄ／Vs＋Ｄ−ｄ／Ve
であらわされる。一般にVsは鋼種によつて決ま
る鋳片の凝固温度と、表面温度計１３によつて測
定された表面温度から平均又は加重平均等によつ
て求めた凝固部の平均温度により超音波伝搬速度
の温度依存特性から算出され、又Veは未凝固部
が過冷却状態にあると考えられることから、この
状態での超音波伝搬速度を実験によつて求められ
た値が使用される。 Now, suppose that there is an unsolidified part left in the slab, and the thickness of the already solidified part is d = d 1 + d 2
Then, the thickness of the unsolidified part should be D-d, so if the speed at which the ultrasonic wave propagates through the solidified part is Vs, and the speed at which the ultrasonic wave propagates through the unsolidified area is Ve, then the thickness of the entire slab should be D-d. The transmission time t for the sound wave to pass through is expressed as t=d/Vs+D−d/Ve. In general, Vs is the temperature of the ultrasonic propagation velocity based on the solidification temperature of the slab, which is determined by the steel type, and the average temperature of the solidified part, which is determined by an average or weighted average from the surface temperature measured by the surface thermometer 13. Ve is calculated from the dependence characteristics, and since the unsolidified portion is considered to be in a supercooled state, the value of the ultrasonic propagation velocity in this state determined by experiment is used.
従つて、凝固厚み演算回路１５の入力として、
前記透過時間ｔ以外に全厚み測定器１４からの厚
み情報Ｄと、表面温度計１３からの表面温度情報
と鋼種によつて決まる鋳片の凝固温度値とを未凝
固部の超音波伝搬速度Veが得られれば前記の関
係式から凝固厚みｄが算出できるわけである。算
出された凝固厚みｄは出力回路１６により表示又
は記録される。 Therefore, as an input to the solidification thickness calculation circuit 15,
In addition to the transmission time t, the thickness information D from the total thickness measuring device 14, the surface temperature information from the surface thermometer 13, and the solidification temperature value of the slab determined by the steel type are used as the ultrasonic propagation velocity Ve of the unsolidified part. If this is obtained, the solidified thickness d can be calculated from the above relational expression. The calculated solidification thickness d is displayed or recorded by the output circuit 16.
しかしながら従来の方法にあつては次のような
問題があつた。すなわち、実際の連続鋳造ライン
での凝固厚み測定においては鋳片７の内部状態お
よび電磁超音波発生器１、電磁超音波受信器２の
各々と鋳片７との間のギヤツプの変化などにより
受信信号が透過時間測定回路１２のダイナミツク
レンジの中に含まれる値にならないことが多い。
これについて第３図を用いて詳述する。ただし、
ここでダイナミツクレンジとは測定可能な振幅の
下限値から上限値までの範囲である。 However, the conventional method has the following problems. In other words, when measuring the solidification thickness on an actual continuous casting line, the reception value depends on the internal condition of the slab 7 and changes in the gap between the electromagnetic ultrasonic generator 1, the electromagnetic ultrasonic receiver 2, and the slab 7. In many cases, the signal does not have a value that is within the dynamic range of the transmission time measuring circuit 12.
This will be explained in detail using FIG. however,
Here, the dynamic range is the range from the lower limit to the upper limit of measurable amplitude.
第３図は、パルス発生回路８で発生した送信パ
ルス電流波形Ｔと受信された電流波形Ｒの増幅器
１０での出力信号を時間軸上で示したものであ
る。 FIG. 3 shows the output signals of the transmitting pulse current waveform T generated by the pulse generating circuit 8 and the received current waveform R at the amplifier 10 on the time axis.
同図において、超音波は送信パルス電流Ｔが発
生すると同時に発生し、電磁超音波受信器２で電
気信号に変換され受信パルス電流Ｒとして検出さ
れる。そして、超音波の鋳片７中の透過時間t0
は、同図の時間軸上で送信パルスの発生する原点
からＡ点までの時間となる。 In the figure, an ultrasonic wave is generated at the same time as a transmission pulse current T is generated, and is converted into an electric signal by an electromagnetic ultrasonic receiver 2 and detected as a reception pulse current R. Then, the transmission time t 0 of the ultrasonic wave in the slab 7
is the time from the origin where the transmission pulse is generated to point A on the time axis in the figure.
詳しく述べると、送信パルス電流波形Ｔは図示
した様な減衰振動波形であり同時に発生する超音
波の振動波形（図示せず）も減衰振動波形になる
が、その様にして発生した超音波は通常鋳片およ
び増幅器を経る間に第３図に示した様な波形にな
る。よつて、送信電流波形の原点に相当するＡ点
が不明になる。そこで実際に透過時間を求めるた
めには次の様な方法を用いる。たとえば、受信電
流波形Ｒにおいて、ピーク値の前後のゼロクロス
点すなわちＢ点とＣ点を検出して周波数を演算し
逆にＡ点を求めるという方法である。 To be more specific, the transmission pulse current waveform T is a damped oscillation waveform as shown in the figure, and the oscillation waveform (not shown) of the ultrasonic waves generated at the same time is also a damped oscillation waveform, but the ultrasonic waves generated in this way are usually While passing through the slab and amplifier, the waveform becomes as shown in Figure 3. Therefore, point A, which corresponds to the origin of the transmission current waveform, becomes unclear. Therefore, the following method is used to actually determine the transmission time. For example, in the received current waveform R, zero crossing points before and after the peak value, that is, points B and C, are detected, the frequency is calculated, and point A is determined conversely.
よつて第３図に示した様な受信信号波形の山の
部分がたとえば透過時間測定回路１２のダイナミ
ツクレンジの上限値を越える場合、正確にピーク
を検出できなくなり、ピーク値の前後のゼロクロ
ス点が不明となるため正確にＡ点を演算すること
ができなくなる。 Therefore, if the peak of the received signal waveform as shown in FIG. 3 exceeds the upper limit of the dynamic range of the transmission time measurement circuit 12, the peak cannot be detected accurately, and the zero cross points before and after the peak value is unknown, making it impossible to accurately calculate point A.
また受信信号がダイナミツクレンジの下限値よ
り小さいとノイズと判別できにくくなるため、ピ
ークの位置が検出しにくくなり、やはりＡ点を正
確に算出できなくなる。 Furthermore, if the received signal is smaller than the lower limit of the dynamic range, it becomes difficult to distinguish it from noise, making it difficult to detect the peak position, and thus making it impossible to accurately calculate point A.
この発明は上記従来の欠点を改善するためにな
されたもので、増幅器のゲインを自動的に制御し
て、増幅器で増幅された受信信号が、透過時間測
定回路のダイナミツクレンジに含まれる値になる
ようにしたことを特徴とする。 This invention was made to improve the above-mentioned conventional drawbacks, and it automatically controls the gain of the amplifier to ensure that the received signal amplified by the amplifier has a value included in the dynamic range of the transmission time measurement circuit. It is characterized by the fact that it is made to be.
第４図は、この発明の実施例を示したものであ
る。１は電磁超音波発生器、２は電磁超音波受信
器、７は鋳片、８はパルス発生回路、９は励磁電
源、１０は増幅器、１１はゲート回路、１２は透
過時間測定回路、１３は表面温度計、１４は鋳片
全厚み測定器、１５は凝固厚み演算回路、１６は
出力回路、２２はピークホールド回路、２３は演
算処理回路、２４はタイミング制御回路である。 FIG. 4 shows an embodiment of the invention. 1 is an electromagnetic ultrasonic generator, 2 is an electromagnetic ultrasonic receiver, 7 is a slab, 8 is a pulse generation circuit, 9 is an excitation power source, 10 is an amplifier, 11 is a gate circuit, 12 is a transmission time measuring circuit, 13 is a 14 is a surface thermometer, 14 is a slab total thickness measuring device, 15 is a solidification thickness calculation circuit, 16 is an output circuit, 22 is a peak hold circuit, 23 is a calculation processing circuit, and 24 is a timing control circuit.
次に第４図に示したこの発明のシエル厚計の動
作例について第５図を併用して以下に説明する。
第５図において、ａおよびｂは電磁超音波受信器
２の出力であつて、各々の振幅の最大値はei,k-1
およびei,kであり、また同図のｃおよびｄは、増
幅器１０で増幅された受信信号であつて、各々の
振幅の最大値はep,k-1およびep,kである。なお、添
字ｋはｋ番目の受信信号の意である。 Next, an example of the operation of the shell thickness gauge of the present invention shown in FIG. 4 will be described below with reference to FIG. 5.
In FIG. 5, a and b are the outputs of the electromagnetic ultrasonic receiver 2, and the maximum value of each amplitude is e i,k-1
and e i,k , and c and d in the figure are received signals amplified by the amplifier 10, and the maximum values of their respective amplitudes are e p,k-1 and e p,k . Note that the subscript k means the k-th received signal.
電磁超音波受信器２の出力の振幅の最大値と増
幅器１０の出力の振幅の最大値との関係は、各々
の場合のゲインGk-1およびGkとすると以下の式
で表わされる。 The relationship between the maximum value of the amplitude of the output of the electromagnetic ultrasound receiver 2 and the maximum value of the amplitude of the output of the amplifier 10 is expressed by the following equation, assuming that gains G k-1 and G k are in each case.
ep,k-1＝Gk-1・ei,k-1 ……(1)
ep,k＝Gk・ei,k ……(2)
いま、透過時間測定回路１２のダイナミツクレ
ンジの中間値をecとすると、ep,kがecを越えない
ようにするにはゲインGkは最大で
Gk＝ec／ei,k ……(3)
(1)式より
ei,k-1＝ep,k-1／Gk-1 ……(4)
が得られ、一方、ei,kはｋ番目より一つ前のｋ−
１番目の信号ei,k-1とほぼ等しいとすると(3)式の
ei,kに(4)式を代入すると、以下に示した関係が得
られる。 e p,k-1 = G k-1・e i,k-1 ...(1) e p,k = G k・e i,k ...(2) Now, the dynamics of the transmission time measurement circuit 12 If the intermediate value of the range is e c , then to prevent e p,k from exceeding e c , the maximum gain G k is G k = e c /e i,k ……(3) (1) Equation From this, e i,k-1 = e p,k-1 /G k-1 ...(4) is obtained, and on the other hand, e i,k is the k-th one before the k-th one.
If it is almost equal to the first signal e i,k-1, then equation (3)
Substituting equation (4) into e i,k yields the relationship shown below.
Gk＝Gk-1×ec／ep,k-1 ……(5)
すなわち、第４図に示した本発明のシエル厚計
の実施例においては、増幅器１０およびゲート回
路１１を経た受信信号からピークホールド回路２
２により振幅の最大値ep,k-1が検出され、増幅器
１０のゲイン、および演算処理回路２３の設定値
２５すなわち透過時間測定回路１２のダイナミツ
クレンジecの３つの値から(5)式の演算処理が演算
処理回路２３が行なわれ、その結果得られたGk
が、電磁超音波受信器２で検出される次の受信信
号に対する増幅器１０のゲインとなる。 G k = G k-1 ×e c /e p,k-1 ...(5) That is, in the embodiment of the shell thickness gauge of the present invention shown in FIG. Peak hold circuit 2 from received signal
( 5 ) The arithmetic processing circuit 23 performs arithmetic processing on the equation, and the resulting G k
is the gain of the amplifier 10 for the next received signal detected by the electromagnetic ultrasonic receiver 2.
なお、ピークホールド回路２２にて振幅の最大
値が検出されるタイミングおよび演算処理回路２
２にて(5)式の演算が行なわれるタイミングは、電
磁超音波受信器２である受信信号が検出されてか
ら次の受信信号が検出されるまでの時間にそれら
の処理が行なわれるよう、パルス発生回路８の指
令によりタイミング制御回路２４が制御する。 Note that the timing at which the maximum amplitude value is detected by the peak hold circuit 22 and the arithmetic processing circuit 2
The timing at which the calculation of equation (5) is performed in 2 is such that the processing is performed during the time from when a received signal is detected by the electromagnetic ultrasonic receiver 2 until the next received signal is detected. The timing control circuit 24 is controlled by the command from the pulse generation circuit 8.
以上述べたようにこの発明によれば、従来のシ
エル厚計に新たにピークホールド回路、演算処理
回路、およびタイミング制御回路を設け、タイミ
ング制御回路によりタイミングを制御されるピー
クホールド回路、演算処理回路によつて前の増幅
器を経た受信信号とそのゲインおよび透過時間測
定回路のダイナミツクレンジに基づき次の受信信
号に対するゲインを演算し、常に、増幅器にて増
幅された受信信号が、上記ダイナミツクレンジを
逸脱しないようにして、透過時間の測定精度を上
げることができる。 As described above, according to the present invention, a peak hold circuit, an arithmetic processing circuit, and a timing control circuit are newly provided in a conventional shell thickness gauge, and a peak hold circuit and an arithmetic processing circuit whose timing is controlled by the timing control circuit are provided. calculates the gain for the next received signal based on the received signal that has passed through the previous amplifier, its gain, and the dynamic range of the transmission time measurement circuit, and the received signal amplified by the amplifier always exceeds the above dynamic range. It is possible to improve the measurement accuracy of the transmission time by not deviating from the .
すなわち、シエル厚計の電磁超音波発生器、お
よび受信器は鋳片ならい装置によつて連続して流
れている鋳片に対し取り付けられており、鋳片の
内部状態や鋳片と電磁超音波発生器および鋳片と
電磁超音波受信器とのギヤツプの急激な変化がな
いため受信信号振幅のある値とその前後の値とで
は大きな変化がない。よつて前回の受信信号に基
づき増幅器の次回のゲインを制御することによつ
て、透過時間測定回路のダイナミツクレンジを逸
脱しないようにできる。 In other words, the electromagnetic ultrasonic generator and receiver of the shell thickness gauge are attached to the slab that is continuously flowing by the slab tracing device, and the electromagnetic ultrasound Since there is no sudden change in the gap between the generator and slab and the electromagnetic ultrasonic receiver, there is no large change between a certain value of the received signal amplitude and the values before and after that value. Therefore, by controlling the next gain of the amplifier based on the previous received signal, it is possible to prevent the transmission time measurement circuit from deviating from its dynamic range.
なお、本実施例では、振幅の最大値を検出する
回路としてピークホールド回路を用いているが、
振幅の最大値を検出する機能をもつ回路ならば、
他のものを用いてもよい。 Note that in this example, a peak hold circuit is used as a circuit for detecting the maximum value of the amplitude.
If the circuit has the function of detecting the maximum value of amplitude,
Others may be used.
また、本実施例では増幅器のゲイン制御に前回
の受信信号のみ用いているが、ある受信信号に対
するゲインを決定するために、前回まで得られた
複数個の受信信号の平均を求めるなど統計処理し
た結果の値を用いてもよい。 In addition, in this embodiment, only the previous received signal is used to control the gain of the amplifier, but in order to determine the gain for a certain received signal, statistical processing such as calculating the average of multiple received signals obtained up to the previous time is performed. The resulting value may be used.
第１図は従来の鋳片凝固厚み測定装置を説明す
るための図、第２図は鋳片凝固厚み測定における
電磁超音波発生および受信の原理を説明するため
の図、第３図は送信パルス電流波形および受信パ
ルス電流波形を示す図、第４図および第５図はこ
の発明による鋳片凝固厚み測定装置を説明するた
めの図であり、１は電磁超音波発生器、２は電磁
超音波受信器、３は電磁超音波発生コイル、４は
電磁超音波検出コイル、５は静磁界用コイル、６
は静磁界用磁極、７は鋳片、８はパルス発生回
路、９は励磁電源、１０は増幅器、１１はゲート
回路、１２は透過時間測定回路、１３は表面温度
計、１４は鋳片全厚み測定器、１５は凝固厚み演
算回路、１６は出力回路、２２はピークホールド
回路、２３は演算処理回路、２４はタイミング制
御回路、２５は演算処理回路の設定値であり、
ep,k-1およびep,kは増幅器１０で増幅されたそれぞ
れｋ−１番目およびｋ番目の受信信号であり、
Gk-1およびGkはそれぞれｋ−１番目およびｋ番
目の増幅器１０のゲインであり、またecは透過時
間測定回路１２のダイナミツクレンジである。な
お、図中同一あるいは相当部分には同一符号を付
して示してある。
Figure 1 is a diagram to explain a conventional slab solidification thickness measuring device, Figure 2 is a diagram to explain the principle of electromagnetic ultrasonic generation and reception in slab solidification thickness measurement, and Figure 3 is a transmission pulse. 4 and 5 are diagrams showing the current waveform and the received pulse current waveform, and are diagrams for explaining the slab solidification thickness measuring device according to the present invention, in which 1 is an electromagnetic ultrasonic generator, 2 is an electromagnetic ultrasonic wave generator, and 2 is an electromagnetic ultrasonic generator. Receiver, 3 is an electromagnetic ultrasonic generation coil, 4 is an electromagnetic ultrasonic detection coil, 5 is a static magnetic field coil, 6
is a magnetic pole for static magnetic field, 7 is a slab, 8 is a pulse generation circuit, 9 is an excitation power supply, 10 is an amplifier, 11 is a gate circuit, 12 is a transmission time measuring circuit, 13 is a surface thermometer, 14 is the total thickness of the slab 15 is a coagulation thickness calculation circuit, 16 is an output circuit, 22 is a peak hold circuit, 23 is a calculation processing circuit, 24 is a timing control circuit, 25 is a setting value of the calculation processing circuit,
e p,k-1 and e p,k are the k-1st and kth received signals amplified by the amplifier 10, respectively;
G k-1 and G k are the gains of the k-1 and k-th amplifiers 10, respectively, and e c is the dynamic range of the transmission time measuring circuit 12. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals.
Claims (1)
高周波パルス電流を通電されるコイルを備えて上
記鋳片表面に超音波を発生させる電磁超音波発生
器と、上記鋳片の他面に設置されて前記超音波を
受信する検出コイルを備えた電磁超音波受信器
と、上記の超音波発生器および受信器の超音波発
生、受信のタイミングから前記鋳片を超音波が前
記一面から他面まで伝搬するに要する時間ｔを求
める時間測定回路と、前記鋳片の全厚みＤを測定
する全厚み測定器と、前記時間測定回路によつて
測定された時間ｔ、前記全厚み測定器によつて測
定された全厚みＤ、前記鋳片の厚みｄの凝固部を
超音波が伝搬する速度Vs、および前記鋳片の厚
みＤ−ｄの未凝固部を超音波が伝搬する速度Ve
とから凝固部厚みｄを算出する演算回路とを備え
た鋳片凝固厚み測定装置において、上記電磁超音
波受信器の出力信号を増幅器と、この増幅器の出
力信号から上記電磁超音波受信器で受信された受
信信号の振幅の最大値を検出する最大値検出手段
と、上記最大値検出手段で検出された受信信号の
振幅の最大値、上記時間測定回路のダイナミツク
レンジおよび上記増幅器のゲインとに基づき上記
電磁超音波受信器で検出される次の受信信号に対
するゲインGkを演算し、そのゲインGkを上記増
幅器に設定する演算処理回路とを具備したことを
特徴とする鋳片凝固厚み測定装置。1. An electromagnetic ultrasonic generator installed on one side of the slab to be continuously cast and equipped with a coil to which a high-frequency pulse current is applied to generate ultrasonic waves on the surface of the slab, and installed on the other side of the slab. and an electromagnetic ultrasonic receiver equipped with a detection coil that receives the ultrasonic waves, and an ultrasonic wave that moves the slab from one side to the other based on the timing of ultrasonic generation and reception of the ultrasonic generator and receiver. a time measuring circuit for determining the time t required for the slab to propagate; a total thickness measuring device for measuring the total thickness D of the slab; and a time measuring circuit for determining the time t required for the slab to propagate to the measured total thickness D, the speed Vs at which the ultrasonic wave propagates through the solidified part of the slab having a thickness d, and the speed Ve at which the ultrasonic wave propagates through the unsolidified part the thickness D-d of the slab.
and an arithmetic circuit for calculating the thickness d of the solidified part from the above, and an amplifier for receiving the output signal of the electromagnetic ultrasonic receiver, and receiving the output signal of the amplifier by the electromagnetic ultrasonic receiver. a maximum value detection means for detecting a maximum value of the amplitude of the received signal detected by the maximum value detection means, a dynamic range of the time measurement circuit, and a gain of the amplifier; A slab solidification thickness measuring device comprising: a calculation processing circuit that calculates a gain Gk for the next received signal detected by the electromagnetic ultrasonic receiver based on the above-mentioned electromagnetic ultrasonic receiver, and sets the gain Gk to the amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11637083A JPS609562A (en) | 1983-06-28 | 1983-06-28 | Device for measuring solidification thickness of billet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11637083A JPS609562A (en) | 1983-06-28 | 1983-06-28 | Device for measuring solidification thickness of billet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS609562A JPS609562A (en) | 1985-01-18 |
| JPH0464788B2 true JPH0464788B2 (en) | 1992-10-16 |
Family
ID=14685290
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11637083A Granted JPS609562A (en) | 1983-06-28 | 1983-06-28 | Device for measuring solidification thickness of billet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS609562A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0648182B2 (en) * | 1988-08-12 | 1994-06-22 | 新日本製鐵株式会社 | Cast solidification thickness gauge |
| JPH0648183B2 (en) * | 1988-08-22 | 1994-06-22 | 新日本製鐵株式会社 | Cast solidification thickness calculator |
| EP1666173B8 (en) | 2001-04-25 | 2008-03-05 | JFE Steel Corporation | Manufacturing method for continuously cast product of steel |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5839288B2 (en) * | 1978-07-04 | 1983-08-29 | 日本鋼管株式会社 | Ultrasonic thickness gauge |
| JPS57190281A (en) * | 1981-05-19 | 1982-11-22 | Yokogawa Hokushin Electric Corp | Ultrasonic wave measuring apparatus |
-
1983
- 1983-06-28 JP JP11637083A patent/JPS609562A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS609562A (en) | 1985-01-18 |
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