JPH0236163B2 - - Google Patents
Info
- Publication number
- JPH0236163B2 JPH0236163B2 JP58138924A JP13892483A JPH0236163B2 JP H0236163 B2 JPH0236163 B2 JP H0236163B2 JP 58138924 A JP58138924 A JP 58138924A JP 13892483 A JP13892483 A JP 13892483A JP H0236163 B2 JPH0236163 B2 JP H0236163B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- amplitude
- slab
- time
- wavelength
- 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
Links
- 238000004364 calculation method Methods 0.000 claims description 50
- 238000001514 detection method Methods 0.000 claims description 30
- 238000007711 solidification Methods 0.000 claims description 14
- 230000008023 solidification Effects 0.000 claims description 14
- 230000002159 abnormal effect Effects 0.000 claims description 13
- 238000005259 measurement Methods 0.000 claims description 11
- 238000007689 inspection Methods 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 description 39
- 238000010586 diagram Methods 0.000 description 8
- 230000005284 excitation Effects 0.000 description 8
- 238000002604 ultrasonography Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000003993 interaction Effects 0.000 description 2
- 239000002436 steel type Substances 0.000 description 2
- 238000005266 casting Methods 0.000 description 1
- 230000015271 coagulation Effects 0.000 description 1
- 238000005345 coagulation Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
- G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Continuous Casting (AREA)
- Length Measuring Devices Characterised By Use Of Acoustic Means (AREA)
Description
【発明の詳細な説明】
本発明は、電磁超音波を用いて連続鋳造におけ
る鋳片の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 during continuous casting using 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ンツの法則により厚
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 by , 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. An electromotive force is generated on the surface of the slab 7 due to the interaction between this vibration and the magnetic field created by the excitation coil 5 excited by the excitation power source 9. 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 received signal.
The signal is 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1
1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
の裏面の他面までに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 measurement circuit 12, the gate circuit 1
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 input from 1 and the pulse output timing signal, and the result is sent to the solidification thickness calculation circuit 15. It will be done.
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Vl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/Vl
であらわされる。一般にVsは鋼種によつて鋳片
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Vl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 area is V s and the speed at which the ultrasonic wave propagates through the unsolidified area is V l , then the entire slab The transmission time t for the ultrasonic wave to pass through is expressed as t=d/V s +D−d/V l . In general, V s is the temperature of the ultrasonic propagation velocity based on the solidification temperature of the slab depending on the steel type and the average temperature of the solidified part determined by an average or weighted average from the surface temperature measured by the surface thermometer 13. It 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 is experimentally determined.
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、未凝固
部の超音波伝搬速度Vl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 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 input. If the ultrasonic propagation velocity V l of the unsolidified portion 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.
従来の鋳片凝固厚み測定装置は以上のように構
成されているので、外来ノイズ等の偶発ノイズが
電磁超音波受信器の検出コイル側に混入された場
合に、これを除外することができず、そのまま受
信信号として処理し、誤まつた判定(誤測定)を
してしまう欠点があつた。 Since the conventional slab solidification thickness measuring device is configured as described above, it is not possible to exclude accidental noise such as external noise from entering the detection coil side of the electromagnetic ultrasonic receiver. However, it has the disadvantage that it is processed as a received signal, leading to incorrect judgments (erroneous measurements).
この発明は、このような欠点を解消するために
なされたもので、前記のノイズ等によつて発生す
る異常波形信号を除外し、さらに統計的処理を付
加することにより、きわめて測定精度の高い鋳片
凝固厚み測定装置を提供するものである。 This invention was made to eliminate these drawbacks, and by excluding abnormal waveform signals caused by the above-mentioned noise, etc., and further adding statistical processing, it is possible to obtain castings with extremely high measurement accuracy. The present invention provides a piece solidification thickness measuring device.
第3図は、この発明の一実施例を示す図であ
る。第3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、22は透過時
間演算回路、23は異常波形除去回路、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。 FIG. 3 is a diagram showing an embodiment of the present invention. In Fig. 3, 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, 22 is a transmission time calculation circuit, and 23 is an abnormal waveform 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.
第4図は、異常波形除去回路23および透過時
間演算回路22の回路構成を示す図である。第4
図において、24はA/D変換回路、25は波形
記憶回路、26は最大振幅点検出回路、27は最
大値記憶回路、28はタイミング制御回路、29
は零クロス点検出回路、30は波長算出回路、3
1は極値点検出回路、32は極値記憶回路、33
は振幅比率演算回路、34は波長条件判定回路、
35は振幅条件判定回路、36および41は定数
設定回路、37は波形情報記憶回路、38は波長
平均値算出回路、39は振幅平均値算出回路、4
0は比較判定回路、42は送信タイミング信号、
43は受信信号、44は透過時間信号、45はデ
ータ有効信号、46は透過時間記憶回路、47は
有効データ判定回路、48は平均値算出回路、4
9は平均透過時間信号である。 FIG. 4 is a diagram showing the circuit configurations of the abnormal waveform removal circuit 23 and the transmission time calculation circuit 22. Fourth
In the figure, 24 is an A/D conversion circuit, 25 is a waveform storage circuit, 26 is a maximum amplitude point detection circuit, 27 is a maximum value storage circuit, 28 is a timing control circuit, and 29 is a maximum amplitude point detection circuit.
is a zero cross point detection circuit, 30 is a wavelength calculation circuit, 3
1 is an extreme value point detection circuit, 32 is an extreme value storage circuit, 33
34 is an amplitude ratio calculation circuit, 34 is a wavelength condition determination circuit,
35 is an amplitude condition determination circuit, 36 and 41 are constant setting circuits, 37 is a waveform information storage circuit, 38 is a wavelength average value calculation circuit, 39 is an amplitude average value calculation circuit, 4
0 is a comparison judgment circuit, 42 is a transmission timing signal,
43 is a received signal, 44 is a transmission time signal, 45 is a data valid signal, 46 is a transmission time storage circuit, 47 is a valid data determination circuit, 48 is an average value calculation circuit, 4
9 is an average transmission time signal.
次に第3図および第4図に示す本発明の一実施
例についてその動作を説明する。パルス発生回路
8により電磁超音波発生器1への送信信号と同期
した送信タイミング信号42が出力され、透過時
間測定回路12および異常波形除去回路23に入
力される。一方励磁電源9により励磁され、受信
可能となつた電磁超音波受信器2からの受信信号
43は増幅器10により増幅され、ゲート回路1
1により必要な信号のみ時間弁別され、前記透過
時間測定回路12および異常波形除去回路23に
入力される。透過時間測定回路12では、前記の
送信タイミング信号42と受信信号43との時間
差から、透過時間tTを求め、これを透過時間信号
44として透過時間演算回路22へ送り、透過時
間記憶回路46に記憶させる。 Next, the operation of an embodiment of the present invention shown in FIGS. 3 and 4 will be described. A transmission timing signal 42 synchronized with the transmission signal to the electromagnetic ultrasonic generator 1 is outputted by the pulse generation circuit 8 and inputted to the transmission time measurement circuit 12 and the abnormal waveform removal circuit 23. On the other hand, the received signal 43 from the electromagnetic ultrasonic receiver 2, which is excited by the excitation power source 9 and becomes receivable, is amplified by the amplifier 10, and the gate circuit 1
1, only necessary signals are time-discriminated and input to the transmission time measuring circuit 12 and the abnormal waveform removing circuit 23. The transmission time measurement circuit 12 calculates the transmission time t T from the time difference between the transmission timing signal 42 and the reception signal 43, sends it as a transmission time signal 44 to the transmission time calculation circuit 22, and stores it in the transmission time storage circuit 46. Make me remember.
さて、異常波形除去回路23では前記の受信信
号43が、まずA/D変換回路24に入力され、、
タイミング制御回路28の指示するタイミングで
サンプリングされ、デイジタル値に変換されて波
形記憶回路25に時系列で記憶される。なおタイ
ミング制御回路28は、前記送信タイミング信号
42と連動し、受信信号43の全波形が充分記憶
されるようタイミング制御を行なつている。 Now, in the abnormal waveform removal circuit 23, the above-mentioned received signal 43 is first inputted to the A/D conversion circuit 24,
The signals are sampled at timings instructed by the timing control circuit 28, converted to digital values, and stored in the waveform storage circuit 25 in time series. Note that the timing control circuit 28 performs timing control in conjunction with the transmission timing signal 42 so that the entire waveform of the reception signal 43 is sufficiently stored.
第5図は以上のようにして波形記憶回路25に
収められた受信信号43の一例を示したものであ
る。なお第5図ではアナログ波形として示してあ
るが、実際には時系列に並んだデイジタル値とし
て記憶されている。受信信号43の記憶が終了す
ると次にタイミング制御回路28の指示により、
データが順に読み出され、最大振幅点検出回路2
6により、最大振幅を与える時刻tMが検出され、
同時に、最大値記憶回路27により、この時の振
幅値VMが記憶される。なお、波形記憶回路25
は時系列にデータを記憶するようになつており、
またデータのサンプリングも、タイミング制御回
路28により予め定められた既知のタイミングで
行なわれているため、波形記憶回路25に記憶さ
れているデータの位置を知ることにより、前記の
時刻tMは容易に求められる。 FIG. 5 shows an example of the received signal 43 stored in the waveform storage circuit 25 as described above. Although the waveforms are shown as analog waveforms in FIG. 5, they are actually stored as digital values arranged in time series. When the storage of the received signal 43 is completed, the timing control circuit 28 next indicates that
The data is read out in order, and the maximum amplitude point detection circuit 2
6, the time t M that gives the maximum amplitude is detected,
At the same time, the maximum value storage circuit 27 stores the amplitude value V M at this time. Note that the waveform storage circuit 25
is designed to store data in chronological order,
Furthermore, data sampling is also performed at a known timing predetermined by the timing control circuit 28, so by knowing the position of the data stored in the waveform storage circuit 25, the above-mentioned time tM can be easily determined. Desired.
次に、時刻tMが最大振幅点検出回路26により
検出されると、この情報はタイミング制御回路2
8に入力する。タイミング制御回路28は、時刻
tMに対応する波形記憶回路25上の位置から、順
に時間をさかのぼる方向および時間を下る方向に
データを読み出し、時刻tM前後の予め設定された
範囲における零クロス時刻tZ-2〜tZ2および極大
値、極小値を示す時刻tP-2〜tP2が、それぞれ零ク
ロス点検出回路29および極値点検出回路31に
より検出される。波長算出回路30では上記零ク
ロス時刻より、たとえばλ=tZ1〜tZ-2として波長
を算出する。もちろん、波長λを求めるに当つて
は、例えばλ=(λZ1−λZ-2+λZ2−λZ-1)/2の
ようにλをtZ-2、tZ-1、tZ1、tZ2の関数として、他
の統計的演算手法を導入してもよい。 Next, when time t M is detected by the maximum amplitude point detection circuit 26, this information is transmitted to the timing control circuit 26.
Enter 8. The timing control circuit 28
From the position on the waveform storage circuit 25 corresponding to t M , data is read out in the backward and downward directions in time, and zero cross times t Z-2 to t Z2 in a preset range before and after time t M are read out. Also, times t P-2 to t P2 indicating the local maximum value and local minimum value are detected by the zero cross point detection circuit 29 and the extreme value point detection circuit 31, respectively. The wavelength calculation circuit 30 calculates the wavelength from the above zero-crossing time, for example, as λ=t Z1 to t Z-2 . Of course, when determining the wavelength λ, for example, λ is expressed as t Z-2 , t Z-1 , t Z1 , λ = (λ Z1 - λ Z-2 + λ Z2 - λ Z-1 ) /2 Other statistical calculation methods may be introduced as a function of t Z2 .
極値記憶回路32は前記極値点検出回路31に
より検出されたそれぞれの極値点tP-2〜tP2におけ
る振幅値VP-2〜VP2の値を記憶し、振幅比率演算
回路33は前記の最大値記憶回路27に記憶され
ている振幅値VMと、このVP-2〜VP2とにより、た
とえばVMに対するそれぞれの振幅比率ki=VPi/
VM(i=−2〜2)を求める。もちろん、この振
幅比率は、VM、VP-2〜VP2よりなるマトリマトリ
クスとして求めるなど、他の演算処理を行なつて
もよい。 The extreme value storage circuit 32 stores the amplitude values V P-2 to V P2 at each of the extreme points t P-2 to t P2 detected by the extreme value point detection circuit 31, and stores the amplitude values V P-2 to V P2 at each of the extreme value points t P-2 to t P2 detected by the extreme value point detection circuit 31. is determined by the amplitude value V M stored in the maximum value storage circuit 27 and these V P-2 to V P2 , for example, the respective amplitude ratio k i to V M = V Pi /
Find V M (i=-2 to 2). Of course, other arithmetic processing may be performed on this amplitude ratio, such as finding it as a matrix consisting of V M , V P-2 to V P2 .
波長条件判定回路34は、波長算出回路30に
より算出された波長λが、定数設定回路36によ
り予め設定された範囲に入つているかを判定し、
この条件を満足しないデータを除去する。同様に
して、振幅条件判定回路35は、振幅比率演算回
路33により求めた振幅比率k-2〜k2が定数設定
回路36により予め設定された条件を満足してい
るかによつてデータの取捨判定を行なう。従つ
て、定数設定回路36による設定条件を満足した
データのみが波長条件判定回路34および振幅条
件判定回路35を通過し、波形情報記憶回路37
に収められる。 The wavelength condition determination circuit 34 determines whether the wavelength λ calculated by the wavelength calculation circuit 30 is within a range preset by the constant setting circuit 36,
Remove data that does not satisfy this condition. Similarly, the amplitude condition determination circuit 35 determines whether or not the data should be discarded based on whether the amplitude ratio k -2 to k 2 obtained by the amplitude ratio calculation circuit 33 satisfies the condition set in advance by the constant setting circuit 36. Do the following. Therefore, only data that satisfies the setting conditions set by the constant setting circuit 36 passes through the wavelength condition determination circuit 34 and the amplitude condition determination circuit 35, and is stored in the waveform information storage circuit 37.
It can be stored in
ここまでの経過をN回の受信について行なえ
ば、波形情報記憶回路37内にはN回分の波長デ
ータのうち前記判定条件を満足したK個(ただK
≦N)の波長データλi(i=1〜K)と振幅比率
データkP-2i〜kP2i(i=1〜K)が記憶されてい
ることになる。 If the process up to this point is repeated for N receptions, the waveform information storage circuit 37 will contain K pieces of wavelength data (only K
≦N) wavelength data λ i (i=1 to K) and amplitude ratio data k P-2i to k P2i (i=1 to K) are stored.
N回の受信が終了した時点でタイミング制御回
路28の指示により波形情報記憶回路37内に記
憶されたK個のデータが順に読み出され、波長平
均値算出回路38および振幅平均値算出回路39
により、それぞれの平均値、P-2〜P2が算出
され、比較判定回路40へ送られる。 When the N times of reception are completed, the K pieces of data stored in the waveform information storage circuit 37 are sequentially read out according to instructions from the timing control circuit 28, and the wavelength average value calculation circuit 38 and the amplitude average value calculation circuit 39
Accordingly, the respective average values P-2 to P2 are calculated and sent to the comparison/judgment circuit 40.
タイミング制御回路28は、波長平均値算出回
路38および振幅平均値算出回路39が、それぞ
れの平均値を比較判定回路40へ送つた後に、再
び波長情報記憶回路37のデータを読み出し、さ
らに比較判定回路40は、これらのデータλi、
kP-2i〜kP2i(i=1〜K)について、前記の平均
値、P-2〜kP2 との比較を行ない、予め定数設
定回路41により設定された偏差値以内に入つた
データに対してのみデータ有効信号45を出力す
る。 The timing control circuit 28 reads the data from the wavelength information storage circuit 37 again after the wavelength average value calculation circuit 38 and the amplitude average value calculation circuit 39 send their respective average values to the comparison judgment circuit 40, and then reads the data from the wavelength information storage circuit 37 again. 40 represents these data λ i ,
Compare k P-2i to k P2i (i = 1 to K) with the above-mentioned average value, P-2 to k P2 , and select the data that falls within the deviation value preset by the constant setting circuit 41. The data valid signal 45 is output only for the data.
ここで、前記の透過時間記憶回路46に記憶さ
れたN回の透過時間データtTi(i=1〜N)のう
ち、前記データ有効信号45に対応した透過時間
データtTj(j=1〜K)のみが透過時間判定回路
47を通過し、平均値算出回路48により透過時
間平均値Tが算出され、平均透過時間信号49と
して凝固厚み演算回路15へ送られる。 Here, among the N times of transmission time data t Ti (i=1 to N) stored in the transmission time storage circuit 46, the transmission time data t Tj (j=1 to N) corresponding to the data valid signal 45 is K) only passes through the transmission time determination circuit 47, and the average transmission time value T is calculated by the average value calculation circuit 48, and is sent to the coagulation thickness calculation circuit 15 as an average transmission time signal 49.
凝固厚み演算回路15では、透過時間演算回路
22による平均透過時間t=Tと、表面温度計1
3による温度Tと、鋳片全厚み測定器14による
全厚みDとから、従来の算出方法と同様にして凝
固厚みを求め、出力回路16により外部へ出力さ
れる。 The solidification thickness calculation circuit 15 calculates the average transmission time t= T by the transmission time calculation circuit 22 and the surface thermometer 1.
3 and the total thickness D measured by the slab total thickness measuring device 14, the solidified thickness is determined in the same manner as the conventional calculation method, and is outputted to the outside by the output circuit 16.
本実施例では、定数設定回路36の設定値が、
予め予想される波長および振幅比率に対して例え
ば±10%となるように設定し、さらに定数設定回
路41の設定値が前記の平均値λ、kP-2〜kP2に
対して、同様に、例えば±3%と設定することに
より、有用なデータを損なうことなく、モータや
電磁開閉器の突入電流等による急峻な立上りをも
つ短波長波形をきわめて効果的に除去し得た。 In this embodiment, the set value of the constant setting circuit 36 is
For example, the set value of the constant setting circuit 41 is set to be ±10% with respect to the wavelength and amplitude ratio expected in advance, and the set value of the constant setting circuit 41 is similarly set with respect to the above average value λ, k P-2 to k P2 . By setting, for example, ±3%, it was possible to very effectively remove short wavelength waveforms with steep rises due to inrush currents of motors and electromagnetic switches, etc., without damaging useful data.
なお、以上はデイジタル化されたデータを扱う
デイジタル回路により説明を行なつたが、この回
路の一部または全部をアナログ回路によつて置き
換えたり、あるいはコンピユータを用いてソフト
ウエアに置き換えたりすることはもちろん可能で
あり、またそれによつて本発明の趣旨は何ほども
損われるものではない。また、本実施例では、極
値点および零クロス点をそれぞれtP-2〜tP2、tZ-2
〜tZ2の8点として説明したが、本発明はこれに
限らず、特に極値点および零クロス点の数を限定
するものではなく、この発明の主旨を逸脱しない
範囲において種々の変形がある。 Although the above explanation has been based on a digital circuit that handles digitized data, it is not possible to replace part or all of this circuit with an analog circuit, or replace it with software using a computer. Of course, this is possible, and the spirit of the present invention is not detracted from it in any way. In addition, in this embodiment, the extreme value points and zero cross points are t P-2 to t P2 and t Z-2, respectively.
Although the explanation has been made using eight points of ~t Z2 , the present invention is not limited to this, and does not particularly limit the number of extreme value points and zero cross points, and various modifications can be made without departing from the gist of the present invention. .
また、本発明による異常波形除去回路および透
過時間演算回路はシエル厚計のみならず、超音波
等の伝播を利用した他の送受信装置、例えば肉厚
計、温度計等にも応用可能である。 Furthermore, the abnormal waveform removal circuit and transmission time calculation circuit according to the present invention can be applied not only to shell thickness gauges but also to other transmitting and receiving devices that utilize propagation of ultrasonic waves, such as wall thickness gauges and thermometers.
以上のように、この発明によれば、外来ノイズ
等の偶発ノイズが電磁超音波受信器の検出コイル
側に混入されること等によつて発生する異常波形
信号を除外し、さらに統計的処理を付加すること
により、きわめて測定精度の高い鋳片凝固厚み測
定を行なうことが可能である。 As described above, according to the present invention, abnormal waveform signals generated due to accidental noise such as external noise being mixed into the detection coil side of an electromagnetic ultrasonic receiver are excluded, and further statistical processing is performed. By adding this, it is possible to measure the solidified slab thickness with extremely high measurement accuracy.
第1図は従来の鋳片凝固厚み測定装置の構成を
示すブロツク図、第2図は電磁超音波発生および
受信の原理を示す図、第3図は本発明装置の一実
施例の構成を示す図、第4図は本発明装置の異常
波形除去回路および透過時間演算回路の回路構成
を示すブロツク図、第5図は本発明装置によつて
得られる受信信号の一例を示す図である。
図中、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は励磁コイル、6は磁心、7
は鋳片、8はパルス発生回路、9は励磁電源、1
0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、17はパルス磁界、18および20は渦電
流、19は超音波の伝播方向、21は電磁超音波
検出コイル4の出力、22は透過時間演算回路、
23は異常波形除去回路、24はA/D変換回
路、25は波形記憶回路、26は最大振幅点検出
回路、27は最大値記憶回路、28はタイミング
制御回路、29は零クロス点検出回路、30は波
長算出回路、31は極値点検出回路、32は極値
記憶回路、33は振幅比率演算回路、34は波長
条件判定回路、35は振幅条件判定回路、36お
よび41は定数設定回路、、37は波形情報記憶
回路、38は波長平均値算出回路、39は振幅平
均値算出回路、40は比較判定回路、42は送信
タイミング信号、43は受信信号、44は透過時
間信号、45はデータ有効信号、46は透過時間
記憶回路、47は有効データ判定回路、48は平
均値算出回路、49は平均透過時間信号である。
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 block diagram showing the configuration of a conventional slab solidification thickness measuring device, Figure 2 is a diagram showing the principle of electromagnetic ultrasonic generation and reception, and Figure 3 is a diagram showing the configuration of an embodiment of the device of the present invention. 4 is a block diagram showing the circuit configuration of the abnormal waveform removal circuit and the transmission time calculation circuit of the device of the present invention, and FIG. 5 is a diagram showing an example of a received signal obtained by the device of the present invention. In the figure, 1 is an electromagnetic ultrasound generator, 2 is an electromagnetic ultrasound receiver, 3 is an electromagnetic ultrasound generation coil, 4 is an electromagnetic ultrasound detection coil, 5 is an excitation coil, 6 is a magnetic core, and 7
1 is a slab, 8 is a pulse generation circuit, 9 is an excitation power source, 1
0 is an amplifier, 11 is a gate circuit, 12 is a transmission time measuring circuit, 13 is a surface thermometer, 14 is a slab total thickness measuring device, 15 is a solidification thickness calculation circuit, 16 is an output circuit, 17 is a pulsed magnetic field, 18 and 20 is an eddy current, 19 is the propagation direction of the ultrasonic wave, 21 is the output of the electromagnetic ultrasonic detection coil 4, 22 is a transmission time calculation circuit,
23 is an abnormal waveform removal circuit, 24 is an A/D conversion circuit, 25 is a waveform storage circuit, 26 is a maximum amplitude point detection circuit, 27 is a maximum value storage circuit, 28 is a timing control circuit, 29 is a zero cross point detection circuit, 30 is a wavelength calculation circuit, 31 is an extreme point detection circuit, 32 is an extreme value storage circuit, 33 is an amplitude ratio calculation circuit, 34 is a wavelength condition determination circuit, 35 is an amplitude condition determination circuit, 36 and 41 are constant setting circuits, , 37 is a waveform information storage circuit, 38 is a wavelength average value calculation circuit, 39 is an amplitude average value calculation circuit, 40 is a comparison judgment circuit, 42 is a transmission timing signal, 43 is a reception signal, 44 is a transmission time signal, and 45 is data. 46 is a transmission time storage circuit, 47 is a valid data determination circuit, 48 is an average value calculation circuit, and 49 is an average transmission time signal.
In the drawings, the same or corresponding parts are designated 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Vl
とから凝固部厚みdを算出する演算回路とからな
る鋳片凝固厚み測定装置において、前記電磁超音
波受信器によつて受信された受信信号を時系列で
記憶する波形記憶回路と、前記波形記憶回路で記
憶された受信信号の最大振幅を示す時刻tMを検出
する最大振幅点検回路と、前記波形記憶回路で記
憶された受信信号から時刻tM前後の予め設定され
た範囲における零クロス時刻を検出する零クロス
点検回路と、前記零クロス時刻を用いて波長λを
求める波長算出回路と、前記波長算出回路λによ
り算出された波長λが予め設定された範囲に入つ
ているかを判定し、この条件を満足しないデータ
を除去する波長条件判定回路と、前記波長条件判
定回路から出力される設定条件を満足した波長デ
ータを記憶する波形情報記憶回路と、前記波形情
報記憶回路に記憶された複数個の波長データを入
力し、その平均値を算出する波長平均値算出回路
と、前記波形情報記憶回路からの出力データを波
長平均値算出回路からの出力データと比較し、予
じめ設定された偏差値以内に入つたデータのみデ
ータ有効信号を出力する比較判定回路とを具備し
た異常波形除去回路を前記電磁超音波受信器と前
記時間測定回路の間に設けたことを特徴とする鋳
片凝固厚み測定装置。 2 連続鋳造される鋳片の一面に設置され、かつ
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Vl
とから凝固部厚みdを算出する演算回路とからな
る鋳片凝固厚み測定装置において、前記電磁超音
波受信器によつて受信された受信信号を、時系列
で記憶する波形記憶回路と、前記波形記憶回路で
記憶された受信信号の最大振幅を示す時刻tMを検
出する最大振幅点検出回路と、前記時刻tMにおけ
る振幅値VMを記憶する最大値記憶回路と、前記
波形記憶回路で記憶された受信信号から時刻tM前
後の予じめ設定された範囲における極大値、極小
値を示す時刻を検出する極値点検出回路と、前記
極値点検出回路により検出された極値点における
振幅値を記憶する極値記憶回路と、前記最大値記
憶回路に記憶されている振幅値VMと前記極値記
憶回路に記憶されている振幅値とを用いて振幅値
VMに対するそれぞれの振幅比率を求める振幅比
率演算回路と、前記振幅比率演算回路により求め
た振幅比率が予じめ設定された条件を満足してい
るかによつてデータの取捨判定を行う振幅条件判
定回路と、前記振幅条件判定回路から出力される
設定条件を満足した振幅データを記憶する波形情
報記憶回路と、前記波形情報記憶回路に記憶され
た複数個の振幅データを入力し、その平均値を算
出する振幅平均値算出回路と、前記波形情報記憶
回路からの出力データを前記振幅平均値算出回路
からの出力データと比較し、予じめ設定された偏
差値以内に入つたデータのみデータ有効信号を出
力する比較判定回路とを具備した異常波形除去回
路を前記電磁超音波受信器と前記時間測定回路の
間に設けたことを特徴とする鋳片凝固厚み測定装
置。 3 連続鋳造される鋳片の一面に設置され、かつ
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Vl
とから凝固部厚みdを算出する演算回路とからな
ることを特徴とする鋳片凝固厚み測定装置におい
て、前記電磁超音波受信器によつて受信された受
信信号を時系列で記憶する波形記憶回路と、前記
波形記憶回路で記憶された受信信号の最大振幅を
示す時刻tMを検出する最大振幅点検出回路と、前
記時刻tMにおける振幅値VMを記憶する最大値記
憶回路と、前記波形記憶回路で記憶された受信信
号から時刻tM前後の予じめ設定された範囲におけ
る零クロス時刻および極大値、極小値を示す時刻
を検出する零クロス点検出回路および極値点検出
回路と、前記零クロス時刻を用いて波長λを求め
る波長算出回路と、前記極値点検出回路により検
出された極値点における振幅値を記憶する極値記
憶回路と、前記最大値記憶回路に記憶されている
振幅値VMと前記極値記憶回路に記憶されている
振幅値とを用いて振幅値VMに対するそれぞれの
振幅比率を求める振幅比率演算回路と、前記波長
算出回路により算出された波長λが予じめ設定さ
れた範囲に入つているかを判定し、この条件を満
足しないデータを除去する波長条件判定回路と、
前記振幅比率演算回路により求めた振幅比率が予
じめ設定された条件を満足しているかによつてデ
ータの取捨判定を行う振幅条件判定回路と、前記
波長条件判定回路および振幅条件判定回路から出
力される設定条件を満足した波長データおよび振
幅データを記憶する波形情報記憶回路と、前記波
形情報記憶回路に記憶された複数個の波長デー
タ、振幅データを入力し、それぞれの平均値を算
出する波長平均値算出回路および振幅平均値算出
回路と前記波形情報記憶回路からの出力データを
波長平均値算出回路および振幅平均値算出回路か
らの出力データと比較し、予じめ設定された偏差
値以内に入つたデータのみデータ有効信号を出力
する比較判定回路とを具備した異常波形除去回路
を前記電磁超音波受信器と前記時間測定回路の間
に設けたことを特徴とする鋳片凝固厚み測定装
置。[Scope of Claims] 1. An electromagnetic ultrasonic generator that is installed on one surface of a slab to be continuously cast and is equipped with a coil to which a high-frequency pulse current is applied to generate ultrasonic waves on the surface of the slab; An electromagnetic ultrasonic receiver equipped with a detection coil installed on the other side of the slab to receive the ultrasonic waves, and an ultrasonic wave generation and reception timing of the ultrasonic generator and receiver described above to ultrasonicate the slab. a time measuring circuit for determining the time t required for propagation from the one surface to the other surface; a total thickness measuring device for measuring the total thickness D of the slab; and the time t measured by the time measuring circuit; The total thickness D measured by the total thickness measuring device, the speed Vs at which the ultrasonic wave propagates through the solidified part of the slab with thickness d, and the ultrasonic wave propagates through the unsolidified part of the slab with thickness D-d. Speed Vl
and an arithmetic circuit for calculating a solidified portion thickness d from a waveform storage circuit for storing received signals received by the electromagnetic ultrasonic receiver in time series; A maximum amplitude checking circuit detects a time t M indicating the maximum amplitude of the received signal stored in the circuit, and a zero cross time in a preset range around time t M is determined from the received signal stored in the waveform storage circuit. A zero cross inspection circuit for detecting a zero cross, a wavelength calculation circuit for calculating a wavelength λ using the zero cross time, and a wavelength calculation circuit for determining whether the wavelength λ calculated by the wavelength calculation circuit λ is within a preset range. a wavelength condition determination circuit that removes data that does not satisfy the conditions; a waveform information storage circuit that stores wavelength data that satisfies the setting conditions output from the wavelength condition determination circuit; and a plurality of waveform information stored in the waveform information storage circuit. A wavelength average value calculation circuit inputs the wavelength data of and calculates the average value, and compares the output data from the waveform information storage circuit with the output data from the wavelength average value calculation circuit, and calculates a preset deviation. The solidified slab thickness is characterized in that an abnormal waveform removal circuit is provided between the electromagnetic ultrasonic receiver and the time measurement circuit and includes a comparison judgment circuit that outputs a data valid signal only for data that falls within a value. measuring device. 2. 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 Vl at which the ultrasonic wave propagates through the unsolidified part of the slab thickness D-d.
and an arithmetic circuit that calculates the solidified portion thickness d from the waveform storage circuit that stores the received signal received by the electromagnetic ultrasonic receiver in time series, and the waveform a maximum amplitude point detection circuit that detects a time t M indicating the maximum amplitude of the received signal stored in the storage circuit; a maximum value storage circuit that stores the amplitude value V M at the time t M ; and a maximum amplitude point detection circuit that stores the amplitude value V M at the time t M; an extreme point detection circuit that detects the times at which local maximum and local minimum values occur in a preset range before and after time t M from the received signal; An extreme value storage circuit that stores amplitude values, and an amplitude value using the amplitude value V M stored in the maximum value storage circuit and the amplitude value stored in the extreme value storage circuit.
An amplitude ratio calculation circuit that calculates each amplitude ratio with respect to V M , and an amplitude condition judgment that determines whether or not data is to be discarded depending on whether the amplitude ratio calculated by the amplitude ratio calculation circuit satisfies a preset condition. A circuit, a waveform information storage circuit that stores amplitude data that satisfies the setting conditions output from the amplitude condition determination circuit, and a plurality of pieces of amplitude data stored in the waveform information storage circuit are input, and the average value thereof is calculated. The output data from the amplitude average value calculation circuit and the waveform information storage circuit are compared with the output data from the amplitude average value calculation circuit, and only data that falls within a preset deviation value is sent as a data valid signal. 1. An apparatus for measuring the solidification thickness of a slab, characterized in that an abnormal waveform removal circuit including a comparison and determination circuit that outputs the following is provided between the electromagnetic ultrasonic receiver and the time measurement circuit. 3. 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 Vl at which the ultrasonic wave propagates through the unsolidified part of the slab thickness D-d.
and an arithmetic circuit for calculating a solidified portion thickness d from a waveform storage circuit that stores received signals received by the electromagnetic ultrasonic receiver in time series. a maximum amplitude point detection circuit that detects a time t M indicating the maximum amplitude of the received signal stored in the waveform storage circuit; a maximum value storage circuit that stores the amplitude value V M at the time t M ; a zero-crossing point detection circuit and an extreme point detection circuit for detecting zero-crossing times, local maximum values, and local minimum values in a preset range before and after time t M from a received signal stored in a storage circuit; a wavelength calculation circuit that calculates the wavelength λ using the zero crossing time; an extreme value storage circuit that stores the amplitude value at the extreme point detected by the extreme point detection circuit; and an amplitude value stored in the maximum value storage circuit. an amplitude ratio calculation circuit that calculates the respective amplitude ratios to the amplitude value V M using the amplitude value V M at which the current value is stored and the amplitude value stored in the extreme value storage circuit; a wavelength condition determination circuit that determines whether the wavelength falls within a preset range and removes data that does not satisfy this condition;
an amplitude condition determination circuit that determines whether or not data is to be discarded depending on whether the amplitude ratio obtained by the amplitude ratio calculation circuit satisfies a preset condition; outputs from the wavelength condition determination circuit and the amplitude condition determination circuit; a waveform information storage circuit that stores wavelength data and amplitude data that satisfy the setting conditions set by the wavelength information storage circuit; The output data from the average value calculation circuit, the amplitude average value calculation circuit, and the waveform information storage circuit are compared with the output data from the wavelength average value calculation circuit and the amplitude average value calculation circuit, and the output data is determined to be within a preset deviation value. A slab solidification thickness measuring device, characterized in that an abnormal waveform removal circuit including a comparison judgment circuit that outputs a data valid signal only for input data is provided between the electromagnetic ultrasonic receiver and the time measurement circuit.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58138924A JPS6031010A (en) | 1983-07-29 | 1983-07-29 | Apparatus for measuring thickness of solidified cast piece |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP58138924A JPS6031010A (en) | 1983-07-29 | 1983-07-29 | Apparatus for measuring thickness of solidified cast piece |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6031010A JPS6031010A (en) | 1985-02-16 |
JPH0236163B2 true JPH0236163B2 (en) | 1990-08-15 |
Family
ID=15233312
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP58138924A Granted JPS6031010A (en) | 1983-07-29 | 1983-07-29 | Apparatus for measuring thickness of solidified cast piece |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6031010A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0648183B2 (en) * | 1988-08-22 | 1994-06-22 | 新日本製鐵株式会社 | Cast solidification thickness calculator |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS557665A (en) * | 1978-07-04 | 1980-01-19 | Nippon Kokan Kk <Nkk> | Thickness gauge of ultrasonic wave type |
-
1983
- 1983-07-29 JP JP58138924A patent/JPS6031010A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS557665A (en) * | 1978-07-04 | 1980-01-19 | Nippon Kokan Kk <Nkk> | Thickness gauge of ultrasonic wave type |
Also Published As
Publication number | Publication date |
---|---|
JPS6031010A (en) | 1985-02-16 |
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