EP0071448B1 - Verfahren und Einrichtung zum Stranggiessen von Stahl - Google Patents

Verfahren und Einrichtung zum Stranggiessen von Stahl Download PDF

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Publication number
EP0071448B1
EP0071448B1 EP19820303943 EP82303943A EP0071448B1 EP 0071448 B1 EP0071448 B1 EP 0071448B1 EP 19820303943 EP19820303943 EP 19820303943 EP 82303943 A EP82303943 A EP 82303943A EP 0071448 B1 EP0071448 B1 EP 0071448B1
Authority
EP
European Patent Office
Prior art keywords
force
brake
cast
control signal
drive
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
Application number
EP19820303943
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English (en)
French (fr)
Other versions
EP0071448A1 (de
Inventor
Osamu C/O Sakaiseitetsusho Tsubakihara
Takashi C/O Sakaiseitetsusho Manno
Makoto C/O Yawataseitetsusho Imamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
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Nippon Steel Corp
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Filing date
Publication date
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Publication of EP0071448A1 publication Critical patent/EP0071448A1/de
Application granted granted Critical
Publication of EP0071448B1 publication Critical patent/EP0071448B1/de
Expired legal-status Critical Current

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    • 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
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/128—Accessories for subsequent treating or working cast stock in situ for removing
    • B22D11/1282—Vertical casting and curving the cast stock to the horizontal
    • 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
    • B22D11/20—Controlling or regulating processes or operations for removing cast stock

Definitions

  • the present invention relates to a method of continuous casting of steel and an apparatus therefor, or more in particular to a method and an apparatus for compression continuous casting of steel in which steel cast is drawn along a path including a curved reforming section and the driving force is applied to the steel cast upstream of the reforming section while the braking force is applied thereto downstream of the reforming section.
  • the steel drive torque or steel pressing force of the drive rollers upstream of the reforming section is controlled in such a manner as to apply a predetermined compressive force to the steel cast at the steel reforming section under given casting conditions.
  • the torque of the drive rollers is increased progressively with advancement of the steel cast.
  • the present invention provides a method of compression continuous casting comprising the steps of drawing a steel cast along a path including a curved reforming section by applying a driving force to driver rollers for feeding the cast upstream of said reforming section, applying a braking force to the cast downstream of said reforming section thereby subjecting said cast to a compressive force at said reforming section, and reducing the braking force when a slip occurs between said cast and at least one of said drive rollers, characterized by:
  • the casting speed is stabilized and the compressive force is maintained at a high value within a predetermined range.
  • Such a slip if caused, changes the casting speed.
  • said braking force is increased when the slip ceases, so that said driving force again approaches said predetermined limit.
  • the compressive force decreases, and if the slip is considerable, the casting speed changes momentarily.
  • the decrease in the brake force due to a slip is larger than the reduction of the brake force which is provided for eliminating the slip.
  • the drive roller and the brake roller are monitored for a slip, and if any of the rollers slips, the brake force of the brake roller is reduced, and when the slip ceases, the brake force thereof is increased again.
  • the invention also provides an apparatus for compression continuous casting in which steel cast is drawn along a path including a curved reforming section, while a drive force is applied to driver rollers means for feeding the cast upstream of said reforming section and a braking force is applied to the cast downstream of said reforming section thereby subjecting said cast to a compression force at said reforming section, said apparatus comprising means for detecting a slip between said cast and said driver roller means and means for controlling said braking force so that said braking force is reduced when the slip is detected, characterized by:
  • guide rollers including drive rollers and brake rollers are divided into a drive group upstream of a curved reforming section 1 and brake groups I and II downstream thereof.
  • the drive force of motors (not shown) coupled to the drive rollers (black circles) of the drive group and the brake force of motors (not shown) coupled to the brake rollers (black circles) of the brake groups I and II are controlled by the brake control device 2.
  • slip sensors 3, and 3 2 The slip, if any, of the drive group is detected by slip sensors 3, and 3 2 , while the slip of the brake group I is detected by slip sensors 3 3 and 3 4 , and that of the brake group II is detected by slip sensors 3 5 and 3 6 .
  • Each of these slip sensors is supplied with a signal generated by a tacho- generator coupled to one of the drive or brake rollers and a signal generated by a tacho- generator coupled to one of non-drive guide rollers.
  • the two signals are smoothed and compared with each other by the slip sensor, and if the rotational speed of the drive roller is higher than that of the non-drive guide roller by more than a predetermined value, or if the rotational speed of the non-drive roller is higher that that of the brake roller by more than a predetermined value, then the slip sensor generates a signal of high level "1", which signal is applied through an OR gate to the brake control device 2.
  • a steel cast sensor 4 1 is arranged at a predetermined position in the brake group I, so that when the leading end of the steel cast entering the particular region reaches that position, it is detected and a signal of high level "1" is generated.
  • This "1" signal is applied to the brake control device 2 as a brake start signal for the brake group I. This is in order not to start the braking operation of the brake group I before the steel cast enters the region of the brake group I by more than a certain distance (hereinafter called the effective brake distance) in view of the fact that a sufficient braking effect does not act on the steel cast unless the steel cast enters the region of the brake group I by more than the effective brake distance.
  • the effective brake distance a certain distance
  • the region of the brake group II includes a steel sensor 4 2 for generating a signal of high level "1" when the steel cast enters the region by the effective brake distance. This "1" signal is applied to the brake control device 2 as a brake start signal for the brake group II.
  • a configuration of the brake control device 2 is shown in Fig. 2.
  • the brake control device 2 is impressed with a target value indicative of the critical drive torque or motor current which is sufficiently large to maintain the speed of the motors (drive group) determined by the casting conditions, and provides the steel cast portion of the curved reforming section with a desired compressive force but not so large as to cause any slip between the steel cast and the drive rollers or the brake rollers.
  • the brake control device 2 is also supplied with an actual drive torque or motor current for driving the drive rollers.
  • the difference (error) between the critical drive torque and the actual drive torque is computed at the device 2 and an error signal representing the difference is applied to a slow ramp circuit 2a.
  • the slow ramp circuit 2a includes a limiter LMC1 and an integrator INT1.
  • the portion of the error signal above the positive limit which is predetermined by taking into consideration the characteristics of the apparatus and the operating conditions thereof and the portion thereof lower than the negative limit similarly predetermined are cut off by the limiter LMC1 so that an error signal confined within the two critical limits is applied to the integrator INT1.
  • the integrator INT1 integrates this error signal by a comparatively long predetermined time constant so that sharp variations of the error signal level are absorbed, thereby producing a stable signal level with moderate variations, if any.
  • the error signal T thus stabilized is applied to brake force proportional distributors 2b 1 and 2b 2 including operational amplifiers.
  • the distributors 2b 1 and 2b 2 are supplied, through a switch SW1a, with the load share or ratio A of the brake torque or motor current of the motors for the brake group I and, through a switch SW2a, with the load share or ratio B of the brake torque or motor current of the motors for the brake group II.
  • the distributors 2b, and 2b 2 produce outputs respectively.
  • the output of the distributor 2b 1 makes up a brake control signal for controlling the brake current for the motors for the brake group I, while the output of the distributor 2b 2 provides a brake control signal for controlling the motors for the brake group II.
  • These signals are applied to the slow ramp circuits 2c, and 2c 2 respectively, which are constructed similarly to the slow ramp circuit 2a and include a limiter for cutting off those portions of the brake current for each brake group which exceed a predetermined critical value, above which a slip may occur, and an integrator for smoothing the brake control current to minimize the unfavorable effect on the casting speed control.
  • the control signal thus smoothed is applied through the switches SW1 and SW2b to brake current control loops 2d, and 2d 2 respectively.
  • the drive speed control loops 2e, and 2e 2 are provided for driving the motors for the brake groups I and II under non-braking conditions, and are supplied with a speed indication signal for indicating the rotational speed through the switches SWIc and SW2c respectively.
  • the integrators or the slow ramp circuits 2c 1 and 2c 2 are connected with a brake reducing circuit 2f, which includes a brake cancel level setter DCV and a switch SW3.
  • a brake reducing circuit 2f which includes a brake cancel level setter DCV and a switch SW3.
  • a switch SW3 When this switch SW3 is closed, a signal corresponding to the setting of the setter DCV is applied to the integrators of the circuits 2c, and 2c 2 .
  • Each of the integrators operates in such a manner as to suspend the integration of a first input from the corresponding limiter and integrate a second input from the setter DCV negatively.
  • the output of the integrators is rapidly reduced at a rate corresponding to the second input, so that the indication value of the brake current (generation current) to the brake current loops 2d, and 2d 2 is reduced thereby to lower the brake torque of the brake motor.
  • This switch SW3 is closed when the output of the OR gate is high at "1", namely, when one of the drive rollers or brake rollers slips, and is opened when the output of the OR gate is reduced to "0" after the slip.
  • the switch SW3 opens, the integrators of the circuits 2c 1 and 2c 2 resume the integration of the first input from the limiters, so that the output thereof increases at a rate corresponding to the first input.
  • the switches SW1a to SW1c are operatively interlocked with each other; the switches SW1a and SW1b being normally open, the switch SW1c being normally closed.
  • the switches SW1a and SW1b are closed and the switch SW1c is opened.
  • the switches SW2a to SW2c are also operatively interlocked with each other in such a manner that when the output of the steel cast sensor 4 2 increases to high level of "1" indicating the detection of steel cast, the switches SW2a and SW2b are closed while the switch SW2c is opened.
  • SW4a and SW4b designate normally-open switches for controlling the drive of the steel cast at the time of drawing thereof.
  • a torque setting of the motors of the drive motor group perdetermined as mentioned above according to the casting conditions and the actual torque or current value of the motors are applied to the brake control device 2. Also, the switches SW4a and SW4b are closed. Since the steel cast sensors 4 1 and 4 2 have not yet detected the steel cast, the switches SW1c and SW2c are closed while the switches SW1b and SW2b are open, and the motors of the brake groups I and II are activated as motors at a speed corresponding to a speed indication.
  • both the brake groups I and II exert the braking force on the steel cast.
  • the braking force does not exceed the above-mentioned upper critical value, in view of the fact that this force is controlled to a target value lower than the upper critical value in consideration of the slip of the drive motors.
  • the limiter and the integrator prevent a sudden change of the total torque applied to the steel cast, and therefore the speed of the motors for the drive group is not changed greatly.
  • a slip may occur, and when such a slip occurs, the switch SW3 is closed, so that the output of the integrators of the slow ramp circuits 2c 1 and 2 C2 is sharply reduced and the braking dynamic current of the brake groups I and II is decreased thereby to sharply reduce the braking force.
  • the slip is rapidly eliminated.
  • the switch SW3 is opened, and the outputs of the integrators of the circuits 2c, and 2 C2 are restored at a slow rate by the difference between the braking current target value and actual braking current, thus increasing the braking force.
  • the switches SW4a and SW4b are opened, while the switches SW1b and SW2b are opened and the switches SW1c and SW2c are closed, with the result that the motors of the brake groups I and II are driven as motors at the designated speed.
  • the outputs of the steel cast sensors 4, and 4 2 and the output of the OR gate are applied to a control board and a drive group motor control system.
  • the motor torque and the motor current are proportional to each other and, in the above description of the embodiment, the motor torque has the same meaning as the motor current.
  • Fig. 3a shows the drawing speed of the steel cast
  • Fig. 3b shows a drive torque setting of the motor for the drive group
  • Fig. 3c shows an energizing current (corresponding to torque) of the motors for the drive group
  • Figs. 3d and 3e show a drive current (+) for speed control and a generation current (corresponding to the braking torque) for braking operation of the motors of the brake groups I and II respectively.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)

Claims (8)

1. Verfahren zum Druchstranggießen mit den folgenden Verfahrensschritten:
Ziehen eines Stahlstrangs entlang eines Wegs einschließlich eines gekrümmten Umformabschnitts (1) durch Anwenden einer Antriebskraft auf Antriebswalzen zum Zuführen des Strangs oberhalb des Umformabschnitts, Anwenden einer Bremskraft auf den Strang unterhalb des Umformabschnitts, wodurch dor Strang am Umformabschnitt einer Druckkraft ausgesetzt wird, und Verringern der Bremskraft, wenn zwischen dem Strang und mindestens einer der Antriebswalzen ein Schlupf auftritt, gekennzeichnet durch:
Steuern der Bremskraft derart, daß dei Antriebskraft einen vorbestimmten Grenzwert, der zur Verhinderung eines Schlupfs zwischen den Antriebswalzen und dem Strang gewählt wurde, nicht überschreitet, aber sich dem Grenzwert so nahe als möglich annähert.
2. Verfahren nach Anspruch 1, wobei die Bremskraft erhöht wird, wenn der Schlupf beendet ist, so daß sich die Antriebskraft wieder dem vorbestimmten Grenzwert annähert.
3. Verfahren nach Anspruch 2, ferner Gekennzeichnet durch die folgenden Verfahrensschritte:
Aufteilen des Abschnitts unterhalb des gekrümmten Umformabschnitts in mehrere Bremsbereiche (I, 11) und Bestimmen des Verhältnisses der Bremskraft, die von jedem der Bereiche Übernommen wird, und
Verteilen des Steueranteils der Bremskraft auf die Bereiche gemäß diesem Verhältnis, so daß die Bremskraft jedes Bereichs gamäß der von diesem Bereich übernommenen Bremskraft gesteuert wird.
4. Verfahren nach Anspruch 3, ferner gekennzeichnet durch folgenden Verfahrensschritt:
Steuern der Bremskraft jedes Bereichs durch Glätten des Steueranteils der Bremskraft, der auf die Bereiche aufgeteilt wird, um eine plötzliche Änderung der Bremskraft zu verhindern.
5. Vorrichtung zum Druckstranggießen, wobei ein Stahlstrang entlang eines Wegs einschließlich eines gekrümmten Umformabschnitts (1) gezogen wird, während eine Antriebskraft auf eine Antriebswalzeneinrichtung zum Zuführen des Strangs oberhalb des Umformabschnitts und eine Bremskraft auf den Strang unterhalb des Umformabschnitts ausgeübt wird, wodurch der Strang am UMformabschnitt einer Druckkraft ausgesetzt wird, und wobei die Vorrichtung eine Einrichtung (31, 3z) zum Erfassen eines Schlupfs zwischen dem Strang und der Antriebswalzeneinrichtung und eine Einrichtung (2f) zum Steuern der Bremskraft derart aufweist, daß die Bremskraft verringert wird, wenn der Schlupf erfaßt wird, gekennzeichnet durch:
eine Einrichtung (2a) zum Vergleichen des tatsächlichen Antriebsdrehmoments der Antriebswalzeneinrichtung mit einem bestimmten Grenzwert des Antriebsdrehmoments, wodurch ein Steuersignal (T) gemäß dem Unterschied zwischen den beiden Werten erzeugt wird, und
eine auf das Steuersignal ansprechende Einrichtung (2b1, 2b2, 2c1, 2c2, 2d1, 2d2) zum Steuern der Bremskraft derart, daß das tatsächliche Antriebsdrehmoment der Antriebswalzeneinrichtung sich dem bestimmten Grenzwert nähert, wenn kein Schlupf erfaßt wird.
6. Vorrichtung nach Anspruch 5, wobei die Steuersignalerzeugungseinrichtung eine erste Einrichtung (LMC1) aufweist, die verhindert, daß das Steuersignal einen bestimmten Grenzwert überschreitet, und eine zweite Einrichtung (INT1) zum Glätten des Steuersignals.
7. Vorrichtung nach Anspruch 6, ferner gekennzeichnet durch:
eine Einrichtung (2bi, 2b2) zum Aufteilen des Teils der Vorrichtung unterhalb des Abschnitts in mehrere Bremsbereiche (I, 11) und Verteilen des Steuersignals auf diese Bereiche gemäß einem bestimmten Verhältnis der Bremskraft, die von jedem Bereich übernommen wird; und
eine für jeden der Bereiche vorgesehene Einrichtung (2ci, 2c2) zum Erzeugen eines Bereichssteuersignals zum Steuern der Bremskraft jedes Bereichs als Antwort auf das verteilte Steuersignal.
8. Vorrichtung nach Anspruch 7, wobei die Erzeugungseinrichtung für das Bereichssteuersignal eine dritte Einrichtung (SLMC1, SLMC2) aufweist, die verhindert, daß das Bereichssteuersignal einen bestimmten Grenzwert übersteigt, und eine vierte Einrichtung (SINT1, SINT2) zum Glätten des Bereichssteuersignals.
EP19820303943 1981-07-28 1982-07-26 Verfahren und Einrichtung zum Stranggiessen von Stahl Expired EP0071448B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP11820881A JPS601108B2 (ja) 1981-07-28 1981-07-28 鋼の連続鋳造方法
JP118208/81 1981-07-28

Publications (2)

Publication Number Publication Date
EP0071448A1 EP0071448A1 (de) 1983-02-09
EP0071448B1 true EP0071448B1 (de) 1986-03-12

Family

ID=14730871

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19820303943 Expired EP0071448B1 (de) 1981-07-28 1982-07-26 Verfahren und Einrichtung zum Stranggiessen von Stahl

Country Status (6)

Country Link
EP (1) EP0071448B1 (de)
JP (1) JPS601108B2 (de)
AU (1) AU530786B2 (de)
CA (1) CA1195088A (de)
DE (1) DE3269813D1 (de)
ES (1) ES514418A0 (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6146364A (ja) * 1984-08-09 1986-03-06 Nippon Kokan Kk <Nkk> 水平連続鋳造機における鋳片の流れ止め制御方法
KR910009363A (ko) * 1989-11-03 1991-06-28 원본미기재 수평 연속 주조기용 동작 제어 시스템
LU90402B1 (de) * 1999-05-31 2000-12-01 Wurth Paul Sa Richttreiberanlage fuer eine Stranggiessanlage fuer Knueppel und Vorbloecke
DE10007706A1 (de) * 2000-02-19 2001-08-23 Sms Demag Ag Verfahren und Anlage zum Gießen von Vorprodukten in einer Stranggießanlage
JP4623619B2 (ja) * 2001-07-18 2011-02-02 新日本製鐵株式会社 連続鋳造機の鋳片圧縮力制御装置
CN111185584B (zh) * 2020-02-27 2021-10-01 北京首钢股份有限公司 一种板坯铸机铸坯控制的方法及系统

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2144750B1 (de) * 1971-07-02 1976-08-06 Mannesmann Ag
US4090549A (en) * 1974-07-12 1978-05-23 United States Steel Corporation Method and mechanism for determining forces on a solidifying casting
US4148349A (en) * 1976-05-08 1979-04-10 Yutaka Sumita Method for controlling slippage between rolls and a slab in a continuous compression casting apparatus
US4056140A (en) * 1976-10-20 1977-11-01 United States Steel Corporation Method and mechanism for controlling forces in a continuous-casting machine

Also Published As

Publication number Publication date
AU530786B2 (en) 1983-07-28
CA1195088A (en) 1985-10-15
JPS5820361A (ja) 1983-02-05
EP0071448A1 (de) 1983-02-09
AU8625082A (en) 1983-03-17
JPS601108B2 (ja) 1985-01-11
ES8401872A1 (es) 1984-01-01
DE3269813D1 (en) 1986-04-17
ES514418A0 (es) 1984-01-01

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