RU2023530C1 - Method of ingots continuous casting machine control - Google Patents

Abstract

FIELD: metallurgy. SUBSTANCE: during control of ingots continuous casting machine, operating in cyclic "pulling and pause" mode, they, changing parameters of pulling and working out control action for mechanism of pulling change speed of casting and step of pulling in every cycle according to average deviation of actual step of pulling from given one. Time of cycle is changed in compliance with given speed of casting, actual step pulling in current cycle, taking into account deviation of actual speed of casting from given one. EFFECT: method is used to control ingots continuous casting machines. 1 dwg

Description

 The invention relates to automation of casting on continuous casting machines of horizontal type with one-sided cyclic pulling of an ingot from a fixed mold.

 A known method for automatically controlling a machine for continuous casting of billets, which consists in the fact that by measuring the surface temperature of the billet at the exit of the mold, the duration of the pause time interval is controlled, and thus the mold is kept at a constant temperature and the thickness of the crust of the solid phase of the billet [1].

 The disadvantage of this method is the inability to control the speed and the pulling step.

 There is also known a device for automatically controlling the process of drawing a workpiece in a horizontal continuous metal casting plant, consisting of a metal receiver, a mold, a drawing device, a cooler flow controller, a workpiece draw frequency controller, the inputs of which are connected to an ingot temperature meter and a cooler flow sensor, a cooler flow regulator, adder and control rectifier and equipped with a compensating differential transformer converter, the toric winding of which is electrically connected to the secondary winding of the master differential transformer installed on the control panel, both windings connected to the input of the phase-sensitive rectifier, the output of which is connected to the input of the amplifier, and the output of the amplifier is connected to an electric screw pair with a rod, and the output shaft of the gearbox with an electric drive stand is mechanically connected to the crosshead using an electromagnetic clutch with a winding connected to the power output controlled ypryamitelya, whose input is connected to the relay pause duration input pin chain which is closed limit switch mounted on the bar at the end point of the return stroke of the first stand [2].

 A disadvantage of the known device is the inability to ensure the stability of steel casting at the GMNZ due to the lack of measurement of the drawing parameters (pitch and time of drawing, pause time).

 The closest in technical essence to the proposed one is the method of controlling the continuous casting machine, which consists in the fact that when zero imbalance is reached between the actual and predetermined surface temperature values of the workpiece at the exit from the mold in the pull-pause cycle, the draw time is reduced without changing the pause time, until an imbalance between the actual and set temperature values is obtained, then the stretching is carried out at the reached stretching time, reducing the pause time, to achieving zero imbalance between the actual and predetermined temperature values, then the process is repeated until cyclicity is acceptable for a given machine [3].

 The disadvantage of this method is the lack of measurement of the pulling parameters (pulling step, pulling time and pause time), which does not allow to stabilize the casting speed and pulling step under conditions of possible slippage of the ingot in the pulling mechanism and drive operation on uncontrolled transient processes of acceleration and braking.

 The purpose of the invention is the provision of technology-specified casting speed and pulling step on a continuous type continuous casting machine under conditions of possible slippage of the ingot in the pulling mechanism and drive operation on uncontrolled transient processes of acceleration and braking without reaching a steady speed.

 The goal is achieved in that the speed and the pulling step are maintained in each cycle, taking into account the possible slipping of the ingot in the pulling mechanism, and the task for moving the ingot is determined taking into account the average deviation of the actual pulling step from the set, and the cycle time in accordance with the given casting speed, the actual step of pulling the current cycle and taking into account the deviation of the actual casting speed from the set.

 The proposed method for maintaining a given casting speed and pulling step is implemented as follows.

At the beginning of each stretch, the time of the previous cycle is measured τ _c (n-1).

sign [V^Ф(i)-V^З(i)]
Определяют задание на перемещение слитка
H^ц(n) = H^З(n)-

[H^Ф(i)-H^З(i)]
По перемещению слитка на величину H^ц(n) на привод механизма вытягивания выдается команда "Стоп". Привод переходит в режим торможения. После остановки слитка принимается сигнал "Пауза". В начале каждой паузы измеряют фактический шаг Н^ф(n). Определяют расчетное время цикла
τ_ц ^p(n) = H^ф(n)/V^з(n) + Δτ_ц(n) где V - скорость литья; Н - шаг вытягивания; τ_ц - время цикла;
τ_в - время вытягивания, τ_n - время паузы;
n - номер текущего цикла вытягивания;
τ_ц ^p(n) - расчетное время цикла n-го цикла вытягивания;
Δτ_ц(n) - корректировка времени цикла для n-го цикла вытягивания;
V^з(n) - заданная скорость литья n-го цикла вытягивания;
Н^з(n) - заданный шаг вытягивания n-го цикла вытягивания;
Н^ц(n) - задание на перемещение слитка в n-м цикле вытягивания;
τ_ц(n) - фактическое время цикла n-го цикла вытягивания;
V^ф(n) - фактическая скорость n-го цикла вытягивания;
Н^ф(n) - фактический шаг n-го цикла вытягивания.The speed of the previous cycle is calculated.
V ^f (n-1) = H ^f (n-1) / τ _c (n-1) and the correction of the cycle time
Δτ _c (n) = 0.01

sign [V ^Ф (i) -V ^З (i)]
Define the task to move the ingot
H ^c (n) = H ^C (n) -

[H ^F (i) -H ^W (i)]
When the ingot is moved by the value of H ^c (n), the Stop command is issued to the drive of the drawing mechanism. The drive goes into braking mode. After the ingot stops, a “Pause" signal is received. At the beginning of each pause, the actual step H ^f (n) is measured. Estimated estimated cycle time
τ _c ^p (n) = H ^f (n) / V ^s (n) + Δτ _c (n) where V is the casting speed; H is the pulling step; τ _c is the cycle time;
τ _in - pulling time, τ _n - pause time;
n is the number of the current pull cycle;
τ _c ^p (n) is the estimated cycle time of the nth pull cycle;
Δτ _c (n) - correction of the cycle time for the n-th pull cycle;
V ^C (n) is the specified casting speed of the n-th pulling cycle;
N ^s (n) is a given stretch step of the nth pull cycle;
N ^c (n) - task to move the ingot in the nth pull cycle;
τ _c (n) is the actual cycle time of the nth pull cycle;
V ^f (n) is the actual speed of the nth pull cycle;
H ^f (n) is the actual step of the nth pull cycle.

 After the estimated cycle time, the Start command is issued to the drive of the pulling mechanism. The drive goes into acceleration mode. From the beginning of the movement of the ingot, the “Pull” signal is received.

 An additional search did not reveal sources with characteristics similar to the distinguishing features of the proposed method, which allows us to conclude that they meet the criteria of "Novelty" and "Inventive step".

 The drawing shows a diagram of the proposed device.

 A device that implements this method contains a metal detector 1, a mold 2, an ingot 3, a pinch roller 4, a pulling mechanism 5. The device consists of a sensor 6 pulses located on the pinch roller 4, a sensor 7 phases of the pull cycle, a drive 8 of the mechanism 5 pull, the adder 9 pulses, block 10 calculates the correction of the cycle time and the task of moving the ingot, determinant 11 phase change, meter 12 time parameters cycle, block 13 comparing tasks for moving the ingot and the actual pulling step, block 14 for specifying the speed and step of pulling, block 15 for calculating the estimated cycle time, block 16 for comparing the calculated and actual cycle time.

 The device operates as follows.

 The liquid metal from the metal receiver 1 enters the mold 2 and hardens in the pauses between the extrusions.

 The ingot 3 is periodically drawn out of the mold 2 by the pulling mechanism 5. The signal from the output of the sensor 7 phases goes to the input of the determinant 11 phase change. At the first output of the determinant of the phase change 11, a pull-on start signal is generated, which is fed to the first inputs of the calculation unit 10 and the comparison unit 13 and initiates their operation. At the second output of the determinant of the phase change, a pause start signal is generated, which arrives at the first inputs of the calculation unit 15 and the comparison unit 16 and initiates their operation.

The signals from the sensor 6 pulses are fed to the first input of the adder 9, the output of which forms a signal corresponding to the actual step N ^f . The latter enters the second inputs of blocks 10, 15 of the calculation and block 13 comparison. The signal from the output of the measuring instrument 12 of the time parameters corresponding to the cycle time is fed to the third input of the computing unit 10 and the second input of the comparing unit 16.

 The signal from the first output of the speed setting unit and the pulling step 14 enters the fourth input of the computing unit 10 and the third input of the computing unit 15. The signal from the second output of the speed setting unit 14 and the pulling step is fed to the fifth input of the computing unit 10.

On the initiative of the start pull signal, the calculation unit 10 generates a cycle time correction signal Δτ _c at the first output, which is fed to the fourth input of the calculation unit 15. At the second output of the computing unit 10, a task signal for moving the ingot N ^c is generated, which is fed to the third input of the comparison unit 13. At the third output of the computing unit 10, a pulse signal appears, which arrives at the second input of the adder 9 and at the input of the time meter 12 and initiates their zeroing.

 Block 13 comparison begins to work on the initiative of the start of the signal at the first input. When the signals of the actual step and the job to move (NF and NU) coincide at the output of the comparison unit 13, the Stop signal appears, which is fed to the first input of the drive 8 of the pulling mechanism 5.

 Braking of the drive begins and the pulling of the ingot stops, which is detected by the 7-phase sensor.

The determinant 11 phase change, removes from the first output signal the beginning of the pull. Simultaneously, at the second output of the determinant of the phase change, a pause start signal arrives at the first input of the calculation unit 15, the output of which is the calculated time signal τ _c ^p , which is fed to the third input of the comparison unit 16. Block 16 comparison begins to work on the initiative of the start pause signal at the first input. When the signals of the actual and estimated cycle time (τ _c and τ _c ^p ) coincide at the output of the comparison unit 16, the “Start” signal appears, which is fed to the second input of the drive 8 of the pull mechanism 5. The acceleration of the drive begins, and at the moment of starting the extrusion of the ingot, the phase 7 sensor gives a signal to the input of the phase change determiner 11, which removes the pause start signal from the second output and outputs the pull start signal at the first output. The cycle repeats.

Claims (1)

 METHOD FOR CONTROL OF THE PREPARATION MACHINE FOR CONTINUOUS CASTING MACHINE, including operation of the pulling mechanism in a cyclic pull-pause mode with changing pull parameters, generating a control action on the drive of the pull mechanism, characterized in that the change in casting speed and pull step is carried out in each cycle according to the average deviation of the actual pull step from the set, and the cycle time - in accordance with the set casting speed, the actual pulling step of the current cycle and taking into account the deviation second casting speed from the set.

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