SU1632541A1 - Device for control of mill stand speed in continuous cold strip mill - Google Patents

Abstract

The invention relates to controlling the speed of the rolls of a stand of continuous cold rolling mills. The goal is to improve the accuracy of maintaining intercellular tensions in the modes of filling the strip and low rolling speed. Negative feedback for static momentum is applied to the input of the proportional-integral speed controller, which reduces the mechanical characteristics of the electric drive as a function of the deviation of the intercellular tension from the specified value. 2 Il. with S (L

Description

The invention relates to controlling the rotational speeds of rolling mills.

The aim of the invention is to improve the accuracy of maintaining intercellular tensions in the modes of filling the strip and low rolling speed.

FIG. 1 shows a functional diagram of the device; in fig. 2 - the characteristic of a nonlinear element.

The device comprises a stand 1 electric drive, a speed controller 2, a speed reference 3, a speed sensor 4, a multiplication unit 5, a static moment meter 6, a nonlinear element 7, an adder 8, a nonlinear element 9, a multiplication unit 10 and a meter 11 for interflux tension wives from a given.

The device works as follows.

The speed reference signal is fed to the input of the speed controller 2 from the output of the setpoint 3 speeds. The output signal from the multiplication unit 5, applied to the input of the speed controller 2, ensures the operation of the electric drive 1 with a reduced mechanical characteristic, at which the speed of the electric drive varies depending on the magnitude of the static moment. The softening of the mechanical characteristic promotes the self-leveling of the intercellular tensions of the strip in the mill, since, as the tension changes (and, accordingly, the static mlment), there occurs a counter-change in velocity

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electric drive, reducing the change in tension.

However, a simple softening of the mechanical characteristic, facilitating self-leveling, does not maintain the tension equal to the given one. This is due to the connection from the output of the meter 11 to the deviation of the tension from the multiplier 10 set to the input. By this connection, the tension control loop closes, with which the tension is kept equal to the set point.

Contour enhances self-leveling action. When the voltage is less than the specified value, the tension deviation signal is negative, the degree of softening of the mechanical characteristic (output of the adder 8) decreases, the speed of the electric drive increases and the tension increases.

When the tension is greater than the specified, on the contrary, there is an additional softening of the mechanical characteristic, which leads to an additional decrease in the speed of the electric drive and a decrease in tension.

Nonlinear element 9 (with a diode characteristic) blocks the passage to the input of block 5 by multiplying a negative signal, preventing the drive from operating with a positive coupling at a static moment (with upward mechanical characteristic). With a working rolling speed, greater filling, the effect of softening the mechanical characteristics of the electric drive on self-leveling tension is significantly weakened, which allows switching to work with rigid mechanical characteristics, which provide better conditions for maintaining the specified strip thicknesses. In accordance with the characteristic of the non-linear element 7 (Fig. 2), as the rolling speed increases, smooth switching off of the mechanical

A device for controlling the speed of a stand of a continuous cold rolling mill strip containing speed references, a speed controller, an electric drive, a speed sensor, an engine static torque meter, a first multiplication unit, a first non-linear element, a measure of the intercellular tension from the target, and the output of the generator speed is connected to the first input of the speed controller and to the input of the first nonlinear element, the output of the speed controller is connected to the input of the electric drive, the second input of the speed controller is connected With the output of a speed sensor connected to an electric drive, the output of the first multiplication unit is connected to the third input of the speed regulator, the first input of the first multiplication unit is connected to the output of the static moment meter, characterized in that, in order to increase the maintenance of the intercellular tension in the modes filling the strip and low rolling speed, it is equipped with an adder, a second block multiplying both and a second nonlinear element, and the second input of the first block of the head is connected to the output of the adder via the second nonlinear electric the input, the first input of the adder is connected to the output of the first nonlinear element, the second input of the adder is connected to the output of the second multiplication unit, the first input of which is connected to the output and the measurer of the interflective n

which characteristics and at speed

higher filling electric work-, t zheni, and the second input - with output

em with a rigid mechanical characteristic of the first nonlinear element.

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due to the proportional integral speed controller.

Thus, the use of the proposed device in comparison with the known one provides an increase in the accuracy of maintaining tension in the filling modes and at low rolling speeds.

Claims (1)

Invention Formula A device for controlling the speed of a stand of a continuous cold rolling mill strip containing a speed controller, a speed controller, an electric drive, a speed sensor, a static engine torque meter, a first multiplication unit, a first non-linear element, a measure of the interfing tension from the set one, and the output speed controller is connected to the first input of the speed controller and to the input of the first non-linear element, the output of the speed controller is connected to the input of the electric drive, the second input of the speed controller and connected to the output of a speed sensor connected to an electric drive, the output of the first multiplication unit is connected to the third input of the speed controller, the first input of the first multiplication unit is connected to the output of a static moment meter, which in order to improve the accuracy of maintaining cell tension in the modes of filling the strip and low rolling speed, it is equipped with an adder, a second multiplication unit and a second nonlinear element, and the second input of the first multiplication unit is connected to the output of the adder via volts swarm nonlinear element, the first adder input connected to the output of the first nonlinear element, the second input of the adder coupled to the output of the second multiplying unit, a first input coupled to an output meter interstand deviation of LLW- I / y /  j ABOUT H cr / o lchiya