SU394121A1 - DEVICE FOR REGULATING THE SPEED OF ROTATION OF THE WORKING ROLLS OF THE MILLING AND ROLLING BITS - Google Patents

Description

one

A device is known for controlling the speed of rotation of the working rolls of an oblique rolling mill and tube rolling, including blocks of derivatives of a controlled parameter, a block for comparing derivatives of a controlled parameter, an actuator.

The proposed device is different in that. that, in order to accurately take into account the axial slip of the rolls relative to the surface of the rolled material, the device is equipped with a motor current comparison unit, an adder, a product axial speed derivative block, a rotation roller speed derivative derivative block, the last two blocks are connected to the speed derivative comparison blocks, which through the adder (its input is connected with the output of the engine of those of the engine) is connected to the actuator.

The drawing shows a block diagram of the rotational speed controller of the work rolls. The block diagram consists of the work rolls of the mill /, the crushed stand 2, the rolled product 3, Yakor engine 4, current sensor dhngatel 5, driver of current 6, device for comparing engine current with task 7, totalizer 8, amplifier 9, repair device ( generator, thyristor converter, converter

frequency ...) 10, tachogenerator / U, axial speed sensor of product 12, unit of the first derivative of rotational speed of work rolls over time 13, unit of the first derivative of axial velocity of product over time M, device comparing the sign of first derived velocities over time 15, energy source sixteen.

To maintain the current at a given level, the speed regulator of the work rolls includes a motor current sensor 5, a current driver 6, a device comparing the current to task 7, an amplifier I, an energy source 16, and an actuator 10 providing an increase or decrease in the rotation speed of the rolls depending on the value of the output signal of the amplifier 9. The actuator can be a generator, a tripristor converter, a frequency converter, etc. To account for the slip of the work rolls, The controller is provided with an axial speed sensor for pipe 12 and a tacho generator 11, which is a sensor for the rotation speed of the work rolls, in the surface of the rolled product. Sensors // and 12 are associated respectively with blocks 13 and M of the first derivative velocities over time. blocks of derivatives are associated with a device. comparison of the sign of derivatives of 15, which

serves to compare the sign of the left derivative of the speed of rotation of the pipe and the first derivative of the speed of the product; in this case, if the derivative is of the same sign, a signal appears at the output of the device allowing the engine to accelerate, if the derivatives have different signs, then there is no enabling signal. The output of the device for comparing the characters of derivatives is connected to the input of the summing device, which serves to prohibit the passage of the control signal from the comparison unit 7 to the actuating device 10. The operation of the pipe mill with the regulator is as follows.

Before the task of the workpiece, the rollers rotate at a speed that provides a good condition for gripping. This speed is set by the operator. After the workpiece is captured by rollers, which can be monitored, for example, by the sensors of the axial speed of the product 12, the current of the engine 4 increases. The signal from the motor current sensor 5 is fed to a motor current comparison device 7 with a current driver b and through the summing device 8 and the amplifier 9 controls the actuator 10, which increases the current of the engine core 4 to an acceptable value, thus increasing the speed of rotation of the engine and associated 2 work rolls with it through a gear stand. The axial velocity of the article 3, controlled by the sensor 12, also increases to a certain limit determined by the sliding conditions. The first derivative of the axial product speed with respect to the time taken from the block of the first derivative 14, and the first derivative of the rotational speed of the rolls removed from the block of the first derivative 13 are compared with the comparison symbol of the derivatives 15, the output of which is fed to the summing device 8.

If an increase or decrease in the speed of the motor shaft causes an increase or decrease in the speed of movement of the product, respectively, then the signs of the first derivatives of the speed of the engine and the product will be the same; in this case, the summing device 8 receives a signal permitting engine acceleration. The motor will accelerate if the motor current detected by sensor 5 is less than the current set by driver 6.

If an increase in the speed of rotation of the motor shaft causes a decrease in the speed of movement of the product, the signs of the first derivatives will be different. Then, from the block of comparison of the sign of the derivatives 15, the totalizer signal will arrive at the summing device 8 and the actuator 10 will decelerate the engine until the derivatives become equal to zero or have the same sign. Engine braking will occur even if the motor current is less than the allowable value. Thus, for the given rolling conditions, the axial speed of the rolled product is maximized. After the end of rolling, i.e., after the product leaves the rolls, the actuator 10 reduces the speed of rotation of the work rolls to the value set by the operator for idling, and the cycle repeats.

Subject invention

A device for controlling the speed of rotation of the working rolls of an oblique rolling mill and pipe raokatka, including blocks of derivatives of a controlled parameter, a comparison block of derivatives of a controlled parameter, an actuator, characterized in that, in order to accurately take into account the axial sliding of the rolls relative to the surface of the rolled material, the device is equipped with a comparison block motor currents, an adder, a block of the derivative of the axial velocity of the product, a block of the derivative of the rotational speed of the work rolls, and two last one unit connected to the comparison unit derivatives velocity which, via an adder (its input coupled to the output currents of the motors comparison unit) is connected to the actuator.