SU884769A1 - System for automatic adjusting of stand eqvivalent rigidity - Google Patents

Description

The invention relates to the automation of rolling mills, namely, systems for automatically controlling the thickness of the rolled strip. A device for adjusting the gap between the rolls in a cage is known in which the rigidity of the cages is kept constant and decreases in size from the first cage to the last. For this purpose, a device was introduced into the device, where data on deviation of strip thickness, rolling forces, and elastic deformation coefficient of stand 1 arrive. The disadvantage of this device is that the distribution of equivalent rigidity of the stands is constant without taking into account the actual eccentricity of the mill rolls, as a result the quality of rolled products along the longitudinal thickness of the strip deteriorates. It is also known to control the gap between the rollers, in which the output signals of the roller position sensor and the rolling force sensor are summed up in the measuring unit to obtain an error signal which is fed through the eccentricity de-blocking unit to the pressure screw drive control system 2J. The main disadvantage of this system is that, in the process of eliminating the influence of the eccentricity of the rolls, the control of the strip thickness by perturbation on the rolling side deteriorates, which leads to a deterioration in the quality of the rolled strip. Closest to the proposed technical essence and the achieved result is a system comprising a rolling force sensor, a stand stretching modulator, a thickness gauge, an inverter, a unit of equivalent rigidity, a hydraulic actuator with a servo drive and a totalizer (subtraction unit), a position sensor of the hydraulic actuator The hydraulic pressure device is connected with a servo drive and an adder, the first input of which is connected to a position sensor of the hydraulic pressure device, the output The driver of the rolling force through the stand stretcher modulator, where the thickness gauge and unit of equivalent rigidity are also connected, are connected to the second input of the adder Z. The disadvantage of the known system is that the operator chooses the equivalent rigidity of the stand without an objective criterion of the quality of the rolling process, not taking into account This is an eccentricity of the rolls, which leads to a deterioration in the quality of the strip. The purpose of the invention is to improve the quality of the rolled strip by eliminating the influence of the eccentricity of the rolls on the longitudinal th thickness. This goal is achieved in that a known system comprising a hydraulic pressure device connected to a servo drive and an adder, to the first input of which a position sensor of the hydraulic pressure device is connected, a rolling force sensor connected to the first input of the subtracting unit, to the second input of which the gain master is connected, the alternating component of the signal component, the filter block, the extremal block, the comparison block, the reference voltage master, and the multiplying block are additionally installed; Sensor of rolling force through a variable component extraction unit, a filter unit and an extremal unit are connected to the first input of the comparator unit, to the second input of which the reference voltage adjuster is connected, the output of the comparator unit is connected to the first input of the multiplication unit, to the second input of which output is connected the subtracting unit; the output of the multiplying unit is connected to the second input of the adder. The quality of the rolled strip is enhanced by automatically adjusting the equivalent stiffness of the grade to a level that limits the effect of the eccentricity of the rolls on the thickness of the strip during the rolling process. The drawing shows the block diagram of the device. The automatic adjustment system of equivalent rigidity of the rolling stand 1 contains a hydraulic pressure device 2 connected to the servo driver 3 and the adder C, to the first input of which the position sensor 5 is connected, the rolling force sensor 6 connected to the first input of the subtracting unit 7 to the second input A rolling force setting unit 8 is connected, in addition, a rolling force sensor 6 through a variable component extraction unit 9, a filter unit 10 and an extreme unit 11 is connected to the first input of the comparison unit 12, to the second input of which The reference voltage adjuster 13 is connected, the output of the comparison unit 12 is connected to the first input of the multiplication unit It, and the output of the subtractive unit 7 is connected to its second input, the output of the multiplication unit I is connected to the second input of the adder D. Extreme block 11 contains the first switch 15 , the first output of which is connected to the first input of the first analog-digital converter 16, and the second output is connected to the first input of the second analog-digital converter 17, the outputs of the analog-digital converters 16 and 17 are connected to the first and second inputs the second switch 18, the first and second terminals of which are connected to the first and second inputs of the key circuit 19, as well as to the first and second inputs of the digital comparator 20, the output of the Digital comparator 20 is connected to the third input of the key circuit 19, the second input of the first switch 15 and the input a clock signal generator 21, the output of which is connected to the third turns of the first switch 15 and the second switch 18, the second inputs of analog-digital converters 16 and 17 are connected to a signal output device End of Work (not shown). The device works as follows. Before rolling the next roll, the rolls are placed in the face. In this case, the signal from the output of the rolling force sensor 6, which characterizes the pressure of the roll on the roll, contains a constant component determined by the force of the forgings and a variable component characterizing the eccentricity of the rolling rolls / and enters the variable component extraction unit 9. The signal from the output of the variable component extraction unit 9 enters the filter unit 10, which separates the low-frequency sinusoidal component (the total eccentricity of the lower and upper support rolls and outputs this signal to the extreme unit 11. In the extreme unit 11, the maximum value of this variable is selected its memorization and output to the input of comparator unit 12. A clock signal generator with an adjustable predetermined discreteness outputs clock signals to control the switches 15, and 18 (key triode assemblies. The first and second analog-to-digital converters 16 and 17 of the extreme block 11 are connected periodically to the output of the filter block 10 periodically. The values of the input signal of the envelope variable component of the forks of the analog-to-digital converters 16 and 17 are converted into binary code, which by switch 18 is connected to the first and second inputs of digital comparator 20 alternately via signals of the clock signal generator 21. The switching resolution of the switches 15 and 18, determined by the frequency of the generator 21, of the clock signals, and the dead zone of the digital comparator 20, which is set when the system is tuned, are determined by the Maximum difference in the diameters of the support rolls and their speed of rotation. In digital comparator 20, a periodic comparison is made from the generator signals of 21 clocking signals received at its first and second inputs. When the signal arriving at the first input of the digital comparator 20 exceeds the signal arriving at its second input by the dead zone of the digital comparator 20, a logic unit signal appears at its output, which closes the clock signal generator 21, opens the key circuit 13 and the control of the switches 15 and 18 is terminated. In this case, the maximum value of the envelope variable of the signal of the intake force comes from the output of the extremal unit 11 to the first input of the comparator unit 12, A signal characterizing the level of the permissible eccentricity of the rolls, determined by the tolerance on the thickness of the rolled strip, is supplied to the second input of which QT of the reference voltage adjuster 13. The deviation signal from the output of the comparator unit 12 is fed to the second input of the multiplication unit 1k, where a controlling effect is created on the installation of the rod of the hydraulic pressure device 2 in the position corresponding to the required rigidity of the stand required for high-quality strip rolling. This completes the process for setting the equivalent stiffness of the stand. In the strip rolling process, the signal of the current value of the rolling force from the output of the sensor 6 is applied to the first rolling force of the subtracting unit 7. where it is compared with the specified value of the rolling force. The deviation signal of the current value of the rolling force from its predetermined value from the output of the subtracting unit 7 is fed to the first input of the multiplication unit k as one of the factors to the second input of this unit as the second factor and from the output of the comparator unit 12 the deviation signal of the maximum value of the variable component rolling, measured at the rolls bottoming (the signal of the maximum value of the eccentricity of the rolls), from the reference value UonC of the output of the block 14 multiplied by. the second input of the adder k receives a signal, the polarity and amplitude of which is determined by the product of the value of the rolling force deviation signal from the setpoint and the maximum roll mill eccentricity deviation signal value from the given C and the first input of the adder receives a signal proportional to the current value of the position of the press cylinder of the pressure device, from the output of the sensor 5 position. The output of the adder 4 generates a signal representing the algebraic sum of the signal of the position of the rod of the hydraulic pressure device 2 and the rolling force deflection signal with a scaling factor, the sign and value of which is determined by the deviation of the maximum measured value of the eccentricity of the rolls from its given value equal to Uoy. A signal from the output of the adder is fed to the input of the servo drive 3 to control the pressure in the hydraulic pressure device 2, providing positive or negative feedback on the deviation of the rolling force with the required transfer coefficients to achieve the required thickness of the strip at the exit of the stand,

If the permissible deviation of the thickness of the strip at the exit of the stand DI is known, then the maximum allowable eccentricity of the rolls d5 and the corresponding UQ, can be determined at which the stand operates in the normal equivalent stiffness mode. At large values of & S, the equivalent stiffness of the stand should be reduced, and at smaller values, it can be increased to compensate for the effect of tackle on the output thickness || (otherwise. The value of AS. Is determined by the following (named after

D5

/

op

m

where m is the real modulus of rigidity of the stand and q - modulus of plastic deformation

rolled metal. Upon completion of the roll rolling, the inputs of the analog-digital converters 16 and 17 of the extreme block 11 receive a logical signal. The end of the work, the extreme extreme block 11 is transferred to its initial state.

Claims (3)

1.CNII TEI World Cup, Review of Seri 7, no. Cold rolling mills of the company Ishikawjima Harim Jiukoge .. Chermetinformatsi, 197. 2. Patent of Great Britain No. 1418758, cl. G 05 O 5/03, 1972. 3. US patent number 3793860, cl. 27-11, B 21 B 37/21, 197t.