SU915999A1 - Method of determining tension in rolled stock of four-high continuous rolling mill - Google Patents

Description

The invention relates to the rolling of metals and can most effectively be used in rough continuous groups of universal hot-rolling broadband mills.

The practice of continuous strip mills shows that the effect of interstand tensions (backwaters) leads to variations in the width and thickness of the strips. Therefore, the task of selecting the interstand tension (backpressure) and maintaining it at a constant level during the rolling process is relevant and its positive solution 15 will make it possible to improve the quality of the finished product at the mill.

The closest to the proposed technical essence and the achieved result is the method of control and regulation of interstage tension or backwater, which consists in measuring the power parameters; The rolling stands during rolling and during rotation of the rolls pressed by the pressure screws 25 to each other with a force equal to the pressure of the metal on the roll measure horizontal forces applied to the work rolls from the rolled metal [1). 50

2

The main disadvantage of this method of controlling and regulating tension is manifested during rolling under conditions of acceleration of the rolls of the stand. It is caused by a patient measurement error, since during the acceleration of the rolls of the quarto stand, the dynamic inertia force of the masses of the rotating rolls of the stand appears, which additionally loads the horizontal force sensors during the acceleration of the rolls and unloads them during deceleration.

The purpose of the invention is to improve the accuracy of measuring interstand tensions during continuous rolling with the acceleration and deceleration of the rolls of the cage.

This goal is achieved by measuring the power parameters of the cage during rolling and when the rolls rotate pressed by pressure screws to each other with a force equal to the metal pressure on the shafts, measure the horizontal forces applied to the work rolls from the rolled metal, "additionally" together with the horizontal forces measure the angular acceleration of rotation of the rolls and determine the rotational forces of the rolls pressed by the pressure screws to each other, the horizontal inertia forces caused by us3

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by rotating the rotation of the support rolls, in the form of the difference of the horizontal forces of interaction between the pillows of the working rolls and the stands of the stand at a steady speed of rotation of the rolls with acceleration, and during rolling they determine the tension in the form of an algebraic sum of horizontal forces applied to the work rolls from the rolled metal and horizontal forces inertia caused by acceleration rotates 10 of the support rolls.

The drawing shows the rolling mill with metal in the rolls, shows the blocks for implementing the proposed method and shows: the direction of action (5 metal pressure forces on the rollers P, tension - rear T _n and front T _n and horizontal forces X. Rolling mill · includes frame 1, work and support rolls 2 and 3, cushions 4 work rolls, '20 cushions 5 back-up rolls, pressure screw b, sensors 7 horizontal forces, engine 8 of drive of work rolls 2.

The scheme for implementing the method includes a calibration unit, the input of which is 25

^ connected to the outputs of the sensors 7 horizontal forces, the acceleration sensor 10 connected to the motor shaft 8, the computing unit 11, the inputs of which are connected to the output of the calibration block 9, 'the outputs of the sensors 7 horizontal forces and through potentiometer 12 to the output of the acceleration sensor 10 and exit

the computing unit 11 is connected to the indicator 13 and with the input of the speed controller 14. The output of the regulator "14 speed ti is connected to the engine 8.

Memory

Equilibrium equation of workers shaft-! 2 when the engine 8 is rotated at a constant speed, according to the rb-chests in the drawing, has the following entry:

vm = r _n - r _n = ΣΧ-ΣΧ _Τ, ¹

where dT is the difference acting on the stand tension,

£ X _T - the sum of the forces of the interaction of the four pillows 4 work rolls with bed 1, when calibrating the cage,

52, X - the sum of the same forces at. rolling.

During the acceleration and deceleration of the stand rolls, the equilibrium condition of the sylles acting on the work rolls 2 should not be equal to (1), since the work rolls 2 from the support rolls 3 also have an additional inertial force of the masses of the rotating support rolls 3, tending load the sensors 7 horizontal forces during acceleration and relieve them when braking the rolls.

A new equilibrium equation for work rolls 2 when rolling with accelerator 65

We have the following entry

^l " ^gvG n- ¹ H" ^, " ^ah " ^1EX g ^{± ha)} > (2)

where λ is the extremal coefficient, and> is the angular acceleration of the shaft

engine drive work rolls

To determine the coefficient λ from equation (2), it suffices to equate dT to zero, then the absolute value of the coefficient λ is written as

55Χ _τ {ώ = ο) -ΕΧ _τ (ώ *)

"wh

where C x (ώ -o) - the value of the horizontal forces obtained by 'calibration when the engine is rotated at a constant speed,

2X _t (ώ £ 0) is the magnitude of the horizontal forces obtained for the same calibration conditions, but with the engine accelerated.

The mutualization represented in the drawing works as follows ..

First, before rolling, calibrate the cage. To do this, include the engine 8 and rotate the work rolls 2 at a constant speed, at the same time using the pressure screw b work rolls 2 are pressed to each other, for example, with a force equal to the pressure P of the metal during rolling. At the same time, due to the presence of the stub A (i.e., displacement of the work rolls with respect to the support rolls), the sensors 7 are loaded and an electrical signal appears at their output, which is fed to the input of the calibration block 9, where it is memorized. The engine is then given a constant acceleration rate, the signal increases at the outputs of sensors 7 of horizontal forces, this signal is perceived by calculator 11 (and not perceived by block 9 (calibration), and the other input of calculator 11 is given a signal from the output of Tat block 9, which is in the memory of the calibration block 9; At the same time, the third input of the calculating block 11 through the potentiometer 12 receives a signal from the output of the acceleration sensor 10, the value of which is adjusted with the help of the potentiometer 12. The potentiometer 12 is adjusted lasts until indicator 13 has a zero reading of the arrow, i.e., until the output of calculation block 11 compensates for the difference of signals arriving at the input of calculation block 11 from sensors 7 of horizontal forces and from the output of calibration block 9.

After this, the calibration ends and all the mechanisms of the cage are transferred.

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are given in the original rolling position.

When rolling from sensors of 7 horizontal forces, signals are received * at the input of calculating unit 11, it is summed with the calibration signal, access 5 from the output of calibration block 9, with a signal proportional to the angular acceleration of the rolls, which comes from acceleration sensor 10, and with the signal T _n , which arrives 10 from the previous stand from the output of the computing unit (not shown) ,. At the output of the computing unit 11, a T1 signal is generated, proportional to the front tension of the cage, which is indicated by the instrument (indicator) 13 and is fed to the input of the speed controller 14,

Gehniko- economic advantages of the proposed method for adjusting the tension bands are to increase the reliability of equipment by eliminating the emergency operation due to a mismatch rotation speed of the rolls of adjacent stands of the rolling mill with acceleration, as well as increasing the accuracy ^ζ geometrical dimensions of rolled width by increasing the precision tension control (backwaters). thirty

The economic effect in the national economy can be obtained by increasing the productivity of the rolling mill and the quality of products. 35

Claims (1)

Claim Method for Determination of Tension in rolling a continuous mill with quarto stands, which consists in measuring the force parameters of the stand during rolling and rotation of the rolls pressed by pressure screws to each other with a force equal to the metal pressure on the rolls, measure the horizontal forces applied to the working rolls from the rolled metal , characterized in that, in order to improve the accuracy of measuring the tension during continuous rolling with acceleration and deceleration of the rolls of the stand, together with the horizontal forces measure the angular acceleration of rotation of the rolls and determine when rolls pressed by push screws to each other horizontal inertia forces caused by the acceleration of the rotation of the support rolls, in the form of the difference of the horizontal forces of interaction between the work roll pillows and the bed of the stand at a steady speed of the rolls and during rotation, rotate the rolls, and determine during rolling tension in the form of an algebraic sum of horizontal forces applied to the work rolls from the rolled metal and horizontal forces of · inertia caused by the acceleration of the rotation of the support rolls.