SU1764865A1 - Fly cutter drive control method and device thereof - Google Patents

Abstract

The invention relates to the field of metal forming and can be used for dimensional cutting of rolled sections on the go. The goal is to improve the accuracy of dimensional cutting and reliability of work. The method realizes the compensation of the disturbing effect on the drive from the nonlinear dynamic moment arising due to changes in the wide limits of the rotation frequency and the moment of inertia of the scissors mechanism and from the nonlinear static moment formed by unbalanced shear masses, and when the scissors drive stops after cutting, the spontaneous sliding of the blades is controlled rental from unbalanced masses and the knives are returned to their previous position. Compensation of the disturbing effect is realized in the electric drive of the flying shears by applying a signal corresponding to the component of the dynamic and static moments, which as a compensatory one is supplied to the drive current regulator. At the same time, linearization of the tracing of knives of flying scissors is ensured and, accordingly, an increase in the quality and accuracy of the measured cut. 2 s, p. f-ly, 1 ill. (Ls

Description

The method of controlling the drive of volatile scissors is in the field of metal forming and can be used to measure the cut of rolled steel on the go.

For guillotine-type flying shears, which must cut profiles of complex shape and high cross-sectional height, which are similar to guillotine shears, which are additionally reported to be forward-return movement consistent with the movement of rolled products, the change is broad.

the moment of inertia of the mechanism in the cutting cycle, as well as the imbalance of the moving masses of the knives and, accordingly, variable static moment depending on the angle of rotation of the knives, which must be overcome by the drive.

A known method of controlling the drive of the flying shears, in which, after cutting, the drive is slowed down to a stop, and then, as the theoretical cutting line approaches the point of the end of the cut, the drive is accelerated to a speed that is synchronous with the rolling, ensuring

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meeting knives with a theoretical line of cut at the box office.

When using a known method to control the drive of guillotine shears, a non-linear tachogram of knives w f (t) takes place due to inconsistency of the inertia moment and unbalance of the moving masses of the scissors mechanism, which leads to a decrease in the synchronization accuracy of the knives and the theoretical line of cut on the rolled stock cut zone, and, as a result, to reduce the accuracy of the dimensional cut rolled on the go. In addition, due to the spontaneous sliding of the knives to rolling under the action of unbalanced masses of scissors, when the drive is stopped in the pauses between the cuts, knives may be driven into moving steel with an emergency due to the thinning of the rolled metal or breaking of the knives. Those. reliability is reduced.

The purpose of the flying scissor drive control method is to increase dimensional cut accuracy and reliability.

The goal is achieved due to the fact that they compensate the disturbing effect on the drive of the dynamic moment of the inertial masses of the scissors mechanism, increasing with advance the moment of the scissors drive in accordance with the expression

L / 1I dto, / uj h d j

Mn J-5T + (-2-) Mp - drive torque;

J is the moment of inertia of the scissors mechanism;

The method is based on the fact that the stock of kinetic energy A of flying shears, driven to the shaft of the latter, is equal to

A, where w - drive rotation frequency;

J - the resulting moment of inertia, reduced to the drive shaft.

The change in time of the accumulated kinetic energy (1), i.e. dynamic power ndin, is equal to

Rdin dA / dt Jo) do) / dt + (a / 2) dJ / dt (2)

This power is covered by the drive power P:

Р - Мп ш, (3)

where Mp is the drive moment.

Equating expressions (2) and (3), we obtain

Mn Jdw / dt + (u / 2/2) dJ / dt, (4) i.e. the moment of the drive Mn is exposed to the dynamic moment of the inertial mass of the shear mechanism, its two components, the first of which is caused by the change in the rotation frequency and the second by the change of the inertia moment J of the shear mechanism.

If we consider that (about d p / dt, where (p is the angle of rotation of the knives, then (4) can be converted to

(five)

o is the rotation frequency; y-angle of the knives, and when the drive stops in the pauses between the cuts control the sliding of the knives for hire under the influence of unbalanced mass of the scissors mechanism from the initial position and return them to their previous position.

By compensating for the effects of nonlinear dynamic and static moments on the scissor drive, they linearize the tachogram of the knives and improve the accuracy of the synchronous movement of the knives and the theoretical cutting line in the cut zone and, accordingly, increase the accuracy of the measured cut.

Thanks to the control of sliding the knives for rolling and returning them to their previous position when the scissors drive is in place, the cut-outs of the billet or breakage of the flying scissors mechanism are eliminated in the pauses between cuts. emergency situations are eliminated and reliability is improved.

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those. The second component of the dynamic moment depends, furthermore, on the degree of change of the moment of inertia of the scissors mechanism as a function of the angle of rotation of the knives in the cutting cycle (dJ / d p).

The compensator is affected by the components (5), i.e. increasing the lead time Mp of the scissor drive in accordance with expression (5), eliminates the influence of the nonlinear dynamic moment on the drive rotation frequency and tachogram of the blades, which increases the accuracy of the measured cut.

The drawing shows a functional diagram of the device for implementing the method

The flying shears 1, cutting continuously-rolled steel 2 into measured lengths, are driven by the drive 3 and have a blade angle sensor 4 and a cut sensor 5 on the shaft. The movement of the car 2 is controlled by the follower rollers 6 and the pulse sensor 7 connected to it. Drive 3 is connected

to the power converter 8, the Digital integrator 9 is connected to the inputs with a setting unit of 10 dimensional length, a pulse sensor 7, a sensor 4 of the angle of rotation of the knives and a cut sensor 5. An adder 11 is connected in series, the input of which is connected to the output of the integrator 9, the intensity adjuster 12, the speed controller 13 and the current regulator 14, the output of which is connected to the input of the power converter 8. The frequency code pulse sensor is connected to the second input of the adder 11 . To the second input of the speed controller 13 is connected through the converter 16 a frequency-code sensor 4 of the angle of rotation of the blades. The output of current sensor 17 is connected to the second input of current regulator 14, the power input of which is connected to the power circuit of drive 3 and power converter 8, the output of multiplier 18 is connected to the third input of current regulator 14, the second input of which is connected to the second output of sensor 12 intensity, and the first input to the output of the functional converter 19, which implements the function J i (p). The input of the latter is connected to the output of the reversible counter 20. The outputs of the reversible counter 20 are also connected to the inputs of functional converters 21 and 22, realizing the functions dJ / d р f (р and Мс%), respectively, where Мс is the static moment of the load from unbalanced mass of the scissors mechanism. The output of the converter 21 is connected to the right input of the adder 23 through a multiplier 24. The output of the converter 16 is connected to the second input of the frequency-code converter via a quadratic converter 25, the output of the converter 22 is connected to the second input of the adder 23, and the output of the latter is connected to the first input of the multiplier 26. K The first and second outputs of the trigger 27 are connected to the second and third inputs of the latter. The output of the multiplier 26 is connected to the fourth input of the current regulator 14,. The output of the adder 11 and the second output of the intensity sensor 12 via the relay links 28 and 29 respectively are connected to the first and second inputs of the OR link 30. The output of the reversible counter 20 is also connected to the first input of the coincident link 31, to the second input of which the controller 32 is connected Code of the rotation angle of the knives. The output of the link 31 is connected to the installation input of the trigger 27.

The counting inputs +1 and -1 of the reversible counter 20 are connected to the first output of the sensor 4 of the angle of rotation of the knives. The first and second outputs of trigger 27 and the output of the OR 30 link are connected to the same inputs according to the And scheme, respectively. The counter-quench inputs 20 and trigger 27 are connected to the cut sensor 5.

The output of the reversible counter 33 is connected to the third input of the speed regulator 13, the counting inputs of which -1 and +1 are connected respectively to the tiger and the second outputs of the angle sensor 4, and

quench input - to the link output OR 30.

The operation of the device is as follows.

At the time of the end of the measured cut with a flying scissors 1 rolled 2

The cut sensor signal 5 is entered into the digital integrator 9 by a code corresponding to the measured length and specified behind the sensor 10. This is the theoretical line of the cut on the uncut part of the car 2.

When entering the code corresponding to the measured length in the digital integrator 9, its output signal compensates for the reference signal of the frequency of rotation of the drive 3 - frequency converter-15 input code

adder 11 and single-quadrant output. In this case, the output signal of the adder 11 disappears and, accordingly, the signal at the input of the intensity setting device 12 disappears, and at the output of the setting device 12 begins to decrease with

at a predetermined rate, the driving frequency of the drive 3 and, accordingly, the driving signal at the input of the speed controller 13 begins to decrease. Drive 3 begins to slow to a stop. The movement of the knives of flying scissors 1 to a stop after cutting is controlled by the angle sensor 4, the pulses from the first output corresponding to the forward movement of the knives go to a digital integrator

9, at the input +1, increasing the number code at the output of the digital integrator 9. This corresponds to the removal of the theoretical cutting line from the axis of the flying shears. The input -1 of the digital integrator 9 receives the pulses of the sensor 7 of the follower rollers 6, which write off the number entered into the digital integrator 9 as it approaches the axis of the flying scissors 1 of the theoretical cutting line. Accordingly, it decreases

a compensating signal at the input of the adder 11 from the side of the digital integrator 9 and a signal appears at the output of the adder 11 causing acceleration of the drive 3 to synchronize the movement and the meeting of the blades

with a theoretical cut line. At the time of synchronization of the movement of the knives and the theoretical line of cut, the latter is located at a distance of a measured length from the end of the uncut rolled metal.

When the drive 3 is stationary in the pauses between the cuts, the knives 1 are rolling to the rental under the action of the moment from the unbalanced mass of the shears, which can lead to an emergency situation. The control of the knives sliding in the pauses between the cuts is carried out using a reversible counter 33, the counting inputs of which -1 and +1 are connected respectively to the first and second inputs of the angle sensor 4, corresponding to the reverse and forward directions of rotation of the knives 1. If sliding occurs in the opposite direction of rotation of the drive, then the pulses of the angle of rotation 4 are fed to the input +1 of the counter 33. At the same time, the output of the latter accumulates a number code with a positive sign and, arriving at the driving input of the speed regulator 13, Vaeth movement of the actuator 3 and the knife 1 in the forward direction returning them to their original position, and vice versa. If the drive 3 signal appears at the output of the adder 11, or if the drive 3 stops after cutting (at the second output of the intensity adjuster 12 there is a deceleration signal d co / dt), relay links 28 or 29 are turned on and at the output of the OR link 30 there is a signal that turns off the counter 33 and prohibits its operation in counting mode. When the driving signals dw / dt are missing, there is no signal at the output of the link OR 30, and the reversible counter 33 provides control of the knife creep and control of the drive return to its original position

When the drive 3 is turned on for rotation with the frequency from to meet the knives 1 with the theoretical cutting line on the hire 2, in each cycle of cutting the measured length there is a change in the inertia moment J of the shear mechanism and an effect on the drive 3 of the nonlinear dynamic moment (5). This causes a change in the frequency of rotation of the drive 3, the non-linearity of the tachogram of the knives with f (t) and, accordingly, the deterioration of the accuracy and quality of the dimensional cut.

The moment of inertia J is a non-linear function of the angle of rotation of the knives 1 - p, J f (f), the character of which depends on the design features of the shear mechanism, and is different for different scissors. At the same time, for all scissors, the functional dependence J f (p) is symmetric about the angle of rotation of the knives 1, p p, due to the symmetry of the mechanism relative to the vertical axis of the scissors. The code of the angle of rotation of the knives p is formed at the output of the reversible counter 20 according to the signals of the sensor 4 of the angle of rotation of the knives.

The functional transducer 19 forms the functional dependence J t (p). The number code corresponding to the moment of inertia J from the output of the functional converter 19 is supplied to the input of the multiplier 18, where it is multiplied by the code of the number corresponding to the drive acceleration 3 - d w / dt. At the output of multiplier 18, a signal is generated corresponding to the component of the dynamic moment (current) (from equation (5):

lo Kfo J (p) -d y / dt (6)

The latter is fed to the input of current regulator 14 and compensates for the negative effect on the tachogram of knives 1 and on the quality and accuracy of the measured cut component of the dynamic moment - J (p) d co / dt (scaling factor). The angle of rotation of the knives in the measured cut cycle changes It is from 0 to 2 l (zero corresponds to the position of the cut). The angle of rotation of the knives, with respect to which the functional dependences J f (), f (f. And Me f (p)) are symmetrical, corresponds to the value of p n (on the position of the cut). The position of the cut is fixed by the sensor 5 of the cut, and the achievement of the angle of symmetry - by the link 31 coincidence. When the knives drive shaft is rotated at an angle p-l from the position of the cut, a coincidence link 31 is triggered, to the second input of which the angle code p p from the setter 32 is supplied.

When link 31 is triggered, trigger 27 is turned on. Signals at the outputs of the last counter inputs of counter 20 switch from tracking to subtraction (from +1 to -1), and with further rotation of the blade drive shaft 1, the code of the output signal of counter 20 begins to decrease to zero (when cutting ). Accordingly, the code of the number at the output of the functional converter 19, corresponding to the magnitude of the moment of inertia J of the shear mechanism, changes symmetrically in the reverse order. Thus, the whole cycle of the change of the angle p is covered: from 0 to and from 1 to 2. The function J (p) corresponds to the derivative dJ / d, which is a factor in the second term of equation (5). The number code corresponding to the derivative dJ / dy is formed at the output of the functional converter 21. The latter, like the functional converter 19, is set to half a cycle of changing the angle p (0 - l} after reaching the angle of symmetry (p l switching the counting inputs of the counter 20 dJ / dp function is reversed.

The number module dJ / d p is supplied from the output of the functional converter 21.

to the input of the multiplier 24, to the second input of which a signal is output from the output of quad 25, which is proportional to the square of the frequency of rotation of the drive - and / 2. At the output of multiplier 24, a signal (Ij) is formed, corresponding on a certain scale

without the modulus of the function - - - (see the second component of equation (5)).

(lj) (Kj ()) (7)

Kj - scaling factor.

In the second half of the cycle of changing the angle / (l - 2 n), the derivative d and% changes the sign to the opposite. To change the sign of the signal 1 (7), a multiplier 26 is used, to the second input of which in the first half of the cycle (p 0 -l) a signal +1 is supplied from the direct output of the trigger 27, and in the second half of the cycle ((p-p - 2n :) to the third input of the multiplier 26 a signal -1 is fed from the inverse of the trigger 27.

The signal Ij with the corresponding dJ / cty derivative is supplied to the input of current regulator 14 and provides compensation for the negative effect on the tachogram of the knives 1 and on the quality and accuracy of the cutting component of the 9

of the momentum J ((see

equation (5)). The compensating signal (Ij) is added on the adder 23 with the signal (1C), which compensates for the negative effect on the tachogram of the non-linear static moment knives MS from the unbalanced mass of the scissors mechanism. Due to the fact that the moment Mc f (p) in the second half of the angle change cycle (p l - 2 l) changes the sign to the opposite, compensating effect of Mc (p), the signal (1C) passes through a factor 26 and is also supplied to the input of current regulator 14.

At the moment of the cut, the signal of the cut sensor 5 is used to extinguish the counter 20, which eliminates the accumulation of the last interference, and also the trigger 27 is turned off, i.e. is brought to the state corresponding to the first half of the cycle of changing the angle p (0 - l).

“Thus, by compensating for disturbances to the drive of volatile scissors for nonlinear dynamic and static moments, linearization of the knife tract is ensured, while the quality and accuracy of the measured cut are increased. In addition, the reliability of operation is improved by eliminating the sliding of the knives on the rolled steel.

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Claims (2)

Claim 1. Method for controlling flying scissors with water, in which, after cutting, the drive is slowed down to a stop, and then, when the theoretical cutting line planned for the moment of the end of the cut is approached, the drive is accelerated to a speed synchronous with hire, ensuring the knives meet. with a theoretical line of cut on the rolled metal, characterized in that, in order to increase the accuracy of the measured cut and reliability of operation, to compensate the disturbance, the impact on the drive of the dynamic moment of the inertial mass of the scissors mechanism, increasing With the lead time of the shear drive in accordance with the expression: 0 five 0 five 0 five 0 five Mn j d (o + ( about dt 2 where Mn is the drive torque, I - the moment of inertia of the mechanism of scissors, o) - rotational frequency, The f-angle of the knives, and when the drive stops in the pauses between the cuts, the rolling of the knives for rolling under the influence of the unbalanced mass of the scissors mechanism from the initial position is controlled and returned to their previous position. 2. A device for carrying out the method according to claim 1, comprising follow-on rollers associated with a pulse sensor and flying scissors with a drive and sensors for the angle of rotation of the knives and cuts, also connected in series with a measuring unit of length, a digital integrator the first adder, the intensity setting unit, the speed controller, the current controller and the power converter connected to the drive through the current sensor, the output of which is connected to the second input of the current controller, a pulse sensor connected not Primarily with the second input of the digital integrator and through the first frequency-code converter with the second input of the first adder, the sensor of the rotation angle of the knives connected to the third and fourth inputs of the digital integrator and through the second frequency-code converter with the second input of the speed regulator and the cut sensor, Connected to the fifth input of a digital integrator, characterized in that the device additionally contains two relay links, two reversible counters, a trigger, a coincidence link, an OR element, a rotation angle setting indicator knives, quadratic converter, sequentially the first functional converter and the first factor connected in series, the second functional converter, the second factor, the second adder and the third factor, the third functional converter are connected, the input and the second output of the intensity indicator are connected respectively via the first and second relay links and through the element connected in series with them OR to the first and second inputs of the first reversible counter and to the input of the second reversible counter, the output of which is connected with the third input of the speed controller, and the first and second counting inputs, respectively, with the first and second outputs of the blade rotation sensor, the second output of the intensity setter is also connected to the second input of the first multiplier, the output connected to the third input of the current controller, the fourth input of which is connected from 29 L IF by the third multiplier, the second and third inputs of this multiplier are connected to the third and fourth inputs of the first reversible counter and respectively to the first and second outputs of the trigger, the quenching input of which is combined with the quenching input of the first reversible counter and connected to the output of the cut sensor, and the trigger setup input is connected with the output of the coincidence link, the first input of which is connected to the knob of the angle of rotation of the knives, and the second input is with the output of the first reversible counter and the inputs of the first, second and third functional transducers, the fifth and sixth inputs of the first reversing counter are connected to the first output of the sensor of the angle of rotation of the knives, and the output of the second transducer frequency maker via quadratic Converter - to the second input of the second multiplier.