SU604636A1 - System for automatic control of rolled stock trimming shears - Google Patents

Description

one

The invention relates to the field of rolling production and is intended for automatic control of the stripping process of the front and rear ends of the sliding bar at the entrance to the finishing group of the stands of a continuous sheet rolling mill.

The closest to the invention in technical essence and the achieved result is a scissor control system comprising a strip control unit consisting of a strip speed meter and a cut section extractor, the output of which is connected to the input of the scissor starting moment calculator, the output of which is associated with the block the electric drive of the shears, containing means for launching the shears, stabilizing the acceleration, setting the ratio of the speeds of the knives and the metal at the moment of cutting and returning the knives to the initial state l.

The aim of the invention is to improve the system by ensuring trouble-free operation of scissors.

This goal is achieved by the fact that, in a known automatic flying scissors control system, having a control unit comprising the strip velocity meter and a cut cross section indicator, the output of which is connected to the input of the scissors launch moment calculation unit, the output of which is associated with the scissors electric drive unit containing means of launching scissors, stabilizing acceleration, setting the ratio of the speed of knives to metal speed at the time of cutting and

returning the blades to the initial state, a contour for correcting the steady speed of the blades is provided based on deviations of the calculated moments of arrival of the blades to the cutting line and the speed of the rolled section intended for cutting, the inputs of which are connected to the strip control unit and the blade path sensor, and the output to the electric drive block. In addition, the contour of correction of the steady speed of the knives by deviations of the calculated moments nx and reaching the cutting line and the speed of the rolled section intended for the cut contains a block for calculating the remaining transportation time of the intended section of the rolled section, the input of which is connected to the means

control of the strip, and the output with the first input of the code comparison circuit, and the block for calculating the remaining time of movement of the knives, the input of which is connected to the knife path sensor, and the output with the second input of the comparison circuit,

the outputs of the comparison circuit are connected to the corresponding relay switching channels of the speed setpoint at the input of the scissors motor drive unit. The drawing shows a structural diagram of the proposed system.

The system contains a strip control unit 1, a scissor start up calculation block 2, a generator of 3 time intervals, a scissor drive unit 4, a contour 5 for correcting the established speed of the scissors blades, tachogenerators 6 and 7, respectively, the roller table and the first stand of the finishing group of the mill.

The strip control unit 1 comprises a cut line 8 selector 8 (for example, a width gauge) and a strip speed meter, consisting of rolled stock indicators 9 and 10, mounted at a fixed distance from each other, and counter 11.

The scissors launch calculation unit 2 comprises a knot 12 unit for calculating the movement time of the knives from the initial state to the cutting line as a function of the strip speed and the code comparison circuit 13.

The scissors electric drive unit 4 comprises a motor 14, a converter 15, a current controller 16, a speed controller 17, an intensity setting device 18, a position controller 19, a knife speed sensor 20, a knife path sensor 21, a knife rotation sensor 22 at a fixed angle.

The contour 5 for the correction of the steady speed of the scissors blades contains a node 23 for calculating the remaining transport time of the cross section of the strip to the cutting line, cutting assembly 24 for calculating the remaining time for moving the blades to the cutting line, a code comparison circuit 25 that has three outputs: "More, Less and" Equally.

The drawing also shows moving rolls 26 (slab), rollers of the roller table 27, drums 28 of flying scissors, rolls 29 of the first stand of the finishing group, and inputs 30-33 of the position adjuster 19.

The device works as follows.

When the front end of the roll-up 26 approaches the indicator 9, the counter 11 begins to receive pulses from the generator 3 time intervals, the counting of the pulses stops when the front end of the roll-up 26 of the indicator 10 reaches. As a result, the output of the counter 11 produces a value opposite to the rental speed, i.e. .

.1 A,

;; y, l 1 &

where MIND - rental speed;

b - time of passage by the end

fixed distance roll-up / b.

The value inverse to the speed of the strip enters the node 12 calculating the time of movement of the knives, which implements the algorithm

p 1 m 1 /

where Um - the duration of the work cycle

scissors; SH - the path of the scissors from the initial state

to the cut line;

  -,

VM

Vs. - scissors speed;

a is a given constant acceleration;

4ap - drive lag time.

In Zzle 23, the calculation of the remaining time Gm of the transporting of the cross section of the strip to be cut to the cut line is implemented.

T - L- 1/1 / m - S „,

where tn is the pulse following period from generator 3.

The values calculated at the time nodes 12 and 23 are compared in the comparison circuit of 13 codes, and if these times are equal, a trigger start signal appears at its output, which enters input 31 of position controller 19. This starts acceleration of the motor 14 with a constant acceleration, the value of which is determined by the intensity adjuster 18. A tachogenerator 7 is connected to the input 30 of the position controller 19.

At the time of rotation of the sensor 22 at a fixed angle, the correction circuit 5 is turned on, allowing the node 24 for calculating the remaining time for moving the blades to the cutting line to receive signals from the sensors 20 and 21, respectively, of the speed and path of the blades. Node 24 implements the algorithm

.-liKT -t

l n

V 11

where SHUT is the cutter's path to the cutting line;

5 tons - the knives pass through; a signal about it is produced by the sensor 21 of the path.

The outputs of the nodes 23 (the remaining MOCT transport time of the cross section intended for cutting) and 24 (the remaining time for the knives to move to the cutting line) are compared in the code comparison circuit 25.

If at the time of triggering the sensor 22

I

Turning knives to a fixed angle of the mrass. The bridge THAT the speed of driving the knives rises to 1.25 1 / m. and if the speed of the knife drive is set

1.05 UM. When this node 24 continues to calculate

remaining time m

knife movements

calc

by their speed, equal to, 15 Um, until Mracsch. After that, two options are possible to control the speed of the knives.

First option; the signal is removed from the input 32 of the position controller 19, and the drive switches to the speed specified by the tachogenerator 6 or 7 with the corresponding value

I am equal to 1.15 or 0.85. This process uses all three outputs of circuit 25 ("More," Less, "Equals) and the last leg of the path after working off the time error scissors passes without correction.

The second option: the output “Equal to the code comparison scheme 25” is not used, the scissors continue to move along the chosen trajectory until the inequality sign changes to the opposite one. In this case, the speed setpoint at the input of the controller 19 from 1.05 UM to 1.25 UM or vice versa switches with each sign change at the output of the comparison circuit.

After the knives have passed the cutting line, the feedback from the path sensor 21 is connected to the input 33 of the position controller 19, and the blades are returned to the initial state.

The proposed automatic scissors control system for trimming the ends is advantageously distinguished by the fact that, while maintaining the high precision of stripping the ends, it reduces the demands on the accuracy of calculating the start of the scissors, which reduces the cost of the computing device and the stability of the drive. The reliability of the system is also increased, since the correction of the drive speed is carried out only in the range of permissible mismatch of the shear and rolling speeds. Therefore, even with the failure of the scissors, the breakage of the scissors mechanism is excluded, and only a reduction in the accuracy of stripping the end of the rolled stock is possible.

Claims (2)

1. Automatic scissor control system for cutting the ends of the rolled stock containing a strip control unit comprising a strip speed meter and a cut section indicator, the output of which is connected to the input of the scissor starting moment calculator, the output of which is associated with the scissors actuator block stabilization of acceleration, setting the ratio of the speeds of the knives and the metal at the time of cutting and returning the knives to the initial state, characterized in that, in order to reduce the cost of the system by reducing the requirements for launch moment calculation scissors, and the stability of the electric drive circuit, as well as to ensure the scissors' failure-free operation, the system contains a contour for correcting the steady speed of the scissors blades according to the deviations of the calculated moments to cut lines for knives and rolled sections intended for cutting; the inputs of which are connected to the strip control unit and the knife path sensor, and the output to the electric drive block. 2. The system of claim 1, wherein That the contour of correction of the established speed of knives by deviations of the calculated moments of arrival to the cutting line of the knives and the rolled section intended for cutting cuts contains a block for calculating the remaining transportation time of the rolled section intended for cutting, the input of which is connected to the means of controlling the strip, and the output with the first input of the comparison circuit codes, and the block for calculating the remaining time of movement of the knives, the input of which is connected to the sensor of the path of the knives, and the output to the second input of the comparison circuit, the outputs of the comparison circuit are connected to the corresponding and relay channels setting the speed at the input of the drive unit scissors. Sources of information taken into account in the examination 1. US Patent No. 3386321, cl. 83-295, 1967.