SU1470473A1 - Flying shears control device - Google Patents

Abstract

The invention relates to the field of rolling-mill automation and is intended to control flying scissors. The goal is to increase the reliability and durability of scissors mechanical equipment by reducing dynamic loads, as well as reducing heat losses in the electric drive. The essence of the invention is that cutting of rolling is carried out on the run for specified lengths by adjusting the ratio of the average for the cutting cycle of the shear speed and the feed speed of the rolled metal with the equalization of these speeds to the time of the cut. Between cuts, the shear speed varies according to the cosine law, which corresponds to a symmetric sine wave acceleration diagram (dynamic current) of the engine. The use of a cosine tachogram significantly reduces the dynamic loads of the mechanical equipment of the flying scissors installation, which helps to reduce wear and increase the service life of the mechanical equipment. The device generates the speed reference signal optimal for a given cosine tachogram, reducing the heat losses in the electric drive, reducing its heating, and creates prerequisites for increasing the productivity of the cutting section. The formation in the proposed device of the corresponding received tachogram of setting the acceleration (dynamic current) of the drive contributes to an increase in the speed of the speed control system. The high precision of cutting the dimensional lengths (including with technological changes in the rolling feed rate) is achieved by eliminating the error caused by the statistics of the speed control system. 1 hp f-ly, 4 ill.

Description

The invention relates to the field of rolling-mill automation and is intended to control flying scissors.

The purpose of the invention - to increase the reliability and durability of mechanical equipment by reducing the dynamic loads in it, as well as reducing heat losses in the electric drive.

FIG. I shows a block diagram of a flying scissors control device; Fig. 2 is a block diagram of the switching unit; in fig. 3 - flying scissors tachograms and acceleration diagrams (proportional to the dynamic currents of the engine),

The flying scissors control unit contains a scissors speed automatic control unit 1, a scissors motor control system 2, rental and scissor speed sensors 3 and 4, a knife set sensor 5, a set length of the rolled steel, adder 7, four multiplying-dividing blocks 8-11, integrators 12 and 13, key 14, switching unit 15, sine-cosine functional converter 16, multiplier-dividing unit 17, the first input of switching unit 15 connected to the input of the blade position sensor 5, and the output from the control A key input 14, the input of which is connected to the output of the rolling speed sensor 3, and the output to the first input of the first multiplier 8. The output of the scissor speed sensor 4 is connected to the first input of the scissors speed automatic control unit 1, the output of which is connected to the input the scissors electric drive control system 2, and the first input of the first integrator 12, the input connected to the second input of the scissors speed automatic adjustment unit 1, the third input of which is connected to the output of the adder 7, the first input connected With the output of the rental speed sensor 3 and the second INPUT of the first integrator 12, the first input of the setting device 6 of the cut length of the rental is connected to the second input of the first multiplier-dividing block B, the third input of which is connected to the second output of the setting 6 of the cutting length of the rental. The output of the third multiplier-divisor unit, 10 is connected to the second input of the adder 7 and the third input of the first integrator 12.

The output of the second multiplier-divider unit 9 is connected to the first input of the fourth multiplier-divisor unit 11, the output of which is connected to the fourth input of the unit 1 automatic scrolling speed control. The first input of the p of the multiplying-dividing block 17

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connected to the output of the first delitelny unit 8, the first input of the second multiplier-divider unit 9 and the second input of the third multiplier-dividing unit 10, the first input of which is connected to the first output of the sine-cosine functional converter 16,

10 whose second output is connected to the second input of the fourth multiplier-separating unit 11, and the input to the second input of the switching unit 14 and to the output of the second integrator

15 13, the input connected to the second

the input of the second multiplying-dividing block 9 and with the output of the 5th multiplying-dividing block I7, the third input of which is connected to the first

The output of the setting unit 6 of the rolled length of hire is 20, and the control input of the second integrator 13 is connected to the output of the blade position sensor 4.

Switching unit 15 contains a comparator 18 and a trigger 19, whose single output is the output of switching unit 15, the zero input of the trigger 19 is connected to the output of comparator 18, and the single input trigger 30 19 is the first input of switching unit 15, the second input which is the input of the comparator 18. In FIG. 3 shows tachograms of 20 and 21 flying scissors and charts.

35 22. and 23 accelerations, where the points P and P,

correspond to the moments of the row for different preset cutting lengths.

The device works as follows.

0V of the initial state corresponding to the moment immediately preceding the next cut, the signals for setting the drive acceleration ats from the output of the fourth multiplicative 5I block 1I and setting the increment of scissors &

The third multiplier-dividing block 10 is equal to zero. The scissors and the band move with the same speed due to the operation of the adder 7 and the first integrator 12, the job and feedback signals from the sensors 3 and 4, respectively, are compared at the inputs.

5: speed strip and scissors. In this case, at the output of the first integrator 12, there is some signal d1o, which compensates for the static error of the automatic adjustment unit 1 unit and the shear speed, which ensures high cutting accuracy.

At the moment of cutting, a pulse signal is generated by the position sensor 5, which flushes the second integrator 13 and sets in one state the trigger 19 of the switching unit 15. At the same time, the key 14 is opened by the signal from the output of switching unit 5, and using multiplying-dividing blocks 8 - П and Г7, integrator 13 and sine-sinus functional converter 16, the scaling speed settings for duct scissors are generated (multiply at the output -drag block 10) and set the acceleration drive ac (output multiplier-dividing block 11) in accordance with the expressions

DUC A (-cosip,) -, (O a „A (x) - sinfn, (2)

where A is the amplitude of the cosinusoid, the signal of which is formed at the output of the multiplication-division block 8 in accordance with the expression

VnL,

(3)

de vr, & l

"3 - rental speed;

-difference between a given cutting length and the minimum length of the cut rolled, equal to the circumference of the scissors drums}

-the amount of rolling movement during time t ,. working off by an electric drive of scissors of a given mismatch, the angular frequency of the cosinusoid.

which signal is formed

at the output of multiplying-delhi

body device 17 in accordance with the expression

Lv.dt COS

оtn о

u) 2jr L-i

(four)

where t.

- conditional angular rolling path, proportional to the relative length of the rolled metal, beyond the cutting line, the signal of which is formed at the output of the integrator 13 V with Z-F

According to the expression | UE dt.

(five)

At a constant feed rate of 15 rolled products, this expression takes the form

L,

fп

t.

(6)

In this case, the sine-cosine converter 16 on the first and second outputs performs, respectively, functional transformations

F, 1 - cos iff,; (7)

25

sin fn

(eight)

() (3), (4)

When the length of the rolled out over the cutting line reaches the value of L, the signal f at the output of the integrator I3 becomes 2TG. At the same time, the comparator 18 of the switching unit 115 switches up, sets the trigger 19 to the zero state and closes, thereby, the key 14, This completes the cosine-tachogram generation cycle. The next cycle starts after the arrival of the next pulse signal from the sensor 5 of the knife position.

At a constant rolling feed rate, an optimized cosine tachogram is formed in the device, providing the specified cutting length, since with and (6) the integral of

scissor speed increments is L:.

- L I., t “23Г

It should be noted that expression (9) is also valid for a variable feed rate of rolling, for example, at technological changes in the speed of the unit, its acceleration, braking, etc.

sin (

Lm o

(9)

 Dh

Thus, the positive effect of the use of the device is created by reducing dynamic loads and increasing the service life of the flying scissors, as well as reducing thermal

Claims (2)

losses in the electric drive, i.e. by directly saving energy and creating a prerequisite for increasing the productivity of the cutting section. Invention Formula one . Flying shears control device containing a scissors speed automatic control unit, a scissors electric drive control system, rental and scissor speed sensors, a knives position sensor, a set length of rolled products, an adder, four multiplier-dividing blocks, two integrators, a key, a switch unit, the first input of which is connected to the output of the knife position sensor, and the output is connected to the control input of the key, the input of which is connected to the output of the speed sensor, and the output is connected to the first input of the switch of the first multiplying-dividing block, the scissor speed sensor output is connected with the first input of the automatic scraper speed control unit, the output of which is connected to the input of the scissor drive control system, and the first input of the first integrator, the output of which is connected to the second input of the automatic scissor speed control unit, the third input of which is connected to the output of the adder, the first input of which is connected to the output of the rolling speed sensor and the second input of the first integrator, the first output of the cutoff sensor of the rolled length of the rolled product is connected to the second input of the first multiplying unit, the third input of which is connected to the second output of the setter of the rolled length, the output of the third multiplier separating unit is connected to the second input of the adder and the third input of the first integrator, the output of the second the multiplying-dividing unit is connected to the first input of the fourth multiplying-dividing unit, the output of which is connected to the fourth input-the automatic scissors speed control unit, which is different from the fact that, in order to increase the reliability and durability of the scissors mechanical equipment, dynamic loads in it, as well as in order to reduce heat losses in the electric drive, it is equipped with a sine-cosine functional converter and a fifth multiplicative dividing unit, the first input of which is En with the output of the first multiplying-dividing unit, the first input of the second multiplying-dividing unit and the second input of the third multiplying-dividing unit, the first input of which is connected to the first output of the sine-cosine functional converter, the second output of which is connected to the second input of the fourth multiplying-dividing unit and the input is connected to the second input of the switching unit and to the output of the second integrator, the input of which is connected to the second input of the second multiplier-dividing unit and to the output of About the multiplying-dividing block, the third input of which is connected to the first output of the setting unit of the rolled length, and the control input of the second integrator is connected to the output of the blade position sensor. 2. The device according to claim 1, wherein the switch unit comprises a comparator and a trigger whose unit output is the output of the switch unit, the zero trigger input is connected to the comparator output, and the single trigger input is the first input of the switch unit, the second input of which is the input of the comparator. (Ofr, if / r, 5) (Ofnd / .H) Jj2. FIG. g 0g / g3