SU1237330A1 - Apparatus for controlling flying shears when cutting strip at termination of coiling cycle in endless-rolling mill - Google Patents

Description

The invention relates to mechanical engineering, in particular, to the design of control systems for rolling equipment.

The aim of the invention is to increase productivity, which is achieved by automating the process of cutting a strip at higher speeds while ensuring the required cutting accuracy.

FIG. 1 shows a functional diagram of the device; in FIG. 2 shows the execution of a signal generation unit for switching on the electric drive of the flying scissors; in fig. 3 - graphs of the change in the length and speed of the strip, as well as signals at the outputs of the trigger

and comparison element.

The device is implemented in relation to an endless rolling mill, the last stand of which 1 and the tension device 2 are installed in front of the flying scissors. The upper 3 and lower 4 drums of scissors are equipped with knives 5 and 6, respectively. Winders 7 and 8 are installed after flying shears. Lane 9, passing cage 1 and tensioning device 2, controls in the latter in length and speed. At the outlet of the tension device 2, the strip 10 is fed to the drums 3 and 4 of the scissors. The strip 11 with the inter-seam weld seam cut is fed to the coiler 8, where it is wound into a roll.

The driving motor 12 of the scissor drum is powered by a thyristor converter 13 connected to the control unit 14, which is switched by the start button 15. Both the drums 3 and 4 of the scissors are connected to each other through the gearbox 16. The control unit also includes welded seam on the section of the mill stand, block 18 for generating the scissor drive signal, element 19 of comparison, trigger 20, keys 21 and 22, as well as block 23 for measuring length and strip speed measuring 24. The unit 18 for generating signals for switching on the electric drive of the shears is made in the form of serially connected multipliers 25 and 26, setpoint constants 27 and 28, and also an adder 29.

FIG. 1-gz accepts the following notation:

and, - the signal from the output of the inter-roll weld from the last mill stand;

and

18

and,; - the assigned value of the weld coordinate relative to the last stand for determining the moment of command output for switching on the electric drive of the flying scissors;

 - a signal to turn on the electric drive of volatile scissors;

and, - the measured value of the weld coordinate relative to the last stand;

and, 2 is the measured value of the strip velocity at the output

the camp;

V is the speed of the strip behind the last cage;

K ,, Kg are the constants used in the formation of a given value of the coordinate position of the inter-web weld (in units 27 and 28);

5 t - the moment of the release of the weld from the last stand;

t, is the moment the scissors drive is switched on;

tg is the moment when the upper drum of the shears reaches the speed of the strip;

tj - cut time;

 - coordinate of the weld relative to the last stand of the mill;

0

to her

0

 K, N

five

spacing,

passable by inter-seam weld from the moment the seam leaves the last stand until the command to turn on the scissors is turned on;

- spacing along the strip traveled by inter-seam weld from the last stand to the scissors;

H speed of the strip and knives of scissors drums at the moment of cutting;

15 - distance traveled

- foot drum; S t distance: traveled

knife for four turns. overhead drum. The constants K and Kg are determined by the following food dependencies:

five

0

t,

- 47D,

k.n gv.8 0.5-103 au -,

: 3

where - the diameter of the upper drum

scissors, mm; but,; - acceleration rate (acceleration)

knives of scissors drums, m / s2.

The device operates as follows.

When the inter-seam weld comes out of the last stand at time t, output 17 of the block 17 shows a signal and, (FIG. 3), which arrives at the first input of flip-flop 20, resulting in a signal U at the second exit of flip-flop 20 (Fig. 3.1}, which is fed to the control of the inputs of the keys 21 and 22. In this case, the block 18 calculates the value:

e ..

her

 K, - K ,.

and

(Fig. 2), arriving at the first input element 19 in the form of a signal U, (Fig. 1). Since the speed V of the strip from the moment of exit of the weld from the last stand to the moment of cutting remains unchanged (Fig. 3) and, therefore, the value of the signal U proportional to the speed Uc of the strip at the mill output does not change, the value of the signal Uj remains unchanged arriving at the first input of the element 19 of the comparison.

At the moment of opening the key 22, the second input of the reference element 19 begins to receive signals proportional to the discrete coordinates of the band, measured by block 23.

As they arrive, the values of the signals are subtracted from the specified

12373304

value and at time t, at U, g Uf, at the output of element 19, the signal Vnif (Fig. 3,) appears, arriving at the second input of unit 14 to turn on 5 electric shears. Besides,

the signal and "is fed to the second input of the trigger 20, as a result of which the signal Uji disappears) at the second output of the trigger (Fig. 3, d) are closed

0 keys 21 and 22, and signals to the inputs of element 19 will not arrive until the next signal U appears, from the output of block 17.

In section tf-tJ (Fig. 3, S), the bans are accelerated to speed V, and in section t -tj move at speed V. In the section, the upper drum makes four turns. On the plot interrupted

0, the seam passes the distance c. N from the last stand to the scissors (Fig. 3a). Block 17 forwards the signal J about the exit of the seam CJEJapHoro from the last stand on the basis of data on the moment of entry

5 stitches to the first stand and time of the stitch passage between the cages.

The proposed device allows not only increasing the cutting accuracy of the strip in the weld zone, but also

0 cut at the maximum allowable speed (up to 8 m / s), which is difficult to implement in a known device.

The efficiency of using the device is achieved by increasing the productivity of the mill due to the automatic cutting of the strip at an increased speed while maintaining the required cutting accuracy.

i: j

.J

tfjuff.i

cr

fpuf. 2

Compiled by V. Stokolov Editor K. Voloshchuk Tehred L.

Zack: h s 229 12 ti p 1 ;;; VOIS cccf VNIIPI State Committee CCLF

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production

printing company, Uzhgorod, Projecto st., 4

Claims (1)

DEVICE FOR MANAGING VARIABLE SCISSORS WHEN CUTTING A STRIP AT THE END OF A ROLL BINDING AT THE ENDLESS ROLLING STATION, containing a thyristor converter connected to a scissors drive motor, a control unit for this converter and a start button connected to the input of the control unit, which distinguishes with the aim of increasing productivity due to automation of strip cutting at higher speeds, ensuring the required accuracy, it is equipped with blocks for measuring the length and speed of the strip at the exit of the mill, trigger, block m tracking the weld in the section of the mill stands, the comparison element and two keys, as well as the unit for generating the signal for turning on the electric drive of flying shears, made in the form of two multipliers and an adder and two constant adjusters connected in series, the output of the first of which is connected to the second input of the second multiplier and the output of the second is connected to the second input of the adder, while one trigger input is connected to the output of the comparison element and the other to the output of the weld tracking unit, the trigger output is connected to control inputs both keys, the information inputs of which are connected respectively to the output of the unit for generating the signal for turning on the electric drive of the flying scissors and to the output of the unit for measuring the strip length at the mill output, the output of the unit for measuring the speed of the strip at the output of the mill is connected to the input of the block for generating the signal for turning on the electric drive of the flying scissors, input the thyristor converter control unit is connected to the output of the comparison element, the two inputs of which are connected respectively to the outputs of both keys. SU „1237330> % ’