SU835545A1 - Method of automatic monitoring of strip slipping in rolls of rolling mill with separate drive of rolling rolls - Google Patents

Description

walks in dangerous mode when braking the main drive. This is due to the fact that the length of the band in the first pass is significantly less than the length of the band in the previous (last) pass (when the band has the longest length), the length comparison does not occur and the automatic slipping control action is not prohibited when the first band is ejected.

False alarms of the device in the first pass are especially dangerous, since the amount of strip reduction is large, the strip (blank) is covered with a thick layer of furnace slag, which contributes to the occurrence of intense and dangerous slip. False fixation of slippage on the first-pass emission in the first pass and, consequently, the lack of reliable determination of slip during multi-ingot rolling does not provide sufficient protection against electrical and mechanical equipment overload of the rolling mill.

The aim of the invention is to improve the reliability of determining the slipping of a strip during multi-coil rolling by preventing false fixations of skidding on the ejection of a strip by rolls.

In the proposed method, this goal is achieved by producing a simultaneous comparison of the varying length of the rolled strip in a given pass with the length of the strip in the previous pass reduced by a fixed amount and the length corresponding to the length of the strip in the last pass with the length corresponding to the length of the strip in the last pass, when rolling the next strip, a comparison is made of the current length of the strip with a fixed length corresponding to the length of the strip in the first pass and with cient until their equality emission band prohibit automatic control and prevent slipping when unauthorized release strip rolling translation engine in the braking mode and the occurrence of slipping in the capture of the next band in the braking mode rolling motors.

. The length corresponding to the length of the strip in the last pass is taken as the minimum final length of the rolled strip within the process tolerances.

The length corresponding to the length of the strip in the first pass is taken as the minimum rolled length of the strip (blank) within the process tolerances.

In the proposed method, when rolling in the last pass of the second strip, the prohibition of automatic control of the slipping of the strip is performed after the rolled portion of the strip reaches the length

lanes in the first pass. This is quite permissible, since in the last pass the reduction of the strip is small, there is no furnace dross on the strip, there are no main 5 causes for the occurrence of hazardous skiddings and in the steady mode of strip rolling in the last skip slip there is practically no.

The drawing shows one of the possible; 10 variants of the device, by means of which the proposed method is realized. The device contains blocks 1 and 2 for measuring the length of the strip, block 3 for control, block 4 for comparing the final length, block 5 for 15 comparison, block 6 for logical comparison, block 7 for the rolling signal, block 8 for determining the slipping.

In blocks 1 and 2, the main drive speed signal is integrated, the length of the 20 rolled strip is determined, and the length information of the previous rolled strip, reduced by the specified value AL, is stored. Block 7 generates a “rolling” signal when the magnitude of the currents of a rolling 5 motors / i or / a exceeds the value of the minimum total current during normal rolling. The control unit 3 on the falling edge of the "rolling" signal switches the operating modes of blocks 1 and 2. At the moment of switching, one of the blocks, for example block 1, is reset to "zero and reset to measure the current length of the next band (during the time “rolling” signal), and block 2 goes into information storage mode. According to the next signal from block 7, block 3 changes the operation modes of blocks 1 and 2 so that block 1 is translated

0 into the information storage mode, and block 2 into the measurement mode of the changing length of the next band. When block 1 (2) is switched to the information storage mode, a prescribed value is subtracted from the full length of the rolled strip, which takes into account the size of the technological tolerances, and the result is stored. Block 5 compares the output signals of blocks 1 and 2 and from the moment of comparison until the signal of a varying length of the rolled strip is greater than the memorized signal, produces a signal that goes to one of the inputs of block 6 of the logical comparison. On the second

5 an input of block 6 is given an enable signal from block 7. When signals are available from blocks 5 and 7 by block 6, a inhibit signal is generated which blocks the output of the skid signal by block 8. Block 8

differentiates the signals of the currents / i and / 2 of the rolling motors when a slip occurs, when there is no control signal for braking the main drive and there is no inhibitory signal from block 6,

produces a skid signal; the inhibit signal is removed from the output of block 6 by the falling edge of the signal of block 7.

Block 4 compares the varying length of the strip with a finite length corresponding to the length of the strip in the last pass, and, if they are equal, generates a signal that, on the falling edge of the signal, the rolling from block 4 to block 1 (2) is recorded and stored (for comparison with the length of the next band) is the initial length corresponding to the length of the band in the first pass.

This method eliminates the cases of unauthorized transition of drive engines to the braking mode when the strip is ejected, including in the first pass.

Claims (2)

1. USSR author's certificate number 276890, cl. At 21B 37/00, 1970. 2. USSR author's certificate number 550191, cl. B 21B 37/00, 1977. -G .u,  iK7 grow iffcffffa2Р fffltffa er in lg "/ 7fff / otXy / f / / f flaS / i faiC (i / i / sg / gta