JPH028801B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Description of the Technical Field The present invention is a steel strip rolling equipment in which a steel strip is passed between a plurality of rolling rolls in one rolling mill, and multiple pass rolling is performed simultaneously in one rolling mill. The present invention relates to an automatic plate thickness control device for simultaneous multi-pass rolling.

(b) Description of the prior art In simultaneous multi-pass rolling, unlike the conventional one-stand one-pass rolling, changes in the roll speed and roll gap in one pass between multiple rolls are different from those in other rolls. Since it also affects the paths, it is necessary to control it by taking into account the interference between these paths, which has the disadvantage that the control becomes very complicated.

(c) Purpose of the invention The present invention has been made in view of the above-mentioned drawbacks.
The purpose of the present invention is to provide a relatively simple and highly accurate automatic plate thickness control device.

(d) Summary of the invention In order to achieve the above object, the present invention has the following configuration. That is, a one-stand multi-pass rolling mill that simultaneously performs multiple passes of rolling, each drive motor that drives each rolling roll of this rolling mill, a speed adjustment device for these drive motors, and a roll gap adjustment device of the rolling mill. , a speed reference and roll reference generator that supplies a roll reference to the roll gap adjustment device and a speed reference to the speed adjustment device, the total rolling pressure from the rolling pressure detector of the rolling mill, and the detection of the push-up cylinder position of the rolling mill. a comparison calculator that controls the total roll gap amount of the roll gap adjustment device based on the rolling roll gap value from the rolling mill and the deviation output from the thickness deviation detector provided on the exit side of the rolling mill;
a first proportional integrator that controls a speed adjustment device related to the final pass to correct the roll circumferential speed according to a rolling schedule based on the deviation output from the thickness deviation detector; and a first proportional integrator provided on the entrance side of the rolling mill and a second proportional integrator that controls the speed adjusting device related to the first pass to correct the roll circumferential speed according to the rolling schedule based on the tracked deviation output of the thickness deviation detector. Therefore, the tension between passes can be kept constant and the plate thickness can be controlled with high precision in the first pass and the final pass.

(e) Structure and operation of the invention First, the principle of the invention will be explained by taking as an example a rolling mill that performs simultaneous three-pass rolling as shown in FIG.

In FIG. 1, the material to be rolled 9 is rolled in the first pass between rolls 1 and 2, rolled in the second pass between rolls 2 and 3, and rolled in the third pass between rolls 3 and 4. This is an example of a simultaneous 3-pass rolling mill.

Set value of rolling roll gap for each pass of 1st to 3rd pass.
S ₁ , S ₂ , S ₃ rolling pressure is P ₁ , P ₂ , P ₃ The exit side rolled material thickness of each pass is h ₁ , h ₂ , h ₃ h ₁ = S ₁ + P ₁ /M (1) h ₂ =S ₂ +P ₂ /M (2) h ₃ =S ³ +P ₃ /M (3) where M: the elastic modulus of the rolling mill. However, each rolling roll is pushed up by one pushing up cylinder 10, and the total value of the gap between each rolling roll, that is, the value of S=S ₁ +S ₂ +S ₃ can be set, and S ₁ , S ₂ ,
The individual values of S ₃ differ under various rolling conditions.

As for the rolling load, it is disadvantageous in terms of equipment cost to detect the load applied to each rolling roll, but it is easy to detect the total rolling load P. Therefore, if we take the sum of equations (1), (2), and (3) and rewrite it as an equation that expresses the amount of minute change from a certain steady state, we get 3 〓 ⁿ⁼¹ Δh _o = ΔS + ΔP/M (4) Can be done.

That is, even without detecting the rolling load and roll gap amount for each pass, the total rolling load change amount ΔP and the total roll roll gap amount ΔS are detected and controlled so that ΔS+ΔP/M=0. By doing so, the plate thickness can be controlled.

However, although this control alone can make the sum of the plate thickness deviations on the output side of each pass zero, it does not necessarily mean that the plate thickness deviation on the output side of the final pass becomes zero.

For this reason, the thickness deviation detector on the exit side of the rolling mill detects
The rolling mill thickness deviation on the exit side of the final pass is detected, and the amount of change ΔS in the total rolling roll gap is corrected so that this deviation amount becomes zero.

As described above, the total rolling roll gap that can obtain the almost desired final exit plate thickness is controlled, so if this continues, there will be mutual interference between each pass, and this effect will appear on the final pass exit thickness. , accurate thickness cannot be obtained.

Therefore, using the final pass exit plate thickness deviation detection signal, the different rate of circumferential speed of the upper and lower rolls of the final pass rolling roll, that is, the circumferential speed of the rolling roll 4, is determined by V ₄ ,
If the circumferential speed of the rolling roll 3 is V ₃ , (V ₄ −V ₃ )/
Control the value of V ₄ . At this time, if the deviation detection signal is set target thickness > actual thickness, change the circumferential speed of V ₄ with respect to the circumferential speed of V ₃ so that the different speed rate becomes smaller, and in the opposite case, the different speed rate increases. .

According to this method, instead of the rolling roll gap,
The thickness is controlled between the rolling rolls in the final pass, making it possible to control the plate thickness at the exit side of the rolling machine without mutual interference between each pass.

However, in the final pass, it may not be preferable to change the speed too much because the shape of the plate is important. Further, if the different speed ratios of the upper and lower rolling rolls are greatly changed, slipping between the upper and lower rolling rolls and the material plate will occur, so it is limited to a certain amount or less. Furthermore, since the control is based on feedback from the final pass exit side plate thickness gauge, rapid plate fluctuations cannot be suppressed. For this reason, although fine control is possible, the control range cannot be widened.
This means that it will not be possible to deal with large variations in the thickness of the base material on the entry side. In order to eliminate this drawback, a plate thickness deviation detector is installed on the inlet side of the rolling mill to track the base material plate thickness deviation signal to the first pass input side, and detect the plate thickness deviation signal immediately before the first pass rolling roll. obtain. Depending on the obtained signal, the different speed ratio of the circumferential speed of the upper and lower rolling rolls in the first pass, that is, if the circumferential speed of rolling roll 2 is V ₂ and the circumferential speed of rolling roll 1 is V ₁ , (V ₂ - V ₁ ) /V ₁
control the value of . At this time, if the deviation signal indicates that the target set thickness is greater than the actual thickness, the different speed rate is decreased, and in the opposite case, the peripheral speed of _V1 is changed relative to the peripheral speed of _V2 so that the different speed rate is increased. According to this method, the thickness is controlled not by the gap between the rolls but between the rolls of the first pass, and it is possible to correct variations in the thickness of the input base material plate without mutual interference between the passes.

As explained above, by controlling the total rolling roll gap according to the total rolling pressure of the rolling mill, and at the same time controlling the different speed ratio between the final pass rolling rolls and the different speed ratio between the first pass rolling rolls. It has a wide width and allows for highly accurate thickness control.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 2, each speed adjustment device 22, 23, 24, 2 is
5 and a roll gap adjustment device 26, a speed reference and a roll gap reference predetermined according to the rolling schedule are outputted. In addition, each speed adjustment device 22,
23, 24, 25 are each rolling roll 1, 2, 3, 4
The rotational speed of each drive electric machine 27, 28, 29, and 30 is controlled so that the roll circumferential speed of the roll coincides with the speed reference value. Further, the roll gap adjustment device 26 adjusts the push-up cylinder 10 so that the amount of push-up by the push-up cylinder 10 becomes the above-mentioned roll gap reference value.
controls the position of

Further, the total rolling load P is detected by the rolling pressure detector 12, and the total roll gap position S is detected by the roll gap position detector 11, and these are input to the comparison calculator 31.
The comparator 31 calculates the total rolling pressure Po at a certain steady state.
and the total roll gap So, and calculate the difference ΔP and ΔS between the current total rolling load P and total roll gap S and the stored values, calculate ΔS−KΔP, and calculate this ΔS− An output proportional to KΔP is output to the roll gap adjustment device 26 to control the position of the push-up cylinder 10 so that ΔS−KΔP=0.

In addition, the signal from the strip thickness deviation detector 13 on the exit side of the rolling machine is input to the comparison calculator 31 at regular intervals, and the comparison calculator 31 corrects the constant K so that the value from this deviation signal converges to zero. .

In addition, the signal from the plate thickness deviation detector 13 on the exit side of the rolling machine is input to the proportional integrator 32, and the proportional integrator 32 integrates the signal G1 obtained by multiplying the thickness deviation signal by a proportional gain, and the signal G1, which is multiplied by the integral gain. The sum with G2 is calculated and this is output to the speed adjustment device 25. The speed adjustment device 25 uses the speed reference value from the speed reference and roll gap reference generator 21 and the proportional integrator 3.
2, and the rotational speed of the drive motor 30 is controlled according to the added signal, thereby controlling the different speed ratio of the circumferential speeds of the rolling rolls 3 and 4.

On the other hand, the signal from the plate thickness deviation detector 14 on the entrance side of the rolling machine and the signal from the pulse transmitter 16 attached to the roll 15 for detecting the amount of material movement are input to the tracking calculation device 34, and the tracking calculation device 34 The plate thickness deviation signal on the machine input side is traced to the first pass input side, and the plate thickness deviation immediately before the first pass rolling roll is output to the proportional integrator 33. The proportional integrator 33 calculates the sum of a signal G3 obtained by multiplying this thickness deviation signal by a proportional gain and a signal G4 obtained by integrating the thickness deviation signal and multiplied by an integral gain,
This is output to the speed adjustment device 22. The speed adjusting device 22 is a speed reference and roll gap reference generating device 2.
1 and the speed correction input from the proportional integrator 33, and control the rotation speed of the drive motor 22 according to the added signal,
Controls the rate of different circumferential speeds between the two.

(f) Effect of the Invention As explained above, according to the present invention, the total rolling roll gap is controlled according to the total rolling load of the rolling mill, and at the same time, the final By controlling the different speed ratios between the pass rolling rolls and the different speed ratios of the first pass rolling rolls based on the board thickness deviation signal on the inlet side of the rolling mill, wide and highly accurate control can be achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a one-stand three-pass simultaneous rolling mill, and FIG. 2 is a diagram showing an embodiment of the present invention for one-stand three-pass simultaneous rolling equipment. 1 to 4... Roll roll, 5, 6... Reinforcement roll,
7, 8... Support roll, 9... Material to be rolled, 10... Push-up cylinder, 11... Push-up cylinder position detector, 12... Rolling pressure detector, 13, 14... Thickness deviation detector, 15... Roll for detecting material movement amount ,1
6...Pulse transmitter, 21...Speed reference and roll gap reference generator, 22-25...Speed adjustment device, 2
6... Roll gap adjustment device, 27-30... Drive motor, 31... Comparison calculator, 32, 33... Proportional integrator, 34... Tracking calculation device.

Claims (1)

[Claims] 1. A one-stand multi-pass rolling mill that simultaneously performs multiple passes of rolling, each drive motor that drives each rolling roll of this rolling mill, a speed adjustment device for these drive motors, and a roll gap adjustment device for the rolling mill;
The roll gap adjustment device includes a speed reference and roll reference generation device that supplies a roll reference and the speed adjustment device a speed reference, and a total rolling pressure from a rolling pressure detector of the rolling mill, and a push-up cylinder of the rolling mill. a comparison calculator for controlling the total roll gap amount of the roll gap adjustment device based on the rolling roll gap value from the position detector and the deviation output from the thickness deviation detector provided on the exit side of the rolling mill; and the thickness deviation a first proportional integrator that controls a speed adjusting device related to the final pass to correct the roll circumferential speed according to the rolling schedule based on the deviation output from the detector; and a thickness control device provided on the entrance side of the rolling mill. It is characterized by comprising a second proportional integrator that controls the speed adjusting device related to the first pass to correct the roll circumferential speed according to the rolling schedule based on the tracked deviation output of the deviation detector. Automatic plate thickness control device.