JPH0798209B2 - Controller for continuous rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Industrial field of application) The present invention controls tension applied to a rolled material between rolling stands arranged in tandem so as to match a target tension value. The present invention relates to a control device for a continuous rolling mill equipped with a tension control means for controlling.

(Prior art) When performing tandem rolling in a rolling facility such as steel,
A loop may occur between the stands due to an imbalance between the rolling stands and the roll gap, which may cause a misroll.

Tandem rolling means rolled material 1 as shown in FIG.
At least two rolling stands arranged side by side
It refers to the state of being simultaneously rolled in 1A and 1B. In tandem rolling, if an imbalance occurs between the material speed on the outgoing side of the first rolling stand 1A and the material speed on the incoming side of the second rolling stand 1B that follows, the rolling material 1 will experience tension or slack due to tension. The compressive force due to acts. Inter-stand tension control is performed to control this tension or compression force. In inter-stand tension control, a method is generally adopted in which the roll speed of the rolling stand 1A and / or the rolling stand 1B is controlled so that the tension acting on the rolled material matches the target tension.

Although there are various tension control methods, the so-called torque arm memory method is widely used. Here, the torque arm means a motor 7 for driving the roll during rolling.
Is a physical quantity given by Gr / P, where Gr is a rolling torque and P is a rolling load detected by a load cell or the like. The torque arm memory method is a control method performed based on the principle that the torque arm Gr / P does not change during rolling.

If the rolling material 1 is now bitten into the rolling stand 1A, but is not biting into the rolling stand 1B yet, that is, when the rolling torque is Gro and the rolling load is Po when the tip has no tension, the torque is The arm will be Gro / Po. The rolling torque of the first rolling stand 1A when the rolled material 1 is advanced and bites into the second rolling stand 1B, that is, when both rolling stands 1A and 1B are performing tandem rolling, When Gra and rolling load are Pa, (Gra / Pa) = (Gro / Po), that is, Gra = Pa (Gro / Po) (1), rolling material 1 between both rolling stands has no tension. Has been rolled in. However, in general, the formula (1) is not satisfied during tandem rolling, and the rolling material 1 is subjected to tension or compression force. Therefore, the rolling torque Gra during tandem rolling and the right side of formula (1) are Is the tension or compression force acting on the rolled material 1 during tandem rolling. The unit tension t acting on the rolled material 1 during tandem rolling is given by t = [Pa (Gro / Po) -Gra] / A (2), where A is the cross-sectional area of the rolled material 1.

This unit tension t is detected by the tension detecting / calculating device 2 in the device shown in FIG. Then, the deviation between the unit tension t and the target tension tr, that is, the tension deviation Δt is obtained by the adder 3, and this is input to the tension control device 4, where PI
The tension control speed correction amount ΔNt is calculated so that the tension deviation Δt becomes zero by performing the D control process. The tension control speed correction amount ΔNt is added to the speed reference value Nro by the adder 5 to create the final speed reference Nr, and the roll driving motor 7 is controlled via the speed control device 6 according to the speed reference Nr.

(Problems to be Solved by the Invention) In the above-described inter-stand tension control, the tension detection calculation by the tension detection calculation device 2 is the basis, and if there is an error in this tension detection calculation, the tension accuracy is calculated. Not only is this unfavorable in terms of operation. Especially when there is an error on the tension side and the target tension value is small,
The rolled material 1 is loosened between the rolling stands, and in some cases, the risk of misrolling increases.

Various tension calculation corrections have been considered in tension detection by such a conventional torque arm memory method, but it is unavoidable that an error is generated, and thus a misroll is also unavoidable.

On the other hand, even when the rolled material has a low temperature spot spot or when the rolled material has a non-uniform thickness, the mass flow balance between the stands is broken and misrolling occurs, as in the case where the tension detection calculation value has an error. Is likely to occur.

If the tension between the stands is controlled in order to remove the slack generated between the rolling stands, the speed correction will be slow.Therefore, the tension control alone will follow the occurrence of fast slack due to a disturbance that causes a misroll. I can't.

Once a misroll occurs, remove the rolled material between the rolling stands, and if the roll is damaged, it will take time to replace the roll, which hinders smooth operation.
Very unfavorable in operation.

Therefore, an object of the present invention is to quickly eliminate slack in a rolled material between rolling stands, thereby eliminating misroll due to slack in the rolled material between rolling stands, and performing stable operation. It is to provide a control device for a continuous rolling mill.

[Structure of Invention]

(Means for Solving Problems) A control device for a continuous rolling mill according to the present invention includes a slack detecting means for detecting slack of a rolled material that occurs between rolling stands,
Speed correction means for correcting the roll speed of the rolling stands is provided so that the slack generated between the rolling stands in accordance with the detection output of the slack detecting means is reduced.

(Operation) According to the above configuration, slack between rolling stands is constantly monitored, and when slack occurs, the progress is corrected in a direction to reduce the slack, so the slack is quickly eliminated, and slack between the rolling stands is reduced. It is possible to eliminate the misroll caused by the occurrence of.

(Embodiment) FIG. 1 shows an embodiment of the present invention. A feature of this embodiment is that a speed correction device 11 is additionally provided in the device shown in FIG. 3 and a slack detector 12 is provided between both rolling stands 1A and 1B. As the slack detector 12, a laser sensor generally known as a loop detector can be used. The slack detector 12 outputs a slack detection signal Sp when the rolled material 1 deviates from the pass line by a predetermined amount. The speed correction device 11 determines the speed correction amount ΔNp and the correction amount integration effective period based on the slack detection signal Sp input from the slack detector 12 and the signal indicating the tension deviation Δt input from the adder 3. When it is determined that the correction amount is valid, the speed correction amount ΔNp is sent to the adder 5 as a negative addition signal.

A detailed configuration of the speed correction device 11 is shown in FIG. The signal representing the tension deviation Δt from the adder 3 is input to the tension deviation comparator 13. This tension deviation comparator 13 is turned on when the tension deviation Δt is equal to or lower than the level Δtp on the compression force side, and an “1” signal is sent to the AN.
The slack detection signal Sp is input to the D gate 14. The AND gate 14 outputs the correction integrated signal C of "1" to the speed correction integration device 15 when both input signals become "1". The speed correction integration device 15 keeps the rated speed 0. while the correction integration signal C input from the AND gate 14 is on (“1”).
Scan unit speed correction amount equivalent to about 25% 10 to 100 m
Add up every s (milliseconds). This integration is continued until the rolled material 1 leaves the first rolling stand 1A located on the upstream side, and the integrated value is cleared when the rolled material 1 leaves the rolling stand 1A. In this way, the first correction integration signal C is sent from the speed correction integration device 15 for each rolled material 1.
The speed correction amount ΔNp is output via the switch 16 which is turned on from when the rolling material 1 is turned on to when the rolled material 1 leaves the first rolling stand 1A.

By additionally providing the speed correction device 11 configured as described above, when a slack is formed between the rolling stands and the tension deviation Δt becomes equal to or lower than the level Δtp on the compression force side, the unit speed correction amount is set. It is possible to integrate and output the integrated speed correction amount to correct the roll speed of the rolling stand, thereby quickly eliminating the slack generated between the rolling stands. Thus, the occurrence of misroll can be prevented and stable operation can be carried out.

In the above embodiment, the case of detecting the tension by the torque arm memory method as the control method of the tension between stands has been described. However, the rolling material 1 is contacted by a roll like a looper between the rolling stands to buffer the tension between stands. If a shock absorber is provided, the tension applied to the rolled material can be directly detected.In that case, the speed deviation should be corrected when a loop is detected between the rolling stands, and the tension deviation level Δtp The tension deviation level signal may be output with = 0. In that case, the slack between rolling stands is detected by the loop amount of the loop between stands made by the looper or more.

In the above embodiment, the speed correction is performed by giving a negative speed correction signal to the upstream rolling stand 1A, but in some cases, a positive speed correction signal is given to the downstream rolling stand 1B. Can achieve exactly the same actions and effects.

〔The invention's effect〕

As described above, according to the present invention, when looseness occurs in a rolled material between rolling stands, speed correction of the rolling stand is performed to quickly eliminate the looseness, and misroll is prevented to ensure stable operation. Can be carried out.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a detailed configuration of the speed correction device 11 in FIG. 1, and FIG. 3 is a block diagram of a control device for a conventional continuous rolling mill. Is. 1 ... Rolled material, 2 ... Tension detection calculation device, 3,5 ... Adder, 4 ... Tension control device, 6 ... Speed control device, 7 ...
Roll drive motor, 11 …… Speed compensator, 12 …… Slack detector, 13 …… Tension deviation comparator, 14 …… AND gate, 15
...... Speed correction integration device, 16 …… Switch.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B21B 37/00 BBM

Claims (3)

[Claims] 1. A controller for a continuous rolling mill comprising tension control means for controlling tension applied to a rolled material between rolling stands arranged in tandem so as to match a target tension value. A slack detecting means for detecting slack of rolling materials generated between each other, and a roll speed of the rolling stand is corrected in accordance with a detection output of the slack detecting means so as to reduce slack generated between the rolling stands. A control device for a continuous rolling mill, comprising: speed correction means. 2. The speed correction means detects a deviation between the tension applied to the rolled material between the rolling stands and a target tension value on the compression force side exceeds a predetermined value, and the slack detecting means detects the slack of the rolled material. The control device for a continuous rolling mill according to claim 1, wherein a speed correction signal is output when the rolling mill is operated. 3. The speed correction signal has a predetermined unit speed correction amount during a period in which the deviation of the tension exceeds a predetermined value on the compression force side and the slack of the rolled material is detected by the slack detecting means. The control device for a continuous rolling mill according to claim 2, wherein the integrated value is cleared by the rolled material passing through an upstream rolling stand.