JPH0585250B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic plate thickness control method for a continuous rolling mill that rolls steel plates and the like.

[Conventional technology]

Conventionally, in continuous rolling mills consisting of multiple stands,
First rolling stand coarse plate thickness control that controls the rolling position of the first rolling stand using the plate thickness gauge on the exit side of the first rolling stand, and finishing plate that corrects the roll speed of the final stand using the plate thickness gauge on the exit side of the final stand. Thickness control is performed, and the tension between each stand is basically controlled by controlling the downstream rolling position. Recently, as in JP-A-59-4912, the target thickness from the second rolling stand to just before the final stand is calculated based on the plate thickness value detected by the plate thickness meter on the outlet side of the first rolling stand. Feedforward control, which tracks the thickness measurement point directly below each stand and controls the circumferential speed of each stand roll according to the target thickness value of each stand, is combined with feedback control using the plate thickness gauge on the exit side of the first rolling stand. , discloses a method that is used in conjunction with feedback control using a final stand outlet thickness gauge.

Among the above methods, the first rolling stand rough plate thickness control and finished plate thickness control cannot increase the response speed of the control system due to the time delay from the plate thickness control unit to the plate thickness detection unit, resulting in sufficient plate thickness accuracy. I can't get it out.
In JP-A No. 59-4912, the control at the intermediate stand was only feed-forward control, which had problems with accuracy and stability. Feedback control was performed using the thickness gauge on the exit side of the first rolling stand, and the thickness gauge on the exit side of the final stand was used. Feedback control has drawbacks such as the inability to increase the response speed of the control system due to the time delay from the plate thickness control section to the plate thickness detection section.

[Purpose of the invention]

The present invention has been made to advantageously solve these difficulties.

[Problem to be solved by the invention]

A feature of the present invention is that when controlling the thickness of a material to be rolled by a rolling mill consisting of multiple rolling stands, the thickness is measured at the entry side of the first rolling stand, and the threading speed is also measured. Based on the results, the rolling timing of the rolled material is determined and the rolling roll rotation speed of the first rolling stand is controlled, while the measurement results of the above-mentioned input side plate thickness and strip passing speed and the measurement of the first rolling stand exit side strip passing speed are determined. Based on the results, calculate the plate thickness at the exit side of the first rolling stand, and control the rotation speed of the rolling rolls of the first rolling stand to achieve the target thickness, and roll the plate to the target thickness. The rolling timing of the second rolling stand is determined based on the calculated sheet thickness and the sheet passing speed on the exit side of the first rolling stand, and the rotation speed of the rolling rolls on the second rolling stand is controlled, while the calculated sheet thickness on the exit side of the first rolling stand is and the first rolling stand exit side sheet passing speed;
The base plate thickness is calculated based on the measurement result of the sheet passing speed on the exit side of the second rolling stand, and the rolling speed of the rolling rolls of the second rolling stand is controlled so as to achieve the target plate thickness, thereby rolling the plate to the target thickness. The present invention relates to an automatic plate thickness control method for a rolling mill.

In the present invention, as described above, the thickness of the material to be rolled is controlled in a rolling mill consisting of a plurality of rolling stands (two or more rolling stands), but in a rolling mill with three or more rolling stands,
The plate thickness control of the second rolling stand as described above is performed sequentially.

That is, in the present invention, the rolling timing is determined from the sheet thickness and the sheet passing speed at the entrance side of each rolling stand, and the rolling stand roll rotation speed is controlled, so that the sheet can be rolled quickly enough to match the response speed of the rolling roll rotation speed. Thickness control is performed, and the plate thickness at the exit side of each rolling stand is determined by calculation, and the rolling stand roll rotation speed is controlled to achieve each target plate thickness, thereby achieving stable and highly accurate control with no wasted time in the control system. By controlling the plate thickness, it is possible to control the plate thickness quickly and with high precision.

〔Example〕

Next, examples of the present invention will be described.

In the drawings, the first to fifth rolling stands 1STD, 2STD, 3STD, 4STD, 5
Each STD has a lowering position control device 1HPC~
5HPC, electric motors 1MOT to 5MOT that drive the rolling rolls of each rolling stand, and speed control devices 1ASR to 5ASR for the motors, and tension meters 1TM to 4TM and tension control devices 1TC to 4TC are installed between each stand. , 1st rolling stand 1STD
Thickness gauges EGM and DGM are installed on the entry side and the exit side of the 5th rolling stand, respectively, and sheet threading speed meters ESM and 1- are installed on the entry side of the 1st rolling stand, between each stand, and on the exit side of the 5th rolling stand. 2SM~4-5SM,
Install DSM.

During rolling, the tension between each stand 1 STD to 5 STD is controlled by the tension value of the steel strip S detected by the tension meter 1 TM to 4 TM, and at the rolling stand 1 STD to 5 STD.
The tension control devices 1TC to 4TC between the rolling stands control the rolling positions 1HPC to 4HPC of the upstream rolling stands to within predetermined upper and lower limits.

Next, thickness control of the steel strip S will be described. first,
At the entry side of the first rolling stand 1STD, the thickness of the steel strip S is measured using a plate thickness meter EGM, and at the same time, the plate threading speed meter
Measure the plate speed with ESM and apply this measurement result to 1FFAGC.
, determines the rolling timing of the steel strip S at the first rolling stand 1STD, and issues a command to control the roll rotational speed to the rolling roll drive motor 1MOT via the rolling roll rotational speed control device 1ASR.

On the other hand, the measurement results of the input side strip thickness and strip threading speed are led to the mass flow calculation device 1MF, and at the same time, the strip threading speed on the exit side of the first rolling stand 1STD is measured by the strip threading speed meter 1-2SM, and the results are used for the above calculation. The steel strip S thickness at the exit side of the first rolling stand 1STD is calculated by guiding it to the device 1MF. The calculation formula is: h ₀ = V _i /V ₀ h _i h ₀ : Plate thickness at the exit side of the 1st rolling stand V ₀ : Plate speed at the exit side of the 1st rolling stand V _i : Plate thickness at the entrance side of the 1st rolling stand h _i : 1st rolling stand Plate speed Rolling stand entrance plate speed In this way, the plate thickness at the exit side of the first rolling stand 1STD is calculated, compared with the target plate thickness that has been input in advance, and the target plate thickness is determined via the 1MFAGC and the rolling roll rotation speed control device 1ASR. and instruct the rolling roll drive motor 1MOT.

Next, the calculated sheet thickness on the exit side of the first rolling stand 1STD and the sheet speed measured by the sheet passing speed meter 1-2SH on the exit side of the first rolling stand 1STD are calculated as 2FFAGC.
determines the rolling timing of the steel strip S on the second rolling stand 2STD, and controls the rolling roll drive motor 2MOT via the rolling roll rotation speed control device 2ASR.
Instructs to control the roll rotation speed. On the other hand, the first
Rolling stand 1 STD exit side calculation plate thickness and 1st rolling stand 1 STD exit side (2nd rolling stand 2 STD
The plate speed measurement result by the plate threading speed meter 1-2SM on the entry side) and the plate speed measured by the plate threading speed meter 2-3SM on the exit side of the second rolling stand 2STD are led to the mass flow calculation device 2MF, and the target plate thickness is calculated. The calculation is performed using the above-mentioned formula, and the target thickness is compared with the target thickness that has been input in advance, and the target thickness is introduced into the mill roll rotational speed control device 2ASR via the 2MFAGC, and is then instructed to the mill roll drive motor 2MOT.

In this way, the third rolling stand 3
STD, the 4th rolling stand 4STD, the 5th rolling stand 5STD and the steel strip S thickness are controlled, and the rolling of the 5th rolling stand 5STD is performed based on the plate thickness deviation measured by the plate thickness meter DGM on the exit side of the 5th rolling stand 5STD. Controls the roll rotation speed of roll 5 MOT, performs feedback speed control, and ensures final thickness accuracy.

〔Effect of the invention〕

By doing so, the thickness of the rolled material can be quickly and reliably controlled, and the yield and quality of the rolled material can be significantly improved.

Furthermore, since the thickness of the rolled material is uniform, excellent effects such as improved yield in workability (press formability, etc.) can be obtained.

[Brief explanation of drawings]

The drawings are explanatory diagrams showing embodiments of the present invention.

Claims (1)

[Claims] 1. When controlling the thickness of a material to be rolled using a rolling mill consisting of multiple rolling stands, the thickness of the material is measured at the entry side of the first rolling stand, and the threading speed is also measured. Based on this measurement result, the thickness of the material to be rolled is The rolling timing of the first rolling stand is determined, and the rotation speed of the rolling rolls of the first rolling stand is controlled. Calculate the rolled plate thickness at the exit side of the rolling stand, control the rolling speed of the rolling rolls of the first rolling stand to achieve the target plate thickness, and roll the plate to the target thickness. Then, calculate the calculated plate thickness at the exit side of the first rolling stand. Depending on the sheet passing speed on the exit side of the first rolling stand, the second
Determine the rolling timing of the rolled material on the rolling stand,
controlling the rotation speed of the rolling rolls in the second rolling stand;
On the other hand, the calculation plate thickness on the exit side of the first rolling stand and the first
Based on the measurement results of the strip passing speed on the exit side of the rolling stand and the threading speed on the exit side of the second rolling stand, the thickness of the strip on the exit side of the second rolling stand is calculated, and the rolling roll rotation of the second rolling stand is performed to achieve the target thickness. control the speed,
An automatic plate thickness control method for a rolling mill, characterized by rolling the plate to a target thickness.