JPS60240328A - Controlling device of plate thickness in hot finishing mill - Google Patents

Abstract

PURPOSE:To provide the titled device performing a proper plate thickness controlling and suppressing the generation of defective product by providing a thickness gage for plate thickness detection of the material to be rolled, a calculator of plate thickness deviation and an arithmetic unit of correcting value between a pair of stands adjoining each other of a hot finish rolling mill. CONSTITUTION:A thickness gage 14 for plate thickness detecting of a steel strip 12 of the material to be rolled at the position between both stands is provided between the 3rd stand 10C and 4th stand 10D of a hot finishing mill 10. An arithmetic unit 16 is also provided to calculate the distribution of rolling reduction in each stand 10A-10G based on the information of the quality of steel strip 12, plate thickness finishing target, the temp. thickness, etc. of the steel strip 12 of at the inlet side of the rolling mill 10. Further a correction values calculating unit 20 to perform a correcting calculation of the plate thickness deviation calculator 18 for the target plate thickness in the position of the thickness gage based on the output signal of the thickness gage 14 and of the distribution of rolling reduction at stands 10D-10G after the thickness gage 14 based on the plate thickness deviation signal outputted from the calculator 18 thereof and to output the correcting signal thereof to the unit 16 is provided.

Description

[Detailed description of the invention]

(Industrial Application Field) This invention relates to improvement of a plate thickness control device in a hot finishing rolling mill for steel plates and the like.

[Conventional technology]

For example, as shown in FIG. 3, plate thickness control in a conventional steel plate hot finishing mill involves a rough rolling mill 1 and a finishing rolling mill 11.
2, on the exit side of the finishing rolling mill 2, based on the detection signals from the plate thickness gauge 4 that detects the plate thickness of the steel strip 3 on the exit side of the rough rolling mill 1, and the thermometer 5 that detects the temperature. The roll gap, rotation speed, and rolling load of each of the finishing mills 2A to 2G in the finishing mill 2 are estimated and set so that the target plate thickness, temperature, and temporary width can be achieved. Furthermore, in this case, a plate thickness gauge 6 is provided on the outlet side of the rolling mill 2, and a meter control device is installed so that the deviation between the actual value measured on the outlet side of the copper strip by the plate thickness gauge 6 and the target value is zero. 7 for each finishing mill 2
The reduction of A to 2G is corrected. However, the plate thickness gauge 4 at the exit side of the rough rolling mill 1
, detection of thermometer 5, etc. (each finishing mill 2A-J based on No. g)
If the estimated values of the 2G roll gap, rotation speed, rolling load, etc. are not accurate, it may not be possible to obtain the prescribed thickness of the copper strip on the exit side of the finishing rolling mill 2, which may result in product defects. . In particular, when rolling the copper strip for the first time after changing lots, it is not possible to obtain information on the thickness at the exit side of the finishing rolling mill 2, making it virtually impossible to control the thickness at the tip of the copper strip.
This often caused product defects.

[Problems to be solved by the invention]

This invention has been made in view of the above-mentioned conventional problems, and includes plate thickness control in a hot finishing mill that suppresses the occurrence of product defects by appropriately controlling the plate thickness even at the tip of the rolled material. The purpose is to provide equipment. [Means for Solving the Problems] The present invention provides a thickness control system that is provided between at least a pair of mutually adjacent stands of a hot finishing rolling mill, and that detects the thickness of a material to be rolled at a position between these stands. The reduction distribution in the winter stand of the hot finishing rolling mill is determined based on information such as the material of the rolled material, the target finished plate thickness, the temperature of the rolled material at the entrance side of the hot finishing rolling mill, and the shore height. a calculation device that performs calculations;
Based on the output signal of the thickness gauge, for the target plate thickness at the thickness needle position. a plate thickness deviation calculator for calculating plate thickness deviation;
a correction value calculation device that corrects and calculates the reduction distribution in the stand from the thickness gauge based on the plate thickness deviation signal output from the plate thickness deviation calculation device, and outputs the correction value to the calculation II device; The above object is achieved by a plate thickness control device for a hot finishing rolling mill. 1 Effect] The plate thickness control device for a hot finishing rolling mill according to the present invention obtains a plate thickness signal using a thickness gauge between the stands of a finishing rolling mill, and thereby obtains a plate thickness signal in the stands after the thickness gauge. The rolling position of the finishing mill is corrected to improve the thickness accuracy of the tip of the rolled material. Here, the relationship between the roll gap, rolling load, and exit plate thickness in a general rolling mill is expressed by the following equations (1) and (2).
It is expressed by the formula. 1+ ='S o +P, /M - (1)h-Ha-P
, -”Q -(2) h: Target exit plate thickness P: Rolling load movement M: Mill constant Q: W! property constant So: Roll gap Ho: Actual plate thickness Ho is Ho
' = Ho + ΔHo, the variation ΔP of the rolling load P is expressed by equation (3) from equations (1) and (2) above. 8P=MQ”M+Q−ΔHo −(,3) At this time, the variation tΔ of the roll gap to ensure the target exit side plate thickness H
So is given by equation (4). ΔS o = Q / M ・ΔHo ・” (4) Therefore, in order to ensure the target exit plate thickness, it is important to accurately predict and set the roll gap So and rolling load ff1P, and Rolling loads P and O- are calculated from the plate thickness deviation value obtained by the thickness gauge installed between the stands.
By correcting the lead gap So, it becomes possible to ensure the target outlet side plate thickness. [Example] Examples of the present invention will be described below with reference to the drawings. As shown in FIG. 1, this embodiment is provided between a third stand 10G and a fourth stand 10D of a hot finishing rolling mill 70, and
A thickness gage 14 detects the thickness of the steel strip 12, which is the material to be rolled, at the intermediate position, and the thickness of the steel strip 12, the target finishing thickness, and the thickness of the steel strip 12 at the 10-man side of the hot finishing mill. Based on information such as temperature and thickness, each stand 10 of the hot finishing rolling*io
Calculation device 16 that calculates the reduction distribution in A to 10G
Based on the output signal of the thickness gauge 14, the thickness gauge 14
A plate thickness deviation calculator 18 that calculates the plate thickness deviation with respect to the target plate thickness at the position, and the fourth stands 10D to 10D after the thickness gauge 14 based on the plate thickness IN signal output from the plate thickness deviation calculator 18. a correction value calculation device 120 that corrects the rolling reduction distribution in the seventh stand 10G and outputs this correction signal to the calculation device 16;
This is a plate thickness control device. The material of the steel strip 12, the target finish thickness, and the hot finish rolling 1! ! Steel strip 1 on the 10 person side
Information such as temperature and thickness of No. 2 is inputted from a rolling schedule setting storage device 22. Specifically, the roll gap signal Si corresponding to the exit target plate thickness in each stand 10A to 10G of the hot finish rolling 110 is determined by the rolling schedule setting record I! device 22
It is now input from This rolling schedule setting storage device i & 22 receives detection signals from the plate thickness 4 and thermometer 5 disposed on the outlet side of the rough rolling mill 1, preset rolling conditions, etc. Each stand 10A to 10 in 10
The exit target plate thickness (rolling schedule) and rolling load at G are set and calculated and stored. The correction value calculation device 120 includes a rolling schedule change value calculation device 20A and a rolling load calculation device 20B. The reduction schedule setting storage device 122 outputs an O-le gap signal Si to the calculation device 16, and also outputs a signal of the exit target plate thickness 113 at the third stand 10C to the plate Jl (1g difference calculation unit 18). , and the reduction schedule change value calculator 2 in the correction calculator @20
For OA, exit target plate thickness signals 114, h5 and 11 at the fourth stand 10D to the sixth stand 10F
The outputs are designed to cover the respective G signals. Further, the plate thickness deviation calculator 18 written in Ii1'J is connected to the thickness gauge 1.
The measured plate thickness H3 of the steel strip 12 on the third stand 10C [side from 4 and the rolling schedule setting storage device
The difference from the third stand exit target plate thickness h3, that is, the plate thickness deviation Δh3, is 8! jw! I, this is the reduction schedule change 1i! The signal is output to the arithmetic unit 2OA. This reduction schedule change value calculator 2OA calculates the output side target plate thickness at these three stands from the plate thickness deviation Δ1)3 and the output side target plate thickness h4 to ha at the fourth stand 10D to the sixth stand 10F. Change1iFlhi
= aiΔh3 (ai is a constant, calculate Σa i=1>,
These are each outputted to the rolling load calculation device 12OR. In this rolling load calculating device 120B, rolling charges R4 to R7 are calculated to obtain the target plate thickness calculated by the reduction schedule change value calculating unit 2-OA. This arithmetic expression is shown by the following equation (5). P'=aikiWi i +i-i (5) ki: Deformation resistance R1: Uneven roll radius Wi: #i width
Qi: Reduction force function Δh i=l+ i −h 1-18 i: Example value 1
11: Stand outlet side plate thickness (Δh4-tls h3) The learned value ai in the above equation (5) is input from the corrector 24. This corrector 24 calculates H2-S 2 +P 2 , /'M based on the mill constant M2, actual reduction #S2, and actual rolling load movement P2 in the second stand 10B, which are input from the reduction schedule setting storage device 22. Calculate 2, this day is 2 and before! ! Output H3 of 14 in total and actual before rolling I
From P 3 and the above equation (5), 3 is calculated for the actual deformation resistance. This actual deformation resistance is set to 3, and the rolling load used when calculating the rolling load in the rolling schedule setting storage device 22 is set to 3.
4th stand 10D to 7th stand 10
Modify 4 to 7 in G. As a modification method, for example, a" = α-a" + (1-a> ・(Ka, /k
3) aL: Current correction @a l + l: The next correction value is the final B L'r +, and the learning of equation (5) in the rolling load calculation calculation 20B is performed! Output as ai. This rolling load calculation device 20B outputs the calculated corrected rolling load Pi′ to the calculation device @16, and this calculation device 16 outputs the corrected exit side target plate thickness bi′ at each IC stand, the rolling load 4Pi', the corrected reduction amount 81' is calculated using the following equation (6). 3i'=b 1-pi"/'Mi...(6)<M
i: each stand mill constant) Difference Si' between this S i + and the reduction amount S1 in the fourth stand 10D to seventh stand 10G preset from the reduction schedule setting storage device 22
−8i=ΔSi is the correction value of the rolling reduction amount for obtaining the corrected target exit side plate thickness in each of these stands. Therefore, the performance device 16 uses the roll reduction setting values S4 to 87 (preset consultation) for the fourth stand 10O to the seventh stand IOG inputted from the roll reduction schedule setting storage device 22 to the rolling load calculation from the rolling load calculation @gi116A. After correction based on P4' to P7', the lowering position correction values ΔS4 to ΔS7 in the fourth stand 10D to the seventh stand 10G are output to the lowering control devices 28D to 28G in the respective stands. The output of the reduction position correction values ΔS4 to Δ87 for the reduction control 0 equipment Wt28D to 28G is such that the steel strip 12 has a total thickness of 1
4 and is output before being bitten by the work roll of the fourth stand 10D. Therefore, in this embodiment, the rolling load and roll gap of the fourth stand 10D to the seventh stand 10G in the finishing rolling mill 10 can be corrected and changed during rolling, thereby improving the accuracy of the exit side plate thickness. become. In other words, the thickness control at the tip of the steel plate, which has not been possible before, is now possible.
This is carried out in the stands after the fourth stand 10D in the finish rolling 1110, and the accuracy of the tip plate thickness is greatly improved. Also, for parts other than the tip of the steel strip 12, the thickness of the steel strip 12 is detected between the stands in the middle of the hot finishing rolling mill 10 using the thickness gauge 14, and the thickness of the steel strip 12 is measured at each stand after the thickness gauge 14. Conventional hot finishing rolling 111
Compared to the plate thickness control using only the thickness gauge provided on the exit side of the plate, the plate thickness accuracy can be further improved. Note that the thickness gauge 14 in the above embodiment is used for the third stand 10G and the fourth stand 10 in the hot finishing rolling mill 10.
Although the present invention is not limited to this, it may be provided between any pair of adjacent stands of a hot finishing mill. However, it is best to install the thickness gauge 14 at an intermediate position between a series of multiple stands in the hot finishing mill 10.
l[Accuracy can be improved. ■Effects of the Invention 1 Since the present invention is configured as described above, it is possible to dynamically correct the rolling position of the mill in each subsequent stand during rolling by the finishing mill to obtain the required thickness. This has the excellent effect of greatly improving the plate thickness accuracy at the tip of the rolled material.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the plate thickness control device for a hot finishing rolling mill according to the present invention, and Fig. 2 shows the relationship between rolling load, roll gap, plate thickness, and exit side plate thickness in hot finishing rolling. A diagram showing the relationship, Figure 3 shows plate thickness control in a conventional hot finishing rolling mill...
Rough rolling mill, 10... hot finishing rolling mill. 10C...Third stand, 100...Fourth stand, 10G...Seventh stand, 12...Steel strip, 1
4...Thickness gauge, 16...AM device, 18...Plate W deviation computing device, 20...Correction lii computing device, 22... Rolling down schedule setting storage device. Agent Keisuke Matsuyama (and 1 other person)

Claims (1)

[Claims] (1) A thickness gauge that is installed between at least a pair of adjacent stands of a hot finishing mill and detects the thickness of the material to be rolled at a position between these stands, and the material and target of the material to be rolled. a calculation device that calculates the reduction distribution in the hot finishing rolling machine stand based on information such as the finished plate thickness, the temperature and thickness of the material to be rolled at the entrance side of the hot finishing rolling machine; and an output signal of the thickness gauge. a plate thickness deviation calculator that calculates the plate thickness deviation with respect to the target plate thickness at the thickness needle position based on the thickness deviation calculator; A plate thickness control device for a hot finishing rolling mill, comprising: a correction value calculation IN device for correcting the rolling reduction distribution in the calculation device and outputting the correction signal to the calculation device.