US3641325A - Method of computer control of rolling mills - Google Patents

Method of computer control of rolling mills Download PDF

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Publication number
US3641325A
US3641325A US12775A US3641325DA US3641325A US 3641325 A US3641325 A US 3641325A US 12775 A US12775 A US 12775A US 3641325D A US3641325D A US 3641325DA US 3641325 A US3641325 A US 3641325A
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United States
Prior art keywords
rolling mill
rolling
mill
stands
control signals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US12775A
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English (en)
Inventor
Tohru Arimura
Masamoto Kamata
Masaru Okado
Takarokuro Ichimaru
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JFE Engineering Corp
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Nippon Kokan Ltd
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Publication date
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    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06G—ANALOGUE COMPUTERS
    • G06G7/00—Devices in which the computing operation is performed by varying electric or magnetic quantities
    • G06G7/48—Analogue computers for specific processes, systems or devices, e.g. simulators
    • G06G7/64—Analogue computers for specific processes, systems or devices, e.g. simulators for non-electric machines, e.g. turbine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
    • B21B37/16—Control of thickness, width, diameter or other transverse dimensions

Definitions

  • a curve representing the power required for reducing steel stock from a blank to the desired gauge is plotted by utilizing rolling data to suitably distribute the driving power to respective stands of a tandem rolling mill with due consideration of the capacity of the. driving motors of respective stands.
  • the output plate gauge of each stand is then determined from a power curve depicted in FIG. 1. Once the gauge is determined, the volume feed rate as well as the rolling speed of each stand can be determined under a fixed condition, and the rolling load can be calculated from the gauge and the speed.
  • This prior art method is characterized in that, when programming a proper schedule for each gauge rolled by the rolling mill, the rolling load, the driving power, gauge at each stand, rolling speed, etc., can be obtained in terms of their absolute values.
  • the rolling load, the driving power, gauge at each stand, rolling speed, etc. can be obtained in terms of their absolute values.
  • computing equations are very complicated.
  • the accuracy of the operation can not be assured using the prior art method.
  • Another object of this invention is to provide an improved computer control method of a rolling mill which can not only preset the mill to produce the desired product but also dynamically correct the preset values during operation.
  • the above-mentioned objects can be accomplished by providing a novel computer method wherein various operating parameters of the mill are respectively divided into a number of groups (or ranges), and the deviation of a parameter from the mean value in each group (or range) corresponding to that parameter is utilized to correct the operation of the rolling mill.
  • the deviation is com- LII puted in accordance with linear equations to increase the accuracy and speed of calculation.
  • FIG. 1 shows a plot of a power curve to explain a conventional method of determining the plate gauge at the exit of each mill stand
  • FIG. 2 is a diagram of a six-stand tandem hot mill employed to carry out this invention.
  • FIG. 2 there is shown a six-stand hot 'tandem mill comprising a final roughening rolling mill 12, a load cell 2 mounted on the roughening rolling mill 12, a temperature measuring device 13 and a series of finishing mill stands 5 including six stands 6 through 11.
  • a computer shown generally at 14 receives data from load cell 2 and from temperature-measuring device 13 operates on this data and controls the screw down of stands 6-1 1 via screw down controller 15. The computer controls the speed of the rolls at stands 6-11 via a speed controller 16.
  • the roll gap and roll speed of each stand should be set first.
  • the setting of the roll gap is determined dependent upon the plate gauge, the rolling load and stiffness of particular mill stand.
  • the roll speed can be determined from a condition that volume feed rate is constant.
  • these parameters are determined in the following manner.
  • equation (7) gives the plate gauge at each stand and equation (10) gives the rolling load at each stand.
  • the mill stiffness is determined by experiment or theoretical calculation as a function of the width of the material
  • this invention is characterized in that both the set values of the roll gap Sr, and roll speed V are obtained by adding linear correction values caused by minute changes (Ah AT AC etc.) to mean values (Sr V so that even when the record of the correction factor (a,,,,-) is not absolutely correct, the schedule finally obtained is extremely accurate.
  • the following diagram illustrates a flow chart of calculating and controlling a rolling mill when the invention is actually applied to preset the same.
  • FIG. 2 shows a computer connected in a mill.
  • Product specifications h T and B are fed into the computer 14 and the computer 14 calculates the nearest possible mean value (h 'Tr- 'P -i'V 'HP 'G B to 1116 said specification, and derives x -01 from out of a memory device therein.
  • the computer calculates first Ah -AC- -AT -b by equations (3) to (ol and computes the values of h -T -Pi-HP -M by equations (7) to (12).
  • this invention is also applicable to the dynamic control for correcting the error of the preset during the rolling operation.
  • One such application to the rolling mill shown in FIG. 2 is as follows.
  • Sr is computed by equation (13).
  • the computer further checks that these values obtained are within the range of the mill capacity and presets the screw downs and the roll speed of the each stand by means of controllers l5 and 16, respectively.
  • the temperature and the gauge of the plate at the exit of the roughening mill 12 are measured directly or indirectly by a suitable gauge meter (not shown) and the thermometer 13 shown in FIG. 2. Further. the rolling load of the final stand of the roughening mill 12 is measured by the load cell 2.
  • the plate gauge at the exit of roughening mill 12 can also he calculated from the output from load cell 2 according to equation 1 in which case, the equation is modified as follows.
  • equations (20) and (21) give the correction value for the preset value so that it is possible to calculate and control the deviation from the mean value by a linear correction.
  • Dynamic change in the preset is effected when the leading end of the material arrives at a point 4 shown in FIG. 2 to the calculation and control of the dynamic control is performed by means of a computer coupled to the roll stands to adjust same in accordance with the correction signals derived as above.
  • the actual control of the roll stands by the output signals from the computer may be implemented by one ordinarily skilled in the steel making and processing art.
  • the computer is also coupled to load cell 2, to thennometer 13 and to a gauge meter (not shown) at the output of toughening mill 12.
  • the invention can be applied to computer control of various mills such as a blooming mill, slab mill, cold tandem mill, cold reversible mill, tamper mill and the like. Further, since all controls are performed in accordance with primary equations, it is possible to perform the calculations in a short period of time so that the invention is most suitable for an online computer control.
  • the mean value (reference value) of each group or range of values for respective operating parameters of the rolling mill is calculated in accordance with simpleprimary equations to correct deviations alone so that control of the rolling mill is provided at high accuracies.
  • a method of controlling a plural stand rolling mill by means of a computer comprising:
  • correction factors predetermining and storing in a storage means a plurality of correction factors, the correction factors being stored as a function of the desired characteristics of the output of said rolling mill and as a function of the properties of the input material to said rolling mill;
  • control signals are calculated and applied to said stands prior to feeding in of the input material, thereby presetting said rolling mill to obtain a predetermined output product for a given input material.
  • control signals are further calculated and applied to said stands during operation of said rolling mill to dynamically vary said preset values.
  • said operating parameters of said rolling mill comprise plate gauge, temperature of the 5 material, rolling load, mill stiffness and roll gap.

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  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Mathematical Physics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Of Metal Rolling (AREA)
  • Control By Computers (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
US12775A 1969-02-21 1970-02-19 Method of computer control of rolling mills Expired - Lifetime US3641325A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44012571A JPS4814300B1 (enrdf_load_stackoverflow) 1969-02-21 1969-02-21

Publications (1)

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US3641325A true US3641325A (en) 1972-02-08

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US12775A Expired - Lifetime US3641325A (en) 1969-02-21 1970-02-19 Method of computer control of rolling mills

Country Status (10)

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US (1) US3641325A (enrdf_load_stackoverflow)
JP (1) JPS4814300B1 (enrdf_load_stackoverflow)
AU (1) AU1165170A (enrdf_load_stackoverflow)
BE (1) BE746320A (enrdf_load_stackoverflow)
CA (1) CA922794A (enrdf_load_stackoverflow)
DE (1) DE2008014A1 (enrdf_load_stackoverflow)
FR (1) FR2031585A1 (enrdf_load_stackoverflow)
GB (1) GB1293872A (enrdf_load_stackoverflow)
NL (1) NL7002483A (enrdf_load_stackoverflow)
SE (1) SE383690B (enrdf_load_stackoverflow)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3713313A (en) * 1971-11-19 1973-01-30 Gen Electric Computer controlled rolling mill
FR2383719A1 (fr) * 1977-03-17 1978-10-13 Bethlehem Steel Corp Controle de laminoir a barres
DE3026229A1 (de) * 1979-07-11 1981-02-19 Hoogovens Ijmuiden Bv Verfahren zur einstellung einer mehrstufigen walzstrasse
US4485497A (en) * 1979-12-27 1984-12-04 Mitsubishi Denki Kabushiki Kaisha Apparatus for controlling re-distribution of load on continuous rolling mill
US4928097A (en) * 1988-06-10 1990-05-22 Westinghouse Electric Corp. Real time process control using multiple communication networks
CN102513371A (zh) * 2011-12-23 2012-06-27 首钢总公司 一种确保连退成品厚度精度的酸轧目标厚度设定方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3545769C2 (de) * 1985-12-20 1994-01-13 Licentia Gmbh Verfahren zur Vorausbestimmung der optimalen Dickenverteilung

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3015974A (en) * 1958-09-18 1962-01-09 Gen Electric Automatic control system for rolling mills and adjustable dies
US3096670A (en) * 1957-07-16 1963-07-09 Westinghouse Electric Corp Apparatus and method for workpiece thickness control
US3104566A (en) * 1958-10-16 1963-09-24 Square D Co Rolling mill control
US3169424A (en) * 1962-01-30 1965-02-16 Gen Electric Automatic control system for rolling mills and adjustable dies
US3204440A (en) * 1963-03-01 1965-09-07 Gen Electric Automatic zeroing for a rolling mill position regulator
US3248916A (en) * 1962-09-21 1966-05-03 Westinghouse Electric Corp Workpiece shape control with a rolling mill
US3478551A (en) * 1966-05-06 1969-11-18 Davy & United Instr Ltd Control systems

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3096670A (en) * 1957-07-16 1963-07-09 Westinghouse Electric Corp Apparatus and method for workpiece thickness control
US3015974A (en) * 1958-09-18 1962-01-09 Gen Electric Automatic control system for rolling mills and adjustable dies
US3104566A (en) * 1958-10-16 1963-09-24 Square D Co Rolling mill control
US3169424A (en) * 1962-01-30 1965-02-16 Gen Electric Automatic control system for rolling mills and adjustable dies
US3248916A (en) * 1962-09-21 1966-05-03 Westinghouse Electric Corp Workpiece shape control with a rolling mill
US3204440A (en) * 1963-03-01 1965-09-07 Gen Electric Automatic zeroing for a rolling mill position regulator
US3478551A (en) * 1966-05-06 1969-11-18 Davy & United Instr Ltd Control systems

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Determination of a Mathematical Model for Rolling Mill Control Schultz et al., Iron and Steel Engineer, May 1965. *
Theoretical Aspects of Hot Mill Automation McKenzie, Steel International, January 1968. *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3713313A (en) * 1971-11-19 1973-01-30 Gen Electric Computer controlled rolling mill
FR2383719A1 (fr) * 1977-03-17 1978-10-13 Bethlehem Steel Corp Controle de laminoir a barres
DE3026229A1 (de) * 1979-07-11 1981-02-19 Hoogovens Ijmuiden Bv Verfahren zur einstellung einer mehrstufigen walzstrasse
US4485497A (en) * 1979-12-27 1984-12-04 Mitsubishi Denki Kabushiki Kaisha Apparatus for controlling re-distribution of load on continuous rolling mill
US4928097A (en) * 1988-06-10 1990-05-22 Westinghouse Electric Corp. Real time process control using multiple communication networks
CN102513371A (zh) * 2011-12-23 2012-06-27 首钢总公司 一种确保连退成品厚度精度的酸轧目标厚度设定方法
CN102513371B (zh) * 2011-12-23 2014-05-28 首钢总公司 一种确保连退成品厚度精度的酸轧目标厚度设定方法

Also Published As

Publication number Publication date
JPS4814300B1 (enrdf_load_stackoverflow) 1973-05-07
CA922794A (en) 1973-03-13
BE746320A (fr) 1970-07-31
SE383690B (sv) 1976-03-29
GB1293872A (en) 1972-10-25
AU1165170A (en) 1971-08-26
NL7002483A (enrdf_load_stackoverflow) 1970-08-25
DE2008014A1 (enrdf_load_stackoverflow) 1970-11-26
FR2031585A1 (enrdf_load_stackoverflow) 1970-11-20

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