US3733866A - Method of controlling a continuous hot rolling mill - Google Patents

Method of controlling a continuous hot rolling mill Download PDF

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Publication number
US3733866A
US3733866A US00151350A US3733866DA US3733866A US 3733866 A US3733866 A US 3733866A US 00151350 A US00151350 A US 00151350A US 3733866D A US3733866D A US 3733866DA US 3733866 A US3733866 A US 3733866A
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United States
Prior art keywords
roll
variation
time
mill
acceleration
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Expired - Lifetime
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US00151350A
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English (en)
Inventor
T Arimura
M Okado
Y Fukuma
Y Ido
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JFE Engineering Corp
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Nippon Kokan Ltd
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Application filed by Nippon Kokan Ltd filed Critical Nippon Kokan Ltd
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    • 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

  • ABSTRACT In a method of controlling a continuous hot rolling mill including a plurality of mill stands during acceleration thereof, variations in the screw down pressure (i.e., rolling load), in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of acceleration, are anticipated, the width of the finished plates, types and compositions of the materials being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations are classified into a plurality of groups, an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant is computed by an electronic computer associated with the rolling mill, and the roll gap and roll peripheral speed are controlled in accordance with the schedule for each mill stand so as to maintain the tension of the material between adjoining stands at a constant value.
  • variations in the screw down pressure i.e., rolling load
  • FIG. 4 Sheets-Sheet 3 TIME (SEC) FIG. 4
  • This invention relates to a method of controlling a continuous hot rolling mill and more particularly to a method of controlling the acceleration of a continuous hot rolling mill wherein the roll gap and the roll peripheral speed of each mill stand is controlled according to a predetermined pattern in order to maintain the gauge of the finished plates at a constant value and to eliminate off-gauge products when accelerating the rolling mill.
  • each mill stand of a continuous rolling mill is provided with a reduction screw, S, an electric motor, M, for driving the screw down, and a load cell, LC, responsive to the load or rolling pressure of the stand.
  • a suitable thickness measuring device for example an X-ray gauge meter
  • the lock-on operation is performed manually or under control of an electronic computer.
  • the plate gauge on the delivery side of respective stands equipped with conventional BISRA type AGC systems '(developed by British Iron and Steel Research Association) (normally, control of all intermediate stands excepting the first and last stands) is computed according to an equation wherein h: plate gauge on the delivery side of a stand P: screw down passage (i.e., rolling load) Po: screw down pressure or rolling load at the zero adjustment M: mill constant S: Set gap of the rolls Thereafter, due to the acceleration of the rolling speed, the temperature of the material and the strain speed vary and the roll gap is varied in accordance with the variation in the screw down pressure according to the following equation, thus maintaining the plate gauge on the delivery side of the stand at a constant value Further, the deviation of the plate gauge measured by the X-ray gauge meter is fed back to the second and following stands to supervise the plate gauge.
  • screw down pressure is synonomous with rolling load.
  • an application of the prior controlling method to the acceleration of the rolling speed results in various troubles and defects.
  • the variation in the screw down pressure increases so that it is necessary to rapidly raise or lower the screw after the AGC system has detected the variation in the screw down pressure.
  • the gauge of certain portions of the plate will deviate from a set value if the screw were raised or lowered after an instant at which the screw down pressure varies. The length of such off gauge portions increases proportionate to the acceleration and presents a substantial loss of production.
  • the variation in the roll peripheral speed and in the screw down pressure results in the variation of the thickness of the oil film of the bearings for back-up rolls, thus varying the set value of the roll gap. Since, in the prior art control system, this variation is the set value of the roll gap, it is controlled in terms of the variation in the screw down pressure, control is effected in the opposite direction. In other words, while the plate gauge decreases with the roll gap, in response to the increased screw down pressure, the prior art AGC system judges that the plate gauge is thick, and decreases the roll gap.
  • Another object of this invention is to provide a new and improved method of controlling a continuous hot rolling mill which can decrease off-gauge products by controlling the roll gap and roll peripheral speed according to a predetermined pattern determined by an electronic computer by anticipating various factors that vary as a result of acceleration.
  • a method of controlling a continuous hot rolling mill including a plurality of mill stands, comprising the steps of anticipating variations in the screw down pressure, in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of accelerating the rolling speed, classifying the widths of the finished plates, types and compositions of the steel being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations into a plurality of groups, computing an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant on the delivery side by means of an electronic computer associated with the rolling mill, and controlling the roll gap and the roll peripheral speed according to said schedule for each mill stand whereby to maintain the tension of the material between adjoining stands at a constant value.
  • FIG. 1 is a diagram to show a prior art AGC system
  • FIG. 2 is a graph to show the variation in the plate gauge during acceleration where the AGC system of the present invention is not used;
  • FIG. 3 is a diagram of a control system utilized to carry out the method of this invention.
  • FIG. 4 is a graph showing the transitional variation of roll gaps and FIG. 5 is a graph showing the transitional variation of the roll peripheral speed.
  • the plate gauge on the delivery side of each stand is determined by taking into consideration three variables viz. (a), the variation with time in the screw down pressure caused by the variations in the temperature and the strain speed (i.e., strain rate which occur during acceleration (b), the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and (c) the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure.
  • a the variation with time in the screw down pressure caused by the variations in the temperature and the strain speed
  • strain rate i.e., strain rate which occur during acceleration
  • the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure
  • the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure.
  • Stand d the pivot stand.
  • the acceleration control apparatus 2 determines a particular acceleration control schedule for the particular material based upon the command from the computer 1, and the differential function generator 3 receives an acceleration pattern for each stand from the acceleration control apparatus 2, selects a group of input data and determines the time variation between roll gaps at each stand, thereby giving commands for varying the roll gap and roll peripheral speed at each stand determined by the abovementioned acceleration control apparatus and differential function generator according to their prescribed pattern concurrently with the initiation of the rolling operation of the material. In this manner, an anticipation control of roll gaps and roll peripheral speed is performed during acceleration of the rolling operation.
  • the conventional AGC system 4 does not operate in the opposite direction.
  • the invention provides a perfect anticipation control wherein the variation in the screw down pressure is also considered.
  • the invention is also applicable to a continuous cold rolling mill.
  • the roll gap and the roll peripheral speed of each stand are varied according to a prescribed pattern for the purpose of preventing the gauge of the finished plate deviating from a predetermined value and preventing the tensions of the material between stands deviating from prescribed valves.
  • a method of computerized control of a continuous rolling mill including a plurality of mill stands comprising the steps of:
  • determining a particular acceleration control schedule of the mill stands for the particular material being operated on in accordance with a given relationship which is a function of at least: said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time in speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness in the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure;
  • Stand 4 the pivot stand.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
US00151350A 1970-06-18 1971-06-09 Method of controlling a continuous hot rolling mill Expired - Lifetime US3733866A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45052579A JPS4937910B1 (ja) 1970-06-18 1970-06-18

Publications (1)

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US3733866A true US3733866A (en) 1973-05-22

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US00151350A Expired - Lifetime US3733866A (en) 1970-06-18 1971-06-09 Method of controlling a continuous hot rolling mill

Country Status (6)

Country Link
US (1) US3733866A (ja)
JP (1) JPS4937910B1 (ja)
CA (1) CA934032A (ja)
DE (1) DE2128237A1 (ja)
FR (1) FR2100785B1 (ja)
GB (1) GB1326993A (ja)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3851509A (en) * 1972-11-06 1974-12-03 Westinghouse Electric Corp Rolling mill gauge control method and apparatus including speed correction
US5291108A (en) * 1991-05-15 1994-03-01 Mannesmann Aktiengesellschaft Method of equalizing the torque on a drive of a pilger rolling mill
US5305624A (en) * 1991-05-22 1994-04-26 Mannesmann Aktiengesellschaft A Corp. Of The Federal Republic Of Germany Sizing-stand group
WO2003103870A1 (fr) * 2002-06-06 2003-12-18 Otkrytoe Aktsionernoe Obschestvo "Magnitogorsky Metallurgichesky Kombinat" Procede d'optimisation de la technique de production de metaux lamines
US20100269556A1 (en) * 2007-06-11 2010-10-28 Arcelormittal France Method of rolling a metal strip with adjustment of the lateral position of a strip and suitable rolling mill
US20110041580A1 (en) * 2007-11-02 2011-02-24 Shigeru Ogawa Rolling mill for a plate or a sheet and its control technique
US20120004757A1 (en) * 2009-03-13 2012-01-05 Toshiba Mitsubishi-Electric Indus. Sys. Corp. Optimization device
US20140367883A1 (en) * 2012-02-08 2014-12-18 Nitto Denko Corporation Producing method of thermally conductive sheet

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3119150A1 (fr) 2021-01-28 2022-07-29 Psa Automobiles Sa Fixation de batteries de traction sous vehicule compatible choc lateral poteau

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA932432A (en) * 1968-02-02 1973-08-21 Andrew W. Smith, Jr. Predictive gauge control method and apparatus with automatic plasticity determination for metal rolling mills
US3618348A (en) * 1968-05-21 1971-11-09 Nippon Kokan Kk Method of controlling rolling of metal strips

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3851509A (en) * 1972-11-06 1974-12-03 Westinghouse Electric Corp Rolling mill gauge control method and apparatus including speed correction
US5291108A (en) * 1991-05-15 1994-03-01 Mannesmann Aktiengesellschaft Method of equalizing the torque on a drive of a pilger rolling mill
US5305624A (en) * 1991-05-22 1994-04-26 Mannesmann Aktiengesellschaft A Corp. Of The Federal Republic Of Germany Sizing-stand group
WO2003103870A1 (fr) * 2002-06-06 2003-12-18 Otkrytoe Aktsionernoe Obschestvo "Magnitogorsky Metallurgichesky Kombinat" Procede d'optimisation de la technique de production de metaux lamines
US20050178481A1 (en) * 2002-06-06 2005-08-18 Obschestovo S Organichennoi Otvetstvennostyu Method for optimising the production technology of rolled products
US7354492B2 (en) 2002-06-06 2008-04-08 Otkrytoe Aktsionernoe Obschestvo “Magnitogorsky Metallurgichesky Kombinat” Method for optimising the production technology of rolled products
US20100269556A1 (en) * 2007-06-11 2010-10-28 Arcelormittal France Method of rolling a metal strip with adjustment of the lateral position of a strip and suitable rolling mill
US8919162B2 (en) * 2007-06-11 2014-12-30 Arcelormittal France Method of rolling a metal strip with adjustment of the lateral position of a strip and suitable rolling mill
US20110041580A1 (en) * 2007-11-02 2011-02-24 Shigeru Ogawa Rolling mill for a plate or a sheet and its control technique
US8720242B2 (en) * 2007-11-02 2014-05-13 Nippon Steel & Sumitomo Metal Corporation Rolling mill for a plate or a sheet and its control technique
US20120004757A1 (en) * 2009-03-13 2012-01-05 Toshiba Mitsubishi-Electric Indus. Sys. Corp. Optimization device
US20140367883A1 (en) * 2012-02-08 2014-12-18 Nitto Denko Corporation Producing method of thermally conductive sheet

Also Published As

Publication number Publication date
GB1326993A (en) 1973-08-15
CA934032A (en) 1973-09-18
FR2100785B1 (ja) 1974-08-19
JPS4937910B1 (ja) 1974-10-14
DE2128237A1 (de) 1971-12-23
FR2100785A1 (ja) 1972-03-24

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