US3334502A - Strip thickness control apparatus for a rolling mill - Google Patents

Strip thickness control apparatus for a rolling mill Download PDF

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Publication number
US3334502A
US3334502A US327027A US32702763A US3334502A US 3334502 A US3334502 A US 3334502A US 327027 A US327027 A US 327027A US 32702763 A US32702763 A US 32702763A US 3334502 A US3334502 A US 3334502A
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United States
Prior art keywords
strip
roll
thickness
roll members
deflection
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Expired - Lifetime
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US327027A
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English (en)
Inventor
Heindel Adolf
Neuffer Ingemar
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Siemens Schuckertwerke AG
Siemens Corp
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Siemens Corp
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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
    • B21B37/48—Tension control; Compression control
    • B21B37/50—Tension control; Compression control by looper control

Definitions

  • the present invention relates in general to strip thickness control apparatus and more particularly to strip thickness control apparatus for a rolling mill having a plurality of stands and wherein at least one between stand sag or tension regulator is provided.
  • the attainment of the requisite thickness of delivery rolled strip during hot rolling entails certain difculties, especially at the rst set of rolls. Since the thickness of the strip emerging from a rolling mill is, to a large approximation, equal to the gap between the rolls of the last stand, it would seem obvious to keep this last stand roll spacing or gap constant. However, it is only possible to measure this roll gap by indirect methods which depend on the rolling pressure and which can be determined either by special pressure pickups such as piezo-electric gauges or by measuring the expansion of the stand framework. These well-known procedures are complicated and of low accuracy because it is not possible, either in whole or in part, to account for the many extraneous disturbing influences.
  • the present invention proposes an alternative and simpler method of controlling the delivery thickness of strip during the hot rolling process. It originates from the realization that if we are to have an unchanged exit velocity from a given stand, any change in strip thickness or change in roll gap of that stand must inevitably result in a change in the entrance velocity of the rolled stock. This is because, according to the well-known principle of continuity, the amount of stock being fed into the rolls of a given mill stand in a specied time interval must be equal to the amount of rolled stock emerging therefrom, the width of the strip being considered as remaining constant.
  • the lpresent invention is concerned with an apparatus for regulating the thickness of the rolled stock in hotmill trains having a plurality of mill stands and having sag (curl, bow) or tension controllers located between the individual stands or sets of rolls.
  • the drive-motors of the plurality of stands are regulated ⁇ with respect to each other so as to have a chosen ratio of revolutions per minute.
  • a regulator is associated with each individual sag-lifter or interstand tension controller and controls the angular tilt or position of the said sag lifter arm to a preset value with respect to the setting of the succeeding stand roll spacing.
  • the drawing shows a multiple stand hot-rolling mill train, in which only the rst stand 10, the second stand 12 and the last stand 14 are shown in the figure.
  • the rolling-stock or workpiece strip is denoted by the numeral 2.
  • the rolling direction runs from left to right, as shown by the arrow.
  • Each set or stand of rolls is driven by la roll motor M to which is connected a revolution speed (rpm.) controller 3, and fed into one side of the latter for each stand in conventional manner is the true r.p.m. from a tachometer T1 and the required (pre-set) value given as a speed reference by potentiometer 4.
  • These required value or speed reference potentiometers may be connected to a common voltage lead and be so adjusted that the individual stand roll-motors have the required rpm. or speed ratio with respect to each other as presently well known in this vart and corresponding to the reduction in thickness of roll-stock 2 in the individual roll stands.
  • the gap between the rolls of the individual mill stands is adjustable via a screwdown servo-motor 5 controlled by ia conventional rpm.
  • regulator 8 for ne adjustment in accord with the existing rolling program, the regulator 8 being fed with the required value as a position reference signal through input connection 18 and with the actual value by the tachometer T2.
  • a sag-lifter or tension controller 6 to which is connected a measured-value transducer or thickness gauge transducer 7 which yields a measurement signal as a proportional function of the sag-lifter angle a.
  • the actual means for raising and positioning the sag-litters is well known per se ⁇ and is not specifically shown.
  • the regulation deviation or error signal Aa is formed in an accommodating transducing and comparison apparatus 7, operative with the actual sag lifter angle a applied to one of its inputs and the reference or desired angle supplied to the other input.
  • This error signal Aa is amplied in a proportional amplifier 11 and serves as the desired value at the rpm. regulator 8 for the servo-motor 5.
  • the roll gap of the succeeding stand is altered via servo-motor 5 with a velocity proportional to the regulator variation Aa until sag-lifter ⁇ 6 again yreaches the required position.
  • the succeeding stand roll gap, and hence the roll-stock emerging strip thickness d2 will have again attained the requisite dimensions.
  • the deviation Aa provided by transducer is fed into ⁇ a proportional amplifier 20.
  • Transducer 7 and amplifier 20 thus form a proportional -regulator which is operative with the r.p.m. controller 3 of the succeeding roll unit and provides it with an additional control signal.
  • the succeeding stand r.p.m. controller 3 ensures a speedy restoration of the sag in the strip head of that stand to its pre-established or desired value should any undesired change occur therein.
  • the control-deviation signal Aa supplied -by transducer 7 is fed into the proportional amplifier 20.
  • Transducer 7 and amplifier 20 for each stand thus form a proportional regulator which is operative with the rotational speed regulator 3 of the succeeding roll unit and provides it with an additional required or control signal value.
  • this speed regulator 3 promotes the rapid return of the sag Iahead of that stand to the required value should any change in the strip sag occur.
  • a single and common error signal amplifier can, of course, be employed for this purpose.
  • the thickness of the strip emerging from the last set of rolls or stand 14 can be measured by means of a thickness gauge V22.
  • the thickness gauge 22 consisting, for example, of a radiography or X-ray apparatus, and, by means of a regulator 13, which can be supplied by a reference signal device 24 with the required thickness value, each that an additional correction signal can be applied to r.p.m. regulator 3 of the last of rolls 14.
  • This correction produces a change in the r.p.m. of the roll motor for the last stand or set of rolls 14 in such a sense that a correction is applied to the roll-gap in conjunction with the change in the angle of the sag-lifter operative with the regulators 5 and 8.
  • the exit thickness d2 from stand 14 is too large as measured by thickness gauge 22, it then follows that the thickness correction signal impressed by regulator 13 on the r.p.m. controller 3 for the last stand 14 produces a corresponding increase in the r.p.m. of the drive motor, and hence a reduction in the angle a of the sag-lifter placed ahead of the last stand 14.
  • the effect of sag regulator 20 on r.p.m. controller 3 can be weakened or augmented as may be desired for any particular strip rolling operation by the provision of the thickness correction signal supplied by thickness regulator 13.
  • thickness control apparatus for a strip rolling mill having a pair of spaced roll members, the combination of strip deflection sensing means responsive to the actual deflection of said strip prior to passing between said roll members, driving means for said roll members to provide a desired operating speed to said roll members, spacing control means for said roll members to provide a desired spacing between said roll members, and thickness control means operative with each of said driving means, said spacing control means and said strip deflection sensing means to control the thickness of said strip emerging from said roll members in accordance with a predetermined deflection error relationship between said actual strip deflection and a desired strip deflection for said strip prior to said roll members.
  • control apparatus for the thickness of a strip operative with a pair of spaced roll members in a strip rolling mill
  • strip tension sensing means for providing a control signal in response to the actual tension of said strip prior to passing between said roll members
  • driving means for said roll members to provide a desired operating speed to said roll members
  • spacing control means for said roll members to provide a desired spacing between said roll members
  • thickness control means operative with at least one of said driving means and said spacing control means and responsive to said control signal to control the thickness of said strip emerging from said roll members in accordance with a predetermined deflection error relationship between said actual strip deflection and a desired strip deflection prior to said roll members.
  • the combina-, tion of strip deflection sensing means for providing a control signal in accordance with the deflection error difference between the actual deflection of said strip at a predetermined location prior to passing between said rollV members as compared to a desired deflectionof said strip, driving means for said rolls members to provide a desired operating speed to said roll members, screwdown control means for said roll members to provide a desired spacing between said roll members, and thickness control means operative with said driving means and said spacing control means in response to said control signal to control the thickness of said strip emerging from said roll members.
  • strip deflection means positioned ahead of each pair of spaced roll members and respectively providing a control signal in accord ance with a pretermined deflection error of the strip ahead of each pair of spaced roll members, driving means for each pair of roll members to provide a desired operating speed relationship between said plurality of roll stands, spacing control means for each pair of spaced roll members for providing a desired spacing between said pair of roll members, and deflection control means operative with said strip deflection means for each respective pair of spaced roll members and said spacing control for each respective pair of spaced roll members for controlling the deflection of said strip ahead of said pair of spaced roll members in response to said control signal in accordance with the deflection error of the strip ahead of said pair of spaced roll members.
  • control apparatus for a strip rolling mill having a plurality of roll stands, with each roll stand including a pair of spaced roll members, the combination of a plurality of strip deection members, with each said deilection member being positioned ahead of a different pair of spaced roll members and providing a control signal in accordance with a predetermined deflection error of the strip ahead of its associated pair of spaced roll members, driving means for each pair of roll members to provide a desired operating speed relationship between said plurality of roll stands, thickness control means for each pair of spaced roll members for providing a desired spacing between said pair of roll members, and deflection control means operative with each pair of spaced roll members and with one of said strip deflection means and said spacing control means operative with its respective pair of spaced roll members for controlling the deiiection of said strip ahead of its respective pair of spaced roll members in response to said control signal from the strip deflection member positioned ahead of its respective pair of spaced roll members.
  • thickness control apparatus for a strip rolling mill having a plurality of roll stands each including a pair of spaced roll members, the combination of strip deection means positioned ahead of at least one pair of spaced roll members and respectively providing a control signal in accordance with a predetermined deflection error of the strip ahead of said one pair of spaced roll members, driving means for each pair of roll members to provide a desired operating speed relationship between said plurality of roll stands, strip thickness control means for at least said one pair of spaced roll members for providing a desired spacing between said pair of roll members, and deilection control means operative with one of said strip deflection means and said spacing, control means for said one pair of spaced r-oll members for controlling the deflection of said strip ahead of said one pair of spaced roll members in response to said control signal, with said deflection control means including a signal integrating device having an integral characteristic in accordance with the deflection error of said strip ahead of said one pair of spaced roll members.
  • thickness control apparatus for a strip rolling mill having a plurality of roll stands each including a pair of spaced roll members, the combination of strip deilection means positioned ahead of one pair of spaced roll members and respectively providing a control signal in accordance with a predetermined deflection error of the strip ahead of each said one pair of spaced roll members, driving means for each pair of roll members to provide a desired operating speed relationship between said plurality of roll stands, strip thickness control means for said one pair of spaced roll members for providing a desired spacing between said one pair of roll members, deection control means operative with said spacing control means for said one pair of spaced roll members for controlling the deflection of said strip ahead of said one pair of spaced roll members in response to said control signal, and strip thickness measuring means operative with the strip leaving said one pair of spaced roll members for providing a thickness error correction signal to said spacing control means for additionally controlling the deflection of said strip ahead of said one pair of spaced roll members.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
US327027A 1962-12-24 1963-11-29 Strip thickness control apparatus for a rolling mill Expired - Lifetime US3334502A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DES83052A DE1290234B (de) 1962-12-24 1962-12-24 Einrichtung zur Regelung der Walzgutdicke in Warmwalzwerken

Publications (1)

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US3334502A true US3334502A (en) 1967-08-08

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US327027A Expired - Lifetime US3334502A (en) 1962-12-24 1963-11-29 Strip thickness control apparatus for a rolling mill

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US (1) US3334502A (en:Method)
AT (1) AT241618B (en:Method)
BE (1) BE641735A (en:Method)
DE (1) DE1290234B (en:Method)
LU (1) LU44801A1 (en:Method)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3457748A (en) * 1966-09-29 1969-07-29 British Iron Steel Research Rolling of strip
US3507134A (en) * 1968-02-20 1970-04-21 Westinghouse Electric Corp Interstand tension control for tandem cold rolling mills
US3744288A (en) * 1971-12-22 1973-07-10 Morgan Construction Co Tensiometer
DE2513882A1 (de) * 1974-04-02 1975-10-09 Lysaght Australia Ltd Verfahren zum steuern des bandzuges bei warmbandwalzwerken
WO2017178145A1 (de) 2016-04-14 2017-10-19 Primetals Technologies Germany Gmbh Robuste bandzugregelung

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2189609A (en) * 1937-03-27 1940-02-06 Westinghouse Electric & Mfg Co Fluid-pressure operated tensiometer
US2297812A (en) * 1939-06-30 1942-10-06 Westinghouse Electric & Mfg Co Draft control system
US2715702A (en) * 1950-08-19 1955-08-16 Westinghouse Electric Corp Motor control systems for tension control
US2851911A (en) * 1954-01-26 1958-09-16 British Iron Steel Research Rolling mills
US3186200A (en) * 1961-10-31 1965-06-01 Gen Electric Automatic thickness regulator for strip rolling mills
US3253438A (en) * 1962-09-21 1966-05-31 Westinghouse Electric Corp Automatic strip gauge control for a rolling mill

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE663248C (de) * 1938-08-02 Erich Howahr Walzenstrasse mit Schlingenbildung zwischen den einzelnen Geruesten
US1145880A (en) * 1913-03-11 1915-07-13 Bridgeport Brass Co Automatic roll adjustment for rolling-mills.

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2189609A (en) * 1937-03-27 1940-02-06 Westinghouse Electric & Mfg Co Fluid-pressure operated tensiometer
US2297812A (en) * 1939-06-30 1942-10-06 Westinghouse Electric & Mfg Co Draft control system
US2715702A (en) * 1950-08-19 1955-08-16 Westinghouse Electric Corp Motor control systems for tension control
US2851911A (en) * 1954-01-26 1958-09-16 British Iron Steel Research Rolling mills
US3186200A (en) * 1961-10-31 1965-06-01 Gen Electric Automatic thickness regulator for strip rolling mills
US3253438A (en) * 1962-09-21 1966-05-31 Westinghouse Electric Corp Automatic strip gauge control for a rolling mill

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3457748A (en) * 1966-09-29 1969-07-29 British Iron Steel Research Rolling of strip
US3507134A (en) * 1968-02-20 1970-04-21 Westinghouse Electric Corp Interstand tension control for tandem cold rolling mills
US3744288A (en) * 1971-12-22 1973-07-10 Morgan Construction Co Tensiometer
DE2513882A1 (de) * 1974-04-02 1975-10-09 Lysaght Australia Ltd Verfahren zum steuern des bandzuges bei warmbandwalzwerken
US3977223A (en) * 1974-04-02 1976-08-31 John Lysaght (Australia) Limited Hot strip mill tension control
WO2017178145A1 (de) 2016-04-14 2017-10-19 Primetals Technologies Germany Gmbh Robuste bandzugregelung
US10780474B2 (en) 2016-04-14 2020-09-22 Primetals Technologies Germany Gmbh Robust band tension control

Also Published As

Publication number Publication date
DE1290234B (de) 1969-03-06
LU44801A1 (en:Method) 1964-01-13
BE641735A (en:Method) 1964-06-24
AT241618B (de) 1965-08-10

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