US3457748A - Rolling of strip - Google Patents

Rolling of strip Download PDF

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Publication number
US3457748A
US3457748A US585871A US3457748DA US3457748A US 3457748 A US3457748 A US 3457748A US 585871 A US585871 A US 585871A US 3457748D A US3457748D A US 3457748DA US 3457748 A US3457748 A US 3457748A
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United States
Prior art keywords
shape
gauge
strip
control
rolls
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
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US585871A
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English (en)
Inventor
John G Wistreich
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British Iron and Steel Research Association BISRA
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British Iron and Steel Research Association BISRA
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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
    • B21B37/58—Roll-force control; Roll-gap control
    • B21B37/64—Mill spring or roll spring compensation systems, e.g. control of prestressed mill stands
    • 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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • 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
    • B21B37/28—Control of flatness or profile during rolling of strip, sheets or plates
    • B21B37/38—Control of flatness or profile during rolling of strip, sheets or plates using roll bending
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2265/00—Forming parameters
    • B21B2265/02—Tension
    • B21B2265/08—Back or outlet tension

Definitions

  • This invention relates to the rolling of strip and is particularly concerned with the automatic control of strip gauge and shape, that is to say, strip thickness and flatness.
  • An object of the invention is to provide a method and apparatus for automatically regulating a strip rolling mill so that deviations from the desired gauge and shape of the rolled strip, which deviations arise naturally in the rolling process, are both maintained within narrow tolerances relative to the desired values.
  • a measure of strip shape can be defined as follows: perfectly flat strip has zero shape, expressed as 2:0; strip with Wavy edges or so-called long edges, has positive shape, 21 0; and strip with a wavy middle or so-called, long middle, has negative shape 2 0.
  • h h
  • Theoretical considerations of the rolling process suggest, and experimental measurements confirm that the two errors occur together and are of the same sign.
  • the error signal is employed to regulate the front and/ or back tension of the strip relative to the mill stand in question, and the magnitude and sense of such regulation is arranged to be such as to eliminate the gauge error.
  • the front and/or back tension can be controlled by the motor or motors driving the associated coiler and/ or uncoiler, respectively; while in the case of a tandem mill the relevant motor drive control may be associated with the rolls of a mill stand adjacent to that in question.
  • Such device may take various forms, such as a plurality of rollers which are urged to engage the strip, from below, say, at different points transverse the strip path.
  • the rollers will assume different heights and an electrical signal representing such height difference can be employed to represent the corresponding error in shape.
  • Other means can be employed to indicate the shape errors but some such arrangement as described above is preferred in that it not only detects manifest shape errors which are superficially apparent from local transverse undulations of the strip, but it also detects latent bad shape represented by transverse variations of longitudinal stresses in the strip.
  • the above described shape sensor device is readily made in robust form and does not require highly accurate signal generation for appropriate accuracy of shape sensing.
  • a shape error signal can be generated and applied to regulate one of the controlling factors of the rolling process, such as roll gap setting, strip tension or roll camber, to correct the process in respect of deviations from required shape.
  • an apparatus for automatically rolling strip material comprising means for producing a signal indicative of the shape of the strip leaving the rolls, means for producing a signal indicative of the gauge of the strip leaving the rolls, and control means for varying the roll separating force in dependence on said gauge signal to maintain a substantially constant gauge leaving the rolls and in dependent on said shape signal to maintain a substantially constant shape of strip leaving the rolls.
  • an apparatus for automatically rolling strip material comprising means for producing an electrical signal indicative of the shape of the strip leaving the rolls, means for producing an electrical signal indicative of the gauge of the strip leaving the rolls, first electric control means for varying the tension at which the strip is pulled through the rolls, and hence the roll separating force, in dependence on said gauge signal to maintain a substantially constant gauge leaving the rolls, and second electric control means for simultaneously varying the roll separating force in dependence on said shape signal to maintain a substantially constant shape of strip leaving the rolls.
  • FIGURE 1 is a graph illustrating the relationship between changes in strip gauge and strip shape and the manner in which certain adjustments for changes in one affect the other and FIGURES 2, 3 and 4 are schematic illustra tions of different embodiments of apparatus for practicing the present invention.
  • FIGURE 1 of the accompanying drawings shows the effects of gauge control by screwdown or tension adjustment on shape.
  • the vertical axis represents rolling force F and also shape 2
  • the horizontal axis represents roll gap setting, ingoing gauge H, and outgoing gauge h.
  • Point A represents the rolling conditions at a particular instant when the ingoing gauge is H and the roll gap screw setting is S.
  • Point A is determined as the intersection of the straight line at which represents the effect of the mill spring on the roll gap, and the deformation curve AH which related the rolling force F to the Outgoing thickness h.
  • AGC(T) tension control
  • AGC(S) automatic shape control
  • shape control through tension is basically compatible with AGC(T) as seen from the above discussion of FIGURE 1 since tension correction to reduce a positive or negative shape error produces a respectively negative or positive gauge variation thereby attenuating the shape error associated with the gauge error that is being corrected.
  • FIGURE 2 of the accompanying drawings A further possibility is to employ roll bending devices in accordance with recent proposals, such as generally indicated in FIGURE 2 of the accompanying drawings, whereby pressure means in the form of hydraulic jacks are located between corresponding back-up and work roll ends.
  • pressure means in the form of hydraulic jacks are located between corresponding back-up and work roll ends.
  • This error will, however, be much smaller than is the case with tension regulation for shape control purposes and one may therefore usefully employ a combination of AGC(T) and ASC(JBW), the latter indicating jacks between back-up and work rolls.”
  • a further possible mode for shape control is by regulating longitudinal strip tension transversely of the strip, by pivotable tension rollers, say, but this will produce a corresponding variation in mill stretch.
  • correction of a positive shape error will be associated with the introduction of a positive gauge error.
  • AGC(T) can be effected by the regulation of back and/or front tension, in accordance with specification No. 681,373, say, in a first control loop, and a shape control error signal is made to actuate the screwdown setting in similar manner to AGC(S).
  • FIGURE 3 of the accompanying drawing One example of AGSC (T/ S) is illustrated schematically in FIGURE 3 of the accompanying drawing.
  • the gauge control is effective by a signal AF proportional to the deviation of the current rolling force from that force at which the current roll gap setting will produce the required gauge.
  • This signal is electronically computed from a signal representing the current rolling force F and derived from the load cells 1, a signal representing the roll gap setting s and derived from the screw position detectors 2, and a signal representing the desired gauge.
  • the computed signal is applied via a torque regulator 5 to control the drive motor or motors 6 of the coiler or uncoiler 7.
  • Shape is corrected by use of a signal representing current strip shape 2 generated by a shape sensor device 8 according to applictaion No. 17,339/65.
  • Signal 2 is applied via a computer 9 to control the screwdown motors 10 and thereby to regulate the roll gap setting s.
  • the computer 9 will control the screwdown motors 10 in predetermined manner in response to the signal 2, such that the roll gap setting s is reduced or increased as E or 0, respectively.
  • a shape correction alters the roll gap setting, which in tum changes the rolling force and so brings the gauge control system into operation by regulation of tension in such a sense as to assist reduction of the original shape error and maintain correct gauge.
  • the shape control computer may be responsive to variables additional to that of shape 2, and such a system is illus trated schematically in FIGURE 4 of the accompanying drawings.
  • the gauge control duplicates that of FIGURE 3, but the shape control is based on the following consideration:
  • N is a constant equal to d/c, as can be derived from the foregoing equations and the accessory screw setting control can be determined, from Equations 5 and 6 as 43%.
  • computer 4 may be arranged to compute the current rolled gauge in accordance with Equation 5 above and to subtract from this the desired gauge h*, so that the signal applied to regulator 5 represents s+F/Mh*.
  • the systems of FIGURES 3 and 4 may be provided with means, such as an X-ray gaugemeter for pro viding a direct measure of the current outgoing gauge h, such means preferably being situated in close proximity to the shape sensor device.
  • the gaugemeter signal can then be compared with signal 12* whereby the resultant gauge error signal (hh*) can be applied to regulator 5, and in the case of FIGURE 3 the load cells and screw position detectors can be dispensed with.
  • Apparatus comprising opposed rolls for automatically rolling strip material, comprising means for sensing at locations spaced transversely of the strip the tension in the strip leaving the rolls and for producing a signal indicative of the shape thereof, means for producing a signal indicative of the gauge of the strip leaving the rolls, first control means, responsive to said signal indicative of gauge for varying the tension at which the strip is pulled through the rolls to maintain a substantially constant gauge leaving the rolls, and second control means, responsive to said signal indicative of shape, for simultaneously varying the magnitude of the roll separating forces to maintain a substantially constant shape of strip leaving the rolls.
  • AF roll separating force
  • Apparatus comprising opposed Work rolls for rolling strip material and back-up rolls therefor, means for sensing at locations spaced transversely of the strip the tension in the strip leaving the rolls and for producing a signal indicative of the shape thereof, means for producing a signal indicative of the gauge of the strip leaving the rolls, first control means, responsive to said signal indicative of gauge, for varying the tension at which the strip is pulled through the rolls to maintain a substantially constant gauge leaving the rolls, and second control means, responsive to said signal indicative of shape, for simultaneously varying the mutual flattening of the work and backup rolls to maintain a supstantially constant shape of strip leaving the rolls.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
  • Metal Rolling (AREA)
US585871A 1966-09-29 1966-10-11 Rolling of strip Expired - Lifetime US3457748A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1966B0089143 DE1527612B2 (de) 1966-09-29 1966-09-29 Einrichtung zum regeln der dicke und querschnittsform bzw. ebenheit von blechen und baendern in walzwerken

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US3457748A true US3457748A (en) 1969-07-29

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US585871A Expired - Lifetime US3457748A (en) 1966-09-29 1966-10-11 Rolling of strip

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US (1) US3457748A (fr)
CH (1) CH459115A (fr)
DE (1) DE1527612B2 (fr)
GB (1) GB1145836A (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3731508A (en) * 1969-09-03 1973-05-08 British Iron Steel Research Rolling of strip or plate material
US20020162375A1 (en) * 2001-05-05 2002-11-07 Bwg Bergwerk- Und Walzwerk-Maschinenbau Gmbh Strip treating line for leveling metal strip
US20090031777A1 (en) * 2005-08-26 2009-02-05 Sma Demag Ag Method for thickness regulation during a hot-rolling process

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2808993C2 (de) * 1978-03-02 1982-03-25 Ishikawajima-Harima Jukogyo K.K., Tokyo Vorrichtung an einem Walzgerüst zur Regelung der Ebenheit von Walzgut

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3103138A (en) * 1960-06-09 1963-09-10 Westinghouse Electric Corp Foil thickness control apparatus
US3194036A (en) * 1958-01-02 1965-07-13 Westinghouse Canada Ltd Material thickness control apparatus
US3315506A (en) * 1964-01-09 1967-04-25 Westinghouse Electric Corp Workpiece tension and shape control method and apparatus
US3334502A (en) * 1962-12-24 1967-08-08 Siemens Ag Strip thickness control apparatus for a rolling mill
US3334508A (en) * 1964-11-09 1967-08-08 American Metal Climax Inc Method and apparatus for controlling flatness in sheet metal

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3194036A (en) * 1958-01-02 1965-07-13 Westinghouse Canada Ltd Material thickness control apparatus
US3103138A (en) * 1960-06-09 1963-09-10 Westinghouse Electric Corp Foil thickness control apparatus
US3334502A (en) * 1962-12-24 1967-08-08 Siemens Ag Strip thickness control apparatus for a rolling mill
US3315506A (en) * 1964-01-09 1967-04-25 Westinghouse Electric Corp Workpiece tension and shape control method and apparatus
US3334508A (en) * 1964-11-09 1967-08-08 American Metal Climax Inc Method and apparatus for controlling flatness in sheet metal

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3731508A (en) * 1969-09-03 1973-05-08 British Iron Steel Research Rolling of strip or plate material
US20020162375A1 (en) * 2001-05-05 2002-11-07 Bwg Bergwerk- Und Walzwerk-Maschinenbau Gmbh Strip treating line for leveling metal strip
US6840076B2 (en) * 2001-05-05 2005-01-11 BWG Bergwerk—Und Walzwerk-Maschinenbau GmbH Strip treating line for leveling metal strip
US20090031777A1 (en) * 2005-08-26 2009-02-05 Sma Demag Ag Method for thickness regulation during a hot-rolling process

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Publication number Publication date
DE1527612B2 (de) 1977-04-07
CH459115A (fr) 1968-07-15
DE1527612A1 (de) 1970-01-22
GB1145836A (en) 1969-03-19

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