US3518857A - Rolling mill automatic slowdown control - Google Patents

Rolling mill automatic slowdown control Download PDF

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Publication number
US3518857A
US3518857A US671347A US3518857DA US3518857A US 3518857 A US3518857 A US 3518857A US 671347 A US671347 A US 671347A US 3518857D A US3518857D A US 3518857DA US 3518857 A US3518857 A US 3518857A
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United States
Prior art keywords
mill
slowdown
speed
diameter
control
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Expired - Lifetime
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US671347A
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English (en)
Inventor
Charles O Hancock
Joseph A Mccarthy
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Westinghouse Electric Corp
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Westinghouse Electric Corp
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Publication date
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Publication of US3518857A publication Critical patent/US3518857A/en
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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
    • B21B37/46—Roll speed or drive motor control

Definitions

  • a strip mill automatic slowdown control includes an arrangement for detecting and comparing the speeds of a payoif reel and an entry deflector roll. When the two speeds reach a predetermined relation, mill slowdown is initiated.
  • a selector control is adjusted according to strip gauge and mill speed to allow delayed mill slowdown for lighter gauge and/or slower mill run speed to allow earlier mill slowdown for heavier gauge and/or faster mill run speed.
  • the present invention relates to control systems for rolling mills and more particularly to rolling mill automatic slowdown controls.
  • a rolling mill such as a non-reversing tandem cold steel strip reduction rolling mill
  • at strip is unwound from a payoff reel, threaded through the roll stands and wound on a windup reel.
  • the mill is accelerated from thread speed to a preselected run speed and operated at the run speed until some operating point at which mill deceleration is initiated to provide safe tailotf, i.e., to prevent the end of the strip from going through the mill at an excessive speed.
  • the tailoff speed is set equal to the thread speed.
  • mill productivity is optimized if the mill is operated at the highest possible average speed.
  • maximum average speed requires slowdown initiation at the latest point in time. at which safe tailotf is enabled.
  • the optimum slowdown point depends principally upon the operating run speed of the mill and the number of strip wraps required on the payotf reel to enable mill deceleration to the tailotf speed just as the strip tail end is coming off the payoff reel and entering the mill.
  • An economic automatic mill slowdown control includes means for detecting a condition representing the payoff coil builddown diameter value over at least a predetermined builddown diameter range.
  • a selector control is set as a function of strip gauge and as desired also as a function of mill run speed in order to define a builddown diameter value at which mill slowdown can be achieved with improved productivity on an economic basis.
  • the slowdown control initiates mill slowdown including payoif reel slowdown when the selector control defined payoff coil slowdown builddown diameter value is reached.
  • FIG. 1 shows a schematic diagram of a payoff reel associated with a typical tandem cold steel reduction rolling mill
  • FIG. 2 shows a schematic diagram of a control arranged in accordance with the principles of the invention to eifect automatic slowdown of a rolling mill such as that shown in FIG. 1.
  • FIG. 1 a typical rolling mill 10 having in this case a plurality of conventional nonreversing tandem roll stands S (only one shown) through which cold steel strip 12 is transported for gauge reduction.
  • a mill in which the invention is to be embodied could be the reversing type and/or it could be arranged to roll materials other than cold steel strip.
  • the strip 12 is supplied from a payoif reel 14 which is suitably driven and speed controlled such as by a drive 16 operated by a CEMF speed control 15 to make the reel speed correspond to the mill speed as the coil builddown diameter increases with the uncoiling of the strip wraps from the reel 14.
  • Mill stand speeds are individually controlled by conventional stand speed controls 18, and
  • a suitable master mill speed control 20 coordinates the payoff reel speed with the mill speed as the mill is operated under threading, accelerating, running and decelerating conditions.
  • the reel 14 would have a mandrel 22 having a diameter D equal to the inner coil diameter D and common to that of other mill mandrels.
  • the inner coil diameter D can therefore be assumed to be constant from payoff reel to payoff reel of operation, except in those cases where the rolling mill plant is provided with two or more sets of mandrels with the mandrel sets having different diameters. In that event, some slowdown control adjustment must be made when switching from one mandrel set to another set as subsequently described more fully.
  • the reduction rolling mill 10 is brought to thread speed and the head end of the strip 12 is then threaded through the roll stands and into the downcoiler (not shown). The mill is then accelerated to a preselected run speed and operated at the run speed until a signal is automatically generated for slowdown to permit safe tailoff.
  • Product strip on the downcoiler has a reduced gauge according to the pre-established mill setup.
  • a suitable electronic timer 38 preferably in the form of a sampling timer, is sequenced to the ON state and in turn respective electronic gates 40 and 42 are turned on to allow pulses generated by the pulse generators 30 and 26 and detected by respective suitable detection circuits 44 and 46 to be gated to respective conventional 10 bit electronic counters 48 and 50.
  • the sampling timer 38 has an ON-OFF cycle primarily to allow reduced counter capacity for feedback pulse counting, i.e., the counters 48 and 50' may have a count capacity as small as 399 or less.
  • the timer ON time interval is adequate to allow sufficient pulse counting for comparison of the payoff reel and the deflector roll speeds.
  • the timer OFF time interval is adequately small to assure the occurrence of a predetermined slowdown initiate roll deflector and payoff roll speed comparison condition during a timer ON time.
  • the ON and OFF intervals are preferably made variable, and a typical timer ON-OF cycle could comprise an ON interval of 0.5 second and an OFF interval of 0.1 second.
  • a conventional difference detector 52 compares the counter outputs, preferably not continuously and only after the end of each timer ON time interval, i.e., during each timer OFF time interval, as controlled by a timer signal indicated by the reference character 54.
  • the gates are operated to block pulses from the pulse generators 30 and 26 and reset signals are generated as indicated by the reference characters 56 and 58 to reset the counters 48 and 50 for the next ON interval.
  • "Prior to counter reset the counts in the counters 48 and 50 are received by the difference detector 52 for comparison. If the counts have a predetermined relation to each other, such as when they are equal, the difference detector 52 generates a slowdown signal to decelerate the mill 10 as previously described.
  • the difference detector 52 identifies a point in time at which a predetermined relation occurs between the coil builddown and deflector roll diameter and the corresponding relation between the reel and roll speeds.
  • the predetermined coil builddown and deflector roll diameter relation is one in which the coil builddown diameter value equals D which is less than the control startup diameter D but nonetheless somewhat greater than that diameter value which assures safe tailoff for all expected payoff gauges and mill run speeds and particularly at the maximum expected mill run speed and payoff strip gauge conditions.
  • the safe tailoff coil builddown diameter D value Once the safe tailoff coil builddown diameter D value is selected, its ratio relation to the deflector roll diameter is fixed by the known roll diameter value D As a consequence, the safe tailoff ratio between the payoff reel speed and the deflector roll speed is fixed.
  • the gearing 28 and 32 is suitably adjusted to take up any difference effect produced by a difference in the roll diameter and the safe tailoff coil builddown diameter. If a change is made in mandrel diameter, the selected safe tailoff coil builddown diameter and the safe tailoff speed ratio are accordingly modified.
  • a gauge/speed selector 54 is included in the control 36 to enable economic adjustment of the slowdown initiation point from the accurately detected safe tailoff builddown diameter value D to a builddown diameter value D which provides safe tailoff and more clearly approaches optimum productivity (i.e., more nearly approaches the builddown diameter corresponding to the latest allowable deceleration time point) according to the actual mill run speed and the gauge of the payoff strip in process.
  • the selector 54 is manually set by the mill operator for each payoff reel as the reel is placed in the mill.
  • the selector can include a dial (not shown) which can be set in any of eight or any other preselected number of preselected positions such as follows:
  • suitable logic circuitry (not shown specifically) forming a part of the selector 54 is operated to generate a corresponding offset count entry in the payoff reel counter 48 at the start of each sample ON time as indicated by the reference character 57.
  • the gauge/speed selector 54 preferably also sets up the time cycle in the sampler timer 38 as indicated by the reference character 59.
  • the OFF time be retained at a constant value and the ON time be increased with increased strip gauge, i.e. the ON time is preferably made longer as the selector dial setting is increased from 1 to 8.
  • the difference detector 52 With the setting of the selector 54, the difference detector 52 generates the slowdown signal during a sample OFF time if the pulse count form the deflector roll pulse generator 26 equals the pulse count from the payoff reel pulse generator 30 less the selector dial offset count registered during any single preceding sample ON time. Since the pulses produced by the generators 26 and 30 represent position increments, the counters 48 and 50 in effect operate as speed detectors and the difference detector 52 accordingly generates the slowdown signal when the ratio of the payoff reel and deflector roll speeds acquires the adjusted safe tailoff value.
  • the slowdown signal is generated at a point in time which reliably results in extended run speed operation and improved mill productivity without requiring expensive electronic computation.
  • 0.125 inch gauge strip may correspond to G in the above table and thus be processed at dial setting 8 and at mill run speed S
  • D builddown diameter
  • An automatic slowdown control for a rolling mill having a payoff reel and an entry deflector roll associated therewith comprising signal generator means associated with the payoff reel, signal generator means as sociated with the entry deflector roll, means coupled to said payoff reel signal generator means for effectively detecting payoff reel speed, means coupled to said deflector roll signal generator means for effectively detecting the deflector roll speed, means for comparing respective outputs from said payoff reel and deflector roll speed detecting means to generate a mill slowdown signal when the speeds reach a predetermined relation, and an operator selector device including means for producing an offset output variably selectable from a range of values corresponding to differing combinations of mill operating speed and the gauge of strip being rolled, the offset output from said selector device coupled to at least one of said speed detecting means in order to control the point at which said comparing means generates the mill slowdown signal.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
  • Metal Rolling (AREA)
  • Control Of Multiple Motors (AREA)
  • Winding, Rewinding, Material Storage Devices (AREA)
US671347A 1967-09-28 1967-09-28 Rolling mill automatic slowdown control Expired - Lifetime US3518857A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US67134767A 1967-09-28 1967-09-28

Publications (1)

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US3518857A true US3518857A (en) 1970-07-07

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Application Number Title Priority Date Filing Date
US671347A Expired - Lifetime US3518857A (en) 1967-09-28 1967-09-28 Rolling mill automatic slowdown control

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US (1) US3518857A (enExample)
BE (1) BE721554A (enExample)
FR (1) FR1581927A (enExample)
GB (1) GB1229977A (enExample)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3834648A (en) * 1972-03-15 1974-09-10 Ampex Apparatus and method for sensing diameter of tape pack on storage reel
US3974490A (en) * 1974-06-01 1976-08-10 Rengo Co., Ltd. Paper roll diameter sensing device for use with paper splicing apparatus
US3979080A (en) * 1975-03-27 1976-09-07 Westinghouse Electric Corporation Analog automatic slowdown system
US4163180A (en) * 1976-12-14 1979-07-31 Westvaco Corporation Stretchable material rewinding machine
US4232371A (en) * 1977-12-29 1980-11-04 Sony Corporation Apparatus for indicating the amount of tape wound upon a reel
US4232369A (en) * 1978-07-31 1980-11-04 Tokyo Shibaura Denki Kabushiki Kaisha Method of controlling the deceleration of a reversing mill
US4438889A (en) * 1981-01-17 1984-03-27 Jagenberg Werke Ag System for decelerating the drive of a web-winding apparatus
US4663573A (en) * 1982-12-24 1987-05-05 Canon Kabushiki Kaisha Web feeding apparatus with web slowdown
US5086964A (en) * 1988-07-29 1992-02-11 Amplas, Inc. Dual drive web feed apparatus and method
US5575435A (en) * 1991-09-26 1996-11-19 Sealed Air Corporation High speed apparatus for forming foam cushions for packaging purposes
US5673584A (en) * 1991-06-21 1997-10-07 Sumitomo Metal Industries, Ltd. Method of and an apparatus for producing wire
US6533207B2 (en) * 2000-05-17 2003-03-18 Grapha-Holding Ag Method and arrangement for producing a roll from printed products
CN114959364A (zh) * 2022-07-01 2022-08-30 温州医科大学附属口腔医院 一种可降解Zn-xRE合金及其制备方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2342767A (en) * 1942-02-21 1944-02-29 Westinghouse Electric & Mfg Co Control system
US3136183A (en) * 1961-08-29 1964-06-09 Gen Electric Slowdown control for reversing hot mill
US3151507A (en) * 1961-05-23 1964-10-06 Datex Corp Speed control system
US3161365A (en) * 1962-02-23 1964-12-15 Gen Electric Uncoiler control system
US3208683A (en) * 1962-12-03 1965-09-28 Gen Electric Automatic control systems for rolling mills
US3421708A (en) * 1966-09-26 1969-01-14 Davy & United Eng Co Ltd Control of strip

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2342767A (en) * 1942-02-21 1944-02-29 Westinghouse Electric & Mfg Co Control system
US3151507A (en) * 1961-05-23 1964-10-06 Datex Corp Speed control system
US3136183A (en) * 1961-08-29 1964-06-09 Gen Electric Slowdown control for reversing hot mill
US3161365A (en) * 1962-02-23 1964-12-15 Gen Electric Uncoiler control system
US3208683A (en) * 1962-12-03 1965-09-28 Gen Electric Automatic control systems for rolling mills
US3421708A (en) * 1966-09-26 1969-01-14 Davy & United Eng Co Ltd Control of strip

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3834648A (en) * 1972-03-15 1974-09-10 Ampex Apparatus and method for sensing diameter of tape pack on storage reel
USRE30868E (en) * 1974-06-01 1982-02-16 Rengo Co., Ltd. Paper roll diameter sensing device for use with paper splicing apparatus
US3974490A (en) * 1974-06-01 1976-08-10 Rengo Co., Ltd. Paper roll diameter sensing device for use with paper splicing apparatus
US3979080A (en) * 1975-03-27 1976-09-07 Westinghouse Electric Corporation Analog automatic slowdown system
US4163180A (en) * 1976-12-14 1979-07-31 Westvaco Corporation Stretchable material rewinding machine
US4232371A (en) * 1977-12-29 1980-11-04 Sony Corporation Apparatus for indicating the amount of tape wound upon a reel
US4232369A (en) * 1978-07-31 1980-11-04 Tokyo Shibaura Denki Kabushiki Kaisha Method of controlling the deceleration of a reversing mill
US4438889A (en) * 1981-01-17 1984-03-27 Jagenberg Werke Ag System for decelerating the drive of a web-winding apparatus
US4663573A (en) * 1982-12-24 1987-05-05 Canon Kabushiki Kaisha Web feeding apparatus with web slowdown
US5086964A (en) * 1988-07-29 1992-02-11 Amplas, Inc. Dual drive web feed apparatus and method
US5673584A (en) * 1991-06-21 1997-10-07 Sumitomo Metal Industries, Ltd. Method of and an apparatus for producing wire
US5575435A (en) * 1991-09-26 1996-11-19 Sealed Air Corporation High speed apparatus for forming foam cushions for packaging purposes
US5679208A (en) * 1991-09-26 1997-10-21 Sealed Air Corporation High speed apparatus for forming foam cushions for packaging purposes
US6533207B2 (en) * 2000-05-17 2003-03-18 Grapha-Holding Ag Method and arrangement for producing a roll from printed products
CN114959364A (zh) * 2022-07-01 2022-08-30 温州医科大学附属口腔医院 一种可降解Zn-xRE合金及其制备方法

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Publication number Publication date
BE721554A (enExample) 1969-03-03
GB1229977A (enExample) 1971-04-28
FR1581927A (enExample) 1969-09-19

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DE3628151A1 (de) Positionierungsanordnung fuer das einem windungsleger einer drahtwalzstrasse zugefuehrte walzmaterial