US3111046A - Automatic control system for continuous strip mill - Google Patents

Automatic control system for continuous strip mill Download PDF

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Publication number
US3111046A
US3111046A US714782A US71478258A US3111046A US 3111046 A US3111046 A US 3111046A US 714782 A US714782 A US 714782A US 71478258 A US71478258 A US 71478258A US 3111046 A US3111046 A US 3111046A
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US
United States
Prior art keywords
stand
thickness
strip
amplifier
bar
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
US714782A
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English (en)
Inventor
George S Koss
Louis E Ringger
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
United States Steel Corp
Original Assignee
United States Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to LU36874D priority Critical patent/LU36874A1/xx
Priority to DENDAT126492D priority patent/DE126492C/de
Application filed by United States Steel Corp filed Critical United States Steel Corp
Priority to US714782A priority patent/US3111046A/en
Priority to DEU5969A priority patent/DE1126492B/de
Priority to NL235960A priority patent/NL103664C/xx
Priority to GB4824/59A priority patent/GB898613A/en
Priority to FR786586A priority patent/FR1222878A/fr
Application granted granted Critical
Publication of US3111046A publication Critical patent/US3111046A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C28/00—Alloys based on a metal not provided for in groups C22C5/00 - C22C27/00
    • 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
    • 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
    • B21B37/165—Control of thickness, width, diameter or other transverse dimensions responsive mainly to the measured thickness of the product

Definitions

  • Amplifier 23 is of conventional character and may be a vacuumtube amplifier or a transistor amplifier. The output of amplifier 23 is applied to a means for establishing a pressure-reference voltage, such as a motor-operated, selfbalancing, bridge-type potentiometer 2d.
  • the potentiometer normally is connected by a back contact 25a of a relay 25 so as to be operated to a setting corresponding to the thickness of the leading end of strip bar El as it leaves stand 1.
  • Relay 25 is energized to open its back contacts 25:! and 250 and close its front contact This changes the circuit 7 connection of device 24 so that thereafter the reference voltage previously established thereby will be opposed to the voltage from amplifier 23, developed by load cells 22.
  • Relay .25 may be a motor-current relay, a pressure relay, or a hot-metal detector relay. That is, it may be of a conventional type responsive either to the increased current drawn by the motor driving stand 1, to the increase in the pressure on the rolls of stand it or to the energy radiated by bar 21.
  • the screw-down controller 15 of each stand is under the control of a device 27, such as a potentiometer, which may be adjusted manually or preset by punched-card apparatus, and develops a voltage proportional to the desired screw setting.
  • a device 27 such as a potentiometer, which may be adjusted manually or preset by punched-card apparatus, and develops a voltage proportional to the desired screw setting.
  • This voltage is applied to a mixer and discriminator 2d, the output of which is applied to an amplifier 29.
  • the output of amplifier 29 operates a reversing controller 15 for screw motor 14.
  • Devices 2")", 23 and 29 preferably embody General Electric Companys numerical positioning control, modified to suit the requirements of screwdown operation which includes the necessary arrangements for a Selsyn generator 30.
  • the resulting adjustment of the screws by operation of motor M is reflected by generator Till, the output of which is applied through circuit Stun to mixer 22; in opposition to the voltage from the potentiometer 27.
  • Amplifier 26 thus exerts a control over amplifier 29 by virtue of circuit 26a extending to mixer 28.
  • an added manual adjustment in amplifier 2s e.g., an additional potentiometer the increment of screw adjustment per volt of error signal may be varied.
  • the amount of correction for thickness variation so as to obtain either a uniform or decreasing thickness of the bar as it emerges 1,3, from stand 2. This permits compensation for the tendency of a strip bar to increase in thickness toward the trailing cnd because of the aforementioned temperature effect.
  • the speed of one of the intermediate stands of the mill, 3 for example, is used as an anchor or reference value, i.e., the speed regulator of its motor is left unchanged, so that the motor speed is affected only to maintain that for which the regulator was originally set manually. Gnce set, the regulator remains unchanged and is not automatically adjusted in response to any of the variable functions attributable to the strip bar being rolled.
  • the rolling of the strip bar proceeds in stands 1, 2 and 3.
  • load cells 31 responsive to the rolling pressure thereby developed, apply a voltage to an amplifier 32.
  • the cells are similar to those shown at 22 and amplifier 32 similar to that shown at 23.
  • ampniler 32 is applied by cricuits 32a and 32b to a selfbalancing, bridgedype potentiometer 33 which operates to establish a reference voltage proportional to the rolling pressure initially developed in stand and, therefore, to the thickness of the leading end of the bar as it leaves stand 4.
  • a relay 34 operates to change the connections of potentiometer 33 by opening back contact 34:; and closing contact 341;, so that thereafter its voltage is opposed to that of amplifier 32 and the difference or error signal is applied to amplifiers 35', one for each of stands 4, 5 and 6 over a circuit 35a, Relay 34 is similar to that shown at 25.
  • Each of these amplifiers incorporates an additional potentiometer 351') which will vary the output in accordance with the desired amount of speed change for stands 4, S and 6.
  • the output of each amplifier 35 is applied by a circuit 35c to the speed-regulator of the motor of one stand through amplifier 1'7.
  • the progressive increase of tension between the last several stands will tend to result in the delivery of strip of uniform thickness out of the last stand.
  • the thickness correction is efiected in the stand where roll pressure is measured, and the increase in the speeds of subsequent stands is necessary as a consequence, in order to maintain the tension on the strip as it travels through these later stands.
  • an X-ray gage 36 of known construction measures the thickness of the strip emerging from stand 6.
  • the output of the gage drives a positioning device 37, preferably a Selsyn transmitter, which operates an additional potentiometer in device 35 preferably by action of a Selsyn receiver, effective over circuits 37a and 37b, to effect an increase or decrease in the error signal in amplifier 35.
  • a positioning device 37 preferably a Selsyn transmitter, which operates an additional potentiometer in device 35 preferably by action of a Selsyn receiver, effective over circuits 37a and 37b, to effect an increase or decrease in the error signal in amplifier 35.
  • Thickness gage 36 also applies a voltage to a thickness deviation Selsyn transmitter 38, such as the standard equipment furnished for General Electric Companys X-ray thickness gages, equipped with adjustable tolerance limits. If the thickness of the strip as measured by gage 36 is outside the limits for which device 38 is adjusted, the latter applies a correcting voltage through a front contact 34c of relay 34, to all or some of the screw-down positioning controls 29 through circuits 38a and 38b connected to the mixer and discriminator 28 of each, so that the thickness of the strip rolled will be brought within the desired range by repositioning of the screws of any or all stands as necessary.
  • a thickness deviation Selsyn transmitter 38 such as the standard equipment furnished for General Electric Companys X-ray thickness gages, equipped with adjustable tolerance limits. If the thickness of the strip as measured by gage 36 is outside the limits for which device 38 is adjusted, the latter applies a correcting voltage through a front contact 34c of relay 34, to all or some of the screw-down positioning controls 29 through circuits 38a and 38b
  • the first bar of a particular series to be rolled furnishes a temperature-reference voltage through a temperature gage 39 by closing of the reference-establishing switch 44, such as a flag switch or manually operated switch.
  • Temperature gage 39 preferably embodies a Leeds and Northrup Company Rayotube device which produces an output voltage proportional to measured temperature of the first bar cause a decrease in the roll setbalancing, bridge type potentiometer 40 similar to 24, for comparison with the temperatures of strip bars subsequently to be rolled.
  • This relay closes its contact in response to a reduction in the load current drawn by the motor 18 driving stand 1, to a reduction in the pressure exerted by the rolls or to the termination of radiant energy from the hot bar.
  • the output of amplifier 42 also affects the setting of the mill screws of any or all the stands by modifying the input through mixers and discriminators 2-3.
  • Switch 44 is adapted to be manually closed when the operator desires to establish or check temperature reference.
  • relay 41 When a slab approaches stand 1, relay 41 is energized, but a signal to amplifier 42 is not permitted until the preceding slab has cleared stand 1 or 2 and relay 25 is deenergized, at which time a screw change signal is transmitted depending on the voltage differential of potentiometer 40 and device 39.
  • relay 41 To complete connections between devices 39, 49 and 42, relay 41 must be energized with its front contact closed and permissive relay 25 deenergized with its contact closed.
  • the system described above provides for thickness control by increasing the tension on the strip between the last several stands of the mill.
  • we may similarly effect the desired control by decreasing the speeds of the motors driving the first several stands, thereby increasing the tension on the material between these stands.
  • a signal from potentiometer 24 would be applied to amplifiers 25 and 35" to reduce the speeds of stands 1, 2 and 3 in a similar manner.
  • a switch 43 permits either stand 4 or stand 5 to be selected as the source of the control signal.
  • the combination with a multi-stand continuous strip mill of means responsive to the thickness of the partially reduced strip entering the rolls of the first stand, means controlled by said thickness-responsive means for reducing the spacing between the rolls of the second stand on an increase in the thickness of the strip entering the first stand and increasing the spacing between rolls on a decrease in the thickness of the strip entering the first stand, means controlled by said thickness-responsive means to establish a reference voltage and means actuated by passage of the leading end of the strip through the second stand for connecting said thickness-responsive means in opposition to said reference voltag 2.
  • the combination with a multi-stand continuous strip mill of means responsive to the temperature of a hot stripbar as it is advanced toward the first stand of the mill, means controlled by said temperature-responsive means for reducing the spacing between the rolls of a plurality of the stands when said temperature is below a predetermined value and for increasing the spacing between the rolls of a plurality of stands when said temperature is above a predetermined value, means also controlled by said temperature-responsive means to establish a reference voltage and means actuated by passage of the trailing end of the bar through the first stand of the mill for connecting said temperature-responsive means in opposition to said reference voltage.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Control Of Metal Rolling (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Ceramic Products (AREA)
US714782A 1958-02-12 1958-02-12 Automatic control system for continuous strip mill Expired - Lifetime US3111046A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
LU36874D LU36874A1 (pl) 1958-02-12
DENDAT126492D DE126492C (pl) 1958-02-12
US714782A US3111046A (en) 1958-02-12 1958-02-12 Automatic control system for continuous strip mill
DEU5969A DE1126492B (de) 1958-02-12 1959-02-09 Einrichtung zur Regelung der Banddicke in kontinuierlichen Warmwalzwerken
NL235960A NL103664C (pl) 1958-02-12 1959-02-10
GB4824/59A GB898613A (en) 1958-02-12 1959-02-11 Automatic control system for continuous strip mill
FR786586A FR1222878A (fr) 1958-02-12 1959-02-12 Installation de commande automatique pour laminoir à bandes continu

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US714782A US3111046A (en) 1958-02-12 1958-02-12 Automatic control system for continuous strip mill

Publications (1)

Publication Number Publication Date
US3111046A true US3111046A (en) 1963-11-19

Family

ID=24871434

Family Applications (1)

Application Number Title Priority Date Filing Date
US714782A Expired - Lifetime US3111046A (en) 1958-02-12 1958-02-12 Automatic control system for continuous strip mill

Country Status (6)

Country Link
US (1) US3111046A (pl)
DE (2) DE1126492B (pl)
FR (1) FR1222878A (pl)
GB (1) GB898613A (pl)
LU (1) LU36874A1 (pl)
NL (1) NL103664C (pl)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3186201A (en) * 1961-06-21 1965-06-01 Steelworks Automation Ltd Production of metal strip
US3186200A (en) * 1961-10-31 1965-06-01 Gen Electric Automatic thickness regulator for strip rolling mills
US3312092A (en) * 1962-10-25 1967-04-04 Moeller & Neumann Verwalt Ges Control arrangement for level rolling metal plates and sheets in reversible rolling mills
US3328987A (en) * 1964-05-14 1967-07-04 Crucible Steel Co America Gage-control apparatus
US3332263A (en) * 1963-12-10 1967-07-25 Gen Electric Computer control system for metals rolling mill
US3357217A (en) * 1965-05-12 1967-12-12 Westinghouse Electric Corp Slave gauge control system for a rolling mill
US3416339A (en) * 1966-12-30 1968-12-17 Bethlehem Steel Corp Automatic control system for rolling mills
US3448600A (en) * 1967-02-01 1969-06-10 Gen Dynamics Corp Thickness reduction control system

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE750610C (de) * 1935-05-31 1945-01-23 Westinghouse Electric & Mfg Co Gesinterte Hartmetallegierung
US3237071A (en) * 1963-04-05 1966-02-22 Allis Chalmers Mfg Co Motor load distributing system for metal rolling mill

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1969536A (en) * 1932-02-18 1934-08-07 Gen Electric Apparatus for controlling the thickness of strip material
US2264095A (en) * 1936-12-18 1941-11-25 Gen Electric Control system
US2268217A (en) * 1937-07-01 1941-12-30 Westinghouse Electric & Mfg Co Tensiometer for tandem mills
US2281083A (en) * 1938-04-28 1942-04-28 Westinghouse Electric & Mfg Co Control system for rolling mills
US2295399A (en) * 1940-10-30 1942-09-08 Westinghouse Electric & Mfg Co Sheet thickness regulator for continuous mills
US2342374A (en) * 1941-03-19 1944-02-22 Sperry Prod Inc Strain gauge for rolling mills and the like
US2343392A (en) * 1939-01-18 1944-03-07 Brown Instr Co Strip mill control
US2544467A (en) * 1947-01-31 1951-03-06 Aluminum Co Of America Tension control system
US2680978A (en) * 1950-07-05 1954-06-15 British Iron Steel Research Production of sheet and strip
US2767604A (en) * 1953-01-19 1956-10-23 Jr Mark E Whalen Apparatus for monitoring the operation of rolling mills

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE721298C (de) * 1935-02-28 1942-06-01 Siemens Ag Einrichtung zum Spannen von faden- oder bandfoermigem Gut, insbesondere von Walzgut, zwischen zwei Walzgeruesten
DE692332C (de) * 1936-12-18 1940-06-18 Aeg Steuerung fuer ein elektromotorisch angetriebenes Walzwerk, insbesondere Bandkaltwalzwerk
DE733411C (de) * 1938-04-28 1943-03-26 Siemens Ag Regeleinrichtung fuer Bandwalzwerke

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1969536A (en) * 1932-02-18 1934-08-07 Gen Electric Apparatus for controlling the thickness of strip material
US2264095A (en) * 1936-12-18 1941-11-25 Gen Electric Control system
US2268217A (en) * 1937-07-01 1941-12-30 Westinghouse Electric & Mfg Co Tensiometer for tandem mills
US2281083A (en) * 1938-04-28 1942-04-28 Westinghouse Electric & Mfg Co Control system for rolling mills
US2343392A (en) * 1939-01-18 1944-03-07 Brown Instr Co Strip mill control
US2295399A (en) * 1940-10-30 1942-09-08 Westinghouse Electric & Mfg Co Sheet thickness regulator for continuous mills
US2342374A (en) * 1941-03-19 1944-02-22 Sperry Prod Inc Strain gauge for rolling mills and the like
US2544467A (en) * 1947-01-31 1951-03-06 Aluminum Co Of America Tension control system
US2680978A (en) * 1950-07-05 1954-06-15 British Iron Steel Research Production of sheet and strip
US2767604A (en) * 1953-01-19 1956-10-23 Jr Mark E Whalen Apparatus for monitoring the operation of rolling mills

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3186201A (en) * 1961-06-21 1965-06-01 Steelworks Automation Ltd Production of metal strip
US3186200A (en) * 1961-10-31 1965-06-01 Gen Electric Automatic thickness regulator for strip rolling mills
US3312092A (en) * 1962-10-25 1967-04-04 Moeller & Neumann Verwalt Ges Control arrangement for level rolling metal plates and sheets in reversible rolling mills
US3332263A (en) * 1963-12-10 1967-07-25 Gen Electric Computer control system for metals rolling mill
US3328987A (en) * 1964-05-14 1967-07-04 Crucible Steel Co America Gage-control apparatus
US3357217A (en) * 1965-05-12 1967-12-12 Westinghouse Electric Corp Slave gauge control system for a rolling mill
US3416339A (en) * 1966-12-30 1968-12-17 Bethlehem Steel Corp Automatic control system for rolling mills
US3448600A (en) * 1967-02-01 1969-06-10 Gen Dynamics Corp Thickness reduction control system

Also Published As

Publication number Publication date
GB898613A (en) 1962-06-14
FR1222878A (fr) 1960-06-14
NL103664C (pl) 1962-12-18
DE126492C (pl)
LU36874A1 (pl)
DE1126492B (de) 1962-03-29

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