US3686907A - Device for automatic thickness control of rolled strips - Google Patents

Device for automatic thickness control of rolled strips Download PDF

Info

Publication number
US3686907A
US3686907A US120845A US3686907DA US3686907A US 3686907 A US3686907 A US 3686907A US 120845 A US120845 A US 120845A US 3686907D A US3686907D A US 3686907DA US 3686907 A US3686907 A US 3686907A
Authority
US
United States
Prior art keywords
pressure
hydraulic
piston
hydraulic cylinder
cylinder
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
US120845A
Other languages
English (en)
Inventor
Evgeny Vyacheslavovich Sokolov
Eduard Petrovich Yashkin
Vadim Ivanovich Sysoev
Rady Savvich Kozhevnikov
Alim Ivanovich Chabanov
Mikhail Ivanovich Shinkarenko
Petr Stepanovich Grinchuk
Georgy Georgievich Fomin
Vladimir Ivanovich Rusaev
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.)
Individual
Original Assignee
Individual
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
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3686907A publication Critical patent/US3686907A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • B21B37/66—Roll eccentricity compensation systems
    • 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
    • B21B37/62—Roll-force control; Roll-gap control by control of a hydraulic adjusting device
    • 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
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C2043/3205—Particular pressure exerting means for making definite articles
    • B29C2043/325—Particular pressure exerting means for making definite articles screws
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/58—Measuring, controlling or regulating
    • B29C2043/5825—Measuring, controlling or regulating dimensions or shape, e.g. size, thickness
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/32—Component parts, details or accessories; Auxiliary operations
    • B29C43/58—Measuring, controlling or regulating

Definitions

  • ABSTRACT A device for automatic thickness control of rolled strips which ensures an accuracy of the rolled material from $0.002 mm to 10.003 mm, does not call for major capital expenses and long stops of the rolling mills for its introduction and is characterized by high operating reliability and simple servicing.
  • the device for automatic thickness control of rolled strips in installations for the manufacture of strip materials comprising symmetrically located on both sides of the roll stand at least one hydraulic power cylinder installed between the supports of the working rolls, a damping hydraulic cylinder whose piston is fixed while the strip is passing through the roll stand, and a controllable valve connected so that the hydraulic system formed by said hydraulic cylinder and valve is closed and creates a local increase in the rigidity of the roll stand within the range of forces which is ap proximately equal to the range of variations of the rolling pressure from the preset value.
  • the device has a positive feedback circuit actuated by the fluid pressure in the closed hydraulic system, this circuit comprising a pressure meter in the hydraulic power cylinder, an element for comparing the measured deviation of pressure with the value proportional to the preset coefficient of positive feedback, connected with the pressure meter, and an actuating element l d. tasaislsaneatisea e t and to th m recting element made in the form of a hydraulic cylinder communicating with the hydraulic power cylinder.
  • the present invention relates to devices for automatic thickness control of rolled strips and can be employed in installations for rolling such strip materials as paper, synthetic films and mainly in the mills for hot and cold rolling of ferrous and nonferrous metals.
  • Known in the art are devices for automatic thickness control of rolled strips in the installations for the manufacture of strip materials. Some of these devices incorporate an actuating mechanism in the form of an electrical (or hydraulic) drive of the pressure screws or hydraulic jacks thrusting apart the supports of the working rolls and a measuring element in the form of dynamometers which measure the full rolling pressure. These devices utilize the relationship between the thickness of the rolled strip, rolling pressure, initial 4 opening between the working rolls determined by the position of the pressure screws, and the rigidity of the roll stand. These devices have the following disadvantages:
  • these devices provide for flexible control of the stand rigidity, from a non-rigid stand to a highly rigid stand, by the introduction of full rolling pressure meters and a powerful hydraulic system which develops forces higher than the maximum rolling pressures. Therefore, for this category of devices the.reduction of the thickness control error to i 0.05-0.03 mm involves the same difficulties as those inherentin the devices discussed above.
  • Another known device for automatic thickness control of rolled strips is based on a local increase in the rigidity of the roll stand, i.e., increasing its rigidity only in a relatively narrow range of variations in the rolling pressure (see USSR Inventors Certificate No. 206499, Cl. 7a, I).
  • This device comprises hydraulic power cylinders installed symmetrically between the supports of the mill rolls on both sides of the stand, damping cylinders whose pistons are fixed while the strip is passing through the roll stand, and controllable valves connected in such a manner that they form a closed and sufficiently rigid hydraulic system.
  • the principle of locality in the given method makes it possible to directly increase the rigidity of the working roll opening and to correct the effect produced by the run-out of the back-up rolls on the: thickness of the strip and the influence of variations in the height and rigidity of the oil wedge in the back-up roll bearings caused by changes in the rolling speed.
  • the principle of locality in increasing the rigidity of the stand makes it possible to dispense with the dynamometers measuring the full rolling pressure. This device reduces considerably the requirements for the electric (or hydraulic) drive of the pressure screws so that the latter operate under the conditions approaching those prevailing in non-automated rolling mills.
  • the preset thickness of the strip at the outlet end of the roll stand is ensured by controlling the volume of the liquid in a closed hydraulic system as a function of, say, a signal sent by a strip thickness meter installed at the output end of the mill. Lagging of the correcting signal may be neglected in the given case since the volume of the liquid in the closed hydraulic system remains virtually unchanged within the period required for the strip to pass from the stand to the meter.
  • An object of the present invention is to provide a device for automatic thickness control of rolled strips, which will provide for obtaining; the rolled material with the accuracy of from i 0.002 to :t 0.003 mm.
  • Another object of the present invention is to provide a device whose realization will not call for considerable capital expenses and prolonged stops of the rolling mills.
  • Still further object of the present invention is to provide a reliable device.
  • the present invention consists in a device for automatic thickness control of rolled strips in installations for the manufacture of strip materials, comprising at least one hydraulic power cylinder installed between the supports of the working rolls, another hydraulic cylinder serving as a damping mechanism whose piston is fixed while the strip is passing through the roll stand, these cylinders being arranged symmetrically on both sides of the roll stand, and a controllable valve connected in such a manner that the hydraulic system formed by said hydraulic cylinders and the valve is closed and provides for a local increase in the rigidity of the roll stand within the range of forces which is approximately equal to the range of deviations of the rolling pressure from the preset value, which device, according to the invention, has a positive feedback channel actuated by the liquid pressure in the closed hydraulic system comprising a pressure meter for measuring pressure in the space of the hydraulic power cylinder, a comparison element which compares the measure deviation of pressure with the value proportional to the preset coefficient of positive feedback, is connected with the pressure meter, and an actuating element connected to said comparison element and to a correcting
  • This increases rigidity in a local section of the elastic deformation characteristic of the stand to the value which is sufficient for controlling the thickness of the rolled strip along its length accurate within 0.0050.003 mm.
  • the positive feedback channel should be made hydromechanical in which the inner space of the hydraulic cylinder which functions as an actuating mechanism is communicated hydraulically with the space of the control valve whose movable piston is kinematically linked at one end with the piston of the hydraulic cylinder used as a pressure meter while its other end is connected to a flexible element which is linked mechanically with the piston of the correcting hydraulic cylinder.
  • the positive feedback channel may be of the electromechanical type in which the pressure meter is connected via a divider which serves as a setter of the positive feedback coefficient and via the comparison element with the actuating element whose function is fulfilled by an electromechanical means which converts electric voltage into motion with negative motion feedback, said means being connected with the piston of the correcting hydraulic cylinder.
  • the device for automatic thickness control of rolled strips comprises a channel for controlling the thrust of working rolls which stabilizes the thrust with relation to the preset value.
  • the channel for controlling the thrust of the working rolls is capable of controlling either the pressure in the hydraulic cylinders installed between each pair of supports of the back-up rolls, or the electric drive of the pressure screws.
  • the roll thrust control channel should comprise a setter of working roll thrust, a separate pressure meter in the space of the hydraulic power cylinder and a control valve whose movable piston should be connected at one end with said pressure meter while its other end should be connected to the working roll thrust setter, the control valve space being in hydraulic communication with the hydraulic cylinder installed between the supports of the back-up rolls.
  • the working roll thrust control channel may comprise a correcting element in the form of a hydraulic cylinder communicating with the hydraulic cylinder installed between the supports of the back-up rolls, and an electromechanical means for converting electric voltage into motion, said means being mechanically linked with the piston of the correcting hydraulic cylinder and electrically connected with the pressure meter of the positive feedback channel.
  • the device may comprise a channel for programmed correction of working roll machining inaccuracy, this channel comprising a memory unit for memorizing the pressure changes in the hydraulic power cylinder as a function of the working roll turning angle, a unit for measuring the current value of the working roll turning angle, an electromechanical means for converting electric voltage into motion which is electrically connected with the above-mentioned units and mechanically linked with the piston of its own correcting hydraulic cylinder, the latter being in hydraulic communication with the hydraulic power cylinder, and a control unit which synchronizes the effect produced by said units on the electromechanical means which converts electrical voltage into motion.
  • FIG. 1 shows a device for automatic thickness control of rolled strips, according to the invention
  • FIG. 2 shows the same device in which the channel of positive feedback and the channel for controlling the working roll thrust are of the electromechanical type, according to the invention
  • FIG. 3 shows a channel for programmed correction of working roll machining inaccuracy, according to the invention.
  • pads 2 used as supports for back-up rolls, pads 3 supporting working rolls, and pressure screws 4 with an electric motor 5.
  • the device comprises a hydraulic power cylinder 6 with a piston 7 at each side of the stand (the drawing shows the elements of the device and their interaction for one side of the stand only), said power cylinder 6 being installed between the supports of the working rolls in such a manner that, being filled with fluid under pressure, it would thrust apart these supports.
  • the device also comprises a damping hydraulic cylinder 8 whose piston 9 is fixed in the extreme position by a spring 10 in the course of the strip rolling. The initial tension of the spring 10 determines the value of pressure corresponding to the beginning of the damping action.
  • the device also comprises a controllable valve 11.
  • FIG. 1 shows a hydromechanical form of this channel.
  • the actuating element in the form of a hydraulic cylinder 12 communicates with a control valve 13 whose movable piston 14 is kinematically linked at one end with piston 15 of a hydraulic cylinder 16 used as a pressure meter while its other end is connected with a flexible element 17'mechanically connected with piston 20 of a correcting hydraulic cylinder 21 via a lever 18 and piston 19 of the hydraulic cylinder 12.
  • the lever 18 is mechanically connected to a movable support 22 which sets the relation between the arms of the lever 18.
  • a pressure meter 23 consists of a magnetoanisotropic force transmitter and a piston 24 which converts fluid pressure into force and is connected to a comparator unit 25 in which the reference voltage is connected in opposition to the voltage of the pressure meter 23 via an autotransformer.
  • the comparator unit 25 is connected to a phase-sew sitive amplifier 26, for example, of the transistorized type, whose output is connected with a comparator unit 28 via a divider 27 made in the form of a potentiometer which sets the coefficient of the positive feedback.
  • the output of the comparator unit 28 is electrically connected via an amplifier 29 with an electric motor 30 which is mechanically linked with a motion feedback transmitter 31 in the form of a potentiometer while the output of the latter is connected with the second input of the comparator unit 28.
  • the electric motor 30 is mechanically linked by a screw-and-nut pair 32 with piston 33 of a correcting hydraulic cylinder 34.
  • the device For stabilizing the transverse profile of the strip, the device comprises a channel for controlling the working roll thrust, this channel being of the hydromechanical type.
  • Piston 35 (FIG. 1) of a hydraulic cylinder 36 serving as a pressure meter in the closed hydraulic system is linked kinematically with one end of movable piston 37 of a control valve 38 while the other end of the piston 37 is mechanically coupled with the working roll thrust setter made in the form of a flexible element 39 with a mechanism 40 for controlling its tension.
  • the space of the control valve 38 communicates with a hydraulic cylinder 41 installed between the supports of the backup rolls.
  • the working roll thrust control channel of the electromechanical type is illustrated in FIG. 2.
  • It comprises a correcting element in the form of a hydraulic cylinder 42 whose piston 43 is mechanically coupled with an electric motor 44.
  • the hydraulic cylinder 42 communicates hydraulically with the hydraulic cylinder 41 installed between the supports of the back-up rolls.
  • the electric motor 44 is electrically connected with the output of the amplifier 26 in the positive feedback channel via an amplifier 45 of, say, transistorized design.
  • Shown in FIG. 3 is a channel from programmed correction of the working roll machining inaccuracy intended to eliminate the limitations in the accuracy of strip thickness control.
  • This channel comprises a unit for measuring the current value of the working roll turning angle which consists of a pulse transmitter 46 of the working roll speed which sends a pulse marking the I beginning of each revolution and a pulse counter 47 with a converter of the number of pulses into a code, said converter employing, say, transistor flip-flops.
  • the counter 47 is connected via a control unit 48 with a memory unit 49 which memorizes pressure changes in the hydraulic power cylinder 6 as a function of the turning angle of the working rolls, said control unit employing, say, ferrite-transistor cells.
  • the amplifier 26 of the positive feedback channel is connected to a converting device in the form of a voltage-code converter 50, connected with the control unit 48 which, in turn, is connected with an electromechanical means 53 converting electric voltage into motion, e.g., with a magnetostrictive converter, via the converting device in the form of a codevoltage" converter 51 and an amplifier 52 employing transistors with a controllable amplification factor.
  • a converting device in the form of a voltage-code converter 50 connected with the control unit 48 which, in turn, is connected with an electromechanical means 53 converting electric voltage into motion, e.g., with a magnetostrictive converter, via the converting device in the form of a codevoltage" converter 51 and an amplifier 52 employing transistors with a controllable amplification factor.
  • the electromechanical means 53 is mechanically linked with piston 54 of a correcting hydraulic cylinder 55.
  • a local increase in the rigidity of the stand is achieved with the aid of a hydraulic system constituted by the hydraulic power cylinders '6, hydraulic cylinder 8 and the controllable valve 11.
  • This hydraulic system will be referred to hereinafter as a roll stand prestressing circuit.
  • the mill operator sets the required opening of the working rolls and feeds the strip into the stand.
  • the strip adds to elastic deformation of the roll stand so that the opening of the working rolls increases correspondingly, while the pistons 7 of the hydraulic cylinders 6 symmetrically arranged in the stand move upward applying the original force to the stand.
  • the mill operator If the mill operator considers that the strip discharged from the stand is of the required thickness and that the setting of the stand is completed, he closes the controlable valve 11 with the aid of a remote drive (not shown in the drawing). This closes the hydraulic system which becomes essentially rigid owing to but a slight deformation of the closed volume of fluid on changes of pressure in it.
  • the piston 9 of the hydraulic cylinder 8 is fixed in the upper position by the force F which is built up by the spring 10 and which is approximately equal to 2 P this force being used to set the upper limit of pressure control in the hydraulic power cylinder 6.
  • said rigid hydraulic system transforms the hydraulic power cylinder 6 with the piston 7 into a rigid pad installed between the supports of the working rolls and prestressed with a force which is considerably smaller than the rolling pressure. If the pressure exerted by the rolled strip on the working rolls varies during rolling, the opening of these rolls also varies correspondingly, thus causing variations in the thickness of the strip discharged from the stand.
  • provision of said rigid pads between the supports of the working rolls reduces materially the variations in the roll openings. For instance, when the rolling pressure increases and the opening of the working rolls becomes correspondingly larger, the forces created in the pads by prestressing are reduced with the increase in the rigidity of the pad, supports, and of the necks and barrels of the working and back-up rolls.
  • the actual rigidity of the elements participating in prestressing the stand is such that the rigidity of the roll stand is increased due to prestressing by only 80-l00 percent in the section of the stand elastic deformation characteristic, this section being determined by the rolling pressure variation range which reduces the variations in the thickness of the rolled strip discharged from the mill only to i 0.08-0.05 mm depending on the rolling conditions.
  • the roll stand prestressing circuit employs the simplest and most economical means for limiting the deviations in the strip thickness to i 008-005 mm; besides, the device responds equally well to the variations in the parameters of the rolled strip, e.g. its temperature, and to the current variations in the parameters of the roll stand, e.g., changes in the height and rigidity of the oil wedge in the bearings of the back-up rolls or the run-out of the back-up rolls, except the variations in the parameters of the working rolls.
  • the operating accuracy of the present device is increased with the aid of the positive fluid pressure feedback channel in the hydraulic system, this channel compensating for the above-mentioned influence of the flexible elements in the stand prestressing circuit on the accuracy of strip thickness control.
  • Said positive feedback channel is intended for partial or complete compensation for the negative feedback effects of the flexible elements of the prestressing Cir cuit on the variations of pressure in the closed hydraulic system during automatic adjustment of working roll opening.
  • the piston 14 will move to the right and pressure P will be fed to the hydraulic cylinder 12, moving the piston 20 to the left.
  • the force of the spring 17 transmitted to the piston 14 grows until a state of equilibrium is reached at which the movable piston 14 comes again to the neutral position and the pressure fluid is no longer fed to the hydraulic cylinder 12.
  • the moment when said process is discontinued during rolling is determined, according to the invention, by setting the value of the positive feedback coefficient which is selected in the hydromechanical channel by setting the relation between the arms of the lever 18.
  • the process of adjusting the positive feedback channel before rolling For this purpose, the working rolls of the roll stand are pressed together by the pressure screws 4 with a force approaching the rolling pressure. This simulates the infinite rigidity of the opening of the working roll barrels because changes in the height of the elastically deformed section of the roll barrels within the range of rolling pressure variations may be neglected.
  • the position of the movable support 22 during setting is selected so that any motion of the piston 20 of the correcting hydraulic cylinder 21 would lead to an identical change in the forces applied to both sides of the movable piston 14 of the control valve 13 without changes in the opening of the working rolls in spite of the pressure changes in the closed hydraulic system.
  • the positive feedback channel makes it possible to dispose of said static error.
  • the pressure increment AP causes the movable piston 14 of the control valve 13 to move to the right thereby shifting the piston 20 of the correcting hydraulic cylinder 21 to the left thus providing for a further rise of pressure in the closed hydraulic system.
  • K is the coefficient of the positive feedback of the channel.
  • the piston of the positive feedback channel moves to the right.
  • the positive feedback channel ensures the above-mentioned relationship between the pressure increment AP, and the movement AS of the piston 20 of the correcting hydraulic cylinder 21.
  • FIG. 2 Shown in FIG. 2 is the positive feedback channel of the electromechanical type. This channel functions as follows:
  • the pressure meter 23 of the closed hydraulic system sends a signal into the comparator unit 25 where the value of AP, of the current value of pressure is determined by comparing it with pressure P,.
  • the amplifier 26 is phase-sensitive so that the sign AP, can be distinguished at its output.
  • the divider 27 is set for a value of the positive feedback coefficient so that the D.C. volt age fed into the comparator unit 28 from the divider output is proportional to the relation AP,/K;
  • the second input of the comparator unit 28 receives a signal from the transmitter 31 indicating the positionof the piston 33 of the correcting hydraulic cylinder 34.
  • the signal which is proportional to the difference between AP,'/K and AS fed from the output of the comparator unit 28 via the amplifier 29 to the input of the electric motor 30 controls the movement of the piston 33 of the correcting hydraulic cylinder 34 so that (AP,'/K)AS 0 or AP, K 'AS.
  • the coefficient of positive feedback can be set more flexibly, for example by a controlling computer.
  • the hydrornechanical positive feedback channel must be provided with a remote control for moving the movable support 22.
  • the positive feedback channel simultaneously increases the amplitude of pressure variations in the closed hydraulic system.
  • the stand prestressing circuit is connected to a channel controlling the thrust of the working rolls.
  • the movable piston 37 of the control valve 38 of this channel is kept in equilibrium by two forces: from the piston 35 of the hydraulic cylinder 36 and from the flexible element 39.
  • the force of the flexible element 39 is set by the mechanism 40.
  • the pressure is controlled in the closed hydraulic system which ensures a local increase in the rigidity of the stand. For example, if the force of the piston 35 grows, the movable piston 37 of the control valve 38 is shifted to the right, pressure is fed into the hydraulic cylinder 41 thrusting apart the supports of the backup rolls. Owing to the increase in the thrust of the back-up rolls, pressure in the hydraulic power cylinders 6 drops, thus restoring the equilibrium between the forces applied to the movable piston 37 of the control valve 38.
  • the signal proportional to AP controls the electric motor 44 which moves the piston 43 in the hydraulic cylinder 42.
  • the piston 43 moves to the left until the value of AP, diminishes to zero (or to the preset insensitivity zone-of the channel) If a negative value of AP, appears at the output of the amplifier 26, the piston 43 moves in the reverse direction.
  • the working roll thrust control channel considered above can be realized so that the output signal of the amplifier 26 will act directly on the electric drive 5 -of the pressure screws 4. In this case it is practicable that an insensitivity zone should be set for this electric drive 5.
  • the roll stand prestressing circuit combined with said channels of positive feedback and working roll thrust control ensures precise correction of all the actual disturbances affecting the thickness of the strip except for the machining inaccuracy of the working rolls.
  • This inaccuracy is one or more orders smaller than the machining inaccuracy of the back-up rolls and is the only cardinal limitation of accuracy in strip thickness control.
  • the device is provided with a circuit for programmed correction of the influence of working roll machining inaccuracy on the thickness of the strip.
  • Such correction is possible with relation to the working rolls because the working rolls of a roll stand are interconnected by a gear stand (not shown in the drawing) so that the runout of the working rolls is strictly regular,,repeating during each revolution of the roll.
  • the relative angular position of the working rolls is measured by a pulse transmitter of roll rotation. A marking pulse continuously indicates the beginning of counting of the angular position of the rolls during each revolution.
  • the pressure meter 23 reads the variations of pressure in the closed hydraulic system caused by the run-out of the working rolls (the run-out of the back-up rolls is absorbed in this case by the stand bed). These pressure variations are transmitted through the control unit 48 into the memory unit 49 which memorizes said variations as a function of the relative angular position of the working rolls.
  • the device for controlling the strip thickness by a computer
  • said device be provided with devices setting the volume of the fluid in the closed hydraulic system by individual electric-powered hydraulic cylinders controlled by a computer. In this case it is not required to open the valve 11 for readjusting the stand. Simultaneously, it is practicable that this channel should introduce corrections in the volume of fluid contained in the closed hydraulic system.
  • the device for controlling the thickness of the roll strip according to the invention has the following advantages:
  • a device for automatic thickness control of rolled strips in installations manufacturing strip materials and having at least one roll stand with back-up and working rolls comprising: symmetrically located at each side of said roll stand at least one hydraulic power cylinder installed between the supports of said working rolls; a damping hydraulic cylinder; a piston of said damping hydraulic cylinder, fixed while the rolled strip is passing through the roll stand; a controllable valve, said hydraulic power cylinder, damping cylinder and controllable valve being so connected that they form a closed hydraulic system which ensures a local increase in the rigidity of the roll stand within the range of forces which is approximately equal to the range of rolling pressure deviations from the preset valve; a positive feedback circuit actuated by the fluid pressure in said closed hydraulic system comprising a pressure meter in said hydraulic power cylinder and communicating hydraulically with the latter, and a comparison element for comparing the measured deviation of pressure with the value which is proportional to the preset coefficient of positive feedback, connected with said pressure meter, an actuating element connected to said comparison element, and a correcting element
  • a device wherein its positive feedback circuit is of the hydromechanical type and comprises a hydraulic cylinder serving as an actuating element; a control valve whose space is in hydraulic communication with said hydraulic cylinder; a second hydraulic cylinder serving as a pressure meter and whose piston is linked kinematically with one of the ends of the piston of said control valve; a flexible element connected to the other end of the piston of said control valve and linked kinematically with the piston of said correcting hydraulic cylinder.
  • the positive feedback circuit is of the electromechanical type and comprises a divider functioning as a setter of the positive feedback coefficient and connected to said pressure meter and to said comparison element, an
  • said working roll thrust control channel comprises a working roll thrust setter; a pressure meter for measuring pressure in the hydraulic power cylinder; a control valve hydraulically communicating with the hydraulic cylinder installed between the supports of the back-up rolls; a movable piston of said control valve one end of which is kinematically connected with said pressure meter of the thrust control channel while its other end is connected to said working roll thrust setter.
  • said working roll thrust control channel comprises a correcting element in the form of a hydraulic cylinder communicating hydraulically with the hydraulic cylinder installed between the supports of said back-up rolls;
  • electromechanical means for converting electrical voltage into motion, mechanically connected with the piston of said correcting hydraulic cylinder and electrically connected with said pressure meter .of said positive feedback channel.
  • a device which has a channel for programmed correction of working roll machining inaccuracies, this channel comprising: a memory unit for memorizing the variations of pressure in said hydraulic power cylinder as a function of the turning angle of the working rolls; a unit for measuring the current values of the working roll turning angle; an electromechanical means for converting electrical voltage into motion, connected electrically to said memory unit and to the unit for measuring current values of turning angles; one more correcting hydraulic cylinder hydraulically connected with said hydraulic power cylinder, the piston of the correcting cylinder being coupled with said electromechanical means of the programmed correction channel; a control unit for controlling said memory unit and current value measuring unit which ensures synchronization of the action of said units on said electromechanical conversion means in the programmed correction channel.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
US120845A 1971-02-24 1971-03-04 Device for automatic thickness control of rolled strips Expired - Lifetime US3686907A (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE2108783A DE2108783C3 (de) 1971-02-24 1971-02-24 Einrichtung zum automatischen Regeln der Dicke von Flachwalzgut
US12084571A 1971-03-04 1971-03-04
FR7110404A FR2129975B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1971-02-24 1971-03-24
GB1066471 1971-04-22

Publications (1)

Publication Number Publication Date
US3686907A true US3686907A (en) 1972-08-29

Family

ID=27431211

Family Applications (1)

Application Number Title Priority Date Filing Date
US120845A Expired - Lifetime US3686907A (en) 1971-02-24 1971-03-04 Device for automatic thickness control of rolled strips

Country Status (4)

Country Link
US (1) US3686907A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE2108783C3 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
FR (1) FR2129975B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1340265A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3875775A (en) * 1974-05-10 1975-04-08 Daniljuk Valery V Device for automatic adjustment of strip thickness in rolling
US4083213A (en) * 1976-11-24 1978-04-11 Vladimir Nikolaevich Vydrin Device for automatic adjustment of the roll gap in a mill stand
US4086797A (en) * 1977-04-14 1978-05-02 Vladimir Nikolaevich Vydrin Device for automatic adjustment of a roll gap between work rolls in mill stand
US4306436A (en) * 1980-05-12 1981-12-22 Rockwell International Corporation Method and apparatus for regulating preselected loads on forming dies
US4420958A (en) * 1980-05-12 1983-12-20 Rockwell International Corporation Method and apparatus for regulating preselected loads on forming dies
US4909060A (en) * 1988-01-26 1990-03-20 United Engineering, Inc. Oil compression compensation system
US5297408A (en) * 1991-02-19 1994-03-29 Keiichiro Yoshida Method of an apparatus for controlling hydraulic rolling reduction in a rolling mill
US20110113848A1 (en) * 2009-11-16 2011-05-19 Quad Engineering Inc. Methods for reducing ridge buckles and annealing stickers in cold rolled strip and ridge-flattening skin pass mill
ITMI20101843A1 (it) * 2010-10-08 2012-04-09 Danieli Off Mecc Sistema di smorzamento di vibrazioni di un laminatoio
CN104204552A (zh) * 2012-03-26 2014-12-10 丹尼尔和科菲森梅克尼齐有限公司 借助于液压致动系统的振动阻尼系统

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4202192A (en) * 1978-06-21 1980-05-13 Nippon Steel Corporation Apparatus for controlling the position of roll in the direction of the roll axis
FR2443885A1 (fr) * 1978-12-13 1980-07-11 Chabanov Alim Dispositif pour la regulation de l'epaisseur de produits lamines
CA1184794A (en) * 1982-02-11 1985-04-02 William I. Deversterre Load-transfer mechanism
DE3803490A1 (de) * 1988-02-05 1989-08-17 Rexroth Mannesmann Gmbh Sicherheitsanordnung fuer stellzylinder, insbesondere fuer kalander mit verstellbaren walzen
CN104815849B (zh) * 2015-04-07 2016-11-30 首钢京唐钢铁联合有限责任公司 一种定宽机夹送辊位置控制系统精度补偿的方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533255A (en) * 1965-08-24 1970-10-13 Raymond Bernard Sims Rolling mill
US3538727A (en) * 1966-12-19 1970-11-10 Forges Cie Des Atel Device for regulating the thickness of rolling-mill products and rollingmills equipped therewith
US3559432A (en) * 1968-05-29 1971-02-02 Textron Inc Roll gap gage control

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1348136A (fr) * 1962-02-15 1964-01-04 Moeller & Neumann Verwalt Ges Cage de laminoir à montants fermés et à dispositif de régulation pour le laminage avec tolérance
FR1356340A (fr) * 1963-02-11 1964-03-27 Spidem Ste Nle Dispositif hydraulique de compensation de cédage pour laminoir à serrage hydromécanique

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533255A (en) * 1965-08-24 1970-10-13 Raymond Bernard Sims Rolling mill
US3538727A (en) * 1966-12-19 1970-11-10 Forges Cie Des Atel Device for regulating the thickness of rolling-mill products and rollingmills equipped therewith
US3559432A (en) * 1968-05-29 1971-02-02 Textron Inc Roll gap gage control

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3875775A (en) * 1974-05-10 1975-04-08 Daniljuk Valery V Device for automatic adjustment of strip thickness in rolling
US4083213A (en) * 1976-11-24 1978-04-11 Vladimir Nikolaevich Vydrin Device for automatic adjustment of the roll gap in a mill stand
US4086797A (en) * 1977-04-14 1978-05-02 Vladimir Nikolaevich Vydrin Device for automatic adjustment of a roll gap between work rolls in mill stand
US4306436A (en) * 1980-05-12 1981-12-22 Rockwell International Corporation Method and apparatus for regulating preselected loads on forming dies
US4420958A (en) * 1980-05-12 1983-12-20 Rockwell International Corporation Method and apparatus for regulating preselected loads on forming dies
US4909060A (en) * 1988-01-26 1990-03-20 United Engineering, Inc. Oil compression compensation system
US5297408A (en) * 1991-02-19 1994-03-29 Keiichiro Yoshida Method of an apparatus for controlling hydraulic rolling reduction in a rolling mill
US8365563B2 (en) * 2009-11-16 2013-02-05 Quad Engineering, Inc. Methods for reducing ridge buckles and annealing stickers in cold rolled strip and ridge-flattening skin pass mill
US20110113848A1 (en) * 2009-11-16 2011-05-19 Quad Engineering Inc. Methods for reducing ridge buckles and annealing stickers in cold rolled strip and ridge-flattening skin pass mill
ITMI20101843A1 (it) * 2010-10-08 2012-04-09 Danieli Off Mecc Sistema di smorzamento di vibrazioni di un laminatoio
WO2012046211A1 (en) 2010-10-08 2012-04-12 Danieli & C. Officine Meccaniche S.P.A. Vibration damping system for a rolling mill with first and second passive hydraulic elements
CN103180063A (zh) * 2010-10-08 2013-06-26 丹尼尔和科菲森梅克尼齐有限公司 用于轧机的具有第一和第二无源液压元件的振动阻尼系统
CN103180063B (zh) * 2010-10-08 2015-05-13 丹尼尔和科菲森梅克尼齐有限公司 用于轧机的具有第一和第二无源液压元件的振动阻尼系统
US9211576B2 (en) 2010-10-08 2015-12-15 Danieli & C. Officine Meccaniche S.P.A. Vibration damping system for a rolling mill with first and second passive hydraulic elements
EA024914B1 (ru) * 2010-10-08 2016-11-30 Даньели Энд К. Оффичине Мекканике С.П.А. Система демпфирования вибраций прокатной клети с первым и вторым пассивными гидравлическими элементами
CN104204552A (zh) * 2012-03-26 2014-12-10 丹尼尔和科菲森梅克尼齐有限公司 借助于液压致动系统的振动阻尼系统
CN104204552B (zh) * 2012-03-26 2016-08-24 丹尼尔和科菲森梅克尼齐有限公司 借助于液压致动系统的振动阻尼系统

Also Published As

Publication number Publication date
DE2108783C3 (de) 1975-12-04
FR2129975A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1972-11-03
DE2108783B2 (de) 1975-04-24
GB1340265A (en) 1973-12-12
DE2108783A1 (de) 1972-09-07
FR2129975B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-08-19

Similar Documents

Publication Publication Date Title
US3686907A (en) Device for automatic thickness control of rolled strips
US3427839A (en) Hydraulic adjusting means for rolling mills
US3247697A (en) Strip rolling mill
US2903926A (en) Method and apparatus for controlling the contour of rolls in a rolling mill
SU420154A3 (ru) Способ автоматического контроляи регулирования профиля полось'. на четырехвалковом прокатном стане
US3084314A (en) Thickness control servosystem
US3389588A (en) Apparatus for controlling the position of work rolls
US3169420A (en) Apparatus for tensioning strip
JPS6132090B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
US3961510A (en) Tension device for a rolling mill and the like
US3054310A (en) Control system
US3517531A (en) Rolling mill gage control actuator system
KR200243120Y1 (ko) 교정기 롤갭의 영점조정장치
US3875775A (en) Device for automatic adjustment of strip thickness in rolling
US3744288A (en) Tensiometer
US4214464A (en) Apparatus for controlling the thickness of rolled products
KR200157532Y1 (ko) 롤 갭 자동 유지 장치
US3436943A (en) Rolling mill taper control system
US2185836A (en) Tension control system
US3092742A (en) Motor positioning device
US3534577A (en) Rolling mills for rolling metal
US3044221A (en) Gear grinding machine
US2303596A (en) Sheet thickness gauge for continuous rolling mills
JPS60174214A (ja) ロ−ラ−矯正装置の自動圧下制御方法
SU931256A1 (ru) Устройство дл стабилизации межвалкового зазора прокатной клети