US3600919A - Process for automatic control of the hot rolling of metal flats - Google Patents

Process for automatic control of the hot rolling of metal flats Download PDF

Info

Publication number
US3600919A
US3600919A US829856A US3600919DA US3600919A US 3600919 A US3600919 A US 3600919A US 829856 A US829856 A US 829856A US 3600919D A US3600919D A US 3600919DA US 3600919 A US3600919 A US 3600919A
Authority
US
United States
Prior art keywords
rolling
thickness
pass
product
force
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
US829856A
Other languages
English (en)
Inventor
Michel Jacques Sindzingre
Guy Eugene Rene Frezon
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.)
Compagnie dEtudes et de Realisation de Cybernetique Industrielle CERCI
Original Assignee
Compagnie dEtudes et de Realisation de Cybernetique Industrielle CERCI
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 Compagnie dEtudes et de Realisation de Cybernetique Industrielle CERCI filed Critical Compagnie dEtudes et de Realisation de Cybernetique Industrielle CERCI
Application granted granted Critical
Publication of US3600919A publication Critical patent/US3600919A/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
    • B21B37/16—Control of thickness, width, diameter or other transverse dimensions

Definitions

  • This invention relates to a process for automatic control of the rolling of metal flats such as heavy and medium gauge sheet metal.
  • the invention finds particular, but not exclusive, application in the hot rolling of such metal flats.
  • the desiderata in this kind of rolling are:
  • condition (a) is a limitation for lesser thicknesses and condition (b) is a limitation for greater thicknesses.
  • Automatic control of rolling implies automatic determination of the consecutive roll nips required to produce a product of a predetermined end thickness under optimum conditions.
  • Another known method, used for rolling series of identical sheets, is to roll on the basis of a pattern of reductions derived from the results obtained with the first sheets of a series. This is a very special method and is of no use for everyday manufacture (which implies very small or substantially no series of sheets). Even in its own limited field this method cannot always ensure the required end-thickness accuracy.
  • a process for automatic control of the rolling of metal flats by determination of consecutive roll nips wherein a Program in the form of a sequence of intermediate thicknesses for the product is devised on the basis of numerical determination of a parameter r based on the plasticity of the metal, and the development of such parameter depending on product thickness and a selected rolling force.
  • thicknesses obtained consecutively during the rolling operation are given indexes in the form of decreasing numbers from the initial thickness e, to the end thickness 2,; similar considerations apply to the rank of rolling passes, the pass of rank n being the pass which brings the product from the thickness e to the thickness e, while the last pass, which has the index 0, brings the product to its end thickness e..
  • FIG. 1 is a graphic representation of the phenomenon and represents the development of a product of initial thickness a. introduced between rolls whose nip s is less than e Product thickness (or roll nip) is plotted along the abscissa and the rolling force is plotted along the ordinate.
  • Curve 1 known as the yieldability curve and passing through abscissa point .r, is a characteristic of the mill and denotes the resistive force of the rolls and roll housing when endeavors are made to force the rolls apart further than corresponds to the adjusted off-load nip.
  • Curve 2, called the plasticity curve and passing through abscissa point a is a characteristic of the rolled product and corresponds to its deformation resistance in dependence upon its thickness reduction. The point of intersection of the curves 1 and 2 corresponds to the abscissa point e,,, denoting the thickness of the sheet after the pass.
  • the parameter r is used; it is defined as follows:
  • This parameter has the interesting feature that its variation in dependence upon product thickness, assuming working with a substantially constant rolling force, can be denoted, if product thickness is plotted along the abscissa and the parameter r along the ordinate, by a family of closely related curves relative to the ordinate axis.
  • the family of curves as defined by the statistical method can be represented in a satisfactory approximation by a family of hyperbolae for lesser thicknesses and by a family of parabolae for larger thicknesses.
  • FIG. 2 shows an exemplary curve family of this kind.
  • the family has been equated.
  • two forms of equation are used. For thicknesses less than 50 mm., the hyperbolic expression:
  • the selected rolling conditions must lie within the power of the driving motors, more particularly as regards their maximum permissible torque, which is usually a factor limiting the working of heavy-gauge material.
  • the maximum possible thickness reduction A without exceeding the permissible torque of the driving motors for a piece of sheet material of given plasticity, width and initial thickness can be determined from theoretical calculations based on observation of the term defining the rolling torque, and is determined by a relation of the kind:
  • a. is a constant characteristics of the drive motors
  • K is the affinity coefiicient of the plasticity curve which is associated with the operation and which is taken from the family defined by the formula
  • 1 denotes product width
  • a denotes product thickness at the entry of the product into the roll nip
  • a, 8,, 1 are the same constants as in formula (4).
  • a description of how the process can be used will now be given with reference to a product of width l and initial thickness e, which is brought to a final thickness e,.
  • a rolling force F is determined by conventional operating practices. For the sake of dimensional tolerances, curvature and flatness, the rolling force F, in the first pass is reduced, the object being to meet these requirements in optimum conditions-Le, more particularly by using the minimum number of passes compatible with the available equipment.
  • the first two passes are performed under manual control; during these passes data which will be used for subsequent automatic calculation are sampled.
  • the rolling force F developed during the operation is measured during the first pass with an off-load nip of r
  • the corresponding yieldability C can be calculated by means of formula (7):
  • a rolling Program can now be devised which defines the consecutive thicknesses to be given the product between the thickness e associated with the termination of the manualcontrol phase, and the end thickness i e,,.
  • FIG. 3 shows in graph form the procedure for calculating the program.
  • the imposed rolling forces 1",, and F have been shown in FIG. 3 on the force-thickness coordinates system used in FIG. 1.
  • formula (9) is used to determine the penultimate thickness e, by the introduction of the special value F,, of the rolling force of the final pass, so that:
  • the rolling Program formed by the sequence of required intermediate thicknesses should following on accurately from the actual value e obtained at the end of the second pass. Only in exceptional circumstances does the rough calculation result lead to this accuracy; as a rule, the calculations give two consecutive intermediate thicknesses e, and e,,on either side ofthe "meeting" thickness c such that:
  • the program is then formed by the required consecutive thicknesses:
  • formula l l is used as in the previous pass but with the introduction into it, as theoretical plasticity parameter r of a value linked to the previous actual values of such parameter, for instance, the mean value of the theoretical parameter 1" during the second pass and of the actual parameter r'ni during the next pass, calculated by:
  • the system simultaneously compares the calculated rolling force F m with the predetermined force F If F remains within predetermined limits of tolerance, for instance, :10 percent of I operations continue; otherwise the system completely recalculates the program in accordance with the principles hereinbefore described.
  • the calculations are made in exactly the same way as described with reference to the end of the second pass. ln general, if the calculated force is outside the indexed limits of tolerance, the program of intermediate thicknesses is recalculated.
  • FIG. 4 represents the calculated and actual values for thicknesses and rolling forces.
  • the hatched zone corresponds to the permissible rolling-force tolerances on either side of F.
  • This method can of course be used for widthwise sizing of the sheets, for in widthwise sizing a predetermined product width is required-Le, actually a given width once the weight or volume of the initial product and the final dimension are known.
  • I. Process for rolling metal flats in a rolling mill having apparatus for measuring the rolling force and apparatus for measuring the nip of the rolls comprising the successive steps of performing two rolling passes and measuring the nip of the rolls and the rolling force on each pass, programming a computer to determine the number of further successive passes and the intermediate thicknesses of the flats to obtain a predetermined final thickness of metal flat utilizing a predetermined relation between the desired final thickness, a predetermined rolling force for the last pass, a predetermined constant rolling force for all the other passes and the measurements of the rolling forces and nips of the first two passes, determining the nip to be given to the rolls for the third pass, then carrying out the third pass, measuring the actual rolling force and the actual nip on the third pass and determining the nip to be given to the next pass utilizing a predetermined relation between the values already known and the actual rolling force and the actual nip of the cylinders measured during the third pass and then repeating these determinations for each following pass.
  • a process as described in claim 1 including measuring the rolling force of each pass and reprogramming the computer when the rolling force exceeds a predetermined value.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Metal Rolling (AREA)
US829856A 1968-07-05 1969-06-03 Process for automatic control of the hot rolling of metal flats Expired - Lifetime US3600919A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR157998 1968-07-05

Publications (1)

Publication Number Publication Date
US3600919A true US3600919A (en) 1971-08-24

Family

ID=8652129

Family Applications (1)

Application Number Title Priority Date Filing Date
US829856A Expired - Lifetime US3600919A (en) 1968-07-05 1969-06-03 Process for automatic control of the hot rolling of metal flats

Country Status (4)

Country Link
US (1) US3600919A (enrdf_load_stackoverflow)
BE (1) BE732011A (enrdf_load_stackoverflow)
DE (1) DE1932463A1 (enrdf_load_stackoverflow)
FR (1) FR1581023A (enrdf_load_stackoverflow)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3927545A (en) * 1974-04-17 1975-12-23 Hitachi Ltd Rolling method for rolling mills

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3253438A (en) * 1962-09-21 1966-05-31 Westinghouse Electric Corp Automatic strip gauge control for a rolling mill
US3332263A (en) * 1963-12-10 1967-07-25 Gen Electric Computer control system for metals rolling mill

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3253438A (en) * 1962-09-21 1966-05-31 Westinghouse Electric Corp Automatic strip gauge control for a rolling mill
US3332263A (en) * 1963-12-10 1967-07-25 Gen Electric Computer control system for metals rolling mill

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
3 Determination of a Mathematical Model for Rolling Mill Control by Schultz and Smith, Jr., Iron and Steel Engineer, May 1965. Copies in the Technical Library and in Class 72/8. *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3927545A (en) * 1974-04-17 1975-12-23 Hitachi Ltd Rolling method for rolling mills

Also Published As

Publication number Publication date
DE1932463A1 (de) 1970-01-29
BE732011A (enrdf_load_stackoverflow) 1969-10-01
FR1581023A (enrdf_load_stackoverflow) 1969-09-12

Similar Documents

Publication Publication Date Title
US3248916A (en) Workpiece shape control with a rolling mill
US3787667A (en) Computer controlled metal rolling mill
US3713313A (en) Computer controlled rolling mill
EP0219844A1 (en) Method of controlling the profile of sheet during rolling thereof
CN116136892B (zh) 一种二十辊轧机轧制力的计算方法及系统
CN110434172B (zh) 一种炉卷和精轧机组连轧的负荷分配计算方法
US3387470A (en) Method for measuring roll crown and improving the operation of a rolling mill
US5086399A (en) Method and apparatus for setting-up rolling mill roll gaps
US3600919A (en) Process for automatic control of the hot rolling of metal flats
US4506532A (en) Method for controlling continuous rolling mill and control apparatus therefor
CN112387791B (zh) 冷轧带钢的轧制温度确定方法及确定系统
JPH06244B2 (ja) 板材の形状制御装置
JP3067879B2 (ja) ストリップ圧延における形状制御方法
US4137741A (en) Workpiece shape control
US4063438A (en) Method of controlling tandem rolling mills
Wang et al. Prediction and optimization of dynamic rolling force in strip rolling process driven by data-mechanism cooperation
US4718262A (en) Method for controlling edge taper in metal rolling mill
JPH0824932B2 (ja) 幅方向に板厚の傾斜を有する鋼板の製造方法
JP2755893B2 (ja) 圧延制御方法および装置
JPS6323848B2 (enrdf_load_stackoverflow)
Sassani et al. Prediction of spread in hot flat rolling under variable geometry conditions
US3807206A (en) Strip gage change during rolling in a tanden rolling mill
US3635059A (en) Calibration of rolling mill screwdown position regulator
SU1576216A1 (ru) Способ управлени процессом холодной прокатки полосы на реверсивном стане
US3813908A (en) Method of adaptive thread