US3733866A - Method of controlling a continuous hot rolling mill - Google Patents
Method of controlling a continuous hot rolling mill Download PDFInfo
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- US3733866A US3733866A US00151350A US3733866DA US3733866A US 3733866 A US3733866 A US 3733866A US 00151350 A US00151350 A US 00151350A US 3733866D A US3733866D A US 3733866DA US 3733866 A US3733866 A US 3733866A
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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
- B21B37/16—Control of thickness, width, diameter or other transverse dimensions
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- ABSTRACT In a method of controlling a continuous hot rolling mill including a plurality of mill stands during acceleration thereof, variations in the screw down pressure (i.e., rolling load), in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of acceleration, are anticipated, the width of the finished plates, types and compositions of the materials being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations are classified into a plurality of groups, an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant is computed by an electronic computer associated with the rolling mill, and the roll gap and roll peripheral speed are controlled in accordance with the schedule for each mill stand so as to maintain the tension of the material between adjoining stands at a constant value.
- variations in the screw down pressure i.e., rolling load
- FIG. 4 Sheets-Sheet 3 TIME (SEC) FIG. 4
- This invention relates to a method of controlling a continuous hot rolling mill and more particularly to a method of controlling the acceleration of a continuous hot rolling mill wherein the roll gap and the roll peripheral speed of each mill stand is controlled according to a predetermined pattern in order to maintain the gauge of the finished plates at a constant value and to eliminate off-gauge products when accelerating the rolling mill.
- each mill stand of a continuous rolling mill is provided with a reduction screw, S, an electric motor, M, for driving the screw down, and a load cell, LC, responsive to the load or rolling pressure of the stand.
- a suitable thickness measuring device for example an X-ray gauge meter
- the lock-on operation is performed manually or under control of an electronic computer.
- the plate gauge on the delivery side of respective stands equipped with conventional BISRA type AGC systems '(developed by British Iron and Steel Research Association) (normally, control of all intermediate stands excepting the first and last stands) is computed according to an equation wherein h: plate gauge on the delivery side of a stand P: screw down passage (i.e., rolling load) Po: screw down pressure or rolling load at the zero adjustment M: mill constant S: Set gap of the rolls Thereafter, due to the acceleration of the rolling speed, the temperature of the material and the strain speed vary and the roll gap is varied in accordance with the variation in the screw down pressure according to the following equation, thus maintaining the plate gauge on the delivery side of the stand at a constant value Further, the deviation of the plate gauge measured by the X-ray gauge meter is fed back to the second and following stands to supervise the plate gauge.
- screw down pressure is synonomous with rolling load.
- an application of the prior controlling method to the acceleration of the rolling speed results in various troubles and defects.
- the variation in the screw down pressure increases so that it is necessary to rapidly raise or lower the screw after the AGC system has detected the variation in the screw down pressure.
- the gauge of certain portions of the plate will deviate from a set value if the screw were raised or lowered after an instant at which the screw down pressure varies. The length of such off gauge portions increases proportionate to the acceleration and presents a substantial loss of production.
- the variation in the roll peripheral speed and in the screw down pressure results in the variation of the thickness of the oil film of the bearings for back-up rolls, thus varying the set value of the roll gap. Since, in the prior art control system, this variation is the set value of the roll gap, it is controlled in terms of the variation in the screw down pressure, control is effected in the opposite direction. In other words, while the plate gauge decreases with the roll gap, in response to the increased screw down pressure, the prior art AGC system judges that the plate gauge is thick, and decreases the roll gap.
- Another object of this invention is to provide a new and improved method of controlling a continuous hot rolling mill which can decrease off-gauge products by controlling the roll gap and roll peripheral speed according to a predetermined pattern determined by an electronic computer by anticipating various factors that vary as a result of acceleration.
- a method of controlling a continuous hot rolling mill including a plurality of mill stands, comprising the steps of anticipating variations in the screw down pressure, in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of accelerating the rolling speed, classifying the widths of the finished plates, types and compositions of the steel being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations into a plurality of groups, computing an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant on the delivery side by means of an electronic computer associated with the rolling mill, and controlling the roll gap and the roll peripheral speed according to said schedule for each mill stand whereby to maintain the tension of the material between adjoining stands at a constant value.
- FIG. 1 is a diagram to show a prior art AGC system
- FIG. 2 is a graph to show the variation in the plate gauge during acceleration where the AGC system of the present invention is not used;
- FIG. 3 is a diagram of a control system utilized to carry out the method of this invention.
- FIG. 4 is a graph showing the transitional variation of roll gaps and FIG. 5 is a graph showing the transitional variation of the roll peripheral speed.
- the plate gauge on the delivery side of each stand is determined by taking into consideration three variables viz. (a), the variation with time in the screw down pressure caused by the variations in the temperature and the strain speed (i.e., strain rate which occur during acceleration (b), the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and (c) the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure.
- a the variation with time in the screw down pressure caused by the variations in the temperature and the strain speed
- strain rate i.e., strain rate which occur during acceleration
- the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure
- the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure.
- Stand d the pivot stand.
- the acceleration control apparatus 2 determines a particular acceleration control schedule for the particular material based upon the command from the computer 1, and the differential function generator 3 receives an acceleration pattern for each stand from the acceleration control apparatus 2, selects a group of input data and determines the time variation between roll gaps at each stand, thereby giving commands for varying the roll gap and roll peripheral speed at each stand determined by the abovementioned acceleration control apparatus and differential function generator according to their prescribed pattern concurrently with the initiation of the rolling operation of the material. In this manner, an anticipation control of roll gaps and roll peripheral speed is performed during acceleration of the rolling operation.
- the conventional AGC system 4 does not operate in the opposite direction.
- the invention provides a perfect anticipation control wherein the variation in the screw down pressure is also considered.
- the invention is also applicable to a continuous cold rolling mill.
- the roll gap and the roll peripheral speed of each stand are varied according to a prescribed pattern for the purpose of preventing the gauge of the finished plate deviating from a predetermined value and preventing the tensions of the material between stands deviating from prescribed valves.
- a method of computerized control of a continuous rolling mill including a plurality of mill stands comprising the steps of:
- determining a particular acceleration control schedule of the mill stands for the particular material being operated on in accordance with a given relationship which is a function of at least: said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time in speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness in the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure;
- Stand 4 the pivot stand.
Abstract
In a method of controlling a continuous hot rolling mill including a plurality of mill stands during acceleration thereof, variations in the screw down pressure (i.e., rolling load), in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of acceleration, are anticipated, the width of the finished plates, types and compositions of the materials being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations are classified into a plurality of groups, an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant is computed by an electronic computer associated with the rolling mill, and the roll gap and roll peripheral speed are controlled in accordance with the schedule for each mill stand so as to maintain the tension of the material between adjoining stands at a constant value.
Description
United States Patent [1 1 Arimura et al.
11 3,733,866 1 May 22, 1973 Primary Examiner-Milton S. Mehr Attorney-Flynn & Frishauf [57] ABSTRACT In a method of controlling a continuous hot rolling mill including a plurality of mill stands during acceleration thereof, variations in the screw down pressure (i.e., rolling load), in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of acceleration, are anticipated, the width of the finished plates, types and compositions of the materials being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations are classified into a plurality of groups, an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant is computed by an electronic computer associated with the rolling mill, and the roll gap and roll peripheral speed are controlled in accordance with the schedule for each mill stand so as to maintain the tension of the material between adjoining stands at a constant value.
5 Claims, 5 Drawing Figures SIGNAL DISTRIBUTOR OF REVOLVING SPEED OF REDUCTION SCREW [54] METHOD OF CONTROLLING A CONTINUOUS HOT ROLLING MILL [75] Inventors: Tohru Arimura; Masaru Okado, both of Kawasaki; Yuji Fukuma; Yoshimitsu ldo, both of Fukuyama, all of Japan [73] Assignee: Nippon Kokan Kabushiki Kaisha,
Chiyoda-ku, Tokyo, Japan [22] Filed: June 9, 1971 [21] Appl.No.: 151,350
[30] Foreign Application Priority Data June 18, I970 Japan ..45/52579 [52] US. Cl ..72/6 [51] Int. Cl. ..B2lb 37/00 [58] Field of Search ..72/6-8, 72/16 [56] References Cited UNITED STATES PATENTS 3,507,134 4/1970 Silva ..72/8 3,365,920 1/1968 Maekawa et al. 3,574,280 4/1971 Smith, Jr. ..72/8
DIFFERENTIAL FUNETION GEN RATOR) (COMPUTER INPUT I DATA 1 TIME ACCELIERATION CONTROL APPARATUS Patented May 22. 1973 3,733,866
4 Sheets-Sheet 1 FIG] PRIOR ART FIG. 2
ACCELERATION PERIOD Patented May 22. 1973 3,733,866
4 Sheets-Sheet 3 TIME (SEC) FIG. 4
METHOD OF CONTROLLING A CONTINUOUS HOT ROLLING MILL BACKGROUND OF THE INVENTION This invention relates to a method of controlling a continuous hot rolling mill and more particularly to a method of controlling the acceleration of a continuous hot rolling mill wherein the roll gap and the roll peripheral speed of each mill stand is controlled according to a predetermined pattern in order to maintain the gauge of the finished plates at a constant value and to eliminate off-gauge products when accelerating the rolling mill.
Heretofore, in order to maintain the gauge of the finished plates at a constant value, an automatic gauge control system (AGC) diagrammatically shown in FIG. 1 has generally been used. As shown, each mill stand of a continuous rolling mill is provided with a reduction screw, S, an electric motor, M, for driving the screw down, and a load cell, LC, responsive to the load or rolling pressure of the stand. According to this system, the gauge of the finished plate that has passed through the final stand is measured by a suitable thickness measuring device, for example an X-ray gauge meter, and when the gauge is brought into a predetermined range, the following method of control, termed as the lock-on operation, is performed manually or under control of an electronic computer. More particularly, the plate gauge on the delivery side of respective stands equipped with conventional BISRA type AGC systems '(developed by British Iron and Steel Research Association) (normally, control of all intermediate stands excepting the first and last stands) is computed according to an equation wherein h: plate gauge on the delivery side of a stand P: screw down passage (i.e., rolling load) Po: screw down pressure or rolling load at the zero adjustment M: mill constant S: Set gap of the rolls Thereafter, due to the acceleration of the rolling speed, the temperature of the material and the strain speed vary and the roll gap is varied in accordance with the variation in the screw down pressure according to the following equation, thus maintaining the plate gauge on the delivery side of the stand at a constant value Further, the deviation of the plate gauge measured by the X-ray gauge meter is fed back to the second and following stands to supervise the plate gauge. As used herein, the term screw down pressure is synonomous with rolling load.
However, an application of the prior controlling method to the acceleration of the rolling speed results in various troubles and defects. For example, there is a trouble caused by the time lag in the raising or lowering of the screw. More particularly, as the acceleration of the material is increased, due to the variation in the temperature and strain speed, the variation in the screw down pressure increases so that it is necessary to rapidly raise or lower the screw after the AGC system has detected the variation in the screw down pressure. However, as there is a limit for the raising or lowering speed of the screw, the gauge of certain portions of the plate will deviate from a set value if the screw were raised or lowered after an instant at which the screw down pressure varies. The length of such off gauge portions increases proportionate to the acceleration and presents a substantial loss of production. Further, there is the problem an incomplete compensation for the variation in the thickness of the oil film. More particularly, the variation in the roll peripheral speed and in the screw down pressure results in the variation of the thickness of the oil film of the bearings for back-up rolls, thus varying the set value of the roll gap. Since, in the prior art control system, this variation is the set value of the roll gap, it is controlled in terms of the variation in the screw down pressure, control is effected in the opposite direction. In other words, while the plate gauge decreases with the roll gap, in response to the increased screw down pressure, the prior art AGC system judges that the plate gauge is thick, and decreases the roll gap.
To eliminate this defect, an improvement has been proposed according to which an acceleration compensation is made wherein the roll gap is varied in response to the variation in the rolling speed. However, inasmuch as such an approach does not make an overall judgement by using an electronic computer, it is impossible to eliminate the effects due to the variation in the thickness of the oil film of the roll bearings caused by the steel species being rolled, and thickness and width of the finished plate. In the absence of the conventional AGC system, plate gauge varies as shown in FIG. 2, thus producing inferior parts. FIG. 2 shows the deviation of gauge in microns where a plate is rolled to have a gauge of 1.85 mm and a width of 800 mm at an acceleration of 0.496 m/sec It is therefore an object of this invention to provide a novel method of controlling a continuous hot rolling mill capable of maintaining the plate gauge at a predetermined value when the mill is accelerated.
Another object of this invention is to provide a new and improved method of controlling a continuous hot rolling mill which can decrease off-gauge products by controlling the roll gap and roll peripheral speed according to a predetermined pattern determined by an electronic computer by anticipating various factors that vary as a result of acceleration.
SUMMARY OF THE INVENTION According to this invention there is provided a method of controlling a continuous hot rolling mill including a plurality of mill stands, comprising the steps of anticipating variations in the screw down pressure, in the speed of the material on the delivery side and in the thickness of the oil film of the back-up roll bearing of each mill stand at the time of accelerating the rolling speed, classifying the widths of the finished plates, types and compositions of the steel being rolled, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations into a plurality of groups, computing an acceleration controlling schedule for each group that satisfies a relation that the product of the volume and speed of the material is constant on the delivery side by means of an electronic computer associated with the rolling mill, and controlling the roll gap and the roll peripheral speed according to said schedule for each mill stand whereby to maintain the tension of the material between adjoining stands at a constant value.
BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:
FIG. 1 is a diagram to show a prior art AGC system;
FIG. 2 is a graph to show the variation in the plate gauge during acceleration where the AGC system of the present invention is not used;
FIG. 3 is a diagram of a control system utilized to carry out the method of this invention; and
FIG. 4 is a graph showing the transitional variation of roll gaps and FIG. 5 is a graph showing the transitional variation of the roll peripheral speed.
DESCRIPTION OF THE PREFERRED EMBODIMENT According to this invention, various variables including widths of the finished plates, types and compositions of the material, plate gauges on the entrance side, pass speeds of the plates, the instants at which the accelerations are initiated, and accelerations are classitied into a plurality of groups and various combinations of these groups are taken into consideration in determining the acceleration control schedules.
The following computations are performed for each schedule. More particularly, the plate gauge on the delivery side of each stand is determined by taking into consideration three variables viz. (a), the variation with time in the screw down pressure caused by the variations in the temperature and the strain speed (i.e., strain rate which occur during acceleration (b), the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and (c) the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure. Then, for a seven stand system, for example, shown in FIG. 1, patterns of variations with time of the roll gap and roll peripheral speed that satisfy a relation that the product of the volume and speed of the material is constant on the delivery side are determined for each roll stand by using following equations uU) M 410) {1 +f41( i u( 1 +f (t))} wherein t: time,
S: set gap of the roll 11: plate gauge on the delivery side,
P: screw down pressure,
P0: zero adjust load,
M: mill constant,
6: sum of the thicknesses of the oil films on the side of the working rolls of the upper and lower back-up rolls,
80: sum of the thicknesses of the oil films on the side of the working rolls of the upper and lower back-up roll at the time of zero adjustment,
V: peripheral speed of the roll,
f: forward slip i: stand number,
j: type of the acceleration control schedule, and
Stand d: the pivot stand.
These values of the variation with time in the roll gap S,,(t) and of the variation with time in the roll peripheral speed V,,(t) are stored in an on-line computer associated with a continuous hot rolling mill.
Reference is now made to FIG. 3. The following control is used for each material. Information regarding the finished width, type and composition of the material, plate gauge on the delivery side, pass speed of the plate, the instant at which acceleration begins and acceleration are stored in the computer 1 as input data when the material passes through the last stand of a coarse mill. Then the acceleration control apparatus 2 determines a particular acceleration control schedule for the particular material based upon the command from the computer 1, and the differential function generator 3 receives an acceleration pattern for each stand from the acceleration control apparatus 2, selects a group of input data and determines the time variation between roll gaps at each stand, thereby giving commands for varying the roll gap and roll peripheral speed at each stand determined by the abovementioned acceleration control apparatus and differential function generator according to their prescribed pattern concurrently with the initiation of the rolling operation of the material. In this manner, an anticipation control of roll gaps and roll peripheral speed is performed during acceleration of the rolling operation.
EXAMPLE Variations with time in the roll gap and roll peripheral speed of the seventh stand under an acceleration control schedule for the following material are shown respectively in FIGS. 4 and 5.
Width of the finished plate 1,000 mm Type of the steel Co 1 Composition C 0.06, Mn 0.40
Plate thickness on the entrance side 30 mm Thickness of the finished plate 1.2 mm
Pass Speed of the plate (F7) 11.7 m/sec.
Time at which acceleration begins 3 sec (The instant at which the leading edge of the material reaches a thermometer on the delivery side of the finishing stand is taken as the origin of the time axis) Acceleration 0.888 m/sec Where the prior art method of control is applied during acceleration of the mill in which the material is accelerated after it has passed the finishing stand, the gauge of certain portion of the finished plate deviates from the prescribed value whereas according to this invention the roll gap and the roll peripheral speed of each stand are varied in accordance with a predetermined acceleration control schedule before the material reaches the finishing mill.
For this reason, it is possible to eliminate the production of off-gauge portions due to the time lag in the raising and lowering of the screw which has been inevitable in the prior art method of control wherein, in order to vary the roll gap and roll peripheral speed of each roll stand, the control is performed in response to the variation in the screw down pressure by anticipating the variation with time in the screw down pressure of each stand due to variations in the temperature and strain speed of the material created at the time of the acceleration, the variation with time in the speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure and the variation with time in the thickness of the oil film of the back-up roll bearing for the purpose of maintaining the product of the volume and speed of the material at a constant valve.
Further, since the variation with time of the thickness of the oil film of the back-up roll bearing has been taken into consideration, the conventional AGC system 4 does not operate in the opposite direction. Thus the invention provides a perfect anticipation control wherein the variation in the screw down pressure is also considered.
The invention is also applicable to a continuous cold rolling mill. In this case, by anticipating variations in the strain speed and in the thickness of the oil film of the back-up roll, the roll gap and the roll peripheral speed of each stand are varied according to a prescribed pattern for the purpose of preventing the gauge of the finished plate deviating from a predetermined value and preventing the tensions of the material between stands deviating from prescribed valves.
We claim:
1. A method of computerized control of a continuous rolling mill including a plurality of mill stands, comprising the steps of:
storing information concerning the finished widths,
types and compositions of material which are to be operated on, plate gauges on the entrance and delivery sides of the mill, pass speeds of the plates, the instants at which accelerations are initiated and the amounts of acceleration;
determining a particular acceleration control schedule of the mill stands for the particular material being operated on in accordance with a given relationship which is a function of at least: said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time in speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness in the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure;
determining the time variation between change in roll gaps at each successive stand as a function of at least: said determined acceleration control schedule, said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time and speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure;
varying the roll gap at each stand as a function of said determined time variation of roll gaps; and
controlling the roll peripheral speed at each stand as a roll peripheral speed of said determined acceleration pattern;
to thereby provide anticipation control of roll gaps and roll peripheral speed during acceleration of the rolling operation, such that the rolling schedule satisfies the relation that the product of the volume and speed of the material is constant on the delivery side of the mill.
2. The method according to claim 1 wherein said stored information is classified into groups of information items, the groups having a particular acceleration control schedule and roll gap change schedule that satisfies said relation that the product of the volume and speed of the material is constant on the delivery side of the mill.
3. The method according to claim 2 wherein said determining steps include determining into which groups of information items the operating conditions and characteristics for a given strip fall.
4. The method according to claim 2 whereinselected combinations of said groups satisfy said relation.
5. A method according to claim 1 wherein said particular acceleration control schedule and said time variation between change in roll gaps at each successive stand are determined to satisfy said relation that the product of the volume and speed of the material is constant on the delivery side by using the following equations:
ou) um) u( o a u 11( 0 ii u( r.l( 110) {1 frJ( u( (1 fij( (2 wherein t: time,
S: set gap of the roll,
h: plate gauge on the delivery side,
P: screw down pressure,
Po: zero adjust load,
M: mill constant,
8: sum of the thicknesses of the oil films on the side of the working roll of the upper and lower back-up rolls,
: sum of the thicknesses of the oil films on the side of the working rolls of the upper and lower back-up rolls at the time of zero adjustment,
V: peripheral speed of the roll,
f: forward slip i: stand number,
j: type of the acceleration control schedule, and
Stand 4: the pivot stand.
Claims (5)
1. A method of computerized control of a continuous rolling mill including a plurality of mill stands, comprising the steps of: storing information concerning the finished widths, types and compositions of material which are to be operated on, plate gauges on the entrance and delivery sides of the mill, pass speeds of the plates, the instants at which accelerations are initiated and the amounts of acceleration; determining a particular acceleration control schedule of the mill stands for the particular material being operated on in accordance with a given relationship which is a function of at least: said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time in speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness in the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure; determining the time variation between change in roll gaps at each successive stand as a function of at least: said determined acceleration control schedule, said stored information, the variation with time in the screw down pressure caused by the variations in the temperature and the strain rate of the plate which occur during acceleration, the variation with time and speed of the material on the delivery side caused by the variation in the forward slip due to the variation in the screw down pressure, and the variation with time in the thickness of the oil film of the back-up roll bearing caused by the variations in the peripheral speed of the roll and in the screw down pressure; varying the roll gap at each stand as a function of said determined time variation of roll gaps; and controlling the roll peripheral speed at each stand as a function of said determined acceleration pattern; to thereby provide anticipation control of roll gaps and roll peripheral speed during acceleration of the rolling operation, such that the rolling schedule satisfies the relation that the product of the volume and speed of the material is constant on the delivery side of the mill.
2. The method according to claim 1 wherein said stored information is classified into groups of information items, the groups having a particular acceleration control schedule and roll gap change schedule that satisfies said relation that the product of the volume and speed of the material is constant on the delivery side of the mill.
3. The method according to claim 2 wherein said determining steps include determining into which groups of information items the operating conditions and characteristics for a given strip fall.
4. The method according to claim 2 wherein selected combinations of said groups satisfy said relation.
5. A method according to claim 1 wherein said particular acceleration control schedule and said time variation between change in roll gaps at each successive stand are determined to satisfy said relation that the product of the volume and speed of the material is constant on the delivery side by using the following equations: Sij(t) hij(t) -(Pij(t) - Po ij ) /Mij -( delta ij(t) - delta o ij ) .................... (1) Vij(t) Hxj(t) . Vxj(t) . (1 + fxj(t) )/(hij(t) . (1 + fij(t) ) .............. (2) wherein t: time, S: set gap of the roll, h: plate gauge on the delivery side, P: scRew down pressure, Po: zero adjust load, M: mill constant, delta : sum of the thicknesses of the oil films on the side of the working rolls of the upper and lower back-up rolls, delta o: sum of the thicknesses of the oil films on the side of the working rolls of the upper and lower back-up rolls at the time of zero adjustment, V: peripheral speed of the roll, f: forward slip i: stand number, j: type of the acceleration control schedule, and x: denotes the ''''pivot'''' stand.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP45052579A JPS4937910B1 (en) | 1970-06-18 | 1970-06-18 |
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| US3733866A true US3733866A (en) | 1973-05-22 |
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| Application Number | Title | Priority Date | Filing Date |
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| US00151350A Expired - Lifetime US3733866A (en) | 1970-06-18 | 1971-06-09 | Method of controlling a continuous hot rolling mill |
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| US (1) | US3733866A (en) |
| JP (1) | JPS4937910B1 (en) |
| CA (1) | CA934032A (en) |
| DE (1) | DE2128237A1 (en) |
| FR (1) | FR2100785B1 (en) |
| GB (1) | GB1326993A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR3119150A1 (en) | 2021-01-28 | 2022-07-29 | Psa Automobiles Sa | FIXING OF COMPATIBLE UNDER-VEHICLE TRACTION BATTERIES SIDE IMPACT POST |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA932432A (en) * | 1968-02-02 | 1973-08-21 | Andrew W. Smith, Jr. | Predictive gauge control method and apparatus with automatic plasticity determination for metal rolling mills |
| US3618348A (en) * | 1968-05-21 | 1971-11-09 | Nippon Kokan Kk | Method of controlling rolling of metal strips |
-
1970
- 1970-06-18 JP JP45052579A patent/JPS4937910B1/ja active Pending
-
1971
- 1971-06-07 CA CA114981A patent/CA934032A/en not_active Expired
- 1971-06-07 DE DE19712128237 patent/DE2128237A1/en active Pending
- 1971-06-09 US US00151350A patent/US3733866A/en not_active Expired - Lifetime
- 1971-06-10 GB GB1987671*[A patent/GB1326993A/en not_active Expired
- 1971-06-18 FR FR7122337A patent/FR2100785B1/fr not_active Expired
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3851509A (en) * | 1972-11-06 | 1974-12-03 | Westinghouse Electric Corp | Rolling mill gauge control method and apparatus including speed correction |
| US5291108A (en) * | 1991-05-15 | 1994-03-01 | Mannesmann Aktiengesellschaft | Method of equalizing the torque on a drive of a pilger rolling mill |
| US5305624A (en) * | 1991-05-22 | 1994-04-26 | Mannesmann Aktiengesellschaft A Corp. Of The Federal Republic Of Germany | Sizing-stand group |
| WO2003103870A1 (en) * | 2002-06-06 | 2003-12-18 | Otkrytoe Aktsionernoe Obschestvo "Magnitogorsky Metallurgichesky Kombinat" | Method for optimising the production technology of rolled products |
| US20050178481A1 (en) * | 2002-06-06 | 2005-08-18 | Obschestovo S Organichennoi Otvetstvennostyu | Method for optimising the production technology of rolled products |
| US7354492B2 (en) | 2002-06-06 | 2008-04-08 | Otkrytoe Aktsionernoe Obschestvo “Magnitogorsky Metallurgichesky Kombinat” | Method for optimising the production technology of rolled products |
| US20100269556A1 (en) * | 2007-06-11 | 2010-10-28 | Arcelormittal France | Method of rolling a metal strip with adjustment of the lateral position of a strip and suitable rolling mill |
| US8919162B2 (en) * | 2007-06-11 | 2014-12-30 | Arcelormittal France | Method of rolling a metal strip with adjustment of the lateral position of a strip and suitable rolling mill |
| US20110041580A1 (en) * | 2007-11-02 | 2011-02-24 | Shigeru Ogawa | Rolling mill for a plate or a sheet and its control technique |
| US8720242B2 (en) * | 2007-11-02 | 2014-05-13 | Nippon Steel & Sumitomo Metal Corporation | Rolling mill for a plate or a sheet and its control technique |
| US20120004757A1 (en) * | 2009-03-13 | 2012-01-05 | Toshiba Mitsubishi-Electric Indus. Sys. Corp. | Optimization device |
| US20140367883A1 (en) * | 2012-02-08 | 2014-12-18 | Nitto Denko Corporation | Producing method of thermally conductive sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2128237A1 (en) | 1971-12-23 |
| CA934032A (en) | 1973-09-18 |
| FR2100785B1 (en) | 1974-08-19 |
| JPS4937910B1 (en) | 1974-10-14 |
| GB1326993A (en) | 1973-08-15 |
| FR2100785A1 (en) | 1972-03-24 |
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