The preferred implementing form of invention
Result as careful investigation and analysis and investigation, the inventor finds, at first, even form certain thrust (be rolled between plate and the work roll and/or work roll and enhancing roll between thrust) such adjusting (such as, adjust the angle of the crossing between the work roll up and down and/or the small angle of the crossing between work roll and the enhancing roll closely) situation under, as shown in Figure 2, be rolled the propulsive thrust of front edge of board after engaging-in (in the figure, measure by the load detector on the thrust bearing that is installed on work roll) and about the rolling load difference measured value (in the figure, the vibration of the impulsive force to following when engaging-in etc. is carried out smoothing processing and is represented) change significantly, through after certain time, keep stable.In addition, also confirmed to follow basically the variation of this measured value, the thickness of slab and the thickness of slab wedge shape that are rolled the front edge of board part after rolling change.
This phenomenon is interpreted as: general, since such as, working roller bearing seat and clamping plate are (in the occasion of the roll mill of the rotating shaft direction mobile device with work roll, the bearing block support position of this mobile device) between, the axial effective gap of rotation that has roll, be so-called play (below, be referred to as " thrust direction play "), the perhaps elasticity at this position (contact) distortion, so the position of (thrust is zero, or small value) during the idle running of roll chock before rolling is after rolling beginning, along thrust (or, such as occasion at 4 grades of roll mills, be rolled the thrust between plate and the work roll, and with work roll and strengthen thrust between the roll with joint efforts) the direction of effect, begin to move, from with the contacted moment of clamping plate, propulsive thrust begins to increase, and is enough to the moment of the propulsive thrust that the rotating shaft direction of supporting by the roll chock of this thrust (or it is with joint efforts) move in arrival, the rotating shaft direction of roll moves and stops, and propulsive thrust is stable.In addition, even be the occasion of certain value in this thrust, above-mentioned being understood that: owing to follow the variation of this propulsive thrust, act on the moment variations of each roll, so about the rolling load difference also change.Promptly, draw following conclusion, as long as above-mentioned thrust direction play, the strain of the rotating shaft direction support of roll chock exists, then from just producing the propulsive thrust after the rolling beginning in essence, about the variation of rolling load difference, and their thicknesss of slab that is rolled front edge of board of causing, the variation of thickness of slab wedge shape, so setting the depressing position in two moment respectively is absolutely necessary, so that the setting of the depressing position of the variation after this rolling beginning has been considered in formation in advance, that is each of stable moment of the rolling zero hour and propulsive thrust depressing position that is fit to constantly.
The present invention draws according to above-mentioned viewpoint.
With reference to the accompanying drawings, embodiments of the invention are specifically described.
Fig. 3 is for 4 grades of roll mills being a kind of schematic diagram of form of the plate roll mill of the example objective for implementation of representing to constitute method of the present invention, between up and down work roll 4a, 4b by up and down enhancing roll 5a, 5b supporting, is rolled being rolled plate 3.The two ends of up and down enhancing roll 5a, 5b are by strengthening roll chock 7a, 7b, 7c, 7d supporting, the two ends of up and down work roll 4a, 4b are by working roller bearing seat 6a, 6b, 6c, 6d supporting, and, carry out the adjustment of the axial position of rotation of roll by the 10a of roll travel mechanism, 10b up and down.To give screwdown gear 2a, 2b by the depressing position setting value that depressing position setting computer 1 calculates, depressing position will be adjusted to this setting value.Propulsive thrust detector 8a, 8b and rolling load detector 9a, 9b, 9c, 9d in the method for the invention, the judgement of the rate of change (stability) of the propulsive thrust after the rolling beginning that is used for will describing the back.In addition, in the present invention, upside, downside refer to be pressed the top of plate, or the below.In addition, the power that adopted in the following description for expression of Fig. 4 (comprises reaction force, load.The power of the direction of arrow among the figure just is) and the schematic diagram of size, the physical quantity of corresponding symbol indication is as described below:
T
WM: act on the thrust that is rolled between plate and the work roll;
T
WB, T
WB T, T
WB B: act on the thrust between work roll and the enhancing roll.Here, superscript character(SPS) T represents upside, and B represents downside.Below also identical;
T
W, T
W T, T
W B: the propulsive thrust that acts on work roll;
T
B, T
B T, T
B B: act on the propulsive thrust that strengthens roll;
P
W, P
D, P
W T, P
D T, P
W B, P
D B: act on the rolling reaction force (rolling load) that strengthens roll bearing point.Here, subscript character W represents active side, and D represents driving side.
P
Df, P
Df T, P
Df B: about rolling reaction force (load) poor.
(such as, P
Df T=P
W TOne P
D T)
h
B, h
B T, h
B B: act on the position of action point of the propulsive thrust that strengthens roll, and act on work roll and strengthen distance between the position of action point of the thrust between the roll.
In addition, below, the left and right difference of physical quantity is defined as (physical quantity of operation side) (physical quantity of driving side).
Fig. 1 is (1) of the present invention of expression, or the schematic diagram of an embodiment of (2) method that provides.Before rolling beginning, at first, prediction in rolling generation be rolled thrust between plate and the work roll and/or the thrust between work roll and the enhancing roll.Be rolled thrust T between plate and the work roll for this
WMPrediction, can adopt such as, disclosed prior art in the flat 6-154832 document of TOHKEMY.In addition, for the thrust T between work roll and the enhancing roll
WBPrediction, can carry out like this, promptly, employing is such as, disclosed prior art in the flat 10-263656 document of TOHKEMY, thrust in this thrust and last mill train (reverse rolling occasion) or the last rolled stock (occasion of tandem rolling) regarded as be equal to, according to this value of being equal to (same definite value), such as, adopt following formula (1), predict.
T
WB pred=F
1(T
WB idnt,P
t meas,P
t pred,
R
old,R
new,D,K) (1)
Wherein:
T
WB Pred: the predicted value of the thrust between work roll and the enhancing roll;
T
WB Idnt: last mill train, or the work roll in last material rolling and strengthen the value that is equal to of thrust between the roll;
P
t Meas: last mill train, or the actual value of the rolling load in last rolled stock rolling (about make a concerted effort);
P
t Pred: the predicted value that be fit to adopt the rolling load (about make a concerted effort) of the rolling mill train of method of the present invention;
R
Old: last mill train, or the rolling condition of last rolled stock (such as, thickness of slab, plate is wide, reduction ratio etc.);
R
New: the rolling condition in the rolling mill train that is suitable for method of the present invention;
D: the dimensional parameters group of roll mill;
K: the rigidity parameter group of roll mill.
Then, according to the predicted value T that is rolled the thrust between plate and the work roll
WM PredAnd/or the predicted value T of the thrust between work roll and the enhancing roll
WB Pred, and the rolling condition R that is fit to the rolling mill train of employing method of the present invention
NewDeng, that calculates the rolling zero hour depresses desired location S
1(depress desired location, that is, the left and right sides mean value component of the setting value of depressing position), S
Df 1(depress desired location, that is, and the left and right difference component of the setting value of depressing position), and the propulsive thrust T that acts on work roll
WThe moment that (below, as long as interrupt especially, it being abbreviated as " propulsive thrust ") is stable depress desired location S
2, S
Df 2
The calculating of depressing desired location in these two moment such as, can adopt following formula (2)~(5) to carry out.
S
1=F
2(T
WM pred,T
WB pred,P
t pred,h
aim,
R
new,D,K,) (2)
S
df 1=F
3(T
WM pred,T
WB pred,P
t pred,P
df pred,
h
df aim,R
new,D,K) (3)
S
2=F
4(T
WM pred,T
WB pred,P
t pred,h
aim,
R
new,D,K,) (4)
S
df 2=F
5(T
WM pred,T
WB pred,P
t pred,P
df pred,
h
df aim,R
new,D,K) (5)
Here,
P
Df Pred: be fit to adopt the left and right difference of predicting in the rolling mill train of method of the present invention that is rolled the face pressure between plate and the work roll;
h
Aim: the thickness of slab after rolling (can be width intermediate plate thickness, any one in the average thickness of slab of width.But in the following description, it is defined as thickness of slab in the middle of the width) desired value.
h
Df Aim: the desired value of the left and right difference of the thickness of slab after rolling (thickness of slab wedge shape).
The predicted value P of the left and right difference that the face between plate and the work roll that is rolled is pressed
Df PredCan according to such as, be rolled the left and right sides temperature difference of plate, thickness of slab wedge shape before rolling etc. and calculating.
Adopt depressing position setting computer 1,, calculate, rolling zero hour of having stored depressed desired location S according to above-mentioned formula (2) and (3)
1, S
Df 1Send screwdown gear 2a, 2b to,, before rolling beginning, depressing position is adjusted, begin rolling according to the mode that forms this desired location.As aforementioned, after rolling beginning, propulsive thrust begins to present variation, transfers to stable state.Depressing position setting computer 1, such as, by method described later, be judged to be the stable moment of propulsive thrust, calculate according to above-mentioned formula (4) and (5), the moment that the propulsive thrust of having stored is stable depress desired location S
2, S
Df 2, send screwdown gear 2a, 2b to, depressed position is modified to this desired location.
Resemble between work roll up and down, do not produce the effective angle of the crossing like that, be assumed to zero occasion in fact in the thrust that will be rolled between plate and the work roll, also can omit this thrust predicted value T in the right of above-mentioned formula (2)~(5)
WM PredInfluence item.
At the thrust T that is rolled between plate and the work roll
WMAnd the thrust T between work roll and the enhancing roll
WBCan be respectively at the rolling zero hour and stable these two moment in the moment of propulsive thrust, the occasion of predicting also can adopt the predicted value T that is rolled the thrust between plate and the work roll of the rolling zero hour in the calculating of formula (2) and formula (3)
WM Pred-1And the predicted value T of the thrust between work roll and the enhancing roll
WB Pred-1, in the calculating of formula (4) and formula (5), adopt the propulsive thrust predicted value T that is rolled the thrust between plate and the work roll in the stable moment
WM Pred-2And the predicted value T of the propulsive thrust between work roll and the enhancing roll
WB Pred-2, calculate the desired location of depressing in these two moment.
As 4 grades of roll mills shown in Figure 3, the occasion that has the contact interface between work roll and the enhancing roll on the edge up and down, replace above-mentioned formula (2)~(5), also can use employing each work roll and strengthen the predicted value of thrust between the roll up and down, such as, also can adopt following formula (2-1)~(5-1).
S
1=F
2 I(T
WM pred,T
WB T:p
red,T
WB B:pred,P
t pred,h
aim,
R
new,D,K,) (2-I)
S
df 1=F
3 I(T
WM pred,T
WB T:pred,T
WB B:pred,P
t pred,P
df pred,
h
df aim,R
new,D,K) (3-I)
S
2=F
4 I(T
WM pred,T
WB T:pred,T
WB B:pred,P
t pred,
h
aim,R
new,D,K,) (4-I)
S
df 2=F
5 I(T
WM pred,T
WB T:pred,T
WB B:pred,P
t pred,
P
df pred,h
df aim,R
new,D,K) (5-I)
Here,
T
WB T:pred: go up the thrust T between work roll 4a and the last enhancing roll 5a
WB TPredicted value;
T
WB B:pred: the thrust T between following work roll 4b and the following enhancing roll 5b
WB BPredicted value.
In addition, equally, in the roll mill more than 4 grades, roll mill with regard to type with the contact interface between a plurality of rolls, occasion in the predicted value that obtains the thrust between the roll that defines at the contact interface between each roll, such as, also can adopt following formula (2-II)~(5-II).
S
1=F
2 II(T
WM pred,T
WB l:pred,…,T
WB i:pred,
…,T
WB N:pred,P
t pred,h
aim,R
new,D,K,)(2-II)
S
df I=F
3 II(T
WM pred,T
WB l:pred,…,T
WB i:pred,
…,T
WB N:pred,P
t pred,P
df pred,h
df aim,R
new,D,K,)(3-II)
S
2=F
4 II(T
WM pred,T
WB l:pred,…,T
WB i:pred,
…,T
WB N:pred,P
t pred,h
aim,R
new,D,K,)(4-II)
S
df 2=F
5 II(T
WM pred,T
WB l:pred,…,T
WB i:pred,
…,T
WB N:pred,P
t pred,P
df pred,h
df aim,R
new,D,K,)(5-II)
Here,
T
WB I:pred: the predicted value of the thrust of the contact interface between the roll of i number (i is illustrated in the integer between 1~N).
Obviously, according to various restriction conditions (such as, the prediction of the thrust of the contact interface between the specific roll is impossible), or precondition (such as, not lubricated fully to the contact interface between the specific roll, thrust does not produce in fact), the occasion of the thrust of the contact interface between the roll of consideration part can adopt the formula except the thrust of this roll shop building contact interface.As 2 grades of roll mills, the occasion that does not have the contact interface between the roll, lubricate sufficient management or the sufficient of the contact interface between the roll because of the play between roll chock~shell, the contact interface place between whole rolls does not produce the occasion of thrust in fact, or because of device-restrictive, the prediction of the thrust of the contact interface between whole rolls is situations such as impossible occasion, do not consider the occasion of the thrust of the contact interface between whole rolls, be fit to adopt (1) of the present invention described method, such as adopting following formula (2-III)~(5-III), replace above-mentioned formula (2)~(5).
S
1=F
2 III(T
WM pred,P
t pred,h
aim,R
new,
D,K,) (2-III)
S
df 1=F
3 III(T
WM pred,P
t pred,P
d fpred,h
df aim,
R
new,D,K,) (3-III)
S
2=F
4 III(T
WM pred,P
t pred,h
aim,R
new,
D,K,) (4-III)
S
df 2=F
5 III(T
WM pred,P
t pred,P
df pred,h
df aim,
R
new,D,K,) (5-III)
At the propulsive thrust of the rolling zero hour in above-mentioned Fig. 2 shown in a schematic way, be assumed to roughly zero occasion, rotate axial dynamic balance condition according to the roll that acts on work roll that provides in the following formula (6), according to the thrust T that is rolled between plate and the work roll
WMPredicted value, ad hoc obtain the thrust T between this work roll constantly and the enhancing roll
WB, thus, in the setting of the depressing position of the rolling zero hour, need not work roll and strengthen the predicted value of the thrust between the roll, (3) described method of the present invention is applicable.
T
WB T-T
WN=T
W T=0 (going up work roll)
T
WN-T
WB B=T
W B=0 (following work roll) (6)
But, owing to the counter-force value in the stable moment of propulsive thrust is generally non-vanishing, so in the calculating of depressing desired location of Keing at this moment, be rolled the thrust T between plate and the work roll
WM, and the thrust T between work roll and the enhancing roll
WBThe predicted value of these two thrusts is necessary.In addition, if consider the equilibrium condition of moment, owing to the predicted value according to each thrust, the rolling load difference P about obtaining
DfSo, also can adopt following better simply formula (2-IV)~(5-IV), to replace above-mentioned formula (2)~(5).
S
1=h
aim-ΔS(P
t pred)-P
df pred-1
{C
w(P
t pred/2)-C
D(P
t pred/2)}
/4 (2-IV)
S
df 1=[h
df aim-{ΔS
w(P
t pred/2-
ΔS
D(P
t pred/2)}-P
df pred-1
{C
w(P
t pred/2)+C
D(P
t pred/2)}
/2]a
B/b (3-IV)
S
2=h
aim-ΔS(P
t pred)-P
df pred-2
{C
w(P
t pred/2)-C
D(P
t pred/2)}
/4 (4-IV)
S
df 2=[h
df aim-{ΔS
w(P
t pred/2)-
ΔS
D(P
t pred/2)}-P
df pred-2
{C
w(P
t pred/2)+C
D(P
t pred/2)}
/2]a
B/b (5-IV)
Here:
Δ S (P): the rolling, drawing amount (with plate wide central authorities define) of rolling load (about make a concerted effort) during for P;
Δ S
w(P): the variable quantity of the operation side mill opening when acting on rolling load that the operation side strengthens roll bearing point and being P (with the widthwise edges location definition of the operation side that is rolled plate);
Δ S
D(P): the variable quantity of the driving side roller aperture when acting on rolling load that driving side strengthens roll bearing point and being P (the cross direction marginal position with the driving side that is rolled plate defines);
C
w(P): the Δ S when acting on rolling load that the operation side strengthens roll bearing point and being P
w(P) tangent slope (compliance);
C
D(P): the Δ S when acting on rolling load that driving side strengthens roll bearing point and being P
D(P) tangent slope;
B: plate is wide;
a
B: the distance between the left and right sides supporting-point of enhancing roll;
Δ S (P), Δ S in the above-mentioned formula
w(P) and Δ S
D(P) can determine according to dimensional parameters of load measurement result, rolling condition and the roll mill of for example touch roll being locked (キ ス ロ one Le Parties め Write body) etc.In addition, P
Df Pred-1Be the predicted value of the rolling load difference about the rolling zero hour, P
Df Pred-2The predicted value of the rolling load difference about when stablizing for propulsive thrust as above-mentioned, according to the equilibrium condition of moment, adopts following formula (7), and calculate (8).
P
df pred-1=2T
WM pred(D
B+h
B T)/a
B+
{b
2/(6a
B)}P
df pred (7)
P
df pred-2={T
WM predD
W+T
WB pred(D
W+2h
B T)}
/a
B+{b
2/(6a
B)}P
df pred (8)
Here,
D
DW: the work roll diameter.
The stability of propulsive thrust also is judged to be from rolling, moment of the stipulated time that experience is predetermined and stablizing.At this moment, for fear of the influence of following the engaging-in impulsive force that is rolled plate, the influence of the response time of screwdown gear 2a, 2b is decided to be from rolling, the moment of experience more than at least 0.2 second.Occasion at common plate roll mill, less than 0.2 second the time, because of this impulsive force, the influence in the reaction time of screwdown gear, the possibility of rolling load, propulsive thrust marked change increases, such as, in the occasion that adopts (5) described method of the present invention, because depressing position setting changes terrifically, producing the danger of plate by fault increases, so be the condition of necessity greater than 0.2 second.Also can suppose the time when propulsive thrust is stablized, with after the rolling beginning be rolled between plate and the work roll, roll rotation axial relative (lift-over) sliding distance is proportional substantially, (that is, be rolled relative slip angle θ between roller and the work roll according to the intersecting angle between the work roll up and down
Slip* 2) with the rotary distance that is rolled the work roll surface of roller after engaging-in (L: the time integral value of the work roll peripheral speed of the relative rolling zero hour), such as, with this relative sliding distance (=L * (sin θ
Slip)) be preset distance L
StableThe moment, be defined as the stable moment of propulsive thrust.In addition, be fit to adopt so-called learning art,, set or revise one by one the elapsed-time standards that is used to judge according to the rolling actual result of last rolled stock or last mill train.
In addition, the occasion that has the testing agency of check propulsive thrust at the roll mill that is adopted, such as, expression in a schematic way in aforesaid Fig. 3 roll mill, between work roll 4a, 4b and the 10a of roll travel mechanism, 10b, occasion with propulsive thrust detector 8a, 8b is fit to adopt the 9th described method of the present invention (with reference to Fig. 5).Such as, also can monitor time rate of change (pace of change) as the measured value of propulsive thrust detector 8a, the 8b index of stability, after the rolling beginning, in the absolute value of this rate of change the moment, judge that propulsive thrust is stable less than predetermined less numerical value.Equally in the occasion of the roll mill that does not have propulsive thrust detector 8a, 8b, such as, rolling load detector 9a, the 9b of upside, the rolling load difference P about momentarily obtaining can be adopted
Df T, at this moment, can judge that propulsive thrust is stable in the absolute value of the time rate of change of this rolling load difference the moment less than predetermined less numerical value.This situation is understood according to following phenomenon, and this phenomenon refers to acting on the propulsive thrust T of work roll
wThe indeclinable in fact occasion of external force in addition, the variation delta P of the rolling load difference of the rolling relatively zero hour
Df(=[P
Df(t): present P constantly
Df] [a P
Df(O): the P of the rolling zero hour
Df]), with the variation delta T of propulsive thrust
W(=[T
W(t): present T constantly
W]-[T
W(O): the T of the rolling zero hour
W]) between relation formula (9) expression of deriving from the equilibrium condition of moment (variable quantity), in addition, its time rate of change is represented by formula (9-I).
In addition, for any side of upside, downside, two formula are all set up.
ΔP
df=ΔT
W(D
W+2h
B)/a
B (9)
d(P
df(t))/d
t={d(T
W(t))/dt}
(D
w+2h
B)/a
B (9-I)
Here,
D (P
Df(t))/and dt: the time rate of change of the rolling load difference about the present moment;
D (T
W(t))/and dt: the moment rate of change of present propulsive thrust constantly.
But, because the detected value of rolling load seldom is subjected to being rolled the influence of the impulsive force of front edge of board when engaging-in, so preferably adopt aforesaid propulsive thrust detector 8a, 8b.Can think: above-mentioned propulsive thrust measured value, the time rate of change of the rolling load difference about rolling relatively starting point relies on the above-mentioned time rate of change that plate and the roll between the work roll rotate axial relative sliding distance that is rolled, promptly, relative sliding velocity, after rolling beginning, the occasion that the roll rotary speed changes also can adopt with the roller rotary speed and remove the time rate of change of propulsive thrust measured value or rolling load difference and the value that obtains.In addition, best, such as, for with the propulsive thrust on acting on work roll stable the time between being engraved in up and down different occasion corresponding, propulsive thrust detector and/or rolling load detector are arranged at the both sides of upside, downside, according to both sides' detected value, judge propulsive thrust T
WStable (such as, satisfy the moment of above-mentioned condition in any one of the detected value of upside, downside, judge propulsive thrust T
WStable), still, the setting of any side in only also can be up and down detects.Obviously, also can be at upside and/or downside, be provided with propulsive thrust detector and rolling load detector the two, also can be arranged on different up and down detectors (such as, downside is the rolling load detector, upside is the propulsive thrust detector).In the occasion of the roll mill more than 5 grades, also can be relatively at work roll with strengthen part or all of intermediate calender rolls group between the roll, the propulsive thrust detector is set.The testing agency of propulsive thrust is fully for the judgement of the rate of change of above-mentioned detected value, there is no need to use the such absolute value precision of so-called load cell (ロ one De ヤ Le), the detector that resolution ratio is good.
In addition, in the occasion of roll mill with propulsive thrust detector and/or independent left and right rolling load detector, also can be after stable moment at above-mentioned propulsive thrust, not only according to the predicted value of above-mentioned thrust, and, adjust depressing position according to the measured value of above-mentioned detector.Such as, in this occasion, at propulsive thrust after stable moment, the equilibrium condition that is considered as the moment of above-mentioned (8) formula description is set up, if with about the measured value of rolling load difference be updated to the left side of this formula, then can be with the predicted value T that is rolled the thrust between plate and the work roll on this formula the right
WM Pred, or the predicted value T of the thrust of the contact interface between work roll and the enhancing roll
WB PredIn any one obtain as presumed value that (face between plate and the work roll that the is pressed left and right difference of pressing adopts predicted value P
Df Pred).Will be based on the presumed value of the thrust of this measured value, be changed to the predicted value of the corresponding thrust in the right in above-mentioned formula (4)~(4-III) and/or the formula (5)~(5-III), desired location is depressed in calculating, thus, only can be higher than depressing position adjustment easily based on the precision of the occasion of predicted value.Obviously, with rolling before the bigger occasion of difference of predicted value adjust depressing position constantly and change excessive possibility owing to produce, so also can adopt these two values of predicted value and presumed value, carry out the depressing position adjustment.
Self-evident, can when the adjustment of depressing position of the present invention, adopt following so-called figure control method, it is the known control method of the acceleration and deceleration processing etc. of so-called operational ton, this image control method refers to from the rolling zero hour, during the stable moment of propulsive thrust, employing is the function of independent variable with the predetermined elapsed time, two depressing positions between the moment are changed smoothly, this known control method referred in the stable moment of propulsive thrust, based on the desired location of depressing of the predicted value before rolling, transfer at leisure then according to what above-mentioned each constantly measured value (or presumed value of the thrust of calculating according to this measured value) was calculated and depress desired location.
About the shell rigidity be uniform, and be rolled the specific electric load and roll deformation amount (the flat amount of the contact interface between plate and work roll and the roll, amount of deflection etc.) about the pass between ties up to uniformly under the situation of occasion etc., in above-mentioned each thrust, when propulsive thrust did not impact the thickness of slab after rolling in fact, the present invention also can only be used to depress the left and right difference S of desired location
Df 1, S
Df 2Calculating (adopting the calculating of above-mentioned formula (3)~(3-III) and formula (5)~(5-III)), the depressing position adjustment.In this occasion, depress the left and right sides mean value S of desired location
1, S
2Calculating can be by general use in the past, carry out such as, following formula (10).
S
1=S
2=F
8(P
t pred,R
new,D,K,…) (10)
Also can adopt so-called learning art in the method for the present invention, according to last mill train, or the rolling actual result till the last rolled stock, such as, calculate the study item S that depresses desired location
Lrn-1, S
Lrn-2, S
Df Lrn-1, S
Df Lrn-2, also add these values (such as handle and aforesaid formula (2)~(5) ... corresponding each the study item in the right (2-III)~(5-III) carries out add operation), calculate and depress desired location.
Embodiment
In prime has 3 the series connection milling train of paired staggered form (ペ ア Network ロ ス) roll mill, adopt (3) and (9) described method of the present invention.At this moment, be rolled thrust T between plate and the work roll
WMPrediction at paired staggered form roll mill, adopt following formula (11), for other roll mill, be zero.In addition, for the thrust T between work roll and the enhancing roll
WB, the rolling actual result according to when the last rolled stock is equal to the coefficient entry β in following formula (12) formula, adopts this formula, predicts.
T
WM pred=α(θ)P
t pred (11)
T
WB pred=βP
t pred (12)
Here, α (θ) is at the definite coefficient entry of each angle of the crossing, and it draws from being equal to according to the rolling actual result data of the various angles of the crossing in advance.In addition, (12) described method of the present invention adopted in the stable judgement of the propulsive thrust after the rolling beginning, with be arranged at upside about the measured value substitution of rolling load detector from following (9-II) that aforementioned formula (9) derives, calculate the presumed value of the variable quantity of propulsive thrust, the value that obtains for removing the time rate of change of this presumed value (absolute value) with the work roll rotary speed, with the moment of various rolling actual result data, be judged as stable less than predetermined judgment value.
ΔT
w={P
df(t)-P
df(O)}
a
B/(D
W+2h
B) (9-II)
Consequently, the thickness of slab that is rolled front edge of board after not only rolling, thickness of slab wedge shape precision improves, and the amount of warpage of front end also significantly alleviates, and the plate that the so-called wrinkle that are rolled front edge of board cause also reduces by half basically by accident.