JPH0659496B2 - Equipment for estimating mill spring constant and material plasticity coefficient in continuous rolling mill - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mill spring constant and material plasticity coefficient estimating device in a continuous rolling mill, and more particularly to a device for accurately estimating the mill spring constant and material plasticity coefficient of each stand. It is a thing.

[Prior Art] First, general operation of a continuous rolling mill will be described with reference to the drawings.

FIG. 2 is an explanatory diagram for explaining how the stands are rolled. In the figure, (1a), (2a) and (3a) are the upper work rolls of each stand, and are collectively referred to as simply the upper work rolls hereinafter. (1b), (2b) and (3b) are lower work rolls of each stand, and are collectively simply referred to as lower work rolls hereinafter.

h is the plate thickness of each stand after rolling, and S is the gap between the upper work roll and the lower work roll when the upper work roll and the lower work roll are not loaded (this is called the no-load roll gap). That is, the unloaded roll gap S is the gap when the rolling reaction force F received by the stand itself when not loaded is zero.

As shown in the figure, when the material (10) having the plate thickness H is conveyed in the case of the unloaded roll gap S, the upper work roll and the lower work roll are pushed up and the gap S also changes. This gap S
Is changed, the stand applies a load to the upper work roll and the lower work roll and rolls.

At this time, the reaction force received by the stand itself is called rolling reaction force.

The relationship between the rolling reaction force F, the unloaded roll gap S, and the plate thickness h exiting the rolling mill will be described below.

FIG. 3 is an explanatory diagram for explaining the relationship between the rolling reaction force F, the plate thickness h exiting the rolling mill, and the plasticity.

In the figure, the curve (a) shows that as the rolling reaction force F increases, the strip thickness h on the delivery side of the rolling mill increases. This curve
The inclination M near the operating point in (a) is called a mill spring constant, and is one of the important characteristic constants in rolling mill control.

Using this mill spring constant M, the strip thickness h on the delivery side of the rolling mill (hereinafter referred to as the delivery side strip thickness) is generally represented by h = S + F / M.

The roll gap is generally detected by the oil column height of the reduction cylinder (hereinafter referred to as the reduction screw) or the movement amount of the reduction screw, and the mill spring constant M is the third.
As is clear from the figure, the rolling reaction force F changes.

Therefore, the above formula of the plate thickness h is used by transforming it into the formula of the differential amount for handling the variation amount, as shown in the formula (1) with reference to the plate thickness at a certain point. is there.

Further, in order to obtain the target plate thickness h, the unloaded roll gap S is changed to the gap S ′.

Then, a predetermined portion of the reduction screw when the reduction screw reduces the material is called a reduction position, and when the reduction screw reduces the material, a predetermined portion of the reduction screw changes. That is, the reduction position of the reduction screw fluctuates, and this variation amount is referred to as the reduction position change amount ΔS, which is the change amount of the reduction position of the reduction screw per a predetermined time, which is based on the previous reduction position and the reference value. This is the amount of change from the current rolling position and is expressed by the following formula.

S′−S = ΔS (hereinafter referred to as the amount of change in the rolling position), and in the process of changing the plate thickness H to h, the rolling reaction force F changes to the rolling reaction force F ′. Is expressed as F′−F = ΔF (hereinafter referred to as the amount of change in the rolling reaction force F), and the amount of change Δh in the plate thickness h at this time is Δh = ΔS + (ΔF / M) ……………… ( 1) and is called a gauge meter type.

The curve (b) shows that the rolling reaction force F increases as the plate thickness is reduced. This is because as the plate thickness is reduced, the force of the material that tends to be plastic increases. The slope Q near the operating point of the curve (b) is particularly called the material plasticity coefficient, which is generally expressed by the following equation.

Q = ΔF / (ΔH-Δh) (2) ΔH; Amount of change in strip thickness on the rolling mill entrance side As shown in FIG. 4, the unloaded roll gap S and the strip thickness H before rolling are When given, the rolling reaction force F and the sheet thickness h after rolling are determined by the intersection (balance point) between the curve (a) and the curve (b).

Therefore, in controlling the plate thickness of the rolled material, it is necessary to accurately estimate the mill spring constant M and the material plasticity coefficient Q.

Therefore, in the past, as a method of knowing the mill spring constant M and the material plasticity coefficient Q, a method of actual measurement or trial rolling work was used. However, time is required for the rolling, and much cost is wasted. There was also a problem above.

On the other hand, there is a device described below as a device for simultaneously estimating the mill spring constant M and the material plasticity coefficient Q based on the measurement signal in the rolled state.

FIG. 4 is a schematic configuration diagram of a conventional continuous rolling mill. In the figure, it is assumed that there are three rolling mills.

In the figure, (1) is the first stand, (2) is the second stand, (3) is the third stand, (1a) is the upper working roll of the first stand (1), and (1b) is the third stand. The lower work roll of the one stand (1) rolling mill, (2a) the upper work roll of the second stand (2) rolling mill, (2b) the lower work roll of the second stand (2) rolling mill, ( 3a) is the upper working roll of the third stand (3) rolling mill, and (3b) is the lower working roll of the third stand (3) rolling mill.

(1c) ~ (3c) is placed on the work roller side under each stand,
A rolling reaction force detection device for detecting the amount of change in rolling reaction force at each stand, 7 is a mill spring constant and a material plasticity coefficient in a continuous rolling mill based on the amount of change in thickness Δh from a delivery side plate thickness detection device described later. Is an estimating device for estimating.

(10) is the rolled material rolled by the continuous rolling mill, (40) is the output sheet thickness that detects the sheet thickness of the rolled material output from the third stand, which is the final stand, and outputs the sheet thickness change amount for each detection. It is a detection device (hereinafter referred to as a plate thickness detection device).

H is the plate thickness of the material before being rolled by the continuous rolling mill, h1 is the plate thickness after being rolled by the rolling mill of the first stand (1),
h2 is the plate thickness after being rolled by the rolling mill of the second stand (2), and h3 is the plate thickness after being rolled by the rolling mill of the third stand (3) which is the final stand.

The continuous rolling mill as described above is called a gauge meter system.In the gauge meter system, the plate thickness after rolling is determined by the roll gap during rolling, and the roll gap during rolling is the unloaded roll gap and the rolling when loaded. It is decided by the amount of deformation of the machine.

Further, the amount of deformation of the rolling mill is determined by the rolling load, and since the deformation of the rolling mill is elastic deformation, it is assumed to be proportional to the rolling load.

In such a continuous rolling mill, the plate thickness change amount Δh3 during rolling at the third stand (3), which is the final stand, is Δh3 = ΔS3 + ΔF3 / M3 (3) ΔS3: third stand ( 3) Rolling position change amount ΔF3; Rolling reaction force change amount of the third stand (3) M3: Mill spring constant of the rolling mill of the third stand (3) Also, the rolling reaction force of the third stand (3) during rolling. The amount of change in force ΔF3 is ΔF3 = Q3 (Δh2 −Δh1) ………… (4) Δh2 ； The amount of change in strip thickness entering the third stand (3) Q3 ； The material plasticity coefficient when rolling at the third stand (3) Is shown as.

Further, in the second stand (2), Δh2 = ΔS2 + ΔF2 / M2 (5) ΔS2: Change in rolling position of the second stand (2) ΔF2: Change in rolling reaction force of the second stand (2) Amount M2; Mill spring constant of the rolling mill of the second stand (2) ΔF2 = Q2 (Δh1 -Δh2) ... (6) Δh1; Amount of change in plate thickness on entry side into the second stand (2) Q2; Second stand It is shown as the material plasticity coefficient when rolled in (2).

Further, in the first stand (1), Δh1 = ΔS1 + ΔF1 / M1 (7) ΔS1: Change in rolling position of the first stand (1) ΔF1: Change in rolling reaction force of the first stand (1) Amount M2; Mill spring constant of the rolling mill of the first stand (1) ΔF1 = Q1 (ΔH-Δh1) ... (8) ΔH; Amount of change in inlet plate thickness entering the first stand (1) Q1; First stand It is shown as the material plasticity coefficient when rolled in (1).

Next, the case of obtaining the actual mill spring constant M and material plasticity coefficient Q of each stand will be described below.

For example, paying attention to a certain point on the center line of the material (10) (hereinafter referred to as "attention point"), and letting this attention point be the rolling reaction force value F1 'at the first stand when passing through the first stand (1),
The change amount of the rolling reaction force F1 at this time is ΔF1 '.

Also, the actual gap S1 'measured between the upper and lower work rolls before rolling is defined as ΔS1', and the rolling position change amount at this time is defined as ΔS1 ', and the rolling reaction at the time when the same point passes through the second stand (2). Let the force value be F2 ', the rolling reaction force change amount of this F2' be ΔF2 ', the actual gap S2' between the upper and lower work rolls before rolling, and the rolling position change amount in this stand be ΔS2 '. Further, the rolling reaction force change amount of the rolling reaction force value F3 'when passing through the third stand (3) is ΔF3.
, And the gap S3 'between the upper and lower work rolls before rolling, and the amount of change in the rolling position at this stand is .DELTA.S3'.

In this case, the rolling reaction force change amount ΔF ′ is defined as a predetermined position of the reduction screw when the reduction screw reduces the material, and when the reduction screw reduces the material, a predetermined portion of the reduction screw fluctuates. To do. That is, the rolling position of the rolling screw changes. Then, the rolling reaction force varies with this variation. Therefore, the amount of change ΔF ′ of the rolling reaction force is the amount of change in the rolling reaction force per predetermined time, and is the amount of change between this reference value and the rolling reaction force of this time with reference to the previous rolling reaction force. .

Then, the plate thickness detecting device (40) arranged at a predetermined position on the exit side of the third stand (3) which is the final stand detects the plate thickness hx ′ as the rolled material reaches this position. Then, the previous sheet thickness detection value hx 'is set as a reference sheet thickness, and the sheet thickness variation amount Δhx' of the rolled material is sequentially obtained from the reference sheet thickness and the present sheet thickness detection value hx '.

That is, Δhx ′ is the amount of change between the previous thickness and the current thickness of the rolled material at the position of the thickness detection device (40), and Δhx ′ = Δhx1 ′, Δhx2 ′ ……………… Δhx
m '.

Further, Δhx ′ is such that Δhx ′ = (ΔFx ′ / M) + ΔSx ′ ... (D) holds.

When the plate thickness detecting device (40) measures the plate thickness change amount Δhx ′, the plate thickness change amount Δh3 ′ at the stand when the measurement point is immediately below the third stand (3) is Δh3 ′. = (ΔF3 ′ / M3) + ΔS′3 (9), and the rolling reaction force change amount at this time is ΔF3 ′ = Q3 {[(ΔF2 ′ / M2) + ΔS2 ′] − Δh′3. (10) Further, when passing through the second stand (2), ΔF2 '= Q2 {[(ΔF1' / M2) + ΔS1 ']-Δh'2 ... (11) is established and the first stand is established. When passing through (1), it is clear that the equations of .DELTA.F1 '= Q1 (.DELTA.H'-. DELTA.h'1) ... (12) hold.

From these relationships, the estimation device (7) is
When {Δhx ', ΔF3 x', ΔS3 x '} in (3) is measured, the mill spring constant M3 is estimated based on the above equation (D), and this result is And

Then, in the above equation (9), this estimated By substituting the value of the above, the plate thickness change amount Δh3 ′ immediately below the third stand (3) when the third stand (3) rolls the point of interest of the rolled material is obtained. That is, the third stand
When rolling the point of interest of the rolled material in (3), {Δh3 ′,
This means that ΔF3 ′, ΔS3 ′} has been obtained.

Further, the material plasticity coefficient Q3 at the third stand (3) and the mill spring constant M2 at the second stand are estimated based on the equation (10) using the measured values {ΔF2 ', ΔS2'}.

According to the above equation (9), Δh3 'when the above-mentioned point of interest is rolled by the third stand (3) is obtained, and the rolling reaction force change amount at the third stand (3) at this time is obtained. Is ΔF3 ', as shown in the equation (10), ΔF3' = Q3 {[(ΔF2 '/ M2) + ΔS2']-Δh3 '. Therefore, from the equation (4), ΔF3' = Q3 ( .DELTA.h2 '-. DELTA.h3'), therefore, based on experience, statistical data, etc., .DELTA.h2 'immediately below the stand in the previous stage and the third stand To estimate.

And the estimated value The measured values {ΔF1 ′, ΔS1 when the second stand (2) rolls the point of interest based on the above equation (5)
′}, Δh1 ′ at the first stand (1) is obtained, and the material plasticity coefficient Q2 at the second stand (2) and the mill spring constant M1 at the first stand are estimated. .

Similarly, the mill spring constant and the material plasticity coefficient of all stands are estimated in the same manner.

[Problems to be Solved by the Invention] However, in such a conventional apparatus, the mill spring constant Mi and the material plasticity coefficient Qi at a certain stand are set.
In order to know, it is necessary to know the entrance side plate thickness at that stand with high accuracy.If a plate thickness measuring instrument is not installed on the entrance side of each stand as in the above device, the mill spring in the stand at the previous stage The constant must be known.

For this reason, when the strip thickness measuring device is not installed on the entrance side of each stand, the measurement value of the strip thickness detecting device arranged on the exit side of the final stand and the rolling reaction force change amount ΔF ′ and The mill spring constant M of the final stand is estimated from the rolling position change amount ΔS ′, and the entry side plate thickness entering the final stand is estimated from experience based on this estimation result, and the material plasticity coefficient Q of this stand is calculated from a complicated calculation formula. Since the mill spring constant of the preceding stage was obtained and the mill spring constant and the material plasticity coefficient of the stand of each preceding stage were similarly estimated, there was a problem that there was a problem in the estimation accuracy.

Then, the mill spring constant and the material plasticity coefficient Q, which are unknown parameters, need to be estimated at the same time in order to improve the responsiveness. Generally, the simultaneous estimation can be estimated by a complicated determinant, for example, (10) For simultaneous estimation of {Q3, M2} in the equation, {ΔF3 ', ΔF2'}
However, in reality, ΔF 2 ′ at the second stand and ΔF 3 ′ at the third stand, which correspond to the same point on the plate, are strongly mutually strong as shown in the above equations. It is influential.

Therefore, the estimated values of the mill spring constant and the material plasticity coefficient of each stand, which were estimated based on the measured values at the final stand, were estimated values in which mutual errors accumulated.
There was a problem that rolling accuracy deteriorates.

The present invention has been made to solve the above problems, and the errors of the mill spring constant and the material plasticity coefficient of each rolling mill do not accumulate, and the rolling accuracy can be improved by a simple calculation. The object is to obtain a mill spring constant and material plasticity coefficient estimation device in a rolling mill.

[Means for Solving the Problems] The mill spring constant and material plasticity coefficient estimating device in the continuous rolling mill of the present invention is provided with a plate thickness detecting device on the exit side of the final stand, and each stand is provided with a rolling position measuring device and a rolling anti-rolling device. In estimating the mill spring constant and material plasticity coefficient of a continuous rolling mill equipped with a force measuring device, a rolling position change signal during material rolling from each rolling position measuring device and rolling during rolling from a rolling reaction force measuring device A storage device that stores the reaction force change signal, a plate thickness change signal measured by the plate thickness measurement device, and a plate thickness measurement point on the rolled material when measured by this plate thickness measurement device are directly below the final stand. The mill spring constant of the final stand is calculated based on the stored rolling position change signal and rolling reaction force change signal when the 1 means,
A second means for estimating the mill spring constant of each rolling mill by multiplying the mill spring constant of the final stand calculated by the first means by a predetermined ratio for each rolling mill of the preceding stage, and this second means Based on the estimated mill spring constant of each rolling mill at the preceding stage and the stored rolling reduction change signal and rolling reaction force change signal at each stand when the plate thickness measurement point was immediately below each stand, The third means for calculating the change amount of the outlet side plate thickness, and the change amount of the inlet side and outlet side plate thicknesses of the stand obtained by the plate thickness measuring device or the third means, and the plate thickness measurement point were directly under the stand. And a fourth means for calculating the material plasticity coefficient of the stand on the basis of the stored rolling reaction force change signal at that time.

[Operation] According to the present invention, the rolling position change signal during rolling and the rolling reaction force change signal from the rolling position measuring device provided in each stand are stored.

Also, the plate thickness change signal measured by the plate thickness detection device arranged on the exit side of the final stand and the plate thickness measurement point on the material when this plate thickness detection device detects the plate thickness are directly below the final stand. When there is, the mill spring constant of the final stand is calculated from the stored rolling position change signal of the final stand and the rolling reaction force change signal.

Then, the mill spring constant of each final rolling mill is estimated by multiplying the mill spring constant of this final stand by the ratio of each rolling mill in the previous stage, and the mill spring constant and plate thickness of each estimated previous rolling mill are estimated. When the measurement point is directly under each stand, the output side plate thickness change amount of the stand is calculated from the rolling position change signal and the rolling reaction force change signal, and the output side plate thickness change amount and the input side plate thickness change amount are calculated. And the rolling reaction force change signal when the plate thickness measurement point is directly under the stand, the material plasticity coefficient of the stand is calculated.

[Embodiment] FIG. 1 is a schematic configuration diagram of an apparatus of the present invention. In the figure, the number of stands is six. In the figure, 1-3, 1a-3a, 1b-3b, 1c-3c, 1
0 and (40) are the same as above.

4 is a 4th stand, 5 is a 5th stand, 6 is a 5th stand, 1d-6d is the pressure reduction position measuring device with which each stand was equipped.

The rolling position measuring devices 1d to 6d use the rolling position before each screw as a reference value, and the amount of change from the rolling position at this time is the rolling position change amount ΔS, and the rolling position change signals ΔS1, ΔS2, ... Output as ΔS6.

Rolling reaction force detectors (1c) to (6c) are respectively arranged on a stand, and the rolling reaction force change amount during rolling, respectively,
The rolling reaction force change signals ΔF1, ΔF2 ... .. .DELTA.F6 are sequentially output.

(70) is an estimation device. The estimating device (70) is a storage unit (71) for storing the rolling position change signal during material rolling from each rolling position measuring device and the rolling reaction force change signal during rolling from the rolling reaction force measuring device, and the plate thickness measurement. The plate thickness change signal measured by the device and the stored reduction position change signal of the final stand when the plate thickness measuring point on the rolled material measured by the plate thickness measuring device is immediately below the final stand. , A first means for calculating the mill spring constant of the final stand based on the rolling reaction force change signal, and a ratio of the mill spring constant of the final stand calculated by the first means for each of the preceding rolling mills determined in advance. The second means for estimating the mill spring constant of each rolling mill by multiplying by, and the mill spring constant of each rolling mill at the preceding stage estimated by this second means,
When the plate thickness measurement point is directly under each stand, the exit side plate thickness change amount of the stand is calculated by the stored rolling position change signal of the final stand and the rolling reaction force change signal in each stand. The third means, the strip thickness measuring device or the amount of change in strip thickness at the stand entrance side and exit side obtained by the third means, and the rolling reaction force stored when the strip thickness measurement point is directly below the stand. The estimation means (72) is provided with at least a fourth means for calculating the material plasticity coefficient of the stand based on the change signal.

The operation of the apparatus configured as described above will be described below.

For example, the mill spring constant at each stand is set to Mi.
(I = 1.2.3 ... 6), the material plasticity coefficient is Qi (i =
1.2.3 ...... 6), and focusing on the three downstream fourth stand (4), fifth stand (5) and sixth stand (6), the following formula is established. .

ΔF4 = -Q4 Δh4 ……………… (13) ΔF5 = Q5 (Δh4 −Δh5) …… (14) ΔF6 = Q6 (Δh5 −Δh6) ………… (15) The amount of change in plate thickness during rolling on the stand is Δh4 = ΔS4 + ΔF4 / M4 ………… (16) Δh5 = ΔS5 + ΔF5 / M5 ………… (17) Δh6 = ΔS6 + ΔF6 / M6 ………… (18) If the point of interest is rolled just below the sixth stand (6) and the point of interest comes to the plate thickness measuring device (40), the point of interest is the plate thickness measuring point in this case.

It is clear that Δh6 = Δhx …………………… (19).

From the above, it can be seen that the mill spring constant Mi in each stand has the following relationship.

For example, the equation (17) of the plate thickness change amount Δh5 at the fifth stand (5) and the plate thickness change amount Δ at the sixth stand (6).
By transforming the equation (18) of h6 as follows, (ΔF5 / M5) = Δh5−ΔS5 (A) (ΔF6 / M6) = Δh6−ΔS6 (B), and the formula (B) becomes (B) When divided by the formula A), it is represented by (ΔF6 / M6) · (ΔF5 / M5) = (Δh6−ΔS6) / (Δh5 / ΔS5). From this formula, the mill spring constant M5 is M5 = [(Δh6−ΔS6 ) / (Δh5 −ΔS5)] × (Δh5 / ΔF6) · M6, and if this [(Δh6 −ΔS6) / (Δh5 −ΔS5)] × (Δh5 / ΔF6) = a5, then M5 = a5 · M6 (20) a5 = (M5 / M6) holds, and similarly, M4 becomes (ΔF4 / M4) = Δh4−ΔS4 (C), and the formula (C) is changed. When divided by the equation (A), it is represented by (ΔF6 / M6) · (ΔF4 / M4) = (Δh6−ΔS6) / (Δh4−ΔS4), and M4 = [(( h6−ΔS6) / (Δh4−ΔS4)] × (ΔF4 / ΔF6) · M6, and [(Δh6−ΔS6) / (Δh4−ΔS4)] × (ΔF4 / ΔF6) = a4, M4 = a4・ M6 ………………………… (21) a4 = M4 / M6. That is, it can be seen that the mill spring constant of each stand depends on the mill spring constant of the final stand.

Then, each constant a for each stand is obtained in advance as described below.

Generally, in a continuous rolling mill, the strip width hardly changes during rolling of a single strip. Further, the roll speed of each stand of the continuous rolling mill is kept substantially constant.

For example, the roll speed of the first stand is 860 (fp
m), the roll speed of the second stand is 1300 (fp)
m), the roll speed of the third stand is 1840 (fp)
m), the roll speed of the 4th stand is 2460 (fp)
m), the roll speed of the fifth stand is 3120 (fp)
m), the roll speed of the 6th stand is 3720 (fpm)
It is kept in that condition.

In such a continuous rolling mill, as described above, the plate thickness change amount Δh, the rolling reaction force change amount ΔF, and the rolling position change amount ΔS.
Is measured, and (1) is transformed to M = ΔF / (Δh / ΔS).

And, for example, a board width of 600 (mm) and a board width of 800 (m
m), board width 1000 (mm), board width 1200 (mm),
It was found that the mill spring constant of each stand when rolling a material having a plate width of 1350 (mm) had the relationship shown in FIG. 2 below.

As shown in the figure, when the plate width is 1000 mm, the first mill spring constant M1 is 81 and the second mill spring constant M is
2 is 78, the third mill spring constant M3 is 76, the fourth
Has a mill spring constant M4 of 74, a fifth mill spring constant M5 of 73, and a sixth mill spring constant M6 of 7.
It is 2.

Therefore, a5 of the fifth stand with a plate width of 1000 mm is a5 = M5 / M6 = 73/72 = 1.013, and a4 of the fourth stand is a4 = M4 / M5 = 74/72 = 1.027. .

Then, for example, as shown in FIG. 2, the minimum plate width is 60
When rolling a maximum strip width of 1360 (mm) with 0 (mm), the range of a5 is as follows: the mill spring constant M6 of the sixth stand is 64 when the strip width is 600 (mm), and the mill of the fifth stand is Since the spring constant M5 is 65, a5 when the strip width is 600 (mm) is a5 = 65/64 = 1.015, and a5 when rolling the strip width 1360 (mm) is
Mill spring constant M6 of the 6th stand is 75,
Since the mill spring constant M5 of the stand is 76,
When the plate width is 13560 (mm), a5 is a5 = 76/75 = 1.013. Therefore, when rolling the minimum strip width of 600 (mm) and the maximum strip width of 1360 (mm), the range of a5 is about 1.015 to 1.013.

Similarly, the range of a4 is the sixth when the plate width is 600 (mm).
Since the mill spring constant M6 of the stand is 64 and the mill spring constant M4 of the fourth stand is 66, a4 when the plate width is 600 (mm) is a4 = 66/64 = 1.031 and the plate width 1360 ( mm4) when rolling a4,
Mill spring constant M6 of the 6th stand is 75,
Since the mill spring constant M4 of the stand is 78,
When the plate width is 13560 (mm), a4 is a4 = 78/75 = 1.04. Therefore, when rolling the minimum strip width of 600 (mm) and the maximum strip width of 1360 (mm), the range of a4 is about 1.04 to 1.031.

From such a relationship, the ratio a at each stand is determined in advance.

The estimation device (70) then adjusts the plate thickness change amount Δ of the final stand.
Using h6, the rolling reaction force change amount ΔF6 of the rolling reaction force F6, and the rolling position change amount ΔS6, the mill spring constant Mi (i = 1.2 ... 6) and the material plasticity coefficient Qi of each stand are as follows.
Estimate (i = 1.2 ... 6).

This is because the point of interest on the material is rolled by the sixth stand, and when this point of interest reaches the plate thickness detection device (40), the plate thickness variation amount Δhx at this time is as shown in the above equation (19). Δhx = Δh6.

Further, the rolling reaction force change amount ΔF6 detected at this time and the rolling position change amount ΔS6 are used to calculate the mill spring constant M of the sixth stand in the same manner as in the conventional case according to the above equation (18).
Find 6 and call this value M6.

Then, using this M6, the mill spring constant M5 of the fifth stand can be easily obtained from the above equation (20).

Further, when the mill spring constant M5 is obtained, the plate thickness change amount Δh5 of the fifth stand when the fifth stand is rolled at the point of interest is obtained by the above equation (17). Using the rolling reaction force change amount ΔF6, the material plasticity coefficient Q6 at the sixth stand is determined by the above equation (15). Let this result be Q6.

Similarly, from the equation (21), the mill spring constant M4 at the fourth stand can be easily determined.

Then, when M4 is obtained, the plate in this stand is calculated by the equation (16) using the rolling reaction force change amount ΔF4 and the rolling position change amount ΔS4 when the point of interest on the material is rolled by the fourth stand. Obtain the thickness variation Δh4.

Then, the material plasticity coefficient Q5 of the fifth stand is determined from the obtained sheet thickness change amount Δh4, sheet thickness change amount Δh5 and rolling reaction force change amount ΔF5 by the equation (14).

The estimation calculation of the material plasticity coefficient Q4 at the fourth stand can be performed by the same procedure.

In addition, by performing the above-described estimation operation any number of times during rolling of one material and averaging the same, the variable estimation result can be made more reliable.

In the apparatus shown in FIG. 1, the storage means in the estimation apparatus is a rolling position change number ΔS1, ΔS2 ......... ΔS6 which is the amount of change in the rolling position of the rolling screw at each stand, and rolling which is the amount of change in rolling reaction force. Reaction force change signals ΔF1, ΔF2 ………
.. .DELTA.F6 is stored, and when the same point (point of interest) on the rolled material reaches the sheet thickness detecting device (40), the estimating means stores the output side sheet thickness measurement result .DELTA.hx and various storage signals in the storing means and correspondences. Using the data (constant a), the calculation according to each of the above formulas is carried out to estimate the mill spring constant M and the material plasticity coefficient Q at each stand.

In the above description, when six rolling stands are used, the constants and coefficients of the three downstream stands are estimated, but the number of stands may be any other number. Alternatively, each constant M and coefficient Q for all stands may be measured.

[Effects of the Invention] As described above, according to the present invention, the mill spring constant of each rolling mill is calculated by multiplying the mill spring constant in the final stand by the predetermined ratio of each rolling mill in the preceding stage, and Based on the mill spring constant of the rolling mill, by estimating the material plasticity coefficient during rolling in the stand of each rolling mill, it is not necessary to obtain the mill spring constant and the material plasticity factor of each rolling mill in a matrix form. Therefore, the processing speed for calculating the optimum rolling force of each rolling mill becomes faster, so that the rolling processing becomes faster and the rolling accuracy is improved.

Further, based on the predetermined ratio constant, while obtaining the mill spring constant of each rolling mill of the preceding stage, based on the mill spring constant of each rolling mill, by estimating the material plasticity coefficient of the preceding stage Since it is not necessary to use the detection data such as the plate thickness change amount, the rolling reaction force change amount and the rolling position change amount in the latter stage, the effect that the accumulated error of the mill spring constant and the material plasticity coefficient in the former stage is eliminated is obtained. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an apparatus of the present invention, FIG. 2 is an explanatory diagram of a mill spring constant and roll speed of each stand when rolling a material, and FIG. 3 is an explanatory diagram of a rolling state of each stand. 4 and 5 are explanatory views for explaining the relationship between the rolling reaction force F, the plate thickness h exiting the rolling mill, and the plasticity, and FIG. 5 is a schematic configuration diagram of a conventional continuous rolling mill. In the figure, (1) is the first stand, (2) is the second stand, (3) is the third stand, (4) is the fourth stand, (5) is the fifth stand, and (6) is the sixth stand. , (1a) to (6a) are the upper work rolls of the rolling mill, (1b) to (6b) are the lower work rolls of the rolling mill, (1c) to (3c) are the rolling reaction force detection devices, and (70) is the estimated apparatus,
(10) is a rolled material, and (40) is a plate thickness detecting device. The same reference numerals in the drawings indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A method for estimating a mill spring constant and a material plasticity coefficient of a continuous rolling mill having a strip thickness detecting device on the exit side of a final stand and a rolling position measuring device and a rolling reaction force measuring device on each stand. , A storage device for storing the rolling position change signal during material rolling from each of the rolling position measurement devices and the rolling reaction force change signal during rolling from the rolling reaction force measurement device, and measured by the plate thickness measurement device. When the plate thickness change signal and the plate thickness measuring point on the rolled material when measured by this plate thickness measuring device is immediately below the final stand,
A first means for calculating the mill spring constant of the final stand based on the stored rolling position change signal and rolling reaction force change signal of the last stand, and the mill spring constant of the final stand calculated by the first means are set in advance. A second means for estimating the mill spring constant of each rolling mill by multiplying the determined ratio for each rolling mill of the preceding stage; a mill spring constant of each rolling mill of the preceding stage estimated by this second means; A third means for calculating the amount of change in the outlet side plate thickness of the stand based on the stored rolling position change signal and rolling reaction force change signal in each stand when the thickness measurement point is immediately below each stand. , The thickness change amount of the stand on the inlet side and the outlet side obtained by the thickness measuring device or the third means, and the stored pressure when the thickness measuring point is directly below the stand. Reaction force change signal and the fourth means and the mill spring constant and material plasticity coefficient estimating apparatus in a continuous rolling mill, characterized in that it comprises a for calculating the material plastic coefficient of the stand.