JPH08252617A - Rolling controller - Google Patents

Abstract

PURPOSE: To reduce thickness deviation due to variation in forward slip. CONSTITUTION: This controller is provided with devices TC6 , TC7 for controlling screw down positions at #6 and #7 stands so that tension between adjacent stands are matched with the target values, a #5 stand speed controller HSC5 for calculating the circumferential speed Vrefi-1 of the rolls at the #5 stand, the changing amount ΔVrefi-1 of the rolls at the #5 stand for compensating thickness deviation ΔH on the inlet side of the #6 stand based on the thickness H on the inlet side of the #6 stand and changing the circumferential speed of the rolls at the #5 stand by that amount, a calculating means FFi for calculating the forward slip fi at the #6 stand, and a #6 stand speed controller FTC for calculating the value corresponding to ΔVrefi=-((fi-fsi)/(1+fsi)).Vrefi based on the forward slip fi at the #6 stand, reference value fsi and the circumferential speed Vrefi of the roll at the #5 stand, and changing the circumferential speed at the ξ6 stand by that amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the thickness and tension of a rolled material between stands when rolling a steel material by a tandem rolling mill.

[0002]

2. Description of the Related Art "Tension control by rolling down" in which tension between the stands is measured between the i-1 stand and the i stand of a hot tandem rolling mill, and the tension is controlled by operating the rolling down position of the i stand. Under tension control, i-
1 Stand output side plate thickness is measured, and at the timing when the measurement point is bitten by the i stand, i-1
"Feedforward plate thickness control" is known in which the peripheral speed of the stand roll is changed, or the peripheral speed of the i-1 stand and the rolling position of the i stand are simultaneously changed to correct the plate thickness. Japanese Patent Publication, JP-A-5
It is disclosed in JP-A-261418 and JP-A-6-269830. In the text below, this "tension control by reduction" and "feedforward plate thickness control"
This combination is called new hot rolling control.

For these, the new hot rolling control is applied to two stands i-1 and i as a group to which the new hot rolling control is applied, or between all the stands or to all the downstream side stands after a certain intermediate stand. The full spec type to be applied is disclosed. In principle, a flat plate can be produced by these new hot rolling controls.

[0004]

It has been confirmed by a simulator that when the full-spec type is applied, the final plate thickness becomes almost flat. In this way, in principle, the new hot rolling control can significantly improve the plate thickness accuracy, but in reality, a plate thickness meter and a plate speed meter are installed between all downstream stands after an intermediate stand. It is considered difficult to install and implement full-spec new hot rolling control due to equipment costs. Therefore, the new hot rolling control is performed only at a specific intermediate stand where the plate thickness gauge and plate speed meter are installed, and the flat stand plate is flattened by adjusting the tension between the stands at the downstream stand by adjusting the rolling force. It is considered that the method of carrying out only is realistic. However, in this way, for example, in an aspect in which the roll peripheral speed of the i-1 stand upstream of the i stand is adjusted to the target value of the outlet side plate thickness of the i stand, a new i + 1 stand downstream of the i stand is newly configured. The tandem simulation may cause a large variation in plate thickness.
It was confirmed in the data.

That is, the simulation was carried out on the hot tine dem finish rolling # 5 to # 7 stands of Kimitsu Works. # 7 Stand-out target thickness value hs = 3.2m
m. Rolling control is a combination of the following two methods in time series.

Conventional type 1: For both the # 5, # 6 and # 7 stands, the variation of the strip thickness on the outlet side of each stand is detected from the rolling load detected by the load cell, and the reduction position (roll gap) is correspondingly detected. Correct (BISRA-AGC). The roll peripheral speed of the # 5 stand is changed according to the angle fluctuation of the looper installed between the # 5 and # 6 stands to operate the stand interplate loop length to keep the looper angle constant. Similarly, the roll peripheral speed of the # 6 stand is changed in accordance with the variation of the looper angle installed between the # 6 and # 7 stands to operate the inter-stand plate loop length to keep the looper angle constant.

Conventional type 2: In the # 5 stand, the variation of the strip thickness on the exit side of the # 5 stand is detected from the rolling load detected by the load cell, and the rolling position is corrected accordingly (BISRA-AG
C). The tension fluctuation between # 5 and # 6 is detected by the tensiometer, and the rolling position (roll gap) of the # 6 stand is corrected so that the tension value becomes the reference value. The tension fluctuation between # 6 and # 7 is detected by the tensiometer, and the rolling position (roll gap) of the # 7 stand is corrected so that the tension value becomes the reference value. The plate thickness between # 5 and # 6 is measured, the measurement position is tracked, and at the timing when the measurement point reaches the # 6 stand, the roll peripheral speed of the # 5 stand is deviated from the reference value of the measured plate thickness. Correct accordingly. This correction amount reflects the change in the advanced ratio f _i of the # 6 stand (that is, the conventional new hot rolling control: Japanese Patent Laid-Open No. Hei 6).
-269830).

In the simulation, the rolling material on the entry side of the # 5 stand has an amplitude of 30 ° C and a change rate of 0.75 ° C /
A plate temperature variation of sec is given, control is performed by the conventional type 1 from the start of rolling to 12 seconds, and from 12 seconds to 22 seconds,
Conventional type 2 was used for control, and 22 seconds later, conventional type 1 was used for control. FIG. 4 shows the results. FIG. 4 (a) shows the obtained # 7 stand entrance side plate thickness variation, and FIG. 4 (b) shows # 7.
Shows the thickness variation of the stand outlet side. During the new hot rolling control period (12 seconds to 22 seconds), the # 7 stand exit side plate is kept flat even though the # 7 stand entrance side plate thickness is kept flat ((a) in FIG. 4). The thickness varies slightly ((b) of FIG. 4). The present inventor analyzed that this variation was due to the following reasons. That is, the peripheral speed of the # 5 stand roll is changed according to the variation of the plate thickness at the # 6 stand entrance side, but this change acts as a disturbance against the tension between the # 5 and # 6 stands, and the tension is kept constant. The rolling reduction of the # 6 stand is changed to correct the plate thickness on the exit side of the # 6 stand (plate thickness on the # 7 stand entry side) (the plate thickness on the # 7 stand entry side is maintained constant). However, by changing the reduction of the # 6 stand, the advanced ratio fi of the # 6 stand changes, and the tension between the # 6 and # 7 stands is disturbed.
The reduction of 7 stands is changed. This reduction is # 7
Since there is no correlation with the plate (plate thickness) immediately below the stand's work roll, plate thickness fluctuation (compression error) occurs.

On the other hand, Japanese Patent Laid-Open No. 6-269830 presents a control method in which the i-1 roll peripheral speed change amount is corrected according to the output side plate speed fluctuation due to the i stand advanced rate fluctuation. Then, although the advanced rate fluctuation due to "tension control by reduction" and "feedforward plate thickness control by reduction" in the i-stand is taken into consideration,
The "tension control by rolling down" in the i-1 stand or the advance rate fluctuation due to rolling down operation of the gauge meter AGC or the like is not taken into consideration, and the mass flow on the inlet side of the i stand cannot be accurately controlled. This will be described in more detail. In JP-A-6-269830, a front stand (hereinafter referred to as N
o. i-1) Mill speed change amount, ΔVref (i-1) =-{(H-Hs) / Hs} · Vref (i-1) + {hs / Hs} · Δvi (1) H : I-stand entrance side plate thickness (measured value or estimated calculation value) Hs: i-stand entrance side plate thickness reference value hs: i-stand exit side plate thickness reference value (target value) Vref (i-1): i-1 roll roll circumference Speed command value ΔVref (i-1): Roll peripheral speed change amount of i-1 stand Δvi: Output side plate speed fluctuation amount of i stand The improvement point is to remove the remaining thickness deviation.

Referring to FIG. 1 of JP-A-6-269830, in the control of JP-A-5-261418, a # 6 stand (i-1 stand) roll by a plate thickness / tension controller HSC ₆ is used. The peripheral speed change amount ΔVref ₆ is given by ΔVref ₆ = − {(H ₇ −Hs ₇ ) / Hs ₇ } · Vref ₆ (2), while in Japanese Patent Laid-Open No. 6-269830, ΔVref _{6 = - {(H 7 -Hs 7} ) / hs 7} · Vref 6 + (hs 7 / hs 7) · Δv 7 ··· (3) Δv 7 = (f 7 -fs 7) · Vref 7 ··· (4) fs _7: # 7 stand (i stand) of the reference forward slip f _7: calculation of # 7 actual forward slip of the stand (f ₇ in JP-a-6-269830 (4) to (7)
It is shown in the formula).

However, the rolling control according to JP-A-6-269830 has the following problems. That is, the i-1 stand roll peripheral speed change amount is obtained by controlling the tension between the i stand / i-1 stand by reducing the i stand, so that the i-1 stand output side plate speed v _i-1 = the i stand input side plate speed. that V _i is satisfied, ie, v _i-1 = V i use the ··· (5), i-1 to operate the v _i by changing the stand roll peripheral speed, mass flow certain law at the i stand H _i · V _i = h _i · v _i (6) (However, it is assumed that the i stand stand-in and exit side plate widths are the same)
Side thickness deviation output for thickness at entrance side deviation [Delta] H _i based on Δ
It is assumed that h _i = 0.

[0012] With the i stand in and out side plate thicknesses H and h,
Let the input and output plate speeds be V _i and v _i, and use i
Assuming that the -1 stand output side plate speed v _i-1 and the i stand input side plate speed V _i match, the i -1, i stand roll peripheral speeds are the roll peripheral speed command values Vref (i-1), Vref. (i) and the advanced rates are f _i−1 and f _i , H · Vref (i−1) · (1 + f _i−1 ) = h · Vref (i) (1 + f _i ) ... (7 ) Holds.

From this equation, H, h, Vref (i-1), Vref
(i), f _i−1 and f _i , the changes ΔH, Δh, ΔVref (i
-1), ΔVref (i), Δf _i-1 and Δf _i , the relationship is ΔH · Vref (i-1) · (1 + f _i-1 ) + H · ΔVref (i-1) · (1 + f _{i- 1) + H · Vref (i} -1) · Δf i-1 = Δh · Vref (i) · (1 + f i) + h · ΔVref (i) · (1 + f i) + h · Vref (i) · Δf i ··· (8) is obtained, and both sides of the equation (8) are divided by the equation (7) to obtain ΔH / H + ΔVref (i-1) / Vref (i-1) + Δf _i-1 / (1 + f _i-1 ) = Δh / h + ΔVref (i) / Vref (i) + Δf _i / (1 + f _i ) ...
(9) ΔVref such that the output side thickness deviation Δh = 0
When (i-1) is calculated (however, the mill speed succession control amount ΔVref (i) / Vref (i-1) is excluded), ΔVref (i-1) = {-ΔH / H-Δf _i-1 / ( 1 + f _i-1 ) + Δf _i / (1 + f _i )} · Vref (i-1) (10) In the control of Japanese Patent Laid-Open No. 5-261418, i
Assuming that there is no change in the advance rate of the -1 stand and the i stand, only the term ΔΗ is taken into consideration.
In Japanese Patent No. 0, the roll peripheral speed is changed in consideration of the terms ΔH and Δf _i , but the reduction is ΔS even in the i−1 stand.
_{If i-1 is} changed, the advanced rate f _{i-1 of the} i-1 stand is also Δf
_i-1 fluctuates. Also in FIG. 1 of JP-A-6-269830, the reduction of the # 6 (= i-1) stand is operated by the AGC or the like, and the advance rate variation Δf ₆ is generated by ΔS ₆ . That is, since there is no compensation for Δf _i−1 , i−
The influence of the 1-stand reduction operation appears in the delivery-side thickness deviation Δh. That is, from the equation (9), Δh / h = ΔH / H−Δf _i / (1 + f _i ) + ΔVref (i-1) /
Vref (i-1) + Δf _i-1 / (1 + f _i-1 ) −ΔVref (i) / Vre
f (i), even if the roll peripheral speed of the i-1 stand is changed by the formula (1) (specifically, the formula (3)), Δh / h = Δf _i-1 / (1 + f _{i -1} ) ... The output side plate thickness fluctuation of (11) remains.

An object of the present invention is to reduce the plate thickness deviation due to the variation of the advanced rate.

[0015]

A rolling control device of the present invention is a rolling material tension between an i-1 stand upstream and an i stand downstream thereof with respect to a moving direction of a rolled material, and an i stand and a downstream thereof. Adjust the rolled material tension of the i + 1 stand so that it matches the target value.
A rolling down control device (TC ₆ , T that controls the rolling down position of one stand
C ₇ ); Roll of the i-1 stand for compensating for the i-stand entry side plate thickness deviation ΔH based on the i-stand entry side plate thickness H and the roll peripheral speed Vref (i-1) of the i-1 stand. I-1 stand speed control device (H-1) for calculating the roll peripheral speed change amount ΔVref (i-1) and changing the roll peripheral speed of the i-1 stand by that amount.
SC ₅ ); Calculation means (F
F _i ); and the advanced rate fi of the i-stand, the advanced rate reference value fsi of the i-stand, and the roll peripheral speed Vref of the i-stand
Based on (i), ΔVref (i) = - {(fi-fsi) / (1 + fs i)} · Vref (i) ··· of correspondingly i stand by calculating a value corresponding to the (16) B -I stand speed controller (FTC) for changing the peripheral speed.

A preferred embodiment of the present invention further comprises a computing means (FF _i-1 ) for calculating an advanced rate f _i-1 of the i-1 stand, and the i-1 stand speed controller (HSC ₅ ) is i-stand entrance side plate thickness H, its reference value Hs and deviation ΔH, i−1 between them
The advance rate f _{i-1 of the} stand, its reference value fs _i-1, and the deviation Δf _i-1 between them, the advance rate fi of the i stand, and its reference value fs _i
And the deviation Δf _i between the two, and the roll peripheral speed Vref (i-1) of the i-1 stand, based on the i-stand entrance side plate thickness deviation Δ
Roll peripheral speed change amount ΔVref (i-1) of the i-1 stand for compensating H, ΔVref (i-1) = {-(ΔH / Hs) -Δf _i-1 / (1 + fs _i-1) ) + Δf _i / (1 + fs _i )} Vref (i-1) (10) is calculated, and the roll peripheral speed of the i-1 stand is changed by the value.

[0017]

The rolling control device (TC ₆ ) controls the rolling position of the i stand so that the rolled material tension T _i-1 between the i-1 stand and the i stand matches the target value Ts _i-1 . , I-
The exit side plate speed v _{i-1 of one} stand is equal to the _i side stand side plate speed V _i . Similarly, the reduction controller (TC ₇ ) sets the rolling material tension T _i between the i stand and the i + 1 stand to the target value Ts _i.
Since the rolling-down position of the i + 1 stand is controlled so as to match with, the output side plate speed v _i of the i stand and the i + 1 stand input side plate speed V _{i + 1} are equal.

Therefore, the i-1 stand speed controller (H
SC ₅ ) is a roll of the i-1 stand for compensating the i-stand entry side plate thickness deviation ΔH based on the i-stand entry side plate thickness H and the roll peripheral speed Vref (i-1) of the i-1 stand. -Since the roll peripheral speed change amount ΔVref (i-1) is calculated and the roll peripheral speed of the i-1 stand is changed by that amount, the i-stand entry side plate thickness H
The i-stand output side plate thickness h due to the fluctuation is eliminated and the target thickness is maintained. That is, the above-mentioned change of the roll peripheral speed of the i-1 stand acts as a disturbance to the tension between the i-1 / i stands, and the reduction of the i stand is changed in order to keep this tension constant. Delivery side plate thickness (i
(Stand-in side plate thickness) is corrected (i-stand-in side plate thickness is maintained constant).

Although the advance rate fi of the i stand may change due to the reduction of the reduction of the i stand, the tension between the i / i + 1 stands may be disturbed. In the present invention, the computing means (FF _i ) changes the advance rate fi of the i stand. calculated, corresponding to the forward slip fi i stand speed controller (FTC) is, ΔVref (i) = - { (fi-fsi) / (1 + fs i)} · Vref (i) ··· (16) The value corresponding to is calculated and the roll peripheral speed of the i stand is changed accordingly. That is, the variation of the advanced rate Δfi = fi−f
Corresponding to si, the roll peripheral speed of the i stand is modified so as to absorb the tension fluctuation due to the fluctuation. As a result, there is no change in the tension Ti between the i / i + 1 stands due to the change .DELTA.fi of the advanced rate, there is no change in the reduction of the i + 1 stand, and no change occurs in the delivery side plate thickness of the i + 1 stand.
Note that i / i-1 which is about to occur due to this ΔVref (i)
The fluctuation of tension between stands is based on the conventionally applied mill speed succession ΔVref (i-1) = {ΔVrefs (i-1) / Vrefs (i)} · ΔVref
It shall be suppressed by (i).

In the preferred embodiment described above, the speed controller (H
SC ₅ ) is the amount of change in roll peripheral speed of the i-1 stand of formula (10) Δ
Since the value corresponding to Vref (i-1) is calculated and the roll peripheral speed of the i-1 stand is changed by the value, the advance rate fluctuation is caused by the fluctuation ΔS _i-1 of the rolling position of the i-1 stand. Even if Δf _i-1 is generated, the corresponding compensation is applied to the change amount ΔVref (i-1) of the roll peripheral speed of the i-1 stand, and the i-stand delivery side plate by the operation of rolling down the i-1 stand Substantially no thickness deviation Δh occurs. In other words, the delivery side plate thickness accuracy of the i stand is high.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0022]

[Example] In FIG. 1, the new hot rolling control is applied to the # 5 stand and the # 6 stand (i stand, i = 6) of the hot tandem finish rolling facility to target the outlet side plate thickness h of the # 6 stand. With the value hs, the constant tension control is applied to the # 7 stand on the downstream side, and in addition, the # 6 stand roll peripheral speed is corrected in order to suppress the variation of the plate thickness on the delivery side of the # 7 stand. An example is shown. In FIG. 1, the steel plate rolled on the # 5 stand is rolled on the # 6 stand and then rolled on the final stand 7. In the # 5 stand, the AGC (automatic plate thickness controller) sets the output plate thickness to the target plate thickness based on the measured load of the load cell LC and the input plate thickness i.
-1 Operate the pressing mechanism HYD of the stand. I.e.
-1 Automatically adjust the roll gap of the stand.

The entry side plate thickness H _{i-1 of the} # 5 stand is the reference value Hs.
_{When i-1} , the advanced rate fs _i-1 of the # 5 stand is fs _i-1 = {0.455-0.233 (1 / μ _i-1 ) √ [(Hs _i-1 -hs _i-1 ) / Re _i-1 ]} ² × γs _i-1 / (1−γs _i-1 ) + G _i-1 (1-0.16γs _i-1 ) √ [(Hs _i-1 −hs _i-1 ) / Re _{i −1} ] × {T _i-1 −T _i-2 (Hs _i-1 / hs _i-1 )} / 2K _i-1 (12 _i-1 ) where γs _i-1 = (Hs _{i -1} -hs _i-1 ) / Hs _i-1 (13 _i-1 ). On the other hand, when the inlet side plate thickness changes to H _i-1 , the leading rate f _i-1 on the outlet side of the i-1 stand is f _i-1 = {0.455-0.233 (1 / μ _i-1 ). √ [(H _i-1 −hs _i-1 ) / Re _i-1 ]} ² × γ _i-1 / (1−γ _i-1 ) + G _i-1 (1-0.16γ _i-1 ) √ [ (H _i-1 −hs _i-1 ) / Re _i-1 ] × {T _i-1 −T _i-2 (H _i-1 / hs _i-1 )} / 2K _i-1 (14 _i-1 ) However, γ _i-1 = (H _i-1 -hs _i-1 ) / H _i-1 (15 _i-1 ) is given. Here, H _i-1 : # 5 stand-in side plate thickness Hs _i-1 : # 5 stand in-side plate thickness reference value hs _i-1 : # 5 stand out-side plate thickness reference value μ _i-1 : # 5 Deformation resistance of stand [kgf / mm ² ] Re _i-1 : # 5 Flattening roll diameter of stand [mm] G _i-1 : Adjustment coefficient K _i-1 : Coefficient T _i-1 : # 5 / # 6 Tension between stands T _i-2 : # 4 / # 5 Tension between stands.

The advanced rate computing unit FF _i-1 uses the above (14 _i-1 ), (1
5 _i-1 ), the advanced rate f _i-1 of the i-1 stand is calculated, and this is calculated as the speed controller HSC ₅ of the i-1 stand.
Give to. In this embodiment, H _i-1 , T _i-1 and T _i-2 are the upstream of the i-1 stand and the upper
It is given to the advanced rate calculator FF _i-1 from the downstream tensiometer, and Hs
_i-1 , hs _i-1 , μ _i-1 , Re _i-1 and K _i-1 are set in the advanced rate calculator FF _i-1 before the start of rolling.

Between the # 5 / # 6 stands, a looper type tensiometer (T, AgD), an X-ray thickness gauge XRay and a plate speed measuring instrument LSM are installed. Tensiometer (T, Ag
D) detects the tension T _i-1 of the steel plate (rolled material) between the # 5 / # 6 stands and gives it to the tension control rolling _- down controller TC ₆ , and also detects the looper angle Ag to determine the speed. Controller HS
It is given to the tracking device 5 of C ₅ . X-ray thickness gauge XRa
y measures the plate thickness H of the rolled material (i-stand insertion side plate thickness) and supplies it to the tracking device 5, and the plate speed setting device LSM measures the rolled material speed V (i-stand insertion side plate speed) and the tracking device 5 Give to.

The tension response reduction controller TC ₆ reduces the _i- stand so that ΔT _i-1 becomes zero corresponding to the deviation ΔT _i-1 of the detected tension T _{i-1 from} the target tension Ts _i-1 . Device HY
Operate D. That is, the roll gap of the i stand is automatically adjusted.

A looper type tensiometer (T) is installed between the # 6 / # 7 stands. Tension meter (T) is # 6
The tension T _{i + 1} of the steel plate (rolled material) between the # 7 and # 7 stands is detected and given to the tension response controller TC ₇ . Reduction controller TC ₇ tension response to the zero [Delta] T _i corresponding to the deviation [Delta] T _i of the detected tension T _i with respect to the target tension Ts _i i
Operate the reduction device HYD of the +1 stand. That is,
Automatically adjust the roll gap of the i + 1 stand.

The entry side plate thickness H _i of the # 6 stand is the reference value Hs _i.
Then, the advanced rate fs _i of the # 6 stand is fs _i = {0.455−0.233 (1 / μ _i ) √ [(Hs _i −hs _i ) / Re _i ]} ² × γs _i / (1−γs _i ) + G _i (1-0.16γs _i ) √ [(Hs _i −hs _i ) / Re _i ] × {T _i −T _i-1 (Hs _i / hs _i )} / 2K _i ... (12 _i ) However, γs _i = (Hs _i −hs _i ) / Hs _i (13 _i ). On the other hand, when the inlet plate thickness changes to H _i ,
Advance rate f on the exit side of i-stand, that is, # 6 stand
_i is f _i = {0.455−0.233 (1 / μ _i ) √ [(H _i −h s _i ) / Re _i ]} ² × γ _i / (1−γ _i ) + G _i (1-0.16γ _i ) √ [(H _i −h s _i ) / Re _i ] × {T _i −T _{i −1} (H _i / _{h s i} )} / 2K _i (14 _i ), where γ _i = (H _i −h s _i ) / H _i ... (15 _i ) is given. Here, H _i : Inlet plate thickness of the # 6 stand (may be simply referred to as H) Hs _i : Inlet plate thickness reference value of the # 6 stand (may be simply referred to as Hs) hs _i : # 6 Stand-out plate thickness reference value (sometimes simply referred to as hs) μ _i : Deformation resistance of # 6 stand [kgf / mm ² ] Re _i : Flattening roll diameter of # 6 stand [mm] G _i : Adjustment coefficient K _i : coefficient T _i : tension between # 6 / # 7 stands (may be simply referred to as T) T _i-1 : tension between # 5 / # 6 stands

The advanced rate computing unit FF _i has the above (14 _i ), (15 _i )
The advanced ratio f _i of the i-stand, which is defined by the formula, is calculated and is given to the speed controller HSC ₅ of the i-1 stand.
In this embodiment, H _i (= H) is the X-ray thickness meter XR.
ay is given to the advanced rate calculator FF _i , T _i (= T) is given from the tensiometer (T), and T _i−1 is the tensiometer (T, Ag).
ds), Hs _i (= Hs), hs _i (= hs), μ _i ,
Re _i and K _i are set in the advanced rate calculator FF _i before the start of rolling.

FIG. 2 shows the speed controller H of the i-1 stand.
The structure of SC ₅ is shown. The tracking device 5 of the speed controller HSC ₅ delays and holds the measurement data H _i (= H) of the X-ray thickness gauge XRay by the moving time of the rolled material from the X-ray thickness gauge XRay to the # 6 stand. When a certain point of the rolled material is bitten into the # 6 stand, the thickness data H _i (= H) of the point is output to the subtractor 1C. That is, the tracking device 5, the thickness H _i (= H) of X-ray thickness gauge XRay is measured, the plate velocity V and tensiometer plate speed meter LSM was measured (T, AGD) was measured Le -
The tracking angle is given to the tracking device 5, and the tracking device 5 writes the plate thickness in the plate thickness memory at a cycle ts described later to determine the looper angle Ag.
The length of the rolled material from directly under the X-ray thickness gauge XRay to the work roll bite position of the # 6 stand is calculated, and the time taken for the rolled material to move this length is calculated. Is divided by the set number n to calculate the data shift period ts,
At this period ts, the thickness data of the plate thickness memory used as the n-stage shift register is shifted, and the thickness data H _i (= H) written in the plate thickness memory before ts × n is calculated as Output to the subtractor 1C. That is, the X-ray thickness gauge XR of the rolled material currently in the work roll biting position of the # 6 stand is first measured.
The plate thickness data H _i (= H) measured by ay is output to the subtractor 1C.

The plate thickness H and the plate thickness reference value Hs are stored in the subtractor 1C.
Is given, the subtractor 1C calculates the inlet side plate thickness deviation ΔH = H−Hs of the # 6 stand, and outputs this to the divider 3C. The divider 3C calculates ΔH / Hs and supplies it to the adjustment coefficient multiplier 4C. The multiplier 4C calculates the adjustment coefficient α1 by ΔH /
Hs is multiplied and given to the subtractor 7.

The subtracter 1A of the speed controller HSC ₆ of the i-1 stand uses the deviation of the advanced rate f _i-1 of the # 6 stand calculated by the advanced rate calculator FF _i-1 from the reference value fs _i-1 . Δ
fi _-1 = fi _-1- fsii _-1 is calculated and given to the divider 3A.
On the other hand, the adder 2A calculates 1 + fs _i-1 and gives it to the divider 3A, and the divider 3A calculates Δf _i-1 / (1 + fs _i-1 ) and gives it to the adjustment coefficient multiplier 4A. The multiplier 4A multiplies the adjustment coefficient α2 by Δf _i-1 / (1 + fs _i-1 ) and subtracts it from the subtractor 6A.
Give to.

The subtractor 1B is the # 6 stand forward slip calculator FF _i is calculated by the forward slip f _i, and calculates a deviation Δf _i = f _i -fs _i relative to the reference value fs _i to a divider 3B give.
On the other hand, the adder 2B calculates 1 + fs _i and gives it to the divider 3B, and the divider 3B calculates Δf _i / (1 + fs _i ) to obtain the adjustment coefficient multiplier 4B and the i-stand speed controller FTC.
(Fig. 1). The multiplier 4B calculates the adjustment coefficient α3 by Δf.
_i / (1 + fs _i ) is multiplied and given to the subtracter 6.

The subtractor 6 outputs the output α3 · Δf of the multiplier 4B.
_{From i} / (1 + fs _i ), the output of multiplier 4A α2 · Δf _i-1 /
(1 + fs _i-1 ) is subtracted and given to the subtractor 7. Subtractor 7
Is -α1 · ΔH / Hs-α2 · Δf _i-1 / (1 + fs _i-1 )
+ Α3 · Δf _i / (1 + fs _i ) is calculated and given to the multiplier 8.
The multiplier 8 multiplies this by the roll peripheral speed reference value Vrefs _i-1 of the # 6 stand to obtain ΔVref _i-1 = {-α1 · ΔH / Hs−α2 · Δf _i-1 / (1 + fs _i−1 ) + α3 · Δf _i / (1 + fs _i )} · Vrefs _i−1 (10r) is output to the adder 9. The expression (10r) is an arithmetic expression corresponding to the expression (10), and ΔVref _i-1 calculated by the expression (10r) is
This corresponds to ΔVref (i-1) calculated by the equation (10).

The adder 9, Hollow # 5 stand output .DELTA.Vref _i-1 of the multiplier 8 - adds Le peripheral speed reference value Vrefs _i-1 to # 5 stands Russia - le peripheral speed target value Vref _{i -1} = Vrefs
_i-1 + ΔVref _{i-1 is given} to the mill motor speed controller ASR of the # 5 stand, and the speed controller ASR determines the roll peripheral speed of the # 5 stand to be the roll peripheral speed target value Vref _i-1. The rotation speed of the mill motor M of the # 5 stand is controlled so that

As described above, the roll peripheral speed of the # 5 stand is changed so that the mass flow on the entrance side of the # 6 stand is kept constant. Even if the advanced rate variation Δf _i-1 is generated due to the variation ΔS _i-1 of the rolling position of the # 5 stand, the corresponding compensation is the variation amount ΔVref _{i-1 of the} roll peripheral speed of the i-1 stand.
The plate thickness deviation Δh of the # 6 stand due to the influence of the pressing operation of the # 5 stand does not substantially occur.

Referring again to FIG. As mentioned above, HS
The C ₃ divider 3B calculates Δf _i / (1 + fs _i ) and supplies it to the i-stand speed controller FTC. In the i-stand speed control device FTC, the multiplier 11 sets the adjustment coefficient α4 to Δf _i /
(1 + fs _i ) is multiplied, and the product α4 · Δf is multiplied by the multiplier 12.
_i / (1 + fs _i ) to i roll roll peripheral speed reference value Vr
by multiplying the efs _i, calculates the _{ΔVref i = α4 · {Δf i} / (1 + fs i)} · Vrefs i ··· (16r). The expression (16r) is an arithmetic expression corresponding to the expression (16), and ΔVref _i calculated by the expression (16r) corresponds to ΔVref (i) calculated by the expression (16). i stand speed controller F
TC is a subtracter 13 which calculates a speed command value (target value) Vref _i = Vrefs _i −ΔVref _i (17) for the # 6 stand mill motor speed control device ASR to calculate the speed of the # 6 stand. Mill motor speed controller A
Give to SR. # 6 stand speed controller ASR
The rotation speed of the mill motor M of the # 6 stand is controlled so that the roll peripheral speed of the # 6 stand becomes the command value Vref _i . This # 6 stand roll peripheral speed change amount ΔVre
The tension fluctuation between the i / i-1 stands, which is about to occur due to f _i, is the conventionally applied mill speed succession ΔVref (i-1) = [Vrefs (i-1) / Vrefs (i)] × ΔVref. It is assumed that the # i-1 stand roll peripheral speed change amount obtained in (i) can be suppressed by subtracting it from the # 5 stand roll peripheral speed command Vref _i-1 calculated by the HSC 5 as shown in FIG.

Next, the simulation result will be described. The simulation was carried out on the # 5 to # 7 stands of hot tine dem finish rolling at Kimitsu Works. The target value of the outlet plate thickness of the # 7 stand is hs = 3.2 mm. Rolling control is a combination of the following two methods in time series.

Conventional type 1: For both the # 5, # 6 and # 7 stands, the variation of the strip thickness on the outlet side of each stand is detected from the rolling load detected by the load cell, and the reduction position (roll gap) is correspondingly detected. Correct (BISRA-AGC). The roll peripheral speed of the # 5 stand is changed according to the angle fluctuation of the looper installed between the # 5 and # 6 stands to operate the stand interplate loop length to keep the looper angle constant. Similarly, the roll peripheral speed of the # 6 stand is changed according to the angle variation of the looper installed between the # 6 and # 7 stands to operate the inter-stand plate loop length to keep the looper angle constant.

INV type: In the # 5 stand, the variation of the plate thickness on the delivery side of each stand is detected from the rolling load detected by the load cell, and the rolling position is corrected accordingly (BISRA-AGC).
The tension fluctuation between # 5 and # 6 is detected by the tensiometer, and the rolling position (roll gap) of the # 6 stand is corrected so that the tension value becomes the reference value. The tension fluctuation between # 6 and # 7 is detected by the tensiometer, and the rolling position (roll gap) of the # 7 stand is corrected so that the tension value becomes the reference value. The plate thickness between # 5 and # 6 is measured, the measurement position is tracked, and the measurement point is # 6.
When you reach the stand, the # 5 stand
The peripheral speed is corrected according to the deviation of the measured plate thickness from the reference value. As described in the above embodiment, the formula (10) or (10r)
Based on the formula, to correct the roll peripheral speed of # 5 stand,
It reflects the variation of the leading rate f _i of the # 6 stand and the variation of the leading rate f _i-1 of the # 5 stand. Further, as described in the above embodiment, the roll peripheral speed change amount ΔVref _i of the # 6 stand is calculated based on the equation (16) or the equation (16r), and the calculated value is calculated by
Change the roll peripheral speed of 6 stands.

In the simulation, the rolling material on the entry side of the # 5 stand had an amplitude of 30 ° C and a change rate of 0.75 ° C /
A plate temperature variation of sec is given, control is performed by the conventional type 1 from the start of rolling to 12 seconds, and from 12 seconds to 22 seconds,
It was controlled by the INV type, and after 22 seconds, it was controlled by the conventional type 1. The result is shown in FIG. FIG. 3A shows the obtained # 7 stand entrance side plate thickness variation, and FIG. 3B shows # 7.
Shows the thickness variation of the stand outlet side. In the INV type control section according to the present invention (12 to 22 seconds section of FIG. 3B),
Highly effective in suppressing plate thickness fluctuations.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing processing functions of a speed control device HSC ₅ shown in FIG.

FIG. 3 is a graph showing a simulation result of rolling control according to an embodiment of the present invention, (a) shows a variation of # 7 stand inlet side plate thickness, and (b) shows a # 7 stand outlet side plate thickness variation. Show. The result of one embodiment of the present invention is 12 in FIG.
Appears in the ~ 22 second section.

FIG. 4 is a case in which one embodiment of Japanese Patent Application Laid-Open No. 6-269830 is applied to # 5 and # 6 stands and the pressure reduction of the # 7 stand is adjusted so as to maintain a constant tension between # 6 and # 7 stands. It is a graph showing the simulation result of
(A) shows the plate thickness variation on the # 7 stand entrance side, and (b) shows #
7 shows the stand-out side plate thickness variation. JP-A-6-26983
The application result of one embodiment of Japanese Unexamined Patent Publication No.
It appears in the 22-second section.

[Explanation of symbols]

FF _i-1 , FF _i : Advanced rate calculator AGC: Automatic thickness control device LD: Road cell HYD: Reduction device M: Mill motor ASR: Speed control device T, Agd: Looper type tension meter ( T: Tensiometer, Ag
d: looper angle detector) LSM: plate speed measuring device XRay: X
Line thickness gauge TC _6, TC _7: tension response pressure control device HSC _5: Speed controller 1A-1C, 6, 7, 13: subtractor 2A, 2B,
9: Adder 3A-3C: Divider 4A-4C,
11: Coefficient multiplier 5: Tracking device 8, 12: Multiplier

Claims (3)

[Claims] 1. A rolling material tension between an i-1 stand upstream and an i stand downstream thereof and a rolling material tension of an i + 1 stand downstream thereof with respect to a moving direction of the rolled material are set to target values, respectively. A roll-down control device for controlling the roll-down positions of the i-stand and the i + 1-stand so as to match; the thickness of the i-stand entry side plate H and the roll of the i-1 stand.
Based on the roll peripheral speed Vref (i-1), the roll peripheral speed change amount ΔVref (i-1) of the i-1 stand for compensating for the i-stand entrance side plate thickness deviation ΔH is calculated, and i is calculated by that amount. -1 stand speed controller for changing the roll peripheral speed of -1 stand; i
Computing means for calculating the advanced rate fi of the stand; and i
Advance rate fi of the stand, advance rate standard value fsi of the i stand
And a value corresponding to ΔVref (i) = − {(fi−fsi) / (1 + fs _i )} · Vref (i) based on the roll peripheral velocity Vref (i) of the i stand A rolling control device comprising: an i-stand speed control device that changes the roll peripheral speed of the i-stand. 2. The i-1 stand speed control device is characterized in that the i stand stand-in side plate thickness H, its deviation ΔH, and the advanced rate f _{i of the} i stand.
And i for compensating the plate thickness deviation ΔH at the i stand on the basis of the roll peripheral speed Vref (i-1) of the i-1 stand.
-1 roll roll speed change amount ΔVref (i-1), ΔVref (i-1) = {-(ΔH / Hs) + Δf _i / (1 + fs _i )} Vr
The rolling control device according to claim 1, wherein a value corresponding to ef (i-1) is calculated, and the roll peripheral speed of the i-1 stand is changed by the value. 3. An i-1 stand speed controller is further provided with a computing means for calculating an advanced rate f _i-1 of the i-1 stand.
Based on the i-stand entrance side plate thickness H, its deviation ΔH, the i-1 stand's advanced rate fi _-1 , the i-stand's advanced rate fi and the i-1 stand's roll peripheral speed Vref (i-1), i-1 stand roll peripheral speed change amount ΔVref (i-1), ΔVref (i-1) = {-(ΔH / Hs) -Δf _i-1 to compensate the i-stand entrance side plate thickness deviation ΔH / (1 + fs _i-1 )
2. The rolling control device according to claim 1, wherein a value corresponding to + Δf _i / (1 + fs _i )} Vref (i-1) is calculated and the roll peripheral speed of the i-1 stand is changed by the value.