JP3234431B2 - Rolling control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus 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 reduction" in which a tension between stands is measured between an i-1 stand and an i stand of a hot tandem rolling mill, and the tension is controlled by manipulating an i stand reduction position; Under tension control, i-
The thickness of the sheet on the exit side of one stand is measured.
“Feed forward plate thickness control” for correcting the plate thickness by changing the stand roll peripheral speed, or simultaneously changing the i-1 stand roll peripheral speed and the i-stand pressing position, is known, for example, Japanese Patent Application Laid-Open No. 4-361809. No. 5, JP-A-5
-261418 and JP-A-6-269830. Hereinafter, in the text, this "tension control by rolling down" and "feed forward thickness control"
Is referred to as new hot rolling control.

[0003] The new hot rolling control is applied to a partial application type in which the new hot rolling control is applied to the two stands i-1 and i as a group, or to all the downstream stands between all the stands or after a certain intermediate stand. Applicable full specification types are disclosed. By these new hot rolling controls, a flat plate can be generated in principle.

[0004]

It has been confirmed by a simulator that when the full specification type is applied, the final plate thickness becomes substantially flat. In this way, in principle, this is a new hot rolling control that can significantly improve the thickness accuracy, but in reality, a thickness gauge and a speed gauge are installed between all the stands downstream from a certain intermediate stand. It is considered difficult to install and carry out full-spec new hot rolling control due to equipment costs. Therefore, new hot-rolling control is performed only at a specific intermediate stand where a thickness gauge and a speedometer are installed, so that the flat side of the plate is controlled at a constant level by adjusting the rolling reduction at the downstream stand. It is considered that a method of performing only the above is realistic. However, in this case, for example, in a mode in which the roll peripheral speed of the i-1 stand on the upstream side is adjusted in order to set the outlet side plate thickness of the i stand to the target value, a new i + 1 stand downstream of the i stand is newly provided. Tandem simulation
Confirmed.

[0005] That is, the simulation was carried out at the # 5 to # 7 stands of hot tinedem finish rolling at Kimitsu Works. Outlet thickness target value hs of # 7 stand = 3.2 m
m. The rolling control is a combination of the following two methods in time series.

Conventional type 1: In each of the stands # 5, # 6 and # 7, variations in the thickness of the outlet side of each stand are detected from the rolling load detected by the load cell, and the rolling position (roll gap) is correspondingly determined. Modify (BISRA-AGC). The roll peripheral speed of the # 5 stand is changed in accordance with the angle fluctuation of the looper installed between the # 5 and # 6 stands, and the loop length between the stands is operated to keep the looper angle constant. Similarly, the loop peripheral speed of the # 6 stand is changed according to the fluctuation of the looper angle installed between the # 6 and # 7 stands, and the loop length between the stands is operated to keep the looper angle constant.

Conventional type 2: In the # 5 stand, the thickness change of 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 a tension meter, 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 a tension meter, 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. Modify according to. The correction amount, to reflect changes in # 6 stand forward slip f _i (i.e. conventional new hot rolled Control: JP 6
-269830).

In the simulation, an amplitude of 30 ° C. and a change rate of 0.75 ° C.
A sheet temperature fluctuation of sec is given, and the conventional type 1 is controlled until 12 seconds elapse from the start of rolling.
The control was performed by the conventional type 2 and after 22 seconds, the control was performed by the conventional type 1. FIG. 4 shows the results. FIG. 4A shows the obtained plate thickness variation on the # 7 stand entry side, and FIG.
The stand thickness variation on the exit side is shown. During the new hot-rolling control period (from the lapse of 12 seconds to the lapse of 22 seconds), although the thickness of the inlet side of the # 7 stand is kept flat ((a) of FIG. 4), the outlet side plate of the # 7 stand. The thickness slightly fluctuates (FIG. 4B). The inventor has analyzed that this variation was due to the following reasons. In other words, the peripheral speed of the # 5 stand roll is changed in accordance with the variation in the plate thickness on the # 6 stand entrance side, and this change acts as a disturbance to the tension between the # 5 / # 6 stands and keeps this tension constant. Then, the reduction of the # 6 stand is changed, thereby correcting the thickness of the # 6 stand exit side plate (the # 7 stand entrance side plate thickness) (the # 7 stand entrance side plate thickness is maintained constant). However, due to the change in the rolling down of the # 6 stand, the advanced ratio fi of the # 6 stand changes, and the tension between the # 6 / # 7 stands is disturbed.
The reduction of the 7 stands is changed. This reduction change is # 7
Since there is no correlation with the plate (plate thickness) directly below the walker of the stand, a plate thickness variation (roll-down error) occurs.

On the other hand, Japanese Patent Application Laid-Open No. Hei 6-269830 discloses a control method for correcting the change amount of the i-1 roll peripheral speed in accordance with the change of the output side plate speed due to the change of the i-stand advanced rate. In the i-stand, the variation of the advance rate due to “tension control by rolling down” and “feedforward plate thickness control by rolling down” is considered,
No consideration is given to the “tension control by rolling down” in the i-1 stand or the advance rate fluctuation due to the rolling down operation of the gauge meter AGC, etc., and the mass flow on the i-stand entrance side cannot be accurately controlled. This will be described in more detail. JP-A-6-269830 discloses a front stand (hereinafter referred to as N
o. The mill speed change amount of i-1) is represented by: ΔVref (i-1) = − {(H−Hs) / Hs} · Vref (i−1) + {hs / Hs} · Δvi (1) H : I-stand entry side plate thickness (actual measured value or estimated calculated value) Hs: i-stand entry side plate thickness reference value hs: i-stand exit plate thickness reference value (target value) Vref (i-1): i-1 stand roll circumference Speed command value ΔVref (i-1): change amount of roll peripheral speed of i-1 stand Δvi: change amount of sheet speed on exit side of i stand The point of improvement is to remove the remaining thickness deviation that occurs.

[0010] With reference to FIG. 1 of JP-A 6-269830 discloses, in the control of JP-5-261418, JP-# 6 stand (i-1 stand) by thickness-tension controller HSC ₆ rolls While the peripheral speed change amount ΔVref ₆ is given by ΔVref ₆ = − {(H ₇ −Hs ₇ ) / Hs ₇ } · Vref ₆ (2), Japanese Patent Application Laid-Open No. 6-269830 discloses that 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)
(Shown in the equation).

However, the rolling control according to Japanese Patent Application Laid-Open No. 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 pressure to obtain the i-1 stand outboard speed v _i-1 = i stand inboard 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) ( where, i stand entry, delivery side width is assumed to be identical)
The exit side thickness deviation Δ with respect to the entrance side thickness deviation ΔH _i based on
h _i = 0.

The thickness of the i-stand entrance and exit sides is H, h,
The inlet and outlet plate speeds are V _i and v _i, and _i is controlled by tension control.
-1 Assuming stand delivery side speed v _i-1 and i stand entry side speed V _i corresponds, b a i-1, i stand roll peripheral speed - Le peripheral speed command value Vref (i-1), Vref (i), and assuming that the advanced rate is 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), the variation ΔH of the f _i-1 and f _i, Δh, ΔVref _(i
-1), ΔVref (i), when determining the relationship between Delta] f _i-1 and _{Δf i, 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) + Δfi _-1 / (1 + fi _-1 ) = Δh / h + ΔVref (i) / Vref (i) + Δf i / (1 + f i) ···
(9) ΔVref such that the exit side plate thickness deviation Δh = 0
When (i−1) is obtained (however, except for the mill speed progressive control ΔVref (i) / Vref (i−1)), ΔVref (i−1) = {− ΔH / H−Δfi ₋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 variation in the advance rate of the -1 stand and the i stand, only the term of ΔΗ is taken into consideration.
0 No. In Japanese [Delta] H, is considering the section Delta] f _i are changing the roll peripheral speed, the pressure also in the i-1 stand ΔS
_{If i-1 is} changed, the advanced rate f _{i-1 of the} i-1 stand is also Δf
fluctuates by _i-1 . 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 advanced rate fluctuation Δf ₆ is generated by ΔS ₆ . That is, since there is no compensation for Δf _i−1 , i−
The influence of the one stand pressure reduction operation appears on the exit side plate thickness deviation Δh. That is, (9) from equation Δh / h = ΔH / H- Δf i / (1 + f i) + ΔVref (i-1) /
Vref (i-1) + Δfi _-1 / (1 + fi _-1 ) -ΔVref (i) / Vre
f (i), and even if the roll peripheral speed of the i-1 stand is changed by equation (1) (specifically, equation (3)), Δh / h = Δfi _-1 / (1 + fi _{) -1} ) ... The variation of the exit side plate thickness in (11) remains.

An object of the present invention is to reduce a thickness deviation due to a change in the advance rate.

[0015]

The rolling control device of the present invention has a thickness measuring device and a tension measuring device between the i-1 stand and the i stand, and operates the rolling amount and the peripheral speed of each stand, In a rolling control device of a hot tandem rolling mill for matching a thickness after rolling to a target value, a target value of a rolled material tension between an i-1 stand upstream and an i stand downstream thereof with respect to a moving direction of a rolled material. I-stand pressure reduction control device for controlling the i-stand stand position so as to match i.
Calculating means for calculating the forward slip f _i-1 of the stand; i calculating means for calculating the forward slip f _i stand; i stand entry side thickness H, forward slip f _i-1 of the deviation delta H, i-1 Stand , I-1 stand advanced rate reference value fs _i−1 , i
Stand advance rate f _i , i-stand advance rate reference value fs
_i− for compensating the thickness deviation ΔH on the i-stand entrance side based on the roll peripheral speed Vref (i−1) of the _i and i−1 stands.
1 stand roll peripheral velocity change amount ΔVref (i-1), ΔVref (i-1) = {- (ΔH / Hs) -Δf i-1 / (1 + fs i-1) + Δf i / (1 + fs i)} Vref (i-1) _{(except, Δf i-1 = f i} -1 -fs i-1, Δf i = f i -fs i) calculating a value corresponding to, roll peripheral speed of the minute i-1 stand i-1 stand speed control device for changing the; provided with a, in the stand after i stand forward slip f _i of i _stands, the i stand forward slip reference value fs _i
And i based on the roll peripheral speed Vref stand (i), ΔVref (i) = - {Δf i / (1 + fs i)} · Vref () to calculate the value corresponding roll periphery of that amount i stand I-stand speed control device for changing the speed; and i + 1-stand press-down control device for controlling the rolling position of the i + 1 stand so that the rolled material tension between the i-stand and the i + 1-th stand downstream thereof matches the rolled material tension target value; Is provided.

[0016]

[Action] pressure control device (TC ₆₎ is, so to control the pressing position of the i stand to match the rolling material tension T _i-1 between the i-1 stand and i stand target value Ts _i-1 It is equal to the i-1 stand delivery side speed _{v i-1} and i stand entry side speed _{V i.}

[0017] Similarly pressure controller (TC ₇₎ is, i stand and i + 1 target value Ts _i the rolling material tension _{T i} between the stand
And controls the pressing position of the i + 1 stand to match the is equal to the side plate velocity v _i and i + 1 stand entry side speed V _{i + 1} out of i stand.

The i-1 stand speed controller (H
SC ₅₎ is, i stand entry side thickness H and i-1 stand Russia - based on Le peripheral speed Vref (i-1), the i-1 stands for compensating i stand entry side thickness deviation ΔH B The roll peripheral speed change amount ΔVref (i-1) is calculated, and the roll peripheral speed of the i-1 stand is changed accordingly.
The i-stand exit side thickness h does not fluctuate due to the fluctuation, and is maintained at the target thickness. That is, the above-described change in the roll peripheral speed of the i-1 stand acts as a disturbance to the tension between the i-1 / i stands, and the pressure reduction of the i stand is changed in order to keep this tension constant. Outer side plate thickness (i
(Stand entry side plate thickness) is corrected (i stand entry side plate thickness is kept constant).

Although the advance rate f _i of the i-stand may change due to the change in the rolling down of the i-stand and the tension between the i / i + 1 stands may be disturbed, in the present invention, the calculating means (FF _i ) sets the advance rate f of the i-stand to f. _i is calculated, in response to the forward slip _{f i} i stand speed controller (FTC) is, ΔVref (i) = - { Δf i / (1 + fs i)} · Vref (i) ··· (16) Is calculated, and the roll peripheral speed of the i-stand is changed accordingly. In other words, changes in the advanced rate Δf _i = _{f i} -
corresponding to fs _i, so as to absorb the tension variations due to the variations, the i stands Russia - Fixing Le peripheral speed. As a result, there is no change in the tension T _i between the i / i + 1 stand due to the change Δf _i of advanced rate, there is no i + 1 pressure change of stand, i + 1 does not cause a change to the side plate thickness out of the stand.
Note that i / i− to be generated by ΔVref (i)
It is assumed that the tension fluctuation between one stand is suppressed by the conventional mill speed progressive ΔVref (i−1) = {Vrefs (i−1) / Vrefs (i)} · ΔVref (i).

The speed controller (HSC ₅ ) is determined by the following equation (10).
A value corresponding to the roll peripheral speed change amount ΔVref (i−1) of the stand is calculated, and the roll peripheral speed of the i−1 stand is changed by the calculated value. Fluctuation ΔS
_{Even if the} advanced rate fluctuation Δfi _-1 is generated by _i-1 , compensation corresponding to the change is made to the roll peripheral speed change amount ΔVref (i-1) of the i-1 stand, and the i-1 stand is changed. Substantially no i-stand exit side thickness deviation Δh due to the rolling-down operation.
That is, the exit 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a new hot rolling control is applied to the # 5 stand and the # 6 stand (i stand, i = 6) of the hot tandem finishing mill, and the outlet side thickness h of the # 6 stand is set as a target. In the present invention, a constant value of tension hs is applied to the downstream # 7 stand, and a constant tension control is applied to the downstream # 7 stand, and in addition to this, the peripheral speed of the # 6 stand roll is corrected in order to suppress the thickness variation at the exit 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 on the final stand 7. In the # 5 stand, the AGC (automatic thickness controller) sets the output side thickness to the target thickness based on the measured load of the load cell LC and the entrance side thickness.
-1 Operate the stand-down mechanism HYD. That is, i
Automatically adjust the roll gap of the -1 stand.

The entry side thickness H _{i-1 of the} # 5 stand is the reference value Hs.
_{In the case of i-1} , the advance 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 thickness of the entrance side plate fluctuates and becomes H _i−1 , the advance rate f _i−1 on the exit side of the i−1 stand is f _i−1 = {0.455−0.233 (1 / μ _i−1 ). {[(H _i-1 −h s _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, given the _{γ i-1 = (H i} -1 -hs i-1) / H i-1 ··· (15 i-1). Here, H _i-1 : the thickness of the entrance side of the # 5 stand Hs _i-1 : the reference value of the entrance side thickness of the # 5 stand hs _i-1 : the reference value of the exit side thickness of the # 5 stand μ _i-1 : # 5 Deformation resistance of the stand [kgf / mm ² ] Re _i-1 : Flattening roll diameter [mm] of the # 5 stand G _i-1 : Adjustment coefficient K _i-1 : Coefficient T _i-1 : # 5 / # 6 Tension between stands Ti _-2 : Tension between # 4 / # 5 stands.

The advanced rate computing unit FF _i-1 calculates the above (14 _i-1 ), (1
5 _i-1 ) The advance rate f _i-1 of the i-1 stand, which is defined by the equation, is calculated, and this is used 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 correspond to the stand upstream of the i−1 stand and the
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 is set to the forward slip calculator FF _i-1 before the start of rolling.

Between the # 5 / # 6 stands, a looper type tension meter (T, AgD), an X-ray thickness gauge XRay and a plate speed measuring instrument LSM are installed. Tensiometer (T, Ag
D) is # 5 / # with providing a pressure control device TC ₆ tension responses by detecting the tension T _i-1 of the steel plate between 6 stands (rolled material), Le - detects the path angle Ag, speed Control device HS
Providing the tracking device 5 C _5. X-ray thickness gauge XRa
y measures the sheet thickness H of the rolled material (i.e., the plate thickness on the i-stand entry side) and gives it to the tracking device 5. The sheet speed setting device LSM measures the speed V of the rolled material (i. Give to.

The tension response pressure reduction control device TC ₆ reduces the pressure of the i-stand so that ΔT _i−1 becomes zero in accordance with the deviation ΔT _i−1 of the detected tension T _{i−1 from} the target tension Ts _i−1 . Equipment HY
Operate D. That is, the roll gap of the i-stand is automatically adjusted.

A looper type tension meter (T) is installed between the # 6 / # 7 stands. Tension meter (T) is # 6
/ # 7 detects the tension T _{i + 1} of the steel plate between the stand (rolled material) applied to the pressure control device TC ₇ tension response. 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 +1 stand pressing device HYD. That is,
The roll gap of the i + 1 stand is automatically adjusted.

The entry side thickness H _i of the # 6 stand is equal to the reference value Hs _i.
When the advanced rate fs _i for # 6 _{stands, 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 ) Where γs _i = (Hs _i −hs _i ) / Hs _i ... (13 _i ). On the other hand, if the thickness at entrance side becomes H _i varies,
Outgoing advance rate f of i-stand, ie, # 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 -hs i) / Re} i ] _{× {T i -T i-1} (H i / hs i)} / 2K i ··· (14 i) However, γ _i = (H _i -hs _i ) / H _i ... (15 _i ). Here, H _i : the entry side plate thickness of the # 6 stand (sometimes simply described as H) Hs _i : the entry side plate thickness reference value of the # 6 stand (sometimes simply described as Hs) hs _i : # 6 Standard value of the thickness of the exit side plate of the stand (may be simply expressed as hs) μ _i : Deformation resistance of the # 6 stand [kgf / mm ² ] Re _i : Flatning roll diameter [mm] of the # 6 stand G _i : Adjustment coefficient K _i : Coefficient T _i : Tension between # 6 / # 7 stands (sometimes simply written as T) T _i-1 : Tension between # 5 / # 6 stands

The advanced rate calculator FF _i is provided by the above (14 _i ), (15 _i )
Defined by the equation, to calculate the forward slip f _i of i stand to be provided to the speed controller HSC ₅ of i-1 stand.
In this embodiment, _Hi (= H) is an X-ray thickness meter XR.
_ai to the advanced rate calculator FF _i , T _i (= T) from the tensiometer (T), and T _i−1 to the tensiometer (T, Ag)
d), Hs _i (= Hs), hs _i (= hs), μ _i ,
Re _i and K _i are set to forward slip calculator FF _i before the start of rolling.

FIG. 2 shows the speed control device H of the i-1 stand.
₃ shows the configuration of SC5. Tracking device 5 of the speed controller HSC ₅ is moved time of the rolled material from the X-ray thickness gauge XRay # to 6 stands, measuring the measurement data of X-ray thickness gauge XRay - delaying retain data H _i (= H) is intended, that a rolling material when it is bitten # 6 stands, the thickness of the point de - output data H _i a (= H) to the subtracter 1C. That is, in the tracking device 5, the plate thickness H _i (= H) measured by the X-ray thickness meter XRay, the plate speed V measured by the plate speed measuring device LSM, and the loop measured by the tensiometer (T, AgD).
The tracking angle Ag is given, and the tracking device 5 writes the sheet thickness into the sheet thickness memory at a cycle ts described later, and the looper angle Ag.
The length of the rolled material from immediately below the X-ray thickness gauge XRay to the position where the # 6 stand is engaged with the work roll is calculated, and the time required for the rolled material to move by this length is calculated. Is divided by the set number n to calculate the data shift period ts,
In this cycle ts, the thickness De of the plate thickness memory used as a shift register having n stages - by shifting the data, the thickness De written in a plate thickness memory before ts × n - data H _i a (= H), Output to the subtractor 1C. In other words, the rolled material which is currently in the position of the # 6 stand in the work-roll bite position, is first put on the X-ray thickness meter XR.
The thickness data H _i (= H) measured in step ay is output to the subtractor 1C.

The sheet thickness H and the sheet thickness reference value Hs are provided to the subtractor 1C.
Is subtracted, and the subtractor 1C calculates the entry-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 the calculated ΔH / Hs to the adjustment coefficient multiplier 4C. The multiplier 4C sets the adjustment coefficient α1 to ΔH /
Hs is multiplied and given to the subtractor 7.

The subtractor 1A of the speed controller HSC ₆ of the i-1 stand calculates the deviation of the advance rate f _i-1 of the # 6 stand calculated by the advance rate calculator FF _i-1 from the reference value fs _i-1 . Δ
f _i-1 = f _i-1 -fs _i-1 is calculated and given to the divider 3A.
On the other hand, the adder 2A calculates 1 + fsi _-1 and supplies it to the divider 3A, and the divider 3A calculates Δfi _-1 / (1 + fsi _-1 ) and supplies 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
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 ), and the adjustment coefficient multiplier 4B and the i-stand speed control device FTC
(FIG. 1). The multiplier 4B sets the adjustment coefficient α3 to Δf
_i / by multiplying (1 + fs _i) providing to the subtractor 6.

The subtractor 6 outputs the output α3 · Δf of the multiplier 4B.
_i / output (1 + fs _i) from the 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 ・ Δfi _-1 / (1 + fsi _-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, and ΔVref _i-1 = {− α1 · ΔH / Hs−α2 · Δfi _-1 / (1 + fs) _{i-1) + α3 · Δf} i / (1 + fs i)} · Vrefs i-1 ··· a (10r) and outputs it 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:
It corresponds to ΔVref (i-1) calculated by the equation (10).

The adder 9 adds the roll peripheral speed reference value Vrefs _i-1 of the # 5 stand to the output ΔVref _i-1 of the multiplier 8, and adds the roll peripheral speed target value Vref _{i of the} # 5 stand. _-1 = Vrefs
_i-1 + .DELTA.Vref _i-1 is supplied to the # 5 stand mill motor speed controller ASR, and the speed controller ASR determines that the roll peripheral speed of the # 5 stand is 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 # 6 stand entrance side mass flow is kept constant. Even if the advance rate variation Δf _i−1 is generated due to the variation ΔS _i−1 of the rolling position of the # 5 stand, the compensation corresponding to the variation ΔF _{i−1 of the} roll peripheral speed of the i−1 stand is ΔVref _i−1.
And the thickness deviation Δh of the # 6 stand exit side due to the influence of the # 5 stand rolling-down operation is not substantially generated.

Referring back to FIG. As mentioned earlier, HS
It gives the i stand speed controller FTC divider 3B of C ₅ are calculated Delta] f _i / a (1 + fs _i). The i-stand speed control device FTC uses the multiplier 11 to adjust the adjustment coefficient α4 to Δf _i /
(1 + fs _i ), and the product α4 · Δf
_i / (1 + fs _i ) is the roll peripheral velocity reference value Vr of the i stand.
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 control device F
The TC calculates the speed command value (target value) Vref _i = Vrefs _i -ΔVref _i (17) to the mill motor speed control device ASR of the # 6 stand by the subtractor 13 to obtain the value of the # 6 stand. Mill motor speed controller A
Give to SR. The # 6 stand speed control device ASR
# 6 stand B - Le peripheral speed so that the command value Vref _i, # 6 stands Mirumo - controlling the rotational speed of the motor M. The # 6 stand roll peripheral speed change amount ΔVre
The tension fluctuation between i / i-1 stands to be caused by f _i is the mill speed successive ΔVref (i−1) = [Vrefs (i−1) / Vrefs (i)] × ΔVref conventionally applied. It is assumed that the # i-1 stand roll peripheral speed change amount obtained in (i) is suppressed by subtracting from the # 5 stand roll peripheral speed command Vref _i-1 calculated by the HSC 5 as shown in FIG.

Next, the results of the simulation will be described. The simulation was carried out at the # 5 to # 7 stands of hot tinedem finish rolling at Kimitsu Works. The exit side thickness target value hs of the # 7 stand is 3.2 mm. The rolling control is a combination of the following two methods in time series.

Conventional type 1: For each of the # 5, # 6, and # 7 stands, the thickness change at the stand-out side of each stand is detected from the rolling load detected by the load cell, and the rolling position (roll gap) is correspondingly determined. Modify (BISRA-AGC). The roll peripheral speed of the # 5 stand is changed in accordance with the angle fluctuation of the looper installed between the # 5 and # 6 stands, and the loop length between the stands is operated to keep the looper angle constant. Similarly, the roll peripheral speed of the # 6 stand is changed in accordance with the angle fluctuation of the looper installed between the # 6 and # 7 stands, and the loop length between stands is operated to keep the looper angle constant.

INV type: In the # 5 stand, the thickness change at the outlet 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 a tension meter, 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 a tension meter, and the rolling position (roll gap) of the # 7 stand is corrected so that the tension value becomes the reference value. The thickness between # 5 and # 6 is measured, the measurement position is tracked, and the measurement point is # 6
At the timing of reaching the 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 expression (10) or (10r)
Based on the formula, to correct the roll peripheral speed of the # 5 stand,
# 6 to reflect the change, as well as # 5 stand fluctuations in the advanced rate f _i-1 of the stand advanced rate f _i. Further, as described in the above embodiment, the roll peripheral speed change amount ΔVref _i of the # 6 stand is calculated based on the expression (16) or (16r), and
Change the roll peripheral speed of 6 stands.

In the simulation, an amplitude of 30 ° C. and a change rate of 0.75 ° C. /
A sheet temperature fluctuation of sec is given, and the conventional type 1 is controlled until 12 seconds elapse from the start of rolling.
Control was performed by INV type, and after 22 seconds, control was performed by Conventional type 1. The result is shown in FIG. FIG. 3A shows the obtained plate thickness variation on the # 7 stand entry side, and FIG.
The stand thickness variation on the exit side is shown. In the INV type control section according to the present invention (12 to 22 seconds section in FIG. 3B),
High effect of suppressing thickness fluctuation.

[Brief description of the drawings]

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

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

FIGS. 3A and 3B are graphs showing simulation results of rolling control according to one embodiment of the present invention, wherein FIG. 3A shows a variation in the thickness of the # 7 stand entrance side, and FIG. Show. The result of one embodiment of the present invention is shown in FIG.
Appears in the ~ 22 seconds section.

FIG. 4 shows a case where one embodiment of JP-A-6-269830 is applied to the # 5 and # 6 stands, and the # 7 / # 7 stand is lowered and adjusted so as to maintain a constant tension between the # 6 and # 7 stands. It is a graph which shows the simulation result of,
(A) shows the thickness change of the # 7 stand entrance side, and (b) shows the
The thickness variation on the exit side of 7 stands is shown. JP-A-6-26983
The results of applying the embodiment of the publication No. 0 to No. 12 in FIG.
Appears in the 22-second section.

[Explanation of symbols]

FF _i-1 , FF _i : Advanced rate calculator AGC: Automatic thickness control device LD: Load cell HYD: Roll-down 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 reduction control device HSC ₅ : Speed control device 1A to 1C, ₆ , ₇ , 13: Subtractors 2A, 2B,
9: adder 3A-3C: divider 4A-4C,
11: Coefficient multiplier 5: Tracking device 8, 12: Multiplier

Continuation of front page (56) References JP-A-8-252616 (JP, A) JP-A-8-57509 (JP, A) JP-A-6-335719 (JP, A) JP-A-5-96316 (JP) JP-A-4-84614 (JP, A) JP-A-61-266111 (JP, A) JP-A-61-147912 (JP, A) JP-A-58-192615 (JP, A) 58-135711 (JP, A) JP-A-58-119415 (JP, A) JP-A-58-81506 (JP, A) JP-A-56-126015 (JP, A) JP-A-53-65246 (JP, A A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 37/18

Claims (1)

(57) [Claims] 1. A plate thickness measuring device and a tension measuring device are provided between an i-1 stand and an i stand to control a rolling amount and a peripheral speed of each stand so that a plate thickness after rolling matches a target value. In the rolling control device of the hot tandem rolling mill, the lower position of the i-stand is set so as to coincide with the target value of the rolled material tension between the i-1 stand on the upstream side and the i stand on the downstream side in the moving direction of the rolled material. calculating means for calculating the forward slip f _i of i stand; calculation means for calculating the i-1 forward slip f _i-1 stand; i stand reduction control device for controlling i stand entry side thickness H, the deviation delta H, The advanced rate f _{i-1 of} the i-1 stand, the advanced rate reference value fs of the i-1 stand
_i-1, i stand forward slip f _i, forward slip reference value fs _i and i-1 stand roll peripheral speed Vref of i stand (i-
Roll peripheral velocity change amount of i-1 stands for compensating i stand entry side thickness deviation delta H on the basis of 1) ΔVref (i-1) , ΔVref (i-1) = {- (ΔH / Hs) - _{Δf i-1 / (1 +} fs i-1) + Δf i / (1 + fs i)} Vref (i-1) ( _{except, Δf i-1 = f i} -1 -fs i-1, Δf i = f i -fs _i ) a speed control device that calculates a value corresponding to _i ) and changes the roll peripheral speed of the i-1 stand accordingly; and in the stands subsequent to the i stand, the advanced rate f _i of the i stand, i-stand advanced rate reference value f
Based on the s _i and i roll peripheral velocity Vref stand (i), ΔVref (i) = - {Δf i / (1 + fs i)} · Vref (i)
I-stand speed control device for calculating the value corresponding to the i-stand and changing the roll peripheral speed of the i-stand accordingly; and so that the rolled-material tension between the i-stand and the i + 1-th stand downstream thereof matches the rolled-material tension target value. To i + 1
A rolling control device comprising: a (i + 1) stand rolling control device that controls a rolling position of a stand.