JPH0581326B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hot rolling process, particularly to strip width control of a steel strip or steel plate manufactured by hot continuous rolling, and particularly to a feed forward control method and a control device. It is something.

BACKGROUND ART Strip width control in rolling equipment that combines a vertical rolling mill and a horizontal rolling mill used in the rough rolling process and plate rolling process of continuous hot rolling has been carried out for a long time. A representative example of this is, for example, Japanese Patent Publication No. 50-24907, and a block diagram of its control technology is shown in FIG. In that diagram,
Steel plates are rolled from the left to the right,
On the entry side of the vertical rolling mill EM, the strip width is measured with a strip width meter W1, 2 is the measurement signal, 1 is the target strip width, and the deviation value is the etching efficiency by the vertical rolling mill with f1. Then, considering the width expansion due to the horizontal rolling mill at f2, the vertical rolling mill
Feed forward control is performed by manipulating the vertical roll position of the EM to control the strip width at the exit side of the horizontal rolling mill HM to be constant. Also, if necessary, HM
Feedforward control and feedback control may be realized by adding a correction value obtained by controlling and calculating the board width deviation value 3 measured by the board width meter W2 on the outlet side. Further, if the length of the steel plate is short and feedback control is not effective, it is desirable to adopt learning control as disclosed in the above-mentioned known example as feedback control between steel plates.

Next, a unique phenomenon in sheet width control of steel sheets will be explained. Fig. 8 shows an example in which the width reduction of a steel plate is carried out using a vertical rolling mill and a horizontal rolling mill.
SLAB' is the same steel plate after rolling, W.A is the longitudinal end of SLAB, W.A' is the same position after rolling, W.
B is the local constant temperature part of the SLAB, also known as the skid mark, W・B' is the same position after rolling, W・C is the local wide part of the SLAB, and W・B' is the same position after rolling.
C′ represents the same position after rolling. Furthermore, E.R.
is a vertical rolling mill, HR is a horizontal rolling mill, and SLAB'' is a
The cross-sectional shape in the thickness direction of point ZZ of SLAB is shown, and W0
is the plate width of SLAB, W1 is the actual roll gap of ER, and W2 is the actual width of the sheet rolled into a rectangle after width reduction by ER and thickness reduction by HR.

When rolling a steel plate with the configuration shown in this figure, the steel plate after being rolled by the vertical rolling mill ER will have locally thickened parts, commonly called dog bones, at both ends in the width direction. Then, when the steel plate is rolled in the next horizontal rolling mill HR, the width of the steel plate increases to W2, so it becomes necessary to adopt the concept of etching efficiency (W0-W2/W0-W1) for sheet width control. This is a phenomenon peculiar to

[Problem to be solved by the invention]

In the strip width control according to the previous example, only the change in the entrance strip width is controlled by feedback, but there are many other disturbances such as temperature changes, strip thickness changes, and component changes, and the effects of these can be controlled by feedback control or Even in the case of feedback control, there is a control delay of several meters on the steel plate due to the constraints on the general mill layout, which limits its effectiveness.

Generally, this strip width control is carried out during the rough rolling stage of hot rolling, so if strip width variation exists at a pitch of 1 meter, the final product stage of the hot steel plate after finish rolling will be several meters long. It is destined to expand to over 30 meters.

Therefore, recently, a single hot rolling mill can perform various types of hot rolling using various rolling methods such as low-temperature rolling, rolling of extremely thick materials, rolling of extremely thin materials, rolling of materials with strict shapes, and rolling of low-rank materials. When we started manufacturing rolled materials,
Plate width control is required to be highly accurate and highly responsive, greatly improving conventional capabilities.

Furthermore, if possible, instead of controlling the width of the steel plate after rough rolling to a constant value, the width of the steel plate in the hot finished product should be kept constant by taking into consideration the characteristics of the width variation of the steel plate in the finishing rolling mill. There has been a demand for such control, that is, control in which the width of the steel plate is not constant after rough rolling but constant after finish rolling, or in other words, overcompensation control with high precision.

[Means to solve the problem]

The present invention provides a highly accurate strip width feedforward control method and device that measures strip width fluctuations on the entry side and rolling load fluctuation values of the upstream vertical rolling mill, and combines control loops corresponding to each. The purpose is to provide.

The means of the present invention for solving the above problems are as follows.

First, a plurality of sets of rolling equipment each comprising a vertical rolling mill and a horizontal rolling mill according to claim 1 are arranged, a strip width gauge is provided on the entry side of the controlled vertical rolling mill to be controlled, and the control vertical rolling mill is In a hot rolling facility in which a front vertical rolling mill in a set in front of a type rolling mill is provided with a rolling load cell, and a steel plate tracking device is provided in the horizontal rolling mill or measuring roll, the steel plate tracking device determines the measuring the rolling load at a certain position on the steel plate with the rolling load meter, calculating the deviation value between the measured value of the rolling load and the pre-calculated predicted value,
A load correction amount is calculated based on the deviation value of the rolling load, a predetermined etching efficiency, and the mill rigidity value of the controlled vertical rolling mill, and the load correction amount is multiplied by the load control gain. The controlled variable is based on the steel plate tracking device, when a certain position on the steel plate reaches the plate width meter, the plate width of the steel plate is measured with the plate width meter, and the plate width measurement value is Sheet width correction control in which a sheet width correction amount is calculated based on a deviation value from a predetermined entry side sheet width target value and a predetermined etching efficiency, and the sheet width correction amount is multiplied by a sheet width control gain. A reduction correction amount of the vertical roll of the controlled vertical rolling mill is calculated by adding the amount, and when a certain position on the steel plate reaches the controlled vertical rolling mill, the vertical roll of the controlled vertical rolling mill A method for controlling the width of a hot-rolled steel plate, characterized in that the rolling position of the vertical roll is repeatedly adjusted in accordance with the reduction correction amount of the vertical roll, and the method is controlled for each predetermined length of the steel plate. In item 2, a plurality of sets of rolling equipment each consisting of a vertical rolling mill and a horizontal rolling mill are arranged, a strip width gauge is provided on the entry side of the controlled vertical rolling mill to be controlled, and the control vertical rolling mill is In a hot rolling facility in which a rolling load cell is installed in the front vertical rolling mill in the previous set, and a steel plate tracking device is installed in the horizontal roll or pinch roll of the horizontal rolling mill, the rolling load is calculated for each predetermined length on the steel plate. is measured by the rolling load meter, the rolling load value is predicted, a deviation value between the measured rolling load value and the predicted value is calculated, and the deviation value of the rolling load and a predetermined etching efficiency are determined. A load correction amount is calculated for each predetermined length based on the mill rigidity value of the controlled vertical rolling mill, and a load correction control amount obtained by multiplying the load correction amount by a load control gain is calculated based on the steel plate tracking device. , When the rolling load measurement position on the steel plate reaches the plate width gauge, the plate width of the steel plate is measured with the plate width gauge, and the plate width measurement value and the predetermined entry side plate width target value are measured. The control vertical shape Calculate the reduction correction amount of the vertical roll of the rolling mill,
When the rolling load measurement position on the steel plate reaches the controlled vertical rolling mill, the rolling position of the vertical roll of the controlled vertical rolling mill is adjusted in accordance with the rolling correction amount of the vertical roll. A method for controlling the width of a hot-rolled steel plate, when applied to a reversible rolling type rolling equipment, as claimed in claim 3, in which a rolling equipment comprising a vertical rolling mill and a horizontal rolling mill is arranged to enable reversible rolling. A strip width gauge is provided on the entry side of the controlled vertical rolling mill to be controlled, a rolling load meter is provided on the controlled vertical rolling mill, and a steel plate tracking device is provided on the horizontal roll or pinch roll of the horizontal rolling mill. In the provided hot rolling equipment, the rolling load is measured by the rolling load meter for each predetermined length on the steel plate, and is stored sequentially, so that the rolling load corresponding to the predetermined length on the steel plate is measured during the next rolling pass in the same direction. For each point, predict the rolling load value at that point, calculate the deviation value between the memorized value of the rolling load at that point and the predicted value, and calculate the deviation value of the rolling load and a predetermined etching efficiency, A load correction amount is calculated based on the mill rigidity value of the controlled vertical rolling mill, and the load correction control amount is obtained by multiplying the load correction amount by a load control gain.
Based on the steel plate tracking device, when a position corresponding to the predetermined length on the steel plate reaches the plate width meter, measure the plate width of the steel plate with the plate width meter, and calculate the plate width measurement value. The board width correction is calculated based on the deviation value between the input side board width target value and the predetermined etching efficiency, and the board width correction is multiplied by the board width control gain. A reduction correction amount of the vertical roll of the controlled vertical rolling mill is calculated by adding the control amount, and when a certain position on the steel plate reaches the controlled vertical rolling mill, the vertical roll of the controlled vertical rolling mill The present invention provides a method for controlling the width of a hot-rolled steel sheet, characterized in that the rolling position of the rolls is adjusted in accordance with the rolling correction amount of the vertical rolls.

Furthermore, when a hot rolling facility in which a hot finishing mill is disposed on the outlet side of a controlled vertical rolling mill is targeted, the so-called overcompensation of claim 4, which controls the strip width after hot rolling to a constant value, is applicable. As a control, in calculating the reduction correction amount, the load correction control amount is multiplied by the load correction control amount based on the temperature fluctuation of the steel plate and the strip width correction control amount based on the steel plate width fluctuation, and the load correction control amount is multiplied by an overcompensation gain. This is a sheet width control method characterized in that a combined overcompensation correction control amount is added.

Furthermore, as a control device, in the hot rolling equipment according to claim 5, in which a plurality of rolling equipment including a vertical rolling mill and a horizontal rolling mill are arranged or arranged so as to be capable of reversible rolling, the controlled vertical rolling to be controlled is performed. A strip width gauge installed on the entry side of the machine, a rolling load meter installed in the front vertical rolling mill in the set in front of the controlled vertical rolling mill, and a rolling roll, pinch roll or measure ring of the horizontal rolling mill. a tracking device configured with a pulse oscillator and a counter provided on the roll; a rolling load measuring section that measures a predetermined length on the steel plate from the rolling load meter in accordance with pulses from the tracking device; a strip width measurement section that measures from the strip width meter in response to pulses from the tracking device for each predetermined length of A memory section stores the rolling load in a memory corresponding to the position on the steel plate at the time of measurement, and the load is calculated based on the memory value of the rolling load stored in the memory section, predetermined etching efficiency, mill rigidity value, and load control gain. At the same time as calculating the correction control amount, the strip width correction control amount is calculated based on the memory value of the strip width at the same position as the memory value of the rolling load, and the predetermined etching efficiency and strip width control gain. After calculating the reduction correction amount of the vertical rolls of the controlled vertical rolling mill by adding the load correction control amount and the strip width correction control amount, the vertical roll reduction amount of the controlled vertical rolling mill is There is a sheet width control device for a hot-rolled steel sheet, characterized by comprising a feed forward control section that outputs the reduction correction amount to a roll positioning device, and also as a control device for realizing overcompensation control. There is also a device in which the feed forward control section described in item 6 is provided with a means for this purpose.

[Effect]

As shown in Fig. 8, the main disturbances in controlling the width of a steel plate are the edges of the steel plate at points W and A, W and B.
These are the low temperature part of the steel plate at the point and the width varying part at the W and C points. The control concept for these disturbances is to perform width reduction at the W/B point by correcting the elongation of the vertical roll ER due to the increase in load in the low-temperature section of the steel plate, and
At point W and A, the width reduction is performed by taking etching efficiency into account and correcting the ER elongation due to the increase in load, and at points W and A, the change in etching efficiency due to the change in metal flow at the edge of the steel plate is calculated. It is necessary to perform a corrected width reduction.

Then, in plate width control, the control gain should be changed depending on these disturbance factors, so high performance cannot be achieved unless a fairly complex control system is used.

It has been desired to establish a sheet width control system in which at least the temperature fluctuation factors of the steel plate and the sheet width fluctuation factors of the steel sheet are separated and multiplied by independent control gains corresponding to each.

It is common knowledge that it is desirable to combine such feedback control with feedback control.

Now, a first example of the sheet width control system of the present invention will be described.
As shown in the figure. E2 is a controlled vertical rolling mill, and R2 is a horizontal rolling mill paired with rolling mill E2. E1 and R1 are a pair of rolling equipment in front of rolling mill E2, and E
1 is a front vertical rolling mill, which is equipped with a load meter that can measure the rolling load value of the vertical rolls, and R1 is a front horizontal rolling mill. The rolling mills R1 and R2 are equipped with tracking devices P1 and P2 consisting of pulse oscillators, counters, etc., which generate starting pulses etc. every time the steel plate advances a certain distance, and perform calculations and commands in each control section. etc. as a start signal, and E
Timing pulses such as starting pulses are also sent to each control section when the rolling load measurement point on the steel plate reaches the plate width gauge W1 and E2.

G1 is a rolling load measurement, in which a rolling load value EF1 is measured using a rolling load system, and a predicted rolling load value F1 is calculated based on the rolling schedule using the following first equation.

F1=k _n1 ×h ₁ ×Ld1×Qp1 ……(1) Here, k _n1 = Deformation resistance of the steel plate during E1 rolling h ₁ = Thickness of 〃〃 Ld1 = Contact arc length of 〃〃 Qp1 = 〃 Rolling force function F1 of 〃 = predicted load value of 〃 Then, deviation value DF of rolling load from EF1 and F1
is calculated using the following second equation.

DF=EF1-F1...(2) The amount dBIF by which the amount due to DF causes width fluctuation on the E2 input side is determined by the following third equation.

dBIF=a ₁ × DF/M1 ...(3) Here, M1 is the mill stiffness value of E1, and a ₁ is E
1 and R1. Then that
The amount by which dBIF changes in width at the R2 output side
dBOF is determined by the fourth equation.

dBOF=(1-a ₂ )dBIF (4) where a ₂ is the etching efficiency of the pair of E2 and R2.

E2 pressure reduction correction dE to offset that dBOF
2F can be found using the fifth equation.

dE2F=dB0F/a ₂ ...(5) Then, from equations 3, 4, and 5, dE2F can also be found using equation 6.

dE2F=a ₁ (1-a ₂ ) DF/a ₂ M1 ...(6) When the first control gain is k ₁ , the correction amount (first value) dEF for the variation in rolling load can be found using the seventh equation .

dEF=k ₁ a ₁ (1-a ₂ )/(a ₂ M1) ...(7) Next, at the timing when the rolling load measurement point in the rolling mill E1 reaches the plate width gauge W1 by the tracking device, The board width is measured, and the deviation value from a predetermined board width target value WS is expressed as DW.

The amount dBOW by which DW changes in width on the output side of R2 is determined by the eighth equation.

dB0W=(1-a ₂ )DW ……(8) E2 pressure reduction correction to offset the dB0W
dE2W can be found using Equation 9.

dE2W=dB0W/a ₂ ...(9) From the above, dE2W can also be found by the following equation 10.

dE2W=(1−a ₂ )DW/a ₂ (10) If the second control gain is k ₂ , the correction amount dEW for the variation in plate width can be found by Equation 11.

dEW=k ₂ (1-a ₂ )DW/a ₂ ...(11) Therefore, the rolling reduction correction amount EX of rolling mill E2 is the above
It is expressed as the sum of dEF and dEW.

EX=dEF+dEW=k ₁ a ₁ (1-a ₂ )DF/(a ₂ M1)+k ₂
(1-a ₂ )DW/a ₂ (12) However, strictly speaking, the plate width variation is also included in the load variation, so it should be excluded. Therefore, the influence coefficient of plate width variation on load variation is b
Then, EX becomes equation 13.

EX= ₍ 1-b) _k1a1 (1- _a2 )DF/ _Ca2M1 )
+k ₂ (1-a ₂ )DW/a ₂ ...(13) However, if (1-b) is included in k ₁ , Equation 12 can be used as is.

Therefore, the plate width control of the present invention is a method in which feedforward control is performed at the same timing according to the 12th or 13th equation.

As for timing adjustment in this control method, the method of adjusting the timing for each predetermined length of the steel plate is a very effective method because the influence of the rolling speed can be eliminated.

In this example, the plate width meter W1 is placed between R1 and E2, but it can of course be placed before E1, and in that case, it is only necessary to slightly change the formula 8 and later. , are basically the same.

The control gain is determined by considering the stability and responsiveness of the process, and ideally it is desirable to set it to 1.0.

Furthermore, when combining with a feedback control system, the above equation 12 may be replaced with the following equation 14.

dx＝ _k1a1 ( ₁ − _a2 )DF／( _a2M1 )＋ _k2 (1−
a ₂ ) DW/a ₂ +k ₃ DW3/a ₂ (14) where k ₃ = feedback control gain DW3 = board width deviation value on the R2 output side.

Various general-purpose controls such as proportional control, proportional-integral control, and proportional-integral-derivative control can be used as is for this _k3 .

When the strip width control explained above is carried out, the strip width at the R2 exit side becomes constant, which is fine for thick plate rolling, etc., but in the case of continuous hot rolling mills, this strip width control keeps the strip width constant. This is rough rolling, and it is natural that a finishing mill is installed after that, and when the plate is rolled by the finishing mill, the width of the plate will fluctuate even if it is rectangular at the entry side. Are known.

As a result of various studies on this point, the inventor of the present invention has found that among various disturbances, factors based on temperature fluctuations of the steel plate, such as skid marks, occur. Furthermore, it has been found that the variation in plate width caused by the finishing mill is approximately determined by the steel type of the steel plate and the width and thickness dimensions of the steel plate.

Based on these findings, as a result of various studies and experiments, it was confirmed that the reduction correction amount EX of E2 can be set to the following equation 15 based on the above equation 12. In other words, the component whose width fluctuates due to DF in Equation 12 and the component whose width fluctuates in the finishing rolling mill in the subsequent process both occur due to the same temperature fluctuation and exhibit the same behavior, so Equation 12 DF The width is corrected in advance by multiplying the term by the coefficient G to correct the finishing width variation amount. Moreover, this coefficient G is an empirical value adjusted in an actual control test. k ₁ a ₁ (1-a ₂ ) in the following formula
DF×G/(a ₂ M1) represents the correction term for the finishing width variation amount.

dx＝ _k1a1 ( ₁ - _a2 )DF/( _a2M1 )+ _k2 (1- _a2 )DW/ _a2
+ _{k1a1 (} 1- _a2 )DF×G/( _a2M1 )= _k1a1 (1- _a2 )DF ₍ 1+G
)/( _a2M1 )+ _k2 (1- _a2 )DW/ _a2 ...(15) Here, G is called overcompensation gain.

G is determined depending on the type, thickness, and width of the steel plate, and the specific value is usually determined based on data from past experiments.
The present invention will be described in detail below according to embodiments.

Embodiment 1 In a hot rolling facility having two sets of rolling equipment as shown in FIG. The roll position is adjusted by receiving the vertical roll reduction correction amount signal f as the positioning correction amount. R2 is a controlled horizontal rolling mill;
This horizontal roll is equipped with a tracking device P2 consisting of a pulse oscillator and a counter, and a board width measuring section G
2 and a feedforward control unit G3, a timing pulse g for activation or command is sent to the feed forward control unit G3.
A board width gauge W1 is placed on the entry side of E2, and g or c
The plate width measurement unit G2 measures the width of the steel plate according to the measurement position, matches the measurement position of the steel strip in the memory in the storage unit, and transmits the measured value to be stored.
It is. There is a front horizontal rolling mill R1 on the entry side of the rolling mill E2, and its horizontal rolls are equipped with a tracking device P1 similar to R2, which generates timing pulses c every predetermined length of the steel strip and detects the rolling load measuring unit. G1
and is sent to the plate width measuring section G2. A front vertical rolling mill E1 is arranged on the entry side of the rolling mill R1, and a rolling load meter EF1 is installed in E1 to measure the rolling load of the steel strip and send the measured value a to G1. There is. The rolling load measuring section G1 samples the measured value a of the rolling load in response to the timing pulse d, and sends it to the storage section as a measured value h. In the memory section,
In G1, it is calculated from the rolling load predicted value signal F1 input in advance and the second equation, and the calculation result is set as a signal h, and in G2, it is obtained as a signal d from the input plate width target value WS and plate width meter W1. It receives the signal j sent out to calculate the deviation from the actual width and set it as DW, and stores those measured values in the DF and DW memories according to the measurement position on the steel strip.

In the feed forward control unit G3, the memory value DF of the rolling load and the memory value of the strip width are retrieved from the memory unit in response to the timing pulse g from the tracking device P2.
Receive DW as l, m, calculate the predicted value of rolling load from DF and predetermined rolling conditions, obtain its deviation value, and then calculate the predetermined etching efficiency, mill rigidity value, and load control gain. The load correction control amount is calculated according to the seventh equation based on the DW, and at the same time, it is calculated according to the eleventh equation based on the DW, its predetermined target value, etching efficiency, and sheet width control gain. After that, EX calculated according to the 12th or 13th equation becomes the rolling opening correction amount of the vertical roll of the controlled vertical rolling mill E2 and is output as a signal f=EX to ES2. ES2 is a rolling opening adjusting device for the controlled vertical rolling mill E2, which adjusts the rolling opening of E2 in accordance with the rolling opening correction amount received as a signal f=EX.

As a result of rolling a steel strip of ordinary steel having the following dimensions using the strip width control device configured as described above, the results shown in a and b in FIG. 5 were obtained. In a, the present invention has a width of 100 mm within the required range of product width + 4.0 to 5.0 mm.
% was within the required range, whereas in the comparative example only 20% was within the required range.

(a) (b) (Thickness) (Width) (Thickness) (Width) Slab dimensions: 250mm×900~1200mm 250mm×6
00~900mm Product dimensions: 1.8~4.5mm x 900~1200mm 1.8~
4.5 mm x 600 to 900 mm The comparative example is the preceding example shown in FIG. 7 mentioned above.

Embodiment 2 As shown in FIG. 2, this is a sheet width control system that combines the feedforward control shown in FIG. 1 with a feedback control system. The feedback control system measures the strip width deviation value of the steel strip with a strip width meter W2 located on the output side of R2, and sends the measured value n to the feedback control section GB. In GB, the measured value n is multiplied by general-purpose proportional control or proportional-integral control as the feedback control gain, and the feedback reduction correction form q is calculated based on the concept of equation 14, q=
It is calculated as _k3・DW3/ _a2 , where _k3 is the feedback control gain, which is a proportional coefficient of, for example, 0.6 to 0.9, and DW3 is the value taken as the measured value n from the plate width meter _W2 above. This is the difference between the plate width target value WS2, _{and a2} is the etching efficiency of the pair of E2 and R2, as in Example 1. This feedback reduction correction amount q is output to ES2.

The results of rolling under the same conditions as in Example 1 using this sheet width control device were almost the same as in Example 1.

Embodiment 3 This is a board width control system configured as shown in FIG. This example is basically the same as Example 1, but differs in the following points. First, a strip width gauge W1 is placed on the entry side of the front vertical rolling mill E1, and then a tracking device is installed on the horizontal rolling mills R1 and R2 and the measuring roll MR on the entry side of the strip width gauge W1. , sending timing pulses to G1, G3, and G2, respectively. Furthermore, in the feedforward control section G3, the calculation method of the correction amount dEW for the variation in the board width with respect to the measurement value with the board width meter is performed using the following equation 16 instead of the above equation 11.

dEW=k ₂ (1-a ₁ ) (1-a ₂ )DW/a ₂ ...(16) The 16th equation is the 11th equation multiplied by (1-a ₁ ), but the above a ₂ is This is the etching efficiency of the set of E2 and R2, which is the same as the explanation of the fourth equation, and _a1 is the etching efficiency of the set of E1 and R1. In other words, in Fig. 3, since the plate width gauge W1 is in front of E1, E1 allows (1-
_a1 ) This is because the width fluctuation becomes smaller by the ratio.

Therefore, the reduction correction amount EX of E2 is calculated using equation 17.

EX=(1 _- b) _k1a1 (1- _a2 )DF/( _a2M1 )+ _k2
(1-a ₁ ) (1-a ₂ ) DW/a ₂ ...(17) Equation 17 is the DW term of Equation 13 multiplied by (1-a ₁ ), but the above Equation 11 Since it was replaced by the 16th expression, the 13th expression also becomes the 17th expression.

All other details are the same as in Example 1.

Further, it goes without saying that a feedback control system may be combined as in the second embodiment using the measured value of the plate width meter W2 provided on the outlet side of R2.

Embodiment 4 As shown in FIG. 4, this is an embodiment of a strip width control system with an overcompensation function applied to a rough rolling mill of a continuous hot rolling mill. The arrangement and connections of each component of the strip width control system are the same as in the third embodiment, except that E2 in the feedforward control section G3
The difference is that the calculation of the reduction correction amount EX is performed using the above-mentioned formula 15. In the figure, RF is a heating furnace, VSB is a vertical slab rolling mill, R0 is a horizontal rolling mill behind VSB, FM is a hot finishing mill, and W
1 is the board width meter on the E1 entrance side, W2 is the board width meter on the rear side of R2, and W3 is the board width meter on the FM exit side.

A representative example of the variation within a steel plate at each point of the plate width control system is the plate width variation value in the plate width system W1.
DW (measured value - target value) with the tip of the steel plate as T,
The rear end is designated as B. The rolling load fluctuation values DF (measured value - predicted value) on the rolling load meter in the rolling mill E1 are expressed from T to B. The measured value of W2, which is the result of controlling the width of the contact plate in consideration of these fluctuations, is
The case where the overcompensation gain is set to zero is expressed as W2a, and in this case, since the control is to keep the plate width constant at W2, it is a substantially constant value. The measured value at W3 after the W2a steel plate is FM rolled is shown as W3a, and as can be seen, the width of the W3a steel plate cannot be said to be constant. On the other hand, when the overcompensation gain is set to an appropriate value in G3, the strip width at the exit side of R2 exhibits a variation that overcompensates for the variation value DF of the rolling load, as shown by W2b. Then, when the steel plate of W2b is rolled by FM, it becomes a substantially constant value as shown in W3b. This is the effect of giving G3 an overcompensation function, and the overcompensation gain G is determined by the steel type, thickness, width, etc. of the steel plate.

Here, the target is ordinary steel, and the slag size is 250.
Hot finishing mill entry size 40 from mm thickness x 1650mm width
It was rolled to a finish mill exit size of 2.71 mm thick and 1590 mm wide with a thickness of mm and a width of 1597 mm. The results of board width control with overcompensation gain G=10 are shown in FIG. 6a. (R,
A chart of the measured values of W2 is shown in B from T of W) for reference, and the measured values of W3 are shown in (F, W), and the plate width variation is within 2 mm. On the other hand, the 6th
FIG. b is the same as the comparative example of Example 1 and does not have an overcompensation function, and (R, W) and (F, W) represent the same as a. W3
The variation in plate width at 7 mm is a large value.

The overcompensation gain is usually within the range of 5 to 50.

〔Effect of the invention〕

As described above, the present invention provides a strip width control system using a feedforward control system that separately measures strip width fluctuations and rolling load fluctuations of a vertical rolling mill, and provides independent control gains for each. As a result of this construction, the width fluctuation range of the steel plate after rolling is reduced,
This not only improved the yield, but also made rolling in the rolling mill, which is the object of strip width control, more stable and improved the work rate.

Furthermore, strip width control in which the overcompensation function is applied only to the rolling load variation system further improves strip width accuracy and greatly improves yield.

[Brief explanation of the drawing]

FIG. 1 is a diagram of a strip width control system according to a first embodiment of the present invention, and FIG. 2 is a diagram of a control system in which a feedback control system is added to FIG. 1. FIG. 3 is a diagram of a board width control system representing another embodiment. FIG. 4 is a diagram of a strip width control system with an overcompensation function intended for continuous hot rolling equipment having a hot finishing mill. FIG. 5 is a comparison diagram of plate width accuracy between an example of the present invention and a comparative example. FIG. 6 is a comparison diagram of the plate width distribution of the embodiment shown in FIG. 4 and the comparative example. FIG. 7 is a diagram of a known plate width control system,
FIG. 8 is a diagram showing the influence of each disturbance on strip width control using a combination of a vertical rolling mill and a horizontal rolling mill. Symbol explanation, E2 = Controlled vertical rolling mill, R2 = Controlled horizontal rolling mill, E1 = Front vertical rolling mill, R1 = Front horizontal rolling mill, MR = Measuring roll, P1, R
2, PM=tracking device, W1=E2 inlet width gauge, W2=R2 outlet width gauge, G1=rolling load measuring section, G2=width measuring section, G3=feed forward control section, SLAB=hot Rolled steel plate, DW=W1
DF = variation in rolling load of E1, EP1 = tracking device of Edger E1 for backup in case of P1 failure, EP2 = tracking device of Edger E2 for backup in case of P2 failure, F1 = pre-calculation WS=predetermined strip width target value of strip width gauge W1, WS2=predetermined strip width target value of strip width gauge W2.

Claims (1)

[Scope of Claims] 1. A plurality of sets of rolling equipment each consisting of a vertical rolling mill and a horizontal rolling mill are arranged, a strip width meter is provided on the entry side of the controlled vertical rolling mill to be controlled, and the controlled vertical rolling mill is A rolling load cell is installed in the front vertical rolling mill in the set in front of the rolling mill,
In a hot rolling facility in which the horizontal rolling mill or measuring roll is provided with a steel plate tracking device, the rolling load at a certain position on the steel plate determined by the steel plate tracking device is measured with the rolling load meter, The deviation value between the measured value of the rolling load and the predicted value calculated in advance is calculated, and based on the deviation value of the rolling load, the predetermined etching efficiency, and the mill rigidity value of the controlled vertical rolling mill. A load correction amount is calculated, and a load correction control amount obtained by multiplying the load correction amount by a load control gain is calculated based on the tracking device for the steel plate, and a certain position on the steel plate reaches the plate width gauge. At times, the width of the steel plate is measured using the plate width meter, and the width correction amount is calculated based on the deviation value between the measured width value and a predetermined entry side width target value, and a predetermined etching efficiency. Calculate,
A reduction correction amount of the vertical roll of the controlled vertical rolling mill is calculated by adding a strip width correction control amount obtained by multiplying the strip width correction amount by the strip width control gain, and a certain position on the steel plate is controlled by the control. Width control of a hot-rolled steel plate, characterized in that, when reaching the vertical rolling mill, the rolling position of the vertical roll of the control vertical rolling mill is repeatedly adjusted in accordance with the rolling correction amount of the vertical roll. Method. 2. A plurality of sets of rolling equipment each consisting of a vertical rolling mill and a horizontal rolling mill are arranged, a strip width gauge is provided on the entry side of the controlled vertical rolling mill to be controlled, and the set in front of the controlled vertical rolling mill is A rolling load meter is installed in the front vertical rolling mill,
In a hot rolling facility in which a steel plate tracking device is provided on the horizontal roll or pinch roll of the horizontal rolling mill, the rolling load is measured for each predetermined length on the steel plate using the rolling load meter, and the rolling load value is predicted. , calculate the deviation value between the measured rolling load value and the predicted value, and calculate the load correction amount based on the deviation value of the rolling load, a predetermined etching efficiency, and the mill rigidity value of the controlled vertical rolling mill. is calculated for each predetermined production, and based on the load correction control amount obtained by multiplying the load correction amount by the load control gain, the rolling load measurement position on the steel plate is determined based on the tracking device of the steel plate. When the steel plate reaches the desired location, the width of the steel plate is measured using the plate width meter, and the deviation value between the measured plate width value and the predetermined entry side plate width target value is determined based on the predetermined etching efficiency. calculating a strip width correction amount, and adding a strip width correction control amount obtained by multiplying the strip width correction amount by a strip width control gain to calculate a reduction correction amount for the hard roll of the controlled vertical rolling mill;
When the rolling load measurement position on the steel plate reaches the controlled vertical rolling mill, the rolling position of the vertical roll of the controlled vertical rolling mill is adjusted in accordance with the rolling correction amount of the vertical roll. Method for controlling the width of hot rolled steel plates. 3. Rolling equipment consisting of a vertical rolling mill and a horizontal rolling mill is arranged to enable reversible rolling, a strip width gauge is provided on the entry side of the controlled vertical rolling mill to be controlled, and rolling is performed on the controlled vertical rolling mill. In a hot rolling facility equipped with a load cell and a tracking device for steel plates on the horizontal rolls or pinch rolls of the horizontal rolling mill, the rolling load is measured at each predetermined length on the steel plate using the rolling load cell, and the rolling load is sequentially measured by the rolling load cell. During the next rolling pass in the same direction, the rolling load value at each point corresponding to a predetermined length on the steel plate is predicted, and the deviation between the memorized rolling load value and the predicted value at that point is calculated. A load correction amount is calculated based on the deviation value of the rolling load, a predetermined etching efficiency, and a mill rigidity value of the controlled vertical rolling mill, and a load control gain is added to the load correction amount. Based on the multiplied load correction control amount and the tracking device of the steel plate,
When the position corresponding to the predetermined length on the steel plate reaches the plate width gauge, the plate width of the steel plate is measured with the plate width gauge, and the plate width measurement value and the predetermined entry side plate width target are measured. The board width correction amount is calculated based on the deviation value from the value and a predetermined etching efficiency, and the board width correction control amount is added by multiplying the board width correction amount by the board width control gain. The reduction correction amount of the vertical roll of the vertical rolling mill is calculated, and when a certain position on the steel plate reaches the control vertical rolling mill, the rolling reduction position of the vertical roll of the controlled vertical rolling mill is adjusted to the position of the vertical roll of the vertical rolling mill. A method for controlling the width of a hot-rolled steel plate, characterized in that the width is adjusted according to a reduction correction amount. 4. In the hot rolling equipment equipped with a hot finishing rolling mill, an overcompensation correction control amount is calculated by multiplying the load correction control amount by a predetermined overcompensation gain, and the plate width is added to the load correction control amount. The method is characterized in that a correction control amount and the overcompensation correction control amount are added to calculate a reduction correction amount of the vertical rolls of the controlled vertical rolling mill, and the plate width of the steel plate is controlled in accordance with the reduction correction amount. A method for controlling the width of a hot rolled steel plate according to any one of claims 1 to 3. 5. In a hot rolling facility in which multiple rolling facilities consisting of a vertical rolling mill and a horizontal rolling mill are arranged or arranged to enable reversible rolling, the strip width provided on the entry side of the controlled vertical rolling mill to be controlled. a rolling load meter installed in the front vertical rolling mill in the set in front of the control vertical rolling mill; and a pulse oscillator and counter installed in the rolling roll, pinch roll or measuring roll of the horizontal rolling mill. a tracking device constructed of the following: a rolling load measuring unit that measures from the rolling load meter every predetermined length on the steel plate in response to pulses from the tracking device; a plate width measuring unit that measures from the plate width meter in response to pulses of the plate width measuring unit; and a plate width measuring unit that receives measured values from the rolling load measuring unit and the plate width measuring unit, and corresponds the measured values to the position on the steel plate at the time of measurement. a memory unit for storing the rolling load in the memory; a memory value of the rolling load stored in the memory unit;
At the same time, the load correction control amount is calculated based on the predetermined etching efficiency, mill rigidity value, and load control gain, and at the same time, the memorized value of the strip width at the same position as the memorized value of the rolling load, the predetermined etching efficiency and After calculating the strip width correction control amount based on the strip width control gain, and adding the load correction control amount and the strip width correction control amount to calculate the rolling reduction correction amount of the vertical roll of the controlled vertical rolling mill. , a hot-rolled steel sheet comprising a feedforward control section that outputs the reduction correction amount to the vertical roll positioning device of the controlled vertical rolling mill in response to pulses from the tracking device. Width control device. 6. In the hot rolling equipment equipped with a hot finishing rolling mill, when calculating the reduction correction amount of the vertical roll in the feedforward control section, the load correction control amount and the strip width correction control amount are further added to the 6. The plate width control device for a hot rolled steel plate according to claim 5, wherein the width control device for a hot rolled steel plate is calculated by adding an overcompensation correction control amount obtained by multiplying the load correction control amount by a predetermined overcompensation gain.