JP2005144559A - Method and device for controlling shape in tandem rolling mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device of shape control in a rolling mill by which stable sheet shape is attained over the entire in the width direction including sheet end parts by a simple method in the control of the sheet shape in rolling. <P>SOLUTION: In this shape controlling method in a tandem rolling mill, by detecting the sheet shape on the outlet side of the final rolling stand, performing the second order differential of the signal of the sheet shape and zoning the driving side and the operating side and the middle part of a rolling mill to the width of the rolled sheet by the derivation, the bender control of the work rolls and the intermediate rolls of the final stand is performed by the sheet shape in the middle part, also the reduction of the final stand is controlled, the shift of the work rolls of the final rolling stand is controlled and the bender of the work rolls or the intermediate rolls of one or a plurality of rolling stands on the side of the early stage of the final rolling stand are controlled by the sheet shape in the end part on the operating side of the rolling mill and the sheet shape in the end part on the driving side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a rolling mill shape control method and apparatus, and more particularly to a control method and apparatus for improving the shape of a plate end.

FIG. 6 is a block diagram showing an outline of a conventional shape control device for a rolling mill. FIG. 6 shows a case where the # 4 stand (fourth) rolling mill 14 has a six-stage rolling mill configuration including a work roll (WR), an intermediate roll (IMR), and a backup roll (BUR). is there. The shape control in the rolling mill includes a plate shape (flatness) on the delivery side of the rolling mill, a feedback signal as a shape signal from a shape detector 4 connected to a shape detection roll installed therein, and a target shape setting device. The control amount is calculated by the shape control output calculation device 5 according to the difference from the target shape signal given by 6, and the plate shape is controlled by operating the actuator of the rolling mill. In the 6-stage rolling mill, as the actuator,
(1) Work roll (work roll; WR) vendor control device (94)
(2) Intermediate roll (intermediate roll; hereinafter IMR) vendor controller (94)
(3) It has a reduction leveling (reduction position control device) (7), and shape control is performed by controlling these.

  Here, the WR bender and the IMR bender each have a function of bending the roll, and by using the deflection of the roll, the distribution of the force that crushes the plate in the width direction of the rolled material is changed to change the overall shape of the plate width. I have control. In addition, the reduction leveling is a control device for a reduction position (roll gap) by a reduction device provided on the working side (WS) and the driving side (DS) of the rolling mill. By manipulating this, the distribution of force for crushing the plate in the width direction of the rolled material can be changed, so that the overall shape of the plate width can be controlled.

  In this way, the actuator used in the conventional shape control can only control the shape of the entire plate width. If the shape of only the plate edge, for example, is poor, only that portion is controlled. (If trying to match the end of the plate to the target shape, the overall shape would be degraded).

Moreover, there exists patent document 1 as a prior art. In the technology disclosed herein, the plate shape recognition is controlled by approximating the sheet width central portion of the rolled material by approximating it with a quadratic expression and the end in the sheet width direction with another quadratic expression. It is a technology that tries to achieve the overall shape improvement. That is, the symmetric component Ys with respect to the sheet width center of the shape of the rolled material is expressed as follows, for example, by a combination of the following quadratic expressions using the width direction coordinate x made dimensionless from the sheet width center.
Ys = S1 · x ² + S2 (x−x0) ²
Here, for example, the operation amounts of the IMR vendor and the WR vendor are determined according to S1, S2: coefficient, x0: starting point of the plate edge region, and the values of S1, S2, respectively.

  However, in reality, there is a local shape change due to the flatness of the roll of the rolling mill or the thermal expansion of the roll at the end of the plate, and it is necessary to introduce a higher order expression to express this with a mathematical expression. Problems related to the introduction of this higher order expression are also described in the prior art, and a large computer is required. Therefore, it becomes difficult for the conventional shape recognition technology and actuator to control the shape change due to the flatness of the roll at the plate end.

  Moreover, there exists patent document 2 as a prior art. This is about the edge drop evaluation method. The plate profile in the vicinity of the rolled material sheet width end is divided into a body crown and an edge drop region, and the body crown is approximated using a polynomial of the fourth-order equation or less, and the polynomial in any sheet width direction within 25 mm from the sheet end. The difference between the value at the extension line in the sheet width direction and the measured value of the sheet profile after rolling is evaluated as the edge drop amount.

  As for edge drop control, there is a method in which a rolling mill having a roll shift facility is used to increase the edge one pass before the final rolling pass and lower the rolling reduction in the final rolling pass. There is a disclosure that it is performed before the rolling pass or one pass.

  Moreover, there exists patent document 3 or patent document 4 about shape control. The former is to adjust the work roll or intermediate roll bending amount according to the distribution in the width direction of the rolling material elongation. In the latter case, the bending apparatus is driven in accordance with the difference between the average value of the elongation or the elongation rate measured in the inner region in the width direction adjacent to the end portion.

JP-A-4-178208 JP-A-6-304623 JP-A-7-303910 JP-A-10-166021

  In the prior art, the plate end portion and the center portion are represented and controlled by different quadratic expressions. However, in order to further increase the accuracy, it may be represented by a higher-order quartic or sixth-order expression. However, there is a problem that a large computer must be used and it is difficult to determine the actual shape of the plate directly from the polynomial.

  Further, even if the control is performed by zoning in the plate width direction, the shape control thereafter is affected depending on the viewpoint of zoning. Further, even though the shape of the entire plate width can be controlled, there has been no established control so far when controlling the end portion.

  The present invention has been made in view of the above-described problems, and a rolling mill shape control method capable of achieving a stable plate shape over the entire plate width direction, including the plate end portion, by a simple method and An object is to provide an apparatus.

  The above problem predicts the shape change region at the end of the rolled material due to the flatness of the roll and the thermal expansion of the roll that occurs during rolling, and the shape change in this region and the shape change of the entire plate width are separated separately. Recognize and each shape correction can be achieved by controlling the actuator. Specifically, the following means is used.

  In the shape control method of a tandem rolling mill having a work roll, an intermediate roll, and a backup roll, the plate shape is detected on the final rolling stand exit side, and zoned in the plate width direction based on the plate shape signal, It is characterized by performing plate shape control by controlling the roll bender control of the rolling mill, rolling roll reduction control, work roll shift control of the rolling stand, and intermediate roll bender in association with the plate shape signal. .

Further, the plate shape is detected at the final rolling stand exit side, the plate shape signal is secondarily differentiated, and the working side, the drive side, and the central portion of the rolling mill are divided into zones according to the differential value with respect to the rolled plate width. And performing the bender control of the work roll and the intermediate roll of the final rolling stand according to the plate shape of the central portion and controlling the reduction of the final rolling stand, the plate shape and the driving side end of the working side end of the rolling mill The plate shape is controlled by controlling the work roll shift of the final rolling stand and the work rolls or intermediate roll benders of the single or plural rolling stands on the front side of the final rolling stand according to the plate shape of the part. Further, when the position where the plate shape of the plate end portion is the largest is within a predetermined distance from the plate end portion, the position between the position where the plate shape is large and the plate end portion is set to the working side and the driving side. Correspondingly, the work side end portion and the drive side end portion are set as the center portion, and the shape control is performed for the respective portions of the rolling stand. Moreover, the predetermined distance from the said board edge part shall be 20-100 mm. Further, the average value of the plate shape of the working side end of the rolling mill and the plate shape of the driving side end is calculated, and based on the average value, the work roll of one or more rolling stands on the front stage side of the final rolling stand or It is characterized by controlling the bender of the intermediate roll and controlling the plate shape.

  Further, a plate shape detector provided on the final rolling stand exit side, a plate shape plate width direction region dividing device that performs zone division based on the detected plate shape signal, and the dividing device and the target shape setting device. A shape recognition device that grasps the plate shape of the zone divided by the signal, and a rolling position control and intermediate roll bender control of the rolling mill, a work roll shift control of the rolling stand, and an intermediate roll shift control based on the output signal of the shape recognition device And a shape control output computing device for computing a signal for controlling the work roll or intermediate roll bender of the rolling stand, a rolling position control device, a roll bender control device, a work roll shift control device, a work roll or an intermediate roll Featured by the vendor control device and work roll shift control device That.

In addition, a plate shape detector provided on the exit side of the final rolling stand, a plate shape signal with a secondary differentiator, and a plate width direction for zoning the both ends and the center with respect to the plate width by the differential value Area dividing device, shape recognition device for the center portion divided by the dividing device, shape recognition device for the work side end divided by the dividing device, and shape of the drive side end divided by the dividing device A recognition unit, a center unit shape control output arithmetic unit for controlling the rolling position of the final rolling stand and an intermediate roll bender by the output of the shape recognition unit of the center unit, and the output of the shape recognition unit of the work side end A center part shape control output computing device for controlling the rolling position of the final rolling stand and the intermediate roll bender by means of a center part shape recognition device; Work roll shift control of the rolling stand and work side edge shape control output computing device for controlling the work roll of one or a plurality of rolling stands on the front side of the final rolling stand or the bender of the intermediate roll, and the work roll of the final rolling stand And a drive-side edge portion shape control output computing device that controls shift control and a work roll or intermediate roll bender of one or a plurality of rolling stands before the final rolling stand.

  According to the present invention, it is possible to improve the product shape system, in particular, the shape of the end of the plate is good, and it is possible to obtain a rolled product having a stable shape in the entire plate width direction.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of a rolling mill shape control apparatus to which the present invention is applied, and shows an example of a four-stand tandem rolling mill in which four rolling mills are continuously arranged. As shown in FIG. 1, the shape control apparatus of an Example is the shape detection roll 3 installed in the rolling mill final stand exit side, the shape detector 4 which converts the signal of a shape detection roll into a shape signal, A plate end shape change region prediction device 58 for predicting a shape change region due to flatness of the roll or thermal expansion from the signal is provided.

  Based on the region prediction result from here, the shape actual value is divided into a plurality of zones in the plate width direction, the plate width direction region dividing device 54, the zoned shape actual value, and the target shape determined by the target shape setting device 6 The shape is recognized for each zone according to the deviation. The shape recognition devices include a center portion shape recognition device 55, a WS edge shape recognition device 56, and a DS edge shape recognition device 57. Based on these shape recognition results, a center part shape control output computing device 51, a WS edge shape control output computing device 52, a DS edge shape control output computing device 53 for computing a shape control output are provided. The stand 14 has a WR shift control device that can change the position of the WR in the plate width direction, and a taper roll (taper roll, which will be described later) is used for the WR. Next, the shape control method of the embodiment will be described with reference to FIGS.

  FIG. 2 explains the division of zones and the division of roles of actuators in each zone in the rolling mill shape control method in this embodiment. First, a method for predicting the roll flat shape variation region will be described. FIG. 2A shows an example of a shape detection signal from the shape detector 3. The plate end shape change region prediction device 58 calculates the second derivative with respect to the plate width direction of the shape FB signal ((A) in FIG. 2) from the shape detector. The result is shown in FIG. As a result, it is possible to detect a portion having a large shape change in the sheet width direction of the rolled material.

  If the position where this shape change is large is obtained and the position is a shape variation region due to roll flattening (if it is within Xmm from the plate end, usually 20mm to 100mm depending on the type of rolled material), the plate end shape due to roll flattening Recognized as the starting point of the change area. However, in practice, the shape detector has a certain width for each channel. Each channel measures the plate shape. Therefore, it is necessary to determine whether to “control” or “do not control” using the shape variation region of the edge portion according to the coverage ratio of the rolled material to the shape detector channel at the plate end. .

  Here, the covering ratio Cv is a ratio of the plate material to the detection channel having a certain width (the covering ratio is Cv ≦ 1.0 at the end portion of the plate, but Cv = 1.0 in the other portions). ). Further, when Cv is smaller than a predetermined value, that portion is not controlled. For example, when Cv <0.25, the channel shape data is not used as a control target.

In this way, the shape variation region due to roll flattening is predicted using the twice-differentiated value of the plate shape, and based on the result, the zones in the plate width direction are respectively shown in the plate width direction as shown in FIG. The zone is divided into three.
(1) Zone 1: rolling mill work side end (WS edge portion), WS roll flat shape region (2) zone 2: center portion (3) zone 3: rolling mill drive side end portion (DS edge portion), DS It is divided into three flat roll shape areas, and the center shape control output calculation device 51 and WS edge shape control are respectively performed based on plate shape recognition (detected values of plate shape) 55, 56, 57 in each zone. A control amount is calculated by the output calculation device 52 and the DS edge portion shape control output calculation device 53, and control is performed by the actuators (91, 92, 93, 94, 7, 8).

The shape control actuator corresponding to each zone is
1 WS edge (52)
# 4 stand (14) WR shift (8), # 1-3 stand (11, 12, 13) WR / IMR vendor (91, 92, 93),
2 Center part (51)
# 4 stand (14) WR / IMR vendor (94), # 4 stand (14) reduction leveling (7),
3 DS edge part (53)
# 4 stand (14) WR shift (8), # 1-3 stand WR / IMR vendor (91, 92, 93),
It corresponds as follows.

  Next, a method for controlling each actuator will be described. However, since the conventional control method is performed for the center portion, description thereof is omitted. FIG. 3 illustrates a control method for the # 4 stand WR shift. As shown to (A) of FIG. 3, a taper roll is used for the upper WR141 and the lower WR142 arrange | positioned up and down of the rolling material 2. As shown in FIG. Tapering is performed only on one end of the roll. The tapered side is arranged so that the work side (WS) and the drive side (DS) of the rolling mill are separated by upper and lower rolls.

  FIG. 3 illustrates an example in which the taper processing of the upper roll is the work side and the lower roll is the drive side. By arranging the taper portion of the roll in this way, the shape of the plate end can be controlled independently on the working side and on the driving side. Since the roll is tapered, the distribution of the rolling force applied to the plate can be changed by changing the position of the roll in the plate width direction. For example, the rolling force applied to the end portion of the plate can be reduced by setting the starting point of the tapering process to the inside of the plate width as shown in a circle pc in FIG. Thereby, the elongation at the end of the plate can be eliminated.

In this shape control method, the difference between the actual shape of the plate end and the target shape is compared to recognize the shape of the plate end, and as a result, the extension and tension of the end are detected. Based on this result, the control direction of the WR shift is determined. FIG. 3B shows a target shape signal in shape control and an FB control signal in shape control. This shape recognition is performed independently for each of the working side (WS) and the driving side (DS) of the rolling mill.
Plate end extension ... Change to WR shift position outside Plate end tension ... Control output is determined independently on the working side and drive side of the rolling mill so as to change to the WR shift position inside. FIG. 3C shows a control block diagram thereof.

  Next, a control method using the # 1 to 3 stands will be described. FIG. 4 is a diagram for explaining the concept of the control method for the # 1 to 3 stands. As shown in FIGS. 4A and 4B, attention is paid to the plate profile on the # 4 stand entry side and the plate shape on the # 4 stand exit side. If the plate profile on the # 4 stand entry side is thick, that is, an edge-up shape, as in (a) of FIG. 4B, the rolling reduction of the plate end by rolling in the # 4 stand. (The extension of the plate end is large), the plate shape on the exit side of the # 4 stand becomes an ear extension.

  In the case of (b) in FIG. 4B, on the other hand, if the plate profile on the # 4 stand entrance side is thin, that is, if it has an edge drop shape, rolling at # 4 stand Since the rolling reduction at the end of the plate is small (the extension at the end of the plate is small), the plate shape on the exit side of the # 4 stand is flat or slightly stretched. From these facts, by controlling the plate profile on the entry side of the # 4 stand using the # 1 to 3 stands, the plate shape on the exit side of the # 4 stand can be controlled as a result.

FIG. 5 is a diagram for explaining a control method of vendors # 1 to # 3. As shown in FIG. 5, the shape recognition on the operation side (WS) and drive side (DS) of the rolling mill is the same as that of the WR shift control method of FIG. 3 described above. It is described as a symmetric bender for side and drive side same amount control. Since the control is the same amount on the operation side and the drive side, the control output is determined using the average value of the shape recognition results recognized separately on the operation side and the drive side. The result of recognition as the average value of the plate shape is
Elongation of plate edge ... # 1-3 stand WR / IMR bender
Decrease board edge tension ... # 1-3 stand WR / IMR bender
The control output is determined so as to increase.

  As a result, it becomes possible to control the shape of only the plate edge, and it is possible to always roll a product having a stable shape. According to the present invention, a stable plate shape can be achieved over the entire plate width direction. Further, the stable plate shape enables more stable rolling with less plate breakage.

  As described above, according to the present invention, the flatness of the roll that occurs during rolling, the shape change of the region near the plate end where the plate shape changes due to thermal expansion, and the shape change of the entire plate width can be obtained. Recognize separately, by operating separately the actuator suitable for shape correction of the plate end, including the WR shift of the rolling mill and the stand stand bender in the tandem rolling mill, and the bender that corrects the shape of the entire plate width The plate shape can be controlled for each of these regions, and a product having a stable shape in the entire plate width direction can be obtained.

It is a block diagram which shows one Example of the shape control apparatus of the rolling mill to which this invention is applied. It is a figure for demonstrating the zone division in the shape control method of a present Example, and the role of an actuator. It is explanatory drawing of the # 4 stand WR shift control method. It is explanatory drawing of # 1-3 stand control method. It is explanatory drawing of # 1-3 stand vendor control method. It is a figure which shows the shape control apparatus of the conventional rolling mill.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Rolled material, 3 ... Shape detection roll, 4 ... Shape detector, 5 ... Shape control output calculating device, 6 ... Target shape setting device, 7 ... Rolling position control device, 8 ... WR shift control device, 11 ... Rolling mill # 1 stand, 12 ... rolling mill # 2 stand, 13 ... rolling mill # 3 stand, 14 ... rolling mill # 4 stand, 51 ... center portion shape control output computing device, 52 ... WS edge portion shape control output computing device, 53 ... DS edge part shape control output computing device, 54... Plate width direction region dividing device, 55... Center part roll deformation shape recognition device, 56... WS edge part roll flat shape recognition device, 57. 58 ... Plate end shape change region prediction device, 60 ... Average value calculation device for shape recognition on the working side and drive side, 91 ... # 1 stand WR / IMR bender control device, 92 ... # 2 stand W / IMR vendor control device, 93 ... # 3 stands WR / IMR vendor control device, 94 ... # 4 stand WR / IMR vendors controller, 141 ... # 4 stand on WR, 142 ... # 4 stand under WR.

Claims (7)

  In the shape control method of a tandem rolling mill having a work roll, an intermediate roll, and a backup roll, the plate shape is detected on the final rolling stand exit side, and zoned in the plate width direction based on the plate shape signal, A tandem that performs plate shape control by controlling a bender control of a roll of the rolling mill, a roll-down control of a rolling stand, a work roll shift control of the rolling stand, and an intermediate roll bender in association with a plate shape signal A rolling mill shape control method.   In the shape control method of a tandem rolling mill having a work roll, an intermediate roll, and a backup roll, the plate shape is detected at the final rolling stand exit side, the plate shape signal is secondarily differentiated, and the rolled plate width is determined by the differential value. On the other hand, the work side and the drive side of the rolling mill and the central part are divided into zones, the work roll of the final rolling stand and the bender control of the intermediate roll are performed by the plate shape of the central part, and the rolling of the final rolling stand is reduced. The work roll shift control of the final rolling stand and the work roll of one or a plurality of rolling stands on the front stage side of the final rolling stand are controlled by the plate shape of the working side end and the driving end of the rolling mill. Alternatively, control the shape of a tandem rolling mill characterized by controlling the bender of the intermediate roll and controlling the plate shape Law.   3. The method according to claim 2, wherein when the position where the plate shape of the plate end portion is the largest is within a predetermined distance from the plate end portion, work is performed between the position where the plate shape is large and the plate end portion. A shape control method for a tandem rolling mill, wherein the work side end and the drive side end corresponding to the side and the drive side, and the other as the center, are used to control the shape of each part of the rolling stand.   4. The shape control method for a tandem rolling mill according to claim 3, wherein the predetermined distance from the plate end is 20 to 100 mm.   In Claim 2, the average value of the plate | board shape of the work side edge part of the said rolling mill and the plate | board shape of a drive side edge part is calculated, and the one or several rolling of the front | former stage side of the said final rolling stand by the said average value A shape control method for a tandem rolling mill, wherein a plate shape control is performed by controlling a work roll of a stand or a bender of an intermediate roll.   In a shape control method of a tandem rolling mill having a work roll, an intermediate roll, and a backup roll, a plate shape detector provided on the exit side of the final rolling stand, and a plate that performs zoning based on the detected plate shape signal Shape plate width direction region dividing device, shape recognition device for grasping the plate shape of the zone divided by the signals of the dividing device and the target shape setting device, and the rolling position control of the rolling mill by the output signal of the shape recognition device And an intermediate roll bender control, a work roll shift control of a rolling stand, an intermediate roll shift control, and a shape control output calculating device for calculating a signal for controlling the work roll of the rolling stand or the bender of the intermediate roll, and a reduction position control device, Roll bender control device, work roll shift control device, work roll or And vendor control apparatus of an intermediate roll, work roll shift control device, a tandem rolling mill of the shape control apparatus characterized in that it is composed of and.   In the shape control device of a tandem rolling mill having a work roll, an intermediate roll, and a backup roll, a plate shape detector provided on the final rolling stand exit side, the plate shape signal by a secondary differentiator, and the differential value A plate width direction region dividing device that divides both the end portion and the center portion with respect to the plate width, a shape recognition device for a center portion divided by the dividing device, and a work side end portion divided by the dividing device. A shape recognition device, a shape recognition device of a driving side end divided by the dividing device, and a center shape control for performing a rolling position control and an intermediate roll bender control of a final rolling stand by an output of the shape recognition device of the center portion An output arithmetic unit and an output of the shape recognition device at the work side end portion result in a final rolling stamp by the center shape recognition device. Center part shape control output computing device for performing the rolling position control and intermediate roll bender control, and the work roll shift control of the final rolling stand and the work rolls or intermediate rolls of the single or plural rolling stands on the upstream side of the final rolling stand Work side edge shape control output computing device for controlling the bender, work roll shift control of the final rolling stand, and drive for controlling the work roll or intermediate roll bender of one or a plurality of rolling stands upstream of the final rolling stand A shape control device for a tandem rolling mill, comprising: a side edge portion shape control output calculation device.

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