JP2014210268A - Control device and control method of hot finishing rolling machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the occurrence of a plate thickness defect part, by precisely controlling an edge plate thickness within a tolerance range.SOLUTION: A control device 10 of a hot finishing rolling machine comprises: a multi-sensor 11 provided on the outlet side of the hot finishing rolling machine and measuring a plate thickness profile in a width direction of a steel plate over the total length of the steel plate and an AGC (Automatic Gauge Control) control device 13 for correcting an AGC control quantity of a center plate thickness of the steel plate in the hot finishing rolling machine based on a deviation quantity from a tolerance limit by calculating a deviation quantity from the tolerance limit of an edge plate thickness when the edge plate thickness of the steel plate measured by the multi-sensor 11 is deviated from the tolerance limit. Thus, the edge plate thickness is precisely controlled within the tolerance range, and the occurrence of the plate thickness defect part can be suppressed.

Description

  The present invention relates to a control device and a control method for a hot finish rolling mill that controls the edge plate thickness of a steel plate within a tolerance range in a hot finish rolling process.

  In the hot finish rolling process, in order to roll the steel sheet in a high temperature state with a high load, the thickness distribution in the width direction of the steel sheet formed in the rough rolling process, the temperature distribution in the width direction of the steel sheet during hot finish rolling, A plate thickness deviation (crown) is formed in the width direction of the steel plate due to the influence of the roll gap, roll deflection, and the like. Therefore, as the plate thickness guarantee of the steel plate, it is necessary to guarantee the plate thickness (center plate thickness) at the center in the width direction of the steel plate and the plate thickness (edge plate thickness) at the end in the width direction (see Patent Document 1). .

JP 11-192506 A

  In the conventional hot finish rolling process, the edge plate thickness is measured by the center plate thickness measured by the fixed plate thickness meter installed on the outlet side of the hot finish rolling mill and the width measured by the scanning plate thickness meter. It is calculated from the plate thickness profile (crown shape) in the direction. At that time, the center plate thickness is measured over the entire length of the steel plate. However, since there is no equipment that can measure the entire length of the steel sheet, only the thickness profile at a specific position in the longitudinal direction of the steel sheet, such as the position where the crown is the largest, is measured. The plate thickness profile is applied to the entire length of the steel plate as a typical plate thickness profile. For this reason, in the conventional hot finish rolling process, when the edge plate thickness deviates from or is likely to deviate from the tolerance range at a position other than the measurement position of the plate thickness profile, the edge plate thickness is accurately controlled, and the plate The defective thickness portion could not be reduced.

  The present invention has been made in view of the above problems, and its object is to accurately control the edge plate thickness within a tolerance range and to suppress the occurrence of a defective plate thickness portion. The present invention provides a control device and a control method.

  The control apparatus for a hot finishing mill according to the present invention is provided on the outlet side of the hot finishing mill, measuring means for measuring the thickness profile in the width direction of the steel sheet over the entire length of the steel sheet, and the measuring means When the edge plate thickness of the steel plate measured by the above is out of the tolerance range, the tolerance deviation amount of the edge plate thickness is calculated, and the AGC control of the center plate thickness of the steel plate in the hot finish rolling mill based on the tolerance deviation amount At least a process of correcting the amount and a process of adjusting the crown size by controlling the bender provided in the hot finishing mill with a constant crown ratio so that the edge plate thickness is within the tolerance range. And a control means for executing one of them.

  The method for controlling a hot finish rolling mill according to the present invention measures the thickness profile in the width direction of the steel sheet over the entire length of the steel sheet using the measuring means provided on the outlet side of the hot finish rolling mill. When the edge thickness of the steel sheet measured in the measuring step and the measuring step is out of the tolerance range, the tolerance deviation amount of the edge sheet thickness is calculated, and the steel sheet in the hot finish rolling mill based on the tolerance deviation amount The size of the crown is controlled by correcting the AGC control amount of the center plate thickness and controlling the bender provided in the hot finishing mill with a constant crown ratio so that the edge plate thickness is within the tolerance range. And a control step for executing at least one of the processes for adjusting.

  According to the control apparatus and control method for a hot finish rolling mill according to the present invention, it is possible to accurately control the edge plate thickness within a tolerance range, and to suppress the occurrence of a defective plate thickness portion.

FIG. 1 is a schematic diagram showing a configuration of a rolling line to which a control device and a control method for a hot finish rolling mill according to the first and second embodiments of the present invention are applied. FIG. 2 is a block diagram showing the configuration of the control device for the hot finish rolling mill according to the first embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of the AGC control device shown in FIG. FIG. 4 is a diagram illustrating an example of a profile of the center plate thickness and the edge plate thickness. FIG. 5 is a block diagram showing a configuration of a control device for a hot finishing mill according to the second embodiment of the present invention.

  Hereinafter, with reference to drawings, the control apparatus and control method of a hot finishing mill which are the 1st and 2nd embodiments of the present invention are explained.

[Composition of rolling line]
First, with reference to FIG. 1, the structure of the rolling line to which the control apparatus and control method of the hot finishing rolling mill which are the 1st and 2nd embodiment of this invention is applied is demonstrated. FIG. 1 is a schematic diagram showing a configuration of a rolling line to which a control device and a control method for a hot finish rolling mill according to the first and second embodiments of the present invention are applied.

  As shown in FIG. 1, a rolling line 1 to which a control device and a control method for a hot finish rolling mill, which are the first and second embodiments of the present invention, are subjected to a rough rolling process on a steel sheet S. A rough rolling mill 2 having three rolling stands R3 to R5, and a hot finishing mill 3 having seven rolling stands F1 to F7 for subjecting the steel sheet S after the rough rolling step to a hot finish rolling step, And a winding facility 4 for winding the steel sheet S after the hot finish rolling process into a coil shape. The control apparatus and control method for a hot finish rolling mill according to the first and second embodiments of the present invention are applied to a hot finish rolling process performed by the hot finish rolling mill 3.

[First Embodiment]
Next, with reference to FIGS. 2-4, the control apparatus and control method of the hot finishing rolling mill which are the 1st Embodiment of this invention are demonstrated.

  FIG. 2 is a block diagram showing the configuration of the control device for the hot finish rolling mill according to the first embodiment of the present invention. FIG. 3 is a block diagram showing a configuration of the AGC control device shown in FIG. As shown in FIG. 2, the control apparatus 10 of the hot finishing rolling mill which is the first embodiment of the present invention controls the center plate thickness of the steel sheet S in the hot finishing rolling process within a tolerance range. , A multi-sensor 11, a plate thickness meter 12, and an AGC (Automatic Gauge Control) control device 13.

  The multi-sensor 11 is provided on the exit side of the hot finish rolling mill 3 shown in FIG. 1 and measures the thickness profile in the width direction of the steel plate S over the entire length of the steel plate S. The multisensor 11 inputs an electrical signal indicating the measured thickness profile in the width direction of the steel sheet S to the AGC control device 13.

  The plate thickness meter 12 is provided on the exit side of the hot finish rolling mill 3 shown in FIG. 1, and measures the plate thickness (center plate thickness) of the central portion in the width direction of the steel plate S over the entire length of the steel plate S. is there. The thickness gauge 12 inputs an electrical signal indicating the measured center plate thickness of the steel sheet S to the AGC control device 13.

  The AGC control device 13 is constituted by an arithmetic processing device such as a microcomputer, and controls the center plate thickness of the steel plate S within a tolerance range by the plate thickness control AGC. Specifically, as shown in FIG. 3, the AGC control device 13 includes a plate thickness calculation unit 131, a lock-on memory 132, a subtractor 133, a center plate thickness deviation calculation unit 134, an edge plate thickness offset amount calculation unit 135, Adders 136 and 137, a gain multiplication unit 138, an upper and lower limit determination unit 139, and a subtractor 140 are provided.

  The sheet thickness calculation unit 131 predicts the sheet thickness of the steel sheet S after the hot finish rolling process using the reduction position and the actual value of the rolling load in each rolling stand of the hot finish rolling mill 3 shown in FIG. is there. The lock-on memory 132 stores a target value of the thickness of the steel sheet S after the hot finish rolling process. The subtracter 133 calculates a deviation between the predicted value of the plate thickness of the steel plate S calculated by the plate thickness calculation unit 131 and the target value of the plate thickness of the steel plate S stored in the lock-on memory 132. .

  The center plate thickness deviation calculating unit 134 calculates a deviation between the center plate thickness of the steel plate S measured by the plate thickness meter 12 and its target value. The edge plate thickness offset amount calculation unit 135 calculates a deviation between the edge plate thickness of the steel plate measured by the multisensor 11 and its lower limit value or upper limit value. The adder 136 calculates the sum of the deviation of the center plate thickness measured by the center plate thickness deviation calculating unit 134 and the deviation of the edge plate thickness calculated by the edge plate thickness offset amount calculating unit 135.

  The adder 137 calculates the sum of the deviation of the plate thickness of the steel sheet S calculated by the subtracter 133 and the output value of the adder 136. The gain multiplication unit 138 calculates a correction amount of the rolling position of each rolling stand constituting the hot finish rolling mill 3 by multiplying the output value of the adder 137 by a gain. The upper / lower limit determination unit 139 determines whether or not the correction amount of the reduction position calculated by the gain multiplication unit 138 is within a predetermined range. When the correction amount of the reduction position is not within the predetermined range, the upper / lower limit determination unit 139 corrects the correction amount of the reduction position to the upper limit value or the lower limit value.

  The subtractor 140 corrects the reduction position of each rolling stand constituting the hot finishing mill 3 by subtracting the correction amount of the reduction position calculated by the gain multiplication unit 138 from the current reduction position, and the corrected reduction An electric signal indicating the position is output to each rolling stand as a reduction command signal.

  The control apparatus 10 for a hot finish rolling mill, which is the first embodiment of the present invention having such a configuration, accurately controls the edge plate thickness within a tolerance range by operating as shown below. Suppresses the occurrence of defective thickness portions. Hereinafter, with reference to FIG. 4, the operation of the control device 10 when the edge plate thickness is controlled will be described. FIG. 4 is a diagram illustrating an example of a profile of the center plate thickness and the edge plate thickness.

  As shown in FIG. 4, when the profile of the center plate thickness shown by the curve L1 becomes smaller than the target value within the tolerance range (point P1), if the crown amount Cr is larger than the predetermined value, the edge plate thickness shown by the curve L2 Is below the lower limit (point P2), a defective thickness portion may occur. FIG. 4 shows a case where the crown is convex upward. When the crown shape is convex downward, when the profile of the center plate thickness is larger than the target value within the tolerance range, if the crown amount Cr is larger than the predetermined value, the edge plate thickness exceeds the upper limit value. As a result, a defective thickness portion may occur.

  Then, in the control apparatus 10 of the hot finishing rolling mill which is the first embodiment of the present invention, the edge plate thickness offset amount calculation unit 135 includes the edge plate thickness of the steel plate measured by the multisensor 11 and the lower limit value thereof. The deviation is calculated. When the calculated deviation is equal to or greater than a predetermined value, the adder 136 uses the calculated deviation as an offset amount and adds the offset amount to the adjustment amount of the center plate thickness within the tolerance range.

  As described above, when the edge plate thickness deviates from the tolerance range, the control device 10 of the hot finish rolling mill according to the first embodiment of the present invention has a center plate within the tolerance range as shown by a curve L3 in FIG. By increasing the thickness, the edge plate thickness is controlled to fall within the tolerance range. As a result, the edge plate thickness can be accurately controlled within the tolerance range, and the occurrence of a defective plate thickness portion can be suppressed. This embodiment is suitable when there is a limit to the control of the crown shape using a bender or when the thickness of the steel sheet S is thin.

[Second Embodiment]
Next, with reference to FIG. 5, the control apparatus and control method of the hot finishing rolling mill which are the 2nd Embodiment of this invention are demonstrated.

  FIG. 5 is a block diagram showing a configuration of a control device for a hot finishing mill according to the second embodiment of the present invention. As shown in FIG. 5, the control device 20 of the hot finish rolling mill according to the second embodiment of the present invention controls the crown shape of the steel sheet S in the hot finish rolling process, and includes a multi-sensor 21, A thickness gauge 22 and a bender control device 23 are provided.

  The multi-sensor 21 is provided on the exit side of the hot finish rolling mill 3 shown in FIG. 1 and measures the thickness profile in the width direction of the steel sheet S over the entire length of the steel sheet S. The multisensor 21 inputs an electrical signal indicating the measured thickness profile of the steel sheet S in the width direction to the bender controller 23.

  The plate thickness meter 22 is provided on the exit side of the hot finish rolling mill 3 shown in FIG. 1, and measures the plate thickness (center plate thickness) of the center portion in the width direction of the steel plate S over the entire length of the steel plate S. is there. The plate thickness meter 22 inputs an electrical signal indicating the measured center plate thickness of the steel plate S to the bender controller 23.

  The bender control device 23 is configured by an arithmetic processing device such as a microcomputer, and controls the bender of each rolling stand based on the plate thickness profile in the width direction of the steel plate S measured by the multisensor 21. The bender means a mechanism that changes the gap between the upper and lower rolls along the roll axis direction into a parabolic shape.

  The control device 20 having such a configuration operates as follows to accurately control the edge plate thickness within a tolerance range and suppress the occurrence of a defective plate thickness portion. That is, in the control device 20 of the hot finish rolling mill that is the second embodiment of the present invention, when the edge plate thickness is out of the tolerance range, the bender control device 23 controls the steel sheet S measured by the multisensor 21. Based on the plate thickness profile in the width direction, the bender of each rolling stand is controlled so that the crown ratio (crown / plate thickness) is constant and the crown size is within the tolerance range.

  As described above, the control device 20 of the hot finish rolling mill according to the second embodiment of the present invention sets the crown ratio (crown / plate thickness) constant based on the plate thickness profile in the width direction of the steel plate S, and increases the size of the crown. The bender of each rolling stand is controlled so that the length is within the tolerance range. As a result, the edge plate thickness can be accurately controlled within the tolerance range, and the occurrence of a defective plate thickness portion can be suppressed. This embodiment is suitable when the plate | board thickness of the steel plate S is thick.

  Although the embodiment to which the invention made by the present inventor is applied has been described above, the present invention is not limited by the description and the drawings that form a part of the disclosure of the present invention according to this embodiment. That is, other embodiments, examples, operational techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Rolling line 2 Rough rolling mill 3 Hot finish rolling mill 10,20 Control device 11,21 Multi sensor 12,22 Sheet thickness meter 13 AGC (Automatic Gauge Control) control device 23 Vendor control device S Steel plate

Claims (2)

A measuring means that is provided on the outlet side of the hot finish rolling mill and measures the thickness profile in the width direction of the steel sheet over the entire length of the steel sheet;
When the edge plate thickness of the steel sheet measured by the measuring means is out of the tolerance range, the tolerance deviation amount of the edge plate thickness is calculated, and the center plate thickness of the steel sheet in the hot finish rolling mill based on the tolerance deviation amount A processing for correcting the AGC control amount and a processing for adjusting the crown size by controlling the bender provided in the hot finishing mill with a constant crown ratio so that the edge plate thickness is within the tolerance range. Control means for executing at least one of
A control device for a hot finish rolling mill. Using the measuring means provided on the exit side of the hot finish rolling mill, a measurement step for measuring the thickness profile in the width direction of the steel sheet over the entire length of the steel sheet,
When the edge plate thickness of the steel plate measured in the measurement step is out of the tolerance range, the tolerance deviation amount of the edge plate thickness is calculated, and the center plate thickness of the steel plate in the hot finish rolling mill based on the tolerance deviation amount A processing for correcting the AGC control amount and a processing for adjusting the crown size by controlling the bender provided in the hot finishing mill with a constant crown ratio so that the edge plate thickness is within the tolerance range. A control step for executing at least one of
A control method for a hot finish rolling mill.

Images