JP4720643B2 - Control method for continuous steel sheet processing equipment - Google Patents

Description

  The present invention relates to a method for controlling a continuous steel sheet processing facility, and specifically, a steel sheet breakage or a plate thickness caused by cold rolling a peracid pickled portion generated on the surface of a steel sheet. The present invention relates to a method for controlling a continuous steel sheet processing facility capable of suppressing fluctuations and further suppressing off-gauge generated before and after stopping by stopping a cold rolling mill.

  When a cold-rolled steel sheet is manufactured by performing cold rolling on the steel sheet, efficiency and yield decrease due to unsteady operations such as passing through the front end of the steel sheet and pulling out the rear end. In order to prevent this, the rear end of the preceding steel plate and the front end of the subsequent steel plate are welded by a welding machine, and the steel plate is continuously rolled. In such cold rolling, prior to cold rolling, a leveler that corrects the flatness of the steel sheet, pickling that removes the scale generated on the surface of the steel sheet, and further, the end in the width direction of the steel sheet is cut. Processing such as trimming to align the plate width is also performed. For this reason, cold rolling of a steel plate is performed using a continuous steel plate processing facility including a welding machine for welding a preceding steel plate and a succeeding steel plate and a plurality of apparatuses that perform the various processes described above. .

  When passing a steel plate in this continuous steel plate processing facility, when a welding point between a preceding steel plate and a subsequent steel plate passes through a plurality of devices that perform the various processes described above, it follows each of the plurality of devices. Since the setting is changed according to the steel plate, it is necessary to decelerate the steel plate once. However, the deceleration timing is different for each device and is not the same timing. For this reason, for example, a welding section including a welding machine for welding a preceding steel sheet and a subsequent steel sheet, a pickling section including a pickling tank for pickling while passing the steel sheet, And by arranging a looper that can be divided into a plurality of sections such as a rolling section including a cold rolling mill that performs cold rolling on a steel plate and that can give a deflection to the steel plate between each section. Steel plates can be passed at different plate speeds.

  By the way, when other equipment other than the pickling tank in the continuous steel plate processing equipment is systematically stopped for inspection or maintenance, the pickling in which the steel plate in the pickling section is accommodated in the pickling tank. If stopped while immersed in the liquid (hereinafter, such stop is referred to as “pickling stop” in the present specification), a per-pickling portion in which the surface of the steel sheet is discolored is generated. When this peracid pickled part is cold-rolled, it breaks or changes in thickness, resulting in a decrease in yield and productivity. Therefore, when other equipment other than the pickling tank is stopped systematically, or when trouble occurs in other equipment other than the pickling tank, and the equipment is decelerated or stopped, the pickling is not stopped. It is important in actual operation.

  Further, if the supply of the steel sheet to the cold rolling mill is delayed, the cold rolling mill must be stopped, and a large thickness variation occurs before and after the stop, resulting in an off gauge. For this reason, it is also important not to cause a shortage of steel sheet supply to the cold rolling mill.

Up to now, for example, Patent Documents 1 and 2 disclose inventions that do not stop pickling.
In Patent Document 1, the accumulated length of the steel plate in the looper arranged on the upstream side of the cold rolling mill is reduced to the minimum state before the cold rolling mill is stopped, and the cold rolling mill is stopped. Discloses an invention for preventing pickling stop at the time of planned stop of a cold rolling mill by determining the pickling speed (feeding speed of pickling tank) based on the estimated stop time and the accumulated length of the steel sheet. ing.

Further, Patent Document 2 uses a continuous steel plate processing facility having two loopers between a pickling tank and a cold rolling mill, and uses a short end side of an upstream looper and a length of a downstream looper. When the synchronization point is set on the end side and the accumulated length of the steel plate in each looper deviates from the synchronization point, the plate passing speed in each section other than the section including the pickling tank is adjusted to An invention is disclosed in which the accumulated length of a steel plate is quickly returned to the synchronization point.
JP-A-6-170430 JP-A-8-132121

  However, Patent Document 1 does not describe a case where a plurality of loopers exist between the pickling tank and the cold rolling mill. For this reason, even if it is based on the invention disclosed by patent document 1, it is unknown whether a pickling stop can be prevented in this case. Further, in the present invention, the accumulated length of the steel plate in the looper arranged on the upstream side of the cold rolling mill is reduced to the minimum state, so there is a possibility that the pickling speed is lowered more than necessary and the productivity is remarkably lowered. .

  Moreover, since the invention disclosed by patent document 2 determines the plate passing speed based only on the current accumulation length of the steel plate in the looper, when equipment other than the pickling tank is planned to stop for a relatively long time. During the stop, the accumulated length of the looper placed upstream of the pickling tank is insufficient, or the accumulated length of the looper placed downstream of the pickling tank reaches the limit (upper limit), and finally the acid There is a risk of stopping washing.

  The present invention divides an equipment group including a pickling equipment and a plurality of equipment different from the pickling equipment into a plurality of sections, and includes a looper between the sections, so that the steel plate has a different speed for each section. In a continuous steel sheet processing facility that enables the passage of steel sheets, the steel plate accumulation length of each looper up to a certain time is predicted at a predetermined time period, and the predicted steel plate accumulation length of each looper satisfies a predetermined constraint condition. Thus, there is provided a control method for a continuous steel sheet processing facility, wherein an upper limit value of the sheet passing speed of each section is set.

  In the method for controlling a continuous steel sheet processing facility according to the present invention, the upper limit value of the sheet passing speed of each section is the steel plate accumulation of each looper arranged upstream of the section including the pickling facility among the plurality of sections. It is desirable to set the total length to be equal to or greater than a predetermined value, or to set the total sum of steel plate accumulation lengths of each looper disposed downstream from the section including the pickling equipment to be equal to or less than a predetermined value. .

  In these control methods for a continuous steel sheet processing facility according to the present invention, the plurality of sections include at least a section including a welding machine, a section including a pickling apparatus, and a section including a cold rolling mill. It is desirable.

  According to the present invention, even if other equipment other than the pickling tank in the continuous steel plate processing equipment having a plurality of loopers upstream or downstream of the pickling tank is systematically stopped, the steel plate passage in each section Since the speed can be prevented from causing the pickling stop, the steel sheet can be manufactured without causing the pickling stop without impairing the productivity more than necessary.

  For this reason, it is possible to suppress steel sheet breakage and sheet thickness fluctuations that occur due to cold rolling of the peracid-washed portion generated on the surface of the steel sheet, thereby improving the yield and productivity of the steel sheet. it can.

  Moreover, it is possible to suppress off-gauge due to large plate thickness fluctuations before and after the stop of the cold rolling mill, which occurs due to the stagnation of the supply of the steel plate to the cold rolling mill, thereby improving the yield of the steel plate. .

Hereinafter, the best mode for carrying out the method for controlling a continuous steel sheet processing facility according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is an explanatory diagram schematically showing the configuration of a continuous steel plate treatment facility 0 used in the present embodiment. Since this continuous steel plate processing facility 0 includes the steel plate continuous processing facility 10 and the control device 80, these will be described.
[Steel plate continuous treatment equipment 10]
As shown in FIG. 1, the steel sheet continuous processing equipment 10 includes an entry side section 23 including a rewinding machine 1 and a welding machine 2, a pickling section 24 including a pickling tank 3, and a trimmer section 25 including a trimmer 4. Between the rolling section 26 including the cold rolling mill 5 and the winder 6, the inlet looper 11 disposed between the inlet section 23 and the pickling section 24, and between the pickling section 24 and the trimmer section 25. The central looper 12 to be disposed and the exit side looper 13 disposed between the trimmer section 25 and the rolling section 26 are provided.

  The rewinding machine 1 pays out while rewinding the second steel plate 22 wound in a coil shape. The tip of the discharged second steel plate 22 is welded to the rear end of the preceding first steel plate 21 by the welding machine 2 to form a steel plate 20. A steel plate 20 is continuously supplied to various facilities 11, 3, 12, 4, 13, 5, and 6 disposed downstream of the welding machine 2.

  The steel plate 20 is guided to the pickling tub 3 and pickled, and after that, the end in the width direction is trimmed by the trimmer 4 to a predetermined plate width, and then rolled by the cold rolling mill 5 to have a predetermined width. The thickness is reduced to the plate thickness. Furthermore, a cold-rolled steel sheet as a product is manufactured by being wound in a coil shape by the winder 6.

  The entrance side looper 11 is installed between the welding machine 2 and the pickling tank 3, that is, between the entry side section 23 and the pickling section 24. Thereby, the plate passing speed of the steel plate 20 in the inlet side section 23 upstream of the inlet looper 11 and the plate passing speed of the steel plate 20 in the pickling section 24 downstream of the inlet looper 11 are set to different speeds. Thus, the steel plate 20 can be passed.

  A central looper 12 is installed between the pickling tank 3 and the trimmer 4, that is, between the pickling section 24 and the trimmer section 25. Thereby, the plate passing speed of the steel plate 20 in the pickling section 24 upstream of the central looper 12 and the plate passing speed of the steel plate 20 in the trimmer section 25 downstream of the central looper 12 are set to different speeds. Twenty passes can be made.

  Furthermore, an exit side looper 13 is installed between the trimmer 4 and the cold rolling mill 5, that is, between the trimmer section 25 and the rolling section 26. Accordingly, the sheet passing speed of the steel plate 20 in the upstream trimmer section 25 of the exit side looper 13 and the sheet passing speed of the steel plate 20 in the rolling section 26 downstream of the exit side looper 13 are set to different speeds. The steel plate 20 can be passed.

  In addition, while the 1st steel plate 21 and the 2nd steel plate 22 are welded with the welding machine 2, the entrance speed of the entrance side looper 11 and the speed paid out from the unwinding machine 1 differ. For this reason, in the following description, “entrance side section speed” means the entrance speed of the entrance side looper 11. On the other hand, when the steel plate 20 is rolled by the cold rolling mill 5, the sheet passing speed of the steel plate 20 increases. For this reason, in the following description, the “rolling section speed” means the outlet speed of the exit side looper 13, that is, the inlet speed of the cold rolling mill 5.

The steel plate continuous processing facility 10 in the present embodiment is configured as described above. Next, the control device 80 will be described.
[Control device 80]
As shown in FIG. 1, the control device 80 includes a result collection device 30, a section speed calculator 40, a looper accumulation length control device 50, a calculator 60, and a speed control device 70.

The performance collecting device 30 includes the position of the welding point of the first steel plate 21 and the second steel plate 22, the plate passing speed of the steel plate 20 in each section 23 to 26, and the accumulated length of the steel plate 20 in each looper 11-13. collects various actual values in real time, it outputs the positional information I ₁ of the welding point in section speed calculation unit 40.

  The section speed calculator 40 decelerates when the welding point passes through the respective facilities 2 to 6, and decelerates and stops the entry side section 23 when welding the first steel plate 21 and the second steel plate 22 with the welding machine 2. The plate passing speed in each of the sections 23 to 26 determined independently regardless of other sections, such as, is obtained and output to the speed controller 70.

Further, the result collection device 30 outputs the collected record results I ₂ of the steel plates 20 in the loopers 11 to 13 to the looper accumulation length control device 50. The looper accumulation length control device 50 controls the sheet passing speed in each section 23 to 26 for controlling the accumulation length of the steel plate 20 in each looper 11 to 13 based on the record of the accumulation length of the steel plate 20 in each looper 11 to 13. Obtained and output to the speed controller 70.

Further, the result collection device 30 outputs the collected result I ₃ of the accumulated length of the steel plate 20 in each of the loopers 11 to 13 to the computer 60. The computer 60 predicts a change in the accumulated length of the steel plate 20 in each of the loopers 11 to 13 after a predetermined time every predetermined time period, and the accumulated length of the steel plate 20 in each of the loopers 11 to 13 is predicted during the predicted period. The plate passing speed in each of the sections 23 to 26 is obtained so as to satisfy a predetermined condition, and is output to the speed control device 70.

  The speed control device 70 calculates a final speed command based on the plate speed output from the section speed calculator 40, the looper accumulation length control device 50, and the computer 60, respectively. To control the plate speed in each of the sections 23 to 26.

  Here, the passage speed of the steel plate 20 in each of the sections 23 to 26 is controlled in this way by the section speed calculator 40, the looper accumulation length control apparatus 50, the computer 60, and the speed control apparatus 70 constituting the control apparatus 80. Explain why.

  In the continuous steel plate treatment facility 0 shown in FIG. 1, troubles occurred in other facilities (for example, the welding machine 2, the trimmer 4, the cold rolling mill 5, etc.) other than the pickling tank 3, and the facilities decelerated or stopped. In order to prevent the pickling from being stopped even in the case, a looper (incoming looper 11, central looper 12 or outgoing looper 13) located between the pickling tank 3 and other equipment in which a trouble has occurred. When the other equipment that stops, such as the welding machine 2, is located upstream of the pickling tank 3, the longer the sum of the accumulated lengths of the steel plates 20 is, for example, the better. When other equipment that stops, such as the rolling mill 5, is located downstream of the pickling tank 3, the shorter the better.

  For example, when the welding time in the welding machine 2 exceeds the schedule, the operation can be continued without stopping the pickling tank 3 by the length of the accumulated length of the steel plate 20 in the entry side looper 11. It is possible to prevent a stoppage.

  On the other hand, for example, when the trimmer 4 is stopped due to the meandering of the steel plate 20 in the trimmer 4, the shorter the accumulation length of the steel plate 20 in the central looper 12, the shorter the trimmer 4 stops after the trimmer 4 stops. Since the length which can accumulate | store 20 increases, an operation can be continued without stopping the pickling tank 3, and it can be prevented from stopping pickling. Further, for example, when the rolling mill 5 cannot be accelerated due to poor flatness of the steel plate 20 or the like in the cold rolling mill 5, the sum of the accumulated lengths of the steel plates 20 in the center looper 12 and the exit side looper 13 is short. As the length that can be accumulated in the central looper 12 and the exit side looper 13 after the cold rolling mill 5 is stopped increases, the operation can be continued without stopping the pickling tank 3, and the pickling is stopped. Can be avoided.

  However, since it is impossible to predict the occurrence of the trouble as described above, the steel sheet accumulation length of the loopers 11 to 13 is actually assumed on the assumption that the operation has been continued systematically without any trouble from the current time. Predicting and adjusting the plate passing speed of each section so that the steel plate accumulation length of the loopers 11 to 13 does not fall within a range where the pickling is stopped when trouble occurs.

  Specifically, the pickling equipment 3 for pickling while letting the first steel plate 21 and the second steel plate 22 join the steel plate 20, and the first steel plate 21, the second steel plate 22 or A plurality of sections 23 to 26 including at least one of the plurality of facilities 2, 4, and 5 that perform processing other than pickling while passing the steel plate 20, and two adjacent sections 23 to 24, The steel plate 20 is continuously provided using the steel plate continuous processing equipment 10 provided with the loopers 11 to 13 which can bend and accumulate the steel plate 20 which is disposed between 24 to 25 and 25 to 26 and is passed through. When processing and manufacturing a cold-rolled steel sheet, troubles occur in other equipment 2, 4 or 5 other than the pickling tank 3, and the pickling is stopped even when the equipment decelerates or stops. To avoid this, between these facilities 2, 4, 5 and pickling tank 3, In the loopers 11 to 13 to be placed, the accumulated length of the steel plates 20 up to a predetermined fixed time is within a predetermined range, that is, the accumulated length of the looper 11 located upstream from the pickling tank 3 is predetermined. The total length of the accumulated lengths of the looper 12 and the looper 13 located on the downstream side of the pickling tank 3 is set to be equal to or greater than the value, and the passage of the steel plate 20 in each of the sections 23 to 26 is set to be equal to or less than a predetermined value. The upper limit value of the plate speed is set to adjust the plate passing speed in each of the sections 23 to 26.

  In this case, the predetermined value to be compared with the sum of the accumulated lengths of the steel plates 20 in each of the loopers 11 to 13 is the minimum speed of pickling necessary to prevent over pickling and the stoppage of equipment other than pickling due to trouble. Considering the preparation time, for example, the following is determined.

In order to prepare for the trouble of the welding machine 2, the lower limit regulation value that the steel plate accumulation length of the entry side looper 11 should satisfy is the product of the trouble time of the welding machine 2 assumed to be the minimum speed of pickling.
In order to prepare for trouble of the trimmer 4, the upper limit regulation value that the steel plate accumulation length of the central looper 12 should satisfy is the trouble of the trimmer 4 that is assumed to be the minimum speed of pickling from the physical steel plate accumulation length upper limit value of the central looper 12. The value obtained by subtracting the product of time.

  In order to prepare for troubles in the cold rolling mill 5, the upper limit regulation value that the sum of the steel plate accumulation lengths of the central looper 12 and the outgoing looper 13 should satisfy is the upper limit value of the physical steel plate accumulation length of the central looper 12 and the outgoing looper 13. The value obtained by subtracting the product of the trouble time of the cold rolling mill 5 that is assumed to be the minimum speed of pickling from the sum of the above.

  Further, in order to prevent the cold rolling mill 5 from being stopped even if trouble occurs in the trimmer 4 and the supply of the steel sheet 20 to the cold rolling mill 5 is delayed, the steel sheet accumulation length of the exit side looper 13 is What is necessary is just to make it become more than predetermined value. This lower limit regulation value is, for example, the product of the trouble time of the trimmer 4 that is assumed to be the minimum speed of the cold rolling mill 5 that does not cause large plate thickness fluctuations.

Next, operations of the section speed calculator 40, the looper accumulation length control device 50, the computer 60, and the speed control device 70 will be described more specifically.
The section speed calculator 40 shown in FIG. 1 is based on the welding point results (welding point position information I ₁ ) given by the result collecting device 30 and is independently determined regardless of other sections. A speed upper limit value VE _{, 1} , a pickling section speed upper limit value VP _{, 1} , a trimmer section speed upper limit value VT _{, 1} and a rolling section speed upper limit value VR _{, 1} are obtained.

  These upper limit values are the upper limits of the plate passing speed for allowing the welded portion of the steel plate 20 to pass through at a low speed or for performing deceleration or stop for welding the first steel plate 21 and the second steel plate 22 with the welding machine 3. It is a value and can be obtained by a well-known and commonly used method.

For example, the entry side section speed upper limit value VE _{, 1} is the rear end withdrawal speed until the rear end of the first steel plate 21 comes out of the rewinding machine 1 and the rear end moves to the welding machine 2. In other cases, the maximum speed of the rewinding machine 1 is obtained.

The pickling section speed upper limit value VP _{and 1} are obtained as the pickling plate speed of the welded portion while the welded portion passes the pickling rod 3, and as the maximum speed of the pickling section 24 in other cases.
The trimmer section speed upper limit value V _{T, 1} is obtained as the trimmer passing plate speed of the welded part before and after the welded part passes the trimmer 4, and as the maximum speed of the trimmer section 25 in other cases.

Further, the rolling section speed upper limit value VR _{, 1} is the cold rolling mill sheet feeding speed of the welded portion when the welded portion passes through the cold rolling mill 5, and the cold rolling mill 5 otherwise. It is determined as the maximum rolling speed determined from the upper limit of motor rotation speed and the upper limit of output.

FIG. 2 shows the looper accumulation length control device 50 based on the looper steel plate accumulation length actual value (actual length I ₂ of the accumulation length of the steel plate 20 in each of the loopers 11 to 13). 13, an entry side section speed upper limit value V _{E, 2} , a pickling section speed upper limit value VP _{, 2} , a trimmer section speed upper limit value V _{T, 2} , a rolling section speed upper limit value VR _{, 2} It is a flowchart which shows the procedure which calculates | requires.

  The looper accumulation length control device 50 is provided with a function of preventing the accumulation length of the steel plate 20 in each of the loopers 11 to 13 from breaking through the facility limit and destroying each of the loopers 11 to 13. Specifically, the looping speed of the steel plate 20 in the upstream sections 23 to 25 of the loopers 11 to 13 is suppressed so as not to break through the upper limit of the accumulation length, and the loopers 11 to 13 so as not to break the lower limit of the accumulation length. The sheet passing speed of the steel plate 20 in the downstream sections 24 to 26 is regulated.

In step (hereinafter abbreviated as “S”) 1 in FIG. 2, the pickling section speed upper limit values VP _{and ENT} are set so that the accumulated length of the steel plate 20 in the entry side looper 11 does not exceed the lower limit. Then, the process proceeds to S2.

In S2, the entry side section speed upper limit values VE _{and ENT} are set so that the accumulation length of the entry side looper 11 does not exceed the upper limit. Then, the process proceeds to S3.
In S3, trimmer section speed upper limit values V _{T and MDL} are set so that the accumulated length of the steel plate 20 in the central looper 12 does not exceed the lower limit. Then, the process proceeds to S4.

In S4, the pickling section speed upper limit values VP _{and MDL} are set so that the accumulated length of the steel plate 20 in the central looper 12 does not exceed the upper limit. Then, the process proceeds to S5.
In S5, the rolling section speed upper limit values VR _{and DEL} are set so that the accumulated length of the steel plate 20 in the outlet looper 13 does not exceed the lower limit. Then, the process proceeds to S6.

In S6, the trimmer section speed upper limit values V _{T and DEL} are set so that the accumulated length of the steel plate 20 in the outlet looper 13 does not exceed the upper limit.
In S7, the minimum value among the plate passing speed upper limit values in the sections 23 to 26 obtained in S1 to S6 is set as the entry side section speed upper limit value V _{E, 2} , pickling section speed by the looper accumulation length control device 50. The upper limit value V _{P, 2} , the trimmer section speed upper limit value V _{T, 2} , and the rolling section speed upper limit value VR ₂ are set.

These can be obtained by a known method. Briefly, for example, the upper limit VP _{and ENT} of the pickling section for preventing the steel plate accumulation length of the entry side looper 11 from exceeding the lower limit are the steel plates in the pickling section 24. The length of the steel plate 20 pulled out from the entry side looper 11 from the start of deceleration at the deceleration rate a _P to the stop is the steel plate accumulated length actual value L _ENT of the entry side looper 11 and the physical value of the entry side looper 11. steel storage length lower limit _{L MIN, so} as not more than the difference between the _{ENT V P, ENT = {2a} P (L ENT -L MIN, ENT)} is determined as ^1/2.

The entry side section speed upper limits VE _{and ENT} for preventing the steel sheet accumulation length of the entry side looper 11 from exceeding the upper limit are entered after the steel sheet 20 in the entry side section 23 starts decelerating at the deceleration rate a _E and stops. The length of the steel plate 20 flowing into the side looper 11 is the empty length of the entry side looper 11 (the physical steel plate accumulation length upper limit L _{MAX, ENT} of the entry side looper 11 and the steel plate accumulation length actual value L of the entry side looper 11. _ENT difference) more become _{lest V E, ENT = {2a E} (L MAX, ENT -L ENT)} obtained as ^1/2.

The upper limit of the trimmer section speed for preventing the steel plate accumulation length of the central looper 12 from breaking the lower limit is obtained as V _{T, MDL} = {2a _T (L _MDL -L _{MIN, MDL} )} ^1/2 .
Central pickling section speed limit for steel accumulation length is not exceeded the upper limit of the looper 12 _{is V P, MDL = {2a P} (L MAX, MDL -L MDL)} is determined as ^1/2.

The upper limit of the rolling section speed for preventing the steel sheet accumulation length of the exit side looper 13 from breaking through the lower limit is obtained as VR _{, DEL} = {2a _R ( _LDEL- LMIN _{, DEL} )} ^1/2 .
Further, the upper limit of the trimmer section speed for preventing the steel sheet accumulation length of the exit side looper 13 from exceeding the upper limit is obtained as V _{T, DEL} = {2a _T (L _{MAX, DEL} −L _DEL )} ^1/2 .

Here, the symbol a _T is the reduction rate of the trimmer section 25, the symbol a _R is the reduction rate of the rolling section 26, the symbol L _MDL is the actual steel plate accumulated length of the central looper 12, and the symbols L _{MIN, MDL} Is the lower limit value of the physical steel plate accumulation length of the central looper 12, the symbols L _{MAX and MDL} are the upper limit values of the physical steel plate accumulation length of the central looper 12, and the symbol L _DEL is the actual steel plate accumulation length of the outgoing looper 13. The values L _{MIN and DEL} are the lower limit values of the physical steel plate accumulation length of the outgoing looper 13, and the symbols L _{MAX and DEL} are the upper limits of the physical steel plate accumulation length of the outgoing looper 13.

Next, the computer 60 predicts a change in the accumulated length of the steel plate 20 in the loopers 11 to 13 within a certain period for each predetermined time period.
This prediction is predicted by calculating based on a difference in sheet passing speed of the steel plate 20 in each of the plurality of sections 23 to 26 up to a certain time. And the change of the accumulation length of the steel plate 20 in the loopers 11-13 until a fixed period is added by adding the change of the accumulation length of the calculated steel plate 20, and the actual value of the accumulation length of the steel plate 20 at the time of this prediction. is expected.

And in the estimated period, the accumulation length of the steel plate 20 in the loopers 11 to 13 is a predetermined restriction condition, that is, in the looper 11 located between the section 23 existing upstream from the section 24 including the pickling tank 3. The total accumulated length of the steel plates 20 is not less than a predetermined value, and the accumulated length of the steel plates 20 in the loopers 12 and 13 located between the sections 25 and 26 existing downstream from the section 24 including the pickling tank 3 is as follows. In order to satisfy "the sum is less than a predetermined value", the entry side section speed upper limit value VE _{, 3} , pickling section speed upper limit value VP _{, 3} , trimmer section speed upper limit value VT _{, 3} , rolling section speed Upper limit values VR _{and 3} are obtained based on the flowchart shown in FIG.

  In S <b> 1 in FIG. 3, first, it is assumed that it is not necessary to decelerate the steel plate 20 in all the sections 23 to 26 as an initial value, and the speed upper limit value is set to infinity. Then, the process proceeds to S2.

  In S2, as will be described later, assuming that the passing speed of the steel plate 20 in each section 23 to 26 is set by the speed control device 70, the accumulated length of the steel plate 20 in each looper 11 to 13 for a certain period is predicted. . Then, the process proceeds to S3.

In S3, when the accumulation length of the steel plate 20 in the entry side looper 11 is equal to or less than a predetermined regulation value of the entry side looper 11 in the fixed period predicted in S2, the accumulation length of the steel plate 20 in the central looper 12 is determined in advance. Or when the sum of the accumulated lengths of the steel plates 20 in the central looper 12 and the outgoing looper 13 is equal to or higher than the predetermined regulatory values of the central looper 12 and the outgoing looper 13. If there is room for the pickling section speed to be reduced because the pickling section speed upper limit value VP ₃ does not reach the pickling section minimum speed, the pickling section speed upper limit value VP ₃ is decelerated and corrected. Then, returning to S2 and performing the calculation of S2, the accumulated length of the steel plate 20 in the entry side looper 11 exceeds the regulation value of the entry side looper 11, and the central looper 12 Until the accumulated length of the steel plates 20 is less than the regulation value of the central looper 12 and the sum of the accumulation lengths of the steel plates 20 in the central looper 12 and the exit side looper 13 is less than the regulation value of the center looper 12 and the exit side looper 13. ,repeat. Then, the calculation ends.

In cases other than these, the process proceeds to S4.
In S4, when the accumulation length of the steel plate 20 in the exit side looper 13 is equal to or less than a predetermined regulation value of the exit side looper 13 in the predetermined period predicted by S2, the rolling section speed upper limit value VR _{, 3} is decelerated. It corrects and returns to S <b> 2 and repeats the calculation of S <b> 2 until the accumulated length of the steel plate 20 in the outgoing looper 13 exceeds the regulation value of the outgoing looper 13. Then, the calculation ends.

In this way, the entry side section speed upper limit value V _{E, 3} , the pickling section speed upper limit value V _{P, 3} , in which the accumulated length of the steel plates 20 in the loopers 11 to 13 satisfies the predetermined constraint condition in the predicted fixed period. Trimmer section speed upper limit value VT _{, 3} and rolling section speed upper limit value VR _{, 3} are obtained.

Speed control device 70, the speed _V E applied from section speed calculation unit _{40, 1, V P, 1} , V T, 1, V R, 1, velocity _{V E} applied from the looper accumulation length control unit _50, 2, Based on V _{P, 2} , V _{T, 2} , V _{R, 2} , and the speeds V _{E, 3} , V _{P, 3} , V _{T, 3} , V _{R, 3} given from the computer 60, the ingress section 23 speed command _{V E} for the speed command _{V P} for pickling section 24, the speed command _{V T} of the center section 25, and a speed command _{V R} for rolling section 26, the speed given from the section speed calculating unit 40 _{V E,} 1, V _{P, 1} , V _{T, 1} , V _{R, 1} , speeds V _{E, 2} , V _{P, 2} , V _{T, 2} , V _{R, 2} , and from the computer 60 Of the speeds given The small value is set as follows.
V _E = min (V _{E, 1} , V _{E, 2} , V _{E, 3} )
V _P = min (V _{P, 1} , V _{P, 2} , V _{P, 3} )
V _T = min (V _{T, 1} , V _{T, 2} , V _{T, 3} )
V _R = min (VR _{, 1} , VR _{, 2} , VR _{, 3} )
The speed control device 70 sets the sheet passing speed of the steel plate 20 in each of the sections 23 to 26 in this way, and outputs it to the drive unit of the steel plate conveying device of each of the sections 23 to 26.

The control device 80 in the present embodiment is configured as described above.
In this Embodiment, since the steel plate 20 is passed using the continuous steel plate processing equipment 0 provided with the steel plate continuous processing equipment 10 and the control apparatus 80, other equipment other than the pickling tank 3 in the steel plate continuous processing equipment 10 Even if 2, 4, 5, and 6 are stopped systematically, it is possible to prevent the plate passing speed of the steel plate 20 in each of the sections 23 to 26 from reaching the speed at which pickling is stopped. Thus, the cold rolled steel sheet can be manufactured without stopping pickling.

  For this reason, according to the present embodiment, it is possible to suppress the breakage and thickness variation of the steel plate 20 caused by cold rolling the peracid-washed portion generated on the surface of the steel plate 20, Thus, it is possible to prevent the yield and productivity of the steel sheet from being lowered.

  Moreover, according to this Embodiment, the off-gauge which generate | occur | produces resulting from the supply of the steel plate 20 to the cold rolling mill 5 can be suppressed, and, thereby, the yield of the steel plate 20 can be improved.

  Furthermore, the present invention will be described more specifically with reference to the results of simulation performed under the simulation conditions shown in Table 1. In the following description, a welding point closest to the cold rolling mill among a plurality of welding points existing on the steel sheet is referred to as a welding point a, and hereinafter referred to as a welding point b, a welding point c,. And

<Simulation 1>
In the continuous steel sheet processing facility 0 shown in FIG. 1, assuming that the roll of the cold rolling mill 5 is changed, a simulation is performed in which the cold rolling mill 5 is systematically stopped for 11 minutes.

  In this example, as shown in Table 1, the physical upper limit of the accumulated length of the steel plate 20 (entrance side loop steel plate accumulation length) in the entrance looper 11 is 630 m, and the accumulated length of the steel plate 20 in the center looper 12 (center loop steel plate). The physical upper limit of (accumulation length) is 210 m, the physical upper limit of the accumulation length of the steel plate 20 (exit-side loop steel plate accumulation length) in the exit side looper 13 is 630 m, and the respective physical lower limit value is 0 m.

  Furthermore, the lower limit regulation value of the accumulated length of the steel plate 20 (entrance side loop steel plate accumulated length) in the entry side looper 11 is that the minimum speed of the pickling section 24 is 0.5 m even if the welding time of the welding machine 2 is extended for 5 minutes. The upper limit of the accumulated length of the steel plate 20 (central loop steel plate accumulated length) in the central looper 12 is stopped for 3 minutes due to a trouble with the trimmer 4 in order to keep pickling at / s. However, it is set to 120 m for the reason that a physical upper limit of 210 m to 90 m is left so that pickling can be continued at a minimum speed of 0.5 m / s in the pickling section 24, the central looper 12 and the exit side The upper limit of the accumulated length of the steel plate 20 in the looper 13 (central loop steel plate accumulated length + outside loop steel plate accumulated length) is the minimum speed of the pickling section 24 even if the cold rolling mill 5 is stopped for 5 minutes due to trouble. Leave a margin of 150 m from the physical upper limit value 840 m (the sum of the physical upper limit value 210 m of the central looper 12 and the physical upper limit value 630 m of the exit side looper 13) so that the operation can be continued at 0.5 m / s. The lower limit of the accumulation length of the steel plate 20 (outside loop steel plate accumulation length) in the exit side looper 13 is cold even if the trimmer 4 stops for 3 minutes due to a trouble. It is determined as 100 m for the reason that the rolling mill 5 can continue rolling at a rolling section speed of 0.56 m / s so as not to cause off-gauge.

  Moreover, as shown in Table 1, the upper limit value of the sheet passing speed of the steel plate 20 in each of the sections 23 to 25 is set according to the present invention, and the steel plate 20 is passed at a sheet passing speed not exceeding this upper limit value. The results of the control for outputting the speed command are shown in a graph in FIG.

In this example, the entry side section speed upper limit value VE _{, 1} is 1 m / s until the rear end of the first steel plate 21 comes out of the rewinding machine 1 and moves to the welding machine 2, and welding is in progress. Is 0 m / s, and in other cases, the maximum speed of the unwinder 1 is 9.17 m / s, and the pickling section speed upper limit VP ₁ is the welded portion while the welded portion passes the pickling rod 3. The pickling plate speed is 2 m / s. In other cases, the maximum speed of the pickling section 24 is 2.5 m / s, and the upper limit of the trimmer section speed V _T is ₁ 5 m before and after the weld passes through the trimmer 4. the weld trimmer through plate speed 0.67 m / s, determined as the maximum speed 5.83m / s of trimmer section 25 otherwise, further rolled sections speed upper limit _{V R, 1} is weld cold rolling When passing through the machine 5, the cold rolling mill plate speed of the weld is 0.8. 25 m / s, in other cases, the maximum rolling speed determined from the upper limit of the number of rotations and the upper limit of the output of the motor of the cold rolling mill 5 is 2.67 m / s. Based on the above-described procedure, the entry side section speed V _E , acid washing section velocity _{V P,} trimmer section velocity _{V T,} the rolling section speed _{V R} determined.

When the time B will be explained as an example in the graph of FIG. 4, since the entry-side section speed upper limit V _{E, 1} is being welded determined as 0 m / s, pickling sections speed upper limit V _{P, 1} is weld acid Since it is not passing through the washing tank 3, the maximum speed of the pickling section is determined as 2.5 m / s, and the trimmer section speed upper limit value V _{T, 1} is not positioned at 5 m before and after the trimmer 4. Is determined as 5.83 m / s, which is the maximum speed of the rolling, and the rolling section speed upper limit value VR _{, 1} is determined as 0 m / s for roll change.

Further, based on the flowchart shown in FIG. 2, the upper limit of the pickling section speed for preventing the steel plate accumulation length of the entry side looper 11 from breaking the lower limit is obtained as VP _{, ENT} = 36.6 m / s. The upper limit of the entry side speed for preventing the steel sheet accumulation length from exceeding the upper limit is VE _{, ENT} = 19.5 m / s, and the upper limit of the trimmer section speed for preventing the steel sheet accumulation length of the central looper 12 from exceeding the lower limit is V _{T , MDL} = 0.5 m / s, and the upper limit of the pickling section speed so that the steel plate accumulation length of the central looper 12 does not exceed the upper limit is determined as VP _{, MDL} = 8.7 m / s, and the steel plate of the outgoing looper 13 The upper limit of the rolling section speed for preventing the accumulated length from exceeding the lower limit is determined as VR _{, DEL} = 16.1 m / s, and the trimmer section speed for preventing the accumulated steel sheet length of the outgoing looper 13 from exceeding the upper limit. The upper limit is determined as VT _{, DEL} = 13.9 m / s, the entry-side section speed upper limit value is determined as V _{E, 2} = VE _{, ENT} = 19.5 m / s, and the pickling section speed upper limit value is determined as VP _{, 2} = min ( _{VP, ENT} , VP _{, MDL} ) = 8.7 m / s, and the trimmer section speed upper limit value is VT _{, 2} = min ( _VT , _MDL , _{VT , DEL} ) = 0.5 m Further, the rolling section speed upper limit value is obtained as VR _{, 2} = VR _{, and DEL} = 16.1 m / s.

Furthermore, with reference to the flowchart shown in FIG. 3, the inlet side section speed upper limit _{V E, 3,} pickling sections speed upper limit _{V P, 3,} trimmer section speed upper limit _{V T, 3,} the rolling section speed upper limit _{V R 3} is obtained.

Since V _{E, 1} = 0 m / s, V _{E, 2} = 19.5 m / s, V _{E, 3} = ∞, V _E = min (V _{E, 1} , V _{E, 2} , V _{E, 3} ) Set to 0 m / s. Since V _{P, 1} = 2.5 m / s, V _{P, 2} = 8.7 m / s, V _{P, 3} = 0.5 m / s, V _P = min (V _{P, 1} , V _{P 2} , VP _{, 3} ) = 0.5 m / s. Also, since V _{T, 1} = 5.83 m / s, V _{T, 2} = 0.5 m / s, V _{T, 3} = ∞, V _T = min (V _{T, 1} , V _{T, 2} , V _{T, 3} ) = 0.5 m / s. _{Further, V R, 1 = 0m /} s, V R, 2 = 16.1m / s, since the V R, 3 = 1.1m / s , V R = min (V R, 1, V R, 2 , VR _{, 3} ) = 0 m / s.

  In addition, the graph of FIG. 4 shows the accumulation length of the steel plate 20 in the entrance side looper 11 (entrance side loop steel plate accumulation length), the accumulation length of the steel plate 20 in the center looper 12 (center loop steel plate accumulation length), and the exit side. The accumulated length of the steel plate 20 in the looper 13 (outgoing loop steel plate accumulated length), the accumulated length of the steel plate 20 in the central looper 12 and the outgoing looper 13 (central loop steel plate accumulated length + outgoing loop steel plate accumulated length), entry side section 23 Plate speed of the steel plate 20 (incoming section speed), plate plate speed of the steel plate 20 in the pickling section 24 (pickling section speed), plate speed of the steel plate 20 in the trimmer section 25 (trimmer section speed) or rolling section 26 shows the change over time in the sheet feeding speed (rolling section speed) of the steel plate 20 at 26. The same applies to FIGS. 5 to 9 described later.

  4A to 4C, when the sheet feeding speed of the normal pickling section 24 is operated, the total accumulated length of the steel plates 20 in the central looper 12 and the outlet looper 13 while the cold rolling mill 5 is stopped. Is expected to be 690 m or more, which is the regulation value for the central looper 12 and the outlet looper 13, so that the plate passing speed of the pickling section 24 is reduced. Thereby, even when the cold rolling mill 5 is stopped (time zone B to C in FIG. 4), the operation can be performed without stopping the pickling by the pickling tank 3.

  Moreover, since the sum total of the accumulation length of the steel plate 20 in the center looper 12 and the exit side looper 13 is suppressed within 690 m, the cold rolling mill 5 is suddenly stopped immediately after the operation of the cold rolling mill 5 is resumed. However, it is possible to prevent the pickling from being stopped immediately until the sum reaches 840 m.

  On the other hand, the result of controlling the steel plate 20 by the conventional method is shown in a graph in FIG. In the conventional method, in the time zone A to B in FIG. 5, the accumulated length of the steel plate 20 in the exit side looper 13 upstream of the cold rolling mill 5 is the time B immediately before the cold rolling mill 5 is stopped. The sheet passing speed of the pickling section 24 is reduced so as to be minimized, and the accumulated length of the steel sheet 20 in the exit side looper 13 does not exceed the upper limit during the time period B to C when the cold rolling mill 5 is stopped. Thus, the plate passing speed of the pickling section 24 is determined.

Also by this conventional method, it is possible to operate without stopping pickling even when the cold rolling mill 5 is stopped (time period B to C in FIG. 5).
However, when comparing the state of the entry side section 23 at the time C immediately after resuming the operation of the cold rolling mill 5, the welding of the welding point f is already completed in the present invention shown by the graph in FIG. In the conventional method shown by the graph in FIG. 5, the welding of the welding point f has not been started yet, and there is a great difference in the progress of the processing of the steel plate 20. This is because in the conventional method, the plate passing speed of the pickling section 24 is reduced more than necessary. From this, the effect of this invention which determines the plate | board speed of the steel plate 20 in each looper 11-13 by predicting the change of the accumulation length of the steel plate 20 in each looper 11-13 is clear.
<Simulation 2>
This simulation is a case where the stop time of the cold rolling mill 5 is shorter than the simulation 1 described above. In addition, subsequent description of each simulation 2-4 is performed about the part different from the simulation 1 mentioned above, and the overlapping description about a common part is abbreviate | omitted suitably.

Assuming that the cold rolling mill 5 is inspected, a simulation is performed to systematically stop the cold rolling mill 5 for one minute. The results controlled by the present invention are shown graphically in FIG.
In the time zone of B to D in the graph of FIG. 6, when operating at the normal sheeting speed of the pickling section 24, the accumulated lengths of the steel plates 20 of the central looper 12 and the exit side looper 13 while the cold rolling mill 5 is stopped. Is estimated to be 690 m or more, which is the regulation value of the central looper 12 and the exit side looper 13, the plate passing speed of the pickling section 24 is reduced. Thereby, even in the time zone of A to C during which the cold rolling mill 5 is stopped, the operation can be performed without stopping the pickling.

  On the other hand, the result of controlling the steel plate 20 by the conventional method is shown in a graph in FIG. In this conventional method, the accumulation length of the steel plate 20 of the exit side looper 13 upstream of the cold rolling mill 5 is minimized at time B, which is immediately before the cold rolling mill 5 is stopped, in the time zone A to B. In the time zone B to C during which the sheet feeding speed of the pickling section 24 is reduced and the cold rolling mill 5 is stopped, pickling is performed so that the accumulated length of the steel plate 20 of the exit side looper 13 does not exceed the upper limit. The plate passing speed of the section 24 is determined.

Even in this conventional method, even in the time zone B to C during which the cold rolling mill 5 is stopped, the operation can be performed without stopping the pickling.
However, when comparing the state of the entry side section 23 at the time C, which is immediately after restarting the operation of the cold rolling mill 5, the welding of the welding point e is already completed in the example of the present invention, whereas in the conventional method, the welding point The welding of e has not yet started.

Further, according to the present invention, the speed of the rolling section 26 is not restricted, but the conventional method performs low speed operation in the time zone C to D in FIG. There is. This is because, in the conventional method, the sheet passing speed of the pickling section 24 has been reduced more than necessary, so that the accumulated length of the steel sheet 20 in the exit looper 13 at time C, which is immediately after the operation of the cold rolling mill 5 is resumed. This is because if the sheet passing speed of the rolling section 26 is not restricted, the accumulation length of the steel plate 20 in the exit side looper 13 will be 100 m or less, which is the regulation value of the exit side looper 13.
<Simulation 3>
Assuming that the welding machine 2 is cleaned, a simulation is performed to systematically stop the entry side section 23 for 13 minutes. The results controlled by the present invention are shown graphically in FIG.

  In the time zone A to D in the graph of FIG. 8, when the normal pickling section 24 is operated at the plate passing speed, the accumulated length of the steel plate 20 in the inlet side looper 11 is reduced while the inlet side section 23 is stopped. Therefore, the plate passing speed of the pickling section 24 is reduced. As a result, even during the time period C to D during which the entry side section 23 is stopped, the operation can be performed without stopping the pickling.

Further, in the time zone B to D in the graph of FIG. 8, when the normal rolling section 26 is operated at the sheet passing speed, the accumulated length of the steel plate 20 in the exit side looper 13 is reduced while the entry side section 23 is stopped. Since the regulation value of 13 is expected to be 100 m or less, the sheet passing speed of the rolling section 26 is reduced. Thereby, the rolling section 26 can be operated without stopping.
<Simulation 4>
Assuming that the blade of the trimmer 4 is replaced, a simulation is performed in which the trimmer 4 is systematically stopped for 5 minutes and 30 seconds. The results controlled by the present invention are shown graphically in FIG.

  In the time zone of A to F in the graph of FIG. 9, when the operation is performed at the normal speed of the pickling section 24, the accumulated length of the steel plate 20 in the central looper 12 is 120 m which is the regulation value of the central looper 12 while the trimmer 4 is stopped. Since it is predicted that this is the case, the plate passing speed of the pickling section 24 is reduced to the minimum speed. Accordingly, the operation can be performed without stopping the pickling even during the time period B to D when the trimmer 4 is stopped.

  Further, during the time period C to E in the graph of FIG. 9, when the trimmer 4 is stopped during operation of the normal rolling section 26, the accumulated length of the steel plate 20 in the outgoing looper 13 is the same as that in the outgoing looper 13. Since the regulation value is predicted to be 100 m or less, the sheet passing speed of the rolling section 26 is reduced. Thereby, the rolling section 26 can be operated without stopping.

It is explanatory drawing which shows roughly the structure of the continuous-type steel plate processing equipment of embodiment. It is a flowchart which shows operation | movement of a looper accumulation length control apparatus. It is a flowchart which shows operation | movement of a computer. Inlet loop steel plate accumulation length, central loop steel plate accumulation length, outgoing loop steel plate accumulation length, central loop steel plate accumulation length + outlet loop steel plate accumulation length, entry side section steel plate accumulation length, pickling section speed, trimmer section speed or rolling section speed It is a graph which shows each time-dependent change. It is a graph which shows the result of controlling a steel plate by the conventional method. It is a graph which shows the result controlled by the present invention. It is a graph which shows the result of controlling a steel plate by the conventional method. It is a graph which shows the result controlled by the present invention. It is a graph which shows the result controlled by the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 0 Continuous type steel plate processing equipment 1 Rewinder 2 Welding machine 3 Pickling tank 4 Trimmer 5 Cold rolling mill 6 Winding machine 10 Steel plate continuous processing equipment 11 Inlet looper 12 Central looper 13 Outlet looper 20 Steel plate 21 Steel plate 22 Second steel plate 23 Entry side section 24 Pickling section 25 Trimmer section 26 Rolling section 30 Results collection device 40 Section speed calculator 50 Looper accumulation length control device 60 Computer 70 Speed control device 80 Control device

Claims (3)

  By dividing the equipment group including the pickling equipment and a plurality of equipment different from the pickling equipment into a plurality of sections and providing a looper between the sections, it is possible to pass through the steel plates at different speeds for each section. In a continuous steel sheet processing facility that enables the steel sheet accumulation length of each looper up to a certain time for each predetermined time period, so that the predicted steel sheet accumulation length of each looper satisfies a predetermined constraint condition. A control method for a continuous steel sheet processing facility, wherein an upper limit value of a sheet passing speed of each section is set.   The upper limit value of the plate passing speed of each section is such that the total sum of the steel plate accumulation lengths of each looper arranged on the upstream side of the section including the pickling equipment among the plurality of sections is a predetermined value or more. Or it sets so that the sum total of the steel plate accumulation length of each looper arrange | positioned downstream from the section containing the said pickling equipment may become below a predetermined value, The continuous-type steel plate process of Claim 1 characterized by the above-mentioned. Equipment control method.   The said some section is comprised from the section containing a welding machine, the section containing a pickling apparatus, and the section containing a cold rolling mill at least, The Claim 1 or Claim 2 characterized by the above-mentioned. Control method for continuous steel sheet processing equipment.

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