JP2018158374A - Flying plate thickness changing method and flying plate thickness changing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent or suppress a trouble such as breaking of a rolled material, reduce an off-gauge part as much as possible, and further improve a yield.SOLUTION: A flying plate thickness changing apparatus timely tracks a presently traveling welded point W and acquiring welded point information Dt; calculates transition pattern information Fs corresponding to transition patterns P1 to P18 at each existence position of three change travel points B, W and E for a plurality of stands 1 to 6, from the obtained timely welded point information Dt; monitoring a change in the transition pattern information Fs; and controls each of the stands 1 to 6 to control values Ct on rolling conditions of each of the stands 1 to 6 associated with the corresponding transition patten Ps with reference to the previously set control table Ct, when the transition pattern information Fs is changed.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a running plate thickness changing method and a running plate thickness changing device in a cold continuous rolling process in a tandem rolling mill having a plurality of stands.

  Generally, in the cold continuous rolling process, the leading end of the preceding material and the leading end of the succeeding material are welded at the entry side of the tandem rolling mill having a plurality of stands, and the preceding material and the succeeding material are continuously connected. The rolled metal strip is continuously rolled with a tandem rolling mill. Then, the metal strip that has been rolled on the exit side of the tandem rolling mill is cut at the position of the product unit, and the cut metal strip is sequentially wound by the tension reel.

  In such a cold continuous rolling process, when the material to be rolled, in which the preceding material and the following material are joined at the welding point, is continuously cold-rolled by a tandem rolling mill having a plurality of stands, the hardness and the base plate thickness. And if any of the finishing thickness is different between the preceding material and the following material, the preceding material and the following material are rolled to the target plate thickness respectively, and the yield is reduced while reducing the line stop as much as possible. In order to improve, “running plate thickness change” is performed in which rolling conditions are changed before and after the welding point during continuous rolling. Usually, the plate thickness change is performed only once when passing the welding point (see, for example, Patent Documents 1 and 2).

  For example, in the technique described in Patent Document 1, even if the plate thickness change amount before and after the welding point is large, in order not to decrease the yield, the roll peripheral speed and the roll gap of each stand are controlled to reduce the running distance. The plate thickness is changed. Moreover, in patent document 2, in order to improve the plate | board thickness precision before and behind a welding point, the running plate | board thickness change which suppressed the tension | tensile_strength variation using the rolling load and advanced rate of each stand is implemented.

By the way, in recent years, the required thickness of products has become thinner, and as the thickness of the metal strip becomes thinner, the risk of breakage at the welding point, the risk of poor winding around the tension reel, etc. will increase. There's a problem. Therefore, in order to prevent such a problem from occurring, thickening (hereinafter, also referred to as “thickening”) is performed before and after the welding point during continuous rolling.
By thickening, the rolling load when passing through the welding point can be reduced to reduce the risk of breakage, and the tip shape at the time of winding the reel is also stabilized, so that winding trouble can be suppressed. In particular, thickening is suitable for producing a metal strip with high efficiency and stability when the plate thickness of the steady portion is thin and the rolling conditions of the steel strip change before and after the welding point.

  However, when such thickening is performed, the three points including the welding point and the front and back of the welding point are used as the running plate thickness change points (hereinafter also referred to as “running change points”), and the rolling conditions of the multiple stands are finely defined. Need to control. Therefore, as in the techniques described in Patent Documents 1 and 2, it is difficult to manufacture a metal strip stably with high efficiency in the running plate thickness changing method in which only one welding point is a running change point. However, it is insufficient for preventing or suppressing troubles such as breakage of the material to be rolled.

  Here, for example, in the technique described in Patent Document 3, thickening is performed before and after a detection part such as a welded part or an ear cracked part in order to prevent breakage at the front and rear of the welded part and at the ear cracked part. That is, in the technique described in the same document, two running inflection points are set, and thickness reduction is performed in which the running plate thickness is changed twice. However, the thickening section where the thickening is performed becomes off-gauge. For this reason, there is a problem in that the yield decreases when the thickening section (cut-off length) becomes longer. Therefore, in order to minimize the off-gauge part when carrying out thickening, it is the case where all of the plurality of running inflection points enter the mill or the two running inflection points enter between the same stand. However, it is desirable that the roll thickness of each stand and the roll gap be reliably controlled to change the desired plate thickness during running.

  On the other hand, when the plate thickness change is performed a plurality of times, the mass flow variation between all the stands and the running variable point passage schedule calculation become more complicated. In particular, as described above, in order to minimize the off-gauge part, when all of the multiple run-off points enter the mill (between the start stand and the final stand), or between the same stand where the two run-off points are the same. However, in the technique described in Patent Document 3, no consideration is given to the case where two run-in points enter the mill. Therefore, the technique described in this document is insufficient for solving the problem that the yield is deteriorated due to the lengthening of the thickening section (cut-off length).

  On the other hand, Patent Document 4 discloses a thinning technique for reducing the thickness before and after the welding point in order to reduce the amount of cut-off before and after the welding point. Unlike the technique described in Patent Document 3, the thinning method disclosed in this document makes it possible to enter two running inflection points in the mill by executing complicated mass flow calculation and schedule calculation. Can also be applied to thickening.

  According to the technique described in this document, according to the result of tracking, all the amount of change of the roll gap and the roll peripheral speed are calculated before the start of the change of the running plate thickness, and according to the order in which the two running change points pass through the four stands. The amount of control change is output sequentially. Therefore, in the technique described in the same document, it is necessary to grasp all the passing order of the plurality of running inflection points corresponding to the plurality of stands before the start of the change in the thickness of the running plate. The order in which the running point passes through the four stands is determined in advance by case.

  However, the technique described in this document is a technique related to a change in the plate thickness between two points when the rolling condition of the steel strip does not change before and after the welding point. Moreover, the technique described in this document is a technique based on the premise that two running inflection points do not enter at the same time between the same rolling stands. Therefore, for the material to be rolled, in which the preceding material and the succeeding material, which are different from each other, are joined at the welding point, the running plate with three running points that changes the rolling condition of the steel strip before and after the mutual welding point. It is not enough to cope with the thickness change.

  In other words, by applying the technique described in the same document, when trying to change the rolling conditions between the preceding material and the following material before and after the welding point, all three running points enter the mill or the same stand If a process including the case where two running inflection points are inserted between them, the number of cases and the schedule calculation corresponding to the number of cases are very complicated and enormous. Therefore, it is difficult to complete necessary mass flow calculation and schedule calculation within a time limited by the response speed on the device side. Therefore, the technique described in this document still leaves room for consideration when outputting the change amount according to the tracking result within the time in which the response can be made before the start of the change of the plate thickness.

JP 2014-12294 A JP 2009-90348 A JP 2006-224119 A JP2013-35061A

  As described above, the conventional plate thickness changing method disclosed in Patent Documents 1 to 4 is configured to change the plate thickness changing process when the positional relationship between one or two running variable points with respect to a plurality of stands is changed. The amount of change such as roll gap value and roll peripheral speed value to be output is calculated immediately before. For this reason, it is complicated to change the thickness of the running plate so that the passing order of the multiple running points with respect to the multiple stands changes more complexly by increasing the number of stands and the number of running points. It becomes more difficult to process the calculation and the case classification within the response time on the device side.

In particular, when the rolling conditions of the steel strip change before and after the welding point for the material to be rolled in which the preceding material and the following material which are different from each other are joined at the welding point, the welding point and the three runs before and after the welding point are changed. When carrying out the running plate thickness change process with an inflection point, assume a transition pattern in which all three running inflection points enter the mill and even a transition pattern in which two running inflection points enter between the same stand In this case, the problem that the intended process is completed within the response time on the device side becomes more conspicuous.
In other words, if the expected processing cannot be completed within the response time on the equipment side, the calculated run-off point passing timing and actual run-off point passing timing will be different, and the change amount to be output to each stand individually Will not reflect the actual situation. In addition, if the response time has a margin, the thickening section (off-gauge portion) becomes longer, and thus the yield cannot be improved.

  Therefore, the present invention has been made paying attention to such problems, and before and after the welding point with respect to the rolled material in which the preceding material and the following material which are different from each other are joined at the welding point. Even when the rolling conditions of the steel strip change, it is possible to prevent or suppress troubles such as breakage of the material to be rolled, and to change the running plate thickness that can further improve the yield by reducing the off-gauge part as much as possible It is an object to provide a method and a running plate thickness changing device.

  In order to solve the above-mentioned problem, a running plate thickness changing method according to an aspect of the present invention is a tandem rolling mill having a plurality of stands for a material to be rolled in which a preceding material and a following material are joined at welding points. This is a running thickness change method that rolls the welding point and the thickness before and after the weld to a thickness different from the thickness of the steady part during continuous rolling. Control table reference step, and when the position where the rolling condition is changed to a plate thickness different from the plate thickness of the steady part during continuous rolling is called a run-in point, the control table setting step includes a plurality of runs for a plurality of stands. A transition pattern setting step for setting a plurality of transition patterns corresponding to each position where an inflection point exists, and calculating a control value of a rolling condition for each stand for each transition pattern, and the calculated control value for each transition pattern A control information setting step for setting as a linked control table, wherein the control table reference step is a tracking step for tracking a welding point that is currently running and acquiring welding point information at any time, and an obtained as needed A transition pattern information calculation step for calculating corresponding transition pattern information from the welding point information, and a change in the calculated value of the transition pattern information is monitored. And a stand control step of controlling each stand to the control value of the rolling condition for each stand linked to the transition pattern corresponding to the transition pattern information with reference to the control table.

  Moreover, in order to solve the said subject, the running plate | board thickness change apparatus which concerns on 1 aspect of this invention is the tandem rolling which has a several stand for the to-be-rolled material to which the preceding material and the succeeding material were joined by the welding point. A control table that performs off-line control table setting processing for rolling plate thickness changing equipment that rolls the welding point and the thickness before and after it to a thickness different from the thickness of the steady part during continuous rolling on the machine. The control means includes a setting means and a control table reference means for executing a control table reference process online, and when the position where the rolling condition is changed to a thickness different from the thickness of the steady portion during continuous rolling is referred to as a running point, the control is performed. The table setting means calculates transition pattern setting means for setting a plurality of transition patterns corresponding to the respective positions of a plurality of running inflection points for a plurality of stands, and calculates a control value of the rolling condition for each stand for each transition pattern. And a control information setting means for setting the calculated control value as a control table linked to each transition pattern, and the control table reference step tracks the welding point currently running and Tracking means for acquiring welding point information, transition pattern information calculating means for calculating corresponding transition pattern information from the obtained welding point information at any time, monitoring changes in the calculated value of the transition pattern information, and the transition pattern When the calculated value of information changes, each stand is controlled to the control value of the rolling condition for each stand linked to the transition pattern corresponding to the transition pattern information with reference to the preset control table And a stand control means.

  According to the present invention, since the setting of the control table is performed off-line, complicated calculations and case-by-case processing can be performed in advance regardless of the response time on the device side. And online, tracking the welding point currently running and calculating the transition pattern information, monitoring the change of the calculated value of the transition pattern information, when the calculated value of the transition pattern information changes, it is set in advance Each stand is controlled to the control value of the rolling condition for each stand associated with the transition pattern corresponding to the transition pattern information with reference to the control table.

  For this reason, the online processing does not require a complicated process for determining the passing order of the run-off points and the control values of a plurality of stands corresponding thereto. Therefore, multiple plate thickness changes can be performed quickly without complicated calculations and case classification. Therefore, according to the present invention, the desired control can be performed within the response time on the equipment side even in the running plate thickness changing process in which the passage order of the plurality of running inflection points with respect to the plurality of stands changes more complicatedly. It can be carried out. Therefore, according to the present invention, even if the rolling conditions of the steel strip change before and after the welding point, the material to be rolled is different from the material to be rolled in which the preceding material and the following material that are different from each other are joined. It is possible to prevent or suppress troubles such as breakage of the material and to further improve the yield by reducing the number of off-gauge parts as much as possible.

  As described above, according to the present invention, it is possible to prevent or suppress troubles such as breakage of the material to be rolled, and to further reduce the off-gauge portion as much as possible to further improve the yield.

It is a schematic diagram which shows one Embodiment of the cold continuous rolling equipment provided with the running sheet thickness change apparatus which concerns on 1 aspect of this invention. It is a schematic diagram which shows the image which changes a running plate | board thickness at three running variable points of the thickness reduction start point of a to-be-rolled material with respect to a some stand, a welding point, and a thickness reduction end point. It is a schematic diagram which shows an example of the transition pattern at the time of three running inflection points passing through six stands (the presence position of the several running inflection points in the mill at any time). In embodiment of this invention, it is a schematic diagram which shows an example of the flag set (transition pattern information) corresponding to a transition pattern. It is a flowchart of the control table setting process which the strip thickness changing apparatus which concerns on one Embodiment of this invention performs offline. It is a flowchart of the control table reference process which the running board thickness change apparatus which concerns on one Embodiment of this invention performs online. It is a figure explaining the process image of the control table reference process performed online ((a)-(c)). It is a graph ((a)-(c)) which shows the simulation result in the cold continuous rolling installation of FIG. 1, Comprising: The figure (a) is a unit tension fluctuation | variation at the time of changing a strip thickness 3 times. (B) and (c) show the run-in point, the load in the vicinity thereof, and the outgoing finish thickness. It is a graph which shows the simulation result in the cold continuous rolling installation of FIG. 1, Comprising: The figure has shown the finishing thickness when the control which puts two running inflection points between stands is performed. In the example of the running plate thickness changing device according to one embodiment of the present invention, the rolling speed, the plate thickness deviation, and the intervals between the stands at the time of carrying out the thickness drawing at the welding point and the three running change points before and after the welding point. It is a graph which shows the track record value of tension.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The drawings are schematic. For this reason, it should be noted that the relationship between the thickness and the planar dimension, the ratio, and the like are different from the actual ones, and the dimensional relationship and the ratio are different between the drawings. Further, the following embodiments exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, structure, and arrangement of components. Etc. are not specified in the following embodiments.

The structure of the cold continuous rolling equipment of this embodiment is shown in FIG. In addition, in the same figure, illustration is abbreviate | omitted about other apparatuses (for example, apparatuses, such as an entrance side unwinder, a welding machine, and a looper, and an exit side cutting machine, a winder), etc. which are attached to an installation. .
As shown in the figure, the cold continuous rolling equipment includes a tandem rolling mill 10, a rolling control computer 12 that controls the tandem rolling mill 10, and a host that manages the cold continuous rolling equipment including the rolling control computer 12. And a computer 11.

The tandem rolling mill 10 is a continuous cold tandem rolling mill having first to sixth stands 1 to 6 in order from the entry side in the sheet passing direction. In the example of this embodiment, the distance between adjacent stands is 4 m, and the total number of stands is 6, so the total length of the tandem rolling mill 10 is 20 m.
Each stand 1-6 is provided with a speed detector 7, a roll speed controller 8 that is an electric motor that changes the roll speed of the work roll, and a roll gap controller 9 that changes the roll gap. In the present embodiment, the host computer 11 sets a later-described control table CT offline, and the rolling control computer 12 is based on the control table CT acquired from the host computer 11 and the roll speed controllers 8 of the stands 1 to 6. And the process which controls the roll gap controller 9 of each stand 1-6 is performed online.

The speed detector 7 of each stand 1 to 6 feeds back the roll gap current value (roll gap feedback value) Tp of each stand 1 to 6 to the rolling control computer 12. And the roll speed controller 8 of each stand 1-6 controls the roll speed of each stand 1-6 according to the roll peripheral speed command Cs from the rolling control computer 12. FIG.
The roll gap controller 9 of each stand 1 to 6 feeds back the roll gap current value (roll gap feedback value) Tp of each stand 1 to 6 to the rolling control computer 12 and rolls from the rolling control computer 12. The roll gap of each stand 1-6 is controlled according to the gap command Cp.

Here, to this tandem rolling mill 10, as shown in FIG. 2, the material to be rolled M in which the preceding material Ma and the following material Mb are joined at the welding point W is passed through. . In the present embodiment, the distance between the run-off points (thickening sections) Sa and Sb between the run-off points B and E set before and after the welding point W with respect to the portion to be thickened is the tandem rolling. Each is set to 2 m on the entry side of the machine 10. The distances Sa and Sb between running points after rolling are about 20 m on the exit side of the tandem rolling mill 10.
In the thickness reduction, when the thickness reduction start point B, the welding point W, and the thickness reduction end point E shown in FIG. On the other hand, it is necessary to appropriately change the roll gap value and the roll peripheral speed value of each of the stands 1 to 6 in accordance with the position where each running inflection point B, W, E exists.

  Therefore, in the present embodiment, in the running plate thickness change process, transition patterns corresponding to all transition states in which a plurality of running inflection points B, W, and E for the plurality of stands 1 to 6 exist are set by thickness reduction. . As shown in the example of transition patterns P1 to Pn (where n is the total number of transition patterns set as necessary) of the positional relationship between a plurality of stands and a plurality of running change points when performing thickening rolling, When the thickness change between three runs is performed with six stands 1 to 6, a number of transition patterns are passed. The example shown in FIG. 3 shows an image that has undergone a total of 18 transition patterns P1 to P18 (n = 18).

Hereinafter, the running plate thickness changing process executed in the cold continuous rolling facility will be described in detail. In the present embodiment, a running plate thickness changing device is configured by the host computer 11 and the rolling control computer 12, and a running plate thickness changing process described later is executed.
First, FIG. 5 shows a flowchart of the control table setting process executed by the host computer 11. The host computer 11 of the present embodiment is a first computer that executes rolling equipment management processing and control table setting processing including management of the rolling control computer 12. When the host computer 11 changes from the rolling-down schedule of the preceding material Ma to the rolling-down schedule of the succeeding material Mb, the three running inflection points B assumed for the respective stands 1 to 6 necessary for the thickness reduction, Control information Ct of roll gap values and roll peripheral speed values corresponding to all the transition patterns P1 to Pn of W and E is calculated in advance, and the result is stored as a control table CT. The control table setting process of the present embodiment corresponds to the control table setting process and the control table setting means described in “Means for Solving Problems”.

  Specifically, when the preceding material Ma and the succeeding material Mb are joined by welding at the welding point W in the upstream process, and the material to be rolled M to be passed through the facility is determined upstream, the upper computer 11 Then, the control table setting process is executed offline. When the control table setting process is executed, as shown in FIG. 5, first, the process proceeds to step S11, and the material to be rolled of the preceding material Ma and the succeeding material Mb scheduled to be rolled is acquired. In subsequent step S12, the rolling condition information necessary for the rolling reduction calculation corresponding to each of the preceding material Ma and the succeeding material Mb is acquired. The material to be rolled and the rolling condition information are stored in advance in a storage device of the host computer 11.

  When the processing shifts to the subsequent step S13, all transition patterns P1 to Pn corresponding to the respective existence positions of the three running inflection points B, W, and E with respect to the plurality of stands 1 to 6 are set at the time of thickness reduction. (Transition pattern setting process). In the present embodiment, a transition pattern is also set when two running break points enter between the stands (see FIG. 3).

  And in step S14, control information Ct of each stand 1-6 corresponding to each transition pattern P1-Pn is calculated beforehand from the result of the simulation based on data, such as a rolling performance. In the present embodiment, for each transition pattern P1 to Pn, the control information Ct of the roll gap value and the roll peripheral speed value of each stand 1 to 6 corresponding to the material M to be rolled is calculated offline.

  That is, when the process moves to step S14, the reduction schedule calculation is performed for the transition pattern Pk to be calculated among the plurality of transition patterns P1 to Pn as in the conventional procedure, and each of the stands 1 to 6 is calculated. Control information Ct (roll gap value and roll peripheral speed value) of the rolling conditions is calculated. In addition, regarding the calculation method of the roll gap value and the roll peripheral speed value in the reduction schedule calculation, for example, the calculation can be performed by a procedure similar to the technique described in Patent Document 4 (Japanese Patent Laid-Open No. 2013-35061).

  In subsequent step S15, the control information Ct calculated in step S14 is associated with the transition pattern Pk and set as the control table CT. In step S16, the presence / absence of the next transition pattern Pk (Pk = Pk + 1) is confirmed. If there is a next transition pattern Pk, the process returns to step S14, and the processes in steps S14 to S15 are performed for other transition patterns Pk. If there is no next transition pattern Pk (Pk = Pn), the process proceeds to step S17. In step S17, the rolling condition control information Ct associated with all the transition patterns Pk is stored as a completed control table CT, and the process is terminated (control information setting step).

  Next, control table reference processing executed online by the rolling control computer 12 will be described with reference to the flowchart shown in FIG. The control table reference process of the present embodiment corresponds to the control table reference process and the control table reference means described in “Means for Solving the Problems”.

  The rolling control computer 12 is a second computer that executes a control table reference process when the material to be rolled M passed through the facility reaches a predetermined position upstream of the entry side. When the control table reference process is executed by the rolling control computer 12, as shown in FIG. 6, first, the process proceeds to step S21, and the contents of the control table CT set in advance by the host computer 11 are stored in the storage area. To do. In the subsequent step S22, tracking of the welding point W currently running is started and the welding point information Dt at any time is acquired (tracking step).

  Here, in the present embodiment, the length of the welded portion at the welding point W in the conveyance direction is about several centimeters on the entry side, and a sensor detection penetrating for tracking at a position corresponding to the welding point W. A hole is drilled in the material M to be rolled. In the present embodiment, for the two front and rear running inflection points B and E, the positional information of the two front and rear running inflection points B and E is calculated using data such as the actual thickness value from the rolling conditions. In addition, with respect to the two running change points B and E before and after, a through hole for sensor detection is drilled in the rolled material M for tracking at positions corresponding to the respective run change points B and E. Similarly, tracking may be performed.

  As a method for tracking the welding point W, for example, an optical or magnetic detection sensor can be used. The optical sensor projects light from the upper or lower surface of the steel plate with a projector, and detects light passing through a detection hole drilled corresponding to the welding point W with a light receiver such as a camera installed on the opposite surface. it can. Further, as the magnetic sensor, for example, an eddy current sensor or the like is installed, and the disturbance of the magnetic field when the detection hole which is the welding point W passes is detected. The rolling control computer 12 acquires the detection hole passage information of the welding point W as the welding point information Dt.

  In the subsequent step S23, the corresponding transition pattern information Fs is calculated from the obtained welding point information Dt at any time (transition pattern information calculation step). The transition pattern information Fs is calculated as a “flag set” based on the setting flag of each stand corresponding to the tracking result of the welding point W. FIG. 4 shows an example of the flag set calculation result.

  The rolling control computer 12 has counters respectively corresponding to the first stand 1 to the sixth stand 6, and every time the three run-off points B, W, E pass the center position of any one stand. The corresponding counter is configured to count up. In the present embodiment, the rolling control computer 12 calculates positional information of the three running break points B, W, and E as needed based on the tracking result of the welding point W. Then, the relative position between the position information of the three running points B, W, and E and the center positions of all the stands 1 to 6 is determined. The positional information of the three running inflection points B, W, and E can be calculated using the roll peripheral speed and the advanced rate of each stand 1-6. The center positions of all the stands 1 to 6 are set immediately before passing through the stands in consideration of the response speed on the device side.

  When the rolling control computer 12 determines that the position information of any one running point coincides with the center position of any one stand by the determination of the relative position, the bit of the unique flag of any one stand Count up. As a result, the relationship between the positional information of the three running points B, W, and E and the relative positions of the central positions of all the stands 1 to 6 is determined by setting the combination of the counter values of all the stands 1 to 6 as “flag set”. , It can be obtained as a value corresponding to the positional relationship of the three running inflection points B, W, E with respect to all the stands 1-6. The value of the flag set calculated by the rolling control computer 12 is stored in the storage area as transition pattern information Fs.

  In a succeeding step S24, a change in the transition pattern information Fs is monitored. That is, when the value of the flag set has not changed, the process returns to step S22, and when the value of the flag set has changed, the process proceeds to step S25. In step S25, the control information CT of rolling conditions for each of the stands 1 to 6 linked to the transition pattern Ps corresponding to the transition pattern information Fs is called with reference to the preset control table CT.

  In the following step S26, the necessary change amount is obtained by subtracting the roll gap current value Tp and the roll circumferential speed current value Ts from the roll gap value and roll circumferential speed value data called as the control information Ct, and the following step. In S27, the corresponding change amounts are output as the roll peripheral speed command Cs and the roll gap command Cp to the roll speed controller 8 and the roll gap controller 9 of each of the six stands 1 to 6, respectively, and the process is performed in step S22. Return to (stand control process).

Next, the operation | movement in the continuous rolling of the strip thickness change apparatus in the cold continuous rolling equipment of this embodiment is demonstrated.
In the cold continuous rolling facility of the present embodiment, when the tandem rolling mill 10 starts to feed the material M to be rolled, the rolling control computer 12 performs online control table reference processing according to a command from the host computer 11. Run with.

  The rolling control computer 12 acquires information of a preset control table CT and starts tracking the welding point W that is currently running. Then, based on the position of the welding point W accompanying the movement of the material M to be rolled during continuous rolling, the position at any time of the three running inflection points B, W, E is calculated to generate transition pattern information Fs. Furthermore, the change of the calculated value of the transition pattern information Fs is monitored.

  And when the calculated value of the transition pattern information Fs changes, the control information of the rolling conditions for each of the stands 1 to 6 linked to the transition pattern Ps corresponding to the transition pattern information Fs is referred to the control table CT. Call Ct. Since the transition pattern information Fs changes whenever any one of the running inflection points passes through each of the stands 1 to 6, the roll gap value and the roll peripheral speed value of each of the stands 1 to 6 are correspondingly set in the control table CT. It is called from.

  Then, the rolling control computer 12 calculates the roll gap change amount and the roll speed change amount as the difference amounts to be controlled from the difference between the roll gap current value Tp and the roll peripheral speed current value Ts, and each of the stands 1 to 6 is calculated. A roll peripheral speed command Cs and a roll gap command Cp, which are control commands of change amounts, are output to the roll speed controller 8 and the roll gap controller 9 which are actuators for each actuator. When the roll speed controller 8 receives the roll peripheral speed command Cs from the rolling control computer 12, the roll speed controller 8 changes the roll peripheral speed accordingly. Further, when the roll gap controller 9 receives the roll gap command Cp from the rolling control computer 12, it changes the roll gap value accordingly.

  Here, a processing image of the control table reference processing executed online by the rolling control computer 12 is shown in FIG. FIG. 3 shows an example of an image when transition is made from transition pattern P9 to transition pattern P10 in FIG. 3, and a transition that is a flag set based on tracking with respect to the transition pattern at any time (FIG. 3A). The pattern information Fs is calculated ((b) in the figure), and the control information Ct for the roll gap value and the roll peripheral speed value associated with the transition pattern Ps corresponding to the calculation result is set in advance. An image of a correspondence relationship of a series of processing called from the table CT ((c) in the same figure) is shown.

  That is, in this embodiment, as shown in the figure, it is determined that any one running inflection point has passed any one of the six stands 1 to 6 based on the tracking result of the welding point W. When this is done, the unique flag of the corresponding stand (second stand 2 in this example) is counted up (2 → 3 in this example), and the flag set is updated from Fs9 to Fs10. When the flag set is updated, the control information Ct of the roll gap value and the roll circumferential speed value associated with the transition pattern 10 corresponding to the updated flag set Fs10 is obtained from the control table CT stored in advance. It is called immediately.

  Thereby, the rolling control computer 12 calculates | requires required change amount by subtracting the roll gap present value Tp and the roll peripheral speed present value Ts, respectively from the control information Ct of the called roll gap value and roll peripheral speed value. The corresponding change amounts can be quickly output to the roll speed controller 8 and the roll gap controller 9 of each of the six stands 1 to 6.

[Example]
In order to show that it is possible to change the running plate thickness three times including the welding point W by the running plate thickness changing device of the above embodiment, a simulation calculation was performed.
As the simulation conditions, the base material thickness is 1.8 mm as the preceding material Ma, the deformation resistance (l = 63.2 m = 0.270n = 0.0337), and the base material thickness is 1. Using the conditions of 8 mm, deformation resistance (l = 67.7 m = 0.270 n = 0.0340), the finished thickness of the thickening section S during thickening is 0.2 mm, the steady portion Ra other than during thickening, The simulation calculation was performed with the finished thickness of Rb being 0.15 mm. In this simulation, the base plate thickness and finish thickness of the preceding material Ma and the following material Mb are unchanged, but the deformation resistance between the preceding material Ma and the following material Mb is different, so that the running distance at the welding point W is different. It is necessary to change the plate thickness 3 times including the plate thickness change.

FIG. 8 shows changes in tension and finished thickness during the change of the running plate thickness performed by the running plate thickness changing method using the running plate thickness changing device of the above embodiment. In addition, the figure is an example in case only one running inflection point is located between the stands in three times of running thickness change.
As shown in the figure, according to the running plate thickness changing method using the running plate thickness changing device of the above embodiment, even if the preceding material Ma and the following material Mb are different materials, It can be seen that there is no steep movement in the graph and the tension is stable in the movement ((a) in the figure). Similarly, in the graph showing the rolling load at the sixth stand 6, it can be seen that there is no steep operation in the graph and that the control result of the rolling load is stable ((b) in the figure).

  And (c) of the figure shows the result of the thickness of the thickened portion and the vicinity thereof, and from the same figure, even if the leading material Ma and the succeeding material Mb are different materials, three running inflection points are obtained. The desired thickness reduction (thickness 0.15 → 0.2 → 0.15) can be performed under stable tension and reduction conditions by running point control by B, W, and E. You can see that Thus, according to the running plate thickness changing method using the running plate thickness changing device of the above-described embodiment, the finished thickness can be controlled to the target value while suppressing the tension fluctuation, so that It can be seen that the plate thickness can be changed.

Next, FIG. 9 shows the result of a change pattern in which two running inflection points are inserted between the stands in the roll gap value and the roll peripheral speed value that brought the result shown in FIG. From the figure, at the timing when the running point passes the stand, the change amount of the roll gap value and the roll peripheral speed value corresponding to the transition pattern corresponding to the flag set is output to the roll speed controller 8 and the roll gap controller 9. You can see that it is made.
In other words, as can be seen from the figure, even if there are two running points between the stands, it is possible to change the plate thickness between three runs, and only one running point between the stands. Is positioned at 120 [m] (see FIG. 8 (c)), the thickness is reduced by half by inserting two running points between the stands. It turns out that it can reduce to 60 [m].

  FIG. 10 shows three running inflection points before and after the welding point W from a finishing thickness of 0.188 mm (thickening thickness of 0.220 mm) to a finishing thickness of 0.172 mm (thickening thickness of 0.210 mm). It is a graph which shows the actual value of the rolling speed in the last stand 6 at the time of thickening implementation, a plate | board thickness deviation, and tension | tensile_strength between each stand in the thickening area over. As can be seen from the figure, the running plate thickness changing device of this embodiment and the running plate thickness changing method according to this embodiment are stable in a real machine without complicated calculations and case divisions. It was confirmed that the controlled operation can be performed quickly.

Next, the effect of the running plate thickness changing device and the running plate thickness changing method according to this embodiment will be described.
As described above, according to the present embodiment, the position information of the plurality of running plate thickness change points B, W, and E is acquired by tracking, and the running change points B, W, and E are obtained from the tracking result. The control commands Cs and Cp for changing the control value can be quickly output by calculating the roll gap change amount and the peripheral speed change amount with reference to the control table CT obtained by calculation in advance immediately before passing through. . Therefore, according to the present embodiment, in the cold continuous rolling equipment, to-be-rolled materials having different thicknesses and deformation resistances before and after the welding point are joined, and the thickness setting different from the steady rolling part is set near the welding point. It can be carried out.

  In addition, according to the present embodiment, the running plate thickness can be changed up to three times for one welding point W, and all three running inflection points B, W, E are within the mill (start stand 1 to 1). Since it is possible to change the thickness of the running plate even when entering the last stand 6) or when two running inflection points enter the same stand, troubles such as breakage of the material M to be rolled can be prevented or suppressed. At the same time, the off-gauge portion can be reduced as much as possible to further improve the yield.

  In particular, the greatest difference between this embodiment and the conventional running plate thickness changing method is to track a welding point W that is currently running, and depending on the tracking result, three running running points B, W, and E as needed. When the transition pattern information Fs is generated from the position of the flag and the value of the flag set that is the calculated value of the transition pattern information Fs changes, the transition pattern corresponding to the flag set is referred to by referring to the preset control table CT Each stand is controlled to the control value of the rolling condition for each stand linked to Ps.

  In other words, in the conventional plate thickness change method, at the time before the start of the plate thickness change, to grasp the passage sequence of the running variable point online, to calculate the amount of change to control each stand, The calculation and case classification for grasping the order are very complicated, and it is difficult to realize a complicated running plate thickness changing process such as changing the running plate thickness three times with six stands.

On the other hand, in the running plate thickness changing device and the running plate thickness changing method using the same according to the present embodiment, the upper computer 11 is off-line for each of the stands 1 to 6 and the three running change points B, W, E. All the positional relationships are set as transition patterns P1 to Pn, and a control table CT in which a roll gap value and a roll peripheral speed value are calculated in advance as control information Ct for each of the transition patterns P1 to Pn is set. The transition patterns P1 to Pn are associated with the calculation result of the control information Ct.
And if the flag set which is the transition pattern information Fs changes online according to the tracking result of the welding point W currently running, the rolling control computer 12 is linked to the transition pattern Ps corresponding to the flag set. Control information Ct is called, the feedback amount of the roll gap current value Tp and the roll circumferential speed current value Ts is subtracted therefrom, and the difference results are used as the roll gap command Cs and the roll circumferential speed command Cp, and the roll gap controller 9 and the roll The speed can be output to the speed controller 8 quickly.

  Therefore, according to the present embodiment, since the setting of the control table CT is performed off-line, complicated calculation and case-by-case processing can be performed in advance regardless of the processing response time on the device side. And on-line, while tracking the welding point M currently drive | working, while calculating the transition pattern information Fs, the change of the calculated value of the transition pattern information Fs is monitored, and when the calculated value of the transition pattern information Fs changes In order to control each stand to the control value of the rolling condition for each stand linked to the corresponding transition pattern Ps with reference to the preset control table CT, in the online processing, the passing of the running point is passed. A complicated process for determining the order and control values of a plurality of stands corresponding to the order immediately before is not necessary.

  Therefore, according to the present embodiment, it is possible to quickly change the running plate thickness a plurality of times without complicated calculation and case classification. Therefore, even if it is a running plate thickness change process in which the passing order of the plurality of running inflection points B, W, E with respect to the plurality of stands 1 to 6 changes more complicatedly, it is desired within the processing response time on the equipment side. Can be controlled. Therefore, according to the present embodiment, the rolling condition of the steel strip changes before and after the welding point W with respect to the material M to which the preceding material Ma and the following material Mb, which are different from each other, are joined. However, troubles such as breakage of the material M to be rolled can be prevented or suppressed, and the off-gauge portion can be reduced as much as possible to further improve the yield.

In addition, in the running plate thickness changing device and the running plate thickness changing method of the present embodiment, since the order of passing the running variable points is not specified online in advance, this is a case where it is applied to a system with a slow response speed on the device side. However, there is also an effect of preventing the actual run-change point passing order and the change amount output order from deviating. Therefore, it is excellent in preventing or suppressing troubles such as breakage of the material to be rolled and further improving the yield by reducing the off-gauge portion as much as possible.
Note that the running plate thickness changing device and method according to the present invention are not limited to the case of performing thickening, but can also be applied to performing thinning rolling, two-stage running plate thickness change, and the like. The present invention can be widely applied to various rolling processes that track the run-in point and output control amounts for a plurality of stands.

DESCRIPTION OF SYMBOLS 1 1st stand 2 2nd stand 3 3rd stand 4 4th stand 5 5th stand 6 6th stand 7 Speed detector 8 Roll speed controller (electric motor)
9 Roll gap controller 10 Tandem rolling mill 11 Host computer (first computer)
12 Rolling control computer (second computer)
Ct control information (control value of rolling conditions)
Cs Roll peripheral speed command Cp Roll gap command CT Control table Dt Tracking information (welding point information)
B Thickening start point (running point)
E Thickening end point (running point)
S Thickening section Sa Thickening section Sb of preceding material Thickening section Ra of following material Ra Steady part Rb of preceding material Steady part W of following material Welding point (running point)
Fs flag set (transition pattern information)
Transition pattern M corresponding to Ps flag set Rolled material Ma Preceding material Mb Subsequent materials P1 to P18 to Pn Transition pattern Ts Roll peripheral speed current value Tp Roll gap current value

Claims (5)

When the material to be rolled, in which the preceding material and the following material are joined at the welding point, is continuously rolled by a tandem rolling mill having a plurality of stands, the thickness of the welding point and the thickness before and after it are different from the thickness of the steady part. A method for changing the thickness of a running plate that is rolled to a thickness,
Including a control table setting step performed offline and a control table reference step performed online;
When the position where the rolling conditions are changed to a plate thickness different from the plate thickness of the steady part during continuous rolling is called the running point,
The control table setting step includes a transition pattern setting step for setting a plurality of transition patterns corresponding to the respective positions of a plurality of running inflection points for a plurality of stands, and a control value of a rolling condition for each stand for each transition pattern. A control information setting step for calculating and setting the calculated control value as a control table linked to each transition pattern,
The control table reference step includes a tracking step of tracking a welding point that is currently running and acquiring welding point information at any time, and a transition pattern information calculation that calculates corresponding transition pattern information from the obtained welding point information at any time. A transition pattern corresponding to the transition pattern information with reference to the control table set in advance when the process and a change in the calculated value of the transition pattern information are monitored and the calculated value of the transition pattern information changes And a stand control step of controlling each stand to a control value of a rolling condition for each stand linked to the stand. The plurality of running change points can be set up to three points for one welding point,
The transition pattern and the corresponding transition pattern information include a pattern in which all three running change points are located from the start stand to the last stand, and a stand where two of the three run change points are the same. The method for changing a running plate thickness according to claim 1, wherein the pattern includes a pattern to be entered. In the transition pattern information calculation step, by tracking the one welding point, the position of the three running change points is calculated using the roll peripheral speed and the advance rate of each stand,
In the stand control step, immediately before the positional relationship between the plurality of stands and the three running change points is changed, the control values of the roll gap value and the roll peripheral speed value of each stand are called from the control table and become the control values. The method for changing a running plate thickness according to claim 2, wherein each stand is controlled as described above. In the control table, roll gap values and roll peripheral speed values in all transition patterns that can be taken by the positional relationship between a plurality of stands and three running change points are calculated and stored in advance.
The stand control processing step compares the transition pattern information generated based on the tracking result with the transition pattern in the control table, and responds to the corresponding transition pattern in the control table; The running thickness change method according to any one of claims 1 to 3, wherein a change amount obtained by subtracting the current value from the roll peripheral speed value is output to each stand. When the material to be rolled, in which the preceding material and the following material are joined at the welding point, is continuously rolled by a tandem rolling mill having a plurality of stands, the thickness of the welding point and the thickness before and after it are different from the thickness of the steady part. A strip thickness changing device that rolls to a thickness,
A control table setting means for executing control table setting processing offline, and a control table reference means for executing control table reference processing online;
When the position where the rolling conditions are changed to a plate thickness different from the plate thickness of the steady part during continuous rolling is called the running point,
The control table setting means includes a transition pattern setting means for setting a plurality of transition patterns corresponding to the respective positions of a plurality of running points for a plurality of stands, and a control value of the rolling condition for each stand for each transition pattern. Control information setting means for calculating and setting the calculated control value as a control table associated with each transition pattern;
The control table reference step includes tracking means for tracking a welding point that is currently running and acquiring welding point information at any time, and transition pattern information calculation for calculating corresponding transition pattern information from the obtained welding point information at any time. And a transition pattern corresponding to the transition pattern information with reference to the control table set in advance when the calculated value of the transition pattern information changes and the calculated value of the transition pattern information changes. A running plate thickness changing device comprising stand control means for controlling each stand to a control value of a rolling condition for each stand linked to the stand.

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