JP2011062735A - Method for manufacturing rolled material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a rolled material, capable of raising the operating rate of a rolling line. <P>SOLUTION: The method for manufacturing the rolled material includes: a collection step for collecting track records of progress in maintenance work of a rolling mill whose rolling operation is stopped; a finishing time prediction step for periodically predicting a finishing time T<SB>k</SB>of maintenance work using track records collected in the collection step and calculating the difference T<SB>k</SB>-T<SB>1</SB>between the predicted finishing time T<SB>k</SB>and present time T<SB>1</SB>; a T<SB>h1</SB>estimation step for estimating the required time T<SB>h1</SB>until the rolled material extracted from a heating furnace is entered into the rolling mill in which maintenance work is performed; and an extracting time decision step for judging whether the difference T<SB>k</SB>-T<SB>1</SB>and the required time T<SB>h1</SB>satisfy T<SB>h1</SB>≥T<SB>k</SB>-T<SB>1</SB>, and deciding T<SB>a</SB>which is the time to extract the material to be rolled at first after the finish of maintenance work from the heating furnace when they satisfy T<SB>h1</SB>≥T<SB>k</SB>-T<SB>1</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a rolled material.

  In a rolling line for rolling a metal material such as a steel plate, the metal material is rolled to a predetermined thickness using a rolling roll. It is known that when the rolling of the metal material is repeated, the surface of the rolling roll is gradually deformed. When the metal material is rolled using the deformed rolling roll, the shape of the metal material is defective. When a shape defect occurs in a metal material, for example, it is necessary to go through a step of correcting the shape defect before shipping the metal material, and thus the productivity of the metal material decreases. Therefore, in order to prevent a decrease in productivity of the metal material, in the rolling line, the rolling line is stopped and the rolling roll is periodically replaced (hereinafter referred to as “roll change” or “roll change”). .) Etc. are carried out.

  In order to improve the operation rate of the rolling line, it is important to reduce the time (hereinafter, sometimes referred to as “non-rolling time”) from when rolling is stopped in the rolling line to when rolling is resumed. It is. The time at which rolling is resumed is specified by the time at which the metal material is first rolled after the rolling line is stopped, and the time at which this first metal material is rolled is the completion of work such as replacement of the rolling roll. After the time. Therefore, in order to reduce the non-rolling time, it is effective to reduce the time until the first metal material is rolled after the work such as the replacement of the rolling roll is completed. Therefore, technical development for improving the operating rate of the rolling line is desired.

  Several techniques related to the rolling line have been disclosed so far. For example, Patent Document 1 predicts and calculates a conveyance time from turning on or off each pass in each rolling equipment including a rolling mill and a finishing mill from heating furnace extraction of each rolled material in a heating furnace in-furnace, A mill pacing control method is disclosed in which a rolling material extraction time is determined so as not to cause interference between two continuously rolled materials, and the rolling material is automatically extracted from a heating furnace and rolled. . Further, in Patent Document 2, in a process line that sequentially conveys a plurality of materials along a line, for each material to be conveyed, the material is created by connecting scheduled conveyance times when the material passes through each set point on the line. The predicted transfer curve storage means for storing the predicted transfer curve and the difference between the actual time and the estimated transfer time obtained from the predicted transfer curve each time the material being transferred reaches each set point. There is disclosed a material transport control device comprising progress detection means for determining the progress of the above and predicted transport curve correcting means for correcting a predicted transport curve for each subsequent material according to the determined progress. Patent Document 3 discloses a steel material extraction method for specifying a time at which a succeeding material is extracted from a heating furnace using a correction value F (t) for correcting an extraction interval from the heating furnace of the preceding material and the succeeding material. The correction value F (t) is a standby start time at which the succeeding material reaches the standby position before reaching the target add-on section position in determining the extraction time for extracting the succeeding material from the heating furnace. The correction amount of the actual standby time obtained from the difference from the time when the succeeding material waiting at the standby position is released from standby, and this correction amount is used as the extraction interval from the heating furnace of the preceding material and the succeeding material. A steel material extraction method for continuous hot rolling is disclosed in which feedback is performed and the extraction time of the subsequent material from the heating furnace is determined.

JP 7-290127 A JP-A-10-250828 JP 2001-205317 A

The techniques disclosed in Patent Documents 1 to 3 are based on the presence of the preceding rolled material, and are controlled to an optimal pitch that does not cause interference between two rolled materials that are continuously rolled. This improves the operating rate of the rolling line. However, since the technologies of Patent Documents 1 to 3 are premised on the presence of the preceding rolled material, the determination of the time for extracting the first rolled material after the stoppage from the heating furnace and the conveyance of the first rolled material are performed. There is no consideration for optimization. That is, in the techniques disclosed in Patent Documents 1 to 3, since the reduction of the non-rolling time after the stoppage as described above is not taken into consideration, even if these techniques are applied, the operation rate of the rolling line is further improved. There were limits.
Furthermore, the techniques of Patent Documents 1 to 3 determine the extraction time in a one-to-one serial relationship between the preceding material and the following material. For example, in the above-described roll changing operation, In some cases, rolls of a plurality of stands are changed. In this case, it is necessary to determine extraction / conveying timing in relation to a plurality of parallel processes. Therefore, even if the techniques of Patent Documents 1 to 3 are simply applied, there is a problem that it is difficult to improve the operation rate of the rolling line.
Also, in order to reduce the non-rolling time, the first rolled material after rolling is resumed is extracted from the heating furnace at the earliest possible time regardless of the progress of the roll changing work, and the extracted rolled material is stopped during the stop operation. A method is also conceivable in which the rolled material is allowed to enter the rolling mill immediately after the stop operation is completed. However, in this method, the waiting time of the rolled material immediately before the rolling mill tends to be long, and the temperature of the rolled material tends to decrease, making it difficult to perform desired rolling. Therefore, in order to avoid such a situation, it is necessary to appropriately determine the heating furnace extraction time of the first rolled material after rolling is resumed.

  Then, this invention makes it a subject to provide the manufacturing method of a rolling material which can improve the operation rate of a rolling line.

  As a result of diligent research, the present inventors have determined that the stop work end time predicted using the progress of the stop work of the equipment, which is a stop factor, and the first rolled material from the heating furnace in order to shorten the non-rolling time. Non-rolling time can be reduced by determining the optimum furnace extraction time of the first rolled material using the time from reaching the rolling mill where the stop work was performed after extraction. As a result, it has been found that the operation rate of the rolling line can be improved, and the present invention has been completed.

  The present invention will be described below.

The present invention is a method for producing a rolled material using a rolling line equipped with a heating furnace and a rolling mill, and a collection step for periodically collecting progress results of maintenance work of the rolling mill that has stopped the rolling operation; The maintenance work end time T _k is periodically predicted using the progress results collected in the collection step, and the difference T _k −T ₁ between the predicted end time T _k and the current time T ₁ is calculated. The difference T calculated in the prediction step, the _{Th 1} estimation step for estimating the required time T _h1 until the rolled material extracted from the heating furnace enters the rolling mill where maintenance work is performed, and the end time prediction step _k -T ₁ and _{T h1} required time estimated by the estimated process _{T h1} is determined whether satisfy _{T h1} ≧ _T k -T _1, when satisfying _{T h1} ≧ _T k -T _1, the maintenance work The first rolled material after the end is heated And having an extraction time determining step of determining a time T _a to al extraction, a method for producing a rolled material.

  Here, in the present invention, "maintenance work" refers to work performed by stopping the rolling line mainly for maintenance and inspection of the rolling line, and representative rolls include the above-described roll change work. Can be mentioned. In the present invention, the “rolled material” refers to a metal material represented by a hot-rolled steel sheet or the like.

Further, in the present invention, between the rolling mill and the heating furnace in which maintenance work is performed, a standby place capable of waiting for the rolled material extracted from the heating furnace is provided, extracted from the heating furnace, A recollecting step for periodically collecting again the progress of the maintenance work of the rolling mill whose rolling operation is stopped before the rolling material first rolled after the maintenance work reaches the standby position; The maintenance work end time T _k is periodically predicted again using the progress results collected in the recollection process, and the difference T _k −T ₂ between the predicted end time T _k and the current time T ₂ is calculated. An end time re-prediction step, a _{Th 2} estimation step for estimating a required time T _h2 until the rolled material enters a rolling mill where maintenance work is performed from a predetermined location before reaching the standby location, and an end time re-estimation calculated in the prediction step difference _T k -T ₂及T _h2 required time _{T h2} was estimated by estimate step to determine whether they meet the _{T h2} ≧ _T k -T _2, if they meet the _{T h2} ≧ _T k -T ₂ is first after completion of the maintenance work If the rolled material to be rolled is allowed to pass without waiting at the standby place and _{Th 2} ≧ T _k −T ₂ is not satisfied, the first rolled material to be rolled first after the maintenance work is waited at the standby place. It is preferable to have a standby necessity determination step for determining in the above.

Here, the “predetermined location before reaching the standby location” is a location between the heating furnace and the standby location, and more specifically, when the difference T _k −T ₂ is calculated in the end time re-prediction step. say where the rolled material is present in the time T _2. In the present invention, the “standby place” may be only one place or two or more places. When there are two standby places, the standby places are, for example, between the rough rolling mills constituting the rough rolling mill row and the rough rolling mill and the finish rolling mill row located on the most downstream side of the rough rolling mill row. Can be provided.

Moreover, in the said this invention which has a _recollection process, an end time re-prediction process, _Th2 estimation process, and a standby necessity judgment process, the rolling material first rolled after the completion | finish of maintenance work extracted from the heating furnace However, when it is determined that the standby is required in the standby necessity determination step, the progress resumption of periodically collecting again the progress of the maintenance work of the rolling mill that has stopped the rolling operation after reaching the standby place. The maintenance process end time T _k is periodically predicted again using the collection process and the progress results collected in the progress re-collection process, and the difference T _k between the predicted end time T _k and the current time T ₃ is predicted again. a time difference calculating step of calculating a -T _3, and T _h3 estimate step of estimating the required time T _h3 to the rolled material enters into the rolling mill, which is performed maintenance work from the standby location, at a time difference calculating step calculated difference _{T k} - ₃ and _{T h3} required time estimated by the estimated process _{T h3} is determined whether satisfy _{T h3} ≧ _T k -T _3, when satisfying _{T h3} ≧ _T k -T _3, the first after the end of the maintenance work It is preferable to include a transport time determining step for determining a time _Tc for transporting the rolled material to be rolled from the standby location toward the rolling mill that is the object of the maintenance work.

According to the present invention, the difference T _k −T ₁ between the maintenance work end time T _k and the current time T ₁ predicted by using the maintenance work progress results collected periodically, and from the heating furnace to the rolling mill When the required time T _h1 satisfies T _h1 ≧ T _k −T ₁ , the extraction from the heating furnace of the rolled material that is first rolled after the stoppage is started, so that the non-rolling time is minimized, and The rolled material that is first rolled after the stoppage can be extracted from the heating furnace at the timing at which the heat loss of the rolled material is minimized. Further, by providing a process of predicting the maintenance work end time T _k again and calculating the difference between the predicted end time T _k and the current time T ₂ again, the progress of the maintenance work is delayed after extraction of the heating furnace. Even if it occurs, since it is possible to wait on the upstream side, it is possible to minimize the heat loss of the rolled material. Therefore, according to this invention, even if the preceding rolling material does not exist, the manufacturing method of a rolling material which can improve the operation rate of a rolling line can be provided.

It is a figure which shows the example of a form of a rolling line. It is a figure explaining non-rolling time. Predicted completion time of maintenance work T _k , heating furnace extraction time T _a , estimated required time T _h1 from extraction of the heating furnace to entry into the rolling mill, predicted time T ₂ before arrival at the waiting area, prediction required from time T ₂ to entry into the rolling mill time T _h2, re-feeding start time T _c from the standby _location, and is a diagram for explaining a predicted required time T _h3 from waiting area to mill entrance. It is a flowchart explaining the manufacturing method of the rolling material of this invention.

  Embodiments of the present invention will be described below.

  FIG. 1 is a diagram showing an example of a rolling line 10 to which the present invention is applied. As shown in FIG. 1, the rolling line 10 includes a heating furnace 1, a rough rolling mill row 2, and a finishing rolling mill row 3, and the rolled material 4 extracted from the heating furnace 1 is rough. After rough rolling in the rolling mill row 2, it is finish-rolled in the finishing rolling mill row 3 and processed into a rolled material having a desired plate thickness. The rough rolling mill row 2 of the rolling line 10 includes six rough rolling mills 2a, 2b, ..., 2f, and between the rough rolling mill 2d and the rough rolling mill 2e, the rough rolling mill 2a to the rough rolling mill 2d. Thus, a space is secured in which the rolled material roughly rolled can be kept on standby. Further, the finishing rolling mill row 3 of the rolling line 10 includes seven finishing rolling mills 3a, 3b,..., 3g, and the rolling roughly rolled by the rough rolling mill row 2 immediately before the finishing rolling mill 3a. Space is available to allow the material to stand by.

FIG. 2 is a diagram illustrating the non-rolling time. In FIG. 2, when the rolling mill entry time of the rolled material that is rolled first after the stoppage is delayed from the stoppage end time (roll recomposition end time) of the rolling mill, this time is wasted time. The dead time causes an increase in the non-rolling time, and contributes to a reduction in the operating rate of the rolling line. Therefore, in the present invention, for example, as a standby place where the rolling can be temporarily stopped from the heating furnace 1 to the rolling mill (for example, the finishing rolling mill row 3) that is the target of roll change, the rough rolling mill 2d and the rough rolling mill 2e are provided. And between the rough rolling mill 2f and the finish rolling mill 3a, the optimum extraction time T _a of the rolling material 4 from the heating furnace 1 and the optimum re-rolling of the rolling material 4 from each standby place. By determining the transport time _Tc , the time from when the finishing rolling mill row 3 stops to the time when the rolled material enters the finishing rolling mill row 3 (non-rolling time) is reduced, and the operation rate of the rolling line 10 is reduced. To improve.

  The roll reassigning work of the finish rolling mill row 3 is performed by only one finish rolling mill (hereinafter sometimes referred to as a “stand”) among the finish rolling mills 3a, 3b,. Single stand recombination ”and“ multiple stand recombination ”for performing roll reassignment work for two or more stands. For multiple stand recombination, roll recombination work for all the stands constituting the finishing mill row 3 is performed. Also included are “all stand recombination”.

  For each stand, the roll reassignment operation is divided into a plurality of stages, and each stage is further divided into a plurality of steps. The roll recombination progress record is collected as a step in which the current work is in progress, and a required time from the step in which the current work is in progress to the completion of the roll reassignment work is predicted. Information relating to the time required from the start of each step to the completion of the roll reassignment work can be stored in advance in the computer as a table.

In the case of a single stand recombination work, only one stand is performing the roll recombination work. Therefore, the predicted roll recombination end time of the corresponding stand is set as the predicted roll recombination end time (hereinafter, “end time T _k ” Or “time T _k ”). On the other hand, in the case of multiple stand reassignment work, for each stand performing the roll reassignment work, the roll work end time T ⁱ _{k of} each stand from the progress of the work (roll recompletion of the i-th stand is completed) The predicted time is set as T ⁱ _k ), and the latest roll reassignment end predicted time T ⁱ _k of the latest stand is set as the end time T _k .

FIG. 3 shows the predicted completion time T _k of the maintenance work, the heating furnace extraction time T _a , the estimated required time T _h1 from the heating furnace extraction to the rolling mill entry, the waiting place arrival time T ₂ , and the rolling mill entry from the time T _2. Estimated time T _{h2 up,} re-feeding start time T _c from the standby _location, and is a diagram for explaining a predicted required time T _h3 from waiting area to mill entrance. In the present invention, as described above, predicts the end time T _k, the difference T _k -T ₁ between the time predicted time T _k and said time T _k predicted (current time T _1), rolling A process of comparing a required time T _h1 (hereinafter sometimes simply referred to as “time T _h1 ”) from when the material is extracted from the heating furnace to the rolling mill that was the target of the roll change. through it, to determine the time T _a to extract the rolled material from the furnace. In addition, when a standby place is provided between the rolling mill and the heating furnace, which are the objects of maintenance work, the maintenance work is performed before the first rolled material extracted from the heating furnace reaches the standby place. The time T _k is again predicted using the progress history of the maintenance work collected again, and the time T _k predicted again and the time (current time T ₂ ) _{where the} time T _k is predicted are collected again. the difference T _k -T ₂ of the rolling material is compared with the required time T _h2 until entering into the rolling mill she has been the subject of maintenance work from a predetermined location before waiting position reached. If _{T h2} ≧ T k -T _2, the first of the rolled material which has been extracted from the heating furnace is passed through without waiting to the standby _location, as long as T h2 _<T k -T _2, is extracted from the heating furnace The first rolled material is put on standby at a waiting place. And when the first rolled material extracted from the heating furnace is made to wait at the standby place, the progress of maintenance work is collected again after the rolled material reaches the standby place, and the progress of maintenance work collected again is collected. Is used to predict the time T _k again, the difference T _k −T ₃ between the time T _k predicted again and the time T _k is predicted (current time T ₃ ), and the rolled material is maintained from the standby position. Through the process of comparing the required time T _h3 (hereinafter, simply referred to as “time T _h3 ”) required to enter the rolling mill that was the object of work, maintenance work is performed on the rolled material from the standby location. The time _Tc to be conveyed toward the rolling mill that was the target of the determination is determined. In the present invention, when a plurality of standby places are provided in the rolling line, the above-described processing performed when the standby place is provided (the first rolled material extracted from the heating furnace reaches the standby place). Each process until the time _Tc is determined after collecting the progress results of the maintenance work before is performed for each standby place.

FIG. 4 is a flowchart for explaining the method for producing a rolled material of the present invention. As shown in FIG. 4, the rolled material manufacturing method of the present invention includes a collection step (S1), an end time prediction step (S2), a _Th1 estimation step (S3), and an extraction time determination step (S4). The rolling material extraction step (S5), the recollection step (S6), the end time re-prediction step (S7), the _Th2 estimation step (S8), the standby necessity determination step (S9), and the standby step ( S10), progress recollection step (S11), time difference calculation step (S12), _Th3 estimation step (S13), transfer time determination step (S14), retransfer step (S15), standby place Confirmation step (S16).

The collecting step S1 is a step of collecting the maintenance work progress record as a step in progress of the work at a predetermined period (for example, every second), and the collected information is the next end time. Used in the prediction step S2. The end time prediction step S2 uses the information collected in the collection step S1 and the table stored in the computer every time the progress of maintenance work is collected in the collection step S1, and calculates the time T _k . It predicted, a step of calculating the difference between _T k -T ₁ between the time _{T 1} of the time predicted time _{T k} and said time _{T k} predicted. The time T _k and the difference T _k −T ₁ are updated every time the current step is collected in the collecting step S1. At the time of changing the plurality of stands, the time _Tk is different for each stand that is performing the roll changing work. Therefore, at the time of rearranging a plurality of stands, the roll rearrangement end predicted time of the i-th stand is T ⁱ _k, and the time T _k is determined by the following equation (1). It should be noted that, at the time of recombinant single stand, it is sufficient to predict the time T _k of one of the stand roll reclassified work is being carried out.

The _Th1 estimation step S3 is a step of estimating a required time _Th1 until the rolled material 4 extracted from the heating furnace 1 enters the rolling mill on which maintenance work is performed. For the time _Th1 , for example, the standard time until the rolled material 4 extracted from the heating furnace enters the rolling mill where maintenance work has been performed is stored in the computer as a table, and is referred to. Can be determined.

Extraction time determining step S4 is whether time _{T h1} estimated by the difference _T k -T ₁ and the _{T h1} estimated process S3 calculated at the end time prediction process S2 satisfies _{T h1} ≧ _T k -T ₁ determining, if they meet the T _h1 ≧ T _k -T _1, a step of determining a time T _a to extract the rolled material 4 is first rolled after completion of the maintenance work from the furnace. In the extraction time determining step S4, for example, be a T _h1 ≧ T _k first time T ₁ which was confirmed at time T _a to be a -T ₁ (i.e., immediately extracted After this case the confirmed be able to). If it is determined that satisfy _{T h1} ≧ _T k -T ₁ is the extraction time determining step S4, the time _{T a} is determined. Then, the time T _a to the rolled material 4 is extracted from the heating furnace 1 (rolled material extraction step S5), the rolled material 4 is rolled by a rough rolling mill train 2. In contrast, when it is determined not to satisfy the _{T h1} ≧ _T k -T ₁ is the extraction time determining step S4, in the step S4 until it is judged to meet the _{T h1} ≧ _T k -T _1, the Steps S1 to S4 are repeated at regular intervals.

Recollected step S6, the rolled material 4 which is extracted from the heating furnace 1 at time T _a in the above step S5 is, if waiting position (first re-collection step in S6, the rough rolling mill 2d and the roughing mill 2e This is a process of periodically collecting again the progress of maintenance work of rolling mills that have stopped rolling operation (for example, every second) before reaching the standby place installed between . The information collected in the recollection step S6 is used in the next end time re-prediction step S7. Since the contents of the recollection step S6 are the same as those of the collection step S1, description thereof is omitted.

The end time re-prediction step S7 uses the information collected in the recollection step S6 and the table stored in the computer every time the progress of maintenance work is collected in the recollection step S6. predict T _k again, a step of calculating the difference _T k -T ₂ and time _{T 2,} when the predicted time _{T k} and said time _{T k} predicted again again. The time T _k and the difference T _k -T ₂ are updated every time the results of the current step are collected in the recollection step S6. Since the contents of the end time re-prediction step S7 are the same as those of the end time prediction step S2, description thereof is omitted.

T _h2 estimate step S8, a predetermined location of the heating furnace 1 rolled material 4 extracted from the waiting position before reaching the (e.g., the location of the rolled material 4 in the time T ₂₎ rolling mill maintenance work from is being carried out This is a step of estimating a required time _Th2 for entering the vehicle. The required time _Th2 is, for example, stored in the computer as a table of the standard time until the rolling material 4 that passes through the predetermined place enters the rolling mill where the maintenance work has been performed. It can be determined by reference.

Whether standby necessity determination step S9, the difference calculated at the end time re prediction step S7 _T k -T ₂ and the _{T h2} time estimated by estimated step S8 _{T h2} satisfies _{T h2} ≧ _T k -T ₂ If it satisfies T _h2 ≧ T _k −T ₂ (that is, if an affirmative determination is made in step S9), the rolling material 4 to be rolled first after the maintenance work is waited at the standby place. passed without, is not satisfied T _h2 ≧ T _k -T ₂ (i.e., if a negative determination is made in step S9, been made), the rolled material 4 waiting area which is first rolled after the completion of maintenance work It is the process of judging to make it stand by. If a negative determination is made in step S9, the rolling material 4 is made to wait at the standby place (standby step S10), and the time _{Tc at} which the rolled material 4 is re-conveyed from the standby place through steps S11 to S14 to be described later. It is determined. On the other hand, when an affirmative determination is made in step S9, the process proceeds to the standby location confirmation step S16.

  The progress recollecting step S11 periodically reports the progress of maintenance work of the rolling mill that has stopped the rolling operation after the rolled material 4 to be put on standby in the standby step S10 reaches the standby place (for example, This is a process of collecting again every second). The information collected in the progress recollection step S11 is used in the next time difference calculation step S12. Since the contents of the progress recollecting step S11 are the same as those of the collecting step S1, description thereof will be omitted.

The time difference calculation step S12 uses the information collected in the progress recollection step S11 and the table stored in the computer every time the progress performance of the maintenance work is collected in the progress recollection step S11. time T _k to predict again, a step of calculating the difference T _k -T ₃ between time T ₃ when the predicted time T _k and said time T _k predicted again again. The time T _k and the difference T _k -T ₃ are updated every time the results of the current step are collected in the progress recollection step S11. Since the content of the time difference calculation step S12 is the same as that of the end time prediction step S2, description thereof is omitted.

The _{Th 3} estimation step S13 is a step of estimating a required time _{Th 3} until the rolled material 4 enters the rolling mill where maintenance work is performed from the standby place. For the required time _Th3 , for example, the standard time until the rolled material 4 that has been re-conveyed from the standby place enters the rolling mill where maintenance work has been performed is stored in the computer as a table. This can be determined by referring to this.

Conveying time determining step S14,, whether or not the difference calculated in the time difference calculating step S12 _T k -T ₃ and the _{T h3} time estimated by estimated step S13 _{T h3} satisfy _{T h3} ≧ _T k -T ₃ Judging and satisfying T _h3 ≧ T _k −T ₃ , the time T _c at which the rolled material 4 that is rolled first after the maintenance work is transported from the standby position to the rolling mill that was the object of the maintenance work This is a step of determining. In the transport time decision step S14, for _example, may be the first time _{T 3} which was confirmed at time _{T c} to be a _{T h3} ≧ _T k -T ₃ (i.e., can be transported in this case immediately) . When it is determined in the transfer time determination step S14 that _{Th 3} ≧ T _k −T ₃ is satisfied, the time T _c is determined, and in the subsequent re-transfer step S15, from the standby place to the rolling mill that is the object of the maintenance work. After the rolling material 4 starts to be conveyed, the rolling material 4 is rolled. In contrast, if it is determined that the transport time determination step S14 does not satisfy the _{T h3} ≧ _T k -T ₃ is in the step S14 until it is determined that satisfy _{T h3} ≧ _T k -T _3, the Process S10-process S14 are repeated with a fixed period.

In the standby place confirmation step S16, the standby place where it is determined that the rolled material is allowed to pass in the step S9 or the standby place where the standby step S10 to the re-transport step S15 is performed is the last provided in the rolling line. It is a step of determining whether or not it is a waiting place. When an affirmative determination is made in step S16, since no further standby place is provided downstream of the rolling line, the rolling material 4 is conveyed as determined in the above step, and the rolling mill subject to maintenance work Enter. On the other hand, when a negative determination is made in step S16, a further standby place is provided on the downstream side of the rolling line. Therefore, in this case, the process returns to the step S6, and the steps S6 to S9 and the step S16 or the steps S6 to S16 are performed at each standby place until an affirmative determination is made in the step S16. It repeats and time _Tc is determined for every waiting place.

According to the present invention in which the time T _a and the time T _c are determined in this way, for example, it is optimal for all rearrangement patterns of a single stand rearrangement of a finishing mill and a multiple stand rearrangement of a finishing mill row A time T _a and a time T _c can be determined. By determining the optimum time T _a, the non-rolling time minimizing, and it is possible to minimize heat loss due to waiting for the rolled material. Furthermore, by determining the optimum time _Tc , even if a delay occurs in the progress of the maintenance work after the extraction from the heating furnace, it is possible to wait further upstream and minimize the heat loss of the rolled material. It becomes possible. Therefore, according to the present invention, it is possible to improve the operation rate of the rolling line even if there is no preceding rolled material.

In the above description regarding the present invention, since the case where the present invention is applied to the rolling line 10 provided with a standby place is illustrated, the embodiment in which the recollection step S6 to the standby place confirmation step S16 are provided is described. The form is not limited. However, for example, there may be a delay in the work progress after the heating furnace extraction time _Ta is determined. When the work is delayed, the rolled material must be kept on the rolling line. Therefore, it is preferable that the rolling line is provided with a standby place and a recollection step S6 to a standby place confirmation step S16. Since it is harder to cool in the state where the rolled material is thick, it is better to set the standby place upstream (on the heating furnace side) as much as possible. Further, the number of places where standby is possible is not limited to one, and a plurality of places may be provided.

  The rolling line to which the present invention is applied is not limited to the rolling line 10, and the present invention is also applied to a rolling line for hot-rolled steel sheets, a rolling line for thick steel sheets, a rolling line for large shape steel, and the like. Is possible.

  The present invention can be used as a method for improving the operating rate of a hot-rolled steel sheet rolling line.

DESCRIPTION OF SYMBOLS 1 ... Heating furnace 2 ... Rough rolling mill row 2a, 2b, 2c, 2d, 2e, 2f ... Rough rolling mill 3 ... Finish rolling mill row 3a, 3b, 3c, 3d, 3e, 3f, 3g ... Finish rolling mill 4 ... Rolled material 10 ... Rolling line

Claims (3)

A method for producing a rolled material using a rolling line equipped with a heating furnace and a rolling mill,
A collection step for periodically collecting progress results of maintenance work of the rolling mill that has stopped rolling operation;
The maintenance work end time T _k is periodically predicted using the progress results collected in the collecting step, and a difference T _k −T ₁ between the predicted end time T _k and the current time T ₁ is calculated. An end time prediction step to perform,
A Th ₁ estimation step for estimating a required time T _h1 until the rolled material extracted from the heating furnace enters the rolling mill in which the maintenance work is performed;
Determines whether the end time predicted the difference calculated in step _T k -T ₁ and the _{T h1} said estimated by estimated process time _{T h1} satisfies _{T h1 ≧ T k -T 1,} T h1 when satisfying ≧ T _k -T _1, an extraction time determining step of determining a time T _a to extract the rolled material which is initially rolled after the completion of the maintenance work from the heating furnace,
A method for producing a rolled material, comprising: Between the rolling mill and the heating furnace where the maintenance work is performed, a standby place is provided that can wait for the rolled material extracted from the heating furnace,
Progress of the maintenance work of the rolling mill that has been stopped from rolling before the rolling material first rolled after the maintenance work, extracted from the heating furnace, reaches the standby location. A re-collection process that periodically collects achievements;
The maintenance work end time T _k is periodically predicted again using the progress results collected in the recollection step, and the difference T _k −T between the predicted end time T _k and the current time T ₂ is predicted again. End time re-prediction step of calculating ₂ ;
A _Th2 estimation step of estimating a required time _Th2 until the rolled material enters the rolling mill where the maintenance work is being performed from a predetermined location before reaching the standby location;
Determines whether the end time again predicted the difference calculated in step _T k -T ₂ and the _{T h2} said estimated by estimated process time _{T h2} satisfies _{T h2 ≧ T k -T 2,} T when satisfying _h2 ≧ T _k -T ₂ is the rolled material which is initially rolled after the completion of the maintenance work is passed through without waiting in the waiting position, it does not satisfy the T _h2 ≧ T _k -T ₂ In this case, a standby necessity determination step for determining to wait the rolled material at the standby place;
It has these, The manufacturing method of the rolling material of Claim 1 characterized by the above-mentioned. When the rolled material first rolled after the maintenance work extracted from the heating furnace is determined to be standby in the standby necessity determination step, after reaching the standby place, rolling is performed. A progress recollecting step of periodically collecting again the progress of the maintenance work of the rolling mill whose operation has stopped,
The maintenance work end time T _k is periodically predicted again using the progress results collected in the progress recollecting step, and the difference T _k − between the predicted end time T _k and the current time T ₃ is predicted again. a time difference calculating step of calculating a T _3,
A _{Th 3} estimation step for estimating a required time T _h3 until the rolled material enters the rolling mill where the maintenance work is performed from the standby place;
And determining whether the required time _{T h3} as estimated by the difference _T k -T ₃ and the _{T h3} estimate step calculated by the time difference calculating step satisfies _{T h3 ≧ T k -T 3,} T h3 When ≧ T _k −T ₃ is satisfied, the time T _c for conveying the rolled material that is rolled first after the maintenance work from the standby place to the rolling mill that is the object of the maintenance work is determined. A transport time determination step,
The manufacturing method of the rolling material of Claim 2 characterized by having.

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