JP4701927B2 - Steel plate manufacturing method - Google Patents

Description

  The present invention relates to a method for manufacturing a steel plate, and more particularly, to a method for manufacturing a steel plate that can improve production efficiency.

  The cooling floor is disposed between the rolling process and the finishing process, and is an important facility that greatly affects the factory capacity. The steel plate that has been adjusted to a predetermined plate thickness, plate width, and plate length in the rolling process and has undergone subsequent correction work is at a high temperature of about 600 to 800 ° C., and has a gentle cooling rate that does not affect the material and In order to perform uniform cooling without impairing the shape, the cooling bed is cooled to about 100 to 200 ° C.

  On the other hand, the cooling bed also serves as a buffer that absorbs the difference in processing capacity between the rolling line (hot rolling process) and the finishing line (shearing process). Therefore, the cooling floor is required to have an area where the cooling can be performed and to have a function as a distribution buffer.

Techniques relating to cooling beds have been previously disclosed. For example, Patent Document 1 discloses a technique related to an automatic control device for a steel sheet cooling floor, and according to such a technique, automatic operation control of a cooling bed for cooling a steel sheet can be performed. Patent Document 2 discloses a technique related to a distribution control method for a production line equipped with a finishing facility on the downstream side, and according to such a technique, the material is moved off-line from the line or vice versa. Provides a physical distribution control method that minimizes the occurrence of material shortage and overload in each processing facility.
JP-A-9-108722 JP-A-11-285716

  However, as disclosed in Patent Document 1, the technology in which the conveyance in the cooling bed is divided into four blocks and the interval of the steel materials charged into one cooling bed is appropriately adjusted between the respective blocks, When the conveyance block in the cooling floor is not divided, there is a problem that it takes a great deal of cost to modify the equipment. In addition, only by optimizing the conveyance in the cooling bed, there is a problem that it is difficult to improve the production efficiency because the difference between the processing pitch in the rolling process and the processing pitch in the finishing process cannot be absorbed. On the other hand, as disclosed in Patent Document 2, in a production line in which two processes such as a rolling process and a refining process are directly connected, a cooling bed as a buffer is not utilized, thereby improving production efficiency. There was a limit.

  Then, this invention makes it a subject to provide the manufacturing method of a steel plate which can improve production efficiency.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiments.

  The invention according to claim 1 is a rolling line (1) for rolling a slab (5a, 5a, ...) supplied for each block, and a finishing line (2) arranged after the rolling line (1). ), And a steel plate manufacturing method used in a manufacturing line (100) provided with cooling beds (3a, 3b) disposed between them, and supplied to the rolling line (1). .., Βn, the specific process for specifying the combination of the blocks β1, β2,..., Βn in order and the refinement line for each combination specified in the specific process. A prediction process for predicting a required time until the process in (2) is completed, an extraction process for extracting a minimum required time from the required time predicted in the prediction process, and a minimum extracted in the extraction process The order of the blocks that will be required A selection step of selecting as the order of the blocks to be supplied to the (1), characterized in that it comprises a by the manufacturing method of the steel sheet to solve the above problems.

Here, “slabs supplied for each block (5a, 5a,...)” Means that, for example, when six slabs are sequentially supplied to the rolling line (1), the first two slabs are supplied to the block β1. This means that the next two are grouped into block β2 and the remaining two are grouped into block β3, and the slabs (5a, 5a,...) That are sequentially supplied to the rolling line (1) are grouped into a plurality of blocks. It means to be divided. In the present invention, “slabs (5a, 5a,...) Supplied for each block” means that the grouped slabs (5a, 5a,...) Are supplied to the rolling line (1), as well as rolling. It is a concept including a form in which the slabs (5a, 5a,...) Supplied to the line (1) are grouped into a plurality of blocks . Furthermore, “specify combinations of the order of blocks β1, β2,..., Βn” means all combinations when β1 to β3 are arranged in order, for example, if the blocks are β1, β2, and β3, (β1 , Β2, β3), (β1, β3, β2), (β2, β1, β3), (β2, β3, β1), (β3, β1, β2), and (β3, β2, β1) Means. In addition, “predicting the time required for finishing the processing in the finishing line (2) for each combination” means, for example, that each slab (5a, β2, β3) in the order of (β1, β2, β3). 5a,...) Is supplied to the rolling line (1), the processing of the rolling line (1) for the first slab (5a) included in the block β1 is started and the last included in the block β3. This means that the time required for finishing the processing on the finishing line (2) for the slab (5a) is estimated. Here, the required time can be predicted by a method of analyzing information on the slabs (5a, 5a,...) And the steel plates (5b, 5b,...) Based on past operation data. In the prediction step of the present invention, the prediction is performed on the combination specified in the specific step. Furthermore, “the order of the blocks supplied to the rolling line (1)” specifically means the order of the blocks supplied to the heating furnace (11) provided in the rolling line (1). . Here, since the blocks supplied to the heating furnace (11) include slabs (5a, 5a,...), “The order of the blocks supplied to the rolling line (1)” is “rolling”. This means the same as “the order of the slabs (5a, 5a,...) Supplied to the heating furnace (11) provided in the line (1)”.

  According to the first aspect of the present invention, it is possible to select an order in which the time required until the processing in the finishing line (2) is completed is minimized. Therefore, if the slabs (5a, 5a,...) Are supplied in this order, the processing time in the production line (100) can be reduced. In addition, with this configuration, it is possible to level the processing load on the rolling line (1) and the finishing line (2) having different processing pitches. Therefore, according to invention of Claim 1, the manufacturing method of the steel plate which can improve production efficiency can be provided.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic view showing a form example of a production line to which the steel sheet production method of the present invention can be applied. The illustrated production line 100 includes a rolling line 1 and a finishing line 2, and a first cooling bed 3a and a second cooling bed 3b (hereinafter, And a control means 4 for controlling the optimal order of the blocks supplied to the rolling line 1 and the like. The slabs 5a, 5a,... Supplied to the rolling line 1 are sent to the heating furnace 11 by the slab supply means 6, heated, and then sent to the rolling mill 12, and the rolling process by the rolling mill 12, and After the cooling process by the cooling device 13, the steel plates 5b, 5b,. The steel plates 5b, 5b,... Are then distributed to the cooling floors 3a, 3b by the steel plate conveying means 7 whose operation is controlled by the control means 4. The steel plates 5b, 5b,... Transported through the inlet side transport means 31a, 31b, the in-floor transport means 32a, 32b, and the outlet side transport means 33a, 33b in the cooling floors 3a, 3b are moved to the finishing line 2. It is carried out and used for processing of the finishing line 2. The finishing line 2 includes cutting machines 21 and 22, inspection means 23, and a warehouse 24, and the steel plates 5 b, 5 b, etc. that have been cut by the cutting machines 21 and 22 are inspected by the inspection means 23. After going through the process, it is stored in the warehouse 24. In addition to the above configuration, the rolling line 1 further includes a rolling line tracking device 15 that should acquire information (for example, position information, dimensional information, etc.) of the steel plates 5b, 5b,. In addition, the finishing line 2 is provided with a finishing line tracking device 25 for acquiring information (for example, position information) of the steel plates 5b, 5b,... Conveyed on the finishing line 2. Information acquired by the rolling line tracking device 15 and / or the finishing line tracking device 25 is sent to the control means 4 and used as data when performing control of the optimal order of blocks.

  The operations of the slab supply means 6 and the steel plate transport means 7 are controlled by the control means 4. The control means 4 is provided with a CPU 41 that performs operation control of the slab supply means 6 and the steel plate transport means 7 and a storage device for the CPU 41. The CPU 41 is configured by combining a microprocessor unit and various peripheral circuits necessary for the operation thereof, and the storage device for the CPU 41 includes, for example, programs and various data necessary for operation control of the slab supply means 6 and the steel plate transport means 7. Are combined with a ROM 43 that functions as a work area for the CPU 41. In addition to the configuration, the control means 4 in the production line 100 functions by combining the CPU 41 with software stored in the ROM 42.

  Output signals from the rolling line tracking device 15 and the finishing line tracking device 25 and signals relating to past operation data reach the CPU 41 as input signals via the input port 45. The CPU 41 controls operation commands to the slab supply unit 6 and the steel plate transport unit 7 through the output port 46 based on the signals from the various input elements and the program stored in the ROM 42. The slab supply means 6 supplies the slabs 5a, 5a,... To the rolling line 1 for each block in the order based on the operation command given from the CPU 41. Moreover, the steel plate conveyance means 7 conveys the steel plates 5b, 5b,... Conveyed on the rolling line 1 to the cooling floors 3a, 3b according to the operation command given from the CPU 41.

  The control mode of the block supply order in the method for manufacturing a steel sheet of the present invention (hereinafter sometimes simply referred to as “manufacturing method”) will be described more specifically.

  FIG. 2 is a conceptual diagram schematically showing an example of a control form of the block supply order in the manufacturing method of the present invention. FIG. 2 (A) shows a state in which idle time is generated in the rolling line. (B) shows a state where no idle time is generated in the rolling line. The left and right direction in FIG. 2 corresponds to the time, and a long length in the left and right direction in the rolling line and the finishing line means that a long time is required for the processing in the rolling line and the finishing line. A short length in the left-right direction of the drawing surface in the rolling line / finishing line means that processing in the rolling line / finishing line can be completed in a short time. In FIG. 2 and the following description, the same reference numerals as those used in FIG. 1 are used for components having the same configuration as the components shown in FIG. In the following description, the first cooling bed 3a and the second cooling bed 3b are collectively referred to as the cooling bed 3. Hereinafter, in the production line 100 in which the cooling floor 3 is filled with the steel plates w to z, the slabs A to Q are supplied from the slab supply means 6 to the heating furnace 11 in alphabetical order (FIG. 2A), And the form (FIG.2 (B)) which changed the supply order of the slab from the said form is assumed, and in the following description, the slabs A-Q rolled by the rolling mill 12 are described with the steel plates A-Q. . When steel plates are charged from the rolling line 1 to the cooling floor 3, it is assumed that the steel plates are transported to the finishing line 2 in the order in which they are charged into the cooling floor 3. Here, it is assumed that the processing time in the rolling line 1 is relatively long for the slabs A, B, and J to Q, and the processing time in the rolling line 1 is short for the slabs C to I. Moreover, as a constraint condition concerning the processing order in the rolling line 1, the slabs A to N may be processed in any order, but the slabs O, P, and Q are in alphabetical order (N → O → It is assumed that the processing needs to be performed in the order of P → Q). Furthermore, it is assumed that the steel plates w to z and the steel plates A to E have a relatively long processing time in the finishing line 2 and the steel plates F to Q have a short processing time in the finishing line 2.

  As shown in FIG. 2 (A), when the slabs A to Q are supplied to the rolling line 1 in alphabetical order, the steel plates A to Q subjected to the rolling treatment are charged into the cooling floor 3 in this order, and in the same order. It is carried out to the finishing line 2. When the processing of the steel plate D in the rolling line 1 is completed, the cooling bed 3 is filled with the steel plate z and the steel plates A to C, and then the steel plate z is carried out from the cooling bed 3 to the finishing line 2. In the meantime, the steel sheet D has to wait on the rolling line 1, and the idle time T1 occurs. Similarly, the steel plates E to I are filled with the steel plates that have been charged up to that point when the processing of the steel plates E to I in the rolling line 1 is completed. Until the steel plate is carried out from 3 to the finishing line 2, the steel plates E to I have to wait on the rolling line 1, resulting in idle times T 2 to T 6. Here, as described above, the processing time in the finishing line 2 is relatively long for the steel plates w to E, and the processing time in the rolling line 1 is short for the slabs C to I. That is, such a time zone corresponds to a time zone in which the processing speed of the finishing line 2 is the rate limiting rate of the production line 100 because the processing speed of the rolling line 1 is faster than the processing speed of the finishing line 2.

  On the other hand, as described above, the steel plates F to I have a short processing time in the finishing line 2. Therefore, after the steel plate F is carried out to the finishing line 2, the steel plates G to I are carried out to the finishing line 2 at intervals shorter than the intervals when the steel plates w to E are carried out, and the rolling line The free time at 1 will be eliminated. And since the steel plate F is carried out from the cooling bed 3 to the finishing line 2 before the process of the steel plate J in the rolling line 1 is complete | finished as shown to FIG. 2 (A), the process in the rolling line 1 is carried out. The finished steel plate J is charged into the cooling floor 3 without waiting on the rolling line 1. Further, as described above, the steel plates J to Q have a relatively long treatment in the rolling line 1 and a short treatment in the finishing line 2. Therefore, before the processing of the steel plates K to Q in the rolling line 1 is finished, the steel plates are successively carried out from the cooling bed 3 to the finishing line 2. And when the process of the steel plate M in the rolling line 1 is complete | finished, the steel plate L is already carried out to the refining line 2, and after that, it cools until the process of the steel plate (steel plates MQ) in the rolling line 1 is complete | finished. The floor 3 shifts to a time zone in which no steel plate exists. In such a time zone, since the processing speed in the rolling line 1 is the rate-limiting of the production line 100, there is a time margin in the finishing line 2, and after the processing of the steel plates M to P in the finishing line 2 is finished, Free times T7 to T10 occur.

  When the production line 100 is operated in a form in which idle times T1 to T6 are generated in the rolling line 1 shown in FIG. 2A, the processing of the rolling line 1 is stagnant during the idle times T1 to T6. Overall production efficiency is reduced. That is, it is preferable to reduce the idle time in the rolling line 1 from the viewpoint of improving production efficiency. Therefore, in the present invention, the steel plates A to Q are changed to the block β1 made of the steel plates A to C, the block β2 made of the steel plates D to I, the block β3 made of the steel plates J to M, and the block β4 made of the steel plates N to Q. By dividing the order of these blocks supplied to the rolling mill 12, the generation of idle time in the rolling line 1 is prevented and the generation of idle time in the finishing line 2 is suppressed, The production efficiency of the line 100 is improved.

  As described above, in the production line 100, when the processing speed of the finishing line 2 is rate-limited, the idle time is likely to occur in the rolling line 1, and when the processing speed of the rolling line 1 is rate-limited, the idle time is reached in the finishing line 2. Is likely to occur. Therefore, in order to prevent occurrence of idle time in the rolling line 1, it is effective to supply a block in which the processing speed of the rolling line 1 is rate-limiting when the idle time is likely to occur in the rolling line 1.

  Here, after the processing of the slab A that is the first slab included in the block β1 is started by the rolling mill 12, the processing in the rolling line 1 for the slab C that is the last slab included in the block β1 is completed. (Time required for block β1 in rolling line 1) is Tr1, and similarly, time required for blocks β2, β3, and β4 in rolling line 1 is Tr2, Tr3, and Tr4, respectively. In addition, after the processing of the steel plate A that is the first steel plate included in the block β1 is started in the finishing line 2, the processing in the finishing line 2 for the steel plate C that is the last steel plate included in the block β1 is completed. Tc1 is the time required for the block β1 in the finishing line 2 and similarly Tc2, Tc3, and Tc4 are the required times for the blocks β2, β3, and β4 in the finishing line 2. ΔT1 = Tr1-Tc1, ΔT2 = Tr2-Tc2, ΔT3 = Tr3-Tc3, and ΔT4 = Tr4-Tc4. At this time, from FIG. 2A, the absolute values of ΔT1 and ΔT2 are relatively small, while the absolute values of ΔT3 and ΔT4 are large, ΔT3 is a positive value, and ΔT4 is a negative value. That is, since the block β3 is a block in which the processing speed of the rolling line 1 is rate-limiting, and the block β4 is a block in which the processing speed of the finishing line 2 is rate-limiting, the production line 100 is likely to have a free time in the rolling line 1. It is effective to supply the block β3 after the block β1 so that the processing speed of the rolling line 1 is rate-limiting.

  FIG. 2B shows a form in which each slab is supplied to the rolling mill 12 in the order of blocks β1, β3, β2, and β4. As shown in FIG. 2B, when the block β3 is supplied following the block β1, the steel plate z is removed from the cooling bed 3 before the processing of the steel plate J, which is the first steel plate included in the block β3, is completed. Since the steel sheet J is carried out to the finishing line 2, it is not necessary for the steel plate J to stand by on the rolling line 1, and no idle time is generated in the rolling line 1. Similarly, the steel plate A is unloaded to the finishing line 2 before the processing of the steel plate K is finished, and the steel plate B is unloaded to the finishing line 2 before the processing of the steel plate L is finished. Since the steel plate C and the steel plate J are carried out to the finishing line 2 before the processing is completed, the steel plates K to M do not have to wait on the rolling line 1 and can prevent the rolling line 1 from being idle. It becomes possible. Furthermore, since the processing time in the finishing line 2 is short for the steel plates J to K of the block β3, the block β2 supplied after the block β3 also has no idle time in the rolling line 1, and after the block β2. Since the processing speed of the rolling line 1 is rate-determined for the supplied block β4, the block β4 also has no idle time in the rolling line 1. Therefore, if the blocks β1, β3, β2, and β4 are supplied in this order, the idle time in the rolling line 1 can be prevented. Furthermore, as shown in FIG. 2B, if the blocks β1, β3, β2, and β4 are supplied in this order, the total free time that occurs in the finishing line 2 as compared with the case of FIG. Can be reduced from “T7 + T8 + T9 + T10” to “T11 + T12”. That is, by supplying the blocks β1, β3, β2, and β4 in this order, the production efficiency of the production line 100 can be improved (see FIG. 2B).

  FIG. 3 is a flowchart schematically showing an example of the manufacturing method according to the present invention. Hereinafter, the procedure of the manufacturing method of the present invention will be described using Tr1, Tr2,..., Tc1, Tc2,..., ΔT1, ΔT2,.

  In the manufacturing method according to the illustrated embodiment, first, a series of slabs to be processed in the rolling line 1 are divided into blocks β1, β2,..., Βn (step S1), and all combinations in the order of blocks β1, β2,. Is specified (step S2; specific step). Next, the processing times Tr1, Tr2,..., Trn of the blocks β1, β2,..., Βn in the rolling line 1 and the processing times Tc1, Tc2, ..., Tn of the blocks β1, β2,. Is predicted (step S3), and for each combination specified in step S2, the time required until the processing in the finishing line 2 is completed is predicted (step S4; prediction step). Then, ΔT1, ΔT2,..., ΔTn are calculated (step S5), and based on the values of ΔT1, ΔT2,..., ΔTn calculated in step S5, etc., from the total required time predicted in step S4, The order of blocks having the minimum required time is extracted (step S6; extraction step), and the order of the blocks is selected as the order of slabs supplied to the rolling mill 12 (step S7; selection step). According to the manufacturing method of the present invention in which the order of the steel plates conveyed through the manufacturing line 100 is selected in such a procedure, the generation of idle time in the rolling line 1 and the finishing line 2 can be suppressed. The production efficiency of the line 100 can be improved.

  In the above description relating to FIG. 3, the embodiment in which all combinations in the order of the blocks β1, β2,..., Βn are specified, but the manufacturing method of the present invention is not limited to the embodiment. The combination of changing only the order of the remaining blocks may be specified after fixing the order of the block to be supplied to the block or the block to be supplied last. Moreover, when not specifying all the combinations of order, as a specific example of the method of deriving easily the combination from which the processing time becomes the minimum among the specified combinations, the processing time in the rolling line 1 and the processing time in the finishing line 2 A method of changing the order by replacing only the block having the largest difference ΔT with other blocks can be cited.

  Moreover, the form of the division | segmentation method at the time of dividing | segmenting a steel plate (slab) into a block with the manufacturing method of this invention is not specifically limited. Specific examples of the division form according to the present invention include a form in which the parts are divided in the order that they can be carried out to the heating furnace 11 and a form in which the parts are divided so as to correspond to the heating conditions in the heating furnace 11.

  Furthermore, when dividing a plurality of steel plates (slabs) into blocks, the number of steel plates (slabs) contained in one block is not particularly limited, but when about 500 steel plates are divided into blocks, the number of blocks is large. Then, the number of blocks is better because the number of combinations in order increases with the factorial and the calculation time in step S4 for predicting the time required to finish the finishing line 2 becomes longer. Conversely, if the number of blocks is too small, the effect of shortening the required time by changing the order becomes small. For this reason, it is preferable to use 50 sheets or less. More preferably, it is 2 or more and 25 or less.

  In the above description, a production line provided with two cooling beds is assumed, but the number of cooling beds provided in a production line to which the production method of the present invention can be applied is not limited to two. It can be any suitable number (eg, 1 or 3). If the production line is equipped with multiple cooling beds, there will be no free time on the steel sheet on the exit side of the rolling line (the entrance side of the cooling bed), depending on the state of the steel sheet transported in each cooling bed. Further, it is preferable that each steel plate is distributed to a plurality of cooling floors. In addition, when a production line is provided with a plurality of cooling floors, the equipment specifications of the plurality of cooling floors are not particularly limited, and all the cooling floors may have the same equipment specifications, or cooling floors having different equipment specifications. May be provided. In addition, for the sake of simplicity, the maximum number of steel plates included in one block is four. However, the number of steel plates is limited to four because it depends on the specifications of the cooling floor and the size of the steel plates. It is not a thing. For example, in the case of a cooling floor in which 10 steel plates having a standard plate width can be inserted, 5 steel plates having a plate width twice that of the standard are inserted, and the plate width is ½ of the standard. When double steel plates are charged, 20 sheets are the number of steel plates that can be charged.

It is the schematic which shows the form example of a manufacturing line which can apply the manufacturing method of the steel plate of this invention. It is a conceptual diagram which shows the example of a control form of the supply order of a block in the manufacturing method of this invention. It is a flowchart which shows the example of a form of the manufacturing method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling line 2 Refinement line 3a, 3b Cooling floor 5a Slab 5b Steel plate 100 Production line

Claims (1)

A rolling line for rolling a slab supplied for each block including a plurality of slabs, a finishing line disposed after the rolling line, and a cooling bed disposed therebetween are provided. A method for producing a steel sheet used in a production line,
When the blocks supplied to the rolling line are β1, β2,..., Βn,
A specifying step for specifying a combination of the order of the blocks β1, β2,..., Βn;
For each combination specified in the specific step, a prediction step for predicting a time required until the processing in the finishing line is completed,
An extraction step for extracting the minimum required time from the required time predicted in the prediction step;
A selection step of selecting the order of the blocks to be the minimum required time extracted in the extraction step as the order of the blocks supplied to the rolling line;
A method for producing a steel sheet, comprising:

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