JPH0818057B2 - Control method of material input pitch in thick steel plate rolling line - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optimally controlling the pitch at which a slab heated in a heating furnace is put into a rolling line when rolling thick steel plates.

[0002]

2. Description of the Related Art A conventional technique of this type will be described with reference to FIG.

FIG. 1 is a conceptual diagram showing an example of a hot rolling line. In the figure, on the hot rolling line 2, a plurality of facilities for subjecting the material to predetermined processing are arranged. As the facilities, from the upstream side (the left side in FIG. 2), the first to the A heating furnace 3 composed of No. 4 heating furnaces 3a to 3d, an edger 4 for removing oxides on the surface of the slab 1a (material) extracted from the heating furnace 3, first to first for roughly rolling the slab 1a. 4 rough rolling mills 5 to 8 (1b in FIG. 2 indicates a steel sheet being rolled), a tip of the rough rolled steel sheet 1c, a crop shear 9 for cutting an irregular portion at the rear end, and a rough rolled steel sheet 1d. First to sixth finish rolling mills 10 for finish rolling
˜15, a winding machine 16 for winding the finished rolled steel plate 1e as a product is provided. The second rough rolling mill 6 is a reverse rolling mill capable of reversible rolling.

The operation of the hot rolling line 2 having the above-described structure is as follows: First, the slab 1a is sequentially heated from the heating furnace 3 by the extraction means (not shown).
Is extracted and put into the hot rolling line 2. Next, the slab 1a is roughly rolled through the edger 4 and the rolling mills 5 to 8 to obtain a steel plate 1c having a predetermined transfer thickness. And
This steel plate 1c is then subjected to a crop shear 9 and a finish rolling mill 1
Finishing rolling is performed through 0 to 15 and the product coil is wound up by a winding machine 16 as a required product coil.

Generally, the material pitch on the hot rolling line 2 as described above is set in advance by processing conditions and the like. However, when the progress of the material being rolled on the hot rolling line 2 is delayed and the inter-material pitch deviates from a preset value, the hot rolling line 2 may be changed depending on the situation. It becomes necessary to correct the inter-material pitch and the extraction pitch of the next extraction material.

Here, the pitch correction between the material and the preceding material and the pitch correction between the material and the next extraction material in the hot rolling line 2 having the above structure will be sequentially described.

(1) Pitch correction between the material and the preceding material The material is at a certain defined point (here, the second
When the final pass rolling of the rough rolling mill 6 is started),
When the distance from the first finish rolling mill 10 to the trailing edge of the preceding material is measured, the measured value is compared with a preset predicted value, and the difference between the measured value and the predicted value is out of the allowable range. In this case, the pitch of the material and the preceding material is corrected.

When the measured value is out of the allowable range and the measured value is smaller than the predicted value (when the distance between the material and the preceding material is wider than the optimum pitch and the preceding material is advanced). , Or if the material is delayed), no pitch correction is performed.

On the other hand, when the measured value is larger than the predicted value (when the distance between the material and the preceding material is narrower than the optimum pitch and the preceding material is delayed or the material is advanced). Caused by either of the cases)
In this case, the material is made to stand by at a certain point, and the pitch with the preceding material is widened to correct the optimum pitch.

(2) Pitch correction between the material and the next input material The pitch correction between the material and the next extraction material is performed according to the above (1).
It is carried out only when the actual measured value is smaller than the predicted value. That is, by delaying the preset time of feeding the next extraction material by the time for which the material was made to stand by in the above (1), the pitch between the material and the next extraction material is kept optimal. (JP-A-55-97
808 publication).

[0011]

In the hot rolling line as described above, generally, the residence time of the material in each facility in the hot rolling line (the above-mentioned rough rolling mills 5-8, finish rolling mills 10-15) Rolling pass schedule) is fixed. Therefore, as the pitch control method, only when the pitch between the material and the preceding material is narrower than the optimum pitch, the material is made to stand by at a certain point as described above,
The standby control is performed to correct the pitch with the preceding material, and the pitch between the material and the next extracted material reduced by this is left to the delay control that corrects by delaying the feeding time of the next extracted material. .

However, it is necessary to correct the pitch between the materials on the line only by the standby control and the delay control as described above.
As a result, the production pitch is delayed as a whole, and as a result, a disadvantage that the required production amount cannot be achieved occurs.

The present invention has been made in order to solve the above-mentioned problems, and in both cases where the material and the preceding material are expanded and contracted with respect to the optimum pitch, It is an object of the present invention to provide a material input pitch control method in a thick steel plate rolling line capable of correcting the pitch between the material and the next extracted material.

[0014]

The invention according to claim 1 is
A thick steel plate rolling line equipped with a plurality of rolling mills for rolling the material, in which the material is input at a preset optimum pitch, and the pass schedule of each rolling mill is set for each material extraction. , Estimating the arrival time of the material to each processing facility, correct the estimated time according to the movement of the material, the material when the material reaches a certain point of the thick steel plate rolling line The pitch between the preceding material and the preceding material is obtained from the estimated time, the degree of pitch deviation is determined from the difference between this pitch and the optimum pitch, and when the pitch deviation is outside the allowable range, the rolling mill By changing the rolling pass schedule of the above, the pitch of the material and the preceding material is corrected to the above-mentioned optimum pitch, while the input time of the next extraction material is set to the above for the material. And modified according to the rolling pass schedule changes caster, thereby to keep it at optimal pitch pitch between each material.

[0015]

According to the invention described in claim 1, when the material moving on the hot rolling line reaches a certain point,
The scheduled time at which the material reaches the finish rolling mill and the scheduled time at which the preceding material finishes rolling on the finish rolling mill are calculated, and the difference between them is calculated. It is judged whether or not this calculated value is within a preset range, and if it is within the range, it is determined that the pitch between the material and the preceding material is within the allowable range, and the pitch between the material and the preceding material is corrected and the material is corrected. The pitch of the next extraction material is not corrected. But,
If it is out of the above range, the rough rolling and finish rolling schedules are changed to advance or delay the material to correct the pitch between the material and the preceding material. Then, the pitch correction of the material and the next extracted material is performed by delaying or advancing the feeding time of the next extracted material according to the delay time of the material due to the change of the rough rolling schedule or the advanced time. Be done.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for controlling a material input pitch in a thick steel plate rolling line according to the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing an example of a hot rolling line according to the present invention. It should be noted that components having the same functions as those of the conventional example will be described with the same reference numerals.

In the figure, on the hot rolling line 2,
There are multiple equipments that perform predetermined processing on the material,
As its equipment, from the upstream side (left side of FIG. 1),
No. 3 to No. 3 heating furnaces 3a to 3c,
A rough rolling machine 6 for roughly rolling the slab 1a, a cooling device 17 for cooling the steel sheet 1c after rough rolling, and a finish rolling machine 18 for finish rolling the steel sheet 1d are provided. In addition,
The rough rolling mill 6 and the finish rolling mill 18 are reverse rolling mills capable of reversible rolling. Further, each processing equipment of the hot rolling line is drive-controlled by a drive controller controlled by a controller (not shown).

The operation of the hot rolling line 2 having the above-described structure is as follows. First, the slab 1a is sequentially heated from the heating furnace 3 by the extraction means (not shown).
Is extracted and put into the hot rolling line 2. Next, the slab 1a is roughly rolled by the rolling mill 6 to obtain a steel plate 1c having a predetermined transfer thickness. And for some materials whose finish rolling temperature is regulated, this steel plate 1c is cooled by the cooling device 1
After cooling by 7, finish rolling is performed via a finish rolling machine 18.

Next, the pitch correction method between the material and the preceding material and the pitch correction method between the material and the next extraction material, which are processed on the hot rolling line 2 having the above-mentioned structure, will be sequentially described.

1. Pass schedule determination and preliminary function setting In the hot rolling line 2, the rough rolling pass schedule, the steel plate cooling time, the finishing rolling pass schedule, the transport time between processes and the extraction time of the next extraction material are the materials from the heating furnace 3. It is set by a control device (not shown) for each extraction.

(A) The rough rolling pass schedule is basically set on the basis of the thickness of the steel sheet transferred from the rough rolling mill 6 to the finish rolling mill 18. At this time, the rough rolling time is calculated from the rough rolling completion time predicted based on the finish rolling completion time of the preceding material, and the optimum transfer steel plate thickness is set based on this calculated value. The rough rolling pass schedule can be set based on the steel plate thickness up to the minimum transfer steel plate thickness that can be calculated due to equipment restrictions.

(B) The finish rolling pass schedule is set based on the optimum transfer steel plate thickness and the product-targeted steel plate thickness set in (a) above.

(C) The steel plate cooling time is set on the basis of the above-mentioned optimum transfer steel plate thickness. This steel plate cooling time is corrected according to the change of the transferred steel plate thickness, but the relationship between the steel plate thickness and the steel plate cooling time can be approximated by a linear function,
Here, the steel plate cooling time for two types of steel plate thickness among the steel plate thicknesses by each pass set in the rough rolling pass schedule is calculated, and the steel plate cooling time and the steel plate thickness are obtained as a linear function formula. deep.

(D) The setting of the time when the next extraction material is charged is
Based on the rough rolling completion scheduled time calculated from the rough rolling pass schedule set in (a) above, it is set in consideration of the transport time from the material extraction until the material reaches the rough rolling mill 6.

(E) The transportation time between each process is the same as that of the rough rolling mill 6.
It is set based on the thickness of the transferred steel sheet transferred from the finish rolling mill 18 to the finish rolling mill 18.

2. Online correction control The above 1. set by the controller. Each rolling mill 6,18
Of the rolling pass schedule, the steel plate cooling time of the cooling device 17, the transfer time between processes, and the time of inputting the next extraction material are
It is corrected in place according to the pitch condition between the materials on the hot rolling line 2.

The above-mentioned modification is performed by using the hot rolling line 2 in which the material is the above-mentioned.
Conveyance time adaptive correction control that is performed when a plurality of correction points provided above are reached, and a predetermined pass of the material in the rough rolling mill 6 (corresponding to the optimum transfer steel plate thickness in the embodiment). This is performed by the optimum pitch correction control for the material and the input pitch correction control for the next extracted material, which is performed at the timing when the rolling of two passes before). The above three types of control, that is, the transport time adaptive correction control, the optimum pitch correction control, and the input pitch correction control are collectively referred to as online correction control.

(A) Conveyance time adaptive correction control In the correction control executed when the material moving on the hot rolling line 2 reaches a plurality of correction points provided on the hot rolling line, Calculate the difference between the measured value and the predicted value of the transport time to reach a certain correction point, and add this calculated value to the predicted transport time until the material reaches the correction point after the correction point. By doing so, the predicted transport time of the material reaching each correction point is corrected. This control is for accurately performing the pitch correction control described later.

(B) Optimum pitch correction control for the material concerned At the scheduled time when the material reaches the finish rolling mill 18 and rolling is started (hereinafter referred to as the scheduled finish start transportation time) and the finish rolling mill 18 of the preceding material. The difference from the scheduled time when the finish rolling is finished (hereinafter, referred to as the scheduled finish completion transportation time) is calculated, and the control device determines whether or not the calculated value is within the constant range. In addition, the arrival time of the material to each facility is corrected at any time by the above-mentioned (a) conveyance time adaptive correction control, and as will be described later in detail, the pitch between the material and the preceding material is kept at an appropriate pitch. If not,
Since the rough rolling pass schedule for the material is changed, the optimum pitch correction control for the material is
Rolling is performed at a position where reliability of the scheduled finishing start transport time for the material is high, that is, the material is rolled a predetermined number of times in the rough rolling mill 6 (in the embodiment, two passes before the optimum transfer steel plate thickness). It is carried out at the timing when it ends.

Here, if the difference between the scheduled finish completion transport time of the preceding material and the scheduled finish start transport time of the material is DELT, the following formula is established. The transport time of each material is calculated as a relative time based on the extraction completion time of each material.

DELT = T1- (T2 + P) (1) Here, T1; scheduled finish completion transport time of the preceding material T2; scheduled finish start transport time of the material P; extracted pitch actual measurement value of the preceding material and the material It is determined whether the DELT value corresponds to the following.

1) CONST1 ≦ DELT ≦ CONST2 (2) 2) CONST1> DELT or DELT> CONST2 (3) where CONST1; judgment constant (negative value) CONST2; judgment constant (positive value) the DELT value Is satisfied with the above equation (2), the pitch between the material and the preceding material is determined to be within the allowable range, and the pitch between the material and the preceding material is not corrected.

However, when the DELT value corresponds to the equation (3), it is determined that the pitch between the material and the preceding material is out of the allowable range, and the pitch between the material and the preceding material is corrected. Be done.

Specifically, the number of passes for the material in the rough rolling mill 6 is increased or decreased (change of rough rolling pass schedule for the material). The number of passes is increased or decreased by 2 passes. This is because the rough rolling mill 6 is a reverse rolling mill, and therefore, in order to transfer the material to the finish rolling mill 18 which is the next process, it is necessary to change every two passes.

The setting of the pass increase / decrease number is determined as follows.

First, in the rough rolling pass schedule already set for the material, the time from the start of rolling of each pass of the material to the end of rolling (in-rolling time) and the rolling of the previous pass for the material is completed. 2 based on the time from the start of rolling to the start of the next pass (outside rolling time)
The increase / decrease time when the number of paths is increased / decreased is calculated.

Then, the increase / decrease time for the above two passes is set to the DEL
It is added to T, and it is determined again whether the expression (2) or the expression (3) is satisfied. As a result, when the above formula (2) is satisfied, the number of passes increase / decrease is set to 2 and the rough rolling schedule and finish rolling pass schedule for the material are changed. On the other hand, when the above expression (3) is satisfied again, the increase / decrease time obtained by further increasing / decreasing two paths is calculated, and the same processing as above is performed.

When the material is rolled in accordance with the modified rough rolling pass schedule, the thickness of the steel sheet transferred between the rough rolling mill 6 and the finish rolling mill 18 is set to the initial optimum value as described above. Changes will be made to the transfer steel plate thickness. Therefore, it is necessary to correct the steel plate cooling time by the cooling device 17 performed between the rough rolling mill 6 and the finish rolling mill 18 for some materials whose rolling temperature is specified for finish rolling.

Here, the above 1. In (c), since the relationship between the steel plate cooling time and the transferred steel plate thickness is obtained as a linear function equation, the transferred steel plate thickness of the material changed as the number of passes by the rough rolling mill 6 increases or decreases. Then, the steel plate cooling time is obtained from the above linear function formula, and the steel plate cooling time is corrected.

(C) Pitch correction control for the next extracted material According to the increase or decrease of the rolling time for the material in the rolling mill 6 corrected by the optimum pitch correction control, this increase / decrease time is scheduled for the next extraction material input. Correct the scheduled time of addition by adding it to the time. Specifically, when the number of passes of the material in the rough rolling mill 6 is increased by 2 passes, the extraction time is delayed by a time corresponding to 2 passes of the rough rolling mill 6, and conversely, 2 passes. If it is decreased by only, the extraction time is advanced by a time corresponding to two passes. As a result, the pitch between the material and the next extraction material is maintained at the optimum value.

The present invention has been focused on the fact that the thickness of the steel sheet transferred between the rough rolling mill 6 and the finish rolling mill 18 can be changed as long as it does not affect the product quality. If the pitch between the material and the preceding material is wide in a state where the material and the preceding material are not maintained at the optimum pitch, the pass in the rough rolling pass schedule of the rough rolling mill 6 for the material is performed. Correct the pitch between the material and the preceding material by advancing the material by reducing the number, and if the pitch between the material and the preceding material is narrow, increase the number of passes in the rough rolling pass schedule, By delaying the material, it is possible to modify the pitch between the material and the preceding material. At this time, by changing the steel plate cooling time and the finishing rolling pass schedule together with the changing of the rough rolling pass schedule, the thickness of the steel sheet transferred between the rough rolling mill 6 and the finishing rolling mill 18 due to the change of the rough rolling pass schedule. The changes are addressed so that they do not affect product quality.

Further, the pitch between the material and the next extraction material can be maintained at the optimum pitch by delaying or advancing the feeding time of the next extraction material in accordance with the change of the rough rolling pass schedule for the material. is there.

Therefore, according to the present invention, since the residence time in each facility is changed in relation to each other, the hot rolling is performed while keeping the optimum pitch between each material without affecting the product quality. It is possible to improve the production capacity of the line.

It should be noted that in 2. of the above embodiment. In (b), the optimum pitch correction control for the material is completed by rolling the material in a predetermined pass in the rough rolling mill 6 (in the example, two passes before the optimum transfer steel plate thickness). Although it is set to be carried out at the timing, it is not always necessary to carry out at this timing. For example, it may be performed at the timing when the material reaches the rough rolling mill 6, and may be appropriately set according to the processing conditions such as the processing equipment of the thick steel plate rolling line and the material.

Further, the above control method can be applied not only to the thick steel plate rolling line, but also to any line capable of changing the residence time in each facility on the line while associating them with each other.

[0046]

As described above, the present invention is provided with a processing facility including a plurality of rolling mills for rolling a material,
In a thick steel plate rolling line in which materials are input at a preset optimum pitch, the pass schedule of the rolling apparatus is set for each material extraction, and at the same time, the arrival time of the materials to each facility is estimated. This estimated time is corrected according to the movement of the material. Then, when the material reaches a certain point on the thick steel plate rolling line, the pitch between the material and the preceding material is obtained from the estimated time, and from the difference between this pitch and the optimum pitch, the pitch Judge the degree of deviation. If this pitch deviation is outside the allowable range, change the rolling pass schedule of the rolling mill,
The pitch between the material and the preceding material is corrected to the optimum pitch. On the other hand, the input time of the next extracted material is corrected according to the change of the rolling pass schedule of the rolling mill for the material. Therefore, it is possible to delay or advance the extraction time of the next extraction material according to the change of the rough rolling pass schedule for the material, and thereby, in the hot rolling line while keeping the optimum pitch between the materials. It is possible to improve production capacity.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a hot rolling line according to the present invention.

FIG. 2 is a conceptual diagram showing a conventional hot rolling line.

[Explanation of symbols]

 2 Hot rolling line 3 Heating furnace 6 Rough rolling mill 17 Cooling device 18 Finishing rolling mill

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-62-30812 (JP, A) JP-A-62-230418 (JP, A) JP-A-59-80721 (JP, A)

Claims (1)

[Claims] 1. A thick steel plate rolling line provided with a processing facility including a plurality of rolling mills for rolling a material, in which the material is introduced at a preset optimum pitch, and the pass schedule setting of each rolling mill is performed. While performing each extraction, the arrival time of each material to each processing facility is estimated, the estimated time is corrected according to the movement of the material, and the material reaches a certain point on the thick steel plate rolling line. When the pitch between the material and the preceding material at the time of is obtained from the estimated time, the degree of pitch deviation is determined from the difference between this pitch and the optimum pitch, and when the deviation of the pitch is out of the allowable range. Changes the rolling pass schedule of the rolling mill to correct the pitch of the material and the preceding material to the optimum pitch, while changing the time of feeding the next extracted material to the material. The mill rolling passes was corrected according to the schedule changes, thereby turned pitch control method of the material in a steel plate rolling line, characterized in that to keep the optimal pitch pitch between the material against.