JPH0651204B2 - Conveyance control method for multi-reversing hot strip steel rough rolling mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to mill pacing control of a multi-reversing hot strip steel rough rolling mill, and more particularly to improving the efficiency of mill pacing control.

[Conventional technology]

A typical arrangement example of a conventional hot strip steel rolling line is shown in FIG. Here, the material heated in the heating furnace 1 is rolled to a predetermined thickness by the rough rolling mill 2, conveyed to the delay table 3, the tip and tail ends of the material are cut by the crop shear 4, and the finish rolling machine 5 is used. Rolled to the required product thickness,
It is conveyed by the hot line table 6 and wound up by the coiler 7. Reference numeral 8 is a transfer table between the rough rolling mills.

Here, the rough rolling mill 2 includes a reversible type and an irreversible type, and a rough rolling facility is configured by combining a plurality of rolling mills. FIG. 9 shows a conventional typical arrangement example of the reversible rough rolling equipment, and the conventional transfer control will be described. Rough rolling mill R1, R2, ...
-For Rn, the edger E1. En is usually added to perform width reduction, and the inter-rough rolling mill transfer table T (8) has table drive units T1, T2, ... Ti.
The drive is controlled (for example, FIG. 2), and the presence or absence of slabs in the table is detected by the tracking sensors S1, S2, ..., S _{i + 1} to perform the position tracking (tracking) of a plurality of slabs on the rolling line. . Rough rolling mill R
The transport table T (8) between 1 and R2 is driven by both of them, and it is necessary to share the transport of the table. R in the figure
When 1 rolls the slab A, the table driving unit numbers T1 to Tj (i ≧ j ≧ 1) that can secure the slab length L1 after the rolling on the transport table T (8) are interlocked and reserved, and
If ~ Tj is not exclusively used in conjunction with another stand (R2), T1 to Tj can be driven in conjunction with R1 to start rolling of the slab A at R1. Other stand (R2)
Slab A will wait until the linkage is released. The interlocked transport table drive unit is
When the tail end of the slab passes over it, the linkage with the rolling mill is released.

Typical operating cases are shown in FIGS. 10a and 10b and specifically described. In case 1 shown in FIG. 10a, both R1 and R2 are rolling in the same direction, and R2 is
Is rolling slab B, and transport table drive unit T1
It is linked to R2 from ~ T4. At this time, R1 is Slab A
In order to roll the slab A, the interlocking reservation is made for the transport table drive units T1 to T3, which are required to secure the length L1 of the slab A after rolling on the transport table. However, in this case, since T1 to T3 are linked to R2,
As the slab B is rolled at R2, when the tail end of the slab B passes the tracking sensor S2, the interlocking with R2 of T1 is released, and similarly, until the interlocking with R2 of T3 is released, R1 remains Stand by without being able to interlock T1 to T3,
When the interlocking with R2 is released from T1 to T3, T1
The slab A can be rolled at R1 by linking T3 with R1.

Next, in case 2 shown in FIG. 10b, which is a case where R1 and R2 are mixed, the length L1 after rolling of the slab A rolled at R1 and the length L2 after rolling of the slab B rolled at R2. If both can be secured on the transport table (T1 to T4), both stands can start rolling. However, if they cannot be secured on the transport table, the transport table works in conjunction with the previously reserved stand and the stand starts rolling. The other person waits for rolling until the state of Case 1 is reached (hereinafter, the above method is referred to as a table reservation method).

However, originally, in case 1, when R1 rolls the slab A, T1 to T3 are linked with R2 in consideration of the rolling speed difference between the stands and the transport time until the slab A is metal-in to R1. You don't have to wait for it to be released. That is, when rolling two slabs in the same transport direction, the transport trajectory (time vs. position) of the tail end thereof is predicted from the rolling schedule of the preceding material (slab B in FIG. 10a) along the transport direction, and similarly, By preparing a transfer control device having a mill pacing function capable of predicting and collating the leading end trajectory of the material (slab B) and controlling the idle time (standby time) of the subsequent material rolling mill to the minimum time, the standby This will save a lot of time.

[Problems to be solved by the invention]

In recent years, the continuous casting ratio of slabs (the ratio of slabs manufactured by continuous casting to the slabs that are subject to rolling) has increased, and the slab size is integrated and the unit weight is increased (the weight of one slab is increased). Since it is remarkable, the bar length (BAR) of the rolled material is increasing. On the other hand, there is a tendency for shortening the inter-stand table and reducing the drive unit in the course of equipment compaction and initial cost reduction. The degree of competition of the inter-stand transfer table is increasing. In addition, the problem of energy saving in hot rolling becomes the most important issue, and the tendency to lower the heating furnace extraction temperature is remarkable, while the rough rolling time is shortened in order to secure the temperature on the outlet side of the rough rolling mill. Further, in establishing CCDR and HCR, it is an essential condition to increase the spare capacity of the hot rolling process, which is a lower process, as a responsibility of the integrated process from steel making to hot rolling.

In addition, in the production of a wide variety of products in small lots, there is an increasing tendency to expand production capacity in large-scale production lines as a result of securing production volume and line consolidation.

Based on such a background, the present invention aims to provide a transport control method that greatly improves the productivity of a multiple reversible rough rolling mill in which mill pacing exerts its maximum effect, and a multiple reversible rough rolling mill is provided. Efficient mill pacing control (hereinafter MP
C) and position control (hereinafter, APC) of side guides (hereinafter, SG) that contribute to this are provided.

[Means for solving problems]

In the present invention, a plurality of reversible rough rolling mills are provided, and in the transport control method of the hot strip steel rough rolling mill for controlling the transport of the hot strip rough rolled material between rolling mills, rolling of two adjacent front and rear rolling units is performed. When rolling different rolled materials in the same direction with the rolling mill, the trailing edge position of the preceding material at the start of the succeeding material is predicted from the trailing trajectory of the succeeding material along the conveying direction, The conveyance of the following material is controlled so that the idle time of is minimized.

That is, focusing on the rolling of separate materials by two adjacent front and rear reversible rolling mills, and when the rolling feed direction (conveying direction) of both rolling mills is the same direction, the material on the upstream side in that direction (subsequent material) ) Is the starting point when the tip of
In accordance with the rolling schedule of the downstream material (predecessor material) and the subsequent material in the above direction, the tail end position and the leading end position of the subsequent material of the preceding material over time are calculated in advance, and the preceding material calculated in advance in that direction The overlapping distance between the preceding material and the trailing material is obtained in advance from the tail end position of the following material and the leading end position of the succeeding material, and the conveyance of the succeeding material is stopped until the preceding material advances by the distance or more and the preceding material or more by the distance or more. After proceeding, the conveyance of the succeeding material is started.

According to this, in the method for controlling the hot strip steel rough rolling mill, in which a plurality of reversible rough rolling mills are provided to control the inter-roller transportation of the hot strip rough rolled material, two rolling mills adjacent to each other are provided. When rolling the material to be rolled in the same direction, the tail end of the material to be rolled (predecessor material) on the downstream side in this direction and the tip of the material to be rolled (successive material) on the upstream side are placed on the same transport table. Rolling succeeding materials without placing them, that is, without causing trouble in rolling and transporting each material, and without substantially creating an empty table between them, that is, without substantially generating idle time (standby time) You can Therefore, the rolling motion rate becomes high.

When there is a side guide, the correlation between the widths of the leading material and the trailing material becomes a problem. For example, when the leading material is narrow and the trailing material is wide, the trailing material collides with the side guide when the conveyance is performed to minimize the idle time as described above.

Therefore, when there is a side guide, the position control required time of the output side guide of the rear rolling mill and the required time of the succeeding material metal in which the opening settings of the preceding material and the following material compete with each other are predicted, and Control the side guides to minimize idle time. That is, when the width of the succeeding material is wider than the width of the preceding material, the time to drive the side guide and set the opening to match the width of the following material is added from the time when the side guide is not necessary for the preceding material. In time, the conveyance of the succeeding material is started at the timing calculated backward from the timing when the leading edge of the succeeding material enters the side guide.

The present invention will be described below with reference to the drawings. FIG. 1 shows the structure of a hot strip steel rough rolling line for carrying out the present invention in one mode. The rough rolling mills R1, R2, ... Rn are reversible (n is arbitrary), and the front and rear edgers are used. E1F, E2F, E2
The presence or absence of B, ... EnF, EnB is optional, the inter-stand transport tables T11, T12, ... Ti, T21, ...
・ T2j, T1i, ... Tn _-1k can have any number of drive system sections, side guides SG1F, SG1B, ... SGn
B is normally installed, but here, the configurations of the rough mill main control devices MC1, ..., MCn, the inter-stand transfer control devices TC1, ... TCn, and the rough rolling schedule setting control device RSu are arbitrary. However, here, each rough rolling mill is automatically operated according to the rough rolling schedule, and the transport table has tracking sensors S11, S12, ...
..., S1 _{i + 1} , S21, ... S2 _{j + 1} , S31,
The presence or absence of slabs on each table can be tracked by S _{n-1k + 1} and controlled for each table drive unit. Furthermore, the slab rolling position of each rolling mill is the tracking sensor S _0h immediately before and after the mill. , S11, S1
_{i + 1} , S21, S2 _{j + 1} , S31, ... S
The positions are _{n-1k + 1} and Sn1.

As described above, these rough rolling control devices and transfer control devices have been conventionally known.

The transfer control between stands applied to the hot rough rolling line configured as described above is shown in FIGS. 2 and 5, which will be described below.

FIG. 2 shows a line configuration example to which the above MPC algorithm is applied and an assumed diagram of a rolling state. R2 is about to roll the slab B, and R1 is about to roll the slab A in the same transport direction as the R2. Where slabs A and B
The distance to metal in to the rough mill is L ₀ 1 and L
₀ 2, the arrival distance after the rolling of the slab A defines the distance from the LB, R1 to each table and L1, L2, L3, L4, L5. In addition, slabs that take into consideration the mill draft and mill advance rate, and the advance rate and draft of each edger for the metal in speed (roll peripheral speed of the mill from the slab stop position to metal in to the mill) and rolling speed of R1 and R2. The tip speed of A is VM1 during metal-in and V1 during rolling, and the tail speed of slab B is VM2 during metal-in and V2 during rolling.

Here, the necessary and sufficient condition for interlocking table switching is that different rolling materials do not ride on the same table drive unit, and when this is satisfied, slab tracking is possible with the tracking sensor, and this is satisfied. There is a need to. Further, as a condition for rolling in the same conveying direction, the front mill needs to start rolling. This requires slab B to be rolled on a predetermined schedule in FIG.

In addition, how to specify "start of forward mill rolling",
That is, it must be clear what timing is defined as the start of rolling. This state that can be regarded as "start of rolling" is shown in FIGS. 3a to 3e. In these drawings, SF and SB are tracking sensors, EF,
EB is an edger and RM is a rough mill.

Case 1 shown in FIG. 3a is a slab (slab A in FIG. 2
This is a case in which the time point when the tip of (corresponding to S1) reaches SB (corresponding to S1 in FIG. 2) is regarded as "start of forward mill rolling". Case 2 shown in FIG. 3b is EB (E1B in FIG. 2).
This is the case where the time point when the value reaches (equivalent to) is regarded as “start of forward mill rolling”. Case 3 shown in FIG. 3c is a case where the time point of RM metal-in is regarded as "start of forward mill rolling". Case 4 shown in FIG. 3d is a case in which the time when the inlet side edger metal is in is regarded as “start of forward mill rolling”. Case 5 shown in FIG. 3e is a case in which the time when the mill is set to the rolling condition and the tip of the slab is detected by the reference sensor is regarded as "start of forward mill rolling". In addition, during the progress of the slab after Case 5 (FIG. 3e), an arbitrary time point (tracking value) can be defined as “start of forward mill rolling” by distance tracking.
In case 5, the effect of C is maximum.

The timing defined below as "start of forward mill rolling" is MP
It is referred to as C timing.

FIG. 4 shows the expected movement trajectory of the tip of the slab A which is the succeeding material and the slab B which is the preceding material when the case 5 shown in FIG. The expected trajectories of the edges are shown. MPC based on this
The algorithm is explained. In FIG. 4, the X axis shows the mill arrangement shown in FIG. 2 and the Y axis shows the passage of time from the MPC timing. MPC timing is reached at tMPC, that is, the tip of the slab A is at the position S _O (corresponding to SF in FIG. 3e) at time tMPC, and the slab A is rolled at R1.
The leading end locus of the metal is metal-in to R1 at t _O at the speed VM1 and thereafter reaches P ₁ at t ₁ by V1 and rides on the table drive unit T1. At this time, the tail end of the slab B may pass through the table drive unit T1. That is, at the time t ₁ , the tail end locus of the slab B passes through the position P ₁ ′ at tM.
The position of the tail end of the slab B on the PC (hereinafter referred to as the initial position) is calculated back by V2 and VM2, and LT is calculated from R1.
The distance is 1. The further progresses rolling R1, slab A tip trace reaches the P ₂ at t _2, rests on the table driving unit T2. Similarly, at t ₂ , slab B
An initial position LT2 that passes P ₂ ′ at t ₂ in order for the trailing end locus of P to pass through the table drive unit T2 is obtained, and LT3 is similarly obtained. This is repeated for each table drive unit reached by the tip locus of the slab A.

LT1 is in the state shown in FIG. 4 (case 5 shown in FIG. 3e).
When the conveyance for rolling the slab A is started at the MPC timing of 1.), the table drive unit T1 does not compete for the conveyance of the slab B and the conveyance of the slab A, and represents the tail end position of the slab B at the MPC timing. If the tail end of the slab B is on the R2 side of LT1 in the state shown in FIG. 4, even if the rolling of the slab A is started (the conveyance for rolling is started at R1), the table drive unit T1 is not moved to the slab B. Does not compete with the transport of Slab A.

Similarly, LT2 represents the tail end position of the slab B because the table drive unit T2 does not compete for the conveyance of the slab B and the slab A, and LT3 indicates that the table drive unit T3 does not compete for the conveyance of the slab B and the slab A. , Slab B tail position.

The maximum value of these LT1, LT2, ... is LT
_max (In the example shown in FIG. 4, LT1 <LT2 <LT3
If it is set to LT3), at MPC timing,
The tail position of slab B must be LT _max .
That is, when the rolling of the slab A is started, the tail end of the slab B must be at a position equal to or higher than LT _max . This is the condition that must be satisfied to the minimum extent. If the tail end position of the slab B is LT _max (for example, LTi, i = 1 to
4) If rolling of the slab A is started when the distance is shorter, a certain table drive unit (i) will compete with the conveyance of the slab B and the slab A.

Therefore, as described above, according to the MPC timing, the LT
By calculating _max, and tracking the tail end of slab B,
If the tail end position of the slab B becomes LT _max or more, rolling of R1 can be started, and when the tail end of the slab B passes each table drive unit, if the table interlocking is switched from R2 to R1, rolling of R1 and R2 can be performed. Can be done smoothly.

FIG. 5 shows an M of an embodiment of the present invention, which is assumed to start at a fixed cycle.
3 shows a flowchart of a PC algorithm. In this case, it is determined in step 1 whether the rolling is in the same direction. If NO, the conventional table reservation control is performed, and if YES, the MPC control is performed. The determination of the rolling feed direction in step 2 is performed in order to improve the efficiency of the arithmetic processing, and the normal rotation (4th
In the figure, the same algorithm is applied in the slab conveyance from right to left) and in the reverse direction (in FIG. 4, the slab conveyance is from left to right). This is to switch the calculation parameter.

The MPC timing in step 3 needs to be satisfied only once when the direction rolling condition in step 1 is satisfied. YES
LT _max at (MPC timing) (step 4)
Is calculated and it is not necessary to perform it thereafter (there is no change in calculation parameters). Here LT _max calculation (step 4)
According to FIG. 4, if the MPC timing is case 5 shown in FIG. 3e, the following equation (1) is obtained. If the MPC timing is assumed to be case 3 or later shown in FIG. 3c,
The third term of equation (1) is not necessary. Further, since the number of repetitions i is an arbitrary number of divisions into table drive units, the upper limit of i is also arbitrary.

LT _i = L _{i + 1} -[(L ₀ 1 / VM1) + (L _i / V1)] × V 2 + [(V2 / VM2) -1] × L ₀ 2 ・ ・ ・ (1) 0 ≦ i ≦ Repeat at 3 until the table where the tip of slab A reaches.

LT _i : Initial position of the trailing edge of the preceding material (shortest value) because the trailing edge of the preceding material has passed through Ti when the succeeding material enters the table drive unit Ti, L _i : Rear mill-table drive Unit Ti distance, L ₀ 1: Metal-in distance of succeeding material, L ₀ 2: Metal-in distance of preceding material, V1: Rolling speed of leading edge of succeeding material, VM1: Metal-in speed of leading edge of succeeding material, V2: Leading material Rolling speed at the tail end, VM2: Metal-in speed at the tail end of the preceding material, the third term in Eq. (1) is the metal-in correction distance of the preceding material.

_{LT max = Lj + ΔL ··· (} 2) LT max ≧ Lj, ΔL = LT max -Lj o Lj: LT max just before the sensor Sj and the rear mill distance, Lj ≧ Lk, (0 ≦ k ≦ j-1).

ΔW = v × t (3) v: SG opening / closing speed, ΔW: opening deviation, t: opening / closing required time.

T ₀ = VM1 × L ₀ 1 (4) T ₀ : Slab A metal-in time, VM1: Metal in-speed at the tip of slab A, L ₀ 1: Rolling standby position of slab A.

Condition 1 ... ΣL> LT _max and ΔW = W ₁ −ω (ω = (W ₁ + W ₂ ) / 2, W ₂ ≦ W ₁ ) ∴ΔW ≧ 0 Condition 2 ... ΣL> LT _max and ΔW = W ₁ −ω (ω = (W ₁ + W ₂ ) / 2, W ₁ ≦ W ₂ ) ∴ΔW ≦ 0 Above, when LT _max is obtained in step 4, the trailing edge of the preceding material is tracked in step 5. Normally, the transfer control device is started at a fixed cycle, so the table speed is multiplied by the sampling time, and the moving distance is calculated by a method of integration. Based on this, the backward mill R1 is used as the base point, and the forward mill R2 direction, The preceding material tail end distance ΣL is calculated. This is the distance from R1.

If ΣL = LT _max is established in step 6, rolling of the rear mill is started and interlocking control switching of the table is performed.

As described above, the MPC timing which can be arbitrarily set for a plurality of reversible pressure rough rolling mills and which has a high efficiency has been described, but basically, regardless of the equipment constraint and the forward and reverse,
It can be applied to any automated line.

Next, FIG. 6a shows an efficient APC algorithm of the side guide SG that does not bring the maximum constraint to the MPC algorithm.
This will be described with reference to FIGS. 6b, 7a and 7b. Figures 6a and 6b show the APC equipment configuration to which the above algorithm is applied. Here, the APC is automatically operated with respect to the set schedule, but this is conventionally known, and the side guide SG is usually longer than the table drive section. Therefore, by MPC, ΣL
Even if the condition of ≧ LT _max is satisfied, there is a case where the rear mill exit side side guide SG cannot perform APC for the succeeding material contact path setting. This will be explained with reference to Figures 7a and 7b. Here, the normal APC (Fig. 6a) is
Due to the low inertia, the acceleration / deceleration characteristics are fast, and the time to reach the predetermined opening is determined by the opening / closing speed, and is approximated by the equation (3).

In case 1 shown in FIG. 7a, the slab 2 (predecessor material) is rolled by the front mill and ΣL> LT _max . Therefore, the slab 1 (subsequent material) can be rolled by RM, but the downstream side guide SGB has the set opening W ₂ of the slab 2, and conventionally, the set opening W ₁ of the slab must be the set opening W _1. 1 can not be rolled, but here the side guides SGB can be opened in the opening direction, which is not obstructed by the slab 2. Side guide SGB for slab 2
It is known that opening does not affect rolling. Regarding the rolling of the slab 1, it is sufficient that the side guide SGB is opened to W ₁ when the tip of the slab 1 reaches RM, and if the slab 1 metal-in required time is T _{0 according} to the equation (4), If ΔW / v ≦ T ₀ , then SGB is open to W ₁ when the tip of slab 1 leaves RE, so ΣL> LT
_When the two conditions of _max and ΔW / v ≦ T ₀ are both satisfied, rolling of the slab 1 can be started and the effect of MPC can be exhibited.

Next, in the case shown in FIG. 7b, it is the reverse of case 1, and it is difficult to start the side guide SGB for APC in the closing direction, but it is possible for the rolling of the slab 1. is there. However, width reversal is large (ΔW is large)
When there is a risk of rough BAR bending, wait until the side guide SGB can perform APC, and then | ΔW | / v ≦ T ₀
The rolling amount of W ₀ is set in order to start rolling of the slab 1 or to improve efficiency (0 ≦ W ₀
If desired, stand by until | ΔW ₀ + ΔW | / v ≦ T ₀ , the MPC effect can be further exhibited. This can also be applied to the case of the RM rear edger EB, and when the slab 2 enters the side guide SGB in the reverse direction, the APC in the opening direction is performed but the APC in the closing direction is performed.
MPC efficiency is improved by not activating. Further, the above method can be applied to the case where the trailing edge of the preceding material is not between the SGB and the side guide SGF on the upstream side, and contributes to the reduction of the APC required time and the improvement of the MPC effect.

(Effect of the invention) As described above, the MPC algorithm and the side guide APC
According to the conveyance control device of the multi-reversible hot strip steel rough rolling mill having the algorithm, efficient rough rolling can be realized even in any combination of random pass schedules, and the productivity is dramatically improved (15 % Or more), it greatly contributes to the expansion of surplus capacity by increasing the production capacity and the promotion of energy saving, and has a function that matches the trends and needs of recent hot rolling.

[Brief description of drawings]

FIG. 1 is a block diagram showing a hot strip steel rough rolling facility provided with a plurality of reversible roughing machines for carrying out the present invention, and FIG. 2 is a side view showing two rolling machines and rolled materials therein. Figures 3a and 3
b, FIG. 3c, FIG. 3d and FIG. 3e are side views showing the relationship between one rolling mill and the position of the rolled material, and FIG. 4 is two rolling mills and rolled material and rolled material. 3 is a side view and a graph showing the time-series transitions of the tail end and the tip position of the, where the horizontal axis indicates the position and the vertical axis indicates the elapsed time. FIG. 5 is a flow chart showing the operational steps of one embodiment of the present invention. FIG. 6a is a plan view showing a side guide of one rolling mill,
FIG. 6b is a side view thereof. 7a and 7b are plan views showing the relationship between the side guides and the rolled material. FIG. 8 is a block diagram showing the structure of a conventional rolling facility, and FIG.
The figure is a side view showing the structure of the rough rolling mill group therein, 10a.
FIG. 10 and FIG. 10b are side views showing the relationship between the rough rolling mill and the rolled material shown in FIG. R1, R2, ...: Coarse rolling mill E1F, E2F, ...: Edger T11, T12, ...: Conveyor table between stands SG1F, SG1B, ...: Side guide MC1, MC2, ...: Coarse Rolling mill main control device TC1, TC2, ...: Inter-stand transfer control device RSu: Rough rolling schedule setting control device S11, S12, ...: Tracking sensor

Claims (2)

[Claims] 1. A transfer control method for a hot strip steel rough rolling mill, wherein a plurality of reversible rough rolling mills are provided to control the transport of the hot strip steel rough rolling material between rolling mills. When rolling different rolled materials in the same direction with the rolling mill, the trailing edge position of the preceding material at the start of the succeeding material is predicted from the trailing trajectory of the succeeding material along the conveying direction, The method for controlling the conveyance of a multi-reversing hot strip steel rough rolling mill is characterized by controlling the conveyance of the succeeding material so that the idle time of is minimized. 2. A transport control method for a hot strip steel rough rolling mill, wherein a plurality of reversible rough rolling mills are provided to control the transport of the hot strip steel rough rolling material between the rolling mills. When rolling different rolled materials in the same direction with the rolling mill, the trailing edge position of the preceding material at the start of the succeeding material is predicted from the trailing trajectory of the succeeding material along the conveying direction, In order to minimize the idle time of the following material, the following material is controlled to be conveyed, and the time required for the position control of the side guide on the exit side of the rear rolling mill where the opening settings of the preceding material and the following material compete with each other A transport control method for a multi-reversible hot strip steel rough rolling mill, which comprises predicting an in-required time and controlling the side guide so that an idle time of a rear rolling mill is minimized.