JPH09122719A - Method for tracking tail end of strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute tracking with high accuracy by executing tail end tracking till the tail end of a strip passes through the final stand and tracking till the tail end reaches a coiler after the tail end passes through the final stand. SOLUTION: The position LC of the tail end from the cutting position of the tail end of the strip is determined by the equation I using a detecting speed VR till the tail end of the strip reaches a rear measuring roll. The position LI of the tail end is determind from the equation II using the position LC of the tail end determined by the equation I and distance LO between a crop shear and the final stand. The correction value LK of a finishing stand is corrected using the equation III. The remaining length LZ of the tail end of the strip isdetermined by the equation IV. The remaining length L, of the tail end is locked on and, further, vertification of accuracy of calculation of the length LZ is executed by the equation VZ. Next, the distance LX between a mandrel and the tail end is determined by the equation VI and tracking till the tail end reaches the coiler after the tail end of the strip passes through the final stand is executed. Where, VP: the circumferential speed of the pinch roll, tS: the duty time of an arithmetic part (m.sec), KH: learning factor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for tracking a strip tail, and more particularly to a novel improvement for automatically tracking a strip tail during rolling.

[0002]

2. Description of the Related Art Conventionally, a method of tracking a tail end of a metal strip, which has been used conventionally, uses a distance timer in consideration of a reduction rate and a leading rate in the speed of a final stand of a finishing rolling mill.
Tracking is performed, and when the tail end of the strip passes through the final stand, tracking is performed by the distance timer from the peripheral speed of the winder. However, since a tracking error occurs in this method, in order to correct the error, an HMD (known as a hot mass detector called HMD) is installed between the finishing rolling mill and the pinch roll, and from this HMD The signal is used to forcibly set a constant for correction.

[0003]

Conventionally, a strip coil wound by a winding machine is opened by opening a wrapper roll holding the outer circumference of the coil, further expanding a mandrel and pushing the coil by a pusher to move the coil on a moving carriage. But
The distance from the final finishing stand to the winder for winding the strip is as long as 100 to 200 m, and the strip tail end position is 1 to 3 m because the strip speed is very fast.
There is some error. For this reason, the tail end position cannot be fixed by the moving carriage, so the tail end is unstable,
In addition, the spring action had a flaw on the flapping strip.

In the past, the necessity of tracking the tail end of the strip was required only after the tail end passed through the final stand of the finishing rolling mill, but in recent years, from the standpoint of productivity, the rough rolling mill is used as a hot bar. Techniques have been introduced to interlock and roll rolled material, requiring accurate tracking of strip joints. Further, in order to accurately stop the tail end of the strip at a predetermined position when the strip is wound, it is necessary to accurately grasp the momentary end position of the strip. The present invention has been made to solve the above problems, and in particular, it is an object of the present invention to provide a strip tail tracking method for automatically tracking the strip tail during rolling.

[0005]

SUMMARY OF THE INVENTION A method of tracking a strip tail according to the present invention comprises a trailing measuring roll for detecting a strip being lowered and until the trailing end of the strip reaches the trailing measuring roll. _{, L C = V R × (} 1/60) determined tail end position from the cutting position of the strip tail end L _C a (mm) in 1 set by crop shear using a detection speed V _R of the rear Measuring roll × ts (1) formula In order to obtain the tail end remaining length L _Z until the tail end of the strip passes the final stand, the final total speed ratio f _T of the finishing rolling stand is locked on, and The tail end position L _I is calculated by the equation 2 using the tail end position L _C obtained in step S1 and the distance L ₀ between the crop shear and the final stand.
The first step and the L _I = L ₀ to -L _c (2) formula wherein tail end position L _I value, a second step of correcting the correction value L _K when delivery side thickness of the stand finishing using three equations to obtain the And L _K = L _I × f _T (3) Equation (3) Mandrel-side pinch roll peripheral velocity V _P and the correction value L
_A third step of obtaining the tail end remaining length L _Z of the strip from _K (L _K is locked on when ts in the formula (1) has elapsed for 1 to 2 seconds) and the learning coefficient K _L by the formula 4, A: At L _K lock-on B: When the final finishing stand is pulled out The tail end of the strip until it passes the final stand of the finishing rolling stand is tracked, and then from the load cell provided in the final stand. locked on the tail remaining length L _Z together with the tail end of the strip signal to detect that it has passed through the final stand, further verification of the calculation accuracy of the tail remaining length L _Z 5
Carried by the _{formula, K L = (L K -L} Z) / L K (5) formula then the tail end of the strip is final finishing stand by obtaining a distance L _X between the said mandrel tail in equation (6) It is a method of tracking after reaching the winder after passing through the machine. However L _X: mandrel and the distance L between the strip tail end _1: finish rolling final distance V from the stand to the coiler _P: pinch roll peripheral velocity ts: calculating portion of the duty time (msec) K _H: learning coefficient A: When the pinch roll is removed B: When the final finishing stand is removed

More specifically, the learning coefficient K _H includes a plurality of HMDs provided on the table between the final stand and the pinch rolls, and the tail end of the strip is the first HMD.
A tail end movement amount calculation value ΔL _X1 that passes through the MD and further passes through the second HMD is obtained.
Tail end movement calculation value passing MD and passing third HMD Δ
This is a method of obtaining L _X2 and then repeating the above-mentioned operation for n HMDs by using Equations 7 to 10. K _H1 = ΔL _X1 / (L ₂ −L ₃ ) (7) Formula K _H2 = ΔL _X2 / (L ₃ −L ₄ ) (8) Formula K _Hn = ΔL _Xn / (L _{n + 1} −L _{n + 2} ) (9) formula However, n: Number of HMDs installed K _H1 : Learning coefficient in first HMD to second HMD K _H2 : Learning coefficient in second HMD to third HMD K _n : In nth HMD to n + 1th HMD Learning coefficient K _H : Total learning coefficient ΔL _X1 : Calculation value of tail end movement while tail end moves from first HMD to second HMD ΔL _X2 : Second end HMD to third HMD tail movement operation value while moving to the L _2: the first HMD~ distance to the mandrel L _3: second HMD~ distance to the mandrel L _4: the distance to the third HMD~ mandrel

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a strip tail tracking method according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an outline of a rolling line, in which a slab 10 is extracted from a heating furnace (not shown) and is extended to a hot bar 10a by a rough rolling mill 1, and an end surface of the hot bar 10a is extracted. It is heated by a well-known edge heater (not shown) to compensate for the temperature drop. Front measuring ring 2 for measuring the length of the hot bar 10a by pressing the upper surface of the hot bar 10a which has exited from the edge heater
After passing through the hot bar 10a, the hot bar 10a is cut by the crop shear 3 in order to align the front end and the tail end of the hot bar 10a, and further passes through the rear surface measuring ring 4 to the finishing rolling stand 6. Usually this hot bar 10a
The tail end of the strip consisting of is made from the end of the finishing stand 5 of the finishing rolling stand 6, but in the present invention, the hot bar 10a, that is, the tail end of the strip is cut by the crop shear 3 and the cut surfaces are aligned. It is performed from the place where it was given. That is, it is roughly divided into two steps: a step of tracking the tail end from the crop shear 3 to the final stand 5 and a step of passing the tail end of the strip through the final stand 5 to reach the winder 9.

First, the tail end of the strip is the final stand 5
The tracking method until passing through is that the trailing edge of the strip from the time when the tail end of the strip is cut by the crop shear 3 to the rear measuring ring 4 is descending and reaches the rear measuring roll 4. Tail end position L _C (mm) using detection speed V _R (mpm)
Is calculated by one equation. _{L C = V R × (1/60} ) × ts (1) equation where ts: Dee tee time calculation unit of the programmable controller (msec)

Next, the tail end tracking from passing through the measuring roll 4 to passing through the final stand 5 is performed by the finishing rolling stand 6 in order to obtain the remaining length L _Z (mm) of the tail end of the strip. The total speed ratio ft of the final finishing rolling stands from F ₁ to F ₇ (the value obtained by summing the speed ratios between adjacent stands) is locked on by the arithmetic unit, and the tail calculated by the above-mentioned formula 1 is obtained. Using the end position L _C , the tail end position L _C is subtracted from the known length L ₀ between the crop shear 3 and the final stand 5, and the tail end position L _{I of the} strip is calculated by the two equations. L _I = L ₀ −L _C (2) Further, a correction value L _K (mm) for correcting the calculated tail end position L _I to a value at the plate thickness on the exit side of the final stand 5 is obtained by the three formulas. L _K = L _I × f _T (3) where f _T : total speed ratio of the finishing mill

This L _K is a value that locks on when ts in the equation (1) has passed 1-2 seconds. Also, the above L _I
Is the tail end position before finish rolling. Next, from the pinch roll speed, the correction value L _K of the tail end of the strip, and the learning coefficient K _L , the length of the tail end remaining until the strip reaches the final stand 5 is obtained by the equation (4). L _Z : Length of tail end remaining to final stand (m
m) L _K : tail end correction value (mm) V _P : pinch roll speed (mpm) ts: duty time (msec) of the arithmetic unit of the programmable controller K _L : learning coefficient A: L _K lock-on time B: When leaving the final finishing stand

The tail end position L _I on the actual line from L _Z thus obtained is L _I = L _K / f _T. Next, tracking after the tail end of the strip has passed the final stand 5 is performed when the tail end of the strip passes the final stand 5 by using a signal from a load cell (not shown) provided in the final stand 5. Since the signal of the load cell is turned off, it is assumed that the tail end has passed by this signal and the last stand 5
The above-mentioned length L _Z of the remaining tail end up to is locked on to the arithmetic unit. At this time, the calculation accuracy of the remaining length of the tail end up to the final stand 5 is verified by the formula (5). The learning coefficient K _L, which is the verification result, is used in the formula (4) for the next rolling. _{K L = L K -L Z /} L K (5) formula

Next, the distance between the mandrel of the winder 9 and the tail end of the strip is calculated by the equation (6). That is, the distance L ₁ between the mandrel of the winder 9 and the tail end of the strip.
As the (initial value), the distance L _X (mm) between the mandrel and the tail end of the strip is obtained. However, L _X : Distance between mandrel and tail end of strip (mm) L ₁ : Distance from final stand to mandrel (mm)
In finish rolling after the tail end position V _P: pinch roll peripheral velocity (mpm) ts: Programmable controllers calculation of duty time (msec) K _H: learning coefficient A: time loss final finish stand B: at exit pinch roll

Further, the learning coefficient K _H is obtained by comparing a plurality of HMDs (known heat mass detectors are referred to as HMDs) provided on the table 10 between the final stand 5 and the pinch rolls 8 on the winder 9 side as shown in FIG. , And the tail end of the strip is first
Tail movement amount calculated value through the further second HMD21 through the HMD20 of △ L seeking _X1, then the tail movement calculated value strip tail end passes through third HMD22 through the second HMD21 ΔL _X2 is obtained, and then the above-mentioned operation is repeated a plurality of times by using each of the HMDs 23 and 24 using the equations 7 to 10. If the distance between the roller table 10 to the final stand 5 and the pinch roll 8 is long, each HMD 20 to
The number of 24 installed increases. K _H1 = ΔL _X1 / (L ₂ −L ₃ ) (7) Formula K _H2 = ΔL _X2 / (L ₃ −L ₄ ) (8) Formula K _Hn = ΔL _Xn / (L _{n + 1} −L _{n + 2} ) (9) formula Here, n: number of installed HMDs K _H1 : learning coefficient in first HMD to second HMD K _H2 : learning coefficient in second HMD to third HMD K _n : nth HMD to n + 1th HMD learning coefficient in K _H: total learning coefficient △ L _X1: tail is the tail movement calculated value while moving in a first HMD~ second HMD △ L _X2: tail of the second HMD~ third Tail end movement calculation value while moving to HMD L ₂ : Distance from first HMD to mandrel L ₃ : Distance from second HMD to mandrel L ₄ : Distance from third HMD to mandrel

It should be noted that the pinch roll 8 comes out and the winding machine 9
Until, the tail end is calculated from the mandrel speed. In addition, in order to track the welding point where the tail end of the previous material and the tip end of the current material in continuous rolling are tracked, the following method is used. First, from the calculated value in the AGC control, the speed ratio f between the entry side speed of each finishing rolling mill and the exit side speed of the final stand f
_{2 to} f ₇ are calculated. Here, f _2: F2 stand inlet side and the F7 stand delivery side speed ratio f _3: F3 stand inlet side and the F7 stand delivery side speed ratio f _4: F4 stand inlet side and F7 speed ratio of the stand delivery side f ₅ : F5 stand inlet side and the F7 stand delivery side speed ratio f _6: F6 stand inlet side and the F7 stand delivery side speed ratio f _7: F7 L _Z (final stand was the stand inlet side and the F7 stand delivery side speed ratio Welding point tracking is performed as follows from the timing of calculating the remaining tail length up to. (1) When the welding point reaches the F1 stand,
It is assumed that the formula (A) is satisfied. −α ₁ <(L _F1 −L _Z / f _t ) <+ α ₁ (A) where α ₁ : Dead band for judgment at F1 stand L _F1 : Distance between F1 stand and F7 stand (2) At F2 stand The timing when the welding point arrives is
Assume that the expression (B) is satisfied. (1) (A) equation after the formation of, replacing f _t to f ₂ performs welding point tracking between F1~F2 stand. −α ₂ <(L _F2 −L _Z / f ₂ ) <+ α ₂ (B) where α ₂ is the dead band for judgment at the F2 stand L _F2 : Distance between the F2 stand and the F7 stand (3) At the F3 stand The timing when the welding point arrives is
It is assumed that the formula (C) is satisfied. After the expression (B) in (2) is established, f ₂ is replaced with f ₃ and the welding point tracking between the F2 and F3 stands is performed. −α ₃ <(L _F3 −L _Z / f ₃ ) <+ α ₃ (C) where α ₃ is the dead band for judgment in the F3 stand L _F3 : Distance between F3 stand and F7 stand (4) In F4 stand The timing when the welding point arrives is
Assume that the equation (D) is satisfied. (3) (C) equation after the formation of, replacing f ₃ to f ₄ performs welding point tracking between F3~F4 stand. −α ₄ <(L _F4 −L _Z / f ₄ ) <+ α ₄ (D) where α ₄ is the dead band for judgment in the F4 stand L _F4 : Distance between F4 stand and F7 stand (5) In F5 stand The timing when the welding point arrives is
It is assumed that the formula (E) is established. After established (D) equation in (4), the welding point tracking between F4~F5 stand replacing f ₄ to f _5. −α ₅ <(L _F5 −L _Z / f ₅ ) <+ α ₅ (E) where α ₅ : Dead band for judgment at F5 stand L _F5 : Distance between F5 stand and F7 stand (6) At F6 stand The timing when the welding point arrives is
It is assumed that the formula (F) is established. After established (E) equation in (5), the welding point tracking between F5~F6 stand replacing f ₅ to f ₆ performed. −α ₅ <(L _F6 −L _Z / f ₆ ) <+ α ₆ (F) where α ₅ : Dead band of judgment at F6 stand L _F6 : Distance between F6 stand and F7 stand (7)
The timing at which the welding point reaches the F7 stand is when the equation (G) is satisfied. After (F) equation in (6) is satisfied, replacing f ₆ to f ₇ performs welding point tracking between F6~F7 stand. −α ₇ <L _Z / f ₇ <+ α ₇ (G) where α ₇ : dead band of judgment at F7 stand

[0015]

Since the strip tail end tracking method according to the present invention is configured as described above, the tail end of the strip can be accurately tracked, so that the tail end wound by the winder is located at a predetermined position. Can be controlled so that the tail end is unstable, and the strip action is not scratched by the spring action. further,
We can accurately track the trailing edge from the crop shear to the final stand and the trailing edge from the final stand to the winder, so that the leading edge of the leading strip and the leading edge of the trailing strip are welded together. When performing continuous rolling by connecting by pressure welding or the like, since the connection point can be accurately tracked by using the present invention, it is possible to accurately perform welding point tracking between finishing stands and disconnection of the connection position after rolling. It is possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a continuous rolling line.

[Fig. 2] HM from the final stand of the finishing mill to the winder
It is a block diagram explaining D installation.

[Explanation of symbols]

 1 Roughing Roller 2 Front Measuring Roll 3 Crop Shear 4 Rear Measuring Roll 5 Final Stand 6 Finishing Roll Stand 20-24 HMD 8 Pinch Roll 9 Winder

Claims (2)

[Claims] 1. The rear measuring roll (4) for detecting a strip is descending and until the tail end of the strip reaches the rear measuring roll (4).
Calculated tail position from the cutting position of the strip tail end L _C a (mm) in 1 set by crop shear using a detection speed V _R of the rear Measuring roll _{L C = V R × (1/60} ) × ts Formula (1) In order to obtain the tail end remaining length L _Z until the tail end of the strip passes the final stand (5), lock on the total speed ratio f _T of the final finishing rolling stand (6). Then
The first step of obtaining the tail end position L _I by the two equations using the tail end position L _C obtained by the above formula 1 and the distance L ₀ between the crop shear and the final stand (5) and L _I = L ₀ − Formula L _C (2) The second step of correcting the tail end position L _I value to the correction value L _K at the time of the exit side plate thickness of the finishing stand by using Formula 3, and L _K = L _I × f _T (3 ) Expression pinch roll peripheral speed V _P on the mandrel side and the correction value L
_A third step of obtaining the tail end remaining length L _Z of the strip from _K (L _K is locked on when ts in the formula (1) has elapsed for 1 to 2 seconds) and the learning coefficient K _L by the formula 4, A: At L _K lock-on B: When the final finishing stand comes out, the tail end of the strip is tracked until it passes the final stand of the finishing rolling stand (6), and then the final stand (5) is set. A signal from the provided load cell causes the tail end of the strip to be the final stand (5).
That the tail end remaining length L _Z is detected.
Lock-on, the verification of the calculation accuracy of the remaining length L _Z of the tail end is performed by the formula 5, and K _L = (L _K −L _Z ) / L _K (5) formula, then the mandrel and the tail end The trailing end of the strip is tracked until it reaches the winder (9) after the trailing end of the strip has passed through the final finishing stand (5) by calculating the distance L _X by the equation 6. Tracking method. However L _X: mandrel and the distance L between the strip tail end _1: finish rolling final distance V from the stand to the coiler _P: pinch roll peripheral velocity ts: calculating portion of the duty time (msec) K _H: learning coefficient A: When the final finishing stand is removed B: When the pinch roll is removed 2. The learning coefficient K _H is the final stand.
A plurality of HMDs (20 to 24) provided on the table between (5) to the pinch roll (8) are provided, and the tail end of the strip is the first HMD.
A tail end movement amount calculation value ΔL _X1 that passes through the MD (20) and further passes through the second HMD (21) is obtained, and then the tail end of the strip passes through the second HMD (21) and passes through the third HMD (21). The tail end of the strip according to claim 1, wherein a tail end movement calculation value ΔL _X2 passing through (22) is obtained, and then the operation is repeated for n HMDs by using formulas 7 to 10. Tracking method. K _H1 = ΔL _X1 / (L ₂ −L ₃ ) (7) Formula K _H2 = ΔL _X2 / (L ₃ −L ₄ ) (8) Formula K _Hn = ΔL _Xn / (L _{n + 1} −L _{n + 2} ) (9) formula However, n: Number of HMDs installed K _H1 : Learning coefficient in first HMD to second HMD K _H2 : Learning coefficient in second HMD to third HMD K _n : In nth HMD to n + 1th HMD Learning coefficient K _H : Total learning coefficient ΔL _X1 : Calculation value of tail end movement while tail end moves from first HMD to second HMD ΔL _X2 : Second end HMD to third HMD tail movement operation value while moving to the L _2: the first HMD~ distance to the mandrel L _3: second HMD~ distance to the mandrel L _4: the distance to the third HMD~ mandrel