JPS6016292B2 - Method of leveling a strip using a roller leveler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a low-foo leveler for correcting defective shapes of strips.
The present invention relates to a method for shingling a strip plate.

In general, a leveler is a device that corrects, for example, curling of a hot rolling steel comb, warping due to shearing, defective shapes during hot rolling, etc. into a flat shape.

FIG. 1 shows a roller leveler 12, in which a strip 1 with an uneven shape passes through a roll gap set by an upper work roll 3 and a lower work roll 2 reinforced by a backup roll 4. As a result, each work roll undergoes repeated bending deformation. FIG. 2 shows this deformation process. The axis in Figure 2 is the work roll number,
The vertical axis is the degree of machining, which will be described later. The deformation inside the roller leveler is uniquely determined by the amount of roll intrusion at the entrance and exit (the roll gap between the upper and lower work rolls), and the deformation is large on the entrance side, after which the amplitude begins to increase and decrease, and then at the exit. It is set so as to eliminate warping (L warp) in the length direction of the strip. To explain the rolling down device for setting the roll pushing amount, a top girder 7 incorporating an upper work roll 3 and a backup roll 4 is lifted up by a hydraulic cylinder 6 fixed to a shingler stand 11.

In order to set a roll gap between the upper and lower work rolls 3 and 4, the top girder 7 is stopped by screws 8 and 8 fixed to a stand 11 with respect to the cylinder 6. The electric motors 10, 10 on the stand 11 are rotated, and the reduction screws 8, 8 are moved up and down through the gears 9, 9, and the reduction settings are made independently on the input and aft sides. Generally, when comparing the degree of deformation of strips having different plate thicknesses, yield point stresses, etc., the degree of work K expressed by the {1} formula is used as an index indicating the degree of work.

K=pe/p……(11However,
pe: elastic limit machining efficiency, p: machining efficiency. Also, as shown in Figure 2, which shows the deformation inside the roller leveler with the above machining degree, after receiving the maximum machining degree at the inlet of the roller leveler,
The residual internal stress of the strip subjected to the reduction degree &~K,3 is the residual internal stress f, (K5, K6, K7...K mountain, K,3
)...It can be found by ■.

Therefore, when setting the rolling reduction on the inlet and outlet sides of the roller leveler, the maximum machining degree Kin on the inlet side and the machining degree Kout on the outlet side shown in FIG. 2 are used as indicators. In general, in a roller leveler, the processing degrees Kin and Kout used to correct the shape of the strip plate are Kin>3.
, Kout Mi1. Also, the normal exit side machining degree Kout ni 1
If the maximum machining degree on the entry side is 3 or more, a substantially flat strip can be obtained. The reduction setting on the inlet and outlet sides of the roller leveler is set by the electric motors 10, 10 via the gear 9.9 and the reduction screw 8.8 so as to obtain the above-mentioned processing degree,
Thread the strip plate 1 with the above rolling setting and level it.
Since the reduction is set based on the relationship between the static reduction setting (roll gap) and the degree of work as described below, it is not possible to always ensure a strip with a good shape after the plater with only this initial reduction setting. was difficult.

In other words, generally, the machining degree, machining curvature, etc. of a roller leveler are defined as follows. (See Figures 3 and 4) [1'
Processing degree K K = peno...p/go = hoe = komo,. ．． ．． ．． ．． (3) However, K: Machining degree Go: Nogo P: Machining distortion
p: Radius of curvature t: Plate thickness E: Young's modulus of plate Yp: Yield strength of plate ■ Machining curvature p P = Ran Toka ...... (4-1) h
= Committee (t-H) ...... (4-2) L' = Gi'
---------- 4-3) However, H:
Reduction setting value (roll gap) '3' Relationship between reduction setting value date and working degree K Reorganize equations {3' and '41 to obtain the following equation.

K=ToL Yoshiku 2 ---------・[51 However, the conventional pressure setting method is
-1) From the graph of formula {5}, the required machining degree K
The reduction setting value for the date is determined and shibelling is performed. However, in such a method, basically the '5th
}The machining degree K shown by the formula is (4-1), (4-2)
, as is clear from the formula for calculating the machining curvature p shown in equation (4-3), when the strip is stopped on the lower work roll group and the upper work roll group is pushed in, rather than the machining degree during straightening. This only holds true.

For example, even if you determine the rolling set value date to obtain the required working degree K from the formula (2), run the strip, perform a bite test, and actually measure the curvature of the strip, the working degree is not achieved. In other words, even if the rolling reduction is set using the formula (2), it is not possible to obtain the required degree of work. Therefore, it is not possible to obtain a strip with a good shape on the exit side of the roller leveler. Observe the condition of the strip on the rear surface of the roller leveler, and if L warping has occurred, the roller leveler 12 shown in FIG. By applying extra bending using the auxiliary roller 5 on the rear surface, the shape is corrected and only the rolling reduction setting on the exit side is corrected, thereby ensuring only the flatness of the strip on the large slope. In this way, if an auxiliary roll is used to secure the shape, the strip will be processed extra.
If only the exit side reduction is adjusted, even if the exit side workability is optimized, it is unclear whether the input side maximum workability is optimal, and a strip with uniform minimum internal residual stress will not be obtained. For this reason, even if a large plate is flat, L warping occurs when it is cut into strips as shown in FIG. In this figure, hmax is the difference in height between the center and the end of the plate length L, and indicates the amount of warpage. As described above, for strips having different thicknesses and yield point stresses, an optimal rolling reduction setting method has not been established to obtain the required degree of processing to produce strips with a good shape and uniform minimum internal residual stress. In view of the above-mentioned circumstances, the present invention has developed the above-mentioned optimal rolling reduction setting method and developed it to make strips with different thicknesses and widths and yield point stresses into strips with a good shape and a uniform minimum internal residual stress. The present invention provides a shibering method.

As a result of various studies on how to calculate the working degree K during shingling, the present invention found that the following theoretical calculation formula was the most suitable in practice.

The plate being passed through the roller leveler reaches the yield bending moment My at the point of contact with the rolls (see Figure 6), and immediately after passing this point, the bending moment My becomes smaller than the bending moment My, and the bending moment My returns to M again.
reaches y. A uniform curvature is maintained until the point of contact with the next roll. Therefore, the deformation of the plate can be considered as a chain of circular arcs connected at the point of contact with each roll. Therefore, as long as the initial conditions for the plate to enter the rollers and the roll arrangement (in other words, the rolling reduction value during roller straightening) are given, the curvature between each roll can be determined as follows. Figure 6 shows the condition of the strip during shibelling.
Hi.

...=aiSin(Matsuju Q.)=(rjuki+p')Sin
(i+iH) ---...side gutter H=aiSi
n ( Kano fake, ): I-ki-r) Sin's other day) .
・a, {sin(i+Qi) one sin(Qi-river)
} = (Koju t) sin (the i+ of the 10,)……(8} Transform, (Koju hi) cos {(the i+, 1 of the i) ノ 2} 10 S sin {(the i+, 1,)/2}=(a+t
) cos {(i+ of i+,)/2(i+, one of,)
If we organize it as /2=, then n={(Kojūt)cos
, Ichiko-hi}/{S 10 (Koju t) sin's;} next i+, = i 12 an-1 {((Koju t) cos i Ichiko - hi)/(S+( Koju t) sin i) ……
...00 Also, the machining curvature pi is pi = r +t/20 {Sc
i+ of os, M of sin}/sin(i+ of i+,) ......(11).

Therefore, the rolling reduction values Hin and Hout during straightening on the input and output sides are determined, and the roll reduction values Hin and Hout are determined for the i-th roll ship. Determine the rolling reduction value hi at the center position between the axes of the i and j+1st rolls Ni1, and as shown in FIG. 1st and 2nd roll rudder. 2, the strip plate 1 enters in a straight line between the first rolled material and the first rolled material. Under the initial condition that the absolute values of , and 2 of the contact angle with the strip plate 1 of the second roll are equal, the contact angle of , and 2 are determined, and the above equation {10 (11) is repeated. If you calculate, each roll N
o. The contact angle i at point i and the machining curvature pi can be determined. Specified entry/exit side rolling reduction setting day 1: Pass the strip under HO, conduct a bite test, calculate the degree of processing of the strip with each roll taking into account the springback of the strip, and then Calculate the straightening reaction force from the processing heat of each roll of the strip using the calculation formula described below, determine the jump amount SB of the upper work roll, and calculate the entrance side rolling reduction value Hin=HI-S during actual roller straightening.
B. Calculate the exit side reduction value Hout = HO-SB, and substitute the reduction value hi determined from the actual reduction values Hin and Hout during straightening into the series of processing degree calculation formulas [IQ (11) [3}, and calculate each When the degree of work with the rolls was calculated, it matched the actual degree of work with each roll determined from the bite test. On the other hand, what can be practically specified in order to minimize the residual machining stress is the maximum machining degree Kin on the entry side and the machining degree Kout on the exit side, as is clear from equation (2). By specifying the exit side working degree and obtaining the above working degree for each plate thickness and yield point stress, the rolling reduction value Hi on the entrance and exit side during roller straightening.
n, Hout are calculated using the above-mentioned formula for calculating the degree of machining during straightening [IQ (1
1) Determined from {3'.

The results are shown below (see Figure 8). {11 When the maximum machining degree Kin on the inlet side and the machining degree Kout on the exit side are specified, Hin=T day Hin for the inlet side rolling value Hin and the exit side rolling value Hout during straightening to obtain the above machining degree
......(12) Hout=T-HHout
…．・．． ...(13).

However, T is the plate thickness of the strip plate, and HHin and HHout are the cutting amount. The killing amounts HHin and HHout are determined by the following equations. HHin=mo(T,YP) ・・・・・・--・
(14-1) = a, T + Volume 10 - T Shibuichi 10 T Tametsubo - also
．．・・・． ...(14-2) HHou
t=f3(T, YP) ......(15-
1) = qT Juki - Ashiju Furuichi Tzuichi - b6
．． ．．・．． ．． - (15-2) a, ~ and b, ~ are constants determined by the above working degrees Kin and Kout, and YP is the yield point stress.

■ Regarding the relationship between the processing degree Kin, Kout and the straightening reaction force P, P=BXTmain XYPCk ‐‐‐‐‐‐‐‐‐‐(1
6) However, Ck in equation (16) is the processing degree Kin
, Kout, where B is the plate width, L is the roll pitch, and T is the plate thickness.

In the present invention, the processing degree Kin, Kout, the constant Ck of the edge U,
is held. {3} Regarding the jumping child SB due to the corrective reaction force P, SB = f4 (P, B)...
・・・・・・・・・(17) SBnie e. P 10 e2 Hei 10 e3 (
e4-B) P10e5. ．．・．． ．． ...(18) However, e
, ~e5 are constants, and B is the plate width.

Therefore, the input side set reduction value HI and exit side set reduction value HO to obtain the specified maximum machining degree Kin and exit side machining degree Kout are HI=Hin-SB (
19) Sun.

It is determined by NiHo Yamaichi SB (20). Therefore, by giving the plate thickness T, the plate width B, the yield point stress YP, the desired maximum machining degree Kin on the entry side, and the machining degree Kout on the exit side, the amount of cutoff can be calculated using equations (14) and (15). HHin and HHout are calculated, and from equations (12) and (13), the entry side rolling reduction value Hin and exit side rolling reduction value Hout during roller straightening to obtain the above working degrees Kin and Ko mountain are calculated, and the following equation (16) is calculated. The correction reaction force P is calculated from Equation (17) or Equation (18), and the jump black SB is calculated from Equation (19) and Equation (20). Inlet and outlet set pressure reduction values m
, HO are calculated.

The maximum machining degree Kin on the input side and the machining degree Kout on the exit side are calculated in advance as the machining degrees to obtain a uniform strip having a good shape and a minimum residual internal stress, and are kept and given.

Specifically, specify the working degree Kin and Kout, further specify the plate thickness T and the yield point stress YP, and calculate HHin and HHout by using equations (14) and (15), and calculate the Shoshita value date. 1. Find HO, find the rolling reduction value hi for each roll from this, find the degree of work Ki for each roll from equations 00, (11), and '3', and find the residual internal stress using equation ①. Then, find the Kin and Ko mountains where the residual internal stress is the maximum of 4. Note that at least Kj must be 1 to ensure flatness. As described above, in the present invention, the maximum machining degree Kin on the entry side, the machining degree Kout on the exit side, and the plate thickness T of the strip plate have a good pre-existing shape and a uniform minimum internal residual stress.
, plate width B, and yield point stress YP are given as information,
The rolling reduction setting to obtain the above working degree can be automatically performed.

If the strip is passed through the strip at the input and exit side set reduction values m and HO calculated as described above, then the shelf support rolls can be operated by looking at the shape of the exit side as in the conventional reduction setting method. It is possible to obtain a small strip with good residual internal stress and a good shape without operating the exit side reduction.

For strips produced in the continuous hot rolling process, the yield stress may vary depending on the cooling temperature and other components, and the thickness may vary between coils due to the thickness control performance, so the stress and/or thickness may deviate from the target value. However, the information given to the leveler will give the above target value. In order to absorb the deviation between this target value and the strip that is actually straightened, when the strip is passed through with the above roll-down setting and the tip of the strip is released from the exit side of the roller leveler, the following roll-down setting value is applied. Make corrections. That is, the correction reaction force is detected, and the parallel correction of the input/output side set pressure reduction value is performed based on the deviation from the calculated correction reaction force. Furthermore, when the tip of the strip discharged from the exit side of the roller leveler lands on the rear table, the input/output side rolling reduction value is corrected for parallelism based on the deviation between the actual motor power and the predicted calculated motor power, and then the rear surface of the roller leveler is specified. The plate height of the strip is detected at the position, and the exit side reduction is corrected to reach the target plate height.The reduction value is repeatedly corrected until the motor power deviation and plate height deviation each converge within the specified range. Let's do it.

The relationship between machining degree and motor power is as follows.

N=Tatatsuri Yoshimi's Poison 2Kp+△N----- (21
) However, N is the required power, V is the threading speed, E is the longitudinal elastic modulus,
ri is the mechanical efficiency, n is the number of rolls, Ki is the machining rate of the i-th roll, △N' is the no-load power, and the above ZKp is almost constant even if the plate thickness T and yield point stress YP change. Therefore, it is held as a constant for each of the input side maximum machining degree Kin and the output side machining degree KoM.

On the other hand, the input side maximum working degree Kin and the exit side working degree Kout are specified (the normal working degree Kout is Kout = 1, and the strip has a flat shape), and the reduction setting can obtain the working degree. If it is, the strip discharged from the roller leveler is flat, and the surface of the discharge angle of the strip is determined by n of out= from the equation (2).

of a specific angle.

FIG. 9 shows a state in which the strip is discharged at the ut and the tip of the strip lands on the rear table. At this time, the height W of the strip at the x position on the rear surface of the roller leveler is set to 0 since the rear tension F shown in the figure is small. heat (ship)
So) (X-So). ...(26) However, 1 is the second moment of area, D is the load per unit length, and E is the longitudinal elastic modulus of the strip.

Here, the skin of the limiting condition x=0, (dW/dx)x=o=,
Wx=o=0, x; evening, (dW/blood) x=gu=0, Wx
The deflection curve with = soni 0 is 〆 = 3 no 2nd place 1's melon t/D (27), and w = saddle (x-
2-so) (x-groove (Koichi 3Z) (X-so) ......(28) is obtained.

In other words, the flatness of the strip, the degree of work on the exit side, or the accuracy of the exit side rolling reduction setting can be confirmed by the height of the plate at a specific position on the rear surface of the roller leveler. That is, the set reduction value of the present invention is corrected by the same amount on both the entry and exit sides so as not to destroy the working degree pattern, which is important in terms of residual processing stress given in the initial reduction setting.

On the other hand, in order to ensure the degree of work on the exit side, which is important for the shape of the strip on the exit side of the roller leveler, the exit side rolling reduction value is corrected according to the plate height deviation on the exit side of the roller leveler. In addition, in order to ensure the exit side workability, which is important for the strip shape, without destroying the workability pattern, which is important for residual machining stress, the parallel reduction is corrected by the motor power deviation, and the exit side reduction is corrected by the plate height deviation mentioned above. This is alternately repeated until the motor power deviation and plate height deviation each converge within a predetermined range.

Hereinafter, an embodiment of a reduction control device for a shibler implementing the method of the present invention will be described with reference to FIG. 10. 12 in the drawing
1 is a roller leveler, 13 and 14 are load cells installed on the leveler 12 to detect the correction reaction force P, 15 is a motor that drives the third group of upper work rolls and the second group of lower work rolls of the leveler 12, and 16 is a motor that drives the third group of upper work rolls and the second group of lower work rolls of the leveler 12 A tacho generator that detects the rotation of the motor 15 and the sheet passing speed V; 17 is a shibler 12;
This is a plate height detector for the strip plate 1 placed on the rear surface of the plate. Note that the symbols indicating other components of the roller leveler 12 are the first
Shows the same thing as the figure. Further, 20 is a setting device, and the setting device 20 includes the plate thickness T, plate width B,
A target maximum machining degree Kin on the input side and a machining degree Kout on the exit side (specifically, Kout=1) are set, aiming at the yield point stress YP, the flatness of the strip 1, and the uniformity of internal residual stress.

21 is a motor power calculator that calculates the required motor power Nc [Kw] using equation (21) using the set plate thickness T, plate width B, stress YP and the above-mentioned workability Kin and Ko mountain; 22 is the above-mentioned motor power calculator; Setting values T, B, YP, Kin, Kou
t, a corrective reaction force calculator that calculates the required corrective reaction force Pc according to equation (16); 23 is the set value T, B, YP,
It is a rolling reduction value calculator that calculates the rolling reduction values Hin, Hout on the input and side sides using Kin, Kout and equations (12) to (15), and 24 is the maximum machining degree Kin on the input side and the machining degree K on the exit side.
The extrusion angle of the strip 1 when the rolling reduction setting to obtain the o-mount is properly set.

Find ut using equation (23), and calculate the angle. A plate height calculator which calculates the reference plate height Wc at the set position of the plate height detector 17 from equations (27) and (28) using ut; 25 and 26 are the above calculators; Equations (18), (19), and (20) are calculated using the input and exit side reduction values Hin and Hout from 23 and the correction reaction force P from the arithmetic unit 22.
From the equation, 27 is a calculator 21 for input side and outlet set pressure reduction values that calculate the input side set pressure reduction value day 1 and the output side set pressure reduction value HO.
The required motor power Nc is compared with the actual motor power N of the motor 15 from the actual motor power calculator 31, and the parallel reduction correction value △ day at which the actual motor power N changes to the required motor power Nc is determined by this power deviation AN. 28 is a parallel reduction correction value calculator that calculates the plate height detector 17
The twisted plate height W and the reference plate height W from the plate height calculator 24
This is a comparator that calculates the deviation ΔW from the reference plate height Wc and outputs an exit side reduction correction signal until the reference plate height Wc is reached. Also 29,30
is an input/output side roll lower layer control device, and an input side set roll reduction value calculator 25, a load cell 13, and a parallel roll reduction correction value calculator 27 are connected to the input terminal of the input side roll lower layer control device 29. . The input terminals of one of the control devices 30 include an output set pressure reduction value calculation 26, a load cell 14, and a parallel reduction correction value calculation unit 2.
7. The comparator 28 mentioned above is connected. The operation of the above control device will be explained below.

First, before passing the strip 1, the thickness T, width B of the strip 1 to be processed,
A target maximum machining degree Kin on the input side and a machining degree Kout on the exit side are set to be 1, aiming at the yield point stress YP, the flatness of the strip plate 1, and the uniformity of internal residual stress. Motor power calculator 2
1 is the required motor power Nc based on equation (21)
[Kw], the correction reaction force calculation unit 22 calculates the required correction reaction force Pc based on equation (16), and the reduction value calculation unit 2
3 calculates the reduction values Hin and Hout on the inlet and outlet sides based on equations (12), (13), (14), and (15), and the plate height calculator 24 calculates the roll-down values of the strip plate 1. of angle. u
Find t using the above equation (23), and use the skin of the angle to calculate the (2)
7) Calculate the reference plate height Wc at the arrangement position of the plate height detector 17 from equations (28). The inlet side and outlet set reduction value calculators 25 and 26 calculate the correction reaction force Pc given from the calculators 22 and 23, and the input and outlet side reduction values Hin, Ho.
ut and the formulas (18), (19), and (20) above, calculate the input side and output side set pressure reduction values day 1 and HO, and then calculate the above calculation unit 2.
5 supplies the roll-down value HI to the roll-down layer control device 29 as a position reference signal, and the arithmetic unit 26 supplies the roll-down value HO to the roll-down layer control device 30 as a position reference signal. Each direct control device controls the roll-down values on the inlet and outlet sides of the roller leveler via the motor 10, gear 9, and screw 8 to the above-mentioned roll-down values m and HO.
When the first setup is completed, the strip 1 is passed through the roller leveler, and when the tip of the strip 1 is detected by the plate height detector 17, the load cells 13 and 14 are first set. The actual correction reaction forces Pi and Po are applied to the rolling lower layer control devices 29 and 30, respectively, and the actual jump amount due to the above-mentioned actual positive reaction forces Pi and Po is calculated using equation (13), and the previous first setup is performed. A signal is given to the motors 10, 10 to correct the roll reduction value by the difference from the jump amount calculated at the time.

When the above-mentioned jump amount correction control is completed, the actual motor power calculator 31 calculates the motor 15 that drives the correction roller.
The actual motor power N [Kw] at the reference line speed is calculated by taking in the current, voltage, and line speed from the tacho generator 16, and provides it to the calculating unit 27.

The arithmetic unit 27 compares the motor power Nc [Kw] given from the arithmetic unit 21 to find the motor power deviation △N, and from this power deviation △N [Kw], the actual power N
Corrected reduction value △ where [Kw] becomes calculated power Nc [Kw]
Set the date and send the above pressure reduction value △ to the pressure lower layer control devices 29 and 30.
It only corrects the pressure and gives a positive signal for the substratum eruption. As a result, the rolling reduction values on the input and output sides are corrected in parallel by △ days. Reduction value △ required to cancel the above motor power deviation △N
The dates are as follows:

The amount of change in motor power △N when the parallel pressure is reduced by the Shoshita value △day is calculated from the multiple regression equation, △N=ETsuruseiko Shizukuhigemi 6.

[Zaju (g・10g2・T+zu・YP)-T-△H]
‐‐‐‐‐‐‐‐‐‐(29). Naozu, g1,
g2 and z are constants. From formula (29), the optimal corrected reduction value △day is △H=[△N-f6(T, YP, V)]/f7(
T, YP, V) ・・・・・・
Find it using (30).

When this parallel reduction correction is completed, the plate height position detector 17
The plate height W of the strip plate 1 is taken in, and the comparator 28 calculates △W.
=Wc-W is given to the pressure lower layer control device 301 on the output side.
As a result, the control device 30 corrects the reduction value on the exit side until lΔWIMIG is reached. For example, let G=2.5.
When this correction is completed, first, the actual motor power N after the reduction value has been corrected is compared with the calculated power Nc in the calculator 27, and it is checked whether the power deviation AN is in the relationship IANI≦Q, and the power deviation △ If N is l△NI≦Q, then
Input and exit side corrections due to power deviation △ are not executed,
Also, no correction is made based on the plate height deviation ΔW. On the other hand, if the power deviation △N is not l△NI≦Q, the calculator 27 outputs the input/output side reduction correction value AN to the control devices 29 and 30 based on the power deviation △N. When this parallel reduction correction is completed, the calculator 28 detects the plate height W from the plate height position detector 17.
First, calculate the board height deviation △W, and then calculate the IAWIS
It is confirmed whether the relationship G is satisfied, and if the relationship is satisfied, the output side shoroshita correction by the plate height deviation ΔW is not performed. On the other hand, if the above relationship does not exist, the exit side reduction is corrected by the plate height deviation ΔW. Thereafter, the process is repeated until the power deviation and plate height deviation of the same machine are each converged within predetermined values. Once converged, no reduction correction is performed for the same strip. For example, the above Q uses 0.0 mark c. Figure 11 shows a strip with a thickness of 9 ribs and a width of 1.5 strips, which is corrected in shape with a roller leveler, cut into 3 lengths, and then cut into 4 to 6 strips as shown in Figure 5. This shows the distribution of the sum of the maximum height values max of the L sliding value. A distribution is the distribution of B when the input and exit side rolling reduction values are set using the conventional rolling method and the auxiliary roller is operated. The distribution is when the strip is plated by setting the roll reduction value on the entry and exit sides using the roll setting method of the present invention, and the C distribution is when the parallel roll correction is performed using the straightening reaction force after the roll reduction is set using the method of the present invention. After setting the roll reduction using the method of the present invention, the D distribution is adjusted using the straightening reaction force, and then the parallel roll reduction is corrected using the motor power deviation and the plate height deviation until the plate height deviation and motor power deviation respectively converge within the specified ranges. The distribution of the maximum height value of the L-slip value when the exit side reduction correction is repeated is shown.

Since the L shear value after strip cutting indicates the residual stress in the strip, it is more effective to set the shoroshita using the reduction setting method of the present invention and perform shibbling alone, compared to the conventional method. is clear.

In addition, if the rolling reduction is corrected based on the plate height deviation and motor power deviation, it is possible to keep it within the range of ±2 degrees, which is the same as a rolled steel plate without a rib (a steel plate that is not rolled up by a coiler).

As described above, according to the shingling method of the present invention, it is possible to obtain a uniform strip with minimum internal residual stress even if the shape is good, and it is extremely effective in straightening the strip.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a roller leveler, Fig. 2 is a model diagram showing the deformation process of a strip by a roller leveler, Figs. 3 and 4 are explanatory diagrams of the conventional rolling reduction setting method, and Fig. 5
The figure is an explanatory diagram of the occurrence of L warpage after stripping, and Figures 6, 7, and 8 are explanatory diagrams of how to calculate the processing degree of the strip during straightening.
Fig. 9 is an explanatory diagram of the state of the strip at the outlet side of the roller leveler, Fig. 10 is an explanatory diagram of the roller leveler implementing the straightening method of the present invention, and Fig. 11 is an explanatory diagram of the effect obtained by implementing the method of the present invention. It is an explanatory diagram. 1... Band plate, 2... Lower work roll, 3...
...Top work roll, 4...Backup roll, 5
...Auxiliary roller, 6...Cylinder, 7...
...Top girder, 8...Down screw, 9...Gear, 10...Electric motor, 1
1...Leveler stand, 12...Roller leveler, 13, 14...Load cell, 15...Work roll drive motor, 16...Evening co-generator,
17...Plate height detector, 18...Tip detector, 20...Setting device, 21...Motor power calculator, 22...・Correction reaction force calculator, 2
3...Reduction value, 24...Plate height calculator, 2
5...Inlet side set pressure reduction value calculator, 26...
- Output side roll reduction value calculator, 27... Parallel roll reduction correction value calculator, 28... Comparator, 29... Inlet side roll reduction direct control device, 30... Outlet pressure lower layer control device. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 11 Figure 10

Claims (1)

[Claims] 1. In a method of leveling a strip using a roller leveler equipped with a mechanism for adjusting rolling reduction values on the inlet and outlet sides, the strip plate has a preset shape with a good and uniform minimum internal residual stress. The maximum machining degree Kin on the input side and the machining degree Kout on the exit side to obtain the strip,
Based on the strip thickness T, strip width B, and yield point stress YP, the optimal setting reduction values HI and H for the input and output sides are determined in steps 1 to 5 below.
A method for leveling a strip using a roller leveler, the method comprising calculating O, setting the rolling reduction values HI and HO, and passing the strip. 2 In a method of leveling a strip using a roller leveler equipped with a mechanism to adjust the rolling reduction value on the input and exit sides, the input side is used to obtain a strip with a good preset shape and uniform internal residual stress. Based on the maximum working degree Kin, the exit side working degree Kout, the strip thickness T, the sheet width B, and the yield point stress YP, the optimum setting reduction values HI and HO for the input and output sides are determined in steps 1 to 5 below.
is calculated, the rolling reduction values HI and HO are set, and the strip is passed through. When the tip of the strip is released from the exit side of the roller leveler, the actual straightening reaction force P is detected, and the actual straightening reaction force P is detected. A method for leveling a strip using a roller leveler, characterized in that the reaction force deviation ΔP from the predicted correction reaction force Pc is determined, the jump amount ΔSB is calculated based on the deviation ΔP, and the rolling reduction values on the input and exit sides are corrected. . 3 In a method of leveling a strip using a roller leveler equipped with a mechanism to adjust the rolling reduction value on the input and exit sides, the input side is used to obtain a strip with a good preset shape and a uniform minimum internal residual stress. Maximum machining degree Kin, exit side machining degree Kout,
Based on the strip thickness T, strip width B, and yield point stress YP, in steps 1 to 5 below, determine the optimal set reduction values HI and H on the inlet and outlet sides.
In addition, in Step 6 below, the required power Nc for leveling is calculated, and in Steps 7 and 8 below, the height Wc of the strip from the table at a specific position on the exit side of the roller leveler is calculated. , with the rolling reduction values HI and HO set, the strip is passed through, and the actual straightening reaction force P at the time when the tip of the strip is released from the exit side of the roller leveler is detected, and the predicted straightening reaction force Pc is calculated. The deviation ΔP is calculated, the jump amount ΔSB is calculated based on the deviation ΔP, the rolling reduction values on the input and exit sides are corrected, and after the correction is completed, the actual load N of the drive motor of the roller leveler is detected, and the load is Adjust the rolling reduction value on the input and exit side so that N is equal to the above required power Nc, then detect the height W of the strip at a specific position on the exit side of the leveler, and check that the height W of the strip is equal to the above board height. The above power Nc should be adjusted to correct the rolling reduction value on the exit side so that
and the actual load N, and the difference between the plate height Wc and the actual plate height W are alternately repeated until each converges within a predetermined range. Step 1 The straightening reaction force P is expressed by the following equation: strip thickness T, strip width B, roll pitch L, yield point stress YP
It is determined based on the relationship between the processing rates Kin and Kout, and a constant Ck determined by the processing degrees Kin and Kout. P=(B×T^2×YP)/LCk Step 2 Machining degree Kin, Kout on the entry and exit sides
The inlet and outlet side kill amounts HHin and HHout are determined by the functions of plate thickness T, yield point stress YP, and constants a_1 to a_6 and b_1 to b_6 expressed by the following formula. HHin=f_2(T,YP)=a_1T+(a_2)
/YP+(a_3)/T-(a_4)/(T×YP)+
(a_5)/(T×YP^2)-a_6HHout=f
_3(T, YP)=b_1T+(b_2)/(YP)-
(b_3)/T+(b_4)/(T×YP)−(b_5
)/(T×YP^2)-b_6 Step 3 Enter above,
The rolling reduction values Hin and Hout on the exit side are determined by the plate thickness T using the following formula.
, is determined from the killing amounts HHin and HHout. Hin=T-HHin Hout=T-HHout Step 4 The jump amount SB due to the straightening reaction force P is expressed by the following formula: the straightening reaction force P, the plate width B, and the constant e.
Determined by the functions _1 to e_5. SB=e_1P+b_2P^2+e_3(e_4-B)
P+e_5 Step 5 Previous entry, exit side reduction value Hin
, Hout by subtracting the jump amount SB as shown in the following formula to determine the optimal set pressure reduction values HI and HO on the input and output sides. HI=Hin-SB HO=Hout-SB Step 6 Strip plate thickness T, plate width B, yield point stress YP
The required power Nc of the drive motor of the roller leveler is determined by the following functional formula expressed by the plate threading speed V, the constant Σ Kp determined by the processing rates Kin and Kout, the modulus of longitudinal elasticity E, the mechanical efficiency η, and the no-load power ΔN. Nc=(B×T×YP^2×V)/(E×η×60×1
02) ΣKp+ΔN Step 7 The ejection angle φout of the strip on the exit side of the roller leveler is expressed by the following relationship expressed by the leveler's roll radius r, inter-roll distance S, plate thickness t, contact angle φi+1, φi, and rolling reduction value hi. Determined from the formula. φi+1=φi+2tan^-^1{((2r+t)c
osφi-2r-hi)/(S+(2rt+t)sin
φi)} Step 8 Set the height Wc of the strip from the table at the specific position on the exit side of the roller leveler to the angle φ
out, height W of the strip at the X position on the rear surface of the roller leveler, position l of the tip of the strip landing on the rear table, load D per unit length, longitudinal elastic modulus E of the strip, quadratic cross-section It is determined by the following functional formula consisting of moment 1. W=(φoutX)/(2l^2)(X-2l)(X-
l)-(DX^2)/(48EI)(2X-3l)(X
-l)