JPH0133246B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a camber control method in thick plate rolling. Conventional camber control has been performed using various known camber measurement devices during metal-off of rolled material.
Most of the methods were simple, in which the left and right roll openings were set up with an appropriate difference based on the average camber amount and camber curvature of the entire length of the plate until the next pass biting. Recently, in addition to this method, a method has been disclosed in which the amount of meandering and its changes after the material has been bitten is grasped and reflected in the control (Japanese Patent Application Laid-open No. 88914/1983). However, these methods do not allow complete control of the camber. This is because the camber that actually occurs is not uniform in the longitudinal direction of the rolled material, as shown in Figure 1, which shows an example of the distribution of camber in the plate length direction.
This is because the curvature often differs considerably between the rear end, especially about 1/5 of the total length, and the center. However, in the conventional method, the initial roll opening degree is calculated and set based on the average camber amount or average camber curvature for the entire length or the length that can be detected by a sensor, and after biting, the approach angle to the rolling mill and the meandering change due to meandering. Compared to the previous open-loop control, which merely attempts to control the left and right roll opening degrees by speed, the closed-loop control as in the above-mentioned Japanese Patent Application Laid-Open No. 55-88914 is an improvement, but rolling We deal with the realities such as the fact that materials generally do not have a uniform camber in the longitudinal direction, and the amount of off-center at the biting end when biting into a plate rolling mill is not always zero. However, it still wasn't enough. The main purpose of this invention is to solve these drawbacks. As mentioned above, as a method to deal with the off-center amount of the biting end during biting and the non-uniform distribution of camber in the longitudinal direction, which are not taken into consideration in conventional camber control, firstly, the biting edge during biting is always Although it is possible to match the pass center of the plate rolling mill roll, including in this case, the off-center amount and off-center amount within the roll bit from the time the rolled material is bit into the plate rolling mill until the time when it is pulled out. In controlling the roll opening degree with respect to the speed of change, it is necessary to express the state at the time of biting (for example, the left and right rolling loads and their rate of change over time) as X, and to capture the relative change ΔX from this state. By detecting this relative change ΔX at regular time or constant distance intervals, the off-center amount ΔX _1i within the roll bite of the plate material at any given time ti and the temporal change rate ΔX _2i of the off-center can be determined. As a result, the left and right roll opening difference ΔS _1i that corrects the left and right plate thickness difference ΔH _1i caused by off-center is calculated using the following formula ΔS _1i = f(ΔH _1i , W, ΔX _1i , K _MW , K _MD , Q _W ,
Q _D ) ...(1) where W: plate width, K _MW : working side mill rigidity,
K _MD : Drive side mill rigidity, Q _W : Working side plastic constant,
Q _D : Driving side plastic constant, expressed as ΔS _1i and its time derivative ΔS _2i =
The basic idea of the present invention is to calculate dΔS _1i /dt at fixed intervals or fixed distances, and to control the left and right roll openings based on this. ΔS _2i is used to increase the responsiveness of the control system and improve the stability of the system. By the way, in a reversible thick plate rolling mill, after the rolled material is pulled out, the amount of kick-out at the pulled-out end is made as small as possible to minimize the idle time between passes. Therefore, as shown in Fig. 2, which shows the conventional camber measurement procedure, a certain distance λ from the edge e of the rolled material w extends beyond the measurement range of the camber measuring instrument, and this is conventionally ignored and generally ignored. In reality, the average camber amount and camber curvature are actually measured during metal-off, and based on these measured values, the next pass roll opening of the plate rolling mill is corrected to allow the material to bite. In the figure, # ₁ is a width gauge, # ₂ , # _{3, .} . . are sensors that constitute a camber measuring device including the # ₁ width gauge, R is a plate rolling mill roll, and T is a roller table. In this way, the camber control accuracy is forced to decline over a certain distance λ from the biting end of the next pass of the rolled material w, and furthermore, because of the off-center of the biting edge width, the initial camber correction becomes insufficient, and thus The absolute amount of off-center after the metal-in of the material cannot be accurately determined, resulting in disadvantages such as problems in controlling the camber that occurs during the metal-in. This invention places emphasis on these points, and first
A certain distance λ between the leading and trailing ends of the rolled material w as shown in the figure
In addition to accurately measuring the uneven camber at The rolled material w is moved in the width direction so that the width center of the next pass biting end coincides with the pass center of the rolling mill roll. In this case, if the initial left and right roll opening degrees are properly set and the off-center amount is detected after the off-center amount is detected with the off-center amount of 0 as a reference at the time of biting, it represents the absolute value of the off-center amount. Therefore, as described above, it is possible to control the roll opening degree based on the change in the amount of off-center and the rate of change in the off-center, and the problems in the conventional camber measurement described above can be more easily solved. Next, in order to properly calculate and set the initial left and right roll opening degrees, the kick-out after the rolled material w has been bit out in each pass from the pass immediately before the start of rolling scheduled as a canvas control target to the final pre-pass. The length of the rolled material is adjusted so that the edge e of the rolled material extends in the camber sensor until it passes through a width gauge located closest to the rolling mill on at least one of the front and rear surfaces of the plate rolling mill. The rolled material w is once additionally sent onto the roller table, and from this state the rolled material w is conveyed by the roller table parallel to the pass center of the plate rolling mill until it is bitten by the pass, so no operations are required during this time. Otherwise, the off-center amount at the width center of the next pass biting end should be the same as the off-center amount at the width center of the previous pass biting end when the previous pass biting end passes the width meter. Therefore, in this way, the amount of off-center during the next pass biting can be predicted and used as a factor for camber control, or the side guide on the roller table attached to the plate rolling machine can be operated according to the amount of off-center. , it is also possible to set the off-center amount of the biting end to 0 during the next pass biting. Also, as mentioned above, from the previous pass biting to the biting end e
Since the rolled material w is sent parallel to the pass center of the plate rolling mill even while passing the width gauge, it is sufficient to measure the camber amount and camber curvature over a range of a certain length λ at the biting end of the next pass during this time. It is possible. Therefore, based on the above-mentioned camber amount and camber curvature, the initial opening degree of the left and right sides of the plate rolling mill rolls at the time of biting in the next pass can be calculated as the difference in the left and right roll opening degrees necessary to correct this, according to known technology. . To be sure, the camber amount and camber curvature over the entire length of the rolled material w, including approximately 1/5 of the total length from the biting end in the next pass, are measured by optical or mechanical contact or non-contact. Various known sensors can be used. To summarize the above points, the present invention provides a camber measuring device consisting of a plurality of sensors including a width gauge, the width gauge is located closest to the rolling mill on at least one of the front and rear surfaces of the rolling mill. When rolling thick plates using a reversible plate rolling machine equipped with
When the rolled material is pulled out from the thick plate rolling mill, the rolled material is once additionally fed out onto the roller table until the rolled material passes through the width gauge, and during this time the rolled material is When the biting end approaches the plate rolling mill again, the off-center amount in which the width center of the rolled material deviates from the pass center of the plate rolling mill is controlled at least from the pass immediately before the start of rolling until the final pass where camber control is performed. Furthermore, depending on the amount of off-center, the amount of off-center can be reduced to zero by using a side guide that is placed in front or behind the plate rolling mill and controls the widthwise position of the rolled material. During the rolling of the rolled material from the plate rolling mill, when there is the above-mentioned additional delivery, the signals from the camber measuring device are used to control the length of the rolled material over the entire length of the rolled material. Equipped with a roll-down control device that can independently adjust the opening degree of the plate rolling mill rolls on the left and right sides according to the output of the device that controls the calculation of the camber amount and camber curvature for each section. Based on the camber amount and camber curvature for each length division range, the left and right roll opening degrees are set up during the next pass biting, and after the rolled material is metal-in to the plate rolling mill until metal-off, The left and right roll opening change signals in response to changes in the camber amount and camber curvature in the longitudinal direction of the rolled material, the left and right roll opening change signals in response to changes in the off-center amount after metal-in, and the off-center amount itself. Comprehensive left and right roll opening control that combines a left and right roll opening signal necessary to cancel the left and right plate thickness difference with a temporal change signal of the left and right roll opening difference that corresponds to the temporal change rate of the off-center amount. This is an attempt to solve the above-mentioned problems by combining this with other activities. The present invention is characterized in that the amount of camber at the end of the rolled material over a length corresponding to about 1/5 of the total length is particularly large from the end of the rolled material, and that the camber amount of the end portion of the rolled material is particularly large. Conventionally, the width gage located closest to the plate rolling mill was separated from the width gage to suppress the amount of kick-out of the rolled material, and the trend of the edge of the edge was not considered as a camber control factor. It can be directly reflected in camber control, and furthermore, it can be advantageously used to align the pass center of the plate rolling mill roll with the width center of the rolled material, and furthermore, it can be applied to any part of the total length of the rolled material. This is derived from the fact that it is more effective to measure the camber amount and camber curvature for each time, and apply individual camber control corresponding to them. Examples of this invention will be described. A plate rolling mill is shown on the left side of Fig. 3a, 1 is an upper reinforcing roll, 2 is a lower reinforcing roll, 3 and 4 are upper and lower work rolls, respectively, and 5 and 6 are on the working side and the driving side, respectively. Hydraulic reduction cylinders are individually arranged; 7 and 8 are rolling load detectors (load cells) which are also individually arranged on the work side and the drive side, respectively;
9 is an adder that calculates the sum of rolling loads P _W and P _D , with subscripts W and D representing the working side and the driving side; 1
0 is an adder that calculates the difference between rolling loads P _W and P _D , and 11 is an adder that calculates the difference between the rolling loads P W and P D. ), this is a device that outputs a metal-in or metal-out signal in accordance with the metal-out judgment reference loads P _MI and P _Mp . In addition, 12 surrounded by a broken line in the same figure is a signal processing device that operates according to the metal out signal, 13 is a left and right roll opening difference calculation circuit at the time of next pass biting, and 14 is a reduction control device. 15 indicated by a broken line
1 is a side guide operating device, and 16 is a roller table forward/reverse control device. In the figure, , , are output signals, and G indicates a gate, indicating that the process proceeds when conditions are met. First, to explain the control procedure for the amount of off-center, after metal-out of the rolled material w is detected in each pass from the pass before the start of the camber control pass to the final pre-pass, the rolled material w is moved directly to the chewing direction. # ₁ Send additionally until it passes the width meter. During this time, the rolled material w
can be assumed to move approximately parallel to the center of the path of the roll of the plate rolling mill on the table roller, so the detection signal obtained from the # ₁ width gauge is processed to determine the value from the plate rolling machine at the point of metal out. While reaching the # ₁ width gauge, the camber amount C _I corresponding to the plate length range represented by I is calculated, and the off-center amount of the width center at the end of the bite, that is, the end of the next pass bite, is detected by the # ₁ width gauge. It is predicted from the off-center amount of the width center, calculated by the signal processing device 12, and outputted to the left and right roll opening degree difference calculating device 13 and the side guide operating device 15 respectively at the time of next pass biting. Based on the camber amount C _I, the left and right roll opening difference calculation device 13 at the time of next pass biting calculates the calculation result ΔS _I
is output to the reduction control device 14. On the other hand, if necessary, based on the predicted output of the off-center amount at the biting end of the next pass, the side guide control device 15 controls the front or rear of the plate rolling machine so that the off-center of the biting end becomes 0 during the biting of the next pass. drive the left and right side guides on the roller table. In addition, in this embodiment, a case was shown that is more advantageous than operating the side guide so that the biting end off-center amount becomes 0, but this operation system is omitted, and therefore the biting end off-center amount is 0
Even if this is not the case, it goes without saying that there is no problem in measuring the off-center amount at the time of biting as described above and correcting the difference in the left and right roll opening degree at the time of biting based on the measured amount. Based on the completion of setting the left and right roll opening difference setting by the reduction control device 14 and the side guide control side completion signal, the rolled material w is sent forward or reversed to the plate rolling mill using the roller table and the forward/reverse control side device 16. , the next pass of rolling is started. At this time, the control command REF is sent from the reduction control device 14.
is connected to the left and right hydraulic lower cylinders 5 and 6 via piping B.
The actual position of the cylinder is output as a command to raise or lower the cylinder, and the actual position of the cylinder is input as an answer back to the reduction control device 14 via the pipe C as a feedback signal FBK. Next, regarding the camber control after the rolled material is metal-in, the command from the metal-in signal output device 11 for that metal-in is as follows:
The subtraction output ΔP of the adder 10 is input as follows to the left/right reduction correction amount calculator 17 and the load difference temporal change rate calculator 18 shown in FIG. 3B. In other words, assuming that the thickness distribution in the width direction on the entrance side of the next pass is uniform, the difference in rolling load ΔP _p between the left and right sides at the time of biting in the next pass is due to the difference in the initial roll opening degree ΔS _I (temporarily ΔP _p ′ However, if ΔP _p ≠ ΔP _p ′, then ΔP _p −ΔP _p ′=ΔΔP _p assumes that the thickness distribution in the axial direction on the entrance side of the next pass is uniform as described above. This is because what I did was wrong. From this ΔΔP _p , I can calculate the width direction distribution of the entry side plate thickness (in this case, the left and right plate thickness difference Δho). Based on this Δho, the left and right roll opening difference correction amount ΔΔS _p ' that corrects the initial setting ΔS _I , which was initially set to assume a uniform widthwise distribution of the entrance side plate thickness, is calculated by the calculator 17, and then Convey corrected output. As a result, the roll opening difference ΔS _I ′ after correction becomes ΔS _I ′=ΔS _I +ΔΔS _p ′. After the above correction is completed, the calculation unit 18 calculates the difference between the load difference ΔP _p at the time of metal-in and the subsequent ΔP, that is,
The temporal change rate of ΔΔP=ΔP−ΔP _p and ΔΔP, that is, d(ΔΔP)/dt, is calculated and output every moment (at a predetermined skinning time pitch). ΔΔP represents the change in the amount of off-center of the material after that, ΔX _1i , based on the metal-in time,
d(ΔΔP)/dt indicates the rate of change ΔX _2i of the amount of off-center after metal-in. Based on these ΔX _1i and ΔX _2i , ΔX _1i
In order to prevent the left and right plate thickness difference ΔH _1i that occurs in the left and right roll opening difference correction amount ΔΔS _I ″, a correction signal is output from the calculator 19 to the reduction control device 14 and added to the left and right reduction correction signal ΔS _I ′. . Also, ΔX _2i outputs a compensation signal by calculating 19 by differentiating the ΔΔS _I ″ and converting it into the form d(ΔΔS _I ″)/dt for the purpose of compensating the responsiveness of the control. Since the camber amount and shape of C are naturally different from the plate length range I, it is necessary to correct the roll opening difference set for the camber amount C _I in the plate length range I, which means that the subsequent camber amount C Assuming that _I ', the necessary roll opening difference ΔΔS _I ' is calculated by the calculator 20 in accordance with C _I' -C _I =ΔC _I , and a correction signal is output. A case in which the width center of the rolled material coincides with the pass center of the plate rolling mill roll and a case in which it is offset and off-center are shown, and the plastic constants are expressed as shown in Table 1.

[Table] In the case of Fig. 4a, both the plastic constants on the working side and the driving side are Q _p /2, but in the case of Fig. 4 b, 1/2 Q _p ±ΔX/WQ _p shown in Table 1. There is an imbalance as shown in the figure, and it is necessary to consider the factors shown in equation (1) first. Next, Figures 5a and 5b show the influence of the plastic constants Q _W , Q _D and mill rigidity K _M on the thickness difference in the width direction of the rolled material, and the horizontal axis of the figure shows the effect of the roll opening depending on it. Thickness trend, vertical axis represents rolling load P, fifth
According to the present invention, the difference in thickness between the left and right plates due to off-center as shown in FIG. 5A can be controlled to the target control thickness H _p as shown in FIG. 5B. Here, the set opening is S _p , and the openings of each roll with subscripts W and D distinguishing the working side and driving side are S _W and S _D. Regarding the mill stiffness K _M and the plastic constants Q _W and Q _D , , Left and right roll opening difference ΔS _W ,
ΔS _D is calculated using the following formulas (2), (3) ΔS _W = S _p −S _W = (1+Q _W /K _W ) (H _pW − H _p ) ……(2) ΔS _D = S _D −S _p = ( 1+Q _W /K _W ) (H _p −H _pD ) ...(3). Next, in Figure 6, the transition in the center of the width of the rolled material after metal out until the end of the roll passes the # ₁ width gauge is indicated by the X mark, and the amount of camber between approximately 1/5l from the end of the roll is indicated by the X mark. In the same figure, where the off-center of the protruding end is indicated by ΔX _I ,
The circle mark indicates how the center of the width of the edge of the roll was aligned with the center of the pass of the plate rolling mill roll by operating the side guide, and the amount of off-center was corrected to 0. Here is the plate thickness difference ΔH required to correct the end camber C _I
is expressed by the following formula ΔH=f(C _I , W, H _i , H _p ) ...(4), and the roll opening difference ΔS _I to give this plate thickness difference is expressed by the following formula ΔS _I = f(ΔH , H _i , H _p , K _MW , K _MD , Q _W , Q _P )
... is given by (5). In FIG. 7a, the working side and the driving side are distinguished by subscripts W and D. Mill stiffness is K _M = K _MW =
Roll opening difference ΔS _I to provide the necessary plate thickness difference when K _MD and the plastic constant is Q = Q _W = Q _D
can be determined according to the diagram. In addition, Fig. 7b shows similar left and right roll opening degrees S _D and S _W when Q _W ≠Q _D ≠Q (Q _W > Q > Q _D ).
It will be shown that the camber _{C I} can be similarly corrected by correcting the opening difference ΔS _I ′ such that the difference ΔS I becomes S′ _W and S′ _D shown in the figure. As described above, the present invention can effectively and appropriately control the camber of a thick plate.

[Brief explanation of drawings]

Figure 1 is a distribution diagram of camber in the plate length direction, Figure 2 is a plan view for explaining the conventional camber measurement procedure, and Figure 3 a.
is a block diagram showing the camber control procedure according to the present invention, FIG. 3b is a partial view of FIG. 3a, FIG. 4a,
b is a comparison diagram of the relationship between off-center and plastic constant, Figures 5a and b are correlation diagrams of rolling load, roll gap, and plate thickness, and Figure 6 is a diagram showing the relationship between rolling load, roll gap, and plate thickness. Figures 7a and 7b, which are diagrams illustrating the procedure for off-center correction using a guide, are correlation diagrams of the rolling load roll opening degree difference and plate thickness difference necessary for correcting the overhang end camber C _I.

Claims (1)

[Scope of Claims] 1. A reversible rolling mill in which a camber measuring device consisting of a plurality of sensors including a width gauge is provided on at least one of the front and rear surfaces of a rolling mill, with the width gauge being located closest to the rolling mill. When rolling a thick plate using a type plate rolling mill, when rolling the material from the plate rolling machine, the rolled material is placed on the roller table until the end of the rolled material passes the width gauge mentioned above. By once additionally sending out the material, during this time, when the feed end, that is, the next pass bite end approaches the plate rolling mill again, the off-center amount in which the width center of the rolled material deviates from the pass center of the plate rolling mill is reduced. , at least to perform camber control in each pass from the pass immediately before the start of rolling to the pass before the final rolling, and to also predict when there is the above-mentioned additional feed during the rolling material being pulled out from the plate rolling mill. The plate rolling mill roll opening is adjusted independently on the left and right sides according to the output of the device that calculates the camber amount and camber curvature for each arbitrary length section over the entire length of the rolled material using the signals from the camber measuring device mentioned above. From the next pass biting end,
Based on the camber amount and camber curvature for each range of arbitrary length divisions, the left and right roll opening degrees are set up during the next pass biting, and after the rolled material is metal-in to the plate rolling mill until metal-off. During this period, the camber amount in the plate length direction of the rolled material, the left and right roll opening change signal according to the change in camber curvature, the left and right roll opening change signal according to the change in the off-center amount after metal-in, and the off-center amount itself are generated. Comprehensive left and right roll opening is achieved by combining the left and right roll opening signal necessary to cancel the left and right thickness difference of the rolled material with the time change signal of the left and right roll opening difference that corresponds to the time change rate of the off-center amount. A camber control method in thick plate rolling comprising the following: 2. A reversible plate rolling mill that is equipped with a camber measuring device consisting of multiple sensors including a width gauge on at least one of the front and rear surfaces of the rolling mill, with the width gauge located closest to the rolling mill. When rolling a thick plate using a plate rolling machine, when pulling out the rolled material from the thick plate rolling machine, the rolled material is once additionally fed onto the roller table until the end of the rolled material passes the width gauge mentioned above. During this time, at least camber control is performed to reduce the off-center amount in which the width center of the rolled material is biased with respect to the pass center of the thick plate rolling mill when the biting end, that is, the next pass biting end reapproaches toward the thick plate rolling mill. The prediction is made in each pass from the pass immediately before the start of rolling to the final pass before rolling, and a side guide is installed at the front or rear of the plate rolling mill to control the widthwise position of the rolled material, depending on the off-center amount. to control the amount of off-center to zero by using the signal from the camber measuring device, and to control the amount of off-center to zero by using the signal of the camber measuring device, including when there is the above-mentioned additional delivery during the rolling of the rolled material from the plate rolling mill. A roll-down control device that can independently adjust the opening degree of the plate rolling mill rolls on the left and right sides according to the output of the device that controls the calculation of the camber amount and camber curvature for each length section, is installed from the next pass biting end. , to set up the left and right roll opening degrees during the next pass biting based on the camber amount and camber curvature for each range of arbitrary length divisions, and to prevent metal-off after the rolled material is metal-in to the plate rolling mill. Until then, the left and right roll opening change signals according to changes in the camber amount and camber curvature in the longitudinal direction of the rolled material, the left and right roll opening change signals according to the off-center amount changes after metal-in, and the off-center amount itself are used. A comprehensive left and right roll system that combines a left and right roll opening signal necessary to cancel the left and right thickness difference of the rolled material with a temporal change signal of the left and right roll opening difference that corresponds to a temporal change rate of the off-center amount. A camber control method in thick plate rolling comprising the following: controlling the opening;