Edge bending roller control method and system

Abstract

The present invention discloses an edge drop bending roll control method and system, which obtains the edge drop value at the outlet position of the upper frame of the cold rolling mill and the actual value of the edge drop bending roll force of the working roll of the frame, and obtains the adjustment amount of the edge drop bending roll force of the working roll of the frame; the edge drop bending roll force of the working roll of the frame realizes the dynamic control of the bending roll force of the cold rolling mill according to the adjustment amount. The present invention realizes the automatic control mode of the working roll bending roll during the rolling process, so as to give full play to the ability of the working roll bending roll in controlling the edge drop, improve the overall level of edge drop control of cold rolled products, and improve the quality level of the physical product.

Description

Technical Field

[0001] The present invention relates to metallurgical machinery / pickling rolling technology, and more particularly to an edge bending roll control method and system. Background Art

[0002] The edge drop of cold rolled products (Edge Drop, also known as edge thinning) is an important parameter of dimensional accuracy. Figure 1 As shown, the traditional definition of edge drop is the difference between the thickness tA at a distance of 100 mm from the edge and the thickness tB at a distance of 15 mm from the edge, that is:

[0003] Edge Drop=tA-tB

[0004] However, as users’ requirements for product quality continue to improve, the traditional definition of edge drop is no longer able to meet the requirements. It often happens that when the traditional Edge Drop control level fully meets the unit control requirements, it still cannot meet the user’s requirements for cross-section shape. Therefore, the concept of edge drop is currently extended to the same plate difference in cold rolling mills that produce high edge drop requirements, that is, the strip center thickness H c Subtract the thickness H at 15mm from the edge 15 The difference, that is:

[0005] Same plate difference (edge ​​drop) = H c -H 15

[0006] The edge drop value calculated in this way can truly reflect the thickness difference within the entire width of the plate and is an excellent indicator to characterize the precision control capability of the unit.

[0007] Currently, UCMW and UCM mills primarily utilize a work roll oscillation feedback control system to control edge drop. The primary control strategy involves using chamfered or specially curved work rolls or intermediate rolls to compensate for edge thinning and reduce edge drop. The specific implementation method for this system involves adjusting the roll oscillation level based on a comparison between the measured data from the mill exit edge drop meter and a set threshold. When the detected difference between the current plate and the plate exceeds the system's set threshold, the feedback control system outputs a roll oscillation command. However, during the roll oscillation process, since work roll oscillation is dependent on the current speed, the oscillation actuator is already executing its corresponding task and is unable to receive new oscillation commands. After the actuator completes its oscillation, it resumes receiving system commands, which results in a significant delay and increases the length of the edge drop segment.

[0008] In addition to roll movement, work roll bending is an important supplementary method for controlling strip thickness differences in rolling mills. Roll bending can rapidly change the effective roll crown, thereby altering the roll gap shape and ensuring uniform cross-sectional distribution of the strip at the mill exit. However, because current roll bending control primarily relies on setting values ​​from a host computer, with no adjustments applied across the entire roll or manual adjustments, its effectiveness has been limited.

[0009] However, as users' requirements for product quality continue to increase, user complaints about edge drop in cold rolling production lines are on the rise. It is particularly important to enhance the bending control of the working rolls and realize real-time feedback control of the bending force of the entire roll.

[0010] To sum up, the main problems currently existing are as follows:

[0011] 1) Cold-rolled products, especially those used in the motor industry for laminated cold-rolled silicon steel products, have extremely high requirements for edge drop. Although the currently commonly used roller (with edge chamfering) movement method can control edge drop to a certain extent, it is still far from meeting user requirements.

[0012] 2) In addition to roll movement, work roll bending is an important supplementary method for controlling strip thickness differences. This is because roll bending can instantly change the effective roll crown, thereby altering the roll gap shape and ensuring a uniform cross-sectional distribution of the strip at the mill exit. However, because current roll bending control methods primarily rely on preset values ​​or manual adjustment, their effectiveness is limited. Summary of the Invention

[0013] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide an edge drop bending roll control method and system that significantly improves the edge drop control level of cold-rolled products, realizes the automatic control mode of working roll bending during the rolling process, so as to give full play to the ability of working roll bending in controlling edge drop, improve the overall level of edge drop control of cold-rolled products, and improve the physical quality level.

[0014] To achieve the above object, the present invention adopts the following technical solutions:

[0015] On the one hand, a method for controlling an edge bending roller:

[0016] Obtain the edge drop value at the exit position of the upper stand of the cold rolling mill and the actual value of the edge drop bending roll force of the work roll of the stand, and obtain the adjustment amount of the edge drop bending roll force of the work roll of the stand;

[0017] According to the feedback of the edge bending force of the working roll of the stand, the dynamic control of the bending force of the cold rolling mill group is realized according to the adjustment amount.

[0018] Preferably, the edge bending force of the working roll of the frame is ΔF 弯辊力i The calculation is as follows:

[0019] △F 弯辊力i =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-α]*β

[0020] In the above formula, (H c -H i ) represents the edge drop value of the rack exit position, α represents the threshold value set according to user needs, β represents the system influencing factors, H c Indicates the thickness of the strip center point, H i Here, i represents the thickness at the distance from the edge of the strip, in mm.

[0021] Preferably, it is determined whether the bending roll force adjustment amount of the working roll edge of the frame is greater than 0;

[0022] When the adjustment amount is greater than 0, determine whether the bending force of the working roll of the frame is less than or equal to the lower limit of the bending force setting or whether it is greater than or equal to the upper limit of the bending force setting;

[0023] When the bending force of the working roll of the frame is less than or equal to the lower limit of the bending force setting or greater than or equal to the upper limit of the bending force setting, the bending force adjustment amount is output.

[0024] Preferably, the set threshold α is in the range of 2 to 20, the system influencing factor β is in the range of 0.05 to 0.5, and the position value i is 5, 10, 15, 20, 25, 30, 50 and 75 mm.

[0025] Preferably, the edge bending force of the working roll of the frame is ΔF 弯辊力i The values ​​of i in are 1, 2, and 3, which respectively correspond to the working rolls of the 1st to 3rd stands on the cold rolling mill group.

[0026] Preferably, the edge bending force ΔF of the working rolls of the second and third stands is 弯辊力2、3 The calculation is as follows:

[0027] △F 弯辊力2、3 =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-α]*β*m

[0028] In the above formula, m represents the adjustment coefficient, and its value range is between 0.05 and 0.8.

[0029] On the other hand, an edge drop bending roll control system includes a cold rolling mill, an edge drop measuring instrument provided at the exit position thereof, and a control device;

[0030] The edge drop measuring instrument is used to obtain the edge drop value and output the edge drop value to the control device;

[0031] The control device executes the edge bending roller control method;

[0032] The cold rolling mill group performs dynamic adjustment of its bending roll force according to the adjustment amount of the stand working roll edge bending roll force fed back by the control device.

[0033] The edge bending roller control method provided by the present invention also has the following beneficial effects:

[0034] 1) The edge drop bending roll control method of the present invention is more in line with on-site needs. In the currently commonly used edge drop control system, working roll bending is an important control means. The bending roll can quickly change the effective convexity of the roll, thereby changing the roll gap shape, so that the extension of the strip at the mill outlet is evenly distributed in the transverse direction. However, since the main bending roll setting value of the currently used bending roll control is issued by the upper computer, the entire roll is not adjusted according to the current status of the incoming material or relies on manual adjustment, so the application effect is not good. Therefore, the current control method can accurately locate the real-time feedback control of the edge drop working roll bending force control to improve the edge drop control level;

[0035] 2) The edge drop bending roll control method of the present invention provides more accurate calculations. Currently, commonly used edge drop control systems rely on setting the bending roll force output or manual adjustments based on experience, failing to implement calculations based on real-time detection of the current strip edge drop. The proposed new work roll bending control system, however, utilizes accurate real-time detection and a clear control objective, resulting in more accurate calculations and a better guarantee of achieving the control objective. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the edge drop definition;

[0037] Figure 2 This is an automatic control flow chart of the edge bending roller control method of the present invention;

[0038] Figure 3 It is a schematic diagram of the principle of the edge bending roller control calculation of the present invention. DETAILED DESCRIPTION

[0039] In order to better understand the above technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to the accompanying drawings and embodiments.

[0040] In the existing cold rolling process, the working roll movement is used to control the edge drop, but the bending roll force is given a set value, and the bending roll force of the entire coil does not change or relies on manual adjustment, which fails to achieve the effect of the bending roll force on the edge drop control. The resulting problem of uncontrolled edge drop is serious.

[0041] Combine Figure 2 and Figure 3 As shown, the present invention provides a method for controlling an edge bending roller:

[0042] Obtain the edge drop value at the exit position of the upper stand of the cold rolling mill and the actual value of the edge drop bending roll force of the work roll of the stand, and obtain the adjustment amount of the edge drop bending roll force of the work roll of the stand;

[0043] The bending force of the working roll edge of the stand is reduced to achieve dynamic control of the bending force of the cold rolling mill according to the adjustment amount.

[0044] According to the feedback of the working roll edge bending force △F of the stand 弯辊力i The calculation is as follows:

[0045] △F 弯辊力i =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-α]*β Formula 1

[0046] In formula 1, (H c -H i ) represents the edge drop value of the rack exit position, α represents the threshold value set according to user needs, β represents the system influencing factors, H c Indicates the thickness of the strip center point, H i Here, i represents the thickness at the distance from the edge of the strip, in mm.

[0047] Among them, the threshold value α is defined according to the requirements of the cold-rolled product users. Its size is mainly related to the user conditions of different products. The higher the user's product edge drop requirement, the smaller this value is. The smaller this parameter is, when the edge drop value of a certain position on the edge of the strip corresponds to the edge drop target value at the rack outlet position (at this time, [(H c -H i )-α]*β=0) The calculated roll bending force has no output. If the α value at a certain location on the edge of a stand on a 5-stand cold rolling mill is 5μm, this indicates that the current strip edge drop control meets the requirements, and the roll bending force calculation has no output value, meaning that roll bending force output is not required. If the strip center thickness minus the thickness at a certain location on the edge is greater than α, a positive roll bending is output to increase edge drop control. If it is less than α, a negative roll bending is output to prevent thickening and folding of the strip at the edge. The threshold α is set between 2 and 20.

[0048] After determining the threshold value α, the system influencing factor β can be set, with the value range between 0.05 and 0.5.

[0049] After determining α and β, the overall edge drop level of the cold-rolled strip cannot be fully described by just one point. It is necessary to detect and weightedly analyze multiple points on the edge of the strip to better describe the edge drop level of the strip. Therefore, 8 position values ​​of 5, 10, 15, 20, 25, 30, 50 and 75 mm away from the edge of the strip are taken to calculate the bending roll force value, among which the adjustment coefficient m at the 15 mm position of the strip edge ranges from 0.25 to 0.45 (the fluctuation of the thickness of the strip edge at 15 mm has a greater impact on the entire control process, so its weighted coefficient m is higher than other points), and the adjustment coefficient m of the remaining position points ranges from 0.05 to 0.15 (because the impact of other points in the control process is basically the same, the adjustment coefficient m has a relatively consistent value range).

[0050] Take a 5-stand cold rolling mill as an example. Its cold rolling outlet thickness is 0.5mm, and the outlet edge drop requirement (15mm from the edge of the strip) is 5μm. In the daily mill control process, the maximum bending roll force of one stand is 15 tons. However, in the rolling state, the actual setting value of the bending roll of one stand is about 10 tons. From the above situation, it can be seen that for this cold rolling mill group, the user product strip constant α value is 5μm, and the basic requirement of the group bending roll force output does not exceed the upper limit of the group bending roll force is [(H c -H i )-α]*β value constant β takes a value of 0.15, the adjustment coefficient m takes a value of 0.39 at 15mm above the upper edge, and the values ​​of other positions are shown in Table 1 below. The bending roll force value is calculated as follows:

[0051] Table 1

[0052]

[0053] The edge drop meter has certain fluctuations. When the edge drop detection is abnormal, it may cause the calculated bending roll force value to be too large. Therefore, the upper and lower limits of the working roll bending roll force need to be set in the system. When the calculated bending roll force value is higher than the upper and lower limits of the bending roll force capacity, the upper and lower limits are set according to the calculated bending roll force value.

[0054] If the bending roll force of stand 1 still fails to meet the edge drop requirements of cold-rolled products after reaching the limit, the bending roll force of stands 2 and 3 can be further increased to meet the edge drop requirements of user products. Since the edge drop meter data are the same, proportional output can be implemented in stands 2 and 3 to ensure the stability, safety and reliability of the system.

[0055] △F 弯辊力2、3 =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-α]*β*m Formula 2

[0056] In Formula 2, m represents a weighting coefficient, and its value range is between 0.05 and 0.8; α is between 2 and 20; and β is between 0.05 and 0.5.

[0057] The corresponding i positions correspond to 8 positions of 5, 10, 15, 20, 25, 30, 50, and 75 mm on the edge of the hot-rolled material, and the corresponding adjustment coefficient m ranges are 0.05~0.15, 0.05~0.15, 0.25~0.45, 0.05~0.15, 0.05~0.15, 0.05~0.15, 0.05~0.15, 0.05~0.15, and 0.05~0.15.

[0058] Combine Figure 3 As shown, the present invention also provides an edge drop bending roll control system, comprising a cold rolling mill group 100 and an edge drop measuring instrument 200 provided at the exit position thereof;

[0059] The edge drop measuring instrument 200 is used to obtain the edge drop value of the strip at the exit position of the cold rolling mill group 100.

[0060] The cold rolling mill 100 executes the edge drop bending roll control method of the present invention according to the actual value of the edge drop roll force of the working rolls of its stand 101 and the edge drop value measured by the edge drop measuring instrument 200.

[0061] The present invention also provides an edge drop bending roll control system, comprising: a cold rolling mill unit, an edge drop measuring instrument provided at the exit position thereof, and a control device;

[0062] The edge drop measuring instrument is used to obtain the edge drop value and output the edge drop value to the control device;

[0063] The control device executes the edge bending roller control method of the present invention;

[0064] The cold rolling mill group performs dynamic adjustment of its bending roll force according to the bending roll force adjustment amount of the stand work roll edge feedback from the control device.

[0065] Example

[0066] For a 5-stand cold rolling mill, the thickness of the hot-rolled incoming strip (center point) is 2.5mm, the cold-rolled outlet thickness is 0.5mm, and the outlet edge drop requirement (15mm from the edge) is 5μm. In the daily control process of the cold rolling mill, the maximum bending roll force of one stand is 15 tons, while in the rolling state, the actual setting value of the bending roll of one stand is about 10 tons. From the above situation, it can be seen that for this cold rolling mill unit, the user product strip constant α value is 5μm, and the unit bending roll force output does not exceed the basic requirement of the unit bending roll force upper limit. According to [(H c -H i)-α]*β value constant β takes a value of 0.15, the adjustment coefficient m takes a value of 0.39 at 15mm above the edge, and the values ​​of other positions are shown in Table 2 below. The bending roll force value is calculated as follows:

[0067] Table 2

[0068]

[0069] During the rolling process of the cold rolling mill, the edge drop bending roll feedback control program is put into operation. The current edge drop does not meet the requirements. The corresponding bending roll force calculation value is shown in the formula. The edge drop bending roll control output in Table 2 above is 1.965 tons.

[0070] Table 3

[0071]

[0072] During the rolling process of the cold rolling mill, the edge drop bending roll feedback control program is put into operation. The edge thickening occurs at the current edge drop. The corresponding bending roll force calculation value is shown in the formula. The edge drop bending roll control output in Table 3 above is -2.685 tons.

[0073] Table 4

[0074]

[0075] During the rolling process of the cold rolling mill, the edge drop bending roll feedback control program is put into use. The current edge drop does not meet the requirements, and the β and adjustment coefficient m values ​​are optimized. The corresponding bending roll force calculation value is shown in the formula. The edge drop bending roll control output in Table 4 above is 2.83 tons.

[0076] This invention utilizes edge drop bending roll feedback control technology based on an edge drop meter at the rear of the cold rolling mill to detect thickness differences and meet user-defined edge drop requirements. This technology provides real-time feedback control of the calculated bending roll forces for the first through third stands, thereby improving edge drop control for cold-rolled strip. The edge drop bending roll control method of this invention can be applied to various five-stand cold rolling mill systems with varying edge drop control capabilities, making it widely applicable to cold rolling mills currently employing roll shifting for edge drop control.

[0077] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present invention and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A method for controlling an edge bending roller, characterized in that: Obtain the edge drop value at the exit position of the upper frame of the cold rolling mill, and the actual value of the edge drop bending roll force of the working roll of the frame, and obtain the edge drop bending roll force adjustment value of the working roll of the frame; According to the feedback of the bending roll force adjustment amount of the working roll edge of the stand, the dynamic control of the bending roll force of the cold rolling mill is realized. The bending force adjustment amount △F of the edge of the working roll of the frame 弯辊力i The calculation of is as follows: △F 弯辊力i =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-a]*b In the above formula, (H c -H i ) represents the marginal drop value of the rack exit position, α represents the threshold value set according to user needs, β represents the system influencing factors, H c Indicates the thickness of the strip center point, H i i represents the thickness of the strip from the edge, in mm. Determine whether the edge bending roll force adjustment amount of the working roll of the frame is greater than 0; When the adjustment amount is greater than 0, it is determined whether the bending force of the working roll of the frame is less than or equal to the lower limit of the bending force setting or whether it is greater than or equal to the upper limit of the bending force setting; When the bending force of the working roll of the frame is less than or equal to the lower limit of the bending force setting or greater than or equal to the upper limit of the bending force setting, the bending force adjustment amount is output.

2. The edge bending roller control method according to claim 1, characterized in that: The set threshold α has a value range of 2 to 20, the system influencing factor β has a value range of 0.05 to 0.5, and the position value i has values ​​of 5, 10, 15, 20, 25, 30, 50 and 75 mm.

3. The edge bending roller control method according to claim 2, characterized in that: The bending force adjustment amount △F of the edge of the working roll of the frame 弯辊力i The values ​​of i in are 1, 2, and 3, which respectively correspond to the working rolls of the 1st to 3rd stands on the cold rolling mill group.

4. The edge bending roller control method according to claim 3, characterized in that: The adjustment amount of the bending force of the working roll edge of the second and third stands △F 弯辊力2、3 The calculation of is as follows: △F 弯辊力2、3 =(F 弯辊力最大值 -F 弯辊力实际值 )*[(H c -H i )-a]*b*m In the above formula, m represents the adjustment coefficient, and its value range is between 0.05 and 0.

8.

5. An edge bending roller control system, comprising: Tandem cold rolling mill, edge drop measuring instrument and control device at its exit; The edge drop measuring instrument is used to obtain the edge drop value and output the edge drop value to the control device; The control device executes the edge bending roller control method as claimed in any one of claims 1 to 4; The cold rolling mill group performs dynamic adjustment of its bending roll force according to the working roll edge lowering bending roll force adjustment amount fed back by the control device.

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