A method for controlling the flattening force of a calendering roll of a rolling mill

Abstract

The application relates to a rolling mill calendering roller flattening force control method, characterized by the following specific steps: step S1, hardware improvement: angle encoders are installed on the swing arm pivot fulcrums of the driving side and the operating side of the rolling mill calendering roller, swing arm angles of the driving side and the operating side are collected in real time, step S2, mathematical model construction: a model is established based on the swing arm angle data, and step S3, PI closed loop control; the application compares the actual force (T dact , T Oact measured by a pressure sensor) of the hydraulic cylinder with the given force (T dref , T Oref ), calculates the deviation (Delta T d , Delta T O ), dynamically adjusts the input current of the proportional valve of the hydraulic cylinder on the two sides through a PI regulator, compensates the deviation in real time, ensures that the flattening forces (F d , F O ) on the two sides are consistent, and thus the unbalance of the forces on the two sides caused by mechanical wear and installation errors can be eliminated, and defects such as one-side waves and layering can be inhibited.

Description

Technical fields:

[0001] This invention relates to the field of aluminum processing and manufacturing technology, and in particular to a method for controlling the ironing force of ironing rolls in aluminum rolling mills. Background technology:

[0002] With the development of aluminum processing and manufacturing technology, modern rolling mills are increasingly designed with wide widths and high speeds, which in turn places higher and higher demands on the technical performance of aluminum strip rolling mills.

[0003] The 2100mm four-roll irreversible cold rolling mill of this application has the performance of wide width, high speed and thickness difference within 3um; due to the use of the ironing rolls for many years, some parameter settings or controls are no longer suitable for the use of the ironing rolls. Especially when producing thin finished products (thickness 0.10-0.20mm) of can bodies and cover materials at high speed, it is easy to cause phenomena such as single-sided wave (aluminum strip is continuously distributed in a wavy shape on one side along the length direction) and layer displacement (aluminum strip has interlayer separation or relative displacement in the thickness direction), which not only affects production, but also easily causes some strips to be scrapped.

[0004] Specifically, the existing ironing roll device of the cold rolling mill is equipped with two types of rollers: plastic rollers and steel rollers. According to the process production requirements, for materials of different thicknesses, the appropriate roller can be switched through a set of hydraulic cylinders. Generally, plastic rollers are used for thin materials, and the ironing rolls play a constant pressure ironing function. Steel rollers are used for thick materials, and the ironing rolls play a position follow-up function. In case of strip breakage or equipment abnormality, they can be quickly pressed down. The lifting and lowering of the ironing rolls is controlled by two sets of proportional valves, which control the hydraulic cylinders on both sides respectively (the hydraulic cylinders on both sides refer to the drive side and the operating side hydraulic cylinders. The rotation of the ironing roll is as a passive roller that rotates passively when it is rolled against other rollers. The drive side refers to the input side of the rolling mill roll power, and the operating side refers to the side away from the rolling mill roll power input).

[0005] Current ironing roller control methods: The main control method for ironing rollers is to ensure that the ironing force remains constant during the winding process as the roll diameter changes. Based on the mechanism design drawing and installation position requirements, the relationship between the force on the hydraulic cylinder and the winding roll diameter is calculated through mathematical modeling. The curve showing the relationship between the roll diameter and the hydraulic cylinder force is shown below. Figure 1 During the winding process, the input current of the proportional valve is automatically adjusted according to the change in the roll diameter, thereby adjusting the unit pressure of the oil cylinder in a timely manner to achieve a constant ironing force.

[0006] The current method of controlling the ironing roll has the following defects: This is the conventional method of controlling the ironing roll. In the early stage of equipment operation, due to the small wear of the ironing roll and the high precision, the operation is relatively reliable and stable. However, with the wear of the equipment, changes in precision, and the disassembly and replacement of the on-site roller system and mechanism, the original parameters will be unsuitable. In particular, it is easy to cause the ironing force on both sides of the ironing roll (drive side and operating side) to be inconsistent, resulting in unstable pressure on both sides of the ironing roll, unilateral wavy strip shape, inability to guarantee end face quality, and other problems that affect the improvement of mill efficiency. Summary of the Invention:

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for controlling the ironing force of a rolling mill ironing roll. This method can make the ironing force control on both sides of the ironing roll more reasonable and can reduce the occurrence of single-sided waviness or layering in aluminum strip.

[0008] The present invention relates to a method for controlling the ironing force of a rolling mill ironing roll, characterized by the following specific steps:

[0009] Step S1, Hardware Improvement: Install angle encoders on the swing arm pivot points on the drive side and operating side of the rolling mill flattening roll to collect the swing arm angles on the drive side and operating side in real time.

[0010] Step S2, Mathematical Model Construction: Based on the swing arm angle data, establish a model.

[0011] a. Torque arm length model: Establish a model of the relationship between the torque arm length of the ironing force F on both sides of the ironing roller and the force T of the hydraulic cylinder and the swing arm angle.

[0012] b. Self-weight moment model: Establish a model of the self-weight moment G of the ironing roller system components at different angles;

[0013] C. Force balance equation: Calculate the given forces of the hydraulic cylinders on both sides using the formula F*H=T*L+G, where F is the ironing force, T is the force of the hydraulic cylinder, H is the torque arm length of the ironing force, L is the torque arm length of the hydraulic cylinder, and G is the self-weight torque of the ironing roller system.

[0014] Step S3, PI closed-loop control:

[0015] Compare the actual force applied by the hydraulic cylinder as measured by the pressure sensor with the given force, and calculate the deviation;

[0016] By dynamically and precisely adjusting the input current of the proportional valves on the drive and operation sides of the ironing roll using a PI regulator, the ironing force on both sides of the ironing roll remains stable throughout the entire production rolling process as the angle of the swing arms on both sides changes, resulting in good sheet shape and coil end face quality.

[0017] Preferably, when changing the ironing roller, the pressure difference between the drive side and the operating side of the ironing roller is calibrated by a weighing sensor, and the target pressure difference is 0.

[0018] Preferably, in step S2, the model for the relationship between the torque arm length of the ironing force on both sides of the ironing roller and the swing arm angle is established as follows: Based on the dimensions and installation position parameters of each component of the mechanism, the torque arm length H of the ironing force on both sides of the ironing roller and the polynomial of the swing arm angle X are calculated after mathematical modeling.

[0019] When using rubber rollers

[0020] H 1d = (-5248*X) d 4 +1682*X d 3 -497X d 2 -70X d +1608) / 1000.0

[0021] H 1O = (-5248*X) O 4 +1682*X O 3 -497X O 2 -70X O +1608) / 1000.0

[0022] Drive-side arm length H 1d Transmission side angle X d Operating arm length H 1O Operating side angle X O ;

[0023] When steel rollers are used

[0024] H 2d =(-5593*X) d 4 +1919*X d 3 -518X d 2 -71X d +1608) / 1000.0

[0025] H 2O =(-5593*X) O 4 +1919*X O 3 -518X O 2 -71X O+1608) / 1000.0

[0026] Drive-side arm length H 2d Transmission side angle X d Operating arm length H 2O Operating side angle X O .

[0027] Preferably, in step S2, the model for the relationship between the torque arm length of the hydraulic cylinders on both sides of the ironing roller and the swing arm angle is established as follows: based on the dimensions and installation position parameters of each component of the mechanism, the torque arm length L of the hydraulic cylinders on both sides is calculated as a polynomial with respect to the angle X after mathematical modeling.

[0028] When using rubber rollers

[0029] L 1d =(-0.8761X) d 2 +0.4155X d +0.7445)

[0030] L 1O =(-0.8761X) O 2 +0.4155X O +0.7445);

[0031] Drive-side arm length L 1d Transmission side angle X d Operating arm length L 1O Operating side angle X O ;

[0032] When steel rollers are used

[0033] L 2d =(-0.7824X) d 2 +0.4326X d +0.7343)

[0034] L 2O =(-0.7824X) O 2 +0.4326X O +0.7343);

[0035] Drive-side arm length L 2d Transmission side angle X d Operating arm length L 2O Operating side angle X O .

[0036] Preferably, the establishment of the self-gravity moment model of the ironing roller system components at different angles in step 2 is as follows:

[0037] Test the self-weight torque of the boom at different angles, that is: given an angle value, when the boom's corresponding action is stably balanced at that angle value, the torque of the hydraulic cylinder is equal to the self-weight torque of the boom. Based on this method, obtain multiple angle data, and calculate the following polynomial after mathematical modeling.

[0038] When using rubber rollers: G 1d =-5200*X d 4 -1020*X d 3 -12800X d 2 -2350X d +K1

[0039] G 1O =-5200*X O 4 -1020*X O 3 -12800X O 2 -2350X O +3100

[0040] Transmission side gravity torque G 1d Transmission side angle X d Operating side gravity torque G 1O Operating side angle X O ;

[0041] When using steel rollers:

[0042] G 2d =-29115X d 4 -1947*X d 3 -9831X d 2 -3479X d +K2

[0043] G 2O =-29115X O 4 -1947*X O 3 -9831X O 2 -3479X O +12954

[0044] Transmission side gravity torque G 2d Transmission side angle X d Operating side gravity torque G2O Operating side angle X O ;

[0045] In the above formula, K1 and K2 are adjusted according to the calibration of the pressing force on both sides of the ironing roller to make the pressing force on both sides equal.

[0046] Preferably, in step 2, the given force count of the hydraulic cylinders on both sides of the ironing roller...

[0047] Set the total ironing force F ref = Unit ironing force * bandwidth / 2, given the ironing force F on the drive side and the operating side of the ironing roller. dref F Oref When considering the adjustment of the ironing force ΔF on both sides of the ironing roller,

[0048] The given force T of the driving side and operating side cylinder of the ironing roller can be calculated using the formula F*H=T*L+G. dref T Oref for:

[0049] T dref =(F ref +ΔF) / 2*H d / L d +G d / L d

[0050] T Oref =(F ref -ΔF) / 2*H O / L O +G O / L O .

[0051] Preferably, the PI closed-loop control in step S3 is as follows:

[0052] (1) Calculation of the actual force of the hydraulic cylinders on both sides of the ironing roller: The actual force T of the cylinders on the drive side and the operating side of the ironing roller dact T Oact The following calculations were performed using two pressure sensors on the hydraulic cylinder rod side and the cavity side, along with the area:

[0053] T dact = Cylinder-side pressure * Cylinder-side acting area - Cavity-side pressure * Cavity-side acting area

[0054] T Oact = Cylinder-side pressure * Cylinder-side action area - Cavity-side pressure * Cavity-side action area;

[0055] (2) The force deviation between the driving side and the operating side cylinder of the ironing roller is controlled by PI: that is, the actual force of the cylinder is equal to the given force of the cylinder, so that the ironing force on the driving side and the operating side of the ironing roller is constant at the given ironing force.

[0056] Preferably, the method to achieve zero pressure difference between the ironing roller drive side and the operation side when changing ironing rollers is (1) connecting the weighing sensor to the pressure detection instrument and zeroing the weight;

[0057] (2) Expand the winding shaft used for winding aluminum strip, switch the ironing roller to the rubber roller, and switch the mode to the pressing mode. Then, place a weighing sensor on the transmission side and the operation side of the contact surface between the ironing roller and the winding shaft.

[0058] And ensure that the distance between the weighing sensor and both ends of the ironing roller is the same.

[0059] (3) Modify G 1d G 2d When the values ​​of K1 and K2 in the polynomial are the same as the pressure force detected by the load cells on the transmission side and the operation side, the calibration is complete.

[0060] Advantages of this invention: By collecting the angle X on the drive side of the ironing roller... d and operating side angle X O This allows for the precise acquisition of the given force T from the driving side and operating side cylinders of the ironing roller, respectively. dref T Oref By controlling the proportional valves on the drive side and the operating side separately through the PI controller, the ironing force on both sides of the ironing roll is kept constant throughout the entire production rolling process, eliminating the instability of the ironing roll pressing on both sides, thereby obtaining good strip shape and coil end face quality, and reducing the occurrence of single-sided waviness or layering of aluminum strip. Attached image description:

[0061] The present invention will be further described below with reference to the accompanying drawings;

[0062] Figure 1 This is a graph showing the relationship between the diameter of an existing aluminum coil and the pressure applied to the aluminum coil;

[0063] Figure 2 This is a schematic diagram of the ironing roller device of the present invention with the addition of an angle encoder;

[0064] Figure 3 This is a schematic diagram showing the force applied to the ironing roller of the present invention. Detailed implementation method:

[0065] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0066] The specific control method of the ironing roller of the present invention is as follows:

[0067] (1) Two angle encoders A1 are added to the ironing roller device, that is, angle encoders A1 are installed at the pivot points of the swing arms A2 on both sides of the ironing roller, such as Figure 2The aforementioned method is used to accurately measure the angular position of the ironing roller on both sides, so as to achieve precise adjustment and control of the ironing force on both sides.

[0068] (2) Establishment of the mathematical model for the control of the ironing roller: Based on the mechanism design drawing and installation position requirements (i.e., based on the dimensions and installation position parameters of each component of the ironing roller mechanism, etc.), the mathematical model relationship between the force on the hydraulic cylinders A3 of the two sides of the ironing roller and the movement angle of the two sides of the ironing roller is obtained after mathematical modeling. The mathematical model includes the following polynomials:

[0069] ① Polynomial of the torque arm length and angle of the ironing force on both sides of the ironing roller:

[0070] Based on the mechanism design drawings and installation location requirements, the torque arm length H and angle X of the ironing force on both sides of the ironing roller were calculated using mathematical modeling:

[0071] Select roller Roll1 (drive side arm length H) 1d Transmission side angle X d Operating arm length H 1O Operating side angle X O )

[0072] H 1d = (-5248*X) d 4 +1682*X d 3 -497X d 2 -70X d +1608) / 1000.0

[0073] H 1O = (-5248*X) O 4 +1682*X O 3 -497X O 2 -70X O +1608) / 1000.0

[0074] Select steel roller Roll2 (drive side arm length H) 2d Transmission side angle X d Operating arm length H 2O Operating side angle X O )

[0075] H 2d =(-5593*X) d 4 +1919*X d 3 -518X d2 -71X d +1608) / 1000.0

[0076] H 2O =(-5593*X) O 4 +1919*X O 3 -518X O 2 -71X O +1608) / 1000.0

[0077] ② The torque arm length and angle polynomial of the hydraulic force applied by the hydraulic cylinders on both sides of the ironing roller:

[0078] Based on the mechanism design drawings and installation location requirements, the torque arm length L and angle X of the two hydraulic cylinders were calculated using mathematical modeling as polynomials:

[0079] Select roller Roll1 (drive side arm length L) 1d Transmission side angle X d Operating arm length L 1O Operating side angle X O )

[0080] L 1d =(-0.8761X) d 2 +0.4155X d +0.7445)

[0081] L 1O =(-0.8761X) O 2 +0.4155X O +0.7445)

[0082] Select steel roller Roll2 (drive side arm length L) 2d Transmission side angle X d Operating arm length L 2O Operating side angle X O )

[0083] L 2d =(-0.7824X) d 2 +0.4326X d +0.7343)

[0084] L 2O =(-0.7824X) O 2 +0.4326X O +0.7343)

[0085] ③ Polynomials of the self-weight torque and angle of each component of the ironing roller device:

[0086] The method of angle control using a position control loop is used to test the self-weight torque of the boom at different angles. That is, given an angle value, when the boom's corresponding action is stably balanced at that angle, the torque of the hydraulic cylinder is equal to the self-weight torque of the boom. Based on this method, multiple angle data are obtained, and the following polynomial is calculated after mathematical modeling:

[0087] Selected rubber roller Roll1 (drive side self-gravity torque G) 1d Transmission side angle X d Operating side gravity torque G 1O Operating side angle X O )

[0088] G 1d =-5200*X d 4 -1020*X d 3 -12800X d 2 -2350X d +K1

[0089] G 1O =-5200*X O 4 -1020*X O 3 -12800X O 2 -2350X O +3100

[0090] Select steel roller Roll2 (drive side self-gravity torque G) 2d Transmission side angle X d Operating side gravity torque G 2O Operating side angle X O )

[0091] G 2d =-29115X d 4 -1947*X d 3 -9831X d 2 -3479X d +K2

[0092] G 2O =-29115X O 4 -1947*X O3 -9831X O 2 -3479X O +12954;

[0093] The value of K1 can be 15000, and the value of K2 can be 17704. The values ​​of K1 and K2 can be adjusted according to the calibration of the pressing force on both sides of the ironing roller to make the pressing force on both sides equal. The calibration process is detailed later.

[0094] 2) Ironing roller control strategy and method:

[0095] like Figure 3 As shown, the ironing force of the ironing roller can be calculated using mechanical formulas:

[0096] F*H=T*L+G

[0097] ① Calculation of the given force of the iron: Assume a given total ironing force F ref (Given total ironing force = unit ironing force * bandwidth), the ironing force on the drive side and the operating side of the ironing roller is given as F. dref F Oref When considering the adjustment of the ironing force ΔF on both sides of the ironing roller,

[0098] The given force T of the driving side and operating side cylinder of the ironing roller can be calculated using the formula F*H=T*L+G. dref T Oref for:

[0099] T dref =(F ref +ΔF) / 2*H d / L d +G d / L d

[0100] T Oref =(F ref -ΔF) / 2*H O / L O +G O / L O

[0101] ② Calculation of the actual force of the cylinder: The actual force T of the cylinder on the driving side and the operating side of the ironing roller. dact T Oact The following calculation can be made using the two pressure sensors (rod-side pressure sensor and cavity-side pressure sensor) and the area of ​​the hydraulic cylinder:

[0102] T dact = Cylinder-side pressure * Cylinder-side acting area - Cavity-side pressure * Cavity-side acting area

[0103] TOact = Cylinder-side pressure * Cylinder-side action area - Cavity-side pressure * Cavity-side action area;

[0104] The deviation ΔT of the hydraulic cylinder force control on the drive side of the ironing roller is as follows: d Calculation formula, ΔT d =T dref -T dact

[0105] The deviation ΔT of the hydraulic cylinder force control on the operating side of the ironing roller is as follows: O Calculation formula, ΔT O =T Oref -T Oact

[0106] ③ The force deviation between the driving side and the operating side cylinder of the ironing roller is controlled by PI: that is, the actual force of the cylinder is equal to the given force of the cylinder, so that the ironing force on the driving side and the operating side of the ironing roller is kept constant at the given ironing force.

[0107] In the aforementioned formula, L d L O (torque arm length of hydraulic cylinder force), H d H O (torque arm length of ironing force), G d G O The self-weight torque is determined and calculated by the swing angles of the ironing roller drive side and the operating side, respectively.

[0108] From the above analysis, it can be concluded that when the angle X on the drive side of the ironing roller is obtained at a certain moment... d and operating side angle X O This allows for the precise acquisition of the given force T from the driving side and operating side cylinders of the ironing roller, respectively. dref T Oref By controlling the proportional valves of the hydraulic cylinders on the transmission side and the operation side through the PI controller, the ironing force on both sides of the ironing roll can be kept constant throughout the entire production rolling process, eliminating the instability of the ironing roll pressing on both sides, and obtaining good plate shape and coil end face quality.

[0109] Ironing roller pressure calibration: When replacing the ironing roller, it is necessary to calibrate it to prevent edge waviness and other quality issues. The specific operation is as follows:

[0110] (1) Connect the weighing sensor to the pressure detection instrument and zero the weight;

[0111] (2) Expand the winding shaft used for winding aluminum strip, switch the ironing roller to the rubber roller, and switch the mode to the pressing mode. Then, place a weighing sensor on the transmission side and the operation side of the contact surface between the ironing roller and the winding shaft.

[0112] And ensure that the distance between the weighing sensor and both ends of the ironing roller is the same.

[0113] (3) Modify G 1d G 2d When the values ​​of K1 and K2 in the polynomial are the same as the pressure force detected by the load cells on both the transmission and operation sides, the calibration is complete. 1d G 2d One embodiment is as follows:

[0114] G 1d =-5200*X d 4 -1020*X d 3 -12800X d 2 -2350X d +15000 (select rubber roller)

[0115] G 2d =-29115X d 4 -1947*X d 3 -9831X d 2 -3479X d +17704 (Select steel roller)

[0116] The working mechanism of the ironing roller pressure calibration is to dynamically adjust the parameters of the self-weight torque model to compensate for the pressure asymmetry on both sides caused by factors such as machining errors and installation deviations, and finally achieve the process of equalizing the pressure values ​​on the transmission side and the operating side. That is, with the goal of "zero pressure difference on both sides", the actual pressure deviation is fed back by the weighing sensor, and the constant terms in the self-weight torque polynomial (such as 15000, 17704) are manually corrected to offset the implicit torque interference caused by the self-weight of the roller system, changes in the swing arm angle, etc., so that the pressure on both sides is dynamically balanced.

[0117] The essential function of calibrating the pressing force of the ironing roller is to transform the nonlinear errors of the mechanical system (such as machining tolerances and assembly clearances) into quantifiable model parameters. Through the "calibration-feedback-correction" closed loop, it provides a precise theoretical target force for subsequent PI control (that is, after eliminating static deviations, PI control only needs to handle dynamic disturbances).

[0118] This invention compares the actual applied force (T) of the hydraulic cylinder. dact T Oact (measured by a pressure sensor) and a given force (T) dref T Oref ), calculate the deviation (ΔT) d ΔT OThe input current of the proportional valves of the hydraulic cylinders on both sides is dynamically adjusted by a PI controller to compensate for deviations in real time and ensure the ironing force (F) on both sides. d F O This ensures consistency, thereby eliminating the imbalance of forces on both sides caused by mechanical wear and installation errors, and suppressing defects such as unilateral wave and layering.

[0119] When selecting rubber rollers, the dimensions and installation positions of each component of the ironing roller mechanism are shown in Table 1 below (equipment width 1800mm, unit ironing pressure 0.1kg / mm):

[0120]

[0121] The following table 2 (test values ​​for ironing force torque arm, hydraulic cylinder torque arm, etc.):

[0122]

[0123] Based on the dimensions and installation position parameters of each component of the mechanism, the polynomials of the torque arm length H and the swing arm angle X of the ironing force on both sides of the ironing roller were calculated after mathematical modeling, as follows:

[0124] The following table 3 (test values ​​of roll diameter and torque arm length H of ironing force when using rubber rollers):

[0125]

[0126] The polynomial was obtained by fitting the data in Table 3 above using the least squares method:

[0127] H = -5.248 * NDS1 4 +1.682*NDS1 3 -0.497*NDS1 2 -0.070*NDS1+1.608

[0128] To verify the formula, the fitted values ​​are compared with the actual values, and the residual is found to be 0.

[0129]

[0130] Similarly, when using steel rollers, a polynomial is obtained:

[0131] H = -5.593 * NDS1 4 +1.919*NDS1 3 -0.518*NDS1 2 -0.071*NDS1+1.608

[0132] Based on the dimensions and installation position parameters of each component of the mechanism, the torque arm length L and angle X polynomial of the two hydraulic cylinders were calculated through mathematical modeling, as follows:

[0133] The following table 4 (test values ​​for roll diameter, radius, and torque arm length L of the hydraulic cylinder when using a rubber roller):

[0134] Roll diameter (mm) NDS1 (radians) The torque arm length L (m) of the hydraulic cylinder. 665 -0.342084528 0.620 1100 -0.216281197 0.680 1584.99 -0.067456974 0.720 2000.15 0.058712875 0.740 2500 0.210 0.700

[0135] The polynomial was obtained by fitting the data in Table 4 above using the least squares method:

[0136] L = -0.8761NDS1 2 +0.4155NDS1+0.4155

[0137] To verify the formula, the fitted values ​​are compared with the actual values, and the residual is found to be 0.

[0138]

[0139] Similarly, when using steel rollers, a polynomial is obtained:

[0140] L = -0.7824NDS1 2 +0.4326NDS1+0.7343.

[0141] One method, relying on a position control loop for angle control, was used to test the self-weight torque of the swing arm at different angles. Multiple angle data points were acquired, and after mathematical modeling, the following polynomial was calculated:

[0142] The following table 5 (test values ​​for roll diameter, radius, and self-weight torque G of the rotating arm when using a rubber roller):

[0143] That is, the polynomial (when using a rubber roller) is obtained by fitting and optimizing the data in Table 5 above.

[0144] Roll diameter (mm) NDS1 (radians) The moment of gravity of the swing arm G 665 -0.342084528 2349.6059 1100 -0.216281197 2376.8363 1584.99 -0.067456974 2354.4287 2000.15 0.058712875 2292.3533 2500 0.210 2163.6468

[0145] G = -5200 * NDS1 4 -1020*NDS1 3 -12800NDS1 2 -2350NDS1+3100

[0146] The formula was validated by comparing the fitted values ​​with the actual values, and the error was found to be less than 0.05%.

[0147]

[0148] Similarly, when using steel rollers, a polynomial is obtained:

[0149] G2O =-29115*NDS1 4 -1947*NDS1 3 -9831NDS1 2 -3479NDS1+12954

[0150] This invention collects the angle X on the drive side of the ironing roller. d and operating side angle X O This allows for the precise acquisition of the given force T from the driving side and operating side cylinders of the ironing roller, respectively. dref T Oref By controlling the proportional valves on the drive side and the operating side separately through the PI controller, the ironing force on both sides of the ironing roll is kept constant throughout the entire production rolling process, eliminating the instability of the ironing roll pressing on both sides, thereby obtaining good strip shape and coil end face quality, and reducing the occurrence of single-sided waviness or layering of aluminum strip.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for controlling the ironing force of a rolling mill ironing roll, characterized in that: The specific steps are as follows: Step S1, Hardware Improvement: Install angle encoders on the swing arm pivot points on the drive side and operating side of the rolling mill flattening roll to collect the swing arm angles on the drive side and operating side in real time. Step S2, Mathematical Model Construction: Based on the swing arm angle data, establish a model. a. Torque arm length model: Establish a model of the relationship between the torque arm length of the ironing force F on both sides of the ironing roller and the force T of the hydraulic cylinder and the swing arm angle. b. Self-weight moment model: Establish a model of the self-weight moment G of the ironing roller system components at different angles; C. Force balance equation: Calculate the given forces of the hydraulic cylinders on both sides using the formula F*H=T*L+G, where F is the ironing force, T is the force of the hydraulic cylinder, H is the torque arm length of the ironing force, L is the torque arm length of the hydraulic cylinder, and G is the self-weight torque of the ironing roller system. Step S3, PI closed-loop control: Compare the actual force applied by the hydraulic cylinder as measured by the pressure sensor with the given force, and calculate the deviation; By dynamically and precisely adjusting the input current of the proportional valves on the drive and operation sides of the ironing roll using a PI regulator, the ironing force on both sides of the ironing roll remains stable as the angle of the swing arms on both sides changes throughout the entire production rolling process, thereby obtaining good plate shape and coil end face quality. In step S2, the model for the relationship between the torque arm length of the ironing force on both sides of the ironing roller and the swing arm angle is established as follows: Based on the dimensions and installation position parameters of each component of the mechanism, the polynomial relationship between the torque arm length H of the ironing force on both sides of the ironing roller and the swing arm angle X is calculated after mathematical modeling. When using rubber rollers H 1d =(-5248*X d 4 +1682*X d 3 -497X d 2 -70X d +1608) / 1000.0 H 1O =(-5248*X O 4 +1682*X O 3 -497X O 2 -70X O +1608) / 1000.0 Drive-side arm length H 1d Transmission side angle X d Operating arm length H 1O Operating side angle X O ; When steel rollers are used H 2d =(-5593*X d 4 +1919*X d 3 -518X d 2 -71X d +1608) / 1000.0 H 2O =(-5593*X O 4 +1919*X O 3 -518X O 2 -71X O +1608) / 1000.0; Drive-side arm length H 2d Transmission side angle X d Operating arm length H 2O Operating side angle X O ; The model for the relationship between the torque arm length of the hydraulic cylinders on both sides of the ironing roller and the swing arm angle in step S2 is established as follows: Based on the dimensions and installation position parameters of each component of the mechanism, the torque arm length L of the hydraulic cylinders on both sides is calculated as a polynomial with respect to the angle X after mathematical modeling. When using rubber rollers L 1d =(-0.8761X d 2 +0.4155X d +0.7445) L 1O =(-0.8761X O 2 +0.4155X O +0.7445); Drive-side arm length L 1d Transmission side angle X d Operating arm length L 1O Operating side angle X O ; When steel rollers are used L 2d =(-0.7824X) d 2 +0.4326X d +0.7343) L 2O =(-0.7824X) O 2 +0.4326X O +0.7343) ; Drive-side arm length L 2d Transmission side angle X d Operating arm length L 2O Operating side angle X O ; Step 2: Establishment of the self-weight torque model of the ironing roller system components at different angles: Test the self-weight torque of the swing arm at different angles, that is: given an angle value, when the corresponding action of the swing arm is stably balanced at that angle value, the torque of the hydraulic cylinder is equal to the self-weight torque of the swing arm. Based on this method, obtain multiple angle data, and calculate the following polynomial after mathematical modeling. When using rubber rollers: G 1d =-5200*X d 4 -1020*X d 3 -12800X d 2 -2350X d +K1 G 1O =-5200*X O 4 -1020*X O 3 -12800X O 2 -2350X O +3100 Transmission side gravity torque G 1d Transmission side angle X d Operating side gravity torque G 1O Operating side angle X O ; When using steel rollers: G 2d =-29115X d 4 -1947*X d 3 -9831X d 2 -3479X d +K2 G 2O =-29115X O 4 -1947*X O 3 -9831X O 2 -3479X O +12954 Transmission side gravity torque G 2d Transmission side angle X d Operating side gravity torque G 2O Operating side angle X O ; In the above formula, K1 and K2 are adjusted according to the calibration of the pressing force on both sides of the ironing roller to make the pressing force on both sides equal.

2. The method for controlling the ironing force of the rolling mill ironing roll according to claim 1, characterized in that: When changing the ironing roller, the pressure difference between the drive side and the operating side of the ironing roller is calibrated by a weighing sensor, and the target pressure difference is 0.

3. The method for controlling the ironing force of the rolling mill ironing roll according to claim 2, characterized in that: In step 2, the given force count of the hydraulic cylinders on both sides of the ironing roller is performed. Set the total ironing force F ref =Unit ironing force * bandwidth, given the ironing force F on the drive side and the operating side of the ironing roller. dref F Oref When considering adjusting the ironing force ∆F on both sides of the ironing roller, The given force T of the driving side and operating side cylinder of the ironing roller can be calculated using the formula F*H=T*L+G. dref T Oref for: T dref =(F ref +∆F) / 2*H d / L d +G d / L d T Oref =(F ref -∆F) / 2*H O / L O +G O / L O 。 4. The method for controlling the ironing force of the rolling mill ironing roll according to claim 3, characterized in that: Step S3: PI closed-loop control (1) Calculation of the actual force of the hydraulic cylinders on both sides of the ironing roller: The actual force T of the cylinders on the drive side and the operating side of the ironing roller dact T Oact The pressure and area on the rod side and cavity side of the hydraulic cylinder are calculated as follows: T dact =Cylinder-side pressure * Cylinder-side acting area - Cavity-side pressure * Cavity-side acting area T Oact =Cylinder-side pressure * Cylinder-side action area - Cavity-side pressure * Cavity-side action area; (2) The force deviation between the driving side and the operating side cylinder of the ironing roller is controlled by PI: that is, the actual force of the cylinder is equal to the given force of the cylinder, so that the ironing force on the driving side and the operating side of the ironing roller is constant at the given ironing force.

5. The method for controlling the ironing force of the rolling mill ironing roll according to claim 4, characterized in that: A method to achieve zero pressure difference between the drive side and the operating side of the ironing roller during roller changing. (1) Connect the load cell to the pressure measuring instrument and zero the weight; (2) Expand the winding shaft used for winding aluminum strip, switch the ironing roller to the rubber roller, and switch the mode to the pressing mode. Then, place a weighing sensor on the transmission side and the operation side of the contact surface between the ironing roller and the winding shaft, and ensure that the weighing sensors are equidistant from both ends of the ironing roller. (3) Modify G 1d G 2d When the values ​​of K1 and K2 in the polynomial are the same as the pressure force detected by the load cells on the transmission side and the operation side, the calibration is complete.

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