A method for compensating oil film thickness by distinguishing acceleration and deceleration of a rolling mill
By recording and fitting the rolling speed and roll joint change data of the speed increase and deceleration stages in the rolling mill, and differentiating and calculating the oil film thickness compensation, the problem of the speed increase and deceleration stage compensation in the prior art affecting AGC adjustment, and rolling is realized The precise oil film thickness adjustment during the manufacturing process improves the strap thickness difference hit rate.
Patent Information
- Application Number
- CN202210758391.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-06-30
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2042-06-30
AI Technical Summary
The prior art uses the same calculation compensation result in both the speed increase and deceleration sections of the rolling mill to compensate the oil film thickness, which affects the automatic gain control AGC adjustment during the rolling process.
By setting the rolling mill pressing and pressure, the rolling mill runs stably at the waiting speed, record the rolling speed and roll joint change data, and fit the data of the speed increase and deceleration stages respectively to obtain the correspondence between the oil film thickness and the rolling force and speed Relationship, achieves the oil film thickness compensation for distinguishing the speed increase and speed reduction stages.
The precise oil film thickness compensation for the speed increase and speed reduction sections during the rolling process is achieved, which solves the problem of thinness and thickness of the strip steel, and improves the thickness difference hit rate of the strip steel.
Smart Images
Figure CN115193926B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of metallurgical automation control, and in particular to an oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill. Background Art
[0002] In the field of metal rolling, when the rolling mill support rolls use oil film bearings, the thickness of the oil film will change with the actual rolling force and rolling speed, thereby affecting the loaded roll gap. Therefore, oil film thickness compensation is often required in the roll gap calculation and automatic gain control AGC adjustment of the rolling process.
[0003] Patent application number CN111553027A proposes a method for calculating the oil film thickness of hot-rolled strip steel based on oil film force. It discloses a method in which a rolling mill keeps the zero roll gap unchanged, collects the pressure change relative to the zero adjustment pressure when the speed increases at different accelerations, and then calculates the oil film thickness used to compensate the roll gap according to the rolling mill stiffness. The paper "Research on the Application of Oil Film Thickness Compensation in Automatic Thickness Control System of Cold Rolling Mill" (Metallurgical Automation, 30(6), 5.) measured the roll gap change value of a cold rolling mill under different roll speeds and rolling pressures, and realized the oil film thickness compensation by using the table lookup method combined with the interpolation method.
[0004] During actual rolling and experimental processes, it was found that when the rolling mill uses the same acceleration and deceleration during the speed-up and deceleration processes, there will still be differences in the change of oil film thickness. Therefore, if the same calculation compensation result is used for compensation in both the speed-up and deceleration sections, it will affect the AGC adjustment compensation during the rolling process. Summary of the invention
[0005] The present invention provides an oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill, so as to solve the technical problem that the prior art uses the same calculation compensation result for compensation in both the acceleration and deceleration sections, which will affect the automatic gain control AGC adjustment compensation during the rolling process.
[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0007] A method for compensating oil film thickness for distinguishing acceleration and deceleration of a rolling mill, comprising:
[0008] S1, set the rolling mill pressing and pressure, make the rolling mill run stably at the waiting speed, adjust the extension of the rolling mill AGC cylinder, make the rolling mill press, and keep the pressure at the set rolling mill pressing and pressure unchanged;
[0009] S2, increasing the speed of the rolling mill from the waiting speed to the maximum rolling speed at the rolling acceleration, and recording the rolling speed and roll gap change data in the speed increase stage from the waiting speed to the maximum rolling speed;
[0010] S3, decelerating the rolling mill from the maximum rolling speed to the waiting speed at the rolling deceleration, and recording the rolling speed and roll gap change data in the deceleration stage from the maximum rolling speed to the waiting speed;
[0011] S4, iteratively executing S1 to S3 until a preset maximum number of iterations is reached, and obtaining multiple sets of rolling speed and roll gap change data in the speed-up stage, as well as rolling speed and roll gap change data in the deceleration stage under different pressing and pressure; wherein different rolling mill pressing and pressure are set in each iteration;
[0012] S5, respectively fitting the rolling speed and roll gap change data in the speed-up stage and the rolling speed and roll gap change data in the deceleration stage under different pressing and pressure, to obtain the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the speed-up stage, and the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the deceleration stage;
[0013] S6, in the speed-up stage and the deceleration stage, the oil film thickness for compensating the roll gap is calculated according to the corresponding relationship between the oil film thickness in the corresponding stage and different rolling forces and rolling speeds, so as to realize the oil film thickness compensation.
[0014] Furthermore, the changing data of the rolling speed and the roll gap in the speed-up stage under different pressing and pressure, and the changing data of the rolling speed and the roll gap in the speed-down stage are respectively fitted, including:
[0015] According to the rolling speed and roll gap variation data in the speed-up stage under different pressing and pressure, the relationship among the rolling speed, pressure and roll gap in the speed-up stage is fitted into a 5×5-order polynomial, and the corresponding equation coefficients are obtained.
[0016] According to the variation data of rolling speed and roll gap in the deceleration stage under different pressing and pressure, the relationship among rolling speed, pressure and roll gap in the deceleration stage is fitted into a 5×5 order polynomial, and the corresponding equation coefficients are obtained.
[0017] Furthermore, the waiting speed is 10% of the maximum operating speed allowed by the rolling mill.
[0018] Furthermore, the maximum number of iterations and the rolling mill pressure and stress during each iteration are adjusted according to actual production needs.
[0019] Furthermore, the rolling acceleration is the acceleration of the rolling mill during the actual production process;
[0020] The value of the acceleration during rolling is adjusted according to actual production needs.
[0021] Furthermore, the deceleration during rolling is the acceleration when the rolling mill decelerates during the actual production process;
[0022] The value of the deceleration during rolling is adjusted according to actual production needs.
[0023] Furthermore, the value of the maximum rolling speed is adjusted according to actual production needs.
[0024] The beneficial effects brought about by the technical solution provided by the present invention include at least:
[0025] The present invention obtains the corresponding relationship between the oil film thickness in the speed-up section and the speed-down section by using the polynomial fitting method through actual measurement data. In the actual rolling process, the speed-up section and the speed-down section can be distinguished to perform accurate oil film thickness compensation, which can effectively solve the problem of thin strip steel in the rolling speed-up process and thick strip steel in the speed-down process, and has positive significance for improving the hit rate of the thickness difference of the rolled strip steel. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0027] Figure 1 It is a flow chart of an oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill provided by an embodiment of the present invention;
[0028] Figure 2 It is a schematic diagram of the vertical movement of the roller; among them, (a) is a schematic diagram of the roller rotating at a low speed, (b) is a schematic diagram of the roller rotating at an accelerated speed, (c) is a schematic diagram of the roller rotating at a high speed, and (d) is a schematic diagram of the roller rotating at a decelerated speed.
[0029] Description of reference numerals:
[0030] 21. Support roller axis; 22. Support roller oil film bearing; 11. Oil film thickness at low speed;
[0031] 12. Oil film thickness during acceleration; 13. Oil film thickness during high-speed rotation; 14. Oil film thickness during deceleration. DETAILED DESCRIPTION
[0032] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0033] This embodiment provides a method for compensating the oil film thickness for distinguishing the acceleration and deceleration of a rolling mill. The method can be implemented by an electronic device, such as Figure 2 As shown, the principle of this method is: under the state of constant pressure waiting speed, the support roller axis 21 rotates in the support roller oil film bearing 22 in a clockwise direction, at which time the oil film thickness is the oil film thickness 11 at low speed, and the speed is increased to the maximum rolling speed at a constant acceleration. During the speed increase process, the oil film thickness is the oil film thickness 12 at accelerated speed, and when the speed is increased to the maximum rolling speed, the oil film thickness is the oil film thickness 13 at high speed. After stabilizing for a period of time, the speed is increased to the waiting speed at a constant deceleration, and the oil film thickness during the deceleration process is the oil film thickness 14 at decelerated speed. Adjust different pressures and maintain them, repeat the above speed increase and deceleration process, record the roll gap and speed data, and use the polynomial fitting method to obtain the corresponding oil film thickness, pressure and speed relationship.
[0034] Specifically, the execution process of this method is as follows Figure 1 As shown, the following steps are included:
[0035] S1, set the rolling mill pressing and pressure, make the rolling mill run stably at the waiting speed, adjust the extension of the rolling mill AGC cylinder, make the rolling mill press, and keep the pressure at the set rolling mill pressing and pressure unchanged;
[0036] The waiting speed is 10% of the maximum operating speed allowed by the rolling mill. The value of the maximum rolling speed can be adjusted according to actual production needs.
[0037] S2, increasing the speed of the rolling mill from the waiting speed to the maximum rolling speed at the rolling acceleration, and recording the rolling speed and roll gap change data in the speed increase stage from the waiting speed to the maximum rolling speed;
[0038] The rolling acceleration is the acceleration of the rolling mill during the actual production process, and the unit is m / s 2 ; The value of the acceleration during rolling can be adjusted according to actual production needs.
[0039] S3, decelerating the rolling mill from the maximum rolling speed to the waiting speed at the rolling deceleration, and recording the rolling speed and roll gap change data in the deceleration stage from the maximum rolling speed to the waiting speed;
[0040] The rolling deceleration is the acceleration of the rolling mill during deceleration in the actual production process, and the unit is m / s. 2 ; The value of the deceleration during rolling can be adjusted according to actual production needs.
[0041] S4, iteratively executing S1 to S3 until a preset maximum number of iterations is reached, and obtaining multiple sets of rolling speed and roll gap change data in the speed-up stage, as well as rolling speed and roll gap change data in the deceleration stage under different pressing and pressure; wherein different rolling mill pressing and pressure are set in each iteration;
[0042] The maximum number of iterations and the rolling mill pressure and stress set in each iteration can be adjusted according to actual production needs.
[0043] S5, respectively fitting the rolling speed and roll gap change data in the speed-up stage and the rolling speed and roll gap change data in the deceleration stage under different pressing and pressure, to obtain the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the speed-up stage, and the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the deceleration stage;
[0044] Specifically, in this embodiment, the data processing process is as follows:
[0045] According to the rolling speed and roll gap variation data in the speed-up stage under different pressing and pressure, the relationship among the rolling speed, pressure and roll gap in the speed-up stage is fitted into a 5×5-order polynomial, and the corresponding equation coefficients are obtained.
[0046] According to the variation data of rolling speed and roll gap in the deceleration stage under different pressing and pressure, the relationship among rolling speed, pressure and roll gap in the deceleration stage is fitted into a 5×5 order polynomial, and the corresponding equation coefficients are obtained.
[0047] S6, in the speed-up stage and the deceleration stage, the oil film thickness for compensating the roll gap is calculated according to the corresponding relationship between the oil film thickness in the corresponding stage and different rolling forces and rolling speeds, so as to realize the oil film thickness compensation.
[0048] Below, take a hot rolling finishing mill as an example to illustrate the implementation process of this method, and operate according to the following steps:
[0049] (1) Define the total number of times the rolling mill presses with different pressures as n, which is 6, the actual number of times the roller presses as i, and the pressure of each press as P. i , i is less than or equal to n, the first pressure is i equal to 1, and the pressure P 1 3000kN;
[0050] Where n is the total number of times the rolling mill presses with different pressures, i is the number of times the rolling mill actually presses with different pressures, P i is the actual pressure that the rolling mill needs to maintain each time it presses, in kN, where n, i, P i Both can be adjusted according to actual production needs.
[0051] (2) The rolling mill is set at a waiting speed S Z Stable operation, where S Z is 10% of the maximum operating speed allowed by the rolling mill. Assuming that the maximum operating speed of the rolling mill is 18.6 m / s, then S ZThe speed is 1.86m / s, and the extension of the AGC cylinder of the rolling mill is adjusted to make the rolling mill press against the pressure, and the pressure is kept constant at 3000kN;
[0052] (3) The rolling mill is accelerated at 0.3 m / s 2 Increase the speed to the maximum rolling speed S at 1.86m / s r , where S is defined r The speed is 13.08m / s, and the speed and roll gap data of the rolling mill in the speed-up section are recorded;
[0053] (4) The rolling mill is decelerated at 0.3 m / s during rolling. 2 Decelerate from 13.08m / s to the waiting speed of 1.86m / s, and record the speed and roll gap data of the rolling mill in the deceleration section;
[0054] (5) Add 1 to the actual number of times the rolling mill presses i, and determine whether i is greater than n. If so, end the pressing process and process the data. If less than n, define P 2 =5000kN, P 3 =7000kN, P 4 =9000kN, P 5 =11000kN, P 6 = 13000 kN, and repeat the above process (2) to (4);
[0055] (6) By obtaining the speed and roll gap data at different pressures, data processing is performed, and the relationship between the speed, pressure and roll gap in the speed-up section and the speed-down section is fitted into a 5×5 order polynomial to obtain the corresponding equation coefficients.
[0056] In summary, the method of this embodiment first defines the total number of times the rollers are pressed against each other at different pressures, so that the rolling mill presses the rollers against each other once at the waiting speed to achieve a constant target pressure, and then increases the speed to the maximum rolling speed, and records the roller gap and speed data of this speed-up section. Then decelerate to the waiting speed, and record the roller gap and speed data of this deceleration section. After completing the above process, a second target pressure pressing is performed, and the above-mentioned acceleration and deceleration process is repeated, and the corresponding roller gap and speed data are recorded until the initial definition of the number of pressings with different pressures is completed, and the data is processed to obtain the relationship between the oil film thickness and the pressure and speed in the acceleration section and the deceleration section. This can solve the problem of thick or thin thickness caused by the acceleration and deceleration of the rolling mill during the rolling process, which has a positive significance for improving the thickness hit rate of the strip.
[0057] In addition, it should be noted that the present invention can be provided as a method, an apparatus or a computer program product. Therefore, the embodiments of the present invention can take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the embodiments of the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.
[0058] The embodiments of the present invention are described with reference to the flowcharts and / or block diagrams of the methods, terminal devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0059] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device, so that a series of operation steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable terminal device provide for implementing the process in the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.
[0060] It should also be noted that, in this article, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the elements.
[0061] Finally, it should be noted that the above is a preferred embodiment of the present invention. It should be pointed out that although the preferred embodiment of the present invention has been described, for those skilled in the art, once the basic creative concept of the present invention is known, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention. Therefore, the attached claims are intended to be interpreted as including the preferred embodiment and all changes and modifications that fall within the scope of the embodiments of the present invention.
Claims
1. A method for compensating oil film thickness for distinguishing acceleration and deceleration of a rolling mill, characterized in that: include: S1, set the rolling mill pressing and pressure, make the rolling mill run stably at the waiting speed, adjust the extension of the rolling mill AGC cylinder, make the rolling mill press, and keep the pressure at the set rolling mill pressing and pressure unchanged; S2, increasing the speed of the rolling mill from the waiting speed to the maximum rolling speed at the rolling acceleration, and recording the rolling speed and roll gap change data in the speed increase stage from the waiting speed to the maximum rolling speed; S3, decelerating the rolling mill from the maximum rolling speed to the waiting speed at the rolling deceleration, and recording the rolling speed and roll gap change data in the deceleration stage from the maximum rolling speed to the waiting speed; S4, iteratively executing S1 to S3 until a preset maximum number of iterations is reached, and obtaining multiple sets of rolling speed and roll gap change data in the speed-up stage, as well as rolling speed and roll gap change data in the deceleration stage under different pressing and pressure; wherein different rolling mill pressing and pressure are set in each iteration; S5, respectively fitting the rolling speed and roll gap change data in the speed-up stage and the rolling speed and roll gap change data in the deceleration stage under different pressing and pressure, to obtain the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the speed-up stage, and the corresponding relationship between the oil film thickness and different rolling forces and rolling speeds in the deceleration stage; S6, in the speed-up stage and the deceleration stage, the oil film thickness for compensating the roll gap is calculated according to the corresponding relationship between the oil film thickness in the corresponding stage and different rolling forces and rolling speeds, so as to realize the oil film thickness compensation; The fitting process is performed on the rolling speed and roll gap variation data in the speed-up phase under different pressing and pressure, and the rolling speed and roll gap variation data in the speed-down phase, respectively, including: According to the rolling speed and roll gap variation data in the speed-up stage under different pressing and pressure, the relationship among the rolling speed, pressure and roll gap in the speed-up stage is fitted into a 5×5-order polynomial, and the corresponding equation coefficients are obtained. According to the variation data of rolling speed and roll gap in the deceleration stage under different pressing and pressure, the relationship among rolling speed, pressure and roll gap in the deceleration stage is fitted into a 5×5 order polynomial, and the corresponding equation coefficients are obtained.
2. The oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill according to claim 1, characterized in that: The waiting speed is 10% of the maximum operating speed allowed by the rolling mill.
3. The oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill according to claim 1, characterized in that: The maximum number of iterations and the mill pressure and stress during each iteration are adjusted according to actual production needs.
4. The oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill according to claim 1, characterized in that: The rolling acceleration is the acceleration of the rolling mill during the actual production process; The value of the acceleration during rolling is adjusted according to actual production needs.
5. The oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill according to claim 1, characterized in that: The rolling deceleration is the acceleration of the rolling mill during deceleration in the actual production process; The value of the deceleration during rolling is adjusted according to actual production needs.
6. The oil film thickness compensation method for distinguishing acceleration and deceleration of a rolling mill according to claim 1, characterized in that: The value of the maximum rolling speed is adjusted according to actual production needs.