Continuous variable convexity roll shape parameter optimization design method

Abstract

The invention provides a continuous variable convexity roll shape parameter optimization design method, and relates to the technical field of metallurgy hot rolling. The method comprises the following steps: firstly, collecting basic equipment parameters and roll shape design parameters, then counting a working roll shifting distribution proportion, determining a roll gap convexity adjustment range optimization direction, and calculating an average roll shifting position and an average roll gap convexity corresponding to a maximum interval of roll shifting in the direction in an actual production record; then an optimization step length is given, the roll gap convexity adjustment range is adjusted, and the corresponding average roll shifting position of the average roll gap convexity of the original roll shifting maximum interval after each convexity adjustment range is optimized is calculated; determining a value for optimizing the convexity adjustment range; and finally, calculating the parameter value of the optimized roller shape to obtain a new roller shape curve of the continuous variable convexity roller. According to the method, the roll gap convexity adjusting range is optimized according to the actual channeling roll distribution of the production line, the plate shape adjusting and controlling capacity of the continuous variable convexity roll is released, the stability of the rolling process is improved, the convexity overrun condition is reduced, and the plate shape control precision and the product competitiveness of the production line are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metallurgical hot rolling, and particularly to an optimization design method for continuously variable crown roll profile parameters. Background Art

[0002] The continuously variable crown technology (Continuously Variable Crown, abbreviated as CVC) realizes continuous changes in the work roll gap shape through axial movement, thereby precisely adjusting the crown, enabling the rolling mill to more flexibly control the thickness of the sheet and meet the crown control requirements of different rolling schedules, so it has been widely used. The CVC roll profile curve generally adopts an S shape, and the commonly used curve is a cubic polynomial. The expression of the upper work roll is:

[0003] y t0 (x) = a1x + a2x 2 + a3x 3

[0004] In the formula, x is the roll body coordinate, and a1, a2, and a3 are roll profile parameters.

[0005] The upper and lower work rolls of the CVC rolling mill are arranged in anti-symmetry. The expression of the lower work roll is:

[0006] y b0 (x) = y t0 (L - x)

[0007] In the formula, L is the roll body length.

[0008] In actual production, an unreasonable roll body curve will cause uneven wear of the roll, greatly reducing the flatness control accuracy of the rolling mill and directly affecting the flatness quality of the finished rolled piece. Some scholars design a reasonable working roll profile curve by optimizing the roll profile parameters, and use the crown formed during the shifting process of the upper and lower working rolls to control the initial crown of the incoming rolled piece. Patent CN112906160B discloses a calculation method for the equivalent roll profile adjustment range of a continuously variable crown working roll, which can quantitatively calculate the equivalent roll profile adjustment range of the optimized continuously variable crown working roll without relying on the experience of flatness experts, improving the utility of the continuously variable crown working roll. Patent CN106547959B discloses a CVC roll profile parameter optimization calculation method based on the minimum variance of roll diameters. It fully considers the differences in the specifications of the incoming rolled pieces and the crown control requirements for different specifications of rolled pieces. For all typical specifications of rolled pieces in the production site, the variance of the roll diameters of the upper and lower working rolls of the CVC temper mill is set as the objective function, and the good flatness of the outgoing rolled piece is used as the constraint condition. By optimizing the calculation of the roll profile parameters, the first-order coefficient of roll profile grinding that meets the actual production is obtained. Literature 1 (Zhou Jie, Liu Jianhua, Xu Zuhong, et al. Research on the Optimization and Application of CVC Roll Profile of 2250 Wide Strip Hot Continuous Rolling Mill in Liugang [J]. China Metallurgy, 2012, 22(06): 17-21.) analyzed and summarized the production data, optimized the crown adjustment range, obtained good results, and improved the flatness quality of the products.

[0009] In the existing CVC roll profile parameter optimization technologies, the optimization methods often rely on general roll profile design experience and standards, failing to pay attention to the distribution of CVC roll shifting in actual industrial production, especially the influence on flatness control when the CVC roll is in the extreme position. There is a lack of a method for quickly optimizing roll profile parameters according to the actual performance during the application of a specific CVC roll profile curve in an industrial production line, making it difficult for process technicians to quickly optimize the CVC roll profile, which is not conducive to improving the flatness quality of products and reducing the competitiveness of products. Summary of the Invention

[0010] In order to solve the technical problem that during the finish rolling process of the rolled piece in the prior art, the proportion of the working roll shifting distribution near the limit is too large, which will cause the roll to often lose the flatness adjustment ability and result in uneven local wear of the roll, thus affecting the rolling stability and the flatness hit rate of the rolled piece, the embodiment of the present invention provides a method for optimizing the design of continuously variable crown roll profile parameters, which optimizes the roll profile parameters according to the shifting distribution situation statistically recorded in the production records. This method effectively avoids the situation where the shifting of the continuously variable crown working roll is in the extreme position during actual operation, thereby releasing the shifting ability, making the shifting adjustment have a surplus, ensuring the stability of production rolling, and improving the accuracy of flatness control. The technical solution is as follows:

[0011] A method for optimizing the design parameters of a continuously variable crown roll profile, the method comprising:

[0012] S1. Collect basic equipment parameters and roll profile design parameters;

[0013] S2. Divide the variation range of the roll shifting amount evenly into N roll shifting intervals, and count the proportion of the actual roll shifting positions of the work rolls in each roll shifting interval in the production records;

[0014] S3. Determine the direction for optimizing the roll gap crown adjustment range, and calculate the average roll shifting position S corresponding to the maximum interval of roll shifting in the optimization direction in the actual production records m and the corresponding average roll gap crown C m ;

[0015] S4. Given the optimization step size △C and the optimization intermediate parameter i, calculate the average roll shifting position S in the corresponding roll shifting interval after the roll gap crown adjustment range is optimized for C m : m_yi S5. According to the average roll shifting position S corresponding to the expected maximum interval of roll shifting after each optimization

[0016] and the average roll shifting position S corresponding to the maximum interval of roll shifting before optimization, determine the value of the optimized crown adjustment range; m_yi m

[0017] S6. Calculate the parameter values a1, a2, and a3 of the new roll profile curve after the crown adjustment range is optimized;

[0018] S7. Calculate the new continuously variable crown roll profile curve.

[0019] The basic equipment parameters in step S1 include the work roll body length L, the roll shifting stroke range [S min , S max , and the normal rolling workpiece width B; the roll profile design parameters include the roll gap crown adjustment range [C1, C2].

[0020] Among them, S min is the minimum roll shifting stroke, S max is the maximum roll shifting stroke; C1 is the minimum roll gap crown adjustment value, and C2 is the maximum roll gap crown adjustment value.

[0021] In step S2, the range of each of the N roll shifting intervals The nth interval is (S min +(n - 1)·ΔN, S min +n·ΔN],

[0022] where n is the roll shifting interval serial number.

[0023] For example, N is taken as 40, and in the hot rolling production line, S​​max is generally a fixed value of 100 mm, then the nth interval is (S min + 5(n - 1), S min + 5n].

[0024] In the step S3, the optimization directions of the roll gap crown adjustment range are divided into three categories: negative, positive, and simultaneous positive and negative direction optimizations. When the proportion of the positive limit of the roll shift is too large, the optimization direction of the roll gap crown adjustment range is negatively optimized. When the proportion of the negative limit of the roll shift is too large, the optimization direction of the roll gap crown adjustment range is positively optimized. When the proportions of both the positive and negative limits of the roll shift are too large, the optimization direction of the roll gap crown adjustment range is simultaneously optimized in both positive and negative directions; among them, if the roll shift interval length is divided by 5, the proportion of the roll shift limit position exceeding 6% is considered too large; if the roll shift interval length is divided by 10, the proportion of the roll shift limit position exceeding 12% is considered too large; the specific calculation process is as follows:

[0025] (1) If the optimization direction of the roll gap crown adjustment range is negative, the largest interval of the roll shift is the n f th, the average roll shift position corresponding to the largest interval is S f , and the corresponding average roll gap crown is C f , then:

[0026]

[0027] (2) If the optimization direction of the roll gap crown adjustment range is positive, the largest interval of the roll shift is the n z th, the average roll shift position corresponding to the largest interval is S z , and the corresponding average roll gap crown is C z , then:

[0028]

[0029]

[0030] Among them, C1 is the minimum value of the roll gap crown adjustment, C2 is the maximum value of the roll gap crown adjustment, and ΔN is the range of each roll shift interval.

[0031] In the step S4, the roll gap crown adjustment range after each optimization is [C 1_yi , C 2_yi , where:

[0032] (1) If the proportion of the positive limit of the roll shift in the production record is too large and the roll gap crown adjustment range needs to be negatively optimized, then C 1_yi = C1, C 2_yi = C2 – i·△C;

[0033] (2) If the proportion of the negative limit of the roll shift in the production record is too large and the roll gap convexity adjustment range needs to be optimized in the positive direction, then C 1_yi = C1 + i·△C, C 2_yi = C2;

[0034] (3) If the proportions of both the positive and negative limits of the roll shift in the production record are too large and the roll gap convexity adjustment range needs to be optimized in both the positive and negative directions, then C 1_yi = C1 + i·△C, C 2_yi = C2 – i·△C;

[0035] Among them, the length of the convexity adjustment range × 1% ≤ △C ≤ the length of the convexity adjustment range × 5%, and the length of the convexity adjustment range = C 2_ - C1;

[0036] Calculate the average roll gap convexity C corresponding to the interval with the largest roll shift in the optimized direction m After each optimization of the convexity adjustment range, the average roll shift position S in the corresponding roll shift interval m_yi :

[0037]

[0038] Among them, i = 1, 2, 3…; C1 is the minimum value of the roll gap convexity adjustment, C2 is the maximum value of the roll gap convexity adjustment; S max is the maximum value of the roll shift stroke.

[0039] In the step S5, by setting the roll shift amount △S released at the expected limit position, the optimization intermediate parameter i is determined, and further the value C of the finally optimized convexity adjustment range is calculated 1_ybest and C 2_ybest ;

[0040] Among them, △S ≤ |S m - S m_yi |; C 1_ybest and C 2_ybest The calculation process is the same as that in step S4. △S is a fixed value, with a minimum of 20mm, and is adjusted in steps of 5 according to actual needs.

[0041] If positive and negative direction optimizations are carried out simultaneously, S m , C m are calculated for both the negative and positive optimization directions. Among them, S f , C f are calculated for the negative direction; S z , C z are calculated for the positive direction. By substituting △S ≤ |S m - S m_yi |, we get: S m_yi - S z ≥ △S, S f - Sm_yi ≥△S, solve the system of these two inequalities to obtain the range of i that meets the conditions, and thus determine the value of i.

[0042] In the step S6, the calculation process of the parameter values a1, a2, and a3 of the new roll profile curve after optimizing the camber adjustment range is as follows:

[0043]

[0044] a1 = -a2L - 3a3(L / 2) 2 -a3B 2 / 4;

[0045] Where: S max is the maximum value of the roll shifting stroke; C 1_ybest is the minimum value of the camber adjustment range after final optimization, C 2_ybest is the maximum value of the camber adjustment range after final optimization; L is the length of the work roll body; B is the width of the regularly rolled workpiece.

[0046] In the step S7, calculate the new continuously variable camber roll profile curve y(x) according to the curve parameters optimized in the step S6:

[0047] y(x) = a1x + a2x 2 + a3x 3 .

[0048] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0049] The optimized roll profile effectively avoids the situation where the roll shifting of the continuously variable camber work roll is at the limit position during actual operation, releases the roll shifting adjustment ability, effectively guarantees the smoothness of the workpiece rolling process, reduces the situation where the camber of the workpiece exceeds the specified range, thereby significantly improving the camber hit rate and enhancing the accuracy of flatness control. At the same time, due to the reduction in the frequent adjustment times near the limit of roll shifting, the equipment wear and maintenance frequency are reduced, thereby extending the service life of the roll and reducing the equipment maintenance cost. In addition, the present invention can adapt to the diverse requirements under different rolling conditions, is suitable for the production of various specifications of products, further enhances the adaptability and efficiency of the production line, reduces the production cost, and improves the economic benefits. Brief Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0051] Figure 1 It is a flowchart of a method for optimizing the design parameters of a continuously variable crown roll shape provided by an embodiment of the present invention;

[0052] Figure 2 It is a comparison between the original roll shape of the production line and the roll shape curve optimized by using the method of the present invention;

[0053] Figure 3 It is a comparison of the roll gap crown between the original roll shape of the production line and the roll shape optimized by using the method of the present invention at different shifting positions of the work roll;

[0054] Figure 4 It is a comparison of the shifting distribution of each on-machine experiment for one month between the original roll shape of the production line and the roll shape optimized by using the method of the present invention;

[0055] Figure 5 It is a comparison of the hit rates of different specifications of crowns between the original roll shape of the production line and the roll shape optimized by using the method of the present invention. Specific embodiments

[0056] The following describes the technical solutions in the present invention with reference to the accompanying drawings.

[0057] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as an "example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly speaking, the use of the word "example" aims to present concepts in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be that both are present, or either one of the two can be selected.

[0058] In the embodiments of the present invention, sometimes subscripts such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meanings they express are the same.

[0059] To make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0060] The embodiments of the present invention provide a method for optimizing the design parameters of a continuously variable crown roll shape. As Figure 1 shown in the flowchart of the method for optimizing the design parameters of a continuously variable crown roll shape, the method may include the following steps:

[0061] S1. Collect basic equipment parameters and roll shape design parameters;

[0062] S2. Divide the variation range of the shifting amount of the work roll into N shifting intervals evenly, and count the proportion of the actual shifting positions of the work roll in each shifting interval in the production records;

[0063] S3. Determine the direction for optimizing the roll gap crown adjustment range, and calculate the average roll shifting position S corresponding to the maximum interval of roll shifting in the optimization direction in the actual production records. m and the corresponding average roll gap crown C. m ;

[0064] S4. Given the optimization step size △C and the optimization intermediate parameter i, calculate the average roll shifting position S in the roll shifting interval corresponding to the optimized roll gap crown adjustment range for C. m : m_yi :

[0065] S5. Determine the value of the optimized crown adjustment range based on the average roll shifting position S corresponding to the maximum interval of the expected roll shifting after each optimization and the average roll shifting position S corresponding to the maximum interval of roll shifting before optimization. m_yi and the average roll shifting position S corresponding to the maximum interval of roll shifting before optimization. m

[0066] S6. Calculate the parameter values a1, a2, and a3 of the new roll profile curve after optimizing the crown adjustment range.

[0067] S7. Calculate the new continuous variable crown roll profile curve.

[0068] The following is illustrated with specific embodiments.

[0069] In the specific design, the steps are as follows:

[0070] Step 1: Collect the basic equipment parameters, the working roll body length L = 2250 mm, the roll shifting stroke range [-100 mm, 100 mm], and the normal rolling workpiece width B = 1675 mm; collect the roll profile design parameters, mainly including the roll gap crown adjustment range [0.579 mm, -0.150 mm].

[0071] Step 2: Divide the change range of the roll shifting amount into 40 roll shifting intervals evenly, and the range of the nth interval is (-100 + 5(n - 1), -100 + 5n]. Statistically analyze the proportion of the actual roll shifting position of the working roll in each roll shifting interval in the production records as shown in Table 1.

[0072] Table 1 Distribution proportion of actual roll shifting positions

[0073]

[0074]

[0075] Step 3: Select to optimize in both the negative and positive directions of the roll gap crown adjustment range. The maximum roll shifting intervals in the negative and positive directions of the crown adjustment range in the production records are (90, 95] and (-100, -95] respectively. Then n f is 39, nz is 1, and the corresponding average roll shift position:

[0076]

[0077] The corresponding average roll gap crown:

[0078]

[0079] Step 4: Given the optimization step size △C = 0.01, optimize the intermediate parameter i (i = 1, 2, 3...;), and make the roll gap crown C after each optimization 1_yi = C1 + i·△C, C 2_yi = C2 – i·△C, calculate the average roll gap crown C corresponding to the maximum range of the original forward and backward roll shifts before optimization m In the roll shift interval corresponding to after optimization, the average roll shift position S m_yi :

[0080] Forward roll shift:

[0081]

[0082] Backward roll shift:

[0083]

[0084] Step 5: By setting the roll shift amount △S = 25 released at the expected limit position, and satisfying △S ≤ |S m - S m_yi |, to determine that the value of the intermediate parameter i can be 10, and further calculate the values of the convexity adjustment range after final optimization C 2_ybest = C2 – 10×0.01 = -0.25, C 1_ybest = C1 + 10×0.01 = 0.679.

[0085] Step 6: Calculate the parameter values of the new roll profile curve after optimizing the convexity adjustment range, a1, a2, a3, where:

[0086]

[0087] a1 = -2250×a2 - 3×a3×(2250 / 2) 2 -(1675 2 / 4)×a3 ≈ 1.70282×10 -3

[0088] Step 7: Calculate the new continuously variable crown roll profile curve y(x) through the curve parameters optimized in Step 6:

[0089] y(x) = 1.70282×10 -3x + (-1.97970×10 -6 )x 2 + 6.11687×10 -10 x 3

[0090] Experimental effect:

[0091] Apply the method for optimizing the design parameters of the continuously variable crown roll shape provided by the embodiment of the present invention to the rolling production of a certain hot strip mill production line. Figure 2 It is a comparison between the original roll shape of the production line and the roll shape curve optimized by using the method of the present invention; Figure 3 It is a comparison of the roll gap crown at different shifting positions between the original roll shape of the production line and the roll shape optimized by using the method of the present invention. The positive and negative crown adjustment ranges of the optimized roll shape are both increased by 0.1 mm, enhancing the crown control ability of shifting. Figure 4 It is a comparison of the shifting distribution of each on-machine experiment for one month between the original roll shape of the production line and the roll shape optimized by using the method of the present invention. It can be clearly seen that after the on-machine experiment of the roll shape optimized by using the method of the present invention, the proportion of the work roll shifting in the negative limit and positive limit ranges decreases significantly. The proportion in the interval (90, 95] decreases from 7.45% of the original roll shape to 3.01%, and the proportions in the positive shifting limit ranges near the intervals (85, 90], (80, 85], etc. also show a downward trend, and the overall shifting distribution is more uniform. Figure 5 It is a comparison of the convexity hit rates of different specifications between the original roll shape of the production line and the roll shape optimized by using the method of the present invention. It can be seen from the figure that the convexity hit rates of the optimized roll shape for different thickness specifications are significantly improved. The improvement of the convexity C40 hit rate for the thickness specification less than or equal to 6 mm is more significant, increasing from 70.21% of the original roll shape to 78.10% after optimization. The method of the present invention effectively reduces the proportion distribution of the work roll near the shifting limit, releases the shifting adjustment ability near the limit, significantly improves the convexity hit rate of the rolled piece, and improves the product quality.

[0092] As mentioned above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A method for optimizing the design of continuously variable crown roll parameters, characterized in that: The method comprises: S1. Collect basic equipment parameters and roll shape design parameters; S2. Divide the range of roll shifting into N roll shifting intervals, and count the proportion of the actual roll shifting position of the working roll in each roll shifting interval in the production records; S3, determine the direction of the optimized roll gap convexity adjustment range, and calculate the average roll shifting position S corresponding to the maximum range of roll shifting in the optimized direction in the actual production record m And the corresponding average roll gap convexity C m ; S4. Given the optimization step size △C and the optimization intermediate parameter i, calculate C m Average roll shifting position S in the corresponding roll shifting interval after the roll gap crown adjustment range is optimized m_yi : S5, the average roller shifting position S corresponding to the maximum range of roller shifting expected after each optimization m_yi The average roller position S corresponding to the maximum interval of the optimized front roller m , to determine the value of the optimized convexity adjustment range; S6, calculating the parameter values ​​a1, a2, a3 of the new roller shape curve after the crown adjustment range is optimized; S7. Calculate and obtain a new continuously variable crown roller shape curve.

2. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: The basic equipment parameters in step S1 include the working roll body length L, the roll shifting stroke range [S min ,S max ], normal rolled workpiece width B; roller shape design parameters include roll gap convexity adjustment range [C1, C2].

3. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In step S2, each of the N roller shifting intervals has a range of The nth interval is (S min +(n-1)·ΔN,S min +n·ΔN], Among them, S max is the maximum value of the roller shifting stroke, S min is the minimum value of the roller shifting stroke, and n is the roller shifting interval number.

4. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In the step S3, the optimization direction of the roll gap convexity adjustment range is divided into three categories: negative, positive, and simultaneous optimization of positive and negative directions. When the positive limit of the roll shifting accounts for too large a proportion, the optimization direction of the roll gap convexity adjustment range is negatively optimized. When the negative limit of the roll shifting accounts for too large a proportion, the optimization direction of the roll gap convexity adjustment range is positively optimized. When the positive and negative limits of the roll shifting account for too large a proportion, the optimization direction of the roll gap convexity adjustment range is simultaneously optimized in the positive and negative directions. Among them, if the length of the roll shifting interval is 5 mm, the proportion of the roll shifting limit position exceeds 6%, which is too large; if the length of the roll shifting interval is 10 mm, the proportion of the roll shifting limit position exceeds 12%, which is too large. The specific calculation process is as follows: (1) If the optimization direction of the roll gap convexity adjustment range is negative, the maximum range of roll shifting is nth f The average roller position corresponding to the maximum interval is S f , the corresponding average roll gap convexity is C f ,but: (2) If the optimization direction of the roll gap convexity adjustment range is positive, the maximum range of roll shifting is nth z The average roller position corresponding to the maximum interval is S z , the corresponding average roll gap convexity is C z ,but: Among them, S max is the maximum value of the roller shifting stroke, S min is the minimum value of the roller shifting stroke, C1 is the minimum value of the roller gap convexity adjustment, C2 is the maximum value of the roller gap convexity adjustment, and ΔN is the range of each roller shifting interval.

5. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In step S4, the roller gap convexity adjustment range after each optimization is [C 1_yi ,C 2_yi ],in: (1) If the positive limit of roll shifting in the production record accounts for too large a proportion, the roll gap crown adjustment range needs to be negatively optimized, then C 1_yi =C1,C 2_yi =C2–i·△C; (2) If the negative limit of roll shifting in the production record accounts for too large a proportion, the roll gap crown adjustment range needs to be positively optimized, then C 1_yi =C1+i·△C,C 2_yi =C2; (3) If the proportion of positive and negative limits of roll shifting in the production record is too large, the roll gap crown adjustment range needs to be optimized in both positive and negative directions, then C 1_yi =C1+i·△C,C 2_yi =C2–i·△C; Among them, the convexity adjustment range length × 1% ≤ △C ≤ convexity adjustment range length × 5%, convexity adjustment range length = C 2_ -C1; If the length of the roller shifting interval is 5mm, the roller shifting limit position accounts for more than 6%, which is too large; if the length of the roller shifting interval is 10mm, the roller shifting limit position accounts for more than 12%, which is too large; Calculate the average roll gap convexity C corresponding to the interval with the largest roll shift in the optimized direction m After each optimization of the crown adjustment range, the average roller position S in the corresponding roller shifting interval is m_yi : Where, i = 1, 2, 3…; C1 is the minimum roll gap crown adjustment value, C2 is the maximum roll gap crown adjustment value; S max It is the maximum value of the roller stroke.

6. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In step S5, the roller displacement ΔS of the expected limit position release is set, and ΔS≤|S m -S m_yi |, to determine the optimization intermediate parameter i, and further calculate the value C of the final optimized convexity adjustment range 1_ybest and C 2_ybest ; C 1_ybest and C 2_ybest The calculation process of is the same as that in step S4; Among them, △S is a fixed value with a minimum of 20mm. It can be increased in steps of 5 according to actual needs.

7. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In step S6, the calculation process of the parameter values ​​a1, a2, and a3 of the new roller shape curve after the convexity adjustment range is optimized is as follows: <h2 style=";text-align:left;direction:ltr">a1 = - a2L - 3a3(L / 2)<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -a3B<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> / 4; Where: S max C is the maximum value of the roller shifting stroke; 1_ybest C is the minimum value of the final optimized convexity adjustment range. 2_ybest is the maximum value of the convexity adjustment range after final optimization; L is the length of the working roll body; B is the width of the workpiece during normal rolling.

8. The method for optimizing the design of continuously variable crown roll parameters according to claim 1, characterized in that: In step S7, a new continuously variable crown roll curve y(x) is calculated by using the curve parameters optimized in step S6: y(x)=a1x+a2x 2 +a3x 3 。

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