Roller profile design method and device for rolling mill work roll based on multi-segment function fitting

Abstract

The present invention relates to the fields of metallurgical machinery, automation and rolling technology, and in particular to a method and device for designing the roll shape of a rolling mill working roll based on multi-segment function fitting. The present invention sequentially carries out four stages: preliminary data statistical analysis stage, compensation curve determination, determination of the compensation curve expression for the cold rolling mill working roll, and determination of the work roll shape. The design of the work roll shape curve can reduce the quarter wave defect of cold-rolled high-strength steel, thereby improving the plate shape quality of the product. After the roll shape is designed, it can be input into the grinder in the form of discrete points for grinding. The present invention is highly feasible and low-cost to implement on a cold rolling mill. After being used on a cold rolling mill in a certain factory, it was shown that this new roll shape can significantly reduce the quarter wave of cold-rolled high-strength steel products and improve the plate shape quality of the products.

Description

Technical Field

[0001] The present invention relates to the fields of metallurgical machinery, automation and rolling technology, and in particular to a method and device for designing the profile of a rolling mill work roll based on multi-segment function fitting. Background Art

[0002] Shape is one of the most important quality indicators for plate and strip products. Shape control technology and processes have become the most value-added and technically demanding components of plate and strip rolling mills. As a high-value-added product, cold-rolled high-strength steel has a relatively good market performance. With increasingly fierce market competition, downstream customers are not only rapidly increasing their demand for high-strength steel, but are also placing strict demands on its dimensional accuracy, surface quality, and performance.

[0003] Currently, the predominant shape defect in high-strength steel is quarter wave, concentrated in high-strength steel grades with a yield strength of 600 MPa and above. Among products with a yield strength of 600 MPa and above, this defect is particularly severe in wide-width high-strength steel. This defect impacts rolling stability and subsequent processing performance, and can also reduce the performance of the final product. The presence of a quarter wave defect can cause high tension at the strip edge, leading to strip breakage and limiting the production of width and thickness extremes. Therefore, to meet customer needs, tailored roll profile design is required for wide-width high-strength steel.

[0004] When the center of the strip is stretched more and subjected to compression, while the edges are stretched less and subjected to tension, a center wave flatness defect may occur. Conversely, when the center is subjected to tension and the edges are subjected to compression, an edge wave flatness defect may occur. When the internal stress distribution is uniform, the flatness of the strip is straight. However, complex high-order wave patterns such as quarter wave and edge-center wave are caused by complex factors and are difficult to control using conventional methods.

[0005] To eliminate strip shape defects, modern shape control methods can be divided into two main aspects: one is to consider compensating for the shape of the loaded roll gap of the rolling mill, and the other is to consider the rolling mill itself. For the former, the main method is to control the finished strip shape through technical means such as improving the original convexity of the incoming strip shape, improving the initial roll gap setting, refining the rolling procedures, and changing the tension distribution. Basically, the strip shape defects can be improved to a certain extent. The latter achieves the purpose of controlling the strip shape by improving the equipment. Currently, the main methods for controlling the strip shape using rolling equipment include: roll tilting technology, hydraulic roll bending technology, roll lateral control technology, roll crossing technology, special roll shape roll technology, and roll segmented cooling control technology.

[0006] The pickling mill has a fast production rhythm and large output, and the high-strength steel produced is of various types and specifications. In order to avoid affecting the normal production rhythm, when using the working roll shape to compensate for the quarter wave of high-strength steel, the high-strength steel production plan in the specific production process should be considered.

[0007] Although there are many studies on solving various types of plate defects, there is a lack of improvement solutions for the quarter wave defect of high-strength steel, and the plate shape problems encountered in actual production have not been solved. There are few studies related to this high-order wave shape with complex causes, and the production problems affecting plate shape quality due to the quarter wave defect have not yet been solved. Summary of the Invention

[0008] In response to the above problems, the present invention provides a rolling mill working roll profile design method and device based on multi-segment function fitting, specifically a working roll profile design method that reduces the quarter wave defect of cold-rolled high-strength steel and improves the quality of cold-rolled high-strength steel plate shape through piecewise function fitting.

[0009] A rolling mill work roll profile design method based on multi-segment function fitting, the method comprising:

[0010] Collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data within multiple roll periods of the cold rolling mill;

[0011] Calculate the roller shape compensation value of each point along the roller length direction on the roller surface to obtain a preliminary compensation curve;

[0012] According to the preliminary compensation curve, the work roll shape curve is fitted in sections to obtain the corresponding fitting curve expression;

[0013] The compensation coefficient is determined based on actual production, and the final discrete point data of the work roll shape is obtained, which is used as the design basis.

[0014] Furthermore, the calculation of the roller shape compensation value at each point on the roller surface along the length direction of the roller body to obtain a preliminary compensation curve specifically includes:

[0015] Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve;

[0016] The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

[0017] Furthermore, the segmented fitting of the work roll shape curve specifically includes:

[0018] The segment positions are determined according to the characteristics of the compensation curve. First, four key points, -X0, -X1, X1, and X0, are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted separately.

[0019] Furthermore, the key points are:

[0020]

[0021] -X1=M1;

[0022] X1=M2;

[0023]

[0024] Among them, M1 and M2 are the coordinates of the transition point, and L is the length of the working roll body; among them, M1 and M2 are determined according to the analysis results of the high-strength steel plate shape data so that the roller profile crown compensation position corresponds to the strip shape defect position.

[0025] Furthermore, the first segment can be expressed by a cubic polynomial curve, as follows:

[0026] y=a0+a1x+a2x 2 +a3x 3 x∈[-X0,-X1]; the second segment can be represented by a sixth-order polynomial curve, as follows:

[0027] y=b0+b2x 2 +b4x 4 +b6x 6 x∈[-X1,X1];

[0028] The third segment can be represented by a cubic polynomial curve, as follows:

[0029] y=c0+c1x+c2x 2 +c3x 3 x∈[X1,X0];

[0030] Among them, a0, a1, a2, a3, b0, b2, b4, b6, c0, c1, c2, and c3 are the coefficients of the cubic and sextic functions respectively;

[0031] x is the transverse coordinate of the roller with the midpoint of the roller surface as the origin, the unit is mm, y is the roller shape value, the unit is μm.

[0032] Furthermore, since the original roller shape is a flat roller, it is tangent to the first section at x1 = -X0, so we get:

[0033]

[0034] Since the third section roll curve and the first section roll curve are symmetrical with respect to the center line of the working roll, the original roll shape is tangent to the third section at x2=X0, so we get:

[0035]

[0036] Furthermore, according to the obtained fitting curve expression, the roll shape value of each point is multiplied by the compensation coefficient to obtain the roll shape of the cold rolling mill work roll, and the discrete point data of the work roll roll shape are obtained.

[0037] A rolling mill work roll profile design device based on multi-segment function fitting comprises: a data statistical analysis unit, a compensation curve determination unit, a segment fitting unit and a work roll profile determination unit.

[0038] Data statistical analysis unit, used to collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data within multiple roll periods of the cold rolling mill;

[0039] The compensation curve determination unit is used to calculate the roller shape compensation value of each point along the roller length direction on the roller surface to obtain a preliminary compensation curve;

[0040] The segmented fitting unit is used to segmentally fit the work roll shape curve based on the preliminary compensation curve to obtain the corresponding fitting curve expression;

[0041] The work roll shape determination unit is used to determine the compensation coefficient based on actual production, obtain the final work roll shape discrete point data, and use it as the design basis.

[0042] Furthermore, the compensation curve determining unit is specifically configured to:

[0043] Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve;

[0044] The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

[0045] Furthermore, the segmented fitting unit is specifically used to:

[0046] The segment positions are determined according to the characteristics of the compensation curve. First, four key points, -X0, -X1, X1, and X0, are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted separately.

[0047] The present invention can reduce the quarter wave defect of cold-rolled high-strength steel by designing the roll curve of the working roll, thereby improving the plate quality of the product. After the roll curve is designed, it can be input into the grinder in the form of discrete points for grinding.

[0048] This invention is highly feasible and cost-effective to implement on a cold rolling mill. Applications on a cold tandem mill at a certain plant have shown that this new roller profile significantly reduces quarter-waves in cold-rolled high-strength steel products, improving product shape quality and ensuring stable strip flow in subsequent processes. Furthermore, the unique edge design of the new roller profile enables "loose-edge" rolling of the strip, helping to prevent edge cracking of high-strength steel strips and effectively improving production efficiency and stability.

[0049] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 A flow chart of a method for designing an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the structure of the device according to an embodiment of the present invention;

[0053] Figure 3 A schematic diagram of a work roll profile curve for controlling a quarter wave according to an embodiment of the present invention;

[0054] Figure 4 Schematic diagram of the roll shape effects of working rolls with different amplitudes according to an embodiment of the present invention;

[0055] Figure 5 Schematic diagram comparing two roller crown adjustment ranges according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0057] In existing technology, the primary flatness defect in high-strength steel is quarter wave, which is concentrated in high-strength steel grades with a yield strength of 600 MPa or above. Among products with a yield strength of 600 MPa or above, this defect is particularly severe in wide-width high-strength steel. This defect impacts rolling stability and subsequent processing performance, and can also reduce the performance of the final product. The presence of quarter wave defects can cause high tension at the strip edges, leading to strip breakage and limiting the production of extreme widths and thicknesses. Therefore, to meet customer needs, tailored roll profile design is required for wide-width high-strength steel.

[0058] To this end, the present invention proposes a rolling mill work roll profile design method and device based on multi-segment function fitting, including a rolling mill work roll profile design method based on multi-segment function fitting and a rolling mill work roll profile design device based on multi-segment function fitting.

[0059] This invention reduces the quarter-wave defect in cold-rolled high-strength steel by designing the work roll profile, thereby improving the flatness quality of the product. Once the roll profile is designed, it can be input into the grinder as discrete points for grinding. Therefore, this invention is highly feasible and cost-effective to implement on a cold rolling mill. Applications on a tandem cold rolling mill at a certain plant have shown that this new roll profile significantly reduces the quarter-wave defect in cold-rolled high-strength steel products, improving product flatness quality.

[0060] First, as Figure 1 As shown, the present invention provides a rolling mill work roll profile design method based on multi-segment function fitting, the method comprising:

[0061] Collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data for multiple roll periods in the UCM cold rolling mill;

[0062] Calculate the roller shape compensation value at each point along the roller length to obtain a preliminary compensation curve.

[0063] According to the preliminary compensation curve, the work roll shape curve is fitted in sections to obtain the corresponding fitting curve expression;

[0064] The compensation coefficient is determined based on actual production, and the final discrete point data of the work roll shape is obtained, which is used as the design basis.

[0065] In specific implementation, the purpose of the present invention is to provide a roller shape optimization design method using multi-segment function fitting based on a large amount of data statistical analysis, which is used to reduce the quarter wave defect of high-strength steel and thus improve the quality of cold-rolled high-strength steel plate shape. The four stages of preliminary data statistical analysis, compensation curve determination, determination of the compensation curve expression of the cold rolling mill working roll and determination of the working roll shape are carried out in sequence.

[0066] In this embodiment, the calculation of the roller shape compensation value at each point along the roller length direction on the roller surface to obtain a preliminary compensation curve specifically includes:

[0067] Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve;

[0068] The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

[0069] In this embodiment, the segmented fitting of the work roll shape curve specifically includes:

[0070] The segment positions are determined according to the characteristics of the compensation curve. First, four key points, -X0, -X1, X1, and X0, are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted separately.

[0071] In this embodiment, the key points are:

[0072]

[0073] -X1=M1;

[0074] X1=M2;

[0075]

[0076] Among them, M1 and M2 are the coordinates of the transition point, and L is the length of the working roll body; among them, M1 and M2 are determined according to the analysis results of the high-strength steel plate shape data so that the roller profile crown compensation position corresponds to the strip shape defect position.

[0077] In this embodiment, the first segment can be represented by a cubic polynomial curve, and the formula is as follows:

[0078] y=a0+a1x+a2x 2 +a3x 3 x∈[-X0,-X1];

[0079] The second segment can be represented by a sixth-order polynomial curve, as follows:

[0080] y=b0+b2x 2 +b4x 4 +b6x 6 x∈[-X1,X1];

[0081] The third segment can be represented by a cubic polynomial curve, as follows:

[0082] y=c0+c1x+c2x 2 +c3x 3 x∈[X1,X0];

[0083] Among them, a0, a1, a2, a3, b0, b2, b4, b6, c0, c1, c2, and c3 are the coefficients of the cubic and sextic functions respectively;

[0084] x is the transverse coordinate of the roller with the midpoint of the roller surface as the origin, the unit is mm, y is the roller shape value, the unit is μm.

[0085] In specific implementation, on the coordinate axis, -X0<-X1 <X1<X0。

[0086] In this embodiment, since the original roller shape is a flat roller, it is tangent to the first section at x1=-X0, so we get:

[0087]

[0088] Since the third section roll curve and the first section roll curve are symmetrical with respect to the center line of the working roll, the original roll shape is tangent to the third section at x2=X0, so we get:

[0089]

[0090] In this embodiment, according to the obtained fitting curve expression, the roll shape value of each point is multiplied by the compensation coefficient to obtain the roll shape of the cold rolling mill work roll, and the discrete point data of the work roll roll shape are obtained.

[0091] In specific implementation, according to the roller shape compensation curves of each section obtained above, the roller shape value of each point is multiplied by the compensation coefficient to obtain the roller shape of the cold rolling mill work roll, and the compensation coefficient is between 0.2 and 0.5.

[0092] Second, as Figure 2 As shown, the present invention provides a rolling mill work roll profile design device based on multi-segment function fitting, including: a data statistical analysis unit, a compensation curve determination unit, a segmented fitting unit and a work roll profile determination unit.

[0093] Data statistical analysis unit, used to collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data within multiple roll periods of the cold rolling mill;

[0094] The compensation curve determination unit is used to calculate the roller shape compensation value of each point along the roller length direction on the roller surface to obtain a preliminary compensation curve;

[0095] The segmented fitting unit is used to segmentally fit the work roll shape curve based on the preliminary compensation curve to obtain the corresponding fitting curve expression;

[0096] The work roll shape determination unit is used to determine the compensation coefficient based on actual production, obtain the final work roll shape discrete point data, and use it as the design basis.

[0097] In this embodiment, the compensation curve determining unit is specifically configured to:

[0098] Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve;

[0099] The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

[0100] In this embodiment, the segmented fitting unit is specifically used to:

[0101] The segment positions are determined according to the characteristics of the compensation curve. First, four key points, -X0, -X1, X1, and X0, are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted separately.

[0102] In specific implementation, the rolling mill work roll profile design device based on multi-segment function fitting and the rolling mill work roll profile design method based on multi-segment function fitting of the present invention correspond one to one, and will not be described in detail here.

[0103] In order to enable those skilled in the art to better understand the present invention, the principles of the present invention are described as follows with reference to the accompanying drawings:

[0104] like Figure 1 As shown in the figure, using the Xichang Steel and Vanadium 2030 tandem cold rolling mill production line as an example, to address the serious problem of quarter-wave defects in high-strength steel, work roll wear and flatness data over multiple rolling cycles were analyzed to design a new work roll profile. Based on the content of this invention, a corresponding work roll profile curve was designed.

[0105] First, the working roll shape wear data and the corresponding high-strength steel plate shape data in multiple roll cycles of the production line are counted to obtain the wear amount at each position of the roll body.

[0106] The curve is fitted in sections to calculate the compensation value of the working roll shape. Since the original roll shape is a flat roll, the unworn part of the wear curve must first be compensated to point X0, and then the compensation values ​​of the remaining points are calculated to preliminarily obtain a compensation curve. Finally, the unworn parts at both ends of the compensation curve are translated to the zero horizontal position to obtain the final compensation curve.

[0107] Then the obtained compensation curve is segmented fitted. Here, the roller profile curve with a roller profile of 30 μm (i.e. Figure 4The roller curve represented by A30 in the figure is fitted, and the formula is as follows:

[0108] When x∈[-1000,-600], it is the first curve.

[0109] y=-631.9879-2.32755x-2.76×10 -3 x 2 -1.06872×10 -6 x 3

[0110] When x∈[-600,600], it is the second curve.

[0111] y=9.80449-2.95681×10 -4 x 2 +7.45998×10 -10 x 4 -2.08674×10 -21 x 6

[0112] When x∈[600,1000], it is the third curve.

[0113] y=-631.9879+2.32755x-2.76×10 -3 x 2 +1.06872×10 -6 x 3

[0114] After the above roll profile segment design is completed, the curves are superimposed. According to the actual working conditions of the cold rolling mill, the compensation coefficient is taken as 0.25. The compensation curve is multiplied by the compensation coefficient and superimposed with the initial roll profile to obtain the new work roll profile. The comprehensive formula is as follows:

[0115] When x∈[-1000,-600],

[0116] y=-157.996975-0.5818875x-6.9×10 -4 x 2 -2.6718×10 -7 x 3

[0117] When x∈[-600,600],

[0118] y=2.4511225-7.392025×10 -5 x 2 +1.864995×10 -10 x 4 +5.21685×10-22 x 6

[0119] When x∈[600,1000],

[0120] y=-157.996975+0.5818875x-6.9×10 -4 x 2 +2.6718×10 -7 x 3

[0121] According to the above formula, the discrete point data of the roller transverse direction (one point at an interval of 25 mm) can be calculated, as follows: Figure 4 As shown in the figure, A90, A75, A60, A45, and A30 are fitted roll profile curves for roll crowns of 90μm, 75μm, 60μm, 45μm, and 30μm, respectively. The A90 curve has the largest fluctuation range, which then decreases in descending order according to roll crown. The A30 curve has the smallest fluctuation range. That is, on the y-axis, the curves A90, A75, A60, A45, and A30 correspond to the curves from top to bottom. Taking the A30 roll profile curve as an example, as shown in Table 1, these are the discrete coordinate points of the A30 roll profile curve. x is the roll transverse coordinate with the roll midpoint as the origin, in mm, and y is the roll profile value, in μm.

[0122] Table 1: Coordinates of discrete points of the work roll profile with a radius crown of 30 μm

[0123] x y x y x y x y -1000 -0.00132 -500 -17.4909 0 9.804493 500 -17.4909 -975 0.129518 -475 -18.9322 25 9.619984 525 -15.0197 -950 0.712514 -450 -19.4803 50 9.069954 550 -11.3755 -925 1.64747 -425 -19.2644 75 8.164894 575 -6.40784 -900 2.834194 -400 -18.4069 100 6.922287 600 0.242825 -875 4.172494 -375 -17.0232 125 5.366613 625 3.849878 -850 5.562178 -350 -15.2218 150 3.529341 650 6.506392 -825 6.903053 -325 -13.1039 175 1.448939 675 8.312559 -800 8.094928 -300 -10.7642 200 -0.82913 700 9.368573 -775 9.037609 -275 -8.28989 225 -3.25243 725 9.774624 -750 9.630905 -250 -5.76149 250 -5.76149 750 9.630905 -725 9.774624 -225 -3.25243 275 -8.28989 775 9.037609 -700 9.368573 -200 -0.82913 300 -10.7642 800 8.094928 -675 8.312559 -175 1.448939 325 -13.1039 825 6.903053 -650 6.506392 -150 3.529341 350 -15.2218 850 5.562178 -625 3.849878 -125 5.366613 375 -17.0232 875 4.172494 -600 0.242825 -100 6.922287 400 -18.4069 900 2.834194 -575 -6.40784 -75 8.164894 425 -19.2644 925 1.64747 -550 -11.3755 -50 9.069954 450 -19.4803 950 0.712514 -525 -15.0197 -25 9.619984 475 -18.9322 975 0.129518 1000 -0.00132

[0124] After processing the above data, import it into the grinding machine in text file format for grinding, and obtain the new working roll profile with a roll crown of 30 μm (see Figure 4 The new work roll profile curve (A30 curve in the middle) has a stronger ability to control high-order flatness compared to traditional flat rolls (non-crown work rolls). The new work roll profile was put into production.

[0125] Figure 5 The wire frame with a square intersection is a flat roll, and the wire frame with a diamond intersection is a new work roll with a roll crown of 30μm. Figure 5 It can be seen that after adopting the new roller shape, although the areas of the two convexity adjustment domains have not changed significantly, this indicates that the new roller shape has not reduced the overall roller shape control capability, and it can be seen that under the same working conditions, the secondary convexity has decreased slightly. Considering that the production of high-strength steel is to maintain a slightly medium-wave shape, this requires that the strip cannot have a large secondary convexity component. Therefore, the new roller shape reduces the secondary convexity, which is beneficial to the target shape control; from the perspective of the fourth convexity, the new roller shape causes the overall convexity adjustment domain to shift to the right, which increases the high-order shape control capability of the cold rolling mill and is beneficial to reducing the quarter-wave defect of the strip.

[0126] like Figure 4 As shown in the figure, based on the same principle, the new roller shape can have different convexities such as 45um (corresponding to A45 curve), 60um (corresponding to A60 curve), 75um (corresponding to A75 curve), and 90um (corresponding to A90 curve), thereby improving the plate shape control capability.

[0127] Actual production shows that by adopting an optimized work roll profile, the cold rolling mill can effectively control the quarter-wave defect of high-strength steel, and the average flatness pass rate of ≤±15IU reaches 90%, which has brought huge economic benefits to the enterprise.

[0128] This article focuses on a new roll design method for controlling strip profile defects. Using a roll with a 30µm crown as an example, the paper details the roll design method, the resulting polynomial function, and its coefficients. The resulting polynomial function is then used to calculate the coordinates of discrete points in the roll profile. These discrete point coordinates are then imported into the grinding machine program as input parameters, and the grinding machine automatically completes the grinding process based on these coordinates. Because the grinding machine program essentially performs automatic grinding based on the given coordinates, no human intervention is required.

[0129] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rolling mill work roll profile design method based on multi-segment function fitting, characterized in that: The method comprises: Collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data within multiple roll periods of the cold rolling mill; Calculate the roller shape compensation value of each point along the roller length direction on the roller surface to obtain a preliminary compensation curve; According to the preliminary compensation curve, the work roll shape curve is fitted in sections to obtain the corresponding fitting curve expression; Determine the compensation coefficient based on actual production, obtain the final discrete point data of the work roll shape, and use it as the design basis; The stepwise fitting of the work roll shape curve specifically includes: The segment positions are determined according to the characteristics of the compensation curve. First, four key points -X0, -X1, X1, and X0 are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted for each segment. The key points are: -X1=M1; X1=M2; Where M1 and M2 are the coordinates of the transition points, and L is the length of the work roll barrel. M1 and M2 are determined based on the results of high-strength steel plate shape data analysis so that the roller crown compensation position corresponds to the strip shape defect position. The first segment is represented by a cubic polynomial curve, and the formula is as follows: y=a0+a1x+a2x 2 +a3x 3 ,x∈[-X0,-X1]; The second segment is represented by a sixth-order polynomial curve, and the formula is as follows: y=b0+b2x 2 +b4x 4 +b6x 6 ,x∈[-X1,X1]; The third segment is represented by a cubic polynomial curve, and the formula is as follows: y=c0+c1x+c2x 2 +c3x 3 ,x∈[X1,X0]; Among them, a0, a1, a2, a3, b0, b2, b4, b6, c0, c1, c2, and c3 are the coefficients of the cubic and sextic functions respectively; x is the transverse coordinate of the roll with the midpoint of the roll surface as the origin, in mm; y is the roll shape value, in μm; Since the original roller shape is a flat roller, it is tangent to the first section at x1 = -X0, so we get: Since the third section roll curve and the first section roll curve are symmetrical with respect to the center line of the working roll, the original roll shape is tangent to the third section at x2=X0, so we get:

2. The method for designing the profile of a rolling mill work roll based on multi-segment function fitting according to claim 1, characterized in that: The calculation of the roller shape compensation value at each point on the roller surface along the length direction of the roller body to obtain a preliminary compensation curve specifically includes: Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve; The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

3. The method for designing the profile of a rolling mill work roll based on multi-segment function fitting according to claim 1, wherein: According to the obtained fitting curve expression, the roll shape value of each point is multiplied by the compensation coefficient to obtain the roll shape of the cold rolling mill work roll, and the discrete point data of the work roll roll shape are obtained.

4. A rolling mill work roll profile design device based on multi-segment function fitting, characterized in that: include: Data statistical analysis unit, compensation curve determination unit, segment fitting unit and work roll shape determination unit; Data statistical analysis unit, used to collect and compile statistics on work roll wear data and corresponding high-strength steel plate shape data within multiple roll periods of the cold rolling mill; The compensation curve determination unit is used to calculate the roller shape compensation value of each point along the roller length direction on the roller surface to obtain a preliminary compensation curve; The segmented fitting unit is used to segmentally fit the work roll shape curve based on the preliminary compensation curve to obtain the corresponding fitting curve expression; The work roll profile determination unit is used to determine the compensation coefficient based on actual production, obtain the final work roll profile discrete point data, and use it as the design basis; The segmented fitting unit is specifically used for: The segment positions are determined according to the characteristics of the compensation curve. First, four key points -X0, -X1, X1, and X0 are defined. Then, the segments are divided into [-X0, -X1], [-X1, X1], and [X1, X0] according to the key points, and curves are fitted for each segment. The key points are: -X1=M1; X1=M2; Where M1 and M2 are the coordinates of the transition points, and L is the length of the work roll barrel. M1 and M2 are determined based on the results of high-strength steel plate shape data analysis so that the roller crown compensation position corresponds to the strip shape defect position. The first segment is represented by a cubic polynomial curve, and the formula is as follows: y=a0+a1x+a2x 2 +a3x 3 ,x∈[-X0,-X1]; The second segment is represented by a sixth-order polynomial curve, and the formula is as follows: y=b0+b2x 2 +b4x 4 +b6x 6 ,x∈[-X1,X1]; The third segment is represented by a cubic polynomial curve, and the formula is as follows: y=c0+c1x+c2x 2 +c3x 3 ,x∈[X1,X0]; Among them, a0, a1, a2, a3, b0, b2, b4, b6, c0, c1, c2, and c3 are the coefficients of the cubic and sextic functions respectively; x is the transverse coordinate of the roll with the midpoint of the roll surface as the origin, in mm; y is the roll shape value, in μm; Since the original roller shape is a flat roller, it is tangent to the first section at x1 = -X0, so we get: Since the third section roll curve and the first section roll curve are symmetrical with respect to the center line of the working roll, the original roll shape is tangent to the third section at x2=X0, so we get:

5. The device for designing the profile of a rolling mill work roll based on multi-segment function fitting according to claim 4, characterized in that: The compensation curve determining unit is specifically configured to: Calculate the wear trend of the work roll and the wear amount at each position of the roll body based on the collected data to obtain the wear trend curve; The compensation curve of the working roll shape is calculated according to the wear trend curve, the roll shape compensation value of each point along the length direction of the roll body on the roll surface is calculated, and the compensation value of the two transition points is calculated to obtain a preliminary compensation curve.

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