Roll shape design method for variable-convexity working roll with medium wave control capability

Abstract

The invention discloses a roll shape design method of a variable-convexity working roll with medium wave control capability. The method comprises the following steps: setting a coordinate origin on a working roll, and setting a conventional cubic CVC curve in a secondary convexity range of the working roll and an M-shaped quartic curve symmetrical about a roll surface midpoint; on the basis of a conventional cubic CVC curve, according to the requirement of no-load roll gap convexity compensation amount at the internal width position of the working roll, an M-shaped quartic curve symmetrical about the midpoint of the roll surface is overlaid on the roll gap, and a variable-convexity working roll shape curve with the middle wave control capacity is obtained; and calculating to obtain the roll shape coefficient of each roll of the roll shape curve of the variable-convexity working roll with the medium wave control capability, so as to finally determine the roll shape curve of the variable-convexity working roll with the medium wave control capability. According to the method, on the basis of not changing the secondary convexity range of the no-load roll gap of the continuous variable convexity section and not changing the plate shape control model, the convexity of the roll gap at different strip steel width positions is increased, and the purpose of medium wave control is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of plate and strip rolling, and in particular to a roll shape design method for a variable crown working roll with mid-wave control capability. Background Art

[0002] In the late 1970s, SMS of Germany took the lead in developing the continuously variable crown (CVC) roll shape. Currently, CVC roll shape is still one of the most important plate shape control methods in the field of plate and strip rolling. This technology can continuously change the crown of the unloaded roll gap through the relative axial movement of the rolls to achieve plate shape control, such as Figure 1 shown.

[0003] like Figure 2 As shown, the upper roller radius function equation of the cubic CVC roller curve is y t (x) = R0 + a1x + a2x 2 +a3x 3 The function equation of the lower roller radius can be obtained based on the antisymmetric properties of the upper and lower rollers. The advantages of this type of roller shape in plate shape control are: the roller shape and control characteristics are relatively simple. If the reduction in the effective roll gap length caused by the axial roll shifting of the roller is not considered, and the effects of the rolling force and the bending roll force are not considered, the secondary convexity of the unloaded roll gap is strictly linearly related to the roll shifting amount of the roller. This characteristic is very beneficial to the design and processing of the roller shape and the plate shape control during the production process.

[0004] Generally speaking, strip steel often has middle waves at the rack exit. To solve the problem of strip steel middle waves, the bending roll technology is often used for real-time regulation. However, for the common problem of middle waves within a certain width range, regulating the middle waves significantly increases the workload of the operator and is not very feasible.

[0005] If the three-stage CVC roller shape is used to control the mid-wave, the following problems will occur:

[0006] First, the three-dimensional CVC roll shape mainly controls the secondary convexity of the roll gap, and does not have the ability to control the fourth-order convexity. It has no ability to regulate the fourth-order plate shape defects that occur during the rolling process of wide and thin strip steel;

[0007] Second, the convexity control ability of the third CVC roll shape is proportional to the square of the strip width. Adjusting the overall secondary convexity range to solve the wave problem at a certain width position may cause the convexity control range to be too large and affect the uniform wear of the working roll, which is not conducive to the plate shape control and rolling stability of wide-specification strip steel. Summary of the invention

[0008] In view of the shortcomings of the prior art, the present invention proposes a roll shape design method for a variable-convex working roll with mid-wave control capability. Without changing the secondary convexity range of the no-load roll gap in the continuous variable-convexity section, the roll shape of the working roll is flexibly designed according to the degree of mid-wave control required, thereby achieving effective control of the middle edge waves of plates and strips of different widths.

[0009] In order to achieve the above-mentioned purpose, the present invention is designed to design a roll shape of a variable crown work roll with mid-wave control capability, which is particularly characterized in that it includes the following steps:

[0010] S1) setting the coordinate origin on the working roll, setting the conventional cubic CVC curve within the quadratic crown range of the working roll and the M-shaped quartic curve symmetrical about the midpoint of the roll surface;

[0011] The conventional cubic CVC curve is expressed as follows

[0012] y t1 (x) = R0 + A1x + A2x 2 +A3x 3

[0013] In the formula,

[0014] y t1 (x) is the working roll shape with continuously variable crown,

[0015] R0 is the initial radius of the roller,

[0016] A1 is the roll shape coefficient,

[0017] A2 is the roll shape coefficient,

[0018] A3 is the roll shape coefficient,

[0019] x is the coordinate of the roller body, and the value range of x is [0, L].

[0020] L is the length of the roller body;

[0021] The M-shaped quartic curve symmetrical about the midpoint of the roller surface is expressed as follows

[0022] y t2 (x) = e2(xL / 2) 2 +e4(xL / 2) 4 -(e2L 2 / 4+e4L 4 / 16)

[0023] In the formula,

[0024] y t2 (x) is the working roll shape that is symmetrical about the midpoint of the roll surface,

[0025] e2 is the roll shape coefficient,

[0026] e4 is the roll shape coefficient,

[0027] x is the coordinate of the roller body, and the value range of x is [0, L].

[0028] L is the length of the roller body;

[0029] S2) Based on the conventional cubic CVC curve, in order to meet the need for the crown compensation of the no-load roll gap at the internal width position of the working roll, an M-shaped quartic curve symmetrical about the midpoint of the roll surface is superimposed on the roll gap to obtain a variable crown working roll roll curve with the ability to control the middle wave, thereby achieving a positive offset of the secondary crown at different strip width positions, increasing the roll gap crown at the same roll shifting position and different strip width positions, and achieving the purpose of controlling the middle wave at the frame outlet;

[0030] The roll shape curve of the variable crown work roll with mid-wave control capability is expressed as follows:

[0031] y t (x) = R0 + a1x + a2x 2 +a3x 3 +a4x 4

[0032] In the formula,

[0033] y t (x) is a variable crown work roll shape with mid-wave control capability.

[0034] R0 is the initial radius of the roller,

[0035] a1 is the roll shape coefficient,

[0036] a2 is the roll shape coefficient,

[0037] a3 is the roll shape coefficient,

[0038] a4 is the roll shape coefficient,

[0039] x is the coordinate of the roller body, and the value range of x is [0, L].

[0040] L is the length of the roller body;

[0041] S3) determine the roller body length, the maximum roller shifting amount, the secondary convexity adjustment range of the unloaded roll gap in the roller shape continuously variable convexity section, the strip width that generates medium waves, the unloaded roll gap convexity compensation amount at the strip width position that generates medium waves, and the normal rolling width when the roller diameter difference is 0. By calculating the roller shape coefficients of the conventional cubic CVC curve in step S1) and the M-shaped quartic curve symmetrical about the midpoint of the roller surface, the roller shape coefficients of the variable convexity working roll roller shape curve with medium wave control capability in step S2) are obtained, thereby finally determining the variable convexity working roll roller shape curve with medium wave control capability.

[0042] Further, in step S2), if the middle wave generated at the frame outlet is large, a larger no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if the middle wave generated at the frame outlet is small, a smaller no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if no middle wave is generated at the frame outlet, the no-load roll gap convexity compensation amount given when designing the roll shape is 0.

[0043] Furthermore, in step S3), the calculated roll shape coefficients of the conventional cubic CVC curve are expressed as follows:

[0044] The roll shape coefficient A3 is expressed as

[0045]

[0046] The roll shape coefficient A2 is expressed as

[0047]

[0048] The roll shape coefficient A1 is expressed as

[0049] A1=-A2L-3A3(L / 2) 2 -A3b 2 / 4

[0050] In the formula,

[0051] L is the length of the roller body,

[0052] s m is the maximum roll shifting amount of the roll,

[0053] C1 is the roller-shaped negative electrode line position -s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown.

[0054] C2 is the roller positive line position s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown.

[0055] b is the normal rolling width when the roller diameter difference is 0.

[0056] Furthermore, in step S3), the calculated roll shape coefficients of the M-shaped quartic curve are expressed as follows:

[0057] The roll shape coefficient e2 is expressed as

[0058]

[0059] The roll shape coefficient e4 is expressed as

[0060]

[0061] In the formula,

[0062] L is the length of the roller body,

[0063] s m is the maximum roll shifting amount of the roll,

[0064] B is the strip width that produces the middle wave,

[0065] △C B It is the no-load roll gap convexity compensation amount at the strip width that produces medium waves.

[0066] Furthermore, in step S3), the roll shape coefficients of the roll shape curve of the variable crown work roll with the ability to control the middle wave are calculated and expressed as follows:

[0067] The roll shape coefficient a4 is expressed as

[0068]

[0069] The roll shape coefficient a3 is expressed as

[0070]

[0071] The roll shape coefficient a2 is expressed as

[0072]

[0073] The roll shape coefficient a1 is expressed as

[0074] a1=-e2L-e4L 3 / 2+A1=-a2L-3a3(L / 2) 2 -a3b 2 / 4-4a4(L / 2) 3 -a4(L / 2)b 2

[0075] In the formula,

[0076] e2 and e4 are the roll shape coefficients of the M-shaped quartic curve symmetrical about the midpoint of the roll surface.

[0077] A1, A2, A3 are the roll shape coefficients of the basic cubic CVC curve,

[0078] L is the length of the roller body,

[0079] s m is the maximum roll shifting amount of the roll,

[0080] C1 is the roller-shaped negative electrode line position -s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown.

[0081] C2 is the roller positive line position s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown.

[0082] B is the strip width that produces the middle wave,

[0083] △C B is the crown compensation amount of the no-load roll gap at the strip width position where the middle wave is generated,

[0084] b is the normal rolling width when the roller diameter difference is 0.

[0085] Furthermore, in step S3), for the finally determined variable crown work roll profile with mid-wave control capability, the no-load roll gap crown compensation value △C at any strip width B1 position is B1 The compensation amount of the no-load roll gap convexity at the strip width B position where the middle wave is generated is △C B The relationship between

[0086]

[0087] In the formula,

[0088] △C B1 is the no-load roll gap crown compensation at any strip width B1 position,

[0089] B1 is the width of any strip steel,

[0090] L is the length of the roller body,

[0091] △C B It is the no-load roll gap convexity compensation amount at the strip width B position where the middle wave is generated, and B is the strip width where the middle wave is generated.

[0092] The advantages of the present invention are:

[0093] 1. The present invention firstly superimposes an M-shaped quartic curve symmetrical about the midpoint of the roll surface on the roll gap based on the conventional cubic CVC curve with the same nominal quadratic crown range according to the need for roll gap crown compensation at a specific width position, and obtains a variable crown work roll roll curve with middle wave control capability in the form of a quartic polynomial function, so as to realize a positive offset of the quadratic crown at different strip width positions, increase the roll gap crown at the same shifting roll position and different strip width positions, and achieve the purpose of controlling the middle wave at the stand outlet;

[0094] 2. The present invention calculates partial roll shape coefficients of conventional cubic CVC curve and M-shaped quartic curve according to the adjustment range of the secondary crown of the no-load roll gap and the roll gap crown compensation amount at a specific width position, and then obtains other roll shape coefficients according to the principle of minimum roll diameter difference under normal rolling width. Finally, the above data are substituted into the working roll quartic polynomial function to obtain the variable crown working roll roll shape curve with mid-wave control capability;

[0095] 3. The present invention utilizes the corresponding relationship between the roller shape coefficients provided, and can flexibly design the roller shape according to the degree of control required for the middle wave, thereby achieving effective control of the side waves in the middle of plates with different widths.

[0096] The roll shape design method of the variable crown working roll with the ability to control the middle wave of the present invention can adjust the middle wave at any strip width position. Compared with the ordinary three-dimensional CVC roll shape, it does not change the secondary crown range of the no-load roll gap in the continuous variable crown section and does not change the plate shape control model. The roll gap crown at different strip width positions is increased, which not only achieves the purpose of middle wave control, but also ensures the overall expression of the roll shape of the variable crown working roll with the ability to control the middle wave. It is suitable for CNC grinders that use an overall polynomial method to enter the roll shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 This is the working principle diagram of the continuous variable crown roller control technology;

[0098] Figure 2 Schematic diagram of axial movement of a continuously variable crown roller;

[0099] Figure 3 It is a schematic diagram of a variable crown roller with mid-wave control capability according to the present invention;

[0100] Figure 4 Three variable crown roller curves with mid-wave control capabilities designed to meet different mid-wave control requirements;

[0101] Figure 5 This is a comparison chart of three M-shaped curves with mid-wave control capabilities;

[0102] Figure 6The roller gap formed by three variable crown roller curves with mid-wave control capability when s = -100 mm;

[0103] Figure 7 The roller gap formed by three variable crown roller curves with mid-wave control capability when s=0mm;

[0104] Figure 8 The roller gap formed by three variable crown roller curves with mid-wave control capability when s=100mm;

[0105] Fig. 9 The roll gap formed by three variable crown roll curves with mid-wave control capability when s=-100mm and B=1250mm;

[0106] Fig.10 The roll gap formed by three variable convex roll curves with mid-wave control capability when s=0mm and B=1250mm;

[0107] Fig.11 The roller gap formed by three variable convex roller curves with mid-wave control capability when s=100mm and B=1250mm. DETAILED DESCRIPTION

[0108] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0109] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0110] The present invention provides a roll shape design method for a variable crown working roll with mid-wave control capability, comprising the following steps:

[0111] S1) Set the coordinate origin on the working roll, set the conventional cubic CVC curve within the quadratic crown range of the working roll and the M-shaped quartic curve symmetrical about the midpoint of the roll surface.

[0112] In this embodiment, the operating side end of the working roll is taken as the coordinate origin, and the conventional cubic CVC curve is expressed as follows

[0113] y t1 (x) = R0 + A1x + A2x 2 +A3x 3

[0114] In the formula,

[0115] y t1 (x) is the work roll shape with continuously variable crown, in mm.

[0116] R0 is the initial radius of the roller, in mm,

[0117] A1 is the roll shape coefficient, unitless,

[0118] A2 is the roll shape coefficient, unit is mm -1 ,

[0119] A3 is the roll shape coefficient, unit is mm -2 ,

[0120] x is the coordinate of the roller body, the value range of x is [0, L], and the unit is mm.

[0121] L is the length of the roller body, in mm.

[0122] The M-shaped quartic curve symmetrical about the midpoint of the roller surface is expressed as follows

[0123] y t2 (x) = e2(xL / 2) 2 +e4(xL / 2) 4 -(e2L 2 / 4+e4L 4 / 16)

[0124] In the formula,

[0125] y t2 (x) is the work roll shape that is symmetrical about the midpoint of the roll surface, in mm.

[0126] e2 is the roll shape coefficient of the roller, in mm -1 ,

[0127] e4 is the roll shape coefficient, unit is mm -3 ,

[0128] x is the coordinate of the roller body, the value range of x is [0, L], and the unit is mm.

[0129] L is the length of the roller body, in mm.

[0130] S2) On the basis of the conventional cubic CVC curve, in order to meet the need for compensation of the no-load roll gap crown at the internal width position of the working roll, an M-shaped quartic curve symmetrical about the midpoint of the roll surface is superimposed on the roll gap to obtain a variable crown working roll roll curve with the ability to control the middle wave, thereby achieving a positive offset of the secondary crown at different strip width positions, increasing the roll gap crown at the same shifting roll position and different strip width positions, and achieving the purpose of controlling the middle wave at the frame outlet.

[0131] The roll shape curve of the variable-convex working roll with the ability to control middle waves in the present invention is a continuous quartic curve, which is a cubic curve with an M-shaped quartic curve symmetrical about x=L / 2 superimposed on it, so as to achieve the purpose of keeping the nominal roll gap convexity of the entire length unchanged and increasing the roll gap convexity of the middle width, thereby solving the middle waves at the frame outlet without changing the control model.

[0132] Specifically, in step S2), if the middle wave generated at the frame outlet is large, a larger no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if the middle wave generated at the frame outlet is small, a smaller no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if no middle wave is generated at the frame outlet, the no-load roll gap convexity compensation amount given when designing the roll shape is 0, and the roll shape of the present invention is a conventional three-time variable convexity roll shape.

[0133] The roll shape curve of the variable crown work roll with mid-wave control capability is expressed as follows:

[0134] y t (x) = R0 + a1x + a2x 2 +a3x 3 +a4x 4

[0135] In the formula,

[0136] y t (x) is the roll shape of the variable crown work roll with mid-wave control capability, in mm.

[0137] R0 is the initial radius of the roller, in mm,

[0138] a1 is the roll shape coefficient, unitless,

[0139] a2 is the roll shape coefficient, unit is mm -1 ,

[0140] a3 is the roll shape coefficient, unit is mm -2 ,

[0141] a4 is the roll shape coefficient, unit is mm -3 ,

[0142] x is the coordinate of the roller body, the value range of x is [0, L], and the unit is mm.

[0143] L is the length of the roller body, in mm.

[0144] S3) determine the roller body length, the maximum roller shifting amount, the secondary convexity adjustment range of the unloaded roll gap in the roller shape continuously variable convexity section, the strip width that generates medium waves, the unloaded roll gap convexity compensation amount at the strip width position that generates medium waves, and the normal rolling width when the roller diameter difference is 0. By calculating the roller shape coefficients of the conventional cubic CVC curve in step S1) and the M-shaped quartic curve symmetrical about the midpoint of the roller surface, the roller shape coefficients of the variable convexity working roll roller shape curve with medium wave control capability in step S2) are obtained, thereby finally determining the variable convexity working roll roller shape curve with medium wave control capability.

[0145] like Figure 3 Shown is a schematic diagram of the roll shape of a variable crown working roll with mid-wave control capability according to the present invention.

[0146] Specifically, in step S3), the calculated roll shape coefficients of the conventional cubic CVC curve are expressed as follows:

[0147] The roll shape coefficient A3 is expressed as

[0148]

[0149] The roll shape coefficient A2 is expressed as

[0150]

[0151] The roll shape coefficient A1 is expressed as

[0152] A1=-A2L-3A3(L / 2) 2 -A3b 2 / 4

[0153] In the formula,

[0154] L is the length of the roller body, in mm.

[0155] s m is the maximum roll shifting amount of the roll, in mm,

[0156] C1 is the roller-shaped negative electrode line position -s m The secondary convexity of the roll gap in the continuous convexity section of the roll shape at the time of no-load roll, the unit is mm,

[0157] C2 is the roller positive line position s m The secondary convexity of the roll gap in the continuous convexity section of the roll shape at the time of no-load roll, the unit is mm,

[0158] b is the normal rolling width when the roller diameter difference is 0, in mm.

[0159] According to the definition of the positive and negative shifting directions of the rollers, C1>C2.

[0160] Specifically, in step S3), the calculated roll shape coefficients of each roll of the M-shaped quartic curve are expressed as follows:

[0161] The roll shape coefficient e2 is expressed as

[0162]

[0163] The roll shape coefficient e4 is expressed as

[0164]

[0165] In the formula,

[0166] L is the length of the roller body, in mm.

[0167] s m is the maximum roll shifting amount of the roll, in mm,

[0168] B is the strip width that produces the middle wave, in mm.

[0169] △C B It is the no-load roll gap convexity compensation amount at the strip width that produces medium waves, in mm.

[0170] Specifically, in step S3), the roll shape coefficients of the roll shape curve of the variable crown work roll with the ability to control the middle wave are calculated and expressed as follows:

[0171] The roll shape coefficient a4 is expressed as

[0172]

[0173] The roll shape coefficient a3 is expressed as

[0174]

[0175] The roll shape coefficient a2 is expressed as

[0176]

[0177] The roll shape coefficient a1 is expressed as

[0178] a1=-e2L-e4L 3 / 2+A1=-a2L-3a3(L / 2) 2 -a3b 2 / 4-4a4(L / 2) 3 -a4(L / 2)b2

[0179] In the formula,

[0180] e2 and e4 are the roll shape coefficients of the M-shaped quartic curve symmetrical about the midpoint of the roll surface.

[0181] A1, A2, A3 are the roll shape coefficients of the basic cubic CVC curve,

[0182] L is the length of the roller body,

[0183] s m is the maximum roll shifting amount of the roll,

[0184] C1 is the roller-shaped negative electrode line position -s m The secondary convexity of the roll gap in the continuous convexity section of the roll shape at the time of no-load roll, the unit is mm,

[0185] C2 is the roller positive line position s m The secondary convexity of the roll gap in the continuous convexity section of the roll shape at the time of no-load roll, the unit is mm,

[0186] B is the strip width that produces the middle wave, in mm.

[0187] △C B The compensation amount of the no-load roll gap crown at the strip width position where the middle wave is generated, in mm.

[0188] b is the normal rolling width when the roller diameter difference is 0, in mm.

[0189] The roller shape of the present invention relies on superimposing an M-shaped curve to achieve the control of the middle wave. The control effect depends on the effective roller gap formed by the M-shaped curve under the width of the plate strip. The final overall comprehensive roller shape is presented in the form of a quartic curve, while ensuring continuous crown control of different widths. Regardless of the width of the plate strip, the size of the crown control range will not change, and a positive offset of the crown control range will occur.

[0190] In this embodiment, when the mill design parameters are: L = 2000 mm, the maximum roll shifting amount s m =100mm and the no-load roll gap secondary convexity adjustment range of the roller shape continuous variable convexity section is [C1, C2] = [0.55mm, -0.05mm], the rolled strip width range is 1000mm ~ 1600mm, according to the design of the present invention, when the strip width B of the middle wave is 1250mm, the no-load roll gap convexity compensation amount △C B The roll shape curve when the diameter difference between the two ends of the working roll is the same is as follows: Figure 4 shown.

[0191] Figure 4 Middle △CB When it is 0mm, it is a conventional cubic curve. When the strip width B that produces the middle wave is 1250mm, △C B When the diameters are 0 mm, 0.02 mm and 0.04 mm respectively, the M-shaped quartic curves superimposed on the conventional cubic curve and symmetrical about the midpoint of the roller surface are as follows: Figure 5 As shown. B As the pressure increases, the difference between the roller edge control section and the three-dimensional CVC roller shape gradually increases, and its effect of compensating for mid-waves also gradually increases.

[0192] like Figures 6 to 8 As shown in FIG. 1 , it is a comparison diagram of the roller gaps formed by the three roller shape curves designed according to the present invention at the three roller shifting positions of s=-100mm, s=0mm and s=100mm. Figures 6 to 8 It can be seen that:

[0193] First, as the roll shifting position moves from the negative limit to the positive limit, the roll gap convexity gradually decreases;

[0194] Second, when adjusting the roll gap shape within the strip width range, the overall no-load roll gap convexity is not affected;

[0195] Third, as the compensation amount ΔC B As the roll gap increases, the difference between the roll gap and the conventional three-time CVC roll shape at nearly 1 / 4 becomes greater, and the difference in the convexity of the no-load roll gap under the rolling width gradually increases;

[0196] Fourth, under different roller shifting positions, the crown compensation amount under the same width remains basically the same. At the positive limit roller shifting position s m and negative limit roller shifting position s m The crown compensation amount is the same when the strip width B1 is at any position, and the no-load roll gap crown compensation amount △C B1 The compensation amount of the no-load roll gap convexity at the strip width B position where the middle wave is generated is △C B The relationship between

[0197]

[0198] In the formula,

[0199] △C B1 is the no-load roll gap crown compensation at any strip width B1 position, in mm.

[0200] B1 is the width of any strip, in mm.

[0201] L is the length of the roller body, in mm.

[0202] △C BThe compensation amount of the no-load roll gap convexity at the strip width B where the middle wave is generated, in mm.

[0203] B is the width of the strip that produces the middle wave, in mm.

[0204] The strip width will not exceed the roll width, and for all specifications of strip, the roll gap convexity within the strip width range at the same roll shifting position will be increased. The strip convexity compensation amount is the largest.

[0205] Depend on Figure 6 and Figure 8 It can be seen that when s = -100mm and s = 100mm, the nominal roll gap crown of the variable crown roller with mid-wave control capability and different three-time CVC roll shapes are the same. For the same width, the increase in the no-load roll gap crown at the positive and negative limit roll shifting positions is the same, and the crown control range is offset. Without changing the roll shifting mode, it is beneficial to increase the roll gap crown under the same strip width at the same roll shifting position to alleviate the mid-wave at the stand exit.

[0206] Depend on Figure 7 It can be seen that at the non-roll shifting extreme position, such as s=0, the full-length nominal roll gap convexity increases slightly; at the same roll shifting position, for the same width, the roll gap convexity under the strip width is increased to alleviate the waves at the frame exit.

[0207] The core of the wave control adjustment of the roller curve of the present invention is: by adjusting the convexity compensation amount ΔC under the width B B , while keeping the no-load convexity unchanged over the entire length range, adjust the convexity under the rolling width.

[0208] ΔC 1250 =0.02mm and ΔC 1250 =0.04mm roll curve as an example, for B = 1250mm, the roll gaps at the three roll shifting positions of s = -100mm, s = 0mm and s = 100mm are as follows Figures 9-11 As shown, according to the convexity compensation amount △C under width B B When the roll shifting position is the same and the roll gap convexity at the same strip width position increases, the regulating ability is positively shifted, which is beneficial to the control of the wave at the frame outlet.

[0209] If the middle wave is large, a larger △C is given when optimizing the roll shape design. B ; If the middle wave is small, a smaller △C is given when designing the roller shape B ; If there is no middle wave, then △C B =0, at this time, the roller shape of the present invention is a conventional three-time variable convexity roller shape.

[0210] The roll shape design method of the variable crown working roll with the ability to control the middle wave of the present invention can adjust the middle wave at any strip width position. Compared with the ordinary three-dimensional CVC roll shape, it does not change the secondary crown range of the no-load roll gap in the continuous variable crown section and does not change the plate shape control model. The roll gap crown at different strip width positions is increased, which not only achieves the purpose of middle wave control, but also ensures the overall expression of the roll shape of the variable crown working roll with the ability to control the middle wave. It is suitable for CNC grinders that use an overall polynomial method to enter the roll shape.

[0211] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A roll shape design method for a variable crown work roll with mid-wave control capability, characterized in that: The steps include: S1) setting the coordinate origin on the working roll, setting the conventional cubic CVC curve within the quadratic crown range of the working roll and the M-shaped quartic curve symmetrical about the midpoint of the roll surface; The conventional cubic CVC curve is expressed as follows y t1 (x)=R0+A1x+A2x 2 +A3x 3 In the formula, y t1 (x) is the working roll shape with continuously variable crown, R0 is the initial radius of the roller, A1 is the roll shape coefficient, A2 is the roll shape coefficient, A3 is the roll shape coefficient, x is the coordinate of the roller body, and the value range of x is [0, L]. L is the length of the roller body; The M-shaped quartic curve symmetrical about the midpoint of the roller surface is expressed as follows y t2 (x)=e2(x-L / 2) 2 +e4(x-L / 2) 4 -(e2L 2 / 4+e4L 4 / 16) In the formula, y t2 (x) is the working roll shape that is symmetrical about the midpoint of the roll surface, e2 is the roll shape coefficient, e4 is the roll shape coefficient, x is the coordinate of the roller body, and the value range of x is [0, L]. L is the length of the roller body; S2) Based on the conventional cubic CVC curve, in order to meet the need for the crown compensation of the no-load roll gap at the internal width position of the working roll, an M-shaped quartic curve symmetrical about the midpoint of the roll surface is superimposed on the roll gap to obtain a variable crown working roll roll curve with the ability to control the middle wave, thereby achieving a positive offset of the secondary crown at different strip width positions, increasing the roll gap crown at the same roll shifting position and different strip width positions, and achieving the purpose of controlling the middle wave at the frame outlet; The roll shape curve of the variable crown work roll with mid-wave control capability is expressed as follows: y t (x)=R0+a1x+a2x 2 +a3x 3 +a4x 4 In the formula, y t (x) is a variable crown work roll shape with mid-wave control capability. R0 is the initial radius of the roller, a1 is the roll shape coefficient, a2 is the roll shape coefficient, a3 is the roll shape coefficient, a4 is the roller shape coefficient, x is the coordinate of the roller body, and the value range of x is [0, L]. L is the length of the roller body; S3) determine the roller body length, the maximum roller shifting amount, the secondary convexity adjustment range of the unloaded roll gap in the roller shape continuously variable convexity section, the strip width that generates medium waves, the unloaded roll gap convexity compensation amount at the strip width position that generates medium waves, and the normal rolling width when the roller diameter difference is 0. By calculating the roller shape coefficients of the conventional cubic CVC curve in step S1) and the M-shaped quartic curve symmetrical about the midpoint of the roller surface, the roller shape coefficients of the variable convexity working roll roller shape curve with medium wave control capability in step S2) are obtained, thereby finally determining the variable convexity working roll roller shape curve with medium wave control capability.

2. The roll shape design method of the variable crown work roll with mid-wave control capability according to claim 1, characterized in that: In step S2), if the middle wave generated at the frame outlet is large, a larger no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if the middle wave generated at the frame outlet is small, a smaller no-load roll gap convexity compensation amount needs to be given when designing the roll shape; if no middle wave is generated at the frame outlet, the no-load roll gap convexity compensation amount given when designing the roll shape is 0.

3. The roll shape design method of the variable crown work roll with mid-wave control capability according to claim 2, characterized in that: In step S3), the calculated roll shape coefficients of the conventional cubic CVC curve are expressed as follows: The roll shape coefficient A3 is expressed as The roll shape coefficient A2 is expressed as The roll shape coefficient A1 is expressed as A1=-A2L-3A3(L / 2) 2 -A3b 2 / 4 In the formula, L is the length of the roller body, s m is the maximum roll shifting amount of the roll, C1 is the roller-shaped negative electrode line position -s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown. C2 is the roller positive line position s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown. b is the normal rolling width when the roller diameter difference is 0.

4. The roll shape design method of the variable crown work roll with mid-wave control capability according to claim 3 is characterized in that: In step S3), the calculated roll shape coefficients of the M-shaped quartic curve are expressed as follows: The roll shape coefficient e2 is expressed as The roll shape coefficient e4 is expressed as In the formula, L is the length of the roller body, s m is the maximum roll shifting amount of the roll, B is the strip width that produces the middle wave, △C B It is the no-load roll gap convexity compensation amount at the strip width that produces medium waves.

5. The roll shape design method of the variable crown work roll with mid-wave control capability according to claim 4, characterized in that: In step S3), the roll shape coefficients of the roll shape curve of the variable crown work roll with the ability to control the middle wave are calculated and expressed as follows: The roll shape coefficient a4 is expressed as The roll shape coefficient a3 is expressed as The roll shape coefficient a2 is expressed as The roll shape coefficient a1 is expressed as a1=-e2L-e4L 3 / 2+A1=-a2L-3a3(L / 2) 2 -a3b 2 / 4-4a4(L / 2) 3 -a4(L / 2)b 2 In the formula, e2 and e4 are the roll shape coefficients of the M-shaped quartic curve symmetrical about the midpoint of the roll surface. A1, A2, A3 are the roll shape coefficients of the basic cubic CVC curve, L is the length of the roller body, s m is the maximum roll shifting amount of the roll, C1 is the roller-shaped negative electrode line position -s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown. C2 is the roller positive line position s m The roller shape continuously changes the crown section, and the unloaded roller gap has a secondary crown. B is the strip width that produces the middle wave, △C B is the crown compensation amount of the no-load roll gap at the strip width position where the middle wave is generated, b is the normal rolling width when the roller diameter difference is 0.

6. The roll shape design method of the variable crown work roll with mid-wave control capability according to claim 5, characterized in that: In step S3), for the final determined variable crown work roll profile with mid-wave control capability, the no-load roll gap crown compensation value △C at any strip width B1 position is B1 The compensation amount of the no-load roll gap convexity at the strip width B position where the middle wave is generated is △C B The relationship between In the formula, △C B1 is the no-load roll gap crown compensation at any strip width B1 position, B1 is the width of any strip steel, L is the length of the roller body, △C B The compensation amount of the no-load roll gap crown at the strip width B where the middle wave is generated, B is the width of the strip that produces the middle wave.

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