Method for reducing the grinding force fluctuation of a cvc roll

Abstract

The application provides a method for reducing the grinding force fluctuation of a CVC roll, comprising the following steps: (1) calculating the grinding depth r of each section of the roll mi ; (2) extracting a common function K according to the following formula i ; (3) obtaining the simplified tangential grinding component F τi and the normal grinding component F ni of each section of the roll according to the obtained common function K i ; (4) calculating the average tangential grinding force and the average normal grinding force of the roll; (5) setting the average tangential grinding force equal to the tangential grinding component, and obtaining the axial grinding feed f ai ; (6) calculating the surface roughness R i of the roll after grinding; (7) judging the surface roughness, if the condition R i ≤0.4 is satisfied, the operation is ended; if R i >0.4, the value of the grinding axial feed f a0 is reduced by 0.1 mm, and the operation returns to step (4).

Description

Technical Field

[0001] This invention belongs to the technical field of hot-rolled strip steel in the metallurgical industry, and specifically relates to a method for reducing the fluctuation of grinding force of CVC rolls. Background Technology

[0002] CVC rolls are a representative type of roll widely used in the shape control of hot-rolled wide strip steel. Due to their ability to continuously change the crown between rolls through roll shifting, they are extensively used in strip steel production. However, during the rolling process of sheet steel, CVC rolls experience wear, which severely impacts the quality of the processed sheet.

[0003] To address the issue of CVC roll wear affecting strip processing quality, domestic experts have proposed optimizing roll grinding process parameters to improve surface quality and increase processing efficiency. Ren Xinyi et al. employed a segmented grinding strategy for the roll body, connecting platform, and chamfering mechanism. Chen Shenchao et al., considering the complex roll shape characteristics of CVC, proposed a method for grinding flat rolls into CVC rolls to address the long grinding time. However, none of these methods considered the working conditions and grinding forces of the CVC roll, thus failing to provide effective guidance for grinding and repairing worn CVC rolls. Furthermore, considering the concentrated working area and relatively concentrated roll movement of CVC rolls, the stress state and fatigue cycle of the roll surface change accordingly, leading to fatigue detachment of the oxide film, localized wear, and severe asymmetric wear as rolling progresses. This asymmetric wear causes significant fluctuations in grinding force during the grinding process, which not only affects the accuracy of the machined surface but also reduces processing efficiency due to the low axial feed rate at sections with small grinding allowances. Furthermore, the quality of the ground surface directly impacts the product surface quality; therefore, it is crucial to maintain the surface roughness of the ground rolls during the grinding process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned shortcomings of the prior art. By combining the working characteristics of CVC rolls and conducting segmented research, and taking into account the roughness of the roll grinding surface, a method for reducing the grinding force fluctuation of CVC rolls is provided.

[0005] The technical problem it aims to solve can be addressed through the following technical solutions.

[0006] A method for reducing grinding force fluctuations in CVC rolls mainly includes the following:

[0007] A) Collect relevant parameters during the CVC roll grinding process: roll body length L, abrasive density correlation coefficient ω, grinding wheel condition coefficient k, surface roughness grinding coefficient K, and grinding wheel speed v. s Grinding axial feed rate setting value f a0 β, the semi-apex angle of the cone, and the radius distribution r along the length of the roll after grinding. wi Radial distribution r along the length of the roll after wear ai Number of roll body division units N, grinding wheel radius r s The parameters are: grinding wheel grit size M, grinding wheel thickness B, machine tool spindle speed n, and empirical constant ε. Among them, the abrasive density correlation coefficient ω ranges from 0.5 to 0.65, the grinding wheel working condition coefficient k ranges from 150 to 200, the roughness grinding coefficient K ranges from 3 to 6, and the empirical constant ε ranges from 0.4 to 0.6.

[0008] B) Calculate the grinding depth r of each section of the roll. mi ;

[0009] r mi =r ai -r wi

[0010] C) Extracting the common function K i ;

[0011]

[0012] D) Based on the obtained common function K i The simplified tangential grinding force F of each section of the roll is obtained. τi and normal grinding component F ni ;

[0013]

[0014] E) Calculate the average tangential grinding force on the rolls. and average normal grinding force

[0015]

[0016] In the formula, ΔL is the length of each unit.

[0017] F) Let the average tangential grinding force equal to the tangential grinding component, and calculate the axial grinding feed rate f. ai ;

[0018]

[0019] G) Calculate the surface roughness R of the roll after grinding. i ;

[0020]

[0021] H) Determine surface roughness R i (1≤i≤N), if condition R is satisfied i The calculation ends if R is ≤0.4; if R is ≤0.4, the calculation ends. i If the value is greater than 0.4, then set the grinding axial feed rate to f. a0 After the value is reduced by 0.1 mm, return to step E).

[0022] This invention balances the tangential grinding force and the average tangential grinding force, and takes into account the surface roughness requirements of the rolls, to finally determine a suitable grinding feed rate, so that the grinding force is always maintained at around the average value, effectively suppressing grinding force fluctuations.

[0023] This invention aims to avoid significant grinding force fluctuations during roll grinding and ensure the surface quality of strip steel products. Based on the working characteristics of CVC rolls, the causes and morphology of their unique asymmetric wear are analyzed, and a method for reducing grinding force fluctuations in CVC rolls is proposed, targeting specific grinding parameters. This method allows for adaptive adjustment of the grinding wheel axial feed to suit different wear conditions, ensuring grinding stability, improving grinding quality, increasing grinding efficiency, and enhancing production benefits. Attached Figure Description

[0024] Figure 1 A schematic diagram of the grinding force during CVC roll grinding;

[0025] Figure 2 This is a flowchart illustrating the overall process of the method for reducing grinding force fluctuations in CVC rolls according to the present invention. Detailed Implementation

[0026] The application of the method for reducing grinding force fluctuations in CVC rolls described in this invention will be further explained in detail below with reference to the accompanying drawings and embodiments.

[0027] Example 1: Grinding a 1700mm forged steel Cr5 work roll with a 5SG 100F grinding wheel

[0028] First, as shown in step (A), collect the relevant parameters during the CVC roll grinding process: roll body length L is 1700mm; abrasive density correlation coefficient ω is 0.6mm; grinding wheel condition coefficient k is 170; surface roughness grinding coefficient K is 4; and grinding wheel speed v is... s The grinding axial feed rate is set at 35 m / s. a0 The values ​​are: 5mm / r, cone semi-apex angle β = 60°, number of roll body division units N = 17, and grinding wheel radius r. sThe parameters are: abrasive particle size M = 100 μm, grinding wheel thickness B = 100 mm, machine tool spindle speed n = 40 r / min, and empirical constant ε = 0.5. Among these parameters, the abrasive particle density correlation coefficient ranges from 0.5 to 0.65, the grinding wheel working condition coefficient ranges from 150 to 200, the roughness grinding coefficient ranges from 3 to 6, and the empirical constant ranges from 0.4 to 0.6.

[0029] Table 1 below shows the radius distribution along the length of a 1700mm roll after grinding and wear.

[0030] Table 1:

[0031]

[0032] Then, calculate the grinding depth r of each section of the roll according to step (B). mi ;

[0033] r mi =r ai -r wi

[0034] As shown in step (C), based on the grinding force model of the CVC roll, the common function K is extracted. i ;

[0035]

[0036] Then, follow step (D) to convert the common function K. i Substituting into the CVC roll grinding force model, we obtain the simplified tangential grinding component F. τi and normal grinding component F ni ;

[0037]

[0038] In the formula, f ai The value is the grinding feed rate, in mm.

[0039] Then, as in step (E), the average tangential grinding force on the roll is calculated. and average normal grinding force

[0040]

[0041] In the formula, ΔL is the length of each unit.

[0042] The average tangential grinding force on the roll is obtained. and average normal grinding force

[0043] Finally, as shown in step (F), let the average tangential grinding force equal to the tangential grinding component force, and calculate the grinding feed rate f. ai ;

[0044]

[0045] Table 2 below shows the calculation results for a 1700mm CVC roll.

[0046] Table 2:

[0047]

[0048]

[0049] G) Calculate the surface roughness R of the roll after grinding. i ;

[0050]

[0051] The surface roughness of the roll after grinding is:

[0052] [0.361,0.362,0.362,0.363,0.364,0.365,0.366,0.367,0.367,0.368,0.368,0.369,0.369,0.369,0.369,0.368,0.367]μm

[0053] Finally, as shown in step H), the surface roughness R is determined. i (1≤i≤N), satisfying condition R i The operation ends when the value is ≤0.4.

[0054] Example 2: Grinding a 2000mm forged steel Cr5 work roll with a 5SG 100F grinding wheel

[0055] First, as shown in step (A), collect the relevant parameters during the CVC roll grinding process: roll body length L is 2000mm; abrasive density correlation coefficient ω is 0.6mm; grinding wheel condition coefficient k is 170; surface roughness grinding coefficient is 4; and grinding wheel speed v... s The grinding axial feed rate is set at 35 m / s. a0 The values ​​are: 5 mm / r, cone semi-apex angle β = 60°, number of roll body division units N = 20, and grinding wheel radius r. sThe parameters are: abrasive particle size M = 100 μm, grinding wheel thickness B = 100 mm, machine tool spindle speed n = 40 r / min, and empirical constant ε = 0.5. Among these parameters, the abrasive particle density correlation coefficient ranges from 0.5 to 0.65, the grinding wheel working condition coefficient ranges from 150 to 200, the roughness grinding coefficient ranges from 3 to 6, and the empirical constant ranges from 0.4 to 0.6.

[0056] Table 3 below shows the radius distribution along the length of a 2000mm roll after grinding and wear.

[0057] Table 3:

[0058]

[0059] Then, calculate the grinding depth r of each section of the roll according to step (B). mi ;

[0060] r mi =r ai -r wi

[0061] As shown in step (C), based on the grinding force model of the CVC roll, the common function K is extracted. i ;

[0062]

[0063] Then, follow step (D) to convert the common function K. i Substituting into the CVC roll grinding force model, we obtain the simplified tangential grinding component F. τi and normal grinding component F ni ;

[0064]

[0065] In the formula, f ai The value is the grinding feed rate, in mm.

[0066] Then, as in step (E), the average tangential grinding force on the roll is calculated. and average normal grinding force

[0067]

[0068] In the formula, ΔL is the length of each unit.

[0069] The average tangential grinding force on the roll is obtained. and average normal grinding force

[0070] Then, as shown in step (F), let the average tangential grinding force equal to the tangential grinding component force, and calculate the grinding feed rate f. ai ;

[0071]

[0072] Table 4 below shows the calculation results for a 2000mm CVC roll.

[0073] Table 4:

[0074]

[0075] Then, as shown in step G), calculate the surface roughness R of the roll after grinding. i ;

[0076]

[0077] The surface roughness of the roll after grinding is:

[0078] [0.414,0.414,0.414,0.414,0.415,0.415,0.415,0.415,0.416,0.416,

[0079] 0.416,0.416,0.417,0.417,0.418,0.417,0.417,0.417,0.417,0.417]μm

[0080] Finally, as shown in step H), the surface roughness R is determined. i (1≤i≤N), condition R is not satisfied. i ≤0.4 Let the grinding axial feed rate setpoint f a0 After reducing the value by 0.1 mm, return to step E) to recalculate. The final results of the surface roughness and grinding feed of the roll after grinding are shown in the table below:

[0081] Table 5 below shows the final calculation results for the 2000mm roll.

[0082] Table 5:

[0083]

Claims

1. A method for reducing grinding force fluctuations in CVC rolls, characterized in that, Includes the following steps: (1) Calculate the grinding depth r of each section of the roll. mi ; (2) Extract the common function K using the following formula. i ; ， In the formula: β is the semi-apex angle of the cone; k is the grinding wheel operating condition coefficient, with a value range of 150~200; ω is the abrasive particle density correlation coefficient, with a value ranging from 0.5 to 0.65; ε is an empirical constant, with a value ranging from 0.4 to 0.6; n is the machine tool spindle speed; r wi The radius distribution along the length of the roll after grinding; r s Where is the radius of the grinding wheel; v s This refers to the grinding wheel speed; (3) Based on the obtained common function K i The simplified tangential grinding force F of each section of the roll is obtained. τi and normal grinding component F ni ; ， In the formula f ai This refers to the axial grinding feed rate; (4) Calculate the average tangential grinding force on the roll. and average normal grinding force ; The average tangential grinding force on the roll is calculated using the following formula. and average normal grinding force : ， In the formula: f a0 Set the axial feed rate for grinding; L is the length of the roll body; ΔL is the length of each unit. N is the number of units that divide the roll body; (5) Let the average tangential grinding force be equal to the tangential grinding component force, and calculate the axial grinding feed rate f. ai ; The axial grinding feed rate f is calculated using the following formula. ai : ， (6) Calculate the surface roughness R of the roll after grinding. i ; (7) Determine the surface roughness R i (1≤i≤N), if condition R is satisfied i The calculation ends if R is ≤0.4; if R is ≤0.4, the calculation ends. i If the value is greater than 0.4, then set the grinding axial feed rate to f. a0 After the value is reduced by 0.1 mm, return to step (4).

2. The method for reducing grinding force fluctuation of CVC rolls according to claim 1, characterized in that, The grinding depth r of each section of the roll in step (1) mi = r ai -r wi ;where r ai This represents the radial distribution along the length of the roll after wear.

3. The method for reducing grinding force fluctuation of CVC rolls according to claim 1, characterized in that, In step (6), the surface roughness R of the roll after grinding is calculated using the following formula. i : ， In the formula: K is the surface roughness grinding coefficient, with a value ranging from 3 to 6; M represents the grinding wheel grit size; B is the thickness of the grinding wheel; r ai This represents the radial distribution along the length of the roll after wear.

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